Circular RNA 0086996 regulates growth and migration of osteosarcoma cells via miR-125b-5p.

Circular RNAs (CircRNAs) have been found to be critical in tumorigenesis; however, the role of CircRNAs in osteosarcoma is to be further studied. In this study, we preliminarily identified the up-expressed CircRNAs and its downstream microRNA in osteosarcoma and investigated its potential regulation mechanism. Hsa_circ_0086996 (Circ_0086996) was found to upregulated in tumor tissue compared to adjacent tissue. Circ_0086996 was significantly overexpressed in osteosarcoma tissue, as well as in osteosarcoma cell lines of SAOS2 and MG-63. Circ_0086996 knockdown significantly suppressed cell proliferation, migration, and invasion. Circ_0086996 knockdown also induced cell cycle arrest in G0/G1 phaseand promoted cell apoptosis in SAOS2 and MG-63 cells. Bioinformatics analysis revealed that miR-125b-5p might be of complementary binding region with Circ_0086996, which was confirmed by dual-luciferase reporter assay. Moreover, Circ_0086996 could reverse the effect of miR-125b-5p, as knockdown of Circ_0086996 or application of miR-125b-5p both can inhibit cell proliferation, migration, invasion and promote cell apoptosis and cell cycle arrest. Our study discovers that Circ_0086996 acts as miR-125b-5p sponge to mediate the tumorigenicity, which could act as a potential biomarker for the osteosarcoma and provides a novel insight for the mechanism in osteosarcoma.