The biological role and regulation of matrix metalloproteinases (MMP) in cancer.

Matrix metalloproteinases (MMP) are zinc-dependent proteolytic enzymes capable of breaking down basement membranes and most extracellular matrix (ECM) components. MMP expression and activation are carefully regulated in physiological conditions in order to prevent uncontrolled destruction of body tissues but this regulation is modified or disrupted in pathological processes, including cancer. This review presents regulatory mechanisms designed to control MMP action. These consist of direct activation and inhibition by tissue inhibitors of MMP (TIMP), signal transduction pathways mediated by adhesion molecules such as integrins and EMMPRIN, involved in activation of MMP synthesis and transcriptional control by the ETS family of transcription factors.