Tetrandrine induces apoptosis in gallbladder carcinoma in vitro.

ABSTRACT

OBJECTIVE: The aims of this study were to observe the apoptosis effects of tetrandrine on human gallbladder carcinoma cell line (SGC-996), and to explore its related mechanism. METHODS: First, the anti-proliferative activities of tetrandrine on SGC-996 cells were determined by using the MTT assays. Then, cell cycle changes were detected by flow cytometry analysis. The apoptosis of cells was detected by the annexin V/propidium iodide double-staining assay. Detection of mitochondrial membrane potential was used to validate the ability of tetrandrine on inducing apoptosis. Finally, the expressions of the apoptosis-related proteins (caspase-3, PARP, Bcl-2, and Bax) were analyzed by western blot. Statistical analyses were performed using the Student’s t-test for comparison of the results obtained from cells with or without treatment of tetrandrine. RESULTS: The MTT assay revealed a significant inhibition of cell proliferation in a dose- and time-dependent manner. Cells treated with tetrandrine were arrested at the S phase, according to the flow cytometric analysis. Tetrandrine produced a dose-dependent increase in the apoptotic cell population compared with control cells. Tetrandrine can also affect mitochondrial function by changing the mitochondrial membrane potential. Furthermore, western blot assay demonstrated that the tetrandrine induced apoptosis in SGC-996 cells by regulating the ratio of Bcl-2/Bax and activating the expression of cleaved caspase-3. CONCLUSIONS: The results indicate that tetrandrine may be a potential agent for the treatment of gallbladder carcinoma.