Effect of microRNA-422a expression on proliferation of osteosarcoma cells

Abstract

Objective To observe the effect of microRNA (miRNA, miR)-422a expression on the proliferation of osteosarcoma cells. Methods 40 healthy male Sprague-Dawley (SD) rats were randomly divided into two groups: osteosarcoma MG63 and U2OS cell line bearing mice. Annexin V/propidium iodide (PI) double staining was used to transfect miR-422a primers and inhibitors to regulate miR-422a, the proliferation and apoptosis of osteosarcoma cells were analyzed under overexpression and miR-422a expression, and the inhibitory effect of miR-422a expression on different cell cycle osteosarcoma cells was examined. Results The proliferation of MG63 and U2OS cells was significantly inhibited at 48 h after transfection of miR-422a, and that of MG63 and U2OS was promoted at 48 h after transfection of miR-422a inhibitor with the difference being statistically significant (P=0.068, 0.035, 0.016, 0.004; 0.072, 0.028, 0.019, 0.003). The apoptosis rate of MG63 cells in the control group at 0 and 96 h was (5.3±0.1)% and (5.2±0.1)% respectively, and that in miR-422a group was (5.3±0.5)% and (5.4±0.4)% respectively. The apoptosis rate of U20S in the control group at 0 and 96 h was (5.2±0.2)% and (5.3±0.2)% respectively, and that in miR-422a group was (5.5±0.1)% and (5.2±0.1)% respectively. After starvation for 48 h, the apoptosis rate of MG63 cells in control group at 0 and 96 h was (5.2±0.4)% and (28.6±2.7)% respectively, and that in miR-422a group was (5.5±0.2)% and (48.5±2.4)% respectively; the apoptosis rate of U20S in control group at 0 and 96 h was (6.2±0.3)% and (18.7±3.1)% respectively, and that in miR-422a group was (6.2±0.2)% and (39.8±3.2)% respectively. As compared with negative control group, the apoptosis rate of osteosarcoma cells had no significant changes in miR-422a group at 96 h. Howdever, the combination of miR-422a transfection and apoptosis induction for 48 h, the number of apoptotic osteosarcoma cells was significantly increased as compared with negative control group. After transfection of miR-422a, the number of cells in G0/G1 phase was significantly increased, and that in G2/M was significantly reduced. Conclusion The high expression of miR-422a can effectively inhibit the proliferation of osteosarcoma cells and increase the apoptosis rate of osteosarcoma cells in harsh environment. Key words: Osteosarcoma; MicroRNA-422a; Cell proliferation; Apoptosis