Advances in Malignant Hematology E-Book

• Herausgeber: John Wiley & Sons
• Kategorie: Fachliteratur
• Sprache: Englisch

Seitenzahl: 1117

Veröffentlichungsjahr: 2011

Beschreibung

This comprehensive book captures and compiles new and current information on hematologic malignancies. New knowledge of cellular disease processes, molecular pathology, and cytogenetic, epigenetic and genomic changes has influenced the current outlook toward haematological malignancies. This recent and ongoing expansion of knowledge on malignant hematology has not previously been utilized to its full capacity due to its diffuse distribution scattered over the internet and research publications. This book is written by experts from the American and European continent, sharing their current thoughts and knowledge on the pathobiology of malignant haematological diseases of the blood, as well as current treatment strategies and future developments in the area of these haematological diseases.

Leseprobe

Contents

Cover

Title Page

Copyright

List of Contributors

Acknowledgemen

Preface

Abbreviations

Part 1: Hematopoiesis

Chapter 1: Normal and Malignant Hematopoiesis

Introduction

Isolation of Hematopoietic Progenitors

Cytokine Regulation

Transcriptional Regulation

MicroRNA regulation

Hematopoietic Microenvironment

Hematopoietic Developmental Pathways

Common Lymphoid Progenitors (CLP)

Common Myeloid Progenitors (CMP)

Megakaryocytopoiesis and Erythropoiesis

Granulocytopoiesis

Eosinophil Formation

Basophil and Mast Cell Formation

Monocyte/Macrophage Development

Dendritic Cell Formation

B-Cell Lymphopoiesis

T-Cell Lymphopoiesis

Natural Killer (NK) Cell Development

Leukemia Stem Cells

Summary

References

Chapter 2: The Leukemia Genome

Introduction

The Leukemic Cell

Chromosomal Rearrangements

Copy Number Changes

DNA Methylation, Histone Modification, and Non-Coding RNAs

Dissecting The Leukemia Genome With Second Generation Sequencing Technologies

Conclusions and Future Directions

References

Part 2: Myeloid Malignancies

Chapter 3: Myeloproliferative Neoplasms

Background on the Myeloproliferative Neoplasms

Current therapy of MPNs: an Overview of Currently Available Therapies

Conclusions

References

Chapter 4: Molecular Pathogenesis of BCR-ABL in Chronic Myeloid Leukemia

Introduction

BCR-ABL As an Oncogene in CML

BCR-ABL in The Treatment of CML

Genomic Instability and BCR-ABL

Transformation to Blast-Stage Crisis

CML Stem Cells

Summary

References

Chapter 5: Standard Management of Patients with Chronic Myeloid Leukemia

Introduction

Treatment with Imatinib

Optimizing Responses Through Careful Monitoring

Resistence to Imatinib

Imatinib dose Escalation

Second-Generation TKIs

Other Drugs

Vaccines

Combination Therapy

Novel Approaches to Prevent Resistance

Allogenic Stem Cell Transplantation

Decision Making

Conclusions

References

Chapter 6: The Molecular Biology of Acute Myeloid Leukemia

Introduction

Recurrent Translocations and Mutations

“Activating” Mutations of Kinase-Mediated Signaling Networks

Other Frequent Mutations in AML

“-Omics” Analyses in AML

Patterns of Mutations and Cytogenetic Lesions

Can AML Biology Dictate Therapy?

Conclusion

References

Chapter 7: Acute Myeloid Leukemia

Introduction

Treatment of Acute Myeloid Leukemia

Post-Remission Therapy

Induction Therapy in Patients with Relapsed or Refractory AML

Supportive Care During the Treatment of AML

Routine follow-up of patients in CR

References

Chapter 8: Acute Promyelocytic Leukemia

Introduction

Clinical and Biological Characteristics of APL

First-Line Treatment of APL

Molecular and Cytogenetic Evaluation

Treatment of Relapsing APL

Treatment in Elderly Patients and in Children

Conclusion

References

Chapter 9: A Pluralistic Approach to the Study of Myelodysplastic Syndromes: Evolving Pathology of the Seed via the Soil

Introduction

Excessive Proliferation-Apoptosis Mediated Through Cytokines

Ribosomal Biogenesis is Deregulated in the Seed of MDS

Is there a Molecular Connection Between the Biologic Characteristics of Excessive Proliferation, Premature Excessive Apoptosis, and Defective Ribogenesis in the Hematopoietic Cells of MDS Patients?

Are Abnormalities of the Seed Sufficient to Explain the Entire Syndrome of Myelodysplasia?

Mouse Models of MDS

Targeting the Seed of MDS by Single Gene Disruption

Miscellaneous

Large-Scale Chromosome Engineering

Targeting the Soil can Generate a MDS-Like Phenotype

Are Mouse Models Sufficiently Faithful to the Human Disease?

A New Paradigm for MDS: Seed via Soil

References

Chapter 10: Myelodysplastic Syndrome: A Review of Current Care

Introduction

Epidemiology/Etiology

Pathophysiology

Classification

Clinical Assessment and Prognosis

Management

Conclusion

References

Chapter 11: Supportive Care in Myelodysplastic Syndrome

Supportive care in MDS

Anemia in MDS and Role of Supportive Care In Management

Iron Overload in MDS and its Management

Oral Iron Chelating Agents and Iron Overload in MDS

Myeloid Growth Factors (G-CSF and GM-CSF): their support for MDS

Thrombocytopenia and its Management in MDS

Therapeutic agents in MDS and Supportive Care

Hypomethylating Agents and Their Supportive role in MDS

Summary

References

Part 3: Lymphoid Malignancies

Chapter 12: Molecular Biology of Chronic Lymphoproliferative Disorders

Chronic Lymphocytic Leukemia

Hairy Cell Leukemia

Large Granular Lymphocytic Leukemia

Conclusions

References

Chapter 13: Chronic Lymphocytic Leukemia

Introduction

Diagnosis

Etiology, Epidemiology and Pathobiology

Clinical and Laboratory Features

Prognostic Indicators

Differential Diagnosis

Management of CLL

Complications of CLL and its Treatment

References

Chapter 14: Acute Lymphoblastic Leukemia

Epidemiology and Etiology

Clinical Presentation and Laboratory Abnormalities

The Therapy of ALL

Disease Subtypes

Summary

References

Chapter 15: Large Granular Lymphocyte Leukemia

Introduction

Normal LGL Development and Maturation

Etiology and Pathogenesis

Clinical Manifestations

Diagnosis

Differential Diagnosis

Therapeutic Algorithm

Conclusions

References

Chapter 16: Hairy Cell Leukemia

Introduction and History

Epidemiology

Etiology/Pathogenesis

Clinical Features

Laboratory Features

Differential Diagnosis (See Table 16.1)

Treatment

Summary and Recommendations

Acknowledgement

References

Chapter 17: Molecular Basis of B-cell Lymphomas

Introduction

Precursor B-cell Development

Pre-Germinal Center Differentiation and Proliferation

Germinal Center Differentiation and Proliferation

Post-Germinal Center Differentiation and Proliferation

Conclusions

References

Chapter 18: Non-Hodgkin Lymphomas

Epidemiology and Incidence

Etiological Clues

Cytogenetics and Molecular Genetics

Classification and Diagnosis of non-Hodgkin lymphoma

Presentation and Natural History of NHL

Treatment – an Overview

Management of non-Hodgkin Lymphoma Subtypes

Late Effects of Treatment

References

Chapter 19: Hodgkin Lymphoma

Epidemiology

Treatment of Limited Stage Hodgkin Lymphoma

Therapy of Advanced-Stage Hodgkin Lymphoma

Hodgkin Lymphoma in Persons with Human Immunodeficiency Virus (HIV) Infection

Positron Emission Tomography (FDG-PET) in Staging, Response Assessment and Prognosis

Refractory and Recurrent Disease: Salvage Therapy

High-Dose Chemotherapy and Autologous Stem Cell Transplantation

Investigational Agents in Relapsed HL Post-Autologous SCT

Reduced Intensity Allogeneic SCT for HL Relapsing After Autologous SCT

References

Part 4: Plasma Cell Disorders

Chapter 20: Multiple Myeloma: Molecular Biology, Diagnosis and Treatment

Background

Etiology and Risk Factors

Pathophysiology

Diagnosis and Differential Diagnosis

Staging and Prognosis

Approach to Treatment of Newly Diagnosed Myeloma

Approach to Therapy in Transplant Eligible Patients

Autologous Stem Cell Transplantation in Myeloma

Tandem autologous stem cell transplantation

Post-Transplant Therapy

Allogeneic stem cell transplantation in myeloma

Approach to therapy in non-transplant eligible Patients

Management of relapsed MM

Supportive Care

References

Chapter 21: Waldenströ m's Macroglobulinemia

Introduction

Diagnosis

Epidemiology

Pathogenesis

Clinical Features

Laboratory Findings

Differential Diagnosis

Treatment

Course and Prognosis

Acknowledgment

References

Chapter 22: Primary Systemic Amyloidosis (AL)

