51
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Kholodenko B, Yaffe MB, Kolch W. Computational approaches for analyzing information flow in biological networks. Sci Signal 2012; 5:re1. [PMID: 22510471 DOI: 10.1126/scisignal.2002961] [Citation(s) in RCA: 126] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The advancements in "omics" (proteomics, genomics, lipidomics, and metabolomics) technologies have yielded large inventories of genes, transcripts, proteins, and metabolites. The challenge is to find out how these entities work together to regulate the processes by which cells respond to external and internal signals. Mathematical and computational modeling of signaling networks has a key role in this task, and network analysis provides insights into biological systems and has applications for medicine. Here, we review experimental and theoretical progress and future challenges toward this goal. We focus on how networks are reconstructed from data, how these networks are structured to control the flow of biological information, and how the design features of the networks specify biological decisions.
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Affiliation(s)
- Boris Kholodenko
- Systems Biology Ireland, University College Dublin, Belfield, Dublin 4, Ireland
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Barium promotes anchorage-independent growth and invasion of human HaCaT keratinocytes via activation of c-SRC kinase. PLoS One 2011; 6:e25636. [PMID: 22022425 PMCID: PMC3192110 DOI: 10.1371/journal.pone.0025636] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2011] [Accepted: 09/08/2011] [Indexed: 01/13/2023] Open
Abstract
Explosive increases in skin cancers have been reported in more than 36 million patients with arsenicosis caused by drinking arsenic-polluted well water. This study and previous studies showed high levels of barium as well as arsenic in the well water. However, there have been no reports showing a correlation between barium and cancer. In this study, we examined whether barium (BaCl2) may independently have cancer-related effects on human precancerous keratinocytes (HaCaT). Barium (5–50 µM) biologically promoted anchorage-independent growth and invasion of HaCaT cells in vitro. Barium (5 µM) biochemically enhanced activities of c-SRC, FAK, ERK and MT1-MMP molecules, which regulate anchorage-independent growth and/or invasion. A SRC kinase specific inhibitor, protein phosphatase 2 (PP2), blocked barium-mediated promotion of anchorage-independent growth and invasion with decreased c-SRC kinase activity. Barium (2.5–5 µM) also promoted anchorage-independent growth and invasion of fibroblasts (NIH3T3) and immortalized nontumorigenic melanocytes (melan-a), but not transformed cutaneous squamous cell carcinoma (HSC5 and A431) and malignant melanoma (Mel-ret) cells, with activation of c-SRC kinase. Taken together, our biological and biochemical findings newly suggest that the levels of barium shown in drinking well water independently has the cancer-promoting effects on precancerous keratinocytes, fibroblast and melanocytes in vitro.
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53
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Kashyap T, Germain E, Roche M, Lyle S, Rabinovitz I. Role of β4 integrin phosphorylation in human invasive squamous cell carcinoma: regulation of hemidesmosome stability modulates cell migration. J Transl Med 2011; 91:1414-26. [PMID: 21769085 PMCID: PMC3184203 DOI: 10.1038/labinvest.2011.104] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Hemidesmosomes (HDs) are multiprotein structures that anchor epithelia to the basement membrane. During squamous cell carcinoma (SCC) invasion, there is a reduction in the number of HDs, which may facilitate dissemination. Mechanisms of HD disassembly are incompletely understood. Previous work has shown that epidermal growth factor (EGF)-induced phosphorylation of the β4 integrin on three of its serines, S(1356)S(1360)S(1364), can induce HD disassembly in normal cells. Here, we examine the role of β4 integrin serine phosphorylation in SCC. We have found that around 60% of invasive cutaneous SCC show increased β4 phosphorylation on S(1356) when compared with carcinoma in situ or normal tissue. To assess the mechanisms by which SCC increases β4 phosphorylation, we performed in vitro analyses. Compared with keratinocytes, SCC cells showed increased levels of S(1356) phosphorylation in the absence of EGF, correlating with reduced HD-like structures. In addition, phospho-S(1356) signal was largely segregated from other HD components. Epidermal growth factor receptor and PKC inhibitors inhibited basal levels of S(1356) phosphorylation in SCC, suggesting that cells use intrinsic mechanisms to activate the EGF signaling pathway to induce β4 phosphorylation. Moreover, these inhibitors stabilized HD-like structures in SCC cells and reduced their migratory ability. Mutation of S(1356)S(1360)S(1364) in SCC cells to non-phosphorylatable alanines stabilized HD-like structures and substantially reduced migration, while mutation into phosphorylation mimicking aspartate reduced HD-like structures but had no effect on migration, suggesting that serine phosphorylation function is releasing anchorage rather than promoting migration. Altogether these results suggest that β4 serine phosphorylation may have an important role during SCC invasion by destabilizing HDs and facilitating migration.
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Affiliation(s)
- Trinayan Kashyap
- Department of Pathology, BIDMC/Harvard Medical School, Boston, MA
| | - Emily Germain
- Department of Pathology, BIDMC/Harvard Medical School, Boston, MA
| | - Michael Roche
- Department of Pathology, UMass Medical School, Worcester, MA
| | - Stephen Lyle
- Department of Pathology, UMass Medical School, Worcester, MA
| | - Isaac Rabinovitz
- Department of Pathology, BIDMC/Harvard Medical School, Boston, MA,Isaac Rabinovitz, Dept. of Pathology, Beth Israel Deaconess Medical Center, 330 Brookline Ave. Boston, MA 02215,
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Sastry SK, Elferink LA. Checks and balances: interplay of RTKs and PTPs in cancer progression. Biochem Pharmacol 2011; 82:435-40. [PMID: 21704606 DOI: 10.1016/j.bcp.2011.06.016] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Revised: 06/08/2011] [Accepted: 06/10/2011] [Indexed: 02/08/2023]
Abstract
In recent years, targeted therapies for receptor tyrosine kinases (RTKs) have shown initial promise in the clinical setting for the treatment of several tumors driven by these oncogenic signaling pathways. Unfortunately, clinical relapse due to acquired resistance to these molecular therapeutics is common. An improved understanding of how tumors bypass the inhibitory effects of RTK-targeted therapies has revealed a rich myriad of possible mechanisms for acquired resistance. Protein tyrosine phosphatases (PTPs) can function as oncogenes or tumor suppressors to either enhance or suppress RTK signaling. Recent studies suggest that the loss or gain of function of PTP's can significantly impinge on RTK signaling during tumor progression. Here we review the interplay between RTKs and PTPs as an emerging mechanism for acquired resistance to RTK-targeted therapies, that may aid in the design of improved therapies to prevent and overcome resistance in treatments for cancer patients.
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Affiliation(s)
- Sarita K Sastry
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA.
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55
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Abstract
The development of multicellular organisms, as well as maintenance of organ architecture and function, requires robust regulation of cell fates. This is in part achieved by conserved signaling pathways through which cells process extracellular information and translate this information into changes in proliferation, differentiation, migration, and cell shape. Gene deletion studies in higher eukaryotes have assigned critical roles for components of the extracellular matrix (ECM) and their cellular receptors in a vast number of developmental processes, indicating that a large proportion of this signaling is regulated by cell-ECM interactions. In addition, genetic alterations in components of this signaling axis play causative roles in several human diseases. This review will discuss what genetic analyses in mice and lower organisms have taught us about adhesion signaling in development and disease.
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Affiliation(s)
- Sara A Wickström
- Paul Gerson Una Group, Skin Homeostasis and Ageing, Max Planck Institute for Biology of Ageing, 50937 Cologne, Germany.
