Abstract

Resveratrol (3,4',5-trans-trihydroxystilbene) is a dietary polyphenol with chemopreventive properties present in grapes, red wine, peanuts and other edible products. The antiproliferative and proapoptotic effect of resveratrol in breast cancer cells can be traced to the accumulation of ceramide. In this study we demonstrate that resveratrol can also exert antiproliferative/proapoptotic effects in association with the accumulation of endogenous ceramide in the androgen receptor (AR)-negative prostate cancer cell line, PC3. Notably, resveratrol shares with other ceramide-inducing agents a phenolic moiety on its structure. For this reason we hypothesize that the phenolic moiety is critical for the ceramide-associated growth-inhibitory effects of resveratrol. We compared the ability to induce both ceramide increase and growth inhibition in PC3 cells of resveratrol and three resveratrol analogs: piceatannol (3,3',4',5-trans-tetrahydroxystilbene), with an additional hydroxyl group in the 3' position; trans-stilbene, the nonhydroxylated analog; and the semisynthetic 3,4',5-trimethoxy-trans-stilbene (TmS), with methoxyl groups in lieu of the hydroxyl groups. Of the three stilbenoids, only piceatannol (and not stilbene or TmS) produced ceramide-associated growth inhibition. These data point to the phenolic moiety of stilbenoids as a critical structural feature necessary to induce ceramide-associated growth inhibition.