Abstract:Objective: To investigate the expression of matrix metalloproteinases 9 (MMP-9) in osteosarcoma tissues and the effect of MMP-9 on the progression of osteosarcoma and its clinical significance. Methods: The expression of MMPs'family in 5 osteosarcoma specimens and 5 normal bone tissues was detected by real-time quantitative PCR. shRNA was used to knockdown the expression of MMP-9 in Saos2 cells. The proliferation, invasion and migration of the cells after transfection were detected for the effects of MMP-9 down-regulation. According to the expression of MMP-9 in osteosarcoma, 64 follow-up cases were grouped and analyzed for survival rate. Results: Screening of MMPs'family revealed that the expression of MMP-9 in osteosarcoma tissues was significantly higher than that in normal bone tissues (t=12.040, P=0.000). In cell proliferation, invasion and scratch test, there was no significant difference between blank control group and negative control group. But compared with negative control group, down-regulation of MMP-9 in Saos2 cells markedly repressed cell proliferation, decreased invasion and migration (t=4.954, P=0.008; t=6.360, P=0.003; t=3.965, P=0.017). In addition, a survival analysis in 64 follow-up cases showed that the overall survival rate of the high-MMP-9 group was significantly lower than that of the low-MMP-9 group (χ2=4.169, P=0.041). Conclusion: The high expression of MMP-9 in osteosarcoma tissue is closely related to the proliferation, invasion and migration of osteosarcoma, which has certain implication for the clinical prognosis of patients.
