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Wallach PM, Birnbaum DR, Ryan ER, Pieczko BT, Hess JL. Medical School Without Walls: 50 Years of Regional Campuses at Indiana University School of Medicine. Acad Med 2022; 97:1765-1772. [PMID: 35976719 PMCID: PMC9698112 DOI: 10.1097/acm.0000000000004940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The history of Indiana University School of Medicine (IUSM) dates to 1871, when Indiana Medical College entered into an affiliation with Indiana University in Bloomington to offer medical education. In 1971, the Indiana General Assembly passed a bill to create and fund a distributed model for medical education for which IUSM was responsible, an innovative approach to implementing a statewide medical education program. IUSM became one of the first U.S. medical schools to implement what is today known as a regional medical campus model. This regional medical campus system has permitted IUSM to expand enrollment based on national and local concerns about physician shortages, increase access to care locally, support expansion of graduate medical education, and provide opportunities for research and scholarship by faculty and students statewide. This effort was made possible by partnerships with other universities and health care systems across the state and the support of local community and state leaders. The model is a forward-thinking and cost-effective way to educate physicians for service in the state of Indiana and is applicable to others. This article highlights milestones in IUSM's 50-year history of regional medical education, describes the development of the regional medical campus model, recognizes significant achievements over the years, shares lessons learned, and discusses considerations for the future of medical education.
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Affiliation(s)
- Paul M. Wallach
- P.M. Wallach is professor of medicine, Dolores and John Read Senior Professorship in Medical Education, executive associate dean, Educational Affairs, and chief academic officer, Indiana University School of Medicine, Indianapolis, Indiana; ORCID: https://orcid.org/0000-0002-7444-5374
| | - Deborah R. Birnbaum
- D.R. Birnbaum is educational affairs innovations director and Scholarly Concentrations Program director, Indiana University School of Medicine, Indianapolis, Indiana; ORCID: https://orcid.org/0000-0002-4344-6630
| | - Elizabeth R. Ryan
- E.R. Ryan is associate dean and director, IUSM-Northwest-Gary, and professor of clinical family medicine, Department of Family Medicine, Indiana University School of Medicine, Gary, Indiana; ORCID: https://orcid.org/0000-0001-8680-3741
| | - Brandon T. Pieczko
- B.T. Pieczko is digital and special collections librarian, Ruth Lilly Medical Library, Indiana University School of Medicine, Indianapolis, Indiana; ORCID: https://orcid.org/0000-0003-0054-7260
| | - Jay L. Hess
- J.L. Hess is dean, Walter J. Daly Professor, professor of pathology and laboratory medicine, and professor of medicine, Indiana University School of Medicine, Indianapolis, Indiana; ORCID: https://orcid.org/0000-0002-5968-4326
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Peng L, Guo H, Ma P, Sun Y, Dennison L, Aplan PD, Hess JL, Friedman AD. HoxA9 binds and represses the Cebpa +8 kb enhancer. PLoS One 2019; 14:e0217604. [PMID: 31120998 PMCID: PMC6532930 DOI: 10.1371/journal.pone.0217604] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 05/14/2019] [Indexed: 12/05/2022] Open
Abstract
C/EBPα plays a key role in specifying myeloid lineage development. HoxA9 is expressed in myeloid progenitors, with its level diminishing during myeloid maturation, and HOXA9 is over-expressed in a majority of acute myeloid leukemia cases, including those expressing NUP98-HOXD13. The objective of this study was to determine whether HoxA9 directly represses Cebpa gene expression. We find 4-fold increased HoxA9 and 5-fold reduced Cebpa in marrow common myeloid and LSK progenitors from Vav-NUP98-HOXD13 transgenic mice. Conversely, HoxA9 decreases 5-fold while Cebpa increases during granulocytic differentiation of 32Dcl3 myeloid cells. Activation of exogenous HoxA9-ER in 32Dcl3 cells reduces Cebpa mRNA even in the presence of cycloheximide, suggesting direct repression. Cebpa transcription in murine myeloid cells is regulated by a hematopoietic-specific +37 kb enhancer and by a more widely active +8 kb enhancer. ChIP-Seq analysis of primary myeloid progenitor cells expressing exogenous HoxA9 or HoxA9-ER demonstrates that HoxA9 localizes to both the +8 kb and +37 kb Cebpa enhancers. Gel shift analysis demonstrates HoxA9 binding to three consensus sites in the +8 kb enhancer, but no affinity for the single near-consensus site present in the +37 kb enhancer. Activity of a Cebpa +8 kb enhancer/promoter-luciferase reporter in 32Dcl3 or MOLM14 myeloid cells is increased ~2-fold by mutation of its three HOXA9-binding sites, suggesting that endogenous HoxA9 represses +8 kb Cebpa enhancer activity. In contrast, mutation of five C/EBPα-binding sites in the +8 kb enhancer reduces activity 3-fold. Finally, expression of a +37 kb enhancer/promoter-hCD4 transgene reporter is reduced ~2-fold in marrow common myeloid progenitors when the Vav-NUP98-HOXD13 transgene is introduced. Overall, these data support the conclusion that HoxA9 represses Cebpa expression, at least in part via inhibition of its +8 kb enhancer, potentially allowing normal myeloid progenitors to maintain immaturity and contributing to the pathogenesis of acute myeloid leukemia associated with increased HOXA9.
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Affiliation(s)
- Lei Peng
- Division of Pediatric Oncology, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Hong Guo
- Division of Pediatric Oncology, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Peilin Ma
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, Indiana, United Sates of America
| | - Yuqing Sun
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, Indiana, United Sates of America
| | - Lauren Dennison
- Division of Pediatric Oncology, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Peter D. Aplan
- Genetics Branch, Center for Cancer Research, NCI/NIH, Bethesda, Maryland, United States of America
| | - Jay L. Hess
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, Indiana, United Sates of America
| | - Alan D. Friedman
- Division of Pediatric Oncology, Johns Hopkins University, Baltimore, Maryland, United States of America
- * E-mail:
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Sun Y, Zhou B, Mao F, Xu J, Miao H, Zou Z, Phuc Khoa LT, Jang Y, Cai S, Witkin M, Koche R, Ge K, Dressler GR, Levine RL, Armstrong SA, Dou Y, Hess JL. HOXA9 Reprograms the Enhancer Landscape to Promote Leukemogenesis. Cancer Cell 2018; 34:643-658.e5. [PMID: 30270123 PMCID: PMC6179449 DOI: 10.1016/j.ccell.2018.08.018] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 06/07/2018] [Accepted: 08/29/2018] [Indexed: 12/19/2022]
Abstract
Aberrant expression of HOXA9 is a prominent feature of acute leukemia driven by diverse oncogenes. Here we show that HOXA9 overexpression in myeloid and B progenitor cells leads to significant enhancer reorganizations with prominent emergence of leukemia-specific de novo enhancers. Alterations in the enhancer landscape lead to activation of an ectopic embryonic gene program. We show that HOXA9 functions as a pioneer factor at de novo enhancers and recruits CEBPα and the MLL3/MLL4 complex. Genetic deletion of MLL3/MLL4 blocks histone H3K4 methylation at de novo enhancers and inhibits HOXA9/MEIS1-mediated leukemogenesis in vivo. These results suggest that therapeutic targeting of HOXA9-dependent enhancer reorganization can be an effective therapeutic strategy in acute leukemia with HOXA9 overexpression.
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Affiliation(s)
- Yuqing Sun
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Bo Zhou
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Fengbiao Mao
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Jing Xu
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Hongzhi Miao
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Zhenhua Zou
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Le Tran Phuc Khoa
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Younghoon Jang
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sheng Cai
- Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA
| | - Matthew Witkin
- Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA
| | - Richard Koche
- Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA
| | - Kai Ge
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Gregory R Dressler
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Ross L Levine
- Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA
| | - Scott A Armstrong
- Dana Farber Cancer Institute, Boston Children's Hospital and Harvard Medical School, Boston, MA 02215, USA
| | - Yali Dou
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA; Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
| | - Jay L Hess
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
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Hess JL, Akutagava-Martins GC, Patak JD, Glatt SJ, Faraone SV. Why is there selective subcortical vulnerability in ADHD? Clues from postmortem brain gene expression data. Mol Psychiatry 2018; 23:1787-1793. [PMID: 29180674 PMCID: PMC6985986 DOI: 10.1038/mp.2017.242] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 08/17/2017] [Accepted: 08/24/2017] [Indexed: 01/25/2023]
Abstract
Sub-cortical volumetric differences were associated with attention-deficit/hyperactivity disorder (ADHD) in a recent multi-site, mega-analysis of 1713 ADHD persons and 1529 controls. As there was a wide range of effect sizes among the sub-cortical volumes, it is possible that selective neuronal vulnerability has a role in these volumetric losses. To address this possibility, we used data from Allen Brain Atlas to investigate variability in gene expression profiles between subcortical regions of typically developing brains. We tested the hypothesis that the expression of genes in a set of curated ADHD candidate genes and five a priori selected, biological pathways would be associated with the Enhancing NeuroImaging Genetics through Meta-Analysis (ENIGMA) findings. Across the subcortical regions studied by ENIGMA, gene expression profiles for three pathways were significantly correlated with ADHD-associated volumetric reductions: apoptosis, oxidative stress and autophagy. These correlations were strong and significant for children with ADHD, but not for adults. Although preliminary, these data suggest that variability of structural brain anomalies in ADHD can be explained, in part, by the differential vulnerability of these regions to mechanisms mediating apoptosis, oxidative stress and autophagy.
