Role of anti-interferon-induced protein with tetratricopeptide repeats 2 in gastric cancer cell lines

Abstract

Objective To investigate the role of anti-interferon-induced protein with tetratricopeptide repeats 2 (IFIT2) in human gastric cancer. Methods IFIT2 was down-regulated by RNA interference (RNAi) method, and the role of IFIT2 in regulation of biological behaviors in human gastric cancer cell lines SGC-7901 and AGS was investigated. Polymerase chain reaction (PCR) and Western blotting were used to examine the mRNA and protein level of IFIT2 expression in the LV-IFIT2-short hairpin RNA (shRNA) and LV-NC groups in both SGC-7901 and AGS cells. Results The Real-time PCR results showed that the mRNA expression level of IFIT2 in SGC-7901 as well as AGS cell lines in LV-IFIT2-shRNA group was significantly lower than that in LV-NC group (SGC-7901: 0.426±0.140 vs. 1.000±0.157, P=0.004; AGS: 0.232±0.090 vs. 1.000±0.194, P=0.003). Western blotting results indicated that the IFIT2 expression at the protein level was significantly decreased in the LV-IFIT2-shRNA group compared with the LV-NC group in both SGC-7901 and AGS cells (SGC-7901: 0.344±0.041 vs. 1.000±0.062, P=0.002; AGS: 0.091±0.001 vs. 1.000±0.106, P=0.000). We performed cell counting kit-8 (CCK-8) assay, wound healing assay, transwell assay and cell cycle assay to examine the role of IFIT2 in cell viability, migration and cell cycle, respectively in human gastric cancer cell lines SGC-7901 and AGS. After 48 and 72 hours of cell culture, the absorbance valueof LV-IFIT2-shRNA group was significantly higher than LV-NC group (SGC-7901: 48 h: 0.348±0.031 vs. 0.276±0.026, P=0.013; 72 h: 0.523±0.042 vs. 0.411±0.027, P=0.004; AGS: 48 h: 0.454±0.034 vs. 0.362±0.038, P=0.011; 72 h: 0.696±0.053 vs. 0.553±0.030, P=0.003), which indicated decreased IFIT2 could markedly inhibit SGC-7901 and AGS cell proliferation. Wound healingassay showed decreased IFIT2 expression in human gastric cancer cell lines SGC-7901 and AGS significantly increasedcell migration (SGC-7901: 0.640±0.029 vs. 0.447±0.056, P=0.006; AGS: 0.444±0.036 vs. 0.166±0.034, P=0.001). The transwellassay also showed decreased IFIT2 expression in human gastric cancer cell lines SGC-7901 and AGS significantly increasedcell invasion, and the number of migrating cells stained by crystal violetof LV-IFIT2-shRNA group was significantly higher than LV-NC group (SGC-7901: 299.3±45.6 vs. 162.3±25.9, P=0.011; AGS: 404.0±44.5 vs. 235.0±30.0, P=0.003). According to the cell cycle analyzed by flow cytometry, the ratios of cell in S phase in LV-IFIT2-shRNA group increased compared to the LV-NC group, which indicated down-regulated IFIT2 in gastric cell lines also had an impact on cell cycle. Conclusion Our present study demonstrated that the decreased IFIT2 expression was involved in the promotion of gastric cancer progression. Key words: Anti-interferon-induced protein with tetratricopeptide repeats 2; Gastric cancer; RNA interference