Rapid tyrosine phosphorylation of focal adhesion kinase, paxillin, and p130Cas by gastrin in human colon cancer cells.
Although the expression of CCK(2) receptors is widely reported in human colorectal cancers, little is known on its role in mediating the proliferative effects of mature amidated gastrin (G17 amide) on colorectal cancers. The purpose of the present study was to determine the effects of G17 amide on tyrosine phosphorylation of focal adhesion kinase (FAK), paxillin, and p130 Crk-associated substrate (p130(Cas)) in Colo 320 cells, a human colorectal cancer cell line which expresses CCK(2) receptors. By immunoprecipitation and immunoblotting, an increase in tyrosine phosphorylation of FAK (tyrosine-397), paxillin (tyrosine-31), and p130(Cas) was detected in a time- and dose-dependent manner. Overexpression of CCK(2) receptors in Colo 320 cells (Colo 320 WT) by stable transfection with the human CCK(2) receptor cDNA resulted in an increased tyrosine phosphorylation of FAK, paxillin, and p130(Cas). After incubation with 1 microM L-365,260, a specific CCK(2) receptor antagonist, this increase was completely inhibited. Our results demonstrate that in human colon cancer cells, gastrin caused a rapid tyrosine phosphorylation of FAK, paxillin, and p130(Cas) by activation of CCK(2) receptor. The phosphorylation of these proteins might be important in mediating gastrin effects on proliferation, apoptosis, and metastasis.
Yu
Hong-Gang
HG
Laboratory for Molecular Gastroenterology, Department of Medicine I, St. Josef-Hospital, Ruhr-University of Bochum, Gudrunstr. 56, D-44791, Bochum, Germany.
Schrader
Henning
H
Otte
Jan-Michel
JM
Schmidt
Wolfgang E
WE
Schmitz
Frank
F
D003110:Colonic Neoplasms / Q000473:pathology; D050719:Crk-Associated Substrate Protein; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D003720:Densitometry; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D005755:Gastrins / Q000378:metabolism*; D006801:Humans; D051419:Paxillin; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011506:Proteins; D043887:Receptor, Cholecystokinin B / Q000235:genetics / Q000378:metabolism; D050717:Retinoblastoma-Like Protein p130; D014407:Tumor Cells, Cultured; D014443:Tyrosine / Q000378:metabolism
C493841:BCAR1 protein, human; D050719:Crk-Associated Substrate Protein; D003598:Cytoskeletal Proteins; D005755:Gastrins; C496061:PXN protein, human; D051419:Paxillin; D010750:Phosphoproteins; D011506:Proteins; D043887:Receptor, Cholecystokinin B; D050717:Retinoblastoma-Like Protein p130; D014443:Tyrosine; D011505:Protein-Tyrosine Kinases; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; C496050:PTK2 protein, human