Over-expression of miR-125a-5p inhibits proliferation in C2C12 myoblasts by targeting E2F3

MicroRNAs (miRNAs) are a class of small non-coding RNAs of 20-25 nucleotides in length. It has been shown that miRNAs play important roles in the proliferation of many types of cells, including myoblasts. In this study, we used real-time quantitative polymerase chain reaction, western blotting, EdU, flow cytometry, and CCK-8 assay to explore the role of miR-125a-5p during the proliferation of C2C12 myoblasts. It was found that the expression of miR-125a-5p was decreased during C2C12 myoblast proliferation. Over-expression of miR-125a-5p inhibited C2C12 myoblast proliferation as indicated by EdU staining, flow cytometry, and CCK8 assay. It was also found that miR-125a-5p could negatively regulate E2F3 expression at posttranscriptional level, via a specific target site in the 30 untranslated region. Knockdown of E2F3 showed a similar inhibitory effect on C2C12 myoblast proliferation. Thus, our findings suggest that miR-125a-5p may act as a negative regulator of C2C12 myoblast proliferation by targeting E2F3.