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Affiliation(s)
- J L Hess
- Department of Psychiatry and Behavioral Sciences, SUNY Upstate Medical University, Syracuse, NY, USA
| | - G C Akutagava-Martins
- Department of Psychiatry and Behavioral Sciences, SUNY Upstate Medical University, Syracuse, NY, USA
| | - J D Patak
- Department of Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, NY, USA
| | - S J Glatt
- Department of Psychiatry and Behavioral Sciences, SUNY Upstate Medical University, Syracuse, NY, USA
- Department of Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, NY, USA
| | - S V Faraone
- Department of Psychiatry and Behavioral Sciences, SUNY Upstate Medical University, Syracuse, NY, USA.
- Department of Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, NY, USA.
- K.G. Jebsen Centre for Research on Neuropsychiatric Disorders, University of Bergen, Bergen, Norway.
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Bousman CA, Cropley V, Klauser P, Hess JL, Pereira A, Idrizi R, Bruggemann J, Mostaid MS, Lenroot R, Weickert TW, Glatt SJ, Everall IP, Sundram S, Zalesky A, Weickert CS, Pantelis C. Neuregulin-1 (NRG1) polymorphisms linked with psychosis transition are associated with enlarged lateral ventricles and white matter disruption in schizophrenia. Psychol Med 2018; 48:801-809. [PMID: 28826413 DOI: 10.1017/s0033291717002173] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND Two single-nucleotide polymorphisms (SNPs) (rs4281084 and rs12155594) within the neuregulin-1 (NRG1) gene have been associated with psychosis transition. However, the neurobiological changes associated with these SNPs remain unclear. We aimed to determine what relationship these two SNPs have on lateral ventricular volume and white matter integrity, as abnormalities in these brain structures are some of the most consistent in schizophrenia. METHODS Structural (n = 370) and diffusion (n = 465) magnetic resonance imaging data were obtained from affected and unaffected individuals predominantly of European descent. The SNPs rs4281084, rs12155594, and their combined allelic load were examined for their effects on lateral ventricular volume, fractional anisotropy (FA) as well as axial (AD) and radial (RD) diffusivity. Additional exploratory analyses assessed NRG1 effects on gray matter volume, cortical thickness, and surface area throughout the brain. RESULTS Individuals with a schizophrenia age of onset ⩽25 and a combined allelic load ⩾3 NRG1 risk alleles had significantly larger right (up to 50%, p adj = 0.01) and left (up to 45%, p adj = 0.05) lateral ventricle volumes compared with those with allelic loads of less than three. Furthermore, carriers of three or more risk alleles, regardless of age of onset and case status, had significantly reduced FA and elevated RD but stable AD in the frontal cortex compared with those carrying fewer than three risk alleles. CONCLUSIONS Our findings build on a growing body of research supporting the functional importance of genetic variation within the NRG1 gene and complement previous findings implicating the rs4281084 and rs12155594 SNPs as markers for psychosis transition.
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Affiliation(s)
- C A Bousman
- Department of Psychiatry,Melbourne Neuropsychiatry Centre, The University of Melbourne and Melbourne Health,Carlton South, VIC,Australia
| | - V Cropley
- Department of Psychiatry,Melbourne Neuropsychiatry Centre, The University of Melbourne and Melbourne Health,Carlton South, VIC,Australia
| | - P Klauser
- Department of Psychiatry,Melbourne Neuropsychiatry Centre, The University of Melbourne and Melbourne Health,Carlton South, VIC,Australia
| | - J L Hess
- Psychiatric Genetic Epidemiology & Neurobiology Laboratory (PsychGENe Lab), Departments of Psychiatry and Behavioral Sciences and Neuroscience and Physiology,SUNY Upstate Medical University,Syracuse, New York
| | - A Pereira
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne,Parkville, VIC,Australia
| | - R Idrizi
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne,Parkville, VIC,Australia
| | - J Bruggemann
- Schizophrenia Research Institute,Sydney,Australia
| | - M S Mostaid
- Department of Psychiatry,Melbourne Neuropsychiatry Centre, The University of Melbourne and Melbourne Health,Carlton South, VIC,Australia
| | - R Lenroot
- Schizophrenia Research Institute,Sydney,Australia
| | - T W Weickert
- Schizophrenia Research Institute,Sydney,Australia
| | - S J Glatt
- Psychiatric Genetic Epidemiology & Neurobiology Laboratory (PsychGENe Lab), Departments of Psychiatry and Behavioral Sciences and Neuroscience and Physiology,SUNY Upstate Medical University,Syracuse, New York
| | - I P Everall
- Department of Psychiatry,Melbourne Neuropsychiatry Centre, The University of Melbourne and Melbourne Health,Carlton South, VIC,Australia
| | - S Sundram
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne,Parkville, VIC,Australia
| | - A Zalesky
- Department of Psychiatry,Melbourne Neuropsychiatry Centre, The University of Melbourne and Melbourne Health,Carlton South, VIC,Australia
| | - C S Weickert
- Schizophrenia Research Institute,Sydney,Australia
| | - C Pantelis
- Department of Psychiatry,Melbourne Neuropsychiatry Centre, The University of Melbourne and Melbourne Health,Carlton South, VIC,Australia
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Abstract
Despite major advances in understanding the genetics and epigenetics of acute myelogenous leukemia, there is still a great need to develop more specific and effective therapies. High throughput approaches involving either genetic approaches or small molecule inhibitor screens are beginning to identify promising new therapeutic targets.
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Affiliation(s)
- Peilin Ma
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, 340 West 10th Street, Fairbanks 6200, Indianapolis, IN 46202-3082, USA
| | - Weihua Song
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, 340 West 10th Street, Fairbanks 6200, Indianapolis, IN 46202-3082, USA
| | - Jay L Hess
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, 340 West 10th Street, Fairbanks 6200, Indianapolis, IN 46202-3082, USA
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Abstract
Schizophrenia's (SZ's) heritability and familial transmission have been known for several decades; however, despite the clear evidence for a genetic component, it has been very difficult to pinpoint specific causative genes. Even so genetic studies have taught us a lot, even in the pregenomic era, about the molecular underpinnings and disease-relevant pathways. Recurring themes emerged revealing the involvement of neurodevelopmental processes, glutamate regulation, and immune system differential activation in SZ etiology. The recent emergence of epigenetic studies aimed at shedding light on the biological mechanisms underlying SZ has provided another layer of information in the investigation of gene and environment interactions. However, this epigenetic insight also brings forth another layer of complexity to the (epi)genomic landscape such as interactions between genetic variants, epigenetic marks-including cross-talk between DNA methylation and histone modification processes-, gene expression regulation, and environmental influences. In this review, we seek to synthesize perspectives, including limitations and obstacles yet to overcome, from genetic and epigenetic literature on SZ through a qualitative review of risk factors and prevailing hypotheses. Encouraged by the findings of both genetic and epigenetic studies to date, as well as the continued development of new technologies to collect and interpret large-scale studies, we are left with a positive outlook for the future of elucidating the molecular genetic mechanisms underlying SZ and other complex neuropsychiatric disorders.
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Affiliation(s)
- J van de Leemput
- University of California, San Diego, La Jolla, CA, United States
| | - J L Hess
- SUNY Upstate Medical University, Syracuse, NY, United States
| | - S J Glatt
- SUNY Upstate Medical University, Syracuse, NY, United States
| | - M T Tsuang
- University of California, San Diego, La Jolla, CA, United States
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Borkin D, He S, Miao H, Kempinska K, Pollock J, Chase J, Purohit T, Malik B, Zhao T, Wang J, Wen B, Zong H, Jones M, Danet-Desnoyers G, Guzman ML, Talpaz M, Bixby DL, Sun D, Hess JL, Muntean AG, Maillard I, Cierpicki T, Grembecka J. Pharmacologic inhibition of the Menin-MLL interaction blocks progression of MLL leukemia in vivo. Cancer Cell 2015; 27:589-602. [PMID: 25817203 PMCID: PMC4415852 DOI: 10.1016/j.ccell.2015.02.016] [Citation(s) in RCA: 260] [Impact Index Per Article: 28.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Revised: 12/11/2014] [Accepted: 02/27/2015] [Indexed: 12/22/2022]
Abstract
Chromosomal translocations affecting mixed lineage leukemia gene (MLL) result in acute leukemias resistant to therapy. The leukemogenic activity of MLL fusion proteins is dependent on their interaction with menin, providing basis for therapeutic intervention. Here we report the development of highly potent and orally bioavailable small-molecule inhibitors of the menin-MLL interaction, MI-463 and MI-503, and show their profound effects in MLL leukemia cells and substantial survival benefit in mouse models of MLL leukemia. Finally, we demonstrate the efficacy of these compounds in primary samples derived from MLL leukemia patients. Overall, we demonstrate that pharmacologic inhibition of the menin-MLL interaction represents an effective treatment for MLL leukemias in vivo and provide advanced molecular scaffold for clinical lead identification.
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Affiliation(s)
- Dmitry Borkin
- Department of Pathology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Shihan He
- Department of Pathology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Hongzhi Miao
- Department of Pathology, University of Michigan, Ann Arbor, MI 48109, USA
| | | | - Jonathan Pollock
- Department of Pathology, University of Michigan, Ann Arbor, MI 48109, USA; Graduate Program in Molecular and Cellular Pathology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Jennifer Chase
- Center for Stem Cell Biology, Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA; Graduate Program in Cellular and Molecular Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Trupta Purohit
- Department of Pathology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Bhavna Malik
- Department of Pathology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Ting Zhao
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, MI 48109, USA
| | - Jingya Wang
- Department of Pathology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Bo Wen
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, MI 48109, USA
| | - Hongliang Zong
- Department of Medicine, Weill Medical College of Cornell University, New York, NY 10065, USA
| | - Morgan Jones
- Center for Stem Cell Biology, Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA; Graduate Program in Cellular and Molecular Biology, University of Michigan, Ann Arbor, MI 48109, USA; Medical Scientist Training Program, University of Michigan, Ann Arbor, MI 48109, USA
| | - Gwenn Danet-Desnoyers
- Department of Medicine, Division of Hematology-Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Monica L Guzman
- Department of Medicine, Weill Medical College of Cornell University, New York, NY 10065, USA
| | - Moshe Talpaz
- Division of Hematology-Oncology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Dale L Bixby
- Division of Hematology-Oncology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Duxin Sun
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, MI 48109, USA
| | - Jay L Hess
- Department of Pathology, University of Michigan, Ann Arbor, MI 48109, USA; School of Medicine, Indiana University, Indianapolis, IN 46202, USA
| | - Andrew G Muntean
- Department of Pathology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Ivan Maillard
- Center for Stem Cell Biology, Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA; Division of Hematology-Oncology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA; Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Tomasz Cierpicki
- Department of Pathology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Jolanta Grembecka
- Department of Pathology, University of Michigan, Ann Arbor, MI 48109, USA.
