CircABCC2 Regulates Hepatocellular Cancer Progression by Decoying MiR-665

Background: Numerous studies have shown that circular RNAs (circRNAs) play vital roles in tumor progression. However, how circRNAs function in hepatocellular cancer (HCC) remains mostly unclear. Methods: We analyzed HCC circRNA expression via a microarray, and the expression of an upregulated circRNA, circABCC2, was detected. We next explored the function of circABCC2 in HCC via a series of experiments. We performed RNA immunoprecipitation (RIP) and luciferase assays to explore the competing endogenous RNA (ceRNA) function of circABCC2 in HCC. Results: qRT-PCR verified that circABCC2 was overexpressed in HCC. Inhibition of circABCC2 suppressed HCC cell proliferation and invasion, but promoted apoptosis. Luciferase assays and RIP showed that circABCC2 and ABCC2 could directly bind to miR-665 and that circABCC2 could regulate ABCC2 expression by sponging miR-665. Conclusions: In summary, circABCC2 regulates ABCC2 expression and HCC progression by sponging miR-665. circABCC2 could be used as a biomarker and therapeutic target in HCC.