LC-MS based sphingolipidomic study on A549 human lung adenocarcinoma cell line and its taxol-resistant strain.
Huang Hao,Tong Tian-Tian,Yau Lee-Fong,Chen Cheng-Yu,Mi Jia-Ning,Wang Jing-Rong,Jiang Zhi-Hong
BACKGROUND:Resistance to chemotherapy drugs (e.g. taxol) has been a major obstacle in successful cancer treatment. In A549 human lung adenocarcinoma, acquired resistance to the first-line chemotherapy taxol has been a critical problem in clinics. Sphingolipid (SPL) controls various aspects of cell growth, survival, adhesion, and motility in cancer, and has been gradually regarded as a key factor in drug resistance. To better understand the taxol-resistant mechanism, a comprehensive sphingolipidomic approach was carried out to investigate the sphingolipid metabolism in taxol-resistant strain of A549 cell (A549T). METHODS:A549 and A549T cells were extracted according to the procedure with optimal condition for SPLs. Sphingolipidomic analysis was carried out by using an UHPLC coupled with quadrupole time-of-flight (Q-TOF) MS system for qualitative profiling and an UHPLC coupled with triple quadrupole (QQQ) MS system for quantitative analysis. The differentially expressed sphingolipids between taxol-sensitive and -resistant cells were explored by using multivariate analysis. RESULTS:Based on accurate mass and characteristic fragment ions, 114 SPLs, including 4 new species, were clearly identified. Under the multiple reaction monitoring (MRM) mode of QQQ MS, 75 SPLs were further quantified in both A549 and A549T. Multivariate analysis explored that the levels of 57 sphingolipids significantly altered in A549T comparing to those of A549 (p < 0.001 and VIP > 1), including 35 sphingomyelins (SMs), 14 ceramides (Cers), 3 hexosylceramides (HexCers), 4 lactosylceramides (LacCers) and 1 sphingosine. A significant decrease of SM and Cer levels and overall increase of HexCer and LacCer represent the major SPL metabolic characteristic in A549T. CONCLUSIONS:This study investigated sphingolipid profiles in human lung adenocarcinoma cell lines, which is the most comprehensive sphingolipidomic analysis of A549 and A549T. To some extent, the mechanism of taxol-resistance could be attributed to the aberrant sphingolipid metabolism, "inhibition of the de novo synthesis pathway" and "activation of glycosphingolipid pathway" may play the dominant role for taxol-resistance in A549T. This study provides insights into the strategy for clinical diagnosis and treatment of taxol resistant lung cancer.
Comparative proteomic analysis of paclitaxel sensitive A549 lung adenocarcinoma cell line and its resistant counterpart A549-Taxol.
Sun Qiang-Ling,Sha Hui-Fang,Yang Xiao-Hua,Bao Guo-Liang,Lu Jing,Xie Yin-Yin
Journal of cancer research and clinical oncology
PURPOSE:Paclitaxel is used as the first-line chemotherapy for Non-Small Cell Lung Cancer (NSCLC), but acquired resistance becomes a critical problem. Several mechanisms have been proposed in paclitaxel resistance, but they are not sufficient to exhaustively explain this resistance emergence. To better investigate molecular resistance mechanisms, a comparative proteomic approach was carried out to identify differentially expressed proteins between human lung adenocarcinoma A549 cell line (paclitaxel sensitive) and A549-Taxol cell line (acquired resistant). METHODS:A paclitaxel-resistant subline (A549-Taxol) derived from the parental-sensitive cell line A549 was established by stepwise selection by paclitaxel. Total proteins in the two cell lines were separated by fluorescent differential gel electrophoresis (DIGE). Image analysis was carried out with the DeCyder 2D 6.5 software. Proteins associated with chemoresistance process were identified by matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry (MALDI-TOF-MS/MS). Some key molecules were valuated by Western blot. RESULTS:Thirty proteins were identified and grouped into eight main functional classes according to the biological processes in which they are likely to participate, i.e. signal transduction, cytoskeleton, redox reaction, energy and metabolism, and so on. Alterations of these processes might be involved in paclitaxel resistance. Most of the proteins showed mitochondrial and cytoplasm location. The up-regulation of CK8, CK18, ALDH1, CAST and ANX I in A549-Taxol cell line was verified by Western blot, in coincidence with the data obtained from proteomic analysis. CONCLUSION:For the first time, differentially expressed proteins between paclitaxel-sensitive cell line and paclitaxel-resistant one were explored by comparative proteomic approach in human lung adenocarcinoma. It may be useful for further studying of resistance mechanisms and screening of resistance biomarkers, so as to develop tailored therapeutic strategies.
Establishment of a paclitaxel resistant human breast cancer cell strain (MCF-7/Taxol) and intracellular paclitaxel binding protein analysis.
Zuo K-Q,Zhang X-P,Zou J,Li D,Lv Z-W
The Journal of international medical research
Multidrug resistance of tumours is one of the most important factors that leads to chemotherapy failure. A multidrug-resistant breast cancer cell line, MCF-7/Taxol, was established from the drug-sensitive parent cell line MCF-7. The biological properties of MCF-7/Taxol, including its drug resistance profile and profile of paclitaxel binding proteins, were analysed and compared with the parent cell line. A number of paclitaxel binding proteins were present in MCF-7 cells but absent from MCF-7/Taxol cells, namely heat shock protein 90, actinin and dermcidin precursor. The identification of differential paclitaxel binding proteins between the multidrug-resistant MCF-7/Taxol cell line and the parent drug-sensitive cell line MCF-7 provides insight into possible mechanisms involved in resistance to these chemotherapy drugs.
MiR-1204 sensitizes nasopharyngeal carcinoma cells to paclitaxel both in vitro and in vivo.
Peng Xiaowei,Cao Peiguo,Li Jingjing,He Dong,Han Shuang,Zhou Jianda,Tan Guolin,Li Wei,Yu Fenghui,Yu Jianjun,Li Zan,Cao Ke
Cancer biology & therapy
Nasopharyngeal carcinoma (NPC) is an endemic tumor with a relatively high incidence in Southern China and Southeast Asia. Paclitaxel combination chemotherapy has been used for treatment of advanced NPC. However, treatment failure often occurs due to development of acquired paclitaxel resistance. In this study, we first established a paclitaxel-resistant CNE-1/Taxol, HNE-2/Taxol and 5-8F/Taxol cell sublines by treating the parental CNE-1, HNE-2 and 5-8F cells with increasing doses of paclitaxel for about 5 months, respectively. Then, microRNA arrays were used to screen differentially expressed miRNAs between the CNE-1/Taxol cells and the parental CNE-1 cells. We found 13 differentially expressed miRNAs, of which miR-1204 was significantly downregulated in the paclitaxel-resistant CNE-1/Taxol cells. We restored miR-1204 expression in the CNE-1/Taxol, HNE-2/Taxol and 5-8F/Taxol cells and found that restoration of miR-1204 re-sensitized the paclitaxel-resistant CNE-1/Taxol, HNE-2/Taxol and 5-8F/Taxol cells to paclitaxel both in vitro. Finally, we demonstrated that restoration of miR-1204 in significantly inhibits tumor growth in vivo. Thus, our study provides important information for the development of targeted gene therapy for reversing paclitaxel resistance in NPC.
Isolation of Taxol-Producing Endophytic Fungi from Iranian Yew Through Novel Molecular Approach and Their Effects on Human Breast Cancer Cell Line.
