Resveratrol-induced apoptosis is associated with activation of p53 and inhibition of protein translation in T47D human breast cancer cells.

BACKGROUND AND
PURPOSE: Trans-resveratrol (RSVL; 3,4',5-trihydroxystilbene), a natural compound found in grapes, berries, peanuts and red wine exerts certain anticancer roles in different human cancer types. However, the exact molecular mechanism(s) behind such a role remains to be elucidated, thus the aim of this study. EXPERIMENTAL APPROACH: T47D human breast cancer cells were treated with RSVL and cell proliferation was measured by cell counting. Apoptosis was analyzed by Giemsa staining, poly(ADP-ribose) polymerase (PARP) fragmentation analysis and annexin V assay. Regulation of p53 tumor suppressor protein, p70S6K, and pS6 ribosomal protein was measured by detecting their phosphorylated active forms using ECL-immunoblot analysis.
RESULTS: The present results show that RSVL-induced growth inhibition in T47D cells is caused by apoptosis as demonstrated by morphological changes and PARP fragmentation. RSVL-induced apoptosis is associated with the activation of the p53 in a dose- and a time-dependent manner. Phosphatidylinositol 3-kinase (PI3K) inhibitors, wortmannin and LY294002 abolished the effect of RSVL on p53 activation. Interestingly, RSVL inhibits the expression of p70S6K and the phosphorylation of pS6RP. CONCLUSIONS AND IMPLICATIONS: These findings demonstrate that RSVL affects multiple intracellular signaling transduction pathways such as p53 activation/protein translation inhibition/apoptosis, and strongly support a contemplated use of this natural compound as a preventive and/or an adjuvant therapeutic drug for breast cancer. The data indicate that these proteins may be used as predictive biomarkers to evaluate the treatment efficacy of RSVL in clinical trials. Copyright (c) 2007 S. Karger AG, Basel.