ABSTRACT
Objective Gambogic acid ( GA) can suppress the growth of multiple tumor cells , including gastric carcinoma , hepatoma , hematologic neoplasms and breast carcinoma , but there have been few reports about its effect on urologic neoplasms .This study was to investigate the possible mechanisms of GA inducing bladder cancer cell apoptosis and cell cycle arrest . Methods We cultured human bladder cancer BIU8-7 cell lines in vitor and treated the cells in the logarithmic growth phase with isotonic saline solu-tion (negative control)or GA at the concentrations of 1.0, 2.0, and 3.0μmol/L, respectively.We determined the expression of the Caspase-3 protein in the tumor tissue using the immunohistochemical S-P method and detected GA-induced apoptosis of the bladder cancer cells and cell cycle changes by flow cytometry . Results The expressions of the Caspase-3 protein were 4.28 ±1.86, 5.03 ± 0.78, and 6.47 ±1.31 in the 1.0, 2.0, and 3.0μmol/L GA groups, respectively, significantly higher than 2.13 ±1.27 in the nega-tive control (P<0.05).Flow cytometry showed a gradual decrease of the cells in the G 0/G1 phase and a gradual increase in the G2/M phase , but no obvious change in the S phase . Conclusion Gambogic acid can promote the apoptosis , arrest the cell cycle , and in-hibit the proliferation of bladder cancer cells by increasing the expression of the Caspase -3 protein.