51
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Zoppi N, Barlati S, Colombi M. FAK-independent alphavbeta3 integrin-EGFR complexes rescue from anoikis matrix-defective fibroblasts. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2008; 1783:1177-88. [PMID: 18405669 DOI: 10.1016/j.bbamcr.2008.03.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2007] [Revised: 02/20/2008] [Accepted: 03/05/2008] [Indexed: 01/08/2023]
Abstract
Extracellular matrix (ECM) binding to integrin receptors regulates cell cycle progression and survival. In adherent cells, ECM disassembly induces anoikis, the apoptotic pathway switched on by loss of adhesion. ECM-deficient Ehlers-Danlos syndrome (EDS) fibroblasts, to adhere to rare fibronectin (FN) fibrils, and to proliferate, only organize, as FN receptor, the alphavbeta3 integrin. We report that in EDS cells the alphavbeta3 integrin is bound to talin and vinculin, but not to tensin, and that actin cytoskeleton is disorganized. Furthermore, in EDS cells Bcl-2 is down-regulated and caspases are active. We provide evidence that the antibody-mediated alphavbeta3 integrin or the FN inhibition induces anoikis in EDS cells. The alphavbeta3 integrin transduces survival signals to pp60src-mediated tyrosine phosphorylated paxillin, instead than to FAK, and interacts with EGF receptor (EGFR). This complex, when activated by EGF and FN, signals for the rescue of EDS cells from anoikis. Therefore, EDS cells, through the alphavbeta3 integrin-EGFR complexes, engage a paxillin- but not FAK-mediated pathway of cell survival.
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Affiliation(s)
- Nicoletta Zoppi
- Division of Biology and Genetics, Department of Biomedical Sciences and Biotechnology, University of Brescia, Viale Europa 11, 25123 Brescia, Italy
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52
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Hayasaka H, Martin KH, Hershey ED, Parsons JT. Disruption of FRNK expression by gene targeting of the intronic promoter within the focal adhesion kinase gene. J Cell Biochem 2008; 102:947-54. [PMID: 17440961 DOI: 10.1002/jcb.21329] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
FRNK, a non-catalytic variant of focal adhesion kinase (FAK), is expressed in major blood vessels throughout mouse development and is postulated to play a role in regulating cell adhesion and signaling in vascular smooth muscle cells (VSMCs). The FRNK transcriptional start site lies within an intron of the FAK gene, suggesting that the FRNK gene is a "gene within a gene". Here, we identified a 1 kb intronic sequence of the FAK gene that is necessary for endogenous FRNK expression. Deletion of this sequence in gene-targeted mice abolished FRNK expression, showing the direct involvement of the FAK intron in the regulation of FRNK expression. The level of FAK expression was normal in the FRNK-deficient mice, indicating that FAK and FRNK are transcriptionally regulated by distinct promoters. The FRNK-deficient mice were viable, fertile, and displayed no obvious histological abnormalities in any of the major blood vessels. Western blot analysis showed that FRNK-deficient and wild-type (WT) cells had comparable levels of steady-state and adhesion-dependent FAK autophosphorylation. Despite the fact that ectopic expression of FRNK suppresses focal adhesion formation in cultured cells, these results suggest that endogenous FRNK is not essential for development or the formation of the mouse vasculature.
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Affiliation(s)
- Haruko Hayasaka
- Department of Microbiology, University of Virginia Health System, Charlottesville, Virginia 22908, USA
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53
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Kamarajan P, Kapila YL. An altered fibronectin matrix induces anoikis of human squamous cell carcinoma cells by suppressing integrin alpha v levels and phosphorylation of FAK and ERK. Apoptosis 2008; 12:2221-31. [PMID: 17879163 DOI: 10.1007/s10495-007-0138-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Fibronectin regulates many cellular processes, including migration, proliferation, differentiation, and survival. Previously, we showed that squamous cell carcinoma (SCC) cell aggregates escape suspension-induced, p53-mediated anoikis by engaging in fibronectin-mediated survival signals through focal adhesion kinase (FAK). Here we report that an altered matrix, consisting of a mutated, nonfunctional high-affinity heparin-binding domain and the V region of fibronectin (V+H-), induced anoikis in human SCC cells; this response was blocked by inhibitors of caspase-8 and caspase-3. Anoikis was mediated by downregulation of integrin alpha v in a panel of SCC cells and was shown to be proteasome-dependent. Overexpression of integrin alpha v or FAK inhibited the increase in caspase-3 activation and apoptosis, whereas suppression of alpha v or FAK triggered a further significant increase in apoptosis, indicating that the apoptosis was mediated by suppression of integrin alpha v levels and dephosphorylation of FAK. Treatment with V+H- decreased the phosphorylation of extracellular signal-regulated kinase (ERK) 1 and 2, and direct activation of ERK by constitutively active MEK1, an ERK kinase, increased ERK1 and ERK2 phosphorylation and inhibited the increase in apoptosis induced by V+H-. ERK acted downstream from alpha v and FAK signals, since alpha v and FAK overexpression inhibited both the decrease in ERK phosphorylation and the increase in anoikis triggered by V+H-. These findings provide evidence that mutations in the high-affinity heparin-binding domain in association with the V region of fibronectin, or altered fibronectin matrices, induce anoikis in human SCC cells by modulating integrin alpha v-mediated phosphorylation of FAK and ERK.
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Affiliation(s)
- Pachiyappan Kamarajan
- Department of Periodontics and Oral Medicine, University of Michigan, School of Dentistry, 1011 N. University Ave, Room 5223, Ann Arbor, MI 48109-1078, USA
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54
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Hebner C, Weaver VM, Debnath J. Modeling morphogenesis and oncogenesis in three-dimensional breast epithelial cultures. ANNUAL REVIEW OF PATHOLOGY 2008; 3:313-339. [PMID: 18039125 DOI: 10.1146/annurev.pathmechdis.3.121806.151526] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Three-dimensional (3D) epithelial culture systems recreate the cardinal features of glandular epithelium in vivo and represent a valuable tool for modeling breast cancer initiation and progression in a structurally appropriate context. 3D models have emerged as a powerful method to interrogate the biological activities of cancer genes and oncogenic pathways, and recent studies have poignantly illustrated their utility in dissecting the emerging role of tensional force in regulating epithelial tissue homeostasis. We review how 3D models are being used to investigate fundamental cellular and biophysical mechanisms associated with breast cancer progression that have not been readily amenable to traditional genetic or biochemical analysis.
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Affiliation(s)
- Christy Hebner
- Department of Surgery and Center for Bioengineering and Tissue Regeneration, University of California, San Francisco, CA, USA.
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55
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Morgan MR, Humphries MJ, Bass MD. Synergistic control of cell adhesion by integrins and syndecans. Nat Rev Mol Cell Biol 2007; 8:957-69. [PMID: 17971838 PMCID: PMC3329926 DOI: 10.1038/nrm2289] [Citation(s) in RCA: 428] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The ability of cells to adhere to each other and to their surrounding extracellular matrices is essential for a multicellular existence. Adhesion provides physical support for cells, regulates cell positioning and enables microenvironmental sensing. The integrins and the syndecans are two adhesion receptor families that mediate adhesion, but their relative and functional contributions to cell-extracellular matrix interactions remain obscure. Recent advances have highlighted connections between the signalling networks that are controlled by these families of receptors. Here we survey the evidence that synergistic signalling is involved in controlling adhesive function and the regulation of cell behaviour in response to the external environment.
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Affiliation(s)
- Mark R. Morgan
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Michael Smith Building, Oxford Road, Manchester, M13 9PT, United Kingdom
| | - Martin J. Humphries
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Michael Smith Building, Oxford Road, Manchester, M13 9PT, United Kingdom
| | - Mark D. Bass
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Michael Smith Building, Oxford Road, Manchester, M13 9PT, United Kingdom
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56
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Bhoopathi P, Chetty C, Kunigal S, Vanamala SK, Rao JS, Lakka SS. Blockade of tumor growth due to matrix metalloproteinase-9 inhibition is mediated by sequential activation of beta1-integrin, ERK, and NF-kappaB. J Biol Chem 2007; 283:1545-1552. [PMID: 17991734 DOI: 10.1074/jbc.m707931200] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We previously showed that matrix metalloproteinase (MMP)-9 inhibition using an adenovirus-mediated delivery of MMP-9 small interfering RNA (Ad-MMP-9), caused senescence in medulloblastoma cells. Regardless of whether or not Ad-MMP-9 would induce apoptosis, the possible signaling mechanism is still obscure. In this report, we demonstrate that Ad-MMP-9 induced apoptosis in DAOY cells as determined by propidium iodide and terminal deoxynucleotidyltransferase-mediated nick end labeling staining. Ad-MMP-9 infection induced the release of cytochrome c, activation of caspase-9 and -3, and cleavage of poly(ADP-ribose) polymerase. Ad-MMP-9 infection stimulated ERK, and electrophoretic mobility shift assay indicated an increase in NF-kappaB activation. ERK inhibition, using a kinase-dead mutant for ERK, ameliorated NF-kappaB activation and caspase-mediated apoptosis in Ad-MMP-9-infected cells. beta1-Integrin expression in Ad-MMP-9-infected cells also increased, and this increase was reversed by the reintroduction of MMP-9. We found that the addition of beta1 blocking antibodies inhibited Ad-MMP-9-induced ERK activation. Taken together, our results indicate that MMP-9 inhibition induces apoptosis due to altered beta1-integrin expression in medulloblastoma. In addition, ERK activation plays an active role in this process and functions upstream of NF-kappaB activation to initiate the apoptotic signal.
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Affiliation(s)
- Praveen Bhoopathi
- Program of Cancer Biology, Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine at Peoria, Peoria, Illinois 61605
| | - Chandramu Chetty
- Program of Cancer Biology, Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine at Peoria, Peoria, Illinois 61605
| | - Sateesh Kunigal
- Program of Cancer Biology, Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine at Peoria, Peoria, Illinois 61605
| | - Sravan K Vanamala
- Program of Cancer Biology, Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine at Peoria, Peoria, Illinois 61605
| | - Jasti S Rao
- Program of Cancer Biology, Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine at Peoria, Peoria, Illinois 61605; Department of Neurosurgery, University of Illinois College of Medicine at Peoria, Peoria, Illinois 61605
| | - Sajani S Lakka
- Program of Cancer Biology, Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine at Peoria, Peoria, Illinois 61605.
