51
|
Iyer G, Price J, Bourgeois S, Armstrong E, Huang S, Harari PM. Insulin-like growth factor 1 receptor mediated tyrosine 845 phosphorylation of epidermal growth factor receptor in the presence of monoclonal antibody cetuximab. BMC Cancer 2016; 16:773. [PMID: 27716204 PMCID: PMC5054590 DOI: 10.1186/s12885-016-2796-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 09/08/2016] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND The epidermal growth factor receptor (EGFR) is frequently overexpressed in head and neck squamous cell carcinoma (HNSCC) and several other human cancers. Monoclonal antibodies, such as cetuximab that block EGFR signaling, have emerged as valuable molecular targeting agents in clinical cancer therapy. Prolonged exposure to cetuximab can result in cells acquiring resistance by a process that remains incompletely understood. METHODS In this study, we analyzed the immediate early molecular response of cetuximab on physical interactions between EGFR and Insulin growth factor 1 like receptor (IGF-1R) in head and neck cancer cells that are resistant to cetuximab. Co-immunoprecipitation, small molecule inhibitors against phospho-Src and IGF-1R, quantitative western blot of EGFR and Src phosphorylation, cell proliferation assays were used to suggest the role of IGF-1R mediated phosphorylation of specific tyrosine Y845 on EGFR via increased heterodimerization of EGFR and IGF-1R in cetuximab resistant cells. RESULTS Heterodimerization of EGFR with IGF-1R was increased in cetuximab resistant HNSCC cell line UMSCC6. Basal levels of phosphorylated EGFR Y845 showed significant increase in the presence of cetuximab. Surprisingly, this activated Y845 level was not inhibited in the presence of Src inhibitor PP1. Instead, inhibition of IGF-1R by picropodophyllin (PPP) reduced the EGFR Y845 levels. Taken together, these results suggest that heterodimerization of EGFR with IGF-1R can lead to increased activity of EGFR and may be an important platform for cetuximab mediated signaling in head and neck tumors that have become resistant to anti-EGFR therapy. CONCLUSIONS EGFR-IGF-1R interaction has a functional consequence of phosphorylation of EGFR Y845 in cetuximab resistant HNSCC cells and dual targeting of EGFR and IGF-1R is a promising therapeutic strategy.
Collapse
Affiliation(s)
- Gopal Iyer
- Department of Human Oncology and the University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, 53792, USA.
| | - James Price
- Department of Human Oncology and the University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, 53792, USA
| | - Shay Bourgeois
- Department of Human Oncology and the University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, 53792, USA
| | - Eric Armstrong
- Department of Human Oncology and the University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, 53792, USA
| | - Shyhmin Huang
- Department of Human Oncology and the University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, 53792, USA
| | - Paul M Harari
- Department of Human Oncology and the University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, 53792, USA
| |
Collapse
|
52
|
Bhatnagar N, Nizery L, Tunstall O, Vyas P, Roberts I. Transient Abnormal Myelopoiesis and AML in Down Syndrome: an Update. Curr Hematol Malig Rep 2016; 11:333-41. [PMID: 27510823 PMCID: PMC5031718 DOI: 10.1007/s11899-016-0338-x] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Children with constitutional trisomy 21 (Down syndrome (DS)) have a unique predisposition to develop myeloid leukaemia of Down syndrome (ML-DS). This disorder is preceded by a transient neonatal preleukaemic syndrome, transient abnormal myelopoiesis (TAM). TAM and ML-DS are caused by co-operation between trisomy 21, which itself perturbs fetal haematopoiesis and acquired mutations in the key haematopoietic transcription factor gene GATA1. These mutations are found in almost one third of DS neonates and are frequently clinically and haematologcially 'silent'. While the majority of cases of TAM undergo spontaneous remission, ∼10 % will progress to ML-DS by acquiring transforming mutations in additional oncogenes. Recent advances in the unique biological, cytogenetic and molecular characteristics of TAM and ML-DS are reviewed here.
Collapse
Affiliation(s)
- Neha Bhatnagar
- Children’s Hospital, John Radcliffe Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, OX3 9DU UK
| | - Laure Nizery
- Paediatric Intensive Care Unit, Robert Debré Hospital, 48 Boulevard Sérurier, 75019 Paris, France
| | - Oliver Tunstall
- Bristol Royal Hospital for Children, Paul O’Gorman Building, Upper Maudlin St, Bristol, BS2 8B UK
| | - Paresh Vyas
- Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, OX3 9DS UK
| | - Irene Roberts
- Department of Paediatrics, Children’s Hospital, University of Oxford, John Radcliffe Hospital, OX3 9DU Oxford, UK
| |
Collapse
|
53
|
Scheer C, Kratz C, Witt O, Creutzig U, Reinhardt D, Klusmann JH. Hematologic Response to Vorinostat Treatment in Relapsed Myeloid Leukemia of Down Syndrome. Pediatr Blood Cancer 2016; 63:1677-9. [PMID: 27191354 DOI: 10.1002/pbc.26062] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 04/14/2016] [Accepted: 04/21/2016] [Indexed: 01/21/2023]
Abstract
Children with Down syndrome are at high risk to develop myeloid leukemia (ML-DS). Despite their excellent prognosis, children with ML-DS particularly suffer from severe therapy-related toxicities and for relapsed ML-DS the cure rates are very poor. Here we report the clinical course of one child with ML-DS treated with the histone deacetylase (HDAC) inhibitor vorinostat (suberoylanilide hydroxamic acid) after second relapse. The child had previously received conventional chemotherapy and stem cell transplantation, yet showed a remarkable clinical and hematologic response. Thus, HDAC inhibitor may represent an effective class of drugs for the treatment of ML-DS.
Collapse
Affiliation(s)
- Carina Scheer
- Department of Pediatric Hematology and Oncology, Hannover Medical School, Hannover, Germany
| | - Christian Kratz
- Department of Pediatric Hematology and Oncology, Hannover Medical School, Hannover, Germany
| | - Olaf Witt
- Pediatric Oncology, German Cancer Research Center (DKFZ), University Hospital and National Center for Tumor Diseases, Heidelberg, Germany
| | - Ursula Creutzig
- Department of Pediatric Hematology and Oncology, Hannover Medical School, Hannover, Germany
| | - Dirk Reinhardt
- Clinic for Pediatrics III, University Hospital Essen, Essen, Germany
| | - Jan-Henning Klusmann
- Department of Pediatric Hematology and Oncology, Hannover Medical School, Hannover, Germany
| |
Collapse
|
54
|
Kay LJ, Smulders-Srinivasan TK, Soundararajan M. Understanding the Multifaceted Role of Human Down Syndrome Kinase DYRK1A. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2016; 105:127-71. [PMID: 27567487 DOI: 10.1016/bs.apcsb.2016.07.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The dual-specificity tyrosine (Y) phosphorylation-regulated kinase DYRK1A, also known as Down syndrome (DS) kinase, is a dosage-dependent signaling kinase that was originally shown to be highly expressed in DS patients as a consequence of trisomy 21. Although this was evident some time ago, it is only in recent investigations that the molecular roles of DYRK1A in a wide range of cellular processes are becoming increasingly apparent. Since initial knowledge on DYRK1A became evident through minibrain mnb, the Drosophila homolog of DYRK1A, this review will first summarize the scientific reports on minibrain and further expand on the well-established neuronal functions of mammalian and human DYRK1A. Recent investigations across the current decade have provided rather interesting and compelling evidence in establishing nonneuronal functions for DYRK1A, including its role in infection, immunity, cardiomyocyte biology, cancer, and cell cycle control. The latter part of this review will therefore focus in detail on the emerging nonneuronal functions of DYRK1A and summarize the regulatory role of DYRK1A in controlling Tau and α-synuclein. Finally, the emerging role of DYRK1A in Parkinson's disease will be outlined.
Collapse
Affiliation(s)
- L J Kay
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, United Kingdom
| | - T K Smulders-Srinivasan
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, United Kingdom
| | - M Soundararajan
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, United Kingdom.
| |
Collapse
|
55
|
Zhao J, Zhang Z, Ren S, Zong Y, Kong X. Co-expression network analysis of Down's syndrome based on microarray data. Exp Ther Med 2016; 12:1503-1508. [PMID: 27588071 DOI: 10.3892/etm.2016.3462] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Accepted: 04/11/2016] [Indexed: 12/17/2022] Open
Abstract
Down's syndrome (DS) is a type of chromosome disease. The present study aimed to explore the underlying molecular mechanisms of DS. GSE5390 microarray data downloaded from the gene expression omnibus database was used to identify differentially expressed genes (DEGs) in DS. Pathway enrichment analysis of the DEGs was performed, followed by co-expression network construction. Significant differential modules were mined by mutual information, followed by functional analysis. The accuracy of sample classification for the significant differential modules of DEGs was evaluated by leave-one-out cross-validation. A total of 997 DEGs, including 638 upregulated and 359 downregulated genes, were identified. Upregulated DEGs were enriched in 15 pathways, such as cell adhesion molecules, whereas downregulated DEGs were enriched in maturity onset diabetes of the young. Three significant differential modules with the highest discriminative scores (mutual information>0.35) were selected from a co-expression network. The classification accuracy of GSE16677 expression profile samples was 54.55% and 72.73% when characterized by 12 DEGs and 3 significant differential modules, respectively. Genes in significant differential modules were significantly enriched in 5 functions, including the endoplasmic reticulum (P=0.018) and regulation of apoptosis (P=0.061). The identified DEGs, in particular the 12 DEGs in the significant differential modules, such as B-cell lymphoma 2-associated transcription factor 1, heat shock protein 90 kDa beta member 1, UBX domain-containing protein 2 and transmembrane protein 50B, may serve important roles in the pathogenesis of DS.
Collapse
Affiliation(s)
- Jianping Zhao
- Clinical Laboratory, Women and Infants Hospital of Zhengzhou, Zhengzhou, Henan 450012, P.R. China
| | - Zhengguo Zhang
- Clinical Laboratory, Henan Provincial Hospital of Traditional Chinese Medicine, Zhengzhou, Henan 450002, P.R. China
| | - Shumin Ren
- Center of Prenatal Diagnosis, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R. China
| | - Yanan Zong
- Center of Prenatal Diagnosis, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R. China
| | - Xiangdong Kong
- Center of Prenatal Diagnosis, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R. China
| |
Collapse
|
56
|
Zucker J, Temm C, Czader M, Nalepa G. A Child With Dyserythropoietic Anemia and Megakaryocyte Dysplasia Due to a Novel 5'UTR GATA1s Splice Mutation. Pediatr Blood Cancer 2016; 63:917-21. [PMID: 26713410 PMCID: PMC5138049 DOI: 10.1002/pbc.25871] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2015] [Accepted: 11/22/2015] [Indexed: 11/09/2022]
Abstract
We describe a child with dyserythropoietic anemia, thrombocytosis, functional platelet defect, and megakaryocyte dysplasia. We show that (i) this constellation of hematopoietic abnormalities was due to a germline mutation within the 5' untranslated region (5'UTR) of globin transcription factor 1 (GATA1); (ii) the mutation impaired a 5'UTR GATA1 splicing site, with promoted production of the shortened GATA1 isoform lacking the N-terminus; and (iii) expression of the GATA1 N-terminus is restricted to erythroblasts and megakaryocytes in normal marrow, consistent with the patient's abnormal erythropoiesis and megakaryopoiesis. Our findings provide insights into the clinically relevant in vivo function of the N-terminal domain of GATA1 in human hematopoiesis.
