The Function Of MMP-2 And TIMP-2 In The Invasion And Metastasis Of Osteosarcoma

PURPOSE: Invasion and metastasis of tumor is not only the main biological characters of malignant tumors but also the important death reason of patients. The mechanism of invasion and metastasis in tumor and the treatment of anti-metastasis have been widely studied in recent years. It is extracellular matrix(ECM) that played an important role in the invasion and metastasis. Matrix metalloproteinases 2(MMP-2) and Tissue inhibitor of metalloproteinases 2(TIMP-2) were important factors regulating the integrity of ECM, and had close correlation to the invasion ,metastasis and prognosis of tumor. Up to now, the research of MMP-2 and TIMP-2 had been focused on carcinoma, but their expression and correlation and correlation between them in OS have rarely been reported. This study explored the function and relationship of MMP-2 and TIMP-2 in the invasion and metastasis of OS. Immunohistochemical method was undertaken to determine the expression of MMP-2 and TIMP-2 in OS specimens and pathological results were compared. MATERIAL AND METHODS: By kept in archives 53 OS and osteochondroma specimens embedded in paraffine were chosen. All 53 OS specimens were divided into 3 groups by pathological criteria, and into 2 groups by whether invasion and metastasis exist or not. Immunohistochemical method (SP) was used to detect MMP-2 and TIMP-2 and the results were analysed statistically by SPSS 11.5 software. The differences of MMP-2 and TIMP-2 among groups were compared by Kruskal-Wallis test. The correlation of MMP-2 and TIMP-2 in OS and that of their homogeneous expression and invasion in OS were compared by Chi-Square test. There was a statistical significance when p<0.05. RESULTS: The positive rate MMP-2 in OS was 69.81%, and 35.5% in osteochondroma, with significant difference between them. It means that the expression of MMP-2 in OS was obviously higher than that in the osteochondroma group, and had no significant difference in different pathological subgroups of OS. There was significant difference in expression of MMP-2 in group according to invasion and metastasis. It means that the expression of MMP-2 in metastasis group was higher than that in no-metastasis group. The positive rate TIMP-2 in OS was 41.51%, and 70% in osteochondroma, with significant difference between them. It means that the expression of TIMP-2 in OS was obviously higher than that in the osteochondroma group, and had no significant difference in different pathological subgroups of OS. There was significant difference in expression of TIMP-2 in group according to invasion and metastasis. It means that the expression of TIMP-2 in metastasis group was higher than that in no-metastasis group. In the same group of OS samples, there was significant difference in the expression of MMP-2 and TIMP-2 among subgroups, that is those with positive MMP-2 had negative trend in TIMP-2. There was significant difference in the homogeneous expression of MMP-2 and TIMP-2 between group with metastasis and group without metastasis, that is both positive MMP-2 and negative TIMP-2 had higher potential of invasion and metastasis. CONCLUSION: 1.The expression of MMP-2 was commonly high and TIMP-2 low in OS. 2. The expression of MMP-2 and TIMP-2 had no correlation to pathological types of OS, but had correlation with invasion and metastasis of soft tissue. 3. There was distinct correlation in the expression of MMP-2 and TIMP-2 in OS. 4. The balance of expression ofMMP-2 and TIMP-2 played an important role in OS invasion and metastasis. Both positive expression of MMP-2 and negative expression of TIMP-2 in OS might indicated higher potential of invasion and metastasis.