Up-regulation of long non-coding RNA Sox2ot promotes hepatocellular carcinoma cell metastasis and correlates with poor prognosis

Background: Long non-coding RNAs (lncRNAs) have been shown to have important regulatory roles in cancer biology, and the lncRNA Sox2ot is up-regulated in some tumors. However, the contributions of Sox2ot to hepatocellular carcinoma (HCC) remain largely unknown. Methods: In the present study, expression of lncRNA Sox2ot was evaluated by quantitative real-time PCR in tumor tissues and adjacent non-tumor tissues in 84 HCC patients. The association of lncRNA Sox2ot expression with clinicopathological features and the prognosis of HCC patients were also analyzed. Survival analysis was performed using the Kaplan-Meier method and Cox's proportional hazards model. Small interfering RNA assay was used to explore the function of lncRNA Sox2ot on HCC cell migration and invasion. Results: lncRNA Sox2ot expression level was significantly higher in HCC tissues compared with adjacent non-tumor tissues (P<0.05). High expression of lncRNA Sox2ot was associated with histological grade, TNM stage, and vein invasion. The 5-year overall survival of high lncRNA Sox2ot expression group was significantly shorter than that of low lncRNA Sox2ot expression group (P<0.05). The multivariate Cox regression analysis indicated that lncRNA Sox2ot expression was an independent prognostic factor for overall survival. In addition, the metastasis ability of HCC cells was significantly decreased by knocking down lncRNA Sox2ot expression. Conclusions: The results suggested that lncRNA Sox2ot played crucial roles in promoting HCC cell migration and invasion, and might represent a novel prognostic biomarker for HCC.