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Cierpicki T, Murai MJ, Pollock J, Purohit T, He S, Yokom A, Hess JL, Muntean AG, Grembecka J. Abstract 3225: LEDGF IBD domain represents therapeutic target for MLL leukemia and HIV. Cancer Res 2014. [DOI: 10.1158/1538-7445.am2014-3225] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Lens epithelium-derived growth factor (LEDGF) is a chromatin associated protein implicated in cell survival, cancer, autoimmune diseases and HIV pathogenesis. LEDGF is also involved in recurring chromosomal translocations with nucleoporin NUP98 in acute leukemia, and the LEDGF/p75 isoform is consistently upregulated in a subset of acute myeloid leukemias (AML) resistant to chemotherapy. Moreover, it has been established that LEDGF is an essential co-factor required for oncogenic activity of MLL fusion proteins in leukemia. LEDGF interacts simultaneously with MLL and menin and is necessary for up-regulation of HOXA9 gene and for leukemogenic transformation by MLL fusion proteins in vivo. Therefore, LEDGF represent a valuable molecular target for therapeutic intervention as a novel targeted therapy for MLL leukemia patients. Furthermore, targeting LEDGF may represent an attractive alternative to inhibition of the menin-MLL interaction as it will allow preserving the function of menin, a known tumor suppressor in endocrine tissues.
We determined the solution structure of MLL fragment bound to LEDGF IBD domain and identified a novel hydrophobic motif within MLL, which we called IBM2, that is required for high affinity interaction with LEDGF. Point mutations within IBM2 abolished leukemogenic activity of MLL-AF9, indicating that IBM2 represents a critical site for formation of a high affinity menin-MLL-LEDGF complex. Furthermore, we found that short peptide corresponding to IBM2 binds to IBD domain and disrupts the interaction of LEDGF with the menin-MLL complex, providing a proof of concept that the novel interface on IBD domain we identified represents a druggable site for small molecule intervention.
LEDGF plays also an essential role in pathogenesis of HIV-1 virus and is required for integration of viral cDNA. Targeting HIV integrase to disrupt the interaction with LEDGF has been recognized as an attractive approach to develop new anti-viral agents. Importantly, the new MLL binding site on IBD domain we found overlaps with the binding site of HIV integrase. Therefore, targeting the IBM2 site on IBD may represent a novel approach to target the LEDGF-integrase interaction. In summary, our findings pave the way towards development of new therapeutic agents with dual applications for both MLL leukemias and HIV.
Citation Format: Tomasz Cierpicki, Marcelo J. Murai, Jonathan Pollock, Trupta Purohit, Shihan He, Adam Yokom, Jay L. Hess, Andrew G. Muntean, Jolanta Grembecka. LEDGF IBD domain represents therapeutic target for MLL leukemia and HIV. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3225. doi:10.1158/1538-7445.AM2014-3225
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Affiliation(s)
| | | | | | | | - Shihan He
- University of Michigan, Ann Arbor, MI
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10
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Shen C, Jo SY, Liao C, Hess JL, Nikolovska-Coleska Z. Targeting recruitment of disruptor of telomeric silencing 1-like (DOT1L): characterizing the interactions between DOT1L and mixed lineage leukemia (MLL) fusion proteins. J Biol Chem 2013; 288:30585-30596. [PMID: 23996074 DOI: 10.1074/jbc.m113.457135] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The MLL fusion proteins, AF9 and ENL, activate target genes in part via recruitment of the histone methyltransferase DOT1L (disruptor of telomeric silencing 1-like). Here we report biochemical, biophysical, and functional characterization of the interaction between DOT1L and MLL fusion proteins, AF9/ENL. The AF9/ENL-binding site in human DOT1L was mapped, and the interaction site was identified to a 10-amino acid region (DOT1L865-874). This region is highly conserved in DOT1L from a variety of species. Alanine scanning mutagenesis analysis shows that four conserved hydrophobic residues from the identified binding motif are essential for the interactions with AF9/ENL. Binding studies demonstrate that the entire intact C-terminal domain of AF9/ENL is required for optimal interaction with DOT1L. Functional studies show that the mapped AF9/ENL interacting site is essential for immortalization by MLL-AF9, indicating that DOT1L interaction with MLL-AF9 and its recruitment are required for transformation by MLL-AF9. These results strongly suggest that disruption of interaction between DOT1L and AF9/ENL is a promising therapeutic strategy with potentially fewer adverse effects than enzymatic inhibition of DOT1L for MLL fusion protein-associated leukemia.
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Affiliation(s)
- Chenxi Shen
- From the Department of Pathology and; the Chemical Biology Doctoral Program, University of Michigan Medical School, Ann Arbor, Michigan 48109 and
| | | | - Chenzhong Liao
- the School of Medical Engineering, Hefei University of Technology, Hefei, Anhui 230009, China
| | - Jay L Hess
- From the Department of Pathology and; the Chemical Biology Doctoral Program, University of Michigan Medical School, Ann Arbor, Michigan 48109 and
| | - Zaneta Nikolovska-Coleska
- From the Department of Pathology and; the Chemical Biology Doctoral Program, University of Michigan Medical School, Ann Arbor, Michigan 48109 and.
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11
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Maethner E, Garcia-Cuellar MP, Breitinger C, Takacova S, Divoky V, Hess JL, Slany RK. MLL-ENL inhibits polycomb repressive complex 1 to achieve efficient transformation of hematopoietic cells. Cell Rep 2013; 3:1553-66. [PMID: 23623499 DOI: 10.1016/j.celrep.2013.03.038] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2012] [Revised: 03/12/2013] [Accepted: 03/22/2013] [Indexed: 01/08/2023] Open
Abstract
Stimulation of transcriptional elongation is a key activity of leukemogenic MLL fusion proteins. Here, we provide evidence that MLL-ENL also inhibits Polycomb-mediated silencing as a prerequisite for efficient transformation. Biochemical studies identified ENL as a scaffold that contacted the elongation machinery as well as the Polycomb repressive complex 1 (PRC1) component CBX8. These interactions were mutually exclusive in vitro, corresponding to an antagonistic behavior of MLL-ENL and CBX8 in vivo. CBX8 inhibited elongation in a specific reporter assay, and this effect was neutralized by direct association with ENL. Correspondingly, CBX8-binding-defective MLL-ENL could not fully activate gene loci necessary for transformation. Finally, we demonstrate dimerization of MLL-ENL as a neomorphic activity that may augment Polycomb inhibition and transformation.
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Affiliation(s)
- Emanuel Maethner
- Department of Genetics, University Erlangen, 91058 Erlangen, Germany
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12
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Wang J, Muntean AG, Wu L, Hess JL. A subset of mixed lineage leukemia proteins has plant homeodomain (PHD)-mediated E3 ligase activity. J Biol Chem 2012; 287:43410-6. [PMID: 23129768 DOI: 10.1074/jbc.m112.423855] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The mixed lineage leukemia protein MLL1 contains four highly conserved plant homeodomain (PHD) fingers, which are invariably deleted in oncogenic MLL1 fusion proteins in human leukemia. Here we show that the second PHD finger (PHD2) of MLL1 is an E3 ubiquitin ligase in the presence of the E2-conjugating enzyme CDC34. This activity is conserved in the second PHD finger of MLL4, the closest homolog to MLL1 but not in MLL2 or MLL3. Mutation of PHD2 leads to MLL1 stabilization, as well as increased transactivation ability and MLL1 recruitment to the target gene loci, suggesting that PHD2 negatively regulates MLL1 activity.
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Affiliation(s)
- Jingya Wang
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA
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13
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Akalin A, Garrett-Bakelman FE, Kormaksson M, Busuttil J, Zhang L, Khrebtukova I, Milne TA, Huang Y, Biswas D, Hess JL, Allis CD, Roeder RG, Valk PJM, Löwenberg B, Delwel R, Fernandez HF, Paietta E, Tallman MS, Schroth GP, Mason CE, Melnick A, Figueroa ME. Base-pair resolution DNA methylation sequencing reveals profoundly divergent epigenetic landscapes in acute myeloid leukemia. PLoS Genet 2012; 8:e1002781. [PMID: 22737091 PMCID: PMC3380828 DOI: 10.1371/journal.pgen.1002781] [Citation(s) in RCA: 232] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2011] [Accepted: 05/04/2012] [Indexed: 11/18/2022] Open
Abstract
We have developed an enhanced form of reduced representation bisulfite sequencing with extended genomic coverage, which resulted in greater capture of DNA methylation information of regions lying outside of traditional CpG islands. Applying this method to primary human bone marrow specimens from patients with Acute Myelogeneous Leukemia (AML), we demonstrated that genetically distinct AML subtypes display diametrically opposed DNA methylation patterns. As compared to normal controls, we observed widespread hypermethylation in IDH mutant AMLs, preferentially targeting promoter regions and CpG islands neighboring the transcription start sites of genes. In contrast, AMLs harboring translocations affecting the MLL gene displayed extensive loss of methylation of an almost mutually exclusive set of CpGs, which instead affected introns and distal intergenic CpG islands and shores. When analyzed in conjunction with gene expression profiles, it became apparent that these specific patterns of DNA methylation result in differing roles in gene expression regulation. However, despite this subtype-specific DNA methylation patterning, a much smaller set of CpG sites are consistently affected in both AML subtypes. Most CpG sites in this common core of aberrantly methylated CpGs were hypermethylated in both AML subtypes. Therefore, aberrant DNA methylation patterns in AML do not occur in a stereotypical manner but rather are highly specific and associated with specific driving genetic lesions. Acute myeloid leukemias (AML) are a group of malignancies that originate in the bone marrow. While many different genetic lesions have been linked to the different forms of this disease, it is also clear that these genetic lesions are not always sufficient to cause AML. DNA methylation plays a role in gene expression regulation, and abnormal distribution of DNA methylation has been observed in many cancers, including AML. Here we demonstrate that changes in DNA methylation in AML are not uniform across all AML subtypes, but rather they display unique patterns, which are closely linked to the underlying genetic lesions of each of the different forms of AML. Furthermore, these unique patterns of DNA methylation have different impacts on gene expression regulation in each AML subtype.
