Figure 3. MiR-21-5p is the target of circ_0008259. (A) Circular RNA Interactome database was used to predict the binding site between circ_0008259 and miR-21-5p. (B) Dual-luciferase reporter assay showed that circ_0008259 adsorbed miR-21-5p. (C) Circ_0008259 and miR-21-5p co-immunoprecipitated with Ago2, which was revealed by RIP assay. (D) RNA pull-down assay showed that circ_0008259 interacted with biotin-labeled miR-21-5p. (E) qRT-PCR was used to detect the effects of overexpression or knockdown of circ_0008259 on miR-21-5p expression in 143B and HOS. (F) qRT-PCR was used to detect the expression of miR-21-5p in OS tissues (n=50) and adjacent tissues (n=50). (G) The expression of circ_0008259 was negatively correlated with the expression of miR-21-5p in OS tissues (R2=0.4259, P<0.001). ***P < 0.001.