The Mechanism Of Gambogic Acid Inhibiting Cell Proliferation And Inducing Programmed Cell Death In Bladder Cancer T24Cells

Part1Mechanism of Gambogic Acid inhibiting Cell Proliferation and Inducing Apoptosis in Bladder Cancer T24CellsObjective:To study the effects of gambogic acid (GA) on proliferation and apoptosis of bladder cancer T24cells.Methods:After administration of0-10μmo1/L GA for24h, the proliferation of T24cells was assayed by using CCK-8colorimetry. The apoptosis of T24cells was tested by using Annexin V-FITC/PI double staining and flow cytometry. The morphological changes of T24cells apoptosis after administration of GA were observed by using Hoechst33258fluorescent staining. After administration of0-1μmol/L GA for12, the invasion and migration of T24cells were examined by using Transwell assay. The levels of XIAP, c-IAP1, c-IAP2, caspase3, caspase8and caspase9proteins were detected by using Western blotting. Results:GA could significantly inhibit proliferation and induce apoptosis of T24cells in a concentration-dependent manner as compared with control group (P<0.05). After administration of1μmol/L GA for24h was significantly decreased and apoptosis rate was significantly increased. The expression levels of XIAP and c-IAP1, but not c-IAP2proteins were down-regulated in T24cells treated with GA, while those of caspase3, caspase8and caspase9proteins were up-regulated. Transwell invasive assay revealed that the invasion and migration capability of T24cells was negatively correlated with the concentration of GA.Conclusion:The results indicated that GA could inhibit the growth of bladder cancer T24cells probably through suppressing cell proliferation, and inducing apoptosis probably via down-regulating the expression of XIAP and cl.APl, but not c-IAP2, and activating caspase-3, caspase-8and caspase-9. Part2Autophagy Induction by Gambogic Acid in Bladder Cancer T24Cells and Possible MechanismObjective:To study autophagy induction by gambogic acid (GA) in bladder cancer T24cells and the action mechansim.Methods:After administration of0-10μmol/L GA for24h, the viability of T24cells was assayed by using CCK-8colorimetry. Western-blot was used to detect the expression levels of P53, Bci-2and Beclin-1proteins. The autophagy in T24cells induced with different concentrations of GA was observed under confocal laser scanning microscope (CLSM).Results:GA could significantly induce the autophagy of T24cells in a concentration-dependent manner as compared with control group (P<0.05). The expression of Bcl-2protein was down-regulated, while that of P53and Beclin-1proteins was up-regulated in T24cells treated with GA. Under CLSM, the autophagy in T24cells was observed after the treatment with different concentrations of GA.Conclusion:The results indicated that GA could inhibit the growth of bladder cancer T24cells probably through suppressing cell proliferation, and inducing autophagy probably via down-regulating the expression of Bcl-2and up-regulating the expression of P53and Beclin-1proteins.