title: Extracellular matrix-derived peptide binds to alpha(v)beta(3) integrin and inhibits angiogenesis.
abstract: Angiogenesis is associated with several pathological disorders as well as with normal physiological maintenance. Components of vascular basement membrane are speculated to regulate angiogenesis in both positive and negative manner. Recently, we reported that tumstatin (the NC1 domain of alpha 3 chain of type IV collagen) and its deletion mutant tum-5 possess anti-angiogenic activity. In the present study, we confirm that the anti-angiogenic activity of tumstatin and tum-5 is independent of disulfide bond requirement. This property of tum-5 allowed us to use overlapping synthetic peptide strategy to identify peptide sequence(s) which possess anti-angiogenic activity. Among these peptides, only the T3 peptide (69-88 amino acids) and T7 peptide (74-98 amino acids) inhibited proliferation and induced apoptosis specifically in endothelial cells. The peptides, similar to tumstatin and the tum-5 domain, bind and function via alpha(v)beta(3) in an RGD-independent manner. Restoration of a disulfide bond between two cysteines within the peptide did not alter the anti-angiogenic activity. Additionally, these studies show that tumstatin peptides can inhibit proliferation of endothelial cells in the presence of vitronectin, fibronectin, and collagen I. Anti-angiogenic effect of the peptides was further confirmed in vivo using a Matrigel plug assay in C57BL/6 mice. Collectively, these experiments suggest that the anti-angiogenic activity of tumstatin is localized to a 25-amino acid region of tumstatin and it is independent of disulfide bond linkage. Structural features and potency of the tumstatin peptide make it highly feasible as a potential anti-cancer drug.
authors.affiliation: Program in Matrix Biology, Department of Medicine and the Cancer Center, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02215, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Maeshima
authors.forename: U L
authors.initials: UL
authors.lastname: Yerramalla
authors.forename: M
authors.initials: M
authors.lastname: Dhanabal
authors.forename: K A
authors.initials: KA
authors.lastname: Holthaus
authors.forename: S
authors.initials: S
authors.lastname: Barbashov
authors.forename: S
authors.initials: S
authors.lastname: Kharbanda
authors.forename: C
authors.initials: C
authors.lastname: Reimer
authors.forename: M
authors.initials: M
authors.lastname: Manfredi
authors.forename: W M
authors.initials: WM
authors.lastname: Dickerson
authors.forename: R
authors.initials: R
authors.lastname: Kalluri
mesh_terms: D000478:Alkylation; D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001324:Autoantigens / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002417:Cattle; D002453:Cell Cycle / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D003094:Collagen / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D024141:Collagen Type IV; D004220:Disulfides / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects; D004789:Enzyme Activation; D016326:Extracellular Matrix Proteins / Q000737:chemistry / Q000378:metabolism*; D005260:Female; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D009389:Neovascularization, Pathologic; D018919:Neovascularization, Physiologic; D010084:Oxidation-Reduction; D010446:Peptide Fragments; D011485:Protein Binding; D019030:Receptors, Vitronectin / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D019096:Vitronectin / Q000378:metabolism
chemical_list: D001324:Autoantigens; D024141:Collagen Type IV; D004220:Disulfides; D016326:Extracellular Matrix Proteins; D010446:Peptide Fragments; D019030:Receptors, Vitronectin; D011994:Recombinant Proteins; D019096:Vitronectin; C000591612:tumstatin (74-98); C057112:type IV collagen alpha3 chain; D003094:Collagen; C505407:CASP3 protein, human; C505409:Casp3 protein, mouse; D053148:Caspase 3; D020169:Caspases