共0篇 平均IF=NaN (-) 更多分析

    加载中

    logo
    LTBPs in biology and medicine: LTBP diseases. Rifkin Daniel B,Rifkin William J,Zilberberg Lior Matrix biology : journal of the International Society for Matrix Biology The latent transforming growth factor (TGF) β binding proteins (LTBP) are crucial mediators of TGFβ function, as they control growth factor secretion, matrix deposition, presentation and activation. Deficiencies in specific LTBP isoforms yield discrete phenotypes representing defects in bone, lung and cardiovascular development mediated by loss of TGFβ signaling. Additional phenotypes represent loss of unique TGFβ-independent features of LTBP effects on elastogenesis and microfibril assembly. Thus, the LTBPs act as sensors for the regulation of both growth factor activity and matrix function. 10.1016/j.matbio.2017.11.014
    Overexpression of latent transforming growth factor-beta 1 (TGF-beta 1) binding protein 1 (LTBP-1) in association with TGF-beta 1 in ovarian carcinoma. Higashi T,Sasagawa T,Inoue M,Oka R,Shuangying L,Saijoh K Japanese journal of cancer research : Gann Using the differential display method, latent transforming growth factor-beta 1 (TGF-beta 1) binding protein 1 (LTBP-1) mRNA was identified as one of the enriched mRNAs in ovarian carcinoma tissues after isolation of genes responsible for the development of ovarian cancer. Semi-quantitative reverse transcription (RT)-PCR analysis showed that expression of LTBP-1 and TGF-beta 1 mRNAs was much higher in both serous and mucinous adenocarcinomas than in their benign counterparts, including serous and mucinous cystadenomas and cystadenomas of low malignant potential (LMPs). Immunohistochemical analysis demonstrated that only proliferating benign adenoma cells were immunoreactive for both LTBP-1 and TGF-beta 1 proteins. In contrast, most serous and mucinous adenocarcinoma cells and their surrounding stroma were intensely immunoreactive for LTBP-1 and TGF-beta 1. LTBP-1 and TGF-beta 1 proteins, and their complex forms were identified in ovarian carcinoma cell lines and in their culture media by western blot analysis, suggesting these products were produced in ovarian carcinoma cells. RT-PCR analysis demonstrated that LTBP-1L, one of the LTBP-1 transcripts that has a strong activity in targeting the latent form of TGF-beta 1 to extracellular matrix (ECM), was predominantly expressed in ovarian carcinomas. Taken together, the results suggest that upregulation of LTBP-1 in ovarian carcinoma cells may have an important role in distributing TGF-beta1 in the stromal tissues surrounding carcinoma cells. 10.1111/j.1349-7006.2001.tb01123.x
    Evidence for the decreased expression of the latent TGF-beta binding protein and its splice form in human liver tumours. Roth-Eichhorn S,Heitmann B,Flemming P,Kubicka S,Trautwein C Scandinavian journal of gastroenterology BACKGROUND:Recently, a splice form of the latent TGF-beta binding protein (LTBP-1) was identified in the liver lacking potential important sequences for matrix association and proteinase cleavage (LTBP-1D, -1delta53). For a better understanding of the unknown (patho)physiological role, the expression levels of LTBP-1D and LTBP-1 (full length) were investigated in normal and malignant human liver on the mRNA and protein level. METHODS:Normal liver (5 specimens), hepatocellular carcinoma (4 specimens) and fibrolamellar carcinoma (2 specimens) were examined by quantitative reverse transcription-polymerase chain reaction and immunohistochemistry, for which specific antibodies were generated. RESULTS:The mRNA levels of LTBP-1/-1D in malignant liver tissues are decreased in comparison to normal liver--more so in HCC than in FLC. This finding was confirmed by a strong decrease of immunostaining of LTBP-1/-1D in neoplastic parenchymal cells of HCC and FLC. However, the intensity of LTBP-1 (full length) protein staining was increased in the extracellular matrix of the carcinomas, while LTBP-1D was not detectable in the matrix. CONCLUSION:Since TGF-beta is known to be over-expressed in liver tumours, the results suggest its enhanced synthesis without binding to LTBP-1. This probably influences the availability of bioactive TGF-beta in the tumour tissue. The missing matrix localization of LTBP-1D indicates that the hinge region containing a heparin-binding site is essential for the binding of LTBP-1 in the extracellular matrix. LTBP-1D may fulfil specific functions for the latency of matrix-unbound TGF-beta.
    Disruption of the gene encoding the latent transforming growth factor-beta binding protein 4 (LTBP-4) causes abnormal lung development, cardiomyopathy, and colorectal cancer. Sterner-Kock Anja,Thorey Irmgard S,Koli Katri,Wempe Frank,Otte Jürgen,Bangsow Thorsten,Kuhlmeier Katharina,Kirchner Thomas,Jin Shenchu,Keski-Oja Jorma,von Melchner Harald Genes & development Transforming growth factor-betas (TGF-betas) are multifunctional growth factors that are secreted as inactive (latent) precursors in large protein complexes. These complexes include the latency-associated propeptide (LAP) and a latent transforming growth factor-beta binding protein (LTBP). Four isoforms of LTBPs (LTBP-1-LTBP-4) have been cloned and are believed to be structural components of connective tissue microfibrils and local regulators of TGF-beta tissue deposition and signaling. By using a gene trap strategy that selects for integrations into genes induced transiently during early mouse development, we have disrupted the mouse homolog of the human LTBP-4 gene. Mice homozygous for the disrupted allele develop severe pulmonary emphysema, cardiomyopathy, and colorectal cancer. These highly tissue-specific abnormalities are associated with profound defects in the elastic fiber structure and with a reduced deposition of TGF-beta in the extracellular space. As a consequence, epithelial cells have reduced levels of phosphorylated Smad2 proteins, overexpress c-myc, and undergo uncontrolled proliferation. This phenotype supports the predicted dual role of LTBP-4 as a structural component of the extracellular matrix and as a local regulator of TGF-beta tissue deposition and signaling. 10.1101/gad.229102
    LTBP-1 blockade in dioxin receptor-null mouse embryo fibroblasts decreases TGF-beta activity: Role of extracellular proteases plasmin and elastase. Gomez-Duran Aurea,Mulero-Navarro Sonia,Chang Xiaoqing,Fernandez-Salguero Pedro M Journal of cellular biochemistry In mouse embryonic fibroblasts (MEF) lacking dioxin receptor (AhR), high levels of latent transforming growth factor-beta (TGF-beta)-binding protein-1 (LTBP-1) correlated with increased TGF-beta1 activity, an observation suggesting that LTBP-1 could contribute to maintain TGF-beta1 levels. Here, using small interfering RNAs (siRNA), we have first analyzed if LTBP-1 expression affected TGF-beta1 activity in MEF cells. We have then determined how LTBP-1 levels could alter the activity of extracellular proteases known to activate TGF-beta1, and finally, whether protease inhibition could reduce TGF-beta1 activation. LTBP-1 inhibition by siRNA in AhR-/- MEF decreased the amount of active TGF-beta1 and reduced plasminogen activators (PA)/plasmin and elastase activities and thrombospondin-1 (TSP-1) expression, without significantly affecting their mRNA levels. On the contrary, LTBP-1 siRNA restored matrix metalloproteinase-2 (MMP-2) activity in AhR-/- MEF. Interestingly, whereas a TGF-beta1 neutralizing antibody mimicked many of the LTBP-1 siRNA effects on extracellular proteases, addition of recombinant TGF-beta1 protein increased proteases activity over basal levels in AhR-/- MEF. These proteases contributed to TGF-beta activation since their specific inhibitors reduced active TGF-beta levels in these cells. These results suggest that LTBP-1 contributes to TGF-beta1 activation in MEF, possibly by influencing the activities of PA/plasmin, elastase, TSP-1, and MMP-2. TGF-beta1, on the other hand, could be also involved in maintaining the activity of these extracellular proteases. Thus, LTBP-1 appears to play a role in TGF-beta1 activation through a process involving extracellular protease activities, which, in turn, could be affected by TGF-beta1 levels. 10.1002/jcb.20637
