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Impact of L-carnitine on imatinib-related muscle cramps in patients with gastrointestinal stromal tumor. Chae Heejung,Ryu Min-Hee,Ma Jungeun,Beck Moyeol,Kang Yoon-Koo Investigational new drugs Introduction Muscle cramps constitute one of the leading adverse events of imatinib, the standard first-line treatment for advanced gastrointestinal stromal tumor (GIST). This study aims to assess the impact of L-carnitine on relieving cramps in patients with GIST taking imatinib. Materials and methods We reviewed our prospective database for patients with GIST who took L-carnitine (500-mg tablet, 2-3 times daily) for muscle cramps in Asan Medical Center. The assessment tool included severity by the numeric rating scale (NRS), frequency, duration of cramps, and questionnaire for the disturbance in basic activities of daily living (ADL), instrumental ADL (iADL), outdoor activity, or sleeping before and after L-carnitine treatment. Results We examined 42 patients [median age: 60 (range: 17-81) years; males, 52.4%] who received L-carnitine for cramps on NRS ≥ 4 intensity during 2016-2017. In 83.3% of patients (n = 35), the NRS score declined to <4 points, with 8 patients (19.0%) experiencing complete disappearance of symptoms [median response time: 10 (range: 2-30) days]. Moreover, the median duration of each episode and frequency decreased from 5 to 2 min and from 30 to 3 times per month (P < 0.001), respectively. We observed substantial improvement in all quality-of-life aspects after L-carnitine (ADL, 73.2%-14.6%; iADL, 73.2%-17.1%; sleeping, 78.0%-22.0%; outdoor activity, 68.3%-17.1%; P < 0.001). ConclusionL-carnitine could effectively relieve imatinib-related muscle cramps in patients with GIST. Accordingly, a randomized phase 3 study is currently ongoing (NCT03426722). 10.1007/s10637-019-00860-x
New therapeutic agents in gastrointestinal stromal tumours. Falkenhorst Johanna,Hamacher Rainer,Bauer Sebastian Current opinion in oncology PURPOSE OF REVIEW:The aim of this study was to provide an update on the most recent developments regarding systemic treatments in the various molecular subtypes of gastrointestinal stromal tumour (GIST). RECENT FINDINGS:Several novel direct inhibitors of KIT and PDGFRA have entered the advanced clinical development in later treatment lines based on promising early clinical trial experience. Both avapritinib and ripretinib are more potent and more specific against various KIT and PDGFRA mutations. For patients with PDGFRA D842V mutations, the next generation of drugs may become the first active treatment options.Comprehensive molecular testing of KIT/PDGFRA-wildtype GIST may unmask clinically relevant targets, including NTRK fusions. SUMMARY:The treatment landscape in GIST is expected to undergo a profound transformation with more potent drugs currently in late-stage clinical development. 10.1097/CCO.0000000000000549
Imatinib induces autophagy via upregulating XIAP in GIST882 cells. Xie Qingqing,Lin Qi,Li Dezhi,Chen Jianming Biochemical and biophysical research communications Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms originating from the gastrointestinal tract with gain of function mutations in receptor tyrosine kinases KIT or platelet-derived growth factor receptor A (PDGFRA). The main effective treatment for GISTs is tyrosine kinase inhibitors, such as imatinib mesylate. However, GISTs respond to imatinib treatment eventually develop acquired resistance, which is a main obstacle for GISTs therapy. Therefore, it's urgent to have a better understanding of the mechanisms underlying the imatinib resistance in GISTs to develop novel therapeutic strategies. X-linked inhibitor of apoptosis (XIAP) is the most potent apoptosis inhibitor among the inhibitor of apoptosis protein (IAP) family members. Increased cellular expression of XIAP often leads to drug resistance in cancers. Here we report that XIAP is induced upon imatinb treatment in GIST882 cells, leading to imatinib-induced autophagy. Imatinib-induced autophagy was impaired in XIAP-knockout cells generated by CRISPR/Cas9 system demonstrated by the decreasing of LC3 lipidation. XIAP knockout sensitizes GIST882 cells to imatinib-induced apoptotic cell death, suggesting that XIAP protects GIST882 cells from imatinib-induced cell death by inducing autophagy. Thus, the resistance of the GIST882 cells to imatinib appears to be, in part, due to the increasing of XIAP and subsequent induction of autophagy. 10.1016/j.bbrc.2017.05.096
Long-term outcome of dasatinib first-line treatment in gastrointestinal stromal tumor: A multicenter, 2-stage phase 2 trial (Swiss Group for Clinical Cancer Research 56/07). Montemurro Michael,Cioffi Angela,Dômont Julien,Rutkowski Piotr,Roth Arnaud D,von Moos Roger,Inauen Roman,Toulmonde Maud,Burkhard Roger O,Knuesli Claudio,Bauer Sebastian,Cassier Philippe,Schwarb Heike,Le Cesne Axel,Koeberle Dieter,Bärtschi Daniela,Dietrich Daniel,Biaggi Christine,Prior John,Leyvraz Serge Cancer BACKGROUND:Tyrosine kinase inhibitors (TKIs) have improved the outcome of patients with gastrointestinal stromal tumors (GISTs), but most patients eventually develop resistance and progress. Dasatinib is a potent inhibitor of BCR-ABL, KIT, and SRC family kinases as well as imatinib-resistant cells. In GISTs, response evaluation is routinely done using computed tomography (CT) and F-fluorodeoxyglucose positron emission tomography coupled to CT (FDG-PET/CT) for early response assessment and outcome prediction. METHODS:This was a 2-stage, phase 2 trial investigating dasatinib 2 × 70 mg per day in patients with histologically proven, TKI-naïve, FDG-PET/CT-positive GIST. The primary endpoint was FDG-PET/CT response. RESULTS:Of 52 planned patients, 47 were enrolled from January 2008 to November 2011, when the trial was terminated because of slow accrual. In total, 42 patients were eligible. The median patient age was 61 years, 24 patients were men, and 18 were women. Performance status was 0 in 29 patients and 1 in 13 patients. The median follow-up was 67.2 months. Patients went off trial for elective surgery (n = 8), after 26 cycles as per protocol (n = 5), for disease progression (n = 14), for toxicity (n = 7), and for other reasons (n = 5); and 3 patients died (2 had discontinued drug and 1 was still receiving drug). Toxicity was grade 4 in 5% and grade 3 in 48% of patients and was most often gastrointestinal or pulmonary. Dose was interrupted or reduced in 25% of cycles. The FDG-PET/CT response rate (complete plus partial responses) at 4 weeks was 74% (95% confidence interval, 56%-85%; 14 patients had a complete response, 17 had a partial response, 6 had stable disease, 3 had progressive disease, and 2 were not evaluable). The median progression-free survival was 13.6 months, and the median overall survival was not reached. CONCLUSIONS:Dasatinib produced high metabolic response rates in TKI-naive patients with FDG-PET/CT-positive GIST. Cancer 2018;124:1449-54. © 2018 American Cancer Society. 10.1002/cncr.31234
Personalized Dose of Adjuvant Imatinib in Patients with Gastrointestinal Stromal Tumors: Results from a Population Pharmacokinetic Analysis. Drug design, development and therapy Purpose:Imatinib is the first-line treatment for patients with gastrointestinal stromal tumors (GIST) after surgery. However, its pharmacokinetic profile varies remarkably between individuals and has not been well characterized in postoperative Chinese patients with GIST. Therefore, this study aimed to develop a population pharmacokinetic (PPK) model and recommend appropriate doses for different patients to achieve the target trough concentration in such a population. Patients and Methods:A total of 110 surgically treated GIST patients were enrolled, of which 85 were applied to conduct a PPK analysis with a nonlinear mixed-effect model and 25 for external validation of the model. Demographic and biomedical covariates, as well as six single nucleotide polymorphisms were tested to explore the sources of variation in pharmacokinetic parameters of imatinib. Monte Carlo simulations were performed to establish the initial dosing regimens. Results:A one-compartment model was established in postoperative GIST patients. The red blood cell count (RBC) and rs2231142 were observed to have a significant effect on the clearance of imatinib. The typical values estimated by the final model were 9.72 L/h for clearance (CL/F) and 229 L for volume of distribution (V/F). Different from the fixed dose regimen of 400 mg each day, patients carrying rs2231142 heterozygous type and with a lower level of RBC (2.9 × 10/L), 300 mg imatinib daily is enough to achieve the target trough concentration. When RBC rises to 4.9 × 10/L, 500 mg daily is recommended. For patients with rs2231142 GG genotype, 500 mg a day is required at RBCs of 3.9 × 10/L and 4.9 × 10/L. Conclusion:RBC and rs2231142 contribute to the pharmacokinetic variation of imatinib and personalized dose recommendations based on patient characteristics may be necessary. 10.2147/DDDT.S400986
Elevated preoperative platelet-to-lymphocyte ratio predicts poor prognosis of patients with primary gastrointestinal stromal tumor. Chang Wei-Long,Yang Wen-Chang,Zeng Xiang-Yu,Li Cheng-Guo,Xiong Zhen,Wang Tao,Zhang Rui-Zhi,Tao Kai-Xiong,Zhang Peng BMC gastroenterology BACKGROUND:The neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are considered to reflect the systemic inflammatory response and clinical prognosis. However, the independent prognostic values of the NLR and PLR for patients with gastrointestinal stromal tumor (GIST) remain debatable. This study aims to evaluate the prognostic value of preoperative NLR and PLR in GIST patients. METHODS:We retrospectively reviewed all GIST patients diagnosed and surgically treated at Union Hospital between 2005 and 2018. The preoperative NLR and PLR were calculated to evaluate recurrence-free survival (RFS) and overall survival (OS) by Kaplan-Meier analysis. Univariate and multivariate Cox regression analyses were performed to estimate the independent prognostic values. RESULTS:The median follow-up time was 49 months (interquartile range, 22-74 months). The preoperative PLR was significantly increased in the GIST patients with intermediate and high tumor risks. Increases in the NLR (≥2.34) and PLR (≥185.04) were associated with shorter RFS and OS (P < 0.01). Moreover, the multivariate analysis revealed that elevated PLR was an independent factor for shorter RFS (hazard ratio [HR]: 3.041; 95% confidence interval [CI]: 2.001-4.622; P < 0.001) and OS (HR: 1.899; 95% CI: 1.136-3.173; P = 0.014). CONCLUSIONS:The preoperative PLR is a potential biomarker of GIST and is related to the clinical outcome. An elevated preoperative PLR predicts poor prognosis of patients with primary GIST after complete surgical resection. 10.1186/s12876-020-01275-2
Beyond the Driver Mutation: Immunotherapies in Gastrointestinal Stromal Tumors. Frontiers in immunology Gastrointestinal stromal tumors (GISTs) are a subtype of soft tissue sarcoma (STS), and have become a concept of oncogenic addiction and targeted therapies.The large majority of these tumors develop after a mutation in or platelet derived growth factor receptor α (), resulting in uncontrolled proliferation. GISTs are highly sensitive to imatinib. GISTs are immune infiltrated tumors with a predominance of tumor-associated macrophages (TAMs) and T-cells, including many CD8+ T-cells, whose numbers are prognostic. The genomic expression profile is that of an inhibited Th1 response and the presence of tertiary lymphoid structures and B cell signatures, which are known as predictive to response to ICI. However, the microtumoral environment has immunosuppressive attributes, with immunosuppressive M2 macrophages, overexpression of indoleamine 2,3-dioxygenase (IDO) or PD-L1, and loss of major histocompatibility complex type 1. In addition to inhibiting the oncogene, imatinib appears to act by promoting cytotoxic T-cell activity, interacting with natural killer cells, and inhibiting the expression of PD-L1. Paradoxically, imatinib also appears to induce M2 polarization of macrophages. There have been few immunotherapy trials with anti-CTLA-4 or anti-PD-L1drugs and available clinical data are not very promising. Based on this comprehensive analysis of TME, we believe three immunotherapeutic strategies must be underlined in GIST. First, patients included in clinical trials must be better selected, based on the identified driver mutation (such as D842V mutation), the presence of tertiary lymphoid structures (TLS) or PD-L1 expression. Moreover, innovative immunotherapeutic agents also provide great interest in GIST, and there is a strong rationale for exploring IDO targeting after disease progression during imatinib therapy. Finally and most importantly, there is a strong rationale to combine of inhibition with immune checkpoint inhibitors. 10.3389/fimmu.2021.715727
Identification of a Multitargeted Tyrosine Kinase Inhibitor for the Treatment of Gastrointestinal Stromal Tumors and Acute Myeloid Leukemia. Lin Wen-Hsing,Wu Su-Ying,Yeh Teng-Kuang,Chen Chiung-Tong,Song Jen-Shin,Shiao Hui-Yi,Kuo Ching-Chuan,Hsu Tsu,Lu Cheng-Tai,Wang Pei-Chen,Wu Tsung-Sheng,Peng Yi-Hui,Lin Hui-You,Chen Ching-Ping,Weng Ya-Ling,Kung Fang-Chun,Wu Mine-Hsine,Su Yu-Chieh,Huang Kuo-Wei,Chou Ling-Hui,Hsueh Ching-Cheng,Yen Kuei-Jung,Kuo Po-Chu,Huang Chen-Lung,Chen Li-Tzong,Shih Chuan,Tsai Hui-Jen,Jiaang Weir-Torn Journal of medicinal chemistry Gastrointestinal stromal tumors (GISTs) are prototypes of stem cell factor receptor (c-KIT)-driven cancer. Two receptor tyrosine kinases, c-KIT and fms-tyrosine kinase (FLT3), are frequently mutated in acute myeloid leukemia (AML) patients, and these mutations are associated with poor prognosis. In this study, we discovered a multitargeted tyrosine kinase inhibitor, compound , with potent inhibition against single or double mutations of c-KIT developed in GISTs. Moreover, crystal structure analysis revealed the unique binding mode of with c-KIT and may elucidate its high potency in inhibiting c-KIT kinase activity. Compound inhibited cell proliferation and induced apoptosis by targeting c-KIT in c-KIT-mutant GIST cell lines. The antitumor effects of were also demonstrated in GIST430 and GIST patient-derived xenograft models. Further studies demonstrated that inhibited the proliferation of c-KIT- and FLT3-driven AML cells in vitro and in vivo. The results of this study suggest that may be a potential anticancer drug for the treatment of GISTs and AML. 10.1021/acs.jmedchem.9b01229
Impact of and Polymorphisms on Imatinib Plasmatic Exposure: An Original Work and Meta-Analysis. International journal of molecular sciences Adequate imatinib plasma levels are necessary to guarantee an efficacious and safe treatment in gastrointestinal stromal tumor (GIST) and chronic myeloid leukemia (CML) patients. Imatinib is a substrate of the drug transporters ATP-binding cassette subfamily B member 1 (ABCB1) and ATP-binding cassette subfamily G member 2 (ABCG2) that can affect its plasma concentration. In the present study, the association between three genetic polymorphisms in (rs1045642, rs2032582, rs1128503) and one in (rs2231142) and the imatinib plasma trough concentration (C) was investigated in 33 GIST patients enrolled in a prospective clinical trial. The results of the study were meta-analyzed with those of other seven studies (including a total of 649 patients) selected from the literature through a systematic review process. The c.421C>A genotype demonstrated, in our cohort of patients, a borderline association with imatinib plasma trough levels that became significant in the meta-analysis. Specifically, homozygous carriers of the c.421 A allele showed higher imatinib plasma C with respect to the CC/CA carriers (C, 1463.2 ng/mL AA, vs. 1196.6 ng/mL CC + AC, = 0.04) in 293 patients eligible for the evaluation of this polymorphism in the meta-analysis. The results remained significant under the additive model. No significant association could be described between polymorphisms and imatinib C, neither in our cohort nor in the meta-analysis. In conclusion, our results and the available literature studies sustain an association between c.421C>A and imatinib plasma C in GIST and CML patients. 10.3390/ijms24043303
Switch Control Inhibition of KIT and PDGFRA in Patients With Advanced Gastrointestinal Stromal Tumor: A Phase I Study of Ripretinib. Journal of clinical oncology : official journal of the American Society of Clinical Oncology PURPOSE:In advanced gastrointestinal stromal tumor (GIST), there is an unmet need for therapies that target both primary and secondary mutations of pathogenic KIT/PDGFRA oncoproteins. Ripretinib is a novel switch-control kinase inhibitor designed to inhibit a wide range of and mutations. PATIENTS AND METHODS:This first-in-human, to our knowledge, phase I study of ripretinib (ClinicalTrials.gov identifier: NCT02571036) included a dose-escalation phase and subsequent expansion phase at the recommended phase II dose (RP2D). Eligible patients included those with advanced GIST, intolerant to or experienced progression on ≥ 1 line of systemic therapy, and other advanced malignancies. Safety, dose-limiting toxicities (DLTs), maximum-tolerated dose (MTD), and preliminary antitumor activity were evaluated. RESULTS:At data cutoff (August 31, 2019), 258 patients (n = 184 GIST) were enrolled, with 68 patients in the dose-escalation phase. Three DLTs were reported: grade 3 lipase increase (n = 2; 100 mg and 200 mg twice a day) and grade 4 increased creatine phosphokinase (n = 1; 150 mg once daily). MTD was not reached (maximum dose evaluated, 200 mg twice a day); 150 mg once daily was established as the RP2D. The most frequent (> 30%) treatment-emergent adverse events in patients with GIST receiving ripretinib 150 mg once daily (n = 142) were alopecia (n = 88 [62.0%]), fatigue (n = 78 [54.9%]), myalgia (n = 69 [48.6%]), nausea (n = 65 [45.8%]), palmar-plantar erythrodysesthesia (n = 62 [43.7%]), constipation (n = 56 [39.4%]), decreased appetite (n = 48 [33.8%]), and diarrhea (n = 47 [33.1%]). Objective response rate (confirmed) of 11.3% (n = 16/142) ranging from 7.2% (n = 6/83; fourth line or greater) to 19.4% (n = 6/31; second line) and median progression-free survival ranging from 5.5 months (fourth line or greater) to 10.7 months (second line), on the basis of investigator assessment, were observed. CONCLUSION:Ripretinib is a well-tolerated, novel inhibitor of KIT and PDGFRA mutant kinases with promising activity in patients with refractory advanced GIST. 10.1200/JCO.20.00522
An Epithelioid Gastrointestinal Stromal Tumor of the Stomach With Strong Expression of Keratin: Clinicopathologic Correlation and Follow-up Post-Imatinib Therapy. Baniak Nick,Lee Lawrence,Zhou Chen,Young Sean,Yu Darryl Applied immunohistochemistry & molecular morphology : AIMM Gastrointestinal stromal tumors (GIST) are the most common mesenchymal neoplasms of the digestive tract. They are relatively rare neoplasms compared with gastrointestinal carcinomas and usually can readily be differentiated from carcinomas based on the morphology of the neoplastic cells that are typically spindled (70%), pure epithelioid, or mixed type. GISTs in general lack expression of cytokeratin and exhibit immunoreactivity toward CD117, CD34, or DOG1. GISTs can demonstrate a pure epithelioid morphology that can appear similar histologically to a carcinoma. Very few epithelioid GISTs have been reported to express cytokeratin, which can lead to diagnostic challenges especially in cases with pure epithelioid morphology. Epithelioid GISTs should be considered in the differential diagnosis when evaluating gastrointestinal neoplasms with overlapping epithelioid and carcinoma-like morphology. An accurate diagnosis can be made using additional immunohistochemical studies directed against CD117, CD34, or DOG1. Advanced investigations such as mutation analysis of KIT using molecular pathology methods can further assist in confirming the diagnosis. 10.1097/PAI.0000000000000493
Mir-22-3p Enhances the Chemosensitivity of Gastrointestinal Stromal Tumor Cell Lines to Cisplatin through PTEN/PI3K/Akt Pathway. Xu Yugang,Cheng Ming,Mi Lei,Qiu Yunping,Hao Wenli,Li Leping Iranian journal of allergy, asthma, and immunology Mir-22-3p is associated with many important biological processes, including neuroprotection, tumorigenesis, and various other tumor progressions. Our study aimed to investigate the roles of Mir-22-3p in chemosensitivity of gastrointestinal stromal tumor (GIST-T1) cells to cisplatin and explore its underlying mechanisms. Mir-22-3p high-expressing cell line was established by transfecting GIST-T1 cell line cells with Mir-22-3p mimic. After treatment with cisplatin (10 μM), Cell counting kits-8 (CCK-8) method was used to detect the cell viability. Flow cytometry was applied to measure the degree of cell apoptosis. Scratch wound healing test was used to detect the migration ability of cells. The protein and mRNA levels of the phosphatase and tensin homolog deleted on chromosome ten (PTEN)/phosphatidylinositol 3 kinase (PI3K)/protein kinase B (Akt) pathway-related factors were analyzed by Western blot and qRT-PCR. The mRNA level of Mir-22-3p was increased in transfected GIST-T1 cells compared with that in control cells. The survival rate and Bcl-2/Bax ratio of GIST-T1 cells treated with both Mir-22-3p analogue and cisplatin were significantly decreased, while the apoptosis rate and protein level of caspase-3 were significantly increased (p<0.05). In addition, the mRNA and protein levels of PTENwere significantly increased in cells treated with both Mir-22-3p analogue and cisplatin (p<0.05), while the expression levels of PI3K and Akt were significantly decreased (p<0.05). Mir-22-3p overexpression can increase the chemosensitivity of cisplatin in human gastrointestinal stromal tumor cells by PTEN/PI3K/Akt pathway. 10.18502/ijaai.v17i4.91
Clinical value of next generation sequencing of plasma cell-free DNA in gastrointestinal stromal tumors. Serrano César,Vivancos Ana,López-Pousa Antonio,Matito Judit,Mancuso Francesco M,Valverde Claudia,Quiroga Sergi,Landolfi Stefania,Castro Sandra,Dopazo Cristina,Sebio Ana,Virgili Anna C,Menso María M,Martín-Broto Javier,Sansó Miriam,García-Valverde Alfonso,Rosell Jordi,Fletcher Jonathan A,George Suzanne,Carles Joan,Arribas Joaquín BMC cancer BACKGROUND:Gastrointestinal stromal tumor (GIST) initiation and evolution is commonly framed by KIT/PDGFRA oncogenic activation, and in later stages by the polyclonal expansion of resistant subpopulations harboring KIT secondary mutations after the onset of imatinib resistance. Thus, circulating tumor (ct)DNA determination is expected to be an informative non-invasive dynamic biomarker in GIST patients. METHODS:We performed amplicon-based next-generation sequencing (NGS) across 60 clinically relevant genes in 37 plasma samples from 18 GIST patients collected prospectively. ctDNA alterations were compared with NGS of matched tumor tissue samples (obtained either simultaneously or at the time of diagnosis) and cross-validated with droplet digital PCR (ddPCR). RESULTS:We were able to identify cfDNA mutations in five out of 18 patients had detectable in at least one timepoint. Overall, NGS sensitivity for detection of cell-free (cf)DNA mutations in plasma was 28.6%, showing high concordance with ddPCR confirmation. We found that GIST had relatively low ctDNA shedding, and mutations were at low allele frequencies. ctDNA was detected only in GIST patients with advanced disease after imatinib failure, predicting tumor dynamics in serial monitoring. KIT secondary mutations were the only mechanism of resistance found across 10 imatinib-resistant GIST patients progressing to sunitinib or regorafenib. CONCLUSIONS:ctDNA evaluation with amplicon-based NGS detects KIT primary and secondary mutations in metastatic GIST patients, particularly after imatinib progression. GIST exhibits low ctDNA shedding, but ctDNA monitoring, when positive, reflects tumor dynamics. 10.1186/s12885-020-6597-x
A naphthalene diimide G-quadruplex ligand inhibits cell growth and down-regulates BCL-2 expression in an imatinib-resistant gastrointestinal cancer cell line. Gunaratnam Mekala,Collie Gavin W,Reszka Anthony P,Todd Alan K,Parkinson Gary N,Neidle Stephen Bioorganic & medicinal chemistry Gastro-intestinal tumours (GISTs) are driven by aberrant expression of the c-KIT oncoprotein. They can be effectively treated by the kinase inhibitor imatinib, which locks the c-KIT kinase domain into an inactive conformation. However resistance to imatinib, driven by active-site mutations, is a recurrent clinical challenge, which has been only partly met by the subsequent development of second and third-generation c-KIT inhibitors. It is reported here that a tetra-substituted naphthalene diimide derivative, which is a micromolar inhibitor of cell growth in a wild-type patient-derived GIST cell line, has a sub-micromolar activity in two distinct patient-derived imatinib-resistant cell lines. The compound has been previously shown to down-regulate expression of the c-KIT protein in a wild-type GIST cell line. It does not affect c-KIT protein expression in a resistant cell line to the same extent, whereas it profoundly down-regulates the expression of the anti-apoptopic protein BCL-2. It is proposed that the mechanism of action involves targeting quadruplex nucleic acid structures, and in particular those in the BCL-2 gene and its RNA transcript. The BCL-2 protein is up-regulated in the GIST-resistant cell line, and is strongly down-regulated after treatment. The compound strongly stabilises a range of G-quadruplexes including a DNA one from the BCL-2 promoter and an RNA quadruplex from its 5'-UTR region. A reporter assay construct incorporating the 5'-UTR quadruplex sequence demonstrates down-regulation of BCL-2 expression. 10.1016/j.bmc.2018.04.050
Serum miR-518e-5p is a potential biomarker for secondary imatinib-resistant gastrointestinal stromal tumor. Kou Youwei,Yang Ren,Wang Qiang Journal of biosciences Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumor of the intestinal tract. Imatinib is used as first-line therapy for GIST patients; however, secondary imatinib resistance poses a significant clinical challenge. Here, we analyzed serum miRNA expression profiles to identify specific serum miRNAs that could be used as early diagnostic markers. Candidate miRNAs were validated using Taqman quantitative PCR with serum samples from secondary imatinibresistant GIST patients (n = 39), imatinib-sensitive GIST patients (n = 37), and healthy controls (n = 28). Serum miR- 518e-5p and miR-548e levels were higher in secondary imatinib-resistant GIST than imatinib-sensitive GIST patients or healthy controls (P less than 0.0001). However, ROC analysis indicated that only miR-518e-5p could distinguish imatinibresistant GIST. To discriminate imatinib-resistant from imatinib-sensitive GIST patients, the AUC for serum miR-518e-5p was 0.9938, with 99.8% sensitivity and 82.1% specificity. Serum miR-518e-5p could also discriminate imatinib-resistant GIST patients from healthy controls with 99.9% sensitivity and 97.4% specificity. These data indicate that serum miR-518e- 5p is a potentially promising non-invasive biomarker for early detection and diagnosis of secondary imatinib-resistant GIST.
Ripretinib intrapatient dose escalation after disease progression provides clinically meaningful outcomes in advanced gastrointestinal stromal tumour. European journal of cancer (Oxford, England : 1990) PURPOSE:Ripretinib is a switch-control tyrosine kinase inhibitor that broadly inhibits KIT and platelet-derived growth factor receptor α kinase signalling. Ripretinib showed preliminary efficacy in patients with advanced gastrointestinal stromal tumour (GIST) in a phase I study across a range of doses. Results were confirmed in the phase III INVICTUS study, and ripretinib 150 mg once daily (QD) was subsequently approved as a ≥fourth-line therapy. Here, we report the phase I study results of intrapatient dose escalation (IPDE) in patients with GIST treated across second, third and later lines of therapy. METHODS:Patients with advanced GIST who experienced disease progression (PD) at ripretinib 150 mg QD could dose escalate to 150 mg twice daily (BID). Progression-free survival (PFS) 1 was calculated from the date of the first dose of ripretinib 150 mg QD to PD (as per Response Evaluation Criteria in Solid Tumours 1.1); PFS2 was from the date of IPDE (150 mg BID) to PD or death. Treatment-emergent adverse events (TEAEs) were summarised by dosing periods and compared descriptively. RESULTS:Of 142 patients with GIST receiving ripretinib 150 mg QD, 67 underwent IPDE. IPDE provided benefit across all lines of therapy; the median PFS2 was 5.6, 3.3 and 4.6 months for patients on second-, third- and ≥fourth-line therapy, respectively. A partial metabolic response after IPDE was demonstrated in 13 of 37 patients with available positron emission tomography scans. TEAEs reported at both doses were similar. CONCLUSION:Ripretinib IPDE after PD provided continued clinical benefit in advanced GIST across second, third and later lines of therapy with a similar safety profile to that observed with the QD regimen. 10.1016/j.ejca.2021.07.010
Imatinib Pharmacokinetics in a Large Observational Cohort of Gastrointestinal Stromal Tumour Patients. Farag Sheima,Verheijen Remy B,Martijn Kerst J,Cats Annemiek,Huitema Alwin D R,Steeghs Neeltje Clinical pharmacokinetics BACKGROUND:Low trough imatinib concentration (C ) values have been associated with poor clinical outcomes in gastrointestinal stromal tumour (GIST) patients. This study describes the pharmacokinetics of imatinib in a large cohort of GIST patients in routine clinical care. METHODS:An observational study was performed in imatinib-treated GIST patients. Patient and tumour characteristics were derived from the Dutch GIST Registry and medical records. Imatinib concentrations were measured by liquid chromatography with tandem mass spectrometry. The analyses included the occurrence of a low imatinib C (<1000 µg/L), the change in the C over time and the correlation between exposure and response. RESULTS:In total, 421 plasma samples were available from 108 GIST patients. Most patients (79.6 %) received an imatinib dose of 400 mg. The inter- and intrapatient variabilities in C were 54 and 23 %, respectively. In the first steady-state sample, 44.4 % of patients presented with C values <1000 µg/L; 32.4 % of patients had values <1000 µg/L in >75 % of their samples. Only 33.3 % of patients had C values ≥1000 µg/L in all measured samples. No decrease in C over time was found (P > 0.05). Fifty-seven (91.9 %) of 62 palliative-treated patients had a tumour response (median C 1271 µg/L). Five palliative patients (8.1 %) did not respond (median C 920 µg/L). Given the limited number of non-responders in this cohort, no statistically significant association with clinical benefit could be demonstrated. CONCLUSION:In routine clinical care, one third of GIST patients are systematically underexposed with a fixed dose of imatinib. Prospective clinical studies are needed to investigate the value of C -guided imatinib dosing in GIST patients. 10.1007/s40262-016-0439-7
Nuclear KIT induces a NFKBIB-RELA-KIT autoregulatory loop in imatinib-resistant gastrointestinal stromal tumors. Hsueh Yuan-Shuo,Chang Hui Hua,Shan Yan-Shen,Sun H Sunny,Fletcher Jonathan Alfred,Li Chien-Feng,Chen Li-Tzong Oncogene Gastrointestinal stromal tumors (GISTs) are frequently driven by auto-activated, mutant KIT and have durable response to KIT tyrosine kinase inhibitor. However, acquired resistance is an increasing clinical issue in GIST patients receiving front-line imatinib therapy. Our previous studies showed the colocalization of KIT with DAPI-stained nuclei in GIST cells without knowing the role of nuclear KIT in GIST tumorigenesis. In this article, we first identified the binding of nuclear KIT to the promoter of NFKB inhibitor beta (NFKBIB) by chromatin immunoprecipitation (ChIP) sequencing and ChIP assays, which was accompanied with enhanced NFKBIB protein expression in GIST cells. Clinically, high NCCN risk GISTs had significantly higher mean expression levels of nuclear phospho-KIT and NFKBIB as compared with those of intermediate or low/very low-risk GISTs. Conversely, downregulation of NFKBIB by siRNA led to RELA nuclear translocation that could bind to the KIT promoter region and subsequently reduced KIT transcription/expression and the viability of GIST cells. These findings were further confirmed by either RELA overexpression or NFKB/RELA inducer, valproic acid, treatment to result in reduced KIT expression and relative cell viability of imatinib-resistant GIST cells. Combining valproic acid with imatinib showed significantly better growth inhibitory effects on imatinib-resistant GIST48 and GIST430 cells in vitro, and in the GIST430 animal xenograft model. Taken together, these results demonstrate the existence of a nuclear KIT-driven NFKBIB-RELA-KIT autoregulatory loop in GIST tumorigenesis, which are potential targets for developing combination therapy to overcome imatinib-resistant of KIT-expressing GISTs. 10.1038/s41388-019-0900-9
Analysis of microbiome in gastrointestinal stromal tumors: Looking for different players in tumorigenesis and novel therapeutic options. Cancer science Preclinical forms of gastrointestinal stromal tumor (GIST), small asymptomatic lesions, called microGIST, are detected in approximately 30% of the general population. Gastrointestinal stromal tumor driver mutation can be already detected in microGISTs, even if they do not progress into malignant cancer; these mutations are necessary, but insufficient events to foster tumor progression. Here we profiled the tissue microbiota of 60 gastrointestinal specimens in three different patient cohorts-micro, low-risk, and high-risk or metastatic GIST-exploring the compositional structure, predicted function, and microbial networks, with the aim of providing a complete overview of microbial ecology in GIST and its preclinical form. Comparing microGISTs and GISTs, both weighted and unweighted UniFrac and Bray-Curtis dissimilarities showed significant community-level separation between them and a pronounced difference in Proteobacteria, Firmicutes, and Bacteroidota was observed. Through the LEfSe tool, potential microbial biomarkers associated with a specific type of lesion were identified. In particular, GIST samples were significantly enriched in the phylum Proteobacteria compared to microGISTs. Several pathways involved in sugar metabolism were also highlighted in GISTs; this was expected as cancer usually displays high aerobic glycolysis in place of oxidative phosphorylation and rise of glucose flux to promote anabolic request. Our results highlight that specific differences do exist in the tissue microbiome community between GIST and benign lesions and that microbiome restructuration can drive the carcinogenesis process. 10.1111/cas.15441
Gain of TP53 Mutation in Imatinib-treated SDH-Deficient Gastrointestinal Stromal Tumor and Clinical Utilization of Targeted Next-generation Sequencing Panel for Therapeutic Decision Support. Wei Christina H,Pettersson Jonas,Campan Mihaela,Chopra Shefali,Naritoku Wesley,Martin Sue E,Ward Pamela M Applied immunohistochemistry & molecular morphology : AIMM Patients with succinate dehydrogenase (SDH)-deficient gastrointestinal stromal tumor (GIST) have few therapeutic options. Despite lack of KIT or platelet-derived growth factor receptor A (PDGFRA) driver mutations, SDH-deficient GISTs display strong expression of KIT by immunohistochemistry and these patients are often treated with tyrosine kinase inhibitors, including imatinib as a first-line therapy. Using a targeted next-generation sequencing panel of mutation hotspots of 50-clinically relevant genes, we investigated (1) concurrence of somatic/actionable mutations and (2) tumor molecular evolution by comparing 2 resection specimens 1.5 years apart while the patient was on imatinib adjuvant therapy. We found the tumors did not harbor KIT, PDGFRA, or any other clinically actionable mutations. However, a TP53 mutation (c.422G>A; p.C141Y) was detected in the second recurrent lesion. This represents the first study to monitor the molecular evolution of a SDH-deficient GIST during adjuvant treatment. These findings emphasize the critical need for next-generation sequencing testing before initiating targeted therapy. 10.1097/PAI.0000000000000482
Molecular modelling evaluation of exon 18 His845_Asn848delinsPro PDGFRα mutation in a metastatic GIST patient responding to imatinib. Nannini Margherita,Tarantino Giuseppe,Indio Valentina,Ravegnini Gloria,Astolfi Annalisa,Urbini Milena,De Leo Antonio,Santini Donatella,Ceccarelli Claudio,Gruppioni Elisa,Altimari Annalisa,Castellucci Paolo,Fanti Stefano,Di Scioscio Valerio,Saponara Maristella,Gatto Lidia,Pession Andrea,Martelli Pier Luigi,Casadio Rita,Pantaleo Maria Abbondanza Scientific reports Platelet-Derived Growth Factor Receptor Alpha (PDGFRA) mutations occur in approximately 5-7% of gastrointestinal stromal tumours (GIST). Over half of all PDGFRA mutations are represented by the substitution at position 842 in the A-loop of an aspartic acid (D) with a valine (V), recognized as D842V, conferring primary resistance to imatinib in vitro and in clinical observations due to the conformation of the kinase domain, which negatively affects imatinib binding. The lack of interaction between imatinib and the D842V PDGFRA mutated model has been established and widely confirmed in vivo. However, for the other PDGFRA mutations, the correlation between pre-clinical and clinical data is still unclear. An in silico evaluation of the p.His845_Asn848delinsPro mutation involving exon 18 of PDGFRA in a metastatic GIST patient responding to first-line imatinib has been provided. Docking analyses were performed, and the ligand-receptor interactions were evaluated with the jCE algorithm for structural alignment. The docking simulation and structural superimposition analysis show that PDGFRA p.His845_Asn848delinsPro stabilizes the imatinib binding site with the residues that are conserved in KIT. The in vivo evidence that PDGFRA p.His845_Asn848delinsPro is sensitive to imatinib was confirmed by the molecular modelling, which may represent a reliable tool for the prediction of clinical outcomes and treatment selection in GIST, especially for rare mutations. 10.1038/s41598-018-38028-x
Orai1 mediates tumor-promoting store-operated Ca entry in human gastrointestinal stromal tumors via c-KIT and the extracellular signal-regulated kinase pathway. Wang Lei,Hao Jiaqi,Zhang Yijian,Yang Ziyi,Cao Yang,Lu Wei,Shu Yijun,Jiang Lin,Hu Yunping,Lv Wenjie,Liu Yingbin,Dong Ping Tumour biology : the journal of the International Society for Oncodevelopmental Biology and Medicine Gastrointestinal stromal tumors originate from interstitial cells of Cajal, the pacemaker cells of the gut. Ca regulates the pacemaker activity of interstitial cells of Cajal. Store-operated Ca entry mediates the majority of Ca entry in most cancer cells and may be a factor in regulating intracellular Ca in interstitial cells of Cajal and gastrointestinal stromal tumors. Therefore, a blockade of this mechanism may affect the progression of gastrointestinal stromal tumors. Orai1 is the pore subunit of store-operated Ca channels. Here, we reported that Orai1 was overexpressed in gastrointestinal stromal tumor tissues and was positively correlated with a high-risk grade in gastrointestinal stromal tumor patients. Furthermore, upon Orai1 silencing, the functional store-operated Ca entry in gastrointestinal stromal tumor cells was decreased, indicating that the function of store-operated Ca entry was mediated by Orai1. Inhibition of Orai1-mediated store-operated Ca entry by Orai1 silencing or store-operated Ca entry blockers (SKF-96365 and 2-aminoethyl diphenylborate) induced obvious cell proliferation suppression, cell-cycle distribution, and apoptosis stimulation in GIST-T1 cells. Conversely, Orai1 overexpression increased store-operated Ca entry and cell proliferation in GIST882 cells. In addition, we found that activation of c-KIT and the extracellular signal-regulated kinase pathway participated in the oncogenic functions of Orai1-mediated store-operated Ca entry in gastrointestinal stromal tumor cells. These results revealed that Orai1-mediated store-operated Ca entry is critical for gastrointestinal stromal tumor cell proliferation via c-KIT and ERK signaling pathway activation. Orai1-mediated store-operated Ca entry plays an oncogenic role and may be a novel prognostic factor and therapeutic target for patients with gastrointestinal stromal tumors. 10.1177/1010428317691426
Gastrointestinal Stromal Tumor of the Prostate: Staging and Evaluation of Response to Therapy With 18F-FDG PET/CT. Alabed Yazan Z Clinical nuclear medicine A 49-year-old man presented for routine general physical examination was found with an enlarged prostate gland without associated symptoms. Ultrasound followed by computed tomography (CT) of abdomen and pelvis confirmed a markedly enlarged heterogeneous prostate gland. Subsequently, a staging flourine-18 fluorodeoxyglucose (F-FDG) positron emission tomography (PET/CT) scan revealed intensely FDG-avid mass involving the prostate, which was biopsied as gastrointestinal stromal tumor (GIST). The patient was treated with imatinib and a follow-up PET/CT scan showed complete metabolic response. F-FDG PET/CT scan is useful in staging and follow-up of this very rare extragastrointestinal stromal tumor (EGIST). 10.1097/RLU.0000000000001906
Preferential MGMT methylation could predispose a subset of KIT/PDGFRA-WT GISTs, including SDH-deficient ones, to respond to alkylating agents. Ricci Riccardo,Martini Maurizio,Ravegnini Gloria,Cenci Tonia,Milione Massimo,Lanza Paola,Pierconti Francesco,Santini Donatella,Angelini Sabrina,Biondi Alberto,Rosa Fausto,Alfieri Sergio,Clemente Gennaro,Persiani Roberto,Cassano Alessandra,Pantaleo Maria A,Larocca Luigi M Clinical epigenetics BACKGROUND:Succinate dehydrogenase (SDH)-deficient gastrointestinal stromal tumors (GISTs) constitute a small KIT/PDGFRA-WT GIST subgroup featuring DNA methylation which, although pervasive, appears nevertheless not randomly distributed. Although often indolent, these tumors are mostly chemorefractory in aggressive cases. Promoter methylation-induced O-methylguanine DNA methyltransferase (MGMT) inactivation improves the efficacy of alkylating agents in gliomas, colorectal cancer and diffuse large B cell lymphoma. MGMT methylation has been found in some GISTs, without determining SDH status. Thirty-six GISTs were enrolled in past sarcoma trials testing alkylating agents, with negative results. Nevertheless, a possible effect on MGMT-methylated GISTs could have escaped detection, since tested GISTs were neither selected by genotype nor investigated for SDH; MGMT was studied in two cases only, revealing baseline activity; these trials were performed prior to the adoption of Choi criteria, the most sensitive for detecting GIST responses to therapy. Under these circumstances, we investigated whether MGMT methylation is preferentially found in SDH-deficient cases (identified by SDHB immunohistochemistry) by analyzing 48 pathogenetically heterogeneous GISTs by methylation-specific PCR, as a premise for possible investigations on the use of alkylating drugs in these tumors. RESULTS:Nine GISTs of our series were SDH-deficient, revealing significantly enriched in MGMT-methylated cases (6/9-67%-, vs. 6/39-15%- of SDH-proficient GISTs; p = 0.004). The pathogenetically heterogeneous KIT/PDGFRA-WT GISTs were also significantly MGMT-methylated (11/24-46%-, vs. 1/24-4%- of KIT/PDGFRA-mutant cases, p = 0.002). CONCLUSIONS:A subset of KIT/PDGFRA-WT GISTs, including their largest pathogenetically characterized subgroup (i.e., SDH-deficient ones), is preferentially MGMT-methylated. This finding could foster a reappraisal of alkylating agents for treating malignant cases occurring among these overall chemorefractory tumors. 10.1186/s13148-018-0594-9
Familial wild-type gastrointestinal stromal tumour in association with germline truncating variants in both SDHA and PALB2. Whitworth James,Casey Ruth T,Smith Philip S,Giger Olivier,Martin Jose Ezequiel,Clark Graeme,Cook Jaqueline,Fernando Marlee S,Taniere Phillipe, ,Maher Eamonn R European journal of human genetics : EJHG Gastrointestinal stromal tumour (GIST) is a mesenchymal neoplasm arising in the gastrointestinal tract. A rare subset of GISTs are classified as wild-type GIST (wtGIST) and these are frequently associated with germline variants that affect the function of cancer predisposition genes such as the succinate dehydrogenase subunit genes (SDHA, SDHB, SDHC, SDHD) or NF1. However, despite this high heritability, familial clustering of wtGIST is extremely rare. Here, we report a mother-son diad who developed wtGIST at age 66 and 34 years, respectively. Comprehensive genetic testing revealed germline truncating variants in both SDHA (c.1534C>T (p.Arg512*)) and PALB2 (c.3113G>A (p.Trp1038*)) in both affected individuals. The mother also developed breast ductal carcinoma in-situ at age 70 years. Immunohistochemistry and molecular analysis of the wtGISTs revealed loss of SDHB expression and loss of the wild-type SDHA allele in tumour material. No allele loss was detected at PALB2 suggesting that wtGIST tumourigenesis was principally driven by succinate dehydrogenase deficiency. However, we speculate that the presence of multilocus inherited neoplasia alleles syndrome (MINAS) in this family might have contributed to the highly unusual occurrence of familial wtGIST. Systematic reporting of tumour risks and phenotypes in individuals with MINAS will facilitate the clinical interpretation of the significance of this diagnosis, which is becoming more frequent as strategies for genetic testing for hereditary cancer becomes more comprehensive. 10.1038/s41431-021-00862-5
