Project description:The effects of demycarosyl-3D-M-NM-2-D-digitoxosyl-mithramycin SK (DIG-MSK; EC-8042), a novel analogue of the antitumor antibiotic mithramycin A, on gene transcription were examined in human A2780 ovarian carcinoma cells. DIG-MSK down-regulated a different set of genes depending on the drug concentration. Moreover, several genes were significantly up-regulated. These results are rationalized in terms of DIG-MSK competition with Sp1 transcription factor for binding to consensus C/G-rich tracts encompassed in gene promoters. Human A2780 ovarian carcinoma cells were treated with either 8 nM or 80 nM DIG-MSK for 24 h, and RNA was extracted from treated cells as well as from untreated (control) cells.
Project description:The effects of demycarosyl-3D-β-D-digitoxosyl-mithramycin SK (DIG-MSK; EC-8042), a novel analogue of the antitumor antibiotic mithramycin A, on gene transcription were examined in human A2780 ovarian carcinoma cells. DIG-MSK down-regulated a different set of genes depending on the drug concentration. Moreover, several genes were significantly up-regulated. These results are rationalized in terms of DIG-MSK competition with Sp1 transcription factor for binding to consensus C/G-rich tracts encompassed in gene promoters.
Project description:Transcriptional profiling of human ovarian cancer cells comparing control vehicle-treated A2780 and OVCAR-3 (Human ovarian cancer cell lines) cells with A2780 and OVCAR-3 cells treated with 5μM LS-98 for 24 hours.Goal was to determine the effects of LS-98 compound on the global A2780 and OVCAR-3 cells gene expression.
Project description:Transcriptional profiling of human ovarian cancer cells comparing control vehicle-treated A2780 and OVCAR-3 (Human ovarian cancer cell lines) cells with A2780 and OVCAR-3 cells treated with 5μM LS-98 for 24 hours.Goal was to determine the effects of LS-98 compound on the global A2780 and OVCAR-3 cells gene expression. One-condition experiment, control vehicle-treated A2780 and OVCAR-3 vs. LS098 treated-A2780 and OVCAR-3 cells. Biological replicates: 2 replicates.
Project description:Drug resistance poses a major challenge to ovarian cancer treatment. Understanding mechanisms of drug resistance is important for finding new therapeutic targets. In the present work, a cisplatin-resistant ovarian cancer cell line A2780-DR was established with a resistance index of 6.64. The cellular accumulation of cisplatin was significantly reduced in A2780-DR cells as compared to A2780 cells consistent with the general character of drug resistance. Quantitative proteomic analysis identified 340 differentially expressed proteins between A2780 and A2780-DR cells, which involve in diverse cellular processes, including metabolic process, cellular component biogenesis, cellular processes and stress responses. Expression levels of Ras-related proteins Rab 5C and Rab 11B in A2780-DR cells were lower than those in A2780 cells as confirmed by real-time quantitative PCR and western blotting. The short hairpin (sh)RNA-mediated knockdown of Rab 5C in A2780 cells resulted in markedly increased resistance to cisplatin whereas overexpression of Rab 5C in A2780-DR cells increases sensitivity to cisplatin, demonstrating that Rab 5C-dependent endocytosis plays an important role in cisplatin resistance. Our results also showed that expressions of glycolytic enzymes PKM, GPI, Aldolase, LDH, and PGK were down-regulated in drug resistant cells, indicating drug resistance in ovarian cancer is directly associated with a decrease in glycolysis. Furthermore, it was found that glutathione reductase were up-regulated in A2780-DR, while vimentin, HSP90, and Annexin A1 and A2 were down-regulated. Taken together, our results suggest that drug resistance in ovarian cancer cell line A2780 is caused by multifactorial traits, including the down-regulation of Rab 5C-dependent endocytosis of cisplatin, glycolytic enzymes and vimentin, and up-regulation of antioxidant proteins, suggesting Rab 5C is a potential target for treatment of drug-resistant ovarian cancer. This constitutes a further step towards a comprehensive understanding of drug resistance in ovarian cancer.