    Novel functional single nucleotide polymorphisms in the latent transforming growth factor-beta binding protein-1L promoter: effect on latent transforming growth factor-beta binding protein-1L expression level and possible prognostic significance in ovarian cancer. Higashi Tomomi,Kyo Satoru,Inoue Masaki,Tanii Hideji,Saijoh Kiyofumi The Journal of molecular diagnostics : JMD Latent transforming growth factor (TGF)-beta binding proteins (LTBPs) play important roles in the secretion and activation of TGF-beta. We previously reported that LTBP-1L is overexpressed in some patients with ovarian cancer. To clarify the molecular mechanism of LTBP-1L regulation, we analyzed DNA sequences in the promoter region of LTBP-1L and identified two novel single nucleotide polymorphisms, -202G/C and +20A/C. While the alleles with -202C and +20C were initially reported, our data demonstrated that -202G and +20A are common in both ovarian cancer patients and healthy patients in the Japanese population. Luciferase reporter assays revealed that the G-A haplotype induced transcriptional activation in a Sp1-dependent manner. Electrophoretic mobility shift assays showed that increased binding affinity of Sp1 to the promoter with -202G and +20A. Interestingly, ovarian cancer patients (n = 42) with G-A/G-A homozygous genotype had increased expression of LTBP-1 and apparently poorer survival than those with other genotypes (P = 0.02). These findings suggest that the single nucleotide polymorphisms -202G/C and +20A/C on the LTBP-1L promoter may affect the clinical outcome of ovarian cancer patients, probably via up-regulating protein expression. Further studies using a larger number of samples will definitively determine the correlation between LTBP-1 haplotype and clinical behavior of ovarian cancer. 10.2353/jmoldx.2006.050133
    Modulation of TGF-beta activity by latent TGF-beta-binding protein 1 in human malignant glioma cells. Tritschler Isabel,Gramatzki Dorothee,Capper David,Mittelbronn Michel,Meyermann Richard,Saharinen Juha,Wick Wolfgang,Keski-Oja Jorma,Weller Michael International journal of cancer High biological activity of the transforming growth factor (TGF)-beta-Smad pathway characterizes the malignant phenotype of malignant gliomas and confers poor prognosis to glioma patients. Accordingly, TGF-beta has become a novel target for the experimental treatment of these tumors. TGF-beta is processed by furin-like proteases (FLP) and secreted from cells in a latent complex with its processed propeptide, the latency-associated peptide (LAP). Latent TGF-beta-binding protein 1 (LTBP-1) covalently binds to this small latent TGF-beta complex (SLC) and regulates its function, presumably via interaction with the extracellular matrix (ECM). We report here that the levels of LTBP-1 protein in vivo increase with the grade of malignancy in gliomas. LTBP-1 is associated with the ECM as well as secreted into the medium in cultured malignant glioma cells. The release of LTBP-1 into the medium is decreased by the inhibition of FLP activity. Gene-transfer mediated overexpression of LTBP-1 in glioma cell lines results in an increase inTGF-beta activity. Accordingly, Smad2 phosphorylation as an intracellular marker of TGF-beta activity is enhanced. Conversely, LTBP-1 gene silencing reduces TGF-beta activity and Smad2 phosphorylation without affecting TGF-beta protein levels. Collectively, we identify LTBP-1 as an important modulator of TGF-beta activation in glioma cells, which may contribute to the malignant phenotype of these tumors. 10.1002/ijc.24443
    Latent TGF-β binding proteins (LTBPs) 1 and 3 differentially regulate transforming growth factor-β activity in malignant mesothelioma. Vehviläinen Piia,Koli Katri,Myllärniemi Marjukka,Lindholm Pamela,Soini Ylermi,Salmenkivi Kaisa,Kinnula Vuokko L,Keski-Oja Jorma Human pathology Malignant mesothelioma is an aggressive cancer of the pleura with poor prognosis. There is a need to identify new biomarkers and therapeutic targets for this invasive and fatal disease. Transforming growth factor β (TGF-β) can promote mesothelioma tumorigenesis through multiple mechanisms. Latent TGF-β binding proteins (LTBPs) regulate TGF-β activation by targeting the growth factor into the extracellular matrix from where it can be released and activated. We investigated here the expression patterns of different LTBP isoforms in malignant mesothelioma tissues and in 2 established malignant mesothelioma cell lines. All LTBPs were expressed, but LTBP-3 was the main isoform in healthy pleura and in cultured nonmalignant mesothelial cells. We observed down-regulation of LTBP-3 expression in malignant mesothelioma, which was associated with high P-Smad2 levels indicative of TGF-β activity specifically in the tumor tissue. Small interfering RNA-mediated suppression of LTBP-3 expression in mesothelioma cells increased the secretion of TGF-β activity. Immunoreactivity of LTBP-1, on the other hand, was markedly strong in the tumor stroma, which showed significantly lower levels of P-Smad2. A strong negative correlation between LTBP-1 and P-Smad2 immunoreactivity was found, implying that LTBP-1 is not likely to contribute directly to the increased levels of TGF-β activity in malignant mesothelioma. Current results suggest that LTBPs 1 and 3 may have specific roles in malignant mesothelioma pathogenesis through the regulation of TGF-β activation in the tumor tissue and the structure of the tumor stroma. 10.1016/j.humpath.2010.07.005
    Control of lung development by latent TGF-β binding proteins. Dabovic Branka,Chen Yan,Choi Jiwon,Davis Elaine C,Sakai Lynn Y,Todorovic Vesna,Vassallo Melinda,Zilberberg Lior,Singh Amanjot,Rifkin Daniel B Journal of cellular physiology The latent TGF-β binding proteins (LTBP-1 -3, and -4) assist in the secretion and localization of latent TGF-β molecules. Ltbp3(-/-) and Ltbp4S(-/-) mice have distinct phenotypes and only in the lungs does deficiency of either Ltbp-3 or Ltbp-4 cause developmental abnormalities. To determine if these two LTBPs have additional common functions, we generated mice deficient for both Ltbp-3 and Ltbp-4S. The only novel defect in Ltbp3(-/-);Ltbp4S(-/-) mice was an early lethality compared to mice with single mutations. In addition lung abnormalities were exacerbated and the terminal air sac septation defect was more severe in Ltbp3(-/-);Ltbp4S(-/-) mice than in Ltbp4S(-/-) mice. Decreased cellularity of Ltbp3(-/-);Ltbp4S(-/-) lungs was correlated with higher rate of apoptosis in newborn lungs of Ltbp3(-/-);Ltbp4S(-/-) animals compared to WT, Ltbp3(-/-), and Ltbp4S(-/-) mice. No differences in the maturation of the major lung cell types were discerned between the single and double mutant mice. However, the distribution of type 2 cells and myofibroblasts was abnormal, and myofibroblast segregation in some areas might be an indication of early fibrosis. We also observed differences in ECM composition between Ltbp3(-/-);Ltbp4S(-/-) and Ltbp4S(-/-) lungs after birth, reflected in decreased incorporation of fibrillin-1 and -2 in Ltbp3(-/-);Ltbp4S(-/-) matrix. The function of the lungs of Ltbp3(-/-);Ltbp4S(-/-) mice after the first week of life was potentially further compromised by macrophage infiltration, as proteases secreted from macrophages might exacerbate developmental emphysema. Together these data indicate that LTBP-3 and -4 perform partially overlapping functions only in the lungs. 10.1002/jcp.22479
    The latent transforming growth factor beta binding protein (LTBP) family. Oklü R,Hesketh R The Biochemical journal The transforming growth factor beta (TGFbeta) cytokines are a multi-functional family that exert a wide variety of effects on both normal and transformed mammalian cells. The secretion and activation of TGFbetas is regulated by their association with latency-associated proteins and latent TGFbeta binding proteins (LTBPs). Over the past few years, three members of the LTBP family have been identified, in addition to the protoype LTBP1 first sequenced in 1990. Three of the LTBP family are expressed in a variety of isoforms as a consequence of alternative splicing. This review summarizes the differences between the isoforms in terms of the effects on domain structure and hence possible function. The close identity between LTBPs and members of the fibrillin family, mutations in which have been linked directly to Marfan's syndrome, suggests that anomalous expression of LTBPs may be associated with disease. Recent data indicating that differential expression of LTBP1 isoforms occurs during the development of coronary heart disease is considered, together with evidence that modulation of LTBP function, and hence of TGFbeta activity, is associated with a variety of cancers.