Collapse
Affiliation(s)
- Jacob Zucker
- Department of Pediatrics, Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN,Division of Pediatric Hematology-Oncology, Bone Marrow Failure Program, Riley Hospital for Children, Indianapolis, IN
| | - Constance Temm
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN
| | - Magdalena Czader
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN
| | - Grzegorz Nalepa
- Department of Pediatrics, Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN,Division of Pediatric Hematology-Oncology, Bone Marrow Failure Program, Riley Hospital for Children, Indianapolis, IN,Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN,Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN,Corresponding author. Grzegorz Nalepa, Indiana University School of Medicine, Department of Pediatrics, Division of Pediatric Hematology-Oncology, Herman B Wells Center for Pediatric Research, 1044 W. Walnut Street, R4-421, Indianapolis, Indiana 46202, USA. Phone: 317.278.9846; Fax: 317.274.0138;
| |
Collapse
|
57
|
Kadri Z, Lefevre C, Goupille O, Penglong T, Granger-Locatelli M, Fucharoen S, Maouche-Chretien L, Leboulch P, Chretien S. Erythropoietin and IGF-1 signaling synchronize cell proliferation and maturation during erythropoiesis. Genes Dev 2016; 29:2603-16. [PMID: 26680303 PMCID: PMC4699388 DOI: 10.1101/gad.267633.115] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Kadri et al. show that erythropoietin activates AKT, which phosphorylates GATA-1 at Ser310, thereby increasing GATA-1 affinity for FOG-1. In turn, FOG-1 displaces pRb/E2F-2 from GATA-1, ultimately releasing free, proproliferative E2F-2. Mice bearing a GATA-1S310A mutation suffer from fatal anemia when a compensatory pathway for E2F-2 production involving IGF-1 signaling is simultaneously abolished. Tight coordination of cell proliferation and differentiation is central to red blood cell formation. Erythropoietin controls the proliferation and survival of red blood cell precursors, while variations in GATA-1/FOG-1 complex composition and concentrations drive their maturation. However, clear evidence of cross-talk between molecular pathways is lacking. Here, we show that erythropoietin activates AKT, which phosphorylates GATA-1 at Ser310, thereby increasing GATA-1 affinity for FOG-1. In turn, FOG-1 displaces pRb/E2F-2 from GATA-1, ultimately releasing free, proproliferative E2F-2. Mice bearing a Gata-1S310A mutation suffer from fatal anemia when a compensatory pathway for E2F-2 production involving insulin-like growth factor-1 (IGF-1) signaling is simultaneously abolished. In the context of the GATA-1V205G mutation resulting in lethal anemia, we show that the Ser310 cannot be phosphorylated and that constitutive phosphorylation at this position restores partial erythroid differentiation. This study sheds light on the GATA-1 pathways that synchronize cell proliferation and differentiation for tissue homeostasis.
Collapse
Affiliation(s)
- Zahra Kadri
- Commissariat à l'Energie Atomique et aux Énergies Alternatives, Institute of Emerging Diseases and Innovative Therapies (iMETI), 92265 Fontenay-aux-Roses, France; UMR-E 007, Université Paris-Saclay, 91400 Orsay, France
| | - Carine Lefevre
- Commissariat à l'Energie Atomique et aux Énergies Alternatives, Institute of Emerging Diseases and Innovative Therapies (iMETI), 92265 Fontenay-aux-Roses, France; UMR-E 007, Université Paris-Saclay, 91400 Orsay, France
| | - Olivier Goupille
- Commissariat à l'Energie Atomique et aux Énergies Alternatives, Institute of Emerging Diseases and Innovative Therapies (iMETI), 92265 Fontenay-aux-Roses, France; UMR-E 007, Université Paris-Saclay, 91400 Orsay, France
| | - Tipparat Penglong
- Commissariat à l'Energie Atomique et aux Énergies Alternatives, Institute of Emerging Diseases and Innovative Therapies (iMETI), 92265 Fontenay-aux-Roses, France; UMR-E 007, Université Paris-Saclay, 91400 Orsay, France; Thalassemia Research Center, Institute of Molecular Biosciences, Mahidol University, 73170 Nakhon Pathom, Thailand
| | - Marine Granger-Locatelli
- Commissariat à l'Energie Atomique et aux Énergies Alternatives, Institute of Emerging Diseases and Innovative Therapies (iMETI), 92265 Fontenay-aux-Roses, France; UMR-E 007, Université Paris-Saclay, 91400 Orsay, France
| | - Suthat Fucharoen
- Thalassemia Research Center, Institute of Molecular Biosciences, Mahidol University, 73170 Nakhon Pathom, Thailand
| | - Leila Maouche-Chretien
- Commissariat à l'Energie Atomique et aux Énergies Alternatives, Institute of Emerging Diseases and Innovative Therapies (iMETI), 92265 Fontenay-aux-Roses, France; UMR-E 007, Université Paris-Saclay, 91400 Orsay, France; Institut National de la Santé et de la Recherche Médicale, 75013 Paris, France
| | - Philippe Leboulch
- Commissariat à l'Energie Atomique et aux Énergies Alternatives, Institute of Emerging Diseases and Innovative Therapies (iMETI), 92265 Fontenay-aux-Roses, France; UMR-E 007, Université Paris-Saclay, 91400 Orsay, France; Thalassemia Research Center, Institute of Molecular Biosciences, Mahidol University, 73170 Nakhon Pathom, Thailand; Genetics Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02215, USA
| | - Stany Chretien
- Commissariat à l'Energie Atomique et aux Énergies Alternatives, Institute of Emerging Diseases and Innovative Therapies (iMETI), 92265 Fontenay-aux-Roses, France; UMR-E 007, Université Paris-Saclay, 91400 Orsay, France; Institut National de la Santé et de la Recherche Médicale, 75013 Paris, France
| |
Collapse
|
58
|
Affiliation(s)
- Alan B Cantor
- Division of Pediatric Hematology-Oncology, Boston Children's Hospital/Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA; Harvard Stem Cell Institute, Cambridge, MA, 02138, USA
| |
Collapse
|
59
|
Thon JN, Medvetz DA, Karlsson SM, Italiano JE. Road blocks in making platelets for transfusion. J Thromb Haemost 2015; 13 Suppl 1:S55-62. [PMID: 26149051 PMCID: PMC5565795 DOI: 10.1111/jth.12942] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The production of laboratory-generated human platelets is necessary to meet present and future transfusion needs. This manuscript will identify and define the major roadblocks that must be overcome to make human platelet production possible for clinical use, and propose solutions necessary to accelerate development of laboratory-generated human platelets to market.
Collapse
Affiliation(s)
- J N Thon
- Hematology Division, Department of Medicine, Brigham and Women's Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
- Platelet BioGenesis, Chestnut Hill, MA, USA
| | - D A Medvetz
- Hematology Division, Department of Medicine, Brigham and Women's Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | | | - J E Italiano
- Hematology Division, Department of Medicine, Brigham and Women's Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
- Platelet BioGenesis, Chestnut Hill, MA, USA
| |
Collapse
|
60
|
Chlon TM, McNulty M, Goldenson B, Rosinski A, Crispino JD. Global transcriptome and chromatin occupancy analysis reveal the short isoform of GATA1 is deficient for erythroid specification and gene expression. Haematologica 2015; 100:575-84. [PMID: 25682601 DOI: 10.3324/haematol.2014.112714] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 02/02/2015] [Indexed: 01/23/2023] Open
Abstract
GATA1 is a master transcriptional regulator of the differentiation of several related myeloid blood cell types, including erythrocytes and megakaryocytes. Germ-line mutations that cause loss of full length GATA1, but allow for expression of the short isoform (GATA1s), are associated with defective erythropoiesis in a subset of patients with Diamond Blackfan Anemia. Despite extensive studies of GATA1s in megakaryopoiesis, the mechanism by which GATA1s fails to support normal erythropoiesis is not understood. In this study, we used global gene expression and chromatin occupancy analysis to compare the transcriptional activity of GATA1s to GATA1. We discovered that compared to GATA1, GATA1s is less able to activate the erythroid gene expression program and terminal differentiation in cells with dual erythroid-megakaryocytic differentiation potential. Moreover, we found that GATA1s bound to many of its erythroid-specific target genes less efficiently than full length GATA1. These results suggest that the impaired ability of GATA1s to promote erythropoiesis in DBA may be caused by failure to occupy erythroid-specific gene regulatory elements.
Collapse
Affiliation(s)
- Timothy M Chlon
- Division of Hematology/Oncology, Northwestern University, Chicago, IL, USA Present address Cincinnati Children's Hospital, Cincinnati, OH, USA
| | - Maureen McNulty
- Division of Hematology/Oncology, Northwestern University, Chicago, IL, USA
| | - Benjamin Goldenson
- Division of Hematology/Oncology, Northwestern University, Chicago, IL, USA
| | - Alexander Rosinski
- Division of Hematology/Oncology, Northwestern University, Chicago, IL, USA
| | - John D Crispino
- Division of Hematology/Oncology, Northwestern University, Chicago, IL, USA
| |
Collapse
|
61
|
Abstract
Children with Down syndrome (DS) and acute leukemias acute have unique biological, cytogenetic, and intrinsic factors that affect their treatment and outcome. Myeloid leukemia of Down syndrome (ML-DS) is associated with high event-free survival (EFS) rates and frequently preceded by a preleukemia condition, the transient abnormal hematopoiesis (TAM) present at birth. For acute lymphoblastic leukemia (ALL), their EFS and overall survival are poorer than non-DS ALL, it is important to enroll them on therapeutic trials, including relapse trials; investigate new agents that could potentially improve their leukemia-free survival; and strive to maximize the supportive care these patients need.
