151
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Robertson MJ, Kahl BS, Vose JM, de Vos S, Laughlin M, Flynn PJ, Rowland K, Cruz JC, Goldberg SL, Musib L, Darstein C, Enas N, Kutok JL, Aster JC, Neuberg D, Savage KJ, LaCasce A, Thornton D, Slapak CA, Shipp MA. Phase II study of enzastaurin, a protein kinase C beta inhibitor, in patients with relapsed or refractory diffuse large B-cell lymphoma. J Clin Oncol 2007; 25:1741-6. [PMID: 17389337 DOI: 10.1200/jco.2006.09.3146] [Citation(s) in RCA: 188] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PURPOSE Protein kinase C beta (PKCbeta) was identified by gene-expression profiling, preclinical evaluation, and independent immunohistochemical analysis as a rational therapeutic target in diffuse large B-cell lymphoma (DLBCL). We conducted a multicenter phase II study of a potent inhibitor of PKCbeta, enzastaurin, in patients with relapsed or refractory DLBCL. PATIENTS AND METHODS Enzastaurin was taken orally once daily until disease progression or unacceptable toxicity occurred. Study end points included freedom from progression (FFP) for > or= two cycles (one cycle = 28 days), objective response, and toxicity. RESULTS Fifty-five patients (median age, 68 years) were enrolled. Patients had received a median number of two prior therapies (range, one to five); six patients relapsed after high-dose therapy and autologous stem-cell transplantation. Only one grade 4 toxicity (hypomagnesemia) occurred. Grade 3 toxicities included fatigue (n = 2), edema (n = 1), headache (n = 1), motor neuropathy (n = 1), and thrombocytopenia (n = 1). No grade 3 or 4 neutropenia occurred. No deaths or discontinuations due to toxicity were reported. Fifteen patients completed less than one cycle of therapy. Twelve of 55 patients (22%; 95% CI, 13% to 46%) experienced FFP for two cycles, and eight patients remained free from progression for four cycles (15%; 95% CI, 6% to 27%). Four patients (7%; 95% CI, 2% to 18%), including three complete responders and one patient with stable disease, continue to experience FFP 20+ to 50+ months after study entry. CONCLUSION Treatment with enzastaurin was well-tolerated and associated with prolonged FFP in a small subset of patients with relapsed or refractory DLBCL. Further studies of enzastaurin in DLBCL are warranted.
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152
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Li S, Phong M, Lahn M, Brail L, Sutton S, Lin BK, Thornton D, Liao B. Retrospective analysis of protein kinase C-beta (PKC-beta) expression in lymphoid malignancies and its association with survival in diffuse large B-cell lymphomas. Biol Direct 2007; 2:8. [PMID: 17313671 PMCID: PMC1805741 DOI: 10.1186/1745-6150-2-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2007] [Accepted: 02/21/2007] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Both mechanistic features and recent correlative findings suggest a potential role for protein kinase C-beta (PKC-beta) in tumor pathogenesis, particularly in B-cell malignancies. To evaluate the role of this gene in lymphoid malignancies, we analyzed global gene expression data to quantify PKC-beta expression across diagnostic groups and, when possible, determined correlations between PKC-beta expression and survival. RESULTS Our analysis showed that the level of PKC-beta expression was highest in chronic lymphocytic leukemia and follicular lymphoma. Within diffuse large-B cell lymphoma (DLBCL), PKC-beta expression was significantly higher in activated B-cell- like subtype than germinal center B-cell- like subtype (P < 0.0001). Elevated PKC-beta appeared to be associated with worse survival in both of these subtypes. When analyzed within clinically defined risk groups established by the International Prognostic Index (IPI), PKC-beta expression was lowest in patients with low IPI scores (0-1). Within intermediate- and high-risk IPI groups, elevated PKC-beta expression was associated with worse survival, suggesting that PKC-beta may expand the prognostic value of the IPI. Results of global gene expression analyses of DLBCL samples corroborate previous observations that anti-apoptosis, cell proliferation, and B-cell proliferation signaling pathways are functionally related to PKC-beta. CONCLUSION We present a first detailed pharmacogenomics report comparing PKC-beta mRNA expression across different lymphoid malignancies and evaluating it as an outcome predictor. Our findings suggest that DLBCL patients with elevated PKC-beta have a worse prognosis, indicating that further evaluation of PKC-beta as a chemotherapeutic target for lymphoid malignancies is warranted.
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Affiliation(s)
- Shuyu Li
- Integrative Biology Informatics, Eli Lilly and Company, Lilly Corporate Center, Indianapolis, IN 46285, USA
| | - Mark Phong
- Integrative Biology Informatics, Eli Lilly and Company, Lilly Corporate Center, Indianapolis, IN 46285, USA
| | - Michael Lahn
- Medical Oncology, Lilly Research Laboratories, Eli Lilly and Company, Bad Homburg, Germany
| | - Leslie Brail
- Medical Oncology, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN 46285, USA
| | - Susan Sutton
- Medical Oncology, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN 46285, USA
| | - Boris K Lin
- Medical Oncology, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN 46285, USA
| | - Donald Thornton
- Medical Oncology, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN 46285, USA
| | - Birong Liao
- Integrative Biology Informatics, Eli Lilly and Company, Lilly Corporate Center, Indianapolis, IN 46285, USA
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153
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Hoek KL, Antony P, Lowe J, Shinners N, Sarmah B, Wente SR, Wang D, Gerstein RM, Khan WN. Transitional B cell fate is associated with developmental stage-specific regulation of diacylglycerol and calcium signaling upon B cell receptor engagement. THE JOURNAL OF IMMUNOLOGY 2007; 177:5405-13. [PMID: 17015726 DOI: 10.4049/jimmunol.177.8.5405] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Functional peripheral mature follicular B (FoB) lymphocytes are thought to develop from immature transitional cells in a BCR-dependent manner. We have previously shown that BCR cross-linking in vitro results in death of early transitional (T1) B cells, whereas late transitional (T2) B cells survive and display phenotypic characteristics of mature FoB cells. We now demonstrate that diacylglycerol (DAG), a lipid second messenger implicated in cell survival and differentiation, is produced preferentially in T2 compared with T1 B cells upon BCR cross-linking. Consistently, inositol 1,4,5-triphosphate is also produced preferentially in T2 compared with T1 B cells. Unexpectedly, the initial calcium peak appears similar in both T1 and T2 B cells, whereas sustained calcium levels are higher in T1 B cells. Pretreatment with 2-aminoethoxydiphenylborate, an inhibitor of inositol 1,4,5-triphosphate receptor-mediated calcium release, and verapamil, an inhibitor of L-type calcium channels, preferentially affects T1 B cells, suggesting that distinct mechanisms regulate calcium mobilization in each of the two transitional B cell subsets. Finally, BCR-mediated DAG production is dependent upon Bruton's tyrosine kinase and phospholipase C-gamma2, enzymes required for the development of FoB from T2 B cells. These results suggest that calcium signaling in the absence of DAG-mediated signals may lead to T1 B cell tolerance, whereas the combined action of DAG and calcium signaling is necessary for survival and differentiation of T2 into mature FoB lymphocytes.
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Affiliation(s)
- Kristen L Hoek
- Department of Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
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154
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Gilboa-Geffen A, Lacoste PP, Soreq L, Cizeron-Clairac G, Le Panse R, Truffault F, Shaked I, Soreq H, Berrih-Aknin S. The thymic theme of acetylcholinesterase splice variants in myasthenia gravis. Blood 2007; 109:4383-91. [PMID: 17272501 DOI: 10.1182/blood-2006-07-033373] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cholinergic signaling and acetylcholinesterase (AChE) influence immune response and inflammation. Autoimmune myasthenia gravis (MG) is mediated by antibodies to the acetylcholine receptor and current therapy is based on anti-AChE drugs. MG is associated with thymic hyperplasia, showing signs of inflammation. The objectives of this study were to analyze the involvement of AChE variants in thymic hyperplasia. We found lower hydrolytic activities in the MG thymus compared with adult controls, accompanied by translocation of AChE-R from the cytoplasm to the membrane and increased expression of the signaling protein kinase PKC-betaII. To explore possible causal association of AChE-R changes with thymic composition and function, we used an AChE-R transgenic model and showed smaller thymic medulla compared with strain-matched controls, indicating that AChE-R overexpression interferes with thymic differentiation mechanisms. Interestingly, AChE-R transgenic mice showed increased numbers of CD4(+)CD8(+) cells that were considerably more resistant in vitro to apoptosis than normal thymocytes, suggesting possibly altered positive selection. We further analyzed microarray data of MG thymic hyperplasia compared with healthy controls and found continuous and discrete changes in AChE-annotated GO categories. Together, these findings show that modified AChE gene expression and properties are causally involved in thymic function and development.
