Fig. 5

FZD2 positively regulates TGF-β1 expression in BC cells via Notch signaling pathway. a The correlation between FZD2 expression and Notch signaling pathway was analyzed based on GESA database. b The protein level of FZD2 was measured in BC cells transfected with si-NC or FZD2-specific siRNAs for 72 h. Notch pathway factors (Notch1, P21 and Hes1) were examined by western blot in indicated BC cells. c Notch pathway factors (Notch1, P21 and Hes1) were tested in BC cells treated with TGF-β1 (0, 2, 5 and 10 ng/ml) for 24 h. d The levels of related proteins (Notch1, Hes1, P21) were measured by western blot in BC cells pre-treated with SB431542 (5 μM) for 2 h, followed by TGF-β1 (10 ng/ml) incubation for another 24 h. e The levels of related proteins (Notch1, Hes1, P21, E-cadherin, N-cadherin, Vimentin, Fibronectin) were measured by western blot in BC cells treated with FLI-06 (50 μm). f The levels of related proteins (Notch1, Hes1, P21) were measured by western blot in BC cells pre-treated with TGF-β1 (10 ng/ml) or SB431542 (10 ng/ml) for 24 h, followed by siFZD2 or oxFZD2 incubation for another 48 h. ^*p < 0.05, ^**p < 0.01, ^***p < 0.001 was a symbol of statistical significance. FZD2, frizzled class receptor 2; BC, breast cancer; EMT, epithelial-to mesenchymal transition, TGF-β1, transforming growth factor-β1