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Badr G, Lefevre EA, Mohany M. Thymoquinone inhibits the CXCL12-induced chemotaxis of multiple myeloma cells and increases their susceptibility to Fas-mediated apoptosis. PLoS One 2011; 6:e23741. [PMID: 21912642 PMCID: PMC3164673 DOI: 10.1371/journal.pone.0023741] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2011] [Accepted: 07/24/2011] [Indexed: 11/18/2022] Open
Abstract
In multiple myeloma (MM), malignant plasma cells reside in the bone marrow, where they accumulate in close contact with stromal cells. The mechanisms responsible for the chemotaxis of malignant plasma cells are still poorly understood. Thus, we investigated the mechanisms involved in the chemotaxis of MDN and XG2 MM cell lines. Both cell lines strongly expressed CCR9, CXCR3 and CXCR4 chemokine receptors but only migrated toward CXCL12. Activation of CXCR4 by CXCL12 resulted in the association of CXCR4 with CD45 and activation of PLCβ3, AKT, RhoA, IκBα and ERK1/2. Using siRNA-silencing techniques, we showed CD45/CXCR4 association is essential for CXCL12-induced migration of MM cells. Thymoquinone (TQ), the major active component of the medicinal herb Nigella sativa Linn, has been described as a chemopreventive and chemotherapeutic compound. TQ treatment strongly inhibited CXCL12-mediated chemotaxis in MM cell lines as well as primary cells isolated from MM patients, but not normal PBMCs. Moreover, TQ significantly down-regulated CXCR4 expression and CXCL12-mediated CXCR4/CD45 association in MM cells. Finally, TQ also induced the relocalization of cytoplasmic Fas/CD95 to the membrane of MM cells and increased CD95-mediated apoptosis by 80%. In conclusion, we demonstrate the potent anti-myeloma activity of TQ, providing a rationale for further clinical evaluation.
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Affiliation(s)
- Gamal Badr
- Zoology Department, College of Science, King Saud University, Riyadh, Saudi Arabia.
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2
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Non-viral systemic delivery of Fas siRNA suppresses cyclophosphamide-induced diabetes in NOD mice. J Control Release 2010; 143:88-94. [PMID: 20004692 DOI: 10.1016/j.jconrel.2009.12.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2009] [Revised: 11/08/2009] [Accepted: 12/02/2009] [Indexed: 12/14/2022]
Abstract
A membrane receptor, Fas (CD95), and its ligand FasL have been considered as key players in diabetes pathogenesis. They are known to mediate interactions between beta cells and cytotoxic T cells, which results in apoptotic cell death. We hypothesized that the interruption of Fas-FasL interactions by suppressing Fas expression in beta cells would affect the development of diabetes. The effect of Fas-silencing siRNA (Fas siRNA) on diabetes development was evaluated in a cyclophosphamide (CY)-accelerated diabetes animal model after intravenous administration using a polymeric carrier, polyethylenimine (PEI). The systemic non-viral delivery of Fas siRNA showed significant delay in diabetes incidence up to 40 days, while the control mice treated with naked Fas siRNA, scrambled dsRNA, or PBS were afflicted with diabetes within 20 days. The retardation of diabetes incidence after the treatment of Fas siRNA may be due to the delayed progression of the pancreatic insulitis. In this study, the potential use of a non-viral carrier based siRNA gene therapy for the prevention of type-1 diabetes is demonstrated.