Kasaei Abdollah,Mobini-Dehkordi Mohsen,Mahjoubi Foruzandeh,Saffar Behnaz
Taxol or paclitaxel, an approved drug by the Food and Drug Administration, is being used for the treatment of human cancers. This study aimed to isolate and determine different species of native endophytic fungi from Iranian Taxus baccata (yew) plants located in the northern forests of Iran. To do so, a novel molecular screening approach was performed for 50 isolated endophytic fungi through amplification of exon No. 1 of taxadine synthase as a key gene in taxol production pathway. We used effective colony-polymerase chain reaction technique for rapid screening of potent taxol-producing fungi instead of genomic DNA extraction. Production of taxol was performed in batch culture by selected fungi individually and produced taxol was assayed quantitatively by high-performance liquid chromatography using standard taxanes. We found that only six fungi could produce taxol and baccatin III. Interestingly, after 7 days of incubation, the highest level of taxol was found to be 129 and that of baccatin 139.2 mg/kg dw for two native isolated Cladosporium sp. named F1 and F3. The fungal taxols could decrease cell viability in MTT assay same as commercial taxol. The fungal taxols semi-quantitatively showed antimitotic effects on MCF-7 cells as human breast cancer cell line. The expression of bcl-2 anti-apoptotic gene, in contrast to bax pro-apoptotic gene, significantly decreased after treatment by standard and fungal taxols. As fungal taxol was produced simpler than other methods and could significantly affect viability and specific genes expression profile, it is recommended that using of taxol-producing fungi from Iranian yew could be a safe and confident procedure to overcome challenges of using other methods.
[Effect of estrogen or progesterone combined with paclitaxel on human ovarian cancer cell growth and Drosha expression].
Yang Yunjie,Han Ke,Xie Yulian
Zhonghua zhong liu za zhi [Chinese journal of oncology]
OBJECTIVE:To investigate the effect of estrogen (E2), progesterone(P4), and paclitaxel (taxol) on the growth of primary human ovarian cancer cells in vitro and the expression of Drosha. METHODS:Human ovarian cancer cells were treated with estrogen, progesterone or in combination with paclitaxel in vitro. The inhibition rate of ovarian cancer cells was assessed by methyl thiazolyl tetrazolium (MTT) assay. Apoptosis rate and cell cycle were determined by FACS analysis. The relative abundence of Drosha expression was detected by real-time quantitative PCR (qRT-PCR) and Western blotting. RESULTS:The inhibition rate of the estrogen group, progesterone group, paclitaxel group, E2(+)Taxol group, P4(+)Taxol group was (31.53 ± 8.21)%, (25.22 ± 15.50)%, (46.71 ± 4.25)%, (69.46 ± 3.71)%, and (47.35 ± 39.02)%, respectively, significantly higher than that of the control group (0%, P<0.05 for all). Relative to the ER (-) in ovarian cancer cells,Drosha mRNA expression level of estrogen group, progesterone group, paclitaxel group, E2(+) Taxol group,and P4(+)Taxol group was 1.62 ± 0.10,1.60 ± 0.10,1.75 ± 0.16,1.95 ± 0.20, and 1.53 ± 0.06, respectively, significantly higher than that of the control group (1.00, P<0.05 for all). Relative to the ER (+)in ovarian cancer cells,the Drosha mRNA expression level of estrogen group, progesterone group, paclitaxel group, E2(+)taxol group, and P4(+)Taxol group was 1.03 ± 0.14, 1.60 ± 0.09, 1.75 ± 0.16, 1.60 ± 0.10, 1.53 ± 0.06, respectively except estrogen group, significantly higher than that of the control group (1.00, P<0.05). Relative to the ER (-) in ovarian cancer cells, the Drosha protein expression levels of the control group, estrogen group, progesterone group, paclitaxel group, E2(+) taxol group, and P4(+) Taxol group were 0.25 ± 0.05, 0.87 ± 0.30, 0.85 ± 0.38, 1.30 ± 0.21, 1.75 ± 0.83, 1.62 ± 0.82, respectively, with a significant difference between the experimental groups and the control group (P<0.05). Relative to the ER(+)ovarian cancer cells, the Drosha protein expression levels in the estrogen group, progesterone group, paclitaxel group, E2(+) taxol group, and P4(+) taxol group, were 0.28 ± 0.16, 0.85 ± 0.38, 1.30 ± 0.21, 0.94 ± 0.18, and 1.62 ± 0.82, respectively except estrogen group, significantly higher than that of the control group (0.25 ± 0.05, P<0.05 for all). CONCLUSIONS:Estrogen and progesterone in combination with paclitaxel can inhibit the growth of human ovarian cancer cells in vitro, and affect the cell apoptosis rate. Estrogen and taxol can alter the cell cycle. Estrogen and progesterone combined with paclitaxel show tumor suppressing or sensitizing effect through upregulated Drosha expression, and are associated with the estrogen receptor expression.
Cytotoxicity of Tanshinone IIA combined with Taxol on drug-resist breast cancer cells MCF-7 through inhibition of Tau.
Lin Hui,Zheng Luya,Li Shixiao,Xie Bojian,Cui Binbin,Xia Aixiao,Lin Zhong,Zhou Peng
Phytotherapy research : PTR
Drug resistance represents a major obstacle to improving the overall response and survival of cancer patients. Taxol is one of the most commonly used chemotherapy agents in breast cancer. As with many cancer therapeutic agents, resistance remains a significant problem when using Taxol to treat malignancies. In this study, estrogen receptor positive breast cancer cells MCF-7 were induced Taxol resistance. And Tanshinone IIA combined with Taxol was chosen to treat it. The drugs combination showed additive effect in most drug concentrations. Drug resistance cancer cells showed a higher microtubule associated protein (Tau) expression, which was considered as one of the reasons for Taxol resistance. Tanshinone IIA inhibited the expression of Tau in MCF-7 cells and resulted in higher sensibility of Taxol. Moreover, Tanshinone IIA also showed cytotoxicity to MCF-7, which might be related to its estrogenicity effect. In conclusion, the combination of Tanshinone IIA and Taxol showed higher cytotoxicity to Taxol resistant MCF-7 cells, which might be related to the inhibition of Tau.
Anti-tubulin agents of natural origin: Targeting taxol, vinca, and colchicine binding domains.
Naaz Fatima,Haider Md Rafi,Shafi Syed,Yar M Shahar
European journal of medicinal chemistry
Microtubules are a protein which is made of α- and β-heterodimer. It is one of the main components of the cell which play a vital role in cell division especially in G2/M-phase. It exists in equilibrium dynamic of polymerization and depolymerization of α- and β-heterodimer. It is one of the best targets for developing anti-cancer drugs. Various natural occurring molecules are well known for their anti-tubulin effect such as vinca, paclitaxel, combretastatin, colchicine etc. These microtubule-targeted drugs are acted through two processes (i) inhibiting depolymerization of tubulin (tubulin stabilizing agents) and (ii) inhibiting polymerization of tubulin (tubulin destabilizing agents). Now days, various binding domains have been explore through which these molecules are binding to tubulin but the three major binding domain of tubulin are taxol, vinca and colchicine binding domain. The present article mainly focus on the classification of various naturally occurring compounds on the basis of their inhibition processes (depolymerization and polymerization) and the site of interaction (targets taxol, vinca and colchicine binding domain) which has been hitherto reported. By placing all the naturally occurring taxol, vinca and colchicine binding site analogues at one place makes a better understanding of the tubulin interactions with known natural tubulin binders that would helps in the discovery of new and potent natural, semi-synthetic and synthetic analogues for treating cancer.