Introduction

Pathophysiology

Clinical Presentation

Laboratory and Imaging Features

Diagnosis

Cytogenetics/Chromosomal Abnormalities

Differential Diagnosis

Treatment

Course and Prognosis

References

Part 5: Bone Marrow Transplantation and Quality of Life

Chapter 23: Advances in Allogeneic Hematopoietic Cell Transplantation: Progress in Transplantation Technology and Disease-Specific Outcomes

Introduction

Advances in Transplantation Technology

Disease-Specific Regimens with Reduced Toxicity

References

Chapter 24: Quality of Life after the Diagnosis of Hematological Malignancies

Introduction

Impact of Conventional Treatments of HM on QOL Aspects

QOL After HCT for Patients with HM

Comparison Studies

Summary, Remaining Problems, and Potential Interventions

References

Colour Plates

Index

This edition first published 2011, © 2011 by Blackwell Publishing Ltd

Blackwell Publishing was acquired by John Wiley & Sons in February 2007. Blackwell's publishing program has been merged with Wiley's global Scientific, Technical and Medical business to form Wiley-Blackwell.

Registered office: John Wiley & Sons Ltd, The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, UK

Editorial offices: 9600 Garsington Road, Oxford, OX4 2DQ, UK

The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, UK

111 River Street, Hoboken, NJ 07030-5774, USA

For details of our global editorial offices, for customer services and for information about how to apply for permission to reuse the copyright material in this book please see our website at www.wiley.com/wiley-blackwell

The right of the author to be identified as the author of this work has been asserted in accordance with the Copyright, Designs and Patents Act 1988.

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, except as permitted by the UK Copyright, Designs and Patents Act 1988, without the prior permission of the publisher.

Designations used by companies to distinguish their products are often claimed as trademarks. All brand names and product names used in this book are trade names, service marks, trademarks or registered trademarks of their respective owners. The publisher is not associated with any product or vendor mentioned in this book. This publication is designed to provide accurate and authoritative information in regard to the subject matter covered. It is sold on the understanding that the publisher is not engaged in rendering professional services. If professional advice or other expert assistance is required, the services of a competent professional should be sought.

The contents of this work are intended to further general scientific research, understanding, and discussion only and are not intended and should not be relied upon as recommending or promoting a specific method, diagnosis, or treatment by physicians for any particular patient. The publisher and the author make no representations or warranties with respect to the accuracy or completeness of the contents of this work and specifically disclaim all warranties, including without limitation any implied warranties of fitness for a particular purpose. In view of ongoing research, equipment modifications, changes in governmental regulations, and the constant flow of information relating to the use of medicines, equipment, and devices, the reader is urged to review and evaluate the information provided in the package insert or instructions for each medicine, equipment, or device for, among other things, any changes in the instructions or indication of usage and for added warnings and precautions. Readers should consult with a specialist where appropriate. The fact that an organization or Website is referred to in this work as a citation and/or a potential source of further information does not mean that the author or the publisher endorses the information the organization or Website may provide or recommendations it may make. Further, readers should be aware that Internet Websites listed in this work may have changed or disappeared between when this work was written and when it is read. No warranty may be created or extended by any promotional statements for this work. Neither the publisher nor the author shall be liable for any damages arising herefrom.

Library of Congress Cataloging-in-Publication Data

Advances in malignant hematology / edited by Hussain I. Saba, Ghulam Mufti.

p.; cm.

Includes bibliographical references and index.

ISBN 978-1-4051-9626-0 (hardcover : alk. paper) – ISBN 978-1-4443-9399-6 (ePDF) – ISBN 978-1-4443-9400-9 (ePub)

1. Leukemia. 2. Lymphomas. 3. Myelodysplastic syndromes. I. Saba, Hussain I. II. Mufti, G. J. [DNLM: 1. Leukemia, Myeloid–metabolism. 2. Leukemia, Lymphoid. 3. Leukemia, Myeloid–therapy. 4. Myelodysplastic Syndromes–therapy. WH 250]

RC643.A35 2011

616.99'446–dc22

2010047405

A catalogue record for this book is available from the British Library.

This book is published in the following electronic formats: ePDF 9781444393996; Wiley Online

Library 9781444394016; ePub 9781444394009

List of Contributors

Lionel Ades

Service d'hématologie clinique, Hôpital Avicenne (Assistance Publique –Hôpitaux de Paris) and Paris 13 University, Bobigny, France

Jessica K. Altman

Northwestern University Feinberg School of Medicine, and Robert H. Lurie Comprehensive Cancer Center, Chicago, Illinois, USA

Claudio Anasetti

Department of Blood and Marrow Transplantation, H. Lee Moffitt Cancer Center, University of South Florida, Tampa, Florida, USA

Jessica Clima

St. Vincent's Comprehensive Cancer Center, New York, New York, USA

Jorge Cortes

Department of Leukemia, University of Texas M.D. Anderson Cancer Center, Houston, Texas, USA

Nicholas C.P. Cross

Wessex Regional Genetics Laboratory, Salisbury and Human Genetics Division, University of Southampton, Southampton, UK

Michael Crump

University of Toronto and Division of Medical Oncology and Hematology, Princess Margaret Hospital, Toronto, Canada

Raymond Cruz

St. Vincent's Comprehensive Cancer Center, New York, New York, USA

Arshia A. Dangol

James A. Haley Veterans' Hospital, and H. Lee Moffitt Cancer Center and Research Institute, University of South Florida College of Medicine, Tampa, Florida, USA

Meletios Athanasios Dimopoulos

Department of Clinical Therapeutics, University of Athens School of Medicine, Athens, Greece

Donald C. Doll

James A. Haley Veterans' Hospital, and H. Lee Moffitt Cancer Center and Research Institute, University of South Florida College of Medicine, Tampa, Florida, USA

Stefan Faderl

Department of Leukemia, The University of Texas M.D. Anderson Cancer Center, Houston, Texas, USA

Pierre Fenaux

Service d'hématologie clinique, Hôpital Avicenne (Assistance Publique –Hôpitaux de Paris) and Paris 13 University, Bobigny, France

Nathan Fowler

Department of Lymphoma/Myeloma, University of Texas M.D. Anderson Cancer Center, Houston, Texas, USA

Naomi Galili

St. Vincent's Comprehensive Cancer Center, New York, New York, USA

Angela Hamblin

Department of Immunohaematology, Cancer Sciences Division, University of Southampton, Southampton, UK

Terry Hamblin

Department of Immunohaematology, Cancer Sciences Division, University of Southampton, Southampton, UK

Monique A. Hartley

Department of Medical Hematology and Oncology, University of South Florida, and Department of Malignant Hematology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida, USA

Suzanne Hayman

Laboratory Medicine and Pathology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA

Lori A. Hazlehurst

Department of Malignant Hematology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida, USA

Elias Jabbour

Department of Leukemia, University of Texas M.D. Anderson Cancer Center, Houston, Texas, USA

Hagop M. Kantarjian

Department of Leukemia, University of Texas M.D. Anderson Cancer Center, Houston, Texas, USA

Efstathios Kastritis

Department of Clinical Therapeutics, University of Athens School of Medicine, Athens, Greece

Ghulam Sajjad Khan

St. Vincent's Comprehensive Cancer Center, New York, New York, USA

Kevin T. Kim

Division of Hematology/Oncology, Scripps Clinic, La Jolla, California, USA

Rami S. Komrokji

H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida, USA

Shaji Kumar

Mayo Clinic College of Medicine, Rochester, Minnesota, USA

Robert A. Kyle

Laboratory Medicine and Pathology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA

Alan List

H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida, USA

Xin Liu

Penn State Hershey Cancer Institute, Penn State University, Hershey, Pennsylvania, USA

Thomas P. Loughran, Jr.

