Prognostic significance of SOX-1 expression in human hepatocelluar cancer

Sex-determining region Y (SRY)-box 1 (SOX1) as a member of the SOX gene superfamily is reported to function as a tumor suppressor in hepatocelluar cancer (HCC). However, the clinicopathological and prognostic significance of SOX-1 expression in HCC is unclear. First, semi-quantitative RT-PCR and Western blot assays were performed to detect the expression of SOX-1 mRNA and protein in 15 paired of HCC tissues and corresponding nontumor tissues. Next, immunohistochemistry was performed to detect SOX-1 protein expression in another 96 cases of HCC tissues, and analyze its correlation with clincopathological factors of patients. Finally, the survival was evaluated by the Kaplan-Meier method and proportional hazards model. Results showed that the expression levels of SOX-1 mRNA and protein in HCC tissues were significantly lower than that in the corresponding nontumor tissues. Statistical analyses indicated that low SOX-1 expression was significantly correlated with higher incidence of venous or lymphatic invasion and advanced TNM stage. Also, patients with high SOX-1 expression showed better overall survival than those with low SOX-1 expression, and multivariate analysis with the Cox proportional hazards indicated that status of SOX-1 expression might be an independent prognostic factor in HCC patients. Collectively, our results indicated that downregulation of SOX-1 was correlated with poor prognosis and tumor development in HCC.