Abstract: Objective To explore the differentially expressed circular RNAs (circRNAs) in hepatocellular carcinoma (HCC) and their association with clinical features and prognosis of HCC patients. Methods RNA sequencing was performed on 56 pairs of HCC and adjacent tissues to identify the differentially expressed circRNAs in HCC, whose expressions were validated by RT-qPCR in another 15 pairs of HCC and adjacent tissues. The correlation of the selected circRNAs with the clinical features and prognosis of the patients was analyzed using Chi-square test, Cox proportional hazards regression model and Kaplan-Meier analysis. The predictive value of the identified circRNA for recurrence-free survival and overall survival of HCC patients was assessed using ROC curves. Results We identified 17 significantly up-regulated and 45 down-regulated circRNAs in HCC tissues using RNA sequencing (P<0.05). Among these circRNAs, hsa_circ_0006834 was found to be significantly down-regulated in HCC tissues, and its expression level was negatively correlated with vascular invasion and Barcelona Clinic Liver Cancer (BCLC) stage and positively with recurrence-free survival and overall survival of the patients (P<0.05). As an independent prognostic factor for HCC, hsa_circ_0006834 had an AUC of 0.750 and 0.7601 for predicting 2-year recurrence-free survival and overall survival of HCC patients, respectively. Conclusion hsa_circ_0006834 is a new potential biomarker for evaluating the prognosis of HCC patients.

Key words: hepatocellular carcinoma; circular RNA; hsa_circ_0006834; prognosis; biomarker