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155
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Pappu BP, Lin X. Potential role of CARMA1 in CD40-induced splenic B cell proliferation and marginal zone B cell maturation. Eur J Immunol 2007; 36:3033-43. [PMID: 17048267 DOI: 10.1002/eji.200535663] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
NF-kappaB activation through B cell receptor (BCR) ligation is critical for B cell development, survival and antigen-mediated activation of B cells. CARD domain and MAGUK-domain containing protein-1 (CARMA1), recently identified adaptor molecule, has been shown to play an essential role in BCR-induced NF-kappaB activation. CARMA1-deficient B cells fail to proliferate upon BCR stimulation, leading to defective humoral responses. Surprisingly, CARMA1-deficient B cells are also defective in CD40-induced proliferation. The mechanisms responsible for CD40-induced proliferation defect have not yet been characterized. In this study, we show that signaling cascades activated by CD40 stimulation are largely unaffected in CARMA1-deficient B cells. Instead, we have found that the defective proliferation of CARMA1-deficient B cells is due to two events. First, CARMA1-deficient B cells show defective cell-cycle progression. Secondly, the numbers of marginal zone (MZ) B cells, which are the main responders upon CD40 stimulation, are greatly diminished in CARMA1-deficient mice. Since B cell maturation requires basal signaling through BCR and NF-kappaB activation, we propose that impaired BCR signaling in CARMA1-deficient mice leads to defective maturation of MZ B cell population, which in turn, contributes to impaired proliferation upon CD40 stimulation.
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Affiliation(s)
- Bhanu P Pappu
- Department of Molecular and Cellular Oncology, The University of Texas, MD Anderson Cancer Center, Houston, TX 77030, USA
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156
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Moreno-García ME, Sommer KM, Bandaranayake AD, Rawlings DJ. Proximal signals controlling B-cell antigen receptor (BCR) mediated NF-kappaB activation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2007; 584:89-106. [PMID: 16802601 DOI: 10.1007/0-387-34132-3_7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Miguel E Moreno-García
- Department of Pediatrics, University of Washington School of Medicine, Seattle, WA 98195, USA
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157
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Abstract
Abstract
Diffuse large B-cell lymphomas (DLBCLs), the most common lymphoid malignancies, are clinically and genetically heterogeneous disorders. Although DLBCL is a chemo-responsive tumor, many patients will not be cured with conventional empiric treatment regimens. Gene expression profiles, analyses of specific genetic abnormalities and functional assays have been used to develop comprehensive molecular signatures of tumors that share similar features and rely upon common survival pathways. These studies are leading to the identification of subtype-specific rational therapeutic targets and associated inhibitors for clinical investigation.
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158
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Abstract
Signal transduction events leading to the survival, differentiation, or apoptosis of cells of the innate or adaptive immune system must be properly coordinated to ensure the normal mounting and termination of immune responses. One of the key transcription factors in immune responses is nuclear factor kappaB (NF-kappaB), which has been the focus of intense investigation over the past two decades. With the identification of the CARMA1-BCL10-MALT1 complex and ongoing progress in understanding the molecular mechanisms connecting T cell and B cell receptor proximal signals to the IkappaB kinase (IKK) complex, a cohesive model of antigen receptor (AgR)-dependent signaling to NF-kappaB activation is beginning to emerge. In this review, we provide an overview of the current state of research into the mechanisms that regulate AgR-mediated NF-kappaB transcriptional activity, with particular focus on the events leading to activation of the IKK complex.
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Affiliation(s)
- Jan Schulze-Luehrmann
- Section of Immunobiology and Department of Molecular Biophysics & Biochemistry, Yale University School of Medicine, New Haven, CT 06520, USA
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159
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Rawlings DJ, Sommer K, Moreno-García ME. The CARMA1 signalosome links the signalling machinery of adaptive and innate immunity in lymphocytes. Nat Rev Immunol 2006; 6:799-812. [PMID: 17063183 DOI: 10.1038/nri1944] [Citation(s) in RCA: 150] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The recognition of antigen by B- or T-cell receptors initiates an intracellular signalling cascade that results in the nuclear translocation and activation of the transcription factor nuclear factor-kappaB (NF-kappaB). NF-kappaB is an important regulator of lymphocyte development and function, and its dysregulation is associated with many immune disorders. Defining the mechanisms that transmit signals from the antigen receptor to NF-kappaB is therefore an important goal for immunologists. In this Review, we merge information gleaned from research of the innate immune system with what we know about antigen-receptor signals in the adaptive immune system, to propose a cohesive model of how antigen receptors activate NF-kappaB.
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Affiliation(s)
- David J Rawlings
- Department of Immunology, Childrens Hospital & Regional Medical Centre, 307 Westlake Avenue North, Suite 300, Seattle, Washington 98109, USA.
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160
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Abstract
One of the primary physiological roles of nuclear factor-kappa B (NF-kappaB) is in the immune system. In particular, NF-kappaB family members control the transcription of cytokines and antimicrobial effectors as well as genes that regulate cellular differentiation, survival and proliferation, thereby regulating various aspects of innate and adaptive immune responses. In addition, NF-kappaB also contributes to the development and survival of the cells and tissues that carry out immune responses in mammals. This review, therefore, describes the role of the NF-kappaB pathway in the development and functioning of the immune system.
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Affiliation(s)
- M S Hayden
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06510, USA
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161
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Klemm S, Ruland J. Inflammatory signal transduction from the FcεRI to NF-κB. Immunobiology 2006; 211:815-20. [PMID: 17113919 DOI: 10.1016/j.imbio.2006.07.001] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2006] [Accepted: 07/07/2006] [Indexed: 11/30/2022]
Abstract
Mast cells are essential effector cells in IgE-associated immune responses. The major receptor for mast cell activation is the high affinity IgE receptor Fc epsilon RI. Fc epsilon RI crosslinking induces mast cell degranulation and de novo synthesis of potent proinflammatory mediators. Recent work identified Bcl10 and Malt1 as central regulators of a specific signaling pathway that controls NF-kappaB activation and proinflammatory cytokine production upon Fc epsilon RI ligation on mast cells. Bcl10 and Malt1 cooperate for the activation of this signaling cascade and selectively function downstream of PKC isoforms. However, Bcl10 and Malt1 are not involved in Fc epsilon RI- or PKC-induced signaling events that control degranulation or leukotriene synthesis. Thus, the Bcl10/Malt1 complex specifically uncouples the pathway for cytokine production from degranulation events. This review will summarize our current knowledge of the regulation of Fc epsilon RI-induced NF-kappaB activation in mast cells and discuss potential implications for allergic inflammatory diseases.
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Affiliation(s)
- Stefanie Klemm
- Third Medical Department, Technical University of Munich, Klinikum rechts der Isar, Ismaninger Street 22, 81675 Munich, Germany
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162
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Underlying mechanisms of hematologic malignancies revealed by gene expression profiling. ACTA ACUST UNITED AC 2006. [DOI: 10.1016/j.ddmec.2006.11.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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163
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Hunter I, Nixon GF. Spatial compartmentalization of tumor necrosis factor (TNF) receptor 1-dependent signaling pathways in human airway smooth muscle cells. Lipid rafts are essential for TNF-alpha-mediated activation of RhoA but dispensable for the activation of the NF-kappaB and MAPK pathways. J Biol Chem 2006; 281:34705-15. [PMID: 16982613 PMCID: PMC2653078 DOI: 10.1074/jbc.m605738200] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Tumor necrosis factor (TNF)-alpha-induced activation of RhoA, mediated by TNF receptor 1 (TNFR1), is a prerequisite step in a pathway that leads to increased 20-kDa light chain of myosin (MLC20) phosphorylation and airway smooth muscle contraction. In this study, we have investigated the proximal events in TNF-alpha-induced RhoA activation. TNFR1 is localized to both lipid raft and nonraft regions of the plasma membrane in primary human airway smooth muscle cells. TNF-alpha engagement of TNFR1 recruited the adaptor proteins TRADD, TRAF-2, and RIP into lipid rafts and activated RhoA, NF-kappaB, and MAPK pathways. Depletion of cholesterol from rafts with methyl-beta-cyclodextrin caused a redistribution of TNFR1 to nonraft plasma membrane and prevented ligand-induced RhoA activation. By contrast, TNF-alpha-induced activation of NF-kappaB and MAPKs was unaffected by methyl-beta-cyclodextrin indicating that, in airway smooth muscle cells, activation of these pathways occurred independently of lipid rafts. Targeted knockdown of caveolin-1 completely abrogated TNF-alpha-induced RhoA activation, identifying this raft-resident protein as a positive regulator of the activation process. The signaling adaptors TRADD and RIP were also found to be necessary for ligand-induced RhoA activation. Taken together, our results suggest that in airway smooth muscle cells, spatial compartmentalization of TNFR1 provides a mechanism for generating distinct signaling outcomes in response to ligand engagement and define a mechanistic role for lipid rafts and caveolin-1 in TNF-alpha-induced activation of RhoA.
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Affiliation(s)
- Irene Hunter
- School of Medical Sciences, University of Aberdeen, IMS Building, Foresterhill, Aberdeen AB25 2ZD, United Kingdom.
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164
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Pike KA, Ratcliffe MJH. Ligand-independent signaling during early avian B cell development. Immunol Res 2006; 35:103-16. [PMID: 17003513 DOI: 10.1385/ir:35:1:103] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/1999] [Revised: 11/30/1999] [Accepted: 11/30/1999] [Indexed: 01/20/2023]
Abstract
Surface immunoglobulin (sIg) expression has been conserved as a critical checkpoint in B lymphocyte development. In the chicken embryo, only sIg+ B cells are selectively expanded in the bursa of Fabricius, a primary lymphoid organ unique to the avian species. We have previously demonstrated that an interaction between the antigen- binding sites of sIg and a specific bursal ligand(s) is not required to regulate this developmental checkpoint. Rather, the requirement for sIg expression can be attributed to the surface expression of the Igalpha/beta heterodimer associated with sIg. More specifically, ligand-independent signaling downstream of the Igalpha cytoplasmic domain drives all bursal stages of B cell development during embryogenesis. We discuss here a site-directed mutagenesis approach to identify the critical membrane proximal events involved in ligand-independent signaling during B cell development.
