Resveratrol-induced PTEN promoter activity is mediated by AR. (A) C4-2 cells were co-transfected with plasmids expressing PTEN-Luc/Renilla-Luc and treated as indicated for 48 h. PTEN promoter activity was measured by dual luciferase assay. AR-ligand DHT inhibited PTEN promoter activity in a dose-dependent manner and resveratrol stimulated PTEN promoter activity. In contrast, AR-antagonist Casodex was shown to stimulate PTEN promoter activity, with resveratrol only adding slightly to this effect (*P < 0.005). (B) Knockdown of AR results in increased PTEN promoter activity. C4-2 cells were co-transfected with control siRNA or anti-AR siRNA and PTEN-luc/Renilla-Luc plasmids. After 48 h of treatment, PTEN promoter activity was measured by luciferase assay. The insert shows the knockdown of AR protein expression (*P < 0.005). (C) DU145 and C4-2 cells were transfected with PTEN-Luc/Renilla-Luc plasmids. Cells were treated with DMSO, or 10 µm resveratrol for 48 h. PTEN promoter activity was measured by luciferase assay. The structures of the −1134 to −1 and truncated −1134 to −1001 PTEN promoters are shown on the left panel. (D) AR-negative DU145 and AR-positive CWR22rv1 cells were treated with DMSO, 10, 20 or 50 µm resveratrol for 48 h. Western blots show PTEN, phospho-AKT, total-AKT and Actin levels. The quantification of phospho-AKT is shown in Supplementary Material, Fig. S3. Note that resveratrol did not change PTEN levels in DU145 cells.