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Koller K, Pichler M, Koch K, Zandl M, Stiegelbauer V, Leuschner I, Hoefler G, Guertl B. Nephroblastomas show low expression of microR-204 and high expression of its target, the oncogenic transcription factor MEIS1. Pediatr Dev Pathol 2014; 17:169-75. [PMID: 24617557 DOI: 10.2350/13-01-1288-oa.1] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
By comparing several studies we identified a possible deregulation of the transcription factors PBX2 (pre-B-cell leukemia homeobox 2) and one of its binding partners, MEIS1 (Meis homeobox 1) in nephroblastomas. The regulation of MEIS1 is complex, and its expression is known to be influenced by changes of promoter methylation and binding of microRNA-204 (miR-204). Therefore, in our study, we assessed the expression of MEIS1 and PBX2 and the factors regulating expression of MEIS1 in nephroblastomas. MEIS1 and PBX2 messenger RNA (mRNA) and protein levels were investigated by quantitative real-time-polymerase chain reaction (qRT-PCR) and immunohistochemistry. Promoter methylation of MEIS1 was evaluated using a methylation-specific PCR assay. Expression levels of miR-204 were examined by qRT-PCR. Eighteen of 21 nephroblastomas showed a high level of MEIS1 mRNA, and 22 of 26 samples had a specific nuclear protein expression. MicroRNA-204 had a statistically significantly lower expression in all nephroblastomas investigated compared with renal parenchyma, but no change of MEIS1 promoter methylation status was noted. Eleven of 23 nephroblastomas had a high expression of PBX2 mRNA, and 15 of 23 samples had a specific nuclear protein expression was noted. In our study, we demonstrated an expression of MEIS1 and its binding partner PBX2 in most nephroblastomas. The statistically significantly lower expression of miR-204 in all nephroblastomas investigated might point to an involvement of miR-204 in the regulation of MEIS1 in nephroblastomas.
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Affiliation(s)
- Karin Koller
- 1 Institute of Pathology, Medical University of Graz, Auenbruggerplatz 25, 8036 Graz, Austria
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Prep1 and Meis1 competition for Pbx1 binding regulates protein stability and tumorigenesis. Proc Natl Acad Sci U S A 2014; 111:E896-905. [PMID: 24578510 DOI: 10.1073/pnas.1321200111] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Pbx-regulating protein-1 (Prep1) is a tumor suppressor, whereas myeloid ecotropic viral integration site-1 (Meis1) is an oncogene. We show that, to perform these activities in mouse embryonic fibroblasts, both proteins competitively heterodimerize with pre-B-cell leukemia homeobox-1 (Pbx1). Meis1 alone transforms Prep1-deficient fibroblasts, whereas Prep1 overexpression inhibits Meis1 tumorigenicity. Pbx1 can, therefore, alternatively act as an oncogene or tumor suppressor. Prep1 posttranslationally controls the level of Meis1, decreasing its stability by sequestering Pbx1. The different levels of Meis1 and the presence of Prep1 are followed at the transcriptional level by the induction of specific transcriptional signatures. The decrease of Meis1 prevents Meis1 interaction with Ddx3x and Ddx5, which are essential for Meis1 tumorigenesis, and modifies the growth-promoting DNA binding landscape of Meis1 to the growth-controlling landscape of Prep1. Hence, the key feature of Prep1 tumor-inhibiting activity is the control of Meis1 stability.
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53
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Velu CS, Chaubey A, Phelan JD, Horman SR, Wunderlich M, Guzman ML, Jegga AG, Zeleznik-Le NJ, Chen J, Mulloy JC, Cancelas JA, Jordan CT, Aronow BJ, Marcucci G, Bhat B, Gebelein B, Grimes HL. Therapeutic antagonists of microRNAs deplete leukemia-initiating cell activity. J Clin Invest 2014; 124:222-36. [PMID: 24334453 PMCID: PMC3871218 DOI: 10.1172/jci66005] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Accepted: 10/10/2013] [Indexed: 12/14/2022] Open
Abstract
Acute myelogenous leukemia (AML) subtypes that result from oncogenic activation of homeobox (HOX) transcription factors are associated with poor prognosis. The HOXA9 transcription activator and growth factor independent 1 (GFI1) transcriptional repressor compete for occupancy at DNA-binding sites for the regulation of common target genes. We exploited this HOXA9 versus GFI1 antagonism to identify the genes encoding microRNA-21 and microRNA-196b as transcriptional targets of HOX-based leukemia oncoproteins. Therapeutic inhibition of microRNA-21 and microRNA-196b inhibited in vitro leukemic colony forming activity and depleted in vivo leukemia-initiating cell activity of HOX-based leukemias, which led to leukemia-free survival in a murine AML model and delayed disease onset in xenograft models. These data establish microRNA as functional effectors of endogenous HOXA9 and HOX-based leukemia oncoproteins, provide a concise in vivo platform to test RNA therapeutics, and suggest therapeutic value for microRNA antagonists in AML.
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MESH Headings
- Animals
- Antineoplastic Combined Chemotherapy Protocols/therapeutic use
- Base Sequence
- Binding Sites
- Cell Transformation, Neoplastic/genetics
- Cell Transformation, Neoplastic/metabolism
- Combined Modality Therapy
- Cytarabine/administration & dosage
- DNA-Binding Proteins/metabolism
- Doxorubicin/administration & dosage
- Gene Expression Regulation, Leukemic
- Homeodomain Proteins/metabolism
- Humans
- Induction Chemotherapy
- Leukemia, Myeloid, Acute/metabolism
- Leukemia, Myeloid, Acute/pathology
- Leukemia, Myeloid, Acute/therapy
- Mice
- Mice, Inbred C57BL
- Mice, Inbred NOD
- Mice, SCID
- MicroRNAs/genetics
- MicroRNAs/metabolism
- Myeloid Ecotropic Viral Integration Site 1 Protein
- Neoplasm Proteins/metabolism
- Neoplastic Stem Cells/physiology
- Phosphorothioate Oligonucleotides/genetics
- Pre-B-Cell Leukemia Transcription Factor 1
- Protein Binding
- Proto-Oncogene Proteins/metabolism
- Regulatory Sequences, Nucleic Acid
- Transcription Factors/metabolism
- Transcriptome
- Xenograft Model Antitumor Assays
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Affiliation(s)
- Chinavenmeni S. Velu
- Division of Immunobiology and
Division of Experimental Hematology and Cancer Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Weill Cornell College of Medicine, New York, New York, USA.
Division of Biomedical Informatics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Loyola University Medical Center, Maywood, Illinois, USA.
University of Chicago, Chicago, Illinois, USA.
University of Colorado, Aurora, Colorado, USA.
The Ohio State University Comprehensive Cancer Center, Columbus, Ohio, USA.
Regulus Therapeutics, San Diego, California, USA.
Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
| | - Aditya Chaubey
- Division of Immunobiology and
Division of Experimental Hematology and Cancer Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Weill Cornell College of Medicine, New York, New York, USA.
Division of Biomedical Informatics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Loyola University Medical Center, Maywood, Illinois, USA.
University of Chicago, Chicago, Illinois, USA.
University of Colorado, Aurora, Colorado, USA.
The Ohio State University Comprehensive Cancer Center, Columbus, Ohio, USA.
Regulus Therapeutics, San Diego, California, USA.
Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
| | - James D. Phelan
- Division of Immunobiology and
Division of Experimental Hematology and Cancer Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Weill Cornell College of Medicine, New York, New York, USA.
Division of Biomedical Informatics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Loyola University Medical Center, Maywood, Illinois, USA.
University of Chicago, Chicago, Illinois, USA.
University of Colorado, Aurora, Colorado, USA.
The Ohio State University Comprehensive Cancer Center, Columbus, Ohio, USA.
Regulus Therapeutics, San Diego, California, USA.
Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
| | - Shane R. Horman
- Division of Immunobiology and
Division of Experimental Hematology and Cancer Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Weill Cornell College of Medicine, New York, New York, USA.
Division of Biomedical Informatics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Loyola University Medical Center, Maywood, Illinois, USA.
University of Chicago, Chicago, Illinois, USA.
University of Colorado, Aurora, Colorado, USA.
The Ohio State University Comprehensive Cancer Center, Columbus, Ohio, USA.
Regulus Therapeutics, San Diego, California, USA.
Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
| | - Mark Wunderlich
- Division of Immunobiology and
Division of Experimental Hematology and Cancer Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Weill Cornell College of Medicine, New York, New York, USA.
Division of Biomedical Informatics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Loyola University Medical Center, Maywood, Illinois, USA.
University of Chicago, Chicago, Illinois, USA.
University of Colorado, Aurora, Colorado, USA.
The Ohio State University Comprehensive Cancer Center, Columbus, Ohio, USA.
Regulus Therapeutics, San Diego, California, USA.
Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
| | - Monica L. Guzman
- Division of Immunobiology and
Division of Experimental Hematology and Cancer Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Weill Cornell College of Medicine, New York, New York, USA.
Division of Biomedical Informatics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Loyola University Medical Center, Maywood, Illinois, USA.
University of Chicago, Chicago, Illinois, USA.
University of Colorado, Aurora, Colorado, USA.
The Ohio State University Comprehensive Cancer Center, Columbus, Ohio, USA.
Regulus Therapeutics, San Diego, California, USA.
Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
| | - Anil G. Jegga
- Division of Immunobiology and
Division of Experimental Hematology and Cancer Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Weill Cornell College of Medicine, New York, New York, USA.
Division of Biomedical Informatics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Loyola University Medical Center, Maywood, Illinois, USA.
University of Chicago, Chicago, Illinois, USA.
University of Colorado, Aurora, Colorado, USA.
The Ohio State University Comprehensive Cancer Center, Columbus, Ohio, USA.
Regulus Therapeutics, San Diego, California, USA.
Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
| | - Nancy J. Zeleznik-Le
- Division of Immunobiology and
Division of Experimental Hematology and Cancer Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Weill Cornell College of Medicine, New York, New York, USA.
Division of Biomedical Informatics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Loyola University Medical Center, Maywood, Illinois, USA.
University of Chicago, Chicago, Illinois, USA.
University of Colorado, Aurora, Colorado, USA.
The Ohio State University Comprehensive Cancer Center, Columbus, Ohio, USA.
