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

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 interference RNA (siRNA) homologous to survivin was designed. pTZU6+1-siRNA-survivin vector was constructed and transfected into BGC-823 cells. The transplanted BGC-823 tumor in nude mice was established to induce RNAi. The changes of survivin gene expression, tumor cell cycle and cell apoptosis were detected by flow cytometry, RT-PCR, Western blotting, immunochemistry 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-siRNA-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.