Regulation of TGFBR2 by micro (mi)RNAs. (A) Silencing of luciferase-TGFBR2 3' UTR by transfected miRNA mimics. Vertical axis: the relative repression of firefly luciferase expression standardized to Renilla luciferase as a transfection control. Error bars = SD for three experiments. miR-20a and miR-34a were expressed in HaCaT cells, whereas miR-373 was not, but all had predicted target sites on the TGFBR2 UTR and could cause repression. miR-34b, which does not have a predicted target site, was used as a negative control. (B) Increase in TGFBR2 mRNA levels (measured by quantitative PCR) as the result of selective inhibition of expressed miRNAs. miRNA inhibitors (such as miR-20ai against miR-20a) were co-transfected with lacZ siRNA. Error bars = SD for three experiments. The result for miR-423 was not consistent with target prediction.