Project description:The second leading cause of cancer death for women in the U.S. is breast cancer. Moreover, a significant number of patients with breast tumors acquire resistance to drugs during therapy. To develop targeted therapeutic strategies to combat drug resistance it is essential to understand the basic molecular mechanisms through which cancer cells control sensitivity to chemotherapeutics. To identify new candidate genes and facilitate the discovery of novel drug resistance pathways, we have generated a resistance profile or ?resistome? of etoposide resistant MCF7 breast cancer cells. Differential expression of over 5000 genes (fold change > 2, P value < 0.05) indicate that several drug resistance mechanisms may be operating in these cells, including up-regulation of ABC transporter genes, down-regulation of the drug target and down-regulation of apoptotic genes. Several transcription factors such as RUNX2, SOX9, ETS1 and SMAD3 were up-regulated in the drug resistant cells. Targeted RUNX2 knockdown in the resistant cells using siRNA increased sensitivity to etoposide and also upregulated expression of pro-apoptotic genes indicating that RUNX2 could be a molecular target against etoposide resistance. Differential miRNA (microRNA) expression was observed among the drug resistant and sensitive cells suggesting that miRNA may also play a role in regulation of drug resistance. Hsa-miR-218, which targets ABCC6, was down-regulated in the drug resistant cell line. Transfection of a miR-218 mimic could down-regulate the expression of the efflux pump ABCC6 by 65% in drug resistant cells suggesting that regulation of miRNA may play an important role in etoposide resistance. long summary Refer to individual Series. This SuperSeries is composed of the following subset Series: GSE28413: Expression profile of etoposide-resistant MCF7 (MCF7VP) cells GSE28414: Expression profile of etoposide-resistant MCF7 (MCF7VP) cells with targeted RUNX2 knockdown

2011-04-08 | E-GEOD-28415 | biostudies-arrayexpress

E-GEOD-38007

Project description:Gene expression profile of MITF expressing cells

2025-01-24 | E-GEOD-38007 | ExpressionAtlas

Expression profile of etoposide-resistant MCF7 (MCF7VP) cells

Project description:The second leading cause of cancer death for women in the U.S. is breast cancer. Moreover, a significant number of patients with breast tumors acquire resistance to drugs during therapy. To develop targeted therapeutic strategies to combat drug resistance it is essential to understand the basic molecular mechanisms through which cancer cells control sensitivity to chemotherapeutics. To identify new candidate genes and facilitate the discovery of novel drug resistance pathways, we have generated a resistance profile or âresistomeâ of etoposide resistant MCF7 breast cancer cells. Differential expression of over 5000 genes (fold change > 2, P value < 0.05) indicate that several drug resistance mechanisms may be operating in these cells, including up-regulation of ABC transporter genes, down-regulation of the drug target and down-regulation of apoptotic genes. Several transcription factors such as RUNX2, SOX9, ETS1 and SMAD3 were up-regulated in the drug resistant cells. Targeted RUNX2 knockdown in the resistant cells using siRNA increased sensitivity to etoposide and also upregulated expression of pro-apoptotic genes indicating that RUNX2 could be a molecular target against etoposide resistance. Differential miRNA (microRNA) expression was observed among the drug resistant and sensitive cells suggesting that miRNA may also play a role in regulation of drug resistance. Hsa-miR-218, which targets ABCC6, was down-regulated in the drug resistant cell line. Transfection of a miR-218 mimic could down-regulate the expression of the efflux pump ABCC6 by 65% in drug resistant cells suggesting that regulation of miRNA may play an important role in etoposide resistance. RNA from MCF7 and etoposide-resistant MCF7 (MCF7VP) cell lines were hybridized to Affymetrix microarrays. Both samples were run in triplicate

2011-04-08 | E-GEOD-28413 | biostudies-arrayexpress

E-GEOD-18322

Project description:Gene expression profile of two Ara-C-resistant cell lines

2015-09-07 | E-GEOD-18322 | ExpressionAtlas

E-MTAB-6235

Project description:Expression profiling of DDX3X and DDX54 knockdown in MCF7 cells

2025-01-23 | E-MTAB-6235 | ExpressionAtlas