title: Glycosylation-dependent binding of galectin-8 to activated leukocyte cell adhesion molecule (ALCAM/CD166) promotes its surface segregation on breast cancer cells.
abstract: We previously demonstrated that the activated leukocyte cell adhesion molecule (ALCAM/CD166) can interact with galectin-8 (Gal-8) in endothelial cells. ALCAM is a member of the immunoglobulin superfamily that promotes homophilic and heterophilic cell-cell interactions. Gal-8 is a "tandem-repeat"-type galectin, known as a matricellular protein involved in cell adhesion. Here, we analyzed the physical interaction between both molecules in breast cancer cells and the functional relevance of this phenomenon.
  
  
  
  We performed binding assays by surface plasmon resonance to study the interaction between Gal-8 and the recombinant glycosylated ALCAM ectodomain or endogenous ALCAM from MDA-MB-231 breast cancer cells. We also analyzed the binding of ALCAM-silenced or control breast cancer cells to immobilized Gal-8 by SPR. In internalization assays, we evaluated the influence of Gal-8 on ALCAM surface localization.
  
  
  
  We showed that recombinant glycosylated ALCAM and endogenous ALCAM from breast carcinoma cells physically interacted with Gal-8 in a glycosylation-dependent fashion displaying a differential behavior compared to non-glycosylated ALCAM. Moreover, ALCAM-silenced breast cancer cells exhibited reduced binding to Gal-8 relative to control cells. Importantly, exogenously added Gal-8 provoked ALCAM segregation, probably trapping this adhesion molecule at the surface of breast cancer cells.
  
  
  
  Our data indicate that Gal-8 interacts with ALCAM at the surface of breast cancer cells through glycosylation-dependent mechanisms.
  
  
  