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Affiliation(s)
- Kelly A Pike
- Department of Immunology, University of Toronto, 1 King's College Circle, Toronto, Ontario, Canada
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165
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Patke A, Mecklenbräuker I, Erdjument-Bromage H, Tempst P, Tarakhovsky A. BAFF controls B cell metabolic fitness through a PKC beta- and Akt-dependent mechanism. ACTA ACUST UNITED AC 2006; 203:2551-62. [PMID: 17060474 PMCID: PMC2118121 DOI: 10.1084/jem.20060990] [Citation(s) in RCA: 157] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
B cell life depends critically on the cytokine B cell–activating factor of the tumor necrosis factor family (BAFF). Lack of BAFF signaling leads to B cell death and immunodeficiency. Excessive BAFF signaling promotes lupus-like autoimmunity. Despite the great importance of BAFF to B cell biology, its signaling mechanism is not well characterized. We show that BAFF initiates signaling and transcriptional programs, which support B cell survival, metabolic fitness, and readiness for antigen-induced proliferation. We further identify a BAFF-specific protein kinase C β–Akt signaling axis, which provides a connection between BAFF and generic growth factor–induced cellular responses.
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Affiliation(s)
- Alina Patke
- Laboratory of Lymphocyte Signaling, The Rockefeller University, New York, NY 10021, USA.
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166
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Abrams ST, Lakum T, Lin K, Jones GM, Treweeke AT, Farahani M, Hughes M, Zuzel M, Slupsky JR. B-cell receptor signaling in chronic lymphocytic leukemia cells is regulated by overexpressed active protein kinase CβII. Blood 2006; 109:1193-201. [PMID: 17003377 DOI: 10.1182/blood-2006-03-012021] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
AbstractSignals through the B-cell antigen receptor (BCR) are important for the survival of chronic lymphocytic leukemia (CLL) cells. Therefore, factors that influence these signals have important pathophysiological roles in this disease. One key mediator of BCR signaling is protein kinase C β (PKCβ), which regulates the activation of I-κB kinases and the deactivation of Bruton tyrosine kinase within the signaling pathways initiated by BCR engagement. The present study demonstrates that overexpression of the PKCβII isoform is a feature of CLL cells and that activity of this enzyme strongly correlates with CLL cell response to BCR engagement. Thus, intracellular Ca2+ release and increases in cell survival after BCR cross-linking were significantly greater in CLL patients with low levels than in CLL patients with high levels of active PKCβII. Furthermore, BCR-induced Ca2+ fluxes could be restored in CLL patients with high levels of active PKCβII by pretreating the cells with the PKCβ-specific inhibitor LY379196. Conversely, BCR-mediated intracellular Ca2+ release could be inhibited in CLL cells with low levels of active PKCβII by pretreatment with the PKC agonist bryostatin. Taken together, these results demonstrate that overexpressed active PKCβII plays a role in the regulation and outcome of BCR signals that can be important for the progression of CLL.
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167
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Nakahira K, Kim HP, Geng XH, Nakao A, Wang X, Murase N, Drain PF, Wang X, Sasidhar M, Nabel EG, Takahashi T, Lukacs NW, Ryter SW, Morita K, Choi AMK. Carbon monoxide differentially inhibits TLR signaling pathways by regulating ROS-induced trafficking of TLRs to lipid rafts. ACTA ACUST UNITED AC 2006; 203:2377-89. [PMID: 17000866 PMCID: PMC2118097 DOI: 10.1084/jem.20060845] [Citation(s) in RCA: 305] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Carbon monoxide (CO), a byproduct of heme catabolism by heme oxygenase (HO), confers potent antiinflammatory effects. Here we demonstrate that CO derived from HO-1 inhibited Toll-like receptor (TLR) 2, 4, 5, and 9 signaling, but not TLR3-dependent signaling, in macrophages. Ligand-mediated receptor trafficking to lipid rafts represents an early event in signal initiation of immune cells. Trafficking of TLR4 to lipid rafts in response to LPS was reactive oxygen species (ROS) dependent because it was inhibited by diphenylene iodonium, an inhibitor of NADPH oxidase, and in gp91phox-deficient macrophages. CO selectively inhibited ligand-induced recruitment of TLR4 to lipid rafts, which was also associated with the inhibition of ligand-induced ROS production in macrophages. TLR3 did not translocate to lipid rafts by polyinosine-polycytidylic acid (poly(I:C)). CO had no effect on poly(I:C)-induced ROS production and TLR3 signaling. The inhibitory effect of CO on TLR-induced cytokine production was abolished in gp91phox-deficient macrophages, also indicating a role for NADPH oxidase. CO attenuated LPS-induced NADPH oxidase activity in vitro, potentially by binding to gp91phox. Thus, CO negatively controlled TLR signaling pathways by inhibiting translocation of TLR to lipid rafts through suppression of NADPH oxidase–dependent ROS generation.
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Affiliation(s)
- Kiichi Nakahira
- Division of Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
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168
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Yamaguchi T, Suzuki M, Kimura H, Kato M. Role of protein kinase C in eosinophil function. Allergol Int 2006; 55:245-52. [PMID: 17075264 DOI: 10.2332/allergolint.55.245] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2006] [Indexed: 11/20/2022] Open
Abstract
Protein kinase C (PKC) isoforms are being elucidated as an increasingly diverse family of enzymes involved in the downstream signal transduction and cell function in various types of cells. To date, 11 PKC isoforms have been identified; they are grouped according to their molecular structure and mode of activation: conventional PKCs (alpha, beta I, beta II, and gamma), novel PKCs (delta, epsilon, mu, theta, and eta), and atypical PKCs (zeta, and iota/lambda). Eosinophils are involved in the pathogenesis of allergic diseases such as bronchial asthma, pollinosis, and atopic dermatitis as well as in the inflammatory response to parasitic infections. Recent studies using selective activators and inhibitors of individual PKC isoforms have revealed that this enzyme is involved in eosinophil dynamics such as cell motility and other functions. However, the role of PKCs in eosinophil functions has been not wholly understood. In this review, we have focused upon and summarized the current knowledge regarding the role of PKC isoforms in eosinophil functions.
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Affiliation(s)
- Takafumi Yamaguchi
- Gunma Prefectural Institute of Public Health and Environmental Sciences, Gunma, Japan
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169
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Lin CH, Cheng HW, Hsu MJ, Chen MC, Lin CC, Chen BC. c-Src Mediates Thrombin-Induced NF-κB Activation and IL-8/CXCL8 Expression in Lung Epithelial Cells. THE JOURNAL OF IMMUNOLOGY 2006; 177:3427-38. [PMID: 16920985 DOI: 10.4049/jimmunol.177.5.3427] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
In this study, we examined the regulation of NF-kappaB activation and IL-8/CXCL8 expression by thrombin in human lung epithelial cells (EC). Thrombin caused a concentration-dependent increase in IL-8/CXCL8 release in a human lung EC line (A549) and primary normal human bronchial EC. In A549 cells, thrombin, SFLLRN-NH2 (a protease-activated receptor 1 (PAR1) agonist peptide), and GYPGQV-NH2 (a PAR4 agonist peptide), but not TFRGAP-NH2 (a PAR3 agonist peptide), induced an increase in IL-8/CXCL8-luciferase (Luc) activity. The thrombin-induced IL-8/CXCL8 release was attenuated by D-phenylalanyl-L-prolyl-L-arginine chloromethyl ketone (a thrombin inhibitor), U73122 (a phosphoinositide-phospholipase C inhibitor), Ro-32-0432 (a protein kinsase C alpha (PKC alpha) inhibitor), an NF-kappaB inhibitor peptide, and Bay 117082 (an IkappaB phosphorylation inhibitor). Thrombin-induced increase in IL-8/CXCL8-Luc activity was inhibited by the dominant-negative mutant of c-Src and the cells transfected with the kappaB site mutation of the IL-8/CXCL8 construct. Thrombin caused time-dependent increases in phosphorylation of c-Src at tyrosine 416 and c-Src activity. Thrombin-elicited c-Src activity was inhibited by Ro-32-0432. Stimulation of cells with thrombin activated IkappaB kinase alphabeta (IKK alphabeta), IkappaB alpha phosphorylation, IkappaB alpha degradation, p50 and p65 translocation from the cytosol to the nucleus, NF-kappaB-specific DNA-protein complex formation, and kappaB-Luc activity. Pretreatment of A549 cells with Ro-32-4032 and the dominant-negative mutant of c-Src DN inhibited thrombin-induced IKK alphabeta activity, kappaB-Luc activity, and NF-kappaB-specific DNA-protein complex formation. Further studies revealed that thrombin induced PKC alpha, c-Src, and IKK alphabeta complex formation. These results show for the first time that thrombin, acting through PAR1 and PAR4, activates the phosphoinositide-phospholipase C/PKC alpha/c-Src/IKK alphabeta signaling pathway to induce NF-kappaB activation, which in turn induces IL-8/CXCL8 expression and release in human lung EC.
