INCREASED TYPE-IV COLLAGEN-DEGRADING ACTIVITY IN METASTASES ORIGINATING FROM PRIMARY TUMORS OF THE HUMAN COLON

The secretion of specific matrix metalloproteinases (MMPs) is consider ed a prerequisite step for tumor cell invasion and metastasis. In the present study we investigated the expression of type IV collagen-degra ding activity in primary tumors of the human colon in correlation to t umor grade and in comparison to activity expressed in arising metastas es. We observed that type ni collagen-degrading activity (MMP-2 and MM P-9), purified by ion exchange, gel filtration and affinity chromatogr aphy and characterized by gelatin zymography, correlates to tumor grad e. Furthermore, in surgical specimens identified as metastases origina ting from primary tumors of the colon, we observed that enzyme activit y was significantly enhanced, relatively to that identified in the pri mary tumor. This observation should be considered when targeting MMPs as a therapeutic intervention to prevent cancer progression.