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3
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Lin CH, Shih WL, Lin FL, Hsieh YC, Kuo YR, Liao MH, Liu HJ. Bovine ephemeral fever virus-induced apoptosis requires virus gene expression and activation of Fas and mitochondrial signaling pathway. Apoptosis 2009; 14:864-77. [PMID: 19521777 DOI: 10.1007/s10495-009-0371-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Although induction of apoptosis by bovine ephemeral fever virus (BEFV) in several cell lines has been previously demonstrated by our laboratory, less information is available on the process of BEFV-induced apoptosis in terms of cellular pathways and specific proteins involved. In order to determine the step in viral life cycle at which apoptosis of infected cells is triggered, chemical and physical agents were used to block viral infection. Treatment of BHK-21 infected cells with ammonium chloride (NH4Cl) or cells infected with UV-inactivated BEFV was seen to abrogate virus apoptosis induction, suggesting that virus uncoating and gene expression are required for the induction of apoptosis. Using soluble death receptors Fc:Fas chimera to block Fas signaling, BEFV-induced apoptosis was inhibited in cells. BEFV infection of BHK-21 cells results in the Fas-dependent activation of caspase 8 and cleavage of Bid. This initiated the dissipation of the membrane potential and the release of cytochrome c but not AIF or Smac/DIABLO from mitochondrial into cytoplasm leading to activation of caspase 9. Combined activation of the death receptor and mitochondrial pathways results in activation of the downstream effecter caspase 3 leading to cleavage of PARP. Fas-mediated BEFV-induced apoptosis could be suppressed by the overexpression of Bcl-2 or by treatment with caspase inhibitors and soluble death receptors Fc:Fas chimera. Taken together, this study provided first evidence demonstrating that BEFV-induced apoptosis requires viral gene expression and occurs through the activation of Fas and mitochondrion-mediated caspase-dependent pathways.
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Affiliation(s)
- Chi-Hung Lin
- Department of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, Taiwan
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4
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Receptor density is key to the alpha2/beta interferon differential activities. Mol Cell Biol 2009; 29:4778-87. [PMID: 19564411 DOI: 10.1128/mcb.01808-08] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Multiple type I interferons (IFN-alpha/beta) elicit Jak/Stat activation, rapid gene induction, and pleiotropic effects, such as differentiation, antiviral protection, and blocks in proliferation, which are dependent on the IFN subtype and the cellular context. To date, ligand- and receptor-specific molecular determinants underlying IFN-alpha/beta differential activities or potencies have been well characterized. To analyze cellular determinants that impact subtype-specific potency, human fibrosarcoma U5A-derived clones, exhibiting a gradient of IFN sensitivity by virtue of increasing receptor levels, were monitored for Jak/Stat signaling, gene induction, cell cycle lengthening, and apoptosis. In cells with scarce receptors, IFN-beta was more potent than IFN-alpha2 in antiproliferative activity, while the two subtypes were equipotent in all other readouts. Conversely, in cells with abundant receptors, IFN-alpha2 matched or even surpassed IFN-beta in all readouts tested. Our results suggest that the differential activities of the IFN subtypes are dictated not only by the intrinsic ligand/receptor binding kinetics but also by the density of cell surface receptor components.
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5
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Rasche S, Busick RY, Quinn A. GAD65-Specific Cytotoxic T Lymphocytes Mediate Beta-Cell Death and Loss of Function. Rev Diabet Stud 2009; 6:43-53. [PMID: 19557295 DOI: 10.1900/rds.2009.6.43] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Autoimmunity to islet cell antigens like glutamic acid decarboxylase 65kD (GAD65) is associated with the destruction of insulin-producing beta-cells and progression to type 1 diabetes (T1D) in NOD mice and humans. T cell responses to GAD65 are detectable in the spleen of prediabetic NOD mice and in the peripheral blood of humans prior to the onset of overt hyperglycemia. Previous findings from our lab revealed that GAD65(546-554)-specific cytotoxic T lymphocytes (CTL) are present in naïve NOD mice and are able to induce islet inflammation upon adoptive transfer into NOD.scid recipients. Additionally, we found that professional antigen-presenting cells (APC) generate the p546-554 epitope from a soluble GAD65 fragment, p530-554, and from GAD65 released by injured beta-cells in vivo. Here, we report that the GAD65 fragment p546-554 is a dominant CTL-inducing epitope which is naturally processed and presented by a GAD65-expressing beta-cell line. Further, co-culture of GAD65(546-554)-specific CTL with the beta-cells leads to a reduction in insulin production and the induction of perforin-mediated cell death. Collectively, these findings support a role for the cross-presentation of GAD65 antigen in the priming and enhancement of dominant GAD65-specific CTL responses, which can directly target beta-cells that display GAD65 epitopes.
