Effects of miRNA-141 on proliferation, apoptosis and cell cycle of hepatocellular carcinoma cells

Objective To investigate the effect of miR-141 up-regulation through miR-141 mimic transfection on proliferation, apoptosis and cell cycle of hepatocellular carcinoma (HCC) cells. Methods Real-time polymerase chain reaction (qPCR) was employed to detect differential expression of miR-141 in normal hepatic epithelial cells (L02) and hepatocellular carcinoma cells (HepG2). Furthermore, miR-141 mimics were used to transfect into HepG2 to up-regulate the expression of miR-141 (experimental group). Blank group (CON) and negative control group (miR-NC) were used as control group. qPCR was used to detect expression of miR-141. CCK8 assay was used to detect the proliferation of HepG2 cells. Flow cytometry was used to detect the apoptosis and cell cycle of HepG2 cells. Results The results of qPCR showed that miR-141 was significantly down-regulated in HepG2 cells (0.64±0.13) compared to L02 cells(1.00±0.18), and the difference was significant (P<0.05). Relative expression of miR-141 was significantly increased after transfection (3.33±0.66), compared to CON group (1.00±0.17, P<0.05) and miR-NC group (1.08±0.14, P<0.05). CCK8 assay showed that the absorbance values of HepG2 of miR-141 group at 48, 72, 96 h (0.67±0.07, 1.17±0.05, 1.36±0.03) were all decreased significantly compared with those in CON group (0.81±0.02; 1.42±0.03; 1.73±0.05, all P<0.05) and miR-NC group (0.78±0.01; 1.38±0.02; 1.69±0.01, all P<0.05). The results showed that miR-141 group [(11.81±0.23)%] had significantly increased apoptosis rate compared to CON group [(4.18±0.18)%] and miR-NC group[(4.04±0.08)%], and the difference was statistically significant (P<0.05). miR-141 group had decreased percentage of S phase cells [(19.89±2.78)%] compared to CON group [(31.87±1.00)%, P<0.05] and miR-NC group [(30.49±1.73)%, P<0.05], while miR-141 group had significantly increased percentage of G1 phase cells [(74.74±2.03)%] compared to CON group (60.85±1.69)% and miR-NC group (60.93±1.95)%, and the differences were all statistically significant (all P<0.05). Conclusions miR-141 was in low expression in HepG2 cells. Upregulation of miR-141 could specifically inhibit proliferation and promote apoptosis of HepG2 and change the distribution of cell cycle. Key words: Hepatocellular carcinoma; MiRNA-141; Proliferation; Apoptosis; Cell cycle