as a direct target of miR-27a. (A) Putative miR-27a binding sites on 3’-UTR of PLK2 mRNA. Three miR-27a binding sites on 3′-UTR of PLK2 mRNA were predicted by the corresponding programs. The designed mutant nucleotides are highlighted in red color. (B) The luciferase activity in the HEK293 cells. HEK293 cells were cotransfected with different miRNAs and the luciferase activities were detected in different groups. Each value is evaluated by the relative luciferase activity of firefly to renilla. (C) Effect of miR-27a on PLK2 protein level in the Hep2 cells. After the Hep2 cells were transfected, the PLK2 protein expression was detected by Western blot. β-actin was used for the internal control. (D) Statistical analysis of the PLK2 protein expression in the Hep2 cells. Data are the mean ± SD of three independent experiments. P < 0.05 is indicated as symbol*.