siRNA Targeting of the SNCG Gene Inhibits the Growth of Gastric Carcinoma SGC7901 Cells in vitro and in vivo by Downregulating the Phosphorylation of AKT/ERK.

The aim of the study was to evaluate the effects of synuclein-γ (SNCG) silencing on gastric cancer SGC7901 cells and to elucidate the associated mechanisms. pGCSIL-lentiviral siRNA targeting of the SNCG gene was employed to inhibit SNCG expression. Several experiments such as quantitative real-time PCR, Western blotting, MTT, colony formation, migration assay, and flow cytometry were performed to investigate the biological behavior of infected SGC7901 cells. BALB/c nude mice were used as tumor xenograft models to assess the effects of SNCG silencing on tumor growth. Western blot analysis was carried out to determine the relative levels of AKT, p-AKT, ERK, and p-ERK expression. Our results showed that SNCG was overexpressed in SGC7901 cells as compared to normal gastric mucosal epithelial cells. SGC7901 cells transfected with SNCG siRNA demonstrated significantly decreased gastric cancer growth (p < 0.01), reduced cell migration, cell cycle arrest in the G0/G1 phase, promoted tumor cell apoptosis (p < 0.01), and inhibited tumorigenesis in xenograft animal models. Western blot analysis indicated that the protein levels of p-AKT and p-ERK were much lower in the SNCG siRNA group than in the control groups. The results of the present study suggest that SNCG siRNA plays a significant role in the proliferation, migration, and tumorigenesis of gastric cancer by downregulating the phosphorylation of AKT and ERK. RNA interference-mediated silencing of SNCG may provide an opportunity to develop a novel treatment strategy for gastric cancer.