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56
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Ren Y, Chen Z, Chen L, Fang B, Win-Piazza H, Haura E, Koomen JM, Wu J. Critical role of Shp2 in tumor growth involving regulation of c-Myc. Genes Cancer 2011; 1:994-1007. [PMID: 21442024 DOI: 10.1177/1947601910395582] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Activating mutants of Shp2 protein tyrosine phosphatase, encoded by the PTPN11 gene, are linked to leukemia. In solid tumors, however, PTPN11 mutations occur at low frequencies while the wildtype Shp2 is activated by protein tyrosine kinases (PTKs) in cancer cells and mediates PTK signaling. Therefore, it is important to address whether the wildtype Shp2 plays a functional role critical for tumor growth. Using shRNAs and a PTP-inactive mutant to inhibit Shp2, we find here that tumor growth of DU145 prostate cancer and H292 lung cancer cells depends on Shp2. Suppression of Shp2 inhibited cell proliferation, decreased c-Myc and increased p27 expression in cell cultures. In H292 tumor tissues, c-Myc-positive cells coincided with Ki67-positive cells and smaller tumors from Shp2 knockdown cells had less c-Myc-positive cells and more nuclear p27. Shp2-regulated c-Myc expression was mediated by Src and Erk1/2. Down-regulation of c-Myc reduced cell proliferation while up-regulation of c-Myc in Shp2 knockdown H292 cells partially rescued the inhibitory effect of Shp2 suppression on cell proliferation. Tyrosine phosphoproteomic analysis of H292 tumor tissues showed that Shp2 could both up- and down-regulate tyrosine phosphorylation on cellular proteins. Among other changes, Shp2 inhibition increased phosphorylation of Src Tyr-530 and Cdk1 Thr-14/Tyr-15 and decreased phosphorylation of Erk1 and Erk2 activating sites in the tumors. Significantly, we found that Shp2 positively regulated Gab1 Tyr-627/Tyr-659 phosphorylation. This finding reveals that Shp2 can auto-regulate its own activating signal. Shp2 Tyr-62/Tyr-63 phosphorylation was observed in tumor tissues, indicating that Shp2 is activated in the tumors.
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Affiliation(s)
- Yuan Ren
- Department of Molecular Oncology, H. Lee Moffitt Cancer Center and Research Institute, 12902 Magnolia Drive, Tampa, Florida, USA
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57
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MET signalling: principles and functions in development, organ regeneration and cancer. Nat Rev Mol Cell Biol 2010; 11:834-48. [PMID: 21102609 DOI: 10.1038/nrm3012] [Citation(s) in RCA: 917] [Impact Index Per Article: 65.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The MET tyrosine kinase receptor (also known as the HGF receptor) promotes tissue remodelling, which underlies developmental morphogenesis, wound repair, organ homeostasis and cancer metastasis, by integrating growth, survival and migration cues in response to environmental stimuli or cell-autonomous perturbations. The versatility of MET-mediated biological responses is sustained by qualitative and quantitative signal modulation. Qualitative mechanisms include the engagement of dedicated signal transducers and the subcellular compartmentalization of MET signalling pathways, whereas quantitative regulation involves MET partnering with adaptor amplifiers or being degraded through the shedding of its extracellular domain or through intracellular ubiquitylation. Controlled activation of MET signalling can be exploited in regenerative medicine, whereas MET inhibition might slow down tumour progression.
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58
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Franco M, Muratori C, Corso S, Tenaglia E, Bertotti A, Capparuccia L, Trusolino L, Comoglio PM, Tamagnone L. The tetraspanin CD151 is required for Met-dependent signaling and tumor cell growth. J Biol Chem 2010; 285:38756-64. [PMID: 20937830 PMCID: PMC2998140 DOI: 10.1074/jbc.m110.145417] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2010] [Revised: 10/07/2010] [Indexed: 01/10/2023] Open
Abstract
CD151, a transmembrane protein of the tetraspanin family, is implicated in the regulation of cell-substrate adhesion and cell migration through physical and functional interactions with integrin receptors. In contrast, little is known about the potential role of CD151 in controlling cell proliferation and survival. We have previously shown that β4 integrin, a major CD151 partner, not only acts as an adhesive receptor for laminins but also as an intracellular signaling platform promoting cell proliferation and invasive growth upon interaction with Met, the tyrosine kinase receptor for hepatocyte growth factor (HGF). Here we show that RNAi-mediated silencing of CD151 expression in cancer cells impairs HGF-driven proliferation, anchorage-independent growth, protection from anoikis, and tumor progression in xenograft models in vivo. Mechanistically, we found that CD151 is crucially implicated in the formation of signaling complexes between Met and β4 integrin, a known amplifier of HGF-induced tumor cell growth and survival. CD151 depletion hampered HGF-induced phosphorylation of β4 integrin and the ensuing Grb2-Gab1 association, a signaling pathway leading to MAPK stimulation and cell growth. Accordingly, CD151 knockdown reduced HGF-triggered activation of MAPK but not AKT signaling cascade. These results indicate that CD151 controls Met-dependent neoplastic growth by enhancing receptor signaling through β4 integrin-mediated pathways, independent of cell-substrate adhesion.
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Affiliation(s)
- Mélanie Franco
- From the Institute for Cancer Research and Treatment (IRCC), University of Turin Medical School, 10060 Candiolo, Torino, Italy
| | - Claudia Muratori
- From the Institute for Cancer Research and Treatment (IRCC), University of Turin Medical School, 10060 Candiolo, Torino, Italy
| | - Simona Corso
- From the Institute for Cancer Research and Treatment (IRCC), University of Turin Medical School, 10060 Candiolo, Torino, Italy
| | - Enrico Tenaglia
- From the Institute for Cancer Research and Treatment (IRCC), University of Turin Medical School, 10060 Candiolo, Torino, Italy
| | - Andrea Bertotti
- From the Institute for Cancer Research and Treatment (IRCC), University of Turin Medical School, 10060 Candiolo, Torino, Italy
| | - Lorena Capparuccia
- From the Institute for Cancer Research and Treatment (IRCC), University of Turin Medical School, 10060 Candiolo, Torino, Italy
| | - Livio Trusolino
- From the Institute for Cancer Research and Treatment (IRCC), University of Turin Medical School, 10060 Candiolo, Torino, Italy
| | - Paolo M. Comoglio
- From the Institute for Cancer Research and Treatment (IRCC), University of Turin Medical School, 10060 Candiolo, Torino, Italy
| | - Luca Tamagnone
- From the Institute for Cancer Research and Treatment (IRCC), University of Turin Medical School, 10060 Candiolo, Torino, Italy
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SHP2 mediates the localized activation of Fyn downstream of the α6β4 integrin to promote carcinoma invasion. Mol Cell Biol 2010; 30:5306-17. [PMID: 20855525 DOI: 10.1128/mcb.00326-10] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Src family kinase (SFK) activity is elevated in many cancers, and this activity correlates with aggressive tumor behavior. The α6β4 integrin, which is also associated with a poor prognosis in many tumor types, can stimulate SFK activation; however, the mechanism by which it does so is not known. In the current study, we provide novel mechanistic insight into how the α6β4 integrin selectively activates the Src family member Fyn in response to receptor engagement. Both catalytic and noncatalytic functions of SHP2 are required for Fyn activation by α6β4. Specifically, the tyrosine phosphatase SHP2 is recruited to α6β4 and its catalytic activity is stimulated through a specific interaction of its N-terminal SH2 domain with pY1494 in the β4 subunit. Fyn is recruited to the α6β4/SHP2 complex through an interaction with phospho-Y580 in the C terminus of SHP2. In addition to activating Fyn, this interaction with Y580-SHP2 localizes Fyn to sites of receptor engagement, which is required for α6β4-dependent invasion. Of significance for tumor progression, phosphorylation of Y580-SHP2 and SFK activation are increased in orthotopic human breast tumors that express α6β4 and activation of this pathway is dependent upon Y1494.