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Affiliation(s)
- Sarah Rasche
- Department of Biological Sciences, University of Toledo, 2801 W. Bancroft, Toledo, OH 43606, USA
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6
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Gaddy DF, Lyles DS. Oncolytic vesicular stomatitis virus induces apoptosis via signaling through PKR, Fas, and Daxx. J Virol 2006; 81:2792-804. [PMID: 17192316 PMCID: PMC1865982 DOI: 10.1128/jvi.01760-06] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Matrix (M) protein mutants of vesicular stomatitis virus (VSV) are promising oncolytic agents for cancer therapy. Previous research has implicated Fas and PKR in apoptosis induced by other viruses. Here, we show that dominant-negative mutants of Fas and PKR inhibit M protein mutant virus-induced apoptosis. Most previous research has focused on the adapter protein FADD as a necessary transducer of Fas-mediated apoptosis. However, the expression of dominant-negative FADD had little effect on the induction of apoptosis by M protein mutant VSV. Instead, virus-induced apoptosis was inhibited by the expression of a dominant-negative mutant of the adapter protein Daxx. These data indicate that Daxx is more important than FADD for apoptosis induced by M protein mutant VSV. These results show that PKR- and Fas-mediated signaling play important roles in cell death during M protein mutant VSV infection and that Daxx has novel functions in the host response to virus infection by mediating virus-induced apoptosis.
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Affiliation(s)
- Daniel F Gaddy
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA
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7
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Rosner D, Stoneman V, Littlewood T, McCarthy N, Figg N, Wang Y, Tellides G, Bennett M. Interferon-gamma induces Fas trafficking and sensitization to apoptosis in vascular smooth muscle cells via a PI3K- and Akt-dependent mechanism. THE AMERICAN JOURNAL OF PATHOLOGY 2006; 168:2054-63. [PMID: 16723718 PMCID: PMC1606618 DOI: 10.2353/ajpath.2006.050473] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Vascular smooth muscle cell (VSMC) apoptosis occurs in advanced atherosclerotic plaques where it may contribute to plaque instability. VSMCs express the death receptor Fas but are relatively resistant to Fas-induced apoptosis due in part to the intracellular sequestration of Fas. Although inflammatory cytokines such as interferon (IFN)-gamma present in plaques can prime VSMCs to FasL-induced death, the mechanism of this effect is unclear. We examined Fas expression and FasL-induced apoptosis in human VSMCs in response to IFN-gamma. IFN-gamma induced Fas trafficking to the cell surface within 24 hours, an effect that required Jak2/Stat1 activity. IFN-gamma also stimulated Akt activity, and both Fas trafficking and Stat1 activation were inhibited by blocking PI3K, Akt, or Jak-2. IFN-gamma increased Fas-induced apoptosis in vitro by 46 +/- 8% (mean +/- SEM, P = 0.04), an event that could be abrogated by inhibition of PI3K, Akt, or Jak-2. IFN-gamma also increased Fas-induced apoptosis in vivo 7.5- to 15-fold (P < 0.05) in human arteries transplanted into immunodeficient mice, accompanied by increased Fas and phospho-Ser727-Stat1. We conclude that IFN-gamma primes VSMCs to Fas-induced apoptosis, in part by relocation of Fas to the cell surface, a process that involves PI3K, Akt, and Jak-2/Stat1. IFN-gamma present in plaques may co-operate with FasL to induce VSMC apoptosis in atherosclerosis.
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Affiliation(s)
- Dalya Rosner
- Division of Cardiovascular Medicine, University of Cambridge Clinical School of Medicine Addenbrooke's Centre for Clinical Investigation, Box 110, Addenbrooke's Hospital, Cambridge, CB2 2QQ, UK
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8
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Burkhardt BR, Lyle R, Qian K, Arnold AS, Cheng H, Atkinson MA, Zhang YC. Efficient delivery of siRNA into cytokine-stimulated insulinoma cells silences Fas expression and inhibits Fas-mediated apoptosis. FEBS Lett 2005; 580:553-60. [PMID: 16412430 DOI: 10.1016/j.febslet.2005.12.068] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2005] [Revised: 12/19/2005] [Accepted: 12/21/2005] [Indexed: 11/29/2022]
Abstract
Fas/FasL interactions have been proposed as a potentially important mechanism mediating beta-cell death in type 1 diabetes. Recent investigations suggest RNA interference, afforded by small interfering RNAs (siRNA), can provide specific and robust gene silencing in mammalian cells. The current study attempted to investigate the effects of silencing Fas expression with siRNA on Fas-mediated apoptosis in mouse insulinoma cells following cytokine incubation. Our results indicate that siRNA is capable of rapid inhibition of cytokine-induced Fas mRNA production and cell surface Fas protein. A complete suppression of the total Fas protein was only observed after prolonged incubation with siRNA, suggesting a slow turn-over of Fas protein. Moreover, siRNA significantly inhibited Fas-mediated beta-cell apoptosis assessed by Caspase-3 and terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling assays, the extent of which positively correlated with the level of cell surface Fas. These observations provide additional evidence supporting a role for the Fas-mediated pathway in beta-cell destruction, and suggest that siRNA targeting Fas may be of therapeutic value in preventing type 1 diabetes and improving islet cell viability in transplantation.
