title: Early adhesion induces interaction of FAK and Fyn in lipid domains and activates raft-dependent Akt signaling in SW480 colon cancer cells.
abstract: Integrin-dependent interaction of epithelial tumor cells with extracellular matrix (ECM) is critical for their migration, but also for hematogenous dissemination. Elevated expression and activity of Src family kinases (SFKs) in colon cancer cells is often required in the disease progression. In this work, we highlighted how focal adhesion kinase (FAK) and SFKs interacted and we analyzed how PI3K/Akt and MAPK/Erk1/2 signaling pathways were activated in early stages of colon cancer cell adhesion. During the first hour, integrin engagement triggered FAK-Y397 phosphorylation and a fraction of FAK was located in lipid rafts/caveolae domains where it interacted with Fyn. The FAK-Y861 and/or -Y925 phosphorylations led to a subsequently FAK translocation out of lipid domains. In parallel, a PI3K/Akt pathway dependent of lipid microdomain integrity was activated. In contrast, the MAPK/Erk1/2 signaling triggered by adhesion increased during at least 4 h and was independent of cholesterol disturbing. Thus, FAK/Fyn interaction in lipid microdomains and a Akt-1 activation occurred at the same time during early contact with ECM suggesting a specific signaling dependent of lipid rafts/caveolae domains.
authors.affiliation: INSERM UMR 911, Centre de Recherche en Oncologie biologique et Oncopharmacologie, Aix-Marseille University, Faculté de Pharmacie, 27, bld Jean Moulin, 13285 Marseille cedex 05, France. gilbert.baillat@pharmacie.univ-mrs.fr
authors.forename: Gilbert
authors.initials: G
authors.lastname: Baillat
authors.forename: Carole
authors.initials: C
authors.lastname: Siret
authors.forename: Estelle
authors.initials: E
authors.lastname: Delamarre
authors.forename: Jose
authors.initials: J
authors.lastname: Luis
mesh_terms: D015153:Blotting, Western; D021941:Caveolae / Q000378:metabolism; D002448:Cell Adhesion / Q000187:drug effects / Q000502:physiology*; D002784:Cholesterol / Q000378:metabolism; D003110:Colonic Neoplasms / Q000378:metabolism* / Q000473:pathology; D051416:Focal Adhesion Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D047468:Immunoprecipitation; D016023:Integrins; D021962:Membrane Microdomains; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010766:Phosphorylation; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D051076:Proto-Oncogene Proteins c-fyn / Q000378:metabolism*; D015398:Signal Transduction; D014162:Transfection; D014407:Tumor Cells, Cultured; D014443:Tyrosine / Q000378:metabolism; D047392:beta-Cyclodextrins / Q000494:pharmacology; D019061:src-Family Kinases / Q000378:metabolism
chemical_list: D016023:Integrins; D047392:beta-Cyclodextrins; C108732:methyl-beta-cyclodextrin; D014443:Tyrosine; D002784:Cholesterol; D019869:Phosphatidylinositol 3-Kinases; C494957:FYN protein, human; D051416:Focal Adhesion Protein-Tyrosine Kinases; D051076:Proto-Oncogene Proteins c-fyn; D019061:src-Family Kinases; D051057:Proto-Oncogene Proteins c-akt; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3