Matrix metalloproteinases and oral cancer

For tumours to invade and metastasise, neoplastic cells must be capable of degrading the extracellular matrix (ECM), and accessing blood vessels and l ymphatics. This process is mediated in the pericellular environment and is a highly controlled cascade of events utilising the same mechanisms that no rmal cells use for migrating through tissue barriers, for example, in devel opment and wound healing. Proteolytic enzymes from several families, includ ing matrix metalloproteinases (MMPs), are involved in ECM remodelling. Incr eased production of these enzymes has been associated with the invasive and /or metastatic phenotype in many tumours. Several MMPs have been shown to p lay a role in the invasion and metastasis of oral carcinoma, and it is incr easingly apparent that tumour cells, as well as producing endogenous MMP, a re capable of utilising MMP produced by tumour stromal cells, indicating an active role for stroma in tumour invasion. It is not clear whether a parti cular invasive system is favoured by oral carcinoma, but it is likely that further understanding of the interactions between carcinoma and stromal cel ls will provide an opportunity to refine the therapeutic interventions that are currently being tested. (C) 1999 Elsevier Science Ltd. All rights rese rved.