title: Generation of biologically active endostatin fragments from human collagen XVIII by distinct matrix metalloproteases.
abstract: Endostatin, a potent inhibitor of endothelial cell proliferation, migration, angiogenesis and tumor growth, is proteolytically cleaved from the C-terminal noncollagenous NC1 domain of type XVIII collagen. We investigated the endostatin formation from human collagen XVIII by several MMPs in vitro. The generation of endostatin fragments differing in molecular size (24-30 kDa) and in N-terminal sequences was identified in the cases of MMP-3, -7, -9, -13 and -20. The cleavage sites were located in the protease-sensitive hinge region between the trimerization and endostatin domains of NC1. MMP-1, -2, -8 and -12 did not show any significant activity against the C-terminus of collagen XVIII. The anti-proliferative effect of the 20-kDa endostatin, three longer endostatin-containing fragments generated in vitro by distinct MMPs and the entire NC1 domain, on bFGF-stimulated human umbilical vein endothelial cells was established. The anti-migratory potential of some of these fragments was also studied. In addition, production of endostatin fragments between 24-30 kDa by human hepatoblastoma cells was shown to be due to MMP action on type XVIII collagen. Our results indicate that certain, especially cancer-related, MMP family members can generate biologically active endostatin-containing polypeptides from collagen XVIII and thus, by releasing endostatin fragments, may participate in the inhibition of endothelial cell proliferation, migration and angiogenesis.
authors.affiliation: Collagen Research Unit, Biocenter Oulu and Department of Medical Biochemistry and Molecular Biology, University of Oulu, PO Box 5000, FIN-90014 Oulu, Finland.
authors.forename: Ritva
authors.initials: R
authors.lastname: Heljasvaara
authors.forename: Pia
authors.initials: P
authors.lastname: Nyberg
authors.forename: Jani
authors.initials: J
authors.lastname: Luostarinen
authors.forename: Mataleena
authors.initials: M
authors.lastname: Parikka
authors.forename: Pia
authors.initials: P
authors.lastname: Heikkilä
authors.forename: Marko
authors.initials: M
authors.lastname: Rehn
authors.forename: Timo
authors.initials: T
authors.lastname: Sorsa
authors.forename: Tuula
authors.initials: T
authors.lastname: Salo
authors.forename: Taina
authors.initials: T
authors.lastname: Pihlajaniemi
mesh_terms: D000595:Amino Acid Sequence; D015153:Blotting, Western; D002460:Cell Line; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D024042:Collagen Type I / Q000378:metabolism; D043170:Collagen Type XVIII / Q000302:isolation & purification / Q000378:metabolism*; D017364:Collagenases / Q000235:genetics / Q000378:metabolism; D017077:Culture Media, Conditioned / Q000737:chemistry; D043169:Endostatins / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D042783:Endothelial Cells / Q000187:drug effects* / Q000378:metabolism; D015870:Gene Expression / Q000235:genetics; D006801:Humans; D006877:Hydroxamic Acids / Q000737:chemistry; D061965:Matrix Metalloproteinase Inhibitors; D020782:Matrix Metalloproteinases / Q000235:genetics / Q000378:metabolism*; D010446:Peptide Fragments / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D011994:Recombinant Proteins; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D024042:Collagen Type I; D043170:Collagen Type XVIII; D017077:Culture Media, Conditioned; D043169:Endostatins; D006877:Hydroxamic Acids; D061965:Matrix Metalloproteinase Inhibitors; D010446:Peptide Fragments; D011994:Recombinant Proteins; C100342:marimastat; D017364:Collagenases; D020782:Matrix Metalloproteinases