siRNA抑制胃癌细胞BGC-823及裸鼠皮下移植瘤中生存素的表达

Inhibition of survivin expression in BGC-823 cells by RNA interference

目的:探讨RNA干扰用于胃癌治疗的可行性与特异性。方法:设计靶向生存素基因的小干扰RNA,并导入胃癌BGC-823细胞株和裸鼠皮下移植瘤,在体内、外诱导RNA干扰,采用MTT、流式细胞检测技术、RT-PCR法、Western bloting、免疫组织化学和TUNEL检测survivin基因表达、细胞周期和细胞凋亡。结果:重组质粒pTZU6+1-siRNA-survivin导入BGC-823后,survivin mRNA和蛋白表达均明显下调;细胞生长被抑制,细胞周期中S期细胞减少,G1/G0期细胞增加,出现明显细胞凋亡。裸鼠皮下移植瘤体积明显缩小,Survivin表达均下调。体内、外对照组各指标均无明显变化。结论:RNA干扰明显抑制靶基因survivin在胃癌细胞BGC-823及裸鼠皮下移植瘤中的表达及肿瘤细胞增殖,并诱导细胞凋亡,且特异性好,可能成为肿瘤治疗的新方法。

AIM： To investigate the feasibility and specificity of gastric carcinoma gene therapy by utilizing RNA interference （RNAi） to inhibit survivin expression in vitro and in vivo. METHODS ： Small interferenee RNA （ siRNA） homologous to survivin was designed, pTZU6 ＋ 1 - siRNA - survivin vector was constructed and transfeeted into BGC -823 cells. The transplanted BGC -823 tumor in nude mice was established to induce RNAi. The ehanges of survivin gene expression, tumor cell cycle and cell apoptosis were deteeted by flow eytometry, RT - PCR, Western blotting, immu- nochemistry and TUNEL. RESULTS： The expression of survivin was obviously inhibited by RNAi in vitro. The phase of cell cycle indicated the reduction of S phase, while G1/G0 phase increased. Cell apoptosis was obvious. Both the mRNA level and the protein expression of survivin decreased obviously. The tumor size reduced after treated with pTZU6 ＋ 1 - siR- NA - survivin vector in vivo. The expression of survivin decreased in siRNA treatment group. In contrast, little change in control group in vitro and in vivo was observed. CONCLUSION ： RNA interference down - regulates survivin gene expression, inhibits BGC -823 cell proliferation and induces cell apoptosis with good specificity, which may be a possible new approach for neoplasm gene therapy.