NCTD enhancing paclitaxel-induced apoptosis in liver cancer cells involving up-regulation of Bim

Paclitaxel has been relatively successfully used for tumor therapy. Apart from cell cycle arrest at G2/M phase, it exerts anti-tumor effect by inducing apoptosis in most types of cancer cells. Norcantharidin (NCTD) is a demethylated analogue of cantharidin, and it has been used for treatment of primary hepatoma and other carcinomas in China. Both of the two regents can arrest cell cycle and inducing cell apoptosis. But, high dose of paclitaxel or NCTD brought serious side effects to patients. So, the present study investigated whether lower concentration of paclitaxel and NCTD could have synergism effect in vitro. It was confirmed that NCTD enhanced paclitaxel-induced apoptosis in liver cancer cell HepG2. The expression of pro-apoptosis protein Bim was up-regulated more proficiently by the combination of them than any of them alone.