Collapse
Affiliation(s)
- Kelly W Maloney
- Center for Cancer & Blood Disorders, Children's Hospital Colorado, 13123 East 16th Avenue, B115, Aurora, CO 80045, USA
| | - Jeffrey W Taub
- Division of Pediatric Hematology/Oncology, Children's Hospital of Michigan, Wayne State University School of Medicine, 3901 Beaubien Boulevard, Detroit, MI 48201, USA.
| | - Yaddanapudi Ravindranath
- Division of Pediatric Hematology/Oncology, Children's Hospital of Michigan, Wayne State University School of Medicine, 3901 Beaubien Boulevard, Detroit, MI 48201, USA
| | - Irene Roberts
- Department of Paediatrics and Molecular Haematology Unit, University of Oxford and Oxford University Hospitals NHS Trust, Oxford, OX3 9DS, UK
| | - Paresh Vyas
- MRC Molecular Haematology Unit, Department of Haematology, Weatherall Institute of Molecular Medicine, Oxford University Hospitals NHS Trust, University of Oxford, Oxford OX3 9DS, UK
| |
Collapse
|
62
|
Fernández-Martínez P, Zahonero C, Sánchez-Gómez P. DYRK1A: the double-edged kinase as a protagonist in cell growth and tumorigenesis. Mol Cell Oncol 2015; 2:e970048. [PMID: 27308401 PMCID: PMC4905233 DOI: 10.4161/23723548.2014.970048] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 09/03/2014] [Accepted: 09/03/2014] [Indexed: 01/12/2023]
Abstract
DYRK1A (dual-specificity tyrosine-regulated kinase 1A) is a kinase with multiple implications for embryonic development, especially in the nervous system where it regulates the balance between proliferation and differentiation of neural progenitors. The DYRK1A gene is located in the Down syndrome critical region and may play a significant role in the developmental brain defects, early neurodegeneration, and cancer susceptibility of individuals with this syndrome. DYRK1A is also expressed in adults, where it might participate in the regulation of cell cycle, survival, and tumorigenesis, thus representing a potential therapeutic target for certain types of cancer. However, the final readout of DYRK1A overexpression or inhibition depends strongly on the cellular context, as it has both tumor suppressor and oncogenic activities. Here, we will discuss the functions and substrates of DYRK1A associated with the control of cell growth and tumorigenesis with a focus on the potential use of DYRK1A inhibitors in cancer therapy.
Collapse
Affiliation(s)
- P Fernández-Martínez
- Instituto de Medicina Molecular Aplicada; Universidad CEU-San Pablo ; Madrid, Spain
| | - C Zahonero
- Neuro-oncology Unit; Instituto de Salud Carlos III-UFIEC ; Madrid, Spain
| | - P Sánchez-Gómez
- Neuro-oncology Unit; Instituto de Salud Carlos III-UFIEC ; Madrid, Spain
| |
Collapse
|
63
|
Byrska-Bishop M, VanDorn D, Campbell AE, Betensky M, Arca PR, Yao Y, Gadue P, Costa FF, Nemiroff RL, Blobel GA, French DL, Hardison RC, Weiss MJ, Chou ST. Pluripotent stem cells reveal erythroid-specific activities of the GATA1 N-terminus. J Clin Invest 2015; 125:993-1005. [PMID: 25621499 DOI: 10.1172/jci75714] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Accepted: 12/15/2014] [Indexed: 01/13/2023] Open
Abstract
Germline GATA1 mutations that result in the production of an amino-truncated protein termed GATA1s (where s indicates short) cause congenital hypoplastic anemia. In patients with trisomy 21, similar somatic GATA1s-producing mutations promote transient myeloproliferative disease and acute megakaryoblastic leukemia. Here, we demonstrate that induced pluripotent stem cells (iPSCs) from patients with GATA1-truncating mutations exhibit impaired erythroid potential, but enhanced megakaryopoiesis and myelopoiesis, recapitulating the major phenotypes of the associated diseases. Similarly, in developmentally arrested GATA1-deficient murine megakaryocyte-erythroid progenitors derived from murine embryonic stem cells (ESCs), expression of GATA1s promoted megakaryopoiesis, but not erythropoiesis. Transcriptome analysis revealed a selective deficiency in the ability of GATA1s to activate erythroid-specific genes within populations of hematopoietic progenitors. Although its DNA-binding domain was intact, chromatin immunoprecipitation studies showed that GATA1s binding at specific erythroid regulatory regions was impaired, while binding at many nonerythroid sites, including megakaryocytic and myeloid target genes, was normal. Together, these observations indicate that lineage-specific GATA1 cofactor associations are essential for normal chromatin occupancy and provide mechanistic insights into how GATA1s mutations cause human disease. More broadly, our studies underscore the value of ESCs and iPSCs to recapitulate and study disease phenotypes.
Collapse
|
64
|
Abstract
Children with Down syndrome (DS) are at increased risk for acute myeloid leukemias (ML-DS) characterized by mixed megakaryocytic and erythroid phenotype and by acquired mutations in the GATA1 gene resulting in a short GATA1s isoform. The chromosome 21 microRNA (miR)-125b cluster has been previously shown to cooperate with GATA1s in transformation of fetal hematopoietic progenitors. In this study, we report that the expression of miR-486-5p is increased in ML-DS compared with non-DS acute megakaryocytic leukemias (AMKLs). miR-486-5p is regulated by GATA1 and GATA1s that bind to the promoter of its host gene ANK1. miR-486-5p is highly expressed in mouse erythroid precursors and knockdown (KD) in ML-DS cells reduced their erythroid phenotype. Ectopic expression and KD of miR-486-5p in primary fetal liver hematopoietic progenitors demonstrated that miR-486-5p cooperates with Gata1s to enhance their self renewal. Consistent with its activation of AKT, overexpression and KD experiments showed its importance for growth and survival of human leukemic cells. Thus, miR-486-5p cooperates with GATA1s in supporting the growth and survival, and the aberrant erythroid phenotype of the megakaryocytic leukemias of DS.
Collapse
|
65
|
Liu B, Filippi S, Roy A, Roberts I. Stem and progenitor cell dysfunction in human trisomies. EMBO Rep 2014; 16:44-62. [PMID: 25520324 DOI: 10.15252/embr.201439583] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Trisomy 21, the commonest constitutional aneuploidy in humans, causes profound perturbation of stem and progenitor cell growth, which is both cell context dependent and developmental stage specific and mediated by complex genetic mechanisms beyond increased Hsa21 gene dosage. While proliferation of fetal hematopoietic and testicular stem/progenitors is increased and may underlie increased susceptibility to childhood leukemia and testicular cancer, fetal stem/progenitor proliferation in other tissues is markedly impaired leading to the characteristic craniofacial, neurocognitive and cardiac features in individuals with Down syndrome. After birth, trisomy 21-mediated premature aging of stem/progenitor cells may contribute to the progressive multi-system deterioration, including development of Alzheimer's disease.
Collapse
Affiliation(s)
- Binbin Liu
- Department of Paediatrics and Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, Oxford, UK
| | - Sarah Filippi
- Department of Statistics, University of Oxford, Oxford, UK
| | - Anindita Roy
- Centre for Haematology, Imperial College London, London, UK
| | - Irene Roberts
- Department of Paediatrics and Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, Oxford, UK
| |
Collapse
|
66
|
Miyauchi J, Kawaguchi H. Fetal liver stromal cells support blast growth in transient abnormal myelopoiesis in Down syndrome through GM-CSF. J Cell Biochem 2014; 115:1176-86. [PMID: 24415393 DOI: 10.1002/jcb.24764] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Accepted: 01/07/2014] [Indexed: 11/08/2022]
Abstract
Transient abnormal myelopoiesis (TAM) in neonates with Down syndrome, which spontaneously resolves within several weeks or months after birth, may represent a very special form of leukemia arising in the fetal liver (FL). To explore the role of the fetal hematopoietic microenvironment in the pathogenesis of TAM, we examined the in vitro influences of stromal cells of human FL and fetal bone marrow (FBM) on the growth of TAM blasts. Both FL and FBM stromal cells expressed mesenchymal cell antigens (vimentin, α-smooth muscle actin, CD146, and nestin), being consistent with perivascular cells/mesenchymal stem cells that support hematopoietic stem cells. In addition, a small fraction of the FL stromal cells expressed an epithelial marker, cytokeratin 8, indicating that they could be cells in epithelial-mesenchymal transition (EMT). In the coculture system, stromal cells of the FL, but not FBM, potently supported the growth of TAM blast progenitors, mainly through humoral factors. High concentrations of hematopoietic growth factors were detected in culture supernatants of the FL stromal cells and a neutralizing antibody against granulocyte-macrophage colony-stimulating factor (GM-CSF) almost completely inhibited the growth-supportive activity of the culture supernatants. These results indicate that FL stromal cells with unique characteristics of EMT cells provide a pivotal hematopoietic microenvironment for TAM blasts and that GM-CSF produced by FL stromal cells may play an important role in the pathogenesis of TAM.
Collapse
Affiliation(s)
- Jun Miyauchi
- Department of Pathology and Laboratory Medicine, Tokyo Dental College Ichikawa General Hospital, Ichikawa, Chiba-ken, Japan
| | | |
Collapse
|
67
|
Pelleri MC, Piovesan A, Caracausi M, Berardi AC, Vitale L, Strippoli P. Integrated differential transcriptome maps of Acute Megakaryoblastic Leukemia (AMKL) in children with or without Down Syndrome (DS). BMC Med Genomics 2014; 7:63. [PMID: 25476127 PMCID: PMC4304173 DOI: 10.1186/s12920-014-0063-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Accepted: 11/12/2014] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND The incidence of Acute Megakaryoblastic Leukemia (AMKL) is 500-fold higher in children with Down Syndrome (DS) compared with non-DS children, but the relevance of trisomy 21 as a specific background of AMKL in DS is still an open issue. Several Authors have determined gene expression profiles by microarray analysis in DS and/or non-DS AMKL. Due to the rarity of AMKL, these studies were typically limited to a small group of samples. METHODS We generated integrated quantitative transcriptome maps by systematic meta-analysis from any available gene expression profile dataset related to AMKL in pediatric age. This task has been accomplished using a tool recently described by us for the generation and the analysis of quantitative transcriptome maps, TRAM (Transcriptome Mapper), which allows effective integration of data obtained from different experimenters, experimental platforms and data sources. This allowed us to explore gene expression changes involved in transition from normal megakaryocytes (MK, n=19) to DS (n=43) or non-DS (n=45) AMKL blasts, including the analysis of Transient Myeloproliferative Disorder (TMD, n=20), a pre-leukemia condition. RESULTS We propose a biological model of the transcriptome depicting progressive changes from MK to TMD and then to DS AMKL. The data indicate the repression of genes involved in MK differentiation, in particular the cluster on chromosome 4 including PF4 (platelet factor 4) and PPBP (pro-platelet basic protein); the gene for the mitogen-activated protein kinase MAP3K10 and the thrombopoietin receptor gene MPL. Moreover, comparing both DS and non-DS AMKL with MK, we identified three potential clinical markers of progression to AMKL: TMEM241 (transmembrane protein 241) was the most over-expressed single gene, while APOC2 (apolipoprotein C-II) and ZNF587B (zinc finger protein 587B) appear to be the most discriminant markers of progression, specifically to DS AMKL. Finally, the chromosome 21 (chr21) genes resulted to be the most over-expressed in DS and non-DS AMKL, as well as in TMD, pointing out a key role of chr21 genes in differentiating AMKL from MK. CONCLUSIONS Our study presents an integrated original model of the DS AMLK transcriptome, providing the identification of genes relevant for its pathophysiology which can potentially be new clinical markers.
