miR-133b directly targets MMP14. (A) Bioinformatics predicted interactions of miR-133b and their binding sites at the 3′UTR of MMP14 (TargetScan 6.0). (B) Luciferase activity assay demonstrated a direct targeting of the 3′UTR of MMP14 by miR-133b. Cells (U87 and U251) were co-transfected with luciferase vectors, either the wild-type MMP14 3′UTR reporter plasmid or mutated MMP14 3′UTR reporter plasmid, together with miR-133b mimics or NC. After 48 h, the luciferase activities were measured (mean ± standard deviation; n=3; *P<0.05). (C) Western blotting of MMP14 in U87 and U251 cells transfected with miR-133b mimics or NC. (a) Representative images of western blotting and (b) quantification of the bands (mean ± standard deviation; n=3; *P<0.05). miR, microRNA; NC, negative control; GBM, glioblastoma; MMP14, matrix metalloproteinase 14; UTR, untranslated region.