Fig. 2

HIF-2α overexpression increases breast cancer cells resistance to PTX, suppresses apoptosis, and up-regulates stem cell marker expression. a HIF-2α expression was detected in stably HIF-2α–cDNA transfected MCF7 and MDA-MB-231 cells by western blot. Densitometric analysis of detected protein expression is also shown. b Top: Cell viability of stable HIF-2α–cDNA transfected MCF7 and MDA-MB-231 cells 48 h after treatment with PTX (0–300 nM and 0–30000 nM, respectively) was measured using the MTT assay. Bottom: Comparison of IC₅₀ values and resistance index (RI). c Cell apoptosis was analyzed by flow cytometry after stable HIF-2α–cDNA transfected MCF7 and MDA-MB-231 cells were incubated with PTX (3 nM and 100 nM, respectively) for 48 h. d Self-renewal ability was analyzed after stable HIF-2α–cDNA transfected MCF7 and MDA-MB-231 cells were incubated with PTX (3 nM or 100 nM, respectively) for 48 h. e Left: Expression of c-Myc, OCT4 and Nanog in HIF-2α–overexpressing MCF7 and MDA-MB-231 cells was detected by western blot. Right: Densitometric analysis of protein expression. Data are the mean ± SD of three independent experiments performed in triplicate. ^*P < 0.05, ^**P < 0.01, ^***P < 0.0001 compared with the NC-cDNA group. ^###P < 0.0001 compared with the NC-cDNA + PTX group