Early response evaluation using 18F-FDG-PET/CT does not influence management of patients with metastatic gastrointestinal stromal tumors (GIST) treated with palliative intent. Farag Sheima,IJzerman Nikki S,Houdijk Matthijs P M,Reyners An K L,Arens Anne Ij,Grünhagen Dirk J,Desar Ingrid M E,Gelderblom Hans,Steeghs Neeltje,de Geus-Oei Lioe-Fee Nuklearmedizin. Nuclear medicine AIM:The aim of this study was to investigate the impact of F-FDG-PET/CT on treatment decision making in metastatic gastrointestinal stromal tumor (GIST) patients. METHODS:This study retrospectively evaluated F-FDG-PET/CT scans to monitor response of metastatic GIST patients treated with palliative intent. Data from the Dutch GIST Registry was used. Early scans (<10 weeks after start of treatment) and late scans (>10 weeks after start of treatment) were scored on the impact in change of treatment. RESULTS:Sixty-one PET/CT scans were performed for treatment evaluation in 39 patients with metastatic GIST of which 36 were early scans and 25 were late scans. Early PET/CT scans led to a change in management in 5.6% of patients and late PET/CT scans led to a change in management in 56% of patients. Change in management was more often seen after scans with lack of metabolic response (48% vs. 11% in scans with metabolic response, p=0.002). Neither metabolic response nor change in treatment were more often seen in patients with mutations compared to patients with non- mutations (metabolic response 65% vs. 46% non-, p=0.33, and change in management 28% vs. 21% non-, p=0.74). CONCLUSION:F-FDG-PET/CT is not recommended for early response evaluation in an unselected patient population with metastatic GIST, since it does not influence treatment decisions. F-FDG-PET/CT, however, can be useful for late response assessment, especially in case of indeterminate CT results. 10.1055/a-1542-6211
Determination of the absolute bioavailability of oral imatinib using a stable isotopically labeled intravenous imatinib-d8 microdose. European journal of clinical pharmacology PURPOSE:The aim of this study was to ascertain whether the absolute bioavailability of oral imatinib (Glivec®) during steady state plasma pharmacokinetics in cancer patients could be determined through a concomitant intravenous administration of a single 100 μg microdose of deuterium labeled imatinib (imatinib-d8). Secondly, the usefulness of liquid chromatography-tandem mass spectrometry (LC-MS/MS) was investigated for simultaneous analysis of orally and intravenously administered imatinib. METHODS:Included patients were on a stable daily dose of 400 mg oral imatinib prior to study participation. On day 1, patients received a 100 μg intravenous imatinib-d8 microdose 2.5 h after intake of the oral dose. Plasma samples were collected for 48 h. Imatinib and imatinib-d8 concentrations were simultaneously quantified using a validated LC-MS/MS assay. The absolute bioavailability was calculated by comparing the dose-normalized exposure with unlabeled and stable isotopically labeled imatinib in plasma. RESULTS:A total of six patients were enrolled. All patients had a history of gastrointestinal stromal tumors (GIST). The median absolute bioavailability of oral imatinib at steady state was 76% (range 44-106%). Imatinib and imatinib-d8 plasma concentrations were quantified in all collected plasma samples, with no samples below the limit of quantification for imatinib-d8. CONCLUSION:The absolute bioavailability of imatinib was successfully estimated at steady state plasma pharmacokinetics using the stable isotopically labeled microdose trial design. This study exhibits the use of a stable isotopically labeled intravenous microdose to determine the absolute bioavailability of an oral anticancer agent in patients with LC-MS/MS as the analytical tool. 10.1007/s00228-020-02888-y
Upregulation of ZNF148 in SDHB-deficient gastrointestinal stromal tumor potentiates Forkhead box M1-mediated transcription and promotes tumor cell invasion. Gao Xiaodong,Ma Chunmin,Sun Xiangwei,Zhao Qin,Fang Yong,Jiang Yuhui,Shen Kuntang,Shen Xian Cancer science Succinate dehydrogenase (SDH) deficiency is associated with gastrointestinal stromal tumor (GIST) oncogenesis, but the underlying molecular mechanism remains to be further investigated. Here, we show that succinate accumulation induced by SDHB loss of function increased the expression of zinc finger protein 148 (ZNF148, also named ZBP-89) in GIST cells. Meanwhile, ZNF148 is found to be phosphorylated by ERK at Ser306, and this phosphorylation results in ZNF148 binding to Forkhead box M1 (FOXM1). Through the complex formation at the promoter, ZNF148 facilitates Histone H3 acetylation and FOXM1-mediated Snail transcription, which eventually promotes cell invasion and tumor growth. The clinical analysis indicates that SDHB deficiency is associated with elevated ZNF148 levels, and ZNF148-S306 phosphorylation level displays a positive correlation with poor prognosis in GIST patients. These findings illustrate an unidentified molecular mechanism underlying FOXM1-regulated gene transcription related to GIST cell invasion, which highlights the physiological effects of SDHB deficiency on the invasiveness of GIST. 10.1111/cas.14348
Oncogenic Kit signalling on the Golgi is suppressed by blocking secretory trafficking with M-COPA in gastrointestinal stromal tumours. Obata Yuuki,Horikawa Keita,Shiina Isamu,Takahashi Tsuyoshi,Murata Takatsugu,Tasaki Yasutaka,Suzuki Kyohei,Yonekura Keita,Esumi Hiroyasu,Nishida Toshirou,Abe Ryo Cancer letters Most gastrointestinal stromal tumours (GISTs) are caused by constitutively active mutations in Kit tyrosine kinase. The drug imatinib, a specific Kit inhibitor, improves the prognosis of metastatic GIST patients, but these patients become resistant to the drug by acquiring secondary mutations in the Kit kinase domain. We recently reported that a Kit mutant causes oncogenic signals only on the Golgi apparatus in GISTs. In this study, we show that in GIST, 2-methylcoprophilinamide (M-COPA, also known as "AMF-26"), an inhibitor of biosynthetic protein trafficking from the endoplasmic reticulum (ER) to the Golgi, suppresses Kit autophosphorylation at Y703/Y721/Y730/Y936, resulting in blockade of oncogenic signalling. Results of our M-COPA treatment assay show that Kit Y703/Y730/Y936 in the ER are dephosphorylated by protein tyrosine phosphatases (PTPs), thus the ER-retained Kit is unable to activate downstream molecules. ER-localized Kit Y721 is not phosphorylated, but not due to PTPs. Importantly, M-COPA can inhibit the activation of the Kit kinase domain mutant, resulting in suppression of imatinib-resistant GIST proliferation. Our study demonstrates that Kit autophosphorylation is spatio-temporally regulated and may offer a new strategy for treating imatinib-resistant GISTs. 10.1016/j.canlet.2017.11.032
A Novel Pathological Prognostic Score (PPS) to Identify "Very High-Risk" Patients: a Multicenter Retrospective Analysis of 506 Patients with High Risk Gastrointestinal Stromal Tumor (GIST). Journal of gastrointestinal surgery : official journal of the Society for Surgery of the Alimentary Tract BACKGROUND:To determine the better risk stratification based on surgical pathology and to assess the clinical outcomes after curative resection with a new scoring system in high risk gastrointestinal stromal tumor (GIST) patients. METHODS:We retrospectively evaluated 506 high-risk GIST patients who underwent curative resection as initial treatment at four centers from 2001 to 2015. RESULTS:Multivariate analysis revealed that only Ki-67 labeling index (LI) and mitotic index were independent prognostic factors of overall survival (OS). For the two tumor-related pathological factors, Ki-67 LI > 7% and mitotic index ≥ 7/50 high power fields were allocated 1 point each. The total score was defined as the Pathological Prognostic Score (PPS). When Ki-67 LI and mitotic index were replaced by PPS, a multivariate analysis still identified PPS as an independent predictor of OS (HR 2.719; 95% CI 1.309-5.650; P = 0.007). Patients with a PPS of 0, 1, or 2 had a 5-year survival of 91.8, 79.8, and 51.0%, respectively (P = 0.001). Furthermore, an elevated PPS (PPS = 2) was associated with larger tumor size, non-stomach tumor, and open resection (all P < 0.05). CONCLUSION:The PPS independently predicted postoperative survival in high-risk GIST, and it might facilitate the selection of appropriate treatment strategy for these patients. 10.1007/s11605-018-3799-5
Mixed response on regorafenib treatment for GIST (gastro-intestinal stromal tumor) according to F-FDG-PET/CT. Van Weehaeghe Donatienne,Gheysens Olivier,Vandecaveye Vincent,Schöffski Patrick,Van Laere Koen,Deroose Christophe M BMC cancer BACKGROUND:Gastro-intestinal stromal tumors (GISTs) are very rare tumors of the gastro-intestinal tract, originating from the interstitial cells of Cajal or a common cell precursor which both express type III tyrosine kinase receptors. Regorafenib is an oral multi-kinase inhibitor used to treat gastro-intestinal stromal tumors. To our knowledge this is the first case in literature to show the response of regorafenib on PET. CASE PRESENTATION:A 37-year-old male with lower abdominal pain and weight loss was referred to our hospital. Abdominal ultrasound and computed tomography (CT) showed diffuse peritoneal implants. Surgical specimen histology showed a GIST with c-KIT exon 11 deletion (c.1708_1728del) and treatment with imatinib 400 mg/day was initiated. Due to disease progression illustrated on baseline versus follow-up F-FDG-PET/CT scans therapy was switched to imatinib 800 mg/day and later to sunitinib 50 mg/day. Upon further disease progression 10 months later, third line treatment with regorafenib 160 mg/day was initiated. F-FDG-PET/CT showed the metabolic responses after 4 months regorafenib treatment ranging from complete response to the appearance of a new lesion in the liver. The new hypermetabolic lesion was only seen on the non-attenuation-corrected images because of breathing motion artifact. CONCLUSION:This case illustrates that metabolic response can occur in GIST lesions without morphological response after third line regorafinib treatment. Furthermore this is the first case in literature to show regorafinib response on PET. 10.1186/s12885-018-4154-7
Efficacy and safety of TAS-116, an oral inhibitor of heat shock protein 90, in patients with metastatic or unresectable gastrointestinal stromal tumour refractory to imatinib, sunitinib and regorafenib: a phase II, single-arm trial. Doi Toshihiko,Kurokawa Yukinori,Sawaki Akira,Komatsu Yoshito,Ozaka Masato,Takahashi Tsuyoshi,Naito Yoichi,Ohkubo Shuichi,Nishida Toshirou European journal of cancer (Oxford, England : 1990) AIM:We evaluated the efficacy and safety of TAS-116, a novel class of an orally active selective inhibitor of heat shock protein 90, in patients with advanced gastrointestinal stromal tumour (GIST) after failure of three or more lines of standard treatment with imatinib, sunitinib and regorafenib. METHODS:In this single-arm phase II study, patients received 160 mg/day oral TAS-116 for five consecutive days, followed by a 2-day rest. The primary end-point was centrally assessed progression-free survival (PFS). The secondary end-points were objective response rate, disease control rate, overall survival (OS), metabolic response rate, safety, pharmacokinetics and pharmacogenomics. RESULTS:Forty-one patients were enrolled in Japan, and 40 patients underwent efficacy and safety evaluation. At the cut-off date, the median PFS was 4.4 months (95% confidence interval [CI], 2.8-6.0) and 12-week progression-free rate was 73.4% (95% CI, 58.1-88.7). Thirty-four patients (85.0%) had stable disease for ≥ 6 weeks. The median OS was 11.5 months (95% CI, 7.0-not reached). All patients experienced at least one treatment-related adverse event (AE), including diarrhoea (80.0%), decreased appetite (45.0%) and increase in blood creatinine level (42.5%). Grade ≥3 AEs and treatment-related grade ≥3 AEs occurred in 23 (57.5%) and 21 (52.5%) patients, respectively. All AEs resolved after dose modification, and no TAS-116-related AEs led to treatment discontinuation. CONCLUSION:TAS-116 showed significant activity in advanced GIST refractory to standard treatment. Further development of TAS-116 is warranted. TRIAL REGISTRATION:JapicCTI-163182. 10.1016/j.ejca.2019.08.009
Pimitespib is effective on cecal GIST in a mouse model of familial GISTs with KIT-Asp820Tyr mutation through KIT signaling inhibition. Kihara Takako,Yuan Jiayin,Watabe Tadashi,Kitajima Kazuhiro,Kimura Neinei,Ohkouchi Mizuka,Hashikura Yuka,Ohkubo Shuichi,Takahashi Tsuyoshi,Hirota Seiichi Experimental and molecular pathology Three families with multiple gastrointestinal stromal tumors (GISTs) caused by a germline Asp820Tyr mutation at exon 17 of the c-kit gene (KIT-Asp820Tyr) have been reported. We previously generated a knock-in mouse model of the family, and the mice with KIT-Asp818Tyr corresponding to human KIT-Asp820Tyr showed a cecal tumor equivalent to human GIST. In the model mice, we reported that tyrosine kinase inhibitor, imatinib, could stabilize but not decrease the cecal tumor volume. In this report, we examined whether a heat shock protein 90 inhibitor, pimitespib (TAS-116), has an inhibitory effect on phosphorylation of KIT-Asp818Tyr and can decrease the cecal tumor volume in the model mice. First, we showed that pimitespib inhibited KIT phosphorylation both dose- and time-dependently in KIT-Asp818Tyr transfected murine Ba/F3 cells. Then, four 1-week courses of pimitespib were orally administered to heterozygous (KIT-Asp818Tyr/+) model mice. Each course consisted of once-daily administration for consecutive 5 days followed by 2 days-off. Cecal tumors were dissected, and tumor volume was histologically analyzed, Ki-67 labeling index was immunohistochemically examined, and apoptotic figures were counted. Compared to the vehicle treated mice, pimitespib administered mice showed statistically significantly smaller cecal tumor volume, lower Ki-67 labeling index, and higher number of apoptotic figures in 10 high power fields (P = 0.0344, P = 0.0019 and P = 0.0269, respectively). Western blotting revealed that activation of KIT signaling molecules was strongly inhibited in the tumor tissues of pimitespib-administered mice compared to control mice. Thus, pimitespib seemed to inhibit in vivo tumor progression effectively in the model mice. These results suggest that the progression of multiple GISTs in patients with germline KIT-Asp820Tyr might be controllable by pimitespib. 10.1016/j.yexmp.2021.104692
Genetic Polymorphisms Contribute to the Individual Variations of Imatinib Mesylate Plasma Levels and Adverse Reactions in Chinese GIST Patients. Liu Jing,Chen Zhiyu,Chen Hanmei,Hou Yingyong,Lu Weiqi,He Junyi,Tong Hanxing,Zhou Yuhong,Cai Weimin International journal of molecular sciences Imatinib mesylate (IM) has dramatically improved the outcomes of gastrointestinal stromal tumor (GIST) patients. However, the clinical responses of IM may considerably vary among single individuals. This study aimed to investigate the influences of genetic polymorphisms of drug-metabolizing enzyme (CYP3A4), transporters (ABCB1, ABCG2), and nuclear receptor (Pregnane X Receptor (PXR, encoded by )) on IM plasma levels and related adverse reactions in Chinese GIST patients. A total of 68 Chinese GIST patients who have received IM 300-600 mg/day were genotyped for six single nucleotide polymorphisms (SNPs) (; ; ; , , ), and the steady-state IM trough plasma concentrations were measured by a validated HPLC method. There were statistically significant variances in the steady-state IM trough plasma concentrations (from 272.22 to 4365.96 ng/mL). Subjects of in , allele carriers in and in had significantly higher steady-state IM dose-adjusted trough plasma concentrations. Subjects of in had significantly higher incidence rate of edema. The genetic polymorphisms of , , were significantly associated with IM plasma levels, and the genetic variations of were significantly associated with the incidence rate of edema in Chinese GIST patients. The current results may serve as valuable fundamental knowledge for IM therapy in Chinese GIST patients. 10.3390/ijms18030603
Direct engagement of the PI3K pathway by mutant KIT dominates oncogenic signaling in gastrointestinal stromal tumor. Bosbach Benedikt,Rossi Ferdinand,Yozgat Yasemin,Loo Jennifer,Zhang Jennifer Q,Berrozpe Georgina,Warpinski Katherine,Ehlers Imke,Veach Darren,Kwok Andrew,Manova Katia,Antonescu Cristina R,DeMatteo Ronald P,Besmer Peter Proceedings of the National Academy of Sciences of the United States of America Gastrointestinal stromal tumors (GISTs) predominantly harbor activating mutations in the receptor tyrosine kinase KIT. To genetically dissect in vivo the requirement of different signal transduction pathways emanating from KIT for tumorigenesis, the oncogenic mutation was combined with point mutations abrogating specific phosphorylation sites on KIT. Compared with single-mutant mice, double-mutant knock-in mice lacking the SRC family kinase-binding site on KIT (pY567) exhibited attenuated MAPK signaling and tumor growth. Surprisingly, abrogation of the PI3K-binding site (pY719) in mice prevented GIST development, although the interstitial cells of Cajal (ICC), the cells of origin of GIST, were normal. Pharmacologic inhibition of the PI3K pathway in tumor-bearing mice with the dual PI3K/mTOR inhibitor voxtalisib, the pan-PI3K inhibitor pilaralisib, and the PI3K-alpha-restricted inhibitor alpelisib each diminished tumor proliferation. The addition of the MEK inhibitor PD-325901 or binimetinib further decreased downstream KIT signaling. Moreover, combining PI3K and MEK inhibition was effective against imatinib-resistant tumors. 10.1073/pnas.1711449114
Differential antitumor activity of compounds targeting the ubiquitin-proteasome machinery in gastrointestinal stromal tumor (GIST) cells. Rausch Jessica L,Ali Areej A,Lee Donna M,Gebreyohannes Yemarshet K,Mehalek Keith R,Agha Aya,Patil Sneha S,Tolstov Yanis,Wellens Jasmien,Dhillon Harbir S,Makielski Kathleen R,Debiec-Rychter Maria,Schöffski Patrick,Wozniak Agnieszka,Duensing Anette Scientific reports The majority of gastrointestinal stromal tumors (GISTs) are driven by oncogenic KIT signaling and can therefore be effectively treated with the tyrosine kinase inhibitor (TKI) imatinib mesylate. However, most GISTs develop imatinib resistance through secondary KIT mutations. The type of resistance mutation determines sensitivity to approved second-/third-line TKIs but shows high inter- and intratumoral heterogeneity. Therefore, therapeutic strategies that target KIT independently of the mutational status are intriguing. Inhibiting the ubiquitin-proteasome machinery with bortezomib is effective in GIST cells through a dual mechanism of KIT transcriptional downregulation and upregulation of the pro-apoptotic histone H2AX but clinically problematic due to the drug's adverse effects. We therefore tested second-generation inhibitors of the 20S proteasome (delanzomib, carfilzomib and ixazomib) with better pharmacologic profiles as well as compounds targeting regulators of ubiquitination (b-AP15, MLN4924) for their effectiveness and mechanism of action in GIST. All three 20S proteasome inhibitors were highly effective in vitro and in vivo, including in imatinib-resistant models. In contrast, b-AP15 and MLN4924 were only effective at high concentrations or had mostly cytostatic effects, respectively. Our results confirm 20S proteasome inhibitors as promising strategy to overcome TKI resistance in GIST, while highlighting the complexity of the ubiquitin-proteasome machinery as a therapeutic target. 10.1038/s41598-020-62088-7
Ki-67 labeling index may be a promising indicator to identify "very high-risk" gastrointestinal stromal tumor: a multicenter retrospective study of 1022 patients. Liu Xuechao,Qiu Haibo,Zhang Peng,Feng Xingyu,Chen Tao,Li Yong,Tao Kaixiong,Li Guoxin,Sun Xiaowei,Zhou Zhiwei, Human pathology We sought to determine whether Ki-67 labeling index (LI) was an independent prognostic factor for gastrointestinal stromal tumor (GIST). A multicenter cohort of 1022 patients undergoing surgical resection of primary GIST between August 2004 and October 2015 was retrospectively analyzed. Immunohistochemical analysis was performed to evaluate expression of Ki-67 in their paraffin-embedded tissue samples. The optimal cutoff value of Ki-67 LI was determined as 6% by receiver operating characteristics curve analysis. Multivariate analysis showed that Ki-67 LI was a significant predictor of overall survival (OS) (hazard ratio: 1.793; 95% confidence interval, 1.240-2.593; P=.002). When stratified by modified National Institutes of Health classification, it was still independently associated with OS in high-risk and non-high-risk patients (P=.001 and P=.055, respectively). Of note, the prognostic significance of Ki-67 LI was also maintained when stratified by tumor size, mitotic index, tumor site, and histological subtype (all Ps<.05). In addition, high-risk patients with Ki-67 LI >6% exhibited a significantly poorer OS rate than those with Ki-67 LI ≤6% (53.6% versus 88.7%, respectively; P=.001). The area under the receiver operating characteristics curve for Ki-67 LI was higher than that of modified National Institutes of Health classification component in high-risk patients (P=.029). Therefore, Ki-67 LI is a promising predictor of outcome in GIST, especially in high-risk patients, and it may have important clinical utility in identifying "very high-risk" patients for rational targeted therapy. 10.1016/j.humpath.2017.09.003
Using the recurrence risk score by Joensuu to assess patients with gastrointestinal stromal tumor treated with adjuvant imatinib: A retrospective cohort study. Tang Jianwei,Zhao Rui,Zheng Xiaobo,Xu Liangliang,Wang Yong,Feng Lei,Ren Shengsheng,Wang Peng,Zhang Ming,Xu Mingqing Medicine In 2014, Joensuu and colleagues devised the first recurrence risk score (RRS) to identify the risk factors for gastrointestinal stromal tumor (GIST) recurrence. However, there are scarce data available on RRS effectiveness and efficiency. Therefore, we retrospectively analyzed clinical data to validate Joensuu's RRS in patients treated with adjuvant imatinib.In this retrospective cohort study, data were collected from patients with GIST who were treated with adjuvant imatinib between December 2005 and May 2017 in the West China Hospital. The study consisted of 137 patients, after application of inclusion and exclusion criteria. Recurrence-free survival (RFS) was the primary end point.The RRSs for 137 patients were divided into 3 groups: low (n = 46), medium (n = 48), and high (n = 43). The RFSs of the 3 groups were significantly different (P < .001). In patients who received adjuvant imatinib for <36 months, the RFS difference was also significant (P < .001), and the result was similar in patients treated with adjuvant imatinib for ≥36 months (P = .03). The area under the curve of the RRS was 0.84 ([95% confidence interval] 0.76-0.92, P < .001), suggesting that the RRS method could accurately assess recurrence risks for patients with GIST who were treated with adjuvant imatinib.It is appropriate to apply the RRS method to assess recurrence risks for patients with GIST who were treated with adjuvant imatinib. A longer adjuvant imatinib duration is recommended for high-risk patients with GIST. It is also important to identify a more effective treatment for patients who are resistant to imatinib. 10.1097/MD.0000000000011400
Gene Expression Profiling of PDGFRA Mutant GIST Reveals Immune Signatures as a Specific Fingerprint of D842V Exon 18 Mutation. Indio Valentina,Ravegnini Gloria,Astolfi Annalisa,Urbini Milena,Saponara Maristella,De Leo Antonio,Gruppioni Elisa,Tarantino Giuseppe,Angelini Sabrina,Pession Andrea,Pantaleo Maria Abbondanza,Nannini Margherita Frontiers in immunology Platelet Derived Growth Factor Receptor Alpha (PDGFRA) mutations occur in only about 5-7% of gastrointestinal stromal tumors (GIST), notably with alterations on exons 12/14/18. The most frequent PDGFRA mutation is the exon 18 D842V, which is correlated to specific clinico-pathological features, such as primary imatinib resistance and higher indolence. Here, we present a gene expression profile (GEP) comparison of D842V vs. PDGFRA with mutations other than D842V (non-D842V). GEP was followed by bioinformatic analysis aimed at evaluating differential expression, tumor microenvironment composition and pathway enrichment. We found a large set of oncogenes, transcription factors and nuclear receptors downregulated in the D842V mutant. Conversely, D842V showed a significant enrichment of immune- and interferon- related gene signatures. Differences in tumor microenvironment composition were also highlighted, including a higher abundance of CD8+ T-cells and an overexpression of the T cell-inflamed signature in the D842V mutant subgroup, which is predictive of immunotherapy response. PDGFRA D842V vs. non-D842V GIST display a different expression profile, with a prominent immunological signature, that could represent a proof of principle for testing immunotherapeutic strategies in this drug-orphan subset of GIST. 10.3389/fimmu.2020.00851
A phase Ib study of BGJ398, a pan-FGFR kinase inhibitor in combination with imatinib in patients with advanced gastrointestinal stromal tumor. Kelly Ciara M,Shoushtari Alexander N,Qin Li-Xuan,D'Angelo Sandra P,Dickson Mark A,Gounder Mrinal M,Keohan Mary Louise,Mcfadyen Chloe,Sjoberg Ana,Singer Samuel,DeMatteo Ronald P,Hwang Sinchun,Heinemann M H,Francis Jasmine H,Antonescu Cristina R,Chi Ping,Tap William D Investigational new drugs Background Preclinical studies suggest that imatinib resistance in gastrointestinal stromal tumor (GIST) can be mediated by MAP-kinase activation via fibroblast growth factor (FGF) signaling. In FGF stimulated GIST cell lines, BGJ398, a pan-FGFR kinase inhibitor in combination with imatinib, was cytotoxic and superior to imatinib therapy alone. In FGF-dependent GIST, the combination of BGJ398 and imatinib may provide a mechanism to overcome imatinib resistance. Methods This phase Ib study of BGJ398 and imatinib was performed in patients with imatinib refractory advanced GIST. A standard 3 + 3 dosing schema was utilized to determine the recommended phase II dose (RP2D). Two treatment schedules were evaluated incorporating imatinib 400 mg daily in combination with (A) BGJ398 daily 3 weeks on, 1 week off or (B) BGJ398 daily 1 week on, 3 weeks off. Results 16 patients enrolled. The median age was 54 years (range: 44-77), 81% were male, and the median number of lines of prior therapy was 4 [range: 2-6, 13 patients had ≥3 prior therapies]. 12 patients received treatment on schedule A [BGJ398 dose range: 25 - 75 mg]: 2 patients experienced dose limiting toxicities (DLT) (n = 1, myocardial infarction & grade (G)4 CPK elevation; n = 1, G3 ALT elevation) on schedule A (BGJ398 75 mg), significant hyperphosphatemia, an on-target effect, was not observed, implying the maximum tolerated dose was below the therapeutic dose. Following protocol amendment, 4 patients enrolled on schedule B [BGJ398 dose range: 75 - 100 mg]: no DLTs were observed. The most common treatment related adverse events occurring in >15% of patients included CPK elevation (50%), lipase elevation (44%), hyperphosphatemia (24%), anemia (19%), and peripheral edema (19%). Among the 12 evaluable patients, stable disease (SD) was the best response observed in 7 patients by RECIST v1.1 and 9 patients by CHOI. Stable disease ≥ 32 weeks was observed in 3 patients (25%). Median progression free survival was 12.1 weeks (95% CI 4.7-19.5 weeks). Conclusions Toxicity was encountered with the combination therapy of BGJ398 and imatinib. Due to withdrawal of sponsor support the study closed before the RP2D or dosing schedule of the combination therapy was identified. In heavily pre-treated patients, stable disease ≥ 32 weeks was observed in 3 of 12 evaluable patients. Trial Registration: NCT02257541 . 10.1007/s10637-018-0648-z
Early Evaluation of Response Using F-FDG PET Influences Management in Gastrointestinal Stromal Tumor Patients Treated with Neoadjuvant Imatinib. Farag Sheima,Geus-Oei Lioe-Fee de,van der Graaf Winette T,van Coevorden Frits,Grunhagen Dirk,Reyners Anna K L,Boonstra Pieter A,Desar Ingrid,Gelderblom Hans,Steeghs Neeltje Journal of nuclear medicine : official publication, Society of Nuclear Medicine F-FDG PET has previously been proven effective as an early way to evaluate the response of gastrointestinal stromal tumors (GISTs) to imatinib treatment. However, it is unclear whether early evaluation of response affects treatment decisions in GIST patients treated with neoadjuvant intent. We retrospectively scored changes in management based on early evaluation of response by F-FDG PET in patients in the Dutch GIST registry treated with neoadjuvant imatinib. Seventy F-FDG PET scans were obtained for 63 GIST patients to evaluate for an early response to neoadjuvant imatinib. The scans led to a change in management in 27.1% of the patients. Change in management correlated strongly with lack of metabolic response ( < 0.001) and non- exon 11-mutated GISTs ( < 0.001). Performing F-FDG PET for early evaluation of response often results in a change of management in GIST patients harboring the non- exon 11 mutation and should be considered the standard of care in GIST patients treated with neoadjuvant intent. 10.2967/jnumed.117.196642
Integrated Molecular Characterization of Gastrointestinal Stromal Tumors (GIST) Harboring the Rare D842V Mutation in PDGFRA Gene. Indio Valentina,Astolfi Annalisa,Tarantino Giuseppe,Urbini Milena,Patterson Janice,Nannini Margherita,Saponara Maristella,Gatto Lidia,Santini Donatella,do Valle Italo F,Castellani Gastone,Remondini Daniel,Fiorentino Michelangelo,von Mehren Margaret,Brandi Giovanni,Biasco Guido,Heinrich Michael C,Pantaleo Maria Aabbondanza International journal of molecular sciences Gastrointestinal stromal tumors (GIST) carrying the D842V activating mutation in the platelet-derived growth factor receptor alpha () gene are a very rare subgroup of GIST (about 10%) known to be resistant to conventional tyrosine kinase inhibitors (TKIs) and to show an indolent behavior. In this study, we performed an integrated molecular characterization of D842V mutant GIST by whole-transcriptome and whole-exome sequencing coupled with protein-ligand interaction modelling to identify the molecular signature and any additional recurrent genomic event related to their clinical course. We found a very specific gene expression profile of D842V mutant tumors showing the activation of G-protein-coupled receptor (GPCR) signaling and a relative downregulation of cell cycle processes. Beyond D842V, no recurrently mutated genes were found in our cohort. Nevertheless, many private, clinically relevant alterations were found in each tumor (-complex). Molecular modeling of PDGFRA D842V suggests that the mutant protein binds imatinib with lower affinity with respect to wild-type structure, showing higher stability during the interaction with other type I TKIs (like crenolanib). D842V mutant GIST do not show any actionable recurrent molecular events of therapeutic significance, therefore this study supports the rationale of novel TKIs development that are currently being evaluated in clinical studies for the treatment of D842V mutant GIST. 10.3390/ijms19030732
Molecular mechanism of D816X mutation-induced c-Kit activation and -mediated inhibitor resistance in gastrointestinal stromal tumor. Jiang Haohai,Shao Weiwei,Wang Yuanjin,Xu Ronghui,Zhou Linsen,Mu Xiangming Journal of molecular graphics & modelling The D816X (X = V, H, Y or F) missense mutation constitutively activates c-Kit kinase in gastrointestinal stromal tumor (GIST) and has been observed to cause acquired resistance against first-line and second-line kinase inhibitors. In the present study, the allosteric mechanism of D816X-induced c-Kit conformational change is investigated at molecular level. The Asp816 residue is located at the activation loop (A-loop) of c-Kit and the mutation can eliminate a negative formal charge from the loop region by substituting the acidic asparagic acid residue with neutral valine, histidine, tyrosine or phenylalanine. Here, we classify the c-Kit kinase into four states in terms of its mutation (wild type or mutant) and conformation (DFG-in or DFG-out). The wild-type kinase is electrostatically stabilized in inactive DFG-out conformation, whereas the D816X mutation can promote the conformational conversion to active DFG-in and then activate the kinase. Structural analysis reveals that the Asp816 residue in DFG-out is surrounded by a number of polar and positively charged residues within its first and second shells of protein context, and kinase conformational change to DFG-in brings this residue into a negative electrostatic potential environment. Dynamics simulation characterizes that the c-Kit conformational conversion from DFG-out to DFG-in can cause local unfavorable effect to type-II inhibitor, while the mutation-induced global structural rearrangement would participate in the favorable interaction of c-Kit with type-I inhibitor. 10.1016/j.jmgm.2018.07.003
Oncogenic signaling by Kit tyrosine kinase occurs selectively on the Golgi apparatus in gastrointestinal stromal tumors. Obata Y,Horikawa K,Takahashi T,Akieda Y,Tsujimoto M,Fletcher J A,Esumi H,Nishida T,Abe R Oncogene Gastrointestinal stromal tumors (GISTs) are caused by gain-of-function mutations in the Kit receptor tyrosine kinase. Most primary GIST patients respond to the Kit inhibitor imatinib, but this drug often becomes ineffective because of secondary mutations in the Kit kinase domain. The characteristic intracellular accumulation of imatinib-sensitive and -resistant Kit protein is well documented, but its relationship to oncogenic signaling remains unknown. Here, we show that in cancer tissue from primary GIST patients as well as in cell lines, mutant Kit accumulates on the Golgi apparatus, whereas normal Kit localizes to the plasma membrane (PM). In imatinib-resistant GIST with a secondary Kit mutation, Kit localizes predominantly on the Golgi apparatus. Both imatinib-sensitive and imatinib-resistant Kit (Kit(mut)) become fully auto-phosphorylated only on the Golgi and only if in a complex-glycosylated form. Kit(mut) accumulates on the Golgi during the early secretory pathway, but not after endocytosis. The aberrant kinase activity of Kit(mut) prevents its export from the Golgi to the PM. Furthermore, Kit(mut) on the Golgi signals and activates the phosphatidylinositol 3-kinase-Akt (PI3K-Akt) pathway, signal transducer and activator of transcription 5 (STAT5), and the Mek-Erk pathway. Blocking the biosynthetic transport of Kit(mut) to the Golgi from the endoplasmic reticulum inhibits oncogenic signaling. PM localization of Kit(mut) is not required for its signaling. Activation of Src-family tyrosine kinases on the Golgi is essential for oncogenic Kit signaling. These results suggest that the Golgi apparatus serves as a platform for oncogenic Kit signaling. Our study demonstrates that Kit(mut)'s pathogenicity is related to its mis-localization, and may offer a new strategy for treating imatinib-resistant GISTs. 10.1038/onc.2016.519
The expression of hematopoietic progenitor cell antigen CD34 is regulated by DNA methylation in a site-dependent manner in gastrointestinal stromal tumours. Bure Irina,Braun Alexander,Kayser Claudia,Geddert Helene,Schaefer Inga-Marie,Cameron Silke,Ghadimi Michael B,Ströbel Philipp,Werner Martin,Hartmann Arndt,Wiemann Stefan,Agaimy Abbas,Haller Florian,Moskalev Evgeny A International journal of cancer The anatomic site-dependent expression of hematopoietic progenitor cell antigen CD34 is a feature of gastrointestinal stromal tumours (GISTs). The basis for the differential CD34 expression is only incompletely understood. This study aimed at understanding the regulation of CD34 in GISTs and clarification of its site-dependent expression. Two sample sets of primary GISTs were interrogated including 52 fresh-frozen and 134 paraffin-embedded and formalin-fixed specimens. DNA methylation analysis was performed by HumanMethylation450 BeadChip array in three cell lines derived from gastric and intestinal GISTs, and differentially methylated CpG sites were established upstream of CD34. The methylation degree was further quantified by pyrosequencing, and inverse correlation with CD34 mRNA and protein abundance was revealed. The gene's expression could be activated upon induction of DNA hypomethylation with 5-aza-2'-deoxycytidine in GIST-T1 cells. In patient samples, a strong inverse correlation of DNA methylation degree with immunohistochemically evaluated CD34 expression was documented. Both CD34 expression and DNA methylation levels were specific to the tumours' anatomic location and mutation status. A constant decrease in methylation levels was observed ranging from almost 100% hypermethylation in intestinal GISTs from duodenum to hypomethylation in rectum. CD34 was heavily methylated in gastric PDGFRA-mutant GISTs in comparison to hypomethylated KIT-mutant counterparts. Next to CD34 hypermethylation, miR-665 was predicted and experimentally confirmed to target CD34 mRNA in GIST-T1 cells. Our results suggest that CD34 expression in GISTs may undergo a complex control by DNA methylation and miR-665. Differential methylation and expression of CD34 in GISTs along the gastrointestinal tract axis and in tumours that harbour different gain-of-function mutations suggest the origin from different cell populations in the gastrointestinal tract. 10.1002/ijc.30905
Association of Imatinib Plasma Concentration and Single-nucleotide Polymorphisms with Adverse Drug Reactions in Patients with Gastrointestinal Stromal Tumors. Zhang Qiang,Xu Jianghao,Qian Yi,Chen Liang,Li Qingya,Xu Kangjing,Chen Ming,Sun Luning,He Zhongyuan,Yang Li,Zhang Diancai,Wang Linjun,Sun Xiaofeng,Wang Yongqing,Xu Hao,Xu Zekuan Molecular cancer therapeutics Gastrointestinal stromal tumors (GIST) are the most prevalent mesenchymal tumors of the digestive tract. To investigate the association of imatinib mesylate plasma concentration with adverse drug reactions (ADRs) and influences of genetic polymorphisms on ADRs in GIST patients taking imatinib, a cohort of GIST patients consecutively treated with imatinib were included in the observational study. Clinical, pathologic and genotype information was recorded at enrollment and blood samples were collected at time as design. The plasma concentration of the imatinib was detected by LC-MS/MS. A questionnaire was used to evaluate the ADRs at each visit. SNPs in 13 genes were analyzed for a possible association with ADRs. The mean plasma trough concentration of 129 patients taking imatinib was 1.45 ± 0.79 μg/ml, average peak concentration was 2.63 ± 1.07 μg/ml. The imatinib concentration in patients treated with 600 mg/day was significantly higher than other dosage groups ( < 0.05). The ADRs were mostly mild. Edema, vomiting, and fatigue were significantly correlated with imatinib concentration ( < 0.05). Mutations of and were related with the incidence of leukopenia and rash in our research, separately ( < 0.05). We confirmed that with the increase of imatinib concentration, the incidence of edema, vomiting, and fatigue rises as well. Mutations of and may be the promising biomarkers to predict the ADRs of imatinib. The results of the study are of guiding significance for the use of imatinib in patients with GIST. 10.1158/1535-7163.MCT-18-0498
Prognostic value of metabolic tumor volume and total lesion glycolysis on preoperative F-FDG PET/CT in patients with localized primary gastrointestinal stromal tumors. Hwang Sang Hyun,Jung Minkyu,Jeong Yong Hyu,Jo KwanHyeong,Kim Soyoung,Wang Jiyoung,Cho Arthur Cancer & metabolism BACKGROUND:This study aimed to evaluate the prognostic value of pretreatment F-fluorodeoxyglucose positron emission tomography/computed tomography (F-FDG PET/CT) in patients with localized primary gastrointestinal stromal tumors (GISTs) and to compare the predictive values of F-FDG PET/CT parameters with those of clinicopathological prognostic factors. METHODS:Sixty-two localized GIST patients who underwent staging with F-FDG PET/CT from January 2007 to December 2013 before surgery were retrospectively enrolled. A volume of interest with a standardized uptake value (SUV) threshold of 2.5 was used to determine the metabolic tumor volume (MTV) and total lesion glycolysis (TLG). These metabolic indices, along with the maximum SUV (SUVmax), were analyzed to evaluate recurrence-free survival (RFS). Other significant clinical and pathologic indices were also retrospectively reviewed for RFS analysis. RESULTS:Patients were followed up for a median of 42.0 months (range, 5.6-111.5). During the follow-up period, 13 patients (21.0%) experienced disease recurrence. In univariate analysis, tumor size (> 5 cm), mitotic count (> 5/high-power field), modified National Institutes of Health (NIH) consensus criteria, adjuvant imatinib treatment, SUVmax (≥ 7.04), MTV (≥ 50.76 cm), and TLG (≥ 228.79 g) were significant prognostic factors affecting RFS (p < 0.05). In multivariate analysis, only MTV (hazard ratio, 17.69; 95% confidence interval [CI], 2.03-154.17, p = 0.009) and TLG (hazard ratio, 20.48; 95% CI, 2.19-191.16, p = 0.008) were independent prognostic factors for RFS. The 5-year RFS rates were 96.4% and 96.6% in patients with a low MTV and TLG and 27.3% and 23.6% in patients with a high MTV and TLG, respectively (p < 0.001). CONCLUSION:MTV and TLG are independent prognostic factors for predicting recurrence in patients with localized primary GIST. Patients with a high MTV or TLG are at risk for poor prognosis and should be closely observed for disease recurrence. 10.1186/s40170-021-00244-x
Detection of ANO1 mRNA in PBMCs is a promising method for GISTs diagnosis. Li Haini,Wu Ancheng,Zhu Wuhui,Hou Feng,Cheng Shaoyun,Cao Jinpeng,Yan Yufen,Zhang Congxiao,Liu Zongtao Scientific reports ANO1 is a calcium-activated chloride channel protein that has been used to diagnose GISTs after tissue biopsy. Recently, ANO1 mRNA amplification in the blood has received considerable attention as a useful method for the diagnosis of GISTs. The aim of this study was to evaluate the diagnostic ability of ANO1 mRNA in distinguishing GIST patients from healthy subjects. We constructed a logistic regression model for examining the diagnostic ability of ANO1 mRNA in comparison with conventional tumor markers, including CEA, CA199, and CA724. Our results showed that ANO1 mRNA was significantly amplified in PBMCs, the average expression level and range of ANO1 mRNA in the blood were increased along with the expression of ANO1 in the tissues, and the extent of amplification of ANO1 was associated with tumor size. In addition, ROC curve analysis showed that ANO1 mRNA in the blood had the highest specificity when compared with conventional tumor markers. Moreover, a combined analysis with ANO1 mRNA and conventional tumor markers had the highest sensitivity in diagnosing GISTs. Our study indicated that detection of ANO1 mRNA in PBMCs is a promising method for diagnosis of GISTs in vitro. 10.1038/s41598-019-45941-2
Discovery of N-(4-{[5-Fluoro-7-(2-methoxyethoxy)quinazolin-4-yl]amino}phenyl)-2-[4-(propan-2-yl)-1 H-1,2,3-triazol-1-yl]acetamide (AZD3229), a Potent Pan-KIT Mutant Inhibitor for the Treatment of Gastrointestinal Stromal Tumors. Kettle Jason G,Anjum Rana,Barry Evan,Bhavsar Deepa,Brown Crystal,Boyd Scott,Campbell Andrew,Goldberg Kristin,Grondine Michael,Guichard Sylvie,Hardy Christopher J,Hunt Tom,Jones Rhys D O,Li Xiuwei,Moleva Olga,Ogg Derek,Overman Ross C,Packer Martin J,Pearson Stuart,Schimpl Marianne,Shao Wenlin,Smith Aaron,Smith James M,Stead Darren,Stokes Steve,Tucker Michael,Ye Yang Journal of medicinal chemistry While the treatment of gastrointestinal stromal tumors (GISTs) has been revolutionized by the application of targeted tyrosine kinase inhibitors capable of inhibiting KIT-driven proliferation, diverse mutations to this kinase drive resistance to established therapies. Here we describe the identification of potent pan-KIT mutant kinase inhibitors that can be dosed without being limited by the tolerability issues seen with multitargeted agents. This effort focused on identification and optimization of an existing kinase scaffold through the use of structure-based design. Starting from a series of previously reported phenoxyquinazoline and quinoline based inhibitors of the tyrosine kinase PDGFRα, potency against a diverse panel of mutant KIT driven Ba/F3 cell lines was optimized, with a particular focus on reducing activity against a KDR driven cell model in order to limit the potential for hypertension commonly seen in second and third line GIST therapies. AZD3229 demonstrates potent single digit nM growth inhibition across a broad cell panel, with good margin to KDR-driven effects. Selectivity over KDR can be rationalized predominantly by the interaction of water molecules with the protein and ligand in the active site, and its kinome selectivity is similar to the best of the approved GIST agents. This compound demonstrates excellent cross-species pharmacokinetics, shows strong pharmacodynamic inhibition of target, and is active in several in vivo models of GIST. 10.1021/acs.jmedchem.8b00938
Dovitinib in patients with gastrointestinal stromal tumour refractory and/or intolerant to imatinib. Joensuu Heikki,Blay Jean-Yves,Comandone Alessandro,Martin-Broto Javier,Fumagalli Elena,Grignani Giovanni,Del Muro Xavier Garcia,Adenis Antoine,Valverde Claudia,Pousa Antonio Lopez,Bouché Olivier,Italiano Antoine,Bauer Sebastian,Barone Carlo,Weiss Claudia,Crippa Stefania,Camozzi Maura,Castellana Ramon,Le Cesne Axel British journal of cancer BACKGROUND:This multicentre phase II trial (DOVIGIST) evaluated the antitumour activity of dovitinib as second-line treatment of patients with gastrointestinal stromal tumour (GIST) refractory to imatinib or who do not tolerate imatinib. METHODS:Patients received oral dovitinib 500 mg day, 5 days on/2 days off, until GIST progression or unacceptable toxicity, with an objective to evaluate efficacy, assessed as the disease control rate (DCR) at 12 weeks. Tumour assessment and response to dovitinib therapy were evaluated by Response Evaluation Criteria In Solid Tumours (RECIST v1.1) and the Choi criteria. Secondary objectives included assessment of progression-free survival (PFS), safety and tolerability, and DCR at the end of treatment. RESULTS:Thirty-eight of the 39 patients enrolled had histologically confirmed GIST. The DCR at 12 weeks was 52.6% (90% confidence interval (CI), 38.2-66.7%) meeting the preset efficacy criterion for the primary end point. The objective response rate (complete response+partial response) was 2.6% (1 of 38; 90% CI, 0.1-11.9%), and 5.3% (n=2; 90% CI, 0.9-15.7%) at the end of the study. The median PFS was 4.6 months (90% CI, 2.8-7.4 months). Dose interruption was required in 26 patients (66.7%), of which 18 (69.2%) were due to adverse events. The most frequently observed grade 3 adverse events included hypertension (n=7), fatigue (n=5), vomiting (n=4), hypertriglyceridaemia (n=4), and γ-glutamyltransferase increase (n=4). CONCLUSIONS:Dovitinib is an active treatment for patients with GIST who are intolerant to imatinib or whose GIST progresses on imatinib. 10.1038/bjc.2017.290
