Figure 4. Knockdown of NRAS notably suppressed hsa_circ_0000073-mediated proliferation, migration and invasion of OS cells. (A) Western blot analysis of NRAS expression in OS and paired paratumor tissues. (B) NRAS expression was also evaluated by qRT-PCR analysis in hFOB 1.19 and OS cells. (C) The link between NRAS and hsa_circ_0000073 expression was confirmed through correlation analysis (r=0.4219, P=0.0357). (D, E) After hsa_circ_0000073 overexpression or knockdown in MG-63 and U2OS cells, NRAS expression was assessed by qRT-PCR and western blot assays. (F, G) MG-63 and U2OS cells were cotransfected with hsa_circ_0000073 plasmid and NRAS shRNAs. Edu staining was utilized in the transfected MG-63 and U2OS cells. Magnification, ×100; Scale bar=100 μm. (H, I) Migration and invasion capacities of the MG-63 and U2OS cells cotransfected with hsa_circ_0000073 plasmid and NRAS shRNAs were tested via Transwell assay in. Magnification, ×100; Scale bar=100 μm. *P<0.05.