Fig. 3

HIF-2α regulates stem phenotype conversion and drug resistance of breast cancer cells by activating the Wnt pathway. a Left: Expression of Wnt pathway-related proteins in HIF-2α–overexpressing MCF7 and MDA-MB-231 cells was detected by western blot. Right: Densitometric analysis of protein expression. b Left: Expression of HIF-2α and Wnt pathway-related proteins was detected after HIF-2α–overexpressing MCF7 cells were treated with DKK (100 ng/ml) for 48 h by western blot. Right: Densitometric analysis of protein expression. c Left: Cell viability was determined in HIF-2α–overexpressing MCF7 cells incubated with PTX combined with DKK (100 ng/ml) for 48 h using the MTT assay. Right: Comparison of IC₅₀ values and resistance index. d Cell apoptosis was measured after HIF-2α–overexpressing MCF7 cells were incubated with PTX (3 nM) combined with DKK (100 ng/ml) for 48 h by flow cytometry. Quantification values are shown. e Self-renewal ability was analyzed after stable HIF-2α cDNA transfected MCF7 cells were incubated with PTX (3 nM) and DKK (100 ng/ml) for 48 h. f Expression of c-Myc, OCT4 and Nanog proteins was detected after HIF-2α–overexpressing MCF7 cells were treated with DKK (100 ng/ml) for 48 h by western blot. Quantification values are shown. 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 < 0.05, ^##P < 0.01, ^###P < 0.0001 compared with the HIF-2α-cDNA group