Figure 3.

miR-222 and its isomiRs inhibit proliferation and share the same target recognition potential. (A–C) MCF10A cells were transfected as indicated and proliferation assessed by (A) confluence, (B) CyQuant and (C) MTS assay. (D) Scratch wound closure assay was also performed after transfection, though effects on proliferation versus migration are difficult to disentangle. (E) The expression of CDKN1A (p21) was determined at both the mRNA and protein level, 48 and 72 h post-transfection of miR-222, miR-222CUCU and the negative controls. (F) Relative luciferase activity was measured for 25 putative and established miR-222 target genes by cloning the respective 3′UTRs downstream of the reporter gene and co-transfecting with miR-222 isoforms or negative controls as indicated. The parental vector was used as a negative control.