HER2-targeted RNA interference inhibits growth and invasion of human gastric carcinoma cell SGC-7901

Objective: To investigate the effect of HER2-targeted RNA interference (RNAi) on growth and invasion of human gastric cancer cell line SGC-7901. Methods: HER2-targeted hairpin small interfering RNA (siRNA) genes, pcDNA3-sihe1 and pcDNA3-sihe2, were obtained by oligonucleotide synthesis and annealing of the complementary single strand DNAs; they were used to transfect SGC-7901 cells in vitro. The expression of HER2 gene in the transfected cells was examined by indirect immunofluorescence assay and the effects of the HER2-targeted siRNA on cell growth, apoptosis and invasion were evaluated by colony formation assay, flow cytometry, and Boyden chamber assay. Results: We successfully constructed siRNA expression vector targeting HER2 gene. Indirect immunofluorescence assay revealed a remarkable decrease of HER2 expression in pcDNA3-sihe1-and pcDNA3-sihe2-transfected cells, but not in pcDNA3 vector transfected cells. The colony-forming ability of cells with low expression of HER2 was decreased. Flow cytometry demonstrated down-regulation of HER2, with resulted in apoptosis of gastric cancer cells. Boyden chamber assays revealed that HER2-targeted RNAi suppressed the invasion ability of SGC-7901 cells.Conclusion: HER2-targeted RNAi can effectively inhibit the expression of HER2 in SGC-7901 cells and subsequently influence the growth and invasion of SGC-7901 cells, which paves a way for studying the relationship between HER2 molecular and tumor growth and metastasis.