Clinical significance of IFIT2 expression in human renal cancer tissues

Background: Interferon (IFN)-induced protein with tetratricopeptide repeats 2 (IFIT2) is an important member of the IFN-stimulated gene (ISG) family. It has been demonstrated that IFIT2 is important in the physiopathological processes of antiviral and antitumor activities. We previously demonstrated that IFIT2 was highly expressed in paracarcinoma tissues compared with gastric cancer tissues, and its expression level was positively correlated with a superior postoperative prognosis of the patients. Methods: We performed immunohistochemical staining of IFIT2 in human clear cell renal cell carcinoma (ccRCC) tissues by using a tissue microarray. RNAseq data of kidney clear cell carcinoma (KIRC) samples from The Cancer Genome Atlas (TCGA) were used to perform the enrichment analyses based on the genes that were highly correlated with IFIT2. Results: Weak staining of IFIT2 was located on the cytoplasm and cell membrane surface of the cancer cells, while positive staining of IFIT2 was located mainly on adjacent normal tissues. Survival analysis showed that patients with higher IFIT2 expression had better overall survival than patients with lower IFIT2 expression (P=0.030). The Cox model further demonstrated that age (P=0.002), pathological stage (P=0.000), TNM stage (P=0.005) and IFIT2 expression (P=0.003) could be used as independent prognostic predictors for ccRCC patients. Additionally, the enrichment analysis based on ccRCC expression profile data extracted from TCGA revealed that the genes highly correlated with IFIT2 were mainly related to the biological processes of virus response, T cells and the innate immune response (GO:0009615, GO:0042110, and GO:0045088) and the pathways of NLR signaling, chemokine signaling, and TLR signaling (hsa04621, hsa04062, and hsa04620). Conclusions: IFIT2 could serve as a potential prognostic marker for ccRCC patients, and the mechanism of decreased IFIT2 expression in the progression of ccRCC merits further investigation.