title: Inhibition of focal adhesion kinase expression or activity disrupts epidermal growth factor-stimulated signaling promoting the migration of invasive human carcinoma cells.
abstract: Elevated focal adhesion kinase (FAK) expression in human tumor cells has been correlated with an increased cell invasion potential. In cell culture, studies with FAK-null fibroblasts have shown that FAK function is required for cell migration. To determine the role of elevated FAK expression in facilitating epidermal growth factor (EGF)-stimulated human adenocarcinoma (A549) cell motility, antisense oligonucleotides were used to reduce FAK protein expression >75%. Treatment of A549 cells with FAK antisense (ISIS 15421) but not a mismatched control (ISIS 17636) oligonucleotide resulted in reduced EGF-stimulated p130(Cas)-Src complex formation, c-Jun NH(2)-terminal kinase (JNK) activation, directed cell motility, and serum-stimulated cell invasion through Matrigel. Because residual FAK protein in ISIS 15421-treated A549 cells was highly phosphorylated at the Tyr-397/Src homology (SH)2 binding site, expression of the FAK COOH-terminal domain (FRNK) was also used as an inhibitor of FAK function. Adenoviral-mediated infection and expression of FRNK promoted FAK dephosphorylation at Tyr-397, resulted in reduced EGF-stimulated JNK as well as extracellular-regulated kinase 2 (ERK2) kinase activation, inhibited matrix metalloproteinase-9 (MMP-9) secretion, and potently blocked both random and EGF-stimulated A549 cell motility. Equivalent expression of a FRNK (S-1034) point-mutant that did not promote FAK dephosphorylation also did not affect EGF-stimulated signaling or cell motility. Dose-dependent reduction in EGF-stimulated A549 motility was observed with the PD98059 MEK1 inhibitor and the batimastat (BB-94) inhibitor of MMP activity, but not with the SB203580 inhibitor of p38 kinase. Finally, comparisons between normal, FAK-null, and FAK-reconstituted fibroblasts revealed that FAK enhanced EGF-stimulated JNK and ERK2 kinase activation that was required for cell motility. These data indicate that FAK functions as an important signaling platform to coordinate EGF-stimulated cell migration in human tumor cells and support a role for inhibitors of FAK expression or activity in the control of neoplastic cell invasion.
authors.affiliation: The Scripps Research Institute, La Jolla, California 92037, USA.
authors.forename: C R
authors.initials: CR
authors.lastname: Hauck
authors.forename: D J
authors.initials: DJ
authors.lastname: Sieg
authors.forename: D A
authors.initials: DA
authors.lastname: Hsia
authors.forename: J C
authors.initials: JC
authors.lastname: Loftus
authors.forename: W A
authors.initials: WA
authors.lastname: Gaarde
authors.forename: B P
authors.initials: BP
authors.lastname: Monia
authors.forename: D D
authors.initials: DD
authors.lastname: Schlaepfer
mesh_terms: D000230:Adenocarcinoma / Q000201:enzymology* / Q000473:pathology; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology*; D004789:Enzyme Activation; D004815:Epidermal Growth Factor / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D006801:Humans; D020935:MAP Kinase Signaling System / Q000187:drug effects / Q000502:physiology; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D061965:Matrix Metalloproteinase Inhibitors; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009361:Neoplasm Invasiveness; D016376:Oligonucleotides, Antisense / Q000235:genetics / Q000494:pharmacology; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors* / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology; D014407:Tumor Cells, Cultured
chemical_list: D061965:Matrix Metalloproteinase Inhibitors; D016376:Oligonucleotides, Antisense; D004815:Epidermal Growth Factor; C113183:FAK-related nonkinase; D011505:Protein-Tyrosine Kinases; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; C496050:PTK2 protein, human; D020928:Mitogen-Activated Protein Kinases; D020780:Matrix Metalloproteinase 9