The effects of TGF-B on the interactions of matrix metalloproteinases MT1-MMP and MMP2 and tissue inhibitor metalloproteinase TIMP2 in the human glioma cell

During normal physiological processes, such as tissue repair and angiogenesis, morphogenesis occurs in which tissues are remodeled by degradation. Enzymes are secreted by the cells in order to initiate the degradation of the extracellular matrix (ECM) (Strongin et al., 1994). The extracellular matrix is the structure and support of the cells and is composed of proteins such as collagen and elastin. Once these tissues have been broken down, the cells are then free to migrate to the newly degraded area and resume their biological processes there (Uhm et al., 1997). In normal tissues there is a balance between degradation and regeneration of new cells that keep the tissues healthy. Cancerous cells lack this balance and it is for this reason that they are able to grow and spread at such a high rate. Pathogenic cells utilize these enzymes to degrade surrounding tissues allowing them to grow and take over what was once healthy tissue. They also secrete hormones and other factors that stimulate the growth of new blood vessels to keep the oxygen supply up to par with the rate at which the cells are metabolizing and growing. Because of the cancer cell\u27s ability to degrade surrounding tissue, it can also metastasize by migrating to other areas of the body via the blood stream by squeezing through the basement membranes of blood vessels that they are now in contact with