Abstract: Objective:To inhibit the expressions of survivin and HIF-1α using RNA interference(RNAi) technique,and to explore their effects on the proliferation and apoptosis of gastric cancer BGC-823 cells. Methods: Two pairs of siRNA were designed against the human survivin and HIF-1α separately.The human gastric cancer BGC-823 cells were transfected with siRNA-survivin,siRNA-HIF-1α and SCR and used as sis group,siH group,and scrambled siRNA (SCR) group;at the same time, blank control group(serum-free medium) was set up.RT-PCR was used to detect the expression levels of survivin and HIF-1α mRNA in the BGC-823 cells in various groups.The BGC-823 cells were transfected with siRNAs using HifectinⅡ.The BGC-823 cells were divided into sis group,sis+siH group,SCR group and blank control group.MTT assay was performed to detect the proliferation activity of cells.The expression levels of survivin and HIF-1α protein in the cells in various groups were detected by Western blotting method.Flow cytometry was used to detect the apoptotic rates of BGC-823 cells in various groups. Results:Compared with blank control group,the expression level of survivin mRNA in sis group was significantly desreased (P<0.05),and the expression level of HIF-1α mRNA in siH group was significantly desreased (P<0.05).Compared with blank control group,the proliferation ability of cells in SCR group had no significant change (P>0.05),and the proliferation abilities of cells in sis group and sis+siH group were significantly decreased(P<0.05);compared with sis group,the proliferation ability of cells in sis+siH group was significantly decreased(P<0.05).Compared with blank control group,the expression levels of survivin and HIF-1α in sis+siH group were significantly decreased (P<0.05 or P<0.01),and the apoptotic rates of BGC-823 cells were significantly increased(P<0.01). Conclusion:The combined targeting silencing surviving and HIF-1α genes can down-regulate the expressions of targeted genes,inhibit the proliferation of gastric cancer BGC-823 cells,and promote the apopotosis,indicating RNAi gene silencing may be a new method to treat gastric cancer.

Key words: human gastric cancer BGC-823 cells, hypoxia inducible factor 1α, apoptosis, cell proliferation, siRNA, survivin