Overexpression of Sox3 is associated with promoted tumor progression and poor prognosis in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a common malignant tumor lacking sensitive biomarkers for prognosis. Sox3, a member of the Sex determining region Y box gene superfamily, has been demonstrated to be an oncogene in many cancers. However, the expression and clinical importance of Sox3 in HCC remains elusive. In this study, fifty pairs of HCC tissues with adjacent non-tumor samples were collected for detecting Sox3 expression by qPCR and immunoblotting analyses. A total of 104 HCC tissues were included for immunohistochemistry assay and analyzed by immunostaining scores. The correlation of Sox3 expression with clinicopathological factors and prognosis of HCC patients were calculated. Sox3 expression in HCC tissues was significantly higher than that in the non-tumor counterparts at the mRNA and protein levels. High staining scores of Sox3 was detected in 75.96% of HCC tissues. Statistical analyses demonstrated that highly expressed Sox3 was significantly correlated with low tumor capsule formation, advanced tumor stage and poor tumor differentiation. Moreover, patients with high Sox3 expression showed worse recurrence-free survival and overall survival than those with low Sox3 expression, and multivariate analyses further indicated that status of Sox3 expression is an independent prognostic factor in HCC patients. Therefore, our results suggested that overexpression of Sox3 in HCC tissues is correlated with increased tumor development and poor prognosis in HCC.