Objective: To explore the expression of microRNA-489 (miR-489) in osteosarcoma, so as to figure out the role and mechanism involved in proliferation and invasion control of osteosarcoma cells for miR-489.
Methods: By comparison miR-489 expression levels in osteosarcoma and normal colonic tissues, or in osteosarcoma cell lines with different metastasis potency by qRT-PCR. In SW480 cell stably overexpressing miR-489 by transfection of miR-489 mimics, proliferation was assessed by MTT(3-(4,5- dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide), and the cell cycle and apoptosis of SW480 was assayed by FACS(fluorescence activated cell sorting). We predicted SOX4 as the specific target gene of miR-489 with the approach of bioinformatics. Then, the protein level of SOX4 in osteosarcoma cells was detected after transfection miR-489 mimics by Western blotting.
Results: The expression level of miR-489 in osteosarcoma tissues was decreased when compared with the matched adjacent non-tumorous colonic tissues. The expression level of miR-489 in HR8348 and HCT116 cells with low metastasis potency were higher than those in HT29 and SW480 cells with high metastasis potency. After transfection with miR-489 mimics for 48 h, the growth speed was significantly inhibited in miR-489 mimic group than those of control group and blank group (P<0.05). Compared with control group, the distribution of cell cycle was not changed but apopotic cells were significantly increased in miR-489-overexpression group (P<0.05). Western blot analytic results confirmed that SOX4 was inhibited in miR-489-transfected cells.
Conclusion: miR-489, acting as an anti-oncogene microRNA, inhibited proliferation and invasion in osteosarcoma. Overexpression of miR-489 could suppress the growth of osteosarcoma cells through induction of cell apoptosis.