1
|
Multi-Faceted Roles of DNAJB Protein in Cancer Metastasis and Clinical Implications. Int J Mol Sci 2022; 23:ijms232314970. [PMID: 36499297 PMCID: PMC9737691 DOI: 10.3390/ijms232314970] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 11/28/2022] [Accepted: 11/28/2022] [Indexed: 12/02/2022] Open
Abstract
Heat shock proteins (HSPs) are highly conserved molecular chaperones with diverse cellular activities, including protein folding, assembly or disassembly of protein complexes, and maturation process under diverse stress conditions. HSPs also play essential roles in tumorigenesis, metastasis, and therapeutic resistance across cancers. Among them, HSP40s are widely accepted as regulators of HSP70/HSP90 chaperones and an accumulating number of biological functions as molecular chaperones dependent or independent of either of these chaperones. Despite large numbers of HSP40s, little is known about their physiologic roles, specifically in cancer progression. This article summarizes the multi-faceted role of DNAJB proteins as one subclass of the HSP40 family in cancer development and metastasis. Regulation and deregulation of DNAJB proteins at transcriptional, post-transcriptional, and post-translational levels contribute to tumor progression, particularly cancer metastasis. Furthermore, understanding differences in function and regulating mechanism between DNAJB proteins offers a new perspective on tumorigenesis and metastasis to improve therapeutic opportunities for malignant diseases.
Collapse
|
2
|
Wu Z, Nicoll M, Ingham RJ. AP-1 family transcription factors: a diverse family of proteins that regulate varied cellular activities in classical hodgkin lymphoma and ALK+ ALCL. Exp Hematol Oncol 2021; 10:4. [PMID: 33413671 PMCID: PMC7792353 DOI: 10.1186/s40164-020-00197-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 12/21/2020] [Accepted: 12/22/2020] [Indexed: 01/07/2023] Open
Abstract
Classical Hodgkin lymphoma (cHL) and anaplastic lymphoma kinase-positive, anaplastic large cell lymphoma (ALK+ ALCL) are B and T cell lymphomas respectively, which express the tumour necrosis factor receptor superfamily member, CD30. Another feature shared by cHL and ALK+ ALCL is the aberrant expression of multiple members of the activator protein-1 (AP-1) family of transcription factors which includes proteins of the Jun, Fos, ATF, and Maf subfamilies. In this review, we highlight the varied roles these proteins play in the pathobiology of these lymphomas including promoting proliferation, suppressing apoptosis, and evading the host immune response. In addition, we discuss factors contributing to the elevated expression of these transcription factors in cHL and ALK+ ALCL. Finally, we examine therapeutic strategies for these lymphomas that exploit AP-1 transcriptional targets or the signalling pathways they regulate.
Collapse
Affiliation(s)
- Zuoqiao Wu
- grid.17089.37Department of Medical Microbiology and Immunology, Li Ka Shing Institute of Virology, University of Alberta, Edmonton, Canada ,grid.17063.330000 0001 2157 2938Present Address: Department of Medicine, University of Toronto, Toronto, Canada
| | - Mary Nicoll
- grid.17089.37Department of Medical Microbiology and Immunology, Li Ka Shing Institute of Virology, University of Alberta, Edmonton, Canada ,grid.14709.3b0000 0004 1936 8649Present Address: Department of Biology, McGill University, Montreal, Canada
| | - Robert J. Ingham
- grid.17089.37Department of Medical Microbiology and Immunology, Li Ka Shing Institute of Virology, University of Alberta, Edmonton, Canada
| |
Collapse
|
3
|
Bejjani F, Evanno E, Zibara K, Piechaczyk M, Jariel-Encontre I. The AP-1 transcriptional complex: Local switch or remote command? Biochim Biophys Acta Rev Cancer 2019; 1872:11-23. [PMID: 31034924 DOI: 10.1016/j.bbcan.2019.04.003] [Citation(s) in RCA: 146] [Impact Index Per Article: 29.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 04/19/2019] [Accepted: 04/22/2019] [Indexed: 12/19/2022]
Abstract
The ubiquitous family of AP-1 dimeric transcription complexes is involved in virtually all cellular and physiological functions. It is paramount for cells to reprogram gene expression in response to cues of many sorts and is involved in many tumorigenic processes. How AP-1 controls gene transcription has largely remained elusive till recently. The advent of the "omics" technologies permitting genome-wide studies of transcription factors has however changed and improved our view of AP-1 mechanistical actions. If these studies confirm that AP-1 can sometimes act as a local transcriptional switch operating in the vicinity of transcription start sites (TSS), they strikingly indicate that AP-1 principally operates as a remote command binding to distal enhancers, placing chromatin architecture dynamics at the heart of its transcriptional actions. They also unveil novel constraints operating on AP-1, as well as novel mechanisms used to regulate gene expression via transcription-pioneering-, chromatin-remodeling- and chromatin accessibility maintenance effects.
