title: Membrane-type 1 matrix metalloproteinase-mediated progelatinase A activation in non-tumorigenic and tumorigenic human keratinocytes.
abstract: Elevated expression of type IV collagenases (MMP-2 and MMP-9) has been strongly correlated with tumour progression and metastasis in various tumours. Here, we analysed expression and activation of these MMPs in non-tumourigenic HaCaT cells and the malignant HaCaT variant II-4(rt). In monolayer cultures, both cell types secreted latent MMP-2 (proMMP-2) in comparable amounts, while MMP-9 production was clearly higher in II-4(rt)cells. Upon contact with fibrillar collagen type I the malignant II-4(rt)cells, but not the HaCaT cells, gained the capability to activate proMMP-2. This process is shown to be membrane-associated and mediated by MT1-MMP. Surprisingly, all membrane preparations from either HaCaT cells or II-4(rt)cells grown as monolayers, as well as within collagen gels, contained considerable amounts of active MT1-MMP. However, within collagen gels HaCaT cells showed significantly higher TIMP-2 levels compared to II-4(rt)cells. This indicates that TIMP-2 might play a central role for MT1-MMP-mediated gelatinolytic activity. Indeed, collagen type I-induced MT1-MMP-mediated proMMP-2 activation by II-4(rt)membranes could be completely abolished by an excess of TIMP-2. In conclusion, our data suggest that MT1-MMP-mediated proMMP-2 activation might be associated with malignant progression of epidermal tumour cells.
authors.affiliation: Department of Dermatology, University of Cologne, Köln, 50924, USA.
authors.forename: P
authors.initials: P
authors.lastname: Baumann
authors.forename: P
authors.initials: P
authors.lastname: Zigrino
authors.forename: C
authors.initials: C
authors.lastname: Mauch
authors.forename: D
authors.initials: D
authors.lastname: Breitkreutz
authors.forename: R
authors.initials: R
authors.lastname: Nischt
mesh_terms: D002471:Cell Transformation, Neoplastic; D017364:Collagenases / Q000378:metabolism; D004792:Enzyme Precursors / Q000096:biosynthesis* / Q000378:metabolism; D018093:Gelatinases / Q000096:biosynthesis* / Q000378:metabolism; D006801:Humans; D015603:Keratinocytes; D020781:Matrix Metalloproteinase 1 / Q000378:metabolism*; D020778:Matrix Metalloproteinase 2 / Q000096:biosynthesis* / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000096:biosynthesis* / Q000378:metabolism; D008666:Metalloendopeptidases / Q000096:biosynthesis* / Q000378:metabolism; D009361:Neoplasm Invasiveness / Q000503:physiopathology; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000378:metabolism; D014407:Tumor Cells, Cultured
chemical_list: D004792:Enzyme Precursors; D019716:Tissue Inhibitor of Metalloproteinase-2; D017364:Collagenases; D018093:Gelatinases; D008666:Metalloendopeptidases; C069860:progelatinase; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9; D020781:Matrix Metalloproteinase 1