title: A peptide mimic of E-selectin ligand inhibits sialyl Lewis X-dependent lung colonization of tumor cells.
abstract: Selectins bind to carbohydrate ligands in a calcium-dependent manner and play critical roles in host defense and possibly in tumor metastasis. To isolate peptides that mimic E-selectin ligands, we screened a phage peptide library using E-selectin as a target molecule. This attempt unexpectedly failed, probably because the binding affinity of E-selectin to its ligand is low. We then took an approach that is analogous to the isolation of anti-idiotype antibodies and were able to isolate peptides that bound to anticarbohydrate antibodies recognizing E-selectin ligands. These peptides, enriched for their binding to anti-Lewis A antibody, were found to bind to E-, P- and L-selectins in a calcium-dependent manner. Phage harboring the identified peptide IELLQAR and synthetic peptides having the same sequence inhibited the binding of sialyl Lewis X or sialyl Lewis A oligosaccharides to E-selectin. The adhesion of HL-60 and B16 melanoma cells expressing sialyl Lewis X to E-selectin was also inhibited by the phage-displaying IELLQAR peptide. Moreover, i.v. injected IELLQAR peptide inhibited the lung colonization of mouse B16 melanoma and human lung tumor cells expressing sialyl Lewis X. These results demonstrate that it is possible to isolate peptides mimicking carbohydrate ligands by screening the peptides for binding to anticarbohydrate antibodies and then using them to inhibit carbohydrate-dependent experimental tumor metastasis.
authors.affiliation: The Burnham Institute, Cancer Research Center, La Jolla, California 92037, USA. michiko@burnham-inst.org
authors.forename: M N
authors.initials: MN
authors.lastname: Fukuda
authors.forename: C
authors.initials: C
authors.lastname: Ohyama
authors.forename: K
authors.initials: K
authors.lastname: Lowitz
authors.forename: O
authors.initials: O
authors.lastname: Matsuo
authors.forename: R
authors.initials: R
authors.lastname: Pasqualini
authors.forename: E
authors.initials: E
authors.lastname: Ruoslahti
authors.forename: M
authors.initials: M
authors.lastname: Fukuda
mesh_terms: D000818:Animals; D058581:Brevican; D002448:Cell Adhesion / Q000187:drug effects / Q000502:physiology*; D011508:Chondroitin Sulfate Proteoglycans / Q000494:pharmacology; D019040:E-Selectin / Q000187:drug effects / Q000502:physiology*; D018922:HL-60 Cells; D006801:Humans; D037181:Lectins, C-Type; D007983:Lewis Blood Group Antigens; D008168:Lung / Q000187:drug effects / Q000473:pathology*; D008175:Lung Neoplasms / Q000473:pathology / Q000517:prevention & control* / Q000556:secondary*; D008546:Melanoma, Experimental / Q000473:pathology*; D051379:Mice; D008810:Mice, Inbred C57BL; D009362:Neoplasm Metastasis / Q000517:prevention & control; D009419:Nerve Tissue Proteins / Q000494:pharmacology; D009842:Oligopeptides / Q000494:pharmacology*; D009844:Oligosaccharides; D010446:Peptide Fragments / Q000494:pharmacology*; D011993:Recombinant Fusion Proteins / Q000187:drug effects / Q000378:metabolism; D000080506:Sialyl Lewis X Antigen; D014162:Transfection
chemical_list: C546938:BCAN protein, human; C553057:Bcan protein, mouse; D058581:Brevican; D011508:Chondroitin Sulfate Proteoglycans; D019040:E-Selectin; D037181:Lectins, C-Type; D007983:Lewis Blood Group Antigens; D009419:Nerve Tissue Proteins; D009842:Oligopeptides; D009844:Oligosaccharides; D010446:Peptide Fragments; D011993:Recombinant Fusion Proteins; D000080506:Sialyl Lewis X Antigen; C404394:isoleucyl-glutamyl-leucyl-leucyl-glutaminyl-alanyl-arginine