三氧化二砷(As2O3)诱导人胃腺癌SGC7901细胞程序化死亡并降低c-myc基因的表达

目的：探讨As₂O₃对胃腺癌SGC7901细胞系的生物学效应及机制。方法：通过MTT还原法检测As₂O₃对该细胞系存活率的影响，从光学显微镜形态观察，流式细胞仪分析，DNA凝胶电泳，细胞凋亡原位检测(TUNEL)进行细胞凋亡的检测。半定量RT-PCR检测基因表达。结果：As₂O₃处理SGC7901细胞后,细胞的存活率明显降低，光学显微镜下可见到明显的凋亡细胞,流式细胞仪测定细胞周期的G1期前有亚2倍体的凋亡峰，DNA凝胶电泳显示出典型的凋亡特征:　DNA有规律断裂形成的梯状图谱,细胞凋亡原位检测发现DNA的断裂,并降低细胞c-myc基因的表达。结论：As₂O₃能诱导人胃腺癌SGC7901细胞程序化死亡并可能通过降低c-myc基因的表达。

ARSENIC TRIOXIDE INDUCES PROGRAMMED CELL DEATH OF HUMAN GASTRIC ADENOCARCINOMA SGC7901 CELLS AND DECREASES C-MYC GENE EXPRESSION

AIM: To study the biological effect of As₂O₃ on human gastric adenocarcinoma SGC7901 cells and its mechanisms. METHODS: MTT reduction assay, morphology investigation, flow cytometry analysis, DNA gel electrophoresis and In situ cell death detection (TUNEL), semiquantitive RT-PCR were adopted. RESULTS: As₂O₃ inhibited the survival of SGC7901 cell line. The cells treated with As₂O₃ showed a typical apoptotic morphology and hypodiploid peak before G1 phase. DNA of the treated SGC7901 cells appeared a ladder pattern characteristic of apoptosis. TUNEL detection analysis also revealed DNA fragmentation. Moreover, As₂O₃ decreased the c-myc gene expression. CONCLUSION: As₂O₃ can induce programmed death of SGC7901 cells mainly via down regulation of c-myc gene expression.