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Affiliation(s)
- Altuna Akalin
- Department of Physiology and Biophysics and the HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medical College, New York, New York, United States of America
| | - Francine E. Garrett-Bakelman
- Department of Medicine, Division of Hematology/Oncology, Weill Cornell Medical College, New York, New York, United States of America
| | - Matthias Kormaksson
- Department of Public Health, Weill Cornell Medical College, New York, New York, United States of America
| | - Jennifer Busuttil
- Department of Medicine, Division of Hematology/Oncology, Weill Cornell Medical College, New York, New York, United States of America
| | - Lu Zhang
- Illumina, Hayward, California, United States of America
| | | | - Thomas A. Milne
- MRC Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Yongsheng Huang
- Department of Pathology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Debabrata Biswas
- Laboratory of Chromatin Biology, The Rockefeller University, New York, New York, United States of America
| | - Jay L. Hess
- Department of Pathology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - C. David Allis
- Laboratory of Chromatin Biology, The Rockefeller University, New York, New York, United States of America
| | - Robert G. Roeder
- Laboratory of Molecular Biology and Biochemistry, The Rockefeller University, New York, New York, United States of America
| | - Peter J. M. Valk
- Department of Hematology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Bob Löwenberg
- Department of Hematology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Ruud Delwel
- Department of Hematology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Hugo F. Fernandez
- Moffitt Cancer Center and Research Institute, Tampa, Florida, United States of America
| | - Elisabeth Paietta
- Cancer Center, Montefiore Medical Center–North Division, Bronx, New York, United States of America
| | - Martin S. Tallman
- Leukemia Service, Memorial Sloan-Kettering Cancer Center, New York, New York, United States of America
| | | | - Christopher E. Mason
- Department of Physiology and Biophysics and the HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine, Weill Cornell Medical College, New York, New York, United States of America
- * E-mail: (CEM); (AM); (MEF)
| | - Ari Melnick
- Department of Medicine, Division of Hematology/Oncology, Weill Cornell Medical College, New York, New York, United States of America
- Department of Pharmacology, Weill Cornell Medical College, New York, New York, United States of America
- * E-mail: (CEM); (AM); (MEF)
| | - Maria E. Figueroa
- Department of Pathology, University of Michigan, Ann Arbor, Michigan, United States of America
- * E-mail: (CEM); (AM); (MEF)
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14
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Grembecka J, He S, Shi A, Purohit T, Muntean AG, Sorenson RJ, Showalter HD, Murai MJ, Belcher AM, Hartley T, Hess JL, Cierpicki T. Menin-MLL inhibitors reverse oncogenic activity of MLL fusion proteins in leukemia. Nat Chem Biol 2012; 8:277-84. [PMID: 22286128 DOI: 10.1038/nchembio.773] [Citation(s) in RCA: 307] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2011] [Accepted: 11/02/2011] [Indexed: 12/12/2022]
Abstract
Translocations involving the mixed lineage leukemia (MLL) gene result in human acute leukemias with very poor prognosis. The leukemogenic activity of MLL fusion proteins is critically dependent on their direct interaction with menin, a product of the multiple endocrine neoplasia (MEN1) gene. Here we present what are to our knowledge the first small-molecule inhibitors of the menin-MLL fusion protein interaction that specifically bind menin with nanomolar affinities. These compounds effectively reverse MLL fusion protein-mediated leukemic transformation by downregulating the expression of target genes required for MLL fusion protein oncogenic activity. They also selectively block proliferation and induce both apoptosis and differentiation of leukemia cells harboring MLL translocations. Identification of these compounds provides a new tool for better understanding MLL-mediated leukemogenesis and represents a new approach for studying the role of menin as an oncogenic cofactor of MLL fusion proteins. Our findings also highlight a new therapeutic strategy for aggressive leukemias with MLL rearrangements.
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Affiliation(s)
- Jolanta Grembecka
- Department of Pathology, University of Michigan, Ann Arbor, Michigan, USA.
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15
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Tan J, Jones M, Koseki H, Nakayama M, Muntean A, Maillard I, Hess JL. CBX8, a polycomb group protein, is essential for MLL-AF9-induced leukemogenesis. Cancer Cell 2011; 20:563-75. [PMID: 22094252 PMCID: PMC3220883 DOI: 10.1016/j.ccr.2011.09.008] [Citation(s) in RCA: 116] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2010] [Revised: 07/21/2011] [Accepted: 09/20/2011] [Indexed: 10/15/2022]
Abstract
Chromosomal translocations involving the mixed lineage leukemia (MLL) gene lead to the development of acute leukemias. Constitutive HOX gene activation by MLL fusion proteins is required for MLL-mediated leukemogenesis; however, the underlying mechanisms remain elusive. Here, we show that chromobox homolog 8 (CBX8), a Polycomb Group protein that interacts with MLL-AF9 and TIP60, is required for MLL-AF9-induced transcriptional activation and leukemogenesis. Conversely, both CBX8 ablation and specific disruption of the CBX8 interaction by point mutations in MLL-AF9 abrogate HOX gene upregulation and abolish MLL-AF9 leukemic transformation. Surprisingly, Cbx8-deficient mice are viable and display no apparent hematopoietic defects. Together, our findings demonstrate that CBX8 plays an essential role in MLL-AF9 transcriptional regulation and leukemogenesis.
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Affiliation(s)
- Jiaying Tan
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Morgan Jones
- Center for Stem Cell Biology, Life Sciences Institute, Graduate Program in Cell and Molecular Biology and MSTP, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Haruhiko Koseki
- Laboratory for Developmental Genetics, RIKEN Research Center for Allergy and Immunology, Yokohama 230-0045, Japan
| | - Manabu Nakayama
- Laboratory of Human Gene Research, Department of Human Genome Research, Kazusa DNA Research Institute, Chiba 292-0818, Japan
| | - Andrew Muntean
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Ivan Maillard
- Center for Stem Cell Biology, Life Sciences Institute, Department of Medicine and Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Jay L. Hess
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
- Corresponding Author: Jay L. Hess M.D., Ph.D., M5240 Medical Sciences I, 1301 Catherine Avenue, Ann Arbor, MI, 48109-0602, Phone: (734) 763-6384, Fax: (734) 763-4782,
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16
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Abstract
Aggressive leukemias arise in both children and adults as a result of rearrangements to the mixed-lineage leukemia gene (MLL) located on chromosome 11q23. MLL encodes a large histone methyltransferase that directly binds DNA and positively regulates gene transcription, including homeobox (HOX) genes. MLL is involved in chromosomal translocations, partial tandem duplications, and amplifications, all of which result in hematopoietic malignancies due to sustained HOX expression and stalled differentiation. MLL lesions are associated with both acute myeloid leukemia and acute lymphoid leukemia and are usually associated with a relatively poor prognosis despite improved treatment options such as allogeneic hematopoietic stem cell transplantation, which underscores the need for new treatment regimens. Recent advances have begun to reveal the molecular mechanisms that drive MLL-associated leukemias, which, in turn, have provided opportunities for therapeutic development. Here, we discuss the etiology of MLL leukemias and potential directions for future therapy.
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Affiliation(s)
- Andrew G Muntean
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA.
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17
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Abstract
Recent studies identified an interaction between the Polymerase Associated Factor complex (PAFc) and Mixed Lineage Leukemia (MLL), including MLL-rearranged oncoproteins. This interaction is critical for MLL transcriptional activity and MLL-rearranged leukemogenesis. Here, we discuss the potential molecular role of the PAFc in transcriptional dysregulation of MLL target genes and the interplay between PAFc and MLL-rearranged oncoproteins in leukemogenesis.
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Affiliation(s)
- Jiaying Tan
- Department of Pathology, University of Michigan Medical School, 5240 Medical Sciences 1, 1301 Catherine Avenue, Ann Arbor MI 48109, USA
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18
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19
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Abstract
CONTEXT Rapid advances in understanding the molecular biology of acute myeloid leukemia are transforming the approach to diagnosis, prognostication, and treatment of these cases. OBJECTIVE To briefly review the current state of AML classification with a particular emphasis on the role of molecular studies and their impact on the management of acute myeloid leukemia and other malignancies. DATA SOURCES Current literature and experience of the authors. CONCLUSIONS While morphology, immunophenotyping, cytogenetics, and clinical history continue to play an important role, an increasing number of molecular tests are now required to properly classify these cases.
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Affiliation(s)
- Bryan L Betz
- Molecular Diagnostics Laboratory, University of Michigan Health System, Ann Arbor, MI 48105-3450, USA.