Regulus Therapeutics, San Diego, California, USA.
Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
| | - Jianjun Chen
- Division of Immunobiology and
Division of Experimental Hematology and Cancer Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Weill Cornell College of Medicine, New York, New York, USA.
Division of Biomedical Informatics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Loyola University Medical Center, Maywood, Illinois, USA.
University of Chicago, Chicago, Illinois, USA.
University of Colorado, Aurora, Colorado, USA.
The Ohio State University Comprehensive Cancer Center, Columbus, Ohio, USA.
Regulus Therapeutics, San Diego, California, USA.
Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
| | - James C. Mulloy
- Division of Immunobiology and
Division of Experimental Hematology and Cancer Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Weill Cornell College of Medicine, New York, New York, USA.
Division of Biomedical Informatics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Loyola University Medical Center, Maywood, Illinois, USA.
University of Chicago, Chicago, Illinois, USA.
University of Colorado, Aurora, Colorado, USA.
The Ohio State University Comprehensive Cancer Center, Columbus, Ohio, USA.
Regulus Therapeutics, San Diego, California, USA.
Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
| | - Jose A. Cancelas
- Division of Immunobiology and
Division of Experimental Hematology and Cancer Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Weill Cornell College of Medicine, New York, New York, USA.
Division of Biomedical Informatics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Loyola University Medical Center, Maywood, Illinois, USA.
University of Chicago, Chicago, Illinois, USA.
University of Colorado, Aurora, Colorado, USA.
The Ohio State University Comprehensive Cancer Center, Columbus, Ohio, USA.
Regulus Therapeutics, San Diego, California, USA.
Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
| | - Craig T. Jordan
- Division of Immunobiology and
Division of Experimental Hematology and Cancer Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Weill Cornell College of Medicine, New York, New York, USA.
Division of Biomedical Informatics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Loyola University Medical Center, Maywood, Illinois, USA.
University of Chicago, Chicago, Illinois, USA.
University of Colorado, Aurora, Colorado, USA.
The Ohio State University Comprehensive Cancer Center, Columbus, Ohio, USA.
Regulus Therapeutics, San Diego, California, USA.
Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
| | - Bruce J. Aronow
- Division of Immunobiology and
Division of Experimental Hematology and Cancer Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Weill Cornell College of Medicine, New York, New York, USA.
Division of Biomedical Informatics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Loyola University Medical Center, Maywood, Illinois, USA.
University of Chicago, Chicago, Illinois, USA.
University of Colorado, Aurora, Colorado, USA.
The Ohio State University Comprehensive Cancer Center, Columbus, Ohio, USA.
Regulus Therapeutics, San Diego, California, USA.
Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
| | - Guido Marcucci
- Division of Immunobiology and
Division of Experimental Hematology and Cancer Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Weill Cornell College of Medicine, New York, New York, USA.
Division of Biomedical Informatics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Loyola University Medical Center, Maywood, Illinois, USA.
University of Chicago, Chicago, Illinois, USA.
University of Colorado, Aurora, Colorado, USA.
The Ohio State University Comprehensive Cancer Center, Columbus, Ohio, USA.
Regulus Therapeutics, San Diego, California, USA.
Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
| | - Balkrishen Bhat
- Division of Immunobiology and
Division of Experimental Hematology and Cancer Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Weill Cornell College of Medicine, New York, New York, USA.
Division of Biomedical Informatics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Loyola University Medical Center, Maywood, Illinois, USA.
University of Chicago, Chicago, Illinois, USA.
University of Colorado, Aurora, Colorado, USA.
The Ohio State University Comprehensive Cancer Center, Columbus, Ohio, USA.
Regulus Therapeutics, San Diego, California, USA.
Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
| | - Brian Gebelein
- Division of Immunobiology and
Division of Experimental Hematology and Cancer Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Weill Cornell College of Medicine, New York, New York, USA.
Division of Biomedical Informatics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Loyola University Medical Center, Maywood, Illinois, USA.
University of Chicago, Chicago, Illinois, USA.
University of Colorado, Aurora, Colorado, USA.
The Ohio State University Comprehensive Cancer Center, Columbus, Ohio, USA.
Regulus Therapeutics, San Diego, California, USA.
Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
| | - H. Leighton Grimes
- Division of Immunobiology and
Division of Experimental Hematology and Cancer Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Weill Cornell College of Medicine, New York, New York, USA.
Division of Biomedical Informatics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA.
Loyola University Medical Center, Maywood, Illinois, USA.
University of Chicago, Chicago, Illinois, USA.
University of Colorado, Aurora, Colorado, USA.
The Ohio State University Comprehensive Cancer Center, Columbus, Ohio, USA.
Regulus Therapeutics, San Diego, California, USA.
Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
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54
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PU.1 is essential for MLL leukemia partially via crosstalk with the MEIS/HOX pathway. Leukemia 2013; 28:1436-48. [PMID: 24445817 DOI: 10.1038/leu.2013.384] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Revised: 11/22/2013] [Accepted: 12/12/2013] [Indexed: 01/07/2023]
Abstract
Mixed lineage leukemia (MLL) fusion proteins directly activate the expression of key downstream genes such as MEIS1, HOXA9 to drive an aggressive form of human leukemia. However, it is still poorly understood what additional transcriptional regulators, independent of the MLL fusion pathway, contribute to the development of MLL leukemia. Here we show that the transcription factor PU.1 is essential for MLL leukemia and is required for the growth of MLL leukemic cells via the promotion of cell-cycle progression and inhibition of apoptosis. Importantly, PU.1 expression is not under the control of MLL fusion proteins. We further identified a PU.1-governed 15-gene signature, which contains key regulators in the MEIS-HOX program (MEIS1, PBX3, FLT3, and c-KIT). PU.1 directly binds to the genomic loci of its target genes in vivo, and is required to maintain active expression of those genes in both normal hematopoietic stem and progenitor cells and in MLL leukemia. Finally, the clinical significance of the identified PU.1 signature was indicated by its ability to predict survival in acute myelogenous leukemia patients. Together, our findings demonstrate that PU.1 contributes to the development of MLL leukemia, partially via crosstalk with the MEIS/HOX pathway.
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55
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Miller PG, Al-Shahrour F, Hartwell KA, Chu LP, Järås M, Puram RV, Puissant A, Callahan KP, Ashton J, McConkey ME, Poveromo LP, Cowley GS, Kharas MG, Labelle M, Shterental S, Fujisaki J, Silberstein L, Alexe G, Al-Hajj MA, Shelton CA, Armstrong SA, Root DE, Scadden DT, Hynes RO, Mukherjee S, Stegmaier K, Jordan CT, Ebert BL. In Vivo RNAi screening identifies a leukemia-specific dependence on integrin beta 3 signaling. Cancer Cell 2013; 24:45-58. [PMID: 23770013 PMCID: PMC3746037 DOI: 10.1016/j.ccr.2013.05.004] [Citation(s) in RCA: 126] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Revised: 02/19/2013] [Accepted: 05/02/2013] [Indexed: 01/05/2023]
Abstract
We used an in vivo small hairpin RNA (shRNA) screening approach to identify genes that are essential for MLL-AF9 acute myeloid leukemia (AML). We found that Integrin Beta 3 (Itgb3) is essential for murine leukemia cells in vivo and for human leukemia cells in xenotransplantation studies. In leukemia cells, Itgb3 knockdown impaired homing, downregulated LSC transcriptional programs, and induced differentiation via the intracellular kinase Syk. In contrast, loss of Itgb3 in normal hematopoietic stem and progenitor cells did not affect engraftment, reconstitution, or differentiation. Finally, using an Itgb3 knockout mouse model, we confirmed that Itgb3 is dispensable for normal hematopoiesis but is required for leukemogenesis. Our results establish the significance of the Itgb3 signaling pathway as a potential therapeutic target in AML.
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Affiliation(s)
- Peter G Miller
- Division of Hematology, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
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56
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Ge Y, Waldemer RJ, Nalluri R, Nuzzi PD, Chen J. Flt3L is a novel regulator of skeletal myogenesis. J Cell Sci 2013; 126:3370-9. [PMID: 23704355 DOI: 10.1242/jcs.123950] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Various cues initiate multiple signaling pathways to regulate the highly coordinated process of skeletal myogenesis. Myoblast differentiation comprises a series of ordered events starting with cell cycle withdrawal and ending with myocyte fusion, with each step probably controlled by multiple extracellular signals and intracellular signaling pathways. Here we report the identification of Fms-like tyrokine kinase 3 ligand (Flt3L) signaling as a novel regulator of skeletal myogenesis. Flt3L is a multifunctional cytokine in immune cells, but its involvement in skeletal muscle formation has not been reported. We found that Flt3L is expressed in C2C12 myoblasts, with levels increasing throughout differentiation. Knockdown of Flt3L, or its receptor Flt3, suppresses myoblast differentiation, which is rescued by recombinant Flt3L or Flt3, respectively. Differentiation is not rescued, however, by recombinant ligand when the receptor is knocked down, or vice versa, suggesting that Flt3L and Flt3 function together. Flt3L knockdown also inhibits differentiation in mouse primary myoblasts. Both Flt3L and Flt3 are highly expressed in nascent myofibers during muscle regeneration in vivo, and Flt3L siRNA impairs muscle regeneration, validating the physiological significance of Flt3L function in myogenesis. We have identified a cellular mechanism for the myogenic function of Flt3L, as we show that Flt3L promotes cell cycle exit that is necessary for myogenic differentiation. Furthermore, we identify Erk as a relevant target of Flt3L signaling during myogenesis, and demonstrate that Flt3L suppresses Erk signaling through p120RasGAP. In summary, our work reveals an unexpected role for an immunoregulatory cytokine in skeletal myogenesis and a new myogenic pathway.
