the biology of CANCER SECOND EDITION Robert A. Weinberg the biology of CANCER SECOND EDITION Robert A. Weinberg Garland Science About the Author Vice President: Denise Schanck Robert A. Weinberg is a founding member of the Whitehead Institute Assistant Editor: Allie Bochicchio for Biomedical Research. He is the Daniel K. Ludwig Professor Production Editor and Layout: EJ Publishing Services for Cancer Research and the American Cancer Society Research Text Editor: Elizabeth Zayatz Professor at the Massachusetts Institute of Technology (MIT). Copy Editor: Richard K. Mickey Dr. Weinberg is an internationally recognized authority on the genetic Proofreader: Sally Huish basis of human cancer and was awarded the U.S. National Medal of Illustrator: Nigel Orme Science in 1997. Designer: Matthew McClements, Blink Studio, Ltd. Front Cover Permissions Coordinator: Becky Hainz-Baxter A micrograph section of a human in situ ductal carcinoma with Indexer: Bill Johncocks α-smooth muscle actin stained in pink, cytokeratins 5 and 6 in red- Director of Digital Publishing: Michael Morales orange, and cytokeratins 8 and 18 in green. (Courtesy of Werner Editorial Assistant: Lamia Harik Böcker and Igor B. Buchwalow of the Institute for Hematopathology, Hamburg, Germany.) © 2014 by Garland Science, Taylor & Francis Group, LLC Tis book contains information obtained from authentic and highly regarded sources. Every efort has been made to trace copyright holders and to obtain their permission for the use of copyright material. Reprinted material is quoted with permission, and sources are indicated. A wide variety of references are listed. Reasonable eforts have been made to publish reliable data and information, but the author and the publisher cannot assume responsibility for the validity of all materials or for the consequences of their use. All rights reserved. No part of this book covered by the copyright hereon may be reproduced or used in any format in any form or by any means— graphic, electronic, or mechanical, including photocopying, recording, taping, or information storage and retrieval systems—without permission of the publisher. ISBNs: 978-0-8153-4219-9 (hardcover); 978-0-8153-4220-5 (softcover). Library of Congress Cataloging-in-Publication Data Weinberg, Robert A. (Robert Allan), 1942- Te biology of cancer. -- Second edition. pages cm Includes bibliographical references. ISBN 978-0-8153-4219-9 (hardback) -- ISBN 978-0-8153-4220-5 (pbk.) 1. Cancer--Molecular aspects. 2. Cancer--Genetic aspects. 3. Cancer cells. I. Title. RC268.4.W45 2014 616.99’4--dc23 2013012335 Published by Garland Science, Taylor & Francis Group, LLC, an informa business, 711 Tird Avenue, New York, NY 10017, USA, and 3 Park Square, Milton Park, Abingdon, OX14 4RN, UK. Printed in the United States of America 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 Visit our website at http://www.garlandscience.com v Dedication dedicate this second edition, as the frst one, to my dear wife, Amy Shulman I Weinberg, who endured long hours of inattention, hearing from me repeatedly the claim that the writing of this edition was almost complete, when in fact years of work lay ahead. She deserved much better! With much love. vii Preface ompared with other areas of biological research, the science of molecular oncol- Cogy is a recent arrival; its beginning can be traced with some precision to a mile- stone discovery in 1975. In that year, the laboratory of Harold Varmus and J. Michael Bishop in San Francisco, California demonstrated that normal cell genomes carry a gene—they called it a proto-oncogene—that has the potential, following alteration, to incite cancer. Before that time, we knew essentially nothing about the molecular mechanisms underlying cancer formation; since that time an abundance of informa- tion has accumulated that now reveals in outline and fne detail how normal cells become transformed into tumor cells, and how these neoplastic cells collaborate to form life-threatening tumors. Te scientifc literature on cancer pathogenesis has grown explosively and today encompasses millions of research publications. So much information would seem to be a pure blessing. After all, knowing more is always better than knowing less. In truth, it represents an embarrassment of riches. By now, we seem to know too much, mak- ing it difcult to conceptualize cancer research as a single coherent body of science rather than a patchwork quilt of discoveries that bear only a vague relationship with one another. Tis book is written in a far more positive frame of mind, which holds that this patch- work quilt is indeed a manifestation of a body of science that has some simple, under- lying principles that unify these diverse discoveries. Cancer research is indeed a feld with conceptual integrity, much like other areas of biomedical