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57
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Frasca F, Pandini G, Malaguarnera R, Mandarino A, Messina RL, Sciacca L, Belfiore A, Vigneri R. Role of c-Abl in Directing Metabolic versus Mitogenic Effects in Insulin Receptor Signaling. J Biol Chem 2007; 282:26077-88. [PMID: 17620332 DOI: 10.1074/jbc.m705008200] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
c-Abl is a cytoplasmic tyrosine kinase involved in several signal transduction pathways. Here we report that c-Abl is involved also in insulin receptor signaling. Indeed, c-Abl tyrosine kinase is activated upon insulin stimulation. Inhibition of c-Abl tyrosine kinase by STI571 attenuates the effect of insulin on Akt/GSK-3beta phosphorylation and glycogen synthesis, and at the same time, it enhances the effect of insulin on ERK activation, cell proliferation, and migration. This effect of STI571 is specific to c-Abl inhibition, because it does not occur in Abl-null cells and is restored in c-Abl-reconstituted cells. Numerous evidences suggest that focal adhesion kinase (FAK) is involved in mediating this c-Abl effect. First, anti-phosphotyrosine blots indicate that c-Abl tyrosine kinase activation is concomitant with FAK dephosphorylation in response to insulin, whereas c-Abl inhibition is accompanied by FAK phosphorylation in response to insulin, a response similar to that observed with IGF-I. Second, the c-Abl effects on insulin signaling are not observed in cells devoid of FAK (FAK(-/-) cells). Taken together these results suggest that c-Abl activation by insulin, via a modification of FAK response, may play an important role in directing mitogenic versus metabolic insulin receptor signaling.
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Affiliation(s)
- Francesco Frasca
- Endocrinologia, Dipartimento di Medicina Interna e di Medicina Specialistica, Università di Catania, Ospedale Garibaldi, Nesima, 95122 Catania, Italy.
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58
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Abstract
Liver fibrosis, a wound-healing response to a variety of chronic stimuli, is characterized by excessive deposition of extracellular matrix (ECM) proteins, of which type I collagen predominates. This alters the structure of the liver leading to organ dysfunction. The activated hepatic stellate cell (HSC) is primarily responsible for excess collagen deposition during liver fibrosis. Two important aspects are involved in mediating the fibrogenic response: first the HSC becomes directly fibrogenic by synthesizing ECM proteins; second, the activated HSC proliferates, effectively amplifying the fibrogenic response. Although the precise mechanisms responsible for HSC activation remain elusive, substantial insight is being gained into the molecular mechanisms responsible for ECM production and cell proliferation in the HSC. The activated HSC becomes responsive to both proliferative (platelet-derived growth factor) and fibrogenic (transforming growth factor-beta[TGF-beta]) cytokines. It is becoming clear that these cytokines activate both mitogen-activated protein kinase (MAPK) signaling, involving p38, and focal adhesion kinase-phosphatidylinositol 3-kinase-Akt-p70 S6 kinase (FAK-PI3K-Akt-p70(S6K)) signaling cascades. Together, these regulate the proliferative response, activating cell cycle progression as well as collagen gene expression. In addition, signaling by both TGF-beta, mediated by Smad proteins, and p38 MAPK influence collagen gene expression. Smad and p38 MAPK signaling have been found to independently and additively regulate alpha1(I) collagen gene expression by transcriptional activation while p38 MAPK, but not Smad signaling, increases alpha1(I) collagen mRNA stability, leading to increased synthesis and deposition of type I collagen. It is anticipated that by understanding the molecular mechanisms responsible for HSC proliferation and excess ECM production new therapeutic targets will be identified for the treatment of liver fibrosis.
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Affiliation(s)
- Christopher J Parsons
- Division of Gastroenterology and Hepatology, Department of Medicine, University of North Carolina, Chapel Hill, North Carolina 27599-7032, USA
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59
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Yasmeen A, Bismar TA, Al Moustafa AE. ErbB receptors and epithelial-cadherin-catenin complex in human carcinomas. Future Oncol 2007; 2:765-81. [PMID: 17155902 DOI: 10.2217/14796694.2.6.765] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The ErbB family of receptor tyrosine kinases have important roles in maintaining normal epithelial cell function. The ErbBs are involved in the interaction between cells and cell-matrix adhesion molecules and have proven critical in maintaining the integrity of the epithelial cell environment. Deregulation of these tyrosine receptors has been associated with several human diseases. In particular, the expression or activation of epidermal growth factor receptor (EGFR) and ErbB2 is altered in many epithelial tumors. Epithelial (E)-cadherin is another major molecule expressed by epithelial cells. To create efficient cell-cell adhesion, E-cadherin couples its cytoplasmic domain to catenins and the actin cytoskeleton. The loss of intercellular adhesion appears to be a fundamental aspect of the neoplastic phenomena. In addition, EGFR and ErbB2 signaling associated with the E-cadherin-catenin complex has been demonstrated in normal and cancer cells. This signaling is involved in regulating cell adhesion and the invasive growth of cancers. This article provides an overview of the interaction between the ErbB tyrosine receptors and the E-cadherin-catenin complex in human carcinomas.
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Affiliation(s)
- Amber Yasmeen
- McGill University, Program in Cancer Genetics, Department of Oncology, Montreal, Quebec, Canada.
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60
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Frigault MM, Naujokas MA, Park M. Gab2 requires membrane targeting and the met binding motif to promote lamellipodia, cell scatter, and epithelial morphogenesis downstream from the met receptor. J Cell Physiol 2007; 214:694-705. [PMID: 17894413 DOI: 10.1002/jcp.21264] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Gab1 and Gab2 are conserved scaffolding proteins that amplify and integrate signals stimulated by many growth factor receptors including the Met receptor. Gab1 acts to diversify the signal downstream from Met through the recruitment of multiple signaling proteins, and is essential for epithelial morphogenesis. However, whereas Gab1 and Gab2 are both expressed in epithelial cells, Gab2 fails to support a morphogenic response. We demonstrate that Gab1 and Gab2 are divergent in their function whereby Gab1, but not Gab2, promotes lamellipodia formation, and is localized to the membrane of lamellipodia upon Met activation. We have identified activation of ERK1/2 as a requirement for lamellipodia formation. Moreover, activated ERK1/2 are localized to lamellipodia in Gab1 expressing cells but not in cells that overexpress Gab2. By structure-function studies, we identify that enhanced membrane localization conferred through the addition of a myristoylation signal, together with the addition of the direct Met binding motif (MBM) from Gab1, are required to promote lamellipodia and confer a morphogenic signaling response to Gab2. Moreover, the morphogenesis competent myristoylated Gab2MBM promotes localization of activated ERK1/2 to the leading edge of lamellipodia in a similar manner to Gab1. Hence, subcellular localization of the Gab scaffold, as well as the ability of Gab to interact directly with the Met receptor, are both essential components of the morphogenic signaling response which involves lamellipodia formation and the localization of ERK1/2 activation in membrane ruffles.
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Affiliation(s)
- Melanie M Frigault
- Department of Biochemistry, Molecular Oncology Group, McGill University Health Centre, McGill University, Montreal, Quebec, Canada
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61
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Zhang D, Pier T, McNeel DG, Wilding G, Friedl A. Effects of a monoclonal anti-alphavbeta3 integrin antibody on blood vessels - a pharmacodynamic study. Invest New Drugs 2006; 25:49-55. [PMID: 17001523 DOI: 10.1007/s10637-006-9013-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2006] [Accepted: 08/30/2006] [Indexed: 11/28/2022]
Abstract
PURPOSE The integrin alphavbeta3 is an adhesion molecule expressed by proliferating endothelial cells and antibodies blocking this integrin inhibit angiogenesis in preclinical models. MEDI-522 is a second generation humanized anti-alphavbeta3 antibody designed for antiangiogenic therapy. The purpose of this study was to examine potential effects of this agent on blood vessels. EXPERIMENTAL DESIGN In a phase I dose escalation study, MEDI-522 was administered by weekly infusions to 25 adult patients with advanced solid organ malignancies. As a surrogate angiogenesis assay, a wound was created by punch biopsy of the arm skin. This wound site was re-biopsied after a 7-day interval. Dual-label immunofluorescence experiments followed by computer-assisted image analysis were conducted to analyze the vasculature. RESULTS Sequential pretreatment and 4-week treatment skin biopsy pairs were available on 4 patients, who had received 6 or 10 mg/kg of MEDI-522. MEDI-522 was detected in the dermal blood vessels as well as the dermal interstitium both in intact and wounded skin sites following treatment. No statistically significant difference was found between pretreatment and treatment samples of skin for vascular area, endothelial cell proliferation and apoptosis, or beta3 integrin levels. Phosphorylated focal adhesion kinase (pFAK) was significantly diminished in skin wound vessels during MEDI-522 treatment compared to the pretreatment samples. CONCLUSIONS MEDI-522 was detectable both in quiescent and in angiogenically active skin blood vessels as well as in the dermal interstitial space. The levels of pFAK were reduced during MEDI-522 treatment, suggesting a modulating effect on this signaling molecule.
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MESH Headings
- Adult
- Angiogenesis Inhibitors/administration & dosage
- Angiogenesis Inhibitors/pharmacokinetics
- Angiogenesis Inhibitors/therapeutic use
- Antibodies, Monoclonal/immunology
- Antibodies, Monoclonal/pharmacokinetics
- Antibodies, Monoclonal/therapeutic use
- Apoptosis/drug effects
- Blood Vessels/drug effects
- Blood Vessels/pathology
- Dose-Response Relationship, Drug
- Drug Administration Schedule
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/metabolism
- Endothelium, Vascular/pathology
- Fluorescent Antibody Technique/methods
- Focal Adhesion Kinase 1/antagonists & inhibitors
- Focal Adhesion Kinase 1/metabolism
- Humans
- Image Processing, Computer-Assisted/methods
- Infusions, Intravenous
- Integrin alphaVbeta3/antagonists & inhibitors
- Integrin alphaVbeta3/immunology
- Lymphoma/pathology
- Lymphoma/physiopathology
- Lymphoma/prevention & control
- Neoplasms/blood supply
- Neoplasms/metabolism
- Neoplasms/prevention & control
- Neovascularization, Pathologic/prevention & control
- Skin/drug effects
- Skin/metabolism
- Skin/pathology
- Time Factors
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Affiliation(s)
- Dahua Zhang
- Department of Pathology and Laboratory Medicine, University of Wisconsin, Madison, WI 53792, USA
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62
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Basson MD, Sanders MA, Gomez R, Hatfield J, Vanderheide R, Thamilselvan V, Zhang J, Walsh MF. Focal adhesion kinase protein levels in gut epithelial motility. Am J Physiol Gastrointest Liver Physiol 2006; 291:G491-9. [PMID: 16899713 DOI: 10.1152/ajpgi.00292.2005] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Mucosal healing requires migration and proliferation. Most studies of focal adhesion kinase (FAK), a protein that regulates motility, proliferation, and apoptosis, have focused on rapid phosphorylation. We reported lower FAK protein levels in motile Caco-2 colon cancer cells and postulated that this reduction in FAK available for activation might impact cell migration and mucosal healing. Therefore, total and active FAK (FAK(397)) immunoreactivity was assessed at the migrating fronts of human Caco-2 and rat IEC-6 intestinal epithelial cells. Caco-2 and IEC-6 motility, quantitated as migration into linear or circular wounds, was examined following FAK protein inhibition by small interfering RNA (siRNA). FAK protein stability and mRNA expression were ascertained by cycloheximide decay, RT-PCR, and in situ hybridization in static and migrating Caco-2 cells. Cells at the migrating front of Caco-2 and IEC-6 monolayers exhibited lower immunostaining for both total and activated FAK than cells immediately behind the front. Western blot analysis also demonstrated diminished FAK protein levels in motile cells by >/=30% in both the differential density seeding and multiple scrape models. siRNA FAK protein inhibition enhanced motility in both the linear scrape (20% in Caco-2) and circular wound (16% in Caco-2 and 19% in IEC-6 cells) models. FAK protein degradation did not differ in motile and static Caco-2 cells and was unaffected by FAK(397) phosphorylation, but FAK mRNA was lower in migrating Caco-2 cells. Thus FAK protein abundance appears regulated at the mRNA level during gut epithelial cell motility and may influence epithelial cell migration coordinately with signals that modify FAK phosphorylation.