Collapse
Affiliation(s)
- Fabienne Bejjani
- Equipe Labellisée Ligue Nationale contre le Cancer, Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, Montpellier, France; PRASE and Biology Department, Faculty of Sciences - I, Lebanese University, Beirut, Lebanon
| | - Emilie Evanno
- Equipe Labellisée Ligue Nationale contre le Cancer, Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, Montpellier, France
| | - Kazem Zibara
- PRASE and Biology Department, Faculty of Sciences - I, Lebanese University, Beirut, Lebanon
| | - Marc Piechaczyk
- Equipe Labellisée Ligue Nationale contre le Cancer, Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, Montpellier, France.
| | - Isabelle Jariel-Encontre
- Equipe Labellisée Ligue Nationale contre le Cancer, Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, Montpellier, France.
| |
Collapse
|
4
|
The AP-1 transcription factor JunB is essential for multiple myeloma cell proliferation and drug resistance in the bone marrow microenvironment. Leukemia 2016; 31:1570-1581. [PMID: 27890927 DOI: 10.1038/leu.2016.358] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Revised: 11/08/2016] [Accepted: 11/11/2016] [Indexed: 12/13/2022]
Abstract
Despite therapeutic advances, multiple myeloma (MM) remains an incurable disease, predominantly because of the development of drug resistance. The activator protein-1 (AP-1) transcription factor family has been implicated in a multitude of physiologic processes and tumorigenesis; however, its role in MM is largely unknown. Here we demonstrate specific and rapid induction of the AP-1 family member JunB in MM cells when co-cultured with bone marrow stromal cells. Supporting a functional key role of JunB in MM pathogenesis, knockdown of JUNB significantly inhibited in vitro MM cell proliferation and survival. Consistently, induced silencing of JUNB markedly decreased tumor growth in a murine MM model of the microenvironment. Subsequent gene expression profiling revealed a role for genes associated with apoptosis, DNA replication and metabolism in driving the JunB-mediated phenotype in MM cells. Importantly, knockdown of JUNB restored the response to dexamethasone in dexamethasone-resistant MM cells. Moreover, 4-hydroxytamoxifen-induced activation of a JunB-ER fusion protein protected dexamethasone-sensitive MM cells against dexamethasone- and bortezomib-induced cytotoxicity. In summary, our results demonstrate for the first time a specific role for AP-1/JunB in MM cell proliferation, survival and drug resistance, thereby strongly supporting that this transcription factor is a promising new therapeutic target in MM.
Collapse
|
5
|
Zhao R, Choi BY, Lee MH, Bode AM, Dong Z. Implications of Genetic and Epigenetic Alterations of CDKN2A (p16(INK4a)) in Cancer. EBioMedicine 2016; 8:30-39. [PMID: 27428416 PMCID: PMC4919535 DOI: 10.1016/j.ebiom.2016.04.017] [Citation(s) in RCA: 243] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Revised: 04/01/2016] [Accepted: 04/14/2016] [Indexed: 12/12/2022] Open
Abstract
Aberrant gene silencing is highly associated with altered cell cycle regulation during carcinogenesis. In particular, silencing of the CDKN2A tumor suppressor gene, which encodes the p16(INK4a) protein, has a causal link with several different types of cancers. The p16(INK4a) protein plays an executional role in cell cycle and senescence through the regulation of the cyclin-dependent kinase (CDK) 4/6 and cyclin D complexes. Several genetic and epigenetic aberrations of CDKN2A lead to enhanced tumorigenesis and metastasis with recurrence of cancer and poor prognosis. In these cases, the restoration of genetic and epigenetic reactivation of CDKN2A is a practical approach for the prevention and therapy of cancer. This review highlights the genetic status of CDKN2A as a prognostic and predictive biomarker in various cancers.