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20
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Sanders DS, Muntean AG, Hess JL. Significance of AF4-MLL reciprocal fusion in t(4;11) leukemias? Leuk Res 2010; 35:299-300. [PMID: 20952059 DOI: 10.1016/j.leukres.2010.09.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2010] [Revised: 09/19/2010] [Accepted: 09/19/2010] [Indexed: 11/27/2022]
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21
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Affiliation(s)
- Jay L Hess
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA. e-mail:
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22
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Monroe SC, Jo SY, Sanders DS, Basrur V, Elenitoba-Johnson KS, Slany RK, Hess JL. MLL-AF9 and MLL-ENL alter the dynamic association of transcriptional regulators with genes critical for leukemia. Exp Hematol 2010; 39:77-86.e1-5. [PMID: 20854876 DOI: 10.1016/j.exphem.2010.09.003] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2010] [Revised: 09/07/2010] [Accepted: 09/08/2010] [Indexed: 11/30/2022]
Abstract
OBJECTIVE The aim of this study was to better understand how mixed lineage leukemia (MLL) fusion proteins deregulate the expression of genes critical for leukemia. MATERIALS AND METHODS The transforming domain of one of the most common MLL fusion partners, AF9, was immunopurified after expression in myeloblastic M1 cells, and associating proteins were identified by mass spectrometric analysis. Chromatin immunoprecipitation followed by quantitative polymerase chain reaction was used to determine how binding of associating proteins compare across Hoxa9 and Meis1 in cell lines with and without MLL fusion proteins and how binding is altered during gene down-regulation and differentiation. RESULTS Consistent with earlier purifications of ENL and AF4 from 293 cells, the 90 amino acid C-terminal domain of AF9 associates with many other MLL translocation partners including Enl, Af4, Laf4, Af5q31, Ell, and Af10. This complex, termed elongation assisting proteins (EAPs), also contains the RNA polymerase II C-terminal domain kinase Cdk9/Cyclin T1/T2 (pTEFb) and the histone H3 lysine 79 methyltransferase Dot1L. Myeloid cells transformed by MLL fusions show higher levels and a broader distribution of EAP components at genes critical for leukemia. Inhibition of EAP components pTEFb and Dot1l show that both contribute significantly to activation of Hoxa9 and Meis1 expression. EAP is dynamically associated with the Hoxa9 and Meis1 loci in hematopoietic cells and rapidly dissociates during induction of differentiation. In the presence of MLL fusion proteins, its dissociation is prevented. CONCLUSIONS The findings suggest that MLL fusion proteins deregulate genes critical for leukemia by excessive recruitment and impaired dissociation of EAP from target loci.
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Affiliation(s)
- Sara C Monroe
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
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23
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Muntean AG, Tan J, Sitwala K, Huang Y, Bronstein J, Connelly JA, Basrur V, Elenitoba-Johnson KSJ, Hess JL. The PAF complex synergizes with MLL fusion proteins at HOX loci to promote leukemogenesis. Cancer Cell 2010; 17:609-21. [PMID: 20541477 PMCID: PMC2888888 DOI: 10.1016/j.ccr.2010.04.012] [Citation(s) in RCA: 181] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Revised: 02/03/2010] [Accepted: 04/15/2010] [Indexed: 11/23/2022]
Abstract
MLL is involved in chromosomal rearrangements that generate fusion proteins with deregulated transcriptional activity. The mechanisms of MLL fusion protein-mediated transcriptional activation are poorly understood. Here we show MLL interacts directly with the polymerase associated factor complex (PAFc) through sequences flanking the CxxC domain. PAFc interacts with RNA polymerase II and stimulates posttranslational histone modifications. PAFc augments MLL and MLL-AF9 mediated transcriptional activation of Hoxa9. Conversely, knockdown of PAFc disrupts MLL fusion protein-mediated transcriptional activation and MLL recruitment to target loci. PAFc gene expression is downregulated during hematopoiesis and likely serves to regulate MLL function. Deletions of MLL that abolish interactions with PAFc also eliminate MLL-AF9 mediated immortalization indicating an essential function for this interaction in leukemogenesis.
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Affiliation(s)
- Andrew G. Muntean
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Jiaying Tan
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Kajal Sitwala
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Yongsheng Huang
- Department of Statistics, Center for Computational Medicine and Bioinformatics, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Joel Bronstein
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - James A. Connelly
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Venkatesha Basrur
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | | | - Jay L. Hess
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
- Corresponding Author: Jay L. Hess M.D. Ph.D. M5240 Medical Sciences I, 1301 Catherine Avenue, Ann Arbor, MI 48109-0602, Phone: (734) 763-6384, Fax: (734) 763-4782,
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24
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Abstract
One of the great paradoxes in cellular differentiation is how cells with identical DNA sequences differentiate into so many different cell types. The mechanisms underlying this process involve epigenetic regulation mediated by alterations in DNA methylation, histone posttranslational modifications, and nucleosome remodeling. It is becoming increasingly clear that disruption of the "epigenome" as a result of alterations in epigenetic regulators is a fundamental mechanism in cancer. This has major implications for the future of both molecular diagnostics as well as cancer chemotherapy.
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Affiliation(s)
- Andrew G Muntean
- Department of Pathology, University of Michigan Medical School, Ann Arbor MI 48109, USA
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25
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Abstract
The field of hematopathology has been a leader in the application of new technologies for both diagnostics and therapy. The ready accessibility of blood cells for examination, the ability to quantify important indices, and the relative responsiveness of otherwise fatal hematologic diseases to chemotherapy have all contributed to rapid advances in the field. Hematopathology provides many insights into the challenges that pathology informatics will face in addressing the needs of a growing and aging population in the era of personalized medicine.
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Affiliation(s)
- Jay L Hess
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109-5602, USA.
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26
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Abstract
Disruption of epigenetic regulators of transcription is a central mechanism of oncogenesis. Many of the advances in the understanding of these mechanisms are attributable to the successful development of chromatin immunoprecipitation (ChIP) for in vivo detection of histone modifications as well as chromatin binding regulatory proteins. This is a powerful technique for analyzing histone modifications as well as binding sites for proteins that bind either directly or indirectly to DNA. Here we present two ChIP protocols. The first is particularly useful for identifying histone modifications or binding at specific, known genomic sites. The second, employing serial analysis of gene expression, is particularly powerful for the discovery of previously unidentified sites of modification or binding.
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Affiliation(s)
- Thomas A Milne
- Department of Pathology, University of Michigan Medical School, M5240 Medical Science Building 1, 1301 Catherine Avenue, Ann Arbor, MI 48109-0602, USA
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28
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Muntean AG, Giannola D, Udager AM, Hess JL. The PHD fingers of MLL block MLL fusion protein-mediated transformation. Blood 2008; 112:4690-3. [PMID: 18796627 PMCID: PMC2597135 DOI: 10.1182/blood-2008-01-134056] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2008] [Accepted: 08/13/2008] [Indexed: 12/27/2022] Open
Abstract
Chromosomal translocations involving the mixed lineage leukemia (MLL) gene are associated with aggressive acute lymphoid and myeloid leukemias. These translocations are restricted to an 8.3-kb breakpoint region resulting in fusion of amino terminal MLL sequences in frame to 1 of more than 60 different translocation partners. The translocations consistently delete the plant homeodomain (PHD) fingers and more carboxyl terminal MLL sequences. The function of the PHD fingers is obscure and their specific role in transformation has not been explored. Here we show that inclusion of the PHD fingers in the MLL fusion protein MLL-AF9 blocked immortalization of hematopoietic progenitors. Inclusion of 2 or more PHD fingers reduced association with the Hoxa9 locus and suppressed Hoxa9 up-regulation in hematopoietic progenitors. These data provide an explanation for why MLL translocation breakpoints exclude the PHD fingers and suggest a possible role for these domains in regulating the function of wild-type MLL.
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MESH Headings
- Animals
- Bone Marrow Cells/drug effects
- Bone Marrow Cells/pathology
- Cell Transformation, Neoplastic/drug effects
- Cell Transformation, Neoplastic/genetics
- Cells, Cultured
- Genes, Transgenic, Suicide/genetics
- Genes, Tumor Suppressor/physiology
- Hematopoiesis/genetics
- Histone-Lysine N-Methyltransferase
- Homeodomain Proteins/chemistry
- Homeodomain Proteins/genetics
- Homeodomain Proteins/pharmacology
- Homeodomain Proteins/physiology
- Mice
- Mice, Inbred C57BL
- Myeloid-Lymphoid Leukemia Protein/antagonists & inhibitors
- Myeloid-Lymphoid Leukemia Protein/chemistry
- Myeloid-Lymphoid Leukemia Protein/genetics
- Myeloid-Lymphoid Leukemia Protein/physiology
- Oncogene Proteins, Fusion/antagonists & inhibitors
- Oncogene Proteins, Fusion/genetics
- Oncogene Proteins, Fusion/physiology
- Protein Structure, Tertiary/genetics
- Protein Structure, Tertiary/physiology
- Transduction, Genetic
- Tumor Stem Cell Assay
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Affiliation(s)
- Andrew G Muntean
- Department ofPathology, University of Michigan Medical School, Ann Arbor, USA
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29
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Abstract
MLL rearrangements in humans lead to both acute myeloid leukemia (AML) and acute lymphoid leukemia (ALL). While AML has been successfully produced in mice, modeling ALL has been more difficult. In this issue of Cancer Cell, Wei et al. (2008) describe generation of AML, ALL, and biphenotypic leukemia by manipulating the cytokine milieu of human progenitor cells expressing MLL-AF9. They demonstrate that both multipotent and lineage-restricted progenitors are targeted by MLL-AF9 fusion proteins and that Rac signaling is crucial for survival. This study demonstrates the heterogeneity of MLL-AF9 leukemic stem cells and the importance of the microenvironment in determining lineage outcome.