    Cellular phenotype transformation occurs during thoracic aortic aneurysm development. Jones Jeffrey A,Zavadzkas Juozas A,Chang Eileen I,Sheats Nina,Koval Christine,Stroud Robert E,Spinale Francis G,Ikonomidis John S The Journal of thoracic and cardiovascular surgery OBJECTIVE:Thoracic aortic aneurysms result from dysregulated remodeling of the vascular extracellular matrix, which may occur as a result of altered resident cellular function. The present study tested the hypothesis that aortic fibroblasts undergo a stable change in cellular phenotype during thoracic aortic aneurysm formation. METHODS:Primary murine aortic fibroblasts were isolated from normal and thoracic aortic aneurysm-induced aortas (4 weeks post induction with 0.5 mol/L CaCl(2) 15 minutes) by the outgrowth method. Normal and thoracic aortic aneurysm cultures were examined using a focused polymerase chain reaction array to determine fibroblast-specific changes in gene expression in the absence and presence of biological stimulation (endothelin-1, phorbol-12-myristate-13-acetate, angiotensin-II). The relative expression of 38 genes, normalized to 4 housekeeping genes, was determined, and genes displaying a minimum 2-fold increase/decrease or genes with significantly different normalized cycle threshold values were considered to have altered expression. RESULTS:At steady state, thoracic aortic aneurysm fibroblasts revealed elevated expression of several matrix metalloproteinases (Mmp2, Mmp11, Mmp14), collagen genes/elastin (Col1a1, Col1a2, Col3a1, Eln), and other matrix proteins, as well as decreased expression of Mmp3, Timp3, and Ltbp1. Moreover, gene expression profiles in thoracic aortic aneurysm fibroblasts were different than normal fibroblasts after equivalent biological stimuli. CONCLUSIONS:This study demonstrated for the first time that isolated primary aortic fibroblasts from thoracic aortic aneurysm-induced mice possess a unique and stable gene expression profile, and when challenged with biological stimuli, induce a transcriptional response that is different from normal aortic fibroblasts. Together, these data suggest that aortic fibroblasts undergo a stable phenotypic change during thoracic aortic aneurysm development, which may drive the enhancement of extracellular matrix proteolysis in thoracic aortic aneurysm progression. 10.1016/j.jtcvs.2009.12.033
    Choreographing metastasis to the tune of LTBP. Chandramouli Anupama,Simundza Julia,Pinderhughes Alicia,Cowin Pamela Journal of mammary gland biology and neoplasia Latent Transforming Growth Factor beta (TGFβ) Binding Proteins (LTBPs) are chaperones and determinants of TGFβ isoform-specific secretion. They belong to the LTBP/Fibrillin family and form integral components of the fibronectin and microfibrillar extracellular matrix (ECM). LTBPs serve as master regulators of TGFβ bioavailability, functioning to incorporate and spatially pattern latent TGFβ at regular intervals within the ECM, and actively participate in integrin-mediated stretch activation of TGFβ in vivo. In so doing they create a highly patterned sensory system where local changes in ECM tension can be detected and transduced into focal signals. The physiological role of LTBPs in the mammary gland remains largely unstudied, however both loss and gain of LTBP expression is found in breast cancers and breast cancer cell lines. Importantly, elevated LTBP1 levels appear in two gene signatures predictive of enhanced metastatic behavior. LTBP may promote metastasis by providing the bridge between structural and signaling components of the epithelial to mesenchymal transition (EMT). 10.1007/s10911-011-9215-3
    Versican G1 and G3 domains are upregulated and latent transforming growth factor-β binding protein-4 is downregulated in breast cancer stroma. Takahashi Yuko,Kuwabara Hiroko,Yoneda Masahiko,Isogai Zenzo,Tanigawa Nobuhiko,Shibayama Yuro Breast cancer (Tokyo, Japan) BACKGROUND:Cancers are supported by a distinct type of stroma, and versican is overexpressed in the stroma of malignant tumors, including breast cancer. Versican interacts with hyaluronan and fibrillin-1 at its amino terminus (G1) and carboxyl terminus (G3), respectively. Fibrillin-1 also associates with latent transforming growth factor-β binding protein (LTBP)-1 and -4. The detailed alteration of these molecules in breast cancer tissues is still unclear. METHODS:In 18 patients, alteration of versican, fibrillin-1 and LTBP-1 and 4 was elucidated in comparison with matched normal tissues, using real-time reverse transcriptase polymerase chain reaction, slot blotting and immunohistochemistry. The relationship between the protein expression and clinicopathological features was also investigated. RESULTS:In breast cancer tissues, mRNAs for versican V1 and V0 were upregulated, and the extracted protein levels of the versican G1 and G3 domains were increased. Meanwhile, LTBP-4 was decreased, and fibrillin-1 and LTBP-1 remained unchanged. The immunohistochemical observations were consistent with the biochemical findings, and the molecules were localized in the stromal tissue rather than in the cancer cells themselves. The expression of versican G3 and G1 domains was positively related to the Ki67 index of carcinoma cells and tumor size, respectively. CONCLUSION:The stromal alterations of versican and LTBP-4 might influence the carcinogenesis and progression of breast tumor cells and modulate their biological phenotypes. 10.1007/s12282-011-0264-7
    TGF-β signaling pathway and breast cancer susceptibility. Scollen Serena,Luccarini Craig,Baynes Caroline,Driver Kristy,Humphreys Manjeet K,Garcia-Closas Montserrat,Figueroa Jonine,Lissowska Jolanta,Pharoah Paul D,Easton Douglas F,Hesketh Robin,Metcalfe James C,Dunning Alison M Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology BACKGROUND:TGF-β acts as a suppressor of primary tumor initiation but has been implicated as a promoter of the later malignant stages. Here associations with risk of invasive breast cancer are assessed for single-nucleotide polymorphisms (SNP) tagging 17 genes in the canonical TGF-β ALK5/SMADs 2&3 and ALK1/SMADs 1&5 signaling pathways: LTBP1, LTBP2, LTBP4, TGFB1, TGFB2, TGFB3, TGFBR1(ALK5), ALK1, TGFBR2, Endoglin, SMAD1, SMAD2, SMAD3, SMAD4, SMAD5, SMAD6, and SMAD7 [Approved Human Gene Nomenclature Committee gene names: ACVRL1 (for ALK1) and ENG (for Endoglin)]. METHODS:Three-hundred-fifty-four tag SNPs (minor allele frequency > 0.05) were selected for genotyping in a staged study design using 6,703 cases and 6,840 controls from the Studies of Epidemiology and Risk Factors in Cancer Heredity (SEARCH) study. Significant associations were meta-analyzed with data from the NCI Polish Breast Cancer Study (PBCS; 1,966 cases and 2,347 controls) and published data from the Breast Cancer Association Consortium (BCAC). RESULTS:Associations of three SNPs, tagging TGFB1 (rs1982073), TGFBR1 (rs10512263), and TGFBR2 (rs4522809), were detected in SEARCH; however, associations became weaker in meta-analyses including data from PBCS and BCAC. Tumor subtype analyses indicated that the TGFB1 rs1982073 association may be confined to increased risk of developing progesterone receptor negative (PR(-)) tumors [1.18 (95% CI: 1.09-1.28), 4.1 × 10(-5) (P value for heterogeneity of ORs by PR status = 2.3 × 10(-4))]. There was no evidence for breast cancer risk associations with SNPs in the endothelial-specific pathway utilizing ALK1/SMADs 1&5 that promotes angiogenesis. CONCLUSION:Common variation in the TGF-β ALK5/SMADs 2&3 signaling pathway, which initiates signaling at the cell surface to inhibit cell proliferation, might be related to risk of specific tumor subtypes. IMPACT:The subtype specific associations require very large studies to be confirmed. 10.1158/1055-9965.EPI-11-0062
