Inhibition of matrix metalloproteinase-14 in osteosarcoma cells by clodronate
article
Background. Bisphosphonates reduce the bone metastasis formation and angiogenesis but the exact molecular mechanisms involved are unclear. Progelatinase A (proMMP-2; 78 KDa) is activated up during the tumor spread and metastasis by a cell surface-associated matrix metalloproteinase (membrane-type matrix metalloproteinase [MT1-MMP] or MMP-14). Material and methods. We evaluated the effects of a bisphosphonate (clodronate) on MT1-MMP mRNA expression and protein production, catalytic activity and proteolytic activation of proMMP-2 by cultured human MG-63 osteosarcoma cells. Results. Clodronate, at therapeutically attainable noncytotoxic concentrations, dose-dependently inhibited phorbol myristic acetate (PMA)-induced proteolytic activation of proMMP-2 by human MG-63 osteosarcoma cells. Clodronate also downregulated the PMA-induced expression of MT1-MMP mRNA and protein production in human MG-63 osteosarcoma cells, as evidenced by Northern analysis and fluorescent immunohistochemistry. Furthermore, clodronate inhibited directly and dose-dependently MT1-MMP activity, and the MT1-MMP inhibition by clodronate was reduced in the presence of an increased (5 mM) Ca2+ concentrations when compared to physiological (1 mM) Ca2+ concentrations. Conclusion. We conclude that (1) the extracellular/cell-associated mechanism of bisphosphonate involves inhibition of MT1-MMP catalytic activity eventually by chelation, and that (2) intracellular mechanism involves downregulation of induced MT1-MMP mRNA and protein expression. The inhibition and downregulation of MT1-MMP by clodronate can be related to their ability to reduce MG-63 osteosarcoma cell invasion and spread. These findings may, at least in part, explain at molecular level the antitumor and antibone resorption activities of clodronate observed in clinical studies. © 2003 Elsevier Inc. All rights reserved.
Topics
Physiological SciencesBisphosphonateInhibitionMMP-2MT1-MMPOsteosarcomaclodronic acidmatrix metalloproteinase 14phorbol 13 acetate 12 myristatearticlecancer cellcell activationcontrolled studycytotoxicitydown regulationenzyme activationenzyme activityenzyme inhibitionhumanhuman cellimmunohistochemistryNorthern blottingosteosarcomapriority journalprotein degradationprotein expressionBinding SitesBlotting, NorthernClodronic AcidCollagenasesCulture Media, ConditionedEnzyme ActivationEnzyme InhibitorsEnzyme PrecursorsFluorescent Antibody TechniqueGelatinasesHumansMatrix Metalloproteinase 13Matrix Metalloproteinase 2Matrix Metalloproteinases, Membrane-AssociatedMetalloendopeptidasesOsteosarcomaRecombinant ProteinsRNA, MessengerTetradecanoylphorbol AcetateTumor Cells, Cultured
TNO Identifier
237063
ISSN
00224804
Source
Journal of Surgical Research, 111(1), pp. 45-52.
Pages
45-52
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