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Affiliation(s)
- Chien-Huang Lin
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taiwan
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170
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Kabu K, Yamasaki S, Kamimura D, Ito Y, Hasegawa A, Sato E, Kitamura H, Nishida K, Hirano T. Zinc Is Required for FcεRI-Mediated Mast Cell Activation. THE JOURNAL OF IMMUNOLOGY 2006; 177:1296-305. [DOI: 10.4049/jimmunol.177.2.1296] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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171
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Abstract
The World Health Organization has included different types of lymphoma under the aggressive category. In the US, diffuse large B-cell lymphoma is the most common aggressive lymphoma and accounts for > 30% of the 55,000 new cases diagnosed annually. Recent advances in the knowledge of the molecular biology have provided an increased understanding of the heterogeneity of non-Hodgkin's lymphoma. New treatments, especially those with the use of monoclonal antibodies, are improving both the survival and the response rate.
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Affiliation(s)
- Luis Fayad
- Department of Lymphoma/Myeloma, University of Texas, MD Anderson Cancer Center, Box # 429, Houston, TX 77030, USA
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172
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Sommer K, Guo B, Pomerantz JL, Bandaranayake AD, Moreno-García ME, Ovechkina YL, Rawlings DJ. Phosphorylation of the CARMA1 linker controls NF-kappaB activation. Immunity 2006; 23:561-74. [PMID: 16356855 DOI: 10.1016/j.immuni.2005.09.014] [Citation(s) in RCA: 275] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2005] [Revised: 09/07/2005] [Accepted: 09/28/2005] [Indexed: 11/23/2022]
Abstract
PKC isoforms and CARMA1 play crucial roles in immunoreceptor-dependent NF-kappaB activation. We tested whether PKC-dependent phosphorylation of CARMA1 directly regulates this signaling cascade. B cell antigen receptor (BCR) engagement led to the progressive recruitment of CARMA1 into lipid rafts and to the association of CARMA1 with, and phosphorylation by, PKCbeta. Furthermore, PKCbeta interacted with the serine-rich CARMA1 linker, and both PKCbeta and PKCtheta phosphorylated identical serine residues (S564, S649, and S657) within this linker. Mutation of two of these sites ablated the functional activity of CARMA1. In contrast, deletion of the linker resulted in constitutive, receptor- and PKC-independent NF-kappaB activation. Together, our data support a model whereby CARMA1 phosphorylation controls NF-kappaB activation by triggering a shift from an inactive to an active CARMA1 conformer. This PKC-dependent switch regulates accessibility of the CARD and CC domains and controls assembly and full activation of the membrane-associated IkappaB kinase (IKK) signalosome.
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Affiliation(s)
- Karen Sommer
- Department of Pediatrics, University of Washington School of Medicine, Seattle, Washington 98195, USA
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173
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Matsumoto R, Wang D, Blonska M, Li H, Kobayashi M, Pappu B, Chen Y, Wang D, Lin X. Phosphorylation of CARMA1 plays a critical role in T Cell receptor-mediated NF-kappaB activation. Immunity 2006; 23:575-85. [PMID: 16356856 DOI: 10.1016/j.immuni.2005.10.007] [Citation(s) in RCA: 246] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2005] [Revised: 10/10/2005] [Accepted: 10/24/2005] [Indexed: 12/22/2022]
Abstract
CARMA1 mediates T cell receptor (TCR)-induced NF-kappaB activation. However, how TCR links to CARMA1 in the signaling pathway is not clear. Here, we show that CARMA1 is inducibly phosphorylated after TCR-CD28 costimulation. This phosphorylation is likely induced by PKCtheta, since PKCtheta induces phosphorylation of CARMA1 in vitro and in vivo. Our results indicate that the PKCtheta-induced phosphorylation of CARMA1 likely occurs on Ser552 on the Linker region of CARMA1. Importantly, expression of CARMA1 mutant, in which Ser552 is mutated, fails to mediate TCR-induced NF-kappaB activation in CARMA1-deficient T cells. The functional defect of this CARMA1 mutant is likely due to the fact that this mutant cannot be phosphorylated at the critical residue, thereby failing to recruit the downstream signaling components into the immunological synapse. Together, our studies provide the first genetic evidence that the phosphorylation of CARMA1 plays a critical role in the TCR signaling pathway.
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Affiliation(s)
- Reiko Matsumoto
- Department of Molecular and Cellular Oncology, University of Texas, M.D. Anderson Cancer Center, Houston, Texas 77030, USA
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174
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Liu SF, Malik AB. NF-kappa B activation as a pathological mechanism of septic shock and inflammation. Am J Physiol Lung Cell Mol Physiol 2006; 290:L622-L645. [PMID: 16531564 DOI: 10.1152/ajplung.00477.2005] [Citation(s) in RCA: 564] [Impact Index Per Article: 31.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The pathophysiology of sepsis and septic shock involves complex cytokine and inflammatory mediator networks. NF-kappaB activation is a central event leading to the activation of these networks. The role of NF-kappaB in septic pathophysiology and the signal transduction pathways leading to NF-kappaB activation during sepsis have been an area of intensive investigation. NF-kappaB is activated by a variety of pathogens known to cause septic shock syndrome. NF-kappaB activity is markedly increased in every organ studied, both in animal models of septic shock and in human subjects with sepsis. Greater levels of NF-kappaB activity are associated with a higher rate of mortality and worse clinical outcome. NF-kappaB mediates the transcription of exceptional large number of genes, the products of which are known to play important roles in septic pathophysiology. Mice deficient in those NF-kappaB-dependent genes are resistant to the development of septic shock and to septic lethality. More importantly, blockade of NF-kappaB pathway corrects septic abnormalities. Inhibition of NF-kappaB activation restores systemic hypotension, ameliorates septic myocardial dysfunction and vascular derangement, inhibits multiple proinflammatory gene expression, diminishes intravascular coagulation, reduces tissue neutrophil influx, and prevents microvascular endothelial leakage. Inhibition of NF-kappaB activation prevents multiple organ injury and improves survival in rodent models of septic shock. Thus NF-kappaB activation plays a central role in the pathophysiology of septic shock.
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Affiliation(s)
- Shu Fang Liu
- Div. of Pulmonary and Critical Care Medicine, Long Island Jewish Medical Center, RM B371, New Hyde Park, NY 11040, USA.
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175
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Moran ST, Cariappa A, Liu H, Boboila C, Shi HN, Holland PM, Peschon JJ, Pillai S. Protein kinase C-associated kinase is not required for the development of peripheral B lymphocyte populations. Mol Immunol 2006; 43:1694-9. [PMID: 16256200 DOI: 10.1016/j.molimm.2005.09.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2005] [Accepted: 09/24/2005] [Indexed: 12/22/2022]
Abstract
Protein kinase C-associated kinase (PKK; DIK/RIP4) is an ankyrin-repeat containing serine/threonine receptor-interacting protein (RIP)-family kinase that can activate NFkappaB, and is required for keratinocyte development. In earlier studies, the expression of a catalytically inactive mutant of PKK in the B cell lineage resulted in a marked decrease in peripheral B cells in the spleen and a severe reduction of B-1 B cells. Here we explore the consequences of a null mutation in PKK with respect to the generation of peripheral B cell lineages and the activation of NFkappaB. We show that PKK is not required for the production of B cells in the bone marrow or for the development and maintenance of all mature B lymphocyte populations. We also show that PKK is not required for the activation of NFkappaB downstream of the BCR, CD40, or TLR-4 in B cells. Taken together, these data demonstrate that the loss of this RIP-family kinase does not compromise B lymphocyte development and maintenance, but leaves open the possibility that PKK may have a redundant role in these processes.
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Affiliation(s)
- Stewart T Moran
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Building 149, 13th Street, Charlestown, MA 02129, USA
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176
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Manthey D, Behl C. From structural biochemistry to expression profiling: Neuroprotective activities of estrogen. Neuroscience 2006; 138:845-50. [PMID: 16343783 DOI: 10.1016/j.neuroscience.2005.10.058] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2005] [Revised: 09/14/2005] [Accepted: 10/09/2005] [Indexed: 12/28/2022]
Abstract
Estrogens are neuromodulatory and neuroprotective hormones. Chemically, estrogens are steroid compounds and unfold most of their activities through the activation of nuclear receptors that bind to specific target genes and control their transcription. Two subtypes of estrogen receptors are known (estrogen receptor alpha and estrogen receptor beta) and they are expressed throughout the body including the CNS and in particular the brain. We employed large scale DNA-chip-analysis to display the gene expression pattern differentially regulated by both estrogen receptor subtypes in human neuronal cells. We identified different gene families regulated by estrogen receptors that complement the knowledge about the estrogen receptor target genes. Some of these genes may serve neuroprotective functions and may therefore mediate the overall neuroprotective activities of estrogens. In addition to estrogen receptor-dependent neuroprotective effects, estrogen (17beta-estradiol) itself is a compound with a phenolic structure that may display also direct and estrogen receptor-independent antioxidant activities which may be important for the defense against oxidative stress. In summary estrogen can display a wide range of neuroprotective activities through different types of mechanisms and we are only understanding part of the molecular control of these activities which may help to develop neuropreventive strategies against neurodegenerative diseases in the future.