    Latent transforming growth factor binding protein 4 (LTBP4) is downregulated in mouse and human DCIS and mammary carcinomas. Kretschmer Celine,Conradi Anne,Kemmner Wolfgang,Sterner-Kock Anja Cellular oncology (Dordrecht) BACKGROUND:Transforming growth factor beta (TGF-ß) is able to inhibit the proliferation of epithelial cells and is involved in the carcinogenesis of mammary tumors. Three latent transforming growth factor-ß binding proteins (LTBPs) are known to modulate TGF-ß functions. METHODS:The current study analyses the expression profiles of LTBP4, its isoforms LTBP1 and LTBP3, and TGF-ß1, TGF-ß2, TGF-ß3, and SMAD2, SMAD3 and SMAD4 in human and murine (WAP-TNP8) DCIS compared to invasive mammary tumors. Additionally mammary malignant (MCF7, Hs578T, MDA-MB361) and non malignant cell lines (Hs578BsT) were analysed. Microarray, q-PCR, immunoblot, immunohistochemistry and immunofluorescence were used. RESULTS:In comparison to non-malignant tissues (n = 5), LTBP4 was downregulated in all human and mouse DCIS (n = 9) and invasive mammary adenocarcinomas (n = 5) that were investigated. We also found decreased expression of bone morphogenic protein 4 (BMP4) and increased expression of its inhibitor gremlin (GREM1). Treatment of the mammary tumor cell line (Hs578T) with recombinant TGF-ß1 rescued BMP4 and GREM1 expression. CONCLUSION:We conclude that the lack of LTBP4-mediated targeting in malignant mammary tumor tissues may lead to a possible modification of TGF-ß1 and BMP bioavailability and function. 10.1007/s13402-011-0023-y
    ATRA modulates mechanical activation of TGF-β by pancreatic stellate cells. Sarper Muge,Cortes Ernesto,Lieberthal Tyler J,Del Río Hernández Armando Scientific reports The hallmark of pancreatic ductal adenocarcinoma (PDAC) is abundant desmoplasia, which is orchestrated by pancreatic stellate cells (PSCs) and accounts for the majority of the stroma surrounding the tumour. Healthy PSCs are quiescent, but upon activation during disease progression, they adopt a myofibroblast-contractile phenotype and secrete and concomitantly reorganise the stiff extracellular matrix (ECM). Transforming growth factor β (TGF-β) is a potent activator of PSCs, and its activation requires spatiotemporal organisation of cellular and extracellular cues to liberate it from an inactive complex with latent TGF-β binding protein (LTBP). Here we study the mechanical activation of TGF-β by PSCs in vitro by investigating LTBP-1 organisation with fibrillar fibronectin and show that all trans-retinoic acid (ATRA), which induces PSC quiescence, down-regulates the ability of PSCs to mechanically organise LTBP-1 and activate TGF-β through a mechanism involving myosin II dependent contractility. Therefore, ATRA inhibits the ability of PSCs to mechanically release active TGF-β, which might otherwise act in an autocrine manner to sustain PSCs in an active state and a tumour-favouring stiff microenvironment. 10.1038/srep27639
    Knockdown of Latent Transforming Growth Factor-β (TGF-β)-Binding Protein 2 (LTBP2) Inhibits Invasion and Tumorigenesis in Thyroid Carcinoma Cells. Wan Fuqiang,Peng Li,Zhu ChaoYu,Zhang XinFa,Chen FangWen,Liu Tao Oncology research Latent transforming growth factor-β (TGF-β)-binding protein 2 (LTBP2) is one of four proteins in the LTBP family of proteins (LTBP1-4) and was shown to play a vital role in tumorigenesis. However, little is known regarding the functional role of LTBP2 in thyroid carcinoma. Therefore, the current study aimed to evaluate the effect of LTBP2 expression on the proliferation, invasion, and tumorigenesis in thyroid carcinoma cells and to explore the molecular mechanism of LTBP2 in tumor progression. Our results showed that the expression of LTBP2 is upregulated in human thyroid carcinoma and cell lines. Knockdown of LTBP2 inhibits the proliferation, invasion, and EMT phenotype in thyroid carcinoma cells. Furthermore, knockdown of LTBP2 attenuates thyroid carcinoma growth in nude mice. Finally, knockdown of LTBP2 inhibits activation of the PI3K/Akt pathway in thyroid carcinoma cells. In summary, the present study has provided further evidence that knockdown of LTBP2 inhibits invasion and tumorigenesis in thyroid carcinoma cells. Our findings may help to further elucidate the molecular mechanisms underlying thyroid carcinoma progression and provide candidate targets for the prevention and treatment of thyroid carcinoma. 10.3727/096504016X14755368915591
    Targeted deep sequencing of plasma circulating cell-free DNA reveals Vimentin and Fibulin 1 as potential epigenetic biomarkers for hepatocellular carcinoma. Holmila Reetta,Sklias Athena,Muller David C,Degli Esposti Davide,Guilloreau Paule,Mckay James,Sangrajrang Suleeporn,Srivatanakul Petcharin,Hainaut Pierre,Merle Philippe,Herceg Zdenko,Nogueira da Costa Andre PloS one Hepatocellular carcinoma (HCC) is the second most common cause of cancer death worldwide, but is still lacking sensitive and specific biomarkers for early diagnosis and prognosis. In this study, we applied targeted massively parallel semiconductor sequencing to assess methylation on a panel of genes (FBLN1, HINT2, LAMC1, LTBP1, LTBP2, PSMA2, PSMA7, PXDN, TGFB1, UBE2L3, VIM and YWHAZ) in plasma circulating cell-free DNA (cfDNA) and to evaluate the potential of these genes as HCC biomarkers in two different series, one from France (42 HCC cases and 42 controls) and one from Thailand (42 HCC cases, 26 chronic liver disease cases and 42 controls). We also analyzed a set of HCC and adjacent tissues and liver cell lines to further compare with 'The Cancer Genome Atlas' (TCGA) data. The methylation in cfDNA was detected for FBLN1, PSMA7, PXDN and VIM, with differences in methylation patterns between cases and controls for FBLN1 and VIM. The average methylation level across analyzed CpG-sites was associated with higher odds of HCC for VIM (1.48 [1.02, 2.16] for French cases and 2.18 [1.28, 3.72] for Thai cases), and lower odds of HCC for FBLN1 (0.89 [0.76, 1.03] for French cases and 0.75 [0.63, 0.88] for Thai cases). In conclusion, our study provides evidence that changes in VIM and FBLN1 methylation levels in cfDNA are associated with HCC and could represent useful plasma-based biomarkers. Also, the potential to investigate methylation patterns in cfDNA could bring new strategies for HCC detection and monitoring high-risk groups and response to treatment. 10.1371/journal.pone.0174265
