title: Src protein kinase pp60c-src influences adhesion stabilization of HT-29 colon carcinoma cells to extracellular matrix components under dynamic conditions of laminar flow.
abstract: Tumor cell adhesion to extracellular matrix (ECM) and its stabilization are important determinants in metastasis formation, and they are mediated, in part, by integrins and regulated by a variety of protein kinases. Protein tyrosine kinase pp60c-src is found in adhesion-dependent focal adhesion plaques where it may regulate different integrin-mediated signaling cascades. Using human HT-29 colon carcinoma cells stably transfected with pp60c-src--specific antisense oligonucleotides (HT-29AS15), we investigated the role of pp60c-src in integrin-mediated adhesion and its stabilization to ECM components collagen I or IV under static and laminar fluid flow conditions. Under static adhesion conditions transfection of pp60c-src antisense oligonucleotides did not modify adhesive properties. Phosphorylation of focal adhesion kinase (FAK) and paxillin induced by static adhesion to collagen I or IV were similar in HT-29P and HT-29AS15 cells. However, using hydrodynamic conditions in a laminar flow chamber we found a slight reduction in early adhesion events and an even greater difference in adhesion stabilization rates (ASRs). The transfected cells showed a significant reduction in their ability to withstand shear forces and stabilize adhesive bounds. These changes correlated with the cellular expression levels of pp60c-src. Our results suggest that pp60c-src may be involved in stabilization of dynamic HT-29 cell adhesion to ECM components, and this kinase appears to be part of a mechanosensory protein complex during integrin-mediated cell adhesion.
authors.affiliation: Institute for Molecular Medicine, Huntington Beach, CA, USA. haier@uni-muenster.de
authors.forename: Jörg
authors.initials: J
authors.lastname: Haier
authors.forename: Garry E
authors.initials: GE
authors.lastname: Gallick
authors.forename: Garth L
authors.initials: GL
authors.lastname: Nicolson
mesh_terms: D002448:Cell Adhesion; D003094:Collagen / Q000378:metabolism; D015179:Colorectal Neoplasms / Q000378:metabolism* / Q000473:pathology*; D003598:Cytoskeletal Proteins / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism*; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D019073:HT29 Cells; D006801:Humans; D051419:Paxillin; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D016392:Proto-Oncogene Proteins pp60(c-src) / Q000378:metabolism*; D013314:Stress, Mechanical; D014407:Tumor Cells, Cultured
chemical_list: D003598:Cytoskeletal Proteins; C496061:PXN protein, human; D051419:Paxillin; D010750:Phosphoproteins; D003094:Collagen; D011505:Protein-Tyrosine Kinases; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; C496050:PTK2 protein, human; D016392:Proto-Oncogene Proteins pp60(c-src)