Fig. 4

Circ_0001875 acts as a sponge for miR-31-5p. a Schematic of the luciferase reporter plasmids of circ-0001875 wild-type (circ-0001875 WT) and mutant-type (circ-0001875 MUT). b Relative luciferase activities of the circ-0001875 WT in 293A cells transfected with 21 candidate miRNAs mimics or mimic NC. c Luciferase activities of the circ-0001875 WT and circ-0001875 MUT transfected with miR-31-5p mimics or mimic NC. d RT-qPCR of the relative expression levels of miR-31-5p in NSCLC various cell lines. e–f Relative expression of miR-31-5p in NSCLC tissues and adjacent nontumor tissues was detected by RT-qPCR (n = 72). g Relative expression of miR-31-5p in A549 and H1299 cells transfected as indicated as detected by RT-qPCR. h Relative expression of miR-31-5p in A549 and H1299 cells transfected with the miR-31-5p mimics and inhibitor was detected by RT-qPCR. i–o Rescue experiments. CCK8, colony formation, wound healing assay and Transwell assays were conducted in cells in four treatment groups (si-NC + inhibitor NC, si-NC + miR-31-5p inhibitor, si-circ-0001875 + inhibitor NC, si-circ-0001875 + miR-31-5p inhibitor). Images are shown at 100 × magnification. Scale bar = 100 μm. Data are shown as the means ± SD. *p < 0.05, **p < 0.01, ***p < 0.001