Penn State Hershey Cancer Institute, Penn State University, Hershey, Pennsylvania, USA

Peter McLaughlin

Department of Lymphoma/Myeloma, University of Texas M.D. Anderson Cancer Center, Houston, Texas, USA

Ruben A. Mesa

Division of Hematology/Oncology, Mayo Clinic, Scottsdale, Arizona, USA

Susan O'Brien

Department of Leukemia, University of Texas M.D. Anderson Cancer Center, Houston, Texas, USA

Eric Padron

Department of Malignant Hematology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida, USA

Ritesh Parajuli

Northwestern University Feinberg School of Medicine, and Robert H. Lurie Comprehensive Cancer Center, Chicago, Illinois, USA

Joseph Pidala

Department of Blood and Marrow Transplantation, H. Lee Moffitt Cancer Center, and University of South Florida, Tampa, Florida, USA

Javier Pinilla-Ibarz

Department of Malignant Hematology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida, USA

Jerald Radich

Fred Hutchinson Cancer Research Center, Seattle, Washington, USA

S. Vincent Rajkumar

Mayo Clinic College of Medicine, Rochester, Minnesota, USA

Azra Raza

Columbia University Medical Center, New York, New York, USA

Hussain I. Saba

James A. Haley Veterans' Hospital, and H. Lee Moffitt Cancer Center and Research Institute, University of South Florida College of Medicine, Tampa, Florida, USA

Elizabeth M. Sagatys

Department of Oncological Sciences and Experimental Therapeutics Program, and Department of Malignant Hematology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida, USA

Alan Saven

Division of Hematology/Oncology, Scripps Clinic, La Jolla, California, USA

Bijal D. Shah

University of South Florida, Tampa, Florida, USA

Kenneth H. Shain

Department of Malignant Hematology, H. Lee Moffitt Cancer Center, Tampa, Florida, USA

Darren S. Sigal

Division of Hematology/Oncology, Scripps Clinic, La Jolla, California, USA

Lubomir Sokol

University of South Florida College of Medicine and Moffitt Cancer Center and Research Institute, Tampa, Florida, USA

Mohamed Sorror

Fred Hutchinson Cancer Research Center and University of Washington, Seattle, Washington, USA

Eduardo M. Sotomayor

Department of Oncological Sciences and Experimental Therapeutics Program, and Department of Malignant Hematology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida, USA

Jamie Stratton

St. Vincent's Comprehensive Cancer Center, New York, New York, USA

Jonathan C. Strefford

Cancer Genomics Group, Cancer Sciences Division, University of Southampton, Southampton, UK

Martin S. Tallman

Northwestern University Feinberg School of Medicine, and Robert H. Lurie Comprehensive Cancer Center, Chicago, Illinois, USA

Jianguo Tao

Department of Oncological Sciences and Experimental Therapeutics Program, and Department of Malignant Hematology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida, USA

Ayalew Tefferi

Department of Hematology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA

Sylvain Thépot

Service d'hématologie clinique, Hôpital Avicenne (Assistance Publique –Hôpitaux de Paris) and Paris 13 University, Bobigny, France

Deborah Thomas

University of Texas M.D. Anderson Cancer Center, Houston, Texas, USA

Kenneth S. Zuckerman

H. Lee Moffitt Cancer Center, and University of South Florida, Tampa, Florida, USA

Acknowledgement

The editors are grateful to Ms. Genevieve A. Morelli for her excellent help and energy in coordinating all the contributors in the development and assembly of this book. Her many organizational skills and tireless efforts in contacting, proofing and coordinating the work of the authors, editors, and publishers of the two subcontinents of Europe and America have been remarkable. The editors greatly appreciate her efforts.

Preface

In the last decade, there has been a remarkable explosion of scientific knowledge in many areas of hematological malignancies. This information has led to many new insights in the understanding of the pathobiology of malignant hematological diseases. New knowledge of cellular disease processes, molecular pathology, and cytogenetic, epigenetic, and genomic changes have impacted our current outlook toward hematological malignancies. There was a time when the practicing hematologist could not offer anything but a few symptomatic treatments for malignant disease states. Now, treatment attempts are being offered to attack and eradicate at their molecular level. This, in some instances, has led us to achieve a near cure and, perhaps a complete cure in the near future, for some of the malignant hematological malignancies.

The recent and ongoing expansion of knowledge in this area has become extensive and dynamic. Important aspects of this information are spread and scattered over the Internet and research publications. It is our belief that much of this important information is not utilized to its full capacity due to diffuse distribution. This has led to the need to capture and compile new and current information about hematologic malignancies in the form of a comprehensive book. Advances in Malignant Hematology is the result of our efforts to fulfill this need. The editors have been able to involve the experts of the American and European continents, and have them share their current thoughts and knowledge about the pathobiology of malignant hematological diseases of the blood, as well as their view on current treatment strategies and future developments in the area of these hematological diseases. It is our hope that this book proves helpful in the battle against hematologic cancer.

We understand that current scientific knowledge is dynamic and constantly changing. What is new information today may well be obsolete tomorrow. This publication presents what is current in this area today. In order to keep up with the evolutionary changes and developing knowledge that will, hopefully, lead to future cures, the editors and publisher have agreed to consider updating this book every three years or sooner. The editors are indebted for the cooperation they have received from all of the expert contributors to this work, and wish to express their deepest appreciation for their dedication to the advancement of science in the area of hematological cancer.

Hussain I. Saba and Ghulam J. MuftiTampa and London

List of Main Abbreviations

Chapter 1

AMLacute myeloid leukemiaAPCadenomatous polyposis coliAGMaorta-gonad-mesonephrosBMPR1Abone morphogenic protein receptor type 1ABFU-Mkburst forming unit-megakaryocyticBFU-Eburst forming unit-erythroidCFUcolony forming unitsCFU-GEMMcolony forming unit-granulocyte, erythroid, macrophage, megakaryocyteCFU-Smegakaryocytic cellsCLCFcardiotrophin-like cytokine factorCLPcommon lymphoid progenitorCMPcommon myeloid progenitorCNTFciliary neurotrophic factorCSFcolony-stimulating factorDCdendritic cellsEBFEarly B-cell factorECMextracellular matrixEDCPearly DC progenitorsEHZFearly hematopoietic zinc fingerEPOerythropoietinFACSfluorescence activated cell sortingFlt3FMS-like tyrosine kinase 3 receptorG-CSFgranulocyte-CSFGHgrowth hormoneGM-CSFgranulocyte-macrophage-CSFGMPgranulocyte-monocyte progenitorsHSChematopoietic stem cellIFNinterferonIgimmunoglobulinILinterleukinLEFlymphocyte enhancer binding factorLICleukemia initiating cellsLIFleukemia inhibitory factorLT-HSClong-term hematopoietic stem cellM-CSF; CSFS-1macrophage-CSFMDPmacrophage dendritic cell progenitorMEPmegakaryocyte-erythroid progenitorsmiRNAmicroRNAMPPmultipotent progenitormRNAmessenger RNANKnatural killer (cells)PI3Kphosphatidylinositol-3 kinasePRLprolactinRARαretinoic acid receptor alphaRBCsred blood cellsSCFstem cell factorSCIDsevere combined immunodeficiencySFsteel factorST-HSCshort-term hematopoietic stem cellTCFTPOT-cell factor thrombopoietinTGFβtumor growth factor-βTNFαtumor necrosis factor-α

Chapter 2

AIDactivation-induced cytidine deaminaseALLacute lymphoblastic leukemiaATRAall-trans retinoic acidCMLchronic myeloid leukemiaDNAdeoxyribonucleic acidDSBdouble-stranded breakageFISHfluorescence in situ hybridizationPCGprotein coding genesPDGFRplatelet-derived growth factor receptorPhPhiladelphia chromosomeRXRretinoid X receptorUPDuniparental disomy

Chapter 3

EMHextramedullary hematopoiesisIFN-αinterferon-alphaIMiDsimmunomodulatory inhibitory drugsIWG-MRTInternational Working Group for Myelofibrosis Research and TreatmentMDSmyelodysplastic syndromesMPNsmyeloproliferative neoplasmsPegasyspegylated interferon-2aPEG-IFN-αpegylated interferon alphaPEG-Intronpegylated (PEG)-IFN-α-2b

Chapter 4

BCRbreakpoint cluster region(BP)-CMLblast phase CMLCEBP-alphaCCAAT/enhancer-binding protein-alpha(CP)-CMLchronic phase CMLFDA(USA) Food and Drug AdministrationGMPgranulocyte-macrophage progenitor cellsIRISInternational Randomized Study of Interferon and STI571 trialLSCsleukemic stem cellsNHEJnon-homologous end joiningROSreactive oxygen speciesTKItyrosine kinase inhibitors

Chapter 5

AEsadverse eventsAPaccelerated phaseBPblast phaseCPchronic phaseEFSevent-free survivalEMAEuropean Medicines AgencyMMRmajor molecular responseOSoverall survivalPFSprogression-free survivalSCTstem cell transplantationSTARTSRC/ABL Tyrosine kinase inhibition Activity Research Trials of dasatinib (START)-C trialTFStransformation-free survivalTOPSTyrosine kinase inhibitor OPtimization and Selectivity trial

