Grape-derived chemopreventive agent resveratrol decreases prostate-specific antigen (PSA) expression in LNCaP cells by an androgen receptor (AR)-independent mechanism.

Trans-resveratrol, a polyphenol present in red wines and various human foods, inhibited the proliferation of LNCaP cells and the expression of a prostate specific gene, PSA. A 4-day treatment with resveratrol reduced the levels of intracellular and secreted PSA by approximately 80%, as compared to controls. To test whether this decrease was coordinated with changes in AR expression, levels of AR were assayed by Western blot analysis, using the cognate antibody, or by binding with the radioactive ligand methyltrienolone [3H]R1881. With either assay, little or no change in AR expression could be detected between control and resveratrol-treated cells. Thus, it would appear that the prostate tumor marker PSA is down regulated by resveratrol, by a mechanism independent of changes in AR.