The role of matrix metalloproteinase expression in lung cancer metastasis

Objective:To investigate the expression of MMP-2 and MMP-9 in lung cancer tissue and its correlation with lung cancer metastasis.Methods:The MMP-2, MMP-9 and theirs mRNA expression of 30 cases of non cancerous lung tissue and 87 cases of lung cancer tissue were detected by means of immunohistochemistry and RT-PCR methods respectively.Results:There were positive MMP-2 and MMP-9 expression both in non cancerous lung tissue and cancer tissue, but the expression were lower in non cancerous lung tissue than cancer lung tissue (P0.05). The MMP-2 positive rate in small cell carcinoma, squamous carcinoma, adenocarcinoma and non cancerous lung tissue were 85.7%, 44.7%, 47.6%, 23.3% respectively and those of MMP-9 were 78.6%, 47.4%, 38.1%, 20.0% respectively. The positive rate was highest in small cell lung cancer tissue(P0.05). The MMP-2 and MMP-9 mRNA expression were higher in low differentiation tissue and the order from high to low was level Ⅰ, levelⅡ, levelⅢ. Among different pathological types of cancer the expression of MMP-2 and MMP-9 mRNA were different significantly and higher in small cell lung cancer tissue than other pathological types and higher in lymph node metastasis than non lymph node metastasis lung cancer tissues(P0.05). Conclusion:The expression of MMP-2 and MMP-9 is correlated with histological types, differentiation grade and lymph node metastasis. Maybe MMP-2 and MMP-9 play an important role in lung cancer metastasis.