Chapter 6

ATRAall-trans retinoic acidCBFxore binding factorCDKscyclin-dependent kinasesCLCcommitted leukemia cellFISHfluorescence in situ hybridizationGAPGTPase activating proteinsGEPgene expression profileHATshistone acetylasesHDAChistone deacetylasesHSChematopoietic stem cellITDinternal tandem duplicationJAK/STATJanus kinase-signal transducer and activator of transcriptionLPCleukemia progenitor cellsLSCleukemia stem cellMAPKmitogen-activating protein kinasesMLLMixed lineage leukemia geneNBsnuclear bodiesRINGreally interesting gene

Chapter 7

APLacute promyelocytic leukemiaATOarsenic trioxideALSGAustralian Leukemia Study GroupATRAall-trans retinoic acidCALGBCancer and Leukemia Group BCRcomplete remissionCRpall criteria for CR except incomplete recovery of plateletsECOGEastern Cooperative Oncology GroupENT1equilibrative nucleoside transporter 1GOGemtuzumab ozogamicinGVHDgraft-versus-host diseaseGVLgraft-versus-leukemicHiDAChigh-dose cytarabineHOVONDutch-Belgian Hemato-Oncology Cooperative GroupHSCThematopoietic stem cell transplantationMDSmyelodysplastic syndromeMPNmyeloproliferative neoplasm(UK) MRCMedical Research Council in the United KingdomMRDminimal residual diseaseMSDmatched sibling donorMUDmatched unrelated donorNCINational Cancer InstituteSEERSurveillance, Epidemiology, and End Results [Program of the NCI]SWOGSouthwest Oncology GroupTRMtransplant-related mortalityWBCwhite blood cell count

Chapter 8

ARDSadult respiratory distress syndromeATRAall-trans retinoic acidBMbone marrowCoRco-repressor complexCIRcumulative incidence of relapseDICdisseminated intravascular coagulationFDPfibrinogen-fibrin degradation productsGOgemtuzumab ozogamycinHAThistone acetyltransferaseHDAChistone deacetylaseLASleukocyte activation syndromeMRDminimal residual diseaseNPMnucleophosminNuMAnuclear matrix associatedNUMAnuclear mitotic apparatusPBperipheral bloodPMLpromyelocytic leukemia genePLZFpromyelocytic leukemia zinc fingerRAREresponse elementsRXRretinoid X receptorSTAT5Bsignal transducer and activator of transcription 5BSTCstem cell transplantationTNFtumor necrosis factor

Chapter 9

SBDSShwachman-Bodian-Diamond syndrome geneTNFαtumor necrosis factor alpha

Chapter 10

AAaplastic anemiaaCMLatypical chronic myelogenous leukemiaANCabsolute neutophil countARAuer rodsBSCbest supportive careCMMLchronic myelomonocytic leukemiaESAerythroid stimulating agentsIPSSInternational Prognostic Scoring SystemITPimmune thrombocytopenic purpura (or: idiopathic thrombocytopenic purpura c.11)ITTintention to treatIWGInternational Working GroupJMMLjuvenile myelomonocytic leukemiaMGFsmyeloid growth factorsORRoverall response ratesPNHparoxysmal nocturnal hemaglobinuriaPRpartial remissionpRBCspacked red blood cellsQOLquality of lifeRArefractory anemiaRARSRA with ringed sideroblastsRAEBRefractory Anemia with Excess BlastsRAEB-TRefractory Anemia with Excess Blasts in TransformationRCUDRefractory Anemia with Unilineage DysplasiaRNrefractory neutropeniaRTrefractory thrombocytopeniashRNAshort hairpin RNASPARCsecretion protein acidic cysteine-richTItransfusion independencet-MDStreatment-related MDS

Chapter 11

DNMTDNA methyl-transferasesG-CSFgranulocyte colony-stimulating factorITPidiopathic thrombocytopenic purpuraPEG-rHuMGDFpegylated recombinant megakaryocyte growth and development factorrhEPOrecombinant erythropoietinrHuTPOrecombinant human thrombopoietinSQsubcutaneousTItransfusion independent/ence

Chapter 12

CDR3complementarity determining region 3(D)diversityDISCdeath-inducing signaling complexFCRfludarabine, cyclophosphamide, and rituxumabGCgerminal centerIgimmunoglobulinIgHVimmunoglobulin heavy chain variableITAMsimmunoreceptor tyrosine-based activation motifs(J)joiningKIRskiller-immunoglobulin-like receptorsMAPKmitogen-activated protein kinasePBMNCperipheral blood mononuclear cellSSNPssingle nucleotide polymorphismsTFStreatment-free survival(V)variable

Chapter 13

AHAautoimmune hemolytic anemiaBCRB-cell receptorCTcomputerized tomographydel 11qdeletion 11q (etc.)IWCLLInternational Workshop on CLLIGHVimmunoglobulin heavy chain variable (NB: italicized)LDTlymphocyte doubling timeMBLmonoclonal B-cell Lymphocytosisp53italicized geneQALYquality-adjusted-life-yearSNPsingle nucleotide polymorphismsTKthymidine kinaseUSultrasound

Chapter 14

CSFcerebrospinal fluidHAARThighly active antiretroviral treatmentGMALLGerman Multicenter Study Group for Adult Acute Lymphoblastic LeukemiaGOELAMSGroupe Ouest-Est d'Etude des Leucémies et Autres Maladies du SangPCRpolymerase chain reactionsIgsurface immunoglobulinTdTterminal deoxynucleotidyl transferaseTCRT-cell receptorXRTirradiation

Chapter 15

EBVEpstein-Barr virusHTLV-IIhuman T-cell leukemia virusKIRskiller cell immunoglobulin-like receptorsMHCmajor histocompatibility complexPAHpulmonary artery hypertensionPCRpolymerase chain reactionPRCApure red cell aplasiaPNHparoxysmal nocturnal hemoglobinuriaXCIPX-chromosome inactivation pattern

Chapter 16

ADAadenosine deaminaseCRcomplete remissionCHRcomplete hematologic remissionFCflow cytometryIHCimmunohistochemistryIFNinterferon alphaPCA-1plasma cell-associated antigenPCRpolymerase chain reactionPLLprolymphocytic leukemiaSLVLSslenic lymphoma with villous lymphocytesSCIDsevere combined immunodeficiency disorderTRAPtartrate-resistant acid phosphatase

Chapter 17

AIDactivation-induced cytosine deaminaseATRataxia telangiectasia and Rad3-related genesB-ALLB-acute lymphoblastic leukemiaBLIMP1B-lymphocyte-induced maturation protein 1CDRcomplementary-determining regionsDLBCLdiffuse large B-cell lymphomasEBBextrafollicular B-blastIgimmunoglobulinIgHimmunoglobulin heavy chainMCLmantle cell lymphomaSHMsomatic hypermutationXBP1X-box binding protein 1

Chapter 18

ABCactivated B-cellAITLangioimmunoblastic T-cell lymphomaALCLanaplastic large cell lymphomaALKanaplastic lymphoma kinaseATLLadult T-cell leukemia/lymphomaBLBurkitt's lymphomaCLLchronic lymphocytic leukemiaDLBCLdiffuse large B-cell lymphomasEFSevent-free survivalFDCfollicular dendritic cellsFISHfluorescence in situ hybridizationFLfollicular lymphomaFLIPIThe Follicular Lymphoma International Prognostic IndexGEPgene expression profilingHAARThighly active antiretroviral therapyHLHodgkin lymphomaHSCThematopoietic stem cell transplantIgHimmunoglobulin heavy chainIMiDsimmunomodulatory drugsIPIInternational Prognostic IndexMCLmantle cell lymphomaMFmycosis fungoidesMALTmucosa-associated lymphoid tissueMZLmarginal zone B-cell lymphomasNHLnon-Hodgkin lymphomaNOSnot otherwise specifiedPCRpolymerase chain reactionPKCprotein kinase CPTCLperipheral T-cell lymphomaPMLBCLprimary mediastinal large B-cell lymphomaREALRevised European-American Lymphoma (scheme)RITradioimmunotherapyRTradiation therapySLLsmall lymphocytic lymphomaTBItotal body irradiationT-LBLT-lymphoblastic leukemia/lymphomaTTFtime to treatment failureWFWorking Formulation

