Comprehensive Circular RNA Profiling Reveals That hsa_circ_0005075, a New Circular RNA Biomarker, Is Involved in Hepatocellular Crcinoma Development

There is increasing evidence that circular RNAs (circRNAs) are involved in cancer development; however, their role in hepatocellular carcinoma (HCC) remains unclear. Here, we aimed to determine the circRNA expression profile in HCC, and investigate relevant mechanisms for cancer progression. The global circRNA expression profile between HCC (n = 3) and adjacent normal liver (n = 3) tissue was significantly different. Three circRNAs (hsa_circ_0000520, hsa_circ_0005075, and hsa_circ_0066444) showed significantly different expression levels in HCC tissues, which were further validated in 60 matched tissue samples using real-time qRT-PCR. Only hsa_circ_0005075 exhibited significant difference in expression (P<0.001) between HCC and normal tissues. Hsa_circ_0005075 expression correlated with HCC tumor size (P = 0.042), and showed good diagnostic potential (AUROC = 0.94). Finally, we constructed a network of hsa_circ_0005075-targeted miRNA-gene interactions, including miR-23b-5p, miR-93-3p, miR-581, miR-23a-5p, and their corresponding mRNAs. Gene oncology analysis revealed that hsa_circ_0005075 could participate in cell adhesion during HCC development. In summary, we identified hsa_circ_0005075 as a potential HCC biomarker; however, further studies are required to confirm the role of this circRNA, and others, in HCC development.