Circ_0010220-mediated miR-503-5p/CDCA4 axis contributes to osteosarcoma progression tumorigenesis

CircRNAs are reported to exert a significant role in modulating genes in cancers, including osteosarcoma progression. Up to now, the function of circ_0010220 in osteosarcoma is still poorly known. The aim of our work was to figure out the potential mechanism of circ_0010220/miR-503-5p/CDCA4 axis in osteosarcoma progression. Firstly, quantitative RT-qPCR was utilized to measure the expression of circ_0010220 in osteosarcoma cells. Then, osteosarcoma cell proliferation, apoptosis, cell cycle, migration and invasion after loss of circ_0010220 were evaluated using CCK-8, flow cytometry, transwell migration, invasion and tumorigenesis experiments respectively. Circ_0010220 expression was markedly increased in osteosarcoma cells. Additionally, knockdown of circ_0010220 significantly depressed tumor growth. CCK-8 analysis indicated that down-regulation of circ_0010220 inhibited osteosarcoma cells proliferation. Flow cytometry assay showed that knockdown of circ_0010220 induced cell apoptosis and blocked cell cycle in the G1 phase. Meanwhile, cell migration an invasion was reduced by circ_0010220. Furthermore, miR-503-5p was predicted as the target for circ_0010220 and miR-503-5p inhibitors reversed cell growth suppressed through silencing circ_0010220. Then, our study demonstrated that Cell Division Cycle-Associated protein 4 (CDCA4) could be a downstream target of miR-503-5p. Additionally, circ_0010220 down-regulation reduced CDCA4 expression level and the inhibitors of miR-503-5p reversed that. In conclusion, we indicated circ_0010220 can be an important biomarker for osteosarcoma via regulating miR-503-5p and CDCA4.