Resveratrol enhances the expression of non-steroidal anti-inflammatory drug-activated gene (NAG-1) by increasing the expression of p53

Abstract
Dietary phenolic substances including resveratrol, a stillbene compound, are found in several fruits and vegetables, and these compounds have been reported to have anti-oxidant, anti-inflammatory and antitumorigenic activities. However, the molecular mechanisms underlying the antitumorigenic or chemopreventive activities of these compounds remain largely unknown. The expression of NAG-1 [non-steroidal anti-inflammatory (NSAID) drug-activated gene-1], a member of the transforming growth factor-beta (TGF-β) superfamily, has been shown to be associated with pro-apoptotic and antitumorigenic activities. Here, we have demonstrated that resveratrol induces NAG-1 expression and apoptosis in a concentration-dependent manner. Resveratrol increases the expression of p53, tumor suppressor protein, prior to NAG-1 induction, indicating that NAG-1 expression by resveratrol is mediated by p53 expression. We also show that the p53 binding sites within the promoter region of NAG-1 play a pivotal role to control NAG-1 expression by resveratrol. Derivatives of resveratrol were examined for NAG-1 induction, and the data suggest that resveratrol-induced NAG-1 and p53 induction is not dependent on its anti-oxidant activity. The data may provide linkage between p53, NAG-1 and resveratrol, and in part, a new clue to the molecular mechanism of the antitumorigenic activity of natural polyphenolic compounds.