title: Role of IIb-IIIa-like glycoproteins in cell-substratum adhesion of human melanoma cells.
abstract: The platelet fibrinogen receptor, glycoprotein complex IIb-IIIa, was isolated from human platelets by lectin and monoclonal antibody affinity chromatography and a polyclonal antiserum (anti-IIb-IIIa) was generated and used to probe for the presence and function of IIb-IIIa-like molecules in two adherent human cell lines. Both C32 melanoma cells and WI38 fibroblasts expressed a IIb-IIIa-like complex on their surface as indicated by immunoprecipitation of detergent extracts of surface radiolabeled cells. When added to cells plated in medium containing 10% serum, the anti-IIb-IIIa antiserum perturbed the adhesion of C32 melanoma cells, but not of WI38 fibroblasts. In a serum-free system, anti-IIb-IIIa antibodies inhibited attachment and spreading of C32 cells to fibrinogen, vitronectin, and fibronectin adsorbed to glass. Anti-IIb-IIIa had no effect on the attachment and spreading of WI38 cells to the extracellular matrix proteins, however. Thus, the IIb-IIIa-like complex appears to play a predominant role in cell-substratum adhesion of C32 cells, but not WI38 cells, and may result from the fact that, on a protein basis, the C32 melanoma cells express approximately 3 times more complex on their surface than do WI38 fibroblasts. The results suggest that the relative abundance of a particular adhesion receptor on the cell surface may govern its importance to cell-substratum adhesion.
authors.affiliation: Lankenau Medical Research Center, Philadelphia, Pennsylvania 19151.
authors.forename: K A
authors.initials: KA
authors.lastname: Knudsen
authors.forename: L
authors.initials: L
authors.lastname: Smith
authors.forename: S
authors.initials: S
authors.lastname: Smith
authors.forename: J
authors.initials: J
authors.lastname: Karczewski
authors.forename: G P
authors.initials: GP
authors.lastname: Tuszynski
mesh_terms: D002448:Cell Adhesion; D002846:Chromatography, Affinity; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007106:Immune Sera; D008545:Melanoma / Q000473:pathology*; D010980:Platelet Membrane Glycoproteins / Q000502:physiology*
chemical_list: D007106:Immune Sera; D010980:Platelet Membrane Glycoproteins