    Protein signatures of molecular pathways in non-small cell lung carcinoma (NSCLC): comparison of glycoproteomics and global proteomics. Yang Shuang,Chen Lijun,Chan Daniel W,Li Qing Kay,Zhang Hui Clinical proteomics BACKGROUND:Non-small cell lung carcinoma (NSCLC) remains the leading cause of cancer deaths in the United States. More than half of NSCLC patients have clinical presentations with locally advanced or metastatic disease at the time of diagnosis. The large-scale genomic analysis of NSCLC has demonstrated that molecular alterations are substantially different between adenocarcinoma (ADC) and squamous cell carcinoma (SqCC). However, a comprehensive analysis of proteins and glycoproteins in different subtypes of NSCLC using advanced proteomic approaches has not yet been conducted. METHODS:We applied mass spectrometry (MS) technology featuring proteomics and glycoproteomics to analyze six primary lung SqCCs and eleven ADCs, and we compared the expression level of proteins and glycoproteins in tumors using quantitative proteomics. Glycoproteins were analyzed by enrichment using a chemoenzymatic method, solid-phase extraction of glycopeptides, and quantified by iTRAQ-LC-MS/MS. Protein quantitation was further annotated via Ingenuity Pathway Analysis. RESULTS:Over 6000 global proteins and 480 glycoproteins were quantitatively identified in both SqCC and ADC. ADC proteins (8337) consisted of enzymes (22.11%), kinases (5.11%), transcription factors (6.85%), transporters (6.79%), and peptidases (3.30%). SqCC proteins (6967) had a very similar distribution. The identified glycoproteins, in order of relative abundance, included membrane (42%) and extracellular matrix (>33%) glycoproteins. Oncogene-coded proteins (82) increased 1.5-fold among 1047 oncogenes identified in ADC, while 124 proteins from SqCC were up-regulated in tumor tissues among a total of 827 proteins. We identified 680 and 563 tumor suppressor genes from ADC and SqCC, respectively. CONCLUSION:Our systematic analysis of proteins and glycoproteins demonstrates changes of protein and glycoprotein relative abundance in SqCC (TP53, U2AF1, and RXR) and in ADC (SMARCA4, NOTCH1, PTEN, and MST1). Among them, eleven glycoproteins were upregulated in both ADC and SqCC. Two glycoproteins (ELANE and IGFBP3) were only increased in SqCC, and six glycoproteins (ACAN, LAMC2, THBS1, LTBP1, PSAP and COL1A2) were increased in ADC. Ingenuity Pathway Analysis (IPA) showed that several crucial pathways were activated in SqCC and ADC tumor tissues. 10.1186/s12014-017-9166-9
    Identifying and as a potential combination of prognostic biomarkers in pancreatic ductal adenocarcinoma using integrated bioinformatics analysis. Ding Jingyi,Liu Yanxi,Lai Yu PeerJ Background:Pancreatic ductal adenocarcinoma (PDAC) is a fatal malignant neoplasm. It is necessary to improve the understanding of the underlying molecular mechanisms and identify the key genes and signaling pathways involved in PDAC. Methods:The microarray datasets GSE28735, GSE62165, and GSE91035 were downloaded from the Gene Expression Omnibus. Differentially expressed genes (DEGs) were identified by integrated bioinformatics analysis, including protein-protein interaction (PPI) network, Gene Ontology (GO) enrichment, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. The PPI network was established using the Search Tool for the Retrieval of Interacting Genes (STRING) and Cytoscape software. GO functional annotation and KEGG pathway analyses were performed using the Database for Annotation, Visualization, and Integrated Discovery. Hub genes were validated via the Gene Expression Profiling Interactive Analysis tool (GEPIA) and the Human Protein Atlas (HPA) website. Results:A total of 263 DEGs (167 upregulated and 96 downregulated) were common to the three datasets. We used STRING and Cytoscape software to establish the PPI network and then identified key modules. From the PPI network, 225 nodes and 803 edges were selected. The most significant module, which comprised 11 DEGs, was identified using the Molecular Complex Detection plugin. The top 20 hub genes, which were filtered by the CytoHubba plugin, comprised , , , , , , , , , , , , , , , , , , , and . These genes were validated using The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) databases, and the encoded proteins were subsequently validated using the HPA website. The GO analysis results showed that the most significantly enriched biological process, cellular component, and molecular function terms among the 20 hub genes were cell adhesion, proteinaceous extracellular matrix, and calcium ion binding, respectively. The KEGG pathway analysis showed that the 20 hub genes were mainly enriched in ECM-receptor interaction, focal adhesion, PI3K-Akt signaling pathway, and protein digestion and absorption. These findings indicated that and appear to be involved in the progression of PDAC. Moreover, patient survival analysis performed via the GEPIA using TCGA and GTEx databases demonstrated that the expression levels of and were correlated with a poor prognosis in PDAC patients ( < 0.05). Conclusions:The results demonstrated that upregulation of and is associated with poor overall survival, and these might be a combination of prognostic biomarkers in PDAC. 10.7717/peerj.10419
    Comprehensive analysis of the lncRNA-miRNA-mRNA regulatory network for bladder cancer. Huang Minyu,Long Yi,Jin Yuzhu,Ya Wentong,Meng Dongdong,Qin Tianzi,Su Lize,Zhou Wei,Wu Jichao,Huang Chunhe,Huang Qun Translational andrology and urology Background:Long non-coding RNAs (lncRNAs) are essential regulators for various human cancers. However, these lncRNAs need to be further classified for cancer. In the present study, we identified novel competing endogenous RNA (ceRNA) network for bladder cancer (BC) and explored the gene functions of the ceRNA regulatory network. Methods:Differential gene expression analysis were performed on The Cancer Genome Atlas Urothelial Bladder Carcinoma (TCGA-BLCA) datasets to identify differentially expressed messenger RNAs (mRNAs), lncRNAs, and microRNAs (miRNAs). Based on the competing endogenous RNA (ceRNA) hypothesis, a lncRNA-miRNA-mRNA network was constructed using the StarBase database and visualization by Cytoscape software. Functional enrichment analyses of Gene Ontology and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway were performed via R package ClusterProfiler. The protein-protein interaction network was constructed by STRING database and visualization by Cytoscape. Finally, we used CIBERSORT and the TIMER database to analyze the immune infiltrations for BC. Results:The regulatory network was constructed via TCGA BLCA cohort. The differential expressions of lncRNA, miRNA, and mRNA were 186, 200, and 2,661, respectively. There were 106 lncRNA, miRNA, and mRNA included in the ceRNA network. In this network, Calcium Voltage-gated Channel Auxiliary Subunit Alpha2delta1 (CACNA2D1, P<0.001), domain containing engulfment adaptor1 (GULP1, P=0.001), latent transforming growth factor beta binding protein 1 (LTBP1, P=0.006), myosin light chain kinase (MYLK, P=0.001), serpin family E member 2 (SERPINE2, P=0.002), spectrin beta non-erythrocytic 2 (SPTBN2, P=0.047), and hsa-miR-590-3p (P<0.001) significantly affected the prognosis of BC patients. Functional enrichment analyses showed that the biological functions included negative regulation of protein phosphorylation, cell morphogenesis, and sensory organ morphogenesis. Important cancer pathways of KEGG included parathyroid hormone synthesis secretion action, the notch signaling pathway, MAPK signaling pathway, the Rap1 signaling pathway, signaling pathways regulating the pluripotency of stem cells, and the transforming growth factor-β signaling pathway. Our findings demonstrated that the ceRNA network has important biological functions and a significant influence on the prognosis of BC. Conclusions:The lncRNA-miRNA-mRNA network constructed in the present study could provide useful insight into the underlying tumorigenesis of BC, and can determine new molecular biomarkers for the diagnosis and therapeutical treatment of BC. 10.21037/tau-21-81
