title: Novel glycoproteins inhibiting the binding of colorectal cancer cells to E-selectin.
abstract: Novel glycoproteins carrying sialyl-LeA (SLeA) antigens (SL-GP) were isolated from ascites fluid from a patient with colorectal cancer by immunoaffinity chromatography. Their characteristics, including binding capacity to E-selectin, were investigated. SL-GP showed a typical mucin type amino acid composition in which Ser, Thr and Pro together accounted for greater than 50% of the total amino acid residues. A large amount of carbohydrate (about 80%) was present in SL-GP. The number of O-glycans carrying SLeA antigens comprised about 9% of the total number of O-glycosidic chains. SL-GP could bind to IL-1 beta treated HUVEC, and the binding was inhibited by anti-E-selectin and anti-SLeA monoclonal antibodies. The binding of colorectal cancer cells, LS 180, to HUVEC was assayed in the presence of SL-GP, oligosaccharides prepared from SL-GP and human milk SLeA hexasaccharide. SL-GP inhibited the binding most effectively, whereas equivalent amounts of the SL-GP oligosaccharides and milk SLeA hexasaccharide inhibited it only slightly. These results constitute direct evidence that a unique arrangement of SLeA antigens on the polypeptide chain, probably a cluster, is essential for the binding to E-selectin.
authors.affiliation: Department of Biotechnology, Faculty of Engineering, Kyoto Sangyo University, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Inoue
authors.forename: H
authors.initials: H
authors.lastname: Nakada
authors.forename: Y
authors.initials: Y
authors.lastname: Oka
authors.forename: N
authors.initials: N
authors.lastname: Tanaka
authors.forename: I
authors.initials: I
authors.lastname: Yamashina
mesh_terms: D000906:Antibodies / Q000494:pharmacology; D001201:Ascites / Q000276:immunology / Q000378:metabolism; D018395:CA-19-9 Antigen; D002448:Cell Adhesion / Q000187:drug effects; D002478:Cells, Cultured; D015179:Colorectal Neoplasms / Q000378:metabolism* / Q000473:pathology; D019040:E-Selectin / Q000276:immunology / Q000378:metabolism*; D004492:Edetic Acid / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D005732:Gangliosides / Q000737:chemistry / Q000276:immunology; D006023:Glycoproteins / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology*; D006801:Humans; D007457:Iodine Radioisotopes; D008895:Milk, Human / Q000737:chemistry; D009077:Mucins / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D009844:Oligosaccharides / Q000737:chemistry / Q000494:pharmacology; D011134:Polysaccharides / Q000737:chemistry; D014471:Umbilical Veins / Q000166:cytology / Q000378:metabolism
chemical_list: D000906:Antibodies; D018395:CA-19-9 Antigen; D019040:E-Selectin; D005732:Gangliosides; D006023:Glycoproteins; D007457:Iodine Radioisotopes; D009077:Mucins; D009844:Oligosaccharides; D011134:Polysaccharides; C064564:sialyl Le(a) ganglioside; D004492:Edetic Acid