Clinical Application of Circulating Tumor DNA in the Genetic Analysis of Patients with Advanced GIST. Xu Hao,Chen Liang,Shao Yang,Zhu Dongqin,Zhi Xiaofei,Zhang Qiang,Li Fengyuan,Xu Jianghao,Liu Xisheng,Xu Zekuan Molecular cancer therapeutics Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumor of digestive tract. In the past, tissue biopsy was the main method for the diagnosis of GISTs. Although, circulating tumor DNA (ctDNA) detection by next-generation sequencing (NGS) may be a feasible and replaceable method for diagnosis of GISTs. We retrospectively analyzed the data for ctDNA and tissue DNA detection from 32 advanced GIST patients. We found that NGS obviously increased the positive rate of ctDNA detection. ctDNA detection identified rare mutations that were not detected in tissue DNA detection. Tumor size and Ki-67 were significant influencing factors of the positive rate of ctDNA detection and concordance between ctDNA and tissue DNA detection. In all patients, the concordance rate between ctDNA and tissue DNA detection was 71.9%, with moderate concordance, but the concordance was strong for patients with tumor size > 10 cm or Ki-67 > 5%. Tumor size, mitotic figure, Ki-67, and ctDNA mutation type were the significant influencing factors of prognosis, but only tumor size and ctDNA mutation type, were the independent prognostic factors for advanced GIST patients. We confirmed that ctDNA detection by NGS is a feasible and promising method for the diagnosis and prognosis of advanced GIST patients. . 10.1158/1535-7163.MCT-17-0436
Association of Hepatic Nuclear Factor 4 Alpha Gene Polymorphisms With Free Imatinib Plasma Levels and Adverse Reactions in Chinese Gastrointestinal Stromal Tumor Patients. Chen Hanmei,Liu Jing,Zhou Yuhong,Hou Yingyong,Ma Guo,Cai Weimin Therapeutic drug monitoring BACKGROUND:As the first-line treatment of gastrointestinal stromal tumor (GIST), the pharmacokinetic and pharmacodynamic of imatinib (IM) were characterized by marked interindividual variability. Pharmacogenetics of IM involved metabolic enzymes and transporters have been extensively reported, but the results remained inconsistent. This study investigated the effect of genetic variants in hepatocyte nuclear factor 4 alpha (HNF4α, encoded by gene NR2A1), a pivotal transcriptional regulator of drug disposition genes, on dose-adjusted IM-free plasma levels and related adverse reactions in Chinese GIST patients. METHODS:Five common polymorphisms of NR2A1 (rs3818247, rs1884613, rs2071197, rs2425640, and rs736824) were genotyped in 70 Chinese GIST patients who had been administered IM 300-600 mg/d. The free IM trough plasma levels were determined based on a method of ultrafiltration coupled with high performance liquid chromatography-tandem mass spectrometry. RESULTS:There were wide interpatient variations in free plasma levels of IM (range, 9.50-67.50 ng/mL), in which significant sex differences were observed (P < 0.01). The dose-adjusted IM-free plasma levels showed a significant negative correlation with body surface area (r = -0.302, P = 0.012). Although there were no significant effects of NR2A1 polymorphisms on dose-adjusted IM-free plasma levels among the study population, polymorphism in rs736824 was found to be significantly associated with dose-adjusted IM-free plasma levels in male subjects (P = 0.031). For the IM-related adverse reaction, polymorphisms in rs3818247 were found to be significantly associated with periorbital edema (P = 0.032). In addition, no significant correlations were found between IM-free plasma levels and IM-related adverse reactions, except for the correlation of IM-free plasma levels with periorbital edema among male patients (P = 0.013). CONCLUSIONS:The research demonstrated that NR2A1 polymorphisms may act as contributors of IM pharmacokinetics and responses in Chinese GIST patients. This represents an attractive opportunity for IM therapy optimization, worth testing in clinical trials. 10.1097/FTD.0000000000000642
MITIGATE-NeoBOMB1, a Phase I/IIa Study to Evaluate Safety, Pharmacokinetics, and Preliminary Imaging of Ga-NeoBOMB1, a Gastrin-Releasing Peptide Receptor Antagonist, in GIST Patients. Gruber Leonhard,Jiménez-Franco Luis David,Decristoforo Clemens,Uprimny Christian,Glatting Gerhard,Hohenberger Peter,Schoenberg Stefan O,Reindl Wolfgang,Orlandi Francesca,Mariani Maurizio,Jaschke Werner,Virgolini Irene Journal of nuclear medicine : official publication, Society of Nuclear Medicine Gastrin-releasing peptide receptors (GRPRs) are potential molecular imaging targets in a variety of tumors. Recently, a Ga-labeled antagonist to GRPRs, NeoBOMB1, was developed for PET. We report on the outcome of a phase I/IIa clinical trial (EudraCT 2016-002053-38) within the EU-FP7 project Closed-loop Molecular Environment for Minimally Invasive Treatment of Patients with Metastatic Gastrointestinal Stromal Tumors ('MITIGATE') (grant agreement no. 602306) in patients with oligometastatic gastrointestinal stromal tumors (GIST). The main objectives were evaluation of safety, biodistribution, dosimetry, and preliminary tumor targeting of Ga-NeoBOMB1 in patients with advanced tyrosine-kinase inhibitors-treated GIST using PET/CT. Six patients with histologically confirmed GIST and unresectable primary lesion or metastases undergoing an extended protocol for detailed pharmacokinetic analysis were included. Ga-NeoBOMB1 was prepared using a kit procedure with a licensed Ge/Ga generator. Ga-NeoBOMB1 (3 MBq/kg of body weight) was injected intravenously, and safety parameters were assessed. PET/CT included dynamic imaging at 5, 11, and 19 min as well as static imaging at 1, 2, and 3-4 h after injection for dosimetry calculations. Venous blood samples and urine were collected for pharmacokinetic analysis. Tumor targeting was assessed on a per-lesion and per-patient basis. Ga-NeoBOMB1 (50 μg) was prepared with high radiochemical purity (yield > 97%). Patients received 174 ± 28 MBq of the radiotracer, which was well tolerated in all patients over a follow-up period of 4 wk. Dosimetry calculations revealed a mean effective dose of 0.029 ± 0.06 mSv/MBq, with the highest organ dose to the pancreas (0.274 ± 0.099 mSv/MBq). Mean plasma half-life was 27.3 min with primarily renal clearance (mean 25.7% ± 5.4% of injected dose 4 h after injection). Plasma metabolite analyses revealed high stability; metabolites were detected only in the urine. In 3 patients, a significant uptake with increasing maximum SUVs (SUV at 2 h after injection: 4.3-25.9) over time was found in tumor lesions. This phase I/IIa study provides safety data for Ga-NeoBOMB1, a promising radiopharmaceutical for targeting GRPR-expressing tumors. Safety profiles and pharmacokinetics are suitable for PET imaging, and absorbed dose estimates are comparable to those of other Ga-labeled radiopharmaceuticals used in clinical routine. 10.2967/jnumed.119.238808
Gene duplication, rather than epigenetic changes, drives FGF4 overexpression in KIT/PDGFRA/SDH/RAS-P WT GIST. Urbini Milena,Astolfi Annalisa,Indio Valentina,Nannini Margherita,Schipani Angela,Bacalini Maria Giulia,Angelini Sabrina,Ravegnini Gloria,Calice Giovanni,Del Gaudio Massimo,Secchiero Paola,Ulivi Paola,Gruppioni Elisa,Pantaleo Maria Abbondanza Scientific reports Gastrointestinal stromal tumours that are wild type for KIT and PDGFRA are referred to as WT GISTs. Of these tumours, SDH-deficient (characterized by the loss of SDHB) and quadruple WT GIST (KIT/PDGFRA/SDH/RAS-P WT) subgroups were reported to display a marked overexpression of FGF4, identifying a putative common therapeutic target for the first time. In SDH-deficient GISTs, methylation of an FGF insulator region was found to be responsible for the induction of FGF4 expression. In quadruple WT, recurrent focal duplication of FGF3/FGF4 was reported; however, how it induced FGF4 expression was not investigated. To assess whether overexpression of FGF4 in quadruple WT could be driven by similar epigenetic mechanisms as in SDH-deficient GISTs, we performed global and locus-specific (on FGF4 and FGF insulator) methylation analyses. However, no epigenetic alterations were detected. Conversely, we demonstrated that in quadruple WT GISTs, FGF4 expression and the structure of the duplication were intimately connected, with the copy of FGF4 closer to the ANO1 super-enhancer being preferentially expressed. In conclusion, we demonstrated that in quadruple WT GISTs, FGF4 overexpression is not due to an epigenetic mechanism but rather to the specific genomic structure of the duplication. Even if FGF4 overexpression is driven by different molecular mechanisms, these findings support an increasing biologic relevance of the FGFR pathway in WT GISTs, both in SDH-deficient and quadruple WT GISTs, suggesting that it may be a common therapeutic target. 10.1038/s41598-020-76519-y
DOG1 expression is common in human tumors: A tissue microarray study on more than 15,000 tissue samples. Jansen Kristina,Farahi Nagina,Büscheck Franziska,Lennartz Maximilian,Luebke Andreas M,Burandt Eike,Menz Anne,Kluth Martina,Hube-Magg Claudia,Hinsch Andrea,Höflmayer Doris,Weidemann Sören,Fraune Christoph,Möller Katharina,Lebok Patrick,Sauter Guido,Simon Ronald,Uhlig Ria,Wilczak Waldemar,Jacobsen Frank,Minner Sarah,Krech Rainer,Clauditz Till,Bernreuther Christian,Dum David,Krech Till,Marx Andreas,Steurer Stefan Pathology, research and practice DOG1 (Discovered on GIST1) is a voltage-gated calcium-activated chloride and bicarbonate channel that is highly expressed in interstitial cells of Cajal and in gastrointestinal stromal tumors (GIST) derived from Cajal cells. To systematically determine in what tumor entities and normal tissue types DOG1 may be further expressed, a tissue microarray (TMA) containing 15,965 samples from 121 different tumor types and subtypes as well as 608 samples of 76 different normal tissue types was analyzed by immunohistochemistry. DOG1 immunostaining was found in 67 tumor types including GIST (95.7%), esophageal squamous cell carcinoma (31.9%), pancreatic ductal adenocarcinoma (33.6%), adenocarcinoma of the Papilla Vateri (20%), squamous cell carcinoma of the vulva (15.8%) and the oral cavity (15.3%), mucinous ovarian cancer (15.3%), esophageal adenocarcinoma (12.5%), endometrioid endometrial cancer (12.1%), neuroendocrine carcinoma of the colon (11.1%) and diffuse gastric adenocarcinoma (11%). Low level-DOG1 immunostaining was seen in 17 additional tumor entities. DOG1 expression was unrelated to histopathological parameters of tumor aggressiveness and/or patient prognosis in cancers of the breast (n = 1002), urinary bladder (975), ovary (469), endometrium (173), stomach (233), and thyroid gland (512). High DOG1 expression was linked to estrogen receptor expression in breast cancer (p < 0.0001) and absence of HPV infection in squamous cell carcinomas (p = 0.0008). In conclusion, our data identify several tumor entities that can show DOG1 expression levels at similar levels as in GIST. Although DOG1 is tightly linked to a diagnosis of GIST in spindle cell tumors, the differential diagnosis is much broader in DOG1 positive epithelioid neoplasms. 10.1016/j.prp.2021.153663
Inhibition of fibroblast growth factor receptor-signaling sensitizes imatinib-resistant gastrointestinal stromal tumors to low doses of topoisomerase II inhibitors. Boichuk Sergei,Dunaev Pavel,Galembikova Aigul,Mustafin Ilshat,Valeeva Elena Anti-cancer drugs The acquired resistance of gastrointestinal stromal tumors (GISTs) to the targeted-based therapy remains the driving force to identify the novel approaches that are capable of increasing the sensitivity of GISTs to the current therapeutic regimens. Our present data show that BGJ398, a selective fibroblast growth factor receptor (FGFR) inhibitor, sensitizes imatinib (IM)-resistant GIST cells with receptor tyrosine kinase (RTK) switch (loss of c-KIT/gain of pFGFR2a) to the low doses of topoisomerase II inhibitors - doxorubicin (Dox) and etoposide (Eto). Mechanistically, pretreatment of IM-resistant GIST cells with BGJ398 for 12 h markedly enhanced proapoptotic and growth-suppressive effects of Dox (or Eto). Indeed, a significant cleavage of PARP and caspase-3 was observed in GIST cells treated with a combination of FGFR and topoisomerase II inhibitor. In contrast, no signs of apoptosis were detected in IM-resistant GIST cells treated with BGJ398, whereas the low doses of Dox (Eto) exerted the minor proapoptotic effects on GISTs. The mechanism of BGJ398-induced sensitization of GIST to topoisomerase II inhibitors might be because of attenuation of DNA damage signaling and repair. Indeed, we observed a marked decrease in Rad51 expression in GIST cells treated with BGJ398 together with Dox. Similar results were obtained when an overexpressed pFGFR2a was knocked down by corresponding siRNA before Dox (Eto) exposure. Moreover, FGFR inhibition/depletion caused a loss of Rad51 foci in Dox-treated GIST cells, suggesting that FGFR-signaling plays an important regulatory role in homology-mediated DNA repair. Our data show that combined therapy (RTKs inhibitors supplemented with low doses of topoisomerase II inhibitors) might be effective for unresectable and metastatic forms of GISTs. In case of resistance to IM because of RTKs switch indicated above, FGFR inhibitors (e.g. BGJ398) might be potentially useful because of their ability to sensitize tumor cells to topoisomerase II inhibitors and induce tumor cell apoptosis by targeting DNA double-strand breaks repair. 10.1097/CAD.0000000000000637
MicroRNA-30a targets BECLIN-1 to inactivate autophagy and sensitizes gastrointestinal stromal tumor cells to imatinib. Chen Wei,Li Zhouqi,Liu Hao,Jiang Sujing,Wang Guannan,Sun Lifeng,Li Jun,Wang Xiaochen,Yu Shaojun,Huang Jianjin,Dong Ying Cell death & disease Gastrointestinal stromal tumors (GISTs), the most widespread type of sarcoma, contain driver gene mutations predominantly of receptor tyrosine kinase and platelet-derived growth factor receptor alpha. However, the inevitable development of resistance to imatinib (IM) cannot be fully attributed to secondary driver gene mutations. In this study, we investigated the role of microRNA-30a in sensitization of GIST cells to IM in vivo and in vitro. Higher levels of miR-30a were detected in GIST-T1 cells, which were more sensitive to IM than GIST-882 cells. IM treatment also reduced miR-30a levels, indicating the possible role of miR-30a in GIST IM resistance. Subsequently, miR-30a was confirmed to be an IM sensitizer via a mechanism that was attributed to its involvement in the regulation of cell autophagy. The interaction of miR-30a and autophagy in IM treated GIST cells was found to be linked by beclin-1. Beclin-1 knockdown increased IM sensitivity in GIST cell lines. Finally, miR-30a was confirmed to enhance IM sensitivity of GIST cells in mouse tumor models. Our study provides evidence for the possible role of miR-30a in the emergence of secondary IM resistance in GIST patients, indicating a promising target for overcoming this chemoresistance. 10.1038/s41419-020-2390-7
Macrophages and CD8 T Cells Mediate the Antitumor Efficacy of Combined CD40 Ligation and Imatinib Therapy in Gastrointestinal Stromal Tumors. Zhang Jennifer Q,Zeng Shan,Vitiello Gerardo A,Seifert Adrian M,Medina Benjamin D,Beckman Michael J,Loo Jennifer K,Santamaria-Barria Juan,Maltbaek Joanna H,Param Nesteene J,Moral John A,Zhao Julia N,Balachandran Vinod,Rossi Ferdinand,Antonescu Cristina R,DeMatteo Ronald P Cancer immunology research Tyrosine kinase inhibition of gastrointestinal stromal tumors (GIST) is effective but typically culminates in resistance and is rarely curative. Immunotherapy has potential application to GIST, as we previously showed that T-cell checkpoint blockade increases the antitumor effects of imatinib. Here, we showed that ligation of CD40 using an agonistic antibody (anti-CD40) activated tumor-associated macrophages (TAMs) in a knock-in mouse model of GIST harboring a germline mutation in exon 11. Activated TAMs had greater TNFα production and NFκB signaling and directly inhibited tumor cells Anti-CD40 required concomitant therapy with imatinib for efficacy and depended on TAMs, and to a lesser extent CD8 T cells, but not on CD4 T cells or B cells. In an analysis of 50 human GIST specimens by flow cytometry, we found that CD40 was expressed on human TAMs and tumor cells yet was downregulated after response to imatinib. CD40 ligation did not have a direct inhibitory effect on human GIST cells. Our findings provide the rationale for combining anti-CD40 and tyrosine kinase inhibition to treat human GIST. . 10.1158/2326-6066.CIR-17-0345
Influence of Cytochrome P450, ABC and SLC Gene Polymorphisms on Imatinib Therapy Outcome of Patients with Gastrointestinal Stromal Tumours (GIST). Folia biologica The efficacy of imatinib-based therapy depends on the proteins involved in its metabolism and transportation. Therefore, the aim of our study was to investigate the possible correlation of selected P450, ABC and SLC polymorphic variants and the outcome of imatinib therapy. A total of 101 patients with advanced, KIT/PDGFRA(+) GIST treated with imatinib were enrolled to the study. DNA was extracted from peripheral blood samples and genotypes were determined by PCR-RFLP and direct sequencing. Deviation from the Hardy-Weinberg equilibrium was only observed for rs2740574. None of the studied SNPs was associated with GIST time to progression. No significant correlation between any specific variant and time to progression was found in the group with KIT exon 11 mutation. However, individuals of at least three potentially unfavourable genotypes presented significantly shorter time to progression in comparison to patients with two or less unfavourable genotypes. 10.14712/fb2017063020078
The V654A second-site KIT mutation increases tumor oncogenesis and STAT activation in a mouse model of gastrointestinal stromal tumor. Zhang Jennifer Q,Bosbach Benedikt,Loo Jennifer K,Vitiello Gerardo A,Zeng Shan,Seifert Adrian M,Medina Benjamin D,Param Nesteene J,Maltbaek Joanna H,Rossi Ferdinand,Antonescu Cristina R,Besmer Peter,DeMatteo Ronald P Oncogene Gastrointestinal stromal tumor (GIST) is the most common human sarcoma and arises in the gastrointestinal tract. Most GISTs are caused by activating mutations in the KIT receptor tyrosine kinase, such as the exon 11 KIT V559Δ mutation. The small molecule imatinib inhibits KIT and has been a mainstay of therapy in GIST. Unfortunately, imatinib-treated patients typically relapse, most often due to clonal emergence of the resistance-associated KIT V654A mutation. To determine the biologic impact of this second-site mutation in vivo, we created a mouse model with the corresponding V558Δ;V653A Kit double mutation restricted (a) spatially to ETV1 cells, which include the interstitial cells of Cajal (ICCs) from which GISTs presumably originate, and (b) temporally through tamoxifen treatment after birth. This resulted in the first in vivo model of the most common second-site mutation associated with imatinib resistance in GIST and the first in vivo demonstration that cell-autonomous expression of mutant KIT in the ICC lineage leads to GIST. GISTs driven by the V558Δ;V653A Kit double mutation were resistant to imatinib, while cabozantinib was more effective in overcoming resistance than sunitinib. Compared to control mice with a single V558Δ Kit mutation, mice with a double V558Δ; V653A Kit mutation had increased tumor oncogenesis and associated KIT-dependent STAT activation. Our findings demonstrate that the biologic consequences of a second-site mutation in an oncogenic driver may include not only a mechanism for drug resistance, but changes in tumor oncogenic potential and differential activation of signaling pathways. 10.1038/s41388-020-01489-4
miRNA-218-loaded carboxymethyl chitosan - Tocopherol nanoparticle to suppress the proliferation of gastrointestinal stromal tumor growth. Tu Lin,Wang Ming,Zhao Wen-Yi,Zhang Zi-Zhen,Tang De-Feng,Zhang Ye-Qian,Cao Hui,Zhang Zhi-Gang Materials science & engineering. C, Materials for biological applications Gastrointestinal stromal tumors (GIST) are one of the most common forms of mesenchymal cancers of the gastrointestinal tract. Although chemotherapeutic drugs inhibited the proliferation of GIST, however, sizable proportion of people developed resistance and therefore difficult to treat. In the present study, O-carboxymethyl chitosan (OCMC)-tocopherol polymer conjugate was synthesized and formulated into stable polymeric nanoparticles. The main aim of present study was to increase the therapeutic efficacy of miR-218 in GIST. The mean size of nanoparticles was ~110nm with a spherical shape. The miR-218 NP has been shown inhibit the cell proliferation and exhibited a superior cell apoptosis. The miR-218 NP inhibited the cell invasion and promoted the apoptosis of GIST cancer cells. In the present study, we have successfully showed that KIT1 is the target gene of miR-218 as shown by the luciferase reporter assay. These findings collectively suggest the miR-218 loaded nanoparticle by virtue of effective transfection could act as a tumor suppressor miRNA in the treatment of GIST. 10.1016/j.msec.2016.10.052
A smooth muscle-derived, Braf-driven mouse model of gastrointestinal stromal tumor (GIST): evidence for an alternative GIST cell-of-origin. The Journal of pathology Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumor of the gut. GISTs are thought to arise solely from interstitial cells of Cajal (ICC), a KIT-positive population that controls gut motility. Activating gain-of-function mutations in KIT and PDGFRA are the most frequent driver events, and most of these tumors are responsive to the tyrosine kinase inhibitor imatinib. Less common drivers include mutant BRAF and these tumors are resistant to imatinib. A mouse model of GIST was recently reported using Etv1, the master transcriptional regulator of ICC-intramuscular (IM) and ICC-myenteric (MY), to induce mutant Braf expression. ICC hyperplasia was observed in Etv1 ;Braf mice but loss of Trp53 was required for development of GIST. We identified previously expression of the pan-ErbB negative regulator, LRIG1, in two distinct subclasses of ICC [ICC-deep muscular plexus (DMP) in small intestine and ICC-submucosal plexus (SMP) in colon] and that LRIG1 regulated their development from smooth muscle cell progenitors. Using Lrig1 to induce Braf , we observed ICC hyperplasia beyond the confines of ICC-DMP and ICC-SMP expression, suggesting smooth muscle cells as the cell-of-origin. To examine this possibility, we selectively activated Braf in smooth muscle cells. Myh11 ;Braf mice developed not only ICC hyperplasia but also GIST and in the absence of Trp53 disruption. In addition to providing a simpler model for mutant Braf GIST, these results provide conclusive evidence for smooth muscle cells as an alternative cell-of-origin for GIST. © 2020 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. 10.1002/path.5552
Inhibition of stromal-interacting molecule 1-mediated store-operated Ca entry as a novel strategy for the treatment of acquired imatinib-resistant gastrointestinal stromal tumors. Yang Ziyi,Pan Lijia,Liu Shilei,Li Fengnan,Lv Wenjie,Shu Yijun,Dong Ping Cancer science Imatinib has revolutionized the treatment of gastrointestinal stromal tumors (GIST); however, primary and secondary resistance to imatinib is still a major cause of treatment failure. Multiple mechanisms are involved in this progression. In the present study, we reported a novel mechanism for the acquired resistance to imatinib, which was induced by enhanced Ca influx via stromal-interacting molecule 1 (STIM1)-mediated store-operated Ca entry (SOCE). We found that the STIM1 expression level was related to the acquired resistance to imatinib in our studied cohort. The function of STIM1 in imatinib-resistant GIST cells was also confirmed both in vivo and in vitro. The results showed that STIM1 overexpression contributed to SOCE and drug response in imatinib-sensitive GIST cells. Blockage of SOCE by STIM1 knockdown suppressed the proliferation of imatinib-resistant GIST cell lines and xenografts. In addition, STIM1-mediated SOCE exerted an antiapoptotic effect via the MEK/ERK pathway. The results from this study provide a basis for further research into potential novel therapeutic strategies in acquired imatinib-resistant GIST. 10.1111/cas.13718
Aberrant accumulation of Dickkopf 4 promotes tumor progression via forming the immune suppressive microenvironment in gastrointestinal stromal tumor. Wang Ming,Ni Bo,Zhuang Chun,Zhao Wen-Yi,Tu Lin,Ma Xin-Li,Yang Lin-Xi,Zhang Zhi-Gang,Cao Hui Cancer medicine BACKGROUND:Drug resistance and tumor recurrence are the major concerns in clinical practices of gastrointestinal stromal tumor (GIST), with the urgent requirement for exploring undiscovered pathways driving malignancy. To deal with these, recent studies have made many efforts to explore prognosis indicators and establish potential therapeutic targets. METHODS:Expression profiles of different risks of GISTs were described and abundant clinical evidences supported our findings in this study. Following exploration in vitro by cell experiments and verification in vivo using tumor microarray were taken to elucidate the underlying mechanism, which drove the malignancy in GIST. RESULTS:Dickkopf 4 (DKK4), as the canonical Wnt pathway antagonist, was unexpectedly and universally upregulated in high-risk GISTs, and aberrant accumulation of DKK4 was closely correlated with poor prognosis. In addition, tumor-derived DKK4 could decrease immune cells infiltration and activation in the tumor microenvironment, which decreased the antitumor effects in return. And this phenomenon was recurrent in human tumor specimens. CONCLUSIONS:Our findings identified DKK4 as a proper tumor biomarker for prognosis predicting and recurrence monitoring, and suggested a novel immune-escape mechanism driving malignancy in GIST, which might be a potential therapeutic target to improve the effects of canonical RTK therapy and combined immunotherapy. 10.1002/cam4.2437
KIT mutation in a naïve succinate dehydrogenase-deficient gastric GIST. Brcic Iva,Kashofer Karl,Skone Daniela,Liegl-Atzwanger Bernadette Genes, chromosomes & cancer Up to 85% of gastrointestinal stromal tumors (GIST) harbor mutually exclusive mutations in the KIT or the PDGFRA gene. Among others, known as wild type GIST, succinate dehydrogenase (SDH)-deficient tumors develop due to genetic or epigenetic alterations in any of four SDH genes. Herein, we present a unique case of SDH-deficient GIST with an unusual heterogeneous SDHA and SDHB staining pattern and mutations detected in the SDHA and KIT gene. A 50-year-old patient presented with a 5 cm large gastric tumor with a multinodular/plexiform growth pattern, mixed epithelioid and spindle cell morphology, and focal pronounced nuclear atypia with hyperchromasia and high mitotic activity. Immunohistochemically, CD117 and DOG-1 were positive. SDHB and SDHA stains showed loss of expression in some of the nodules, whereas others presented with an unusually weak patchy positivity. Molecular analysis revealed a point mutation in exon 5 of the SDHA gene and a mutation in exon 11 of the KIT gene. We hypothesize that based on the allele frequency of SDHA and KIT mutations the tumor is best regarded as SDH-deficient GIST in which the SDHA mutation represents the most likely driver mutation. The identified KIT mutation raises the distinct possibility that the KIT mutation is a secondary event reflecting clonal evolution. This is the first case of a treatment naïve GIST harboring a somatic SDHA and a KIT mutation, challenging the dogma that oncogenic mutations in treatment naïve GIST are mutually exclusive. 10.1002/gcc.22768
New insight on the correlation of immune landscapes with immune markers expression in different risk classification of gastrointestinal stromal tumors. Journal of gastroenterology BACKGROUND:The immune landscapes of gastrointestinal stromal tumors (GISTs) are still unclear. We aimed to explore the immune status of GISTs with different recurrence risks and sought potential immunotherapeutic targets. METHODS:Immune cell infiltration and the expression of 93 tumor markers of 65 GISTs with different recurrence risks from public datasets were analyzed via bioinformatic methods. Infiltrating immune cell and OX40L expression of 417 patients from the Zhongshan cohort were analyzed by immunohistochemistry and immunofluorescence. The clinicopathological data of the patients were collected and the prognostic factors were analyzed by univariate and multivariate methods. RESULTS:Macrophages, T cells and NK cells were the most abundant immune cells in tumor microenvironment. OX40L was the only differentially expressed marker in high- and low-risk patients, as well as in patients with primary and recurrent GIST. The positive rate of OX40L in GIST was 54%. OX40L was highly expressed in patients with no metastasis, low mitotic index and relapse risk. The amount of CD68 + macrophages was the independent factor of OX40L expression. The OX40L expression was positively correlated with M2 and resting mast cells. OX40L co-located with CD4 + T cells, M2 and activated mast cells. Patients with high OX40L levels experienced more prolonged relapse-free survival (RFS). CONCLUSIONS:We first reported that GIST cells could express OX40L, patients with high OX40L experienced longer RFS. The colocalization of OX40L with immune cells indicates that OX40L could be a promising potential target for immunotherapy in GIST. 10.1007/s00535-023-01981-0
Ethyl-2-amino-pyrrole-3-carboxylates are active against imatinib-resistant gastrointestinal stromal tumors in vitro and in vivo. Boichuk Sergei,Galembikova Aigul,Dunaev Pavel,Micheeva Ekaterina,Novikova Maria,Khromova Natalya,Kopnin Pavel Anti-cancer drugs We showed recently that ethyl-2-amino-pyrrole-3-carboxylates (EAPCs) exhibit potent antiproliferative activities against a broad spectrum of soft tissue sarcoma and gastrointestinal stromal tumor (GIST) cell lines in vitro. The molecular mechanism of action was owing to inhibition of tubulin polymerization and induction of a robust G2/M cell-cycle arrest, leading to the accumulation of tumor cells in the M-phase and induction of apoptosis. Given that more than 50% of the patients with GISTs develop resistance to imatinib (IM) over the 2 years of IM-based therapy, we examined whether EAPCs exhibit activity against IM-resistant GISTs in vitro and in vivo. A real-time antiproliferation assay illustrated the potent antiproliferative activities of EAPCs against IM-sensitive and IM-resistant GISTs. This was in agreement with the colony formation assay, which revealed potent antiproliferative activities of EAPCs against IM-resistant GISTs, being much stronger when compared with IM and doxorubicin, a topoisomerase II inhibitor. Next, we tested the efficacy of EAPCs in the xenograft model of GISTs, exhibiting secondary IM resistance owing to RTK switch (loss of c-KIT/gain of FGFR2α). A total of 30 5- to 8-week-old female nu/nu mice were subcutaneously inoculated into the flank areas with IM-resistant GIST-T1-R cells (100 μl of 1×10 GIST T-1R cells/ml suspension, in Dulbecco's PBS). Mice were randomized as control (untreated), IM (50 mg/kg), EAPC-20 (10 mg/kg) or EAPC-24 (10 mg/kg) and were treated orally for 10 days. IM has a minor inhibitory effect on tumor size, thus revealing GIST resistance to IM. In contrast, both of EAPCs effectively reduced the tumor size. This was associated with an increased intratumoral apoptosis as detected by immunohistochemical staining for cleaved caspase-3 on day 5 of the treatment. Furthermore, both EAPCs significantly reduced the proliferative activity of tumor cells in the central zones of tumors as measured by positivity for Ki-67 staining. More importantly, in EAPC-24-treated GISTs, the histological response was mainly characterized by the induction of necrosis, whereas EAPC-20 induced the signs of intratumoral fibrosis and myxoid degeneration. Collectively, our data suggest that EAPC-20 and EAPC-24 are the perspective antitumor agents that exhibit antiproliferative and cytotoxic activity against GISTs exhibiting secondary resistance to IM. 10.1097/CAD.0000000000000753
The progressive fragmentation of the KIT/PDGFRA wild-type (WT) gastrointestinal stromal tumors (GIST). Nannini Margherita,Urbini Milena,Astolfi Annalisa,Biasco Guido,Pantaleo Maria A Journal of translational medicine Recent advances in molecular biology have revolutionized the concept of KIT/PDGFRA wild type (WT) gastrointestinal stromal tumors (GIST) than the past. Indeed, from being defined as GIST without KIT or PDGFRA mutations, we are now faced with the opposite scenario, where KIT/PDGFRA WT GIST are "positively" defined according to their specific molecular alterations. In particular, if until recently KIT/PDGFRA GIST without abnormalities of KIT, PDGFRA, SDH, and the RAS signaling pathway were referred as quadruple WT GIST, today also this small subset of GIST is emerging out as a group of heterogeneous distinct entities with multiple different molecular alterations. Therefore, given this still growing and rapidly evolving scenario, the progressive molecular fragmentation may inevitably lead over the time to the disappearance of KIT/PDGFRA WT GIST, destined to be singularly defined by their molecular fingerprint. 10.1186/s12967-017-1212-x
Inhibition of human UDP-glucuronosyltransferase enzyme by ripretinib: Implications for drug-drug interactions. Toxicology and applied pharmacology Ripretinib, a tyrosine kinase inhibitor (TKI), is the first FDA approved fourth-line therapy for adults with advanced gastrointestinal stromal tumor (GIST). Studies have shown that several TKIs for treating GIST were potent inhibitors of human UDP-glucosyltransferase (UGTs) enzymes. However, whether ripretinib affects the activity of UGTs remains unclear. The aim of this study was to investigate the effects of ripretinib on major UGT isoforms, as well as to evaluate its potential drug-drug interactions (DDIs) risk caused by the inhibition of UGTs activities. The inhibitory effects and inhibition modes of ripretinib on UGTs were systematically evaluated using high-performance liquid chromatography (HPLC) and enzyme kinetic studies, respectively. Our data showed that ripretinib exhibited potent inhibition against UGT1A1, UGT1A3, UGT1A4, UGT1A7 and UGT1A8. Enzyme kinetic studies indicated that ripretinib was not only a competitive inhibitor of UGT1A1, UGT1A4 and UGT1A7, but also a noncompetitive inhibitor of UGT1A3, as well as a mixed inhibitor of UGT1A8. The prediction results of in vitro-in vivo extrapolation (IVIVE) demonstrated that ripretinib might bring the potential risk of DDIs when combined with substrates of UGT1A1, UGT1A3, UGT1A4, UGT1A7 or UGT1A8. Therefore, special attention should be paid when ripretinib is used in conjunction with other drugs metabolized by UGTs to avoid risk of DDIs in clinic. 10.1016/j.taap.2023.116490
Aberrant expression of Wnt/β-catenin signaling pathway genes in aggressive malignant gastric gastrointestinal stromal tumors. Fujiya Keiichi,Ohshima Keiichi,Kitagawa Yuko,Hatakeyama Keiichi,Nagashima Takeshi,Aizawa Daisuke,Sugino Takeshi,Urakami Kenichi,Yamaguchi Ken,Terashima Masanori European journal of surgical oncology : the journal of the European Society of Surgical Oncology and the British Association of Surgical Oncology INTRODUCTION:Recent reports on gene expression profiling (GEP) show several genes associated with malignant progression of GIST. However, genes associated with malignant transformation have not been clarified. Here, we aimed to reveal distinct genes in aggressive malignant GIST, using comprehensive gene expression analysis. MATERIALS AND METHODS:We investigated GEP obtained by microarrays for 43 gastric GISTs, which mostly harbored KIT and PDGFRA mutations and integrated clinicopathological risk information. RT-PCR and immunohistochemistry were performed for FZD7, a receptor of Wnt ligands. RESULTS:GEP divided 43 gastric GISTs into two clusters. A cluster included seven of eight high-risk GISTs (88%) in modified NIH classification and was defined as high-risk cluster; the other cluster was defined as low-risk cluster. The number of probes with over 3-fold changes between the two clusters was 1,177, in which probes corresponding to 16 oncogenes were included. Genes involved in the Wnt signaling pathway were the most abundant among the 16 oncogenes. Focusing on 73 Wnt signaling pathway genes of the 21,578 probes, 12 upregulated and 5 downregulated genes were found in the high-risk cluster. Major cascade genes promoting the Wnt/β-catenin signaling pathway, including WNT11, FZD family, and DVL2, were upregulated in the high-risk cluster. SNAI1, SNAI2, and BIRC5, which are activated by this pathway and increase cell proliferation, were also upregulated. These gene expression alterations were consistent in the positive direction of this pathway. GISTs in high-risk cluster strongly expressed FZD7. CONCLUSION:Wnt/β-catenin signaling pathway may play an important role in malignant transformation of indolent GIST. 10.1016/j.ejso.2020.02.036
Genetic Polymorphisms and Adverse Events on Unbound Imatinib and Its Active Metabolite Concentration in Patients With Gastrointestinal Stromal Tumors. Qian Yi,Sun Lu-Ning,Liu Yang-Jie,Zhang Qiang,Xu Jiang-Hao,Ma Zeng-Qing,Zhang Xue-Hui,Xu Hao,Wang Yong-Qing Frontiers in pharmacology Imatinib is a first-line drug for the treatment of gastrointestinal stromal tumors (GIST). This study aims to investigate the influence of different kinds of protein concentrations and genetic polymorphisms of metabolizing enzymes and drug transporters on unbound imatinib and its active metabolite N-desmethyl-imatinib concentration, as well as the relationship between adverse drug reactions (ADRs) and drug concentration. A total of 62 Chinese patients with GIST were genotyped for five single nucleotide polymorphisms (SNPs). Total and unbound 3h and trough concentration of imatinib and N-desmethyl-imatinib in GIST patients were determined by an LC-MS/MS method combined with an equilibrium dialysis. Single-Use Red Plate with inserts was used to separate the unbound drug. When the protein concentration became higher, the unbound imatinib and N-desmethyl-imatinib plasma concentration got higher ( < 0.05). Patients with GA genotype in had significantly higher unbound N-desmethyl-imatinib dose-adjusted trough plasma concentrations ( = 0.012). Patients with CC genotype in had significantly higher unbound imatinib dose-adjusted trough plasma concentrations ( = 0.040). The mean total imatinib C of patients with ADRs (3.10 ± 0.96 µg/ml) was significantly higher than that of patients without ADRs ( = 0.023). The mean total N-desmethyl-imatinib C of patients (0.64 ± 0.21 µg/ml) with ADRs was significantly higher than that of patients without ADRs ( = 0.004). The mean unbound N-desmethyl-imatinib C of patients with ADRs (6.49 ± 2.53 ng/ml) was significantly higher than that of patients without ADRs ( = 0.042). The total and unbound C of imatinib and N-desmethyl-imatinib in patients with ADRs was significantly higher than that in patients without ADRs ( < 0.05). Protein concentrations have great influence on the unbound imatinib and N-desmethyl-imatinib concentrations. The genetic polymorphisms of and were significantly associated with unbound imatinib and N-desmethyl-imatinib dose-adjusted trough plasma levels. The total and unbound imatinib or N-desmethyl-imatinib concentration in patients with GIST was also significantly correlated with ADRs. 10.3389/fphar.2019.00854
Discovery of Potent, Selective Stem Cell Factor Receptor/Platelet Derived Growth Factor Receptor Alpha (c-KIT/PDGFRα) Dual Inhibitor for the Treatment of Imatinib-Resistant Gastrointestinal Stromal Tumors (GISTs). Lu Yanli,Mao Fei,Li Xiaokang,Zheng Xinyu,Wang Manjiong,Xu Qing,Zhu Jin,Li Jian Journal of medicinal chemistry Stem cell factor receptor (c-KIT) and platelet derived growth factor receptor alpha (PDGFRα) kinases play an important role in gastrointestinal stromal tumors (GISTs). Here, we have discovered an c-KIT/PDGFRα dual inhibitor, compound 31, with single-digit nanomolar potency against c-KIT and PDGFRα. Compared to Imatinib (1), 31 showed better antiproliferative efficacy against various TEL-c-KIT/PDGFRα-BaF3 isogenic cells, including three 1-resistant BaF3 cell lines, as well as against GIST-T1 and GIST-882 cell lines. Furthermore, compound 31 showed a good KinomeScan selectivity (468 kinases) (S score (1) = 0.01 at 1 μM concentration), good metabolic stability in liver microsomes, and no hERG inhibitory activity. It was worth noting that 31 inhibited GIST-T1 tumor growth (TGI = 81.5%) and even the BaF3-TEL-cKIT-T670I tumor progression (TGI = 41.9%, 1-resistant GISTs) at a dosage of 100 mg/kg/day without exhibiting apparent toxicity. 10.1021/acs.jmedchem.7b00468
Model-based Dose Individualization of Sunitinib in Gastrointestinal Stromal Tumors. Centanni Maddalena,Krishnan Sreenath M,Friberg Lena E Clinical cancer research : an official journal of the American Association for Cancer Research PURPOSE:Various biomarkers have been proposed for sunitinib therapy in gastrointestinal stromal tumor (GIST). However, the lack of "real-life" comparative studies hampers the selection of the most appropriate one. We, therefore, set up a pharmacometric simulation framework to compare each proposed biomarker. EXPERIMENTAL DESIGN:Models describing relations between sunitinib exposure, adverse events (hand-foot syndrome, fatigue, hypertension, and neutropenia), soluble VEGFR (sVEGFR)-3, and overall survival (OS) were connected to evaluate the differences in survival and adverse events under different dosing algorithms. Various fixed dosing regimens [4/2 (weeks on/weeks off) or 2/1 (50 mg), and continuous daily dosing (37.5 mg)] and individualization approaches [concentration-adjusted dosing (CAD), toxicity-adjusted dosing (TAD), and sVEGFR-3-adjusted dosing (VAD)] were explored following earlier suggested blood sampling schedules and dose-reduction criteria. Model-based forecasts of biomarker changes were evaluated for predictive accuracy and the advantage of a model-based dosing algorithm was evaluated for clinical implementation. RESULTS:The continuous daily dosing regimen was predicted to result in the longest survival. TAD (24.5 months) and VAD (25.5 months) increased median OS as compared with a fixed dose schedule (19.9 and 21.5 months, respectively) and CAD (19.7 and 21.3 months, respectively), without markedly raising the risk of intolerable toxicities. Changes in neutrophil count and sVEGFR-3 were accurately forecasted in the majority of subjects (>65%), based on biweekly blood sampling. CONCLUSIONS:Dose adjustments based on the pharmacodynamic biomarkers neutrophil count and sVEGFR-3 can increase OS while retaining drug safety. Future efforts could explore the possibility of incorporating a model-based dose approach in clinical practice to increase dosing accuracy for these biomarkers. 10.1158/1078-0432.CCR-20-0887
Identification of key genes and associated pathways in KIT/PDGFRA wild‑type gastrointestinal stromal tumors through bioinformatics analysis. Wang Wen-Jie,Li Hong-Tao,Yu Jian-Ping,Li Yu-Min,Han Xiao-Peng,Chen Peng,Yu Wen-Wen,Chen Wei-Kai,Jiao Zuo-Yi,Liu Hong-Bin Molecular medicine reports Gastrointestinal stromal tumors (GISTs) are the most common type of mesenchymal tumor in the gastrointestinal tract. The present study aimed to identify the potential candidate biomarkers that may be involved in the pathogenesis and progression of v‑kit Hardy‑Zuckerman 4 feline sarcoma viral oncogene homolog (KIT)/platelet‑derived growth factor receptor α (PDGFRA) wild‑type GISTs. A joint bioinformatics analysis was performed to identify the differentially expressed genes (DEGs) in wild‑type GIST samples compared with KIT/PDGFRA mutant GIST samples. Gene Ontology function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of DEGs was conducted using Database for Annotation, Visualization and Integrated Discovery and KEGG Orthology‑Based Annotation System (KOBAS) online tools, respectively. Protein‑protein interaction (PPI) networks of the DEGs were constructed using Search Tool for the Retrieval of Interacting Genes online tool and Cytoscape, and divided into sub‑networks using the Molecular Complex Detection (MCODE) plug‑in. Furthermore, enrichment analysis of DEGs in the modules was analyzed with KOBAS. In total, 546 DEGs were identified, including 238 upregulated genes primarily enriched in 'cell adhesion', 'biological adhesion', 'cell‑cell signaling', 'PI3K‑Akt signaling pathway' and 'ECM‑receptor interaction', while the 308 downregulated genes were predominantly involved in 'inflammatory response', 'sterol metabolic process' and 'fatty acid metabolic process', 'small GTPase mediated signal transduction', 'cAMP signaling pathway' and 'proteoglycans in cancer'. A total of 25 hub genes were obtained and four modules were mined from the PPI network, and sub‑networks also revealed these genes were primarily involved in significant pathways, including 'PI3K‑Akt signaling pathway', 'proteoglycans in cancer', 'pathways in cancer', 'Rap1 signaling pathway', 'ECM‑receptor interaction', 'phospholipase D signaling pathway', 'ras signaling pathway' and 'cGMP‑PKG signaling pathway'. These results suggested that several key hub DEGs may serve as potential candidate biomarkers for wild‑type GISTs, including phosphatidylinositol‑4,5‑bisphosphate 3‑kinase, catalytic subunit γ, insulin like growth factor 1 receptor, hepatocyte growth factor, thrombospondin 1, Erb‑B2 receptor tyrosine kinase 2 and matrix metallopeptidase 2. However, further experiments are required to confirm these results. 10.3892/mmr.2018.9457
