Effect of RNAi-mediated survivin and Hypoxia-inducible factor 1α gene silencing on proliferation, invasion, migration and apoptosis of gastric cancer BGC-823 cells

Abstract Objective: To investigate the effect of RNAi-mediated survivin and Hypoxia-inducible factor 1α (HIF-1α) gene silencing on proliferation and apoptosis of gastric cancer BGC-823 cells. Methods: Small interfering RNAs (siRNAs) targeting survivin and HIF1α mRNAs were designed and synthesized, respectively, while scrambled siRNAs (SCRs) were synthesized. The hypoxia sensitive gastric cancer line BGC-823 was identified and transfected by Hifectin II in vitro under hypoxia condition. The cells transfected with siRNA-survivin, siRNA-HIF-1α and SCR were named as sis group, siH group and SCR group, respectively.The expression of survivin and HIF-1α were assessed by RT-PCR and Western blotting assay respectively. Cell apoptosis were determined by flow cytometry. Cell proliferation was measured by MTT assay. The abilities of invasion and migration were evaluated by transwell assays and wound healing assays respectively. Results: The HIF-1α expression of BGC-823 cells increased apparently under hypoxia condition. The survivin targeting siRNA transfection decreased the expression of survivin under hypoxia condition, the combined transfection of survivin targeting siRNA and HIF-1α targeting siRNA down-regulated both the expression of survivin and HIF-1α obviously. Compared with the blank control group, the combined siRNA transfection group displayed obvious features with decreased invasion and migration ability under hypoxia, the apoptosis rate increased and the cell proliferation decreased obviously. Conclusion: The down-regulation of survivin and HIF-1α in BGC-823 cell lines may induce an anticancer effect by enhancing cell apoptosis, and decrease the proliferation, migration and invasion ability.