Decreased Expression Of Schlafen5 (Slfn5) Correlates With Unfavorable Survival In Human Hepatocellular Carcinoma

As a type I IFN inducible-gene, schlafen5 (SLFN5) has been identified as a special tumor suppressor in the growth and invasion of human malignant melanoma and renal cell carcinoma. However, the association between SLFN5 expression and the clinicopathological characteristics of HCC is still unknown. We conducted this study to examine the expression of SLFN5 in HCC and investigate the association between SLFN5 expression and the clinicopathological manifestations of HCC patients. Real time-quantitative PCR, Western blotting and IHC analyses were used to evaluate the expression of SLFN5 in HCC cell lines and tissues. Kaplan-Meier survival and Cox regression analyses were applied to evaluate the prognosis of 90 HCC patients. The data showed significantly decreased SLFN5 expression in HCC tissues compared to corresponding non-cancerous cells and tissues. Moreover, we compared the HCC and self-paired non-cancerous tissue for SLFN5 expression by measuring the decrease in SLFN5 expression (denoted Delta SLFN5). Results showed that a higher Delta SLFN5 correlates with malignant behavior of HCC, including higher pathological grade (P = 0.003), higher TNM stage (P = 0.014) and bigger tumor diameter (P = 0.017). Cox regression analysis further revealed that Delta SLFN5 = 150 is an independent prognostic factor for overall survival (HR: 4.101; 95% CI: 1.135-14.815; P = 0.031). These data are the first to indicate that decreased expression of SLFN5 in HCC, which is closely related to poor histological grade, advanced TNM and larger tumor size. The low-expression of SLFN5 suggests poor survival outcomes in HCC patients.