Selective function-blocking monoclonal human antibody highlights the important role of membrane type-1 matrix metalloproteinase (MT1-MMP) in metastasis.
The invasion-promoting MT1-MMP is a cell surface-associated collagenase with a plethora of critical cellular functions. There is a consensus that MT1-MMP is a key protease in aberrant pericellular proteolysis in migrating cancer cells and, accordingly, a promising drug target. Because of high homology in the MMP family and a limited success in the design of selective small-molecule inhibitors, it became evident that the inhibitor specificity is required for selective and successful MT1-MMP therapies. Using the human Fab antibody library (over 1.25×109 individual variants) that exhibited the extended, 23-27 residue long, VH CDR-H3 segments, we isolated a panel of the inhibitory antibody fragments, from which the 3A2 Fab outperformed others as a specific and potent, low nanomolar range, inhibitor of MT1-MMP. Here, we report the in-depth characterization of the 3A2 antibody. Our multiple in vitro and cell-based tests and assays, and extensive structural modeling of the antibody/protease interactions suggest that the antibody epitope involves the residues proximal to the protease catalytic site and that, in contrast with tissue inhibitor-2 of MMPs (TIMP-2), the 3A2 Fab inactivates the protease functionality by binding to the catalytic domain outside the active site cavity. In agreement with the studies in metastasis by others, our animal studies in acute pulmonary melanoma metastasis support a key role of MT1-MMP in metastatic process. Conversely, the selective anti-MT1-MMP monotherapy significantly alleviated melanoma metastatic burden. It is likely that further affinity maturation of the 3A2 Fab will result in the lead inhibitor and a proof-of-concept for MT1-MMP targeting in metastatic cancers.
Infectious and Inflammatory Disease Center/Cancer Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA.
Albert G
AG
Remacle
Infectious and Inflammatory Disease Center/Cancer Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA.
Piotr
P
Cieplak
Department of Chemical and Environmental Engineering, University of California, Riverside, Riverside, CA 92512, USA.
Dong Hyun
DH
Nam
Infectious and Inflammatory Disease Center/Cancer Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA.
Sergey A
SA
Shiryaev
Department of Chemical and Environmental Engineering, University of California, Riverside, Riverside, CA 92512, USA.
Xin
X
Ge
Infectious and Inflammatory Disease Center/Cancer Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA.
Alex Y
AY
Strongin
D000818:Animals; D019138:Antibodies, Blocking / Q000737:chemistry / Q000494:pharmacology*; D000074322:Antineoplastic Agents, Immunological / Q000737:chemistry / Q000494:pharmacology*; D001667:Binding, Competitive; D020134:Catalytic Domain; D045744:Cell Line, Tumor; D002465:Cell Movement; D002470:Cell Survival; D003094:Collagen / Q000378:metabolism; D004195:Disease Models, Animal; D004789:Enzyme Activation / Q000187:drug effects; D005260:Female; D064593:Heterografts; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000737:chemistry / Q000494:pharmacology; D053511:Matrix Metalloproteinase 14 / Q000378:metabolism*; D061965:Matrix Metalloproteinase Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D051379:Mice; D008958:Models, Molecular; D008968:Molecular Conformation; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D009369:Neoplasms / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology*; D011485:Protein Binding; D059748:Proteolysis; D011994:Recombinant Proteins / Q000378:metabolism
D019138:Antibodies, Blocking; D000074322:Antineoplastic Agents, Immunological; D007140:Immunoglobulin Fab Fragments; D061965:Matrix Metalloproteinase Inhibitors; D011994:Recombinant Proteins; D003094:Collagen; C507086:MMP14 protein, human; D053511:Matrix Metalloproteinase 14
MT1-MMP; antibody; cancer; metastasis; proteinase