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Affiliation(s)
- D Manthey
- Molecular Neuroprotection and Aging Research, Department of Pathobiochemistry, Johannes Gutenberg University Mainz, Medical School, Germany
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177
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Abstract
Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin's lymphoma. Although it represents a curable disease, less than half of the patients are cured with conventional chemotherapy. The highly variable outcome reflects a heterogeneous group of tumors, with different genetic abnormalities and response to therapy. The International Prognostic Index (IPI) is useful in predicting the outcome of DLBCL patients. However, patients with identical IPI still exhibit marked variability in survival, suggesting the presence of significant residual heterogeneity within each IPI category. The discovery of specific genetic alterations and the assessment of protein expression led to the identification of multiple novel single molecular markers capable of predicting the outcome of DLBCL patients independently of clinical variables. The recent application of DNA microarrays and tissue array technologies allowed a better understanding of the biology of lymphoma and the development of novel diagnostic tools capable of improving the current models for outcome prediction. However, much confusion exists in the literature regarding the importance of different prognostic biomarkers and their applicability in routine practice. This review summarizes the recent advances in our understanding of prognostic biomarkers in DLBCL and discusses whether this is the right time for biomarkers-guided risk-adjusted therapy.
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Affiliation(s)
- Izidore S Lossos
- Department of Medicine, Division of Hematology/Oncology, University of Miami/Sylvester Comprehensive Cancer Center, Miami, FL 33136, USA.
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178
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Shinohara H, Yasuda T, Aiba Y, Sanjo H, Hamadate M, Watarai H, Sakurai H, Kurosaki T. PKC beta regulates BCR-mediated IKK activation by facilitating the interaction between TAK1 and CARMA1. ACTA ACUST UNITED AC 2006; 202:1423-31. [PMID: 16301747 PMCID: PMC2212994 DOI: 10.1084/jem.20051591] [Citation(s) in RCA: 135] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The B cell antigen receptor (BCR)–mediated activation of IκB kinase (IKK) and nuclear factor–κB require protein kinase C (PKC)β; however, the mechanism by which PKCβ regulates IKK is unclear. Here, we demonstrate that another protein kinase, TGFβ-activated kinase (TAK)1, is essential for IKK activation in response to BCR stimulation. TAK1 interacts with the phosphorylated CARMA1 (also known as caspase recruitment domain [CARD]11, Bimp3) and this interaction is mediated by PKCβ. IKK is also recruited to the CARMA1–Bcl10–mucosal-associated lymphoid tissue 1 adaptor complex in a PKCβ-dependent manner. Hence, our data suggest that phosphorylation of CARMA1, mediated by PKCβ, brings two key protein kinases, TAK1 and IKK, into close proximity, thereby allowing TAK1 to phosphorylate IKK.
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Affiliation(s)
- Hisaaki Shinohara
- Laboratory for Lymphocyte Differentiation, RIKEN Research Center for Allergy and Immunology, Yokohama, Kanagawa 230-0045, Japan
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179
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Wang Q, Wang X, Zhou Y, Evers BM. PKCdelta-mediated regulation of FLIP expression in human colon cancer cells. Int J Cancer 2006; 118:326-34. [PMID: 16052516 PMCID: PMC1850992 DOI: 10.1002/ijc.21373] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
FLICE-like inhibitory protein (FLIP), a naturally occurring caspase-inhibitory protein that lacks the critical cysteine domain necessary for catalytic activity, is a negative regulator of Fas-induced apoptosis. Decreased FLIP levels sensitize tumor cells to Fas- and TRAIL-mediated apoptosis; however, the cellular mechanisms regulating FLIP expression have not been defined. Here, we examined the roles of the PKC and NF-kappaB pathway in the regulation of FLIP in human colon cancers. FLIP mRNA levels were increased in Caco-2 cells by treatment with PMA; actinomycin D completely inhibited the induction of FLIP by PMA, indicating transcriptional regulation. PKC inhibitors Gö6983 and Ro-31-8220 blocked PMA-stimulated FLIP expression. Pretreatment with the PKCdelta-selective inhibitor rottlerin or transfection with PKCdelta siRNA inhibited PMA-induced FLIP expression, which identifies a role for PKCdelta in FLIP induction. Treatment with the proteasome inhibitor, MG132, or the NF-kappaB inhibitor (e.g., PDTC and gliotoxin), or overexpression of the superrepressor of IkappaB-alpha inhibited PMA-induced upregulation of FLIP. Moreover, PMA-induced NF-kappaB transactivation was blocked by GF109203x. In conclusion, our results demonstrate a critical role for PKCdelta/NF-kappaB in the regulation of FLIP in human colon cancer cells.
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Affiliation(s)
- Qingding Wang
- Department of Surgery, University of Texas Medical Branch, Galveston, TX 77555, USA
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180
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Karnell FG, Monroe JG. The Role of Membrane Lipids in the Regulation of Immune Cell Activity. Transfus Med Hemother 2006. [DOI: 10.1159/000090192] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
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181
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Muris JJF, Meijer CJLM, Vos W, van Krieken JHJM, Jiwa NM, Ossenkoppele GJ, Oudejans JJ. Immunohistochemical profiling based on Bcl-2, CD10 and MUM1 expression improves risk stratification in patients with primary nodal diffuse large B cell lymphoma. J Pathol 2006; 208:714-23. [PMID: 16400625 DOI: 10.1002/path.1924] [Citation(s) in RCA: 178] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Clinical outcome in patients with diffuse large B cell lymphomas (DLBCL) is poorly predictable. Expression of proteins related to germinal centre B (GCB) cell or activated B cells (ABC) and expression of apoptosis-regulating proteins Bcl-2 and XIAP have been found previously to be strongly associated with clinical outcome. In this study we aimed to develop an algorithm based on expression of GCB/ABC-related proteins CD10, Bcl-6 and MUM1 and apoptosis-inhibiting proteins Bcl-2, XIAP and cFLIP for optimal stratification of DLBCL patients into prognostically favourable and unfavourable groups. Expression of CD10 and cFLIP was associated with better overall survival (both p = 0.03), whereas expression of MUM1, Bcl-2 and XIAP was associated with poor clinical outcome (p = 0.01, p = 0.0007 and p = 0.03, respectively). Multivariate analysis revealed that Bcl-2 was the strongest prognostic marker followed by CD10 and MUM1. Stratification of patients according to a new algorithm based on expression of these three markers improved patient risk stratification into low and particularly high clinical risk groups (p = 0.04 and p < 0.0001, respectively). We conclude that, in our group of primary nodal DLBCLs, a new algorithm, based on expression of the apoptosis-inhibiting protein Bcl-2 and the GCB/ABC-related proteins CD10 and MUM1, strongly predicts outcome in International Prognostic Index (IPI)-low and -high patients. Its predictive power is stronger than previously published algorithms based on only GCB/ABC- or apoptosis-regulating proteins.
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Affiliation(s)
- J J F Muris
- Department of Pathology, VU Medical Centre, Amsterdam, The Netherlands
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182
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Cohen-Solal JFG, Jeganathan V, Grimaldi CM, Peeva E, Diamond B. Sex hormones and SLE: influencing the fate of autoreactive B cells. Curr Top Microbiol Immunol 2006; 305:67-88. [PMID: 16724801 DOI: 10.1007/3-540-29714-6_4] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The prevalence of systemic lupus erythematosus (SLE) is far higher in females than in males and numerous investigations to understand this gender bias have been conducted. While it is plausible that some sex-linked genes may contribute to the genetic predisposition for the disease, other likely culprits are the sex hormones estrogen and prolactin. In this chapter we review studies that have addressed the influence of sex hormones in SLE activity and discuss the recent data established in a BALB/c mouse transgenic for the heavy chain of an anti-DNA antibody. These mice are prone to develop lupus following exposure to exogenous sex hormones. We describe how estrogen and prolactin influence B cell maturation and selection, permitting B cells to mature to immunocompetence. Finally, we discuss the relevance and implications of these data for human disease.
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Affiliation(s)
- J F G Cohen-Solal
- Department of Medicine, Columbia University Medical Center, New York, NY 10032, USA
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183
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Abstract
Antigen receptor-induced NF-kappaB activation depends on receptor-proximal and -distal signaling events. Two papers in this issue of Immunity demonstrate that PKC-dependent phosphorylation of CARMA1 is the critical molecular link that controls the activation of the IKK signalosome and NF-kappaB.
