Abstract: Objective To investigate the expression of interferon induced protein with tetratricopeptide repeats 3 (IFIT3) in nasopharyngeal carcinoma CNE⁃2R cells and its effect on the ability of invasion, metastasis and epithelial⁃mesenchymal transition (EMT). Methods The expression levels of IFIT3 in nasopharyngeal carcinoma CNE⁃2R cells and normal nasopharyngeal NP69 cells were detected by RT⁃qPCR and Western blot. The nasopharyngeal carcinoma cells CNE⁃2R were infected with IFIT3 shRNA sequences LV1, LV2 and LV3, and the negative control group (NC group) was set up. The expression of epithelial marker E⁃cadherin, mesenchymal markers N⁃cadherin and Vimentin were detected by RT⁃qPCR and Western blot. The migration and invasion ability of cells were detected by the scratch assay and the Transwell assay. Results Compared with NP69 cells, the mRNA and protein expression levels of IFIT3 were significantly up⁃regulated in CNE⁃2R cells (all P<0.001). The mRNA and protein expression levels of IFIT3 in the LV1, LV2 and the LV3 groups were the lower than those in the NC group (all P<0.001) and the expression levels were the lowest in the LV2 and LV3 groups. Compared with the NC group, the cell migration rate, the number of migrating and invasive cells, the expression of N⁃cadherin and Vimentin protein were significantly decreased in both the LV2 and LV3 groups (all P<0.001), while the expression of E⁃cadherin protein was significantly increased (all P<0.001). Conclusions sThe expression of IFIT3 is up⁃regulated in nasopharyngeal carcinoma CNE⁃2R cells, and the invasion and metastasis ability of  CNE⁃2R cells and EMT are significantly inhibited after IFIT3 silencing. 

Key words: Nasopharyngeal carcinoma, IFIT3, CNE?2R cells, Invasion, Metastasis, Epithelial?mesenchymal transition