Project description:Differences in gene expression in A2780C20 vs. A2780 and A2780 treated with temsirolimus at 24-hr and 48-hr. The A2780 are human ovarian carcinoma cellls were purchased to the European Collection of Cell Cultures (ECACC). The A2780CP20 are cisplatin resisatnt cells derived of the A2780 cells. A2780CP20 cells were generated by Dr. Robert Ozols (J. Natl. Cancer Inst. 84, 264-267 (1992) by treatment of A2780 cells with incresing concentrations of cisplatin. The goal of this study is to determine whether the cisplatin and temsirolimus resistance are co-regulated. The objectives of this study are to identify additional genes differentially expressed in cisplatin sensitive and cisplatin resistant ovarain cancer cells and the changes in gene expreession upon temsirolimus treatment of A2780 cells.
Project description:Rhabdoid tumor is a pediatric cancer characterized by the biallelic inactivation of SMARCB1, a subunit of the SWI/SNF chromatin remodeling complex. SMARCB1 inactivation leads to SWI/SNF redistribution to favor a proliferative dedifferentiated cellular state. Although this deletion is the known oncogenic driver, SWI/SNF therapeutic targeting remains a challenge. Here we show mithramycin and a second-generation analogue EC-8042 are effective in this tumor type. Mithramycin evicts SWI/SNF from chromatin triggering a cellular response characterized by chromatin compartment remodeling and promoter reprogramming. These effects lead to differentiation and marked xenograft tumor regressions in vivo. This study provides a therapeutic candidate for rhabdoid tumor and an approach that may be applicable to the more than 20% of cancers characterized by mutated SWI/SNF.
Project description:Rhabdoid tumor is a pediatric cancer characterized by the biallelic inactivation of SMARCB1, a subunit of the SWI/SNF chromatin remodeling complex. SMARCB1 inactivation leads to SWI/SNF redistribution to favor a proliferative dedifferentiated cellular state. Although this deletion is the known oncogenic driver, SWI/SNF therapeutic targeting remains a challenge. Here we show mithramycin and a second-generation analogue EC-8042 are effective in this tumor type. Mithramycin evicts SWI/SNF from chromatin triggering a cellular response characterized by chromatin compartment remodeling and promoter reprogramming. These effects lead to differentiation and marked xenograft tumor regressions in vivo. This study provides a therapeutic candidate for rhabdoid tumor and an approach that may be applicable to the more than 20% of cancers characterized by mutated SWI/SNF.
Project description:Rhabdoid tumor is a pediatric cancer characterized by the biallelic inactivation of SMARCB1, a subunit of the SWI/SNF chromatin remodeling complex. SMARCB1 inactivation leads to SWI/SNF redistribution to favor a proliferative dedifferentiated cellular state. Although this deletion is the known oncogenic driver, SWI/SNF therapeutic targeting remains a challenge. Here we show mithramycin and a second-generation analogue EC-8042 are effective in this tumor type. Mithramycin evicts SWI/SNF from chromatin triggering a cellular response characterized by chromatin compartment remodeling and promoter reprogramming. These effects lead to differentiation and marked xenograft tumor regressions in vivo. This study provides a therapeutic candidate for rhabdoid tumor and an approach that may be applicable to the more than 20% of cancers characterized by mutated SWI/SNF.
Project description:Differences in gene expression in A2780C20 vs. A2780 and A2780 treated with temsirolimus at 24-hr and 48-hr. The A2780 are human ovarian carcinoma cellls were purchased to the European Collection of Cell Cultures (ECACC). The A2780CP20 are cisplatin resisatnt cells derived of the A2780 cells. A2780CP20 cells were generated by Dr. Robert Ozols (J. Natl. Cancer Inst. 84, 264-267 (1992) by treatment of A2780 cells with incresing concentrations of cisplatin. The goal of this study is to determine whether the cisplatin and temsirolimus resistance are co-regulated. The objectives of this study are to identify additional genes differentially expressed in cisplatin sensitive and cisplatin resistant ovarain cancer cells and the changes in gene expreession upon temsirolimus treatment of A2780 cells. RNA was isolated from A2780, A2780CP20, A2780 plus temsirolimus 24-hr, and A2780 plus temsirolimus 48-hr. Labelled samples were hybridized to Affymetrix GeneChip Gene 1.0 ST Human Arrays.