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60
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Soung YH, Clifford JL, Chung J. Crosstalk between integrin and receptor tyrosine kinase signaling in breast carcinoma progression. BMB Rep 2010; 43:311-8. [PMID: 20510013 DOI: 10.5483/bmbrep.2010.43.5.311] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
This review explored the mechanism of breast carcinoma progression by focusing on integrins and receptor tyrosine kinases (or growth factor receptors). While the primary role of integrins was previously thought to be solely as mediators of adhesive interactions between cells and extracellular matrices, it is now believed that integrins also regulate signaling pathways that control cancer cell growth, survival, and invasion. A large body of evidence suggests that the cooperation between integrin and receptor tyrosine kinase signaling regulates certain signaling functions that are important for cancer progression. Recent developments on the crosstalk between integrins and receptor tyrosine kinases, and its implication in mammary tumor progression, are discussed.
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Affiliation(s)
- Young Hwa Soung
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, Shreveport, Louisiana 71130, USA
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61
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Chen W, Garcia JGN, Jacobson JR. Integrin beta4 attenuates SHP-2 and MAPK signaling and reduces human lung endothelial inflammatory responses. J Cell Biochem 2010; 110:718-24. [PMID: 20512931 DOI: 10.1002/jcb.22582] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We previously identified the marked upregulation of integrin beta4 in human lung endothelial cells (EC) treated with simvastatin, an HMG coA-reductase inhibitor with vascular-protective and anti-inflammatory properties in murine models of acute lung injury (ALI). We now investigate the role of integrin beta4 as a novel mediator of vascular inflammatory responses with a focus on mitogen-activated protein kinases (MAPK) signaling and the downstream expression of the inflammatory cytokines (IL-6 and IL-8) essential for the full elaboration of inflammatory lung injury. Silencing of integrin beta4 (siITGB4) in human lung EC resulted in significant increases in both basal and LPS-induced phosphorylation of ERK 1/2, JNK, and p38 MAPK, consistent with robust integrin beta4 regulation of MAPK activation. In addition, siITB4 increased both basal and LPS-induced expression of IL-6 and IL-8 mRNA and protein secretion into the media. We next observed that integrin beta4 silencing increased basal and LPS-induced phosphorylation of SHP-2, a protein tyrosine phosphatase known to modulate MAPK signaling. In contrast, inhibition of SHP-2 enzymatic activity (sodium stibogluconate) abrogated the increased ERK phosphorylation associated with integrin beta4 silencing in LPS-treated EC and attenuated the increases in levels of IL-6 and IL-8 in integrin-beta4-silenced EC. These findings highlight a novel negative regulatory role for integrin beta4 in EC inflammatory responses involving SHP-2-mediated MAPK signaling. Upregulation of integrin beta4 may represent an important element of the anti-inflammatory and vascular-protective properties of statins and provides a novel strategy to limit inflammatory vascular syndromes.
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Affiliation(s)
- Weiguo Chen
- Department of Medicine, University of Chicago, Chicago, Illinois 60637, USA
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62
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Bertotti A, Bracco C, Girolami F, Torti D, Gastaldi S, Galimi F, Medico E, Elvin P, Comoglio PM, Trusolino L. Inhibition of Src impairs the growth of met-addicted gastric tumors. Clin Cancer Res 2010; 16:3933-43. [PMID: 20628031 DOI: 10.1158/1078-0432.ccr-10-0106] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE We examined whether inhibition of Src tyrosine kinase, a downstream effector of the MET oncogene, can hinder the malignant properties of gastric tumors dependent on Met for growth and survival. EXPERIMENTAL DESIGN Sensitivity to Src inhibition was determined in vitro by measuring clonogenic survival (anchorage-independent growth) and in vivo by establishing xenograft models. Four "Met-addicted" gastric carcinoma cell lines (GTL16, MKN45, HS746T, and SNU5) and three Met-independent gastric carcinoma cell lines (KATO III, AGS, and NCI-N87) were treated with the Src inhibitor saracatinib (AZD0530). In GTL16 and KATO III, Src neutralization was also achieved by dasatinib and RNA interference. The biochemical and transcriptional consequences of Src inhibition were explored using anti-phosphoprotein antibodies and oligonucleotide microarrays. RESULTS Inhibition of Src in Met-addicted gastric carcinoma cell lines (a) decreased the phosphorylation/activation levels of signaling intermediates involved in cell proliferation and protection from apoptosis and down-modulated the expression of several cell cycle regulators; (b) reduced anchorage-independent growth; (c) enhanced impairment of cell viability produced by Met inhibition; and (d) delayed tumorigenesis in xenotransplantation models. Immunohistochemical analysis of tumor xenograft tissues following systemic treatment with saracatinib showed a reduction of tumor cell proliferation index, increased apoptosis, and diminished phospho-focal adhesion kinase and phospho-paxillin staining. Tumor stroma parameters such as angiogenesis or inflammatory infiltration were unaffected. In clonogenic survival assays, gastric carcinoma cells without addiction to Met were less sensitive than Met-addicted cells to Src inhibition. CONCLUSIONS Src is as a key downstream transducer of Met-driven tumor growth. Targeting Src might provide therapeutic benefit in Met-addicted tumors.
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Affiliation(s)
- Andrea Bertotti
- Division of Molecular Oncology and Laboratory of Functional Genomics, The Oncogenomics Center, Institute for Cancer Research and Treatment, University of Torino Medical School, Strada Provinciale 142, Candiolo, Turin, Italy
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63
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Beaulieu JF. Integrin α6β4 in colorectal cancer. World J Gastrointest Pathophysiol 2010; 1:3-11. [PMID: 21607137 PMCID: PMC3097941 DOI: 10.4291/wjgp.v1.i1.3] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2010] [Revised: 03/18/2010] [Accepted: 03/25/2010] [Indexed: 02/06/2023] Open
Abstract
The ability of cells to interact with extracellular matrix macromolecules is at the forefront of the regulation of cell phenotype and organization. Indeed most if not all cells bear specific cell surface receptors for these molecules, namely the integrins, which are specific for the ligation of various macromolecules such as the laminins, fibronectins and tenascins. It is now well established that integrins can regulate a variety of biological activities, most notably cell cycle and tissue-specific gene expression. In the intestine, several observations suggest functional roles for cell-matrix interactions in the regulation of epithelial cell functions. This article focuses on integrin α6β4 as a paradigm to illustrate the importance as well as the complexity of integrins in the mediation of cell-matrix interactions. Indeed, α6β4 has been well-characterized for its involvement as a link between the cytoskeleton and extracellular matrix molecules as well as in the activation of a variety of intracellular signalization processes in cooperation with growth factor receptors. Furthermore, recent studies show that distinct forms of α6 and β4 subunits are expressed in the human intestine and, more importantly, recent work provides experimental evidence that various forms of α6β4 can differentially regulate intestinal epithelial cell functions under both normal and pathological conditions. For instance, it has been discovered that colorectal cancer cells express a hybrid form of α6β4 that is never seen in normal cells. Although further work is needed, integrin α6β4 is emerging as a key regulator of intestinal functions in both intestinal health and disease.
