P62 regulates resveratrol-mediated Fas/Cav-1 complex formation and transition from autophagy to apoptosis. Oncotarget

Resveratrol is a potential polyphenol drug used in cancer treatment. We examined the relationship between autophagy and apoptosis in RSV-treated non-small lung adenocarcinoma A549 cells. Resveratrol treatment increased autophagy and autophagy-mediated degradation of P62. Immunocytochemistry revealed P62 co-localized with Fas/Cav-1 complexes, known to induce apoptosis. However, siRNA-mediated P62 downregulation enhanced formation of Fas/Cav-1 complexes, suggesting that P62 inhibited Fas/Cav-1 complex formation. Fas/Cav-1 complexes triggered caspase-8 activation and cleavage of Beclin-1, releasing a C-terminal Beclin-1 peptide that translocated to the mitochondria and initiate apoptosis. Inhibition of autophagy by siRNA-mediated repression of Beclin-1 also blocked RSV-induced apoptosis, showing a dependence of apoptosis on autophagy. P62 knockdown by siRNA accelerated the activation of caspase-8 and initiate apoptosis, while Cav-1 knockdown inhibited apoptosis, but increased autophagy. Inhibition of autophagy by 3-MA prevented both P62 degradation and induction of apoptosis, wherea