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Affiliation(s)
- Yejing Ge
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, 601 S. Goodwin Avenue B107, Urbana, IL 61801, USA
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57
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Jiang X, Huang H, Li Z, Li Y, Wang X, Gurbuxani S, Chen P, He C, You D, Zhang S, Wang J, Arnovitz S, Elkahloun A, Price C, Hong GM, Ren H, Kunjamma RB, Neilly MB, Matthews JM, Xu M, Larson RA, Le Beau MM, Slany RK, Liu PP, Lu J, Zhang J, He C, Chen J. Blockade of miR-150 maturation by MLL-fusion/MYC/LIN-28 is required for MLL-associated leukemia. Cancer Cell 2012; 22:524-35. [PMID: 23079661 PMCID: PMC3480215 DOI: 10.1016/j.ccr.2012.08.028] [Citation(s) in RCA: 139] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2012] [Revised: 06/21/2012] [Accepted: 08/30/2012] [Indexed: 12/18/2022]
Abstract
Expression of microRNAs (miRNAs) is under stringent regulation at both transcriptional and posttranscriptional levels. Disturbance at either level could cause dysregulation of miRNAs. Here, we show that MLL fusion proteins negatively regulate production of miR-150, an miRNA widely repressed in acute leukemia, by blocking miR-150 precursors from being processed to mature miRNAs through MYC/LIN28 functional axis. Forced expression of miR-150 dramatically inhibited leukemic cell growth and delayed MLL-fusion-mediated leukemogenesis, likely through targeting FLT3 and MYB and thereby interfering with the HOXA9/MEIS1/FLT3/MYB signaling network, which in turn caused downregulation of MYC/LIN28. Collectively, we revealed a MLL-fusion/MYC/LIN28⊣miR-150⊣FLT3/MYB/HOXA9/MEIS1 signaling circuit underlying the pathogenesis of leukemia, where miR-150 functions as a pivotal gatekeeper and its repression is required for leukemogenesis.
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Affiliation(s)
- Xi Jiang
- Section of Hematology/Oncology, Department of Medicine, University of Chicago, Chicago, IL 60637, USA
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58
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Abstract
HOX proteins are widely involved in hematopoietic development. These transcription factors combine a conserved DNA-binding homeobox with a divergent N-terminus that mediates interaction with variable cofactors. The resulting combinatorial diversity is thought to be responsible for mammalian HOX specificity. Contrasting this proposed mechanism for normal HOX function, here we demonstrate that, in the context of hematopoietic immortalization and leukemogenesis, individual HOX properties are governed almost exclusively by the homeodomain. Swap experiments between HOXA1 and HOXA9, 2 members of nonrelated paralog groups, revealed that gene expression patterns of HOX transformed cells in vitro are determined by the nature of the homeodomain. Similar results were seen in vivo during HOX-mediated leukemogenesis. An exchange of the homeodomains was sufficient to convert the slow, low-penetrance phenotype of HOXA1-induced leukemia to the aggressive fast-acting disease elicited by HOXA9 and vice versa. Mutation and deletion studies identified several subregions within the DNA binding domain responsible for paralog specificity. Previously defined binding sites for PBX cofactors within the exchangeable, nonhomeobox segment were dispensable for in vitro oncogenic HOX activity but affected in vivo disease development. The transcriptional activator domain shared by HOXA1 and HOXA9 at the very N-terminus proved essential for all transformation.
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59
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Schnerch D, Yalcintepe J, Schmidts A, Becker H, Follo M, Engelhardt M, Wäsch R. Cell cycle control in acute myeloid leukemia. Am J Cancer Res 2012; 2:508-528. [PMID: 22957304 PMCID: PMC3433102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Accepted: 07/27/2012] [Indexed: 06/01/2023] Open
Abstract
Acute myeloid leukemia (AML) is the result of a multistep transforming process of hematopoietic precursor cells (HPCs) which enables them to proceed through limitless numbers of cell cycles and to become resistant to cell death. Increased proliferation renders these cells vulnerable to acquiring mutations and may favor leukemic transformation. Here, we review how deregulated cell cycle control contributes to increased proliferation in AML and favors genomic instability, a prerequisite to confer selective advantages to particular clones in order to adapt and independently proliferate in the presence of a changing microenvironment. We discuss the connection between differentiation and proliferation with regard to leukemogenesis and outline the impact of specific alterations on response to therapy. Finally, we present examples, how a better understanding of cell cycle regulation and deregulation has already led to new promising therapeutic strategies.
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Affiliation(s)
- Dominik Schnerch
- Department of Hematology, Oncology and Stem Cell Transplantation, University Medical Center Freiburg, Germany
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60
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Novak RL, Harper DP, Caudell D, Slape C, Beachy SH, Aplan PD. Gene expression profiling and candidate gene resequencing identifies pathways and mutations important for malignant transformation caused by leukemogenic fusion genes. Exp Hematol 2012; 40:1016-27. [PMID: 22885519 DOI: 10.1016/j.exphem.2012.08.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Revised: 07/30/2012] [Accepted: 08/02/2012] [Indexed: 12/20/2022]
Abstract
NUP98-HOXD13 (NHD13) and CALM-AF10 (CA10) are oncogenic fusion proteins produced by recurrent chromosomal translocations in patients with acute myeloid leukemia (AML). Transgenic mice that express these fusions develop AML with a long latency and incomplete penetrance, suggesting that collaborating genetic events are required for leukemic transformation. We employed genetic techniques to identify both preleukemic abnormalities in healthy transgenic mice as well as collaborating events leading to leukemic transformation. Candidate gene resequencing revealed that 6 of 27 (22%) CA10 AMLs spontaneously acquired a Ras pathway mutation and 8 of 27 (30%) acquired an Flt3 mutation. Two CA10 AMLs acquired an Flt3 internal-tandem duplication, demonstrating that these mutations can be acquired in murine as well as human AML. Gene expression profiles revealed a marked upregulation of Hox genes, particularly Hoxa5, Hoxa9, and Hoxa10 in both NHD13 and CA10 mice. Furthermore, mir196b, which is embedded within the Hoxa locus, was overexpressed in both CA10 and NHD13 samples. In contrast, the Hox cofactors Meis1 and Pbx3 were differentially expressed; Meis1 was increased in CA10 AMLs but not NHD13 AMLs, whereas Pbx3 was consistently increased in NHD13 but not CA10 AMLs. Silencing of Pbx3 in NHD13 cells led to decreased proliferation, increased apoptosis, and decreased colony formation in vitro, suggesting a previously unexpected role for Pbx3 in leukemic transformation.
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Affiliation(s)
- Rachel L Novak
- Leukemia Biology Section, Genetics Branch, Center for Cancer Research, National Cancer Institute, National Institute of Health, Bethesda, MD 20892, USA
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61
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Abstract
The clustered homeobox proteins play crucial roles in development, hematopoiesis, and leukemia, yet the targets they regulate and their mechanisms of action are poorly understood. Here, we identified the binding sites for Hoxa9 and the Hox cofactor Meis1 on a genome-wide level and profiled their associated epigenetic modifications and transcriptional targets. Hoxa9 and the Hox cofactor Meis1 cobind at hundreds of highly evolutionarily conserved sites, most of which are distant from transcription start sites. These sites show high levels of histone H3K4 monomethylation and CBP/P300 binding characteristic of enhancers. Furthermore, a subset of these sites shows enhancer activity in transient transfection assays. Many Hoxa9 and Meis1 binding sites are also bound by PU.1 and other lineage-restricted transcription factors previously implicated in establishment of myeloid enhancers. Conditional Hoxa9 activation is associated with CBP/P300 recruitment, histone acetylation, and transcriptional activation of a network of proto-oncogenes, including Erg, Flt3, Lmo2, Myb, and Sox4. Collectively, this work suggests that Hoxa9 regulates transcription by interacting with enhancers of genes important for hematopoiesis and leukemia.
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62
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Abstract
The three-amino-acid loop extension (TALE) class homeodomain proteins MEIS1 and PKNOX1 (PREP1) share the ability to interact with PBX and HOX family members and bind similar DNA sequences but appear to play opposing roles in tumor development. Elevated levels of MEIS1 accelerate development of HOX- and MLL-induced leukemias, and this pro-tumorigenic property has been associated with transcriptional activity of MEIS1. In contrast, reduction of PKNOX1 levels has been linked with cancer development despite the absence of an identifiable transactivating domain. In this report, we show that a chimeric protein generated by fusion of the MEIS1 C-terminal region encompassing the transactivating domain with the full-length PKNOX1 (PKNOX1-MC) acquired the ability to accelerate the onset of Hoxa9-induced leukemia in the mouse bone marrow transduction/transplantation model. Gene expression profiling of primary bone marrow cells transduced with Hoxa9 plus Meis1, or Hoxa9 plus Pknox1-MC revealed perturbations in overlapping functional gene subsets implicated in DNA packaging, chromosome organization, and in cell cycle regulation. Together, results presented in this report suggest that the C-terminal domain of MEIS1 confers to PKNOX1 an ectopic transactivating function that promotes leukemogenesis by regulating expression of genes involved in chromatin accessibility and cell cycle progression.
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63
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Targeting levels or oligomerization of nucleophosmin 1 induces differentiation and loss of survival of human AML cells with mutant NPM1. Blood 2011; 118:3096-106. [PMID: 21719597 DOI: 10.1182/blood-2010-09-309674] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Nucleophosmin 1 (NPM1) is an oligomeric, nucleolar phosphoprotein that functions as a molecular chaperone for both proteins and nucleic acids. NPM1 is mutated in approximately one-third of patients with AML. The mutant NPM1c+ contains a 4-base insert that results in extra C-terminal residues encoding a nuclear export signal, which causes NPM1c+ to be localized in the cytoplasm. Here, we determined the effects of targeting NPM1 in cultured and primary AML cells. Treatment with siRNA to NPM1 induced p53 and p21, decreased the percentage of cells in S-phase of the cell cycle, as well as induced differentiation of the AML OCI-AML3 cells that express both NPMc+ and unmutated NPM1. Notably, knockdown of NPM1 by shRNA abolished lethal AML phenotype induced by OCI-AML3 cells in NOD/SCID mice. Knockdown of NPM1 also sensitized OCI-AML3 to all-trans retinoic acid (ATRA) and cytarabine. Inhibition of NPM1 oligomerization by NSC348884 induced apoptosis and sensitized OCI-AML3 and primary AML cells expressing NPM1c+ to ATRA. This effect was significantly less in AML cells coexpressing FLT3-ITD, or in AML or normal CD34+ progenitor cells expressing wild-type NPM1. Thus, attenuating levels or oligomerization of NPM1 selectively induces apoptosis and sensitizes NPM1c+ expressing AML cells to treatment with ATRA and cytarabine.