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64
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Haenssen KK, Caldwell SA, Shahriari KS, Jackson SR, Whelan KA, Klein-Szanto AJ, Reginato MJ. ErbB2 requires integrin alpha5 for anoikis resistance via Src regulation of receptor activity in human mammary epithelial cells. J Cell Sci 2010; 123:1373-82. [PMID: 20332114 DOI: 10.1242/jcs.050906] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
ErbB2, a receptor tyrosine kinase highly expressed in many tumors, is known to inhibit apoptotic signals. Overexpression of ErbB2 causes anoikis resistance that contributes to luminal filling in three-dimensional mammary epithelial acinar structures in vitro. Given that integrins and growth factor receptors are highly interdependent for function, we examined the role of integrin subunits in ErbB2-mediated survival signaling. Here, we show that MCF-10A cells overexpressing ErbB2 upregulate integrin alpha5 via the MAP-kinase pathway in three-dimensional acini and found elevated integrin alpha5 levels associated with ErbB2 status in human breast cancer. Integrin alpha5 is required for ErbB2-mediated anoikis resistance and for optimal ErbB2 signaling to the Mek-Erk-Bim axis as depletion of integrin alpha5 reverses anoikis resistance and Bim inhibition. Integrin alpha5 is required for full activation of ErbB2 tyrosine phosphorylation on Y877 and ErbB2 phosphorylation is associated with increased activity of Src in the absence of adhesion. Indeed, we show that blocking elevated Src activity during cell detachment reverses ErbB2-mediated survival and Bim repression. Thus, integrin alpha5 serves as a key mediator of Src and ErbB2-survival signaling in low adhesion states, which are necessary to block the pro-anoikis mediator Bim, and we suggest that this pathway represents a potential novel therapeutic target in ErbB2-positive tumors.
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Affiliation(s)
- Keneshia K Haenssen
- Department of Biochemistry and Molecular Biology, 245 N 15 Street, Drexel University College of Medicine, Philadelphia, PA 19102, USA
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65
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Wang H, Leavitt L, Ramaswamy R, Rapraeger AC. Interaction of syndecan and alpha6beta4 integrin cytoplasmic domains: regulation of ErbB2-mediated integrin activation. J Biol Chem 2010; 285:13569-79. [PMID: 20181947 DOI: 10.1074/jbc.m110.102137] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The alpha6beta4 integrin is a laminin 332 (LN332) receptor central to the formation of hemidesmosomes in epithelial layers. However, the integrin becomes phosphorylated by keratinocytes responding to epidermal growth factor in skin wounds or by squamous cell carcinomas that overexpress/hyperactivate the tyrosine kinase ErbB2, epidermal growth factor receptor, or c-Met. We show here that the beta4-dependent signaling in A431 human squamous carcinoma cells is dependent on the syndecan family of matrix receptors. Yeast two-hybrid analysis identifies an interaction within the distal third (amino acids 1473-1752) of the beta4 cytoplasmic domain and the conserved C2 region of the syndecan cytoplasmic domain. Via its C2 region, Sdc1 forms a complex with the alpha6beta4 integrin along with the receptor tyrosine kinase ErbB2 and the cytoplasmic kinase Fyn in A431 cells. Engagement of LN332 or clustering of the alpha6beta4 integrin with integrin-specific antibodies causes phosphorylation of ErbB2, Fyn, and the beta4 subunit as well as activation of phosphatidylinositol 3-kinase and Akt and their assimilation into this complex. This leads to phosphatidylinositol 3-kinase-dependent cell spreading and Akt-dependent protection from apoptosis. This is disrupted by RNA interference silencing of Sdc1 but can be rescued by mouse Sdc1 or Sdc4 but not by syndecan mutants lacking their C-terminal C2 region. This disruption does not prevent the phosphorylation of ErbB2 or Fyn but blocks the Fyn-mediated phosphorylation of the beta4 tail. We propose that syndecans engage the distal region of the beta4 cytoplasmic domain and bring it to the plasma membrane, where it can be acted upon by Src family kinases.
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Affiliation(s)
- Haiyao Wang
- Department of Pathology and Laboratory Medicine, University of Wisconsin, Madison, Wisconsin 53705, USA
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66
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Abstract
The integrin family of cell adhesion receptors regulates a diverse array of cellular functions crucial to the initiation, progression and metastasis of solid tumours. The importance of integrins in several cell types that affect tumour progression has made them an appealing target for cancer therapy. Integrin antagonists, including the alphavbeta3 and alphavbeta5 inhibitor cilengitide, have shown encouraging activity in Phase II clinical trials and cilengitide is currently being tested in a Phase III trial in patients with glioblastoma. These exciting clinical developments emphasize the need to identify how integrin antagonists influence the tumour and its microenvironment.
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Affiliation(s)
- Jay S Desgrosellier
- Department of Pathology, Moores University of California at San Diego Cancer Center, La Jolla, 92093-0803, United States
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67
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Hanna JA, Bordeaux J, Rimm DL, Agarwal S. The function, proteolytic processing, and histopathology of Met in cancer. Adv Cancer Res 2009; 103:1-23. [PMID: 19854350 DOI: 10.1016/s0065-230x(09)03001-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The hepatocyte growth factor (HGF) and its receptor, the Met receptor tyrosine kinase, form a signaling network promoting cell proliferation, invasion, and survival in normal and cancer cells. Improper regulation of this pathway is attributed to many cancer types through overexpression, activating mutations, or autocrine loop formation. Many studies describe the localization of Met as membranous/cytoplasmic, but some studies using antibodies targeted to the C-terminal domain of Met report nuclear localization. This chapter seeks to highlight the histopathology and expression of Met in cancer and its association with clinicopathological characteristics. We also discuss recent studies of the proteolytic processing of Met and effects of the processing on the subcellular localization of Met. Finally, we comment on Met as a therapeutic target for cancer treatment.
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Affiliation(s)
- Jason A Hanna
- Department of Pathology, Yale University School of Medicine, New Haven, Connecticut 06520, USA
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Sun C, Wang N, Huang J, Xin J, Peng F, Ren Y, Zhang S, Miao J. Inhibition of phosphatidylcholine-specific phospholipase C prevents bone marrow stromal cell senescence in vitro. J Cell Biochem 2009; 108:519-28. [PMID: 19626662 DOI: 10.1002/jcb.22282] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Bone marrow stromal cells (BMSCs) can proliferate in vitro and can be transplanted for treating many kinds of diseases. However, BMSCs become senescent with long-term culture, which inhibits their application. To understand the mechanism underlying the senescence, we investigated the activity of phosphatidylcholine-specific phospholipase C (PC-PLC) and levels of integrin beta4, caveolin-1 and ROS with BMSC senescence. The activity of PC-PLC and levels of integrin beta4, caveolin-1 and ROS increased greatly during cell senescence. Selective inhibition of increased PC-PLC activity with D609 significantly decreased the number of senescence-associated beta galactosidase positive cells in BMSCs. Furthermore, D609 restored proliferation of BMSCs and their differentiation into adipocytes. Moreover, D609 suppressed the elevated levels of integrin beta4, caveolin-1 and ROS. The data suggest that PC-PLC is involved in senescence of BMSCs, and its function is associated with integrin beta4, caveolin-1 and ROS.
