Gene Expression Pattern in EP300 knocked-down MCF7 cells and corresponding paclitaxel resistant derivatives

EP300, a transcriptional co-activator of E-cadherin, has been recently found by our group to regulate doxorubicin resistance via by-pass of senescence and paclitaxel resistance by overcoming apoptosis in a minimally transformed mammary epithelial cells (MTMEC). Moreover, EP300 deleted MTMEC cells exhibit an multi-drug resistant (MDR) phenotype independent of P-glycoprotein (ABCB1), an efflux pump or ABC drug transporter. This whole transcriptome array study was undertaken in order to explore the downstream targets in the EP300-mediated drug resistance, epidermal-to-mesenchymal transition and cancer stem cell phenotypes in breast cancer cell line MCF7. MCF7 cells were stably knocked down for EP300 by RNA interferance using short hairpins cloned into pGIPZ. Two different lentiviral shEP300 constructs were used. Stable lines were selected with puromycin. The stable lines obtained were further used to generate their corresponding paclitaxel resistant derivatives, which were also included in the study. MCF7 cells carrying empty pGIPZ vector was used as control.