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Affiliation(s)
- Brant R Burkhardt
- University of Pennsylvania, Children's Hospital of Philadelphia, Department of Pathology, PA, USA
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9
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Augstein P, Bahr J, Wachlin G, Heinke P, Berg S, Salzsieder E, Harrison LC. Cytokines activate caspase-3 in insulinoma cells of diabetes-prone NOD mice directly and via upregulation of Fas. J Autoimmun 2004; 23:301-9. [PMID: 15571924 DOI: 10.1016/j.jaut.2004.09.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2003] [Revised: 09/14/2004] [Accepted: 09/15/2004] [Indexed: 11/26/2022]
Abstract
In type 1 diabetes, autoimmune inflammation of pancreatic islets of Langerhans ('insulitis') results in destruction of insulin-producing beta cells. Cytokines released from islet-infiltrating mononuclear cells are known to be cytotoxic both directly and by upregulating Fas for FasL-induced apoptosis. To investigate the role of caspase-3, a major effector of apoptosis in beta-cell death, we asked whether cytokine- and/or FasL-induced apoptosis was associated with increased activity of caspase-3 in NIT-1 insulinoma cells and islets of autoimmune diabetes-prone NOD mice. Measurement of caspase-3 activity using a fluorogenic cleavage assay was validated in NOD mouse thymocytes undergoing dexamethasone (Dex)-induced apoptosis. For cytokine-induced apoptosis, NIT-1 cells or islets were exposed to IL-1 beta and IFN-gamma for 24 h. Caspase-3-like activity was increased 2.1+/-0.7 and 2.4+/-0.9-fold in lysates of cytokine-treated NIT-1 cells and NOD mouse islets, respectively. However, NIT-1 cells exhibited 2.1% (4.7 pg active caspase-3/microg protein) and islets 0.8% (1.9 pg active caspase-3/microg protein) of the active caspase-3 content observed in Dex-treated thymocytes (225.1 pg active caspase-3/microg protein). After 24 h cytokine-exposure, the percentage of Fas-positive NIT-1 cells increased from 1.4+/-1.1 to 29.7+/-11.6%. Addition of FasL for a further 3 h increased caspase-3-like activity an additional 1.8-fold in cytokine-treated NIT-1 cells. In summary, exposure of NOD mouse insulinoma cells or islets to IL-1 beta and IFN-gamma for 24 h induced caspase-3-like activity that, in the case of insulinoma cells at least, can be further enhanced by interaction of cytokine-induced Fas receptor with FasL. Compared to thymocytes, insulinoma cells and islets from NOD mice were characterised by low basal and cytokine-induced caspase-3 activity.
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Affiliation(s)
- Petra Augstein
- Institute of Diabetes Gerhardt Katsch Karlsburg e.V., Greifswalder Strasse 11e, 17495 Karlsburg, Germany.
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10
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Hui H, Dotta F, Di Mario U, Perfetti R. Role of caspases in the regulation of apoptotic pancreatic islet beta-cells death. J Cell Physiol 2004; 200:177-200. [PMID: 15174089 DOI: 10.1002/jcp.20021] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The homeostatic control of beta-cell mass in normal and pathological conditions is based on the balance of proliferation, differentiation, and death of the insulin-secreting cells. A considerable body of evidence, accumulated during the last decade, has emphasized the significance of the disregulation of the mechanisms regulating the apoptosis of beta-cells in the sequence of events that lead to the development of diabetes. The identification of agents capable of interfering with this process needs to be based on a better understanding of the beta-cell specific pathways that are activated during apoptosis. The aim of this article is fivefold: (1) a review of the evidence for beta-cell apoptosis in Type I diabetes, Type II diabetes, and islet transplantation, (2) to review the common stimuli and their mechanisms in pancreatic beta-cell apoptosis, (3) to review the role of caspases and their activation pathway in beta-cell apoptosis, (4) to review the caspase cascade and morphological cellular changes in apoptotic beta-cells, and (5) to highlight the putative strategies for preventing pancreatic beta-cells from apoptosis.