The Pharmacokinetic-Pharmacodynamic (PKPD) Relationships of AZD3229, a Novel and Selective Inhibitor of KIT, in a Range of Mouse Xenograft Models of GIST. Pilla Reddy Venkatesh,Anjum Rana,Grondine Michael,Smith Aaron,Bhavsar Deepa,Barry Evan,Guichard Sylvie M,Shao Wenlin,Kettle Jason G,Brown Crystal,Banks Erica,Jones Rhys D O Clinical cancer research : an official journal of the American Association for Cancer Research PURPOSE:The emergence of secondary mutations is a cause of resistance to current KIT inhibitors used in the treatment of patients with gastrointestinal stromal tumors (GIST). AZD3229 is a selective inhibitor of wild-type KIT and a wide spectrum of primary and secondary mutations seen in patients with GIST. The objective of this analysis is to establish the pharmacokinetic-pharmacodynamic (PKPD) relationship of AZD3229 in a range of mouse GIST tumor models harboring primary and secondary KIT mutations, and to benchmark AZD3229 against other KIT inhibitors. EXPERIMENTAL DESIGN:A PKPD model was developed for AZD3229 linking plasma concentrations to inhibition of phosphorylated KIT using data generated from several preclinical tumor models, and data generated in a panel of Ba/F3 cell lines. RESULTS:AZD3229 drives inhibition of phosphorylated KIT in an exposure-dependent manner, and optimal efficacy is observed when >90% inhibition of KIT phosphorylation is sustained over the dosing interval. Integrating the predicted human pharmacokinetics into the mouse PKPD model predicts that an oral twice daily human dose greater than 34 mg is required to ensure adequate coverage across the mutations investigated. Benchmarking shows that compared with standard-of-care KIT inhibitors, AZD3229 has the potential to deliver the required target coverage across a wider spectrum of primary or secondary mutations. CONCLUSIONS:We demonstrate that AZD3229 warrants clinical investigation as a new treatment for patients with GIST based on its ability to inhibit both ATP-binding and A-loop mutations of KIT at clinically relevant exposures. 10.1158/1078-0432.CCR-19-2848
Survivin is a novel transcription regulator of KIT and is downregulated by miRNA-494 in gastrointestinal stromal tumors. Yun SeongJu,Kim Won Kyu,Kwon Yujin,Jang Mi,Bauer Sebastian,Kim Hoguen International journal of cancer Gain-of-function mutations of KIT are pathognomonic in sporadic gastrointestinal stromal tumors (GISTs). Several microRNAs have been shown to be dysregulated in GISTs and impact KIT expression. Little is known though on KIT-independent targets of KIT-regulating mRNAs. We sought to investigate how miR-494 inhibits GIST proliferation and to identify novel target gene. We used microarray-based gene expression analyses to identify pathways and target genes affected by miR-494. The expressional relationship between survivin and miR-494 was determined in 35 GIST tissues. Cell proliferation assay, FACS analysis, colony formation assay, promoter assays and chromatin immunoprecipitation (ChiP) were performed to clarify the roles of survivin in GIST progression. Gene expression microarray analysis revealed that miR-494 inhibited GISTs by affecting multiple genes in the cell cycle pathway. Survivin (BIRC5) was a key target of miR-494, and its expression showed an inverse correlation with miR-494 expression in 35 GIST tissues (Pearson's correlation coefficient, r = -0.418, p = 0.012). Downregulation of survivin inhibited proliferation and colony formation, and resulted in cell cycle alteration. Induced survivin overexpression relieved miR-494-mediated inhibition of GIST progression. Targeting PI3K effectively suppressed proliferation of GISTs with downregulation of survivin. Survivin also regulated KIT expression at the transcription level. Immunohistochemical analysis using 113 GISTs revealed that survivin expression was significantly correlated with overall survival of GIST patients (p = 0.004). Our findings indicated that miR-494 synergistically suppressed GISTs by concomitantly targeting survivin and KIT. 10.1002/ijc.31235
Expression of cell cycle regulators and frequency of TP53 mutations in high risk gastrointestinal stromal tumors prior to adjuvant imatinib treatment. Ihle Michaela Angelika,Huss Sebastian,Jeske Wiebke,Hartmann Wolfgang,Merkelbach-Bruse Sabine,Schildhaus Hans-Ulrich,Büttner Reinhard,Sihto Harri,Sundby Hall Kirsten,Eriksson Mikael,Reichardt Peter,Joensuu Heikki,Wardelmann Eva PloS one Despite of multitude investigations no reliable prognostic immunohistochemical biomarkers in GIST have been established so far with added value to predict the recurrence risk of high risk GIST besides mitotic count, primary location and size. In this study, we analyzed the prognostic relevance of eight cell cycle and apoptosis modulators and of TP53 mutations for prognosis in GIST with high risk of recurrence prior to adjuvant treatment with imatinib. In total, 400 patients with high risk for GIST recurrence were randomly assigned for adjuvant imatinib either for one or for three years following laparotomy. 320 primary tumor samples with available tumor tissue were immunohistochemically analyzed prior to treatment for the expression of cell cycle regulators and apoptosis modulators cyclin D1, p21, p16, CDK4, E2F1, MDM2, p53 and p-RB1. TP53 mutational analysis was possible in 245 cases. A high expression of CDK4 was observed in 32.8% of all cases and was associated with a favorable recurrence free survival (RFS), whereas high expression of MDM2 (12.2%) or p53 (35.3%) was associated with a shorter RFS. These results were independent from the primary KIT or PDGFRA mutation. In GISTs with higher mitotic counts was a significantly increased expression of cyclin D1, p53 and E2F1. The expression of p16 and E2F1 significantly correlated to a non-gastric localization. Furthermore, we observed a significant higher expression of p21 and E2F1 in KIT mutant GISTs compared to PDGFRA mutant and wt GISTs. The overall frequency of TP53 mutations was low (n = 8; 3.5%) and could not be predicted by the immunohistochemical expression of p53. In summary, mutation analysis in TP53 plays a minor role in the subgroup of high-risk GIST before adjuvant treatment with imatinib. Strong expression of MDM2 and p53 correlated with a shorter recurrence free survival, whereas a strong expression of CDK4 correlated to a better recurrence free survival. 10.1371/journal.pone.0193048
The Relationship of Clinicopathological Findings and PDGFR-β Expression With Tumor Recurrence in Gastrointestinal Stromal Tumors. The Turkish journal of gastroenterology : the official journal of Turkish Society of Gastroenterology BACKGROUND:Considering the difficulty in predicting the biological behavior of gastrointestinal stromal tumors (GISTs) based on histological findings alone, genetic abnormalities have recently become an area of focus. Platelet-derived growth factor receptor (PDGFR), with 2 isoforms (α and β) is one of the mutations that play a role in the development of GIST. There are very little data determining the relationship of GIST with PDGFRβ which is associated with poor prognosis in other mesenchymal and epithelial tumors. In this study, we aimed to show the relationship between clinicopathological criteria and recurrence. We also wanted to evaluate the effect of PDGFRβ expression on recurrence and clinicopathological findings. METHODS:We evaluated 40 GIST patients retrospectively for detailed clinicopathological findings, postoperative immunohistochemical tumor markers (CD117, Ki67), and also for tumor recurrence. Immunohistochemical examination for PDGFRβ was performed for the all GIST cases. RESULTS:Tumor recurrence was related to male gender (P = .003), serosal localization (P = .004), surgical margins positivity (P = .001), risk group (P = .011), mitotic activity (P = .000), and Ki67 proliferation index (P = .000). PDGFRβ was not significantly associated with tumor recurrence (P = .277). CONCLUSION:We can say that the most important parameters related with recurrence of GISTs are mitotic activity and the Ki67 proliferation index. The determination of the cut-off value of the Ki67 proliferation index as 13% instead of 10% would be much more specific and sensitive. Although PDGFRβ may be used for the diagnosis of GIST as an alternative for PDGFRα in cases with cKIT negativity, it is not an indicator of tumor recurrence as in other tumors. 10.5152/tjg.2021.21148
Downregulation of lncRNA CCDC26 contributes to imatinib resistance in human gastrointestinal stromal tumors through IGF-1R upregulation. Yan Jingyi,Chen Didi,Chen Xiaolei,Sun Xuecheng,Dong Qiantong,Hu Changyuan,Zhou Feng,Chen Wei Brazilian journal of medical and biological research = Revista brasileira de pesquisas medicas e biologicas Imatinib is the first line of therapy for patients with metastatic or gastrointestinal stromal tumors (GIST). However, drug resistance limits the long-term effect of imatinib. Long non-coding RNAs (lncRNAs) are emerging as key players in regulating drug resistance in cancer. In this study, we investigated the association between lncRNA CCDC26 and IGF-1R in GIST and their involvement in drug resistance. Considering the key role of lncRNAs in drug resistance in cancer, we hypothesized that IGF-1R is regulated by lncRNAs. The expression of a series of reported drug resistance-related lncRNAs, including CCDC26, ARF, H19, NBR2, NEAT1, and HOTAIR, in GIST cells treated with imatinib H19 was examined at various time-points by qRT-PCR. Based on our results and published literature, CCDC26, a strongly down-regulated lncRNA following imatinib treatment, was chosen as our research target. GIST cells with high expression of CCDC26 were sensitive to imatinib treatment while knockdown of CCDC26 significantly increased the resistance to imatinib. Furthermore, we found that CCDC26 interacted with c-KIT by RNA pull down, and that CCDC26 knockdown up-regulated the expression of IGF-1R. Moreover, IGF-1R inhibition reversed CCDC26 knockdown-mediated imatinib resistance in GIST. These results indicated that treatments targeting CCDC26-IGF-1R axis would be useful in increasing sensitivity to imatinib in GIST. 10.1590/1414-431x20198399
Overexpressed Fatty Acid Synthase in Gastrointestinal Stromal Tumors: Targeting a Progression-Associated Metabolic Driver Enhances the Antitumor Effect of Imatinib. Li Chien-Feng,Fang Fu-Min,Chen Yen-Yang,Liu Ting-Ting,Chan Ti-Chun,Yu Shih-Chen,Chen Li-Tzong,Huang Hsuan-Ying Clinical cancer research : an official journal of the American Association for Cancer Research In gastrointestinal stromal tumors (GIST), lipid-metabolizing enzymes remain underexplored, including fatty acid synthase (FASN). Forty GISTs were quantitated for mRNA abundance. FASN immunoexpression was informative in 350 GISTs, including 213 with known genotypes. In imatinib-resistant FASN-overexpressing GIST cells, the roles of overexpressed FASN and FASN-targeting C75 in tumor phenotypes, apoptosis and autophagy, transcription, PI3K/AKT/mTOR activation, and imatinib resistance were analyzed by RNAi or myristoylated-AKT transfection. The therapeutic relevance of dual blockade of FASN and KIT was evaluated mRNA abundance significantly increased from very low/low-risk to high-risk levels of NCCN guidelines ( < 0.0001). FASN overexpression was associated with a nongastric location ( = 0.05), unfavorable genotype ( = 0.005), and increased risk level ( < 0.001) and independently predicted shorter disease-free survival ( < 0.001). , FASN knockdown inhibited cell growth and migration, inactivated the PI3K/AKT/mTOR pathway, and resensitized resistant GIST cells to imatinib. C75 transcriptionally repressed the promoter, downregulated KIT expression and phosphorylation, induced LC3-II and myristoylated AKT-suppressible activity of caspases 3 and 7, attenuated the PI3K/AKT/mTOR/RPS6/4E-BP1 pathway activation, and exhibited dose-dependent therapeutic additivism with imatinib. Compared with both monotherapies, the C75/imatinib combination more effectively suppressed the growth of xenografts, exhibiting decreased KIT phosphorylation, Ki-67, and phosphorylated PI3K/AKT/mTOR levels and increased TUNEL labeling. We have characterized the prognostic, biological, and therapeutic implications of overexpressed FASN in GISTs. C75 represses transactivation, abrogates PI3K/AKT/mTOR activation, and provides a rationale for dual blockade of KIT and FASN in treating imatinib-resistant GISTs. . 10.1158/1078-0432.CCR-16-2770
SDHC epi-mutation testing in gastrointestinal stromal tumours and related tumours in clinical practice. Casey Ruth T,Ten Hoopen Rogier,Ochoa Eguzkine,Challis Benjamin G,Whitworth James,Smith Philip S,Martin Jose Ezequiel,Clark Graeme R,Rodger Fay,Maranian Mel,Allinson Kieren,Madhu Basetti,Roberts Thomas,Campos Luis,Anstee Joanne,Park Soo-Mi,Marker Alison,Watts Colin,Bulusu Venkata R,Giger Olivier T,Maher Eamonn R Scientific reports The enzyme succinate dehydrogenase (SDH) functions in the citric acid cycle and loss of function predisposes to the development of phaeochromocytoma/paraganglioma (PPGL), wild type gastrointestinal stromal tumour (wtGIST) and renal cell carcinoma. SDH-deficient tumours are most commonly associated with a germline SDH subunit gene (SDHA/B/C/D) mutation but can also be associated with epigenetic silencing of the SDHC gene. However, clinical diagnostic testing for an SDHC epimutation is not widely available. The objective of this study was to investigate the indications for and the optimum diagnostic pathways for the detection of SDHC epimutations in clinical practice. SDHC promoter methylation analysis of 32 paraffin embedded tumours (including 15 GIST and 17 PPGL) was performed using a pyrosequencing technique and correlated with SDHC gene expression. SDHC promoter methylation was identified in 6 (18.7%) tumours. All 6 SDHC epimutation cases presented with SDH deficient wtGIST and 3/6 cases had multiple primary tumours. No case of constitutional SDHC promoter hypermethylation was detected. Whole genome sequencing of germline DNA from three wtGIST cases with an SDHC epimutation, did not reveal any causative sequence anomalies. Herein, we recommend a diagnostic workflow for the detection of an SDHC epimutation in a service setting. 10.1038/s41598-019-46124-9
Regorafenib regresses an imatinib-resistant recurrent gastrointestinal stromal tumor (GIST) with a mutation in exons 11 and 17 of c-kit in a patient-derived orthotopic xenograft (PDOX) nude mouse model. Miyake Kentaro,Kawaguchi Kei,Kiyuna Tasuku,Miyake Masuyo,Igarashi Kentaro,Zhang Zhiying,Murakami Takashi,Li Yunfeng,Nelson Scott D,Elliott Irmina,Russell Tara,Singh Arun,Hiroshima Yukihiko,Momiyama Masashi,Matsuyama Ryusei,Chishima Takashi,Endo Itaru,Eilber Fritz C,Hoffman Robert M Cell cycle (Georgetown, Tex.) Gastrointestinal stromal tumor (GIST) with a mutation in exons 11 and 17 of c-kit is a rare type of sarcoma. The aim of this study was to determine drug sensitivity for a regionally-recurrent case of GIST using a patient-derived orthotopic xenograft (PDOX) model. The PDOX model was established in the anterior wall of the stomach. GIST PDOX models were randomized into 5 groups of 6 mice each when the tumor volume reached 60 mm: G1, control group; G2, imatinib group (oral administration (p.o.), daily, for 3 weeks); G3, sunitinib group (p.o., daily, for 3 weeks); G4, regorafenib (p.o., daily, for 3 weeks); G5, pazopanib (p.o., daily, for 3 weeks). All mice were sacrificed on day 22. Tumor volume was evaluated on day 0 and day 22 by laparotomy. Body weight were measured 2 times per week. Though regorafenib is third-line therapy for GIST, it was the most effective drug and regressed the tumor significantly (p < 0.001). Sunitinib suppressed tumor growth compared to the control group (p = 0.002). Imatinib, first-line therapy for GIST, and pazopanib did not have significant efficacy compared to the control group (p = 0.886, p = 0.766). The implications of this result is discussed for GIST patients. 10.1080/15384101.2017.1423223
Antihypertensive drug telmisartan inhibits cell proliferation of gastrointestinal stromal tumor cells in vitro. Kobara Hideki,Fujihara Shintaro,Iwama Hisakazu,Matsui Takanori,Fujimori Ayako,Chiyo Taiga,Tingting Shi,Kobayashi Nobuya,Nishiyama Noriko,Yachida Tatsuo,Tadokoro Tomoko,Oura Kyoko,Tani Joji,Fujita Koji,Nomura Takako,Yoneyama Hirohito,Morishita Asahiro,Okano Keiichi,Suzuki Yasuyuki,Mori Hirohito,Masaki Tsutomu Molecular medicine reports Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the digestive tract. The angiotensin II type 1 receptor blockers, telmisartan and candesartan, are widely used antihypertensive drugs that inhibits cancer cell proliferation; however, its underlying mechanisms in mesenchymal tumors, including GIST, remains unknown. The present study aimed to investigate the effect of telmisartan on GIST‑T1 cells and its underlying mechanism. Telmisartan and candesartan inhibited the proliferation of these cells by blocking the G0 to G1 cell cycle transition, which was accompanied by a decrease in cell cycle‑related proteins such as cyclin D1. Furthermore, telmisartan exposure significantly altered microRNA expression in vitro. In conclusion, telmisartan suppressed human GIST cell proliferation by inducing cell cycle arrest in vitro. 10.3892/mmr.2020.11144
DDR1/2 enhance KIT activation and imatinib resistance of primary and secondary KIT mutants in gastrointestinal stromal tumors. Molecular carcinogenesis Gastrointestinal stromal tumors (GISTs) are predominantly initiated by KIT mutations. In this study, we observed that discoidin domain receptors 1 and 2 (DDR1 and DDR2) exhibited high expression in GISTs, were associated with KIT, and enhanced the activation of both wild-type KIT and primary KIT mutants. Inhibition of DDR1/2 led to a reduction in the activation of KIT and its downstream signaling molecules, ultimately impairing GIST cell survival and proliferation in vitro. Consequently, treatment of mice carrying germline KIT/V558A mutation with DDR1/2 inhibitor significantly impeded tumor growth, and the combined use of DDR1/2 inhibitor and imatinib, the first-line targeted therapeutic agent for GISTs, markedly enhanced tumor growth suppression. In addition, DDR1/2 inhibition resulted in decreased KIT expression, while KIT inhibition led to upregulation of DDR1/2 expression in GISTs. The presence of DDR1/2 also decreased the sensitivity of wild-type KIT or primary KIT mutants to imatinib, indicating a possible role for DDR1/2 in promoting GIST survival during KIT-targeted therapy. The development of drug-resistant secondary KIT mutations is a primary factor contributing to GIST recurrence following targeted therapy. Similar to primary KIT mutants, DDR1/2 can associate with and enhance the activation of secondary KIT mutants, further diminishing their sensitivity to imatinib. In summary, our data demonstrate that DDR1/2 contribute to KIT activation in GISTs and strengthen resistance to imatinib for both primary and secondary KIT mutants, providing a rationale for further exploration of DDR1/2 targeting in GIST treatment. 10.1002/mc.23637
SLUG transcription factor: a pro-survival and prognostic factor in gastrointestinal stromal tumour. Pulkka Olli-Pekka,Nilsson Bengt,Sarlomo-Rikala Maarit,Reichardt Peter,Eriksson Mikael,Hall Kirsten Sundby,Wardelmann Eva,Vehtari Aki,Joensuu Heikki,Sihto Harri British journal of cancer BACKGROUND:The SLUG transcription factor has been linked with the KIT signalling pathway that is important for gastrointestinal stromal tumour (GIST) tumourigenesis. Its clinical significance in GIST is unknown. METHODS:Influence of SLUG expression on cell proliferation and viability were investigated in GIST48 and GIST882 cell lines. The association between tumour SLUG expression in immunohistochemistry and recurrence-free survival (RFS) was studied in two clinical GIST series, one with 187 patients treated with surgery alone, and another one with 313 patients treated with surgery and adjuvant imatinib. RESULTS:SLUG downregulation inhibited cell proliferation, induced cell death in both cell lines, and sensitised GIST882 cells to lower imatinib concentrations. SLUG was expressed in 125 (25.0%) of the 500 clinical GISTs evaluated, and expression was associated with several factors linked with unfavourable prognosis. SLUG expression was associated with unfavourable RFS both when patients were treated with surgery alone (HR=3.40, 95% CI=1.67-6.89, P=0.001) and when treated with surgery plus adjuvant imatinib (HR=1.83, 95% CI=1.29-2.60, P=0.001). CONCLUSIONS:GIST patients with high tumour SLUG expression have unfavourable RFS. SLUG may mediate pro-survival signalling in GISTs. 10.1038/bjc.2017.82
miR-182 controls cell growth in gastrointestinal stromal tumors by negatively regulating CYLD expression. Ling Tianlong,Yu Fengrong,Cao Hui Oncology reports Gastrointestinal stromal tumors (GISTs) are the most common type of mesenchymal tumor of the digestive tract. MicroRNAs (miRNAs) are short non-coding RNAs, which control gene expression at a post-transcriptional level. Dysregulated miRNAs are involved in various types of human disease, including cancer. In the present study, it was revealed that miRNA-182 (miR-182) expression was significantly upregulated in human GISTs compared with adjacent normal tissues. Overexpression of miR-182 enhanced GIST-T1 cell growth, with increased proliferation and decreased apoptosis. miR-182 upregulation also promoted colony formation and migration of GIST-T1 cells. In addition, cylindromatosis (CYLD) was identified as a direct target of miR-182. Overexpression of miR-182 suppressed CYLD expression and enhanced downstream nuclear factor (NF)-κB activation. It was also determined that the expression of CYLD was downregulated in association with upregulated miR-182 in human GISTs. In conclusion, these results demonstrated that miR-182 promoted GIST cell growth by negatively regulating CYLD expression. These findings indicated that miR-182 antagonist may be a promising therapeutic strategy for the treatment of human GIST. 10.3892/or.2018.6765
5-aminolaevulinic acid (5-ALA) accumulates in GIST-T1 cells and photodynamic diagnosis using 5-ALA identifies gastrointestinal stromal tumors (GISTs) in xenograft tumor models. PloS one Gastrointestinal stromal tumor (GIST) diagnosis using conventional gastrointestinal endoscopy is difficult because such malignancies cannot be distinguished from other types of submucosal tumors. Photodynamic diagnosis (PDD) is based on the preferential uptake of photosensitizers by tumor tissues and its detection by fluorescence emission upon laser excitation. In this study, we investigated whether PDD using 5-aminolevulinic acid (5-ALA), a standard photosensitizer used worldwide, could be used for GIST diagnosis. 5-ALA is metabolized to endogenous fluorescent protoporphyrin IX (PpIX). We examined the accumulation of PpIX in GIST-T1 cells using flow cytometry and immunofluorescent staining. Furthermore, we established GIST-T1 xenograft mouse models and examined PpIX accumulation in the resultant tumors. PpIX accumulated in GIST-T1 cells and was localized mainly to lysosomes. PpIX accumulation was also observed in murine xenograft tumors. Moreover, tumor and normal tissues could be distinctly identified by relative PpIX fluorescence. Thus, our results demonstrated that PDD with 5-ALA has substantial clinical potential for GIST diagnosis. 10.1371/journal.pone.0249650
Imatinib Regulates and Mitochondrial Respiratory Complexes in Gastrointestinal Stromal Tumors. Huang Wen-Kuan,Shi Hao,Akçakaya Pinar,Zeljic Katarina,Gangaev Anastasia,Caramuta Stefano,Yeh Chun-Nan,Bränström Robert,Larsson Catharina,Lui Weng-Onn International journal of molecular sciences Metabolic adaptation to increased oxidative phosphorylation (OXPHOS) has been found in gastrointestinal stromal tumor (GIST) upon imatinib treatment. However, the underlying mechanism of imatinib-induced OXPHOS is unknown. Discovering molecules that mediate imatinib-induced OXPHOS may lead to the development of therapeutic strategies synergizing the efficacy of imatinib. In this study, we explored the role of microRNAs in regulating OXPHOS in GIST upon imatinib treatment. Using a microarray approach, we found that was one of the most downregulated miRNAs in imatinib-treated tumors compared to untreated tumors. Using an extended series of GIST samples, we further validated the downregulation of in imatinib-treated GIST samples by RT-qPCR. Using both gain- and loss-of-function experiments, we showed that could regulate mitochondrial respiratory Complex II expression, suggesting its role in OXPHOS regulation. Functionally, overexpression could rescue imatinib-induced cell death. These findings provide the molecular link for imatinib-induced OXPHOS expression and the biological role of in regulating cell viability upon imatinib treatment. 10.3390/ijms221910600
Prognostic significance of serum CA125 in the overall management for patients with gastrointestinal stromal tumors. BMC gastroenterology BACKGROUND:Carbohydrate antigen 125 (CA125) is elevated as a tumor marker in many carcinomas, but its association with gastrointestinal stromal tumor (GIST) has received less attention. This study intends to evaluate whether CA125 level can predict tumor progression and overall survival (OS) of GIST patients. METHODS:We retrospectively analyzed the clinical data and follow-up records of GIST patients who underwent surgical resection in Nanjing Drum Tower Hospital from August 2010 to December 2020. All patients were classified according to serum CA125 level. The relationship between CA125 and clinical outcomes was then examined. RESULTS:A total of 406 GIST patients were enrolled in this study, among which 46 patients had preoperative elevated serum CA125 level and 13 patients with high CA125 level both preoperative and postoperative were observed. Preoperative CA125 concentration was significantly related to rupture status, resection style, tumor site, tumor size, mitotic index, NIH risk grade and c-kit exons. According to Kaplan-Meier curve analysis, high expression of postoperative CA125 was significantly correlated with worse progression-free survival (PFS) and OS among patients with preoperative elevated CA125 level. Ultimately, Cox proportional regression model analysis revealed that increase of preoperative and concurrent postoperative CA125 concentration was an independent predictive factor for PFS. CONCLUSIONS:The concurrent abnormality of serum CA125 before and after operation was an independent risk factor for GIST progression, suggesting its significance as a serum biomarker in the overall management of GIST patients. 10.1186/s12876-023-02655-0
Wnt/β-catenin Signaling Contributes to Tumor Malignancy and Is Targetable in Gastrointestinal Stromal Tumor. Zeng Shan,Seifert Adrian M,Zhang Jennifer Q,Cavnar Michael J,Kim Teresa S,Balachandran Vinod P,Santamaria-Barria Juan A,Cohen Noah A,Beckman Michael J,Medina Benjamin D,Rossi Ferdinand,Crawley Megan H,Loo Jennifer K,Maltbaek Joanna H,Besmer Peter,Antonescu Cristina R,DeMatteo Ronald P Molecular cancer therapeutics Gastrointestinal stromal tumor (GIST) is the most common type of sarcoma and usually harbors either a or mutation. However, the molecular basis for tumor malignancy is not well defined. Although the Wnt/β-catenin signaling pathway is important in a variety of cancers, its role in GIST is uncertain. Through analysis of nearly 150 human GIST specimens, we found that some human GISTs expressed β-catenin and contained active, dephosphorylated nuclear β-catenin. Furthermore, advanced human GISTs expressed reduced levels of the Wnt antagonist DKK4. Accordingly, in human GIST T1 cells, Wnt stimulation increased β-catenin-mediated transcriptional activity in a reporter assay as well as transcription of the downstream target genes and In contrast, overexpression in GIST T1 cells reduced Wnt/β-catenin signaling. In addition, we showed that nuclear β-catenin stability was partially regulated by the E3 ligase COP1, as demonstrated with coimmunoprecipitation and COP1 knockdown. Three molecular inhibitors of the Wnt/β-catenin pathway demonstrated antitumor efficacy in various GIST models, both and Notably, the tankyrase inhibitor G007-LK alone had substantial activity against tumors of genetically engineered mice, and the effect was increased by the addition of the Kit inhibitor imatinib mesylate. Collectively, our findings demonstrate that Wnt/β-catenin signaling is a novel therapeutic target for selected untreated or imatinib-resistant GISTs. . 10.1158/1535-7163.MCT-17-0139
A Novel Receptor Tyrosine Kinase Switch Promotes Gastrointestinal Stromal Tumor Drug Resistance. Boichuk Sergei,Galembikova Aigul,Dunaev Pavel,Valeeva Elena,Shagimardanova Elena,Gusev Oleg,Khaiboullina Svetlana Molecules (Basel, Switzerland) The fact that most gastrointestinal stromal tumors (GISTs) acquire resistance to imatinib (IM)-based targeted therapy remains the main driving force to identify novel molecular targets that are capable to increase GISTs sensitivity to the current therapeutic regimens. Secondary resistance to IM in GISTs typically occurs due to several mechanisms that include hemi- or homo-zygous deletion of the wild-type KIT allele, overexpression of focal adhesion kinase (FAK) and insulin-like growth factor receptor I (IGF-1R) amplification, BRAF mutation, a RTK switch (loss of c-KIT and gain of c-MET/AXL), etc. We established and characterized the IM-resistant GIST T-1 cell line (GIST T-1R) lacking secondary c-KIT mutations typical for the IM-resistant phenotype. The resistance to IM in GIST T-1R cells was due to RTK switch (loss of c-KIT/gain of FGFR2α). Indeed, we have found that FGFR inhibition reduced cellular viability, induced apoptosis and affected the growth kinetics of the IM-resistant GISTs in vitro. In contrast, IM-naive GIST T-1 parental cells were not susceptible to FGFR inhibition. Importantly, inhibition of FGF-signaling restored the susceptibility to IM in IM-resistant GISTs. Additionally, IM-resistant GISTs were less susceptible to certain chemotherapeutic agents as compared to parental IM-sensitive GIST cells. The chemoresistance in GIST T-1R cells is not due to overexpression of ABC-related transporter proteins and might be the result of upregulation of DNA damage signaling and repair (DDR) genes involved in DNA double-strand break (DSB) repair pathways (e.g., XRCC3, Rad51, etc.). Taken together, the established GIST T-1R cell subline might be used for in vitro and in vivo studies to examine the efficacy and prospective use of FGFR inhibitors for patients with IM-resistant, un-resectable and metastatic forms of GISTs with the type of RTK switch indicated above. 10.3390/molecules22122152
Long noncoding RNA HOTAIR is upregulated in an aggressive subgroup of gastrointestinal stromal tumors (GIST) and mediates the establishment of gene-specific DNA methylation patterns. Bure Irina,Geer Sandra,Knopf Jasmin,Roas Maike,Henze Sabine,Ströbel Philipp,Agaimy Abbas,Wiemann Stefan,Hoheisel Jörg D,Hartmann Arndt,Haller Florian,Moskalev Evgeny A Genes, chromosomes & cancer Aberrant alterations of DNA methylation are common events in oncogenesis. The origin of cancer-associated epigenetic defects is of interest for mechanistic understanding of malignant transformation and-in the long run-therapeutic modulation of DNA methylation in a locus-specific manner. Given the ability of certain long noncoding RNAs to operate as an interface between DNA and the epigenetic modification machinery which can interact with DNA methyltransferases, we hypothesized-considering HOTAIR as an example-that this transcript may contribute to gene specificity of DNA methylation. Using gastrointestinal stromal tumors (GISTs, n = 67) as a model, we confirmed upregulation of HOTAIR in tumors with high risk of recurrence and showed high abundance of the transcript in GIST cell lines. HOTAIR knockdown in GIST-T1 cells triggered transcriptional response of genes involved in the organization and disassembly of the extracellular matrix and, notably, induced global locus-specific alterations of DNA methylation patterns. Hypomethylation was induced at a total of 507 CpG sites, whereas 382 CpG dinucleotides underwent gain of methylation upon HOTAIR depletion. Importantly, orchestrated gain or loss of methylation at multiple individual CpG sites was shown for cancer-related DPP4, RASSF1, ALDH1A3, and other targets. Collectively, our data indicate that HOTAIR enables target specificity of DNA methylation in GIST and is capable of dual (hypo- and hypermethylation) regulation by a yet to be defined mechanism. The results further suggest the feasibility of manipulating DNA methylation in a targeted manner and are of interest in the context of epigenetic cancer therapy. 10.1002/gcc.22672
PCAT6 mediates cellular biological functions in gastrointestinal stromal tumor via upregulation of PRDX5 and activation of Wnt pathway. Bai Fangyun,Zhang Na,Fang Wei,He Xiangyi,Zheng Yan,Gu Donghua Molecular carcinogenesis Gastrointestinal stromal tumor (GIST) is a common mesenchymal tumor in the gastrointestinal tract. Prostate cancer associated transcript 6 (PCAT6) is a long noncoding RNA (lncRNA) and plays a pivotal role in tumor formation. Present study was designed to explore the function of PCAT6 in GIST. Ki67 staining, colony formation and trypan blue staining assays revealed that PCAT6 boosted GIST cell proliferation but inhibited cell apoptosis. Also, sphere formation assay and Western blot uncovered the promoting role of PCAT6 in GIST stemness. Then, we identified that PCAT6 could activate Wnt/β-catenin pathway. And the tumor facilitator role of Wnt/β-catenin pathway was validated in the rescue assays. Next, miR-143-3p was identified as the downstream microRNA of PCAT6. Moreover, miR-143-3p itself served as a tumor suppressor in GIST. Subsequently, peroxiredoxin 5 (PRDX5) was verified as the target of miR-143-3p. PCAT6 promoted GIST cell proliferation and stemness via sponging miR-143-3p to upregulate PRDX5. In a word, PCAT6 promoted GIST cell proliferation and stemness but inhibited cell apoptosis via competing endogenous RNA pattern and activation of Wnt pathway, which might contribute to GIST treatment. 10.1002/mc.23199
Targeting of FGF-Signaling Re-Sensitizes Gastrointestinal Stromal Tumors (GIST) to Imatinib In Vitro and In Vivo. Molecules (Basel, Switzerland) Dysregulation of the fibroblast growth factor (FGF)/fibroblast growth factor receptor (FGFR) signaling pathway is frequently observed in multiple human malignancies, and thus, therapeutic strategies targeting FGFs and FGFRs in human cancer are being extensively explored. We observed the activation of the FGF/FGFR-signaling pathway in imatinib (IM)-resistant gastrointestinal stromal tumor (GIST) cells. Furthermore, we found that the activation of FGFR signaling has a significant impact on IM resistance in GISTs in vitro. Next, we tested the efficacy of BGJ398, a potent and selective FGFR1⁻3 inhibitor, in xenograft models of GISTs exhibiting secondary IM resistance due to receptor-tyrosine kinase (RTK) switch (loss of c-KIT/gain of FGFR2a). Five to eight-week-old female nu/nu mice were subcutaneously inoculated into the flank areas with GIST T-1R cells. Mice were randomized as control (untreated), IM, BGJ398, or a combination and treated orally for 12 days. IM had a moderate effect on tumor size, thus revealing GIST resistance to IM. Similarly, a minor regression in tumor size was observed in BGJ398-treated mice. Strikingly, a 90% decrease in tumor size was observed in mice treated with a combination of IM and BGJ398. Treatment with BGJ398 and IM also induced major histopathologic changes according to a previously defined histopathologic response score and resulted in massive myxoid degeneration. This was associated with increased intratumoral apoptosis as detected by immunohistochemical staining for cleaved caspase-3 on day 5 of the treatment. Furthermore, treatment with BGJ398 and IM significantly reduced the proliferative activity of tumor cells as measured by positivity for Ki-67 staining. In conclusion, inhibition of FGFR signaling substantially inhibited the growth of IM-resistant GISTs in vitro and showed potent antitumor activity in an IM-resistant GIST model via the inhibition of proliferation, tumor growth, and the induction of apoptosis, thereby suggesting that patients with advanced and metastatic GISTs exhibiting IM resistance might benefit from therapeutic inhibition of FGFR signaling. 10.3390/molecules23102643
Involvement of Bmi-1 gene in the development of gastrointestinal stromal tumor by regulating p16/p14 gene expressions: An in vivo and in vitro study. Wang Jiang-Li,Wu Jiang-Hong,Hong Cai,Wang Ya-Nong,Zhou Ye,Long Zi-Wen,Zhou Ying,Qin Hai-Shu Pathology, research and practice OBJECTIVE:This study was conducted in order to explore the role that Bmi-1 plays during the development of a gastrointestinal stromal tumor (GIST) by regulation of the p16 and p14 expressions. METHODS:Eighty-six patients diagnosed with GIST were selected to take part in this experiment. The Bmi-1 protein expressions in GIST and adjacent normal tissues were detected using immunohistochemistry and further analyzed by using photodensitometry. To monitor and track the progression of the GIST, a 3-year follow-up was conducted for all affected patients. After cell transfection, the GIST cells were assigned into the control group (without transfection), the negative control (NC) group (transfected with Bmi-1-Scramble plasmid), and the Bmi-1 shRNA group (transfected with the pcDNA3.1-Bmi-1 shRNA plasmid). Protein and mRNA expressions collected from Bmi-1, p16, P14, cyclin D1, and CDK4 were measured using both the RT-qPCR and western blotting methods Cell senescence was assessed and obtained by using the β-Galactosidase (β-Gal) activity assay. The use of a Soft agar colony formation assay and CCK-8 assay were performed in order to detect the cell growth and subsequent proliferation. Cell invasion and migration were analyzed using the Transwell assay and scratch test. RESULTS:Bmi-1 in the GIST tissues was found to be significantly higher and the p16 and P14 expressions were lower than those in the adjacent normal tissues. Bmi-1 was negatively correlated with p16 and P14 expressions according to the correlation analysis. Bmi-1 expression was associated with the TNM stage, postoperative recurrence, metastasis, tumor size, and the 5-year survival rate. Area under ROC curve was calculated at 0.884, and sensitivity, specificity, and accuracy of Bmi-1 predicting the GIST were 67.44%, 97.67%, and 65.12%, respectively. Patients exhibiting a high Bmi-1 expression in the GIST tissues had lower survival rates than those with low Bmi-1 expression. In comparison with the control group, P14 and p16 were up-regulated, while cyclinD 1 and CDK4 were down-regulated, cell senescence was promoted, and cell proliferation, invasion, and migration also showed some regression in the Bmi-1 shRNA group. CONCLUSIONS:These collection of data indicated that the down-regulated Bmi-1 might inhibit the proliferation, invasion, and migration of GIST cells and can be subsequently linked to the incidence and developing a prognosis of GIST. 10.1016/j.prp.2017.09.013
A novel anti-c-Kit antibody-drug conjugate to treat wild-type and activating-mutant c-Kit-positive tumors. Molecular oncology c-Kit overexpression and activating mutations, which are reported in various cancers, including gastrointestinal stromal tumor (GIST), small-cell lung cancer (SCLC), acute myeloid leukemia, acral melanoma, and systemic mastocytosis (SM), confer resistance to tyrosine kinase inhibitors (TKIs). To overcome TKI resistance, an anti-c-Kit antibody-drug conjugate was developed in this study to treat wild-type and mutant c-Kit-positive cancers. NN2101, a fully human IgG1, was conjugated to DM1, a microtubule inhibitor, through N-succinimidyl-4-(N-maleimidomethyl) cyclohexane-1-carboxylate (SMCC) (to give NN2101-DM1). The antitumor activity of NN2101-DM1 was evaluated in vitro and in vivo using various cancer cell lines. NN2101-DM1 exhibited potent growth-inhibitory activities against c-Kit-positive cancer cell lines. In a mouse xenograft model, NN2101-DM1 exhibited potent growth-inhibitory activities against imatinib-resistant GIST and SM cells. In addition, NN2101-DM1 exhibited a significantly higher anti-cancer effect than carboplatin/etoposide against SCLC cells where c-Kit does not mediate cancer pathogenesis. Furthermore, the combination of NN2101-DM1 with imatinib in imatinib-sensitive GIST cells induced complete remission compared with treatment with NN2101-DM1 or imatinib alone in mouse xenograft models. These results suggest that NN2101-DM1 is a potential therapeutic agent for wild-type and mutant c-Kit-positive cancers. 10.1002/1878-0261.13084
Complementary activity of tyrosine kinase inhibitors against secondary kit mutations in imatinib-resistant gastrointestinal stromal tumours. British journal of cancer BACKGROUND:Most patients with KIT-mutant gastrointestinal stromal tumours (GISTs) benefit from imatinib, but treatment resistance results from outgrowth of heterogeneous subclones with KIT secondary mutations. Once resistance emerges, targeting KIT with tyrosine kinase inhibitors (TKIs) sunitinib and regorafenib provides clinical benefit, albeit of limited duration. METHODS:We systematically explored GIST resistance mechanisms to KIT-inhibitor TKIs that are either approved or under investigation in clinical trials: the studies draw upon GIST models and clinical trial correlative science. We subsequently modelled in vitro a rapid TKI alternation approach against subclonal heterogeneity. RESULTS:Each of the KIT-inhibitor TKIs targets effectively only a subset of KIT secondary mutations in GIST. Regorafenib and sunitinib have complementary activity in that regorafenib primarily inhibits imatinib-resistance mutations in the activation loop, whereas sunitinib inhibits imatinib-resistance mutations in the ATP-binding pocket. We find that rapid alternation of sunitinib and regorafenib suppresses growth of polyclonal imatinib-resistant GIST more effectively than either agent as monotherapy. CONCLUSIONS:Our data highlight that heterogeneity of KIT secondary mutations is the main mechanism of tumour progression to KIT inhibitors in imatinib-resistant GIST patients. Therapeutic combinations of TKIs with complementary activity against resistant mutations may be useful to suppress growth of polyclonal imatinib-resistance in GIST. 10.1038/s41416-019-0389-6
Epigenetic Regulation of CD133 in Gastrointestinal Stromal Tumors. Geddert Helene,Braun Alexander,Kayser Claudia,Dimmler Arno,Faller Gerhard,Agaimy Abbas,Haller Florian,Moskalev Evgeny A American journal of clinical pathology OBJECTIVES:This study ascertained the regulation of the stem cell marker CD133 and its potential applicability for prognostication of gastrointestinal stromal tumors (GISTs). METHODS:A total of 95 resected GISTs were included in the study. CD133 protein expression was assessed immunohistochemically on tissue microarrays. Methylation percentage was quantified by pyrosequencing. Gene expression in cell lines GIST48b and GIST882 upon treatment with DNA demethylation agent 5-aza-2'-deoxycytidine was analyzed by quantitative polymerase chain reaction. RESULTS:The expression of hypermethylated CD133 could be reactivated in the GIST cell line upon hypomethylation with the drug. Similarly, in patient material, CD133 methylation percentage correlated inversely with the protein expression and reflected tumor size with hypermethylation in small (<2 cm) tumors and virtually no methylation in large (>10 cm) GISTs. The gene's methylation percentage and expression level were clearly specific to anatomic sites and distinct driver mutations. KIT -mutant gastric GISTs exhibited significantly lower methylation degrees and concomitant high CD133 protein abundance compared with KIT -mutant GISTs from the small intestine. CD133 hypermethylation was documented in PDGFRA -mutant gastric GISTs along with low CD133 expression compared with KIT -mutant gastric GISTs. High CD133 expression was a prognosticator of shorter disease-free survival in all patients. In a subgroup of KIT -mutant gastric GISTs, low CD133 methylation degree was correlated with a shorter disease-free survival. CONCLUSIONS:Our results strongly suggest epigenetic regulation of CD133 expression by promoter methylation in GISTs. Pending further validation studies, high abundance of the protein can serve as a marker for malignant GISTs. 10.1093/ajcp/aqx028
Hedgehog signalling pathway activation in gastrointestinal stromal tumours is mediated by primary cilia. Iruzubieta Pablo,Monzón Marta,Castiella Tomás,Ramírez Teresa,Junquera Concepción Gastric cancer : official journal of the International Gastric Cancer Association and the Japanese Gastric Cancer Association BACKGROUND:Gastrointestinal stromal tumour (GIST) is a mesenchymal cancer which derives from interstitial cells of Cajal. To determine whether a relationship between Hedgehog (Hh) signalling pathway and primary cilia exists in GIST tumours is intended here. METHODS:Immunohistochemical, immunofluorescence and ultrastructural techniques were performed in this study. RESULTS:We show that GIST cells present primary cilia (an antenna-like structure based on microtubules). But, moreover, we prove Hedgehog signalling pathway activation in these tumours (a pathway related with tumoural features such as proliferation, migration or stemness) and we show for the first time that this signalling pathway activation in GIST is mediated by primary cilia, likely in a paracrine way. CONCLUSION:Thus, primary cilia and Hedgehog signalling would be fundamental in tumoural microenvironment control of GIST cells for their maintenance, differentiation and proliferation. 10.1007/s10120-019-00984-2
