[Matrix metalloproteinases and colorectal cancer]

Malignant tumors have the ability to invade normal tissue and to spread to distant sites giving rise to metastasis, which are major factors in the morbidity and mortality of colorectal cancer. Invasion and metastasis involve attachment of tumor cells to the basement membrane, degradation of the local connective tissue, and penetration and migration through proteolyzed stroma. The key enzymes responsible for ECM breakdown are matrix metalloproteinases (MMPs). To date, 26 MMP genes have been identified in humans, and many are implicated in cancer. ECM degradation by MMPs not only enhances tumor invasion, but also affects tumor cell behavior and leads to cancer progression. This review highlights recent developments with regard to the cellular and molecular mechanisms of MMPs that influence colorectal tumor cell growth, invasion, and metastasis.