Background: | Matrix metallopeptidase 9 (MMP-9) is an enzyme encoded by the MMP9 gene. This protein, which is produced by normal alveolar macrophages and granulocytes, can be activated by 4-aminophenylmercuric acetate and phorbol ester and up-regulated by ARHGEF4, SPATA13 and APC via the JNK signaling pathway in colorectal tumor cells. MMP-9 is involved in the breakdown of extracellular matrix in normal physiological processes, such as embryonic development, reproduction, angiogenesis, bone development, wound healing, cell migration, learning and memory, as well as in pathological processes, such as arthritis, intracerebral hemorrhage, and metastasis. |