Fig. 2

P-gp expression levels and ATPase activity modulate collateral sensitivity to tamoxifen—Panel (A) shows P-gp expression in total cell lysates from drug sensitive (AuxB1 and MDA-MB-231), and – resistant (CHO^RC5, MDA-Doxo⁴⁰⁰) cells probed with P-gp-specific monoclonal antibody (C219 mAb) and anti-α-tubulin. Panel (B) shows the proliferation of the above drug sensitive and resistant cell lines (AuxB1, MDA-MB-231, CHO^RC5, MDA-Doxo⁴⁰⁰) in the presence of increasing concentrations of tamoxifen, without and with 2 μM PSC-833. Graphs represent the mean ± SD of three independent experiments done in triplicate