Chapter 19

CMTcombined modality therapyEFRTextended-field radiotherapyEORTCEuropean Organization for Research and Treatment of CancerEscescalatedFDG-PETfluorodeoxyglucose positron emission tomographyFFTFfreedom from treatment failureFF2Ffreedom from/free of second treatment failureGELAGroupe d'Etude des Lymphomes de l'AdulteGHSGGerman Hodgkin Study GroupGISLIntergruppo Italiano LinfomiIFRTinvolved field radiotherapyINRTinvolved nodal radiationMOPPMOPP regimen (mechlorethamine, vincristine, procarbazine, prednisonemTORmammalian target of rapamycinPRpartial responseSEERSurveillance Epidemiology and End Results (program)STNIsubtotal nodal (or “extended field”) radiationTRMtreatment-related mortality

Chapter 20

BMTbone marrow transplantCCTconventional chemotherapyDVTdeep vein thrombosisMGUSmonoclonal gammopathy of undetermined significanceMMmultiple myelomaHGFhepatocyte growth factorIGF-1insulin like growth factorONJosteonecrosis of the jawRICreduced-intensity conditioningROTIrelated organ or tissue impairmentSDFstromal dependent growth factorSMMsmoldering myelomaTBItotal body irradiationTTPtime to progressionTWiSTtime without symptoms, treatment, and toxicityVEGFvascular endothelial growth factorVGPRvery good partial response

Chapter 21

AL amyloidosisamyloidosis of AL type (primary)anti-MAGanti-myelin associated glycoproteinCAPcyclophosphamide, doxorubicin (adriamycin), and prednisoneCHOPcyclophosphamide, doxorubicin, vincristine, and prednisoneCLLchronic lymphocytic leukemiaIgMimmunoglobulin MIPSS WMInternational Prognostic Staging System for WMLDHlactate dehydrogenaseLPLlymphoplasmacytic lymphomaMGUSmonoclonal gammopathy of unknown significanceMMmultiple myelomaSWMsmoldering WMWMWaldenström's macroglobulinemia

Chapter 22

AAamyloid AAL amyloidosisprimary systemic amyloidosis (AL)CHFcongestive heart failureESRDend-stage renal diseaseFLCfree light chainHDM-ASCThigh-dose melphalan with autologous stem cell transplantationIFEimmunofixation electrophoresisLCDDlight chain deposition diseaseMDexmelphalan with dexamethasoneMPmelphalan with prednisoneSAPserum amyloid P

Chapter 23

aGVHDacute graft- versus.- host diseaseAMLacute myelogenous leukemiaATGantithymocyte globulinBMSCbone marrow stem cellsBMT CTNBlood and Marrow Transplant Clinical Trials NetworkBUbusulfancGVHDchronic graft-versus-host diseaseCIBMTRCenter for International Blood and Marrow Transplant ResearchCMLchronic myelogenous leukemiaCMVcytomegalovirusCR1first complete remissionCSAcyclosporineCYcyclophosphamideDLIdonor lymphocyte infusionFLUfludarabineHLAhuman leukocyte antigenISimmunosuppressive treatmentMCLmantle cell lymphomaMDSmyelodysplastic syndromeMELmelphalanMHCmajor histocompatibility complexMMmultiple myelomaMMFmycophenolate mofetilMTXmethotrexateNIHNational Institutes of Health (USA)NMDPNational Marrow Donor Program (USA)NRMnon-relapse mortalityPBSCperipheral blood stem cellsPCRpolymerase chain reactionQOLquality of lifeRICreduced-intensity conditioningSIRsirolimusTACtacrolimusTBItotal body irradiationTregsregulatory T-cellsVGPRvery good partial responseZAP-70zeta-associated protein 70

Chapter 24

BSFIBrief Sexual Function InventoryCFchronic fatigueEFexecutive functionEORTCEuropean Organization for Research and Treatment of CancerEWBemotional well-beingFACITFunctional Assessment of Chronic Illness TherapyFLICFunctional Living Index – CancerGELAGroupe d'Études des Lymphomes de l'AdulteIFN+LDACinterferon alfa plus subcutaneous low-dose cytarabineHMhematological malignanciesLHluteinizing hormoneMFI-20Multidimensional Fatigue InventoryNHPNottingham Health ProfileSF12Medical Outcomes Study Short Form 12SF-36Short Form-36SFWBsocial and family well-beingSIPSickness Impact ProfileTFtotal fatigueTOItrial outcome index

Part 1

Hematopoiesis

Chapter 1

Normal and Malignant Hematopoiesis

Bijal D. Shah1 and Kenneth S. Zuckerman1,2

1University of South Florida, Tampa, Florida, USA

2H. Lee Moffitt Cancer Center, Tampa, FL, USA

Introduction

Hematopoiesis, simply stated, describes the regulated process of hematopoietic stem cell (HSC) self-renewal and differentiation into lineage committed progeny. Pluripotent HSC are rare cells (<1 of 10 000 bone marrow cells) specifically characterized by their proliferative capacity (though under steady state conditions >95% of HSC are quiescent, non-dividing cells at any one time), pluripotency (they can regenerate the entire spectrum of mature blood derived cells), and self-renewal. The hierarchy of hematopoietic cell differentiation is depicted in Figure 1.1. HSC reside in close association with hematopoietic stromal cells within specific microenvironmental niches that function in concert with a variety of both multilineage and single lineage-specific hematopoietic growth factors, stromal cells, and extracellular matrix molecules to regulate their survival, cell cycle progression, proliferation, and differentiation. These processes of self-renewal, proliferation, differentiation, and cell death are tightly regulated under normal conditions throughout life. A normal individual maintains steady state numbers of blood cells within a very tight range with no more than a few percent variation from day-to-day, with constant production of the number of new cells required to replace the number of senescent cells that die. On average erythrocytes survive in the circulation for about 120 days, platelets for about 10 days, and neutrophils for about 6–12 hours. In order to replace senescent blood cells, the bone marrow of normal adult humans must produce about 180–250 billion erythrocytes, 60–100 billion neutrophils, and 80–150 billion platelets every day, or about 1016 (10 quadrillion) blood cells in a lifetime, with only minimal reduction in the bone marrow cell production capacity as a result of aging. The bone marrow can respond rapidly, in lineage-specific manner, to increase production of new blood cells by 6- to 8-fold over baseline under conditions of demand for each specific type of blood cells, such as in vivo destruction of erythrocytes, platelets, or neutrophils, infections requiring increased neutrophil production, and hemorrhage requiring increased erythrocyte production. Regulation of lymphocyte numbers is much less clearly understood, although it is known that some types of T and B lymphocytes may survive for many years. An understanding of these normal regulatory components in normal hematopoiesis is essential to unraveling the mechanisms that drive malignancy.

Figure 1.1 Schematic diagram of hematopoiesis highlighting identifying cell surface markers (in gray) and cytokines affecting each stage of hematopoietic differentiation (in italic). (A) Differentiation from hematopoietic stem cells through erythrocytes and megakaryocytes/platelets. (B) Differentiation from hematopoietic stem cells through granulocytes and monocytes/macrophages. (C) Differentiation from hematopoietic stem cells through lymphocytes.

Isolation of Hematopoietic Progenitors

In 1961, Till and McCulloch isolated single cell-derived colonies of myeloid, erythroid, and megakaryocytic cells (CFU-S) from the spleens of lethally irradiated mice 1–2 weeks after rescue by bone marrow transplantation [1]. These colonies were capable of extensive proliferation in vivo, exhibited some potential for self-renewal and, for the first time, conclusively demonstrated the presence of a multipotent hematopoietic progenitor cell. However, the lack of lymphoid colony development, as well as experiments in which 5-fluoruracil killed CFU-S without killing cells capable of replenishing CFU-S suggested that a more primitive “pre-CFU-S” must exist [2].

These data were further refined with the advent of flow cytometry, fluorescence activated cell sorting (FACS), in vitro hematopoietic progenitor cell systems, and xenotransplantation models, which revealed that long-term bone marrow repopulating HSCs were distinct from CFU cells, or multipotent progenitors (MPPs), and could be further subdivided into cells with short-term (ST-HSC) and long-term (LT-HSC) hematopoietic stem cell repopulation capacity. Specifically, LT-HSCs are defined by their extensive self-renewal capacity, allowing for full reconstitution of an irradiated host following transplantation of these cells. ST-HSCs, alternatively, have less capacity for self-renewal and instead more avidly differentiate into more committed MPPs. As such, ST-HSCs provide short-term hematopoietic cell reconstitution, but are incapable of permanently rescuing humans or other mammals with an aplastic bone marrow after lethal ionizing radiation.