Collapse
Affiliation(s)
- Maria Chiara Pelleri
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), Unit of Histology, Embryology and Applied Biology, University of Bologna, Via Belmeloro 8, 40126, Bologna, BO, Italy.
| | - Allison Piovesan
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), Unit of Histology, Embryology and Applied Biology, University of Bologna, Via Belmeloro 8, 40126, Bologna, BO, Italy.
| | - Maria Caracausi
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), Unit of Histology, Embryology and Applied Biology, University of Bologna, Via Belmeloro 8, 40126, Bologna, BO, Italy.
| | - Anna Concetta Berardi
- Research Laboratory Stem Cells, U.O.C. Immunohematology-Transfusion Medicine and Laboratory of Hematology, Santo Spirito's Hospital, Via del Circuito, 65100, Pescara, Italy.
| | - Lorenza Vitale
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), Unit of Histology, Embryology and Applied Biology, University of Bologna, Via Belmeloro 8, 40126, Bologna, BO, Italy.
| | - Pierluigi Strippoli
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), Unit of Histology, Embryology and Applied Biology, University of Bologna, Via Belmeloro 8, 40126, Bologna, BO, Italy. .,Interdepartmental Center for Cancer Research Giorgio Prodi (CIRC), S. Orsola-Malpighi Hospital, University of Bologna, Via Massarenti 9, 40138, Bologna, BO, Italy.
| |
Collapse
|
68
|
Martelotto LG, Ng CK, De Filippo MR, Zhang Y, Piscuoglio S, Lim RS, Shen R, Norton L, Reis-Filho JS, Weigelt B. Benchmarking mutation effect prediction algorithms using functionally validated cancer-related missense mutations. Genome Biol 2014; 15:484. [PMID: 25348012 PMCID: PMC4232638 DOI: 10.1186/s13059-014-0484-1] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Accepted: 09/30/2014] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Massively parallel sequencing studies have led to the identification of a large number of mutations present in a minority of cancers of a given site. Hence, methods to identify the likely pathogenic mutations that are worth exploring experimentally and clinically are required. We sought to compare the performance of 15 mutation effect prediction algorithms and their agreement. As a hypothesis-generating aim, we sought to define whether combinations of prediction algorithms would improve the functional effect predictions of specific mutations. RESULTS Literature and database mining of single nucleotide variants (SNVs) affecting 15 cancer genes was performed to identify mutations supported by functional evidence or hereditary disease association to be classified either as non-neutral (n = 849) or neutral (n = 140) with respect to their impact on protein function. These SNVs were employed to test the performance of 15 mutation effect prediction algorithms. The accuracy of the prediction algorithms varies considerably. Although all algorithms perform consistently well in terms of positive predictive value, their negative predictive value varies substantially. Cancer-specific mutation effect predictors display no-to-almost perfect agreement in their predictions of these SNVs, whereas the non-cancer-specific predictors showed no-to-moderate agreement. Combinations of predictors modestly improve accuracy and significantly improve negative predictive values. CONCLUSIONS The information provided by mutation effect predictors is not equivalent. No algorithm is able to predict sufficiently accurately SNVs that should be taken forward for experimental or clinical testing. Combining algorithms aggregates orthogonal information and may result in improvements in the negative predictive value of mutation effect predictions.
Collapse
Affiliation(s)
- Luciano G Martelotto
- Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
69
|
Caldwell JT, Ge Y, Taub JW. Prognosis and management of acute myeloid leukemia in patients with Down syndrome. Expert Rev Hematol 2014; 7:831-40. [PMID: 25231553 DOI: 10.1586/17474086.2014.959923] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Children with Down syndrome (DS) are at a substantially increased risk to develop acute myeloid leukemia (AML). This increase in incidence is tempered, however, by favorable overall survival rates of approximately 80%, whereas survival for non-DS children with similar leukemic subtypes is <35%. In this review, the clinical studies that have contributed to this overall high survival will be presented and their individual successes will be discussed. Important issues including intensity of treatment regimens, the role of bone marrow transplants and prognostic indicators will be reviewed. In particular, the roles of high- vs low- vs very low-dose cytarabine will be discussed, as well as potential therapeutic options in the future and the direction of the field over the next 5 years. In summary, children with DS and AML should be treated with a moderate-intensity cytarabine-based regimen with curative intent.
Collapse
Affiliation(s)
- J Timothy Caldwell
- MD/PhD Program, Wayne State University School of Medicine, 110 East Warren Ave, Detroit, MI 48201, USA
| | | | | |
Collapse
|
70
|
Abstract
Children with constitutional trisomy 21 (cT21, Down Syndrome, DS) are at a higher risk for both myeloid and B-lymphoid leukaemias. The myeloid leukaemias are often preceded by a transient neonatal pre-leukaemic syndrome, Transient Abnormal Myelopoiesis (TAM). TAM is caused by cooperation between cT21 and acquired somatic N-terminal truncating mutations in the key haematopoietic transcription factor GATA1. These mutations, which are not leukaemogenic in the absence of cT21, are found in almost one-third of neonates with DS. Analysis of primary human fetal liver haematopoietic cells and of human embryonic stem cells demonstrates that cT21 itself substantially alters human fetal haematopoietic development. Consequently, many haematopoietic developmental defects are observed in neonates with DS even in the absence of TAM. Although studies in mouse models have suggested a pathogenic role of deregulated expression of several chromosome 21-encoded genes, their role in human leukaemogenesis remains unclear. As cT21 exists in all embryonic cells, the molecular basis of cT21-associated leukaemias probably reflects a complex interaction between deregulated gene expression in haematopoietic cells and the fetal haematopoietic microenvironment in DS.
Collapse
Affiliation(s)
- Irene Roberts
- Paediatrics and Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | | |
Collapse
|
71
|
Emmrich S, Streltsov A, Schmidt F, Thangapandi VR, Reinhardt D, Klusmann JH. LincRNAs MONC and MIR100HG act as oncogenes in acute megakaryoblastic leukemia. Mol Cancer 2014; 13:171. [PMID: 25027842 PMCID: PMC4118279 DOI: 10.1186/1476-4598-13-171] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Accepted: 07/03/2014] [Indexed: 12/02/2022] Open
Abstract
Background Long non-coding RNAs (lncRNAs) are recognized as pivotal players during developmental ontogenesis and pathogenesis of cancer. The intronic microRNA (miRNA) clusters miR-99a ~ 125b-2 and miR-100 ~ 125b-1 promote progression of acute megakaryoblastic leukemia (AMKL), an aggressive form of hematologic cancers. The function of the lncRNA hostgenes MIR99AHG (alias MONC) and MIR100HG within this ncRNA ensemble remained elusive. Results Here we report that lncRNAs MONC and MIR100HG are highly expressed in AMKL blasts. The transcripts were mainly localized in the nucleus and their expression correlated with the corresponding miRNA clusters. Knockdown of MONC or MIR100HG impeded leukemic growth of AMKL cell lines and primary patient samples. The development of a lentiviral lncRNA vector to ectopically express lncRNAs without perturbing their secondary structure due to improper termination of the viral transcript, allowed us to study the function of MONC independent of the miRNAs in cord blood hematopoietic stem and progenitor cells (HSPCs). We could show that MONC interfered with hematopoietic lineage decisions and enhanced the proliferation of immature erythroid progenitor cells. Conclusions Our study reveals an unprecedented function of lncRNAs MONC and MIR100HG as regulators of hematopoiesis and oncogenes in the development of myeloid leukemia.
Collapse
Affiliation(s)
| | | | | | | | | | - Jan-Henning Klusmann
- Pediatric Hematology and Oncology, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany.
| |
Collapse
|
72
|
Emmrich S, Rasche M, Schöning J, Reimer C, Keihani S, Maroz A, Xie Y, Li Z, Schambach A, Reinhardt D, Klusmann JH. miR-99a/100~125b tricistrons regulate hematopoietic stem and progenitor cell homeostasis by shifting the balance between TGFβ and Wnt signaling. Genes Dev 2014; 28:858-74. [PMID: 24736844 PMCID: PMC4003278 DOI: 10.1101/gad.233791.113] [Citation(s) in RCA: 124] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
miR-99a/100, let-7, and miR-125b paralogs are encoded in two tricistrons and are highly expressed in hematopoietic stem cells (HSCs). Emmrich et al. demonstrate that miR-99a/100∼125b tricistrons are transcribed as a polycistronic message and functionally converge at the combinatorial block of the TGFβ pathway. Down-regulating tumor suppressor genes APC/APC2 stabilized active β-catenin and enhanced Wnt signaling. These tricistronic miRNAs promoted sustained expansion of murine and human HSCs by switching the balance between Wnt and TGFβ signaling. Although regulation of stem cell homeostasis by microRNAs (miRNAs) is well studied, it is unclear how individual miRNAs genomically encoded within an organized polycistron can interact to induce an integrated phenotype. miR-99a/100, let-7, and miR-125b paralogs are encoded in two tricistrons on human chromosomes 11 and 21. They are highly expressed in hematopoietic stem cells (HSCs) and acute megakaryoblastic leukemia (AMKL), an aggressive form of leukemia with poor prognosis. Here, we show that miR-99a/100∼125b tricistrons are transcribed as a polycistronic message transactivated by the homeobox transcription factor HOXA10. Integrative analysis of global gene expression profiling, miRNA target prediction, and pathway architecture revealed that miR-99a/100, let-7, and miR-125b functionally converge at the combinatorial block of the transforming growth factor β (TGFβ) pathway by targeting four receptor subunits and two SMAD signaling transducers. In addition, down-regulation of tumor suppressor genes adenomatous polyposis coli (APC)/APC2 stabilizes active β-catenin and enhances Wnt signaling. By switching the balance between Wnt and TGFβ signaling, the concerted action of these tricistronic miRNAs promoted sustained expansion of murine and human HSCs in vitro or in vivo while favoring megakaryocytic differentiation. Hence, our study explains the high phylogenetic conservation of the miR-99a/100∼125b tricistrons controlling stem cell homeostasis, the deregulation of which contributes to the development of AMKL.
Collapse
Affiliation(s)
- Stephan Emmrich
- Pediatric Hematology and Oncology, Hannover Medical School, Hannover 30625, Germany
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
73
|
Satgé D. Are GATA1 mutations occurring at random in Down syndrome transient leukemia? Med Hypotheses 2014; 83:154-9. [PMID: 24880866 DOI: 10.1016/j.mehy.2014.05.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Revised: 04/30/2014] [Accepted: 05/07/2014] [Indexed: 01/23/2023]
Abstract
The somatic mutation theory of cancer proposes that cancer begins with a somatic mutation occurring at random in a single cell that then passes the mutation to its progeny, generating a clone of premalignant cells. This clone leads to a full malignant tumor through additional mutations and selection processes. Strikingly, the best-documented human model of early oncogenesis, i.e., transient myeloproliferative disorder followed by acute megakaryoblastic leukemia (AMKL) in infants with Down syndrome (DS, or trisomy 21), exhibits important discrepancies with the SMT. Somatic mutations in megakaryocytic precursors occur at least 100,000 times more frequently in the GATA1 gene in fetuses with DS compared to the general population. Further, mutations are limited to GATA1 only; the general mutation rate does not significantly differ between individuals with DS and euploid individuals. Importantly, the mutations are also lineage-specific, occurring only in the megakaryocytic lineage, and proliferative anomalies of the megakaryocytic lineage are observed before the occurrence of GATA1 mutations. Thus, GATA1 mutations in fetuses with DS cannot be random events occurring in normal cells. Here, transcription-associated mutagenesis is proposed as the mechanism by which the earliest mutations of AMKL occur in DS. Transcription-associated mutagenesis is observed in non-dividing cells when a gene is over-expressed. The over-expression of GATA1 in the megakaryocytic lineage in DS fetal liver cells is proposed to be the cause of targeted GATA1 somatic mutations. As transcription-associated mutagenesis is a universal process, this mechanism may also apply to early oncogenesis in other situations, including after birth and following exposure to a carcinogenic agent. Thus, this hypothesis represents a new avenue for understanding and exploring oncogenesis in the context of DS and in other disease states.
