Fig. 3.

Knockdown of ER-α36 restores cisplatin sensitivity in cisplatin-resistant breast cancer cells. a, b MCF-7/DDP cells were transfected with siER-α36 and negative control siRNA (siNC) for 48 h. The cells were collected and analyzed for ER-α36 protein expression using western blot (a). The transfected MCF-7/DDP cells were treated with 5 μg/mL cisplatin (DDP) for 48 h, and cell proliferation was measured with CCK-8 assay kit (b). c ER-α36 expression in MCF-7/DDP cells expressing ER-α36 shRNA and the control cells analyzed using western blot. d Cisplatin sensitivity of MCF-7/DDP cells expressing ER-α36 shRNA and the control cells was examined by monolayer colony formation assay. e, f MCF-7/ER-α36 were treated as in (a, b), then the peotein level of ER-α36 was detected by western blot (e). The proliferation of the transfected MCF-7/ER-α36 cells was evaluated using CCK-8 assay kit (f). g ER-α36 expression in MCF-7/ER-α36 cells expressing ER-α36 shRNA and the control cells analyzed using western blot. h Cisplatin sensitivity of MCF-7/ER-α36 cells expressing ER-α36 shRNA and the control cells was examined by monolayer colony formation assay. ^*P < 0.05, ^**P < 0.01, ^***P < 0.001