Circular RNA hsa_circ_0056836 functions an oncogenic gene in hepatocellular carcinoma through modulating miR-766-3p/FOSL2 axis

Background: Circular RNA (circRNA) remains a tumour-related factor in various biological cells and plays regulatory roles in gene expression. It is a type of non-coding RNA, whereas the function of human circRNA in hepatocellular carcinoma (HCC) is still not clear yet. Our investigation used the HCC cell line to uncover the biological function of hsa_circ_0056836 in the development and progression of hepatocellular carcinoma. Results: The present study showed that hsa_circ_0056836 revealed high expressions in HCC cell lines and tissues compared with corresponding controls. Silencing of Hsa_circ_0056836 decreased cell migration, proliferation and invasion. Silencing of hsa_circ_0056836 inhibited the development of HCC in xenograft nude mice. Mechanistically, we found that hsa_circ_0056836 directly bound to miR-766-3p, thereby alleviating the targeted inhibition of Fos-related antigen 2 (FOSL2). The results of this study indicated that hsa_circ_0056836 is a novel oncogenic RNA of vast potential as a tumor biomarker. Conclusion: In summary, the hsa_circ_0056836 / miR-766-3p / FOSL2 axis may serve as a promising strategy for HCC treatment. Method: First, the expressions of hsa_circ_0056836 in HCC tissues and corresponding para-cancerous tissues as well as in HCC cell lines and normal hepatocytes THLE-3 were detected by RT-PCR. Subcellular localization of hsa_circ_0056836 was confirmed by FISH. To detect the association between hsa_circ_0056836 and miR-766-3p, AGO2-RIP and Luciferase reporter assay were adopted. Loss of function study was applied to assess the role of hsa_circ_0056836 in HCC and to determine tumorigenesis in nude mice.