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64
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Bonadies N, Foster SD, Chan WI, Kvinlaug BT, Spensberger D, Dawson MA, Spooncer E, Whetton AD, Bannister AJ, Huntly BJ, Göttgens B. Genome-wide analysis of transcriptional reprogramming in mouse models of acute myeloid leukaemia. PLoS One 2011; 6:e16330. [PMID: 21297973 PMCID: PMC3030562 DOI: 10.1371/journal.pone.0016330] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2010] [Accepted: 12/12/2010] [Indexed: 11/27/2022] Open
Abstract
Acute leukaemias are commonly caused by mutations that corrupt the transcriptional circuitry of haematopoietic stem/progenitor cells. However, the mechanisms underlying large-scale transcriptional reprogramming remain largely unknown. Here we investigated transcriptional reprogramming at genome-scale in mouse retroviral transplant models of acute myeloid leukaemia (AML) using both gene-expression profiling and ChIP-sequencing. We identified several thousand candidate regulatory regions with altered levels of histone acetylation that were characterised by differential distribution of consensus motifs for key haematopoietic transcription factors including Gata2, Gfi1 and Sfpi1/Pu.1. In particular, downregulation of Gata2 expression was mirrored by abundant GATA motifs in regions of reduced histone acetylation suggesting an important role in leukaemogenic transcriptional reprogramming. Forced re-expression of Gata2 was not compatible with sustained growth of leukaemic cells thus suggesting a previously unrecognised role for Gata2 in downregulation during the development of AML. Additionally, large scale human AML datasets revealed significantly higher expression of GATA2 in CD34+ cells from healthy controls compared with AML blast cells. The integrated genome-scale analysis applied in this study represents a valuable and widely applicable approach to study the transcriptional control of both normal and aberrant haematopoiesis and to identify critical factors responsible for transcriptional reprogramming in human cancer.
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Affiliation(s)
- Nicolas Bonadies
- Department of Haematology, Cambridge Institute for Medical Research, Cambridge University, Cambridge, United Kingdom
| | - Samuel D. Foster
- Department of Haematology, Cambridge Institute for Medical Research, Cambridge University, Cambridge, United Kingdom
| | - Wai-In Chan
- Department of Haematology, Cambridge Institute for Medical Research, Cambridge University, Cambridge, United Kingdom
| | - Brynn T. Kvinlaug
- Department of Haematology, Cambridge Institute for Medical Research, Cambridge University, Cambridge, United Kingdom
| | - Dominik Spensberger
- Department of Haematology, Cambridge Institute for Medical Research, Cambridge University, Cambridge, United Kingdom
| | - Mark A. Dawson
- Department of Haematology, Cambridge Institute for Medical Research, Cambridge University, Cambridge, United Kingdom
| | - Elaine Spooncer
- School of Cancer and Imaging Sciences, University of Manchester, Manchester, United Kingdom
| | - Anthony D. Whetton
- School of Cancer and Imaging Sciences, University of Manchester, Manchester, United Kingdom
| | - Andrew J. Bannister
- Gurdon Institute and Department of Pathology, Cambridge University, Cambridge, United Kingdom
| | - Brian J. Huntly
- Department of Haematology, Cambridge Institute for Medical Research, Cambridge University, Cambridge, United Kingdom
| | - Berthold Göttgens
- Department of Haematology, Cambridge Institute for Medical Research, Cambridge University, Cambridge, United Kingdom
- * E-mail:
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65
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Gwin K, Frank E, Bossou A, Medina KL. Hoxa9 regulates Flt3 in lymphohematopoietic progenitors. THE JOURNAL OF IMMUNOLOGY 2010; 185:6572-83. [PMID: 20971928 DOI: 10.4049/jimmunol.0904203] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Early B cell factor (EBF) is a transcription factor essential for specification and commitment to the B cell fate. In this study, we show downregulation of a developmentally regulated cluster of hoxa genes, notably hoxa9, coincides with induction of EBF at the Pro-B cell stage of B cell differentiation. Analysis of the hematopoietic progenitor compartment in Hoxa9(-/-) mice revealed significantly reduced frequencies and expression levels of Flt3, a cytokine receptor important for lymphoid priming and the generation of B cell precursors (BCPs). We show that Hoxa9 directly regulates the flt3 gene. Chromatin immunoprecipitation analysis revealed binding of Hoxa9 to the flt3 promoter in a lymphoid progenitor cell line. Knockdown of Hoxa9 significantly reduced Flt3 transcription and expression. Conversely, forced expression of Hoxa9 increased Flt3 transcription and expression in a Pro-B cell line that expressed low levels of Flt3. Hoxa9 inversely correlated with ebf1 in ex vivo-isolated bone marrow progenitors and BCPs, suggesting that EBF might function to silence a Hoxa9 transcriptional program. Restoration of EBF function in an EBF(-/-) cell line induced B lineage gene expression but did not directly suppress hoxa9 transcription, revealing alternate mechanisms of Hoxa9 regulation in BCPs. These data provide new insight into Hoxa9 function and regulation during lymphoid and B cell development. Furthermore, they suggest that failure to upregulate Flt3 provides a molecular basis for the lymphoid/early B cell deficiencies in Hoxa9(-/-) mice.
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Affiliation(s)
- Kimberly Gwin
- Department of Immunology, College of Medicine, Mayo Clinic, Rochester, MN 55905, USA
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66
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Gfi1-cells and circuits: unraveling transcriptional networks of development and disease. Curr Opin Hematol 2010; 17:300-7. [PMID: 20571393 DOI: 10.1097/moh.0b013e32833a06f8] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
PURPOSE OF REVIEW The review will integrate current knowledge of transcriptional circuits whose dysregulation leads to autoimmunity, neutropenia and leukemia. RECENT FINDINGS Growth factor independent-1 (Gfi1) is a transcriptional repressor with essential roles in controlling hematopoietic stem cell biology, myeloid and lymphoid differentiation and lymphocyte effector functions. Recent work has suggested that Gfi1 competes or collaborates with other transcription factors to modulate transcription programs and lineage decisions. SUMMARY Gfi1 is central to several transcriptional circuits whose dysregulation leads to abnormal or malignant hematopoiesis. These functional relationships are conserved from Drosophila development. Such conserved pathways represent central oncogenic or 'gatekeeper' pathways that are pivotal to understanding the process of cellular transformation, and illustrate key targets for clinical intervention.
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67
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FLT3 internal tandem duplication associates with adverse outcome and gene- and microRNA-expression signatures in patients 60 years of age or older with primary cytogenetically normal acute myeloid leukemia: a Cancer and Leukemia Group B study. Blood 2010; 116:3622-6. [PMID: 20656931 DOI: 10.1182/blood-2010-05-283648] [Citation(s) in RCA: 178] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The clinical impact of FLT3-internal tandem duplications (ITDs), an adverse prognostic marker in adults aged < 60 years with primary cytogenetically normal acute myeloid leukemia (CN-AML), requires further investigation in older patients. In CN-AML patients aged ≥ 60 years treated on Cancer and Leukemia Group B frontline trials, we found that FLT3-ITD remained associated with shorter disease-free survival (P < .001; hazard ratio = 2.10) and overall survival (P < .001; hazard ratio = 1.97) in multivariable analyses. This impact on shorter disease-free survival and overall survival was in patients aged 60-69 (P < .001, each) rather than in those aged ≥ 70 years. An FLT3-ITD-associated gene-expression signature revealed overexpression of FLT3, homeobox genes (MEIS1, PBX3, HOXB3), and immunotherapeutic tar-gets (WT1, CD33) and underexpression of leukemia-associated (MLLT3, TAL1) and erythropoiesis-associated (GATA3, EPOR, ANK1, HEMGN) genes. An FLT3-ITD-associated microRNA-expression signature included overexpressed miR-155 and underexpressed miR-144 and miR-451. FLT3-ITD identifies older CN-AML patients with molecular high risk and is associated with gene- and microRNA-expression signatures that provide biologic insights for novel therapeutic approaches.
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68
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Abstract
Trib1 is a myeloid oncogene that cooperates with Hoxa9 and Meis1. Although the MAPK pathway and C/EBP transcription factors are known to interact with Trib proteins, the mechanisms by which Trib1 contributes to myeloid leukemogenesis remains to be clarified. Here we report that interaction between Trib1 and MEK1 is required for Trib1-induced leukemogenesis. The C-terminal ILLHPWF motif that is well conserved among Trib family proteins is required for MEK1 binding, enhancement of ERK phosphorylation, enhanced self-renewal activity of bone marrow cells and leukemogenic activity by Trib1. The motif is also important for Trib1-induced C/EBPα degradation though interaction between Trib1 and C/EBPα is not necessary. Inhibition of ERK phosphorylation suppressed Trib1-induced C/EBPα degradation, indicating an important role for Trib1/MEK1 interaction. These results suggest that Trib1 may be a key mediator between the RTK-MAPK pathway and the C/EBP transcription factor in myeloid leukemogenesis.
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69
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Linkage of the potent leukemogenic activity of Meis1 to cell-cycle entry and transcriptional regulation of cyclin D3. Blood 2010; 115:4071-82. [PMID: 20237320 DOI: 10.1182/blood-2009-06-225573] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
MEIS1 is a three-amino acid loop extension class homeodomain-containing homeobox (HOX) cofactor that plays key roles in normal hematopoiesis and leukemogenesis. Expression of Meis1 is rate-limiting in MLL-associated leukemias and potently interacts with Hox and NUP98-HOX genes in leukemic transformation to promote self-renewal and proliferation of hematopoietic progenitors. The oncogenicity of MEIS1 has been linked to its transcriptional activation properties. To further reveal the pathways triggered by Meis1, we assessed the function of a novel engineered fusion form of Meis1, M33-MEIS1, designed to confer transcriptional repression to Meis1 target genes that are otherwise up-regulated in normal and malignant hematopoiesis. Retroviral overexpression of M33-Meis1 resulted in the rapid and complete eradication of M33-Meis1-transduced normal and leukemic cells in vivo. Cell-cycle analysis showed that M33-Meis1 impeded the progression of cells from G(1)-to-S phase, which correlated with significant reduction of cyclin D3 levels and the inhibition of retinoblastoma (pRb) hyperphosphorylation. We identified cyclin D3 as a direct downstream target of MEIS1 and M33-MEIS1 and showed that the G(1)-phase accumulation and growth suppression induced by M33-Meis1 was partially relieved by overexpression of cyclin D3. This study provides strong evidence linking the growth-promoting activities of Meis1 to the cyclin D-pRb cell-cycle control pathway.