A Phase I Study of Binimetinib (MEK162) Combined with Pexidartinib (PLX3397) in Patients with Advanced Gastrointestinal Stromal Tumor. Rosenbaum Evan,Kelly Ciara,D'Angelo Sandra P,Dickson Mark A,Gounder Mrinal,Keohan Mary L,Movva Sujana,Condy Mercedes,Adamson Travis,Mcfadyen Chloe R,Antonescu Christina R,Hwang Sinchun,Singer Sam,Qin Li-Xuan,Tap William D,Chi Ping The oncologist LESSONS LEARNED:The combination of pexidartinib and binimetinib was safe and tolerable and demonstrated encouraging signs of efficacy in two patients with advanced gastrointestinal stromal tumor (GIST) refractory to tyrosine kinase inhibitors (TKIs).Molecular profiling of GISTs at diagnosis and upon progression may provide insight into the mechanisms of response or resistance to targeted therapies.Additional trials are needed to further explore combined KIT and MEK inhibition in treatment-naïve and TKI-refractory patients with advanced GIST. BACKGROUND:Nearly all patients with advanced gastrointestinal stromal tumor (GIST) develop resistance to imatinib, and subsequent treatments have limited efficacy. Dual inhibition of KIT and MAPK pathways has synergistic antitumor activity in preclinical GIST models. METHODS:This was an investigator-initiated, phase I, dose escalation study of the MEK inhibitor binimetinib combined with pexidartinib, a potent inhibitor of CSF1R, KIT, and FLT3, in patients with advanced or metastatic GIST who progressed on imatinib. The primary endpoint was phase II dose determination; secondary endpoints included safety, tolerability, and efficacy. An expansion cohort to further evaluate safety and efficacy was planned. RESULTS:Two patients were treated at dose level one (binimetinib 30 mg b.i.d. and pexidartinib 400 mg every morning and 200 mg every evening), after which the study was terminated by the manufacturer. No dose-limiting toxicities (DLTs) were reported, and treatment was well tolerated. The only grade ≥3 treatment-emergent adverse event (TEAE) was asymptomatic elevated creatine phosphokinase (CPK). Both patients had a best response of stable disease (SD) by RECIST. Progression-free survival (PFS) and overall survival (OS) were 6.1 and 14.6 months, respectively, in one patient with five prior lines of therapy. The second patient with -mutant GIST had a 27% decrease in tumor burden by RECIST and remains on study after 19 months of treatment. CONCLUSION:Pexidartinib combined with binimetinib was tolerable, and meaningful clinical activity was observed in two imatinib-refractory patients. 10.1634/theoncologist.2019-0418
Altered chromosomal topology drives oncogenic programs in SDH-deficient GISTs. Flavahan William A,Drier Yotam,Johnstone Sarah E,Hemming Matthew L,Tarjan Daniel R,Hegazi Esmat,Shareef Sarah J,Javed Nauman M,Raut Chandrajit P,Eschle Benjamin K,Gokhale Prafulla C,Hornick Jason L,Sicinska Ewa T,Demetri George D,Bernstein Bradley E Nature Epigenetic aberrations are widespread in cancer, yet the underlying mechanisms and causality remain poorly understood. A subset of gastrointestinal stromal tumours (GISTs) lack canonical kinase mutations but instead have succinate dehydrogenase (SDH) deficiency and global DNA hyper-methylation. Here, we associate this hyper-methylation with changes in genome topology that activate oncogenic programs. To investigate epigenetic alterations systematically, we mapped DNA methylation, CTCF insulators, enhancers, and chromosome topology in KIT-mutant, PDGFRA-mutant and SDH-deficient GISTs. Although these respective subtypes shared similar enhancer landscapes, we identified hundreds of putative insulators where DNA methylation replaced CTCF binding in SDH-deficient GISTs. We focused on a disrupted insulator that normally partitions a core GIST super-enhancer from the FGF4 oncogene. Recurrent loss of this insulator alters locus topology in SDH-deficient GISTs, allowing aberrant physical interaction between enhancer and oncogene. CRISPR-mediated excision of the corresponding CTCF motifs in an SDH-intact GIST model disrupted the boundary between enhancer and oncogene, and strongly upregulated FGF4 expression. We also identified a second recurrent insulator loss event near the KIT oncogene, which is also highly expressed across SDH-deficient GISTs. Finally, we established a patient-derived xenograft (PDX) from an SDH-deficient GIST that faithfully maintains the epigenetics of the parental tumour, including hypermethylation and insulator defects. This PDX model is highly sensitive to FGF receptor (FGFR) inhibition, and more so to combined FGFR and KIT inhibition, validating the functional significance of the underlying epigenetic lesions. Our study reveals how epigenetic alterations can drive oncogenic programs in the absence of canonical kinase mutations, with implications for mechanistic targeting of aberrant pathways in cancers. 10.1038/s41586-019-1668-3
Combination of Imatinib Mesylate and AKT Inhibitor Provides Synergistic Effects in Preclinical Study of Gastrointestinal Stromal Tumor. Zook Phillip,Pathak Harsh B,Belinsky Martin G,Gersz Lawrence,Devarajan Karthik,Zhou Yan,Godwin Andrew K,von Mehren Margaret,Rink Lori Clinical cancer research : an official journal of the American Association for Cancer Research PURPOSE:Gastrointestinal stromal tumors (GIST) generally harbor activating mutations in the receptor tyrosine kinase KIT or in the related platelet-derived growth factor receptor alpha (PDGFRA). GIST treated with imatinib mesylate or second-line therapies that target mutant forms of these receptors generally escape disease control and progress over time. Inhibiting additional molecular targets may provide more substantial disease control. Recent studies have implicated the PI3K/AKT pathway in the survival of imatinib mesylate-resistant GIST cell lines and tumors. EXPERIMENTAL DESIGN:Here, we performed in vitro and in vivo studies evaluating the novel combination of imatinib mesylate with the AKT inhibitor MK-2206 in GIST. Whole-transcriptome sequencing (WTS) of xenografts was performed to explore the molecular aspects of tumor response to this novel combination and to potentially identify additional therapeutic targets in GIST. RESULTS:This drug combination demonstrated significant synergistic effects in a panel of imatinib mesylate-sensitive and -resistant GIST cell lines. Furthermore, combination therapy provided significantly greater efficacy, as measured by tumor response and animal survival, in imatinib mesylate-sensitive GIST xenografts as compared with treatment with imatinib mesylate or MK-2206 alone. WTS implicated two neural genes, brain expressed X-linked 1 and neuronal pentraxin I, whose expression was significantly upregulated in combination-treated tumors compared with tumors treated with the two monotherapies. CONCLUSIONS:These studies provide strong preclinical justification for combining imatinib mesylate with an AKT inhibitor as a front-line therapy in GIST. In addition, the WTS implicated the BCL-2/BAX/BAD apoptotic pathway as a potential mechanism for this enhanced combination effect. Clin Cancer Res; 23(1); 171-80. ©2016 AACR. 10.1158/1078-0432.CCR-16-0529
High expression of G protein subunit gamma 13 is associated with poor prognosis of gastrointestinal stromal tumor. Ju Ke-Cheng,Zhang Bin,Hu Yi-Lin,Feng Ying,Li Xiao-Hong,Liu Yi-Fei,Li Peng,Mao Qin-Sheng,Xue Wan-Jiang Pathology, research and practice The G protein subunit gamma 13 (GNG13) plays an important role in olfaction, vision, and biological behavior. However, our knowledge of the relationship between GNG13 expression and the clinicopathological features of gastrointestinal tumors is insufficient. Therefore, we used the Oncomine database to evaluate the expression of GNG13 mRNA in gastric cancer, the result showed that there was no significant difference in the expression of GNG13 between gastric cancer and adjacent normal tissues, and GNG13 mRNA expression was assessed in 32 matched pairs of Gastrointestinal adenocarcinoma tissues and adjacent normal tissues as well as 32 matched pairs of gastrointestinal stromal tumor (GIST) and adjacent normal tissues by quantitative reverse transcription-polymerase chain reaction analysis. The results suggested that GNG13 is upregulated in gastrointestinal stromal tumors. Immunohistochemical analysis was used to detect the GNG13 in the tissues of 123 patients with GIST. High cytoplasmic expression of GNG13, which was observed in 65.85 % of GIST patients, significantly correlated with mitotic index(P = 0.036) and tumor size(P = 0.024). Multiple logistic regression analysis showed that the expression of GNG13 was significantly associated with tumor size. Kaplan-Meier analysis indicated that high GNG13 expression was associated with poor prognosis of GIST. Multivariate Cox regression analysis indicated that the expression of GNG13, mitotic index and tumor size were independent adverse prognostic factors of GIST. These findings suggest that GNG13 is associated with the malignant phenotype of GIST and may serve as a marker of poor prognosis. 10.1016/j.prp.2020.153143
Inhibition of FGFR2-Signaling Attenuates a Homology-Mediated DNA Repair in GIST and Sensitizes Them to DNA-Topoisomerase II Inhibitors. Sergei Boichuk,Pavel Dunaev,Aigul Galembikova,Firyuza Bikinieva,Ilmira Nurgatina,Ilshat Mustafin,Aida Aukhadieva,Refat Kurtasanov,Natalia Andriutsa,Elena Shagimardanova,Vera Gorbunova International journal of molecular sciences Deregulation of receptor tyrosine kinase (RTK)-signaling is frequently observed in many human malignancies, making activated RTKs the promising therapeutic targets. In particular, activated RTK-signaling has a strong impact on tumor resistance to various DNA damaging agents, e.g., ionizing radiation and chemotherapeutic drugs. We showed recently that fibroblast growth factor receptor (FGFR)-signaling might be hyperactivated in imatinib (IM)-resistant gastrointestinal stromal tumors (GIST) and inhibition of this pathway sensitized tumor cells to the low doses of chemotherapeutic agents, such as topoisomerase II inhibitors. Here, we report that inhibition of FGFR-signaling in GISTs attenuates the repair of DNA double-strand breaks (DSBs), which was evidenced by the delay in γ-H2AX decline after doxorubicin (Dox)-induced DNA damage. A single-cell gel electrophoresis (Comet assay) data showed an increase of tail moment in Dox-treated GIST cells cultured in presence of BGJ398, a selective FGFR1-4 inhibitor, thereby revealing the attenuated DNA repair. By utilizing GFP-based reporter constructs to assess the efficiency of DSBs repair via homologous recombination (HR) and non-homologous end-joining (NHEJ), we found for the first time that FGFR inhibition in GISTs attenuated the homology-mediated DNA repair. Of note, FGFR inhibition/depletion did not reduce the number of BrdU and phospho-RPA foci in Dox-treated cells, suggesting that inhibition of FGFR-signaling has no impact on the processing of DSBs. In contrast, the number of Dox-induced Rad51 foci were decreased when FGFR2-mediated signaling was interrupted/inhibited by siRNA FGFR2 or BGJ398. Moreover, Rad51 and -H2AX foci were mislocalized in FGFR-inhibited GIST and the amount of Rad51 was substantially decreased in -H2AX-immunoprecipitated complexes, thereby illustrating the defect of Rad51 recombinase loading to the Dox-induced DSBs. Finally, as a result of the impaired homology-mediated DNA repair, the increased numbers of hypodiploid (i.e., apoptotic) cells were observed in FGFR2-inhibited GISTs after Dox treatment. Collectively, our data illustrates for the first time that inhibition of FGF-signaling in IM-resistant GIST interferes with the efficiency of DDR signaling and attenuates the homology-mediated DNA repair, thus providing the molecular mechanism of GIST's sensitization to DNA damaging agents, e.g., DNA-topoisomerase II inhibitors. 10.3390/ijms21010352
Tyrosine Kinase Inhibitors Reduce Glucose Uptake by Binding to an Exofacial Site on hGLUT-1: Influence on F-FDG PET Uptake. Damaraju Vijaya L,Aminpour Maral,Kuzma Michelle,Winter Philip,Preto Jordane,Tuszynski Jack,McEwan Alexander B J,Sawyer Michael B Clinical and translational science Positron emission tomography (PET) using 2-deoxy-2-[ F]fluoro-d-glucose ([ F]FDG), a marker of energy metabolism and cell proliferation, is routinely used in the clinic to assess patient response to chemotherapy and to monitor tumor growth. Treatment with some tyrosine kinase inhibitors (TKIs) causes changes in blood glucose levels in both nondiabetic and diabetic patients. We evaluated the interaction of several classes of TKIs with human glucose transporter-1 (hGLUT-1) in FaDu and GIST-1 cells by measuring [ H]2-deoxy-d-glucose ([ H]2-DG) and [ H]FDG uptake. Uptake of both was inhibited to varying extents by the TKIs, and representative TKIs from each class showed competitive inhibition of [ H]2-DG uptake. In GIST-1 cells, [ H]FDG uptake inhibition by temsirolimus and nilotinib was irreversible, whereas inhibition by imatinib, gefitinib, and pazopanib was reversible. Molecular modeling studies showed that TKIs form multiple hydrogen bonds with polar residues of the sugar binding site (i.e., Q161, Q282, Q283, N288, N317, and W388), and van der Waals interactions with the H-pocket site. Our results showed interaction of TKIs with amino acid residues at the glucose binding site to inhibit glucose uptake by hGLUT-1. We hypothesize that inhibition of hGLUT-1 by TKIs could alter glucose levels in patients treated with TKIs, leading to hypoglycemia and fatigue, although further studies are required to evaluate roles of other SLC2 and SLC5 members. In addition, TKIs could affect tumor [ F]FDG uptake, increasingly used as a marker of tumor response. The hGLUT-1 inhibition by TKIs may have implications for routine [ F]FDG-PET monitoring of tumor response in patients. 10.1111/cts.12943
Integrated analysis of long non-coding RNAs and mRNAs associated with malignant transformation of gastrointestinal stromal tumors. Yin Xiaonan,Yin Yuan,Dai Lei,Shen Chaoyong,Chen Na,Li Junshu,Cai Zhaolun,Jiang Zhiyuan,Wang Jian,Zhao Zhou,Chen Xin,Deng Hongxin,Zhang Bo Cell death & disease Malignant transformation of gastrointestinal stromal tumors (GISTs) is correlated with poor prognosis; however, the underlying biological mechanism is not well understood. In the present study, low-risk (LR) GISTs, GISTs categorized as high-risk based on tumor size (HBS), and on mitotic rate (HBM) were collected for RNA sequencing. Candidate hub lncRNAs were selected by Oncomine analysis. Expression of a selected hub lncRNA, DNM3OS, and its correlation with patients' prognosis were analyzed using FISH staining, followed with the determination of function and underlying mechanism. Our results revealed a series of key pathways and hub lncRNAs involved in the malignant transformation of GISTs. Oncomine analysis revealed a tight association between clinical signatures and DNM3OS and suggested that DNM3OS is a hub lncRNA that is involved in the Hippo signaling pathway. In addition, DNM3OS was upregulated in HBS, HBM, and HBS/M GIST and correlated with worse prognosis in patients with GISTs. In addition, DNM3OS promoted GIST cell proliferation and mitosis by regulating the expression of GLUT4 and CD36. Collectively, these results improve our understanding of the malignant transformation of GISTs and unveil a series of hub lncRNAs in GISTs. 10.1038/s41419-021-03942-y
E3 ubiquitin ligase Atrogin-1 mediates adaptive resistance to KIT-targeted inhibition in gastrointestinal stromal tumor. Oncogene KIT/PDGFRA oncogenic tyrosine kinase signaling is the central oncogenic event in most gastrointestinal stromal tumors (GIST), which are human malignant mesenchymal neoplasms that often feature myogenic differentiation. Although targeted inhibition of KIT/PDGFRA provides substantial clinical benefit, GIST cells adapt to KIT/PDGFRA driver suppression and eventually develop resistance. The specific molecular events leading to adaptive resistance in GIST remain unclear. By using clinically representative in vitro and in vivo GIST models and GIST patients' samples, we found that the E3 ubiquitin ligase Atrogin-1 (FBXO32)-the main effector of muscular atrophy in cachexia-resulted in the most critical gene derepressed in response to KIT inhibition, regardless the type of KIT primary or secondary mutation. Atrogin-1 in GISTs is transcriptionally controlled by the KIT-FOXO3a axis, thus indicating overlap with Atrogin-1 regulation mechanisms in nonneoplastic muscle cells. Further, Atrogin-1 overexpression was a GIST-cell-specific pro-survival mechanism that enabled the adaptation to KIT-targeted inhibition by apoptosis evasion through cell quiescence. Buttressed on these findings, we established in vitro and in vivo the preclinical proof-of-concept for co-targeting KIT and the ubiquitin pathway to maximize the therapeutic response to first-line imatinib treatment. 10.1038/s41388-021-02049-0
Inhibition of AKT-Signaling Sensitizes Soft Tissue Sarcomas (STS) and Gastrointestinal Stromal Tumors (GIST) to Doxorubicin via Targeting of Homology-Mediated DNA Repair. International journal of molecular sciences Activation of the phosphoinositide 3-kinase (PI3K)/Akt/mTOR pathway is well documented for a broad spectrum of human malignancies supporting their growth and progression. Accumulating evidence has also implicated AKT as a potent modulator of anti-cancer therapies via regulation of DNA damage response and repair (DDR) induced by certain chemotherapeutic agents and ionizing radiation (IR). In the present study, we examined the role of AKT signaling in regulating of Rad51 turnover and cytotoxic effects of topoisomerase II inhibitor, doxorubicin (Dox) in soft tissue sarcomas (STS) and gastrointestinal stromal tumors (GIST) in vitro. Blocking of AKT signaling (MK-2206) enhanced cytotoxic and pro-apoptotic effects of Dox in vast majority of STS and GIST cell lines. The phosphorylated form of Akt co-immunoprecipitates with Rad51 after Dox-induced DNA damage, whereas Akt inhibition interrupts this interaction and decreases Rad51 protein level by enhancing protein instability via proteasome-dependent degradation. Inhibition of Akt signaling in Dox-treated cells was associated with the increased number of γ-H2AX-positive cells, decrease of Rad51 foci formation and its colocalization with γ-H2AX foci, thereby revealing unsuccessful DDR events. This was also in consistency with an increase of tail moment (TM) and olive tail moment (OTM) in Dox-treated GIST and STS cells cultured in presence of Akt inhibitor after Dox washout. Altogether, our data illustrates that inhibition of AKT signaling is STS and GIST might potentiate the cytotoxic effect of topoisomerase II inhibitors via attenuating the homology-mediated DNA repair. 10.3390/ijms21228842
Overexpressed transferrin receptor implied poor prognosis and relapse in gastrointestinal stromal tumors. Frontiers in oncology Ferroptosis, as a novel-induced programmed cell death, plays critical roles in the pathogenesis of cancers. However, the promising biomarkers of ferroptosis in gastrointestinal stromal tumor (GIST) remain to be elucidated. Herein, the expression of ferroptosis-related genes was analyzed in GIST. Among the 64 ferroptosis-related genes, transferrin receptor (TFRC) expression presented a remarkable upregulation in high-risk patients through Gene Expression Omnibus (GEO) dataset analysis, as well as its significant change after imatinib was treated. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of TFRC-relevant genes revealed that TFRC expression was closely associated with cell growth pathways and metabolism-related pathways. Furthermore, patients at high risk of recurrence were more likely to exhibit high TFRC expression by immunohistochemistry. Additionally, high TFRC expression indicated an undesirable state of patient relapse, which could serve as a powerful significant independent predictor of recurrence-free survival (RFS). In summary, we systematically summarize the expression characteristics and clinical relevance of TFRC and show that TFRC can be used as a prognostic factor, which can be considered a potential therapeutic target in GIST. 10.3389/fonc.2023.1151687
Sustained Mutant KIT Activation in the Golgi Complex Is Mediated by PKC-θ in Gastrointestinal Stromal Tumors. Kim Won Kyu,Yun SeongJu,Park Cheol Keun,Bauer Sebastian,Kim Jiyoon,Lee Min Goo,Kim Hoguen Clinical cancer research : an official journal of the American Association for Cancer Research PURPOSE:Tumorigenesis of gastrointestinal stromal tumors (GIST) is driven by gain-of-function mutations in the KIT gene, which result in overexpression of activated mutant KIT proteins (MT-KIT). However, the mechanism of MT-KIT overexpression is poorly understood. EXPERIMENTAL DESIGN:By protein expression analysis and immunofluorescent microscopic analysis, we determine the stability and localization of MT-KIT in four GIST cell lines with different mutations and HeLa cells transfected with mutant KIT model vectors. We also used 154 human GIST tissues to analyze the relationship between the expression of PKC-θ and MT-KITs, and correlations between PKC-θ overexpression and clinicopathological parameters. RESULTS:We report that four different MT-KIT proteins are intrinsically less stable than wild-type KIT due to proteasome-mediated degradation and abnormally localized to the endoplasmic reticulum (ER) or the Golgi complex. By screening a MT-KIT-stabilizing factor, we find that PKC-θ is strongly and exclusively expressed in GISTs and interacts with intracellular MT-KIT to promote its stabilization by increased retention in the Golgi complex. In addition, Western blotting analysis using 50 GIST samples shows strong correlation between PKC-θ and MT-KIT expression (correlation coefficient = 0.682, P < 0.000001). Immunohistochemical analysis using 154 GISTs further demonstrates that PKC-θ overexpression significantly correlates with several clinicopathological parameters such as high tumor grade, frequent recurrence/metastasis, and poor patient survival. CONCLUSIONS:Our findings suggest that sustained MT-KIT overexpression through PKC-θ-mediated stabilization in the Golgi contributes to GIST progression and provides a rationale for anti-PKC-θ therapy in GISTs. Clin Cancer Res; 23(3); 845-56. ©2016 AACR. 10.1158/1078-0432.CCR-16-0521
Co-targeting of ACK1 and KIT triggers additive anti-proliferative and -migration effects in imatinib-resistant gastrointestinal stromal tumors. Biochimica et biophysica acta. Molecular basis of disease Most gastrointestinal stromal tumors (GIST) harbor mutated receptor tyrosine kinase (RTK) KIT/PDGFRA, which provides an attractive therapeutic target. However, a majority of GISTs ultimately develop resistance to KIT/PDGFRA inhibitor imatinib, multiple therapeutic targets will be identified as a reasonable strategy in imatinib-resistant GISTs. Biological mechanisms of non-RTK activated CDC42 associated kinase 1 (ACK1) are still unclear, which has been found to be activated in GISTs. In the current report, ACK1 overexpression is demonstrated in GIST cell lines and biopsies. RNA-seq analysis and immunoblotting show that ACK1 expression is dependent on imatinib treatment time in GIST-T1 cell line. The colocalization/complex of KIT and ACK1 in GIST cells are observed, and ACK1 activation is in a partially KIT and CDC42 dependent manner. Treatment with a specific ACK1 inhibitor AIM-100 or ACK1 siRNA, mildly suppresses cell viability, but markedly inhibits cell migration in imatinib sensitive and in imatinib resistant GIST cell lines, which is associated with inactivation of PI3K/AKT/mTOR and RAF/MAPK signaling pathways, and inhibition of epithelial-mesenchymal transition, evidencing upregulation of E-cadherin and downregulation of ZEB1, N-cadherin, vimentin, snail, and/or β-catenin after treatment with AIM-100 or ACK1/CDC42 shRNAs. Combination inhibition of ACK1 and KIT results in additive effects of anti-proliferation and pro-apoptosis as well as cell cycle arrest, and inhibition of invasiveness and migration in vitro and in vivo, compared to either intervention alone through dephosphorylation of KIT downstream intermediates (AKT, S6, and MAPK). Our data suggest that co-targeting of ACK1 and KIT might be a novel therapeutic strategy in imatinib-resistant GIST. 10.1016/j.bbadis.2023.166690
The rs17084733 variant in the 3' UTR disrupts a miR-221/222 binding site in gastrointestinal stromal tumour: a sponge-like mechanism conferring disease susceptibility. Ravegnini Gloria,Serrano César,Simeon Vittorio,Sammarini Giulia,Nannini Margherita,Roversi Erica,Urbini Milena,Ferrè Fabrizio,Ricci Riccardo,Tarantino Giuseppe,Pantaleo Maria A,Hrelia Patrizia,Angelini Sabrina Epigenetics Several miRNAs are dysregulated in gastrointestinal stromal tumours (GIST), and miR-221/222 appear to have a prominent role in GIST biology. Therefore, we investigated the role of DNA variants located in miR-221/222 precursor sequences and their target 3'UTR. Ninety-five polymorphisms were analysed in 115 GIST cases and 88 healthy controls. 3'UTR rs17084733 and pri-miR-222 rs75246947 were found significantly associated with GIST susceptibility. Specifically, rs17084733 A allele was more common in GIST, particularly in KIT wild-type (WT) patients (Padj = 0.017). rs17084733 variant is located within one of the three miR-221/222 binding sites in the 3'UTR, resulting in a mismatch in this seed region. Conversely, KIT mRNA levels were lower in patients carrying the variant allele, except for mutant GIST. Luciferase assay data in GIST cells, generated using a construct containing all the three miR-221/222 binding sites, are consistent with KIT mRNA levels in GIST patients. Reporter assay data, generated using a construct containing only the site encompassing rs17084733, confirmed that this is a functional variant disrupting the miR-221/222 binding site. In conclusion, this is the first study investigating the role of SNPs on miR-221/222 precursor sequences and their binding region on 3'UTR in GIST. We identified the variant rs17084733 as a possible novel genetic biomarker for risk of developing -WT GIST. Moreover, our findings suggest the role of one of the three miR-221/222 binding sites on 3'UTR as endogenous sponge, soaking up and subtracting miR-221/222 to the other two sites characterized by a higher affinity. 10.1080/15592294.2019.1595997
Combination of pimitespib (TAS-116) with sunitinib is an effective therapy for imatinib-resistant gastrointestinal stromal tumors. International journal of cancer Despite the effectiveness of imatinib, most gastrointestinal stromal tumors (GISTs) develop resistance to the treatment, mainly due to the reactivation of KIT tyrosine kinase activity. Sunitinib, which inhibits the phosphorylation of KIT and vascular endothelial growth factor (VEGF) receptor, has been established as second-line therapy for GISTs. The recently-developed heat shock protein 90 (HSP90) inhibitor pimitespib (PIM; TAS-116) demonstrated clinical benefits in some clinical trials; however, the effects were limited. The aim of our study was therefore to clarify the effectiveness and mechanism of the combination of PIM with sunitinib for imatinib-resistant GISTs. We evaluated the efficacy and mechanism of the combination of PIM with sunitinib against imatinib-resistant GIST using imatinib-resistant GIST cell lines and murine xenograft models. In vitro analysis demonstrated that PIM and sunitinib combination therapy strongly inhibited growth and induced apoptosis in imatinib-resistant GIST cell lines by inhibiting KIT signaling and decreasing auto-phosphorylated KIT in the Golgi apparatus. In addition, PIM and sunitinib combination therapy enhanced antitumor responses in the murine xenograft models compared to individual therapies. Further analysis of the xenograft models showed that the combination therapy not only downregulated the KIT signaling pathway but also decreased the tumor microvessel density. Furthermore, we found that PIM suppressed VEGF expression in GIST cells by suppressing protein kinase D2 and hypoxia-inducible factor-1 alpha, which are both HSP90 client proteins. In conclusion, the combination of PIM and sunitinib is effective against imatinib-resistant GIST via the downregulation of KIT signaling and angiogenic signaling pathways. 10.1002/ijc.34461
Metabolomic and transcriptomic response to imatinib treatment of gastrointestinal stromal tumour in xenograft-bearing mice. Translational oncology BACKGROUND:Although imatinib is a well-established first-line drug for treating a vast majority of gastrointestinal stromal tumours (GIST), GISTs acquire secondary resistance during therapy. Multi-omics approaches provide an integrated perspective to empower the development of personalised therapies through a better understanding of functional biology underlying the disease and molecular-driven selection of the best-targeted individualised therapy. In this study, we applied integrative metabolomic and transcriptomic analyses to elucidate tumour biochemical processes affected by imatinib treatment. MATERIALS AND METHODS:A GIST xenograft mouse model was used in the study, including 10 mice treated with imatinib and 10 non-treated controls. Metabolites in tumour extracts were analysed using gas chromatography coupled with mass spectrometry (GC-MS). RNA sequencing was also performed on the samples subset (n=6). RESULTS:Metabolomic analysis revealed 21 differentiating metabolites, whereas next-generation RNA sequencing data analysis resulted in 531 differentially expressed genes. Imatinib significantly changed the profile of metabolites associated mainly with purine and pyrimidine metabolism, butanoate metabolism, as well as alanine, aspartate, and glutamate metabolism. The related changes in transcriptomic profiles included genes involved in kinase activity and immune responses, as well as supported its impact on the purine biosynthesis pathway. CONCLUSIONS:Our multi-omics study confirmed previously known pathways involved in imatinib anticancer activity as well as correlated imatinib-relevant downregulation of expression of purine biosynthesis pathway genes with the reduction of respectful metabolites. Furthermore, considering the importance of the purine biosynthesis pathway for cancer proliferation, we identified a potentially novel mechanism for the anti-tumour activity of imatinib. Based on the results, we hypothesise metabolic modulations aiming at the reduction in purine and pyrimidine pool may ensure higher imatinib efficacy or re-sensitise imatinib-resistant tumours. 10.1016/j.tranon.2023.101632
Gain of FGF4 is a frequent event in KIT/PDGFRA/SDH/RAS-P WT GIST. Urbini Milena,Indio Valentina,Tarantino Giuseppe,Ravegnini Gloria,Angelini Sabrina,Nannini Margherita,Saponara Maristella,Santini Donatella,Ceccarelli Claudio,Fiorentino Michelangelo,Vincenzi Bruno,Fumagalli Elena,Casali Paolo Giovanni,Grignani Giovanni,Pession Andrea,Ardizzoni Andrea,Astolfi Annalisa,Pantaleo Maria Abbondanza Genes, chromosomes & cancer Gastrointestinal stromal tumors (GIST) lacking mutations in KIT/PDGFRA or RAS pathways and retaining an intact SDH complex are usually referred to as KIT/PDGFRA/SDH/RAS-P WT GIST or more simply quadruple WT GIST (~5% of all GIST). Despite efforts made, no recurrent genetic event in quadruple WT GIST has been identified so far. To further investigate this disease, we performed high throughput copy number analysis on quadruple WT GIST specimens identifying a recurrent focal gain in band 11q13.3 (involving FGF3/FGF4) in 6/8 cases. This event was not found in the other molecular GIST subgroups. FGF3/FGF4 duplication was associated with high expression of FGF4, both at mRNA and protein level, a growth factor normally not expressed in adult tissues or in KIT/PDGFRA-mutated GIST. FGFR1 was found to be the predominant FGF receptor expressed and phosphorylation of AKT was detected, suggesting that a FGF4-FGFR1 autocrine loop could stimulate downstream signaling in quadruple WT GIST. Together with the recent reports of quadruple WT cases carrying FGFR1 activating alterations, these findings strengthen the hypothesis of a potential involvement of FGFR pathway deregulation in quadruple WT GIST, which may represent a rationale for novel therapeutic approaches. 10.1002/gcc.22753
Enhancer Domains in Gastrointestinal Stromal Tumor Regulate KIT Expression and Are Targetable by BET Bromodomain Inhibition. Cancer research Gastrointestinal stromal tumor (GIST) is a mesenchymal neoplasm characterized by activating mutations in the related receptor tyrosine kinases KIT and PDGFRA. GIST relies on expression of these unamplified receptor tyrosine kinase (RTK) genes through a large enhancer domain, resulting in high expression levels of the oncogene required for tumor growth. Although kinase inhibition is an effective therapy for many patients with GIST, disease progression from kinase-resistant mutations is common and no other effective classes of systemic therapy exist. In this study, we identify regulatory regions of the enhancer essential for gene expression and GIST cell viability. Given the dependence of GIST upon enhancer-driven expression of RTKs, we hypothesized that the enhancer domains could be therapeutically targeted by a BET bromodomain inhibitor (BBI). Treatment of GIST cells with BBIs led to cell-cycle arrest, apoptosis, and cell death, with unique sensitivity in GIST cells arising from attenuation of the enhancer domain and reduced gene expression. BBI treatment in KIT-dependent GIST cells produced genome-wide changes in the H3K27ac enhancer landscape and gene expression program, which was also seen with direct KIT inhibition using a tyrosine kinase inhibitor (TKI). Combination treatment with BBI and TKI led to superior cytotoxic effects and , with BBI preventing tumor growth in TKI-resistant xenografts. Resistance to select BBI in GIST was attributable to drug efflux pumps. These results define a therapeutic vulnerability and clinical strategy for targeting oncogenic kinase dependency in GIST. SIGNIFICANCE: Expression and activity of mutant KIT is essential for driving the majority of GIST neoplasms, which can be therapeutically targeted using BET bromodomain inhibitors. 10.1158/0008-5472.CAN-18-1888
Expression and phosphorylation of FOXO1 influences cell proliferation and apoptosis in the gastrointestinal stromal tumor cell line GIST-T1. Wang Tao,Zhao Hui,Gao Hua,Zhu Changming,Xu Yao,Bai Liping,Liu Junbo,Yan Feng Experimental and therapeutic medicine The mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3K) pathways are activated during pathogenesis of gastrointestinal stromal tumors (GISTs). Forkhead box protein O1 (FOXO1) is a transcription factor regulated by the MAPK and PI3K pathways and is associated with multiple metabolic reactions. The present study aims to investigate the association of FOXO1 with cell proliferation and apoptosis in the cell line, GIST-T1. Cell counting kit-8 assay revealed that cell growth was inhibited by the PI3K inhibitor, LY294002, and/or MAPK inhibitor, UO126. Western blotting demonstrated that the expression of p-FOXO1 and B-cell lymphoma 2 (Bcl2) were significantly reduced, whereas the expression of Bcl-2-associated X protein was significantly increased following treatment with LY294002 and/or UO126 (all P<0.05). However, no significant change was revealed in the level of total FOXO1. Flow cytometry revealed that apoptosis was significantly increased by the pathway inhibitors (P<0.05). Specifically, the proportion of cells in the G1 phase was increased whereas the proportion in the S phase was reduced. The changes of protein expression and cell apoptosis were more evident in the LY294002 + UO126 group than in either single-inhibitor group. The results indicated that FOXO1 was able to affect cell proliferation, apoptosis and the cell cycle of GISTs. The regulation of FOXO1 was part of the PI3K and MAPK signaling network, while this regulation was mostly activated by phosphorylation of FOXO1. 10.3892/etm.2018.5853
Synthesis, in vitro and in vivo evaluation of F-fluoronorimatinib as radiotracer for Imatinib-sensitive gastrointestinal stromal tumors. Prause Martin,Niedermoser Sabrina,Wängler Carmen,Decristoforo Clemens,Seibold Uwe,Riester Stephanie,Taguchi Takahiro,Schirrmacher Ralf,Fricker Gert,Wängler Björn Nuclear medicine and biology INTRODUCTION:Gastrointestinal stromal tumors (GIST) have a wide range of mutations, but can mostly be treated with Imatinib, until eventually resistance towards this tyrosine kinase inhibitor is acquired. Early and non-invasive determination of the sensitivity of the tumor and its metastases towards Imatinib by positron emission tomography (PET) would be beneficial for therapy planning and monitoring. METHODS:We developed a synthesis strategy towards the precursor molecule, performed the F-synthesis and in the following evaluated the radioligand in vitro regarding its lipophilicity, stability and biological activity (KIT binding properties) as well as its in vivo properties in GIST tumor-bearing mice. RESULTS:[F]fluoronorimatinib could be obtained in an overall radiochemical yield of 22.2±3.3% within 90min. The radioligand showed high GIST cell uptake and was able to distinguish between Imatinib-sensitive and resistant tumor cell lines (GIST-T1, GIST882, GIST430) in vitro. Further biological evaluations of the ligand towards 9 different GIST-relevant KIT mutations showed comparable binding affinities compared to the structural lead Norimatinib (65nM vs. 53nM for wt-KIT). The in vivo evaluation of the newly developed radioligand showed tumor-to-background-ratios comparable to previously described, similar radiotracers. CONCLUSIONS:Thus, [F]fluoronorimatinib is able to distinguish between Imatinib-resistant and sensitive KIT mutations. Although no improvement of in vivo tumor-to-background ratios could be achieved compared to formerly described radioligands, the hepatic uptake could be considerably reduced, being advantageous for the imaging of GIST. Advances in knowledge and implications for patient care: We were able to show that it is possible to significantly reduce the unfavorably high hepatic uptake of small-molecule radioligands applicable for GIST PET imaging. This work can thus be the basis for further work intending to develop a PET-radioligand for Imatinib-dependent GIST imaging. 10.1016/j.nucmedbio.2017.11.004
Inhibition of PI3K and MAPK pathways along with KIT inhibitors as a strategy to overcome drug resistance in gastrointestinal stromal tumors. PloS one Activating mutations in KIT/PDGFRA receptor tyrosine kinases drive gastrointestinal stromal tumors (GIST). KIT/PDGFRA inhibitors, such as imatinib do not evoke an effective cytocidal response, leaving room for quiescence and development of multiple secondary resistance mutations. As the majority of the secondary resistance clones activate PI3K and MAPK pathways, we investigated whether combined targeting of KIT/PI3K/MAPK (KPM) pathways overcomes drug resistance and quiescence in GIST cells. We monitored the proliferation of imatinib-sensitive and-resistant GIST cell lines after treating them with various combinations of drugs to inhibit KPM pathways. Cytocidal response was evaluated through proliferation, apoptosis and colony outgrowth assays. Combined inhibition of KPM signaling pathways using a KPM inhibitor cocktail decreased the survival of drug-resistant GIST cells and dramatically reduced their proliferation. Downstream pathway analysis showed that the residual PI3K/MAPK signaling observed after KIT inhibitor treatment plays a role in mediating quiescence and drug resistance. The KPM inhibitor cocktail with sunitinib or regorafenib effectively induced apoptosis and prevented colony outgrowth after long-term drug removal, suggesting that it can be used as an effective strategy against quiescence and drug resistance in metastatic GIST. 10.1371/journal.pone.0252689
Mesenchymal stromal cells promote the drug resistance of gastrointestinal stromal tumors by activating the PI3K-AKT pathway via TGF-β2. Journal of translational medicine BACKGROUND:Gastrointestinal stromal tumors (GISTs) are the prevailing sarcomas of the gastrointestinal tract. Tyrosine kinase inhibitors (TKIs) therapy, exemplified by Imatinib mesylate (IM), constitutes the established adjuvant therapy for GISTs. Nevertheless, post-treatment resistance poses a challenge that all patients must confront. The presence of tumor heterogeneity and secondary mutation mechanisms fail to account for some instances of acquired drug resistance. Certain investigations suggest a strong association between tumor drug resistance and mesenchymal stromal cells (MSC) in the tumor microenvironment, but the underlying mechanism remains obscure. Scarce research has explored the connection between GIST drug resistance and the tumor microenvironment, as well as the corresponding mechanism. METHODS:Immunofluorescence and fluorescence-activated cell sorting (FACS) methodologies were employed to detect the presence of MSC in GIST samples. The investigation encompassed the examination of MSC migration towards tumor tissue and the impact of MSC on the survival of GIST cells under IM treatment. Through ELISA, western blotting, and flow cytometry analyses, it was confirmed that Transforming Growth Factor Beta 2 (TGF-β2) triggers the activation of the PI3K-AKT pathway by MSC, thereby facilitating drug resistance in GIST. RESULTS:Our findings revealed a positive correlation between a high proportion of MSC and both GIST resistance and a poor prognosis. In vitro studies demonstrated the ability of MSC to migrate towards GIST. Additionally, MSC were observed to secrete TGF-β2, consequently activating the PI3K-AKT pathway and augmenting GIST resistance. CONCLUSIONS:Our investigation has revealed that MSC within GISTs possess the capacity to augment drug resistance, thereby highlighting their novel mechanism and offering a promising target for intervention in GIST therapy. 10.1186/s12967-023-04063-0
Targeted therapy for drug-tolerant persister cells after imatinib treatment for gastrointestinal stromal tumours. British journal of cancer BACKGROUND:Despite the effectiveness of tyrosine kinase inhibitors (TKI), gastrointestinal stromal tumours (GIST) develop after the withdrawal of TKI. Based on previous studies, a subpopulation of drug-tolerant cells called "persister cells" may be responsible for the recurrence and have thus, gained attention as a novel target in cancer therapy. METHODS:The metabolic changes were investigated in imatinib-derived persister GIST cells. We investigated the efficacy and the mechanism of GPX4 inhibitor, which is known as a major inducer of "ferroptosis". We also evaluated the effects of RSL3 to the gefitinib-derived persister lung cancer cells. RESULTS:We demonstrated a downregulation of glucose metabolism, subsequent decrease in the glutathione level and sensitivity to glutathione peroxidase 4 (GPX4) inhibitor, RSL3 in persister cells. As the cell death induced by RSL3 was found to be "iron-dependent" and "caspase-independent", loss of GPX4 function could have possibly induced selective persister cell ferroptotic death. In the xenograft model, we confirmed the inhibition of tumour regrowth after discontinuation of imatinib treatment. Moreover, RSL3 prevented the growth of gefitinib-derived persister lung cancer cells. CONCLUSIONS:RSL3 combined with TKI may be a promising therapy for both GIST and epidermal growth factor receptor-mutated lung cancer. 10.1038/s41416-021-01566-9
Cyclin D1 is a mediator of gastrointestinal stromal tumor KIT-independence. Ou Wen-Bin,Ni Nan,Zuo Rui,Zhuang Weihao,Zhu Meijun,Kyriazoglou Anastasios,Wu Duolin,Eilers Grant,Demetri George D,Qiu Haibo,Li Bin,Marino-Enriquez Adrian,Fletcher Jonathan A Oncogene Oncogenic KIT or PDGFRA tyrosine kinase mutations are compelling therapeutic targets in most gastrointestinal stromal tumors (GISTs), and the KIT inhibitor, imatinib, is therefore standard of care for patients with metastatic GIST. However, some GISTs lose expression of KIT oncoproteins, and therefore become KIT-independent and are consequently resistant to KIT-inhibitor drugs. We identified distinctive biologic features in KIT-independent, imatinib-resistant GISTs as a step towards identifying drug targets in these poorly understood tumors. We developed isogenic GIST lines in which the parental forms were KIT oncoprotein-dependent, whereas sublines had loss of KIT oncoprotein expression, accompanied by markedly downregulated expression of the GIST biomarker, protein kinase C-theta (PRKCQ). Biologic mechanisms unique to KIT-independent GISTs were identified by transcriptome sequencing, qRT-PCR, immunoblotting, protein interaction studies, knockdown and expression assays, and dual-luciferase assays. Transcriptome sequencing showed that cyclin D1 expression was extremely low in two of three parental KIT-dependent GIST lines, whereas cyclin D1 expression was high in each of the KIT-independent GIST sublines. Cyclin D1 inhibition in KIT-independent GISTs had anti-proliferative and pro-apoptotic effects, associated with Rb activation and p27 upregulation. PRKCQ, but not KIT, was a negative regulator of cyclin D1 expression, whereas JUN and Hippo pathway effectors YAP and TAZ were positive regulators of cyclin D1 expression. PRKCQ, JUN, and the Hippo pathway coordinately regulate GIST cyclin D1 expression. These findings highlight the roles of PRKCQ, JUN, Hippo, and cyclin D1 as oncogenic mediators in GISTs that have converted, during TKI-therapy, to a KIT-independent state. Inhibitors of these pathways could be effective therapeutically for these now untreatable tumors. 10.1038/s41388-019-0894-3