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Affiliation(s)
- Hongxiang Hui
- Division of Diabetes, Endocrinology and Metabolism, Cedars-Sinai Medical Center, Los Angeles, California 90048, USA
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11
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Augstein P, Heinke P, Salzsieder E, Berg S, Rettig R, Salzsieder C, Harrison LC. Fas ligand down-regulates cytokine-induced Fas receptor expression on insulinoma (NIT-1), but not islet cells, from autoimmune nonobese diabetic mice. Endocrinology 2004; 145:2747-52. [PMID: 15033908 DOI: 10.1210/en.2003-0754] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In the pathogenesis of autoimmune type 1 diabetes, the apoptosis receptor Fas appears de novo on the surface of insulin-producing beta-cells. Fas expression is thought to be induced by proinflammatory cytokines, such as IL-1beta, interferon-gamma (IFNgamma), and TNFalpha, released by islet-infiltrating mononuclear cells. To determine whether beta-cells can modulate their sensitivity to apoptosis at the level of Fas, we investigated the effect of Fas ligand (FasL) on surface expression of Fas in NIT-1 insulinoma cells from nonobese diabetic (NOD) mice prone to autoimmune diabetes and islet cells from NOD and nonautoimmune BALB/c mice. In NIT-1 insulinoma cells, Fas expression induced by the cytokine combination IL-1beta and IFNgamma was reduced in the presence of FasL, whereas in islet cells Fas expression was unaffected by FasL. The effect of FasL on NIT-1 cells was evident during and after the induction of Fas expression by IL-1beta and IFNgamma. Thus, FasL down-regulates cytokine-induced Fas expression in NOD mouse-derived NIT-1 cells, but not in NOD or BALB/c mouse islets. The ability of NIT-1 cells to down-regulate Fas receptor in response to ligation is similar to that of a variety of tumor cells, which may use this mechanism to escape destruction by cytotoxic T cells. Islets apparently cannot protect themselves against FasL-induced apoptosis by down-regulating the Fas receptor. Understanding how NIT-1 insulinoma cells down-regulate Fas receptor in response to ligation by FasL has therapeutic implications for protecting normal beta-cells in autoimmune type 1 diabetes.
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Affiliation(s)
- P Augstein
- Institute of Diabetes Gerhardt Katsch Karlsburg e.V, Greifswalder Strasse 11e, 17495 Karlsburg, Germany.
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12
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Ivanov VN, Lopez Bergami P, Maulit G, Sato TA, Sassoon D, Ronai Z. FAP-1 association with Fas (Apo-1) inhibits Fas expression on the cell surface. Mol Cell Biol 2003; 23:3623-35. [PMID: 12724420 PMCID: PMC164761 DOI: 10.1128/mcb.23.10.3623-3635.2003] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
As revealed by intracellular pools of nonactive Fas (Apo-1), export of Fas to the cell surface is often impaired in human tumors, thereby inactivating Fas ligand-mediated apoptosis. Here, we demonstrate that association with Fas-associated phosphatase 1 (FAP-1) attenuates Fas export to the cell surface. Forced expression of FAP-1 reduces cell surface Fas levels and increases the intracellular pool of Fas within the cytoskeleton network. Conversely, expression of dominant-negative forms of FAP-1, or inhibition of FAP-1 expression by short interfering RNA, efficiently up-regulates surface expression of Fas. Inhibition of Fas surface expression by FAP-1 depends on its association with the C terminus of Fas. Mutation within amino acid 275 results in decreased association with FAP-1 and greater export of Fas to the cell surface in melanomas, normal fibroblasts, or Fas null cells. Identifying the role of FAP-1 in binding to, and consequently inhibition of, Fas export to the cell surface provides novel insight into the mechanism underlying the regulation of Fas trafficking, which is commonly impaired in advanced tumors with FAP-1 overexpression.
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Affiliation(s)
- Vladimir N Ivanov
- Ruttenberg Cancer Center, Department of Molecular and Developmental Biology, Mount Sinai School of Medicine, One Gustave L. Levy Place, New York, NY 10029-6574, USA
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