title: Tetraspan and beta-1 integrins expression pattern of the epithelial lung adenocarcinoma cell line A549 and its sensitivity to divalent cations.
abstract: BACKGROUND
  Tetraspans are ubiquitous integral transmembrane molecules associated on the cell surface with such adhesion molecules as integrins. Their expression has been shown to vary in tumors, but has seldom been described on lung tumoral epithelial cells, and the conditions required for a proper association of tetraspans and integrins have not yet been fully explored.
  
  
  METHODS
  We investigated the expression of 10 tetraspans and six beta1 integrins on the tumoral lung epithelial cell line A549. Cells were examined both in quantitative flow cytometry and as monolayers, under normal or chelated conditions, in order to determine the cation dependency of their expression.
  
  
  RESULTS
  Five tetraspans and four beta1 integrins are expressed on the membrane of A549 cells. Both quantitative and qualitative surface and cytoplasmic modifications of this pattern were induced in chelating conditions, suggesting the importance of divalent cations for the expression of these molecules.
  
  
  CONCLUSIONS
  These data indicate that a specific pattern of tetraspans and integrins, relying strongly on the availability of divalent cations in the microenvironment, is expressed by tumoral epithelial cells.
authors.affiliation: Laboratoire d'Immunologie, Faculté de Médecine de Nancy, Vandoeuvre lès Nancy, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Massin
authors.forename: Eric
authors.initials: E
authors.lastname: Rubinstein
authors.forename: Gilbert C
authors.initials: GC
authors.lastname: Faure
authors.forename: Yves
authors.initials: Y
authors.lastname: Martinet
authors.forename: Claude
authors.initials: C
authors.lastname: Boucheix
authors.forename: Marie C
authors.initials: MC
authors.lastname: Béné
mesh_terms: D000230:Adenocarcinoma; D015703:Antigens, CD / Q000378:metabolism*; D002413:Cations, Divalent / Q000378:metabolism*; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism; D002614:Chelating Agents / Q000494:pharmacology; D004492:Edetic Acid / Q000494:pharmacology; D005434:Flow Cytometry; D006801:Humans; D039641:Integrin beta Chains / Q000378:metabolism*; D008175:Lung Neoplasms; D008565:Membrane Proteins / Q000378:metabolism*; D020545:Respiratory Mucosa / Q000378:metabolism*
chemical_list: D015703:Antigens, CD; D002413:Cations, Divalent; D002614:Chelating Agents; D039641:Integrin beta Chains; D008565:Membrane Proteins; D004492:Edetic Acid