    The first stage of transforming growth factor beta1 activation is release of the large latent complex from the extracellular matrix of growth plate chondrocytes by matrix vesicle stromelysin-1 (MMP-3). Maeda S,Dean D D,Gomez R,Schwartz Z,Boyan B D Calcified tissue international Transforming growth factor beta-1 (TGF-beta1) is secreted in a biologically inactive form and stored in the extracellular matrix as a 290 kDa complex consisting of the mature TGF-beta1 homodimer (Mr 25 kDa), the latency-associated peptide (LAP; Mr 75 kDa), and the latent TGF-beta1 binding protein-1 (LTBP1; Mr 190 kDa). Latent TGF-beta1, composed of these three components, is known as the "large latent TGF-beta1 complex." In contrast, latent TGF-beta1 without LTBP1 is known as "small latent TGF-beta1." For all latent forms, dissociation of the TGF-beta1 homodimer from LAP is necessary for growth factor activation and acquisition of biological activity. Matrix vesicles produced by growth plate chondrocytes contain matrix metalloproteinases that can activate small latent TGF-beta1. The enzyme responsible for this is matrix metalloproteinase-3 (MMP-3), although matrix vesicles also contain MMP-2 and plasminogen activator. The present study tested the hypothesis that matrix vesicle enzymes are also involved in the release of the large latent TGF-beta1 complex stored in the extracellular matrix. Matrix vesicles were isolated from cultures of resting zone and growth zone chondrocytes and metalloproteinases present in the matrix vesicles extracted with guanidine-HCl. Chondrocyte extracellular matrices were prepared by lysing confluent cultures and removing the lysed cells. The matrices were incubated with matrix vesicle extracts and the release of total and active TGF-beta1 was determined. To determine if MMP-2 or MMP-3 was involved in the release, matrix vesicle extracts were preincubated with anti-MMP-2 antibody or anti-MMP-3 antibody to selectively deplete the enzyme activity. Matrices were also treated with rhMMP-2 or rhMMP-3. To determine the identity of the released protein(s), digests were separated on SDS-polyacrylamide gels and Western blotting analysis was performed using a specific antibody to LTBP1. Matrix vesicle extracts released both active and total (=latent + active) TGF-beta1 in a time-dependent manner, with peak release after 1 hour of incubation. The amount of total TGF-beta1 released was 10 times higher than the release of active TGF-beta1. The effect of the matrix vesicle extracts was dose-dependent; in addition, the amount and ratio of active to total TGF-b1 released was very similar, irrespective of the source of matrix or matrix vesicle extracts. Pre-incubation of matrix vesicle extracts with anti-MMP-3 antibody blocked the release of active and total TGF-beta1, whereas pre-incubation with pre-immune IgG or anti-MMP-2 antibody had no effect. The addition of rhMMP-3, but not rhMMP-2, caused a dose-dependent increase in the release of total, but not active, TGF-beta1. Western analysis confirmed that both matrix vesicle extracts and rhMMP-3 released the large latent TGF-beta1 complex from the matrix. In addition to the expected 290, 230, and 190 kDa bands, samples run without reduction also contained proteins of molecular weights 110 and 50 kDa that reacted with the anti-LTBP1 antibody. When these same samples were electrophoresed after reduction, the high molecular weight immunoreactive bands disappeared and three bands of molecular weight 75, 32, and 25 kDa were observed. These results indicate that matrix vesicles contain enzymes, especially MMP-3, which are responsible for the release of TGF-beta1 from the matrix, most of which is in latent form. Further, the data suggest that release of the large complex occurs via cleavage at several novel sites in the 130 kDa LTBP1 molecule. Since matrix vesicle MMP-3 is also able to activate small latent TGF-beta1, these results suggest that the large latent TGF-beta1 complex protects against activation of the small latent TGF-beta1. Thus, the data suggest that release of the large latent TGF-bl complex from the matrix and activation of the latent growth factor are only two steps of what must be at least a three-step process. 10.1007/s002230010032
    Identification of gastric cancer subtypes based on pathway clustering. Li Lin,Wang Xiaosheng NPJ precision oncology Gastric cancer (GC) is highly heterogeneous in the stromal and immune microenvironment, genome instability (GI), and oncogenic signatures. However, a classification of GC by combining these features remains lacking. Using the consensus clustering algorithm, we clustered GCs based on the activities of 15 pathways associated with immune, DNA repair, oncogenic, and stromal signatures in three GC datasets. We identified three GC subtypes: immunity-deprived (ImD), stroma-enriched (StE), and immunity-enriched (ImE). ImD showed low immune infiltration, high DNA damage repair activity, high tumor aneuploidy level, high intratumor heterogeneity (ITH), and frequent TP53 mutations. StE displayed high stromal signatures, low DNA damage repair activity, genomic stability, low ITH, and poor prognosis. ImE had strong immune infiltration, high DNA damage repair activity, high tumor mutation burden, prevalence of microsatellite instability, frequent ARID1A mutations, elevated PD-L1 expression, and favorable prognosis. Based on the expression levels of four genes (TAP2, SERPINB5, LTBP1, and LAMC1) in immune, DNA repair, oncogenic, and stromal pathways, we developed a prognostic model (IDOScore). The IDOScore was an adverse prognostic factor and correlated inversely with immunotherapy response in cancer. Our identification of new GC subtypes provides novel insights into tumor biology and has potential clinical implications for the management of GCs. 10.1038/s41698-021-00186-z
