Anti-prostate cancer potential of gossypetin via inducing apoptotic and autophagic cell death

Gossypetin (GTIN), a naturally occurring hexahydroxy flavone, has been shown to possess antimutagenic, antioxidant, antimicrobial, and antiatherosclerotic effects. Here, we investigated the mechanism(s) underlying the anticancer potential of GTIN. In this study, investigations were showed that GTIN preferentially induces programed cell death of prostate cancer (PCa) cells in vitro and in vivo. MTT data showed that GTIN exhibited the anti-proliferation effect on human PCa cells in a dose- and time-dependent manner. Among two kinds of PCa cells, androgen-dependent LNCaP cells were the most susceptible to GTIN. GTIN was evaluated for apoptotic and autophagic activities in LNCaP cells, but not in androgen-independent DU145 cells with mutant Atg5 and resistant to autophagy. Molecular data showed the apoptotic effect of GTIN at a high dose in PCa cells might be mediated via mitochondrial pathway. The lower dose of GTIN-induced autophagy enhances LNCaP cell death, and is dependent on class III PI3K and Atg5 pathway. Finally, GTIN was evidenced by its inhibition on the growth of LNCaP cells in xenograft tumor studies. As a result, our data presented the first evidence of GTIN as an inducer of apoptotic and autophagic cell death in LNCaP cells, and provide a new mechanism for its anticancer activity.