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70
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Longobardi E, Iotti G, Di Rosa P, Mejetta S, Bianchi F, Fernandez-Diaz LC, Micali N, Nuciforo P, Lenti E, Ponzoni M, Doglioni C, Caniatti M, Di Fiore PP, Blasi F. Prep1 (pKnox1)-deficiency leads to spontaneous tumor development in mice and accelerates EmuMyc lymphomagenesis: a tumor suppressor role for Prep1. Mol Oncol 2010; 4:126-34. [PMID: 20106730 DOI: 10.1016/j.molonc.2010.01.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2009] [Revised: 12/28/2009] [Accepted: 01/04/2010] [Indexed: 02/02/2023] Open
Abstract
The Prep1 homeodomain transcription factor is essential for embryonic development. 25% of hypomorphic Prep1(i/i) embryos, expressing the gene at 2% of the normal levels, survive pregnancy and live a normal-length life. Later in life, however, these mice develop spontaneous pre-tumoral lesions or solid tumors (lymphomas and carcinomas). In addition, transplantation of E14.5 fetal liver (FL) Prep1(i/i) cells into lethally irradiated mice induces lymphomas. In agreement with the above data, haploinsufficiency of a different Prep1-deficient (null) allele accelerates EmuMyc lymphoma growth. Therefore Prep1 has a tumor suppressor function in mice. Immunohistochemistry on tissue micrroarrays (TMA) generated from three distinct human cohorts comprising a total of some 1000 human tumors revealed that 70% of the tumors express no or extremely low levels of Prep1, unlike normal tissues. Our data in mice are thus potentially relevant to human cancer.
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Affiliation(s)
- E Longobardi
- Università Vita Salute San Raffaele, via Olgettina 60, Milano 20132, Italy
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71
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Haematopoietic malignancies caused by dysregulation of a chromatin-binding PHD finger. Nature 2009; 459:847-51. [PMID: 19430464 PMCID: PMC2697266 DOI: 10.1038/nature08036] [Citation(s) in RCA: 327] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2008] [Revised: 06/11/2009] [Accepted: 04/02/2009] [Indexed: 01/26/2023]
Abstract
Histone H3 Lys4 methylation (H3K4me) was proposed as a critical component in regulating the gene expression, epigenetic states, and cellular identities1. The biological meaning of H3K4me is interpreted via conserved modules including plant homeodomain (PHD) fingers that recognize varied H3K4me states1,2. The dysregulation of PHD finger has been implicated in a variety of human diseases including cancers and immune or neurological disorders3. Here we report that fusing an H3K4-trimethylation (H3K4me3)-binding PHD finger, such as the C-terminal PHD finger of JARID1A or PHF23 (JARID1APHD3, PHF23PHD), to a common fusion partner nucleoporin-98 (NUP98) as identified in human leukemias4,5, generated potent oncoproteins that arrested hematopoietic differentiation and induced acute myeloid leukemia (AML). In these processes, a PHD finger that specifically recognizes H3K4me3/2 marks was essential for leukemogenesis. Mutations in PHD fingers that abrogated H3K4me3-binding also abolished leukemic transformation. NUP98-PHD fusion prevented the differentiation-associated removal of H3K4me3 at many loci encoding lineage-specific transcription factors (Hox(s), Gata3, Meis1, Eya1, Pbx1), and enforced their active gene transcription. Mechanistically, NUP98-PHD fusions act as ‘chromatin boundary factors’, dominating over polycomb-mediated gene silencing to ‘lock’ developmentally crucial loci into an active chromatin state (H3K4me3 with induced histone acetylation), a state that defined leukemia stem cells. Collectively, our studies represent the first report wherein the deregulation of PHD finger, ‘effector’ of specific histone modification, perturbs the epigenetic dynamics on developmentally critical loci, catastrophizes cellular fate decision-making, and even causes oncogenesis during development.
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72
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Goh SL, Looi Y, Shen H, Fang J, Bodner C, Houle M, Ng ACH, Screaton RA, Featherstone M. Transcriptional activation by MEIS1A in response to protein kinase A signaling requires the transducers of regulated CREB family of CREB co-activators. J Biol Chem 2009; 284:18904-12. [PMID: 19473990 PMCID: PMC2707216 DOI: 10.1074/jbc.m109.005090] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2009] [Revised: 05/21/2009] [Indexed: 01/08/2023] Open
Abstract
The transcription factor encoded by the murine ecotropic integration site 1 gene (MEIS1) is a partner of HOX and PBX proteins. It has been implicated in embryonic patterning and leukemia, and causally linked to restless legs syndrome. The MEIS1A C terminus harbors a transcriptional activation domain that is stimulated by protein kinase A (PKA) in a manner dependent on the co-activator of cAMP response element-binding protein (CREB), CREB-binding protein (CBP). We explored the involvement of another mediator of PKA-inducible transcription, namely the CREB co-activators transducers of regulated CREB activity (TORCs). Overexpression of TORC1 or TORC2 bypassed PKA for activation by MEIS1A. Co-immunoprecipitation experiments demonstrated a physical interaction between MEIS1 and TORC2 that is dependent on the MEIS1A C terminus, whereas chromatin immunoprecipitation revealed PKA-inducible recruitment of MEIS1, PBX1, and TORC2 on the MEIS1 target genes Hoxb2 and Meis1. The MEIS1 interaction domain on TORC1 was mapped to the N-terminal coiled-coil region, and TORC1 mutants lacking this domain attenuated the response to PKA on a natural MEIS1A target enhancer. Thus, TORCs physically cooperate with MEIS1 to achieve PKA-inducible transactivation through the MEIS1A C terminus, suggesting a concerted action in developmental and oncogenic processes.
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Affiliation(s)
- Siew-Lee Goh
- From the McGill Cancer Centre, McGill University, Montreal, Quebec H3G 1Y6, Canada
- the School of Biological Sciences, Nanyang Technological University, Singapore 637551, and
| | - Yvonne Looi
- the School of Biological Sciences, Nanyang Technological University, Singapore 637551, and
| | - Hui Shen
- the School of Biological Sciences, Nanyang Technological University, Singapore 637551, and
| | - Jun Fang
- From the McGill Cancer Centre, McGill University, Montreal, Quebec H3G 1Y6, Canada
| | - Caroline Bodner
- From the McGill Cancer Centre, McGill University, Montreal, Quebec H3G 1Y6, Canada
| | - Martin Houle
- From the McGill Cancer Centre, McGill University, Montreal, Quebec H3G 1Y6, Canada
| | - Andy Cheuk-Him Ng
- the Apoptosis Research Centre, Children's Hospital of Eastern Ontario, Departments of Pediatrics and Biochemistry, Immunology and Microbiology, University of Ottawa, Ottawa K1H 8L1, Canada
| | - Robert A. Screaton
- the Apoptosis Research Centre, Children's Hospital of Eastern Ontario, Departments of Pediatrics and Biochemistry, Immunology and Microbiology, University of Ottawa, Ottawa K1H 8L1, Canada
| | - Mark Featherstone
- the School of Biological Sciences, Nanyang Technological University, Singapore 637551, and
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Abstract
In patients with severe congenital neutropenia (SCN) and mice with growth factor independent-1 (Gfi1) loss of function, arrested myeloid progenitors accumulate, whereas terminal granulopoiesis is blocked. One might assume that Gfi-null progenitors accumulate because they lack the ability to differentiate. Instead, our data indicate that Gfi1 loss of function deregulates 2 separable transcriptional programs, one of which controls the accumulation and lineage specification of myeloid progenitors, but not terminal granulopoiesis. We demonstrate that Gfi1 directly represses HoxA9, Pbx1, and Meis1 during normal myelopoiesis. Gfi1-/- progenitors exhibit elevated levels of HoxA9, Pbx1 and Meis1, exaggerated HoxA9-Pbx1-Meis1 activity, and progenitor transformation in collaboration with oncogenic K-Ras. Limiting HoxA9 alleles corrects, in a dose-dependent manner, in vivo and in vitro phenotypes observed with loss of Gfi1 in myeloid progenitor cells but did not rescue Gfi1-/- blocked granulopoiesis. Thus, Gfi1 integrates 2 events during normal myeloid differentiation; the suppression of a HoxA9-Pbx1-Meis1 progenitor program and the induction of a granulopoietic transcription program.
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74
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Argiropoulos B, Palmqvist L, Yung E, Kuchenbauer F, Heuser M, Sly LM, Wan A, Krystal G, Humphries RK. Linkage of Meis1 leukemogenic activity to multiple downstream effectors including Trib2 and Ccl3. Exp Hematol 2008; 36:845-59. [DOI: 10.1016/j.exphem.2008.02.011] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2008] [Revised: 02/19/2008] [Accepted: 02/26/2008] [Indexed: 12/15/2022]
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75
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Chromosomal binding sites of the homeotic cofactor Homothorax. Mol Genet Genomics 2008; 280:73-81. [PMID: 18481089 DOI: 10.1007/s00438-008-0347-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2007] [Accepted: 04/24/2008] [Indexed: 02/05/2023]
Abstract
The Meis family oncoproteins play a crucial role in leukemogenesis and are highly expressed in other types of cancer as well. The transforming potential of Meis proteins depends on their ability to activate gene expression and therefore, revealing the identity of their target genes is very important. The genome of the fruit fly Drosophila melanogaster contains a single Meis gene, homothorax (hth), which plays multiple roles in embryonic and adult development. Mutations in hth affect the development of numerous embryonic and adult tissues, suggesting that Hth regulates the transcription of a large number of genes. However, it is not known how many genes are regulated directly by Hth and what is the nature of these genes. To address this question, we examined the distribution of the in vivo binding sites of Hth on polytene chromosomes. We found that in the salivary glands (SG) of third instar larvae, Hth binds to approximately 150 chromosomal sites in a very reproducible pattern. More than hundred of these sites were mapped cytologically. Interestingly, Hth accumulates at high levels in some of the most prominent hormone-induced chromosomal puffs, pointing to a possible role of Hth in activation of ecdysone-induced targets. Interfering with the normal transcriptional activity of Hth in larval SGs leads to dramatic reduction in cell size and DNA content implicating Hth in the regulation of cell growth and endoreplication in larval SGs.
