β-catenin／Akt信号通路在亚硒酸钠诱导的胃癌细胞凋亡中的机制研究

摘要

目的：探讨β-catenin／Akt信号通路在亚硒酸钠诱导的胃癌细胞凋亡中的机制研究。方法培养胃癌细胞株SGC-7901，0、5、10、20μmol／L亚硒酸钠处理细胞，24 h后流式细胞仪检测细胞的凋亡率变化；10μmol／L的亚硒酸钠处理细胞，24 h后流式细胞仪检测细胞周期变化；10μmol／L的亚硒酸钠处理细胞，0、6、12、24 h后Western blot检测β-catenin、cyclin D1和survivin的蛋白表达量及蛋白激酶B（protein kinase B，Akt）的活性。结果5、10、20μmol／L亚硒酸钠处理细胞的凋亡率显著高于0μmol／L（P＜0.01）。10μmol／L的亚硒酸钠作用于胃癌细胞24 h后，与对照组比较，G0／G1期细胞显著减少，S期及G2／M期细胞显著增加（P＜0.05）， G2／M期细胞增加（ P＜0.05）；10μmol／L的亚硒酸钠作用于胃癌细胞后，β-catenin、cyclin D1和survivin在6、12和24 h的蛋白表达量显著低于0h（P＜0.01），且随着时间的延长，蛋白的表达量逐渐减少；10μmol／L的亚硒酸钠作用于胃癌细胞后，p-Akt在6、12和24 h的含量显著低于0 h（P＜0.01），而Akt各时间点比较差异无统计学意义。结论亚硒酸钠能诱导胃癌细胞的凋亡，阻滞细胞于S期，其作用机制可能与β-catenin／Akt信号通路有关。%Objective To explore the mechanism of β-catenin/Akt signaling pathway in the apoptosis of gastric cancer cells induced by selenite sodium.Methods Gastric cancer cell line SGC-7901 was cultured, and 0 mol/L, 5 mol/L, 10 mol/L and 20 mol/L selenite sodium treated cells; flow cytometry was used to detect the cell apoptosis rate after 24 h;10 mol/L sodium selenite treated cells, flow cytometry was used to detect the cell cycle changes after 24 h;10 mol/L sodium selenite treated cells,protein expression ofβ-catenin,cyclin D1 and protein kinase B ( Akt) activity were detected by Western blot after 0,6,12,24 h.Results Cells apoptosis rate was significantly higher than 0 mol/L after cells was treated by 5 mol/L, 10 mol/L and 20 mol/L sodium selenite, due to cells apoptosis rate was higher by 10 mol/L sodium selenite treated than 5 mol/L and 20 mol/L, 10 mol/L sodium selenite treated cells for follow-up study;gastric cancer cells was treated by 10 mol/L sodium selenite for 24 h, compared with the control group, G0/G1 phase cells decreased, cells in S phase and G2/M phase significantly increased(P<0.05);gastric cancer cells was treated by 10 mol/L sodium selenite for 0 h, 6 h, 12 h and 24 h,protein expression of β-catenin and cyclin D1 and Survivin in 6 h, 12 h and 24 h was significantly lower than that in 0 hour (P<0.01),and with the extension of time, protein expression gradually decreased;gastric cancer cells was treated by 10 mol/L sodium selenite could significantly decrease the phosphorylation of p-Akt in 6,12,24 h, while there was no significant difference of Akt among difference time points( P <0.01).Conclusion Sodium selenite could induce apoptosis of gastric cancer cells, and the cells were arrested in S phase.The mechanism may be associated with beta-catenin/Akt signaling pathway.