Collapse
Affiliation(s)
- Ran Zhao
- China-US (Henan) Hormel Cancer Institute, No.127, Dongming Road, Jinshui District, Zhengzhou, Henan 450008, China
| | - Bu Young Choi
- Department of Pharmaceutical Science and Engineering, Seowon University, Cheongju 361-742, South Korea
| | - Mee-Hyun Lee
- China-US (Henan) Hormel Cancer Institute, No.127, Dongming Road, Jinshui District, Zhengzhou, Henan 450008, China.
| | - Ann M Bode
- The Hormel Institute, University of Minnesota, Austin, MN 55912, USA
| | - Zigang Dong
- China-US (Henan) Hormel Cancer Institute, No.127, Dongming Road, Jinshui District, Zhengzhou, Henan 450008, China; The Hormel Institute, University of Minnesota, Austin, MN 55912, USA.
| |
Collapse
|
6
|
Highly recurrent mutations of SGK1, DUSP2 and JUNB in nodular lymphocyte predominant Hodgkin lymphoma. Leukemia 2015; 30:844-53. [DOI: 10.1038/leu.2015.328] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 10/15/2015] [Accepted: 11/17/2015] [Indexed: 12/19/2022]
|
7
|
Schneckenleithner C, Hoelbl-Kovacic A, Sexl V. Modeling BCR/ABL-driven malignancies in the mouse. Methods Mol Biol 2015; 1267:263-282. [PMID: 25636473 DOI: 10.1007/978-1-4939-2297-0_12] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In this chapter, we describe model systems to study leukemia driven by the Abelson oncogene. In people, the Abelson oncogene results from the chromosomal translocation t(9;22)(q34;q11) that is found in more than 90 % of all human chronic myeloid leukemia (CML) patients and in 20-25 % of patients suffering from acute lymphoid leukemia (ALL). This translocation is also called Philadelphia chromosome and encodes the BCR/ABL oncogene, a constitutive active tyrosine kinase. BCR/ABL renders hematopoietic cells independent from exogenous growth-stimulatory signals by continuously engaging signaling pathways including JAK-STAT signaling and the MAPK pathway. The enforced expression of BCR/ABL suffices to transform hematopoietic cells which made it to one of the best studied model systems in the field. Here we present methods to study BCR/ABL-triggered leukemia and solid lymphoid tumor formation.
Collapse
|
8
|
Kollmann K, Heller G, Schneckenleithner C, Warsch W, Scheicher R, Ott R, Schäfer M, Fajmann S, Schlederer M, Schiefer AI, Reichart U, Mayerhofer M, Hoeller C, Zöchbauer-Müller S, Kerjaschki D, Bock C, Kenner L, Hoefler G, Freissmuth M, Green A, Moriggl R, Busslinger M, Malumbres M, Sexl V. A kinase-independent function of CDK6 links the cell cycle to tumor angiogenesis. Cancer Cell 2013; 24:167-81. [PMID: 23948297 PMCID: PMC3743049 DOI: 10.1016/j.ccr.2013.07.012] [Citation(s) in RCA: 203] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Revised: 05/17/2013] [Accepted: 07/22/2013] [Indexed: 12/20/2022]
Abstract
In contrast to its close homolog CDK4, the cell cycle kinase CDK6 is expressed at high levels in lymphoid malignancies. In a model for p185BCR-ABL+ B-acute lymphoid leukemia, we show that CDK6 is part of a transcription complex that induces the expression of the tumor suppressor p16INK4a and the pro-angiogenic factor VEGF-A. This function is independent of CDK6's kinase activity. High CDK6 expression thus suppresses proliferation by upregulating p16INK4a, providing an internal safeguard. However, in the absence of p16INK4a, CDK6 can exert its full tumor-promoting function by enhancing proliferation and stimulating angiogenesis. The finding that CDK6 connects cell-cycle progression to angiogenesis confirms CDK6's central role in hematopoietic malignancies and could underlie the selection pressure to upregulate CDK6 and silence p16INK4a.