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MESH Headings
- Animals
- Apoptosis
- Bone Marrow/metabolism
- Cell Culture Techniques
- Cell Line, Transformed
- Cell Lineage
- Cell Proliferation
- Cell Transformation, Neoplastic/genetics
- Cell Transformation, Neoplastic/metabolism
- Cell Transformation, Neoplastic/pathology
- Environment
- Fetal Stem Cells/immunology
- Fetal Stem Cells/metabolism
- Fetal Stem Cells/pathology
- Gene Expression Regulation, Leukemic
- Genotype
- Humans
- Intercellular Signaling Peptides and Proteins/metabolism
- Leukemia, Myeloid, Acute/genetics
- Leukemia, Myeloid, Acute/metabolism
- Leukemia, Myeloid, Acute/pathology
- Multipotent Stem Cells/immunology
- Multipotent Stem Cells/metabolism
- Multipotent Stem Cells/pathology
- Myeloid-Lymphoid Leukemia Protein/genetics
- Myeloid-Lymphoid Leukemia Protein/metabolism
- Neoplastic Stem Cells/immunology
- Neoplastic Stem Cells/metabolism
- Neoplastic Stem Cells/pathology
- Oncogene Proteins, Fusion/genetics
- Oncogene Proteins, Fusion/metabolism
- Phenotype
- Precursor Cell Lymphoblastic Leukemia-Lymphoma/genetics
- Precursor Cell Lymphoblastic Leukemia-Lymphoma/metabolism
- Precursor Cell Lymphoblastic Leukemia-Lymphoma/pathology
- Signal Transduction
- Time Factors
- rac GTP-Binding Proteins/metabolism
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Affiliation(s)
- Andrew G Muntean
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
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30
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Sitwala KV, Dandekar MN, Hess JL. HOX proteins and leukemia. Int J Clin Exp Pathol 2008; 1:461-474. [PMID: 18787682 PMCID: PMC2480589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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31
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Mueller D, Bach C, Zeisig D, Garcia-Cuellar MP, Monroe S, Sreekumar A, Zhou R, Nesvizhskii A, Chinnaiyan A, Hess JL, Slany RK. A role for the MLL fusion partner ENL in transcriptional elongation and chromatin modification. Blood 2007; 110:4445-54. [PMID: 17855633 PMCID: PMC2234781 DOI: 10.1182/blood-2007-05-090514] [Citation(s) in RCA: 305] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Chimeric proteins joining the histone methyltransferase MLL with various fusion partners trigger distinctive lymphoid and myeloid leukemias. Here, we immunopurified proteins associated with ENL, a protein commonly fused to MLL. Identification of these ENL-associated proteins (EAPs) by mass spectrometry revealed enzymes with a known role in transcriptional elongation (RNA polymerase II C-terminal domain kinase [RNAPolII CTD] positive transcription elongation factor b [pTEFb]), and in chromatin modification (histone-H3 methyltransferase DOT1L) as well as other frequent MLL partners (AF4, AF5q31, and LAF4), and polycomb group members (RING1, CBX8, and BCoR). The composition of EAP was further verified by coimmunoprecipitation, 2-hybrid analysis, pull-down, and colocalization experiments. Purified EAP showed a histone H3 lysine 79-specific methylase activity, displayed a robust RNAPolII CTD kinase function, and counteracted the effect of the pTEFb inhibitor 5,6-dichloro-benzimidazole-riboside. In vivo, an ENL knock-down diminished genome-wide as well as gene-specific H3K79 dimethylation, reduced global run-on elongation, and inhibited transient transcriptional reporter activity. According to structure-function data, DOT1L recruitment was important for transformation by the MLL-ENL fusion derivative. These results suggest a function of ENL in histone modification and transcriptional elongation.
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Abstract
Rearrangements of the mixed lineage leukemia gene MLL are associated with aggressive lymphoid and myeloid leukemias. The resulting MLL fusion proteins enforce high-level expression of HOX genes and the HOX cofactor MEIS1, which is pivotal for leukemogenesis. Both wild-type MLL and MLL fusion proteins interact with the tumor suppressor menin and with the Hoxa9 locus in vivo. Here, we show that MLL sequences between amino acids 5 and 44 are required for interaction with menin and for the transformation of hematopoietic progenitors. Blocking the MLL-menin interaction by the expression of a dominant negative inhibitor composed of amino terminal MLL sequences down-regulates Meis1 expression and inhibits cell proliferation, suggesting that targeting this interaction may be an effective therapeutic strategy for leukemias with MLL rearrangements.
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Affiliation(s)
- Corrado Caslini
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Zhaohai Yang
- Department of Pathology, University of Alabama, Birmingham, Alabama
| | - Mohamad El-Osta
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Thomas A. Milne
- Laboratory of Biochemistry and Molecular Biology, The Rockefeller University, New York, New York
| | - Robert K. Slany
- Department of Genetics, University of Erlangen, Erlangen, Germany
| | - Jay L. Hess
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan
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33
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Abstract
Trimethylation of histone H3 Lys4 (H3K4) is associated with transcriptional activation. One of the chief effectors of H3K4 methylation is mixed-lineage leukemia 1 (MLL1), a gene that is disrupted by chromosomal translocation in acute leukemia and a master regulator of Hox and other genes. In a recent paper, core components of the human MLL histone methyltransferase (MT) complex were found to form a structural platform, with one component (WDR5) mediating association between the specific histone H3K4 substrate and the MT. This novel regulatory mechanism, which is conserved from yeast to human, is required for both methylation and downstream target gene transcription.
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Affiliation(s)
- Brendan D Crawford
- Department of Pathology, University of Michigan Medical School, 1301 Catherine Road, M5240 MS1, Ann Arbor, Michigan 48109-0602, USA
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Abstract
Oligomerization of AML1-ETO contributes to leukemogenesis through obscure mechanisms. In this issue of Cancer Cell, Bushweller and colleagues show the crystal structure of the ETO NHR2 domain to be a tetramer. Tetramer formation is important for maturation arrest and self-renewal, and gene expression is altered in the absence of self-association. Loss of oligomer formation disrupts interactions between AML1-ETO and members of the ETO corepressor family, but not other corepressor molecules posited to be important for leukemogenesis. The findings clarify the role of oligomer formation in AML1-ETO function and suggest a possible therapeutic strategy of targeting ETO-corepressor interactions.
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Affiliation(s)
- Kajal V Sitwala
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA
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35
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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36
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Chen YX, Yan J, Keeshan K, Tubbs AT, Wang H, Silva A, Brown EJ, Hess JL, Pear WS, Hua X. The tumor suppressor menin regulates hematopoiesis and myeloid transformation by influencing Hox gene expression. Proc Natl Acad Sci U S A 2006; 103:1018-23. [PMID: 16415155 PMCID: PMC1326489 DOI: 10.1073/pnas.0510347103] [Citation(s) in RCA: 126] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Menin is the product of the tumor suppressor gene Men1 that is mutated in the inherited tumor syndrome multiple endocrine neoplasia type 1 (MEN1). Menin has been shown to interact with SET-1 domain-containing histone 3 lysine 4 (H3K4) methyltransferases including mixed lineage leukemia proteins to regulate homeobox (Hox) gene expression in vitro. Using conditional Men1 knockout mice, we have investigated the requirement for menin in hematopoiesis and myeloid transformation. Men1 excision causes reduction of Hoxa9 expression, colony formation by hematopoietic progenitors, and the peripheral white blood cell count. Menin directly activates Hoxa9 expression, at least in part, by binding to the Hoxa9 locus, facilitating methylation of H3K4, and recruiting the methylated H3K4 binding protein chd1 to the locus. Consistent with signaling downstream of menin, ectopic expression of both Hoxa9 and Meis1 rescues colony formation defects in Men1-excised bone marrow. Moreover, Men1 excision also suppresses proliferation of leukemogenic mixed lineage leukemia-AF9 fusion-protein-transformed myeloid cells and Hoxa9 expression. These studies uncover an important role for menin in both normal hematopoiesis and myeloid transformation and provide a mechanistic understanding of menin's function in these processes that may be used for therapy.
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Affiliation(s)
- Ya-Xiong Chen
- Abramson Family Cancer Research Institute, Department of Cancer Biology, Abramson Cancer Center, University of Pennsylvania, Philadelphia, PA 19104-6160, USA
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37
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Milne TA, Martin ME, Brock HW, Slany RK, Hess JL. Leukemogenic MLL fusion proteins bind across a broad region of the Hox a9 locus, promoting transcription and multiple histone modifications. Cancer Res 2005; 65:11367-74. [PMID: 16357144 DOI: 10.1158/0008-5472.can-05-1041] [Citation(s) in RCA: 144] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Chromosome translocations involving the mixed lineage leukemia gene MLL are associated with aggressive acute leukemias in both children and adults. Leukemogenic MLL fusion proteins delete the MLL SET domain Lys(4) methyltransferase activity and fuse MLL to 1 of >40 different translocation partners. Some MLL fusion proteins involve nuclear proteins that are transcriptional activators, whereas others have transcriptional activating activity but instead dimerize the truncated MLL molecule. Both types of MLL fusion proteins enforce persistent expression of Hox a9 and Meis1, which is pivotal for leukemogenesis through mechanisms that remain obscure. Here, we show that nuclear and dimerizable forms of MLL bind with a similar pattern to the Hox a9 locus that overlaps the distribution of wild-type MLL and deregulate transcription of three isoforms of Hox a9. Induction of MLL fusion protein activity is associated with increased levels of histone acetylation and Lys(4) methylation at Hox target genes. In addition, the MLL-ENL-ER protein, but not dimerized MLL, also induces dimethylation of histone H3 at Lys(79), suggesting alternative mechanisms for transcriptional activation.