Abraxane® versus Taxol® for patients with advanced breast cancer: A prospective time and motion analysis from a Chinese health care perspective.
Dranitsaris George,Yu Bo,Wang Leiping,Sun Weili,Zhou Yan,King Jennifer,Kaura Satyin,Zhang Adams,Yuan Peng
Journal of oncology pharmacy practice : official publication of the International Society of Oncology Pharmacy Practitioners
BACKGROUND:Abraxane® and Taxol® are both effective drugs for the treatment of advanced stage breast cancer. However, each agent possesses unique drug delivery characteristics with the former not requiring premedication and having a considerably shorter recommended infusion time (i.e. 30 min vs. 2-4 h). To measure the overall efficiency and cost-saving potential associated with Abraxane® relative to Taxol®, a time and motion study was undertaken in breast cancer patients treated in China. METHODS:Baseline patient data collection included age, disease stage, number and sites of metastatic disease, and performance status. Time and resource use data were then collected from breast patients being treated with Abraxane® (n = 12) or Taxol® (n = 15) in one of three cancer clinics located in Jiangsu, Shanghai, and Beijing. Resource use and time impact on clinical staff were quantified using unit cost estimates. This included costs for drug preparation, administration, materials and supplies, premedication, patient chair time, labor costs, and all acute adverse drug reactions. Outcomes were presented as a mean total time and cost for delivering a dose of Abraxane® or Taxol® and were compared using parametric and non-parametric statistical tests where appropriate. All costs were reported in US dollars (US$1 = 6.1 RMB, as of January 2014). RESULTS:Patients were comparable with respect to mean age, number of metastatic sites, and performance status. Approximately 9 of 12 (75%) patients received Abraxane® as on a weekly schedule (vs. every 3 weeks) compared to 6 of 15 (40%) with Taxol®. There were 5 (33.3%) acute adverse drug reactions with Taxol®, 3 of which required a physician visit and the initiation of supportive interventions. In contrast, there was only one minor event with Abraxane® (8.3%), which was easily managed with a temporary stoppage of the infusion. From the time and motion study, the mean total time for Abraxane® and Taxol® delivery (preparation, administration, premedication, total chair time, and adverse effects management) was 84 and 282 min respectively (p < 0.001), with the associated costs being US$59 and US$254 respectively per dose (p < 0.001). CONCLUSION:To our knowledge, this is first such study in breast cancer patients to be undertaken in China. Abraxane® was associated with fewer acute adverse drug reactions and significant reductions in health care resources, physician/nurse time and overall drug delivery costs compared to Taxol®.
CXCR4 blockade with AMD3100 enhances Taxol chemotherapy to limit ovarian cancer cell growth.
Reeves Patrick M,Abbaslou Mojgan A,Kools Farah R W,Poznansky Mark C
The standard of care for ovarian cancer includes initial treatment with chemotherapy. Despite initial efficacy, over 70% of patients develop recurrence; thus, there is a need to identify novel approaches that can improve therapeutic outcomes. We evaluated AMD3100 (Plerixafor), an FDA-approved CXCR4 inhibitor, as a potential adjunctive therapy for low-dose Taxol (Paclitaxel) by assessing the impact on in-vitro ovarian cancer cell proliferation. Proliferation was a measure for both human TOV-112D and murine ID8 ovarian cancer cells incubated with AMD3100 and Taxol, either individually or in combination. Impact of treatment was first determined for the simultaneous administration of AMD3100 and Taxol. We next assessed a sequential application of AMD3100 pretreatment, followed by AMD3100, Taxol, or a combination to test for sensitization to Taxol. In addition, we measured the impact of AMD3100 and Taxol, individually and in combination, on colony formation, an in-vitro model assay of tumor growth. Expression data, as measured by flow cytometry, show that both ID8 and TOV-112D cells are positive for CXCR4, CXCR7, and CXCL12. Combination treatment with AMD3100 (≤10 μmol/l) sensitized both ID8 and TOV-112D cells to low concentrations of Taxol (≤5 nmol/l), limiting cell proliferation and colony formation in vitro. Pretreatment with AMD3100 significantly increased the sensitivity of human ovarian cancer to low-dose Taxol or the combination of AMD3100 and Taxol, although this effect was not evident in murine cells. Importantly, for both human and murine cells, incubation with a combination of AMD3100 and Taxol had the largest impact on limiting cell proliferation. AMD3100 in combination with low-dose Taxol offers improved efficacy and the potential of reduced toxicity for the treatment of ovarian cancer.
Iso-Seq analysis of the Taxus cuspidata transcriptome reveals the complexity of Taxol biosynthesis.
Kuang Xuejun,Sun Sijie,Wei Jianhe,Li Ying,Sun Chao
BMC plant biology
BACKGROUND:Taxus cuspidata is well known worldwide for its ability to produce Taxol, one of the top-selling natural anticancer drugs. However, current Taxol production cannot match the increasing needs of the market, and novel strategies should be considered to increase the supply of Taxol. Since the biosynthetic mechanism of Taxol remains largely unknown, elucidating this pathway in detail will be very helpful in exploring alternative methods for Taxol production. RESULTS:Here, we sequenced Taxus cuspidata transcriptomes with next-generation sequencing (NGS) and third-generation sequencing (TGS) platforms. After correction with Illumina reads and removal of redundant reads, more than 180,000 nonredundant transcripts were generated from the raw Iso-Seq data. Using Cogent software and an alignment-based method, we identified a total of 139 cytochrome P450s (CYP450s), 31 BAHD acyltransferases (ACTs) and 1940 transcription factors (TFs). Based on phylogenetic and coexpression analysis, we identified 9 CYP450s and 7 BAHD ACTs as potential lead candidates for Taxol biosynthesis and 6 TFs that are possibly involved in the regulation of this process. Using coexpression analysis of genes known to be involved in Taxol biosynthesis, we elucidated the stem biosynthetic pathway. In addition, we analyzed the expression patterns of 12 characterized genes in the Taxol pathway and speculated that the isoprene precursors for Taxol biosynthesis were mainly synthesized via the MEP pathway. In addition, we found and confirmed that the alternative splicing patterns of some genes varied in different tissues, which may be an important tissue-specific method of posttranscriptional regulation. CONCLUSIONS:A strategy was developed to generate corrected full-length or nearly full-length transcripts without assembly to ensure sequence accuracy, thus greatly improving the reliability of coexpression and phylogenetic analysis and greatly facilitating gene cloning and characterization. This strategy was successfully utilized to elucidate the Taxol biosynthetic pathway, which will greatly contribute to the goals of improving the Taxol content in Taxus spp. using molecular breeding or plant management strategies and synthesizing Taxol in microorganisms using synthetic biological technology.
Anaphase Chromosomes in Crane-Fly Spermatocytes Treated With Taxol (Paclitaxel) Accelerate When Their Kinetochore Microtubules Are Cut: Evidence for Spindle Matrix Involvement With Spindle Forces.