Collapse
Affiliation(s)
- Karoline Kollmann
- Institute of Pharmacology and Toxicology, University of Veterinary Medicine Vienna, 1210 Vienna, Austria
| | - Gerwin Heller
- Clinical Division of Oncology, Department of Medicine I, Comprehensive Cancer Center, Medical University of Vienna, 1090 Vienna, Austria
| | | | - Wolfgang Warsch
- Institute of Pharmacology and Toxicology, University of Veterinary Medicine Vienna, 1210 Vienna, Austria
| | - Ruth Scheicher
- Institute of Pharmacology and Toxicology, University of Veterinary Medicine Vienna, 1210 Vienna, Austria
| | - Rene G. Ott
- Institute of Pharmacology, Center of Biomolecular Medicine and Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
| | - Markus Schäfer
- Research Institute of Molecular Pathology, Vienna Biocenter, 1030 Vienna, Austria
| | - Sabine Fajmann
- Institute of Pharmacology and Toxicology, University of Veterinary Medicine Vienna, 1210 Vienna, Austria
| | - Michaela Schlederer
- Department of Clinical Pathology, Medical University of Vienna, 1090 Vienna, Austria
| | - Ana-Iris Schiefer
- Department of Clinical Pathology, Medical University of Vienna, 1090 Vienna, Austria
| | - Ursula Reichart
- Institute of Animal Breeding and Genetics, University of Veterinary Medicine Vienna, 1210 Vienna, Austria
| | - Matthias Mayerhofer
- Department of Laboratory Medicine, Medical University of Vienna, 1090 Vienna, Austria
| | - Christoph Hoeller
- Department of Dermatology, Medical University of Vienna, 1090 Vienna, Austria
| | - Sabine Zöchbauer-Müller
- Clinical Division of Oncology, Department of Medicine I, Comprehensive Cancer Center, Medical University of Vienna, 1090 Vienna, Austria
| | - Dontscho Kerjaschki
- Department of Clinical Pathology, Medical University of Vienna, 1090 Vienna, Austria
| | - Christoph Bock
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, 1090 Vienna, Austria
| | - Lukas Kenner
- Ludwig Boltzmann Institute for Cancer Research, 1090 Vienna, Austria
| | - Gerald Hoefler
- Department of Pathology, Medical University of Graz, 8036 Graz, Austria
| | - Michael Freissmuth
- Institute of Pharmacology, Center of Biomolecular Medicine and Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
| | - Anthony R. Green
- Cambridge Institute for Medical Research and Wellcome Trust/MRC Stem Cell Institute, University of Cambridge, Cambridge CB2 0XY, UK
- Department of Hematology, University of Cambridge, Cambridge CB2 0XY, UK
- Department of Hematology, Addenbrooke’s Hospital, Cambridge CB2 0XY, UK
| | - Richard Moriggl
- Ludwig Boltzmann Institute for Cancer Research, 1090 Vienna, Austria
| | - Meinrad Busslinger
- Institute of Pharmacology, Center of Biomolecular Medicine and Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
| | - Marcos Malumbres
- Cell Division and Cancer Group, Molecular Oncology Programme, Centro Nacional de Investigaciones Oncológicas (CNIO), 28029 Madrid, Spain
| | - Veronika Sexl
- Institute of Pharmacology and Toxicology, University of Veterinary Medicine Vienna, 1210 Vienna, Austria
- Corresponding author
| |
Collapse
|
9
|
Gervasi M, Bianchi-Smiraglia A, Cummings M, Zheng Q, Wang D, Liu S, Bakin AV. JunB contributes to Id2 repression and the epithelial-mesenchymal transition in response to transforming growth factor-β. ACTA ACUST UNITED AC 2012; 196:589-603. [PMID: 22391036 PMCID: PMC3307698 DOI: 10.1083/jcb.201109045] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
JunB helps set in motion the transcriptional program necessary for the epithelial–mesenchymal transition and tissue fibrosis in response to TGF-β. The process of epithelial–mesenchymal transition (EMT) in response to transforming growth factor–β (TGF-β) contributes to tissue fibrosis, wound healing, and cancer via a mechanism that is not fully understood. This study identifies a critical role of JunB in the EMT and profibrotic responses to TGF-β. Depletion of JunB by small interfering ribonucleic acid abrogates TGF-β–induced disruption of cell–cell junctions, formation of actin fibers, focal adhesions, and expression of fibrotic proteins. JunB contributes to Smad-mediated repression of inhibitor of differentiation 2 through interaction with transcription repressor activating transcription factor 3. Importantly, JunB mediates the TGF-β induction of profibrotic response factors, fibronectin, fibulin-2, tropomyosin (Tpm1), and integrin-β3, which play critical roles in matrix deposition, cell–matrix adhesion, and actin stress fibers. In summary, JunB provides important input in setting the transcriptional program of the EMT and profibrotic responses to TGF-β. Thus, JunB represents an important target in diseases associated with EMT, including cancer and fibrosis.