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Affiliation(s)
- Marc D Basson
- Chief, Surgical Service, John D. Dingell VA Medical Center, 4646 John R. St., Detroit, MI 48201-1932, USA.
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63
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Hong T, Grabel LB. Migration of F9 parietal endoderm cells is regulated by the ERK pathway. J Cell Biochem 2006; 97:1339-49. [PMID: 16329137 DOI: 10.1002/jcb.20728] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Cell migration is regulated by the action of many signaling pathways that are activated in specific regions of migrating cells. Extracellular regulated kinase 1/2 (ERK) signaling can modulate the migration of cells by controlling the turnover of focal adhesions and the dynamics of actin polymerization. Focal adhesion turnover is necessary for cell migration, and the formation of strong actin stress fibers and mature focal adhesions puts the brakes on cell migration. We used F9 wild-type and vinculin null (vin-/-) parietal endoderm (PE) outgrowth to study the role of the ERK signaling pathway in cell migration. Upon plating of F9 embryoid bodies (EBs) onto laminin-coated dishes, PE cells migrate away from the EBs, providing an in vitro model for studying directed migration of this embryonic cell type. Our results suggest that the ERK pathway regulates PE cell migration by affecting the formation of focal adhesions and lamellipodia through the action of myosin light chain kinase (MLCK).
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Affiliation(s)
- Tao Hong
- Department of Biology, Wesleyan University, Hall-Atwater Labs, Lawn Avenue, Middletown, Connecticut 06459, USA
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64
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Abstract
Kruppel-like factor 8 (KLF8) is a member of the family of KLF transcription factors. Several KLF members have been shown to play a role in oncogenesis. We have previously demonstrated that KLF8 mediates cell cycle progression downstream of focal adhesion kinase (FAK) by upregulating cyclin D1. FAK plays a critical role in transformation and tumorigenesis and is aberrantly upregulated in many types of human cancer. Little is known about the function of KLF8 in these regards. Here we provide evidence suggesting a novel role of KLF8 in oncogenic transformation. We show that KLF8 expression is elevated in several types of human cancer cells and primary tumor tissues. Induced expression of ectopic KLF8 causes serum-independent growth and morphological transformation in NIH3T3 cells and enhances anchorage-independent growth of v-Src-transformed cells. In contrast, expression of a dominant-negative mutant of KLF8 dramatically suppresses the transformed phenotypes induced by v-Src. In addition, the KLF8-enhanced transformation in the v-Src cells was prevented by ablating cyclin D1 expression. Overall, these results indicate that KLF8 is required for v-Src-induced transformation and may play a role in tumor progression of human cancer.
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Affiliation(s)
- X Wang
- Center for Cell Biology and Cancer Research, Albany Medical College, Albany, NY 12208, USA
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65
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Jang JH, Chung CP. Fibronectin-mediated adhesion rescues cell cycle arrest induced by fibroblast growth factor-1 by decreased expression of p21(cip/waf) in human chondrocytes. In Vitro Cell Dev Biol Anim 2006; 41:126-9. [PMID: 16153144 DOI: 10.1290/0412082.1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
In chondrocytes, fibroblast growth factors (FGFs) inhibit chondrocytes proliferation by upregulation of the cell cycle inhibitor p21(cip/waf). In this report, we first investigated the roles of fibronectin (FN)-mediated cell adhesion in the modulation of FGF-1's antiproliferative function in chondrocytes. In this study, we found that FN-mediated signaling could rescue cell cycle arrest induced by FGF-1 in primary human chondrocytes. This prevention of cell cycle arrest induced by FGF-1 was due to the suppression of the cell cycle inhibitor p21(cip/waf) expression on adhesion to FN and its downstream activation of signaling pathways. Finally, we showed that this rescue induced by FN-mediated adhesion is dependent on the extracellular regulated kinase (ERK) signaling pathway. Taken together, these studies support that, despite FGF-FGF receptor's growth-inhibitory function, the FN-mediated signaling can collaborate to compensate for its negative effect on chondrocytes proliferation, providing evidence for cross talk between signals emerging from these cell surface molecules in chondrocyte.
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Affiliation(s)
- Jun-Hyeog Jang
- Department of Biochemistry, Inha University College of Medicine, Jung-Gu, Incheon 400-712, Korea.
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66
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Toruner M, Fernandez-Zapico M, Sha JJ, Pham L, Urrutia R, Egan LJ. Antianoikis Effect of Nuclear Factor-κB through Up-regulated Expression of Osteoprotegerin, BCL-2, and IAP-1. J Biol Chem 2006; 281:8686-96. [PMID: 16407217 DOI: 10.1074/jbc.m512178200] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Epithelial cells undergo a form of apoptosis termed anoikis when they lose extracellular attachments. We evaluated the role of transcription factor NF-kappaB in the regulation of anoikis susceptibility of intestinal epithelial cells. Culture of rat intestinal epithelial cells in suspension induced NF-kappaB activation, which blocked the anoikis of those cells, as assessed by internucleosomal DNA fragmentation and caspase-3 cleavage. Activation of NF-kappaB after the loss of extracellular attachments required focal adhesion kinase tyrosine 397 phosphorylation. This triggered a signaling cascade through phosphatidylinositol 3-kinase and AKT, to induce DNA binding of the RelA/p65 NF-kappaB polypeptide. NF-kappaB activated in this manner induced the up-regulated expression of a distinct program of genes that included osteoprotegerin, BCL-2, and IAP-1 (inhibitor of apoptosis protein-1). Chromatin immunoprecipitation experiments revealed that NF-kappaB directly regulated the promoters of these 3 genes. Knock-down of the expression of osteoprotegerin, BCL-2, or inhibitor of apoptosis protein-1 by RNA interference showed that these factors inhibit anoikis, and genetic reconstitution of their expression alone or in combination restored normal levels of anoikis to NF-kappaB-inactive intestinal epithelial cells. Together, these findings have identified the molecular components of a previously unrecognized antianoikis pathway in intestinal epithelial cells.
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Affiliation(s)
- Murat Toruner
- Gastroenterology Research Unit and Molecular Medicine Program, Mayo Clinic, Rochester, Minnesota 55905, USA
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67
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Barton ER. Impact of sarcoglycan complex on mechanical signal transduction in murine skeletal muscle. Am J Physiol Cell Physiol 2006; 290:C411-9. [PMID: 16162659 DOI: 10.1152/ajpcell.00192.2005] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Loss of the dystrophin glycoprotein complex (DGC) or a subset of its components can lead to muscular dystrophy. However, the patterns of symptoms differ depending on which proteins are affected. Absence of dystrophin leads to loss of the entire DGC and is associated with susceptibility to contractile injury. In contrast, muscles lacking γ-sarcoglycan (γ-SG) display little mechanical fragility and still develop severe pathology. Animals lacking dystrophin or γ-SG were used to identify DGC components critical for sensing dynamic mechanical load. Extensor digitorum longus muscles from 7-wk-old normal (C57), dystrophin- null ( mdx), and γ-SG-null ( gsg−/−) mice were subjected to a series of eccentric contractions, after which ERK1/2 phosphorylation levels were determined. At rest, both dystrophic strains had significantly higher ERK1 phosphorylation, and gsg−/− muscle also had heightened ERK2 phosphorylation compared with wild-type controls. Eccentric contractions produced a significant and transient increase in ERK1/2 phosphorylation in normal muscle, whereas the mdx strain displayed no significant proportional change of ERK1/2 phosphorylation after eccentric contraction. Muscles from gsg−/− mice had no significant increase in ERK1 phosphorylation; however, ERK2 phosphorylation was more robust than in C57 controls. The reduction in mechanically induced ERK1 phosphorylation in gsg−/− muscle was not dependent on age or severity of phenotype, because muscle from both young and old (age 20 wk) animals exhibited a reduced response. Immunoprecipitation experiments revealed that γ-SG was phosphorylated in normal muscle after eccentric contractions, indicating that members of the DGC are modified in response to mechanical perturbation. This study provides evidence that the SGs are involved in the transduction of mechanical information in skeletal muscle, potentially unique from the entire DGC.
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Affiliation(s)
- Elisabeth R Barton
- Department of Anatomy and Cell Biology, School of Dental Medicine, and Pennsylvania Muscle Institute, University of Pennsylvania, Philadelphia 19104, USA.
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Benlimame N, He Q, Jie S, Xiao D, Xu YJ, Loignon M, Schlaepfer DD, Alaoui-Jamali MA. FAK signaling is critical for ErbB-2/ErbB-3 receptor cooperation for oncogenic transformation and invasion. ACTA ACUST UNITED AC 2006; 171:505-16. [PMID: 16275754 PMCID: PMC2171271 DOI: 10.1083/jcb.200504124] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The overexpression of members of the ErbB tyrosine kinase receptor family has been associated with cancer progression. We demonstrate that focal adhesion kinase (FAK) is essential for oncogenic transformation and cell invasion that is induced by ErbB-2 and -3 receptor signaling. ErbB-2/3 overexpression in FAK-deficient cells fails to promote cell transformation and rescue chemotaxis deficiency. Restoration of FAK rescues both oncogenic transformation and invasion that is induced by ErbB-2/3 in vitro and in vivo. In contrast, the inhibition of FAK in FAK-proficient invasive cancer cells prevented cell invasion and metastasis formation. The activation of ErbB-2/3 regulates FAK phosphorylation at Tyr-397, -861, and -925. ErbB-induced oncogenic transformation correlates with the ability of FAK to restore ErbB-2/3–induced mitogen-activated protein kinase (MAPK) activation; the inhibition of MAPK prevented oncogenic transformation. In contrast, the inhibition of Src but not MAPK prevented ErbB–FAK-induced chemotaxis. In migratory cells, activated ErbB-2/3 receptors colocalize with activated FAK at cell protrusions. This colocalization requires intact FAK. In summary, distinct FAK signaling has an essential function in ErbB-induced oncogenesis and invasiveness.
