Figure 5.

Knockdown of PCNA expression abolishes the inhibitory effects of PCNA-I1S (P-I1S) on AR activity. (A) PC-3 cell extracts transfected with PCNA siRNA (PCNA-si) for three days in stripped medium were analyzed by western blot analysis. PC-3 cells in stripped medium were transfected with PCNA siRNA for three days. During the last 24 h, the cells were co-transfected with (B) CMV-AR and PSA-luc or (C) p21(-215)-luc, respectively, and treated without or with P-I1S (1 µM) in the absence or presence of DHT (10 nM), followed by luciferase assay. ^*P<0.05 and ^**P<0.01, siRNA plus DHT vs. DHT alone. PCNA, proliferating cell nuclear antigen; DHT, dihydrotestosterone.