Forer Arthur,Sheykhani Rozhan,Berns Michael W
Frontiers in cell and developmental biology
Various experiments have indicated that anaphase chromosomes continue to move after their kinetochore microtubules are severed. The chromosomes move poleward at an accelerated rate after the microtubules are cut but they slow down 1-3 min later and move poleward at near the original speed. There are two published interpretations of chromosome movements with severed kinetochore microtubules. One interpretation is that dynein relocates to the severed microtubule ends and propels them poleward by pushing against non-kinetochore microtubules. The other interpretation is that components of a putative "spindle matrix" normally push kinetochore microtubules poleward and continue to do so after the microtubules are severed from the pole. In this study we distinguish between these interpretations by treating cells with taxol. Taxol eliminates microtubule dynamics, alters spindle microtubule arrangements, and inhibits dynein motor activity . If the dynein interpretation is correct, taxol should interfere with chromosome movements after kinetochore microtubules are severed because it alters the arrangements of spindle microtubules and because it blocks dynein activity. If the "spindle matrix" interpretation is correct, on the other hand, taxol should not interfere with the accelerated movements. Our results support the spindle matrix interpretation: anaphase chromosomes in taxol-treated crane-fly spermatocytes accelerated after their kinetochore microtubules were severed.
Exploration of paclitaxel (Taxol) as a treatment for malignant tumors in cats: a descriptive case series.
Kim Jennifer,Doerr Mary,Kitchell Barbara E
Journal of feline medicine and surgery
Paclitaxel, an effective chemotherapeutic agent in human oncology, has received little evaluation in feline patients. The diluent used to solubilize paclitaxel, polyoxyethylated castor oil (Cremophor EL), causes anaphylactoid reactions in human and dogs, which limits enthusiasm for use of this agent in veterinary oncology. Nine feline patients with measurable malignant tumors were treated with paclitaxel at a dosage of 80 mg/m(2) intravenously every 21 days for up to two doses. Adverse effects, including evidence of toxicity and anaphylactoid reactions, were assessed. Tumor response, progression and patient time to progression (TTP) were also recorded. Adverse effects included grade III and IV thrombocytopenia, grade III gastrointestinal signs (vomiting and constipation) and hypersensitivity reactions, seen in a total of five patients. Anaphylactoid reactions resolved with appropriate management. Stable disease and partial response were observed in 56% of feline patients. Median TTP was 28 days (range 15-45 days). Intravenous paclitaxel is a safe treatment option for feline malignant tumor patients. Future investigation is warranted to explore the effectiveness and appropriate application of this agent for specific tumor types.
Assessment of novel core-shell FeO@poly l‑DOPA nanoparticles for targeted Taxol® delivery to breast tumor in a mouse model.
Hashemi-Moghaddam Hamid,Zavareh Saeed,Gazi Elnaz Mirsaeed,Jamili Mahdi
Materials science & engineering. C, Materials for biological applications
Drug delivery systems using nanoparticles can deliver to tumor cells without affecting normal cells. In this study, a novel well dispersed magnetic nano drug was synthesized. Thus, a selective drug delivery system was designed for potential cancer treatment. A new nanocomposite, poly 3,4‑dihydroxy‑l‑phenylalanine/FeO (l‑DOPA/FeO), was synthesized and used for targeted Taxol® delivery to breast tumor in inbreed Balb/c mice model with or without magnetic field. Fe and Taxol® concentrations were measured by flame atomic absorption spectrometry and high-performance liquid chromatography, respectively. Antitumor effectiveness was investigated in terms of tumor growth features. In the presence of magnetic field, Taxol® was significantly deposited in tumor tissue in Taxol-nanocomposite-treated group. In addition, the Taxol®-nanocomposite-treated group with magnetic field showed higher antitumor efficacy than the commercial Taxol and Taxol-nanocomposite without magnetic field. The magnetic nanocomposite is promising for targeted Taxol® delivery to breast tumor in a mouse model yielding high performance.
Upregulation of miR-129-5p increases the sensitivity to Taxol through inhibiting HMGB1-mediated cell autophagy in breast cancer MCF-7 cells.
Shi Ying,Gong Weihua,Lu Lu,Wang Yunfeng,Ren Jingjing
Brazilian journal of medical and biological research = Revista brasileira de pesquisas medicas e biologicas
Although Taxol has improved the survival of cancer patients as a first-line chemotherapeutic agent, an increasing number of patients develop resistance to Taxol after prolonged treatment. The potential mechanisms of cancer cell resistance to Taxol are not completely clear. It has been reported that microRNAs (miRNAs) are involved in regulating the sensitivity of cancer cells to various chemotherapeutic agents. In this study, we aimed to explore the role of miR-129-5p in regulating the sensitivity of breast cancer cells to Taxol. Cell apoptosis and autophagy, and the sensitivity of MCF-7 cells to Taxol were assessed with a series of in vitro assays. Our results showed that the inhibition of autophagy increased the Taxol-induced apoptosis and the sensitivity of MCF-7 cells to Taxol. Up-regulation of miR-129-5p also inhibited autophagy and induced apoptosis. Furthermore, miR-129-5p overexpression increased the sensitivity of MCF-7 cells to Taxol. High mobility group box 1 (HMGB1), a target gene of miR-129-5p and a regulator of autophagy, was negatively regulated by miR-129-5p. We found that interference of HMGB1 enhanced the chemosensitivity of Taxol by inhibiting autophagy and inducing apoptosis in MCF-7 cells. Taken together, our findings suggested that miR-129-5p increased the chemosensitivity of MCF-7 cells to Taxol through suppressing autophagy and enhancing apoptosis by inhibiting HMGB1. Using miR-129-5p/HMGB1/autophagy-based therapeutic strategies may be a potential treatment for overcoming Taxol resistance in breast cancer.
The cancer chemotherapeutic agent paclitaxel (Taxol) reduces hippocampal neurogenesis via down-regulation of vesicular zinc.
Lee Bo Eun,Choi Bo Young,Hong Dae Kee,Kim Jin Hee,Lee Song Hee,Kho A Ra,Kim Haesung,Choi Hui Chul,Suh Sang Won
Chemotherapy-induced cognitive impairment (CICI) is increasingly recognized as a major unwanted side effect of an otherwise highly valuable life-saving technology. In part, this awareness is a result of increased cancer survival rates following chemotherapy. Altered hippocampal neurogenesis may play a role in mediating CICI. In particular, zinc could act as a key regulator of this process. To test this hypothesis, we administered paclitaxel (Px) to male C57BL/6 mice for set time periods and then evaluated the effects of Px treatment on hippocampal neurogenesis and vesicular zinc. We found that vesicular zinc levels and expression of zinc transporter 3 (ZnT3) were reduced in Px-treated mice, compared to vehicle-treated mice. Moreover, Px-treated mice demonstrated a significant decrease in the number of neuroblasts present. However, no difference in the number of progenitor cells were observed. In addition, zinc supplementation by treatment with ZnCl ameliorated the Px-induced decrease in hippocampal neurogenesis and cognitive impairment. These results suggest that via disruption of vesicular zinc stores in hippocampal mossy fiber terminals, chemotherapy may impinge upon one or more of the sequential stages involved in the maturation of new neurons derived via adult neurogenesis and thereby leads to the progressive cognitive decline associated with CICI.
Synthesis of Taxol and Docetaxel by Using 10-Deacetyl-7-xylosyltaxanes.