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Affiliation(s)
- Naciba Benlimame
- Department of Medicine, Lady Davis Institute of the Sir Mortimer B. Davis Jewish General Hospital, McGill University, Montreal, Quebec H3T 1E2, Canada
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Fischhaber PL, McDaniel LD, Friedberg EC. DNA Polymerases for Translesion DNA Synthesis: Enzyme Purification and Mouse Models for Studying Their Function. Methods Enzymol 2006; 408:355-78. [PMID: 16793380 DOI: 10.1016/s0076-6879(06)08022-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
This chapter discusses experimental methods and protocols for the purification and preliminary characterization of DNA polymerases that are specialized for the replicative bypass (translesion DNA synthesis) of base or other types of DNA damage that typically arrest high-fidelity DNA synthesis, with particular emphasis on DNA polymerase kappa (Polkappa from mouse cells). It also describes some of the methods employed in the evaluation of mouse strains defective in genes that encode these enzymes.
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Affiliation(s)
- Paula L Fischhaber
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, USA
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70
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Walker JL, Fournier AK, Assoian RK. Regulation of growth factor signaling and cell cycle progression by cell adhesion and adhesion-dependent changes in cellular tension. Cytokine Growth Factor Rev 2005; 16:395-405. [PMID: 15886049 DOI: 10.1016/j.cytogfr.2005.03.003] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2005] [Accepted: 03/07/2005] [Indexed: 12/20/2022]
Abstract
The proliferation of most non-transformed cell types requires cell adhesion and cellular tension as well as exposure to mitogenic growth factors. Integrins and cadherins provide the adhesion signals, which ultimately allow for the cytoskeletal changes that control cellular tension. This review discusses the roles of integrins, cadherins, and the actin cytoskeleton as mediators of the mechanical tension critical for growth factor-dependent signaling and cell cycle progression.
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Affiliation(s)
- Janice L Walker
- Department of Pharmacology, University of Pennsylvania School of Medicine, Philadelphia, 19104-6084, USA
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Sawai H, Okada Y, Funahashi H, Matsuo Y, Takahashi H, Takeyama H, Manabe T. Activation of focal adhesion kinase enhances the adhesion and invasion of pancreatic cancer cells via extracellular signal-regulated kinase-1/2 signaling pathway activation. Mol Cancer 2005; 4:37. [PMID: 16209712 PMCID: PMC1266395 DOI: 10.1186/1476-4598-4-37] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2005] [Accepted: 10/06/2005] [Indexed: 02/02/2023] Open
Abstract
Background Interaction with integrin and focal adhesion kinase (FAK) regulates the cancer cell adhesion and invasion into extracellular matrix (ECM). In addition, phosphorylation of FAK correlates with the increase of cell motility and invasion. Adhesion and spreading of cancer cells on a variety of ECM proteins, including collagen type IV (Coll IV), leads to an increase in tyrosine phosphorylation and activation of FAK. In this study, we investigated the mechanism of activation of FAK and its downstream extracellular signal-regulated kinase (ERK)-1/2 signaling following stimulation by interleukin (IL)-1α and adhesion to ECM with subsequent enhancement of pancreatic cancer cell adhesion and invasion. Results In immunoblotting analysis, all three pancreatic cancer cell lines (AsPC-1, BxPC-3, and Capan-2) expressed the protein of FAK and β1 integrin. Enhancement of FAK protein association with β1 integrin when cells were plated on Coll IV was more increased by stimulation with IL-1α. Preincubation with anti-β1 integrin antibody and FAK siRNA transfection inhibited the association of FAK with β1 integrin of pancreatic cancer cells. FAK phosphorylation was observed by adhesion to Coll IV, furthermore, stronger FAK phosphorylation was observed by stimulation with IL-1α of pancreatic cancer cells adhered to Coll IV in time-dependent manner. Genistein, a tyrosine kinase inhibitor, markedly inhibited the FAK phosphorylation. IL-1α stimulation and Coll IV adhesion enhanced the activation of Ras, as evidenced by the increased Ras-GTP levels in pancreatic cancer cells. Activation of Ras correlated with the phosphorylation of ERK. While not statistical affecting the apoptosis of pancreatic cancer cells, IL-1α-induced adhesion and invasion on Coll IV were inhibited with FAK gene silencing by siRNA, β1 integrin blocking, and inhibition of FAK phosphorylation. PD98059, a MEK inhibitor, also inhibited IL-1α-induced enhancement of adhesion and invasion in pancreatic cancer cells. Conclusion
Our results demonstrated that activation of FAK is involved with the aggressive capability in pancreatic cancer through Ras/ERK signaling pathway. Based on our results, we suggest that the modification of IL-1, FAK, and integrins functions might be a novel therapeutic approach to aggressive spread of pancreatic cancer.
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Affiliation(s)
- Hirozumi Sawai
- Department of Gastroenterological Surgery, Nagoya City University Graduate School of Medical Sciences, Nagoya 4678601, Japan
| | - Yuji Okada
- Department of Gastroenterological Surgery, Nagoya City University Graduate School of Medical Sciences, Nagoya 4678601, Japan
| | - Hitoshi Funahashi
- Department of Gastroenterological Surgery, Nagoya City University Graduate School of Medical Sciences, Nagoya 4678601, Japan
| | - Yoichi Matsuo
- Department of Gastroenterological Surgery, Nagoya City University Graduate School of Medical Sciences, Nagoya 4678601, Japan
| | - Hiroki Takahashi
- Department of Gastroenterological Surgery, Nagoya City University Graduate School of Medical Sciences, Nagoya 4678601, Japan
| | - Hiromitsu Takeyama
- Department of Gastroenterological Surgery, Nagoya City University Graduate School of Medical Sciences, Nagoya 4678601, Japan
| | - Tadao Manabe
- Department of Gastroenterological Surgery, Nagoya City University Graduate School of Medical Sciences, Nagoya 4678601, Japan
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Clemente CFMZ, Corat MAF, Saad STO, Franchini KG. Differentiation of C2C12myoblasts is critically regulated by FAK signaling. Am J Physiol Regul Integr Comp Physiol 2005; 289:R862-70. [PMID: 15890789 DOI: 10.1152/ajpregu.00348.2004] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This study examined whether focal adhesion kinase (FAK) plays a role in the differentiation of C2C12myoblasts into myotubes. Differentiation of C2C12myoblasts induced by switch to differentiation culture medium was accompanied by a transient reduction of FAK phosphorylation at Tyr-397 (to ∼50%, at 1 and 2 h), followed by an increase thereafter (to 240% up to 5 days), although FAK protein expression remained unchanged. FAK and phosphorylated FAK were found at the edge of lamellipodia in proliferating cells, whereas the later increase in FAK phosphorylation in differentiating cells was accompanied by its preferential location at the tip of well-organized actin stress fibers. Hyperexpression of FAK autophosphorylation site (Tyr-397) mutant (MT-FAK) reduced FAK phosphorylation at Tyr-397 in proliferating cells and was accompanied by reduction of cyclin D1 and increase of myogenin expression. These cells failed to progress to myotubes in differentiation medium. In contrast, hyperexpression of a wild-type FAK construction (WT-FAK) increased baseline and abolished the transient reduction of FAK phosphorylation at Tyr-397 in serum-starved C2C12cells. Cells transfected with WT-FAK failed to reduce cyclin D1 and to increase myogenin expression, as well as to progress to terminal differentiation in differentiation medium. These data indicate that FAK signaling plays a critical role in the control of cell cycle as well as in the progression of C2C12cells to terminal differentiation. Transient inhibition of FAK phosphorylation at Tyr-397 contributes to trigger the myogenic genetic program, but its later activation is also central to terminal differentiation into myotubes.
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Affiliation(s)
- Carolina F M Z Clemente
- Departamento de Clínica Médica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Cidade Universitária Zefferino Vaz, 13081-970 Campinas, SP, Brazil
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73
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Moissoglu K, Sachdev S, Gelman IH. Enhanced v-Src-induced oncogenic transformation in the absence of focal adhesion kinase is mediated by phosphatidylinositol 3-kinase. Biochem Biophys Res Commun 2005; 330:673-84. [PMID: 15809050 DOI: 10.1016/j.bbrc.2005.03.025] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2005] [Indexed: 11/21/2022]
Abstract
We showed previously [K. Moissoglu, I.H. Gelman, J. Biol. Chem. 278 (2003) 47946-47959] that oncogenic v-Src could induce 7- to 10-fold greater anchorage-independent growth (AIG) in FAK-null mouse embryo fibroblasts (MEF) compared to those expressing FAK. Here, we demonstrate that the enhanced AIG (eAIG) correlates with increased activation levels of phosphatidylinositol 3-kinase (PI3K) and not with changes in the protein levels of the p85 regulatory subunit of PI3K, PDK1 or PTEN- modulators, and/or mediators of PI3K activity. eAIG could be blunted selectively by treatment with the PI3K inhibitor, LY294002, or by overexpression of either the PI3K antagonist, PTEN, dominant-interfering alleles of PI3K or a downstream PI3K mediator, AKT, but not by the MEK inhibitor, PD98059, dominant-interfering alleles of MEK or the signal transducer and activator of transcription (STAT)-3. In contrast, RNAi-mediated knockdown of FAK resulted in increased v-Src-induced AIG. Expression of a constitutively active PI3K allele was sufficient to induce higher levels of AIG, whereas overexpression of v-Src produced only larger-sized colonies in soft agar. Interestingly, FAK was required for full activation of PI3K by PDGF whereas the activation of PI3K by insulin was significantly increased in FAK-/- cells. Thus, although FAK is dispensable for v-Src-induced oncogenic transformation in vitro, it may exert either positive or negative effects on signaling or motility depending on which pathways are activated in cancer cells.
