Project description:K562 cells were treated with different HSP90 inhibitors (PuH71 and Coumermycin A1) and the CNV profil was compared to the parental K562 (untreated). In addition, the CNV profile of HSP90AB1 knockout K562 cells was analyzed.
Project description:We generated H460 cells with acquired TRAIL resistance by exposing the parental sentisitve cells to subtoxic concentrations of TRAIL for 6 months. Then we compared the gene expression profile of the sensitive versus the resistant cells. We generated acquired TRAIL-resistant H460 cells from the sentisitve cells by treating subtoxic range of TRAIL for 6 month. And we tried to compare the expressional profile of the genes between two cell types to isolate genes regulating acquired TRAIL-resistance
Project description:We generated H460 cells with acquired TRAIL resistance by exposing the parental sentisitve cells to subtoxic concentrations of TRAIL for 6 months. Then we compared the gene expression profile of the sensitive versus the resistant cells. We generated acquired TRAIL-resistant H460 cells from the sentisitve cells by treating subtoxic range of TRAIL for 6 month. And we tried to compare the expressional profile of the genes between two cell types to isolate genes regulating acquired TRAIL-resistance H460 cells were treated with subtoxic concentrations of TRAIL for 6 month. After confirmation of the resistance, the RNA was extracted and the gene expression profile was analyzed.
Project description:A comparison between parental K562 cells (CML) and two clones derived from this cell line : ImaR and PDR which are resistant against Imatinib mesylate and PD166326 respectively , two inhibitors of BCR-ABL. Keywords: gene expression, comparison
Project description:Proteasome inhibitor (PI) resistance remains a central challenge in multiple myeloma. To identify pathways mediating resistance, we first mapped proteasome-associated genetic co-dependencies. We identified cytosolic heat shock protein 70 (HSP70) chaperones as potential targets, consistent with proposed mechanisms of myeloma tumor cells overcoming PI-induced stress. These results led us to explore allosteric HSP70 inhibitors (JG compounds) as myeloma therapeutics. We showed these compounds exhibit increased efficacy against acquired and intrinsic PI-resistant myeloma models, unlike HSP90 inhibition. Surprisingly, shotgun and pulsed-SILAC mass spectrometry found that JGs have the most pronounced effect on the proteome not through inhibiting cytosolic HSP70s but instead through mitochondrial-localized HSP70, HSPA9/mortalin, destabilizing the 55S mitoribosome. Analysis of myeloma patient data further supports strong effects of global proteostasis capacity, and particularly HSPA9 expression, on PI response. Our results characterize myeloma proteostasis networks under therapeutic pressure while motivating further investigation of HSPA9 as a specific vulnerability in PI-resistant disease.
Project description:We generated H460 cells with acquired TRAIL resistance by exposing the parental sentisitve cells to subtoxic concentrations of TRAIL for 6 months. Then we compared the microRNA expression profile in the sensitive versus resistant cells.
Project description:Colon cancer cell lines with partial sensitivity to the BRAF inhibitor PLX4720 were grown in increasing concentration of the drug to develop acquired resistance. Gene expression was performed for comparison of the resistant clones to the parental lines. Colon cancer cell lines with partial sensitivity to the BRAF inhibitor PLX4720 were grown in increasing concentration of the drug to develop acquired resistance. Gene expression was performed for comparison of the resistant clones to the parental lines.
Project description:Resistance to endocrine therapy agents has presented a clinical obstacle in the treatment of hormone-dependent breast cancer. Our laboratory has initiated a study of microRNA regulation of signaling pathways that may result in breast cancer progression on aromatase inhibitors (AI). Microarray analysis of microRNA expression identified 115 significantly regulated microRNAs, of which 49 microRNAs were believed to be hormone-responsive. Within the AI-resistant cells, microRNAs were differentially expressed between the steroidal and non-steroidal AI-resistant lines. Also, a group of microRNAs were inversely expressed in the AI-resistant lines versus LTEDaro and tamoxifen-resistant. We focused our work on hsa-miR-128a which was hormone-responsive and up-regulated in the letrozole-resistant cell lines. Human miR-128a was shown to negatively target TGFBRI protein expression by binding to the 3âUTR region of the gene. Loss of TGFBRI resulted in compromised sensitivity to the growth inhibitory effects of TGFB in the letrozole-resistant lines. Inhibition of endogenous miR-128a resulted in re-sensitization of the letrozole-resistant lines to TGFB growth inhibitory effects. This data suggests that the hormone-responsive miR-128a can modulate TGFB signaling and survival of the letrozole-resistant cell lines. To our knowledge, this is the first study to address the role of microRNA regulation as well as TGFB signaling in AI-resistant breast cancer cell lines. We believe that in addition to estrogen-modulation of gene expression, hormone-regulated microRNAs may provide an additional level of post-transcriptional regulation of signaling pathways critically involved in breast cancer progression and AI-resistance. To look at microRNA expression profiles of breast cancer cell lines derived from MCF-7 cells that are resistant to endocrine therapy agents. MCF-7 cells that overexpress aromatase (MCF-7aro) were cultured long-term in the presence of endocrine therapy agents until cells acquired resistance. Three different aromatase inhibitors (letrozole, anastrozole or exemestane) were used, as well as the ER antagonist tamoxifen, or the hormone-free long-term estrogen deprived cells (LTED). Three replicates of the control cells (MCF-7aro) and all resistant cells were used for microarray experiments. Total of 23 samples were analyzed by microarray.
Project description:After over 25cycle and 18month's induction of shikonin, K562 cell show maginal resistance to shikonin but great change in gene expression We use microarray to detect the global gene expression change of shikonin resistant cell K562 cell was treated by 4uM shikonin for 4hours, then allowed to die and grow back in fresh medium. Once recovered, cells were immidiatly subjected to another treatment.