Fig. 2.

Overexpression of ER-α36 contributes to cisplatin resistance in breast cancer cells. a MCF-7 cells stably overexpressing ER-α36 were screened using G418 for 4 weeks and identified by western blot. b The quantitative analysis of ER-α36 expression of (a). c MCF-7/V and MCF-7/ER-α36 cells were treated with increasing concentrations of cisplatin (DDP) for 48 h, and then cell proliferation was measured with CCK-8 assay kit. d Cisplatin sensitivity of MCF-7/V and MCF-7/ER-α36 cells was examined by monolayer colony formation assay. e, f MCF-7/V and MCF-7/ER-α36 cells were treated with or without 5 μg/mL cisplatin for 48 h. The cell nucleus were stained with Hoechst 33258 and then observed under fluorescence microscope. The representative images were shown and the typical apoptotic bodies were marked with white arrows (e). The cells were stained with annexin V-FITC/PI. Then the percentage of apoptotic cells was calculated using flow cytometry (f). ^*P < 0.05, ^** P < 0.01, ^***P < 0.001