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Affiliation(s)
- Konstadinos Moissoglu
- Department of Cancer Genetics, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, NY 14623, USA
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74
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Abstract
Cell adhesion and migration are essential for embryonic development, tissue regeneration, but also for tumor development. The physical link between the extracellular matrix (ECM) and the actin cytoskeleton is mainly mediated by receptors of the integrin family. Through signals transduced upon integrin ligation to ECM proteins, this family of proteins plays key roles in regulating tumor growth and metastasis as well as tumor angiogenesis. During melanoma development, changes in integrin expression, intracellular control of integrin functions and signals perceived from integrin ligand binding impact upon the ability of tumor cells to interact with their environment and enable melanoma cells to convert from a sessile, stationary to a migratory and invasive phenotype. Antagonists of several integrins are now under evaluation in clinical trials to determine their potential as therapeutics for malignant melanoma and other kinds of cancer.
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Affiliation(s)
- Silke Kuphal
- Institute of Pathology, University of Regensburg, Germany
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75
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Lacoste J, Aprikian AG, Chevalier S. Focal adhesion kinase is required for bombesin-induced prostate cancer cell motility. Mol Cell Endocrinol 2005; 235:51-61. [PMID: 15866427 DOI: 10.1016/j.mce.2004.06.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2004] [Accepted: 06/28/2004] [Indexed: 11/29/2022]
Abstract
Clinical evidence links neuroendocrine differentiation (NED) to prostate cancer progression. In the prostate carcinoma PC-3 cell model, the action of the gastrin releasing peptide (GRP) analog, bombesin (BN), on the activation of focal adhesion kinase (FAK) and invasiveness suggests that this kinase might favor metastasis. Given that components of the FAK signalling pathway are also up regulated in prostate cancer, the aim of the present investigation was to test if FAK function is required for BN-induced motility in PC-3 cells. In wound assays designed to investigate the fate of FAK in cells undergoing BN-induced motility, it was observed that BN treatment resulted in relocalization of FAK in focal contacts concomitantly with its tyrosine phosphorylation on residue 397 (FAK [pY(397)]) and with the formation of actin lamellipodia. Moreover, BN-induced cell motility was significantly reduced in the presence of FAK inhibitors (either anti-FAK [pY(397)] antibody or FRNK, the FAK-related non-kinase). Altogether, these observations point towards a critical role for FAK in the action of BN on PC-3 cell motility.
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Affiliation(s)
- Judith Lacoste
- Urologic Oncology Research Group, Urology Division, Departmentof Surgery, McGill University Health Center (MUHC) Research Institute, Montreal, QC, Canada H3G 1A4
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76
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Mukhopadhyay NK, Gordon GJ, Chen CJ, Bueno R, Sugarbaker DJ, Jaklitsch MT. Activation of focal adhesion kinase in human lung cancer cells involves multiple and potentially parallel signaling events. J Cell Mol Med 2005; 9:387-97. [PMID: 15963258 PMCID: PMC6741146 DOI: 10.1111/j.1582-4934.2005.tb00364.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Integrins are adhesion receptors that transmit signals bidirectionally across the plasma membrane. In our previous report we have shown that the squamous lung cancer cell line, Calu-1, binds to collagen type IV (Coll IV) through beta1-integrin and results in phosphorylation of focal adhesion kinase (FAK) (Ann Thorac Surg 2004; 78:450-457). Considering the critical role of FAK in cell migration, proliferation, and survival, here we investigated potential mechanisms of its activation and regulation in Calu-1 cells. We observed the phosphorylation of Tyr397 of FAK (the autophosphorylation site of FAK) and paxillin, the immediate downstream substrate of FAK following the adhesion of Calu-1 cells to Coll IV. FAK remains phosphorylated during proliferation either on Coll IV or on uncoated plates for 72 h, as determined by peroxivanadate treatment. Exposure of Calu-1 cells with 60 microM genistein, reduces FAK phosphorylation (7.6 fold) and cell proliferation. Extracellular signal regulated kinases (ERKs) were also phosphorylated after Coll IV attachment. Disruption of Calu-1 cell cytoskeleton integrity by 1-5 muM Cytochalasin D resulted in the inhibition of cell adhesion (50% to 75%, p<0.19 - 6.6 x 10(7)) and ERKs phosphorylation (2 fold) without any effect on FAK phosphorylation. Protein Kinase C inhibitor, Calphostin C at 100 and 250 nM concentrations did not block Coll IV induced FAK phosphorylation but activated the ERKs in a dose dependent manner. beta1-integrin is essential for Coll IV induced FAK activation, but it is not physically associated with FAK as determined by immunodetection assay. Collectively, this report defines the existence of multiple and potentially parallel Coll IV/beta1-integrin mediated signaling events in Calu-1 cells, which involve FAK, ERKs, and PKC.
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Affiliation(s)
- Nishit K Mukhopadhyay
- Division of Thoracic Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, 02115, USA
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77
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Abstract
The growth of new blood vessels is a dynamic yet highly regulated process that depends on coordinated signaling by growth factor and cell adhesion receptors. As part of the molecular program regulating angiogenesis, endothelial cells acquire a proliferative and invasive phenotype but also show increased susceptibility to apoptotic stimuli. Integrins are the principle adhesion receptors used by endothelial cells to interact with their extracellular microenvironment, and integrin-mediated interactions play a critical role in regulating cell proliferation, migration, and survival. Alterations in the repertoire and?or activity of integrins, as well as the availability and structural property of their ligands, regulate the vascular cell during the growth or repair of blood vessels.
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Affiliation(s)
- D G Stupack
- Department of Immunology, The Scripps Research Institute, La Jolla, California 9203, USA
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78
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Sood AK, Coffin JE, Schneider GB, Fletcher MS, DeYoung BR, Gruman LM, Gershenson DM, Schaller MD, Hendrix MJC. Biological significance of focal adhesion kinase in ovarian cancer: role in migration and invasion. THE AMERICAN JOURNAL OF PATHOLOGY 2004; 165:1087-95. [PMID: 15466376 PMCID: PMC1618649 DOI: 10.1016/s0002-9440(10)63370-6] [Citation(s) in RCA: 200] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Focal adhesion kinase (FAK) is a nonreceptor tyrosine kinase that is activated by integrin clustering. There are limited data regarding the functional role of FAK in ovarian cancer migration and invasion. In the current study, FAK expression was evaluated in ovarian cell lines (nontransformed and cancer), 12 benign ovarian samples, and in 79 invasive epithelial ovarian cancers. All three ovarian cancer cell lines overexpressed FAK compared to the nontransformed cells. The dominant-negative construct called FAK-related nonkinase (FRNK) was introduced into two ovarian cancer cell lines (SKOV3 and 222). FRNK promoted FAK dephosphorylation without changing total FAK levels in these cell lines. Furthermore, FRNK decreased the in vitro invasive ability of ovarian cancer cells by 56 to 85% and decreased migration by 52 to 68%. FRNK-transfected cells also displayed poor cell spreading. Immunohistochemical analysis revealed that the surface epithelium from all benign ovarian samples had weak FAK expression. In contrast, 68% of invasive ovarian cancers overexpressed FAK. FAK overexpression was significantly associated with high tumor stage, high tumor grade, positive lymph nodes and presence of distant metastasis (all P values <0.05). FAK overexpression was also associated with shorter overall survival (P = 0.008). Multivariate analysis revealed that FAK overexpression and residual disease >1 cm were independent predictors of poor survival. These data indicate that FAK is overexpressed in most invasive ovarian cancers and plays a functionally significant role in ovarian cancer migration and invasion. Thus, FAK may be an important therapeutic target in ovarian carcinoma.
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Affiliation(s)
- Anil K Sood
- Department of Gynecologic Oncology, The University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA.
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79
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Abstract
Mechanical forces play an important role in the organization, growth, maturation, and function of living tissues. At the cellular level, many of the biological responses to external forces originate at two types of specialized microscale structures: focal adhesions that link cells to their surrounding extracellular matrix and adherens junctions that link adjacent cells. Transmission of forces from outside the cell through cell-matrix and cell-cell contacts appears to control the maturation or disassembly of these adhesions and initiates intracellular signaling cascades that ultimately alter many cellular behaviors. In response to externally applied forces, cells actively rearrange the organization and contractile activity of the cytoskeleton and redistribute their intracellular forces. Recent studies suggest that the localized concentration of these cytoskeletal tensions at adhesions is also a major mediator of mechanical signaling. This review summarizes the role of mechanical forces in the formation, stabilization, and dissociation of focal adhesions and adherens junctions and outlines how integration of signals from these adhesions over the entire cell body affects how a cell responds to its mechanical environment. This review also describes advanced optical, lithographic, and computational techniques for the study of mechanotransduction.
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Affiliation(s)
- Christopher S Chen
- Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, Maryland 21205, USA.
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80
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Westhoff MA, Serrels B, Fincham VJ, Frame MC, Carragher NO. SRC-mediated phosphorylation of focal adhesion kinase couples actin and adhesion dynamics to survival signaling. Mol Cell Biol 2004; 24:8113-33. [PMID: 15340073 PMCID: PMC515031 DOI: 10.1128/mcb.24.18.8113-8133.2004] [Citation(s) in RCA: 199] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Integrin-associated focal adhesions not only provide adhesive links between cellular actin and extracellular matrix but also are sites of signal transmission into the cell interior. Many cell responses signal through focal adhesion kinase (FAK), often by integrin-induced autophosphorylation of FAK or phosphorylation by Src family kinases. Here, we used an interfering FAK mutant (4-9F-FAK) to show that Src-dependent FAK phosphorylation is required for focal adhesion turnover and cell migration, by controlling assembly of a calpain 2/FAK/Src/p42ERK complex, calpain activation, and proteolysis of FAK. Expression of 4-9F-FAK in FAK-deficient fibroblasts also disrupts F-actin assembly associated with normal adhesion and spreading. In addition, we found that FAK's ability to regulate both assembly and disassembly of the actin and adhesion networks may be linked to regulation of the protease calpain. Surprisingly, we also found that the same interfering 4-9F-FAK mutant protein causes apoptosis of serum-deprived, transformed cells and suppresses anchorage-independent growth. These data show that Src-mediated phosphorylation of FAK acts as a pivotal regulator of both actin and adhesion dynamics and survival signaling, which, in turn, control apparently distinct processes such as cell migration and anchorage-independent growth. This also highlights that dynamic regulation of actin and adhesions (which include the integrin matrix receptors) is critical to signaling output and biological responses.
