title: Cell surface chondroitin sulfate glycosaminoglycan in melanoma: role in the activation of pro-MMP-2 (pro-gelatinase A).
abstract: We previously reported that CS (chondroitin sulfate) GAG (glycosaminoglycan), expressed on MCSP (melanoma-specific CS proteoglycan), is important for regulating MT3-MMP [membrane-type 3 MMP (matrix metalloproteinase)]-mediated human melanoma invasion and gelatinolytic activity in vitro. In the present study, we sought to determine if CS can directly enhance MT3-MMP-mediated activation of pro-MMP-2. Co-immunoprecipitation studies suggest that MCSP forms a complex with MT3-MMP and MMP-2 on melanoma cell surface. When melanoma cells were treated with betaDX (p-nitro-beta-D-xylopyranoside) to inhibit coupling of CS on the core protein, both active form and proform of MMP-2 were no longer co-immunoprecipitated with either MCSP or MT3-MMP, suggesting a model in which CS directly binds to MMP-2 and presents the gelatinase to MT3-MMP to be activated. By using recombinant proteins, we determined that MT3-MMP directly activates pro-MMP-2 and that this activation requires the interaction of the C-terminal domain of pro-MMP-2 with MT3-MMP. Activation of pro-MMP-2 by suboptimal concentrations of MT3-MMP is also significantly enhanced in the presence of excess C4S (chondroitin 4-sulfate), whereas C6S (chondroitin 6-sulfate) or low-molecular-mass hyaluronan was ineffective. Affinity chromatography studies using CS isolated from aggrecan indicate that the catalytic domain of MT3-MMP and the C-terminal domain of MMP-2 directly bind to the GAG. Thus the direct binding of pro-MMP-2 with CS through the C-domain would present the catalytic domain of pro-MMP-2 to MT3-MMP, which facilitates the generation of the active form of MMP-2. These results suggest that C4S, which is expressed on tumour cell surface, can function to bind to pro-MMP-2 and facilitate its activation by MT3-MMP-expressing tumour cells to enhance invasion and metastasis.
authors.affiliation: Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN 55455, USA. iidax002@tc.umn.edu
authors.forename: Joji
authors.initials: J
authors.lastname: Iida
authors.forename: Krista L
authors.initials: KL
authors.lastname: Wilhelmson
authors.forename: Janet
authors.initials: J
authors.lastname: Ng
authors.forename: Peter
authors.initials: P
authors.lastname: Lee
authors.forename: Charlotte
authors.initials: C
authors.lastname: Morrison
authors.forename: Eric
authors.initials: E
authors.lastname: Tam
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Overall
authors.forename: James B
authors.initials: JB
authors.lastname: McCarthy
mesh_terms: D011508:Chondroitin Sulfate Proteoglycans / Q000378:metabolism*; D002809:Chondroitin Sulfates / Q000502:physiology*; D004792:Enzyme Precursors / Q000378:metabolism*; D018093:Gelatinases / Q000378:metabolism*; D006801:Humans; D053513:Matrix Metalloproteinase 16 / Q000502:physiology*; D061965:Matrix Metalloproteinase Inhibitors; D008545:Melanoma / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D008666:Metalloendopeptidases / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D000099216:Chondroitin Sulfate Proteoglycan 4
chemical_list: D011508:Chondroitin Sulfate Proteoglycans; D002809:Chondroitin Sulfates; D004792:Enzyme Precursors; D018093:Gelatinases; D053513:Matrix Metalloproteinase 16; D061965:Matrix Metalloproteinase Inhibitors; D008565:Membrane Proteins; D008666:Metalloendopeptidases; D019716:Tissue Inhibitor of Metalloproteinase-2; C101390:CSPG4 protein, human; D000099216:Chondroitin Sulfate Proteoglycan 4; C069860:progelatinase