Although some controversy exists, the most widely accepted model suggests that hematopoietic lineage commitment is both a stochastic and instructive process that occurs at specific branchpoints, manifested at the time of cell division. During cell division, HSCs can either divide asymmetrically (a maintenance event with the production of one identical immature daughter cell and one differentiating daughter cell), symmetrically (an expansion/self-renewal event which serves to generate two identically immature daughter cells (self-renewal)), or terminally differentiate (an extinction event, in which both daughter cells are committed to terminal differentiation). The hierarchy of differentiation from HSC to mature end-stage hematopoietic cells is shown in Figure 1.1. As cells progressively differentiate into functional components of the hematopoietic system, they lose proliferative and multilineage differentiation capacity. Regulation of self-renewal, cell cycling, terminal differentiation, and apoptosis is therefore critically important to maintaining the production of hematopoietic elements over a lifetime. It is now clear that extrinsic and intrinsic systems act in concert to generate a network of events that govern HSC fate.

Cytokine Regulation

Cytokines/growth factors include interleukins, lymphokines, monokines, interferons, chemokines, colony-stimulating factors (CSFs), and other hematopoietic hormones. These secreted factors interact with receptors on both pluripotent stem cells and committed hematopoietic progenitor cells to affect their survival, proliferation, and differentiation. The stages of differentiation from pluripotent HSC to fully mature hematopoietic cells of all lineages and the growth factors that play roles in these differentiation events are shown in Figure 1.1. Kit-ligand (also known as stem cell factor (SCF), and Steel factor (SF)) and Flt3 ligand, which function to drive proliferation by binding to the Kit and Flt3 tyrosine kinase receptors, respectively, on CD34+CD38− progenitors are important regulators of the early stages of hematopoietic differentiation from HSC. SCF, in particular, cooperates with multiple cytokines and cytokine receptors to influence differentiation, as well as upregulating BCL-2, BCL-XL, and perhaps other antiapoptotic molecules to promote target cell survival. These receptors are downregulated during normal differentiation. Colony-stimulating factors, including erythropoietin (EPO), thrombopoietin (TPO), granulocyte-macrophage-CSF (GM-CSF), granulocyte-CSF (G-CSF), and macrophage-CSF (M-CSF; CSF-1), induce the differentiation and function of specific hematopoietic cell lineages. These factors accordingly are named for the lineages that they predominantly stimulate, although several also have effects on multipotent hematopoietic progenitors and perhaps even on pluripotent HSC. Alternatively, TGFβ (tumor growth factor-β), TNFα (tumor necrosis factor-α), and IFNs (interferons) all tend to negatively influence hematopoiesis.

Although cytokine-receptor interactions would appear to generate a level of specificity with regards to transcriptional and genomic regulation and, hence, lineage-specific cell differentiation, the convergence of similar molecular pathways upon genomic targets makes it difficult to delineate this. What can be said, however, is that cytokine receptors appear to fall into specific families based upon their signal transducing subunits (see Table 1.1), and that these signaling subunits rely on three major pathways to ultimately influence transcription. These pathways include the JAK-STAT pathway, the MAPK pathway, and the PI3/AKT pathways, although other pathways involving NF-κB, TGF/SMAD, and protein kinase C pathways also play roles in the regulation of hematopoiesis. Importantly, mutations that affect these pathways are well described in lymphomas, myeloproliferative neoplasms, and leukemias [3–6].

Table 1.1 Cytokine receptor families.

Type I Cytokine receptorsHomodimerizing receptorsG-CSF-R, EPO-R, TPO-RHeterodimerizing receptorsgp130 receptor familyIL6-Rα, LIF-Rβ, IL11-Rα,

Oncostatin M-Rα,

CNTF-Rα, CLCF-R

βC (Common β receptor) receptor familyGM-CSFRα, IL3-Rα, IL5-RαIL2-R family (γ chain) receptor familyIL4-Rα, IL7-Rα,

IL9-Rα, IL13-Rα,

IL15-Rα, IL21-Rα

Type II Cytokine receptors (interferon family)IFNα-R, IFNγ-R1/2,

IL10-R1/2

Receptors with intrinsic tyrosine kinase activityFlt3, c-KitG: granulocyte; CSF: colony-stimulating factor; R: receptor; EPO: erythropoietin; TPO: thrombopoietin; IL: interleukin; LIF: leukemia inhibitory factor; CNTF: ciliary neurotrophic factor; CLCF: cardiotrophin-like cytokine factor; GM: granulocyte-macrophage; IFN: interferon.

Mechanistically, growth factors and cytokines act as ligands for transmembrane receptors that are located on the surface of hematopoietic cells, with differing receptor expression on HSC, multipotent progenitors, single lineage precursors and mature hematopoietic cells of different lineages. Dimerization (or conformational change) of receptors occurs following ligand binding. This receptor dimerization and conformational change leads to autophosphorylation of the intracellular portion of the receptors and recruitment of signaling molecules to docking sites on the activated receptors. This leads, in turn, to recruitment, phosphorylation, and activation of a broad range of cytoplasmic effector signaling molecules, such as STATs, Src-kinases, protein phosphatases, Shc, Grb2, IRS1/2 and PI3K via binding at the conserved SH2 domains and phosphorylation sites on the receptors themselves. For example, phosphorylation of STATs leads to the generation of STAT homo- and hetero-dimers, which are then translocated to the nucleus, where they can bind specific nucleotide sequences in the regulatory regions of specific genes to influence transcription of those genes, which determines the proliferation, survival, differentiation, and function of those cells. Similarly, phosphorylation of Grb2 facilitates the activation of SOS, which in turn, influences transcription via activation of the Ras/Raf/Mek/Erk, and the Rho/Mlk-Mekk/Mek/p38-JNK pathways. Activation of phosphatidylinositol-3 kinase (PI3K), either directly or indirectly via RAS or IRS 1 and 2, generates PIP3, which in turn activates PKC, SGK, RAC1/CDC42 and AKT. Activation of AKT is particularly relevant to both normal and malignant hematopoiesis, as it can phosphorylate multiple transcription factors, leading to activation of mTOR, MDM2, and NFκB and inhibition GSK3β, FKHR, and BAD. Notably, multiple related proteins and isoforms of many of the signal transduction molecules exist (including JAK, STAT, Mek, Mlk, Mekk, Erk, p38, JNK, PI3K, PIP3, and AKT), and appear to have different nuclear targets depending on the cell type in which activation occurs [3–5].

Transcriptional Regulation

Transcription factors are proteins that interact with the regulatory region of genes, either alone or in protein complexes, to increase or decrease expression of genes that contain specific sequences of nucleotides in these regulatory regions, which are recognized by the specific transcription factors. Transcriptional networks play a central role in the intrinsic regulation of HSC and lineage-committed progenitor cell survival, proliferation, and differentiation. Accordingly, these pathways are commonly perturbed in hematopoietic malignancies. Unfortunately, our knowledge in many cases is limited to non-human and in vitro models, which may not accurately reflect human hematopoiesis. Nonetheless, these experimental approaches have helped to define several important concepts in transcriptional regulation, including timing, autonomous and antagonistic pathways, cofactor regulation, and cellular signaling-related changes to transcription factor activity/function. A summary of relevant transcription factors thought to be involved in varying steps in the hematopoietic differentiation pathways is provided in Figure 1.2 and the transcriptional regulatory factors involved in each of the specific lineages of hematopoietic differentiation are described in more detail in the sections below on each of those lineages.

Figure 1.2 Schematic diagram of hematopoiesis highlighting transcription factors (in italic) and microRNAs (in gray) that are active at each of the stages of hematopoietic differentiation.

MicroRNA regulation

MicroRNAs (miRNA) have been recently implicated in the control of gene expression in hematopoiesis (Figure 1.2). miRNAs are small non-coding RNAs that bind to the 3′-untranslated regions and destabilize messenger RNAs (mRNAs) leading to their rapid degradation or, less commonly, may bind to the coding region of targeted genes and inhibit transcription of those genes. To date over 700 miRNAs have been identified in humans, with over 33% of human genes identified as potential targets of these miRNAs, based on identification of sequences in those genes that are reverse complements of specific miRNAs. A thorough review of the involvement of miRNAs in hematopoiesis is beyond the scope of this review; however, interested readers are referred to several recent reviews highlighting the importance of miRNA in both normal and malignant hematopoiesis [7–11].

