Bax overexpression enhances apoptosis induced by adriamycin in HCC-9204 cells

Objective: To investigate the effect of overexpression of Bax to the sensitivity of human HCC-9204 cells to adriamycin (ADR). Methods: Human cultured hepatocellular carcinoma cell line HCC-9204 was exposed in vitro to adriamycin for various time. An inducible vector containing Bax gene, with ZnSO 4 as external inducer was constructed. Cell apoptosis was ascertained by morphological criteria, detection of apoptotic DNA fragmentation by TUNEL assay and flow cytometry. Tetrazolium blue (MTT) assay was used to evaluate the differences in drug sensitivity of HCC-9204 cells after Bax-transfection. Results: HCC-9204 cells treated with adriamycin at 20 µ mol/L showed extensive cell death. TUNEL assay showed nucleus fragmentation. And apoptotic peak was also shown by flow cytometry. FACS analyses showed a significant sub-G 1 peak and apoptosis in 31% cells at 24h after treatment. Furthermore, the time-course of cell viability following exposure of HCC-9204/Bax cells to adriamycin showed that Bax was able to significantly decrease cell survival following exposure to adriamycin. Conclusion: These results indicate that apoptosis can be induced effectively by adriamycin and overexpression of Bax can sensitize HCC-9204 cells to apoptosis induced by adriamycin.