ETV1-Positive Cells Give Rise to -Mutant Gastrointestinal Stromal Tumors. Ran Leili,Murphy Devan,Sher Jessica,Cao Zhen,Wang Shangqian,Walczak Edward,Guan Youxin,Xie Yuanyuan,Shukla Shipra,Zhan Yu,Antonescu Cristina R,Chen Yu,Chi Ping Cancer research Gastrointestinal stromal tumor (GIST) is the most common subtype of sarcoma. Despite clinical advances in the treatment of -mutant GIST, similar progress against wild-type GIST, including mutant BRAF-driven tumors, has been limited by a lack of model systems. ETV1 is a master regulator in the intestinal cells of Cajal (ICC), thought to be the cells of origin of GIST. Here, we present a model in which the ETV1 promoter is used to specifically and inducibly drive Cre recombinase in ICC as a strategy to study GIST pathogenesis. Using a conditional allele for , a mutation observed in clinical cases of GIST, we observed that activation was sufficient to drive ICC hyperplasia but not GIST tumorigenesis. In contrast, combining activation with loss was sufficient to drive both ICC hyperplasia and formation of multifocal GIST-like tumors in the mouse gastrointestinal tract with 100% penetrance. This mouse model of sporadic GIST model was amenable to therapeutic intervention, and it recapitulated clinical responses to RAF inhibition seen in human GIST. Our work offers a useful model of human sporadic forms of -mutant GIST to help unravel its pathogenesis and therapeutic response to novel experimental agents. . 10.1158/0008-5472.CAN-16-3510
LIX1 Controls MAPK Signaling Reactivation and Contributes to GIST-T1 Cell Resistance to Imatinib. International journal of molecular sciences Gastrointestinal stromal tumor (GIST), the most common sarcoma, is mainly caused by an oncogenic mutation in the KIT receptor tyrosine kinase. Targeting KIT using tyrosine kinase inhibitors, such as imatinib and sunitinib, provides substantial benefit; however, in most patients, the disease will eventually progress due to KIT secondary mutations leading to treatment failure. Understanding how GIST cells initially adapt to KIT inhibition should guide the selection of appropriate therapies to overcome the emergence of resistance. Several mechanisms have been broadly implicated in the resistance to imatinib anti-tumoral effects, including the reactivation of MAPK signaling upon KIT/PDGFRA targeted inhibition. This study provides evidence that LImb eXpression 1 (LIX1), a protein we identified as a regulator of the Hippo transducers YAP1 and TAZ, is upregulated upon imatinib or sunitinib treatment. LIX1 silencing in GIST-T1 cells impaired imatinib-induced MAPK signaling reactivation and enhanced imatinib anti-tumor effect. Our findings identified LIX1 as a key regulator of the early adaptative response of GIST cells to targeted therapies. 10.3390/ijms24087138
Targeting the WEE1 kinase strengthens the antitumor activity of imatinib via promoting KIT autophagic degradation in gastrointestinal stromal tumors. Liu Weizhen,Zeng Xiangyu,Yin Yuping,Li Chengguo,Yang Wenchang,Wan Wenze,Shi Liang,Wang Guobin,Tao Kaixiong,Zhang Peng Gastric cancer : official journal of the International Gastric Cancer Association and the Japanese Gastric Cancer Association BACKGROUND:Activating mutation of KIT or PDGFRA is the primary molecular mechanism for gastrointestinal stromal tumors (GISTs). Although imatinib has a revolutionary effect on GIST therapeutics, the benefits are not durable. Increasing reports have demonstrated that cell cycle checkpoint plays critical roles in GIST. Here, we explore the role of WEE1 kinase in GIST progression. METHODS:Oncomine public database, western blotting, and immunohistochemistry were used to analyze WEE1 expression in GISTs. Using MTT assays, colony formation analysis, and flow cytometry, we examined the role of WEE1 in GIST cells and the antitumor activity of the inhibitor MK1775 alone, or in combination with imatinib. Cycloheximide chase assay and pharmacological inhibition of autophagy and proteasome pathway were performed to analyze KIT expression. Additionally, autophagic markers Beclin1 and LC3B were detected by western blotting. RESULTS:Upregulated WEE1 expression was observed in GIST tissues and correlated with tumor size, mitotic count, and risk grade. Inhibition of WEE1 significantly suppressed GIST cell proliferation, induced apoptosis and cell cycle arrest. Imatinib and MK1775 co-treatment markedly enhanced the antitumor activity. Targeting WEE1 decreased the expression of KIT expression. Moreover, WEE1 stabilized KIT protein and KIT reduction observed upon WEE1 inhibition could be reversed by pharmacological inhibition of autophagy, but not proteasome pathway. WEE1 inhibition also increased Beclin1 expression and LC3B II/I ratio in GIST cells. CONCLUSIONS:Our data suggest that WEE1 plays a pivotal role in GIST proliferation. WEE1 inhibition could promote KIT autophagic degradation and, therefore, targeting WEE1 might represent a novel strategy for GIST therapies. 10.1007/s10120-019-00977-1
Small Molecules in Rare Tumors: Emerging Role of MicroRNAs in GIST. International journal of molecular sciences Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of gastrointestinal tract. GISTs have very different clinical phenotypes and underlying molecular characteristics that are not yet completely understood. microRNAs (miRNAs) have been shown to participate in carcinogenesis pathways through post-transcriptional regulation of gene expression in different tumors. Over the last years emerging evidence has highlighted the role of miRNAs in GISTs. This review provides an overview of original research papers that analyze miRNA deregulation patterns, functional role, diagnostic, therapeutic and prognostic implications in GIST as well as provides directions for further research in the field. 10.3390/ijms19020397
HIF-1α regulates cellular metabolism, and Imatinib resistance by targeting phosphogluconate dehydrogenase in gastrointestinal stromal tumors. Xu Kangjing,He Zhongyuan,Chen Ming,Wang Nuofan,Zhang Diancai,Yang Li,Xu Zekuan,Xu Hao Cell death & disease The pentose phosphate pathway (PPP) plays a critical role in maintaining cellular redox homeostasis in tumor cells and macromolecule biosynthesis. Upregulation of the PPP has been shown in several types of tumor. However, how the PPP is regulated to confer selective growth advantages on drug resistant tumor cells is not well understood. Here we show a metabolic shift from tricarboxylic acid cycle (TCA) to PPP after a long period induction of Imatinib (IM). One of the rate-limiting enzymes of the PPP-phosphogluconate dehydrogenase (PGD), is dramatically upregulated in gastrointestinal stromal tumors (GISTs) and GIST cell lines resistant to Imatinib (IM) compared with sensitive controls. Functional studies revealed that the overexpression of PGD in resistant GIST cell lines promoted cell proliferation and suppressed cell apoptosis. Mechanistic analyses suggested that the protein level of hypoxia inducible factor-1α (HIF-1α) increased during long time stimulation of reactive oxygen species (ROS) produced by IM. Importantly, we further demonstrated that HIF-1α also had positive correlation with PGD, resulting in the change of metabolic pathway, and ultimately causing drug resistance in GIST. Our findings show that long term use of IM alters the metabolic phenotype of GIST through ROS and HIF-1α, and this may contribute to IM resistance. Our work offers preclinical proof of metabolic target as an effective strategy for the treatment of drug resistance in GIST. 10.1038/s41419-020-02768-4
Targeting the translational machinery in gastrointestinal stromal tumors (GIST): a new therapeutic vulnerability. Scientific reports Although KIT-mutant GISTs can be effectively treated with tyrosine kinase inhibitors (TKIs), many patients develop resistance to imatinib mesylate (IM) as well as the FDA-approved later-line agents sunitinib, regorafenib and ripretinib. Resistance mechanisms mainly involve secondary mutations in the KIT receptor tyrosine kinase gene indicating continued dependency on the KIT signaling pathway. The fact that the type of secondary mutation confers either sensitivity or resistance towards TKIs and the notion that secondary mutations exhibit intra- and intertumoral heterogeneity complicates the optimal choice of treatment in the imatinib-resistant setting. Therefore, new strategies that target KIT independently of its underlying mutations are urgently needed. Homoharringtonine (HHT) is a first-in-class inhibitor of protein biosynthesis and is FDA-approved for the treatment of chronic myeloid leukemia (CML) that is resistant to at least two TKIs. HHT has also shown activity in KIT-mutant mastocytosis models, which are intrinsically resistant to imatinib and most other TKIs. We hypothesized that HHT could be effective in GIST through downregulation of KIT expression and subsequent decrease of KIT activation and downstream signaling. Testing several GIST cell line models, HHT led to a significant reduction in nascent protein synthesis and was highly effective in the nanomolar range in IM-sensitive and IM-resistant GIST cell lines. HHT treatment resulted in a rapid and complete abolishment of KIT expression and activation, while KIT mRNA levels were minimally affected. The response to HHT involved induction of apoptosis as well as cell cycle arrest. The antitumor activity of HHT was confirmed in a GIST xenograft model. Taken together, inhibition of protein biosynthesis is a promising strategy to overcome TKI resistance in GIST. 10.1038/s41598-022-12000-2
Activated tyrosine kinases in gastrointestinal stromal tumor with loss of KIT oncoprotein expression. Cell cycle (Georgetown, Tex.) Oncogenic KIT or PDGFRA receptor tyrosine kinase (TK) mutations are compelling therapeutic targets in gastrointestinal stromal tumors (GISTs), and the KIT/PDGFRA kinase inhibitor, imatinib, is the standard of care for patients with metastatic GIST. However, approximately 10% of KIT-positive GIST metastases lose KIT expression at the time of clinical progression during imatinib therapy. In the present report, we performed TK-activation screens, using phosphotyrosine-TK double immunoaffinity purification and mass spectrometry, in GIST in vitro models lacking KIT expression. These studies demonstrated tyrosine-phosphorylated EGFR, AXL, and EPHA2 in four of six KIT-negative GIST lines (GIST62, GIST522, GIST54, GIST226, GIST48B, and GIST430B), and tyrosine-phosphorylated focal adhesion kinase (FAK) in each of the six KIT-negative lines. AXL expression was strong in KIT-negative or -weak clinical GIST samples that were obtained from progressing metastases during imatinib therapy. AXL knockdown inhibited viability in three KIT-negative GIST cell lines (GIST62, GIST54, and GIST522), but not in an AXL-negative, KIT-positive GIST control cell line (GIST430). AXL inhibition by R428, a specific AXL kinase inhibitor, reduced viability in AXL-activated GIST54. AXL knockdown in GIST62, GIST522, and GIST54 was accompanied by an increase in p21, p27, and p53 expression. By contrast, gefitinib-mediated EGFR inhibition, PF562271-mediated FAK inactivation, and shRNA-mediated knockdowns of EPHA2 and FAK had no effect on viability or colony formation of the KIT-negative GISTs. These findings highlight the potential relevance of AXL/p53 signaling as a therapeutic target in a subset of GISTs that have lost KIT oncoprotein expression. 10.1080/15384101.2018.1553335
Bromodomain and extraterminal domain inhibitor enhances the antitumor effect of imatinib in gastrointestinal stromal tumours. Journal of cellular and molecular medicine In gastrointestinal stromal tumours (GISTs), the function of bromodomain-containing 4 (BRD4) remains underexplored. BRD4 mRNA abundance was quantified in GISTs. In the current study, we investigated the role of BRD4 in GISTs. Our results show a significant enhancement in BRD4 mRNA and a shift from very low-risk/low-risk to high-risk levels as per NCCN specifications. Overexpression of BRD4 correlated with unfavourable genotype, nongastric location, enhanced risk and decreased disease-free survival, which were predicted independently. Knockout of BRD4 in vitro suppressed KIT expression, which led to inactivation of the KIT/PI3K/AKT/mTOR pathway, impeded migration and cell growth and made the resistant GIST cells sensitive to imatinib. The expression of KIT was repressed by a BRD4 inhibitor JQ1, which also induced myristoylated-AKT-suppressible caspases 3 and 9 activities, induced LC3-II, exhibited dose-dependent therapeutic synergy with imatinib and attenuated the activation of the PI3K/AKT/mTOR pathway. In comparison with their single therapy, the combination of JQ1/imatinib more efficiently suppressed the growth of xenografts and exhibited a reduction in KIT phosphorylation, a decrease in Ki-67 and in the levels of phosphorylated PI3K/AKT/mTOR and enhanced TUNEL staining. Thus, we characterized the biological, prognostic and therapeutic implications of overexpressed BRD4 in GIST and observed that JQ1 suppresses KIT transactivation and nullifies the activation of PI3K/AKT/mTOR, providing a potential strategy for treating imatinib-resistant GIST through dual blockade of KIT and BRD4. 10.1111/jcmm.14945
SOCS1 gene therapy has antitumor effects in imatinib-resistant gastrointestinal stromal tumor cells through FAK/PI3 K signaling. Sugase Takahito,Takahashi Tsuyoshi,Serada Satoshi,Fujimoto Minoru,Ohkawara Tomoharu,Hiramatsu Kosuke,Nishida Toshirou,Hirota Seiichi,Saito Yurina,Tanaka Koji,Miyazaki Yasuhiro,Makino Tomoki,Kurokawa Yukinori,Yamasaki Makoto,Nakajima Kiyokazu,Hanasaki Kazuhiro,Kishimoto Tadamitsu,Mori Masaki,Doki Yuichiro,Naka Tetsuji Gastric cancer : official journal of the International Gastric Cancer Association and the Japanese Gastric Cancer Association BACKGROUND:Most of the gastrointestinal stromal tumors (GIST) have mutations in the KIT gene, encoding a receptor tyrosine kinase. Imatinib, a receptor tyrosine kinase inhibitor, is the first-line therapy for unresectable and metastatic GISTs. Despite the revolutionary effects of imatinib, some patients are primarily resistant to imatinib and many become resistant because of acquisition of secondary mutations in KIT. This study investigated the antitumor effects of SOCS1 gene therapy, which targets several signaling pathways. METHODS:We used GIST-T1 (imatinib-sensitive) and GIST-R8 (imatinib-resistant) cells. We infected both cell lines with an adenovirus expressing SOCS1 (AdSOCS1) and examined antitumor effect and mechanisms of its agent. RESULTS:The latter harboured with secondary KIT mutation and had imatinib resistance > 1000-fold higher than the former cells. We demonstrated that AdSOCS1 significantly decreased the proliferation and induced apoptosis in both cell lines. Moreover, SOCS1 overexpression inhibited the phosphorylation of signal transducer and activator of transcription 3 (STAT3), AKT, and focal adhesion kinase (FAK) in both of them. Inhibition of JAK signaling did not affect the proliferation enough. However, inhibition of the FAK signaling with an FAK inhibitor or RNA interference significantly showed inhibitory effect on cell growth and suppressed the phosphorylation of AKT, indicating a cross-talk between the AKT and FAK pathways in both the imatinib-sensitive and imatinib-resistant GIST cells. CONCLUSIONS:Our results indicate that the activation of FAK signaling is critical for proliferation of both imatinib-sensitive and -resistant GIST cells and the interference with FAK/AKT pathway might be beneficial for therapeutic target. 10.1007/s10120-018-0822-1
miR-125a-5p regulation increases phosphorylation of FAK that contributes to imatinib resistance in gastrointestinal stromal tumors. Huang Wen-Kuan,Akçakaya Pinar,Gangaev Anastasia,Lee Linkiat,Zeljic Katarina,Hajeri Praveensingh,Berglund Erik,Ghaderi Mehran,Åhlén Jan,Bränström Robert,Larsson Catharina,Lui Weng-Onn Experimental cell research The use of imatinib mesylate has greatly improved the clinical outcome for gastrointestinal stromal tumor (GIST) patients. However, imatinib resistance is still a major clinical challenge, and the molecular mechanisms are not fully understood. We have previously shown that miR-125a-5p and its mRNA target PTPN18 modulate imatinib response in GIST cells. Herein, we evaluated phosphorylated FAK (pFAK) as a candidate downstream target of PTPN18 and the possible association of this regulation with imatinib resistance in GIST. FAK and pFAK expressions were evaluated in GIST882 cells transfected with short hairpin RNA or short interfering RNA targeting PTPN18 or miR-125a-5p mimic, imatinib-resistant GIST882R subclones and clinical samples using Western blot analyses. FAK phosphorylation was blocked using the FAK inhibitor 14 (FAKi) and the effects on cell viability and apoptosis were evaluated using WST-1 assay and cleaved PARP expression. Clinical associations of FAK and pFAK expression with imatinib resistance, KIT mutation and patient outcome were assessed by Fisher's exact test or log-rank test. Over-expression of miR-125a-5p and silencing of PTPN18 increased pFAK, but not FAK, expression in GIST cells. Higher pFAK expression was observed in the GIST882R subclones with acquired imatinib resistance compared to their imatinib-sensitive parental cells. Treatment with FAKi in imatinib-resistant GIST882R cells reduced cell viability and increased apoptosis upon imatinib treatment. Additionally, FAKi could rescue the imatinib resistance effect mediated by miR-125a-5p over-expression. In clinical samples, high FAK and pFAK expressions were associated with KIT mutation status, and high FAK expression was also associated with metastasis in GIST. Higher pFAK was found in cases with shorter overall survival. Our findings highlight an important role for miR-125a-5p regulation and its downstream target pFAK for imatinib resistance in GIST. pFAK and FAK may have prognostic values in GIST. 10.1016/j.yexcr.2018.08.028
The KDM6A-SPARCL1 axis blocks metastasis and regulates the tumour microenvironment of gastrointestinal stromal tumours by inhibiting the nuclear translocation of p65. British journal of cancer BACKGROUND:It is urgent to explore the pathogenic mechanism of gastrointestinal stromal tumours (GISTs). KDM6A, a histone demethylase, can activate gene transcription and has not been reported in GISTs. SPARCL1 may serve as a metastasis marker in GIST, but the molecular mechanism remains to be further explored. This study aimed to explore the biological function and molecular mechanism of KDM6A and SPARCL1 in GIST. METHODS:CCK-8, live cell count, colony formation, wound-healing and Transwell migration and invasion assays were employed to detect the cell proliferation, migration and invasion. A xenograft model and hepatic metastasis model were used to assess the role of KDM6A and SPARCL1 in vivo. RESULTS:KDM6A inhibited the proliferation, migration and invasion of GIST cells. Mechanistically, KDM6A promotes the transcription of SPARCL1 by demethylating histone H3 lysine trimethylation and consequently leads to the inactivation of p65. SPARCL1 affected the metastasis of GIST cells in a mesenchymal-epithelial transition- and matrix-metalloproteinase-dependent manner. SPARCL1 knockdown promoted angiogenesis, M2 polarisation and macrophage recruitment by inhibiting the phosphorylation of p65. Moreover, KDM6A and SPARCL1 inhibited hepatic metastasis and macrophage infiltration in vivo. CONCLUSIONS:Our findings establish the critical role of the KDM6A-SPARCL1-p65 axis in restraining the malignancy of GIST. 10.1038/s41416-022-01728-3
The synergistic therapeutic effect of imatinib and protein kinase CK2 Inhibition correlates with PI3K-AKT activation in gastrointestinal stromal tumors. Clinics and research in hepatology and gastroenterology BACKGROUND:Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. Casein kinase 2 (CK2) has been reported to be involved in several cellular processes in multiple cancers. However, the role of CK2 in GIST remains unclear. AIM:We aimed to investigate the combinatorial treatment of imatinib (IM) and CK2 inhibition on the progression of GISTs. METHODS:GIST biopsies and adjacent normal tissues were collected from patients. GIST882 and GIST48 cell lines were subjected to investigate the effect of IM and CK2 inhibition in GIST cells. CCK-8 assay, Caspase-3 activity assay, western blotting, and flow cytometry analysis were employed in the present investigation. RESULTS:Our results showed that CK2 was highly expressed in GIST biopsies, and inhibition of CK2 resulted in decrease in cell viability and increase in apoptosis of GIST cells. Moreover, the combination treatment with CX-4945 (CX) and IM resulted in a more significant decrease in cell viability and increase in cell apoptosis compared with mono-treatment. Mechanistically, the combination treatment influenced the activation of the PI3K/AKT pathway. The activation of the PI3K/AKT pathway reversed the synergistic impacts of the combined treatment on cell viability and apoptosis. CONCLUSION:Our results demonstrated that inhibition of CK2 combined with IM exhibited a synergistic anti-cancer effect on GIST cells through inactivation of the PI3K/AKT pathway. 10.1016/j.clinre.2022.101886
P16 overexpression in BRAF-mutated gastrointestinal stromal tumors. Shi Shan-Shan,Wang Xuan,Xia Qiu-Yuan,Rao Qiu,Shen Qin,Ye Sheng-Bin,Li Rui,Shi Qun-Li,Lu Zhen-Feng,Ma Heng-Hui,Zhou Xiao-Jun Expert review of molecular diagnostics BACKGROUND:The aims of this study were to analyze the histopathology, immunophenotype, molecular features, and prognosis in cases of BRAF-mutated gastrointestinal stromal tumors (GISTs) and to examine the p16 expression in these tumors, and further discuss its effects on tumor formation and progression. METHODS:In all, 283 GIST cases (201 KIT mutants, 12 PDGFRA mutants and 70 wild-type) from the 2010 to 2014 surgical pathology files of the Department of Pathology at Nanjing Jinling Hospital were analyzed for mutations in BRAF exon 15. Patient follow-up and clinical data were collected if available in the medical records. To determine the clinicopathological features and potential molecular mechanism, the authors examined 10 BRAF-mutated GIST cases for KIT, DOG1, SMA, desmin, S-100, Ki-67 and p16 expression. RESULTS:The authors identified 10 cases (3.5%) of BRAF (V600E) mutations in a series of 283 primary GISTs, without KIT (exons 9, 11, 13, 17) or PDGFRA (exons 12, 18) gene mutations. All 10 cases exhibited spindle-cell features, and the morphology and immunophenotype of these cases were no different from those in cases of KIT-mutated GISTs. The clinical results indicated that BRAF-mutated GISTs tended to occur more frequently in females (7/10), older individuals (mean age, 54.9 years) and the stomach (7/10), and that these tumors were low risk and exhibited low recurrence and mortality rates. Two different forms of p16 were identified, which presented with simultaneously strong and diffuse nuclear and cytoplasmic expression patterns. CONCLUSION:GISTs with the BRAF V600E mutation are relatively benign tumors with a distinctive molecular mechanism. The expression of the nuclear and cytoplasmic forms of p16 represent two independent mechanisms, and both seemed to control proliferation in response to oncogenic stimuli, protecting the cell from malignant transformation in BRAF-mutated GISTs. 10.1080/14737159.2017.1272413
LIX1 regulates YAP activity and controls gastrointestinal cancer cell plasticity. Guérin Amandine,Martire Delphine,Trenquier Eva,Lesluyes Tom,Sagnol Sébastien,Pratlong Marine,Lefebvre Elise,Chibon Fréderic,de Santa Barbara Pascal,Faure Sandrine Journal of cellular and molecular medicine Gastrointestinal stromal tumours (GISTs), the most common mesenchymal neoplasm of the gastrointestinal tract, result from deregulated proliferation of transformed KIT-positive interstitial cells of Cajal that share mesenchymal progenitors with smooth muscle cells. Despite the identification of selective KIT inhibitors, primary resistance and relapse remain a major concern. Moreover, most patients develop resistance partly through reactivation of KIT and its downstream signalling pathways. We previously identified the Limb Expression 1 (LIX1) gene as a unique marker of digestive mesenchyme immaturity. We also demonstrated that LIX1 regulates mesenchymal progenitor proliferation and differentiation by controlling the Hippo effector YAP1, which is constitutively activated in many sarcomas. Therefore, we wanted to determine LIX1 role in GIST development. We found that LIX1 is strongly up-regulated in GIST samples and this is associated with unfavourable prognosis. Moreover, LIX1 controls GIST cell proliferation in vitro and in vivo. Upon LIX1 inactivation in GIST cells, YAP1/TAZ activity is reduced, KIT (the GIST signature) is down-regulated, and cells acquire smooth muscle lineage features. Our data highlight LIX1 role in digestive mesenchyme-derived cell-fate decisions and identify this novel regulator as a target for drug design for GIST treatment by influencing its differentiation status. 10.1111/jcmm.15569
KIT Cells Mediate Imatinib Resistance in Gastrointestinal Stromal Tumor. Molecular cancer therapeutics Gastrointestinal stromal tumor (GIST) is commonly driven by oncogenic mutations that are effectively targeted by imatinib (IM), a tyrosine kinase inhibitor (TKI). However, IM does not cure GIST, and adjuvant therapy only delays recurrence in high-risk tumors. We hypothesized that GIST contains cells with primary IM resistance that may represent a reservoir for disease persistence. Here, we report a subpopulation of CD34KIT human GIST cells that have intrinsic IM resistance. These cells possess cancer stem cell-like expression profiles and behavior, including self-renewal and differentiation into CD34KIT progeny that are sensitive to IM treatment. We also found that TKI treatment of GIST cell lines led to induction of stem cell-associated transcription factors ( and ) and concomitant enrichment of the CD34KIT cell population. Using a data-driven approach, we constructed a transcriptomic-oncogenic map (Onco-GPS) based on the gene expression of 134 GIST samples to define pathway activation during GIST tumorigenesis. Tumors with low KIT expression had overexpression of cancer stem cell gene signatures consistent with our findings. Additionally, these tumors had activation of the Gas6/AXL pathway and NF-κB signaling gene signatures. We evaluated these targets and found that primary IM-resistant GIST cells were effectively targeted with either single-agent bemcentinib (AXL inhibitor) or bardoxolone (NF-κB inhibitor), as well as with either agent in combination with IM. Collectively, these findings suggest that CD34KIT cells represent a distinct, but targetable, subpopulation in human GIST that may represent a novel mechanism of primary TKI resistance, as well as a target for overcoming disease persistence following TKI therapy. 10.1158/1535-7163.MCT-20-0973
MiR-374b Promotes Proliferation and Inhibits Apoptosis of Human GIST Cells by Inhibiting PTEN through Activation of the PI3K/Akt Pathway. Molecules and cells Gastrointestinal stromal tumours (GIST) are the most common mesenchymal tumors of the gastrointestinal (GI) tract. In order to investigate a new treatment fot GIST, we hypothesized the effect of miR-374b targeting PTEN gene-mediated PI3K/Akt signal transduction pathway on proliferation and apoptosis of human gastrointestinal stromal tumor (GIST) cells. We obtained GIST tissues and adjacent normal tissues from 143 patients with GIST to measure the levels of miR-374b, PTEN, PI3K, Akt, caspase9, Bax, MMP2, MMP9, ki67, PCNA, P53 and cyclinD1. Finally, cell viability, cell cycle and apoptosis were detected. According to the KFGG analysis of DEGs, PTEN was involved in a variety of signaling pathways and miRs were associated with cancer development. The results showed that MiR-374b was highly expressed, while PTEN was downregulated in the GIST tissues. The levels of miR-374b, PI3K, AKT and PTEN were related to tumor diameter and pathological stage. Additionally, miR-374b increased the mRNA and protein levels of PI3K, Akt, MMP2, MMP9, P53 and cyclinD1, suggesting that miR-374b activates PI3K/Akt signaling pathway in GIST-T1 cells. Moreover, MiR-374b promoted cell viability, migration, invasion, and cell cycle entry, and inhibited apoptosis in GIST cells. Taken together, the results indicated that miR-374b promotes viability and inhibits apoptosis of human GIST cells by targeting PTEN gene through the PI3K/Akt signaling pathway. Thus, this study provides a new potential target for GIST treatment. 10.14348/molcells.2018.2211
F-FDG PET/CT and MR imaging features of liver metastases in gastrointestinal stromal tumors: a cross-sectional analysis. Annals of translational medicine Background:Early detection of gastrointestinal stromal tumor (GIST) liver metastases is crucial for the management and prognosis. In our experience, GIST liver metastases can display hypermetabolism on F-fluorodeoxyglucose positron emission tomography/computed tomography (F-FDG PET/CT) and marked enhancement on magnetic resonance imaging (MRI), which are uncommon in other tumors before treatment. Most literature focus on the imaging evaluation, prognosis after treatment and less is known about imaging features on both imaging methods before treatment. This study analyzes the imaging features of newly diagnosed GIST liver metastases on F-FDG PET/CT and MRI, with goal of improving diagnostic accuracy. Methods:This retrospective study included 55 patients with pathological or radiographical confirmed GIST liver metastases who underwent PET/CT (n=29), MRI (n=22), or both methods (n=4). PET/CT and MRI interpretation including lesion's morphologic features, number, density or signal intensity, hemorrhage, cystic changes or necrosis, maximum standardized uptake value (SUV) of liver metastases and liver background on PET imaging, degree and pattern of enhancement on MRI were obtained by two experienced nuclear medicine physicians and two radiologists respectively. Data are presented as numbers, percentages, means ± standard deviations or median (interquartile range). The correlation between diameter and SUV of metastases, and primary tumor SUV and synchronous liver metastases SUV were analyzed by Spearman's rank test. Results:On PET/CT visual analysis, 38.9%, 23.9%, and 37.2% of lesions showed significant hypermetabolism, slightly higher metabolism, and equal or lower metabolism than liver, respectively. There was a weak correlation between the diameter and SUV of liver metastases ( =0.370, P<0.001), and a moderate correlation between SUV of synchronous liver metastases and the primary tumors ( =0.492, P<0.001). On contrast-enhanced MRI, 90.8% of lesions showed heterogeneous enhancement in the arterial phase with the variable presentation, and 74.3% had different enhancement patterns between margins and intratumoral parenchyma. Conclusions:Liver lesions in GIST displaying significant, slight hypermetabolism on F-FDG PET/CT, marked or heterogeneous gradual enhancement within the intratumoral parenchyma with ring-like enhancement on MRI may denote the diagnosis of liver metastasis. However, GIST liver metastases may also display equal or lower metabolism than liver parenchyma on PET, making small lesions more difficult to diagnose. 10.21037/atm-22-5181
Circ-CCS enhances autophagy during imatinib resistance of gastrointestinal stromal tumor by regulating miR-197-3p/ATG10 signaling. Journal of cancer research and therapeutics Context:Drug resistance in gastrointestinal stromal tumors (GISTs) is connected with autophagy activation. Accumulating data demonstrates the critical role of circular RNAs (circRNAs) dysregulation in this development. Aim:To explore the possible function of hsa_circ_0092306 (circ-CCS) in GIST imatinib resistance. Materials and Methods:Quantitative real-time reverse transcription PCR (RT-qPCR) was used to determine the expression levels of circ-CCS and miR-197-3p. The vitality and apoptosis of cells were determined using the Cell Counting Kit-8 and TUNEL assays, respectively. Western blot analysis was used to evaluate the relative protein expression. A dual-luciferase reporter assay was used to validate the link between circ-CCS, miR-197-3p, and ATG10. Statistical Analysis Used:Comparisons of two groups were analyzed using Student's t tests, and analysis of variance (ANOVA) with Tukey's post hoc test was used to compare three or more groups. Results:Circulating-CCS expression was considerably increased in the serum of imatinib-resistant GIST patients (P < 0.001). Circulating-CCS deficiency decreased cell proliferation and autophagy in GIST-882 and GIST-T1 cells, but promoted apoptosis (P < 0.05). Additionally, circ-CCS was predominantly found in the cytoplasm. Mechanically, circ-CCS targeted miR-197-3p, which may influence autophagy by downregulating ATG10, in order to modulate GIST cells' malignant tendencies. Moreover, silencing miR-197-3p reversed the effect of circ-CCS knockdown on apoptosis and autophagy in GIST cells. Conclusions:By modulating the miR-197-3p/ATG10 axis, circ-CCS increased imatinib resistance in GIST cells, establishing a potential target for reversing medication resistance in such patients. 10.4103/jcrt.jcrt_625_22
Enhancer of zeste homolog 2-mediated paired box 8 methylation promotes gastrointestinal stromal tumor progression through Wnt4 downregulation. Cancer gene therapy Gastrointestinal stromal tumor (GIST) is a refractory malignant tumor without satisfactory therapy. In recent years, aberrant gene methylation has been highlighted as an inducer for tumor progression. In this study, we explored whether enhancer of zeste homolog 2 (EZH2)-mediated paired box 8 (PAX8) methylation affects GIST development through regulation of Wnt4. A total of 50 cases of GIST tissues were collected and the human GIST cell lines were cultured. PAX8 methylation was examined using MS-PCR. Following loss- and gain-function approaches, GIST cell proliferation, migration, invasion, and apoptosis were examined by CCK-8 assay, Transwell assay and flow cytometry. The expression of proliferation related factors and apoptosis related factors was determined. Finally, xenograft tumors in nude mice were observed to examine in vivo tumorigenicity of GIST cells. Downregulated PAX8 and upregulated EZH2 expression was found in GIST tissues. Overexpression of PAX8 or suppression of PAX8 methylation using DNA methyltransferase inhibitor 5-Aza-dC inhibited the proliferation, migration, and invasion of GIST cells while promoting their apoptosis (diminished PCNA, Ki67 and Bcl-2, elevated Bax, and cleaved caspase-3). EZH2 promoted PAX8 methylation to inhibit its expression. Downregulated PAX8 decreased Wnt4 expression to accelerate GIST progression both in vitro and in vivo. Collectively, EZH2 inhibits PAX8 expression by promoting its methylation, which thus downregulates Wnt4 expression, thereby promoting the development of GIST. 10.1038/s41417-020-00266-5
Low Distribution of TIM-3 Cytotoxic Tumor-Infiltrating Lymphocytes Predicts Poor Outcomes in Gastrointestinal Stromal Tumors. Zhuang Chun,Ni Bo,Zhang Zi-Zhen,Zhao Wen-Yi,Tu Lin,Ma Xin-Li,Yang Lin-Xi,Cao Hui,Wang Ming Journal of immunology research There are multiple tumor-infiltrating lymphocytes (TILs) and relevant immune checkpoints existing in gastrointestinal stromal tumor (GIST), which provides opportunities and rationales for developing effective immunotherapies. Recent studies have suggested that checkpoint TIM-3/Gal-9 plays a pivotal role on immune response in multiple tumors, similar to the PD-1/PD-L1, emerging as a potential therapeutic target. However, their functions in GIST are unrevealed. Hence, the expression of immune checkpoints TIM-3 and Gal-9, as well as the infiltration of CD8 T cells and NK cells, is described in 299 cases of GIST specimens. The results showed that TIM-3 and Gal-9 are mainly expressed in TILs, rarely in tumor cells. Expression levels of TIM-3 and Gal-9 significantly differ in varying risks of GIST and exert opposite distribution trends. Indicated by prognosis analysis, high TIM-3 expression of TILs was associated with improved outcome, while low expression levels of TIM-3 in combination with low amounts of CD8 and CD56 TILs predict extremely poor survival. The integrated analysis of TIM-3, CD8, and CD56 TILs as one biomarker is a reliable independent predictor of prognosis. In conclusion, low densities of TIM-3 TILs are associated with poor survival, and integrated immune biomarkers lead to superior predictors of GIST prognosis. 10.1155/2021/6647292
Mitochondrial Inhibition Augments the Efficacy of Imatinib by Resetting the Metabolic Phenotype of Gastrointestinal Stromal Tumor. Vitiello Gerardo A,Medina Benjamin D,Zeng Shan,Bowler Timothy G,Zhang Jennifer Q,Loo Jennifer K,Param Nesteene J,Liu Mengyuan,Moral Alec J,Zhao Julia N,Rossi Ferdinand,Antonescu Cristina R,Balachandran Vinod P,Cross Justin R,DeMatteo Ronald P Clinical cancer research : an official journal of the American Association for Cancer Research Imatinib dramatically reduces gastrointestinal stromal tumor (GIST) F-FDG uptake, providing an early indicator of treatment response. Despite decreased glucose internalization, many GIST cells persist, suggesting that alternative metabolic pathways are used for survival. The role of mitochondria in imatinib-treated GIST is largely unknown. We quantified the metabolic activity of several human GIST cell lines. We treated human GIST xenografts and genetically engineered mice with the mitochondrial oxidative phosphorylation inhibitor VLX600 in combination with imatinib and analyzed tumor volume, weight, histology, molecular signaling, and cell cycle activity. assays on human GIST cell lines were also performed. Imatinib therapy decreased glucose uptake and downstream glycolytic activity in GIST-T1 and HG129 cells by approximately half and upregulated mitochondrial enzymes and improved mitochondrial respiratory capacity. Mitochondrial inhibition with VLX600 had a direct antitumor effect while appearing to promote glycolysis through increased AKT signaling and glucose transporter expression. When combined with imatinib, VLX600 prevented imatinib-induced cell cycle escape and reduced p27 expression, leading to increased apoptosis when compared to imatinib alone. In mice, VLX600 alone did not induce tumor cell death, but had a profound antitumor effect when combined with imatinib. Our findings show that imatinib alters the metabolic phenotype of GIST, and this may contribute to imatinib resistance. Our work offers preclinical proof of concept of metabolic targeting as an effective strategy for the treatment of GIST. . 10.1158/1078-0432.CCR-17-2697
Insights into the Proteome of Gastrointestinal Stromal Tumors-Derived Exosomes Reveals New Potential Diagnostic Biomarkers. Atay Safinur,Wilkey Daniel W,Milhem Mohammed,Merchant Michael,Godwin Andrew K Molecular & cellular proteomics : MCP Developing tumors continuously release nano-sized vesicles that represent circulating "fingerprints" of the tumor's identity. In gastrointestinal stromal tumor (GIST), we have previously reported that these tumors release "oncosomes" carrying the constitutively activated tyrosine kinase (TK) receptor KIT. Despite the clinical utility of TK inhibitors, such as imatinib mesylate (IM), recurrence and metastasis are clinical problems that urge the need to identify new tumor-derived molecules. To this aim, we performed the first high quality proteomic study of GIST-derived exosomes (GDEs) and identified 1,060 proteins composing the core GDE proteome (cGDEp). The cGDEp was enriched in diagnostic markers ( KIT, CD34, ANO1, PROM1, PRKCQ, and ENG), as well as proteins encoded by genes previously reported expressed in GIST ( DPP4, FHL1, CDH11, and KCTD12). Many of these proteins were validated using cell lines, patient-derived KIT exosomes, and GIST tissues. We further show that and -derived GDE, carry proteins associated with IM response, such as Sprouty homolog 4 (SPRY4), surfeit 4 (SURF4), ALIX, and the cGMP-dependent 3',5'-cyclic phosphodiesterase 2A (PDE2A). Additionally, we report that the total exosome levels and exosome-associated KIT and SPRY4 protein levels have therapeutic values. In fact, molecular characterization of -derived KIT exosomes indicate significant sorting of p-KIT, total KIT, and SPRY4 after IM-treatment of metastatic patients as compared with the pre-IM levels. Our data suggest that analysis of circulating exosomes levels and molecular markers of IM response in GIST patients with primary and metastatic disease is suitable to develop liquid based biopsies for the diagnosis, prognosis, and monitoring of response to treatment of these tumors. In summary, these findings provide the first insight into the proteome of GIST-derived oncosomes and offers a unique opportunity to further understand their oncogenic elements which contribute to tumorigenesis and drug resistance. Data are available via ProteomeXchange with identifier PXD007997. 10.1074/mcp.RA117.000267
Proteomic Maps of Human Gastrointestinal Stromal Tumor Subgroups. Molecular & cellular proteomics : MCP Gastrointestinal stromal tumor (GIST) is a common sarcoma of gastrointestinal tract (GIT) with high metastatic and recurrence rates, but the proteomic features are still less understood. Here we performed systematic quantitative proteome profiling of GIST from 13 patients classified into very low/low, intermediate and high risk subgroups. An extended cohort of GIST ( = 131) was used for immunohistochemical validation of proteins of interest. In total, 9177 proteins were quantified, covering 55.9% of the GIT transcriptome from The Human Protein Altas. Out of the 9177 quantified proteins, 4930 proteins were observed in all 13 cases with 517 upregulated and 187 downregulated proteins in tumorous tissues independent of risk stage. Pathway analysis showed that the downregulated proteins were mostly enriched in metabolic pathway, whereas the upregulated proteins mainly belonged to spliceosome pathway. In addition, 131 proteins showed differentially expressed patterns among GIST subgroups with statistical significance. The 13 GIST cases were classified into 3 subgroups perfectly based on the expression of these proteins. The intensive comparison of molecular phenotypes and possible functions of quantified oncoproteins, tumor suppressors, phosphatases and kinases between GIST subgroups was carried out. Immunohistochemical analysis of the phosphatase PTPN1 ( = 117) revealed that the GIST patients with high PTPN1 expression had low chances of developing metastasis. Collectively, this work provides valuable information for understanding the inherent biology and evolution of GIST. 10.1074/mcp.RA119.001361
SPK1/S1P axis confers gastrointestinal stromal tumors (GISTs) resistance of imatinib. Gastric cancer : official journal of the International Gastric Cancer Association and the Japanese Gastric Cancer Association BACKGROUND:Imatinib mesylate (IM) is highly effective in the treatment of gastrointestinal stromal tumors (GISTs). However, the most of GISTs patients develop secondary drug resistance after 1-3 years of IM treatment. The aim of this study was to explore the IM-resistance mechanism via the multi-scope combined with plasma concentration of IM, genetic polymorphisms and plasma sensitive metabolites. METHODS:This study included a total of 40 GISTs patients who had been regularly treated and not treated with IM. The plasma samples were divided into three experiments, containing therapeutic drug monitoring (TDM), OCT1 genetic polymorphisms and non-targeted metabolomics. According to the data of above three experiments, the IM-resistant cell line, GIST-T1/IMR cells, was constructed for verification the IM-resistance mechanism. RESULTS:The results of non-targeted metabolomics analysis suggested that the sphingophospholipid metabolic pathway including the SPK1/S1P axis was inferred in IM-insensitive patients with GISTs. A GIST cell line (GIST-T1) was immediately induced as an IM resistance cell model (GIST-T1/IMR) and we found that blocking the signal pathway of SPK1/S1P in the GIST-T1/IMR could sensitize treatment of IM and reverse the IM-resistance. CONCLUSIONS:Our findings suggest that IM secondary resistance is associated with the elevation of S1P, and blockage the signaling pathway of SPK1/S1P warrants evaluation as a potential therapeutic strategy in IM-resistant GISTs. The design of this study from blood management, group information collection, IM plasma concentration with different elements, identification of sphingolipid metabolism and lastly verification the function of SPK1/S1P in the IM-resistance GISTs cells. 10.1007/s10120-022-01332-7
FoxM1 is regulated by both HIF-1α and HIF-2α and contributes to gastrointestinal stromal tumor progression. Bai Chenguang,Liu Xiaohong,Qiu Cen,Zheng Jianming Gastric cancer : official journal of the International Gastric Cancer Association and the Japanese Gastric Cancer Association BACKGROUND:FoxM1 plays important regulatory roles in a variety of diseases. However, the functional role of FoxM1 and mechanisms responsible for its expression in gastrointestinal stromal tumor (GIST) is not thoroughly understood. METHODS:FoxM1 protein expression and biological function were examined in human GIST tissues and cells using immunohistochemistry, quantitative real-time PCR, western blot, CCK-8, wound-healing- and Matrigel invasion assays, respectively. The role of hypoxia-inducible factor (HIF) signaling in FoxM1 expression was investigated using chromatin immunoprecipitation and luciferase reporter and in vivo tumor growth assays. RESULTS:FoxM1 was highly expressed in highly proliferative and migratory/invasive GIST specimens. Upregulation of FoxM1 was positively correlated with the expression of HIF-1α and HIF-2α in GIST specimens, and hypoxia-induced FoxM1 expression in GIST cells. Functionally, ectopic expression of FoxM1 significantly promoted GIST cell proliferation, cell cycle progression, migration and invasion, whereas the knockdown of endogenous FoxM1 of hypoxic GIST cells had the opposite effects. Molecularly, FoxM1 was transcriptionally regulated by HIF-2α under normoxia, whereas it was upregulated by both HIF-1α and HIF-2α under hypoxia. The xenograft tumor data further confirmed the regulated effect of HIF-1α and HIF-2α on FoxM1, and demonstrated that the simultaneous downregulation of both HIF-1α and HIF-2α inhibited GIST tumor growth. CONCLUSIONS:Our data demonstrated the critical role of FoxM1 in promoting GIST progression and uncovered a novel HIF-1α/HIF-2α-FoxM1 axis. These findings identify FoxM1 as a possible new molecular target for designing novel therapeutic treatments to control GIST progression. 10.1007/s10120-018-0846-6
