FIG. 7.

Pin1 expression in PCa cells antagonizes β-catenin coactivation of AR and prevents AR-mediated suppression of β-catenin/Tcf4 activity. (A) LNCaP cells were transfected with ARE₄-luciferase reporter (100 ng), pRL-CMV control (2.5 ng), β-catenin, and Pin1 expression vectors for 24 h as indicated (+, used; −, not used). Cells were then stimulated with DHT (10 nM) for 24 h, and firefly versus Renilla luciferase activities were determined. (B) CWR22D1 cells in medium with 10% FBS were transfected with pTopflash (20 ng), pRL-CMV (2.5 ng), β-catenin, and Pin1 plasmids as indicated for 24 h and assayed after another 24 h as described for panel A. (C) CWR22D1 cells were transfected and treated as described for panel A. (D) LNCaP cells were transfected with pTopflash reporter (50 ng), pCMV-RL (2.5 ng), and Pin1 (10 ng) expression vectors for 24 h as indicated, followed by another 24 h in steroid hormone-depleted medium. They were then stimulated for 1 or 2 h with 10 nM DHT and assayed for luciferase versus Renilla activity. (E) Control or stable Pin1-expressing LNCaP cells (P1 and P2) were transfected with pTopflash (50 ng) and pCMV-RL (2.5 ng) vectors for 24 h, and luciferase versus Renilla activities were determined after another 24 h. Results are given in relative light units (RLU).