MiR-486-5p inhibits SMAD2 expression via binding to its 3' UTR and is downregulated in NSCLC tissues and cell lines. (A) Schematic diagram showing the subcloning of the predicted miR-486-5p-binding site at position 304-310 of the SMAD2 3' UTR into a psiCHECK-2 luciferase construct. Predicted duplex formation between miR-486-5p and the wild-type or mutant miR-486-5p-binding site is indicated (upper). Luciferase activity of the construct containing the wild-type or mutant SMAD2 reporter gene in A549 (bottom, left) and H226 (bottom, right) cells co-transfected with the negative control (miR-NC) or miR-486-5p. Scrambled sequences were used as the NC. Relative Renilla luciferase activity was determined and normalized against firefly luciferase activity. (B) Data obtained from the GEO database (GSE36681) were analyzed to compare the expression of miR-486-5p between NSCLC tissues and noncancerous lung tissues. (C) The mRNA expression levels of miR-486-5p were determined using qRT-PCR, and the data were compared between 65 NSCLC and paired adjacent noncancerous lung tissues. (D) qRT-PCR analysis of relative miR-486-5p expression in human NSCLC cell lines. Data are shown as the mean ± SD. *, **, and *** indicate significant differences compared with the control (* P < 0.05; ** P < 0.01; ***P < 0.001).