Fig. 1
miR-146b directly targets DICER1, which in turn blocks miR-146b-induced proliferation, migration and invasion. a Table shows the main up- and downregulated miRNAs in thyroid cancer [25] and their predicted binding sites in the DICER 3′UTR (position and the mirSVR score for the miRs predicted by miRanda). Also shown is the fold change (FC) of normal vs PTC and the correlations between DICER1 and miRNAs using Cancer Regulome analysis in TCGA database. b, c Stable cell lines were generated from Nthy-ori cells transfected with a pEGP-Null vector (Null cells) or a pEGP-miR-146b vector (146b cells). b Left: relative DICER1 expression by qPCR. Right: immunoblot of DICER1 expression (results are representative of 3 experiments). c Direct targeting of DICER1 3′UTR by miR-146b. Luciferase reporter activity relative to Renilla level was evaluated in cells 72 h after transfection of pIS1 DICER1 long UTR (WT) or DICER1 3′UTR mutated in the miR-146b binding site (MUT). d Representative images of crystal violet-stained cells 48 h after transfection with the DICER1 expression vector. e Representative images of a wound healing assay 0 and 48 h after scratching. f Relative quantification of the invasive capacity of cells was analyzed using Matrigel-coated Transwell assays. Left: representative images of the lower chamber (invading cells). Right: cell invasion relative to that of “Null” cells. Values represent mean ± SD (n = 3). **p < 0.01; ***p < 0.001; n.s. non-significant.
