miR-431 acted as a target for circ_0008450 in hepatocellular cancer cells. (A) The binding sites of circ_0008450 in miR-431 were predicted using the CircRNA interactome database. Luciferase intensities of the WT and MUT luciferase reporter vectors of circ_0008450 in 293T cells transfected with (B) miRNA NC, miR-431 mimic, (C) inhibitor NC or miR-431 inhibitor were determined by dual-luciferase reporter assays. (D) Effect of circ_0008450 on the expression of miR-431 was assessed using RT-qPCR. (E) The expression of miR-431 in THLE-2, SNU-387 and Huh7 cells treated with hypoxia was detected by RT-qPCR. The transfection efficiency of miR-431 (F) overexpression and (G) silencing on SNU-387 and Huh7 cells treated with hypoxia was evaluated by RT-qPCR. *P<0.05. miR, microRNA; circ, circular; WT, wild-type; MUT, mutant; NC, negative control; RT-qPCR, reverse transcription-quantitative PCR; N, normoxic; H, hypoxic.