Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases that degrade components of the extracellular matrix (ECM) and play essential roles in various physiological and pathological processes such as morphogenesis, differentiation, angiogenesis, tissue remodeling, and tumor invasion. MMPs are synthesized as pro-enzymes and converted to active form by extracellular proteinases. MMP7, also referred to as matrilysin, is the smallest member of the MMP family and differs from other MMP members in that it lacks the C-terminal hemopexin-like domain. MMP7 is produced primarily by mucosal epithelia, and is capable of degrading various ECM proteins including proteoglycans, fibronectin, elastin and casein. This enzyme serves essential functions in both innate defense and wound healing, and appears to be one of the most important MMPs in human colon cancers. It has been reported that MMP7 contributes to tumor malignancy probably by cleaving cell surface proteins such as Fas ligand, degradation of IgG or inducing E-cadherin-mediated cell aggregation. In addition, matrilysin is also identified as a mediator of pulmonary fibrosis and a potential therapeutic target.