The Incidence of Gastrointestinal Stromal Tumors in Obese Patients-A Large Single Center Experience. Dowgiałło-Gornowicz Natalia,Sztaba Klaudia,Lech Paweł,Botulińska Anna,Michalik Maciej Medicina (Kaunas, Lithuania) : Gastrointestinal stromal tumors (GISTs) are rare mesenchymal neoplasms located mainly in the fundus (60-70%). The incidence of GIST is approximately 10 per million population per year in Europe, with a peak incidence at the age of 63. Recent studies suggest that morbidly obese patients have a higher incidence of GIST than the general population. The aim of this study was to analyze the incidence of GIST in patients undergoing laparoscopic sleeve gastrectomy (LSG) in our department. : this paper present the retrospective study of prospectively collected data of 1564 patients who underwent LSG in a single large bariatric center from October 2013 to September 2021. After surgery, each sample of the resected stomach was sent for histopathological examination. For the analysis, we included patients diagnosed with GIST intraoperatively or postoperatively. : GISTs were found in five patients (0.31%). There were three men and two women. The mean age was 50.2 (range 32-63 ± 11.8) and the mean preoperative body mass index was 43.3 kg/m (40-49.4 ± 3.2). In four cases, GISTs were found in the fundus (80%), and in one in the pylorus (20%). None of the tumors were larger than 7 mm in diameter and all were diagnosed as a very low-risk category. No adjuvant treatment was required. All patients achieved good or satisfactory bariatric and metabolic results. : The incidence of GIST in our study was estimated at 0.31%. All patients had a very low-risk GIST and no recurrence until follow-up. Recent literature suggests that the risk of GIST is higher in the obese population, and therefore surgeons should be aware of the risk of incidental GIST during LSG. 10.3390/medicina57111242
Identification of long intergenic non-coding RNAs (lincRNAs) deregulated in gastrointestinal stromal tumors (GISTs). Gyvyte Ugne,Kupcinskas Juozas,Juzenas Simonas,Inciuraite Ruta,Poskiene Lina,Salteniene Violeta,Link Alexander,Fassan Matteo,Franke Andre,Kupcinskas Limas,Skieceviciene Jurgita PloS one Long intergenic non-coding RNAs (lincRNAs) are >200 nucleotides long non-coding RNAs, which have been shown to be implicated in carcinogenic processes by interacting with cancer associated genes or other non-coding RNAs. However, their role in development of rare gastrointestinal stromal tumors (GISTs) is barely investigated. Therefore, the aim of this study was to define lincRNAs deregulated in GIST and find new GIST-lincRNA associations. Next-generation sequencing data of paired GIST and adjacent tissue samples from 15 patients were subjected to a web-based lincRNA analysis. Three deregulated lincRNAs (MALAT1, H19 and FENDRR; adjusted p-value < 0.05) were selected for expression validation in a larger group of patients (n = 22) by RT-qPCR method. However, only H19 and FENDRR showed significant upregulation in the validation cohort (adjusted p < 0.05). Further, we performed correlation analyses between expression levels of deregulated lincRNAs and GIST-associated oncogenes or GIST deregulated microRNAs. We found high positive correlations between expression of H19 and known GIST related oncogene ETV1, and between H19 and miR-455-3p. These findings expand the knowledge on lincRNAs deregulated in GIST and may be an important resource for the future studies investigating lincRNAs functionally relevant to GIST carcinogenesis. 10.1371/journal.pone.0209342
The role of metabolic enzymes in mesenchymal tumors and tumor syndromes: genetics, pathology, and molecular mechanisms. Laboratory investigation; a journal of technical methods and pathology The discovery of mutations in genes encoding the metabolic enzymes isocitrate dehydrogenase (IDH), succinate dehydrogenase (SDH), and fumarate hydratase (FH) has expanded our understanding not only of altered metabolic pathways but also epigenetic dysregulation in cancer. IDH1/2 mutations occur in enchondromas and chondrosarcomas in patients with the non-hereditary enchondromatosis syndromes Ollier disease and Maffucci syndrome and in sporadic tumors. IDH1/2 mutations result in excess production of the oncometabolite (D)-2-hydroxyglutarate. In contrast, SDH and FH act as tumor suppressors and genomic inactivation results in succinate and fumarate accumulation, respectively. SDH deficiency may result from germline SDHA, SDHB, SDHC, or SDHD mutations and is found in autosomal-dominant familial paraganglioma/pheochromocytoma and Carney-Stratakis syndrome, describing the combination of paraganglioma and gastrointestinal stromal tumor (GIST). In contrast, patients with the non-hereditary Carney triad, including paraganglioma, GIST, and pulmonary chondroma, usually lack germline SDH mutations and instead show epigenetic SDH complex inactivation through SDHC promoter methylation. Inactivating FH germline mutations are found in patients with hereditary leiomyomatosis and renal cell cancer (HLRCC) syndrome comprising benign cutaneous/uterine leiomyomas and renal cell carcinoma. Mutant IDH, SDH, and FH share common inhibition of α-ketoglutarate-dependent oxygenases such as the TET family of 5-methylcytosine hydroxylases preventing DNA demethylation, and Jumonji domain histone demethylases increasing histone methylation, which together inhibit cell differentiation. Ongoing studies aim to better characterize these complex alterations in cancer, the different clinical phenotypes, and variable penetrance of inherited and sporadic cancer predisposition syndromes. A better understanding of the roles of metabolic enzymes in cancer may foster the development of therapies that specifically target functional alterations in tumor cells in the future. Here, the physiologic functions of these metabolic enzymes, the mutational spectrum, and associated functional alterations will be discussed, with a focus on mesenchymal tumor predisposition syndromes. 10.1038/s41374-017-0003-6
BRD4 promotes tumor progression and NF-κB/CCL2-dependent tumor-associated macrophage recruitment in GIST. Mu Jianfeng,Sun Pengfei,Ma Zhiming,Sun Pengda Cell death & disease The most commonly occurring sarcoma of the soft tissue is gastrointestinal stromal tumor (GIST). Treatment and prevention of the disease necessitate an understanding of the molecular mechanisms involved. However, the role of BRD4 in the progression of GIST is still unclear. While it is known there are abundant infiltrating tumor-associated macrophages (TAMs) in the tumor microenvironment, the exact role of these cells has yet to be studied. This work showed an upregulation of BRD4 in GIST that was associated with GIST prognosis. Through gain and loss of function studies, it was found that BRD4 promotes GIST growth and angiogenesis in vitro and in vivo. Mechanistically, BRD4 enhances CCL2 expression by activating the NF-κB signaling pathway. Furthermore, this CCL2 upregulation causes recruitment of macrophages into the tumor leading to tumor growth. A likely mechanism for interactions in the GIST microenvironment has been outlined by this work to show the role and potential use of BRD4 as a treatment target in GIST. 10.1038/s41419-019-2170-4
Systemic therapy of advanced/metastatic gastrointestinal stromal tumors: an update on progress beyond imatinib, sunitinib, and regorafenib. Mohammadi Mahmoud,Gelderblom Hans Expert opinion on investigational drugs : Discovery of oncogenic mutations in the KIT and PDGFRA tyrosine kinase receptor was a crucial step for the development of tyrosine kinase inhibitors (TKIs). Since then, GIST became a model for the development of molecular-targeted therapy, which led to dramatically improved median overall survival of advanced GIST. Still, further progress is needed after third-line or for TKI resistant mutations. : In this review, after a brief introduction on imatinib, sunitinib, and regorafenib, an overview of TKIs that was evaluated beyond these drugs is provided, with a main focus on the novel approved TKIs. : Combination therapies have thus far not fulfilled their promise in GIST, nor did immunotherapy. Increased understanding of GIST and advances in the development of molecular-targeted drugs led to the introduction of ripretinib and avapritinib. Furthermore, NTRK inhibitors became available for ultrarare NTRK fusions. Solutions for NF1 and BRAF mutated and SDH-deficient GIST are still to be awaited. This all underlines the need for adequate molecular profiling of high-risk GISTs before treatment is started. Possibly by using circulating tumor DNA in the future, targeting resistance mutations with specific drugs along the course of the disease would be easier, avoiding multiple tumor biopsies. 10.1080/13543784.2021.1857363
CYP2D6 and CYP2C8 pharmacogenetics and pharmacological interactions to predict imatinib plasmatic exposure in GIST patients. British journal of clinical pharmacology AIMS:Patients on treatment with oral fixed dose imatinib are frequently under- or overexposed to the drug. We investigated the association between the gene activity score (GAS) of imatinib-metabolizing cytochromes (CYP3A4, CYP3A5, CYP2D6, CYP2C9, CYP2C19, CYP2C8) and imatinib and nor-imatinib exposure. We also investigated the impact of concurrent drug-drug-interactions (DDIs) on the association between GAS and imatinib exposure. METHODS:Serial plasma samples were collected from 33 GIST patients treated with imatinib 400 mg daily within a prospective clinical trial. Imatinib and nor-imatinib C were quantified by liquid chromatography with tandem mass spectrometry (LC-MS/MS). Genetic polymorphisms with a functional impact on imatinib-metabolizing cytochromes were identified and a GAS was calculated for each gene. A DDI-adjusted GAS was also generated. RESULTS:Imatinib and nor-imatinib C were measured in 161 plasma samples. CYP2D6 GAS and metabolizer status based on genotype were associated with imatinib and (imatinib + nor-imatinib) C . CYP2D6 poor and intermediate metabolizers were predicted to have a lower nor-imatinib/imatinib metabolic ratio than normal metabolizers (0.197 and 0.193 vs. 0.247, P = .0205), whereas CYP2C8*3 carriers had a higher ratio than CYP2C8*1/*1 patients (0.263 vs. 0.201, P = .0220). CYP2C9 metabolizer status was inversely related to the metabolic ratio with an effect probably driven by the linkage disequilibrium between CYP2C9*2 and CYP2C8*3. The CYP2D6 DDI-adjusted GAS was still predictive of imatinib exposure. CONCLUSIONS:These findings highlight that CYP2D6 plays a major role in imatinib pharmacokinetics, but other players (i.e., CYP2C8) may influence imatinib exposure. These findings could drive the selection of patients more susceptible to imatinib under- or overexposure who could be candidates for personalized treatment and intensified monitoring strategies. 10.1111/bcp.15551
Immune-infiltration based signature as a novel prognostic biomarker in gastrointestinal stromal tumour. Wei Zhe-Wei,Wu Jing,Huang Wei-Bin,Li Jin,Lu Xiao-Fang,Yuan Yu-Jie,Xiong Wen-Jun,Zhang Xin-Hua,Wang Wei,He Yu-Long,Zhang Chang-Hua EBioMedicine BACKGROUND:Accumulating evidence indicates that tumour-infiltrating lymphocytes (TILs) are the primary determinant of survival outcomes in various tumours. Thus, we sought to investigate the TIL distribution and density in gastrointestinal stromal tumours (GISTs) and to develop an immune infiltration (II)-based signature to predict prognosis. METHODS:The expression of 8 immune features in the tumour centre (TC) and tumour margin (TM) and PD-L1 in 435 GIST patients was investigated by immunohistochemistry. Then, a 4-feature-based II-GIST signature integrating the CD3 TC, CD3 TM, CD8 TM and CD45RO TM parameters was developed using a LASSO Cox regression model in the training cohort and was validated in two separate validation cohorts. FINDINGS:High CD3 TC, CD3 TM, CD8 TC, CD8 TM, CD45RO TM, NKp46 TM and CD20 TM correlated with improved survival. Patients with high II-GIST scores have better RFS and OS outcomes than those with low II-GIST scores. Multivariable analyses demonstrated that the II-GIST signature is an independent prognostic factor. The receiver operating characteristic (ROC) curve demonstrated that the prognostic accuracy of the II-GIST signature is superior to that of the NIH risk criteria. Further analysis showed that moderate- and high-risk GIST patients with high II-GIST scores could gain survival benefits from adjuvant imatinib therapy. INTERPRETATION:The novel II-GIST signature accurately predicted the survival outcomes of GIST patients. In addition, the II-GIST signature was a useful predictor of survival benefit from imatinib therapy amongst moderate- and high-risk patients with GIST. FUNDING:This project was supported by National Natural Science Foundation of China (81702325), Natural Science Foundation of Guangdong Province (2017A030310565), and 3&3 Project of the First Affiliated Hospital of Sun Yat-sen University. 10.1016/j.ebiom.2020.102850
Dual Targeting of Insulin Receptor and KIT in Imatinib-Resistant Gastrointestinal Stromal Tumors. Chen Weicai,Kuang Ye,Qiu Hai-Bo,Cao Zhifa,Tu Yuqing,Sheng Qing,Eilers Grant,He Quan,Li Hai-Long,Zhu Meijun,Wang Yuexiang,Zhang Rongqing,Wu Yeqing,Meng Fanguo,Fletcher Jonathan A,Ou Wen-Bin Cancer research Oncogenic KIT or PDGFRA receptor tyrosine kinase (RTK) mutations are compelling therapeutic targets in gastrointestinal stromal tumors (GIST), and treatment with the KIT/PDGFRA inhibitor imatinib is the standard of care for patients with metastatic GIST. Most GISTs eventually acquire imatinib resistance due to secondary mutations in the KIT kinase domain, but it is unclear whether these genomic resistance mechanisms require other cellular adaptations to create a clinically meaningful imatinib-resistant state. Using phospho-RTK and immunoblot assays, we demonstrate activation of KIT and insulin receptor (IR) in imatinib-resistant GIST cell lines (GIST430 and GIST48) and biopsies with acquisition of secondary mutations, but not in imatinib-sensitive GIST cells (GIST882 and GIST-T1). Treatment with linsitinib, a specific IR inhibitor, inhibited IR and downstream intermediates AKT, MAPK, and S6 in GIST430 and GIST48, but not in GIST882, exerting minimal effect on KIT phosphorylation in these cell lines. Additive effects showing increased apoptosis, antiproliferative effects, cell-cycle arrest, and decreased pAKT and pS6 expression, tumor growth, migration, and invasiveness were observed in imatinib-resistant GIST cells with IR activation after coordinated inhibition of IR and KIT by linsitinib (or shRNA) and imatinib, respectively, compared with either intervention alone. IGF2 overexpression was responsible for IR activation in imatinib-resistant GIST cells, whereas IR activation did not result from amplification, mutation, or KIT phosphorylation. Our findings suggest that combinatorial inhibition of IR and KIT warrants clinical evaluation as a novel therapeutic strategy in imatinib-resistant GISTs. . 10.1158/0008-5472.CAN-17-0917
Clinicopathological value of long non-coding RNA profiles in gastrointestinal stromal tumor. PeerJ BACKGROUND:Long non-coding RNAs (lncRNAs) have been implicated in diagnosis and prognosis in various cancers. However, few lncRNA signatures have been established for prediction of gastrointestinal stromal tumors (GIST). We aimed to explore a lncRNA signature profile that associated with clinical relevance by mining data from Gene Expression Ominus (GEO) and Surveillance, Epidemiology, and End Results (SEER) Program. METHODS:Using a lncRNA-mining approach, we performed non-negative matrix factorization (NMF) consensus algorithm in Gastrointestinal stromal tumors (GISTs) cohorts (61 patients from GSE8167 and GSE17743) to cluster LncRNA expression profiles. Comparative markers selection, and Gene Set Enrichment Analysis (GSEA) algorithm were performed between distinct molecular subtypes of GIST. The survival rate of GIST patients from SEER stratified by gender were compared by Kaplan-Meier method and log-rank analysis. lncRNA-mRNA co-expression analysis was performed by Pearson correlation coefficients (PCC) using R package LINC. Somatic copy number alterations of GIST patients (GSE40966) were analyzed web server GenePattern GISTIC2 algorithm. RESULTS:A total of four lncRNA molecular subtypes of GIST were identified with distinct biological pathways and clinical characteristics. LncRNA expression profiles well clustered the GIST samples into small size (<5 mm) and large size tumors (>5 mm), which is a fundamental index for GIST malignancy diagnosis. Several lncRNAs with abundant expression (LRRC75A-AS1, HYMAI, NEAT1, XIST and FTX) were closely associated with tumor size, which may suggest to be biomarkers for the GIST malignancy. Particularly, LRRC75A-AS1 was positively associated with tumor diameters and suggested an oncogene in GIST. Co-expression analysis suggested that chromosome region 17p11.2-p12 may contribute to the oncogenic process in malignant GIST. Interestingly, the gender had a strong influence on clustering by lncRNA expression profile. Data from the Surveillance, Epidemiology, and End Results (SEER) Program were further explored and 7983 patients who were diagnosed with GISTs from 1973 to 2014 were enrolled for analysis. The results also showed the favorable prognosis for female patients. The survival rate between male and female with GIST was statistically significant ( < 0.0001). Gene set enrichment analysis (GSEA) indicated distinct pathways between female and male, and malignant GIST was associated with several cancer metabolism and cell cycle associated pathways. CONCLUSIONS:This lncRNAs-based classification for GISTs may provide a molecular classification applicable to individual GIST that has implications to influence lncRNA markers selection and prediction of tumor progression. 10.7717/peerj.11946
Non-Coding RNAs, a Novel Paradigm for the Management of Gastrointestinal Stromal Tumors. Amirnasr Azadeh,Sleijfer Stefan,Wiemer Erik A C International journal of molecular sciences Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal malignancies found in the gastrointestinal tract. At a molecular level, most GISTs are characterized by gain-of-function mutations in V-Kit Hardy-Zuckerman 4 Feline Sarcoma Viral Oncogene Homolog () and Platelet Derived Growth Factor Receptor Alpha (), leading to constitutive activated signaling through these receptor tyrosine kinases, which drive GIST pathogenesis. In addition to surgery, treatment with the tyrosine kinase inhibitor imatinib forms the mainstay of GIST treatment, particularly in the advanced setting. Nevertheless, the majority of GISTs develop imatinib resistance. Biomarkers that indicate metastasis, drug resistance and disease progression early on could be of great clinical value. Likewise, novel treatment strategies that overcome resistance mechanisms are equally needed. Non-coding RNAs, particularly microRNAs, can be employed as diagnostic, prognostic or predictive biomarkers and have therapeutic potential. Here we review which non-coding RNAs are deregulated in GISTs, whether they can be linked to specific clinicopathological features and discuss how they can be used to improve the clinical management of GISTs. 10.3390/ijms21186975
Differential quantities of immune checkpoint-expressing CD8 T cells in soft tissue sarcoma subtypes. Klaver Yarne,Rijnders Maud,Oostvogels Astrid,Wijers Rebecca,Smid Marcel,Grünhagen Dirk,Verhoef Cornelis,Sleijfer Stefan,Lamers Cor,Debets Reno Journal for immunotherapy of cancer INTRODUCTION:Local T-cell immunity is recognized for its contribution to the evolution and therapy response of various carcinomas. Here, we investigated characteristics of tumor-infiltrating lymphocytes (TILs), as well as T-cell evasive mechanisms in different soft tissue sarcoma (STS) subtypes. METHODS:Liposarcoma, gastrointestinal stromal tumor (GIST), leiomyosarcoma, myxofibrosarcoma and pleomorphic sarcomas were assessed for T-cell numbers and phenotypes using flow cytometry. Next-generation sequencing was used to analyze T-cell receptor repertoire, mutational load, immune cell frequencies, and expression of immune-related genes. RESULTS:GIST, myxofibrosarcoma and pleomorphic sarcoma showed high numbers of CD8+ TILs, with GIST having the lowest fraction of effector memory T cells. These TILs coexpress the immune checkpoints PD1, TIM3, and LAG3 in myxofibrosarcoma and pleomorphic sarcoma, yet TILs coexpressing these checkpoints were near negligible in GIST. Fractions of dominant T-cell clones among STS subtypes were lowest in GIST and liposarcoma, whereas mutational load was relatively low in all STS subtypes. Furthermore, myeloid-derived cells and expression of the costimulatory ligands CD86, ICOS-L and 41BB-L were lowest in GIST when compared with other STS subtypes. CONCLUSION:STS subtypes differ with respect to number and phenotypical signs of antitumor responsiveness of CD8+ TILs. Notably, GIST, myxofibrosarcoma and pleomorphic sarcoma harbor high numbers of CD8+ T cells, yet in the GIST microenvironment, these T cells are less differentiated and non-exhausted, which is accompanied with a relatively low expression of costimulatory ligands. 10.1136/jitc-2019-000271
Potential Value of Circular RNA circTBC1D4 in Gastrointestinal Stromal Tumors. Journal of immunology research Aims:To explore the expression of circular RNA (circRNA) in gastrointestinal stromal tumors. Background:Gastrointestinal stromal tumors (GIST) are mainly distributed in the stomach and small intestine. Recently, it has been verified that circular RNA (circRNA) has an important function in the regulation of GIST. Nevertheless, detailed investigations of circRNA-miRNA-mRNA regulatory networks in GIST are lacking. Objective:To analyze the gastrointestinal stromal tumor circRNA-miRNA-mRNA network, assessing the effect of circle RNA in gastrointestinal stromal tumors. Method:All the differential circRNAs and mRNAs were obtained from Gene Expression Omnibus (GEO) microarray data (GSE131481 and GSE147303, GSE131481, and GSE13861). Furthermore, a circRNA-miRNA-mRNA network was established. Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment were used to reveal the correlation between the functions of signaling pathways and target genes. The hub genes of protein-protein interaction (PPI) network and cytoHubba were also defined. Quantitative real-time PCR (qRT-PCR) was used to measure the expression levels of hsa-circ-0002917 (circTBC1D4), hsa-miR-590-5p (miR-590-5p), and PLN. Results:PPI network and Cytoscape showed that ATP1A2, PLN, KCNMA1, and SCNN1B were four central DEGs. GO analysis results revealed that DEGs were involved in negative management of myocardial contraction, regulation of myocardial cell contraction, ethanol oxidation, cellular potassium ion homeostasis, and relaxation of cardiac muscle, and KEGG analysis showed that major DEGs were with cGMP-PKG signaling pathway. Moreover, we obtained two pairs of axes, namely, hsa-circ-0039216/hsa-miR-338-3p/ATP1A2 and hsa-circ-0002917/hsa-miR-590-5p/PLN. The target of TBC1D4 is miR-590-5p, and miR-590-5p increased after knocking down TBC1D4. Moreover, PLN was the target of miR-590-5p, and miR-590-5p exerts antitumor effects by reducing PLN. Conclusions:In this study, we constructed a circRNA-miRNA-mRNA management network interrelated with GIST and researched the potential roles of circRNA. Moreover, we discovered a new molecular landmarker for the prediction, diagnosis, and therapy of patients. 10.1155/2022/9019097
HAND1 and BARX1 Act as Transcriptional and Anatomic Determinants of Malignancy in Gastrointestinal Stromal Tumor. Clinical cancer research : an official journal of the American Association for Cancer Research PURPOSE:Gastrointestinal stromal tumor (GIST) arises from interstitial cells of Cajal (ICC) or their precursors, which are present throughout the gastrointestinal tract. Although gastric GIST is commonly indolent and small intestine GIST more aggressive, a molecular understanding of disease behavior would inform therapy decisions in GIST. Although a core transcription factor (TF) network is conserved across GIST, accessory TFs HAND1 and BARX1 are expressed in a disease state-specific pattern. Here, we characterize two divergent transcriptional programs maintained by HAND1 and BARX1, and evaluate their association with clinical outcomes. EXPERIMENTAL DESIGN:We evaluated RNA sequencing and TF chromatin immunoprecipitation with sequencing in GIST samples and cultured cells for transcriptional programs associated with HAND1 and BARX1. Multiplexed tissue-based cyclic immunofluorescence and IHC evaluated tissue- and cell-level expression of TFs and their association with clinical factors. RESULTS:We show that HAND1 is expressed in aggressive GIST, modulating and core TF expression and supporting proliferative cellular programs. In contrast, BARX1 is expressed in indolent and micro-GISTs. HAND1 and BARX1 expression were superior predictors of relapse-free survival, as compared with standard risk stratification, and they predict progression-free survival on imatinib. Reflecting the developmental origins of accessory TF programs, HAND1 was expressed solely in small intestine ICCs, whereas BARX1 expression was restricted to gastric ICCs. CONCLUSIONS:Our results define anatomic and transcriptional determinants of GIST and molecular origins of clinical phenotypes. Assessment of HAND1 and BARX1 expression in GIST may provide prognostic information and improve clinical decisions on the administration of adjuvant therapy. 10.1158/1078-0432.CCR-20-3538
Coordinated targeting of CK2 and KIT in gastrointestinal stromal tumours. Huang Mengyuan,Yang Wenyu,Zhu Jiaqing,Mariño-Enríquez Adrián,Zhu Chennianci,Chen Jiaming,Wu Yuehong,Quan Yanping,Qiu Haibo,Li Xuhui,Chai Li,Fletcher Jonathan A,Ou Wen-Bin British journal of cancer BACKGROUND:Most gastrointestinal stromal tumours (GIST) are driven by activating oncogenic mutations of KIT/PDGFRA, which provide a compelling therapeutic target. Our previous studies showed that CDC37, regulated by casein kinase 2 (CK2), is a crucial HSP90 cofactor for KIT oncogenic function and a promising and more selective therapeutic target in GIST. METHODS:Biologic mechanisms of CK2-mediated CDC37 regulation were assessed in GISTs by immunoblotting, immunoprecipitations, knockdown and inactivation assays. The effects of a combination of KIT and CK2 inhibition were assessed by immunoblotting, cell viability, colony growth, cell cycle analysis, apoptosis, migration and invasiveness. RESULTS:CK2 overexpression was demonstrated by immunoblotting in GIST cell lines and patient biopsies. Treatment with a specific CK2 inhibitor, CX4945, leads to CDC37 dephosphorylation and inhibits KIT signalling in imatinib-sensitive and in imatinib-resistant GIST cell lines. Immunoprecipitation demonstrated that CK2 inhibition blocks KIT:HSP90:CDC37 interaction in GIST cells. Coordinated inhibition of CK2 and KIT by CX4945 (or CK2 shRNA) and imatinib, respectively, leads to increased apoptosis, anti-proliferative effects and cell cycle arrest and decreased p-AKT and p-S6 expression, migration and invasiveness in all GIST cell lines compared with either intervention alone, indicating additive effects of inhibiting these two important regulators of GIST biology. CONCLUSION:Our findings suggest that combinatorial inhibition of CK2 and KIT warrants evaluation as a novel therapeutic strategy in GIST, especially in imatinib-resistant GIST. 10.1038/s41416-019-0657-5
Identification of New Tumor-Related Gene Mutations in Chinese Gastrointestinal Stromal Tumors. Feng Yuyang,Yao Surui,Pu Zhening,Cheng Han,Fei Bojian,Zou Jian,Huang Zhaohui Frontiers in cell and developmental biology Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. As the main GIST drivers, gain-of-function mutations in or are closely associated with not only tumor development and progression but also therapeutic response. In addition to the status of KIT and PDGFRA, little is known about other potential GIST-related genes. In this study, we identified the mutation profiles in 49 KIT-mutated GIST tumors using the whole exome sequencing (WES) method. Furthermore, some representative mutations were further validated in an independent GIST cohort using the SNaPshot SNP assay. We identified extensive and diverse mutations of KIT in GIST, including many undescribed variants. In addition, we revealed some new tumor-related gene mutations with unknown pathogenicity. By enrichment analyses of gene function and protein-protein interaction network construction, we showed that these genes were enriched in several important cancer- or metabolism-related signaling pathways, including PI3K-AKT,RTK-RAS, Notch, Wnt, Hippo, mTOR, AMPK, and insulin signaling. In particular, DNA repair-related genes, including , , , , and , are frequently mutated in GISTs, suggesting that immune checkpoint blockade may have promising clinical applications for these GIST subpopulations. In conclusion, in addition to extensive and diverse mutations of , some genes related to DNA-repair and cell metabolism may play important roles in the development, progression and therapeutic response of GIST. 10.3389/fcell.2021.764275
The microphthalmia-associated transcription factor is involved in gastrointestinal stromal tumor growth. Cancer gene therapy Gastrointestinal stromal tumors (GISTs) are the most common neoplasms of mesenchymal origin, and most of them emerge due to the oncogenic activation of KIT or PDGFRA receptors. Despite their relevance in GIST oncogenesis, critical intermediates mediating the KIT/PDGFRA transforming program remain mostly unknown. Previously, we found that the adaptor molecule SH3BP2 was involved in GIST cell survival, likely due to the co-regulation of the expression of KIT and Microphthalmia-associated transcription factor (MITF). Remarkably, MITF reconstitution restored KIT expression levels in SH3BP2 silenced cells and restored cell viability. This study aimed to analyze MITF as a novel driver of KIT transforming program in GIST. Firstly, MITF isoforms were characterized in GIST cell lines and GIST patients' samples. MITF silencing decreases cell viability and increases apoptosis in GIST cell lines irrespective of the type of KIT primary or secondary mutation. Additionally, MITF silencing leads to cell cycle arrest and impaired tumor growth in vivo. Interestingly, MITF silencing also affects ETV1 expression, a linage survival factor in GIST that promotes tumorigenesis and is directly regulated by KIT signaling. Altogether, these results point to MITF as a key target of KIT/PDGFRA oncogenic signaling for GIST survival and tumor growth. 10.1038/s41417-022-00539-1
Tumor-associated macrophages mediate gastrointestinal stromal tumor cell metastasis through CXCL2/CXCR2. Cellular immunology BACKGROUND:Tumor-associated macrophages (TAMs) are linked with the progression and poor prognosis of multifarious solid tumors, but the regulatory mechanisms involved in gastrointestinal stromal tumors (GIST) remain indistinct. This study intended to delve into the job of TAM-derived chemokines in promoting metastasis in GIST microenvironment. METHODS:Expression levels of M2-TAM markers and CXCL2 in primary and metastatic tissues of GIST were analyzed by bioinformatics methods, and we analyzed the correlation between CXCL2 and M2-TAM markers. Immunofluorescence was applied to assay CXCL2 and M2-TAM marker protein (CD68 and CD206) expression in tumor tissues. Serum CXCL2 concentration in metastatic and non-metastatic patients was assayed by ELISA. The differentiation of THP-1 cells was tested by flow cytometry. Cell function test was utilized to analyze the viability, invasion and migration of GIST cells. Western blot was used to examine the expression of epithelial-mesenchymal transition (EMT)-related proteins. The mouse liver metastasis model was established, and the effects of CXCL2 and EMT-related genes on metastasis were confirmed by hematoxylin-eosin staining and immunohistochemistry experiments. RESULTS:Bioinformatics analysis ascertained that M2-TAM marker proteins and chemokine CXCL2 were highly expressed in GIST metastatic tissues, and CXCL2 and TAM were co-located in tumor tissues. Results of in vitro cell function experiments displayed that CXCL2 secreted by M2-TAM promoted the invasion, migration and EMT of GIST tumor cells, and the anti-CXCL2 antibody could block the metastasis promoting effect of CXCL2. Additionally, the silencing of CXCR2 in GIST cells inhibited the metastasis promoting effect of CXCL2. Animal studies further confirmed that CXCL2 promoted liver metastasis of GIST in vivo. CONCLUSION:This study preliminarily revealed the mechanism of M2-TAM promoting tumor metastasis by secreting CXCL2 in GIST tumor microenvironment, and proffered theoretical reference for the development of immunotherapy strategies targeting M2-TAM. 10.1016/j.cellimm.2022.104642
Immune Infiltration, Cancer Stemness, and Targeted Therapy in Gastrointestinal Stromal Tumor. Wang Jingjing,Ren Hui,Wu Wenhui,Zeng Qianlin,Chen Jingyao,Han Juanjuan,Lin Minquan,Zhang Changhua,He Yulong,Li Mingzhe Frontiers in immunology Objective:To investigate the characteristics of the tumor immune microenvironment in patients with gastrointestinal stromal tumor (GIST) and identify cancer stem-like properties of GIST to screen potential druggable molecular targets. Methods:The gene expression data of 60 patients with GIST was retrieved from the Array Express database. CIBERSORT was applied to calculate the level of immune infiltration. ssGSEA and ESTIMATE were used to calculate the cancer stemness index and tissue purity. The Connectivity Map (CMAP) database was implemented to screen targeted drugs based on cancer stem-like properties of GIST. Result:There was a difference in the level of immune infiltration between the metastasis and non-metastasis GIST groups. The low level of T-cell infiltration was correlated with high tumor purity and tumor stemness index, and the correlation coefficients were -0.87 and -0.61 (p < 0.001), respectively. Furthermore, there was a positive correlation between cancer stemness index and cell purity (p < 0.001). The cancer stemness index in the metastasis group was higher than that in the non-metastasis group (p = 0.0017). After adjusting for tumor purity, there was no significant correlation between T-cell infiltration and cancer stemness index (p = 0.086). Through the pharmacological mechanism of topoisomerase inhibitors, six molecular complexes may be the targets of GIST treatment. Conclusion:Immune infiltration in GIST patients is related to cancer stem-like properties, and the correlation relies on tumor purity. Cancer stemness index can be used as a new predictive biomarker of tumor metastasis and targets of drug therapy for GIST patients. 10.3389/fimmu.2021.691713
Heterogeneity of Metabolic Vulnerability in Imatinib -Resistant Gastrointestinal Stromal Tumor. Huang Wen-Kuan,Gao Jiwei,Chen Ziqing,Shi Hao,Yuan Juan,Cui Huanhuan L,Yeh Chun-Nan,Bränström Robert,Larsson Catharina,Li Shuijie,Lui Weng-Onn Cells Metabolic reprogramming is a hallmark of cancer cells in response to targeted therapy. Decreased glycolytic activity with enhanced mitochondrial respiration secondary to imatinib has been shown in imatinib-sensitive gastrointestional stromal tumors (GIST). However, the role of energy metabolism in imatinib-resistant GIST remains poorly characterized. Here, we investigated the effect of imatinib treatment on glycolysis and oxidative phosphorylation (OXPHOS), as well as the effect of inhibition of these energy metabolisms on cell viability in imatinib-resistant and -sensitive GIST cell lines. We observed that imatinib treatment increased OXPHOS in imatinib-sensitive, but not imatinib-resistant, GIST cells. Imatinib also reduced the expression of mitochondrial biogenesis activators (peroxisome proliferator-activated receptor coactivator-1 alpha (PGC1α), nuclear respiratory factor 2 (NRF2), and mitochondrial transcription factor A (TFAM)) and mitochondrial mass in imatinib-sensitive GIST cells. Lower TFAM levels were also observed in imatinib-sensitive GISTs than in tumors from untreated patients. Using the Seahorse system, we observed bioenergetics diversity among the GIST cell lines. One of the acquired resistant cell lines (GIST 882R) displayed a highly metabolically active phenotype with higher glycolysis and OXPHOS levels compared with the parental GIST 882, while the other resistant cell line (GIST T1R) had a similar basal glycolytic activity but lower mitochondrial respiration than the parental GIST T1. Further functional assays demonstrated that GIST 882R was more vulnerable to glycolysis inhibition than GIST 882, while GIST T1R was more resistant to OXPHOS inhibition than GIST T1. These findings highlight the diverse energy metabolic adaptations in GIST cells that allow them to survive upon imatinib treatment and reveal the potential of targeting the metabolism for GIST therapy. 10.3390/cells9061333
Pharmacogenetics in the treatment of gastrointestinal stromal tumors - an updated review. Expert opinion on drug metabolism & toxicology INTRODUCTION:Gastrointestinal stromal tumors (GIST) are the best example of a targeted therapy in solid tumors. The introduction of tyrosine kinase inhibitors (TKIs) deeply improved the prognosis of this tumor. However, a degree of inter-patient variability is still reported in response rates and pharmacogenetics may play an important role in the final clinical outcome. AREAS COVERED:In this review, the authors provide an updated overview of the pharmacogenetic literature analyzing the role of polymorphisms in both GIST treatment efficacy and toxicity. EXPERT OPINION:Besides the primary role of somatic DNA in dictating the clinical response to TKIs, several polymorphisms influencing their pharmacokinetics and pharmacodynamics have been identified as being potentially involved. In the last 10 years, many potential biomarkers have been proposed to predict clinical response and toxicity after TKI administration. However, the evidence is still too limited to promote a clinical translation. To date, the somatic mutational status represents the main player in clinical response to TKIs in GIST treatment; however, pharmacogenetics could still explain the degree of inter-patient variability observed in GIST patients. A combination of different theoretical approaches, experimental model systems, and statistical methods is clearly needed, in order to translate pharmacogenetics to clinical practice in the near future. 10.1080/17425255.2020.1789589
Histone demethylase KDM4D promotes gastrointestinal stromal tumor progression through HIF1β/VEGFA signalling. Hu Fuqing,Li Haijie,Liu Lu,Xu Feng,Lai Senyan,Luo Xuelai,Hu Junbo,Yang Xi Molecular cancer BACKGROUND:Gastrointestinal stromal tumour (GIST) is the most common soft tissue sarcoma. The identification of the molecular mechanisms regulating GIST progression is vital for its treatment and prevention. Increasing reports have demonstrated that epigenetic alterations play critical roles in GIST development. However, the role of the histone demethylase KDM4D in GIST progression is poorly understood. METHODS:In clinically matched GIST tissues, KDM4D protein levels were measured by Western blot and immunohistochemical (IHC) staining. KDM4D mRNA levels were examined by quantitative real-time PCR (qRT-PCR). Bioinformatics analysis was used to examine KDM4D expression. The biological effects of KDM4D were investigated in vitro using CCK-8, BrdU/PI, wound healing, colony formation, tube formation and Transwell assays and in vivo using a xenograft mice model. Luciferase assays were used to assess regulation of HIF1β gene promoter activity by KDM4D. ChIP assays were performed to assess KDM4D, H3K36me3 and H3K9me3 occupancy on the HIF1β gene promoter. RESULTS:We observed a significant upregulation of KDM4D in GIST tissue compared with matched normal tissue and further explored the oncogenic function of KDM4D both in vitro and in vivo. Furthermore, we demonstrated that KDM4D directly interacted with the HIF1β gene promoter and regulated its activity, promoting tumour angiogenesis and GIST progression both in vitro and in vivo. Finally, we demonstrated that KDM4D transcriptionally activates HIF1β expression via H3K9me3 and H3K36me3 demethylation at the promoter region. CONCLUSIONS:Our findings reveal the important roles of the KDM4D/HIF1β/VEGFA signalling pathway in GIST progression, and this pathway may act as a potential therapeutic target for GIST patients. 10.1186/s12943-018-0861-6
Preclinical Activity of PI3K Inhibitor Copanlisib in Gastrointestinal Stromal Tumor. García-Valverde Alfonso,Rosell Jordi,Serna Garazi,Valverde Claudia,Carles Joan,Nuciforo Paolo,Fletcher Jonathan A,Arribas Joaquín,Politz Oliver,Serrano César Molecular cancer therapeutics KIT or PDGFRA gain-of-function mutations are the primary drivers of gastrointestinal stromal tumor (GIST) growth and progression throughout the disease course. The PI3K/mTOR pathway is critically involved in the transduction of KIT/PDGFRA oncogenic signaling regardless of the type of primary and secondary mutations, and therefore emerges as a relevant targetable node in GIST biology. We evaluated in GIST preclinical models the antitumor activity of copanlisib, a novel pan-class-I PI3K inhibitor with predominant activity against p110α and p110δ isoforms, as single-agent and in combination with first-line KIT inhibitor imatinib. studies undertaken in one imatinib-sensitive (GIST-T1) and two imatinib-resistant (GIST-T1/670 and GIST430/654) GIST cell models showed that single-agent copanlisib effectively suppressed PI3K pathway activation leading to decreased cell viability and proliferation in both imatinib-sensitive and -resistant cells irrespective of the type of primary or secondary KIT mutations. Simultaneous PI3K and KIT inhibition with copanlisib and imatinib resulted in enhanced impairment of cell viability in both imatinib-sensitive and -resistant GIST cell models, although apoptosis was mostly triggered in GIST-T1. Single-agent copanlisib inhibited GIST growth , and conjoined inhibition of PI3K and KIT was the most active therapeutic intervention in imatinib-sensitive GIST-T1 xenografts. IHC stain for cleaved-caspase 3 and phospho-S6 support a predominant antiproliferative effect of copanlisib in GIST. In conclusion, copanlisib has single-agent antitumor activity in GIST regardless KIT mutational status or sensitivity to imatinib. Effective KIT inhibition is necessary to achieve synergistic or additive effects with the combination of imatinib and any given PI3K/mTOR pathway inhibition. 10.1158/1535-7163.MCT-19-1069
Fibrinogen-like protein 2 in gastrointestinal stromal tumour. Journal of cellular and molecular medicine Gastrointestinal stromal tumour (GIST), the most common sarcoma of the gastrointestinal tract, can be treated effectively with tyrosine kinase inhibitors, such as imatinib. Cancer immune therapy has limited efficacy, and little is known about the immune suppressive factors in GISTs. Fibrinogen-like protein 2 (FGL2) is expressed either as a membrane-associated protein or as a secreted soluble protein that has immune suppressive functions. We found that GISTs expressed FGL2 mRNA highly compared to other types of cancer in a large human cancer transcriptome database. GIST expressed FGL2 frequently also when studied using immunohistochemistry in two large clinical series, where 333 (78%) out of the 425 GISTs were FGL2 positive. The interstitial cells of Cajal, from which GISTs may originate, expressed FGL2. FGL2 expression was associated with small GIST size, low mitotic counts and low tumour-infiltrating lymphocyte (TIL) counts. Patients whose GIST expressed FGL2 had better recurrence-free survival than patients whose GIST lacked expression. Imatinib upregulated FGL2 in GIST cell lines, and the patients with FGL2-negative GIST appeared to benefit most from long duration of adjuvant imatinib. We conclude that GISTs express FGL2 frequently and that FGL2 expression is associated with low TIL counts and favourable survival outcomes. 10.1111/jcmm.17163
Contribution of Interstitial Cells of Cajal to Gastrointestinal Stromal Tumor Risk. Medical science monitor : international medical journal of experimental and clinical research BACKGROUND Gastrointestinal stromal tumors (GISTs), which originate from interstitial cells of Cajal (ICCs), are one of most common mesenchymal tumors of the gastrointestinal tract. This study explored the impact of ICCs and immunological markers on GIST risk. MATERIAL AND METHODS A total of 122 patients diagnosed with GISTs who underwent surgery were recruited for the study. Demographic and clinical information, including modified NIH criteria, sex, age, tumor site, and tumor size, of all patients were collected. GIST risk was assessed using the modified NIH risk classification for primary GISTs. Paraffin-embedded GIST specimens were evaluated by hematoxylin-eosin staining and ICCs immunohistochemistry. RESULTS According to the modified NIH criteria, most GIST cases (44 cases, 36.07%) were at very low risk. Females had greater incidence of high-risk GISTs (P<0.05). The mean age at GIST diagnosis was 58.69±9.90 years and had no impact on GIST risk (P>0.05). Most GISTs were located in the stomach (87 cases, 71.73%), and the size of the tumors varied (0.5-20 cm). CD117/c-kit and CD34 were specific immuno-markers for ICCs and GIST. Most patients with GIST were CD117-positive (115 cases, 94.26%), 111 cases (90.98%) were CD34-positive, and 109 cases (89.34%) were positive for both CD117/c-kit and CD34. With increasing GIST risk, CD117 (also named c-k0it) and CD34 expression levels increased, as well as the number of ICCs (all P<0.05). CONCLUSIONS ICCs have a great impact on GISTs incidence. CD117/c-kit and CD34 expression, as well ICCs levels, appear to affect GIST risk. 10.12659/MSM.929575