Hematopoietic Microenvironment

HSCs are most likely generated independently in the yolk sac and aorta-gonad-mesonephros (AGM) region in the developing embryo, after which they migrate to the placenta, attaching via VE-cadherin, and subsequently to the liver and spleen via β1 integrin-dependent interactions with the extracellular matrix (ECM). Mesenchymal cell development in the liver and spleen creates a unique microenvironment that fosters HSC survival and expansion. During most of human fetal development the liver is the primary source of hematopoietic cell production, with erythrocyte production predominating, and the spleen contributes a small proportion of fetal hematopoiesis. Shortly before birth, HSCs migrate to the bone marrow, presumably under the influence of CXCL12/CXCR4, c-Kit/SCF, CD44/hyaluronic acid, and α4β1 integrin (VLA-4)/ECM and stromal cell interactions. At that point, hepatic and splenic hematopoiesis virtually ceases, and essentially all subsequent human hematopoietic cell production is restricted to the bone marrow. It is now well accepted that stem cells routinely circulate into and out of the bone marrow niche throughout life, although the purpose of circulating hematopoietic stem and progenitor cells is not known. The same molecules that are involved in movement of HSCs to the bone marrow during development appear to play similar roles in HSC homing and marrow engraftment throughout adulthood. Curiously, in adults, CD44 is fucosylated, converting it to an E-selectin ligand, and accordingly facilitates binding and retention by bone marrow endothelial cells [12, 13]. CD44/hyaluronic acid and CD44/E-selectin interactions, which serve redundant roles in normal stem cell homing and engraftment, also have been found to be required for both human CML and AML leukemia cell growth in mouse xenograft models [14, 15].

HSC and early hematopoietic progenitors tend to predominantly lodge into endosteal niches near N-cadherin-expressing osteoblasts, where they tend to remain quiescent, perhaps under the influence of osteoblast-secreted Angiopoietin-1, active at HSC TIE2 receptors. Increasing the osteoblast population via conditional inactivation of bone morphogenic protein receptor type 1A (BMPR1A) or administration of PTH leads to an increase in the number of HSCs in the marrow. PTH also increases CXCL12 expression by osteoblasts, and indeed CXCR4 appears to retain its importance in HSC repopulation even after homing. SCF and extracellular calcium-ion concentration (sensed via the calcium receptor, CaR) also may play a role in localization to the endosteum (reviewed in [12]).

Interestingly, a separate population of HSCs is also found adjacent to endothelial cells, where N-cadherin expression is lower. Endothelial interactions likely play a role in HSC retention and egress, and may also facilitate HSC expansion and differentiation. For example, Tie2 is also expressed on endothelial cells, and blocking of this receptor impairs neoangiogenesis and delays hematopoiesis following myelosuppression. Angiopoietin-1, conversely, can rescue hematopoiesis in TPO-deficient mice [16]. Together these data suggest that two pools of HSCs may exist, a quiescent fraction adjacent to osteoblasts in the endosteal niche, and a more rapidly proliferating and differentiating fraction adjacent to blood vessels.

Adhesive interactions via osteopontin/CD44 and β1 integrins, N-cadherin, c-Kit/SCF, CXCL12/ CXCR4, Jagged1/Notch and TIE2/Angiopoietin-1 all play roles in maintenance of the bone marrow niche and in HSC quiescence. These adhesive interactions are commonly altered in hematologic malignancies. Increased expression appears to confer a more aggressive and more drug-resistant “stem cell” phenotype, while decreased expression, as seen with AML1/ETO translocations, appears to confer a more migratory phenotype (reviewed in [17]). CXCL12 is particularly important in HSC retention, and interestingly has been found to be expressed at a higher level among a subset of stromal reticular cells. These CXCL12-abundant reticular cells, or CAR cells, are found throughout the marrow, generally surrounding sinusoidal endothelial cells. Rhythmic noradrenaline secretion via local sympathetic nerves modulates CXCL12 expression via β3 adrenoreceptor-mediated regulation of Sp1 levels. HSC egress is commonly provoked using high doses of G-CSF, which acts on neutrophils to facilitate proteolytic cleavage of these adhesive interactions, and may also regulate CXCL12 expression via CSF receptors found on sympathetic nerves [12]. Importantly, the marrow niche also critically regulates more mature cells as well. Osteoblast and endothelial cell niches play a role in both myelopoiesis (via G-CSF secretion) and B-cell lymphopoiesis (via IL-7 secretion and VCAM-1/cannabinoid receptor 2 expression). On the other hand, erythroid maturation is critically dependent on specialized bone marrow macrophage interactions [18].

Hematopoietic Developmental Pathways

Human HSCs with long-term repopulation potential were initially found in the CD34+CD38−CD90+ bone marrow compartment. Later flow cytometry-based studies have disclosed a rare “side population” with a CD34− or CD34lo phenotype with 1000-fold greater repopulating potential [19]. It remains unclear whether CD34− cells serve as progenitors to CD34+ cells, as expression of this protein does not appear to be a terminal event. In fact, HSCs likely cycle expression of CD34 depending on specific microenvironmental niches, wherein CD34 expression may facilitate adhesion and decreased proliferation [20].

Pluripotent, self-renewing, long-term repopulating HSCs appear to progress through several stages of MPPs, which probably have reduced self-renewal capacity, before beginning the process of what is recognizable as differentiation by proceeding down either a lymphoid (CLP, common lymphoid progenitor) or myeloid (CMP, common myeloid progenitor) developmental pathway, after which they are incapable of self-renewal in xenotransplant models. The lymphoid pathway ultimately generates T-cells, B-cells, natural killer (NK) cells, and dendritic cells. The myeloid pathway generates all the remaining mature hematopoietic phenotypes, including red blood cells (RBCs), granulocytes (neutrophils, eosinophils, basophils), mast cells, monocyte-macrophages, and megakaryocytes-platelets, and provides an additional mechanism for generating dendritic cells. This hierarchy of differentiation from HSC to the broad spectrum of mature hematopoietic cells, cell surface molecules that serve as markers of the various stages of differentiation, and the growth factors that impact the differentiation processes, are depicted in Figure 1.1.

The initial decision to pursue either a lymphoid or myeloid fate is understandably important and the product of extensive investigation. Although much remains unknown about the mechanisms of these cell fate determinations, changes in regulation of gene expression through transcription factors, miRNA expression, epigenetic changes such as histone methylation or acetylation, among others, are thought to be critical to such cell-fate decisions. An analysis of SCL and E2A expression suggests that SCL encourages myeloid differentiation, while high levels of E2A (a helix-loop-helix protein) may be required for lymphoid development [21, 22]. Graded expression of the Ets family member, PU.1, likewise impacts myeloid/lymphoid lineage decisions, with low and high levels specifying lymphoid and myeloid commitment, respectively [23]. RUNX1 may play an early role in CMP lineage commitment by increasing PU.1 expression [24].

Common Lymphoid Progenitors (CLP)

Galy et al. were the first to characterize human lymphoid committed progenitors (CD34+CD38+ CD45RA+CD10+) from the bone marrow using both xenotransplant and in vitro culture systems. Using limiting dilution assays, this population was found to contain B, NK, and DC progenitors. Additionally, injection of CD34+CD10+ cells into fetal thymic organs provided evidence that these cells could also develop into T-cells [25]. IL-7Rα, a critical marker for murine CLPs, has since been found among CD34+CD45RA+CD10+ adult human marrow CLPs. In fact, these cells were found to express transcripts for both B-cells (including Pax-5 and Igβ) and T-cells (including GATA3 and pTα). Interestingly, however, in vitro studies suggest a bias towards B-cell development among this subset (though limited NK cell development was observed) [26]. Indeed, a bias towards T- and NK cell lineage commitment appears to be found among CD34+CD45RA+CD7+CD10−IL-7Rα− cells. Whether both populations derive from a CD34+CD45RA+CD10+CD7+ cell population remains unknown, largely due to the scarcity of this phenotype in adult marrow (0.3% of cells) [27, 28].

Low levels of PU.1, likely act in parallel with Ikaros to provide transcriptional control of the maturation of HSCs into lymphoid precursors. In this context, PU.1 promotes IL-7Rα and EBF1 expression, while Ikaros promotes Flt3 receptor expression, all important in B- and T-cell development (reviewed in [29]). Additional regulation via the Notch1 receptor appears to be critical in T lineage commitment from the CLP. Deletion or inhibition of Notch receptor signaling in CLPs prevents T-cell formation and promotes development of B-cells [30].

In the absence of Notch, the transcription factors E2A and EBF1 (early B-cell factor) appear to work together to induce expression of Pax-5. Indirect data implicating EBF in B-cell lineage commitment comes from an analysis of the EBF inhibitor, EHZF (early hematopoietic zinc finger). EHZF is highly expressed in CD34+ cells, but absent following differentiation to CD19+ B-cells [31]. Furthermore, in vitro inhibition of E2A with Id3 inhibits B-cell formation, possibly by inhibiting development/survival of CD10+IL-7Rα+ expressing B-cell biased lymphoid progenitors [32]. Pax-5 also plays an important role in the activation of B-cell lineage-specific genes, and repression of lineage-inappropriate genes, such as Notch1, c-Fms (which encodes the macrophage colony-stimulating factor receptor, and accordingly supports myeloid development), and CCL3 (which promotes osteoclast formation) [33–35]. Finally, Bcl11a (a zinc finger transcription factor) is also critical to B-cell lineage commitment, as its absence blocks B lymphopoiesis from the CLP [36]. Translocations involving Bcl11a are particularly relevant in malignant transformation [37].

