Abstract:Objective:To investigate the molecular mechanism of camptothecin enhancement of TRAIL-induced apoptosis in hepatocellular carcinoma cell lines.
Methods :The HepG2 and Hep3B cell cycles were analysed by flow cytometry after co-treated with camptothecin and TRAIL, and the expression of signal transduction protein, such as Caspase-8, Caspase-3, Caspase-9, DR4, DR5, DcR1, c-FLIP, RIP, Cytc, Smac, Bid were detected by Western blot before and after the treatment.
Results:Pretreatment with lower dose of Camptothecin could increase the sensitivity of HepG2 and Hep3B cells to TRAIL-induced apoptosis, and could downregulate the expression of c-FLIP and RIP, upregulate the expression of Cytc, Smac and Bid, but had no effect on the expression of DR4, DR5 and DcR1.
Conclusions:Camptothecin could sensitize HepG2 and Hep3B cells to TRAIL-induced apoptosis, and the mechanism is by downregulation of c-FLIP and RIP, activation of apoptosis death receptor pathway, upregulation of Bid and amplification of the mitochondrial pathway. The expression of death receptor not involved in this process.