FOXF1 Defines the Core-Regulatory Circuitry in Gastrointestinal Stromal Tumor. Ran Leili,Chen Yuedan,Sher Jessica,Wong Elissa W P,Murphy Devan,Zhang Jenny Q,Li Dan,Deniz Kemal,Sirota Inna,Cao Zhen,Wang Shangqian,Guan Youxin,Shukla Shipra,Li Katie Yang,Chramiec Alan,Xie Yuanyuan,Zheng Deyou,Koche Richard P,Antonescu Cristina R,Chen Yu,Chi Ping Cancer discovery The cellular context that integrates upstream signaling and downstream nuclear response dictates the oncogenic behavior and shapes treatment responses in distinct cancer types. Here, we uncover that in gastrointestinal stromal tumor (GIST), the forkhead family member FOXF1 directly controls the transcription of two master regulators, and , both required for GIST precursor-interstitial cells of Cajal lineage specification and GIST tumorigenesis. Further, FOXF1 colocalizes with ETV1 at enhancers and functions as a pioneer factor that regulates the ETV1-dependent GIST lineage-specific transcriptome through modulation of the local chromatin context, including chromatin accessibility, enhancer maintenance, and ETV1 binding. Functionally, FOXF1 is required for human GIST cell growth and murine GIST tumor growth and maintenance The simultaneous control of the upstream signaling and nuclear response sets up a unique regulatory paradigm and highlights the critical role of FOXF1 in enforcing the GIST cellular context for highly lineage-restricted clinical behavior and treatment response. We uncover that FOXF1 defines the core-regulatory circuitry in GIST through both direct transcriptional regulation and pioneer factor function. The unique and simultaneous control of signaling and transcriptional circuitry by FOXF1 sets up an enforced transcriptional addiction to FOXF1 in GIST, which can be exploited diagnostically and therapeutically. . 10.1158/2159-8290.CD-17-0468
Clinical relevance of integrin alpha 4 in gastrointestinal stromal tumours. Pulkka Olli-Pekka,Mpindi John-Patrick,Tynninen Olli,Nilsson Bengt,Kallioniemi Olli,Sihto Harri,Joensuu Heikki Journal of cellular and molecular medicine The molecular mechanisms for the dissemination and metastasis of gastrointestinal stromal tumours (GIST) are incompletely understood. The purpose of the study was to investigate the clinical relevance of integrin alpha 4 (ITGA4) expression in GIST. GIST transcriptomes were first compared with transcriptomes of other types of cancer and histologically normal gastrointestinal tract tissue in the MediSapiens in silico database. ITGA4 was identified as an unusually highly expressed gene in GIST. Therefore, the effects of ITGA4 knock-down and selective integrin alpha 4 beta 1 (VLA-4) inhibitors on tumour cell proliferation and invasion were investigated in three GIST cell lines. In addition, the prognostic role of ITGA4 expression in cancer cells was investigated in a series of 147 GIST patients with immunohistochemistry. Inhibition of ITGA4-related signalling decreased GIST cell invasion in all investigated GIST cell lines. ITGA4 protein was expressed in 62 (42.2%) of the 147 GISTs examined, and expression was significantly associated with distant metastases during the course of the disease and several adverse prognostic features. Patients whose GIST expressed strongly ITGA4 had unfavourable GIST-specific survival and overall survival compared to patients with low or no ITGA4 expression. Taken together, ITGA4 is an important integrin in the molecular pathogenesis of GIST and may influence their clinical behaviour. 10.1111/jcmm.13502
Molecular subtypes of gastrointestinal stromal tumors and their prognostic and therapeutic implications. Szucs Zoltan,Thway Khin,Fisher Cyril,Bulusu Ramesh,Constantinidou Anastasia,Benson Charlotte,van der Graaf Winette Ta,Jones Robin L Future oncology (London, England) Gastrointestinal stromal tumors (GISTs) are composed of various molecular subtypes, with differing prognostic and predictive relevance. Previously, tumors lacking mutations in the KIT and PDGFRA genes have been designated as 'wild-type' GISTs; however, they represent a heterogeneous group currently undergoing further subclassification. Primary and secondary resistance to imatinib poses a significant clinical challenge, therefore ongoing research is trying to evaluate mechanisms to overcome resistance. Thorough understanding of the prognostic and predictive relevance of different genetic subtypes of GIST can guide clinical decision-making both in the adjuvant and the metastatic setting. Further work is required to identify tailored therapies for specific subgroups of GISTs wild-type for KIT and PDGFRA mutations and to identify predictive factors of resistance to currently approved systemic therapies. 10.2217/fon-2016-0192
The Role of miR-375-3p and miR-200b-3p in Gastrointestinal Stromal Tumors. Gyvyte Ugne,Lukosevicius Rokas,Inciuraite Ruta,Streleckiene Greta,Gudoityte Greta,Bekampyte Justina,Valentini Serena,Salteniene Violeta,Ruzgys Paulius,Satkauskas Saulius,Zviniene Kristina,Kupcinskas Juozas,Skieceviciene Jurgita International journal of molecular sciences Deregulated microRNA (miRNA) expression profiles and their contribution to carcinogenesis have been observed in virtually all types of human cancer. However, their role in the pathogenesis of rare mesenchymal gastrointestinal stromal tumors (GISTs) is not well defined, yet. In this study, we aimed to investigate the role of two miRNAs strongly downregulated in GIST-miR-375-3p and miR-200b-3p-in the pathogenesis of GIST. To achieve this, miRNA mimics were transfected into GIST-T1 cells and changes in the potential target gene mRNA and protein expression, as well as alterations in cell viability, migration, apoptotic cell counts and direct miRNA-target interaction, were evaluated. Results revealed that overexpression of miR-375-3p downregulated the expression of KIT mRNA and protein by direct binding to KIT 3'UTR, reduced GIST cell viability and migration rates. MiR-200b-3p lowered expression of ETV1 protein, directly targeted and lowered expression of EGFR mRNA and protein, and negatively affected cell migration rates. To conclude, the present study identified that miR-375-3p and miR-200b-3p have a tumor-suppressive role in GIST. 10.3390/ijms21145151
Establishment of Patient-Derived Succinate Dehydrogenase-Deficient Gastrointestinal Stromal Tumor Models for Predicting Therapeutic Response. Clinical cancer research : an official journal of the American Association for Cancer Research PURPOSE:Gastrointestinal stromal tumor (GIST) is the most common sarcoma of the gastrointestinal tract, with mutant succinate dehydrogenase () subunits (A-D) comprising less than 7.5% (i.e., 150-200/year) of new cases annually in the United States. Contrary to GISTs harboring or mutations, -mutant GISTs affect adolescents/young adults, often metastasize, and are frequently resistant to tyrosine kinase inhibitors (TKI). Lack of human models for any mutant tumors, including GIST, has limited molecular characterization and drug discovery. EXPERIMENTAL DESIGN:We describe methods for establishing novel patient-derived -mutant (m) GIST models and interrogated the efficacy of temozolomide on these tumor models and in clinical trials of patients with m GIST. RESULTS:Molecular and metabolic characterization of our patient-derived m GIST models revealed that these models recapitulate the transcriptional and metabolic hallmarks of parent tumors and SDH deficiency. We further demonstrate that temozolomide elicits DNA damage and apoptosis in our m GIST models. Translating our discovery to the clinic, a cohort of patients with -mutant GIST treated with temozolomide ( = 5) demonstrated a 40% objective response rate and 100% disease control rate, suggesting that temozolomide represents a promising therapy for this subset of GIST. CONCLUSIONS:We report the first methods to establish patient-derived m tumor models, which can be readily employed for understanding patient-specific tumor biology and treatment strategies. We also demonstrate that temozolomide is effective in patients with m GIST who are refractory to existing chemotherapeutic drugs (namely, TKIs) in clinic for GISTs, bringing a promising treatment option for these patients to clinic.. 10.1158/1078-0432.CCR-21-2092
Current status of immunotherapy for gastrointestinal stromal tumor. Tan Y,Trent J C,Wilky B A,Kerr D A,Rosenberg A E Cancer gene therapy Gastrointestinal stromal tumors (GIST) contain tumor-infiltrating immune cells and their presence provides an opportunity and rationale for developing effective forms of immunotherapy. The types of tumor-infiltrating inflammatory cells and relevant immune checkpoint inhibitors are the focus of active investigation. The most numerous tumor-infiltrating inflammatory cells are tumor-associated macrophages (TAMs) and CD3+ T cells. Studies have shown that patients with GISTs that harbor increased numbers of CD3+ T cells have better outcomes. However, the clinical behavior of GIST has not been shown to correlate with the number of TAMs. The biological significance of other less frequent tumor-infiltrating immune cells including tumor-infiltrating neurtrophils (TINs), natural killer cells (NKs), B cells, dendritic cells (DCs) remains unclear. The immune checkpoint inhibitors CTLA-4, PD1/PDL1 and TIM3/galectin-9 are molecules that can be targeted by synthesized antibodies. Clinical and pre-clinical trials using this approach against immune checkpoint inhibitors, anti-KIT antibody and the generation of chimeric antigen receptor (CAR) T-cells have shown promising results. The treatment of GIST with immunotherapy is complex and evolving; this article reviews its current status for patients with GISTs. 10.1038/cgt.2016.58
CTCF-activated SNHG16 facilitates gastrointestinal stromal tumor by targeting miR-128-3p/CASC3 axis. Experimental cell research In this study, it was ascertained that SNHG16 was up-regulated in gastrointestinal stromal tumor (GIST) tissues and cells, and was responsible for the aggravated malignant behaviors of GIST cells. CTCF served as a transcription activator responsible for the overexpression of SNHG16 in GIST cells. MiR-128-3p was negatively regulated by SNHG16 and exerted anti-tumor effects. Moreover, CASC3 was the direct target mRNA of miR-128-3p, through which miR-128-3p exerted function influence on GIST cell malignant behaviors. SNHG16 competitively bound with miR-128-3p against CASC3, thus positively regulating CASC3 expression. Finally, functional assays carried out in vitro proved SNHG16 could modulate GIST cell proliferation, migration, invasion and apoptosis via miR-128-3p/CASC3 axis. Animal experiments were also designed and implemented in a rescue way and evidenced that up-regulation of CASC3 countervailed the inhibitory impacts of SNHG16 silence on the progression of GIST. In summary, SNHG16 up-regulated by CTCF facilitated the progression of GIST through miR-128-3p/CASC3. 10.1016/j.yexcr.2022.113131
Clinical significance of F-FDG PET/CT imaging in 32 cases of gastrointestinal stromal tumors. European journal of medical research OBJECTIVES:To explore the clinical significance of F-FDG metabolic imaging in the diagnosis and biological risk assessment of gastrointestinal stromal tumors (GIST). METHODS:This study is a clinical retrospective study. The research subjects were patients with GIST who were admitted to our hospital from January 2014 to December 2019 and underwent F-FDG metabolic imaging, and the relationship between biological risk and FDG metabolism was analyzed retrospectively. RESULTS:A total of 32 patients with GIST were included in this study, of which 17 patients had very low and low-risk lesions, and the FDG metabolism level did not increase; five patients had moderate-risk gastric lesions, and the FDG metabolism level was abnormally increased; 10 patients had high-risk lesions, and except for one patient with multiple lesions, the FDG metabolism level of these patients was increased. CONCLUSIONS:The level of glucose metabolism is abnormally increased in tumor cells with vigorous mitosis and has higher biological risk. The F-FDG metabolism level can determine the biological risk of GIST and whether high-risk lesions involve other tissues and organs, as it more comprehensively reflects the distribution of lesions, the activity of tumor cells and the stage of the disease. 10.1186/s40001-022-00806-9
The Story of Imatinib in GIST - a Journey through the Development of a Targeted Therapy. Reichardt Peter Oncology research and treatment The introduction of the tyrosine kinase inhibitor (TKI) imatinib 15 years ago has radically changed the treatment of advanced/metastatic gastrointestinal stroma tumours (GIST). This review describes and discusses the development of this successful targeted therapy. It shows the evolution of imatinib to become the standard first-line treatment for advanced/metastatic GIST, starting from the first dose-finding trials to the pivotal trials. Other themes discussed are the detection of predictive factors, the results of discontinuing treatment and how long the treatment should last. The discoveries described in the development and research of imatinib now serve as models for treating many other cancers. However, there are still unanswered questions, so research into treating GIST with TKI or other compounds continues. 10.1159/000487511
Ripretinib and MEK Inhibitors Synergize to Induce Apoptosis in Preclinical Models of GIST and Systemic Mastocytosis. Gupta Anu,Singh Jarnail,García-Valverde Alfonso,Serrano César,Flynn Daniel L,Smith Bryan D Molecular cancer therapeutics The majority of gastrointestinal stromal tumors (GIST) harbor constitutively activating mutations in KIT tyrosine kinase. Imatinib, sunitinib, and regorafenib are available as first-, second-, and third-line targeted therapies, respectively, for metastatic or unresectable KIT-driven GIST. Treatment of patients with GIST with KIT kinase inhibitors generally leads to a partial response or stable disease but most patients eventually progress by developing secondary resistance mutations in KIT. Tumor heterogeneity for secondary resistant KIT mutations within the same patient adds further complexity to GIST treatment. Several other mechanisms converge and reactivate the MAPK pathway upon KIT/PDGFRA-targeted inhibition, generating treatment adaptation and impairing cytotoxicity. To address the multiple potential pathways of drug resistance in GIST, the KIT/PDGFRA inhibitor ripretinib was combined with MEK inhibitors in cell lines and mouse models. Ripretinib potently inhibits a broad spectrum of primary and drug-resistant KIT/PDGFRA mutants and is approved by the FDA for the treatment of adult patients with advanced GIST who have received previous treatment with 3 or more kinase inhibitors, including imatinib. Here we show that ripretinib treatment in combination with MEK inhibitors is effective at inducing and enhancing the apoptotic response and preventing growth of resistant colonies in both imatinib-sensitive and -resistant GIST cell lines, even after long-term removal of drugs. The effect was also observed in systemic mastocytosis (SM) cells, wherein the primary drug-resistant KIT D816V is the driver mutation. Our results show that the combination of KIT and MEK inhibition has the potential to induce cytocidal responses in GIST and SM cells. 10.1158/1535-7163.MCT-20-0824
Germline Mutations in SDH-Deficient GISTs: A Current Update. Genes Loss of function of the succinate dehydrogenase complex characterizes 20-40% of all -negative GIST. Approximately half of SDH-deficient GIST patients lack mutations and are caused by a hypermethylation of the promoter, which causes the repression of transcription and depletion of SDHC protein levels through a mechanism described as epimutation. The remaining 50% of SDH-deficient GISTs have mutations in one of the SDH subunits and mutations are the most common (30%), with consequent loss of SDHA and SDHB protein expression immunohistochemically. , , and mutations in GIST occur in only 20-30% of cases and most of these SDH mutations are germline. More recently, germline mutations in have also been described in several patients with loss of function of the SDH complex. -mutant patients usually carry two mutational events at the locus, either the loss of the wild type allele or a second somatic event in compound heterozygosis. This review provides an overview of all data in the literature regarding -mutated GIST, especially focusing on the prevalence of germline mutations in SDH-deficient GIST populations who harbor somatic mutations, and offers a view towards understanding the importance of genetic counselling for -variant carriers and relatives. 10.3390/genes14030646
New treatments in advanced gastrointestinal stromal tumor. Current opinion in oncology PURPOSE OF REVIEW:The current article revisits the most recent advances that occurred in the field of gastrointestinal stromal tumor (GIST) therapeutics. RECENT FINDINGS:GIST is driven by the oncogenic activation of KIT or PDGFRA receptor tyrosine kinases, and agents targeting these receptors lead to substantial benefit throughout the entire course of the disease. Two new drugs were approved in 2020. On one hand, ripretinib obtained the regulatory approval for the treatment of GIST patients after progression to all standard treatments. On the other hand, avapritinib became the first agent ever displaying activity in GIST driven by the multiresistant PDGFRA D842V mutation. The addition of both drugs to GIST therapeutics constitutes a remarkable milestone, particularly considering that the last agent approved was back in 2012. Similarly, the recent identification of neurotrophic tyrosine receptor kinase (NTRK) fusions in a subset of KIT/PDGFRA wild-type GISTs led to an open window for tailored treatment using specific NTRK inhibitors. Finally, multiple efforts have been made toward the clinical implementation of circulating tumor DNA evaluation to guide clinical decisions in GIST. SUMMARY:GIST has been consolidated over the years as a paradigmatic model in personalized medicine for the successful development of novel therapeutic strategies through targeted inhibition of oncogenic drivers. 10.1097/CCO.0000000000000745
Characteristics and clinical significance of lipid metabolism in patients with gastrointestinal stromal tumor. Lipids in health and disease BACKGROUND:To investigate the characteristics and clinical significance of serum lipids in patients with gastrointestinal stromal tumors (GISTs). METHODS:The clinical and pathological data of 694 GIST patients in Liyuan hospital and Union hospital from 2012 to 2016 were retrospectively analyzed. Blood lipid levels in patients with varying degrees of risk were compared. RESULTS:The findings showed that LDL-C, HDL-C, and CHOL increased significantly in women, and CD34 positive. In patients with tumors size less than 5 cm in diameter, TG, HDL-C, and CHOL were significantly higher. TG levels were significantly higher in DOG-1 (a marker and has a high specificity and sensitivity in the diagnosis of GIST) positive patients than in DOG-1 negative patients (P < 0.05). S-100 positive patients had lower HDL-C levels than S-100 negative patients (P < 0.05). Lipids indexes were found to be correlated with GIST risk stratification and tumor site (P < 0.05). TG/HDL-C was were significantly different among patients with GIST in different locations (P < 0.05). CONCLUSION:The clinical and pathological characteristics of the patients with GIST are closely related to the level of blood lipids. To a certain extent, information about level of blood lipids can be helpful for distinguishing benign and malignant GIST. 10.1186/s12944-021-01613-7
Current management of succinate dehydrogenase-deficient gastrointestinal stromal tumors. Cancer metastasis reviews Gastrointestinal stromal tumors (GISTs) are increasingly recognized as having diverse biology. With the development of tyrosine kinase inhibitors molecularly matched to oncogenic KIT and PDGFRA mutations, GISTs have become a quintessential model for precision oncology. However, about 5-10% of GIST lack these driver mutations and are deficient in succinate dehydrogenase (SDH), an enzyme that converts succinate to fumarate. SDH deficiency leads to accumulation of succinate, an oncometabolite that promotes tumorigenesis. SDH-deficient GISTs are clinically unique in that they generally affect younger patients and are associated with GIST-paraganglioma hereditary syndrome, also known as Carney-Stratakis Syndrome. SDH-deficient GISTs are generally resistant to tyrosine-kinase inhibitors, the standard treatment for advanced or metastatic GIST. Thus, surgical resection is the mainstay of treatment for localized disease, but recurrence is common. Clinical trials are currently underway investigating systemic agents for treatment of advanced SDH-deficient GIST. However, further studies are warranted to improve our understanding of SDH-deficient GIST disease biology, natural history, surgical approaches, and novel therapeutics. 10.1007/s10555-019-09818-0
Anagrelide for Gastrointestinal Stromal Tumor. Pulkka Olli-Pekka,Gebreyohannes Yemarshet K,Wozniak Agnieszka,Mpindi John-Patrick,Tynninen Olli,Icay Katherine,Cervera Alejandra,Keskitalo Salla,Murumägi Astrid,Kulesskiy Evgeny,Laaksonen Maria,Wennerberg Krister,Varjosalo Markku,Laakkonen Pirjo,Lehtonen Rainer,Hautaniemi Sampsa,Kallioniemi Olli,Schöffski Patrick,Sihto Harri,Joensuu Heikki Clinical cancer research : an official journal of the American Association for Cancer Research PURPOSE:Gastrointestinal stromal tumor (GIST) is a common type of soft-tissue sarcoma. Imatinib, an inhibitor of KIT, platelet-derived growth factor receptor alpha (PDGFRA), and a few other tyrosine kinases, is highly effective for GIST, but advanced GISTs frequently progress on imatinib and other approved tyrosine kinase inhibitors. We investigated phosphodiesterase 3 (PDE3) as a potential therapeutic target in GIST cell lines and xenograft models. EXPERIMENTAL DESIGN:The GIST gene expression profile was interrogated in the MediSapiens IST Online transcriptome database comprising human tissue and cancer samples, and PDE3A and PDE3B expression was studied using IHC on tissue microarrays (TMA) consisting of 630 formalin-fixed human tissue samples. GIST cell lines were screened for sensitivity to 217 anticancer compounds, and the efficacy of PDE inhibitors on GIST was further studied in GIST cell lines and patient-derived mouse xenograft models. RESULTS:GISTs expressed PDE3A and PDE3B frequently compared with other human normal or cancerous tissues both in the database and the TMAs. Anagrelide was identified as the most potent of the PDE3 modulators evaluated. It reduced cell viability, promoted cell death, and influenced cell signaling in GIST cell lines. Anagrelide inhibited tumor growth in GIST xenograft mouse models. Anagrelide was also effective in a GIST xenograft mouse model with exon 9 mutation that may pose a therapeutic challenge, as these GISTs require a high daily dose of imatinib. CONCLUSIONS:PDE3A and PDE3B are frequently expressed in GIST. Anagrelide had anticancer efficacy in GIST xenograft models and warrants further testing in clinical trials. 10.1158/1078-0432.CCR-18-0815
New drugs in gastrointestinal stromal tumors. Martin-Broto Javier,Moura David S Current opinion in oncology PURPOSE OF REVIEW:Tyrosine kinase inhibitors (TKIs) are the backbone for advanced gastrointestinal stromal tumor (GIST) treatment. The increasing knowledge concerning the structure and the changing conformational status because of some mutations in KIT and PDGFRα, allowed the development of new efficient compounds, with the main goal to overcome resistance in GIST. This review summarizes the latest developments in the treatment of GIST patients. RECENT FINDINGS:Amongst the several TKIs currently being studied in GIST, ripretinib, avapritinib and crenolanib had shown promising potent activity in preclinical studies and clinical trials. Ripretinib is a type II inhibitor that exerts its main action in the switch pocket of the activation loop, by mimicking the inhibition exerted by the regulatory region in this domain. Ripretinib is considered the new standard in the fourth line in advanced GIST. Avapritinib is a type I inhibitor synthesized to exerts its activity in the active conformation of the activation loop of KIT and PDFGRα. The relevant activity reported with avapritinib in patients carrying the D842 v mutation represents, for first time, an active therapeutic option in this resistant mutant. Crenolanib is a type I selective inhibitor of PDGFRα-resistant mutants, mainly D842 V, which is currently under clinical trial. SUMMARY:New potent TKIs are being approved, adding value to the already three registered drugs. Other agents, such as MEK inhibitors, immunotherapy and TRK-targeted therapy are potential new options in specific subsets of GIST patients. 10.1097/CCO.0000000000000642
Epigenetics: an alternative pathway in GISTs tumorigenesis. Jasek K,Kasubova I,Holubekova V,Stanclova A,Plank L,Lasabova Z Neoplasma Many diseases have different pathological backgrounds responsible for abnormal cell behavior and exhibiting altered function and signal transduction. This is especially true for tumors and although changes affecting DNA sequence, irreversible mutations and chromosomal aberrations in gastrointestinal stromal tumors (GISTs) have been widely studied, the importance of reversible epigenetic changes increasingly recognized in many cancers has received insufficient attention in these tumors. Epigenetic mechanisms are part of normal development and gene expression under normal conditions, but malfunction of these processes leads to malignant transformation by disturbing both intra- and intercellular communication. GISTs are a specific group of gastrointestinal tract tumors resistant to conventional chemotherapy and radiotherapy. Although they account for only 1% to 2% of tumors, they are among the most widespread gastrointestinal mesenchymal tumors. DNA hyper/hypomethylation overexpression/underexpression of miRNAs or abnormal histone modification may provide an alternative to the genetic modifications responsible for GIST pathology, response to treatment, prognosis and overall survival. This review summarizes the known epigenetic mechanisms involved in GIST pathogenesis; including onset, progression, and GISTs resistance. Reversible epigenetic changes are a novel and appropriate approach to halt the spread of metastases and the emergence of resistance in GIST treatment, and these changes depend on the type of epigenetic alternation, including inhibitors of histone acetyltranferase and deacetylase and DNA methyltransferases. 10.4149/neo_2018_170726N504
Gastrointestinal stromal tumors (GIST): Facing cell death between autophagy and apoptosis. Ravegnini Gloria,Sammarini Giulia,Nannini Margherita,Pantaleo Maria A,Biasco Guido,Hrelia Patrizia,Angelini Sabrina Autophagy Autophagy and apoptosis are 2 fundamental biological mechanisms that may cooperate or be antagonistic, although both are involved in deciding the fate of cells in physiological or pathological conditions. These 2 mechanisms coexist simultaneously in cells and share common upstream signals and stimuli. Autophagy and apoptosis play pivotal roles in cancer development. Autophagy plays a key function in maintaining tumor cell survival by providing energy during unfavorable metabolic conditions through its recycling mechanism, and supporting the high energy requirement for metabolism and growth. This review focuses on gastrointestinal stromal tumors and cell death through autophagy and apoptosis, taking into account the involvement of both of these processes in tumor development and growth and as mechanisms of drug resistance. We also focus on the crosstalk between autophagy and apoptosis as an emerging field with major implications for the development of novel therapeutic options. 10.1080/15548627.2016.1256522
[Wild-type gastroinestinal stromal tumors]. Djerouni Mohamed,Dumont Sarah N Bulletin du cancer Gastrointestinal stromal tumors (GIST) are the most common non-epithelial tumors of the gastrointestinal tract. Wild-type GISTs (WT-GIST) consist of a rare heterogeneous group characterized by the lack of activating mutations in the tyrosine kinase receptor (Kit) and/or platelet derived growth factor receptor A (PDGFRA). However, WT-GIST is characterized by other genomic alterations, including dehydrogenase succinate (SDH) deficiency or mutations in the Ras pathway. Recent studies have reported many mutations in others genes that may be incriminated in the development of WT-GISTs. Moreover, WT-GIST is frequently associated with hereditary cancer syndromes such as the Carney Triad and Type 1 Neurofibromatosis (NF1). WT-GIST affects usually young and pediatric patients. Most WT-GIST subtypes are insensitive to imatinib; therefore, their therapeutic management is somewhat different from usual GISTs. This review resumes the molecular and therapeutic features of this rare entity. 10.1016/j.bulcan.2019.12.007
Coding and Non-coding: Molecular Portrait of GIST and its Clinical Implication. Bure I,Haller F,Zaletaev D V Current molecular medicine Gastrointestinal stromal tumours are the most common mesenchymal tumours of the gastrointestinal tract. Despite similar mutation pattern of activating mutations in KIT or PDGFRA receptors in 85% of cases, they demonstrate significantly heterogeneous clinical behaviour and pathological characteristics. This heterogeneity opens the question of the role of other factors and mechanisms of regulation in the development of GIST. Additional mutations in downstream effectors of GIST related signalling pathways or aberrant expression of non-coding RNAs may be additional contributing factors, the latter being increasingly recognized in carcinogenesis in general. Recently, a substantial progress has been achieved in understanding the functional roles of lncRNAs in GIST suggesting their potential employment as biomarkers and therapeutic targets in GIST. Moreover, some miRNAs have recently been found to be able to sensitize cells to imatinib, which could be an attractive option to overcome the resistance to the drug, which hampers the efficacy of GIST treatment. Therefore, the advantage can be taken of both coding and non-coding parts of the genome in order to significantly improve prognostication and help find personalized therapy for patients, depending on a subtype of GIST and personal characteristics. 10.2174/1566524018666181004113436
Identification and Therapeutic Targeting of GPR20, Selectively Expressed in Gastrointestinal Stromal Tumors, with DS-6157a, a First-in-Class Antibody-Drug Conjugate. Iida Kenji,Abdelhamid Ahmed Amr H,Nagatsuma Akiko Kawano,Shibutani Tomoko,Yasuda Satoru,Kitamura Michiko,Hattori Chiharu,Abe Manabu,Hasegawa Jun,Iguchi Takuma,Karibe Tsuyoshi,Nakada Takashi,Inaki Koichiro,Kamei Reiko,Abe Yuki,Nomura Taisei,Andersen Jessica L,Santagata Sandro,Hemming Matthew L,George Suzanne,Doi Toshihiko,Ochiai Atsushi,Demetri George D,Agatsuma Toshinori Cancer discovery Currently, the only approved treatments for gastrointestinal stromal tumor (GIST) are tyrosine kinase inhibitors (TKI), which eventually lead to the development of secondary resistance mutations in KIT or PDGFRA and disease progression. Herein, we identified G protein-coupled receptor 20 (GPR20) as a novel non-tyrosine kinase target in GIST, developed new GPR20 IHC, and assessed GPR20 expression in cell lines, patient-derived xenografts, and clinical samples from two institutes (United States and Japan). We studied GPR20 expression stratified by treatment line, KIT expression, GIST molecular subtype, and primary tumor location. We produced DS-6157a, an anti-GPR20 antibody-drug conjugate with a novel tetrapeptide-based linker and DNA topoisomerase I inhibitor exatecan derivative (DXd). DS-6157a exhibited GPR20 expression-dependent antitumor activity in GIST xenograft models including a GIST model resistant to imatinib, sunitinib, and regorafenib. Preclinical pharmacokinetics and safety profile of DS-6157a support its clinical development as a potential novel GIST therapy in patients who are refractory or have resistance or intolerance to approved TKIs. SIGNIFICANCE: GPR20 is selectively expressed in GIST across all treatment lines, regardless of / genotypes. We generated DS-6157a, a DXd-based antibody-drug conjugate that exhibited antitumor activity in GIST models by a different mode of action than currently approved TKIs, showing favorable pharmacokinetics and safety profiles.. 10.1158/2159-8290.CD-20-1434
N-methyladenosine modification regulates imatinib resistance of gastrointestinal stromal tumor by enhancing the expression of multidrug transporter MRP1. Xu Kangjing,Zhang Qiang,Chen Ming,Li Bowen,Wang Nuofan,Li Chao,Gao Zhishuang,Zhang Diancai,Yang Li,Xu Zekuan,Li Xueming,Xu Hao Cancer letters N-methyladenosine (mA) is a frequently occurring mRNA modification, which regulates mRNA stability, splicing, and translation. However, its role in drug resistance of gastrointestinal stromal tumor (GIST) is not known. Here, we report that mA modification levels are elevated in imatinib-resistant GIST cells and tissues, and that methyltransferase METTL3 is one of the main protein responsible for this aberrant modification. Increased METTL3 levels contributed to imatinib resistance and worse progression-free survival of GIST patients. Mechanistic studies revealed that METTL3-mediated mA modification of the 5'UTR of the multidrug transporter MRP1 mRNA promoted drug resistance of GIST by stimulating MRP1 mRNA translation, via binding with YTHDF1 and eEF-1. Further, METTL3 transcription in imatinib resistant GIST cells was activated by ETV1, leading to the increased mA methylation of MRP1 mRNA. This is the first report showing a novel regulatory mechanism whereby ETV1, METTL3, and the YTHDF1/eEF-1 complex mediate the translation of MRP1 mRNA in an mA-dependent manner to regulate the intracellular concentration of imatinib and drug resistance of GIST. These findings highlight MRP1 as a new potential therapeutic target for imatinib resistance of GIST. 10.1016/j.canlet.2022.01.008
PD-1/PD-L1 blockade rescue exhausted CD8+ T cells in gastrointestinal stromal tumours via the PI3K/Akt/mTOR signalling pathway. Zhao Rui,Song Yinghan,Wang Yong,Huang Yuqian,Li Zhigui,Cui Yaping,Yi Mengshi,Xia Lin,Zhuang Wen,Wu Xiaoting,Zhou Yong Cell proliferation OBJECTIVES:Although targeted therapy has revolutionized the treatment of gastrointestinal stromal tumours (GIST), it is almost never curative in GIST, and resistance commonly develops. One potential strategy is to combine targeted therapy with immunotherapy. MATERIALS AND METHODS:We first studied Programmed cell death 1 ligand 1 (PD-L1) expression and tumour-infiltrating T cells (TILs) in GIST. IFN-γ was used to induce the upregulation of PD-L1 expression in GIST-882 cells, a well-known GIST cell line. CD8+ T-cell apoptosis was determined by flow cytometry. The PI3K/Akt/mTOR levels in CD8+ T cells were examined by Western blotting. RESULTS:PD-L1 expression was an independent factor of poor prognosis in GIST and resulted in exhausted T cells in the TILs population or the blood. Then, we found that PD-L1 blockade alone could not increase tumour cell apoptosis in GIST. The apoptosis rate of CD8+ T cells was higher when T cells were cultured with PD-L1+ GIST-882 cells (GIST-882 cells with high PD-L1 expression) than when T cells were cultured with control GIST-882 cells. However, when the PD-L1 blockade was used, the apoptosis rates of the CD8+ T cells in the two groups became similar. Then, Western blotting showed the PI3K/Akt/mTOR levels of the CD8+ T cells rescued by the PD-1/PD-L1 blockade were higher than those of the CD8+ T cells not treated with the PD-1/PD-L1 blockade. CONCLUSIONS:PD-L1 expression was an independent poor prognosis factor in GIST. PD-1/PD-L1 blockade rescued exhausted CD8+ T cells in GIST via the PI3K/Akt/mTOR signalling pathway. In GIST, PD-1/PD-L1 not only function as predictive biomarkers but also improve current therapies as treatment targets. 10.1111/cpr.12571
Integrated Screens Identify CDK1 as a Therapeutic Target in Advanced Gastrointestinal Stromal Tumors. Lu Xiaojing,Pang Yuzhi,Cao Hui,Liu Xiaoxiao,Tu Lin,Shen Yanying,Jia Xiaona,Lee Jen-Chieh,Wang Yuexiang Cancer research Oncogenic KIT or PDGFRA receptor tyrosine kinase mutations are compelling therapeutic targets in gastrointestinal stromal tumor (GIST), and treatment with the KIT/PDGFRA inhibitor imatinib is the standard of care for patients with advanced GIST. Polyclonal emergence of secondary mutations is the main mechanism of imatinib progression, making it challenging to overcome KIT/PDGFRA-inhibitor resistance. It is unclear whether there are other therapeutic targets in advanced GIST. Using genome-wide transcriptomic profiling of advanced versus early-stage GIST and CRISPR knockout functional screens, we demonstrate that CDK1 is frequently highly expressed in advanced GIST but not in early-stage GIST across three patient cohorts. High expression of CDK1 was associated with malignancy in GIST. CDK1 was critically required for advanced GIST, including imatinib-resistant GIST. CDK1 ablation led to robust proliferation inhibition. A mass spectrometry-based proteomics screen further revealed that AKT is a novel substrate of CDK1 kinase in GIST. CDK1 bound AKT and regulated its phosphorylation, thereby promoting GIST proliferation and progression. Importantly, a pharmacologic inhibitor of CDK1, RO-3306, disrupted GIST cell proliferation in CDK1 highly expressed GIST but not in CDK1-negative GIST cells and nontransformed fibroblast cells. Treatment with RO-3306 reduced tumor growth in both imatinib-resistant and imatinib-sensitive GIST xenograft mouse models. Our findings suggest that CDK1 represents a druggable therapeutic target in GIST and warrants further testing in clinical trials. SIGNIFICANCE: These findings propose CDK1 as a novel cell-cycle-independent vulnerability in gastrointestinal stromal tumors, representing a new therapeutic opportunity for patients with advanced disease. 10.1158/0008-5472.CAN-20-3580
THZ1 targeting CDK7 suppresses c-KIT transcriptional activity in gastrointestinal stromal tumours. Cell communication and signaling : CCS BACKGROUND:Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal tumours of the gastrointestinal tract and are characterized by activating mutations of c-KIT or PDGFRa receptor tyrosine kinases (RTKs). Despite the clinical success of tyrosine kinase inhibitors (TKIs), more than half of GIST patients develop resistance due to a second mutation. Cyclin-dependent kinase 7 (CDK7) is the catalytic subunit of CDK-activating kinase (CAK), and it plays an important role in the regulation of cell cycle transitions and gene transcription. THZ1, a CDK7 inhibitor, exhibits a dose-dependent inhibitory effect in various cancers. METHODS:Data from the public GEO database and tissue microarray were used to analyse the gene expression levels of CDKs in GISTs. The impact of CDK7 knockdown and the CDK7 inhibitor THZ1 on GIST progression was investigated in vitro using CCK-8, colony formation, and flow cytometry assays and in vivo using a xenograft mouse model. RNA sequencing was performed to investigate the mechanism of GIST cell viability impairment mediated by THZ1 treatment. RESULTS:Our study demonstrated that CDK7 is relatively overexpressed in high-risk GISTs and predicts a poor outcome. A low concentration of THZ1 exhibited a pronounced antineoplastic effect in GIST cells in vivo and in vitro. Moreover, THZ1 exerted synergistic anticancer effects with imatinib. THZ1 treatment resulted in transcriptional modulation by inhibiting the phosphorylation of Ser2, Ser5, and Ser7 within RNA polymerase II (RNAPII). c-KIT, an oncogene driver of GIST, was transcriptionally repressed by THZ1 treatment or CDK7 knockdown. Transcriptome sequencing analysis showed that OSR1 acts as a downstream target of CDK7 and regulates c-KIT expression. Taken together, our results highlight elevated CDK7 expression as a predictor of poor outcome in GIST and present the combination of CDK7 and RTK inhibitors as a potent therapeutic strategy to improve the efficacy of GIST treatment. Video abstract. 10.1186/s12964-022-00928-x
Avapritinib: First Approval. Dhillon Sohita Drugs Avapritinib (AYVAKIT™) is a potent and selective tyrosine kinase inhibitor of platelet-derived growth factor receptor alpha (PDGFRA) and KIT activation loop mutants. It is being developed by Blueprint Medicines for the treatment of gastrointestinal stromal tumours (GIST), solid tumours and systemic mastocytosis. Avapritinib is approved in the USA for PDGFRA exon 18 (including D842V) mutant GIST and is undergoing regulatory assessment in the USA as a 4th-line treatment for GIST. Avapritinib is also undergoing regulatory assessment in the EU for PDGFRA D842V mutant GIST. This article summarizes the milestones in the development of avapritinib leading to this first approval for the treatment of adults with unresectable or metastatic GIST harbouring a PDGFRA exon 18 mutation, including PDGFRA D842V mutations. Clinical development of avapritinib is also underway for the treatment of systemic mastocytosis and late-stage solid tumours in several countries. 10.1007/s40265-020-01275-2
N-methyladenosine-modified USP13 induces pro-survival autophagy and imatinib resistance via regulating the stabilization of autophagy-related protein 5 in gastrointestinal stromal tumors. Cell death and differentiation Secondary resistance to imatinib (IM) represents a major challenge for therapy of gastrointestinal stromal tumors (GISTs). Aberrations in oncogenic pathways, including autophagy, correlate with IM resistance. Regulation of autophagy-related protein 5 (ATG5) by the ubiquitin-proteasome system is critical for autophagic activity, although the molecular mechanisms that underpin reversible deubiquitination of ATG5 have not been deciphered fully. Here, we identified USP13 as an essential deubiquitinase that stabilizes ATG5 in a process that depends on the PAK1 serine/threonine-protein kinase and which enhances autophagy and promotes IM resistance in GIST cells. USP13 preferentially is induced in GIST cells by IM and interacts with ATG5, which leads to stabilization of ATG5 through deubiquitination. Activation of PAK1 promoted phosphorylation of ATG5 thereby enhancing the interaction of ATG5 with USP13. Furthermore, N-methyladenosine methyltransferase-like 3 (METTL3) mediated stabilization of USP13 mRNA that required the mA reader IGF2BP2. Moreover, an inhibitor of USP13 caused ATG5 decay and co-administration of this inhibitor with 3-methyladenine boosted treatment efficacy of IM in murine xenograft models derived from GIST cells. Our findings highlight USP13 as an essential regulator of autophagy and IM resistance in GIST cells and reveal USP13 as a novel potential therapeutic target for GIST treatment. 10.1038/s41418-022-01107-8
Efficacy of SCF drug conjugate targeting c-KIT in gastrointestinal stromal tumor. BMC medicine BACKGROUND:Gastrointestinal stromal tumor (GIST) is a rare type of cancer that occurs in the gastrointestinal tract. The majority of GIST cases carry oncogenic forms of KIT, the receptor for stem cell factor (SCF). Small molecule kinase inhibitor imatinib is effective in prolonging the survival of GIST patients by targeting KIT. However, drug resistance often develops during the therapeutic treatment. Here, we produced a SCF-emtansine drug conjugate (SCF-DM1) with favorable drug efficacy towards GIST cells. METHODS:Recombinant human SCF (rhSCF) was expressed in E. coli cells and further purified with Ni-NTA Sepharose and Phenyl Sepharose. It was then conjugated with DM1, and the conjugated product SCF-DM1 was evaluated using in vitro cell-based assays and in vivo xenograft mouse model. RESULTS:SCF-DM1 was effective in inhibiting imatinib-sensitive and -resistant GIST cell lines and primary tumor cells, with IC values of < 30 nM. It induced apoptosis and cell cycle arrest in GIST cells. In xenograft mouse model, SCF-DM1 showed favorable efficacy and safety profiles. CONCLUSIONS:rhSCF is a convenient and effective vector for drug delivery to KIT positive GIST cells. SCF-DM1 is an effective drug candidate to treat imatinib-sensitive and -resistant GIST. 10.1186/s12916-022-02465-3
Pimitespib: First Approval. Drugs Pimitespib (Jeselhy) is an oral small molecule inhibitor of the α and β isoforms of heat shock protein 90 (HSP90). HSP90α and HSP90β regulate the stability and activity of a number of proteins that are crucial for tumour development. Pimitespib is being developed by Taiho Pharmaceutical for the treatment of solid tumours, including gastrointestinal stromal tumour (GIST), and in June 2022 it received its first approval in Japan for GIST that has progressed after chemotherapy. Pimitespib is undergoing phase I development for the treatment of solid tumours in the EU and the USA. This article summarizes the milestones in the development of pimitespib leading to this first approval for GIST that has progressed after chemotherapy. 10.1007/s40265-022-01764-6
MOZ and Menin-MLL Complexes Are Complementary Regulators of Chromatin Association and Transcriptional Output in Gastrointestinal Stromal Tumor. Cancer discovery Gastrointestinal stromal tumor (GIST) is commonly characterized by activating mutations in the receptor tyrosine kinase KIT. Tyrosine kinase inhibitors are the only approved therapy for GIST, and complementary treatment strategies are urgently needed. As GIST lacks oncogene amplification and relies upon an established network of transcription factors, we hypothesized that unique chromatin-modifying enzymes are essential in orchestrating the GIST epigenome. We identified through genome-scale CRISPR screening that MOZ and Menin-MLL chromatin regulatory complexes are cooperative and unique dependencies in GIST. These complexes were enriched at GIST-relevant genes and regulated their transcription. Inhibition of MOZ and Menin-MLL complexes decreased GIST cell proliferation by disrupting interactions with transcriptional/chromatin regulators, such as DOT1L. MOZ and Menin inhibition caused significant reductions in tumor burden in vivo, with superior effects observed with combined Menin and KIT inhibition. These results define unique chromatin regulatory dependencies in GIST and identify potential therapeutic strategies for clinical application. SIGNIFICANCE:Although many malignancies rely on oncogene amplification, GIST instead depends upon epigenetic regulation of KIT and other essential genes. Utilizing genome-scale CRISPR dependency screens, we identified complementary chromatin-modifying complexes essential to GIST and characterize the consequences of their disruption, elucidating a novel therapeutic approach to this disease. This article is highlighted in the In This Issue feature, p. 1599. 10.1158/2159-8290.CD-21-0646