苦参碱抑制Akt信号通路诱导结肠癌SW480细胞凋亡

目的:研究苦参碱对人结肠癌SW480细胞的促凋亡作用及其可能的分子机制。方法:噻唑蓝比色法(MTT)测定苦参碱对SW480细胞株增殖的影响;Hoechst33258染色检测苦参碱对SW480细胞凋亡的影响,流式细胞术检测细胞凋亡率;蛋白免疫印迹法(Western blot)检测苦参碱对SW480细胞中总蛋白激酶B(Akt),磷酸化蛋白激酶B(p-Akt),B细胞淋巴瘤-2(Bcl-2),Bcl-2相关X蛋白(Bax)表达的干预作用。结果:苦参碱(0.25,0.5,1.0,1.5,2.0 g·L~(-1))能浓度和时间依赖性地抑制SW480细胞增殖。作用24,48,72 h的半数抑制浓度(IC50)分别为1.72,1.08,0.67 g·L~(-1),Hochest33258染色和流式细胞术结果显示苦参碱能显著诱导细胞凋亡(P0.01),随着药物质量浓度的提高,细胞凋亡率逐渐上升。Western blot检测显示,SW480细胞加入苦参碱后,胞内总Akt的含量无显著变化,但p-Akt的生成被显著抑制,凋亡抑制性蛋白Bcl-2表达降低,促凋亡蛋白Bax表达增高(P0.05)。结论:苦参碱能够诱导SW480细胞凋亡,该药理作用可能与苦参碱对Akt信号通路的抑制有关。

Matrine Induces Apoptosis of Human Colon Cancer Cell Line SW480 by Inhibition of Akt Signaling Pathway

Objective: To investigate the effect of matrine on the apoptosi of human colon cancer cell line SW480, and to explore its underlying mechanism. Method: The effect of matrine on SW480 cell line proliferation was detected by methylthiazolyldiphenyl-tetrazolium bromide(MTT) assay, its effect on SW480 cell apoptosis was detected by Hoechst33258 staining and flow cytometry was used to determine the apoptosis rate. Protein levels of proteinkinase B (Akt), p-Akt, B-cell lymphoma-2 (Bcl-2), and Baxin SW480 cells were detected by Western blot. Result: Matrine(0.25, 0.5, 1.0, 1.5, 2.0 g·L^-1) inhibited SW480 cell proliferation in time and dose-dependent manners. The half maximal inhibitory concentration(IC₅₀) was 1.72, 1.08, 0.67 g·L^-1 respectively for 24, 48, 72 h. Hoechst33258 staining and flow cytometry showed that matrine could significantly induce apoptosis of SW480(P<0.01). The apoptosis rate was gradually increased with the increase of drug concentration. Western blot results showed that after adding matrine in the SW480 cells, the expression levels of p-Akt and Bcl-2 were down-regulated (P<0.05), while the expression level of Bax was up-regulated and the expression level of total Akt wasn''t affected. Conclusion: Matrine could induce apoptosis in SW480 cells, which may be related to the inhibition of Akt Signaling Pathway and the related downstream targets.