北五味子多糖对人膀胱癌T24细胞增殖和凋亡的影响及其机制

Effect of Schisandra chinensis polysaccharide on proliferation and apoptosis of human bladder cancer T24 cells and its mechanisms

目的:探讨北五味子多糖(SCP)对体外培养人膀胱癌T24细胞增殖和凋亡的影响,并阐明其可能的作用机制。方法:体外培养人膀胱癌T24细胞,分为对照组和50、100及200 mg·L^(-1)SCP组。不同剂量SCP干预24~48 h后,采用MTT法检测各组T24细胞增殖抑制率,Hoechst 33258荧光染色法检测各组T24细胞凋亡情况,AnnexinⅤ-FITC/碘化丙啶(PI)双染法检测各组T24细胞凋亡率,流式细胞术检测各组T24细胞不同细胞周期细胞百分率和细胞凋亡率,Western blotting法检测各组T24细胞中磷酸酶和张力蛋白同源物(PTEN)、磷酸化磷脂酰肌醇-3激酶(p-PI3K)、蛋白激酶B (Akt)和磷酸化Akt (p-Akt)蛋白表达水平。结果:与对照组比较,50、 100和200 mg·L^(-1)SCP组T24细胞增殖抑制率明显升高(P<0.05或P<0.01);T24细胞凋亡率明显升高(P<0.05或P<0.01);50、100和200 mg·L^(-1)SCP组T24细胞G_(0)/G_(1)期细胞百分率明显升高(P<0.05或P<0.01),100和200 mg·L^(-1)SCP组T24细胞S期和G2/M期细胞百分率明显降低(P<0.01);50、100和200 mg·L^(-1)SCP组T24细胞中PTEN蛋白表达水平明显升高(P<0.05或P<0.01),p-PI3K蛋白表达水平和p-Akt/Akt比值明显降低(P<0.05或P<0.01)。结论:SCP能够抑制T24细胞增殖,促进其凋亡,其机制可能与调控PTEN和PI3K/Akt信号通路相关蛋白表达有关。

Objective:To investigate the effect of Schisandra chinensis polysaccharide(SCP) on the proliferation and apoptosis of human bladder cancer T24 cells,and to elucidate its possible mechanisms.Methods:The human bladder cancer T24 cells were cultured in vitro and divided into control group and 50,100,and 200 mg·L^(-1)SCP groups. After 24-48 h of intervention with different doses of SCP,the inhibitory rates of proliferation of T24 cells in various groups were detected by MTT method,the apoptosis of T24 cells in various groups was detected by Hoechst 33258 fluorescence staining method,the apoptotic rates of T24 cells in various groups were detected by Annexin Ⅴ-FITC/propidium iodide(PI) double staining method,the percentages of T24 cells in different cell cycles and the apoptotic rates of T24 cells in various groups were detected by flow cytometry,and the expression levels of phosphatase and tensin homolog deleted on chromosome ten(PTEN),phosphorylated phosphatidylinositol-3 kinase(p-PI3K),protein kinase B(Akt)and phosphorylated Akt(p-Akt)proteins in the T24 cells in various groups were detected by Western blotting method. Results:Compared with control group,the inhibitory rates of proliferation of T24 cells in 50,100,and 200 mg·L^(-1)SCP groups were significantly increased(P<0. 05 or P<0. 01);the apoptotic rates of T24 cells were significantly increased(P<0. 05 or P<0. 01);the percentages of T24 cells in 50,100 and 200 mg·L^(-1)SCP groups in G_(0)/G_(1)phase were significantly increased(P<0. 05 or P<0. 01),the percentages of T24 cells in 100 and 200 mg·L^(-1)SCP groups in S phase and G_(2)/M phase were significantly decreased(P<0. 01);the expression levels of PTEN protein in the T24 cells in 50,100,and 200 mg·L^(-1)SCP groups were significantly increased(P<0. 05 or P<0. 01),the expression levels of p-PI3K protein and the ratios of p-Akt/Akt in the T24 cells were significantly decreased(P<0. 05 or P<0. 01). Conclusion:SCP can inhibit the proliferation of T24 cells and promote their apoptosis,and its mechanism may be related to the regulation of expressions of PTEN and PI3K/Akt signaling pathway-related proteins.