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Affiliation(s)
- Chunhui Sun
- Institute of Developmental Biology, School of Life Science, Shandong University, Jinan 250100, China
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69
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Kim TH, Kim HI, Soung YH, Shaw LA, Chung J. Integrin (alpha6beta4) signals through Src to increase expression of S100A4, a metastasis-promoting factor: implications for cancer cell invasion. Mol Cancer Res 2009; 7:1605-12. [PMID: 19808905 DOI: 10.1158/1541-7786.mcr-09-0102] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Integrin alpha6beta4 is linked to cancer cell motility and invasion in aggressive and metastatic cancer cells. In this study, we showed that expression of the beta4 integrin in MDA-MB-435 cancer cells (MDA-MB-435/beta4) leads to a dramatic increase in expression of a metastasis-promoting factor, S100A4, as determined by affymetrix gene chip microarray, quantitative real-time PCR, and Western blot analysis. Alternatively, knocking down beta4 integrin expression in MDA-MB-231 breast carcinoma cells by shRNA reduced the level of S100A4 expression. The mechanism by which alpha6beta4 enhances S100A4 expression involves Src, Akt, and NFAT. We have further shown that Y1494, a tyrosine residue of the ITIM motif in the cytoplasmic domain of the beta4 integrin subunit, is essential for alpha6beta4-dependent S100A4 expression. Reduction of S100A4 expression by shRNA blocked migration, invasion, and anchorage-independent growth of MDA-MB-435/beta4, SUM-159, and MDA-MB-231 cells. These studies define a novel mechanism by which integrin alpha6beta4 promotes cancer cell motility and invasion, and provides insight into how S100A4 expression is regulated in cancer cells.
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Affiliation(s)
- Tae Hyong Kim
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, Shreveport, Louisiana, USA
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70
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Abstract
The development of pulmonary metastasis is the major cause of death in osteosarcoma, and its molecular basis is poorly understood. In this study, we show that beta4 integrin is highly expressed in human osteosarcoma cell lines and tumor samples. Furthermore, highly metastatic MNNG-HOS cells have increased levels of beta4 integrin. Suppression of beta4 integrin expression by shRNA and disruption of beta4 integrin function by transfection of dominant-negative beta4 integrin was sufficient to revert this highly metastatic phenotype in the MNNG-HOS model without significantly affecting primary tumor growth. These findings suggest a role for beta4 integrin expression in the metastatic phenotype in human osteosarcoma cells. In addition, we identified a previously uncharacterized interaction between beta4 integrin and ezrin, a membrane-cytoskeletal linker protein that is implicated in the metastatic behavior of osteosarcoma. The beta4 integrin-ezrin interaction appears to be critical for maintenance of beta4 integrin expression. These data begin to integrate ezrin and beta4 integrin expression into a model of action for the mechanism of osteosarcoma metastases.
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71
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MET receptor tyrosine kinase as a therapeutic anticancer target. Cancer Lett 2009; 280:1-14. [DOI: 10.1016/j.canlet.2008.10.045] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2008] [Revised: 10/24/2008] [Accepted: 10/24/2008] [Indexed: 12/23/2022]
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72
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Bonuccelli G, Casimiro MC, Sotgia F, Wang C, Liu M, Katiyar S, Zhou J, Dew E, Capozza F, Daumer KM, Minetti C, Milliman JN, Alpy F, Rio MC, Tomasetto C, Mercier I, Flomenberg N, Frank PG, Pestell RG, Lisanti MP. Caveolin-1 (P132L), a common breast cancer mutation, confers mammary cell invasiveness and defines a novel stem cell/metastasis-associated gene signature. THE AMERICAN JOURNAL OF PATHOLOGY 2009; 174:1650-62. [PMID: 19395651 DOI: 10.2353/ajpath.2009.080648] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Here we used the Met-1 cell line in an orthotopic transplantation model in FVB/N mice to dissect the role of the Cav-1(P132L) mutation in human breast cancer. Identical experiments were performed in parallel with wild-type Cav-1. Cav-1(P132L) up-regulated the expression of estrogen receptor-alpha as predicted, because only estrogen receptor-alpha-positive patients have been shown to harbor Cav-1(P132L) mutations. In the context of primary tumor formation, Cav-1(P132L) behaved as a loss-of-function mutation, lacking any tumor suppressor activity. In contrast, Cav-1(P132L) caused significant increases in cell migration, invasion, and experimental metastasis, consistent with a gain-of-function mutation. To identify possible molecular mechanism(s) underlying this invasive gain-of-function activity, we performed unbiased gene expression profiling. From this analysis, we show that the Cav-1(P132L) expression signature contains numerous genes that have been previously associated with cell migration, invasion, and metastasis. These include i) secreted growth factors and extracellular matrix proteins (Cyr61, Plf, Pthlh, Serpinb5, Tnc, and Wnt10a), ii) proteases that generate EGF and HGF (Adamts1 and St14), and iii) tyrosine kinase substrates and integrin signaling/adapter proteins (Akap13, Cdcp1, Ddef1, Eps15, Foxf1a, Gab2, Hs2st1, and Itgb4). Several of the P132L-specific genes are also highly expressed in stem/progenitor cells or are associated with myoepithelial cells, suggestive of an epithelial-mesenchymal transition. These results directly support clinical data showing that patients harboring Cav-1 mutations are more likely to undergo recurrence and metastasis.
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Affiliation(s)
- Gloria Bonuccelli
- Department of Cancer Biology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107, USA.
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73
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Legate KR, Fässler R. Mechanisms that regulate adaptor binding to beta-integrin cytoplasmic tails. J Cell Sci 2009; 122:187-98. [PMID: 19118211 DOI: 10.1242/jcs.041624] [Citation(s) in RCA: 272] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Cells recognize and respond to their extracellular environment through transmembrane receptors such as integrins, which physically connect the extracellular matrix to the cytoskeleton. Integrins provide the basis for the assembly of intracellular signaling platforms that link to the cytoskeleton and influence nearly every aspect of cell physiology; however, integrins possess no enzymatic or actin-binding activity of their own and thus rely on adaptor molecules, which bind to the short cytoplasmic tails of integrins, to mediate and regulate these functions. Many adaptors compete for relatively few binding sites on integrin tails, so regulatory mechanisms have evolved to reversibly control the spatial and temporal binding of specific adaptors. This Commentary discusses the adaptor proteins that bind directly to the tails of beta integrins and, using talin, tensin, filamin, 14-3-3 and integrin-linked kinase (ILK) as examples, describes the ways in which their binding is regulated.
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Affiliation(s)
- Kyle R Legate
- Department of Molecular Medicine, Max Planck Institute of Biochemistry, Martinsried, Germany.
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74
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Xuan W, Li YJ, Liu G, Ben-David Y, Archer MC. Interleukin-24 induces expression of beta4 integrin but suppresses anchorage-independent growth of rat mammary tumor cells by a mechanism that is independent of beta4. Mol Cancer Res 2009; 7:433-42. [PMID: 19258414 DOI: 10.1158/1541-7786.mcr-08-0252] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Wistar-Furth rats develop multiple mammary adenocarcinomas following initiation with methylnitrosourea, whereas Copenhagen rats are resistant to the development of mammary tumors. We have previously isolated cell lines from tumors induced in resistant Copenhagen x Wistar-Furth F(1) rats by infusion of a retrovirus harboring v-Ha-ras directly into the main mammary ducts. Some of the cell lines were able to grow in soft agar, but a significant number did not display anchorage-independent growth. Here, we compared by microarray analysis genes that are differentially expressed in these cell lines. The expression of interleukin-24 (IL-24) and beta(4) integrin was highly correlated with the inability of cells to grow in soft agar. Ectopic expression of IL-24 in anchorage-independent cells inhibited their growth in monolayer culture, in soft agar, and in nude mice in vivo and inhibited their ability to migrate and invade in in vitro assays. Furthermore, growth suppression by IL-24 was associated with the transcriptional up-regulation of p27(Kip1) via the activation of Stat3. We showed, for the first time, that beta(4) integrin is a downstream target of IL-24. However, beta(4) does not play a direct role in regulating the proliferative capacity of rat mammary tumor cells. Our results show that IL-24 suppresses the growth of rat mammary carcinoma cells and may play a role in the resistance of Copenhagen rats to mammary carcinogenesis.
