MicroRNA-21 accelerates hepatocyte proliferation in vitro via PI3K/Akt signaling by targeting PTEN

•miRNAs-expression patterns of primary hepatocytes under proliferative status.•miR-21 expression level peaked at 12h after stimulated by EGF.•miR-21 drive rapid S phase entry of primary hepatocytes.•PI3K/Akt signaling was modulated via targeting PTEN by miR-21. MicroRNAs (miRNAs) are involved in controlling hepatocyte proliferation during liver regeneration. In this study, we established the miRNAs-expression patterns of primary hepatocytes in vitro under stimulation of epidermal growth factor (EGF), and found that microRNA-21 (miR-21) was appreciably up-regulated and peaked at 12h. In addition, we further presented evidences indicating that miR-21 promotes primary hepatocyte proliferation through in vitro transfecting with miR-21 mimics or inhibitor. We further demonstrated that phosphatidylinositol 3′-OH kinase (PI3K)/Akt signaling was altered accordingly, it is, by targeting phosphatase and tensin homologue deleted on chromosome 10, PI3K/Akt signaling is activated by miR-21 to accelerate hepatocyte rapid S-phase entry and proliferation in vitro.