    Latent TGFβ complexes are transglutaminase cross-linked to fibrillin to facilitate TGFβ activation. Lockhart-Cairns Michael P,Cain Stuart A,Dajani Rana,Steer Ruth,Thomson Jennifer,Alanazi Yasmene F,Kielty Cay M,Baldock Clair Matrix biology : journal of the International Society for Matrix Biology TGFβ superfamily members are potent growth factors in the extracellular matrix with essential roles in all aspects of cellular behaviour. Latent TGFβ binding proteins (LTBPs) are co-expressed with TGFβ, essential for correct folding and secretion of the growth factor, to form large latent complexes. These large latent complexes bind extracellular proteins such as fibrillin for sequestration of TGFβ in the matrix, essential for normal tissue function, and dysregulated TGFβ signalling is a hallmark of many fibrillinopathies. Transglutaminase-2 (TG2) cross-linking of LTBPs is known to play a role in TGFβ activation but the underlying molecular mechanisms are not resolved. Here we show that fibrillin is a matrix substrate for TG2 and that TG2 cross-linked complexes can be formed between fibrillin and LTBP-1 and -3, and their latent TGFβ complexes. The structure of the fibrillin-LTBP1 complex shows that the two elongated proteins interact in a perpendicular arrangement which would allow them to form distal interactions between the matrix and the cell surface. Formation of the cross-link with fibrillin does not change the interaction between latent TGFβ and integrin αVβ6 but does increase TGFβ activation in cell-based assays. The activating effect may be due to direction of the latent complexes to the cell surface by fibrillin, as competition with heparan sulphate can ameliorate the activating effect. Together, these data support that TGFβ activation can be enhanced by covalent tethering of LTBPs to the matrix via fibrillin. 10.1016/j.matbio.2022.01.005
    Differential effects on lung and bone metastasis of breast cancer by Wnt signalling inhibitor DKK1. Zhuang Xueqian,Zhang Hao,Li Xiaoyan,Li Xiaoxun,Cong Min,Peng Fangli,Yu Jingyi,Zhang Xue,Yang Qifeng,Hu Guohong Nature cell biology Metastatic cancer is a systemic disease, and metastasis determinants might elicit completely different effects in various target organs. Here we show that tumour-secreted DKK1 is a serological marker of breast cancer metastasis organotropism and inhibits lung metastasis. DKK1 suppresses PTGS2-induced macrophage and neutrophil recruitment in lung metastases by antagonizing cancer cell non-canonical WNT/PCP-RAC1-JNK signalling. In the lungs, DKK1 also inhibits WNT/Ca-CaMKII-NF-κB signalling and suppresses LTBP1-mediated TGF-β secretion of cancer cells. In contrast, DKK1 promotes breast-to-bone metastasis by regulating canonical WNT signalling of osteoblasts. Importantly, targeting canonical WNT may not be beneficial to treatment of metastatic cancer, while combinatory therapy against JNK and TGF-β signalling effectively prevents metastasis to both the lungs and bone. Thus, DKK1 represents a class of Janus-faced molecules with dichotomous roles in organotropic metastasis, and our data provide a rationale for new anti-metastasis approaches. 10.1038/ncb3613
    Abrogation of both short and long forms of latent transforming growth factor-β binding protein-1 causes defective cardiovascular development and is perinatally lethal. Horiguchi Masahito,Todorovic Vesna,Hadjiolova Krassimira,Weiskirchen Ralf,Rifkin Daniel B Matrix biology : journal of the International Society for Matrix Biology Latent transforming growth factor-β binding protein-1 (LTBP-1) is an extracellular protein that is structurally similar to fibrillin and has an important role in controlling transforming growth factor-β (TGF-β) signaling by storing the cytokine in the extracellular matrix and by being involved in the conversion of the latent growth factor to its active form. LTBP-1 is found as both short (LTBP-1S) and long (LTBP-1L) forms, which are derived through the use of separate promoters. There is controversy regarding the importance of LTBP-1L, as Ltbp1L knockout mice showed multiple cardiovascular defects but the complete null mice did not. Here, we describe a third line of Ltbp1 knockout mice generated utilizing a conditional knockout strategy that ablated expression of both L and S forms of LTBP-1. These mice show severe developmental cardiovascular abnormalities and die perinatally; thus these animals display a phenotype similar to previously reported Ltbp1L knockout mice. We reinvestigated the other "complete" knockout line and found that these mice express a splice variant of LTBP-1L and, therefore, are not complete Ltbp1 knockouts. Our results clarify the phenotypes of Ltbp1 null mice and re-emphasize the importance of LTBP-1 in vivo. 10.1016/j.matbio.2015.03.006
    Hepatic cyclooxygenase-2 overexpression induced spontaneous hepatocellular carcinoma formation in mice. Chen H,Cai W,Chu E S H,Tang J,Wong C-C,Wong S H,Sun W,Liang Q,Fang J,Sun Z,Yu J Oncogene Cyclooxygenase (COX)-2 is upregulated in hepatocellular carcinoma (HCC). However, the direct causative effect of COX-2 in spontaneous HCC formation remains unknown. We thus investigate the role and molecular pathogenesis of COX-2 in HCC by using liver-specific COX-2 transgenic (TG) mice. We found spontaneous HCC formation with elevated inflammatory infiltrates and neovessels in male TG mice (3/21, 14.3%), but not in any of male WT mice (0/19). Reduced representation bisulfite sequencing (RRBS) and gene expression microarrays were performed in the HCC tumor and non-HCC liver tissues to investigate the molecular mechanisms of COX-2-driven HCC. By RRBS, DNA promoter hypermethylation was identified in HCC from TG mice. Induction of promoter hypermethylation was associated with reduced tet methylcytosine dioxygenase 1 (TET1) expression by COX-2. TET1 could catalyze the conversion of 5-methylcytosine into 5-hydroxymethylcytosine (5hmC) and prevents DNA hypermethylation. In keeping with this, loss of 5hmC was demonstrated in COX-2-induced HCC. Consistently, COX-2 overexpression in human HCC cell lines could reduce both TET1 expression and 5hmc levels. Integrative analyses of DNA methylation and gene expression profiles further identified significantly downregulated genes including LTBP1, ADCY5 and PRKCZ by promoter methylation in COX-2-induced HCC. Reduced expression of LTBP1, ADCY5 and PRKCZ by promoter hypermethylation was further validated in human HCCs. Bio-functional investigation revealed that LTBP1 inhibited cell proliferation in HCC cell lines, suggesting its potential role as a tumor suppressor in HCC. Gene expression microarrays revealed that signaling cascades (AKT (protein kinase B), STK33 (Serine/Threonine kinase 33) and MTOR (mechanistic target of rapamycin) pathways) were enriched in COX-2-induced HCC. In conclusion, this study demonstrated for the first time that enhanced COX-2 expression in hepatocytes is sufficient to induce HCC through inducing promoter hypermethylation by reducing TET1, silencing tumor-suppressive genes and activating key oncogenic pathways. Inhibition of COX-2 represents a mechanism-based target for HCC prevention. 10.1038/onc.2017.73
    CD109 regulates in vivo tumor invasion in lung adenocarcinoma through TGF-β signaling. Taki Tetsuro,Shiraki Yukihiro,Enomoto Atsushi,Weng Liang,Chen Chen,Asai Naoya,Murakumo Yoshiki,Yokoi Kohei,Takahashi Masahide,Mii Shinji Cancer science Stromal invasion is considered an important prognostic factor in patients with lung adenocarcinoma. The mechanisms underlying the formation of tumor stroma and stromal invasion have been studied in the lung; however, they are still unclear. CD109 is a glycosylphosphatidylinositol-anchored glycoprotein highly expressed in several types of human malignant tumors including lung cancers. In this study, we investigated the in vivo functions of CD109 protein in malignant lung tumors. Initially, we identified an association between higher expression of CD109 protein in human lung adenocarcinoma and a significantly worse prognosis, according to immunohistochemical analysis. We also showed that CD109 deficiency significantly reduced the area of stromal invasive lesions in a genetically engineered CD109-deficient lung adenocarcinoma mouse model, which correlated with the results observed in human lung adenocarcinoma. Furthermore, we identified latent TGF-β binding protein-1 (LTBP1) as a CD109-interacting protein using mass spectrometry and confirmed their interaction by co-immunoprecipitation. Importantly, increased CD109 expression enhanced stromal TGF-β activation in the presence of LTBP1. Therefore, these data suggest the significance of the regulation of TGF-β signaling through CD109 and LTBP1 interaction in tumor stroma and also reveal the importance of CD109 expression levels in promoting lung cancer cell proliferation, migration, and invasion, and thus predicting the outcome of patients suffering from lung adenocarcinoma. Therefore, CD109 protein could be a potential therapeutic target for this disease. 10.1111/cas.14673
