[Role of microRNA-21 in the proliferation and apoptosis of ovarian epithelial carcinoma cells]

To investigate the role and mechanism of microRNA-21(miR-21) in the proliferation and apoptosis of ovarian epithelial carcinoma cells.A short-hairpin RNA specifically targeting miR-21 plasmid was constructed, and the recombinant was identified by restriction endonuclease analysis and DNA sequencing. Three experimental groups were included, transfection group (transfected with pSIREN-miR-21), negative control group (transfected with pSIREN-miR-21-neg) and blank control group (without transfection plasmid). The expression of miR-21 was detected by stem-loop real-time reverse transcription (RT)-PCR in OVCAR3 cells, and western blot was used to detect the expression of programmed cell death 4 (PDCD4) protein. Tethyl thiazolyl tetrazolium(MTT) and flow cytometry method were used respectively.Recombinant plasmid (pSIREN-miR-21) was constructed successfully and identified by restriction endonuclease analysis and DNA sequencing. The relative expression level of miR-21 in cells transfection, negative control and blank control group was 0.26 ± 0.08, 1.26 ± 0.21 and 1.00 respectively. The level of miR-21 in the cells in transfection group was significantly lower than those in the negative control and blank control group (P0.01). The gray scale of PDCD4 protein was 1443 ± 33, 858 ± 19 and 846 ± 16 in the transfection group, negative control and blank control group respectively. The value of PDCD4 in transfection group was higher than other control groups, and there were significantly difference among them(P0.01). Moreover, the optical density of the cells in transfection group was 0.661 ± 0.015, significantly lower than those in two control groups (0.848 ± 0.150 for negative control, 0.935 ± 0.133 for blank control, P0.01). Forty-eight hours after transfection, the rate of viable apoptotic cell was significantly higher than negative control and blank control group [(25.821 ± 0.763)% vs. (0.010 ± 0.003)% vs. (0.238 ± 0.023)%; P0.01]; 72 hours after transfection, the rates of viable apoptotic cell and necrotic cell were all higher than the two control groups [the rate of viable apoptotic cell was (30.480 ± 0.821)%, (7.792 ± 0.312)% and (7.033 ± 0.257)% respectively (P0.01); the rate of necrotic cell was (3.558 ± 0.211)%, (1.557 ± 0.067)% and (1.049 ± 0.028)%, respectively (P0.01)].miR-21 might play an important role in the proliferation and apoptosis of ovarian epithelial carcinoma cells through negatively control the expression of PDCD4.