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Affiliation(s)
- Daniel Rueda
- Department of Biochemistry, University of Lausanne, BIL Biomedical Research Center, Chemin des Boveresses 155, CH-1066 Epalinges, Switzerland
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184
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Kim DC, Kim SH, Jeong MW, Baek NI, Kim KT. Effect of rottlerin, a PKC-δ inhibitor, on TLR-4-dependent activation of murine microglia. Biochem Biophys Res Commun 2005; 337:110-5. [PMID: 16182255 DOI: 10.1016/j.bbrc.2005.09.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2005] [Accepted: 09/01/2005] [Indexed: 11/25/2022]
Abstract
In microglia, Toll-like receptors have been shown to recognize pathogen-associated molecular patterns and initiate innate immune responses upon interaction with infectious agents. The effect of rottlerin, a PKC-delta specific inhibitor, on TLR-4-mediated signaling was investigated in murine microglia stimulated with lipopolysaccharide and taxol. Pretreatment of microglia cells with rottlerin decreased LPS- and taxol-induced nitric oxide production in a concentration-dependent manner (IC50 = 99.1+/-1.5 nM). Through MTT and FACS analysis, we found that the inhibition effect of rottlerin was not due to microglial cell death. Rottlerin pretreatment also attenuated LPS-induced phosphorylation of IkappaB-alpha, nuclear translocation of NF-kappaB, and expression of type II nitric oxide synthase. In addition, microglial phagocytosis in response to TLR-4 activation was diminished in which rottlerin was pretreated. Together, these data raise the possibility that certain PKC-delta specific inhibitors can modulate TLR-4-derived signaling and inflammatory target gene expression, and can alter susceptibility to microbial infection and chronic inflammatory diseases in central nervous system.
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Affiliation(s)
- Dong-Chan Kim
- Division of Molecular and Life Science, SBD-NCRC, Pohang University of Science and Technology, Pohang, Republic of Korea
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185
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Graff JR, McNulty AM, Hanna KR, Konicek BW, Lynch RL, Bailey SN, Banks C, Capen A, Goode R, Lewis JE, Sams L, Huss KL, Campbell RM, Iversen PW, Neubauer BL, Brown TJ, Musib L, Geeganage S, Thornton D. The protein kinase Cbeta-selective inhibitor, Enzastaurin (LY317615.HCl), suppresses signaling through the AKT pathway, induces apoptosis, and suppresses growth of human colon cancer and glioblastoma xenografts. Cancer Res 2005; 65:7462-9. [PMID: 16103100 DOI: 10.1158/0008-5472.can-05-0071] [Citation(s) in RCA: 373] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Activation of protein kinase Cbeta (PKCbeta) has been repeatedly implicated in tumor-induced angiogenesis. The PKCbeta-selective inhibitor, Enzastaurin (LY317615.HCl), suppresses angiogenesis and was advanced for clinical development based upon this antiangiogenic activity. Activation of PKCbeta has now also been implicated in tumor cell proliferation, apoptosis, and tumor invasiveness. Herein, we show that Enzastaurin has a direct effect on human tumor cells, inducing apoptosis and suppressing the proliferation of cultured tumor cells. Enzastaurin treatment also suppresses the phosphorylation of GSK3betaser9, ribosomal protein S6(S240/244), and AKT(Thr308). Oral dosing with Enzastaurin to yield plasma concentrations similar to those achieved in clinical trials significantly suppresses the growth of human glioblastoma and colon carcinoma xenografts. As in cultured tumor cells, Enzastaurin treatment suppresses the phosphorylation of GSK3beta in these xenograft tumor tissues. Enzastaurin treatment also suppresses GSK3beta phosphorylation to a similar extent in peripheral blood mononuclear cells (PBMCs) from these treated mice. These data show that Enzastaurin has a direct antitumor effect and that Enzastaurin treatment suppresses GSK3beta phosphorylation in both tumor tissue and in PBMCs, suggesting that GSK3beta phosphorylation may serve as a reliable pharmacodynamic marker for Enzastaurin activity. With previously published reports, these data support the notion that Enzastaurin suppresses tumor growth through multiple mechanisms: direct suppression of tumor cell proliferation and the induction of tumor cell death coupled to the indirect effect of suppressing tumor-induced angiogenesis.
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Affiliation(s)
- Jeremy R Graff
- Lilly Research Labs, Eli Lilly and Company, Indianapolis, Indiana 46285, USA.
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186
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Hans CP, Weisenburger DD, Greiner TC, Chan WC, Aoun P, Cochran GT, Pan Z, Smith LM, Lynch JC, Bociek RG, Bierman PJ, Vose JM, Armitage JO. Expression of PKC-beta or cyclin D2 predicts for inferior survival in diffuse large B-cell lymphoma. Mod Pathol 2005; 18:1377-84. [PMID: 15920548 DOI: 10.1038/modpathol.3800434] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
We sought to determine whether identification of poor-risk subgroups of diffuse large B-cell lymphoma (DLBCL) using immunohistochemical stains would have practical utility with regard to prognosis and therapeutic decisions. Tissue microarray blocks were created using replicate samples of formalin-fixed, paraffin-embedded tissue from 200 cases of de novo DLBCL. The sections were stained with antibodies to proteins that are expressed by activated or proliferating B cells including MUM1, FOXP1, bcl-2, survivin, protein kinase C-beta (PKC-beta), cyclin D2, cyclin D3, and Ki-67. In univariate analysis, tumor expression of cyclin D2 (P = 0.025) or PKC-beta (P = 0.015) was associated with a worse overall survival, whereas none of the other markers was predictive of overall survival. Patients with DLBCL that expressed either cyclin D2 or PKC-beta had a 5-year overall survival of only 30% as compared to 52% for those who were negative for both markers (P = 0.0019). In multivariate analysis, the expression of cyclin D2 or PKC-beta was an independent predictor of poor overall survival (P = 0.035). Cyclin D2 and PKC-beta expression will be useful in designing a 'biological prognostic index' for patients with DLBCL.
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Affiliation(s)
- Christine P Hans
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE 68198-3135, USA.
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187
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Pearce HL, Alice Miller M. The evolution of cancer research and drug discovery at Lilly Research Laboratories. ACTA ACUST UNITED AC 2005; 45:229-55. [PMID: 16143373 DOI: 10.1016/j.advenzreg.2005.02.017] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
This review highlights the discovery and development of chemotherapy at Eli Lilly & Company over the past 30 years from the Vinca alkaloids-vincristine, vinblastine, and vindesine-to targeted therapy. During the late 1970s, Lilly began an exploration of new synthetic compounds based on solid tumor screening models. Several novel antimetabolites with the potential to treat solid tumors were identified. Two such agents, gemcitabine and pemetrexed, underwent clinical development and are now among Lilly's portfolio of approved anticancer drugs. Gemcitabine, a pyrimidine nucleoside that has a profound effect on DNA synthesis, has been approved for the treatment of pancreatic, non-small cell lung, bladder, and most recently, breast, and ovarian cancer. Pemetrexed, a novel antifolate with potent cytotoxic effects, is distinguished from other antifolates by virtue of its ability to inhibit multiple folate-dependent enzymes. Pemetrexed, given in combination with cisplatin, has been recently approved for the treatment of malignant pleural mesothelioma and as second-line treatment for non-small cell lung cancer. Spurred by advances in the understanding of cancer as a disease process, Lilly's anticancer drug program began to transition to a more "targeted" approach during the 1990s. These efforts have recently culminated in the identification and development of enzastaurin, a PKCbeta inhibitor with potent anti-angiogenic properties. Enzastaurin has shown promising single-agent activity in patients with relapsed diffuse large B-cell lymphoma and recurrent glioblastoma multiforme, and is an excellent candidate for combination with cytotoxic agents.
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Affiliation(s)
- Homer L Pearce
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana, USA
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188
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Siebenlist U, Brown K, Claudio E. Control of lymphocyte development by nuclear factor-kappaB. Nat Rev Immunol 2005; 5:435-45. [PMID: 15905862 DOI: 10.1038/nri1629] [Citation(s) in RCA: 228] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The evolutionarily conserved nuclear factor-kappaB family of transcription factors is known to have a crucial role in rapid responses to stress and pathogens, inducing transcription of many genes that are essential for host defence. Now, studies of mice that are deficient in nuclear factor-kappaB-family members (or deficient in the activation of these factors) reveal that nuclear factor-kappaB is extensively involved in the development of T cells and B cells. And, as we review here, although these factors have several roles, their primary cell-autonomous function is to ensure lymphocyte survival at various developmental stages. This function is subverted in numerous diseases and can lead, for example, to survival of self-reactive lymphocytes or tumour cells.
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Affiliation(s)
- Ulrich Siebenlist
- Immune Activation Section, Laboratory of Immune Regulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892-1876, USA.
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189
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Mizuno T, Rothstein TL. B cell receptor (BCR) cross-talk: CD40 engagement creates an alternate pathway for BCR signaling that activates I kappa B kinase/I kappa B alpha/NF-kappa B without the need for PI3K and phospholipase C gamma. THE JOURNAL OF IMMUNOLOGY 2005; 174:6062-70. [PMID: 15879100 DOI: 10.4049/jimmunol.174.10.6062] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BCR signaling is propagated by a series of intermediaries and eventuates in NF-kappaB activation, among other outcomes. Interruption of several mediators that constitute the signalosome, such as PI3K and phospholipase Cgamma2, completely blocks BCR signaling for NF-kappaB. We show here that this accepted, conventional paradigm is, in fact, limited to naive B cells. CD40L treatment reprograms normal B cells such that a novel, alternate pathway for BCR signaling is created. Through this alternate pathway BCR triggering induces nuclear NF-kappaB without the need for PI3K or for phospholipase Cgamma2. Induction of NF-kappaB via the alternate pathway is accompanied by IkappaB kinase beta (IKKbeta) phosphorylation, IkappaBalpha phosphorylation, and IkappaBalpha degradation, and inhibition of IKKbeta blocked IkappaBalpha degradation. Several key events in the conventional pathway, including early protein tyrosine phosphorylation, were unimpeded by generation of the alternate pathway which appears to operate in parallel, rather than in competition, with classical BCR signaling. These results demonstrate cross-talk between CD40 and BCR, such that the requirements for BCR signaling are altered by prior B cell exposure to CD40L. The alternate BCR signaling pathway bypasses multiple signalosome elements and terminates in IKKbeta activation.