    Marek's disease virus-encoded analog of microRNA-155 activates the oncogene c-Myc by targeting LTBP1 and suppressing the TGF-β signaling pathway. Chi Jia-Qi,Teng Man,Yu Zu-Hua,Xu Hui,Su Jing-Wei,Zhao Pu,Xing Guang-Xu,Liang Hong-De,Deng Rui-Guang,Qu Liang-Hu,Zhang Gai-Ping,Luo Jun Virology Marek's disease virus (MDV) is a representative alpha herpes virus able to induce rapid-onset T-cell lymphoma in its natural host and regarded as an ideal model for the study of virus-induced tumorigenesis. Recent studies have shown that the mdv1-miR-M4-5p, a viral analog of cellular miR-155, is critical for MDV׳s oncogenicity. However, the precise mechanism whereby it was involved in MD lymphomagenesis remained unknown. We have presently identified the host mRNA targets of mdv1-miR-M4-5 and identified the latent TGF-β binding protein 1 (LTBP1) as a critical target for it. We found that during MDV infection, down-regulation of LTBP1 expression by mdv1-miR-M4-5p led to a significant decrease of the secretion and activation of TGF-β1, with suppression of TGF-β signaling and a significant activation of expression of c-Myc, a well-known oncogene which is critical for virus-induced tumorigenesis. Our findings reveal a novel and important mechanism of how mdv1-miR-M4-5p potentially contributes to MDV-induced tumorigenesis. 10.1016/j.virol.2014.11.027
    LTBP1 promotes esophageal squamous cell carcinoma progression through epithelial-mesenchymal transition and cancer-associated fibroblasts transformation. Journal of translational medicine BACKGROUND:Esophageal squamous cell carcinoma (ESCC) is one of the most prevalent cancers worldwide. Due to its high morbidity and mortality rates, it is urgent to find a molecular target that contributes to esophageal carcinogenesis and progression. In this research, we aimed to investigate the functions of Latent transforming growth factor β binding protein 1(LTBP1) in ESCC progression and elucidate the underlying mechanisms. METHODS:The tandem mass tag-based quantitative proteomic approach was applied to screen the differentially expressed proteins (DEPs) between 3 cases of ESCC tumor samples and paired normal tissues. Then the DEPs were validated in human ESCC tissues using western blot assays and GEPIA database respectively. The expression level of LTBP1 was detected in 152 cases of ESCC tissues and paired normal tissues. Loss-of-function assays were performed to detect the function of LTBP1 in vivo and in vitro. Immunofluorescence and Western blot assays were used to detect the expression of apoptosis, epithelial-mesenchymal transition (EMT) and cancer-associated fibroblasts (CAFs) markers. RESULTS:A total of 39 proteins were screened to be up-regulated (ratio > 2.0) in all three ESCC tissues. The results of immunohistochemistry assays indicated that the expression level of LTBP1 was higher in ESCC tissues than that in paired normal tissues (p < 0.001). Overexpression of LTBP1 was positively associated with lymphatic metastasis in ESCC (p = 0.002). Down-regulation of LTBP1 inhibited the invasion and migration as well as metastatic abilities in vitro and in vivo. It was also observed the down-regulation of LTBP1 not only decreased the mesenchymal phenotypes but also inhibited TGFβ-induced EMT in ESCC cells. We further found that down-regulation of LTBP1 enhanced ESCC cells' sensitivity to 5-FU treatment. Inhibition of LTBP1 expression could also attenuate induction of CAFs transformation and restrain fibroblast express fibronectin (FN1) in ESCC cells. CONCLUSION:Overexpression of LTBP1 was associated with lymph node metastasis in ESCC. Our results indicated that LTBP1 not only increased the malignant behaviors of ESCC cells but also induced EMT and CAFs transformation. Our studies suggested an oncogenic role of LTBP1 in ESCC progression and it may serve as a potential therapeutic target for ESCC patients. 10.1186/s12967-020-02310-2
    LTBP1-ALK: A novel fusion identified in malignant pleural effusions from a patient with advanced lung adenocarcinoma. Lung cancer (Amsterdam, Netherlands) 10.1016/j.lungcan.2020.03.025
    Suppression of latent transforming growth factor-β (TGF-β)-binding protein 1 (LTBP1) inhibits natural killer/ T cell lymphoma progression by inactivating the TGF-β/Smad and p38 pathways. Lin Rui,Li Xiaoli,Wu Shaoxuan,Qian Siyu,Hou Huting,Dong Meng,Zhang Xudong,Zhang Mingzhi Experimental cell research BACKGROUND:Natural killer/T cell lymphoma (NKTCL) is a distinct subtype of Non-Hodgkin's lymphoma with highly aggressive clinical behavior. We aim to investigate the function of Latent transforming growth factor β binding protein 1 (LTBP1) and transforming growth factor beta1 (TGF-β1) and complex molecular pathogenesis of this disease. METHODS:NKTCL patients and reactive lymph nodes patients were recruited in this study. The expression of LTBP1 and TGF-β1 was examined using qRT-PCR, Western blot, IHC and ELISA analyses in biopsied tissues and serum from participants and NKTCL cell lines. Cell proliferation was determined using CFSE. Cell cycle and apoptosis were evaluated using flow cytometric analyses. The expression of Ki-67, CDK4 and cyclinD1 proteins was measured using Western blot analyses. The roles of LTBP-1/TGF-β1 in EMT program were determined by measuring E-cadherin, N-cadherin and Vimentin using Western blot analyses. The effects of LTBP-1 and TGF-β1 on tumor progression in vivo were determined by animal experiments. RESULTS:LTBP-1 and TGF-β1 levels were elevated in NKTCL tissues and serum. The expression of LTBP-1 was positively correlated with the expression of TGF-β1 in NKTCL tissues. LTBP-1 was overexpressed in NKTCL cells. Knockdown of LTBP-1 suppressed cell proliferation and cell cycle progression, induced cell apoptosis, and suppressed EMT program in NKTCL cells. These effects of LTBP-1 knockdown were attenuated after TGF-β1 stimulation. Knockdown of LTBP-1 inhibited NKTCL tumor weight and volume in vivo. Also, stimulation of TGF-β1 attenuated the suppressive effects on tumor growth from sh-LTBP-1. Silencing of LTBP-1 lowered cellular TGF-β1, phosphorylated-Smad2, phosphorlyatd-Smad3, and phosphorylated-p38 and the suppressive effects were reversed after stimulation of TGF-β1. CONCLUSION:Our findings suggested that inhibition of LTBP-1/TGF-β1 suppressed the malignant phenotypes of NKTCL cells and tumor growth via inactivating the canonical TGF-β/Smad signaling and p38 signaling. 10.1016/j.yexcr.2021.112790