IGF-1 was a direct target of miR-190b.

<p>(A) Base pairing complement suggests two putative miR-190b binding positions at 844–850 and 1752–1758 of the IGF-1 3′UTR. (B) The effect of precursor miR-190b or miR-190b inhibitor on pEZX-IGF-1 3′UTR luciferase activity. Luciferase assays were done on HEK293 T cells. Significant differences were compared to each negative control (NC). (C) HEK293T cells were transiently transfected with pre-miR-190b or pre-NC vector together with the pEZX-MT01 empty vector, a modified pEZX-MT01 vector containing wild-type IGF-1 3′UTR, or two mutant IGF-1 3′UTR carrying mutations for each putative miR-190b binding site. Luciferase activity of pEZX-MT01 empty plasmid was set to 1. ***, <i>P</i><0.001; **, <i>P</i><0.01; *, <i>P</i><0.05.