Xue Baoyu,Zhao Junhong,Fan Yange,Chen Shipeng,Li Wenfeng,Chen Jin,Li Zheng,Wang Hongxing,Kong Hongjun
Chemistry & biodiversity
A mixture of taxols was prepared from 10-deacetyl-7-xylosyltaxanes by three-step reactions: redox, acetylation, and deacetylation. The mixture was separated by column chromatography on silica gel to afford Taxol, Taxol B (Cephalomannine) and Taxol C. The mixture of Taxol B and Taxol C was converted to Docetaxel by Schwartz's reagent. The structures of Taxol and Docetaxel were characterized by HPLC, H-NMR, C-NMR and MS. This synthetic process has expanded the source of biomass for the chemical semi-synthesis of Taxol and Docetaxel, reduced the production costs, and increased the biomass resource of taxanes.
The Akt inhibitor MK-2206 enhances the cytotoxicity of paclitaxel (Taxol) and cisplatin in ovarian cancer cells.
Lin Ying-Hsi,Chen Bert Yu-Hung,Lai Wei-Ting,Wu Shao-Fu,Guh Jih-Hwa,Cheng Ann-Lii,Hsu Lih-Ching
Naunyn-Schmiedeberg's archives of pharmacology
Abnormalities in the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway are commonly observed in human cancers and contribute to chemotherapy resistance. Combination therapy, involving the use of molecular targeted agents and traditional cytotoxic drugs, may represent a promising strategy to lower resistance and enhance cytotoxicity. Here, we demonstrate the efficacy of an Akt inhibitor, MK-2206, in increasing the cytotoxic effect of either paclitaxel (Taxol) or cisplatin against the ovarian cancer cell lines SKOV3 (with constitutively active Akt) and ES2 (with inactive Akt). Sequential treatment of Taxol or cisplatin, followed by MK-2206, induced a synergistic inhibition of cell proliferation and effectively promoted cell death, either by inhibiting the phosphorylation of Akt and its downstream effectors 4E-BP1 and p70S6K in SKOV3 cells or by restoring p53 levels, which were downregulated after Taxol or cisplatin treatment, in ES2 cells. Combination treatment also downregulated the pro-survival protein Bcl-2 in both SKOV3 and ES2 cells, which may have contributed to cell death. In addition, we discovered that Taxol/MK-2206 or cisplatin/MK-2206 combination treatment resulted in significant enhancement of intracellular reactive oxygen species (ROS) induced by MK-2206, in both SKOV3 and ES2 cells; however, MK-2206-induced growth inhibition was reversed by a ROS scavenger only in ES2 cells. MK-2206 also suppressed DNA repair, particularly in SKOV3 cells. Taken together, our results demonstrate that the Akt inhibitor MK-2206 enhances the efficacy of cytotoxic agents in both Akt-active and Akt-inactive ovarian cancer cells but through different mechanisms.
[Reverse of the resistance to paclitaxel of the heparin binding-epidermal growth factor-like growth factor inhibitor in ovarian cancer].
Tang X H,Lu M S,Deng S,Li M
Zhonghua fu chan ke za zhi
To investigate the effect and mechanism of CRM197, the heparin binding-epidermal growth factor-like growth factor (HB-EGF) inhibitor, on the reverse of the resistance of ovarian cancer to paclitaxel. (1)The effect of CRM197 on the 50% inhibitory concentrations (IC(50)) of human ovarian carcinoma cell line A2780 and paclitaxel-resistant ovarian carcinoma cell line A2780/Taxol was tested by methyl thiazolyl tetrazolium (MTT) assay. Western blot was used to detect the effect of CRM197 on the expression of HB-EGF, epidermal growth factor receptor (EGFR) and plasma membrane glycoprotein (P-gp) protein in A2780 and A2780/Taxol cells. Real-time PCR was used to examine the MDR1 mRNA expression in these cells. (2) A2780/Taxol cells were divided into 4 groups, including the cells transfected with empty vector and saline treatment (empty vector group), MDR1 small interference RNA (siRNA) vector and saline treatment (MDR1 siRNA group), empty vector and CRM197 treatment (empty vector+CRM197 group) and MDR1 siRNA vector and CRM197 treatment (MDR1 siRNA+CRM197 group), respectively. Flow cytometry was used to detecte the effect of intracellular rhodomine 123 (Rh123) accumulation, and caspase-3 activity assay was used to test the effect of apoptosis in four groups of A2780/Taxol cells. (3) In experiments in vivo, A2780/Taxol cells were inoculated to nude mouse subcutaneously to determine the EGFR and P-gp protein expression following CRM197 treatment by immunohistochemistry. (1) In vitro, MTT examination showed that the IC(50) of A2780/Taxol cells to paclitaxel in A2780/Taxol+CRM197 group [(6.4±0.3) μmol/L] was significantly lower than the IC(50) in A2780/Taxol group [ (34.1±0.5) μmol/L, 0.01], and the reveral fold of CRM197 was 5.3. The expression level of HB-EGF protein in A2780/Taxol+CRM197 group (1.44±0.29) was significantly lower than HB-EGF protein in A2780/Taxol group (2.72±0.32), respectively (0.05). The expression level of EGFR protein (0.71±0.25) and P-gp protein (0.82±0.19) in A2780/Taxol+CRM197 group was significantly lower than EGFR protein (1.87±0.31) and P-gp protein (1.84±0.27) of A2780/Taxol group (0.05). Compared with A2780/Taxol group (1.78±0.27) , MDR1 mRNA was significantly down-regulated in A2780/Taxol+CRM197 group (0.79±0.13, 0.05). (2) The fluorescence intensity of Rh123 of the A2780/Taxol cells in empty vector group, MDR1 siRNA group,empty vector+CRM197 group, MDR1 siRNA+CRM197 group was 33.4±1.6, 56.3±3.3, 43.5±3.1,100.4±7.4, and the pNA of the A2780/Taxol cells was (11.4±1.2) , (52.8±0.9) , (71.2±3.6) , (82.7±3.8) μmol/L. The expression levels in MDR1 siRNA+CRM197 group were both higher than the expression levels in empty vector+CRM197 group, and the expression levels in empty vector+CRM197 group, MDR1 siRNA group were both higher than the expression levels in empty vector group (0.05). (3) In vivo, the expression scores of EGFR protein in A2780/Taxol+CRM197 tumors (4.4±1.4) were lower than that in A2780/Taxol tumors (10.2±3.1, 0.05). The expression scores of P-gp protein in A2780/Taxol+CRM197 tumors (3.8±1.1) were lower than that in A2780/Taxol tumors (8.8±2.7, 0.05). CRM197 reverses the resistance of ovarian cancer to paclitaxel by increasing caspase-3 activity to advance apoptosis via EGFR/MDR1/P-gp pathway.
How Taxol/paclitaxel kills cancer cells.
Weaver Beth A
Molecular biology of the cell
Taxol (generic name paclitaxel) is a microtubule-stabilizing drug that is approved by the Food and Drug Administration for the treatment of ovarian, breast, and lung cancer, as well as Kaposi's sarcoma. It is used off-label to treat gastroesophageal, endometrial, cervical, prostate, and head and neck cancers, in addition to sarcoma, lymphoma, and leukemia. Paclitaxel has long been recognized to induce mitotic arrest, which leads to cell death in a subset of the arrested population. However, recent evidence demonstrates that intratumoral concentrations of paclitaxel are too low to cause mitotic arrest and result in multipolar divisions instead. It is hoped that this insight can now be used to develop a biomarker to identify the ∼50% of patients that will benefit from paclitaxel therapy. Here I discuss the history of paclitaxel and our recently evolved understanding of its mechanism of action.
