小干扰RNA抑制胃癌细胞环氧合酶-2的表达

目的 观察瞬时转染环氧合酶-2特异性小干扰RNA(COX-2 siRNA)对胃癌细胞增殖与凋亡的影响,探讨COX-2在胃癌发生中的作用和RNA干扰方法 对肿瘤的治疗作用.方法 以胃癌细胞系SGC7901为研究对象,瞬时转染COX-2 siRNA,转染后72 h用RT-PCR方法 分别检测COX-2siRNA组、无意义siRNA组及空白对照组的COX-2 mRNA表达;免疫组化法与Western blot检测3组细胞的COX-2蛋白质的表达;流式细胞仪检测3组的细胞周期和凋亡情况.转染后1周内每天同一时间用噻唑蓝比色分析法(MTr)检测3组癌细胞的活力并计算癌细胞的相对生存率.结果 COX-2siRNA对胃癌细胞中COX-2 mRNA及蛋白表达均有明显抑制作用,胃癌细胞增殖受到抑制,凋亡增加,但细胞周期分布无明显变化.结论 在胃癌细胞中,COX-2表达的抑制可降低胃癌细胞的增殖速度,促进肿瘤细胞凋亡,COX-2在胃癌的发生中可能具有重要作用.

The effect of siRNA on inhibiting cyclooxygenase-2 gene expression in gastric adenocarcinoma cell

OBJECTIVE: To observe the cyclooxygenase-2 (COX-2) expression and the cell proliferation and apoptosis of gastric adenocarcinoma cells after transiently transfecting gastric cancer cells using specific COX-2 small interfering RNA (siRN) and discuss the role of COX-2 in gastric tumorigenesis and the effect of RNA interference (RNAi) as anti-cancer gene therapy. METHODS: Three groups were included in the study, i. e. a COX-2 siRNA group, a non-sense siRNA group and a control group. Gastric adenocarcinoma cells SGC7901 were cultured at 37 degrees C in an atmosphere containing 5% CO2. 72 hours after transfecting SGC7901 cells with specific COX-2 siRNA or non-sense siRNA, RT-PCR was used to detect COX-2 mRNA, immunohistochemistry and Western blot were taken to detect the expression of COX-2 protein and flow cytometry was taken to detect the cell cycle and apoptosis. MTT method was used to detect the proliferation and activity of the cells every day for one week after transfection. RESULTS: The expression of COX-2 mRNA and protein in the COX-2 siRNA group was obviously suppressed as compared with non-sense siRNA group and control group. No change was found between the non-sense siRNA group and the control group. The reduced expression of COX-2 could inhibit SGC7901 cells proliferation and induce cell apoptosis, but had no effect on cancer cell cycle. CONCLUSIONS: The experimental results suggest that effectively inhibiting the expression of COX-2 can suppress the proliferation of gastric adenocarcinoma cell and promote the process of cancer cell apoptosis, so RNAi is a powerful tool of gene therapeutic method.