title: Endothelial integrin α3β1 stabilizes carbohydrate-mediated tumor/endothelial cell adhesion and induces macromolecular signaling complex formation at the endothelial cell membrane.
abstract: Blood borne metastatic tumor cell adhesion to endothelial cells constitutes a critical rate-limiting step in hematogenous cancer metastasis. Interactions between cancer associated carbohydrate Thomsen-Friedenreich antigen (TF-Ag) and endothelium-expressed galectin-3 (Gal-3) have been identified as the leading molecular mechanism initiating tumor/endothelial cell adhesion in several types of cancer. However, it is unknown how these rather weak and transient carbohydrate/lectin mediated interactions are stabilized. Here, using Western blot and LC tandem mass spectrometry analyses of pull-downs utilizing TF-Ag loaded gold nanoparticles, we identified Gal-3, endothelial integrin α3β1, Src kinase, as well as 5 additional molecules mapping onto focal adhesion pathway as parts of the macromolecular complexes formed at the endothelial cell membranes downstream of TF-Ag/Gal-3 interactions. In a modified parallel flow chamber assay, inhibiting α3β1 integrin greatly reduced the strength of tumor/endothelial cell interactions without affecting the initial cancer cell adhesion. Further, the macromolecular complex induced by TF-Ag/Gal-3/α3β1 interactions activates Src kinase, p38, and ERK1/2, pathways in endothelial cells in a time- and α3β1-dependent manner. We conclude that, following the initial metastatic cell attachment to endothelial cells mediated by TF-Ag/Gal-3 interactions, endothelial integrin α3β1 stabilizes tumor/endothelial cell adhesion and induces the formation of macromolecular signaling complex activating several major signaling pathways in endothelial cells.
authors.affiliation: Research Service, Harry S. Truman Memorial Veterans Hospital, Columbia, MO.
authors.forename: Olga V
authors.initials: OV
authors.lastname: Glinskii
authors.forename: Feng
authors.initials: F
authors.lastname: Li
authors.forename: Landon S
authors.initials: LS
authors.lastname: Wilson
authors.forename: Stephen
authors.initials: S
authors.lastname: Barnes
authors.forename: Kate
authors.initials: K
authors.lastname: Rittenhouse-Olson
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: Barchi
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Pienta
authors.forename: Vladislav V
authors.initials: VV
authors.lastname: Glinsky
mesh_terms: D015295:Antigens, Tumor-Associated, Carbohydrate / Q000378:metabolism*; D002448:Cell Adhesion / Q000502:physiology*; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism; D042783:Endothelial Cells / Q000737:chemistry / Q000502:physiology*; D037502:Galectin 3 / Q000032:analysis / Q000378:metabolism*; D006801:Humans; D039201:Integrin alpha3beta1 / Q000032:analysis / Q000378:metabolism*; D020935:MAP Kinase Signaling System; D046911:Macromolecular Substances / Q000378:metabolism; D008297:Male; D009362:Neoplasm Metastasis / Q000503:physiopathology*; D011471:Prostatic Neoplasms / Q000378:metabolism*; D019061:src-Family Kinases / Q000032:analysis / Q000378:metabolism
chemical_list: D015295:Antigens, Tumor-Associated, Carbohydrate; D037502:Galectin 3; D039201:Integrin alpha3beta1; D046911:Macromolecular Substances; C016467:Thomsen-Friedenreich antigen; D019061:src-Family Kinases