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Affiliation(s)
- M A Westhoff
- The Beatson Institute for Cancer Research, Cancer Research UK, Glasgow G61 1BD, Scotland, United Kingdom
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81
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Campos LS, Leone DP, Relvas JB, Brakebusch C, Fässler R, Suter U, ffrench-Constant C. Beta1 integrins activate a MAPK signalling pathway in neural stem cells that contributes to their maintenance. Development 2004; 131:3433-44. [PMID: 15226259 DOI: 10.1242/dev.01199] [Citation(s) in RCA: 255] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The emerging evidence that stem cells develop in specialised niches highlights the potential role of environmental factors in their regulation. Here we examine the role of beta1 integrin/extracellular matrix interactions in neural stem cells. We find high levels of beta1 integrin expression in the stem-cell containing regions of the embryonic CNS, with associated expression of the laminin alpha2 chain. Expression levels of laminin alpha2 are reduced in the postnatal CNS, but a population of cells expressing high levels of beta1 remains. Using neurospheres - aggregate cultures, derived from single stem cells, that have a three-dimensional architecture that results in the localisation of the stem cell population around the edge of the sphere - we show directly that beta1 integrins are expressed at high levels on neural stem cells and can be used for their selection. MAPK, but not PI3K, signalling is required for neural stem cell maintenance, as assessed by neurosphere formation, and inhibition or genetic ablation of beta1 integrin using cre/lox technology reduces the level of MAPK activity. We conclude that integrins are therefore an important part of the signalling mechanisms that control neural stem cell behaviour in specific areas of the CNS.
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Affiliation(s)
- Lia S Campos
- Department of Medical Genetics, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
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82
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Slack-Davis JK, Parsons JT. Emerging views of integrin signaling: implications for prostate cancer. J Cell Biochem 2004; 91:41-6. [PMID: 14689580 DOI: 10.1002/jcb.10665] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Integrins are heterodimeric transmembrane cellular receptors that link the cell to its underlying substratum. Alterations in integrin expression and signaling have been implicated in many aspects of tumorigenesis and metastasis including cell survival, migration, and invasion. In prostate cancer, the progression from normal to metastatic cells is accompanied by changes in the repertoire of integrins expressed and up-regulation of key adhesion-dependent signaling pathways. Recent work from several laboratories indicates the emergence of new mechanisms for the regulation of growth and migratory pathways by integrin engagement. These pathways are likely to provide novel sites of therapeutic intervention for the treatment of prostate cancer.
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Affiliation(s)
- Jill K Slack-Davis
- Department of Microbiology, University of Virginia Health Sciences System, Charlottesville, Virginia 22908, USA.
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83
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Hammar E, Parnaud G, Bosco D, Perriraz N, Maedler K, Donath M, Rouiller DG, Halban PA. Extracellular matrix protects pancreatic beta-cells against apoptosis: role of short- and long-term signaling pathways. Diabetes 2004; 53:2034-41. [PMID: 15277383 DOI: 10.2337/diabetes.53.8.2034] [Citation(s) in RCA: 140] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
We have shown previously that culture of beta-cells on matrix derived from 804G cells and rich in laminin-5 improves their function. The purpose of this study was to investigate whether this matrix protects beta-cells against apoptosis and to elucidate signaling pathways involved. Matrix protected sorted rat beta-cells against apoptosis under standard conditions (11.2 mmol/l glucose, 10% serum), after serum deprivation (1% serum), and in response to interleukin-1beta (IL-1beta; 2 ng/ml), compared with control (poly-L-lysine [pLL]). Caspase-8 activity was reduced in cells cultured on matrix, whereas focal adhesion kinase (FAK), protein kinase B (PKB, or Akt), and extracellular signal-regulated kinase (ERK) phosphorylation was augmented. Treatment (4 h) with an anti-beta1 integrin antibody, with the ERK pathway inhibitor PD98059, and/or with the phosphatidylinositol 3-kinase inhibitor LY294002 augmented cell death on 804G matrix but not on pLL. In long-term assays (48 h), PD98059 but not LY294002 drastically augmented cell death on 804G matrix but did so to a lesser extent on pLL. The protein inhibitor of nuclear factor-kappaB (IkappaBalpha) was overexpressed in cells cultured 18 h on matrix with partial blockade by PD98059. In summary, this study provides evidence for activation of signaling pathways and gene expression by extracellular matrix leading to improved beta-cell survival.
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Affiliation(s)
- Eva Hammar
- Department of Genetic Medecine and Development, University Medical Center, Geneva, Switzerland.
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84
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Schlaepfer DD, Mitra SK, Ilic D. Control of motile and invasive cell phenotypes by focal adhesion kinase. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2004; 1692:77-102. [PMID: 15246681 DOI: 10.1016/j.bbamcr.2004.04.008] [Citation(s) in RCA: 350] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2004] [Accepted: 04/08/2004] [Indexed: 01/09/2023]
Abstract
Cell motility is stimulated by extracellular stimuli and initiated by intracellular signaling proteins that localize to sites of cell contact with the extracellular matrix termed focal contacts. Focal adhesion kinase (FAK) is an intracellular protein-tyrosine kinase (PTK) that acts to regulate the cycle of focal contact formation and disassembly required for efficient cell movement. FAK is activated by a variety of cell surface receptors and transmits signals to a range of targets. Thus, FAK acts as an integrator of cell motility-associated signaling events. We will review the stimulatory and regulatory mechanisms of FAK activation, the different signaling connections of FAK that are mediated by a growing number of FAK-interacting proteins, and the modulation of FAK function by tyrosine and serine phosphorylation. We will also summarize findings with regard to FAK function in vertebrate and invertebrate development as well as recent insights into the mechanistic role(s) of FAK in promoting cell migration. As increased FAK expression and tyrosine phosphorylation have been correlated with the progression to an invasive cell phenotype, there is growing interest in elucidating the important FAK-related signaling connections promoting invasive tumor cell movement. To this end, we will discuss the effects of FAK inhibition via the dominant-negative expression of the FAK C-terminal domain termed FAK-related non-kinase (FRNK) and how these studies have uncovered a distinct role for FAK in promoting cell invasion that may differ from its role in promoting cell motility.
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Affiliation(s)
- David D Schlaepfer
- Department of Immunology, Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
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85
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Abstract
Rho-family proteins control signalling pathways that regulate a wide range of biological processes. In vitro studies implicating Rho proteins in cell adhesion, migration, transcriptional activation, cell-cycle progression and transformation suggested roles for these proteins in the formation and progression of tumours in vivo. Studies using different recombinant mouse models have recently confirmed this idea. Rho signalling pathways crosstalk with different oncogenic signalling cascades, including those downstream of Ras and Wnt, and contribute to various aspects of tumourigenesis, including survival, growth and progression of tumour cells.
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Affiliation(s)
- Angeliki Malliri
- The Netherlands Cancer Institute, Division of Cell Biology, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands.
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86
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Hecker TP, Ding Q, Rege TA, Hanks SK, Gladson CL. Overexpression of FAK promotes Ras activity through the formation of a FAK/p120RasGAP complex in malignant astrocytoma cells. Oncogene 2004; 23:3962-71. [PMID: 15077193 DOI: 10.1038/sj.onc.1207541] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Focal adhesion kinase (FAK) signaling may be mediated through the modulation of Ras activity. We have shown previously that grade III malignant astrocytoma biopsy samples exhibit elevated levels of FAK, and that overexpression of FAK in U-251MG malignant astrocytoma cells promotes the phosphorylation of Shc, a potential upstream mediator of Ras activity. Here, we report that overexpression of FAK promotes Ras activity in U-251MG malignant astrocytoma cells cultured in aggregate suspension or as monolayers adherent to vitronectin. The overexpression of FAK also promoted the association of FAK with p120RasGAP, which is a negative regulator of Ras activity, in the U-251MG cells cultured in aggregate suspension, with this association being abrogated upon plating of the cells onto vitronectin. An association of FAK with p120RasGAP also was observed in malignant astrocytoma biopsy samples, but not in normal brain samples. As overexpression of FAK in U-251MG cells in aggregate suspension culture reduced the amount of p120RasGAP complexed with active Ras, we hypothesize that the association of FAK with p120 RasGAP may facilitate Ras activity. The overexpression of a mutated FAK in which the Y397 had been mutated to F did not result in the formation of the FAK/p120RasGAP complex and did not promote Ras activity, indicating that the Y397 residue of FAK plays a role in the formation of this complex and in the activation of Ras. Moreover, the overexpression of mutated FAK (397F) was found to inhibit anchorage-independent growth. These data provide the basis for a previously undescribed mechanism in which the elevated expression of FAK can promote Ras activity through its competitive recruitment of p120RasGAP, thereby diminishing the association of p120RasGAP with active Ras.
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Affiliation(s)
- Timothy P Hecker
- Department of Pathology, Division of Neuropathology, The University of Alabama at Birmingham, Birmingham, AL 35294, USA
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87
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Gao G, Prutzman KC, King ML, Scheswohl DM, DeRose EF, London RE, Schaller MD, Campbell SL. NMR Solution Structure of the Focal Adhesion Targeting Domain of Focal Adhesion Kinase in Complex with a Paxillin LD Peptide. J Biol Chem 2004; 279:8441-51. [PMID: 14662767 DOI: 10.1074/jbc.m309808200] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase that is regulated by integrins. Upon activation, FAK generates signals that modulate crucial cell functions, including cell proliferation, migration, and survival. The C-terminal focal adhesion targeting (FAT) sequence mediates localization of FAK to discrete regions in the cell called focal adhesions. Several binding partners for the FAT domain of FAK have been identified, including paxillin. We have determined the solution structure of the avian FAT domain in complex with a peptide mimicking the LD2 motif of paxillin by NMR spectroscopy. The FAT domain retains a similar fold to that found in the unliganded form when complexed to the paxillin-derived LD2 peptide, an antiparallel four-helix bundle. However, noticeable conformational changes were observed upon the LD2 peptide binding, especially the position of helix 4. Multiple lines of evidence, including the results obtained from isothermal titration calorimetry, intermolecular nuclear Overhauser effects, mutagenesis, and protection from paramagnetic line broadening, support the existence of two distinct paxillin-binding sites on the opposite faces of the FAT domain. The structure of the FAT domain-LD2 complex was modeled using the program HADDOCK based on our solution structure of the LD2-bound FAT domain and mutagenesis data. Our model of the FAT domain-LD2 complex provides insight into the molecular basis of FAK-paxillin binding interactions, which will aid in understanding the role of paxillin in FAK targeting and signaling.