  A novel heterophilic interaction between ALCAM and Gal-8 is demonstrated here, suggesting its physiologic relevance in the biology of breast cancer cells.
authors.affiliation: Institute of Studies in Humoral Immunology, University of Buenos Aires (UBA) and National Council Research (CONICET), Microbiology, Immunology and Biotechnology Department, School of Pharmacy and Biochemistry, University of Buenos Aires (UBA), Buenos Aires, Argentina.
authors.forename: Marisa M
authors.initials: MM
authors.lastname: Fernández
authors.affiliation: Institute of Biochemistry and Biophysics (IQUIFIB), UBA-CONICET, Biological Chemistry Department, School of Pharmacy and Biochemistry, UBA, Buenos Aires, Argentina.
authors.forename: Fátima
authors.initials: F
authors.lastname: Ferragut
authors.affiliation: Institute of Biochemistry and Biophysics (IQUIFIB), UBA-CONICET, Biological Chemistry Department, School of Pharmacy and Biochemistry, UBA, Buenos Aires, Argentina.
authors.forename: Víctor M
authors.initials: VM
authors.lastname: Cárdenas Delgado
authors.affiliation: Institute of Biochemistry and Biophysics (IQUIFIB), UBA-CONICET, Biological Chemistry Department, School of Pharmacy and Biochemistry, UBA, Buenos Aires, Argentina.
authors.forename: Candelaria
authors.initials: C
authors.lastname: Bracalente
authors.affiliation: Molecular Pathology Department, "Eva Perón" HIGA Hospital, Buenos Aires, Argentina.
authors.forename: Alicia I
authors.initials: AI
authors.lastname: Bravo
authors.affiliation: Laboratory of Functional and Molecular Glycomics, Institute of Biology and Experimental Medicine (IBYME), CONICET, Buenos Aires, Argentina.
authors.forename: Alejandro J
authors.initials: AJ
authors.lastname: Cagnoni
authors.affiliation: Department of Mathematics and Statistics, School of Pharmacy and Biochemistry, UBA, Buenos Aires, Argentina.
authors.forename: Myriam
authors.initials: M
authors.lastname: Nuñez
authors.affiliation: Laboratory of Functional and Molecular Glycomics, Institute of Biology and Experimental Medicine (IBYME), CONICET, Buenos Aires, Argentina; Laboratory of Immunopathology, IBYME, CONICET, Buenos Aires, Argentina.
authors.forename: Luciano G
authors.initials: LG
authors.lastname: Morosi
authors.affiliation: Institute of Biochemistry and Biophysics (IQUIFIB), UBA-CONICET, Biological Chemistry Department, School of Pharmacy and Biochemistry, UBA, Buenos Aires, Argentina.
authors.forename: Héctor R
authors.initials: HR
authors.lastname: Quinta
authors.affiliation: Institute of Biochemistry and Biophysics (IQUIFIB), UBA-CONICET, Biological Chemistry Department, School of Pharmacy and Biochemistry, UBA, Buenos Aires, Argentina.
authors.forename: María V
authors.initials: MV
authors.lastname: Espelt
authors.affiliation: Institute of Biochemistry and Biophysics (IQUIFIB), UBA-CONICET, Biological Chemistry Department, School of Pharmacy and Biochemistry, UBA, Buenos Aires, Argentina.
authors.forename: María F
authors.initials: MF
authors.lastname: Troncoso
authors.affiliation: Institute of Biochemistry and Biophysics (IQUIFIB), UBA-CONICET, Biological Chemistry Department, School of Pharmacy and Biochemistry, UBA, Buenos Aires, Argentina.
authors.forename: Carlota
authors.initials: C
authors.lastname: Wolfenstein-Todel
authors.affiliation: Laboratory of Functional and Molecular Glycomics, Institute of Biology and Experimental Medicine (IBYME), CONICET, Buenos Aires, Argentina.
authors.forename: Karina V
authors.initials: KV
authors.lastname: Mariño
authors.affiliation: Institute of Studies in Humoral Immunology, University of Buenos Aires (UBA) and National Council Research (CONICET), Microbiology, Immunology and Biotechnology Department, School of Pharmacy and Biochemistry, University of Buenos Aires (UBA), Buenos Aires, Argentina.
authors.forename: Emilio L
authors.initials: EL
authors.lastname: Malchiodi
authors.affiliation: Laboratory of Immunopathology, IBYME, CONICET, Buenos Aires, Argentina; Faculty of Exact and Natural Sciences, UBA, Buenos Aires, Argentina.
authors.forename: Gabriel A
authors.initials: GA
authors.lastname: Rabinovich
authors.affiliation: Institute of Biochemistry and Biophysics (IQUIFIB), UBA-CONICET, Biological Chemistry Department, School of Pharmacy and Biochemistry, UBA, Buenos Aires, Argentina. Electronic address: mt_elola@yahoo.com.
authors.forename: María T
authors.initials: MT
authors.lastname: Elola
mesh_terms: D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism*; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology; D002448:Cell Adhesion / Q000235:genetics; D015816:Cell Adhesion Molecules, Neuronal / Q000235:genetics / Q000378:metabolism*; D002450:Cell Communication / Q000235:genetics; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000235:genetics; D042783:Endothelial Cells / Q000378:metabolism; D005260:Female; D005326:Fetal Proteins / Q000235:genetics / Q000378:metabolism*; D037161:Galectins / Q000235:genetics / Q000378:metabolism*; D006031:Glycosylation; D006801:Humans; D011485:Protein Binding; D060066:Protein Interaction Maps / Q000235:genetics*; D013499:Surface Properties; D020410:Activated-Leukocyte Cell Adhesion Molecule
chemical_list: D015703:Antigens, CD; D015816:Cell Adhesion Molecules, Neuronal; D005326:Fetal Proteins; D037161:Galectins; C105613:ALCAM protein, human; D020410:Activated-Leukocyte Cell Adhesion Molecule; C091991:LGALS8 protein, human
keywords: ALCAM/CD166; Breast cancer cell; Galectin-8; Physical interaction; Receptor segregation