Collapse
Affiliation(s)
- Megan Gervasi
- Department of Cancer Genetics, Roswell Park Cancer Institute, Buffalo, NY 14263, USA
| | | | | | | | | | | | | |
Collapse
|
10
|
Abstract
A novel way by which the AP-1 factor c-JUN interferes with tumorigenesis has recently been elucidated [1]. In a model of murine leukemia, c-JUN prevents the epigenetic silencing of the cell cycle kinase CDK6. In the absence of c-JUN, CDK6 is down-regulated and the 5'region of the gene is methylated. Down-regulation of CDK6 results in significantly delayed leukemia formation. Here we show that c-JUN is also involved in protecting the promoter region of the tumor suppressor p16INK4a, which is consistently methylated over time in c-JUN deficient cells. In cells expressing c-JUN, p16INK4a promoter methylation is a less frequent event. Our study unravels a novel mechanism by which the AP-1 factor c-JUN acts as a “bodyguard”, and preventing methylation of a distinct set of genes after oncogenic transformation.
Collapse
|
11
|
The cardinal role of the phospholipase A2/cyclooxygenase-2/prostaglandin E synthase/prostaglandin E2 (PCPP) axis in inflammostasis. Inflamm Res 2011; 60:1083-92. [DOI: 10.1007/s00011-011-0385-7] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Revised: 08/15/2011] [Accepted: 09/06/2011] [Indexed: 12/20/2022] Open
|
12
|
c-JUN promotes BCR-ABL-induced lymphoid leukemia by inhibiting methylation of the 5' region of Cdk6. Blood 2011; 117:4065-75. [PMID: 21300982 DOI: 10.1182/blood-2010-07-299644] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The transcription factor c-JUN and its upstream kinase JNK1 have been implicated in BCR-ABL-induced leukemogenesis. JNK1 has been shown to regulate BCL2 expression, thereby altering leukemogenesis, but the impact of c-JUN remained unclear. In this study, we show that JNK1 and c-JUN promote leukemogenesis via separate pathways, because lack of c-JUN impairs proliferation of p185(BCR-ABL)-transformed cells without affecting their viability. The decreased proliferation of c-Jun(Δ/Δ) cells is associated with the loss of cyclin-dependent kinase 6 (CDK6) expression. In c-Jun(Δ/Δ) cells, CDK6 expression becomes down-regulated upon BCR-ABL-induced transformation, which correlates with CpG island methylation within the 5' region of Cdk6. We verified the impact of Cdk6 deficiency using Cdk6(-/-) mice that developed BCR-ABL-induced B-lymphoid leukemia with significantly increased latency and an attenuated disease phenotype. In addition, we show that reexpression of CDK6 in BCR-ABL-transformed c-Jun(Δ/Δ) cells reconstitutes proliferation and tumor formation in Nu/Nu mice. In summary, our study reveals a novel function for the activating protein 1 (AP-1) transcription factor c-JUN in leukemogenesis by antagonizing promoter methylation. Moreover, we identify CDK6 as relevant and critical target of AP-1-regulated DNA methylation on BCR-ABL-induced transformation, thereby accelerating leukemogenesis.
