title: Targeting focal adhesion assembly by ethoxyfagaronine prevents lymphoblastic cell adhesion to fibronectin.
abstract: BACKGROUND
  Leukemic cell adhesion to proteins of the bone marrow microenvironment provides signals which control morphology, motility and cell survival. We described herein the ability of ethoxyfagaronine (etxfag), a soluble synthetic derivative of fagaronine, to prevent leukemic cell adhesion to fibronectin peptide (FN/V).
  
  
  METHODS
  Phosphorylation of fak and pyk2 were evaluated by immunoblotting. Labelled proteins were localized by confocal microscopy. PI 3-kinase activity was evaluated by in vitro kinase assay.
  
  
  RESULTS
  Subtoxic concentration of etxfag reduced L1210 cell adhesion to FN/V dependently of β1 integrin engagement. Etxfag impaired FN-dependent formation of β1 clustering without modifying β1 expression at the cell membrane. This was accompanied by a decrease of focal adhesion number, a diminution of fak and pyk2 phosphorylation at Tyr-576, Tyr-861 and Tyr-579, respectively leading to their dissociations from β1 integrin and inhibition of PI 3-kinase activity. Etxfag also induced a cell retraction accompanied by a redistribution of phosphorylated fak and pyk2 in the perinuclear region and lipid raft relocalization.
  
  
  CONCLUSIONS
  Through its anti-adhesive potential, etxfag, combined with conventional cytotoxic drugs could be potentially designed as a new anti-leukemic drug.
authors.affiliation: Université de Reims Champagne Ardenne, CNRS MEDyC, Laboratoire SiRMa, IFR Interactions Cellules-Microenvironnement, France.
authors.forename: F
authors.initials: F
authors.lastname: Ouchani
authors.forename: J
authors.initials: J
authors.lastname: Devy
authors.forename: A
authors.initials: A
authors.lastname: Rusciani
authors.forename: J J
authors.initials: JJ
authors.lastname: Helesbeux
authors.forename: S
authors.initials: S
authors.lastname: Salesse
authors.forename: I
authors.initials: I
authors.lastname: Letinois
authors.forename: D
authors.initials: D
authors.lastname: Gras-Billart
authors.forename: L
authors.initials: L
authors.lastname: Duca
authors.forename: O
authors.initials: O
authors.lastname: Duval
authors.forename: L
authors.initials: L
authors.lastname: Martiny
authors.forename: E
authors.initials: E
authors.lastname: Charpentier
mesh_terms: D000818:Animals; D053119:Benzophenanthridines / Q000494:pharmacology*; D015153:Blotting, Western; D002448:Cell Adhesion / Q000187:drug effects; D045744:Cell Line, Tumor; D005353:Fibronectins / Q000378:metabolism*; D051417:Focal Adhesion Kinase 1 / Q000378:metabolism; D051418:Focal Adhesion Kinase 2 / Q000378:metabolism; D022001:Focal Adhesions / Q000187:drug effects* / Q000378:metabolism; D019012:Integrin beta1 / Q000235:genetics / Q000378:metabolism*; D007939:Leukemia L1210 / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D007945:Leukemia, Lymphoid / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D021962:Membrane Microdomains / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D018613:Microscopy, Confocal; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D021381:Protein Transport / Q000187:drug effects; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014443:Tyrosine / Q000378:metabolism
chemical_list: D053119:Benzophenanthridines; D005353:Fibronectins; D019012:Integrin beta1; C568781:N-methyl-12-ethoxy-2-hydroxy-3,8,9-trimethoxybenzo(c)phenanthridinium; D014443:Tyrosine; D019869:Phosphatidylinositol 3-Kinases; D051417:Focal Adhesion Kinase 1; D051418:Focal Adhesion Kinase 2; C496051:Ptk2 protein, mouse; C496053:Ptk2b protein, mouse