Medium chain triglyceride (MCT) rich, paclitaxel loaded self nanoemulsifying preconcentrate (PSNP): a safe and efficacious alternative to Taxol.
Patel Ketan,Patil Anand,Mehta Miten,Gota Vikram,Vavia Pradeep
Journal of biomedical nanotechnology
The current work was aimed to develop Medium Chain Triglyceride (MCT) rich self nanoemulsifying preconcentrate of paclitaxel (PTX) for parenteral delivery. Very high concentrations of Cremophor EL and ethanol in Taxol have rendered patients to severe side effects. Years of extensive research on development of cost effective and safer vehicle for PTX, have failed to provide a promising replacement for Taxol. MCT was selected as oil owing to its parenteral acceptability, high solubilization capacity and multiple therapeutic benefits in cancer cachexia. PTX precipitation kinetics and reported toxicity profile of Kolliphor HS15 has favored its selection for PTX Self Nanoemulsifying Preconcentrate (PSNP). Presence of 30% free PEG in Kolliphor HS15 (PEG-15-hydroxystearate) restricts its miscibility with MCT, imposing significant challenge in development of MCT rich self nanoemulsifying preconcentrate. Removal of PEG layer from oil-surfactant mixture facilitated the formulation of PSNP with 51% w/w MCT. PSNP exhibited better precipitation kinetic profile, higher PTX loading with negligible hemolysis and histamine release compared to Taxol. PSNP was bioequivalent to Taxol, though V(d) and MRT was significantly higher than Taxol. PSNP showed distinctly better profile in inhibiting tumor growth and maintaining body weight with significantly higher % survival. Thus, PSNP can be a safer vehicle with potential clinical benefits.
Novel resources of Taxol from endophytic and entomopathogenic fungi: Isolation, characterization and LC-Triple mass spectrometric quantification.
El-Maali Nagwa Abo,Mohrram Ahmed M,El-Kashef Hussein,Gamal Khaled
This work presents a second-to-none method for Taxol isolation from the Endophytic fungus Cladosporium sphaerospermum (AUMC 6896) and the Entomopathogenic fungus Metarizium anisopliae (AUMC 5130). The extracts were analyzed by high performance liquid chromatography (HPLC) and Liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) using positive electrospray ionization (ESI) in the multiple reaction monitoring (MRM) mode. This is rapid, consistent, reproducible, accurate, and sensitive for quantifying Taxol across multiple samples. The yield of crude Taxol product obtained from Potato Dextrose broth (PDB) medium inoculated with Cladosporium sphaerospermu and Metarizium anisopliae was found to be 3.732, and 0.0023 μg L respectively. The yield can be improved by adding ammonium acetate or salicylic acid to the culture broth. Addition of ammonium acetate (AA) (20 mg L) to culture media resulted in an increase of Taxol yield to 30.365 and 27.289 μg L respectively. Production of Taxol was 29.844 and 67.254 μg L for the two fungus species when ammonium acetate was substituted by 90 mg L salicylic acid (SA). Adding both AA (20 mg L) and SA (90 mg L) to the culture media resulted in an increase of the Taxol yield to 4.054 and 116.373 μg L respectively. Our proposed analytical method offers very fast (3 min) quantitation of Taxol in comparison with other published methods. These findings represent a new bioprospecting of the endophytic fungi that may serve as a potential material for the production of Taxol for anticancer treatment.
Isolation of taxol producing endophytic fungus Alternaria brassicicola from non-Taxus medicinal plant Terminalia arjuna.
Gill Harman,Vasundhara M
World journal of microbiology & biotechnology
In the present study, an endophytic fungal strain was isolated from its non-Taxus host plant Terminalia arjuna and identified as Alternaria brassicicola based on its morphological characteristics and internal transcribed spacer sequence analysis. This fungus was grown in potato dextrose broth and analyzed for the presence of taxol by using chromatographic and spectrometric techniques. The ethyl acetate extract of A.brassicicola was subjected to column chromatography. Among the different fractions, the fraction 7 showed positive to taxol, which was further confirmed by UV absorption, HPLC, FTIR spectra and LC-ESI-MS by comparing with the authentic taxol (Paclitaxel). The peaks of fraction 7 obtained by UV spectroscopy, FTIR and HPLC analysis were quite similar to that of standard taxol confirming the presence of taxol. A parent ion peak of m/z 854.95 was observed in the LC-ESI-MS spectrum which was similar to paclitaxel with reported m/z of 854 [M+H] ion. A. brassicicola produced about 140.8 μg/l taxol as quantified through HPLC. Present study results suggest that the endophytic fungus A.brassicicola serves as a potential source for the production of taxol isolated from non-Taxus plant.
Synthetic paclitaxel-octreotide conjugate reversing the resistance of A2780/Taxol to paclitaxel in xenografted tumor in nude mice.
Chen Xi,Zhang Xiao-Yu,Shen Yang,Fan Li-Li,Ren Mu-Lan,Wu Yong-Ping
Peptide hormone-based targeted therapy to tumors has been studied extensively. Our previous study shows that somatostatin receptor expresses high level on drug-resistant human ovarian cancer. The paclitaxel-octreotide conjugate (POC) exhibits enhanced growth inhibition, as well as reduced toxicity, in paclitaxel-resistant human ovarian cancer cells. The aim of this study was to investigate the effect of targeted cytotoxicity and potential reversal mechanism of resistance in paclitaxel-resistant human ovarian cancer cells xenografted into nude mice. The SSTR2 shows higher expression levels in tumor tissue. Moreover, fluorescein-labeled POC displays favorable targeting in tumor cells. POC presents the perfect efficacy in inhibiting tumor growth and exerts lower or no toxic effects on normal tissues. Real-time PCR and Western Blotting has demonstrated that the mRNA and protein expressions of SSTR2 in POC group were significantly higher, while MDR1, α-tubulin, βIII-tubulin, VEGF and MMP-9 were significantly lower than in the other treatment groups and controls. Combined with the previous study in vitro, this study evaluates an effective approach on the treatment of paclitaxel-resistant ovarian cancer which expresses somatostatin receptor SSTR. Our investigation has also revealed the possible molecular mechanism of POC in treating the ovarian cancer, and therefore, provided a theoretical basis for the clinical application of this newly-invented compound.
[Role and mechanism of the regulation of nuclear factor-κB by heparin binding-epidermal growth factor-like growth factor in the induction of paclitaxel resistance of ovarian cancer].