Collapse
|
13
|
Abstract
B-cell chronic lymphocytic leukemia (CLL), the most common leukemia in the Western world, results from an expansion of a rare population of CD5+ mature B-lymphocytes. CLL occurs in two forms, aggressive and indolent. For the most part indolent CLL is characterized by low ZAP-70 expression and mutated IgH V(H); aggressive CLL shows high ZAP-70 expression and unmutated IgH V(H). Although clinical features and genomic abnormalities in CLL have been studied extensively, molecular mechanisms underlying disease development are still emerging. In the last few years, several important insights were reported in this area. MiR-15/16 targeting BCL2 and MCL1 and DLEU7 targeting TNF pathway were proposed as tumor suppressors at 13q14, a commonly deleted region in indolent CLL. Molecular details of how activation of TCL1, a critical oncogene in aggressive CLL, results in the initiation of this malignancy were clarified. Importance of these pathways was supported by investigations of several mouse models of CLL. Here, we present what has been learned from these new pathways, discuss mouse CLL models and how these mouse models recapitulate the molecular mechanisms of this common leukemia.
Collapse
Affiliation(s)
- Yuri Pekarsky
- Human Cancer Genetics Program and Department of Molecular Virology, Immunology and Medical Genetics, OSU School of Medicine, Ohio State University, Columbus, OH 43210, USA.
| | | | | |
Collapse
|
14
|
Tcl1 functions as a transcriptional regulator and is directly involved in the pathogenesis of CLL. Proc Natl Acad Sci U S A 2008; 105:19643-8. [PMID: 19064921 DOI: 10.1073/pnas.0810965105] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
B cell chronic lymphocytic leukemia (B-CLL) is the most common human leukemia. Deregulation of the T cell leukemia/lymphoma 1 (TCL1) oncogene in mouse B cells causes a CD5-positive leukemia similar to aggressive human B-CLLs. To examine the mechanisms by which Tcl1 protein exerts oncogenic activity in B cells, we investigated the effect of Tcl1 expression on NF-kappaB and activator protein 1 (AP-1) activity. We found that Tcl1 physically interacts with c-Jun, JunB, and c-Fos and inhibits AP-1 transcriptional activity. Additionally, Tcl1 activates NF-kappaB by physically interacting with p300/CREB binding protein. We then sequenced the TCL1 gene in 600 B-CLL samples and found 2 heterozygous mutations: T38I and R52H. Importantly, both mutants showed gain of function as AP-1 inhibitors. The results indicate that Tcl1 overexpression causes B-CLL by directly enhancing NF-kappaB activity and inhibiting AP-1.
Collapse
|
15
|
Thorne JL, Campbell MJ, Turner BM. Transcription factors, chromatin and cancer. Int J Biochem Cell Biol 2008; 41:164-75. [PMID: 18804550 DOI: 10.1016/j.biocel.2008.08.029] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2008] [Revised: 08/15/2008] [Accepted: 08/18/2008] [Indexed: 01/26/2023]
Abstract
Transcription factors, chromatin and chromatin-modifying enzymes are key components in a complex network through which the genome interacts with its environment. For many transcription factors, binding motifs are found adjacent to the promoter regions of a large proportion of genes, requiring mechanisms that confer binding specificity in any given cell type. These include association of the factor with other proteins and packaging of DNA, as chromatin, at the binding sequence so as to inhibit or facilitate binding. Recent evidence suggests that specific post-translational modifications of the histones packaging promoter DNA can help guide transcription factors to selected sites. The enzymes that put such modifications in place are dependent on metabolic components (e.g. acetyl CoA, S-adenosyl methionine) and susceptible to inhibition or activation by environmental factors. Local patterns of histone modification can be altered or maintained through direct interaction between the transcription factor and histone modifying enzymes. The functional consequences of transcription factor binding are also dependent on protein modifying enzymes, particularly those that alter lysine methylation at selected residues. Remarkably, the role of these enzymes is not limited to promoter-proximal events, but can be linked to changes in the intranuclear location of target genes. In this review we describe results that begin to define how transcription factors, chromatin and environmental variables interact and how these interactions are subverted in cancer. We focus on the nuclear receptor family of transcription factors, where binding of ligands such as steroid hormones and dietary derived factors provides an extra level of environmental input.