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76
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Pronk CJH, Rossi DJ, Månsson R, Attema JL, Norddahl GL, Chan CKF, Sigvardsson M, Weissman IL, Bryder D. Elucidation of the phenotypic, functional, and molecular topography of a myeloerythroid progenitor cell hierarchy. Cell Stem Cell 2008; 1:428-42. [PMID: 18371379 DOI: 10.1016/j.stem.2007.07.005] [Citation(s) in RCA: 471] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2007] [Revised: 06/11/2007] [Accepted: 07/10/2007] [Indexed: 01/26/2023]
Abstract
The major myeloid blood cell lineages are generated from hematopoietic stem cells by differentiation through a series of increasingly committed progenitor cells. Precise characterization of intermediate progenitors is important for understanding fundamental differentiation processes and a variety of disease states, including leukemia. Here, we evaluated the functional in vitro and in vivo potentials of a range of prospectively isolated myeloid precursors with differential expression of CD150, Endoglin, and CD41. Our studies revealed a hierarchy of myeloerythroid progenitors with distinct lineage potentials. The global gene expression signatures of these subsets were consistent with their functional capacities, and hierarchical clustering analysis suggested likely lineage relationships. These studies provide valuable tools for understanding myeloid lineage commitment, including isolation of an early erythroid-restricted precursor, and add to existing models of hematopoietic differentiation by suggesting that progenitors of the innate and adaptive immune system can separate late, following the divergence of megakaryocytic/erythroid potential.
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Affiliation(s)
- Cornelis J H Pronk
- Lund Strategic Research Center for Stem Cell Biology and Cell Therapy, Lund University, BMC I13, 221 84 Lund, Sweden; Immunology Unit, Institution for Experimental Medical Science, Lund University, BMC I13, 221 84 Lund, Sweden
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77
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Sitwala KV, Dandekar MN, Hess JL. HOX proteins and leukemia. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2008; 1:461-474. [PMID: 18787682 PMCID: PMC2480589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 03/24/2008] [Accepted: 03/30/2008] [Indexed: 05/26/2023]
Abstract
HOX and three amino acid loop extension (TALE) proteins cooperate to induce transformation in mouse leukemia models, and are dysregulated in a variety of human leukemias. Despite decades of research, the mechanism of action for Hox proteins in embryogenesis and hematopoiesis remains unclear. Recent studies on the roles of Hoxa9 and Meis1 in leukemia has led to a wealth of new data, but their molecular mechanisms of action and synergy remain obscure. Advances in genome-wide technologies offer new avenues for understanding how homeodomain-containing transcription factors exert their programs in normal and neoplastic development.
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Affiliation(s)
- Kajal V Sitwala
- Department of Pathology, The University of Michigan Medical School Ann Arbor, Michigan, USA
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78
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Argiropoulos B, Yung E, Humphries RK. Unraveling the crucial roles of Meis1 in leukemogenesis and normal hematopoiesis. Genes Dev 2007; 21:2845-9. [PMID: 18006680 DOI: 10.1101/gad.1619407] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Bob Argiropoulos
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, British Columbia, Canada
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79
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Wong P, Iwasaki M, Somervaille TCP, So CWE, So CWE, Cleary ML. Meis1 is an essential and rate-limiting regulator of MLL leukemia stem cell potential. Genes Dev 2007; 21:2762-74. [PMID: 17942707 DOI: 10.1101/gad.1602107] [Citation(s) in RCA: 223] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Oncogenic mutations of the MLL histone methyltransferase confer an unusual ability to transform non-self-renewing myeloid progenitors into leukemia stem cells (LSCs) by mechanisms that remain poorly defined. Misregulation of Hox genes is likely to be critical for LSC induction and maintenance but alone it does not recapitulate the phenotype and biology of MLL leukemias, which are clinically heterogeneous--presumably reflecting differences in LSC biology and/or frequency. TALE (three-amino-acid loop extension) class homeodomain proteins of the Pbx and Meis families are also misexpressed in this context, and we thus employed knockout, knockdown, and dominant-negative genetic techniques to investigate the requirements and contributions of these factors in MLL oncoprotein-induced acute myeloid leukemia. Our studies show that induction and maintenance of MLL transformation requires Meis1 and is codependent on the redundant contributions of Pbx2 and Pbx3. Meis1 in particular serves a major role in establishing LSC potential, and determines LSC frequency by quantitatively regulating the extent of self-renewal, differentiation arrest, and cycling, as well as the rate of in vivo LSC generation from myeloid progenitors. Thus, TALE proteins are critical downstream effectors within an essential homeoprotein network that serves a rate-limiting regulatory role in MLL leukemogenesis.
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Affiliation(s)
- Piu Wong
- Department of Pathology, Stanford University School of Medicine, Stanford, California 94305, USA
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80
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81
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Palmqvist L, Pineault N, Wasslavik C, Humphries RK. Candidate genes for expansion and transformation of hematopoietic stem cells by NUP98-HOX fusion genes. PLoS One 2007; 2:e768. [PMID: 17712416 PMCID: PMC1942085 DOI: 10.1371/journal.pone.0000768] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2007] [Accepted: 07/24/2007] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Hox genes are implicated in hematopoietic stem cell (HSC) regulation as well as in leukemia development through translocation with the nucleoporin gene NUP98. Interestingly, an engineered NUP98-HOXA10 (NA10) fusion can induce a several hundred-fold expansion of HSCs in vitro and NA10 and the AML-associated fusion gene NUP98-HOXD13 (ND13) have a virtually indistinguishable ability to transform myeloid progenitor cells in vitro and to induce leukemia in collaboration with MEIS1 in vivo. METHODOLOGY/PRINCIPAL FINDINGS These findings provided a potentially powerful approach to identify key pathways mediating Hox-induced expansion and transformation of HSCs by identifying gene expression changes commonly induced by ND13 and NA10 but not by a NUP98-Hox fusion with a non-DNA binding homedomain mutation (N51S). The gene expression repertoire of purified murine bone marrow Sca-1+Lin- cells transduced with retroviral vectors encoding for these genes was established using the Affymetrix GeneChip MOE430A. Approximately seventy genes were differentially expressed in ND13 and NA10 cells that were significantly changed by both compared to the ND13(N51S) mutant. Intriguingly, several of these potential Hox target genes have been implicated in HSC expansion and self-renewal, including the tyrosine kinase receptor Flt3, the prion protein, Prnp, hepatic leukemia factor, Hlf and Jagged-2, Jag2. Consistent with these results, FLT3, HLF and JAG2 expression correlated with HOX A cluster gene expression in human leukemia samples. CONCLUSIONS In conclusion this study has identified several novel Hox downstream target genes and provides important new leads to key regulators of the expansion and transformation of hematopoietic stem cells by Hox.
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Affiliation(s)
- Lars Palmqvist
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, British Columbia, Canada
- Institute of Biomedicine, Sahlgrenska University Hospital, Göteborg, Sweden
| | - Nicolas Pineault
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, British Columbia, Canada
| | - Carina Wasslavik
- Institute of Biomedicine, Sahlgrenska University Hospital, Göteborg, Sweden
| | - R. Keith Humphries
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, British Columbia, Canada
- Departments of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
- * To whom correspondence should be addressed. E-mail:
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82
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Wang GG, Cai L, Pasillas MP, Kamps MP. NUP98-NSD1 links H3K36 methylation to Hox-A gene activation and leukaemogenesis. Nat Cell Biol 2007; 9:804-12. [PMID: 17589499 DOI: 10.1038/ncb1608] [Citation(s) in RCA: 305] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2006] [Accepted: 05/30/2007] [Indexed: 12/11/2022]
Abstract
Nuclear receptor-binding SET domain protein 1 (NSD1) prototype is a family of mammalian histone methyltransferases (NSD1, NSD2/MMSET/WHSC1, NSD3/WHSC1L1) that are essential in development and are mutated in human acute myeloid leukemia (AML), overgrowth syndromes, multiple myeloma and lung cancers. In AML, the recurring t(5;11)(q35;p15.5) translocation fuses NSD1 to nucleoporin-98 (NUP98). Here, we present the first characterization of the transforming properties and molecular mechanisms of NUP98-NSD1. We demonstrate that NUP98-NSD1 induces AML in vivo, sustains self-renewal of myeloid stem cells in vitro, and enforces expression of the HoxA7, HoxA9, HoxA10 and Meis1 proto-oncogenes. Mechanistically, NUP98-NSD1 binds genomic elements adjacent to HoxA7 and HoxA9, maintains histone H3 Lys 36 (H3K36) methylation and histone acetylation, and prevents EZH2-mediated transcriptional repression of the Hox-A locus during differentiation. Deletion of the NUP98 FG-repeat domain, or mutations in NSD1 that inactivate the H3K36 methyltransferase activity or that prevent binding of NUP98-NSD1 to the Hox-A locus precluded both Hox-A gene activation and myeloid progenitor immortalization. We propose that NUP98-NSD1 prevents EZH2-mediated repression of Hox-A locus genes by colocalizing H3K36 methylation and histone acetylation at regulatory DNA elements. This report is the first to link deregulated H3K36 methylation to tumorigenesis and to link NSD1 to transcriptional regulation of the Hox-A locus.