Collapse
Affiliation(s)
- Daniel Satgé
- Team Biostatistics Epidemiology Public Health, EA 2415, Oncodefi Project, University Institute for Clinical Research, Montpellier, France.
| |
Collapse
|
74
|
Abstract
The fetal/neonatal hematopoietic system must generate enough blood cells to meet the demands of rapid growth. This unique challenge might underlie the high incidence of thrombocytopenia among preterm neonates. In this study, neonatal platelet production and turnover were investigated in newborn mice. Based on a combination of blood volume expansion and increasing platelet counts, the platelet mass increased sevenfold during the first 2 weeks of murine life, a time during which thrombopoiesis shifted from liver to bone marrow. Studies applying in vivo biotinylation and mathematical modeling showed that newborn and adult mice had similar platelet production rates, but neonatal platelets survived 1 day longer in circulation. This prolonged lifespan fully accounted for the rise in platelet counts observed during the second week of murine postnatal life. A study of pro-apoptotic and anti-apoptotic Bcl-2 family proteins showed that neonatal platelets had higher levels of the anti-apoptotic protein Bcl-2 and were more resistant to apoptosis induced by the Bcl-2/Bcl-xL inhibitor ABT-737 than adult platelets. However, genetic ablation or pharmacologic inhibition of Bcl-2 alone did not shorten neonatal platelet survival or reduce platelet counts in newborn mice, indicating the existence of redundant or alternative mechanisms mediating the prolonged lifespan of neonatal platelets.
Collapse
|
75
|
Elagib KE, Rubinstein JD, Delehanty LL, Ngoh VS, Greer PA, Li S, Lee JK, Li Z, Orkin SH, Mihaylov IS, Goldfarb AN. Calpain 2 activation of P-TEFb drives megakaryocyte morphogenesis and is disrupted by leukemogenic GATA1 mutation. Dev Cell 2014; 27:607-20. [PMID: 24369834 DOI: 10.1016/j.devcel.2013.11.013] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Revised: 08/01/2013] [Accepted: 11/18/2013] [Indexed: 12/11/2022]
Abstract
Megakaryocyte morphogenesis employs a "hypertrophy-like" developmental program that is dependent on P-TEFb kinase activation and cytoskeletal remodeling. P-TEFb activation classically occurs by a feedback-regulated process of signal-induced, reversible release of active Cdk9-cyclin T modules from large, inactive 7SK small nuclear ribonucleoprotein particle (snRNP) complexes. Here, we have identified an alternative pathway of irreversible P-TEFb activation in megakaryopoiesis that is mediated by dissolution of the 7SK snRNP complex. In this pathway, calpain 2 cleavage of the core 7SK snRNP component MePCE promoted P-TEFb release and consequent upregulation of a cohort of cytoskeleton remodeling factors, including α-actinin-1. In a subset of human megakaryocytic leukemias, the transcription factor GATA1 undergoes truncating mutation (GATA1s). Here, we linked the GATA1s mutation to defects in megakaryocytic upregulation of calpain 2 and of P-TEFb-dependent cytoskeletal remodeling factors. Restoring calpain 2 expression in GATA1s mutant megakaryocytes rescued normal development, implicating this morphogenetic pathway as a target in human leukemogenesis.
Collapse
Affiliation(s)
- Kamaleldin E Elagib
- Department of Pathology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Jeremy D Rubinstein
- Department of Pathology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Lorrie L Delehanty
- Department of Pathology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Valerie S Ngoh
- Department of Pathology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Peter A Greer
- Department of Pathology and Molecular Medicine, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - Shuran Li
- Department of Public Health Sciences, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Jae K Lee
- Department of Public Health Sciences, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Zhe Li
- Division of Hematology/Oncology, Children's Hospital Boston, Harvard Stem Cell Institute, Harvard Medical School, Boston, MA 02115, USA; Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Stem Cell Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Stuart H Orkin
- Division of Hematology/Oncology, Children's Hospital Boston, Harvard Stem Cell Institute, Harvard Medical School, Boston, MA 02115, USA; Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Stem Cell Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Ivailo S Mihaylov
- Department of Pathology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Adam N Goldfarb
- Department of Pathology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA.
| |
Collapse
|
76
|
Ferrer-Marin F, Gutti R, Liu ZJ, Sola-Visner M. MiR-9 contributes to the developmental differences in CXCR-4 expression in human megakaryocytes. J Thromb Haemost 2014; 12:282-285. [PMID: 24735119 PMCID: PMC3989549 DOI: 10.1111/jth.12469] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Indexed: 01/26/2023]
Affiliation(s)
- Francisca Ferrer-Marin
- Division of Newborn Medicine, Children’s Hospital Boston
- Hematology and Medical Oncology Unit, Hospital Morales-Meseguer, Centro de Hemodonación, Murcia, Spain
| | - Ravi Gutti
- Division of Newborn Medicine, Children’s Hospital Boston
- Department of Biochemistry, University of Hyderabad, Hyderabad, India
| | - Zhi-Jian Liu
- Division of Newborn Medicine, Children’s Hospital Boston
| | | |
Collapse
|
77
|
Zhang Z, Jia H, Zhang Q, Wan Y, Zhou Y, Jia Q, Zhang W, Yuan W, Cheng T, Zhu X, Fang X. Assessment of hematopoietic failure due to Rpl11 deficiency in a zebrafish model of Diamond-Blackfan anemia by deep sequencing. BMC Genomics 2013; 14:896. [PMID: 24341334 PMCID: PMC3890587 DOI: 10.1186/1471-2164-14-896] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Accepted: 12/10/2013] [Indexed: 01/18/2023] Open
Abstract
Background Diamond–Blackfan anemia is a rare congenital red blood cell dysplasia that develops soon after birth. RPL11 mutations account for approximately 4.8% of human DBA cases with defective hematopoietic phenotypes. However, the mechanisms by which RPL11 regulates hematopoiesis in DBA remain elusive. In this study, we analyzed the transcriptome using deep sequencing data from an Rpl11-deficient zebrafish model to identify Rpl11-mediated hematopoietic failure and investigate the underlying mechanisms. Results We characterized hematological defects in Rpl11-deficient zebrafish embryos by identifying affected hematological genes, hematopoiesis-associated pathways, and regulatory networks. We found that hemoglobin biosynthetic and hematological defects in Rpl11-deficient zebrafish were related to dysregulation of iron metabolism-related genes, including tfa, tfr1b, alas2 and slc25a37, which are involved in heme and hemoglobin biosynthesis. In addition, we found reduced expression of the hematopoietic stem cells (HSC) marker cmyb and HSC transcription factors tal1 and hoxb4a in Rpl11-deficient zebrafish embryos, indicating that the hematopoietic defects may be related to impaired HSC formation, differentiation, and proliferation. However, Rpl11 deficiency did not affect the development of other blood cell lineages such as granulocytes and myelocytes. Conclusion We identified hematopoietic failure of Rpl11-deficient zebrafish embryos using transcriptome deep sequencing and elucidated potential underlying mechanisms. The present analyses demonstrate that Rpl11-deficient zebrafish may serve as a model of DBA and may provide insights into the pathogenesis of mutant RPL11-mediated human DBA disease.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | - Xiaofan Zhu
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China.
| | | |
Collapse
|
78
|
Maroz A, Stachorski L, Emmrich S, Reinhardt K, Xu J, Shao Z, Käbler S, Dertmann T, Hitzler J, Roberts I, Vyas P, Juban G, Hennig C, Hansen G, Li Z, Orkin S, Reinhardt D, Klusmann JH. GATA1s induces hyperproliferation of eosinophil precursors in Down syndrome transient leukemia. Leukemia 2013; 28:1259-70. [PMID: 24336126 PMCID: PMC4047213 DOI: 10.1038/leu.2013.373] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 12/01/2013] [Accepted: 12/03/2013] [Indexed: 02/06/2023]
Abstract
Transient leukemia (TL) is evident in 5–10% of all neonates with Down syndrome (DS) and associated with N-terminal truncating GATA1-mutations (GATA1s). Here we report that TL cell clones generate abundant eosinophils in a substantial fraction of patients. Sorted eosinophils from patients with TL and eosinophilia carried the same GATA1s-mutation as sorted TL-blasts, consistent with their clonal origin. TL-blasts exhibited a genetic program characteristic of eosinophils and differentiated along the eosinophil lineage in vitro. Similarly, ectopic expression of Gata1s, but not Gata1, in wild-type CD34+-hematopoietic stem and progenitor cells induced hyperproliferation of eosinophil promyelocytes in vitro. While GATA1s retained the function of GATA1 to induce eosinophil genes by occupying their promoter regions, GATA1s was impaired in its ability to repress oncogenic MYC and the pro-proliferative E2F transcription network. ChIP-seq indicated reduced GATA1s occupancy at the MYC promoter. Knockdown of MYC, or the obligate E2F-cooperation partner DP1, rescued the GATA1s-induced hyperproliferative phenotype. In agreement, terminal eosinophil maturation was blocked in Gata1Δe2 knockin mice, exclusively expressing Gata1s, leading to accumulation of eosinophil precursors in blood and bone marrow. These data suggest a direct relationship between the N-terminal truncating mutations of GATA1 and clonal eosinophilia in DS patients.
