熊果酸诱导前列腺癌细胞株PC-3凋亡的实验研究

目的:探讨熊果酸(Ursolic acid,UA)对人前列腺癌细胞株PC-3细胞周期、凋亡的影响及其作用机制.方法:人前列腺癌细胞株PC-3以不同浓度的UA作用不同的时间后,分别使用四甲基偶氮唑蓝比色法(4 methyl thiazolyl tetrazolium assay,MTT),免疫组织化学SP法,流式细胞术(Flow cytometry,FCM),Western blot等实验方法检测PC-3细胞的增殖抑制情况,细胞周期和凋亡率的变化,以及细胞内bcl-2、bax 2个重要的细胞凋亡相关基因和细胞凋亡相关特殊蛋白cox-2、caspase 3表达的变化.结果:UA对PC-3细胞有增殖抑制作用,其作用随着药物浓度和作用时间的增加而增强.24、48 h和72 h 3个时间段UA分别作用于PC-3细胞后的IC_(50)分别为50.87、37.91 μmol/L和27.86μmol/L;熊果酸作用后PC-3细胞周期的主要特点是大量细胞累积于G_1期,进入S期的细胞减少.UA能够诱导PC-3细胞凋亡,经过24、48 h和72h 3个时间段UA浓度50μmol/L作用后,细胞凋亡率为6.21%、7.81%和13.31%;细胞内bcl-2和cox-2的表达随着药物浓度增加逐渐减少;bax和caspase 3蛋白的表达随着药物浓度增加逐渐增加.结论:UA能够抑制PC-3细胞的增殖,并使细胞大量累积于G_1期,进入s期的细胞减少.可能通过使bcl-2和cox-2的表达减少、bax和caspase 3蛋白的表达增加来诱导细胞凋亡.

Empirical study on ursolic acid inducing apoptosis in human prostatic carcinoma cell line PC-3

Objective:To investigate the proliferation inhibition and apoptosis in human prostatic carcinoma cell line PC-3 induced by ursolic acid and their mechanism.Methods:PC-3 were treated by ursolic acid with different concentration and time.MTF assay,flow cytomerry(FCM),SP method of immunocytochemistry,Western blot were used to observe the cell proliferation inhibition,cell cycle and apoptosisrate,the expressions of bcl-2,cox-2,bax and caspase 3.Results:Ursolic acidinhibited the proliferation of PC-3 cells in dosage and time dependent manner.The IC_(50) of PC-3 cells that were treated by ursolic acid for 24,48h and 72h are 50.87,37.91μmol/L and 27.86μmol/L.The apoptosis rate of the PC-3 cells hightened with the increasing of the ursolic acid density and time.The apoptosis rates of the PC-3 cells that treated by 50 μmol/L ursolic acid for 24,48 h and 72h are 6.21,7.81% and 13.31%.Ursolic acid induced a G_1 cell cycle arrest and reduced the cell population in S phase.With the increasing of the medicine density,the expression of bcl-2 and cox-2 was down-regulated,while the expression of bax and easpase 3 up-regulated in the apoptosis.Conclusion:Ursolic acid can inhibit proliferation of the PC-3 cells and induced a G_1 cell cycle arrest and reduced the cellpopulation in S phase.It also can induce apoptosis of human prostatic carcinoma throush down-regulating the expressions of bcl-2 and cox-2,up-regulating the expression of bax,and caspase3.