Project description:Drug resistance in breast cancer is the major obstacle to a successful outcome following chemotherapy treatment. While upregulation of multidrug resistance (MDR) genes is a key component of drug resistance in multiple cancers, the complexity and hierarchy of non-MDR driven drug resistance pathways are still largely unknown. The aim of this study was to identify pathways contributing to anthracycline resistance using isogenic drug resistant breast cancer cell lines. We generated isogenic MDA-MB-231, MCF7, SKBR3 and ZR-75-1 epirubicin-resistant breast cancer cell lines, which were cross-resistant to doxorubicin and SN-38; the SKBR3 cell line was also resistant to taxanes. Epirubicin-resistant cells were morphologically different from native cells, and had alterations in apoptosis and cell cycle profile. Using gene expression and small-molecule inhibitor analyses we identified deregulation of histone H2A and H2B genes in all four cell lines. These genes contribute to several biological pathways, which include cell cycle, chromosomal maintenance, epigenetics, RNA and mitochondrial transcription. Histone deacetylase and cell cycle/DNA damage small molecule inhibitors reversed resistance and were cytotoxic for all four epirubicin-resistant cell lines confirming that histone and cell cycle pathways are associated with epirubicin resistance. This study has established model systems for investigating drug resistance in all four breast cancer subtypes and revealed key pathways that contribute to anthracycline resistance. The global gene expression analysis included 4 parental (anthracycline sensitive) and 4 resistant breast cancer cell lines, in biological triplicates.
Project description:Reliable clinical tests for predicting cancer chemotherapy response are not available and individual markers failed to correctly predict resistance against anticancer agents. We hypothesized that gene expression patterns attributable to chemotherapy-resistant cells can be used as a classification tool for chemoresistance and provide novel candidate genes involved in anthracycline resistance mechanisms. We contrasted the expression profiles of 4 different human tumor cell lines of gastric, pancreatic, colon and breast origin and of their counterparts resistant to the topoisomerase inhibitors daunorubicin or doxorubicin. We also profiled the sensitive parental cells treated with doxorubicin for 24h. We interrogated Affymetrix HGU133A and U95A arrays independently. We applied two independent methods for data normalization and used Prediction Analysis of Microarrays (PAM) for feature selection. In addition, we established data sets related to drug resistance by using a “virtual array” composed of features represented on both types of oligonucleotide arrays. We identified 71 candidate genes associated with doxorubicine/daunorubicine resistance. To validate the microarray data, we also analyzed the expression of 12 selected genes by quantitative RT-PCR or immunocytochemistry, respectively. While the comparison of drug-sensitive versus drug-resistant cells yields candidates associated with drug resistance, the 24h treatment of sensitive parental cells produced a distinct transcriptional profile related to short-term drug effects. Keywords: superSeries This reference Series links data in the following related Series: GSE3926 Anthracycline treatment and resistance in four human cancer cell lines (HGU133A) GSE3927 Anthracycline resistance in four human cancer cell lines (HGU95A)
Project description:Drug resistance in breast cancer is the major obstacle to a successful outcome following chemotherapy treatment. While upregulation of multidrug resistance (MDR) genes is a key component of drug resistance in multiple cancers, the complexity and hierarchy of non-MDR driven drug resistance pathways are still largely unknown. The aim of this study was to identify pathways contributing to anthracycline resistance using isogenic drug resistant breast cancer cell lines. We generated isogenic MDA-MB-231, MCF7, SKBR3 and ZR-75-1 epirubicin-resistant breast cancer cell lines, which were cross-resistant to doxorubicin and SN-38; the SKBR3 cell line was also resistant to taxanes. Epirubicin-resistant cells were morphologically different from native cells, and had alterations in apoptosis and cell cycle profile. Using gene expression and small-molecule inhibitor analyses we identified deregulation of histone H2A and H2B genes in all four cell lines. These genes contribute to several biological pathways, which include cell cycle, chromosomal maintenance, epigenetics, RNA and mitochondrial transcription. Histone deacetylase and cell cycle/DNA damage small molecule inhibitors reversed resistance and were cytotoxic for all four epirubicin-resistant cell lines confirming that histone and cell cycle pathways are associated with epirubicin resistance. This study has established model systems for investigating drug resistance in all four breast cancer subtypes and revealed key pathways that contribute to anthracycline resistance.
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
Project description:To explore novel lncRNAs relative to chemo-resistance in breast cancer, we performed lncRNA microarray analysis using three anthracycline-resistant tissues and three anthracycline-sensitive tissues collected before neoadjuvant chemotherapy by Arraystar Human LncRNA Microarray V3.0.