Figure 5: PM down-regulates Bcl-2 and Bcl-xL and overexpression of Bcl-2 increases resistance to PM. (A) LNCaP and PC-3 cells were treated with PM at 0 to 10 μM for 20 h. Cellular lysates were analyzed for Bcl-2 and Bcl-xL or β-actin (loading control) by western blotting. (B) Effect of overexpression of Bcl-2 on response to PM. LNCaP and PC-3 cells were transfected with Bcl-2 expression plasmid as described in Materials and Methods section and overexpression of Bcl-2 was confirmed by western blotting (insets). Response to PM was measured in MTS assay as described in Figure 1. Overexpression of Bcl-2 significantly reduced the susceptibility of both cell lines to PM at 1.25 to 10 μM (p<0.05). Each experiment was repeated three times.