Figure 4

The role of mPRα in the P4-repressed EMT of MB468 and MB231 cells. (a) The growth-arrested MB468 cells were treated with diverse concentrations of progesterone (P4) for 24 hours. (PC: HEK293 cell lysate as a positive control for membrane progesterone receptor (mPR) α expression.) (b) MB231 cells and MB468 cells were treated with/without P4 at 30 ng/ml for 24 hours. Western blot analyses were performed with anti-mPRα, anti-snail, and anti-α-tubulin antibodies. (c) MB468 cells were transfected with 50 nM of mPRα siRNA and 50 nM of scramble siRNA; and then treated with P4 at 30 ng/ml for 24 hours. The Western blot analyses showed similar patterns of snail/epithelial-mesenchymal transition (EMT) protein expressions in the cells transfected with scramble siRNA and equivalent levels of snail/EMT proteins in the cells transfected by mPRα siRNA, indicating the roles of specifically knocking down mPRα in MB231 cells. (d) The parent MB231 and mPRα stably-expressing MB231 cells were treated with/without bpV(phen) at 1 μM for one hour, followed by P4 treatment at 30 ng/ml. Western blot analyses were performed with anti-snail, anti-mPRα, and anti-α-tubulin antibodies. The data are representative for three individual experiments.