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Affiliation(s)
- Guanghua Gao
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina 27599, USA
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88
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Abstract
The renal glomerulus is composed of three types of glomerular cells (mesangial cell (MC), endothelial cell and podocyte) and extracellular matrix (ECM) consisting of the glomerular basement membrane (GBM) and mesangial matrix. It constitutes a highly specialized microcirculation in which the permeability characteristics of the capillary wall allow its unique filtration function. The proliferation of MCs, an increase of mesangial ECM and detachment podocyte from GBM are key biological features of progressive glomerulonephritis (GN), leading to glomerular scarring and dysfunction. Thus, the study of the molecular and cellular mechanisms responsible for pathological glomerular alterations may help to elucidate the pathogenesis of progressive glomerular diseases. A growing body of evidence indicates that beta1 integrin family (beta1 integrins), that mainly mediates cell adhesion to ECM, controls cell behaviors such as cell migration, proliferation, apoptosis and ECM assembly. In addition, a correlation between glomerular expression of beta1 integrins and their ligand ECM components is observed in various human and experimental GN, suggesting that altered beta1 integrins-mediated cell behaviors may contribute to the progression of GN. It is now becoming apparent that the expression of glomerular beta1 integrins is not only critical for maintaining the glomerular capillary permeability but it modulates cell signaling pathways regulating the cell phenotypes involved in the progression of glomerular diseases.
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Affiliation(s)
- Shoji Kagami
- Department of Pediatrics, The University of Tokushima School of Medicine, Tokushima, Japan
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89
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Stähle M, Veit C, Bachfischer U, Schierling K, Skripczynski B, Hall A, Gierschik P, Giehl K. Mechanisms in LPA-induced tumor cell migration: critical role of phosphorylated ERK. J Cell Sci 2003; 116:3835-46. [PMID: 12902401 DOI: 10.1242/jcs.00679] [Citation(s) in RCA: 122] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Lysophosphatidic acid (LPA) is a serum-borne phospholipid with hormone and growth factor-like properties. LPA has been shown to modulate tumor cell invasion and malignant cell growth. Here, we report that two human pancreatic carcinoma cell lines, PANC-1 and BxPC-3, express functionally active LPA receptors coupled to pertussis toxin-sensitive Gi/o-proteins. In contrast to other cell types, LPA does not act as a mitogen, but is an efficacious stimulator of cell migration of these tumor cells. LPA-induced chemotaxis is markedly dependent on activation of PTX-sensitive heterotrimeric G-proteins, on activation of the small GTPases Ras, Rac and RhoA, and on GTPase-dependent activation of ERK. LPA-induced ERK activation results in a transient translocation of the phosphorylated ERK to newly forming focal contact sites at the leading edge of the migrating cells. Inhibition of ERK activation and its subsequent translocation impaired LPA-induced chemotaxis and LPA-induced actin reorganization. Thus, pancreatic tumor cell migration in response to LPA is essentially controlled by activation of a Gi/o-ERK pathway and requires the LPA-induced activation of Ras, Rac1 and RhoA.
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Affiliation(s)
- Martina Stähle
- Department of Pharmacology and Toxicology, University of Ulm, 89069 Ulm, Germany
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90
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Goel HL, Dey CS. Role of protein kinase C during insulin mediated skeletal muscle cell spreading. J Muscle Res Cell Motil 2003; 23:269-77. [PMID: 12630700 DOI: 10.1023/a:1022028808806] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Protein kinase C (PKC) is known to play important roles in integrin mediated cell spreading. This study investigated the role of PKC during insulin mediated muscle cell spreading, which was independent of integrin alpha5. We found that PKC-alpha becomes active and localise to membrane during insulin mediated cell spreading. We also found that PKC activation is essential for cell spreading stimulated by insulin and this activation enhances the cell spreading. PKC activation increased the tyrosine phosphorylation of focal adhesion kinase (FAK) and paxillin as well as tyrosine kinase activity of FAK. We also observed that PKC activation enhanced the FAK associated PI 3-kinase activity and also increased the activation of ERK-1/-2. Moreover, the effect of PKC activation on insulin mediated cell spreading as well as tyrosine phosphorylation of FAK and paxillin depends upon integrity of actin cytoskeleton. Thus, PKC is an important signaling protein during insulin mediated muscle cell spreading.
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Affiliation(s)
- Hira Lal Goel
- Signal Transduction Research Laboratory, Department of Biotechnology, National Institute of Pharmaceutical Education and Research, Sector 67, S.A.S. Nagar, Punjab 160 062, India
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91
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Hood JD, Frausto R, Kiosses WB, Schwartz MA, Cheresh DA. Differential alphav integrin-mediated Ras-ERK signaling during two pathways of angiogenesis. J Cell Biol 2003; 162:933-43. [PMID: 12952943 PMCID: PMC2172815 DOI: 10.1083/jcb.200304105] [Citation(s) in RCA: 202] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Antagonists of alphavbeta3 and alphavbeta5 disrupt angiogenesis in response to bFGF and VEGF, respectively. Here, we show that these alphav integrins differentially contribute to sustained Ras-extracellular signal-related kinase (Ras-ERK) signaling in blood vessels, a requirement for endothelial cell survival and angiogenesis. Inhibition of FAK or alphavbeta5 disrupted VEGF-mediated Ras and c-Raf activity on the chick chorioallantoic membrane, whereas blockade of FAK or integrin alphavbeta3 had no effect on bFGF-mediated Ras activity, but did suppress c-Raf activation. Furthermore, retroviral delivery of active Ras or c-Raf promoted ERK activity and angiogenesis, which anti-alphavbeta5 blocked upstream of Ras, whereas anti-alphavbeta3 blocked downstream of Ras, but upstream of c-Raf. The activation of c-Raf by bFGF/alphavbeta3 not only depended on FAK, but also required p21-activated kinase-dependent phosphorylation of serine 338 on c-Raf, whereas VEGF-mediated c-Raf phosphorylation/activation depended on Src, but not Pak. Thus, integrins alphavbeta3 and alphavbeta5 differentially regulate the Ras-ERK pathway, accounting for distinct vascular responses during two pathways of angiogenesis.
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Affiliation(s)
- John D Hood
- Department of Immunology, The Scripps Research Institute, La Jolla, CA 92037, USA
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92
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Sundberg LJ, Galante LM, Bill HM, Mack CP, Taylor JM. An endogenous inhibitor of focal adhesion kinase blocks Rac1/JNK but not Ras/ERK-dependent signaling in vascular smooth muscle cells. J Biol Chem 2003; 278:29783-91. [PMID: 12782622 DOI: 10.1074/jbc.m303771200] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Humoral factors and extracellular matrix are critical co-regulators of smooth muscle cell (SMC) migration and proliferation. We reported previously that focal adhesion kinase (FAK)-related non-kinase (FRNK) is expressed selectively in SMC and can inhibit platelet-derived growth factor BB homodimer (PDGF-BB)-induced proliferation and migration of SMC by attenuating FAK activity. The goal of the current studies was to identify the mechanism by which FAK/FRNK regulates SMC growth and migration in response to diverse mitogenic signals. Transient overexpression of FRNK in SMC attenuated autophosphorylation of FAK at Tyr-397, reduced Src family-dependent tyrosine phosphorylation of FAK at Tyr-576, Tyr-577, and Tyr-881, and reduced phosphorylation of the FAK/Src substrates Cas and paxillin. However, FRNK expression did not alter the magnitude or dynamics of ERK activation induced by PDGF-BB or angiotensin II. Instead, FRNK expression markedly attenuated PDGF-BB-, angiotensin II-, and integrin-stimulated Rac1 activity and attenuates downstream signaling to JNK. Importantly, constitutively active Rac1 rescued the proliferation defects in FRNK expressing cells. Based on these observations, we hypothesize that FAK activation is required to integrate integrin signals with those from receptor tyrosine kinases and G protein-coupled receptors through downstream activation of Rac1 and that in SMC, FRNK may control proliferation and migration by buffering FAK-dependent Rac1 activation.
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Affiliation(s)
- Liisa J Sundberg
- Department of Pathology, University of North Carolina, Chapel Hill, North Carolina 27599, USA
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93
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Kracklauer MP, Schmidt C, Sclabas GM. TGFbeta1 signaling via alphaVbeta6 integrin. Mol Cancer 2003; 2:28. [PMID: 12935295 PMCID: PMC184456 DOI: 10.1186/1476-4598-2-28] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2003] [Accepted: 08/07/2003] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Transforming growth factor beta1 (TGFbeta1) is a potent inhibitor of epithelial cell growth, thus playing an important role in tissue homeostasis. Most carcinoma cells exhibit a reduced sensitivity for TGFbeta1 mediated growth inhibition, suggesting TGFbeta1 participation in the development of these cancers. The tumor suppressor gene DPC4/SMAD4, which is frequently inactivated in carcinoma cells, has been described as a key player in TGFbeta1 mediated growth inhibition. However, some carcinoma cells lacking functional SMAD4 are sensitive to TGFbeta1 induced growth inhibition, thus requiring a SMAD4 independent TGFbeta1 pathway. RESULTS Here we report that mature TGFbeta1 is a ligand for the integrin alphaVbeta6, independent of the common integrin binding sequence motif RGD. After TGFbeta1 binds to alphaVbeta6 integrin, different signaling proteins are activated in TGFbeta1-sensitive carcinoma cells, but not in cells that are insensitive to TGFbeta1. Among others, interaction of TGFbeta1 with the alphaVbeta6 integrin resulted in an upregulation of the cell cycle inhibitors p21/WAF1 and p27 leading to growth inhibition in SMAD4 deleted as well as in SMAD4 wildtype carcinoma cells. CONCLUSIONS Our data provide support for the existence of an alternate TGFbeta1 signaling pathway that is independent of the known SMAD pathway. This alternate pathway involves alphaVbeta6 integrin and the Ras/MAP kinase pathway and does not employ an RGD motif in TGFbeta1-sensitive tumor cells. The combined action of these two pathways seems to be necessary to elicit a complete TGFbeta1 signal.
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Affiliation(s)
- Martin P Kracklauer
- Section of Molecular Cell and Developmental Biology, Institute for Cellular and Molecular Biology, The University of Texas at Austin, 1 University Station, A4800, 78712, Austin, TX, USA
| | - Christian Schmidt
- Department of Surgical Oncology and Molecular Oncology, University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030, USA
| | - Guido M Sclabas
- Department of Surgical Oncology and Molecular Oncology, University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030, USA
- Department of Visceral and Transplantation Surgery, The University of Bern, Inselspital, Bern, 3010, Switzerland
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94
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Slack-Davis JK, Eblen ST, Zecevic M, Boerner SA, Tarcsafalvi A, Diaz HB, Marshall MS, Weber MJ, Parsons JT, Catling AD. PAK1 phosphorylation of MEK1 regulates fibronectin-stimulated MAPK activation. J Cell Biol 2003; 162:281-91. [PMID: 12876277 PMCID: PMC2172784 DOI: 10.1083/jcb.200212141] [Citation(s) in RCA: 210] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Activation of the Ras-MAPK signal transduction pathway is necessary for biological responses both to growth factors and ECM. Here, we provide evidence that phosphorylation of S298 of MAPK kinase 1 (MEK1) by p21-activated kinase (PAK) is a site of convergence for integrin and growth factor signaling. We find that adhesion to fibronectin induces PAK1-dependent phosphorylation of MEK1 on S298 and that this phosphorylation is necessary for efficient activation of MEK1 and subsequent MAPK activation. The rapid and efficient activation of MEK and phosphorylation on S298 induced by cell adhesion to fibronectin is influenced by FAK and Src signaling and is paralleled by localization of phospho-S298 MEK1 and phospho-MAPK staining in peripheral membrane-proximal adhesion structures. We propose that FAK/Src-dependent, PAK1-mediated phosphorylation of MEK1 on S298 is central to the organization and localization of active Raf-MEK1-MAPK signaling complexes, and that formation of such complexes contributes to the adhesion dependence of growth factor signaling to MAPK.