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Affiliation(s)
- Wanli Xuan
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
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75
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Mendoza M, Khanna C. Revisiting the seed and soil in cancer metastasis. Int J Biochem Cell Biol 2009; 41:1452-62. [PMID: 19401145 DOI: 10.1016/j.biocel.2009.01.015] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2008] [Revised: 01/21/2009] [Accepted: 01/22/2009] [Indexed: 12/12/2022]
Abstract
Metastasis remains the overwhelming cause of death for cancer patients. During metastasis, cancer cells will leave the primary tumor, intravasate into the bloodstream, arrest at a distant organ, and eventually develop into gross lesions at the secondary sites. This intricate process is influenced by innumerable factors and complex cellular interactions described in 1889 by Stephen Paget as the seed and soil hypothesis. In this review, we revisit this seed and soil hypothesis with an emerging understanding of the cancer cell (i.e. seed) and its microenvironment (i.e. soil). We will provide background to suggest that a critical outcome of the seed-soil interaction is resistance of the stresses that would otherwise impede metastasis.
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Affiliation(s)
- Martin Mendoza
- Tumor and Metastasis Biology Section, Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, 37 Convent Drive, Bethesda, MD 20892, USA
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76
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Chen LL, Gabarra V, Cho S, Browning B, Cao X, Huet H, Cheung A, Morena R, Ramirez M, Shields M, Blake Pepinsky R, McLachlan K. Functional characterization of integrin alpha6beta4 adhesion interactions using soluble integrin constructs reveals the involvement of different functional domains in the beta4 subunit. ACTA ACUST UNITED AC 2008; 15:317-31. [PMID: 18979297 DOI: 10.1080/15419060802428356] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Integrin alpha6beta4-mediated adhesion interactions play key roles in keratinocyte and epithelial tumor cell biology. In order to evaluate how alpha6beta4 adhesion interactions contribute to these important cellular processes, the authors generated soluble versions of the integrin by recombinant expression of the subunit ectodomains fused to a human immunoglobulin G (IgG) Fc constant domain. Coexpression of the appropriate subunits enabled dimerization, secretion and purification of stable Fc-containing alpha6beta4 heterodimers. The soluble proteins exhibited the same metal ion and ligand dependency in their binding characteristics as intact alpha6beta4. Using these reagents in combination with anti-beta4 antibodies, the authors identified two distinct functional epitopes on the beta4 subunit. They demonstrated the involvement of one epitope in adhesion interactions and the other in regulating adhesion-independent growth in alpha6beta4-expressing tumor cell lines. The availability of these soluble integrin reagents and the data provided herein help to further delineate the structure-function relationships regulating alpha6beta4 signaling biology.
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77
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Dutta U, Shaw LM. A key tyrosine (Y1494) in the beta4 integrin regulates multiple signaling pathways important for tumor development and progression. Cancer Res 2008; 68:8779-87. [PMID: 18974120 DOI: 10.1158/0008-5472.can-08-2125] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Expression of the alpha6beta4 integrin is associated with poor patient prognosis and reduced survival in a variety of human cancers. In recent years, a limited number of in vivo studies have examined the contribution of this integrin receptor to cancer progression and they have revealed that the alpha6beta4 integrin plays a multifaceted role in regulating tumor development and progression. In the current study, we investigated the mechanism by which one tyrosine residue in the beta4 subunit cytoplasmic domain, Y1494, contributes to the tumor-promoting functions of the alpha6beta4 integrin in vivo. We show that Y1494 participates in the stimulation of diverse signaling pathways that promote alpha6beta4-dependent tumor growth and invasion. Mutation of Y1494 inhibits the ability of the alpha6beta4 integrin to support anchorage-independent growth in vitro and tumor development and angiogenesis in vivo, a result that mimics the loss of total expression of the beta4 subunit. Our results support the hypothesis that Y1494 regulates alpha6beta4-dependent anchorage-independent growth through activation of the extracellular signal-regulated kinase 1/2 signaling pathway, and invasion through the combined activation of phosphatidylinositol 3-kinase and Src. Collectively, our results identify Y1494 as a major regulatory site for signaling from the alpha6beta4 integrin to promote tumor development and progression.
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Affiliation(s)
- Udayan Dutta
- Department of Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
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78
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Yang L, Zhang L, Wu Q, Boyd DD. Unbiased screening for transcriptional targets of ZKSCAN3 identifies integrin beta 4 and vascular endothelial growth factor as downstream targets. J Biol Chem 2008; 283:35295-304. [PMID: 18940803 DOI: 10.1074/jbc.m806965200] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
We previously described the novel zinc finger protein ZKSCAN3 as a new "driver" of colon cancer progression. To investigate the underlying mechanism and because the predicted structural features (tandem zinc fingers) are often present in transcription factors, we hypothesized that ZKSCAN3 regulates the expression of a gene(s) favoring tumor progression. We employed unbiased screening to identify a DNA binding motif and candidate downstream genes. Cyclic amplification and selection of targets using a random oligonucleotide library and ZKSCAN3 protein identified KRDGGG as the DNA recognition motif. In expression profiling, 204 genes were induced 2-29-fold, and 76 genes reduced 2-5-fold by ZKSCAN3. To enrich for direct targets, we eliminated genes under-represented (<3) for the ZKSCAN3 binding motif (identified by CAST-ing) in 2 kilobases of regulatory sequence. Up-regulated putative downstream targets included genes contributing to growth (c-Met-related tyrosine kinase (MST1R), MEK2; the guanine nucleotide exchanger RasGRP2, insulin-like growth factor-2, integrin beta 4), cell migration (MST1R), angiogenesis (vascular endothelial growth factor), and proteolysis (MMP26; cathepsin D; PRSS3 (protease serine 3)). We pursued integrin beta 4 (induced up to 6-fold) as a candidate target because it promotes breast cancer tumorigenicity and stimulates phosphatidyl 3-kinase implicated in colorectal cancer progression. ZKSCAN3 overexpression/silencing modulated integrin beta 4 expression, confirming the array analysis. Moreover, ZKSCAN3 bound to the integrin beta 4 promoter in vitro and in vivo, and the integrin beta 4-derived ZKSCAN3 motif fused upstream of a tk-Luc reporter conferred ZKSCAN3 sensitivity. Integrin beta 4 knockdown by short hairpin RNA countered ZKSCAN3-augmented anchorage-independent colony formation. We also demonstrate vascular endothelial growth factor as a direct ZKSCAN3 target. Thus, ZKSCAN3 regulates the expression of several genes favoring tumor progression including integrin beta 4.