research and even sci- ences like physics and chemistry, and the bewildering diversity of the cancer research literature can indeed be understood through these underlying principles. Prior to the pioneering fndings of 1975, we knew almost nothing about the molecular and cellular mechanisms that create tumors. Tere were some intriguing clues lying around: We knew that carcinogenic agents often, but not always, operate as mutagens; this suggested that mutant genes are involved in some fashion in programming the abnormal proliferation of cancer cells. We knew that the development of cancer is often a long, protracted process. And we knew that individual cancer cells extracted from tumors behave very diferently than their counterparts in normal tissues. Now, almost four decades later, we understand how mutant genes govern the diverse traits of cancer cells and how the traits of these individual cells determine the behav- ior of tumors. Many of these advances can be traced to the stunning improvements in experimental tools. Te techniques of genetic analysis, which were quite primitive at the beginning of this period, have advanced to the stage where we can sequence entire tumor cell genomes in several days. (Tis is in sharp contrast to the state of afairs in 1975, when the sequencing of oligonucleotides represented a formidable task!) Given the critical role of genotype in determining phenotype, we now understand, as least in outline, why cancer cells behave the way that they do. On the one hand, the molecular diferences among individual cancers suggest hundreds of distinct types of human cancer. On the other, molecular and biochemical analyses reveal that this bewildering diversity really manifests a small number of underlying common biochemical traits and molecular processes. viii Preface Amusingly, much of this unifcation was preordained by decisions made 600 million years ago. Once the laws and mechanisms of organismic development were estab- lished, they governed all that followed, including the behavior of both normal and neoplastic cells. Modern cancer researchers continue to beneft from this rigid adher- ence to the fundamental, evolutionarily conserved rules of life. As is evident repeat- edly throughout this book, much of what we understand about cancer cells, and thus about the disease of cancer, has been learned by studying the cells of worms and fruit fies and frogs. Tese laws and principles are invoked repeatedly to explain the com- plex behaviors of human tumors. By providing context and perspective, they can be used to help us understand all types of human cancer. While these basic principles are now in clear view, critical details continue to elude us. Tis explains why modern cancer research is still in active ferment, and why new, fascinating discoveries are being reported every month. While they create new per- spectives, they do not threaten the solidity of the enduring truths, which this book attempts to lay out. Tese principles were already apparent seven years ago when the frst edition of this book appeared and, reassuringly, their credibility has not been undermined by all that has followed. In part, this book has been written as a recruiting pamphlet, as new generations of researchers are needed to move cancer research forward. Tey are so important because the lessons about cancer’s origins, laid out extensively in this book, have not yet been successfully applied to make major inroads into the prevention and cure of this disease. Tis represents the major frustration of contemporary cancer research: the lessons of disease causation have rarely been followed, as day follows night, by the development of defnitive cures. And yes, there are still major questions that remain murky and poorly resolved. We still do not understand how cancer cells create the metastases that are responsible for 90% of cancer-associated mortality. We understand rather little of the role of the immune system in preventing cancer development. And while we know much about the individual signaling molecules operating inside individual human cells, we lack a clear understanding of how the complex signaling circuitry formed by these mol- ecules makes the life-and-death decisions that determine the fate of individual cells within our body. Tose decisions ultimately determine whether or not one of our cells begins the journey down the long road leading to cancerous proliferation and, fnally, to a life-threatening tumor. Contemporary cancer research has enriched numerous other areas of modern bio- medical research. Consequently, much of what you will learn from this book will be useful in understanding many aspects of immunology, neurobiology, developmental biology, and a dozen other biomedical research felds. Enjoy the ride! Robert A. Weinberg Cambridge, Massachusetts March 2013