Expression of 72 kDa Type IV Collagenase in Human Colorectal Cancer

ABSTRACT

Type IV collagenases are thought to play a role in the proteolysis of the basement membrane and the extracellular matrix by the malignant cells that occur early in the development of invasive tumors. In several human tumors, including breast, colonic, ovarian, and hepatocellular carcinomas, type IV collagenase expression has been positively correlated with tumor invasiveness. In this study, we examined the expression and the activation of 72 kDa type IV collagenase in cancerous and normal tissues of the colon and, we attempted to clarify its clinical significance in 45 cases of human colorectal cancer by using northern blot analysis and gelatin zymography.This study showed that the level of 72 kDa type IV collagenase mRNA was increased in colorectal cancer and that this increase was associated with increased enzymatic activity. While there was a difference in the expression and the activation of this enzyme between T2 and T3, this enzyme activity did not show a definite correlation with cancer progress as measured by the depth of tumor invasion and lymph node metastasis.