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Affiliation(s)
- Jill K Slack-Davis
- Department of Microbiology, University of Virginia Health System, Charlottesville, VA 22908, USA
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95
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Corral T, Jiménez M, Hernández-Muñoz I, Pérez de Castro I, Pellicer A. NF1 modulates the effects of ras oncogenes: Evidence of other NF1 function besides its GAP activity. J Cell Physiol 2003; 197:214-24. [PMID: 14502561 DOI: 10.1002/jcp.10349] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Neurofibromin (NF1) (the product of Nf1 gene) is a large cytosolic protein known as a negative regulator of Ras. A fragment of some 400 residues located at the center of the NF1 GAP-Related Domain (NF1-GRD) has strong identity with other molecules of the GAP family, which comprises, among others, the mammalian proteins NF1 and p120GAP, and the yeast proteins IRA1 and IRA2. GAP family members are known by their ability to promote the GTPase activity of Ras proteins, facilitating the transit of those proteins to their inactive state. Recent findings (Tong et al., 2002, Nat Neurosci 5:95-96) indicate that NF1 may be involved in the regulation of adenyl cyclase activity. Our results show that NF1-GRD cooperates with Ras in the anchorage-independent growth capacity of Ras-expressing fibroblasts, without affecting: (i) their ability to grow in low serum, (ii) their cellular adhesion capability, or (iii) the expression of key proteins involved in cell-cell and cell-matrix interactions. On the other hand, NF1 overexpression induces an increase in the expression levels of the focal adhesion kinase (FAK), and specific changes in the activation status of the mitogen-activated protein kinases (MAPKs). These results suggest the existence of a Ras-independent NF1-dependent pathway able to modify the levels of expression of FAK and the levels of activation of MAPKs. Because FAK and many proteins recently found to bind NF1 have a role in the cytoskeleton, this pathway may involve rearrangement of cytoskeletal components that facilitate anchorage independence.
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Affiliation(s)
- Teresa Corral
- Department of Pathology, New York University School of Medicine, New York, New York, USA
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96
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Zhao J, Bian ZC, Yee K, Chen BPC, Chien S, Guan JL. Identification of transcription factor KLF8 as a downstream target of focal adhesion kinase in its regulation of cyclin D1 and cell cycle progression. Mol Cell 2003; 11:1503-15. [PMID: 12820964 DOI: 10.1016/s1097-2765(03)00179-5] [Citation(s) in RCA: 129] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Focal adhesion kinase (FAK) is an important mediator of integrin signaling in the regulation of cell adhesion, migration, survival, and proliferation. Here we report the identification of the transcription factor KLF8 as a target of FAK in cell cycle regulation. KLF8 is induced by FAK and decreased by FAK dominant-negative mutant DeltaC14. Overexpression of KLF8 increases cell cycle progression, whereas inhibition of endogenous KLF8 by siRNA reduces it. Cyclin D1 promoter is identified as a target of KLF8, which is activated both directly by KLF8 binding to the GT box A and by an indirect mechanism through its repression of a potential inhibitory regulator of cyclin D1. Transcription activation of cyclin D1 by FAK requires both Ets family and KLF8 factors in a temporally differential manner. Together, our data provide further insights into molecular mechanism for FAK to regulate cell cycle progression.
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Affiliation(s)
- Jihe Zhao
- Department of Molecular Medicine, Cornell University College of Veterinary Medicine, Ithaca, NY 14853, USA
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97
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Roovers K, Assoian RK. Effects of rho kinase and actin stress fibers on sustained extracellular signal-regulated kinase activity and activation of G(1) phase cyclin-dependent kinases. Mol Cell Biol 2003; 23:4283-94. [PMID: 12773570 PMCID: PMC156148 DOI: 10.1128/mcb.23.12.4283-4294.2003] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
We recently reported that Rho kinase is required for sustained ERK signaling and the consequent mid-G(1) phase induction of cyclin D1 in fibroblasts. The results presented here indicate that these Rho kinase effects are mediated by the formation of stress fibers and the consequent clustering of alpha5beta1 integrin. Mechanistically, alpha5beta1 signaling and stress fiber formation allowed for the sustained activation of MEK, and this effect was mediated upstream of Ras-GTP loading. Interestingly, disruption of stress fibers with ML-7 led to G(1) phase arrest while comparable disruption of stress fibers with Y27632 (an inhibitor of Rho kinase) or dominant-negative Rho kinase led to a more rapid progression through G(1) phase. Inhibition of either MLCK or Rho kinase blocked sustained ERK signaling, but only Rho kinase inhibition allowed for the induction of cyclin D1 and activation of cdk4 via Rac/Cdc42. The levels of cyclin E, cdk2, and their major inhibitors, p21(cip1) and p27(kip1), were not affected by inhibition of MLCK or Rho kinase. Overall, our results indicate that Rho kinase-dependent stress fiber formation is required for sustained activation of the MEK/ERK pathway and the mid-G(1) phase induction of cyclin D1, but not for other aspects of cdk4 or cdk2 activation. They also emphasize that G(1) phase cell cycle progression in fibroblasts does not require stress fibers if Rac/Cdc42 signaling is allowed to induce cyclin D1.
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Affiliation(s)
- Kristin Roovers
- Department of Pharmacology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104-6084, USA
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98
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Walker HA, Whitelock JM, Garl PJ, Nemenoff RA, Stenmark KR, Weiser-Evans MCM. Perlecan up-regulation of FRNK suppresses smooth muscle cell proliferation via inhibition of FAK signaling. Mol Biol Cell 2003; 14:1941-52. [PMID: 12802066 PMCID: PMC165088 DOI: 10.1091/mbc.e02-08-0508] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2002] [Revised: 12/17/2002] [Accepted: 12/27/2002] [Indexed: 12/25/2022] Open
Abstract
We previously reported that fully assembled basement membranes are nonpermissive to smooth muscle cell (SMC) replication and that perlecan (PN), a basement membrane heparan sulfate proteoglycan, is a dominant effector of this response. We report here that SMC adhesion to basement membranes, and perlecan in particular, up-regulate the expression of focal adhesion kinase-related nonkinase (FRNK), a SMC-specific endogenous inhibitor of FAK, which subsequently suppresses FAK-mediated, ERK1/2-dependent growth signals. Up-regulation of FRNK by perlecan is actively and continuously regulated. Relative to the matrix proteins studied, the effects are unique to perlecan, because plating of SMCs on several other basement membrane proteins is associated with low levels of FRNK and corresponding high levels of FAK and ERK1/2 phosphorylation and SMC growth. Perlecan supports SMC adhesion, although there is reduced cell spreading compared with fibronectin (FN), laminin (LN), or collagen type IV (IV). Despite the reduction in cell spreading, we report that perlecan-induced up-regulation of FRNK is independent of cell shape changes. Growth inhibition by perlecan was rescued by overexpressing a constitutively active FAK construct, but overexpressing kinase-inactivated mutant FAK or FRNK attenuated fibronectin-stimulated growth. These data indicate that perlecan functions as an endogenously produced inhibitor of SMC growth at least in part through the active regulation of FRNK expression. FRNK, in turn, may control SMC growth by downregulating FAK-dependent signaling events.
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Affiliation(s)
- Heather A Walker
- Department of Pediatrics, Renal Division, University of Colorado Health Sciences Center, Denver 80262, USA
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99
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Abstract
The protein tyrosine kinase focal adhesion kinase (FAK) plays a prominent role in integrin signaling. FAK activation, demonstrated by an increase in phosphorylation of Tyr397 as well as other sites in the protein, is best understood in the context of the engagement of integrins at the cell surface. Activation of FAK results in recruitment of a number of SH2-domain- and SH3-domain-containing proteins, which mediate signaling to several downstream pathways. FAK-dependent activation of these pathways has been implicated in a diverse array of cellular processes, including cell migration, growth factor signaling, cell cycle progression and cell survival.
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Affiliation(s)
- J Thomas Parsons
- Department of Microbiology, University of Virginia Health System, Charlottesville, VA 22908, USA.
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100
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Reif S, Lang A, Lindquist JN, Yata Y, Gabele E, Scanga A, Brenner DA, Rippe RA. The role of focal adhesion kinase-phosphatidylinositol 3-kinase-akt signaling in hepatic stellate cell proliferation and type I collagen expression. J Biol Chem 2003; 278:8083-90. [PMID: 12502711 DOI: 10.1074/jbc.m212927200] [Citation(s) in RCA: 234] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Following a fibrogenic stimulus, the hepatic stellate cell (HSC) undergoes a complex activation process associated with increased cell proliferation and excess deposition of type I collagen. The focal adhesion kinase (FAK)-phosphatidylinositol 3-kinase (PI3K)-Akt signaling pathway is activated by platelet-derived growth factor (PDGF) in several cell types. We investigated the role of the FAK-PI3K-Akt pathway in HSC activation. Inhibition of FAK activity blocked HSC migration, cell attachment, and PDGF-induced PI3K and Akt activation. Both serum- and PDGF-induced Akt phosphorylation was inhibited by LY294002, an inhibitor of PI3K. A constitutively active form of Akt stimulated HSC proliferation in serum-starved HSCs, whereas LY294002 and dominant-negative forms of Akt and FAK inhibited PDGF-induced proliferation. Transforming growth factor-beta, an inhibitor of HSC proliferation, did not block PDGF-induced Akt phosphorylation, suggesting that transforming growth factor-beta mediates its antiproliferative effect downstream of Akt. Expression of type I collagen protein and alpha1(I) collagen mRNA was increased by Akt activation and inhibited when PI3K activity was blocked. Therefore, FAK is important for HSC migration, cell attachment, and PDGF-induced cell proliferation. PI3K is positioned downstream of FAK. Signals for HSC proliferation are transduced through FAK, PI3K, and Akt. Finally, expression of type I collagen is regulated by the PI3K-Akt signaling pathway.
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Affiliation(s)
- Shimon Reif
- Division of Digestive Diseases, Department of Medicine, University of North Carolina, Chapel Hill 27599, USA
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