Matrix metalloproteases expression in different histological types of colorectal polyps.

INTRODUCTION Colorectal carcinoma (CC) may begin as benign polyps, which may be classified in different histological types with a different risk to develop cancer. Matrix metalloproteases (MMPs) are able to degrade all components in the extracellular matrix and are important tissue-remodeling enzymes and key elements in tumor invasion and metastasis. The aim of this study was to investigate the expression and clinical relevance of MMPs in different histological types of colorectal polyps. METHODS The expression levels of MMP-1, 2, 7, 9, 11, 13 and 14 were analyzed by real-time PCR, Western-blot and immunohistochemistry in 50 patients with different histological types of colorectal polyps, 28 of which developed CC. RESULTS The results indicate that hyperplastic polyps had the lowest levels of MMP-1 and MMP-7, tubular polyps showed higher levels of both MMP-7 and MMP-14, and tubulovillous adenoma showed higher levels of MMP-1, MMP-7 and MMP-14. CONCLUSION MMP expression was decreased in hyperplastic, tubular and tubulovillous adenoma polyps from patients who developed CC. Our findings suggest that MMP expression may be a pathological marker of colorectal polyps and for cancer susceptibility, which may improve strategies for CC prevention based on screening colonoscopy.