Effects of bufalin on the proliferation of human choriocarcinoma cells.

OBJECTIVE: Bufalin is a traditional Chinese medicine, and it induces apoptosis in some lines of human tumor cells. METHODS: We investigated the effect of bufalin in the choriocarcinoma cell line, BeWo. BeWo cells were treated with various concentrations of bufalin, and changes in cell growth, the cell cycle, apoptosis, and related parameters were examined. RESULTS: An 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay showed that BeWo cells were sensitive to the growth inhibitory effect of bufalin. Cell cycle analysis indicated that exposure to bufalin decreased the proportion of cells in the synthesis phase and increased the proportion in the G0/G1 phases of the cell cycle. Induction of apoptosis was confirmed by annexin V staining of externalized phosphatidylserine and by the loss of mitochondrial transmembrane potential. This induction occurred in conjunction with the altered expression of genes related to cell growth, malignant phenotype, and apoptosis. CONCLUSIONS: These results suggest that bufalin may serve as a therapeutic agent for the treatment of choriocarcinoma.