Matrix metalloproteinases in gastrointestinal cancer

Matrix metalloproteinases (MMPs) are a family of enzymes that are responsible for the breakdown of connective tissue proteins. These enzymes play a central role in tissue remodelling associated with growth, development and repair. In these physiological processes MMP activity is tightly regulated. However, it is clear that aberrant MMP expression can contribute to the pathogenesis of several diseases including rheumatoid arthritis, tumour invasion and metastasis, multiple sclerosis, cerebral haemorrhage, and inflammatory bowel disease. The focus of this short article is the expression of MMP activity in gastrointestinal cancer. Rather than provide a complete overview of research in this area the article will consider areas of particular clinical relevance, such as the potential use of MMPs as prognostic markers and the use of MMP inhibitors in the treatment of cancer. For further insight into the role of MMPs in tumour invasion and metastasis the reader is referred to the recent review by Chambers and Matrisian.