氧化砷对结肠癌细胞凋亡的诱导及机制的探讨

A Study on the Effects and Mechanism of Arsenic Trioxide in Inducing Apoptosis of Colonic Cancer Cell Line

目的 探讨氧化砷 (As2 O3 )对人结肠癌细胞的凋亡诱导作用及其分子机制。方法 应用显微镜和流式细胞仪观察As2 O3 对SW480细胞株的形态学改变和诱发凋亡率 ;免疫组化技术检测bcl-2、Fas、二种基因编码蛋白的表达。结果 As2 O3 作用于细胞后 ,可看到较典型的细胞凋亡形态学改变。AO/EB荧光染色法显示 ,细胞凋亡率为 2 1%～ 10 6%。As2 O3 诱导SW480细胞凋亡作用呈时间和浓度依赖性。流式细胞仪DNA直方图上呈现典型的亚二倍体凋亡峰。As2 O3 主要作用于细胞周期的G2 /M期。经As2 O3 作用的SW 480细胞bcl -2基因编码蛋白表达减少 ,Fas基因编码蛋白表达增加。结论 As2 O3 有诱导SW480细胞凋亡作用 ,其诱导细胞凋亡的分子机制可能是下调bcl -2基因编码蛋白表达 ,增强Fas基因编码蛋白表达。

Objective To explore the effects and molecular mechanisms of arsenic trioxide(As 2O 3) in inducing apoptosis of colonic cancer cell line SW480. Methods The morphologic changes and apoptotic rate of SW480 cells induced by As 2O 3 were observed with fluorescent microscopy and flow cytometry. The bcl-2 and Fas expressions induced by As 2O 3 in SW480 cells were examined by immunohistochemical method. Results 24 hours after exposed to As 2O 3, SW480 cells exhibited typical morphologic changes of apoptosis, the apoptotic rate of which was 2.1%～10.6%. A typical subdiploid peak before G 1 phase was observed by flow cytometry, and As 2O 3 mainly acted in G 2/M phase. As 2O 3 decreased bcl-2 expression and increased Fas expression in SW480 cells. Conclusion As 2O 3 could induce apoptosis of SW480 cells. The molecular mechanism of As 2O 3-induced apoptosis of SW480 cells might be down-regulating the bcl-2 expression and up-regulating the Fas expression.