miR-7 decreases FAK expression by directly targeting its 3′-UTR.

<p>(A) The potential binding sequences for miR-7 within the FAK 3′-UTR of human (H.s), chimpanzee (P.t), mouse (M.m), guinea pig (C.p), rabbit (O.c), rat (R.n), and dog (C.f). Seed sequences are highlighted and underlined. (B) Luciferase reporter plasmids were constructed by the insertion of full length FAK 3′-UTR into the region immediately downstream of the luciferase gene. The sequences of two predicted miR-7 binding sites within the FAK 3′-UTR, including wild-type full-length UTR or mutant (highlighted and underlined) binding site are shown. (C) Relative luciferase activity was analyzed after the above reporter plasmids or control reporter plasmid were cotransfected with miR-7 mimics or control mimics in MDA-MB-435s cells. (D) Relative expression of miR-7 by quantitative PCR (top) and immunoblot for FAK expression (bottom) in the indicated cell lines. NT, non-tumorigenic. (E) Immunoblot assays of endogenous FAK protein levels in MDA-MB-435s and MDA-MB-231 cells transfected with miR-7 mimics or control mimics and those in HBL-100 cells transfected with miR-7 inhibitor or control inhibitor.