Tang X H,Lu M S,Deng S,Li M
Zhonghua fu chan ke za zhi
To investigate the role and mechanism of the regulation of nuclear factor-κB (NF-κB) by heparin binding-epidermal growth factor-like growth factor (HB-EGF) in paclitaxel resistance of ovarian cancer in vitro and in vivo. (1) The detection of NF-κB expression: parental (A2780) and paclitaxel-resistant (A2780/Taxol) ovarian carcinoma cells were divided into four groups, named A2780 group, A2780+cross-reacting material 197 (CRM197, HB-EGF inhibitor) group, A2780/Taxol group and A2780/Taxol+CRM197 group. Among four groups, the expression level HB-EGF and epidermal growth factor receptor (EGFR) were examined by immunofluorescence double staining on confocal microscopy. Western blot was used to detect the expression level of NF-κB. In vivo, A2780 and A2780/Taxol cells were injected intraperitoneally to nude mouse to determine the expression level of NF-κB of the tumors from these four groups by immunohistochemistry method. (2) The detection on the function of NF-κB: A2780/Taxol cells were divided into four groups, named transfected with empty vector+saline group, NF-κB small interference RNA (siRNA)+saline group, empty vector+CRM197 group and NF-κB siRNA+CRM197 group respectively. Among four groups, the 50% inhibitory concentrations (IC(50)) of A2780/Taxol cells to paclitaxel, the expression level of plasma membrane glycoprotein (P-gp) and the effect of intracellular rhodomine123 (Rh123) accumulation were detected. (1) The detection of NF-κB expression: the expression scores of HB-EGF protein among four groups were 5.6±1.3, 2.1±1.2, 11.7±3.5 and 6.2±1.4; the expression scores of EGFR protein were 5.1±1.6, 2.8±0.6, 10.4±3.1 and 5.6±1.9, respectively. The expression levels of NF-κB protein in the cells of the group named A2780, A2780+CRM197, A2780/Taxol and A2780/Taxol+CRM197 group were 1.89±0.23, 0.74±0.12, 3.45±0.16 and 1.31±0.08, respectively; the expression scores of NF-κB protein in the tissue tumors from four groups were 3.3±1.1, 1.4±0.4, 8.7±2.3 and 3.6±1.2, respectively. The expression level of HB-EGF, EGFR and NF-κB protein between A2780 and A2780/Taxol groups in vivo and in vitro were higher than these in A2780+CRM197 and A2780/Taxol+CRM197 group, while the expression level of HB-EGF, EGFR and NF-κB protein in A2780 group were lower than those in A2780/Taxol groups in vivo and in vitro (<0.05). (2) The examination of NF-κB function: the IC(50) of A2780/Taxol cells to paclitaxel in groups transfected with empty vector+saline, NF-κB siRNA+saline, empty vector+CRM197 and NF-κB siRNA+CRM197 group were respectively (39.4±0.8), (7.6±0.6), (6.7±0.5) and (4.2±0.4) μmol/L, while the expression levels of P-gp protein among four groups were respectively 3.11±0.23,1.45±0.16, 1.73±0.21 and 0.68±0.14, the cellular Rh123 accumulation among four groups were respectively 110±15, 246±19, 231±22 and 296±24. The expression levels of IC(50) and P-gp protein in groups transfected with NF-κB siRNA+saline, empty vector+CRM197 and NF-κB siRNA+CRM197 group were significantly higher than those in group transfected with empty vector+saline group (0.01), while the cellular Rh123 accumulation among three groups were significantly lower than that in group transfected with empty vector+saline (0.01). The expression of NF-κB may contributes to the paclitaxel resistance to ovarian cancer. HB-EGF may induce the paclitaxel resistance of ovarian cancer by the regulation of EGFR/NF-κB/P-gp pathway.
[Down-regulated βIII-tubulin expression can reverse paclitaxel resistance in A549/taxol cells lines].
Zhuo Yinling,Guo Qisen
Zhongguo fei ai za zhi = Chinese journal of lung cancer
BACKGROUND:Chemotherapy drug resistance is the primary causes of death in patients with pulmonary carcinoma which make tumor recurrence or metastasis. β-tubulin is the main cell targets of anti-microtubule drug. Increased expression of βIII-tubulin has been implicated in non-small cell lung cancer (NSCLC) cell lines. To explore the relationship among the expression level of βIII-tubulin and the sensitivity of A549/Taxolcell lines to Taxol and cell cycles and cell apoptosis by RNA interference-mediated inhibition of βIII-tubulin in A549/Taxol cells. METHODS:Three pairs of siRNA targetd βIII-tubulin were designed and prepared, which were transfected into A549/Taxol cells using LipofectamineTM 2000. We detected the expression of βIII-tubulin mRNA using Real-time fluorescence qRT-PCR. Tedhen we selected the most efficient siRNA by the expression of βIII-tubulin mRNA in transfected group. βIII-tubulin protein level were mesured by Western blot. The taxol sensitivity in transfected group were evaluated by MTT assay. And the cell apoptosis and cell cycles were determined by flow cytometry. RESULTS:βIII-tubulin mRNA levels in A549/Taxol cells were significantly decreased in transfected grop by Real-time qRT-PCR than control groups. And βIII-tubulin siRNA-1 sequence showed the highest transfection efficiency, which was (87.73±4.87)% (P<0.01); Western blot results showed that the expressional level of BIII tublin protein was significantly down-reulated in the transfectant cells than thant in the control cells. By MTT assay, we showed that the inhibition ratio of Taxol to A549/Taxol cells transfeced was higher than that of control group (51.77±4.60)% (P<0.01). The early apoptosis rate of A549/Taxol cells in transfected group were significantly higher than that of control group (P<0.01); G2-M content in taxol group obviously increased than untreated samples by the cell cycle (P<0.05). CONCLUSIONS:βIII-tubulin down-regulated significantly sensitized NSCLC A549/Taxol cells to Paclitaxel.
Liposomal paclitaxel induces fewer hematopoietic and cardiovascular complications than bioequivalent doses of Taxol.
Huang Shih-Ting,Wang Yi-Ping,Chen Yen-Hui,Lin Chin-Tarng,Li Wen-Shan,Wu Han-Chung
International journal of oncology
Paclitaxel (PTX) exhibits potent antineoplastic activity against various human malignancies; however, clinical application must overcome the inherent hydrophobicity of this molecule. The commercialized Taxol formulation utilizes Cremophor EL (CrEL)/ethanol as a solvent to stabilize and dispense PTX in an aqueous solution. However, adverse CrEL‑induced hypersensitivity reactions have been reported in ~30% of recipients, and 40% of patients receiving premedication may also experience this adverse effect. Therefore, the development of a CrEL-free delivery system is crucial, in order to fully exploit the therapeutic efficacy of PTX. In the present study, a novel liposomal PTX (lipo‑PTX) formulation was optimized with regards to encapsulation rate and long‑term stability, arriving at a molar constituent ratio of soybean phosphatidylcholine:cholesterol:N-(carbonyl-methoxy-poly-ethylene glycol 2000)‑1,2‑distearoyl‑sn-glycero‑3-phosphoethanolamine, sodium salt:PTX at 95:2:1:2. Comparable doses of lipo‑PTX and Taxol were bioequivalent in terms of therapeutic efficacy in xenograft tumor models. However, the systemic side effects, including hematopoietic toxicity, acute hypersensitivity reactions and cardiac irregularities, were significantly reduced in lipo‑PTX‑treated mice compared with those infused with reference formulations of PTX. In conclusion, the present study reported that lipo‑PTX exhibited a higher therapeutic index than clinical PTX formulations.
Rethinking production of Taxol® (paclitaxel) using endophyte biotechnology.