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MESH Headings
- Acetylation
- Acute Disease
- Amino Acid Sequence
- Animals
- Cell Transformation, Neoplastic
- Cells, Cultured
- Epigenesis, Genetic
- Gene Expression Regulation, Neoplastic
- Histone Methyltransferases
- Histone-Lysine N-Methyltransferase
- Histones/metabolism
- Homeodomain Proteins/genetics
- Homeodomain Proteins/metabolism
- Humans
- Intracellular Signaling Peptides and Proteins/genetics
- Intracellular Signaling Peptides and Proteins/physiology
- Leukemia, Myeloid/genetics
- Leukemia, Myeloid/metabolism
- Leukemia, Myeloid/pathology
- Methylation
- Mice
- Mice, Knockout
- Molecular Sequence Data
- Mutation
- Myeloid Progenitor Cells/physiology
- Nuclear Pore Complex Proteins/genetics
- Nuclear Pore Complex Proteins/physiology
- Nuclear Proteins/genetics
- Nuclear Proteins/physiology
- Oncogene Proteins, Fusion/genetics
- Oncogene Proteins, Fusion/physiology
- Spectrophotometry, Atomic
- Transcriptional Activation
- Translocation, Genetic
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Affiliation(s)
- Gang G Wang
- Department of Pathology, University of California at San Diego, School of Medicine, 9500 Gilman Drive, La Jolla, CA 92093, USA
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83
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84
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Jin G, Yamazaki Y, Takuwa M, Takahara T, Kaneko K, Kuwata T, Miyata S, Nakamura T. Trib1 and Evi1 cooperate with Hoxa and Meis1 in myeloid leukemogenesis. Blood 2007; 109:3998-4005. [PMID: 17227832 DOI: 10.1182/blood-2006-08-041202] [Citation(s) in RCA: 122] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Cooperative activation of Meis1 and Hoxa9 perturbs myeloid differentiation and eventually leads myeloid progenitors to leukemia, yet it remains to be clarified what kinds of subsequent molecular processes are required for development of overt leukemia. To understand the molecular pathway in Hoxa9/Meis1-induced leukemogenesis, retroviral insertional mutagenesis was applied using retrovirus-mediated gene transfer. The mice that received Hoxa9/Meis1-transduced bone marrow cells developed acute myeloid leukemia (AML), and Trib1, Evi1, Ahi1, Raralpha, Pitpnb, and AK039950 were identified as candidate cooperative genes located near common retroviral integration sites. Trib1 and Evi1 were up-regulated due to retroviral insertions, and coexpression of these genes significantly accelerated the onset of Hoxa9/Meis1-induced AML, suggesting that Trib1 and Evi1 are the key collaborators. Furthermore, Trib1 by itself is a novel myeloid oncogene, enhancing phosphorylation of ERK, resulting in inhibition of apoptosis. These results demonstrate the importance of specific oncogene interaction in myeloid leukemogenesis.
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Affiliation(s)
- Guang Jin
- Department of Carcinogenesis, The Cancer Institute, Genome Center, Japanese Foundation for Cancer Research, 3-10-6 Ariake, Koto-ku, Tokyo 135-8550, Japan
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85
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Abstract
Abstract
HOX genes, MEIS1, and FLT3 are frequently up-regulated in human myeloid leukemias. Meis1 cooperates with Hox genes to induce leukemias in mice, hypothetically the consequence of Meis1-induced Flt3 overexpression. To test this, we compared the properties of Flt3−/− and Flt3+/+ progenitors transduced with Hoxa9 or Hoxa9/Meis1. In a myeloid clonogenic assay, Meis1 greatly enhanced the proliferation of Hoxa9-expressing cells, massively up-regulating Flt3 protein. However, the transforming potential of Hoxa9/Meis1 was unaltered in Flt3−/− cells. All mice that received Hoxa9/Meis1-transduced progenitors succumbed to rapid acute myeloid leukemias regardless of Flt3 genotype. Flt3 expression levels in leukemic blasts did not correlate with parameters reflecting their proliferative rate or their impaired differentiation. Furthermore, analysis of c-Myb expression levels in Hoxa9/Meis1-transformed cells showed that the up-regulation of this critical downstream effector was independent of Flt3. Altogether, our findings demonstrate that Flt3 is dispensable to the oncogenic cooperation of Meis1 with Hoxa9.
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Affiliation(s)
- Ester Morgado
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7151, Hôpital Saint-Louis, 1 Avenue Claude Vellefaux, 75010 Paris, France
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86
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Dekel B, Metsuyanim S, Schmidt-Ott KM, Fridman E, Jacob-Hirsch J, Simon A, Pinthus J, Mor Y, Barasch J, Amariglio N, Reisner Y, Kaminski N, Rechavi G. Multiple imprinted and stemness genes provide a link between normal and tumor progenitor cells of the developing human kidney. Cancer Res 2006; 66:6040-9. [PMID: 16778176 DOI: 10.1158/0008-5472.can-05-4528] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Wilms' tumor (WT), the embryonic kidney malignancy, is suggested to evolve from a progenitor cell population of uninduced metanephric blastema, which typically gives rise to nephrons. However, apart from blastema, WT specimens frequently contain cells that have differentiated into renal tubular or stromal phenotypes, complicating their analysis. We aimed to define tumor-progenitor genes that function in normal kidney development using WT xenografts (WISH-WT), in which the blastema accumulates with serial passages at the expense of differentiated cells. Herein, we did transcriptional profiling using oligonucleotide microarrays of WISH-WT, WT source, human fetal and adult kidneys, and primary and metastatic renal cell carcinoma. Among the most significantly up-regulated genes in WISH-WT, we identified a surprising number of paternally expressed genes (PEG1/MEST, PEG3, PEG5/NNAT, PEG10, IGF2, and DLK1), as well as Meis homeobox genes [myeloid ecotropic viral integration site 1 homologue 1 (MEIS1) and MEIS2], which suppress cell differentiation and maintain self-renewal. A comparison between independent WISH-WT and WT samples by real-time PCR showed most of these genes to be highly overexpressed in the xenografts. Concomitantly, they were significantly induced in human fetal kidneys, strictly developmentally regulated throughout mouse nephrogenesis and overexpressed in the normal rat metanephric blastema. Furthermore, in vitro differentiation of the uninduced blastema leads to rapid down-regulation of PEG3, DLK1, and MEIS1. Interestingly, ischemic/reperfusion injury to adult mouse kidneys reinduced the expression of PEG3, PEG10, DLK1, and MEIS1, hence simulating embryogenesis. Thus, multiple imprinted and stemness genes that function to expand the renal progenitor cell population may lead to evolution and maintenance of WT.
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Affiliation(s)
- Benjamin Dekel
- Department of Pediatrics, Chaim Sheba Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
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87
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Palmqvist L, Argiropoulos B, Pineault N, Abramovich C, Sly LM, Krystal G, Wan A, Humphries RK. The Flt3 receptor tyrosine kinase collaborates with NUP98-HOX fusions in acute myeloid leukemia. Blood 2006; 108:1030-6. [PMID: 16861351 DOI: 10.1182/blood-2005-12-007005] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
In leukemogenesis, several genetic changes conferring a proliferative and/or survival advantage to hematopoietic progenitor cells in addition to a block in differentiation are required. Here, we demonstrate that overexpression of the wild-type (wt) Flt3 receptor tyrosine kinase collaborates with NUP98-HOX fusions (NUP98-HOXA10 and NUP98-HOXD13) to induce aggressive acute myeloid leukemia (AML). We used a mouse transplantation model to show their synergism in cotransduced bone marrow cells as well as in a cellular model of leukemic progression. Furthermore, our data support the finding that Meis1 overexpression leads to marked elevation in Flt3 transcription and extend it to the context of NUP98-HOX–induced leukemia. Together, these results support a multistep model where the synergism between NUP98-HOX and wt-Flt3 is the result of the ability of Flt3 to increase proliferation of myeloid progenitors blocked in differentiation by NUP98-HOX fusions and reveal a direct role for wt-Flt3 in the pathobiology of AML. Given the similarities in the leukemogenic role of native HOX and NUP98-fused HOX genes, our results underscore the clinical significance of the recurrent co-overexpression of wt-FLT3 and HOX in human leukemia and suggest that specific FLT3 inhibitors could be useful in treatment of HOX-induced AML or acute lymphoblastic leukemia (ALL).
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Affiliation(s)
- Lars Palmqvist
- Terry Fox Laboratory, British Columbia Cancer Agency, 11th Floor, 675 West 10th Ave, Vancouver, BC, Canada V5Z 1L3
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88
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Wang GG, Pasillas MP, Kamps MP. Persistent transactivation by meis1 replaces hox function in myeloid leukemogenesis models: evidence for co-occupancy of meis1-pbx and hox-pbx complexes on promoters of leukemia-associated genes. Mol Cell Biol 2006; 26:3902-16. [PMID: 16648484 PMCID: PMC1488994 DOI: 10.1128/mcb.26.10.3902-3916.2006] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Homeobox transcription factors Meis1 and Hoxa9 promote hematopoietic progenitor self-renewal and cooperate to cause acute myeloid leukemia (AML). While Hoxa9 alone blocks the differentiation of nonleukemogenic myeloid cell-committed progenitors, coexpression with Meis1 is required for the production of AML-initiating progenitors, which also transcribe a group of hematopoietic stem cell genes, including Cd34 and Flt3 (defined as Meis1-related leukemic signature genes). Here, we use dominant trans-activating (Vp16 fusion) or trans-repressing (engrailed fusion) forms of Meis1 to define its biochemical functions that contribute to leukemogenesis. Surprisingly, Vp16-Meis1 (but not engrailed-Meis1) functioned as an autonomous oncoprotein that mimicked combined activities of Meis1 plus Hoxa9, immortalizing early progenitors, inducing low-level expression of Meis1-related signature genes, and causing leukemia without coexpression of exogenous or endogenous Hox genes. Vp16-Meis1-mediated transformation required the Meis1 function of binding to Pbx and DNA but not its C-terminal domain (CTD). The absence of endogenous Hox gene expression in Vp16-Meis1-immortalized progenitors allowed us to investigate how Hox alters gene expression and cell biology in early hematopoietic progenitors. Strikingly, expression of Hoxa9 or Hoxa7 stimulated both leukemic aggressiveness and transcription of Meis1-related signature genes in Vp16-Meis1 progenitors. Interestingly, while the Hoxa9 N-terminal domain (NTD) is essential for cooperative transformation with wild-type Meis1, it was dispensable in Vp16-Meis1 progenitors. The fact that a dominant transactivation domain fused to Meis1 replaces the essential functions of both the Meis1 CTD and Hoxa9 NTD suggests that Meis-Pbx and Hox-Pbx (or Hox-Pbx-Meis) complexes co-occupy cellular promoters that drive leukemogenesis and that Meis1 CTD and Hox NTD cooperate in gene activation. Chromatin immunoprecipitation confirmed co-occupancy of Hoxa9 and Meis1 on the Flt3 promoter.
