Author(s): Sareen D, van Ginkel PR, Takach JC, Mohiuddin A, Darjatmoko SR, Albert DM, Polans AS. Mitochondria as the primary target of resveratrol-induced apoptosis in human retinoblastoma cells. Invest Ophthalmol Vis Sci. 2006 Sep;47(9):3708-16. PMID 16936077
PURPOSE To determine the molecular mechanisms by which resveratrol induces retinoblastoma tumor cell death.
METHODS After resveratrol treatment, Y79 tumor cell viability was measured using a fluorescence-based assay, and proapoptotic and antiproliferative effects were characterized by Hoechst stain and flow cytometry, respectively. Mitochondrial transmembrane potential (DeltaPsim) was measured as a function of drug treatment using 5,5′,6,6′-tetrachloro-1,1′,3,3′-tetraethyl-benzamidazolocarbocyanin iodide (JC-1), whereas the release of cytochrome c from mitochondria was assayed by immunoblotting and caspase activities were determined by monitoring the cleavage of fluorogenic peptide substrates.
RESULTS Resveratrol induced a dose- and time-dependent decrease in Y79 tumor cell viability and inhibited proliferation by inducing S-phase growth arrest and apoptotic cell death. Preceding cell death, resveratrol evoked a rapid dissipation of DeltaPsim. This was followed by the release of cytochrome c into the cytoplasm and a substantial increase in the activities of caspase-9 and caspase-3. Additionally, in a cell-free system, resveratrol directly induced the depolarization of isolated mitochondria.
CONCLUSIONS These results demonstrate that resveratrol, a nontoxic natural plant compound, inhibits Y79 cell proliferation and stimulates apoptosis through activation of the mitochondrial (intrinsic) apoptotic pathway and may warrant further exploration as an adjuvant to conventional anticancer therapies for retinoblastoma.