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Affiliation(s)
- Takuya Mizuno
- Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA
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190
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Abstract
The proliferation and differentiation of lymphocytes are regulated by receptors localized on the cell surface. Engagement of these receptors induces the activation of intracellular signaling proteins that transmit the receptor signals to distinct targets and control the cellular responses. The first signaling proteins to be discovered in higher organisms were the products of oncogenes. For example, the kinases Src and Abelson (Abl) were originally identified as oncogenes and were later characterized as important proteins for signal transduction in various cell types, including lymphocytes. Now, as many cellular signaling molecules have been discovered and ordered into certain pathways, we can better understand why particular signaling proteins are associated with tumorigenesis. In this review, we discuss recent progress in unraveling the molecular mechanisms of signaling pathways that control the proliferation and differentiation of early B cells. We point out the concepts of auto-inhibition and subcellular localization as crucial aspects in the regulation of B cell signaling.
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Affiliation(s)
- Hassan Jumaa
- Institute for Biology III, Albert-Ludwigs University of Freiburg and Max Planck Institute for Immunobiology, 79108 Freiburg, Germany.
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191
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Fu K, Iqbal J, Chan WC. Recent advances in the molecular diagnosis of diffuse large B-cell lymphoma. Expert Rev Mol Diagn 2005; 5:397-408. [PMID: 15934816 DOI: 10.1586/14737159.5.3.397] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The field of molecular diagnostics is changing and adapting to new information obtained from genetic, genomic and proteomic profiling of diseases. One of the novel technologies that has made significant impact on the molecular diagnosis of lymphoid malignancies is DNA microarray technology. It has allowed the profiling of the most common types of lymphomas, identifying distinct molecular signatures of these diseases as well as novel subtypes that cannot otherwise be identified by conventional methods. In addition, it has also allowed the construction of molecularly defined prognostic models for various types of lymphomas and to better understand the molecular mechanisms that determine the behavior of the tumor. In this review, recent advances in the molecular diagnosis of diffuse large B-cell lymphoma are highlighted, using examples of how gene expression profiling has been used in disease classification and outcome predictions. The future development of this field and its applications in the clinical arena will also be discussed.
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MESH Headings
- Animals
- Gene Expression Profiling
- Humans
- Immunohistochemistry
- Lymphoma, B-Cell/classification
- Lymphoma, B-Cell/diagnosis
- Lymphoma, B-Cell/genetics
- Lymphoma, B-Cell/therapy
- Lymphoma, Large B-Cell, Diffuse/classification
- Lymphoma, Large B-Cell, Diffuse/diagnosis
- Lymphoma, Large B-Cell, Diffuse/genetics
- Lymphoma, Large B-Cell, Diffuse/therapy
- Molecular Diagnostic Techniques
- Reverse Transcriptase Polymerase Chain Reaction
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Affiliation(s)
- Kai Fu
- Nebraska Medical Center, Department of Pathology & Microbiology, Omaha, NE 68198-3135, USA.
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192
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Hosokawa Y. Anti-apoptotic action of API2-MALT1 fusion protein involved in t(11;18)(q21;q21) MALT lymphoma. Apoptosis 2005; 10:25-34. [PMID: 15711920 DOI: 10.1007/s10495-005-6059-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
At least three distinct chromosomal translocations, t(11;18)(q21;q21), t(1;14)(p22;q32) and t(14;18)(q32;q21) involving the API2 (also known as c-IAP2)-MALT1 fusion protein, BCL10, and MALT1, respectively, have been implicated in the molecular pathogenesis of mucosa associated lymphoid tissue (MALT) lymphoma. Our findings showed that several variants of the API2-MALT1 fusion protein can occur in patients with t(11;18)(q21;q21), and that API2-MALT1 can potently enfance activation of nuclear factor (NF)-kappaB signaling, which may be relevant to the pathogenesis of MALT lymphomas. We also found that MALT1 is rapidly degraded via the ubiquitin-proteasome pathway, as is the case with API2, but upon the synthesis of fusion, API2-MALT1 becomes stable against this pathway. This stability of API2-MALT1 may thus result in inappropriate nuclear factor (NF)-kappaB activation, thereby contributing to the pathogenesis of MALT lymphoma. Recent biochemical and genetic studies have clearly shown that BCL10 and MALT1 form a physical and functional complex and are both required for NF-kappaB activation by antigen receptor stimulation in T and B lymphocytes. It has also been shown that CARMA1, a newly discovered member of the membrane-associated guanylate kinase (MAGUK) families, is critical for antigen receptor-stimulated NF-kappaB activation. It can be assumed that API2-MALT1 can bypass this normal BCL10/MALT1 cellular signaling pathway linked to NF-kappaB activation, thereby inducing antigen receptor-independent proliferation of lymphocytes. Furthermore, BCL10/MALT1- and API2-MALT1-induced NF-kappaB activation may contribute to anti-apoptotic action probably through NF-kappaB-mediated upregulation of apoptotic inhibitor genes. We recently provided direct evidence that API2-MALT1 indeed exerts anti-apoptotic action, in part, through its direct interaction with apoptotic regulators including Smac. Taken together, these findings prompt us to hypothesize that the anti-apoptotic action of API2-MALT1 may be mediated partly by the direct interaction with apoptotic regulators as well as partly by upregulation of apoptotic inhibitor genes. Further studies can be expected to stimulate research into the development of therapeutic drugs that specifically inhibit the antigen receptor signaling-stimulated NF-kappaB activation pathway: such molecule targeting drugs should be useful for interfering with inappropriate proliferation of lymphocytes associated with inflammatory and neoplastic disorders.
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MESH Headings
- Apoptosis
- Chromosomes, Human, Pair 11
- Chromosomes, Human, Pair 18
- Humans
- Inhibitor of Apoptosis Proteins
- Lymphoma, B-Cell, Marginal Zone/genetics
- Lymphoma, B-Cell, Marginal Zone/metabolism
- Models, Biological
- NF-kappa B/antagonists & inhibitors
- Proteins/metabolism
- Proteomics
- Receptors, Antigen/metabolism
- Translocation, Genetic
- Ubiquitin/metabolism
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Affiliation(s)
- Y Hosokawa
- Division of Molecular Medicine, Aichi Cancer Center Research Institute, Nagoya, 464-8681, Japan.
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193
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Karnell FG, Brezski RJ, King LB, Silverman MA, Monroe JG. Membrane cholesterol content accounts for developmental differences in surface B cell receptor compartmentalization and signaling. J Biol Chem 2005; 280:25621-8. [PMID: 15878848 DOI: 10.1074/jbc.m503162200] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Recent studies argue for an important role for cholesterol in maintaining plasma membrane heterogeneity and influencing a variety of cellular processes, including signaling, adhesion, and permeability. Here, we document that tolerance-sensitive transitional immature B cells maintain significantly lower membrane unesterified cholesterol levels than mature-stage splenic B cells. In addition, the relatively low level of cholesterol in transitional immature B cells impairs compartmentalization of their B cell receptor (BCR) into cholesterol-enriched domains following BCR aggregation and reduces their ability to sustain certain aspects of BCR signaling as compared with mature B cells. These studies establish an unexpected difference in the lipid composition of peripheral transitional immature and mature B cells and point to a determining role for development-associated differences in cholesterol content for the differential responses of these B cells to BCR engagement.
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Affiliation(s)
- Fredrick G Karnell
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6160, USA
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194
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Johnson K, Shapiro-Shelef M, Tunyaplin C, Calame K. Regulatory events in early and late B-cell differentiation. Mol Immunol 2005; 42:749-61. [PMID: 15829263 DOI: 10.1016/j.molimm.2004.06.039] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2004] [Accepted: 06/18/2004] [Indexed: 01/29/2023]
Abstract
We are studying transcriptional control of critical developmental decision points in B lymphocytes. Commitment to the B-lymphocyte lineage is dependent on the transcriptional regulator Pax5 and committed B lymphocytes represent the first developmental stage when V(H)-to-DJ recombination occurs in the immunoglobulin (Ig) heavy chain locus. We summarize our recent studies showing that methylation of histone H3 lysine 9, a heterochromatic chromatin modification, is present in the Ig V(H) region in hematopoietic progenitors and in non-B lineage hematopoietic cells. Pax5 is both necessary and sufficient to remove this heterochromatic mark in B cells. Using genetically altered mice, we have shown that terminal differentiation of B cells to memory and Ig-secreting plasma cells depends on the transcriptional repressor Blimp-1. Recent studies demonstrating a requirement for Blimp-1 in the formation of pre-plasma memory B cells, Ig-secreting plasma cells as well as preliminary data suggesting a requirement for Blimp-1 in the maintenance of long-lived plasma cells are summarized. We also summarize our recent studies on the regulation of Blimp-1, showing direct repression by Bcl-6 and providing evidence for activation by NF-kappaB following toll-like receptor signaling.