Collapse
Affiliation(s)
- A Maroz
- Department of Pediatric Hematology and Oncology, Hannover Medical School, Hannover, Germany
| | - L Stachorski
- Department of Pediatric Hematology and Oncology, Hannover Medical School, Hannover, Germany
| | - S Emmrich
- Department of Pediatric Hematology and Oncology, Hannover Medical School, Hannover, Germany
| | - K Reinhardt
- Department of Pediatric Hematology and Oncology, Hannover Medical School, Hannover, Germany
| | - J Xu
- 1] Division of Hematology/Oncology, Boston Children's Hospital, Boston, MA, USA [2] Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA [3] Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - Z Shao
- 1] Division of Hematology/Oncology, Boston Children's Hospital, Boston, MA, USA [2] Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA [3] Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - S Käbler
- Department of Pediatric Hematology and Oncology, Hannover Medical School, Hannover, Germany
| | - T Dertmann
- Department of Pediatric Hematology and Oncology, Hannover Medical School, Hannover, Germany
| | - J Hitzler
- Division of Hematology/Oncology, Department of Pediatrics, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - I Roberts
- Oxford University Department of Paediatrics, Childrens Hospital and Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, UK
| | - P Vyas
- 1] MRC Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK [2] Department of Haematology, Oxford University Hospital, NHS Trust, Oxford, UK
| | - G Juban
- 1] MRC Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK [2] Department of Haematology, Oxford University Hospital, NHS Trust, Oxford, UK
| | - C Hennig
- Department of Pediatric Pneumology, Hannover Medical School, Hannover, Germany
| | - G Hansen
- Department of Pediatric Pneumology, Hannover Medical School, Hannover, Germany
| | - Z Li
- Division of Genetics, Brigham & Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - S Orkin
- 1] Division of Hematology/Oncology, Boston Children's Hospital, Boston, MA, USA [2] Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA [3] Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - D Reinhardt
- Department of Pediatric Hematology and Oncology, Hannover Medical School, Hannover, Germany
| | - J-H Klusmann
- Department of Pediatric Hematology and Oncology, Hannover Medical School, Hannover, Germany
| |
Collapse
|
79
|
miR-9 is a tumor suppressor in pediatric AML with t(8;21). Leukemia 2013; 28:1022-32. [PMID: 24270738 DOI: 10.1038/leu.2013.357] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 11/13/2013] [Accepted: 11/14/2013] [Indexed: 12/12/2022]
Abstract
MicroRNAs (miRNAs) play a pivotal role in the regulation of hematopoiesis and development of leukemia. Great interest emerged in modulating miRNA expression for therapeutic purposes. In order to identify miRNAs, which specifically suppress leukemic growth of acute myeloid leukemia (AML) with t(8;21), inv(16) or mixed lineage leukemia (MLL) rearrangement by inducing differentiation, we conducted a miRNA expression profiling in a cohort of 90 cytogenetically characterized, de novo pediatric AML cases. Four miRNAs, specifically downregulated in MLL-rearranged, t(8;21) or inv(16) AMLs, were characterized by their tumor-suppressive properties in cell lines representing those respective cytogenetic groups. Among those, forced expression of miR-9 reduced leukemic growth and induced monocytic differentiation of t(8;21) AML cell lines in vitro and in vivo. The tumor-suppressive functions of miR-9 were specifically restricted to AML cell lines and primary leukemic blasts with t(8;21). On the other hand, these functions were not evident in AML blasts from patients with MLL rearrangements. We showed that miR-9 exerts its effects through the cooperation with let-7 to repress the oncogenic LIN28B/HMGA2 axis. Thus, miR-9 is a tumor suppressor-miR which acts in a stringent cell context-dependent manner.
Collapse
|
80
|
Histone deacetylase inhibitors induce apoptosis in myeloid leukemia by suppressing autophagy. Leukemia 2013; 28:577-88. [PMID: 24080946 PMCID: PMC3947652 DOI: 10.1038/leu.2013.264] [Citation(s) in RCA: 102] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Revised: 08/25/2013] [Accepted: 08/28/2013] [Indexed: 12/29/2022]
Abstract
Histone deacetylase (HDAC)-inhibitors (HDACis) are well characterized anti-cancer agents with promising results in clinical trials. However, mechanistically little is known regarding their selectivity in killing malignant cells while sparing normal cells. Gene expression-based chemical genomics identified HDACis as being particularly potent against Down syndrome associated myeloid leukemia (DS-AMKL) blasts. Investigating the anti-leukemic function of HDACis revealed their transcriptional and posttranslational regulation of key autophagic proteins, including ATG7. This leads to suppression of autophagy, a lysosomal degradation process that can protect cells against damaged or unnecessary organelles and protein aggregates. DS-AMKL cells exhibit low baseline autophagy due to mTOR activation. Consequently, HDAC inhibition repressed autophagy below a critical threshold, which resulted in accumulation of mitochondria, production of reactive oxygen species, DNA-damage and apoptosis. Those HDACi-mediated effects could be reverted upon autophagy activation or aggravated upon further pharmacological or genetic inhibition. Our findings were further extended to other major acute myeloid leukemia subgroups with low basal level autophagy. The constitutive suppression of autophagy due to mTOR activation represents an inherent difference between cancer and normal cells. Thus, via autophagy suppression, HDACis deprive cells of an essential pro-survival mechanism, which translates into an attractive strategy to specifically target cancer cells.
Collapse
|
81
|
Ghevaert C. Megakaryopoiesis through the ages: from the twinkle in the eye to the fully grown adult. J Thromb Haemost 2013; 11:1727-9. [PMID: 23848222 DOI: 10.1111/jth.12349] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Indexed: 12/22/2022]
Affiliation(s)
- C Ghevaert
- Department of Haematology, University of Cambridge, Cambridge, UK; NHS Blood and Transplant, Cambridge, UK
| |
Collapse
|
82
|
Roberts I, O'Connor D, Roy A, Cowan G, Vyas P. The impact of trisomy 21 on foetal haematopoiesis. Blood Cells Mol Dis 2013; 51:277-81. [PMID: 23932236 DOI: 10.1016/j.bcmd.2013.07.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Accepted: 07/03/2013] [Indexed: 01/09/2023]
Abstract
The high frequency of a unique neonatal preleukaemic syndrome, transient abnormal myelopoiesis (TAM), and subsequent acute myeloid leukaemia in early childhood in patients with trisomy 21 (Down syndrome) points to a specific role for trisomy 21 in transforming foetal haematopoietic cells. N-terminal truncating mutations in the key haematopoietic transcription factor GATA1 are acquired during foetal life in virtually every case. These mutations are not leukaemogenic in the absence of trisomy 21. In mouse models, deregulated expression of chromosome 21-encoded genes is implicated in leukaemic transformation, but does not recapitulate the effects of trisomy 21 in a human context. Recent work using primary human foetal liver and bone marrow cells, human embryonic stem cells and iPS cells shows that prior to acquisition of GATA1 mutations, trisomy 21 itself alters human foetal haematopoietic stem cell and progenitor cell biology causing multiple abnormalities in myelopoiesis and B-lymphopoiesis. The molecular basis by which trisomy 21 exerts these effects is likely to be extremely complex, to be tissue-specific and lineage-specific and to be dependent on ontogeny-related characteristics of the foetal microenvironment.
Collapse
Affiliation(s)
- Irene Roberts
- Centre for Haematology, Imperial College London, UK.
| | | | | | | | | |
Collapse
|
83
|
Ferrer-Marin F, Stanworth S, Josephson C, Sola-Visner M. Distinct differences in platelet production and function between neonates and adults: implications for platelet transfusion practice. Transfusion 2013; 53:2814-21; quiz 2813. [PMID: 23889476 DOI: 10.1111/trf.12343] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Revised: 05/14/2013] [Accepted: 05/14/2013] [Indexed: 01/19/2023]
Abstract
Thrombocytopenia is a common problem among sick neonates admitted to the neonatal intensive care unit. Among neonates, preterm infants are the subgroup at highest risk for thrombocytopenia and hemorrhage, which is frequently intracranial. Although there is no evidence of a relationship between platelet (PLT) count and occurrence of major hemorrhage, preterm infants are commonly transfused prophylactically when PLT counts fall below an arbitrary limit, and this threshold is usually higher than for older infants or adults. This liberal practice has been influenced by the observation that, in vitro, neonatal PLTs are hyporeactive in response to multiple agonists. However, full-term infants exhibit normal to increased primary hemostasis due to factors in neonatal blood that enhance the PLT-vessel wall interaction. Additionally, cardiorespiratory problems are considered the main etiologic factors in the development of neonatal intraventricular hemorrhage. In this review, we will discuss the developmental differences that exist in regard to PLT production and function, as well as in primary hemostasis in preterm and term neonates, and the implications of these developmental differences to transfusion medicine. PLT transfusions are not exempt of risk, and a better understanding of the PLT function and the hemostatic profile of premature infants and their changes over time and in response to illness is the starting point to design randomized controlled trials to define optimal use of PLT transfusions in premature neonates. Without these future trials, the marked disparities in PLT transfusion practice in neonates between hospitals and countries will remain over time.
Collapse
Affiliation(s)
- Francisca Ferrer-Marin
- Unidad de Hematología y Oncología Médica, Hospital Universitario Morales-Meseguer, Centro de Hemodonacion, Murcia, Spain; Department of Haematology/Transfusion Medicine, NHS Blood & Transplant/Oxford University Hospitals NHS Trust, Oxford, UK; Center for Transfusion and Cellular Therapies, Department of Pathology and Laboratory Medicine, Emory University, Atlanta, Georgia; Division of Newborn Medicine, Children's Hospital Boston, Boston, Massachusetts
| | | | | | | |
Collapse
|
84
|
Woo AJ, Wieland K, Huang H, Akie TE, Piers T, Kim J, Cantor AB. Developmental differences in IFN signaling affect GATA1s-induced megakaryocyte hyperproliferation. J Clin Invest 2013; 123:40609. [PMID: 23863621 PMCID: PMC3726146 DOI: 10.1172/jci40609] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Accepted: 05/02/2013] [Indexed: 01/14/2023] Open
Abstract
About 10% of Down syndrome (DS) infants are born with a transient myeloproliferative disorder (DS-TMD) that spontaneously resolves within the first few months of life. About 20%-30% of these infants subsequently develop acute megakaryoblastic leukemia (DS-AMKL). Somatic mutations leading to the exclusive production of a short GATA1 isoform (GATA1s) occur in all cases of DS-TMD and DS-AMKL. Mice engineered to exclusively produce GATA1s have marked megakaryocytic progenitor (MkP) hyperproliferation during early fetal liver (FL) hematopoiesis, but not during postnatal BM hematopoiesis, mirroring the spontaneous resolution of DS-TMD. The mechanisms that underlie these developmental stage-specific effects are incompletely understood. Here, we report a striking upregulation of type I IFN-responsive gene expression in prospectively isolated mouse BM- versus FL-derived MkPs. Exogenous IFN-α markedly reduced the hyperproliferation FL-derived MkPs of GATA1s mice in vitro. Conversely, deletion of the α/β IFN receptor 1 (Ifnar1) gene or injection of neutralizing IFN-α/β antibodies increased the proliferation of BM-derived MkPs of GATA1s mice beyond the initial postnatal period. We also found that these differences existed in human FL versus BM megakaryocytes and that primary DS-TMD cells expressed type I IFN-responsive genes. We propose that increased type I IFN signaling contributes to the developmental stage-specific effects of GATA1s and possibly the spontaneous resolution of DS-TMD.
Collapse
Affiliation(s)
- Andrew J. Woo
- Division of Pediatric Hematology-Oncology, Boston Children’s Hospital/Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA.
Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas, USA.
Harvard Stem Cell Institute, Cambridge, Massachusetts, USA
| | - Karen Wieland
- Division of Pediatric Hematology-Oncology, Boston Children’s Hospital/Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA.
Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas, USA.
Harvard Stem Cell Institute, Cambridge, Massachusetts, USA
| | - Hui Huang
- Division of Pediatric Hematology-Oncology, Boston Children’s Hospital/Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA.
Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas, USA.
Harvard Stem Cell Institute, Cambridge, Massachusetts, USA
| | - Thomas E. Akie
- Division of Pediatric Hematology-Oncology, Boston Children’s Hospital/Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA.
Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas, USA.
Harvard Stem Cell Institute, Cambridge, Massachusetts, USA
| | - Taylor Piers
- Division of Pediatric Hematology-Oncology, Boston Children’s Hospital/Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA.
Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas, USA.
Harvard Stem Cell Institute, Cambridge, Massachusetts, USA
| | - Jonghwan Kim
- Division of Pediatric Hematology-Oncology, Boston Children’s Hospital/Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA.
Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas, USA.
Harvard Stem Cell Institute, Cambridge, Massachusetts, USA
| | - Alan B. Cantor
- Division of Pediatric Hematology-Oncology, Boston Children’s Hospital/Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA.
Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas, USA.
Harvard Stem Cell Institute, Cambridge, Massachusetts, USA
| |
Collapse
|
85
|
Exome sequencing identifies putative drivers of progression of transient myeloproliferative disorder to AMKL in infants with Down syndrome. Blood 2013; 122:554-61. [PMID: 23733339 DOI: 10.1182/blood-2013-03-491936] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Some neonates with Down syndrome (DS) are diagnosed with self-regressing transient myeloproliferative disorder (TMD), and 20% to 30% of those progress to acute megakaryoblastic leukemia (AMKL). We performed exome sequencing in 7 TMD/AMKL cases and copy-number analysis in these and 10 additional cases. All TMD/AMKL samples contained GATA1 mutations. No exome-sequenced TMD/AMKL sample had other recurrently mutated genes. However, 2 of 5 TMD cases, and all AMKL cases, showed mutations/deletions other than GATA1, in genes proven as transformation drivers in non-DS leukemia (EZH2, APC, FLT3, JAK1, PARK2-PACRG, EXT1, DLEC1, and SMC3). One patient at the TMD stage revealed 2 clonal expansions with different GATA1 mutations, of which 1 clone had an additional driver mutation. Interestingly, it was the other clone that gave rise to AMKL after accumulating mutations in 7 other genes. Data suggest that GATA1 mutations alone are sufficient for clonal expansions, and additional driver mutations at the TMD stage do not necessarily predict AMKL progression. Later in infancy, leukemic progression requires "third-hit driver" mutations/somatic copy-number alterations found in non-DS leukemias. Putative driver mutations affecting WNT (wingless-related integration site), JAK-STAT (Janus kinase/signal transducer and activator of transcription), or MAPK/PI3K (mitogen-activated kinase/phosphatidylinositol-3 kinase) pathways were found in all cases, aberrant activation of which converges on overexpression of MYC.
Collapse
|
86
|
Perturbation of fetal hematopoiesis in a mouse model of Down syndrome's transient myeloproliferative disorder. Blood 2013; 122:988-98. [PMID: 23719302 DOI: 10.1182/blood-2012-10-460998] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Children with Down syndrome develop a unique congenital clonal megakaryocytic proliferation disorder (transient myeloproliferative disorder [TMD]). It is caused by an expansion of fetal megakaryocyte-erythroid progenitors (MEPs) triggered by trisomy of chromosome 21 and is further enhanced by the somatic acquisition of a mutation in GATA1. These mutations result in the expression of a short-isoform GATA1s lacking the N-terminal domain. To examine the hypothesis that the Hsa21 ETS transcription factor ERG cooperates with GATA1s in this process, we generated double-transgenic mice expressing hERG and Gata1s. We show that increased expression of ERG by itself is sufficient to induce expansion of MEPs in fetal livers. Gata1s expression synergizes with ERG in enhancing the expansion of fetal MEPs and megakaryocytic precursors, resulting in hepatic fibrosis, transient postnatal thrombocytosis, anemia, a gene expression profile that is similar to that of human TMD and progression to progenitor myeloid leukemia by 3 months of age. This ERG/Gata1s transgenic mouse model also uncovers an essential role for the N terminus of Gata1 in erythropoiesis and the antagonistic role of ERG in fetal erythroid differentiation and survival. The human relevance of this finding is underscored by the recent discovery of similar mutations in GATA1 in patients with Diamond-Blackfan anemia.
Collapse
|
87
|
Piovesan A, Vitale L, Pelleri MC, Strippoli P. Universal tight correlation of codon bias and pool of RNA codons (codonome): The genome is optimized to allow any distribution of gene expression values in the transcriptome from bacteria to humans. Genomics 2013; 101:282-9. [PMID: 23466472 DOI: 10.1016/j.ygeno.2013.02.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Revised: 02/18/2013] [Accepted: 02/21/2013] [Indexed: 10/27/2022]
Abstract
Codon bias is the phenomenon in which distinct synonymous codons are used with different frequencies. We define here the "codonome value" as the total number of codons present across all the expressed mRNAs in a given biological condition. We have developed the "CODONOME" software, which calculates the codon bias and, following integration with a gene expression profile, estimates the actual frequency of each codon at the transcriptome level (codonome bias) of a given tissue. Systematic analysis across different human tissues and multiple species shows a surprisingly tight correlation between the codon bias and the codonome bias. An aneuploidy and cancer condition such as that of Down Syndrome-related acute megakaryoblastic leukemia (DS-AMKL), does not appear to alter this relationship. The law of correlation between codon bias and codonome emerges as a property of the distribution and range of the number, sequence and expression level of the genes in a genome.
Collapse
Affiliation(s)
- Allison Piovesan
- Department of Experimental, Diagnostic and Specialty Medicine, Activity of Histology, Embryology and Applied Biology, University of Bologna, via Belmeloro 8, 40126 Bologna (BO), Italy.
| | | | | | | |
Collapse
|
88
|
Naturally occurring oncogenic GATA1 mutants with internal deletions in transient abnormal myelopoiesis in Down syndrome. Blood 2013; 121:3181-4. [PMID: 23440243 DOI: 10.1182/blood-2012-01-405746] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Children with Down syndrome have an increased incidence of transient abnormal myelopoiesis (TAM) and acute megakaryoblastic leukemia. The majority of these cases harbor somatic mutations in the GATA1 gene, which results in the loss of full-length GATA1. Only a truncated isoform of GATA1 that lacks the N-terminal 83 amino acids (GATA1-S) remains. We found through genetic studies of 106 patients with TAM that internally deleted GATA1 proteins (GATA1-IDs) lacking amino acid residues 77-119 or 74-88 (created by splicing mutations) contributed to the genesis of TAM in 6 patients. Analyses of GATA1-deficient embryonic megakaryocytic progenitors revealed that the GATA1 function in growth restriction was disrupted in GATA1-IDs. In contrast, GATA1-S promoted megakaryocyte proliferation more profoundly than that induced by GATA1 deficiency. These results indicate that the internally deleted regions play important roles in megakaryocyte proliferation and that perturbation of this mechanism is involved in the pathogenesis of TAM.
Collapse
|
89
|
Abstract
The requirement that leukemic GATA1 mutations be present in cells harboring trisomy 21 led to the discovery that overexpression of ERG drives aberrant megakaryopoiesis. Given that constitutive PI3K/AKT signaling is a frequent component of hematologic malignancies and the relationship between AKT and Notch in this lineage, we studied the cross talk between AKT signaling and ERG in megakaryopoiesis. We discovered that constitutive AKT signaling is associated with a dramatic increase in apoptosis of WT MKs, but that overexpression of ERG blocks AKT-induced death. We further found that Gata1 mutations protect megakaryocytes from activated AKT-induced apoptosis. As a consequence, however, the enhanced signaling inhibits differentiation of Gata1 mutant, but not WT, megakaryocytes. Gata1 mutant cells that overexpress ERG with hyperactive AKT are characterized by diminished FOXO1/3a expression and an increased dependency on the c-Jun pathway similar to that seen in AMKL cell lines, AML with knockdown of FOXO3a, or AML with expression of myrAKT. Additionally, we found that the AKT allosteric inhibitor MK2206 caused reduced cell viability and proliferation of AMKL cell lines. The contribution of aberrant AKT signaling during the ontogeny of DS-TMD/AMKL indicates that AKT is a therapeutic target in this form of AML.
Collapse
|
90
|
Platelets in the neonatal period: developmental differences in platelet production, function, and hemostasis and the potential impact of therapies. Hematology 2012. [DOI: 10.1182/asheducation.v2012.1.506.3798532] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
Thrombocytopenia is a common problem among sick neonates admitted to the neonatal intensive care unit. Frequently, platelet transfusions are given to thrombocytopenic infants in an attempt to decrease the incidence or severity of hemorrhage, which is often intracranial. Whereas there is very limited evidence to guide platelet transfusion practices in this population, preterm infants in the first week of life (the highest risk period for bleeding) are nearly universally transfused at higher platelet counts than older infants or children. To a large extent, this practice has been influenced by the observation that neonatal platelets are hyporeactive in response to multiple agonists in vitro, although full-term infants exhibit normal to increased primary hemostasis. This apparently paradoxical finding is due to factors in the neonatal blood that enhance the platelet-vessel wall interaction and counteract the platelet hyporeactivity. Relatively few studies have evaluated the platelet function and primary hemostasis of preterm infants, the subset of neonates at highest risk of bleeding and those most frequently transfused. Current understanding of platelet production and function in preterm and full-term neonates, how these factors affect their response to thrombocytopenia and their primary hemostasis, and the implications of these developmental differences to transfusion medicine are reviewed herein.
Collapse
|
91
|
Goupille O, Penglong T, Lefèvre C, Granger M, Kadri Z, Fucharoen S, Maouche-Chrétien L, Leboulch P, Chrétien S. BET bromodomain inhibition rescues erythropoietin differentiation of human erythroleukemia cell line UT7. Biochem Biophys Res Commun 2012; 429:1-5. [PMID: 23137537 DOI: 10.1016/j.bbrc.2012.10.112] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Accepted: 10/26/2012] [Indexed: 01/08/2023]
Abstract
Malignant transformation is a multistep process requiring oncogenic activation, promoting cellular proliferation, frequently coupled to inhibition of terminal differentiation. Consequently, forcing the reengagement of terminal differentiation of transformed cells coupled or not with an inhibition of their proliferation is a putative therapeutic approach to counteracting tumorigenicity. UT7 is a human leukemic cell line able to grow in the presence of IL3, GM-CSF and Epo. This cell line has been widely used to study Epo-R/Epo signaling pathways but is a poor model for erythroid differentiation. We used the BET bromodomain inhibition drug JQ1 to target gene expression, including that of c-Myc. We have shown that only 2 days of JQ1 treatment was required to transitory inhibit Epo-induced UT7 proliferation and to restore terminal erythroid differentiation. This study highlights the importance of a cellular erythroid cycle break mediated by c-Myc inhibition before initiation of the erythropoiesis program and describes a new model for BET bromodomain inhibitor drug application.