Common Myeloid Progenitors (CMP)

CMPs (also known as CFU-GEMM; colony-forming unit-granulocyte, erythroid, macrophage, megakaryocyte) give rise to all myeloid lineages. CMPs are thought to give rise to two or more intermediate differentiated multipotent progenitor cell types. Granulocyte-monocyte progenitors (GMP), give rise to neutrophils, eosinophils, basophils, and monocyte/macrophages. The other, called megakaryocyte- erythroid progenitors (MEP) subsequently give rise to two separate lineages of hematopoietic cells, erythroid and megakaryocytic. The CMP, GMP, and MEP have all been isolated within the CD34+CD38+ compartment in both human marrow and cord blood. These cells lack the lymphoid markers CD10, CD7, and IL-7Rα, and can be isolated according to CD45RA and IL-3Rα expression: CMPs are CD45RA−IL-3Rαlo; GMPs are CD45RA+IL-3Rαlo; and MEPs are CD45RA−IL-3Rα−. Importantly CD33 is also expressed by CMPs but lost beyond the myelocyte stage and accordingly is a recognized target for the treatment of certain types of acute myeloid leukemia (AML) [38].

Another important marker in hematopoiesis is the FMS-like tyrosine kinase 3 receptor (Flt3). Interestingly, expression of Flt3 in human progenitor populations differs considerably from that of mice. Around 40–80% of human CD34+ bone marrow and cord blood cells are Flt3+, and its presence appears to correlate with a capacity for long-term repopulation. Specifically, a fraction of both Flt3+ and Flt3− populations generate multilineage colonies containing all the myelo-erythroid components, with Flt3+ populations forming more GM colonies, and Flt3− populations more erythroid colonies [39]. Further exploration using xenotransplant models has characterized the Flt3+CD34+CD38− as LT-HSCs, and has identified Flt3 on both GMPs and CLPs [40, 41]. In contrast, murine Flt3 expression is limited to MPPs with both granulocytic and lymphocytic (but not megakaryocytic-erythroid) potential. Cells with similar potential have not been isolated in humans. The specific role of Flt3 is still being delineated; however, persistent activation as a consequence of activating mutations is commonly seen in AML, and is associated with a worse prognosis.

Transcriptional control of lineage bifurcation between the MEP and GMP populations is at least driven by antagonism between PU.1 and GATA1, with the former driving GMP formation, and the latter encouraging MEP development. PU.1 in association with Rb, binds to the promoters of GATA1 target genes, inhibiting their transcription, and has specifically been shown to inhibit α-globin expression and erythroid differentiation. GATA1 also suppresses myeloid differentiation via binding to the Ets domain of PU.1, blocking binding of the coactivator c-Jun and, accordingly, inhibiting PU.1 DNA-binding [42, 43].

Megakaryocytopoiesis and Erythropoiesis

Megakaryocytes and erythroid cells originate from the CMP/CFU-GEMM. The process begins with differentiation of the CMP into the MEP intermediate. Progression beyond the MEP stage is associated with lineage commitment to either the erythroid or megakaryocyte lineages. Specifically, the MEP initially differentiates into a highly proliferative burst forming unit-megakaryocytic or burst forming unit-erythroid (BFU-Mk or BFU-E), which is followed by further maturation to colony forming units (CFU-Mk or CFU-E, respectively), and ultimately either megakaryocyte/platelet formation or erythroid cell production. In fact, the existence of MEP cells was postulated prior to their isolation, given the numerous similarities in transcriptional regulation (SCL, GATA1, GATA2, NF-E2), cell surface molecules (TER119, CD235a/glycophorin A), and cytokine receptors (IL-3, SCF, EPO, and TPO). Additionally, several erythroid and megakaryocytic leukemia cell lines can be induced to display features of both lineages. Furthering this concept are the structural and downstream signaling similarities after binding of EPO and TPO to their respective cell surface receptors, which display a modest degree of synergy in stimulating the growth of progenitors of both lineages.

Although the mechanisms by which these differentiation decisions are made are not fully elucidated, it is known that specific transcription factors play roles in determining whether MEPs proceed down the differentiation pathway towards erythropoiesis or megakaryocytopoiesis. Here, Fli-1 and EKLF appear to play similarly antagonistic roles, with Fli-1 supporting the development of BFU-Mk, and EKLF the formation of BFU-E. EKLF expression relies on GATA1 and CP1. Cells committed to the megakaryocytic lineage express CD41 and CD61 (integrin αIIβ3), CD42 (glycoprotein I) and glycoprotein V, von Willebrand factor, platelet factor 4 and other platelet proteins. As MEP maturation along the erythroid pathway occurs, they lose CD41 expression, and express the transferrin receptor (CD71) at the BFU-E stage, and subsequently erythroid membrane proteins, erythroid enzymes, and hemoglobins.

Megakaryocytopoiesis

The mature megakaryocyte progenitor proceeds down a regimented pathway, forming promegakaryoblasts, which generate megakaryoblasts, and in turn produce megakaryocytes. Megakaryocytes are unique among hematopoietic cells, in that after the CFU-MK stage, DNA replication is not accompanied by cell division, resulting in production of progressively larger cells with complex nuclei containing 4N to as high as 128N chromosomes. Platelets are generated by fragmentation of the mature megakaryocyte cytoplasmic pseudopodial projections, called proplatelets. The sliding of microtubules over one another drives the elongation of proplatelet processes and organelle transportation (into the proplatelets) in a process that consumes the megakaryocyte and results in production of 2000–3000 platelets from each mature megakaryocyte (reviewed in [44]).

Although influenced by multiple cytokines (SCF, GM-CSF, IL-3, IL-6, IL-7, IL-11, EPO), TPO and IL-3 are particularly important in the generation and release of mature platelets [45]. Studies conducted following the purification of TPO have found that it is capable of stimulating the growth of 75% of all CFU-MKs, with the remainder proliferating with the addition of IL-3. Additionally, TPO and either IL-3 or SCF are required for the generation of more complex, larger hematopoietic colonies from earlier progenitor populations [46]. Consistent with these experimental data is the observation of amegakaryocytic thrombocytopenia among those with inactivating TPO receptor mutations. The relative contributions of elevated levels of TPO or increased TPO receptor expression to enhancement of megakaryocyte and platelet production remain unclear, though it is likely that both play roles in vivo.

Several megakaryocyte DNA promoter binding domains have been identified in mice, with some clinical homology demonstrated in humans with mutations involving associated proteins. It should be stressed that these proteins likely interact with one another, as well as with other transcriptional proteins to ultimately affect the generation of mature progeny.

GATA1 and GATA2 are the major GATA zinc finger DNA binding-proteins influencing differentiation in both the erythroid and megakaryocytic lineages. In both series, GATA1 levels increase while GATA2 levels decrease with progressive differentiation. Additionally, GATA proteins are co-regulated by FOG1 (friend of GATA), a large multifinger protein that influences transcription independent of DNA-binding. GATA1 and FOG1 knockout mice both demonstrate abnormalities in erythropoiesis and megakaryocytopoiesis. Interestingly, human mutations affecting the binding of GATA1 to FOG1 appear to have greater impact on megakaryocytopoiesis than erythropoiesis (reviewed in [47]). Indeed, GATA1-mediated expression of Gfi-1b and repression via interactions with Eto-2 are required for terminal differentiation of megakaryocytes [48, 49]. In fact, mutations involving both Gfi-1b and Eto-2 have been observed in leukemias [50, 51]. GATA2 instead contributes to proliferation of progenitor cells [52].

Another transcriptional regulator is the family of core binding factors, consisting of the DNA binding proteins RUNX1–3 and the non-DNA binding element, CBFβ. The complex of RUNX1 and CBFβ is particularly important in hematopoietic ontogeny. In fact mutations involving these proteins are commonly observed in human acute leukemias. Inactivation of either RUNX1 or CBFβ in murine models leads to a profound defect in megakaryocytic differentiation (with little impact on erythropoiesis). Clinically, RUNX1 mutations are associated with the autosomal dominant familial platelet disorder with predisposition to AML (FPD/AML), with these leukemias likely occurring as a direct consequence of perturbed HSC homeostasis [53].