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Affiliation(s)
- Kristen Johnson
- Department of Microbiology, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA
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195
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Affiliation(s)
- Pedro Farinha
- Department of Pathology and Laboratory Medicine, British Columbia Cancer Agency and the University of British Columbia, Vancouver, Canada
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196
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Abstract
Lymphocyte activation plays a critical role in immune responses. Dysregulation of lymphocyte activation can cause autoimmune, immunodeficient diseases, or leukemia/lymphoma. Lymphocyte activation is triggered by stimulation of antigen receptors, T cell receptors (TCR) or B cell receptors (BCR), on the surfaces of T or B lymphocyte, respectively. Stimulation of TCR or BCR induces a series of signal transduction cascades leading to activation of multiple transcription factors including NF-kappaB. Recent studies demonstrate that CARMA1, a scaffold protein, plays an essential role in mediating TCR- or BCR-induced NF-kappaB activation by recruiting two adaptor proteins, Bcl10 and MALT1, to lipid rafts following stimulation of antigen receptors. In this review, we will discuss the mechanism by which proximal signaling components connect antigen receptor signaling to CARMA1, and how CARMA1 regulates Bcl10 and MALT1, leading to activation of NF-kappaB. In addition, the roles of CARMA1, Bcl10, and MALT1 in lymphocyte activation and development will also be discussed.
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Affiliation(s)
- Xin Lin
- Department of Microbiology and Immunology, University at Buffalo, 138 Farber Hall, 3435 Main Street, Buffalo, NY 14214, USA.
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197
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Abramson JS, Shipp MA. Advances in the biology and therapy of diffuse large B-cell lymphoma: moving toward a molecularly targeted approach. Blood 2005; 106:1164-74. [PMID: 15855278 DOI: 10.1182/blood-2005-02-0687] [Citation(s) in RCA: 157] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Diffuse large B-cell lymphoma (DLBCL) displays striking heterogeneity at the clinical, genetic, and molecular levels. Clinical prognostic models can define a population at high risk for relapse following empiric chemotherapy, although such models do not account for underlying biologic differences among tumors. Commonly observed genetic abnormalities that likely contribute to pathogenesis include translocations of BCL6, BCL2, cMYC, and FAS(CD95) mutations, and aberrant somatic hypermutation. Despite recent advances in empiric chemotherapy, including interval reduction of CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) and the incorporation of anti-CD20 monoclonal antibodies, a significant proportion of patients still die of their disease. Gene expression profiling has shed light on the molecular heterogeneity within DLBCL by highlighting similarities between subsets of tumors and normal B cells, identifying features associated with unfavorable responses to empiric combination chemotherapy, and defining robust subtypes with comprehensive transcriptional signatures. Such strategies have suggested distinct routes to lymphomagenesis and have identified promising rational therapeutic targets. Additional novel therapies under investigation include those targeting BCL6 and BCL2, as well as development of novel monoclonal antibody-based therapies. Our increasing molecular understanding of the heterogeneous subsets within DLBCL will likely improve the current empiric therapy of DLBCL by identifying rational therapeutic targets in specific disease subtypes.
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Affiliation(s)
- Jeremy S Abramson
- Department of Medical Oncology, Dana-Farber Cancer Institute, 44 Binney St, Boston, MA 02115, USA
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198
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Moreno-García ME, López-Bojórques LN, Zentella A, Humphries LA, Rawlings DJ, Santos-Argumedo L. CD38 signaling regulates B lymphocyte activation via a phospholipase C (PLC)-gamma 2-independent, protein kinase C, phosphatidylcholine-PLC, and phospholipase D-dependent signaling cascade. THE JOURNAL OF IMMUNOLOGY 2005; 174:2687-95. [PMID: 15728476 DOI: 10.4049/jimmunol.174.5.2687] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The CD38 cell surface receptor is a potent activator for splenic, B lymphocytes. The molecular mechanisms regulating this response, however, remain incompletely characterized. Activation of the nonreceptor tyrosine kinase, Btk, is essential for CD38 downstream signaling function. The major Btk-dependent substrate in B cells, phospholipase C-gamma2 (PLC-gamma2), functions to generate the key secondary messengers, inositol-1,4,5 trisphosphate and diacylglycerol. Surprisingly, CD38 ligation results in no detectable increase in phosphoinositide metabolism and only a minimal increase in cytosolic calcium. We hypothesized that Btk functioned independently of PLC-gamma2 in the CD38 signaling pathway. Accordingly, we demonstrate that CD38 cross-linking does not result in the functional phosphorylation of PLC-gamma2 nor an increase in inositol-1,4,5 trisphosphate production. Furthermore, splenic B cells exhibit a normal CD38-mediated, proliferative response in the presence of the phosphoinositide-PLC inhibitor, U73122. Conversely, protein kinase C (PKC) beta-deficient mice, or PKC inhibitors, indicated the requirement for diacylglycerol-dependent PKC isoforms in this pathway. Loss of PKC activity blocked CD38-dependent, B cell proliferation, NF-kappaB activation, and subsequent expression of cyclin-D2. These results suggested that an alternate diacylglycerol-producing phospholipase must participate in CD38 signaling. Consistent with this idea, CD38 increased the enzymatic activity of the phosphatidylcholine (PC)-metabolizing enzymes, PC-PLC and phospholipase D. The PC-PLC inhibitor, D609, completely blocked CD38-dependent B cell proliferation, IkappaB-alpha degradation, and cyclin-D2 expression. Analysis of Btk mutant B cells demonstrated a partial requirement for Btk in the activation of both enzymes. Taken together, these data demonstrate that CD38 initiates a novel signaling cascade leading to Btk-, PC-PLC-, and phospholipase D-dependent, PLC-gamma2-independent, B lymphocyte activation.
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Affiliation(s)
- Miguel E Moreno-García
- Departments of Cell Biology, Centro de Investigación y Estudios Avanzados, Mexico D.F. Mexico
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199
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Asehnoune K, Strassheim D, Mitra S, Yeol Kim J, Abraham E. Involvement of PKCα/β in TLR4 and TLR2 dependent activation of NF-κB. Cell Signal 2005; 17:385-94. [PMID: 15567069 DOI: 10.1016/j.cellsig.2004.08.005] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2004] [Revised: 08/18/2004] [Accepted: 08/19/2004] [Indexed: 01/23/2023]
Abstract
Protein kinase C (PKC)alpha/beta dependent signaling events downstream of TLR4 or TLR2 were investigated in neutrophils stimulated with LPS or PGN. Pretreatment of neutrophils with the structurally distinct PKCalpha/beta inhibitors Go6976 or GF109203X decreased nuclear translocation of NF-kappaB and production of the proinflammatory cytokine TNF-alpha. Inhibition of PKCalpha/beta also prevented LPS or PGN induced phosphorylation of IKKalpha/beta, phosphorylation and degradation of IkappaB-alpha, as well as phosphorylation of the p65 subunit of NF-kappaB. Activation of p38, JNK, and ERK 1/2 in response to TLR2 engagement was diminished in neutrophils in which PKCalpha/beta was inhibited. However, no alteration in the activation of these kinases was found in TLR4 stimulated neutrophils when PKCalpha/beta was blocked. Such results indicate that distinct intracellular signalling pathways leading to MAPK activation are induced by TLR4 and TLR2 stimulation. PKCalpha/beta can regulate NF-kappaB dependent transcription in neutrophils both by enhancing nuclear translocation of NF-kappaB and also by stimulating phosphorylation of the p65 subunit.
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Affiliation(s)
- Karim Asehnoune
- Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Health Sciences Center, Box C272, 4200 East 9th Ave, Denver, CO 80262, USA
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200
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del Rio R, Rincón M, Layseca-Espinosa E, Fierro NA, Rosenstein Y, Pedraza-Alva G. PKCtheta is required for the activation of human T lymphocytes induced by CD43 engagement. Biochem Biophys Res Commun 2005; 325:133-43. [PMID: 15522211 DOI: 10.1016/j.bbrc.2004.10.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2004] [Indexed: 12/12/2022]
Abstract
The turnover of phosphoinositides leading to PKC activation constitutes one of the principal axes of intracellular signaling. In T lymphocytes, the enhanced and prolonged PKC activation resulting from the engagement of the TcR and co-receptor molecules ensures a productive T cell response. The CD43 co-receptor promotes activation and proliferation, by inducing IL-2 secretion and CD69 expression. CD43 engagement has been shown to promote phosphoinositide turnover and DAG production. Moreover, PKC activation was found to be required for the activation of the MAP kinase pathway in response to CD43 ligation. Here we show that CD43 engagement led to the membrane translocation and enzymatic activity of specific PKC isoenzymes: cPKC (alpha/beta), nPKC (epsilon and theta;), aPKC (zeta) and PKCmu. We also show that activation of PKCtheta; resulting from CD43 ligation induced CD69 expression through an ERK-dependent pathway leading to AP-1, NF-kappaB activation and an ERK independent pathway promoting NFAT activation. Together, these data suggest that PKCtheta; plays a critical role in the co-stimulatory functions of CD43 in human T cells.
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Affiliation(s)
- Roxana del Rio
- Instituto de Biotecnología/Universidad Nacional Autónoma de México, AP 510-3 Cuernavaca, Mor. 62250, Mexico
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