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Affiliation(s)
- Thomas A Milne
- Department of Pathology, University of Pennsylvania School of Medicine, Philadelphia, USA
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38
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Tarakanova VL, Suarez F, Tibbetts SA, Jacoby MA, Weck KE, Hess JL, Speck SH, Virgin HW. Murine gammaherpesvirus 68 infection is associated with lymphoproliferative disease and lymphoma in BALB beta2 microglobulin-deficient mice. J Virol 2005; 79:14668-79. [PMID: 16282467 PMCID: PMC1287585 DOI: 10.1128/jvi.79.23.14668-14679.2005] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2005] [Accepted: 09/12/2005] [Indexed: 11/20/2022] Open
Abstract
Human gammaherpesvirus infections are associated with development of lymphoproliferative disease. Understanding of the mechanisms of gammaherpesvirus lymphomagenesis during chronic infection in a natural host has been limited by the exquisite species specificity of human gammaherpesviruses and the expense of primates. Murine gammaherpesvirus gammaHV68 is genetically and biologically related to human gammaherpesviruses and herpesvirus saimiri and has been reported to be associated with lymphoproliferative disease in mice (N. P. Sunil-Chandra, J. Arno, J. Fazakerley, and A. A. Nash, Am. J. Pathol. 145:818-826, 1994). We report the development of an animal model of gammaHV68 lymphomagenesis in BALB/c beta2 microglobulin-deficient mice (BALB beta2m-/-). GammaHV68 infection induced two lymphoproliferative lesions: B-cell lymphoma and atypical lymphoid hyperplasia (ALH). ALH lesion histology resembled lesions of Epstein-Barr virus-associated posttransplant lymphoproliferative disease and was characterized by the abnormal infiltration of the white pulp with cells expressing the plasma cell marker CD138. Lymphomas observed in gammaHV68-infected animals were B220+/CD3- large-cell lymphomas. GammaHV68-infected cells were common in ALH lesions as measured by in situ hybridization with a probe specific for viral tRNAs (vtRNAs), but they were scarce in gammaHV68-infected spleens with normal histology. Unlike ALH lesions, gammaHV68 vtRNA-positive cells were rare in lymphomas. GammaHV68 infection of BALB beta2m-/- mice results in lymphoproliferation and lymphoma, providing a valuable tool for identifying viral and host genes involved in gammaherpesvirus-associated malignancies. Our findings suggest that gammaHV68 induces lymphomas via hit-and-run oncogenesis, paracrine effects, or stimulation of chronic inflammation.
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Affiliation(s)
- Vera L Tarakanova
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
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39
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Milne TA, Dou Y, Martin ME, Brock HW, Roeder RG, Hess JL. MLL associates specifically with a subset of transcriptionally active target genes. Proc Natl Acad Sci U S A 2005; 102:14765-70. [PMID: 16199523 PMCID: PMC1253553 DOI: 10.1073/pnas.0503630102] [Citation(s) in RCA: 167] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2005] [Indexed: 02/06/2023] Open
Abstract
MLL (mixed-lineage leukemia) is a histone H3 Lys-4 specific methyltransferase that is a positive regulator of Hox expression. MLL rearrangements and amplification are common in acute lymphoid and myeloid leukemias and myelodysplastic disorders and are associated with abnormal up-regulation of Hox gene expression. Although MLL is expressed throughout hematopoiesis, Hox gene expression is sharply down-regulated during differentiation, suggesting that either the activity of MLL or its association with target promoters must be regulated. Here we show that MLL associates with actively transcribed genes but does not remain bound after transcriptional down-regulation. Surprisingly, MLL is associated not only with promoter regions but also is distributed across the entire coding regions of genes. MLL interacts with RNA polymerase II (pol II) and colocalizes with RNA pol II at a subset of actively transcribed target in vivo. Loss of function Mll results in defects in RNA pol II distribution. Together the results suggest that an intimate association between MLL and RNA pol II occurs at MLL target genes in vivo that is required for normal initiation and/or transcriptional elongation.
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Affiliation(s)
- Thomas A Milne
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
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40
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Dou Y, Milne TA, Tackett AJ, Smith ER, Fukuda A, Wysocka J, Allis CD, Chait BT, Hess JL, Roeder RG. Physical association and coordinate function of the H3 K4 methyltransferase MLL1 and the H4 K16 acetyltransferase MOF. Cell 2005; 121:873-85. [PMID: 15960975 DOI: 10.1016/j.cell.2005.04.031] [Citation(s) in RCA: 513] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2005] [Revised: 03/25/2005] [Accepted: 04/28/2005] [Indexed: 12/27/2022]
Abstract
A stable complex containing MLL1 and MOF has been immunoaffinity purified from a human cell line that stably expresses an epitope-tagged WDR5 subunit. Stable interactions between MLL1 and MOF were confirmed by reciprocal immunoprecipitation, cosedimentation, and cotransfection analyses, and interaction sites were mapped to MLL1 C-terminal and MOF zinc finger domains. The purified complex has a robust MLL1-mediated histone methyltransferase activity that can effect mono-, di-, and trimethylation of H3 K4 and a MOF-mediated histone acetyltransferase activity that is specific for H4 K16. Importantly, both activities are required for optimal transcription activation on a chromatin template in vitro and on an endogenous MLL1 target gene, Hox a9, in vivo. These results indicate an activator-based mechanism for joint MLL1 and MOF recruitment and targeted methylation and acetylation and provide a molecular explanation for the closely correlated distribution of H3 K4 methylation and H4 K16 acetylation on active genes.
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Affiliation(s)
- Yali Dou
- Laboratory of Biochemistry and Molecular Biology, The Rockefeller University, New York, New York 10021, USA
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41
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Zeisig DT, Bittner CB, Zeisig BB, García-Cuéllar MP, Hess JL, Slany RK. The eleven-nineteen-leukemia protein ENL connects nuclear MLL fusion partners with chromatin. Oncogene 2005; 24:5525-32. [PMID: 15856011 DOI: 10.1038/sj.onc.1208699] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Mixed lineage leukemia (MLL) fusion proteins are derived from translocations at 11q23 that occur in aggressive subtypes of leukemia. As a consequence, MLL is joined to different unrelated proteins to form oncogenic transcription factors. Here we demonstrate a direct interaction between several nuclear MLL fusion partners and present evidence for a role of these proteins in histone binding. In two-hybrid studies, ENL interacted with AF4 and AF5q31 as well as with a fragment of AF10. A structure-function analysis revealed that the AF4/AF5q31/AF10 binding domain in ENL coincided with the C-terminus that is essential for transformation by MLL-ENL. The ENL/AF4 association was corroborated by GST-pulldown experiments and by mutual coprecipitation. Both proteins colocalized in vivo in a nuclear speckled pattern. Moreover, AF4 and ENL coeluted on sizing columns together with the known ENL binding partner Polycomb3, suggesting the presence of a multiprotein complex. The overexpression of ENL alone activated a reporter construct and a mutational screen indicated the conserved YEATS domain as essential for this function. Overlay and pulldown-assays finally showed a specific and YEATS domain-dependent association of ENL with histones H3 and H1. In summary, our studies support a common role for nuclear MLL fusion partners in chromatin biology.
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Affiliation(s)
- Deniz T Zeisig
- Department of Genetics, University Erlangen, Staudtstrasse 5, 91058 Erlangen, Germany
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42
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Milne TA, Hughes CM, Lloyd R, Yang Z, Rozenblatt-Rosen O, Dou Y, Schnepp RW, Krankel C, Livolsi VA, Gibbs D, Hua X, Roeder RG, Meyerson M, Hess JL. Menin and MLL cooperatively regulate expression of cyclin-dependent kinase inhibitors. Proc Natl Acad Sci U S A 2005; 102:749-54. [PMID: 15640349 PMCID: PMC545577 DOI: 10.1073/pnas.0408836102] [Citation(s) in RCA: 339] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mutations in the MEN1 gene are associated with the multiple endocrine neoplasia syndrome type 1 (MEN1), which is characterized by parathyroid hyperplasia and tumors of the pituitary and pancreatic islets. The mechanism by which MEN1 acts as a tumor suppressor is unclear. We have recently shown that menin, the MEN1 protein product, interacts with mixed lineage leukemia (MLL) family proteins in a histone methyltransferase complex including Ash2, Rbbp5, and WDR5. Here, we show that menin directly regulates expression of the cyclin-dependent kinase inhibitors p27Kip1 and p18Ink4c. Menin activates transcription by means of a mechanism involving recruitment of MLL to the p27Kip1 and p18Ink4c promoters and coding regions. Loss of function of either MLL or menin results in down-regulation of p27Kip1 and p18Ink4c expression and deregulated cell growth. These findings suggest that regulation of cyclin-dependent kinase inhibitor transcription by cooperative interaction between menin and MLL plays a central role in menin's activity as a tumor suppressor.
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Affiliation(s)
- Thomas A Milne
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
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43
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Wang J, Iwasaki H, Krivtsov A, Febbo PG, Thorner AR, Ernst P, Anastasiadou E, Kutok JL, Kogan SC, Zinkel SS, Fisher JK, Hess JL, Golub TR, Armstrong SA, Akashi K, Korsmeyer SJ. Conditional MLL-CBP targets GMP and models therapy-related myeloproliferative disease. EMBO J 2005; 24:368-81. [PMID: 15635450 PMCID: PMC545811 DOI: 10.1038/sj.emboj.7600521] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2004] [Accepted: 11/24/2004] [Indexed: 11/09/2022] Open
Abstract
Chromosomal translocations that fuse the mixed lineage leukemia (MLL) gene with multiple partners typify acute leukemias of infancy as well as therapy-related leukemias. We utilized a conditional knockin strategy to bypass the embryonic lethality caused by MLL-CBP expression and to assess the immediate effects of induced MLL-CBP expression on hematopoiesis. Within days of activating MLL-CBP, the fusion protein selectively expanded granulocyte/macrophage progenitors (GMP) and enhanced their self-renewal/proliferation. MLL-CBP altered the gene expression program of GMP, upregulating a subset of genes including Hox a9. Inhibition of Hox a9 expression by RNA interference demonstrated that MLL-CBP required Hox a9 for its enhanced cell expansion. Following exposure to sublethal gamma-irradiation or N-ethyl-N-nitrosourea (ENU), MLL-CBP mice developed myelomonocytic hyperplasia and progressed to fatal myeloproliferative disorders. These represented the spectrum of therapy-induced acute myelomonocytic leukemia/chronic myelomonocytic leukemia/myelodysplastic/myeloproliferative disorder similar to that seen in humans possessing the t(11;16). This model of MLL-CBP therapy-related myeloproliferative disease demonstrates the selectivity of this MLL fusion for GMP cells and its ability to initiate leukemogenesis in conjunction with cooperating mutations.