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Affiliation(s)
- Lin Yang
- Department of Cancer Biology, University of Texas, MD Anderson Cancer Center, Houston, Texas 77030, USA
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79
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Regulation of hemidesmosome disassembly by growth factor receptors. Curr Opin Cell Biol 2008; 20:589-96. [DOI: 10.1016/j.ceb.2008.05.001] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2008] [Accepted: 05/13/2008] [Indexed: 11/20/2022]
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80
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Macias-Perez I, Borza C, Chen X, Yan X, Ibanez R, Mernaugh G, Matrisian LM, Zent R, Pozzi A. Loss of integrin alpha1beta1 ameliorates Kras-induced lung cancer. Cancer Res 2008; 68:6127-35. [PMID: 18676835 DOI: 10.1158/0008-5472.can-08-1395] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The collagen IV binding receptor integrin alpha1beta1 has been shown to regulate lung cancer due to its proangiogenic properties; however, it is unclear whether this receptor also plays a direct role in promoting primary lung tumors. To investigate this possibility, integrin alpha1-null mice were crossed with KrasLA2 mice that carry an oncogenic mutation of the Kras gene (G12D) and develop spontaneous primary tumors with features of non-small cell lung cancer. We provide evidence that KrasLA2/alpha1-null mice have a decreased incidence of primary lung tumors and longer survival compared with KrasLA2/alpha1 wild-type controls. Tumors from KrasLA2/alpha1-null mice were also smaller, less vascularized, and exhibited reduced cell proliferation and increased apoptosis, as determined by proliferating cell nuclear antigen and terminal deoxynucleotidyl-transferase-mediated dUTP nick-end staining, respectively. Moreover, tumors from the KrasLA2/alpha1-null mice showed diminished extracellular signal-regulated kinase (ERK) but enhanced p38 mitogen-activated protein kinase activation. Primary lung tumor epithelial cells isolated from KrasLA2/alpha1-null mice showed a significant decrease in anchorage-independent colony formation, collagen-mediated cell proliferation, ERK activation, and, most importantly, tumorigenicity when injected into nude mice compared with KrasLA2/alpha1 wild-type tumor cells. These results indicate that loss of the integrin alpha1 subunit decreases the incidence and growth of lung epithelial tumors initiated by oncogenic Kras, suggesting that both Kras and integrin alpha1beta1 cooperate to drive the growth of non-small cell lung cancer in vivo.
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Affiliation(s)
- Ines Macias-Perez
- Department of Medicine, Division of Nephrology, Vanderbilt University Medical Center, Veterans Affairs Hospital, Nashville, Tennessee 37232, USA
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81
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Zhou X, Coad J, Ducatman B, Agazie YM. SHP2 is up-regulated in breast cancer cells and in infiltrating ductal carcinoma of the breast, implying its involvement in breast oncogenesis. Histopathology 2008; 53:389-402. [PMID: 18643929 DOI: 10.1111/j.1365-2559.2008.03103.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
AIMS To determine whether Src homology phosphotyrosyl phosphatase 2 (SHP2) is up-regulated in breast cancer and, if so, to determine whether its up-regulation has any relationship with clinical variables of breast cancer. METHODS AND RESULTS Immunoblotting, immunohistochemistry and immunofluorescence microscopy were used to assess the state of SHP2 expression in breast cancer cells and in infiltrating ductal carcinoma (IDC) of breast. The possible role of SHP2 in breast cancer cell transformation was determined by dominant-negative expression and anchorage-independent growth assays. All of the breast cancer cell lines tested and 72% of IDC breast tumours analysed had increased amounts of the SHP2 protein. In support of its positive role, dominant-negative SHP2 blocked anchorage-independent growth of breast cancer cells. Furthermore, overexpression of SHP2 seemed to have a positive relationship to HER2 overexpression, nuclear accumulation of hormone receptors, higher tumour grade and lymph node metastasis, but not to age of breast cancer patients. CONCLUSION SHP2 is a widely overexpressed signalling protein in IDC breast tumours. Given SHP2's positive role in cell growth, transformation and stem cell survival, the positive relationship of its overexpression to lymph node metastasis, nuclear accumulation of hormone receptors and higher tumour grade suggests that SHP2 promotes breast oncogenesis.
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Affiliation(s)
- X Zhou
- Department of Biochemistry and Molecular Biology, West Virginia University, Morgantown, WV 26506, USA
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82
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Abstract
Diverse cellular processes are regulated by tyrosyl phosphorylation, which is controlled by protein-tyrosine kinases (PTKs) and protein-tyrosine phosphatases (PTPs). De-regulated tyrosyl phosphorylation, evoked by gain-of-function mutations and/or over-expression of PTKs, contributes to the pathogenesis of many cancers and other human diseases. PTPs, because they oppose the action of PTKs, had been considered to be prime suspects for potential tumor suppressor genes. Surprisingly, few, if any, tumor suppressor PTPs have been identified. However, the Src homology-2 domain-containing phosphatase Shp2 (encoded by PTPN11) is a bona fide proto-oncogene. Germline mutations in PTPN11 cause Noonan and LEOPARD syndromes, whereas somatic PTPN11 mutations occur in several types of hematologic malignancies, most notably juvenile myelomonocytic leukemia and, more rarely, in solid tumors. Shp2 also is an essential component in several other oncogene signaling pathways. Elucidation of the events underlying Shp2-evoked transformation may provide new insights into oncogenic mechanisms and novel targets for anti-cancer therapy.
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83
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Drug development of MET inhibitors: targeting oncogene addiction and expedience. Nat Rev Drug Discov 2008; 7:504-16. [PMID: 18511928 DOI: 10.1038/nrd2530] [Citation(s) in RCA: 646] [Impact Index Per Article: 40.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The MET tyrosine kinase stimulates cell scattering, invasion, protection from apoptosis and angiogenesis, thereby acting as a powerful expedient for cancer dissemination. MET can also be genetically selected for the long-term maintenance of the primary transformed phenotype, and some tumours appear to be dependent on (or 'addicted' to) sustained MET activity for their growth and survival. Because of its dual role as an adjuvant, pro-metastatic gene for some tumour types and as a necessary oncogene for others, MET is a versatile candidate for targeted therapeutic intervention. Here we discuss recent progress in the development of molecules that inhibit MET function and consider their application in a subset of human tumours that are potentially responsive to MET-targeted therapies.
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84
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Abstract
Integrin beta 4, one of the heterodimeric receptors, is expressed predominantly on epithelial cells. It is concentrated at the basement membrane zone, where it localizes to specialized adhesion structures called hemidesmosomes. In addition to its adhesive functions, novel insights have emerged regarding the specific roles of integrin beta 4 in their attachment to extracellular matrix and in their signal transduction pathways within the central nervous system (CNS) and peripheral nervous system in the past few years. It has been reported that integrin beta 4 is expressed in several kinds of neural cells including astrocyte, Schwann cells, neurons, and neural stem cells. In the mean while, it is expressed by some Schwann cells in the peripheral nervous system and mediated the Mycobacterium leprae invade the peripheral nervous system to reach the Schwann cells. This review highlights recent progress in the function and regulation of integrin beta 4 in neural cells.
