[Metalloproteinases in tumor progression. Review]

The two biological characteristics that determine the malignancy of cancer are infiltration and metastasis. The study of these mechanisms is related to the invasion of tumoral cells and the relationship of these cells with their stroma, which interact producing the movement and accumulation of inflammatory cells, the formation of new blood vessels, multiplication of fibroblasts and the synthesis of the components of the extra cellular matrix production. Tumoral invasion is conditioned through various enzyme activities, in particular proteases which degrade the matrix, thus facilitating the progression of the tumor. The metalloproteinases (MMP) are a family of proteinases that play an important role in cancer as well as in numerous other diseases. MMP are, therefore, a potential factor in cancer therapy. Several synthetic MMP inhibitors have been developed and have shown successful anti-tumor activity in a variety of animal species, but in clinical studies of patients with advanced forms of cancer, this therapeutic strategy has not resulted as effective. In this article, due to the biological and clinical importance of this therapy, we summarize the current views on the role of metalloproteinases (MMP) in tumor promotion, proliferation, invasion, metastasis and angiogenesis.