Kusari Souvik,Singh Satpal,Jayabaskaran Chelliah
Trends in biotechnology
Taxol® (generic name paclitaxel) represents one of the most clinically valuable natural products known to mankind in the recent past. More than two decades have elapsed since the notable discovery of the first Taxol®-producing endophytic fungus, which was followed by a plethora of reports on other endophytes possessing similar biosynthetic potential. However, industrial-scale Taxol® production using fungal endophytes, although seemingly promising, has not seen the light of the day. In this opinion article, we embark on the current state of knowledge on Taxol® biosynthesis focusing on the chemical ecology of its producers, and ask whether it is actually possible to produce Taxol® using endophyte biotechnology. The key problems that have prevented the exploitation of potent endophytic fungi by industrial bioprocesses for sustained production of Taxol® are discussed.
Synthetic paclitaxel-octreotide conjugate reverses the resistance of paclitaxel in A2780/Taxol ovarian cancer cell line.
Shen Yang,Zhang Xiao-Yu,Chen Xi,Fan Li-Li,Ren Mu-Lan,Wu Yong-Ping,Chanda Kenneth,Jiang Shi-Wen
The high mortality of ovarian cancer is partly due to the frequent resistance of ovarian cancer to current chemotherapy agents such as paclitaxel and platinum. Somatostatin analogue (SSTA) has been shown to inhibit the proliferation of some tumors through binding to somatostatin receptor (SSTR) and activation of Ras-, Rapl- and B-Raf-dependent extracellular signal-regulated kinase 2 (Erk2). It was reported that paclitaxel-octreotide conjugate (POC) exhibited enhanced tumor growth inhibition with reduced toxicity. In the present study, we prepared the POC and investigated its effects and mechanism for the reversal of drug resistance in paclitaxel-resistant ovarian cancer cell line. We demonstrated that treatment with POC led to more cell apoptosis than either paclitaxel or octreotide (OCT) alone. Moreover, the expression of multidrug resistance 1 (MDR1) and vascular endothelial growth factor (VEGF) mRNA, and protein decreased in a dose-dependent manner while the expression of SSTR remained stable following treatment with POC. Although the exact action, in vivo effects and pharmacologic kinetics of POC remain to be investigated, we have demonstrated the feasibility for the synthesis of POC, and more significantly, provided a potential approach to overcome the resistance of ovarian cancer against taxol. The findings also shed some new light on the mechanisms underlying the development of resistance to taxol by ovarian cancer cells.
Ultrasound-induced mild hyperthermia improves the anticancer efficacy of both Taxol® and paclitaxel-loaded nanocapsules.
Boissenot Tanguy,Bordat Alexandre,Larrat Benoît,Varna Mariana,Chacun Hélène,Paci Angelo,Poinsignon Vianney,Fattal Elias,Tsapis Nicolas
Journal of controlled release : official journal of the Controlled Release Society
We study the influence of ultrasound on paclitaxel-loaded nanocapsules in vitro and in vivo. These nanocapsules possess a shell of poly(dl-lactide-co-glycolide)-poly(ethylene glycol) (PLGA-PEG) and a liquid core of perfluorooctyl bromide (PFOB). In vitro experiments show that mechanical effects such as cavitation are negligible for nanocapsules due to their small size and thick and rigid shell. As the mechanical effects were unable to increase paclitaxel delivery, we focused on the thermal effects of ultrasound in the in vivo studies. A focused ultrasound sequence was therefore optimized in vivo under magnetic resonance imaging guidance to obtain localized mild hyperthermia with high acoustic pressure. Ultrasound-induced mild hyperthermia (41-43°C) was then tested in vivo in a subcutaneous CT-26 colon cancer murine model. As hyperthermia is applied, an inhibition of tumor growth for both paclitaxel-loaded nanocapsules and the commercial formulation of paclitaxel, namely Taxol® have been observed (p<0.05). Ultrasound-induced mild hyperthermia at high acoustic pressure appears as an interesting strategy to enhance cytotoxic efficacy locally.
Overexpression of miR-203 sensitizes paclitaxel (Taxol)-resistant colorectal cancer cells through targeting the salt-inducible kinase 2 (SIK2).
Liu Yingyi,Gao Sujie,Chen Xuebo,Liu Meihan,Mao Cuiying,Fang Xuedong
Tumour biology : the journal of the International Society for Oncodevelopmental Biology and Medicine
MicroRNAs (miRNAs) are short non-coding RNAs that regulate gene expression through the endogenous RNA interference machinery. Treatments with combination of chemotherapy with surgery are essential for advanced-stage colorectal cancer. However, the development of chemoresistance is a major obstacle for clinical application of anticancer drugs. In this study, we report a miR-203-SIK2 axis that involves in the regulation of Taxol sensitivity in colon cancer cells. MiR-203 is downregulated in human colon tumor specimens and cell lines compared with their normal counterparts. We report miR-203 is correlated with Taxol sensitivity: overexpression of miR-203 sensitizes colon cancer cells and the Taxol-resistant cells display downregulated miR-203 compared with Taxol-sensitive cells. We identify SIK2 as a direct target of miR-203 in colorectal cancer cells. Overexpression of miR-203 complementary pairs to the 3' untranslated region (UTR) of SIK2, leading to the sensitization of Taxol resistant cells. In addition, miR-203 and the salt-inducible kinase 2 (SIK2) are reverse expressed in human colorectal tumors. Finally, we demonstrate recovery of SIK2 by overexpression of SIK2-desensitized Taxol-resistant cells, supporting the miR-203-mediated sensitization to Taxol, is through the inhibition of SIK2. In general, our study will provide mechanisms of the microRNA-based anti-tumor therapy to develop anti-chemoresistance drugs.
Altered Mitochondrial Dynamics, Biogenesis, and Functions in the Paclitaxel-Resistant Lung Adenocarcinoma Cell Line A549/Taxol.
Zhou Xiang,Li Rui,Chen Ruohua,Liu Jianjun
Medical science monitor : international medical journal of experimental and clinical research
BACKGROUND Chemoresistance is a primary hindrance for current cancer treatments. The influence of abnormal mitochondria in chemotherapy resistance is not well known. To explore the correlation between mitochondria and acquired chemoresistance, this work studied alterations in mitochondrial dynamics, biogenesis, and functions for paclitaxel-resistant cancer cell line A549/Taxol and its parental line A549. MATERIAL AND METHODS Mitochondrial morphology was observed by transmission electron microscopy and confocal microscopy. We measured the mitochondrial mass and mitochondrial membrane potential using fluorescent dyes. The glucose metabolic profile and ATP (adenosine triphosphate) content were determined by bioluminescent cell assays. Seahorse bio-energy analyzer XF24 was used to detect the mitochondrial respiratory function. The expressions of mitochondrial dynamics and biogenesis related genes were quantified using real-time polymerase chain reaction. RESULTS We observed fusion morphology of the mitochondrial network in A549/Taxol cells, with upregulation of fusion genes (Mfn1 and Mfn2) and downregulation of fission gene Fis1. In A549/Taxol cells, mitochondrial mass showed a significant decrease, while the mitochondrial biogenesis pathway was strongly activated. Despite the decreased mitochondrial membrane potential, the capability for mitochondrial respiration was not impaired in A549/Taxol cells. CONCLUSIONS Our study revealed a series changes of mitochondrial characteristics in paclitaxel-resistant cells. Mfn1 and Mfn2 and PGC-1alpha increased, while Fis1 expression and mitochondrial oxidative phosphorylation decreased in A549/Taxol cell lines. These changes to mitochondrial fusion, fission, and biological function contributed to the occurrence of paclitaxel resistance in tumor cells which induced paclitaxel resistance.