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85
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Zhou XD, Agazie YM. Inhibition of SHP2 leads to mesenchymal to epithelial transition in breast cancer cells. Cell Death Differ 2008; 15:988-96. [DOI: 10.1038/cdd.2008.54] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
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86
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87
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Lv X, Su L, Yin D, Sun C, Zhao J, Zhang S, Miao J. Knockdown of integrin beta4 in primary cultured mouse neurons blocks survival and induces apoptosis by elevating NADPH oxidase activity and reactive oxygen species level. Int J Biochem Cell Biol 2007; 40:689-99. [PMID: 18006359 DOI: 10.1016/j.biocel.2007.10.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2007] [Revised: 10/02/2007] [Accepted: 10/03/2007] [Indexed: 12/20/2022]
Abstract
Recently, the specific roles of integrin beta4 in the signaling networks that drive pathological angiogenesis and tumor progression have been revealed. Our previous study showed that integrin beta4 might be involved in neuron survival signal transduction. To further our study on the role of integrin beta4 in the survival and apoptosis of primary cultured mouse neurons, we inhibited the expression of integrin beta4 by its specific small interfering RNA. Viability of the cells remarkably declined, and neurons underwent apoptosis with down-regulation of integrin beta4. Next, we investigated the effect of siRNA-mediated down-regulation of integrin beta4 on the level of intracellular reactive oxygen species and the activities of NADPH oxidase and superoxide dismutase. The level of reactive oxygen species in the neurons was elevated significantly, the activities of manganese-dependent superoxide dismutase and copper/zinc-dependent superoxide dismutase were not altered, but the activity of NADPH oxidase was increased. Furthermore, inhibition of NADPH oxidase by its specific inhibitor dibenziodolium chloride attenuated the neuronal death induced by integrin beta4 knockdown. The data suggest that integrin beta4 is a key factor in neuron survival and apoptosis and indicate that this integrin subunit might perform its action through regulating NADPH oxidase and the level of reactive oxygen species in neuronal survival and apoptosis.
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Affiliation(s)
- Xin Lv
- Institute of Developmental Biology, Shandong University, Jinan 250100, China
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88
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The molecular functions of Shp2 in the Ras/Mitogen-activated protein kinase (ERK1/2) pathway. Cell Signal 2007; 20:453-9. [PMID: 17993263 DOI: 10.1016/j.cellsig.2007.10.002] [Citation(s) in RCA: 248] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2007] [Accepted: 10/03/2007] [Indexed: 01/13/2023]
Abstract
Shp2 is a ubiquitous tyrosine phosphatase containing Src Homology 2 domains which plays major biological functions in response to various growth factors, hormones or cytokines. This is essentially due to its particularity of promoting the activation of the Ras/Mitogen-activated protein kinase pathway. Recent progresses have been made in the understanding of the molecular mechanisms involved in this regulation. We review here, and discuss the physiological relevance, of the following molecular functions of Shp2 that have been proposed to couple the phosphatase to Ras activation: promoter of Grb2/Sos recruitment through direct binding to Grb2, binding partner and regulator of SHPS-1, negative regulator of Sprouty, negative regulator of RasGAP recruitment, and activator of Src through dephosphorylation of Src-regulatory proteins.
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89
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Giancotti FG. Targeting integrin β4 for cancer and anti-angiogenic therapy. Trends Pharmacol Sci 2007; 28:506-11. [PMID: 17822782 DOI: 10.1016/j.tips.2007.08.004] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2007] [Revised: 06/12/2007] [Accepted: 08/29/2007] [Indexed: 10/22/2022]
Abstract
The integrins play key roles in the signaling networks that drive pathological angiogenesis and tumor progression. Integrin beta4 is a laminin receptor upregulated in tumor cells and angiogenic endothelial cells. Biochemical studies have indicated that beta4 combines with and enhances the signaling function of multiple receptor tyrosine kinases, including ErbB2, EGF-R and Met. Genetic studies have revealed that beta4 signaling promotes both angiogenesis and tumorigenesis. Here, I discuss the hypothesis that beta4 promotes both processes by amplifying receptor-tyrosine-kinase signaling. Therefore, I propose that a simultaneous blockade of beta4 and receptor-tyrosine-kinase signaling represents a rational approach to cancer and anti-angiogenic therapy.
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Affiliation(s)
- Filippo G Giancotti
- Cell Biology Program, Sloan-Kettering Institute for Cancer Research, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, Box 216, New York, NY 10021, USA.
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Merdek KD, Yang X, Taglienti CA, Shaw LM, Mercurio AM. Intrinsic Signaling Functions of the β4 Integrin Intracellular Domain. J Biol Chem 2007; 282:30322-30. [PMID: 17711859 DOI: 10.1074/jbc.m703156200] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A key issue regarding the role of alpha6beta4 in cancer biology is the mechanism by which this integrin exerts its profound effects on intracellular signaling, including growth factor-mediated signaling. One approach is to evaluate the intrinsic signaling capacity of the unique beta4 intracellular domain in the absence of contributions from the alpha6 subunit and tetraspanins and to assess the ability of growth factor receptor signaling to cooperate with this domain. Here, we generated a chimeric receptor composed of the TrkB extracellular domain and the beta4 transmembrane and intracellular domains. Expression of this chimeric receptor in beta4-null cancer cells enabled us to assess the signaling potential of the beta4 intracellular domain alone or in response to dimerization using brain-derived neurotrophic factor, the ligand for TrkB. Dimerization of the beta4 intracellular domain results in the binding and activation of the tyrosine phosphatase SHP-2 and the activation of Src, events that also occur upon ligation of intact alpha6beta4. In contrast to alpha6beta4 signaling, however, dimerization of the chimeric receptor does not activate either Akt or Erk1/2. Growth factor stimulation induces tyrosine phosphorylation of the chimeric receptor but does not enhance its binding to SHP-2. The chimeric receptor is unable to amplify growth factor-mediated activation of Akt and Erk1/2, and growth factor-stimulated migration. Collectively, these data indicate that the beta4 intracellular domain has some intrinsic signaling potential, but it cannot mimic the full signaling capacity of alpha6beta4. These data also question the putative role of the beta4 intracellular domain as an "adaptor" for growth factor receptor signaling.
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Affiliation(s)
- Keith D Merdek
- Department of Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
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Wilhelmsen K, Litjens SH, Kuikman I, Margadant C, van Rheenen J, Sonnenberg A. Serine phosphorylation of the integrin beta4 subunit is necessary for epidermal growth factor receptor induced hemidesmosome disruption. Mol Biol Cell 2007; 18:3512-22. [PMID: 17615294 PMCID: PMC1951768 DOI: 10.1091/mbc.e07-04-0306] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Hemidesmosomes (HDs) are multiprotein adhesion complexes that promote attachment of epithelial cells to the basement membrane. The binding of alpha6beta4 to plectin plays a central role in their assembly. We have defined three regions on beta4 that together harbor all the serine and threonine phosphorylation sites and show that three serines (S1356, S1360, and S1364), previously implicated in HD regulation, prevent the interaction of beta4 with the plectin actin-binding domain when phosphorylated. We have also established that epidermal growth factor receptor activation, which is known to function upstream of HD disassembly, results in the phosphorylation of only one or more of these three residues and the partial disassembly of HDs in keratinocytes. Additionally, we show that S1360 and S1364 of beta4 are the only residues phosphorylated by PKC and PKA in cells, respectively. Taken together, our studies indicate that multiple kinases act in concert to breakdown the structural integrity of HDs in keratinocytes, which is primarily achieved through the phosphorylation of S1356, S1360, and S1364 on the beta4 subunit.
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Affiliation(s)
- Kevin Wilhelmsen
- Division of Cell Biology, The Netherlands Cancer Institute, 1066 CX Amsterdam, The Netherlands
| | - Sandy H.M. Litjens
- Division of Cell Biology, The Netherlands Cancer Institute, 1066 CX Amsterdam, The Netherlands
| | - Ingrid Kuikman
- Division of Cell Biology, The Netherlands Cancer Institute, 1066 CX Amsterdam, The Netherlands
| | - Coert Margadant
- Division of Cell Biology, The Netherlands Cancer Institute, 1066 CX Amsterdam, The Netherlands
| | - Jacco van Rheenen
- Division of Cell Biology, The Netherlands Cancer Institute, 1066 CX Amsterdam, The Netherlands
| | - Arnoud Sonnenberg
- Division of Cell Biology, The Netherlands Cancer Institute, 1066 CX Amsterdam, The Netherlands
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