Expression of peroxisome proliferator activated receptor-gamma in non-small cell lung carcinoma: correlation with histological type and grade

For the metastasis and invasion of cancer cells, destruction of extracellular matrix is essential. In this process, collagen is broken down by some matrix metalloproteinases. Matrix metalloproteinase 2 (MMP2) is able to cleave type IV collagen, and membrane-type-1-matrix metalloproteinase (MT1-MMP) induces activation of proMMP2. We investigated the expressions of MT1-MMP and MMP2 and their relation to both clinicopathologic parameters and clinical outcome in non-small cell lung carcinomas (NSCLC). Eighty-nine specimens of NSCLC were examined using in situ hybridization and immunohistochemistry. Each metalloproteinase was expressed within the cytoplasm of tumor cells with or without stromal cells in NSCLC. Tumors in which tumor cells strongly stained for MT1-MMP mRNA or protein made up more than 50% of the tumor area were found in 44 and 26% of cases, respectively. The corresponding values for MMP-2 mRNA and protein, were 51 and 26%. Our analysis of clinicopathological findings revealed a significant positive relationship between MT1-MMP mRNA and p-M. The correlation between MMP2 protein-staining status and overall survival rate reached significance in the univariate analysis. However, an association was not demonstrated in the multivariate analysis. The detection of MT1-MMP and MMP2 is likely to be of limited value in informing the prognosis in NSCLC.