Collapse
Affiliation(s)
- James L Thorne
- University of Birmingham Medical School, Edgbaston, Birmingham, B15 2TT, UK
| | | | | |
Collapse
|
16
|
Abstract
BACKGROUND Primary cutaneous B-cell lymphoma (PCBCL) consists mainly of primary cutaneous marginal zone B-cell lymphoma (PCMZL), primary cutaneous follicle centre lymphoma (PCFCL) and primary cutaneous large B-cell lymphoma, leg type (PCLBCL-LT). The activator protein 1 (AP-1) transcription factor includes JUN, FOS and other family members. OBJECTIVES To assess the expression pattern of AP-1 transcription factors in PCBCL. METHODS We analysed paraffin tissue sections from nine cases of PCMZL, seven PCFCL, six PCLBCL-LT and two unspecified PCBCL cases by using immunohistochemistry with antibodies against c-JUN, JUNB, JUND, c-FOS, RAF1, alphaPAK, CD30 and CCND1. RESULTS A positive staining for JUND (++) was observed in six cases of PCFCL (86%), five PCLBCL-LT (83%) and five PCMZL (56%). Positive CCND1 protein expression was present in four cases of PCLBCL-LT (67%), four PCFCL (57%) and four PCMZL (44%), and the two unspecified PCBCL cases. Expression of alphaPAK protein was seen in three cases of PCLBCL-LT (50%), two PCMZL (22%) and one PCFCL. However, c-JUN, c-FOS and RAF1 protein were rarely expressed in the PCBCL cases analysed; JUNB and CD30 protein expression was absent in these cases. CONCLUSIONS These findings suggest that the presence of abnormal AP-1 protein expression is associated with upregulation of JUND, CCND1 and alphaPAK and downregulation of JUNB in PCBCL.
Collapse
Affiliation(s)
- X Mao
- Skin Tumour Unit, St John's Institute of Dermatology, St Thomas' Hospital, King's College London, UK.
| | | |
Collapse
|
17
|
Garaude J, Farrás R, Bossis G, Charni S, Piechaczyk M, Hipskind RA, Villalba M. SUMOylation regulates the transcriptional activity of JunB in T lymphocytes. THE JOURNAL OF IMMUNOLOGY 2008; 180:5983-90. [PMID: 18424718 DOI: 10.4049/jimmunol.180.9.5983] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The AP-1 family member JunB is a critical regulator of T cell function. JunB is a transcriptional activator of various cytokine genes, such as IL-2, IL-4, and IL-10; however, the post-translational modifications that regulate JunB activity in T cells are poorly characterized. We show here that JunB is conjugated with small ubiquitin-like modifier (SUMO) on lysine 237 in resting and activated primary T cells and T cell lines. Sumoylated JunB associated with the chromatin-containing insoluble fraction of cells, whereas nonsumoylated JunB was also in the soluble fraction. Blocking JunB sumoylation by mutation or use of a dominant-negative form of the SUMO-E2 Ubc-9 diminished its ability to transactivate IL-2 and IL-4 reporter genes. In contrast, nonsumoylable JunB mutants showed unimpaired activity with reporter genes controlled by either synthetic 12-O-tetradecanoylphorbol-13-acetate response elements or NF-AT/AP-1 and CD28RE sites derived from the IL-2 promoter. Ectopic expression of JunB in activated human primary CD4(+) T cells induced activation of the endogenous IL-2 promoter, whereas the nonsumoylable JunB mutant did not. Thus, our work demonstrates that sumoylation of JunB regulates its ability to induce cytokine gene transcription and likely plays a critical role in T cell activation.
Collapse
Affiliation(s)
- Johan Garaude
- Institut de Génétique Moléculaire de Montpellier, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5535, 1919 route de Mende, Montpellier cedex 5, France.
| | | | | | | | | | | | | |
Collapse
|