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Affiliation(s)
- Gang G Wang
- Department of Pathology and Molecular Pathology Graduate Program, Leichtag 249B, University of California at San Diego School of Medicine, 9500 Gilman Dr., La Jolla, California 92093, USA.
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89
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Wang GG, Calvo KR, Pasillas MP, Sykes DB, Häcker H, Kamps MP. Quantitative production of macrophages or neutrophils ex vivo using conditional Hoxb8. Nat Methods 2006; 3:287-93. [PMID: 16554834 DOI: 10.1038/nmeth865] [Citation(s) in RCA: 271] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2005] [Accepted: 02/13/2006] [Indexed: 11/09/2022]
Abstract
Differentiation mechanisms and inflammatory functions of neutrophils and macrophages are usually studied by genetic and biochemical approaches that require costly breeding and time-consuming purification to obtain phagocytes for functional analysis. Because Hox oncoproteins enforce self-renewal of factor-dependent myeloid progenitors, we queried whether estrogen-regulated Hoxb8 (ER-Hoxb8) could immortalize macrophage or neutrophil progenitors that would execute normal differentiation and normal innate immune function upon ER-Hoxb8 inactivation. Here we describe methods to derive unlimited quantities of mouse macrophages or neutrophils by immortalizing their respective progenitors with ER-Hoxb8 using different cytokines to target expansion of different committed progenitors. ER-Hoxb8 neutrophils and macrophages are functionally superior to those produced by many other ex vivo differentiation models, have strong inflammatory responses and can be derived easily from embryonic day 13 (e13) fetal liver of mice exhibiting embryonic-lethal phenotypes. Using knockout or small interfering RNA (siRNA) technologies, this ER-Hoxb8 phagocyte maturation system represents a rapid analytical tool for studying macrophage and neutrophil biology.
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Affiliation(s)
- Gang G Wang
- Department of Pathology & Molecular Pathology Graduate Program, School of Medicine, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
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90
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Hess JL, Bittner CB, Zeisig DT, Bach C, Fuchs U, Borkhardt A, Frampton J, Slany RK. c-Myb is an essential downstream target for homeobox-mediated transformation of hematopoietic cells. Blood 2006; 108:297-304. [PMID: 16507773 PMCID: PMC1895838 DOI: 10.1182/blood-2005-12-5014] [Citation(s) in RCA: 133] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Abdominal-type HoxA genes in combination with Meis1 are well-documented on-cogenes in various leukemias but it is unclear how they exert their transforming function. Here we used a system of conditional transformation by an inducible mixed lineage leukemia-eleven-nineteen leukemia (MLL-ENL) oncoprotein to overexpress Hoxa9 and Meis1 in primary hematopoietic cells. Arrays identified c-Myb and a c-Myb target (Gstm1) among the genes with the strongest response to Hoxa9/Meis1. c-Myb overexpression was verified by Northern blot and quantitative reverse transcription-polymerase chain reaction (RT-PCR). Also MLL-ENL activated c-Myb through up-regulation of Hoxa9 and Meis1. Consequently, short-term suppression of c-Myb by small inhibitory RNA (siRNA) efficiently inhibited transformation by MLL-ENL but did not impair transformation by transcription factor E2A-hepatic leukemia factor (E2A-HLF). The anti c-Myb siRNA effect was abrogated by coexpression of a c-Myb derivative with a mutated siRNA target site. The introduction of a dominant-negative c-Myb mutant had a similar but weaker effect on MLL-ENL-mediated transformation. Hematopoietic precursors from mice homozygous for a hypo-morphic c-Myb allele were more severely affected and could be transformed neither by MLL-ENL nor by E2A-HLF. Ectopic expression of c-Myb induced a differentiation block but c-Myb alone was not transforming in a replating assay similar to Hoxa9/Meis1. These results suggest that c-Myb is essential but not sufficient for Hoxa9/Meis1 mediated transformation.
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Affiliation(s)
- Jay L Hess
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA
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91
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Bourquin JP, Subramanian A, Langebrake C, Reinhardt D, Bernard O, Ballerini P, Baruchel A, Cavé H, Dastugue N, Hasle H, Kaspers GL, Lessard M, Michaux L, Vyas P, van Wering E, Zwaan CM, Golub TR, Orkin SH. Identification of distinct molecular phenotypes in acute megakaryoblastic leukemia by gene expression profiling. Proc Natl Acad Sci U S A 2006; 103:3339-44. [PMID: 16492768 PMCID: PMC1413912 DOI: 10.1073/pnas.0511150103] [Citation(s) in RCA: 141] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Individuals with Down syndrome (DS) are predisposed to develop acute megakaryoblastic leukemia (AMKL), characterized by expression of truncated GATA1 transcription factor protein (GATA1s) due to somatic mutation. The treatment outcome for DS-AMKL is more favorable than for AMKL in non-DS patients. To gain insight into gene expression differences in AMKL, we compared 24 DS and 39 non-DS AMKL samples. We found that non-DS-AMKL samples cluster in two groups, characterized by differences in expression of HOX/TALE family members. Both of these groups are distinct from DS-AMKL, independent of chromosome 21 gene expression. To explore alterations of the GATA1 transcriptome, we used cross-species comparison with genes regulated by GATA1 expression in murine erythroid precursors. Genes repressed after GATA1 induction in the murine system, most notably GATA-2, MYC, and KIT, show increased expression in DS-AMKL, suggesting that GATA1s fail to repress this class of genes. Only a subset of genes that are up-regulated upon GATA1 induction in the murine system show increased expression in DS-AMKL, including GATA1 and BACH1, a probable negative regulator of megakaryocytic differentiation located on chromosome 21. Surprisingly, expression of the chromosome 21 gene RUNX1, a known regulator of megakaryopoiesis, was not elevated in DS-AMKL. Our results identify relevant signatures for distinct AMKL entities and provide insight into gene expression changes associated with these related leukemias.
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Affiliation(s)
- Jean-Pierre Bourquin
- Department of Pediatric Oncology, Dana–Farber Cancer Institute and Children’s Hospital, Harvard Medical School, Boston, MA 02115
- Department of Pediatric Oncology, Universitäts-Kinderklinik Zurich, CH-8032 Zurich, Switzerland
| | - Aravind Subramanian
- The Broad Institute of Massachusetts Institute of Technology and Harvard University, Cambridge, MA 02141
| | | | - Dirk Reinhardt
- Medizinische Hochschule Hannover, D-30625 Hannover, Germany
| | - Olivier Bernard
- Institut National de la Santé et de la Recherche Médicale E0210, Hôpital Necker, F-75015 Paris, France
| | - Paola Ballerini
- Service d’Hématologie Biologique, Hôpital A Trousseau, F-75012 Paris, France
| | - André Baruchel
- Services d’Hématologie Pédiatrique et Adulte, Laboratoire Central d’Hématologie, Hôpital Saint-Louis, 75010 Paris, France
| | - Hélène Cavé
- Laboratoire de Biochimie Génétique, Hôpital Robert Debré, F-75019 Paris, France
| | - Nicole Dastugue
- Laboratoire d’Hématologie, Génétique des Hémopathies, Hôpital Purpan, F-31059 Toulouse, France
| | - Henrik Hasle
- Skejby Hospital, Aarhus University, 8200 Aarhus N, Denmark
| | - Gertjan L. Kaspers
- Department of Pediatric Hematology/Oncology, Vrije Universiteit Medical Center, 1007 MB Amsterdam, The Netherlands
- Dutch Childhood Oncology Group, The Hague, The Netherlands
| | - Michel Lessard
- Laboratoire d’Hématologie, Hôpital de Hautepierre, Hôpitaux Universitaires de Strasbourg, F-67098 Strasbourg, France
| | | | - Paresh Vyas
- Department of Haematology, Oxford Radcliffe Hospital, Oxford OX3 9DU, United Kingdom
| | | | - Christian M. Zwaan
- Dutch Childhood Oncology Group, The Hague, The Netherlands
- Department of Pediatric Oncology, Erasmus Medical Center, 3000 CB Rotterdam, The Netherlands; and
| | - Todd R. Golub
- Department of Pediatric Oncology, Dana–Farber Cancer Institute and Children’s Hospital, Harvard Medical School, Boston, MA 02115
- The Broad Institute of Massachusetts Institute of Technology and Harvard University, Cambridge, MA 02141
| | - Stuart H. Orkin
- Department of Pediatric Oncology, Dana–Farber Cancer Institute and Children’s Hospital, Harvard Medical School, Boston, MA 02115
- To whom correspondence should be addressed. E-mail:
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92
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Horton SJ, Grier DG, McGonigle GJ, Thompson A, Morrow M, De Silva I, Moulding DA, Kioussis D, Lappin TRJ, Brady HJM, Williams O. Continuous MLL-ENL expression is necessary to establish a "Hox Code" and maintain immortalization of hematopoietic progenitor cells. Cancer Res 2005; 65:9245-52. [PMID: 16230385 DOI: 10.1158/0008-5472.can-05-1691] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The t[(11;19)(p22;q23)] translocation, which gives rise to the MLL-ENL fusion protein, is commonly found in infant acute leukemias of both the myeloid and lymphoid lineage. To investigate the molecular mechanism of immortalization by MLL-ENL we established a Tet-regulatable system of MLL-ENL expression in primary hematopoietic progenitor cells. Immortalized myeloid cell lines were generated, which are dependent on continued MLL-ENL expression for their survival and proliferation. These cells either terminally differentiate or die when MLL-ENL expression is turned off with doxycycline. The expression profile of all 39 murine Hox genes was analyzed in these cells by real-time quantitative PCR. This analysis showed that loss of MLL-ENL was accompanied by a reduction in the expression of multiple Hoxa genes. By comparing these changes with Hox gene expression in cells induced to differentiate with granulocyte colony-stimulating factor, we show for the first time that reduced Hox gene expression is specific to loss of MLL-ENL and is not a consequence of differentiation. Our data also suggest that the Hox cofactor Meis-2 can substitute for Meis-1 function. Thus, MLL-ENL is required to initiate and maintain immortalization of myeloid progenitors and may contribute to leukemogenesis by aberrantly sustaining the expression of a "Hox code" consisting of Hoxa4 to Hoxa11.
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Affiliation(s)
- Sarah J Horton
- Molecular Haematology and Cancer Biology Unit, Institute of Child Health, University College London
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