Apple polyphenol induces cell apoptosis, cell cycle arrest at G2/M phase, and mitotic catastrophe in human bladder transitional carcinoma cells

Bladder cancer is a common human cancer with very high recurrence rate. Apple polyphenols (APs) possess anti-cancer, anti-oxidation, and anti-inflammation properties. The effect of APs in human bladder transitional cell carcinoma (TCC, TSGH-8301 cells) was examined. The results showed AP reduces cell viability and causes cell cycle arrest at G2/M phase involving the decrease of cyclin B1 and cdc2. AP also increases the subG1 ratio in cell cycle, decreases the mitochondrial membrane potential, and alters the expression of apoptosis related proteins, apoptosis inducing factor (AIF), Bcl2, and caspase 3. It can cause the phenomenon of mitotic catastrophe with multi-nucleation and reduction of microtubule molecule. AP markedly reduces tumor size in TSGH-8301 cells-xenografted examination and induced the pattern of cell death as well as in cell system. In conclusion, AP possesses the potential to mediate cell cycle arrest, apoptosis, and mitotic catastrophe in TCC.