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Affiliation(s)
- Jing Wang
- Department of Pathology and Medicine, Howard Hughes Medical Institute, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - Hiromi Iwasaki
- Department of Pathology, Harvard Medical School, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Andrei Krivtsov
- Division of Hematology/Oncology, Children's Hospital, Boston, MA, USA
| | - Phillip G Febbo
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Aaron R Thorner
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Patricia Ernst
- Department of Pathology and Medicine, Howard Hughes Medical Institute, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - Ema Anastasiadou
- Harvard Institutes of Medicine, Harvard Medical School, Boston, MA, USA
| | - Jeffery L Kutok
- Department of Pathology, Harvard Medical School, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Scott C Kogan
- Comprehensive Cancer Center and Department of Laboratory Medicine, University of California, San Francisco, CA, USA
| | - Sandra S Zinkel
- Department of Pathology and Medicine, Howard Hughes Medical Institute, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - Jill K Fisher
- Department of Pathology and Medicine, Howard Hughes Medical Institute, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - Jay L Hess
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | - Todd R Golub
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Scott A Armstrong
- Division of Hematology/Oncology, Children's Hospital, Boston, MA, USA
| | - Koichi Akashi
- Department of Pathology, Harvard Medical School, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Stanley J Korsmeyer
- Department of Pathology and Medicine, Howard Hughes Medical Institute, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
- Howard Hughes Medical Institute, Dana-Farber Cancer Institute, 44 Binney Street, Boston, MA 02115, USA. Tel.: +1 617 632 6402; Fax: +1 617 632 6401; E-mail:
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44
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Affiliation(s)
- Jay L Hess
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
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45
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Abstract
Rearrangements of the MLL gene, which is located at chromosome 11q23, are associated with aggressive acute leukemias in both children and adults. MLL regulates Hox gene expression through direct promoter binding and histone modification. MLL rearrangements occurring in leukemia include MLL fusion genes, partial tandem duplications of MLL and MLL amplification. MLL fusions and amplification upregulate Hox expression, apparently resulting in a block of hematopoietic differentiation. Future therapies for MLL-associated leukemia might involve blocking Hox gene upregulation by using fusion proteins or inhibiting the activity of Hox proteins themselves.
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Affiliation(s)
- Jay L Hess
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, 413b Stellar Chance Laboratories, Philadelphia, PA 19104, USA.
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46
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Mitra-Kaushik S, Harding JC, Hess JL, Ratner L. Effects of the proteasome inhibitor PS-341 on tumor growth in HTLV-1 Tax transgenic mice and Tax tumor transplants. Blood 2004; 104:802-9. [PMID: 15090453 DOI: 10.1182/blood-2003-11-3967] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Recent studies have shown that the transcription factor nuclear factor kappaB (NF-kappaB) regulates critical survival pathways in a variety of cancers, including human T-cell leukemia/lymphotrophic virus 1 (HTLV-1)-transformed CD4 T cells. The activation of NF-kappaB is controlled by proteasome-mediated degradation of the inhibitor of nuclear factor kappaBalpha (IkappaBalpha). We investigated the effects of PS-341, a peptide boronate inhibitor of the proteasome in HTLV-1 Tax transgenic tumors in vitro and in vivo. In Tax transgenic mice, PS-341 administered thrice weekly inhibited tumor-associated NF-kappaB activity. Quantitation of proliferation, apoptosis, and interleukin 6 (IL-6) and IL-10 secretion by tumor cells in culture revealed that the effects of PS-341 on cell growth largely correlated with inhibition of pathways mediated by NF-kappaB. However, the effect of PS-341 on the growth of tumors in Tax transgenic mice revealed heterogeneity in drug responsiveness. The tumor tissues treated with PS-341 show no consistent inhibition of NFkappaB activation in vivo. Annexin V staining indicated that PS-341 response in vivo correlated with sensitivity to apoptosis induced by gamma irradiation. On the other hand, transplanted Tax tumors in Rag-1 mice showed consistent inhibition of tumor growth and prolonged survival in response to the same drug regimen. TUNEL staining indicated that PS-341 treatment sensitizes Tax tumors to DNA fragmentation.
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Affiliation(s)
- Shibani Mitra-Kaushik
- Department of Internal Medicine, Washington University School of Medicine, St Louis, MO 63110, USA
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Hughes CM, Rozenblatt-Rosen O, Milne TA, Copeland TD, Levine SS, Lee JC, Hayes DN, Shanmugam KS, Bhattacharjee A, Biondi CA, Kay GF, Hayward NK, Hess JL, Meyerson M. Menin associates with a trithorax family histone methyltransferase complex and with the hoxc8 locus. Mol Cell 2004; 13:587-97. [PMID: 14992727 DOI: 10.1016/s1097-2765(04)00081-4] [Citation(s) in RCA: 479] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2003] [Revised: 12/30/2003] [Accepted: 02/04/2004] [Indexed: 12/17/2022]
Abstract
The cellular function of the menin tumor suppressor protein, product of the MEN1 gene mutated in familial multiple endocrine neoplasia type 1, has not been defined. We now show that menin is associated with a histone methyltransferase complex containing two trithorax family proteins, MLL2 and Ash2L, and other homologs of the yeast Set1 assembly. This menin-associated complex methylates histone H3 on lysine 4. A subset of tumor-derived menin mutants lacks the associated histone methyltransferase activity. In addition, menin is associated with RNA polymerase II whose large subunit carboxyl-terminal domain is phosphorylated on Ser 5. Men1 knockout embryos and cells show decreased expression of the homeobox genes Hoxc6 and Hoxc8. Chromatin immunoprecipitation experiments reveal that menin is bound to the Hoxc8 locus. These results suggest that menin activates the transcription of differentiation-regulating genes by covalent histone modification, and that this activity is related to tumor suppression by MEN1.
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Affiliation(s)
- Christina M Hughes
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA
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Zeisig BB, Milne T, García-Cuéllar MP, Schreiner S, Martin ME, Fuchs U, Borkhardt A, Chanda SK, Walker J, Soden R, Hess JL, Slany RK. Hoxa9 and Meis1 are key targets for MLL-ENL-mediated cellular immortalization. Mol Cell Biol 2004; 24:617-28. [PMID: 14701735 PMCID: PMC343796 DOI: 10.1128/mcb.24.2.617-628.2004] [Citation(s) in RCA: 258] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
MLL fusion proteins are oncogenic transcription factors that are associated with aggressive lymphoid and myeloid leukemias. We constructed an inducible MLL fusion, MLL-ENL-ERtm, that rendered the transcriptional and transforming properties of MLL-ENL strictly dependent on the presence of 4-hydroxy-tamoxifen. MLL-ENL-ERtm-immortalized hematopoietic cells required 4-hydroxy-tamoxifen for continuous growth and differentiated terminally upon tamoxifen withdrawal. Microarray analysis performed on these conditionally transformed cells revealed Hoxa9 and Hoxa7 as well as the Hox coregulators Meis1 and Pbx3 among the targets upregulated by MLL-ENL-ERtm. Overexpression of the Hox repressor Bmi-1 inhibited the growth-transforming activity of MLL-ENL. Moreover, the enforced expression of Hoxa9 in combination with Meis1 was sufficient to substitute for MLL-ENL-ERtm function and to maintain a state of continuous proliferation and differentiation arrest. These results suggest that MLL fusion proteins impose a reversible block on myeloid differentiation through aberrant activation of a limited set of homeobox genes and Hox coregulators that are consistently expressed in MLL-associated leukemias.
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Affiliation(s)
- Bernd B Zeisig
- Department of Genetics, University Erlangen, Staudtstrasse 5, 91058 Erlangen, Germany
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Hess JL. Mechanisms of Transformation by MLL. Crit Rev Eukaryot Gene Expr 2004. [DOI: 10.1615/critreveukargeneexpr.v14.i4.10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Abstract
Rearrangements of the mixed-lineage leukemia gene MLL1 (MLL, HRX, ALL1), the human homologue of the Drosophila gene trithorax, are associated with aggressive acute leukemias in both children and adults. Transformation by rearranged forms of MLL1, including in-frame fusion proteins, partial tandem duplications, and amplification of MLL1 through upregulation of Hox gene and cofactor expression apparently results in a block in hematopoietic differentiation. MLL1 regulates Hox gene expression via direct promoter binding and histone H3 Lys 4 methylation mediated by the intrinsic methyltransferase activity of the SET domain. Mll1 knockout leads to loss of Hox gene expression, defects in hematopoiesis, and embryonic lethality. A close homologue, MLL2 is amplified in some solid tumors. MLL2 also has histone H3 Lys 4 methyltransferase activity that is dependent on menin, a protein mutated in multiple neoplasia type I (MEN1) and which is required for normal Hox expression. These findings underscore the importance of the MLL histone methyltransferases in development and disease.
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Affiliation(s)
- Jay L Hess
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, 413b Stellar Chance Laboratories, Philadelphia, PA 19104, USA.
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