三氧化二砷诱导人胃癌SGC-7901细胞凋亡及其部分机制探讨

目的探讨三氧化二砷(AS_2 O3)诱导人胃癌 SGC-7901细胞凋亡的可能机制。方法光学及电子显微镜观察细胞形态学变化,流式细胞术(flow cytometry,FCM)及末端脱氧核苷酸转移酶介导的脱氧三磷酸尿嘧啶缺口末端标记法(terminal deoxynucleotidy transferase-mediated dUTP nick end labeling,TUNEL)判定细胞凋亡;免疫组织化学 SABC 法检测凋亡相关基因蛋白 Bcl-2、Bax、c-Myc 及 P53的表述;流式细胞术检测Caspase-3蛋白表达;以二硫代苏糖醇(Dithiothreitol,DTT)为二硫键还原剂,观察其对 As_2O_3所致的 SGC-7901细胞凋亡的影响。结果 As_2O_3作用后光镜及电镜下观察到典型凋亡细胞的形态学特征;FCM 检测在细胞周期 G_1期前出现亚二倍体凋亡峰,同时见不同程度的 G_2/M 期阻滞;TUNEL 标记发现 DNA 链的断裂;As_2O_3 作用后 Bcl-2蛋白表达降低,Bax、Caspase-3蛋白表达明显升高,c-Myc 蛋白在 As_2O_3处理12、24 h 后表...

Study on Arsenic Trioxide-Induced Human Gastric Carcinoma SGC-7901 Cell Apoptosis and on Its Partial Mechanism

Objective To explore the possible mechanism of human gastric carcinoma SGC-7901 cell apoptosis induced by ar- senic trioxide(As_2O_3).Methods Cytomorphological change was observed under light and electron microscope and cell apoptosis judged by flow cytometry(FCM)and terminal deoxynucleotidy transferase-mediated dUTP nick end labeling (TUNEL).Apoptosis related gene protein expression of Bcl-2,Bax,c-Myc and P53 were determined by immunohistoche- mistry SABC method and Caspase-3 protein expression by FCM.Dithiothreitol(DTT)was used as a disulfide bond-reducing agent to observe effect of SGC-7901 cell apoptosis induced by As_2O_3.Results Typical cytomorphological characteristics of apoptotic cells after As_2O_3 induction could be observed under light and electron microscope.Hypodiploid apoptosis peak appeared before G_1 stage of cell cycle by FCM test.At the same time arrest of different degrees in G_2/M stage could be seen.TUNEL detection analysis revealed DNA fragmentation.Bcl-2 protein expression decreased after As_2O_3 induction while Bax,Caspaes-3protein expression obviously raised,c-Myc protein showed a decreased expression 12,24 hours after As203 induction while it increased slightly 48 hours after that.P53 showed no expression in experimental group as well as in the control group.DTT could partially inhibit As_2O_3 induced human gastric carcinoma SGC-7901 cell apoptosis.Con- clusion As_2O_3 could obviously induce SGC-7901 cell apoptosis.Arrest in G_2/M stage was one of its mechanisms.Bcl-2, Bax,c-Myc and Caspase-3 protein participated the process of As_2O_3 induced human gastric carcinoma SGC-7901 cell apoptosis,Thiols may be one of the targets of As_2O_3 induction.