Prinomastat, a hydroxamate inhibitor of matrix metalloproteinases, has a complex effect on migration of breast carcinoma cells.
Membrane type-1 matrix metalloproteinase (MT1-MMP) and alphavbeta3 integrin have been directly implicated in tumor cell dissemination and metastasis. We have demonstrated that in the case of breast carcinoma MCF7 cells co-expressing MT1-MMP and alphavbeta3 integrin, the proteinase processes the pro-alphav integrin subunit, thus facilitating alphavbeta3 integrin maturation and cell migration on vitronectin. Our findings show that cell surface MT1-MMP is a short-lived protein with a life span in the range of several hours. In contrast, turnover of alphavbeta3 integrin is much slower. The half-life of alphavbeta3 heterodimer is about 24 hr. This large difference in life span allowed us to distinguish between the effects of MT1-MMP on cell migration brought by matrix proteolysis from those imposed through alphavbeta3 integrin maturation. We then modulated the enzyme's activity by a potent hydroxamate MMP inhibitor, Prinomastat (AG3340), to analyze the divergent effects of MT1-MMP on cell migration. Although Prinomastat immediately blocked MT1-MMP-mediated matrix degradation, the pool of MT1-MMP-modified alphavbeta3 integrin molecules was still capable of mediating cell-matrix interactions. To our considerable surprise, inhibition of MT1-MMP-dependent vitronectin proteolysis by Prinomastat allowed a several-fold increase in migration of MCF7 cells co-expressing MT1-MMP and alphavbeta3 integrin. In contrast, long-term Prinomastat inhibition of MT1-MMP-dependent pro-alphav cleavage and thus alphavbeta3 integrin maturation strongly inhibited cell motility. Our studies suggest that MT1-MMP could actually promote cell migration via modification of the cell surface receptors, including alphavbeta3 integrin, rather than facilitate cell migration through direct cleavage of the matrix proteins.
Deryugina
Elena I
EI
Cancer Research Center, The Burnham Institute, La Jolla, CA 92037, USA.
Ratnikov
Boris I
BI
Strongin
Alex Y
AY
D000970:Antineoplastic Agents / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000473:pathology*; D002465:Cell Movement / Q000187:drug effects*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D039302:Integrin alphaVbeta3 / Q000378:metabolism; D053504:Matrix Metalloproteinases, Membrane-Associated; D008666:Metalloendopeptidases / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D009930:Organic Chemicals; D014407:Tumor Cells, Cultured; D019096:Vitronectin / Q000378:metabolism
D000970:Antineoplastic Agents; D004791:Enzyme Inhibitors; D039302:Integrin alphaVbeta3; D009930:Organic Chemicals; D019096:Vitronectin; C113282:prinomastat; D053504:Matrix Metalloproteinases, Membrane-Associated; D008666:Metalloendopeptidases