Novel MT1-MMP Small-Molecule Inhibitors Based on Insights into Hemopexin Domain Function in Tumor Growth

Abstract

Membrane type-1 matrix metalloproteinase (MT1-MMP) is a promising drug target in malignancy. The structure of MT1-MMP includes the hemopexin domain (PEX) that is distinct from and additional to the catalytic domain. Current MMP inhibitors target the conserved active site in the catalytic domain and, as a result, repress the proteolytic activity of multiple MMPs instead of MT1-MMP alone. In our search for non-catalytic inhibitors of MT1-MMP, we compared the pro-tumorigenic activity of wild-type MT1-MMP with a MT1-MMP mutant lacking PEX (ΔPEX). In contrast to MT1-MMP, ΔPEX did not support tumor growth in vivo, and its expression resulted in small fibrotic tumors that contained increased levels of collagen. Because these findings suggested an important role for PEX in tumor growth, we performed an inhibitor screen to identify small molecules targeting the PEX domain of MT1-MMP. Using the Developmental Therapeutics Program (NCI/NIH) virtual ligand screening compound library as a source and the X-ray crystal structure of PEX as a target, we identified and validated a novel PEX inhibitor. Low dosage, intratumoral injections of PEX inhibitor repressed tumor growth and caused a fibrotic, ΔPEX-like tumor phenotype in vivo. Together, our findings provide a preclinical proof-of-principle rationale for the development of novel and selective MT1-MMP inhibitors that specifically target the PEX domain.

Epigallocatechin Gallate Targeting of Membrane Type 1 Matrix Metalloproteinase-mediated Src and Janus Kinase/Signal Transducers and Activators of Transcription 3 Signaling Inhibits Transcription of Colony-stimulating Factors 2 and 3 in Mesenchymal Stromal Cells

“…Accordingly, preclinical proof of principle rationale was recently provided for the design and development of novel and selective MT1-MMP inhibitors that specifically target its hemopexin domain (42), whereas recent molecular profiling has identified actinonin, originally classified as an aminopeptidase N/CD13 pharmacological inhibitor, with MT1-MMP targeting functions (43). Finally, impact on lymphangiogenesis with selective targeting of MT1-MMP was also achieved through the use of specific monoclonal antibodies (44), whereas AG3340, a potent small molecule MT1-MMP antagonist, was required for the design of novel therapies for type 1 diabetes (45).…”

Non-destructive and Selective Imaging of the Functionally Active, Pro-invasive Membrane Type-1 Matrix Metalloproteinase (MT1-MMP) Enzyme in Cancer Cells

“…Gelatin Zymography and Western Blotting-Gelatin zymography of the conditioned medium aliquots and Western blotting of the cell lysate samples were performed as described earlier (65,66). For gelatin zymography, where indicated, the purified MMP-2 proenzyme (0.5 nM) was added to the cells.…”

Matrix metalloproteinases in head and neck cancer: current perspectives

“…In both in vitro and in vivo systems, designed small molecules and peptides exert their inhibitory effects by preventing dimerization, thereby reducing tumor size, MMP-induced migration, and angiogenesis. [158][159][160] Promising studies have shown that these selective compounds could bind on specific sites for each MMP inside their hemopexin domain and prevent dimer-induced functions of several MMPs, including MMP14 and -9. [158][159][160][161][162] A more sophisticated approach proposed a bifunctional fusion protein able to bind and inactivate both the catalytic and hemopexin domains of MMP2.…”