Matrix metalloproteinases (MMPs), the entities responsible for eradicating the structure of extracellular matrix -ECM, are the zinc or calcium ion-dependent enzymes. This family of enzymes embodies a vast spectrum of proteases ranging from collagenases, stromelysins to the membrane type MMPs. The tasks linked with these enzymes are significant not only for a sound and stable development of the body but are also found guilty of carrying out angiogenesis, promoting tumor development and thus providing means to disseminate the cancer cells to the sites other than the primary tumor locale. At each step of angiogenesis, MMPs are operating, thereby featuring endothelial cells and several growth factors like VEGF, FGF, etc. Activation of pro-MMP2 with the involvement of MT1-MMP is one of the key steps that lead to the synthesis of blood vessels from an already existing one. For limiting the action of MMPs, various therapeutic techniques highlighting the mechanism of MMP inhibition have been studied. Several agents have been investigated for phase I, II and III clinical trials in combination with other anti-cancer therapies. Natural endogenous inhibitors of MMPs, TIMPs have a limited half-life and are thus not suitable for the desired outcome. Synthetic agents like Marimastat and BMS-275291 have shown reliable results. Nonetheless, explicit research is required for novel agents being designed and synthesized to attenuate the activity of matrix metalloproteinases that are accountable for cancer metastasis. Basic domain structure of a MMPs (modified), consisting of minimal domain (S; signal peptide, Pro; pro-peptide, Cysteine switch motif (PRCGXPD) with a -SH thiol group, Cat; catalytic region with a zinc ion binding motif (HEXGHXXGXXH)), hinge region or linker (L1) of variable lengths, Hpx; hemopexin like domain that comprises of 4 repeats and has a disulfide linkage (S-S) between its first and last sub-domains. FN; fibronectin type II like domain, V; vitronectin insertion (promotes cell adhesion), L2; linker 2 [91], I; type 1 transmembrane domain, II; type 2 trnasmembrane domain, Cp; cytoplasmic domain; Ca; cysteine array, Ig; IgG like domain, G; GpI anchor, Furin cleavage site.the cysteine switch to change into a proteolytically active state. The cysteine switch is characterized by the action of convertases, involving the removal of the prodomain that leads to disruption of the linkage between the cysteine residue and the zinc ion, either in the extracellular environment by other MMPs or proteinases like plasmin or in the Citation: Khalid A, Javaid MA (2016) Matrix Metalloproteinases: New Targets in Cancer Therapy. J Cancer Sci Ther 8: 143-153. doi:10.4172/1948-5956 domain assembly, and conservation within the sequences. The general features on the basis of which a proteinase is assessed before designating it as an MMP are sequence similarity with that of collagenase 1 (MMP-1), the factor found in the pro-peptide that is responsible for maintaining the matrix metalloproteinases in a zymogen form, the cysteine-s...
