Matrix metalloproteinases in oral cancer: A catabolic activity on extracellular matrix components

Zinc-dependent proteolytic enzymes known as matrix metalloproteinases (MMPs) are a class of structurally related enzymes that are known to be crucial in the catabolic turnover of extracellular matrix (ECM) components. MMPs are thought to control the activity of a number of non-ECM bioactive substrates, such as growth factors, cytokines, chemokines, and cell receptors, which control the tissue microenvironment. The interaction between cells and ECM plays a key role in normal development and differentiation of organism and many pathological states as well. The primary class of controlling proteases in the ECM is known as MMPs. Aspects of normal physiology and pathology depend on the ability of MMPs to change the structural integrity of tissues. Uncontrolled ECM turnover, tissue remodeling, inflammatory response, cell proliferation, and migration are pathogenic alterations that can result from an imbalance between the concentration of active metalloproteinases and their inhibitors (tissue inhibitors of metalloproteinases [TIMPs]). This detailed review provides some information on the function of MMPs in inflammatory, caries and periapical, cancer, and other oral diseases. Blood and saliva are the two biological fluids that are most frequently used to diagnose oral disorders. Most of the ECM components in patients undergo digestion to lower molecular weight forms, resulting in much higher amounts of MMPs in their saliva/blood than in healthy individuals. Conventional treatment successfully reduces the levels of MMPs which inhibits the progressive breakdown of collagens in ECM components.