miR-448 targets ZEB1 and ZEB2 directly in breast cancer cell lines. (a) Putative miR-448 binding sites in the 3′-UTR sequence of ZEB1 and ZEB2. (b) Luciferase activity of MDA-MB-231 or MCF-7 cells transfected with plasmids carrying a wild-type or mutant 3′UTR of ZEB1, in response to miR-448 mimics or inhibitor. (c) Luciferase activity of MDA-MB-231 or MCF-7 cells transfected with plasmids carrying a wild-type or mutant 3′UTR of ZEB2, in response to miR-448 mimics or inhibitor. (d) mRNA levels of ZEB1 and ZEB2 (e) examined by qRT-PCR in MDA-MB-231 or MCF-7 cells transfected with miR-448-mimics, miR-448-inhibitor, or scramble miRNA. *P < 0.05 compared with the scramble miRNA group. (f) ZEB1 and ZEB2 levels were analyzed by Western blotting in MDA-MB-231 or MCF-7 cells transfected with miR-448-mimics, miR-448-inhibitor, or scramble miRNA. (A color version of this figure is available in the online journal.)