Collapse
Affiliation(s)
- Olivier Goupille
- CEA, Institute of Emerging Diseases and Innovative Therapies, Fontenay-aux-Roses, France
| | | | | | | | | | | | | | | | | |
Collapse
|
92
|
Shimizu R, Yamamoto M. Contribution of GATA1 dysfunction to multi-step leukemogenesis. Cancer Sci 2012; 103:2039-44. [PMID: 22937757 DOI: 10.1111/cas.12007] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Revised: 08/19/2012] [Accepted: 08/23/2012] [Indexed: 01/01/2023] Open
Abstract
In mammals, hematopoietic homeostasis is maintained by a fine-tuned balance among the self-renewal, proliferation, differentiation and survival of hematopoietic stem cells and their progenies. Each process is also supported by the delicate balance of the expression of multiple genes specific to each process. GATA1 is a transcription factor that comprehensively regulates the genes that are important for the development of erythroid and megakaryocytic cells. Accumulating evidence supports the notion that defects in GATA1 function are intimately linked to hematopoietic disorders. In particular, the somatic mutation of the GATA1 gene, which leads to the production of N-terminally truncated GATA1, contributes to the genesis of transient myeloproliferative disorder and acute megakaryoblastic leukemia in infants with Down syndrome. Similarly, a mutation in the GATA1 regulatory region that reduces GATA1 expression is involved in the onset of erythroid leukemia in mice. In both cases, the accumulation of immature progenitor cells caused by GATA1 dysregulation underlies the pathogenesis of the leukemia. This review provides a summary of multi-step leukemogenesis with a focus on GATA1 dysfunction.
Collapse
Affiliation(s)
- Ritsuko Shimizu
- Department of Molecular Hematology, Tohoku University Graduate School of Medicine, Sendai, Japan
| | | |
Collapse
|
93
|
Altered hematopoiesis in trisomy 21 as revealed through in vitro differentiation of isogenic human pluripotent cells. Proc Natl Acad Sci U S A 2012; 109:17567-72. [PMID: 23045682 DOI: 10.1073/pnas.1215468109] [Citation(s) in RCA: 115] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Trisomy 21 is associated with hematopoietic abnormalities in the fetal liver, a preleukemic condition termed transient myeloproliferative disorder, and increased incidence of acute megakaryoblastic leukemia. Human trisomy 21 pluripotent cells of various origins, human embryonic stem (hES), and induced pluripotent stem (iPS) cells, were differentiated in vitro as a model to recapitulate the effects of trisomy on hematopoiesis. To mitigate clonal variation, we isolated disomic and trisomic subclones from the same parental iPS line, thereby generating subclones isogenic except for chromosome 21. Under differentiation conditions favoring development of fetal liver-like, γ-globin expressing, definitive hematopoiesis, we found that trisomic cells of hES, iPS, or isogenic origins exhibited a two- to fivefold increase in a population of CD43(+)(Leukosialin)/CD235(+)(Glycophorin A) hematopoietic cells, accompanied by increased multilineage colony-forming potential in colony-forming assays. These findings establish an intrinsic disturbance of multilineage myeloid hematopoiesis in trisomy 21 at the fetal liver stage.
Collapse
|
94
|
Perturbation of fetal liver hematopoietic stem and progenitor cell development by trisomy 21. Proc Natl Acad Sci U S A 2012; 109:17579-84. [PMID: 23045701 DOI: 10.1073/pnas.1211405109] [Citation(s) in RCA: 115] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The 40-fold increase in childhood megakaryocyte-erythroid and B-cell leukemia in Down syndrome implicates trisomy 21 (T21) in perturbing fetal hematopoiesis. Here, we show that compared with primary disomic controls, primary T21 fetal liver (FL) hematopoietic stem cells (HSC) and megakaryocyte-erythroid progenitors are markedly increased, whereas granulocyte-macrophage progenitors are reduced. Commensurately, HSC and megakaryocyte-erythroid progenitors show higher clonogenicity, with increased megakaryocyte, megakaryocyte-erythroid, and replatable blast colonies. Biased megakaryocyte-erythroid-primed gene expression was detected as early as the HSC compartment. In lymphopoiesis, T21 FL lymphoid-primed multipotential progenitors and early lymphoid progenitor numbers are maintained, but there was a 10-fold reduction in committed PreproB-lymphoid progenitors and the functional B-cell potential of HSC and early lymphoid progenitor is severely impaired, in tandem with reduced early lymphoid gene expression. The same pattern was seen in all T21 FL samples and no samples had GATA1 mutations. Therefore, T21 itself causes multiple distinct defects in FL myelo- and lymphopoiesis.
Collapse
|
95
|
Trisomy 21-associated defects in human primitive hematopoiesis revealed through induced pluripotent stem cells. Proc Natl Acad Sci U S A 2012; 109:17573-8. [PMID: 23045704 DOI: 10.1073/pnas.1211175109] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Patients with Down syndrome (trisomy 21, T21) have hematologic abnormalities throughout life. Newborns frequently exhibit abnormal blood counts and a clonal preleukemia. Human T21 fetal livers contain expanded erythro-megakaryocytic precursors with enhanced proliferative capacity. The impact of T21 on the earliest stages of embryonic hematopoiesis is unknown and nearly impossible to examine in human subjects. We modeled T21 yolk sac hematopoiesis using human induced pluripotent stem cells (iPSCs). Blood progenitor populations generated from T21 iPSCs were present at normal frequency and proliferated normally. However, their developmental potential was altered with enhanced erythropoiesis and reduced myelopoiesis, but normal megakaryocyte production. These abnormalities overlap with those of T21 fetal livers, but also reflect important differences. Our studies show that T21 confers distinct developmental stage- and species-specific hematopoietic defects. More generally, we illustrate how iPSCs can provide insight into early stages of normal and pathological human development.
Collapse
|
96
|
Abstract
If assessed by a number of criteria for cancer predisposition, Down's syndrome (DS) should be an overwhelmingly cancer-prone condition. Although childhood leukaemias occur more frequently in DS, paradoxically, individuals with DS have a markedly lower incidence of most solid tumours. Understanding the mechanisms that are capable of overcoming such odds could potentially open new routes for cancer prevention and therapy. In this Opinion article, we discuss recent reports that suggest unique and only partially understood mechanisms behind this paradox, including tumour repression, anti-angiogenic effects and stem cell ageing and availability.
Collapse
Affiliation(s)
- Dean Nižetić
- The Barts and The London School of Medicine and Dentistry, The Blizard Institute, Centre for Paediatrics, and Stem Cell Laboratory, National Centre for Bowel Research and Surgical Innovation, Queen Mary University of London, UK.
| | | |
Collapse
|
97
|
Groß B, Pittermann E, Reinhardt D, Cantz T, Klusmann JH. Prospects and challenges of reprogrammed cells in hematology and oncology. Pediatr Hematol Oncol 2012; 29:507-28. [PMID: 22857266 DOI: 10.3109/08880018.2012.708707] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Induced pluripotent stem cells (iPSCs) have emerged as a promising basis for modeling pediatric genetic disorders, allowing the derivation, study, and genetic correction of disease and patient-specific cell lines in vitro. Similar to embryonic stem cells (ESCs), iPSCs are capable of unlimited in vitro expansion and derivation of many cell types, including hematopoietic stem cells (HSCs). These may not only allow large scale screenings to develop therapeutic compounds, but also help to overcome cross-species barriers of genetically engineered animal models, which do not adequately recapitulate the associated human phenotype. Here, we review the current state and emerging developments of iPSC research, which can be exploited as a tool in modeling pediatric hematopoietic disorders and could lead to new clinical applications in gene and cell therapies.
Collapse
Affiliation(s)
- Benjamin Groß
- Department of Pediatric Hematology and Oncology, Hannover Medical School, Hannover, Germany
| | | | | | | | | |
Collapse
|
98
|
Seewald L, Taub JW, Maloney KW, McCabe ERB. Acute leukemias in children with Down syndrome. Mol Genet Metab 2012; 107:25-30. [PMID: 22867885 DOI: 10.1016/j.ymgme.2012.07.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Revised: 07/12/2012] [Accepted: 07/12/2012] [Indexed: 12/21/2022]
Abstract
Children with Down syndrome (DS) often present with hematopoietic abnormalities, and are at increased risk of developing leukemia. Specifically, 3-10% of newborns with DS are diagnosed with transient myeloproliferative disease, and children with DS are 500 times more likely to develop acute megakaryoblastic leukemia (AMKL) and 20 times more likely to develop acute lymphoblastic leukemia (ALL) than typical children. This review examines the characteristics of these leukemias and their development in the unique genetic background of trisomy 21. A discussion is also provided for areas of future research and potential therapeutic development.
Collapse
Affiliation(s)
- Laura Seewald
- Linda Crnic Institute for Down Syndrome, University of Colorado School of Medicine, Aurora, CO, USA.
| | | | | | | |
Collapse
|
99
|
Diagnosis and management of acute myeloid leukemia in children and adolescents: recommendations from an international expert panel. Blood 2012; 120:3187-205. [PMID: 22879540 DOI: 10.1182/blood-2012-03-362608] [Citation(s) in RCA: 363] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Despite major improvements in outcome over the past decades, acute myeloid leukemia (AML) remains a life-threatening malignancy in children, with current survival rates of ∼70%. State-of-the-art recommendations in adult AML have recently been published in this journal by Döhner et al. The primary goal of an international expert panel of the International BFM Study Group AML Committee was to set standards for the management, diagnosis, response assessment, and treatment in childhood AML. This paper aims to discuss differences between childhood and adult AML, and to highlight recommendations that are specific to children. The particular relevance of new diagnostic and prognostic molecular markers in pediatric AML is presented. The general management of pediatric AML, the management of specific pediatric AML cohorts (such as infants) or subtypes of the disease occurring in children (such as Down syndrome related AML), as well as new therapeutic approaches, and the role of supportive care are discussed.
Collapse
|
100
|
Roy A, Roberts I, Vyas P. Biology and management of transient abnormal myelopoiesis (TAM) in children with Down syndrome. Semin Fetal Neonatal Med 2012; 17:196-201. [PMID: 22421527 DOI: 10.1016/j.siny.2012.02.010] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Children with Down syndrome (DS) have an increased risk of Acute Myeloid Leukaemia (ML-DS), particularly megakaryoblastic leukaemia, which is clonally -related to the neonatal myeloproliferative syndrome, Transient Abnormal Myelopoiesis (TAM) unique to infants with DS. Molecular, biological, and clinical data indicate that TAM is initiated before birth when fetal liver haematopoietic cells trisomic for chromosome 21 acquire mutations in GATA1. TAM usually resolves spontaneously by 6 months; however 20-30% subsequently develop ML-DS harbouring the same GATA1 mutation(s). This review focuses on recent studies describing haematological, clinical and biological features of TAM and discusses approaches to diagnose, treat and monitor minimal residual disease in TAM. An important unanswered question is whether ML-DS is always preceded by TAM as it may be clinically and possibly haematologically 'silent'. We have briefly discussed the role of population-based screening for TAM and development of treatment strategies to eliminate the preleukaemic TAM clone, thereby preventing ML-DS.
Collapse
Affiliation(s)
- Anindita Roy
- Centre for Haematology, Imperial College London, United Kingdom
| | - Irene Roberts
- Centre for Haematology, Imperial College London, United Kingdom.
| | - Paresh Vyas
- MRC Molecular Haematology Unit and Department of Haematology, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Oxford, United Kingdom.
| |
Collapse
|