miR-17 directly targets the RB gene. (A) The target sites and free energy of binding between miR-17 and RB mRNA-3′UTR predicted by RNA hybrid and miRBase targets. (B) Schematic for the luciferase reporter plasmid constructs that contained the RB mRNA-3′UTR or MUT RB mRNA-3′UTR. (C) miR-17 suppressed expression of the luciferase reporter gene directed by the RB mRNA-3′UTR WT. (D) miR-17 did not suppress expression of the luciferase reporter gene directed by the RB mRNA-3′UTR MUT. (E) The levels of pri-miR-17 in miR-17 mimic-transfected cells. (F) The levels of miR-17 in miR-17 inhi transfected cells. (G) Expression of RB protein in VSMCs was decreased by overexpression of miR-17 mimic but not by overexpression of miR-17 inhi. The expression of RB protein was determined using an immunocytochemistry assay. (H) Expression of RB protein in VSMCs was decreased by overexpression of miR-17 mimic but not by overexpression of miR-17 inhi. The relative expression levels were quantitated using densitometry. Representative results were obtained from three repeats. *P<0.05 and **P<0.01 vs. miR-NC; #P<0.05 and ##P<0.01 vs. inhi-NC. miR, microRNA; RB, retinoblastoma; UTR, untrans-lated region; MUT, mutants; WT, wild-type; inhi, inhibitor; NC, negative control.