The Biology Of Cancer (2007) - Robert A. Weinberg -

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About the Author Dr. Robert A. Weinberg is a founding member of the Whitehead Institute for Biomedical Research. He is also the Daniel K. Ludwig Professor for Cancer Research at the Massachusetts Institute of Technology (MIT) and American Cancer Society Research Professor.

Front Cover Carcinoma cells at the outer edge of an island of these tumor cells often undergo an epithelial-mesenchymal transition, which enables them to become motile and to invade the adjacent stroma. Seen here are experimentally transformed human mammary epithelial cells, which express cytokeratins (red), which are typical of epithelial cells. However, human carcinoma cells that are in contact with the surrounding mouse stroma (revealed by blue nuclei) have shed their cytokeratin expression and express instead vimentin (green), a marker of mesenchymal cells. These cells have also changed shape and some have already invaded deep into the surrounding stroma. (Courtesy of Kimberly A. Hartwell and Tan A. Ince.)

© 2007 by Garland Science, Taylor & Francis Group, LLC

This book contains information obtained from authentic and highly regarded sources. Reprinted material is quoted with permission, and sources are indicated. Every attempt has been made to source the figures accurately. Reasonable efforts 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.

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Library of Congress Cataloging-in-Publication Data Weinberg, Robert A. (Robert Allan) The biology of cancer I by Robert A. Weinberg. p.;cm. Includes bibliographical references and index. ISBN 0-8153-4078 -8 (hardcover) -- ISBN 0-8153-4076-1 (softcover) 1. Cancer--Molecular aspects. 2. Cancer-- Genetic aspects. 3. Cancer cells. I. Title. [DNLM: 1. Neoplasms--genetics. 2. Cell Transformation, Neoplastic. 3. Genes, Neoplasm. QZ 202 W423b 2007] RC268.4.W45 2007 616.99 '4071--dc22 2006001825

Published by Garland Science, Taylor & Francis Group, LLC, an informa business 210 ~Iadison Avenue, ewYork, NY 10016, USA, and 2 Park quare, Milto n Park, Abingdon, OX14 4RN, UK Printed in the United States of America 15 14

l3 12 11 10 9 8 7 6 5 4 3

1111 inform a:

Contents

1

Chapter 1

The Biology and Genetics of Cells and Organisms

Chapter 2

The Nature of Cancer

25

Chapter 3

Tumor Viruses

57

Chapter 4

Cellular Oncogenes

91

Chapter 5

Growth Factors and Their Receptors

119

Chapter 6

Cytoplasmic Signaling Circuitry Programs Many of the Traits of Cancer

159

Chapter 7

Tumor Suppressor Genes

209

Chapter 8

pRb and Control of the Cell Cycle Clock

255

Chapter 9

p53 and Apoptosis: Master Guardian and Executioner

307

Chapter 10 Eternal Life: Cell Immortalization and Tumorigenesis

357

Chapter 11 Multistep Tumorigenesis

399

Chapter 12 Maintenance of Genomic Integrity and the Development of Cancer

463

Chapter 13 Dialogue Replaces Monologue: Heterotypic Interactions and the Biology of Angiogenesis

527

Chapter 14 Moving Out: Invasion and Metastasis

587

Chapter 15

655

Crowd Control: Tumor Immunology and Immunotherapy

Chapter 16 The Rational Treatment of Cancer

725

Abbreviations

A:1

Glossary

G:1

Index

I:1 Xlll

List of Headings

Chapter 1

Chapter 3

The Biology and Genetics of Cells and Organisms

1

1.1

1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 1.10

Mendel establishes the basic rules of genetics Mendelian genetics helps to explain Darwinian evolution Mendelian genetics governs how both genes and chromosomes behave Chromosomes are altered in most types of cancer cells Mutations causing cancer occur in both the germ line and the soma Genotype embodied in DNA sequences creates phenotype through proteins Gene expression patterns also control phenotype Transcription factors control gene expression Metazoa are formed from components conserved over vast evolutionary time periods Gene cloning techniques revolutionized the study of normal and malignant cells

Tumor Viruses

57 58

2

3.1 3.2

4

3.3

7

3.4

10

3.5

11 15 19 21 22 23

2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 2.10 2.11

Tumors arise from normal tissues Tumors arise from many specialized cell types throughout the body Some types of tumors do not fit into the major classifications Cancers seem to develop progressively Tumors are monoclonal growths Cancers occur with vastly different frequencies in different human populations The risks of cancers often seem to be increased by assignable influences including lifestyle Specific chemical agents can induce cancer Both physical and chemical carcinogens act as mutagens Mutagens may be responsible for some human cancers Synopsis and prospects Key concepts Thought questions Additional reading

3.7 3.8 3.9 3.10 3.11

Chapter 2 The Nature of Cancer

3.6

25 26

3.12 3.13

28

Peyton Rous discovers a chicken sarcoma virus Rous sarcoma virus is discovered to transform infected cells in culture The continued presence of RSV is needed to maintain transformation Viruses containing DNA molecules are also able to induce cancer Tumor viruses induce multiple changes in cell phenotype including acquisition of tumorigenicity Tumor virus genomes persist in virustransformed cells by becoming part of host cell DNA Retroviral genomes become integrated into the chromosomes of infected cells A version of the src gene carried by RSV is also present in uninfected cells RSV exploit a kidnapped cellular gene to transform cell The vertebrate genome carries a large group of proto-oncogenes Slowly transforming retroviruses activate proto-oncogenes by inserting their genomes adjacent to these cellular genes Some retroviruses naturally carry oncogenes Synopsis and prospects Key concepts Thought questions Additional reading

34 34 39

Chapter 4

43

Cellular Oncogenes

45 46

4.1

48 52 54 55 56 56

4.2 4.3 4.4

Can cancers be triggered by the activation of endogenous retroviruses? Transfection of DNA provides a strategy for detecting nonviral oncogenes Oncogenes discovered in human tumor cell lines are related to those carried by transforming retroviruses Proto-oncogenes can be activated by genetic changes affecting either protein expression or structure

61 63 65 69

71

73 75 77 80 82 84 86 88 90 90

91 92

93 98 103

List of H eadings -+.5

4.6 4.7

Variations on a theme: the myc oncogene can arise via at least three additional distinct mechanisms A diverse array of structural changes in proteins can also lead to oncogene activation Synopsis and prospects Key concepts Thought questions Additional reading

6.6 107

6.7

111 112 115 117 117

6.8

6.9

6.10

Chapter 5 Growth Factors, Receptors, and Cancer 5.1

5.2 5.3 5.4

5.5 5.6

5.7

5.8 5.9

5.10

Normal metazoan cells control each other's ' lives The Src protein functions as a tyrosine kinase The EGF receptor functions as a tyrosine kinase An altered growth factor receptor can function as an oncoprotein A growth factor gene can become an oncogene: the case of sis Transphosphorylation underlies the operations of receptor tyrosine kinases Yet other types of receptors enable mammalian cells to communicate with their environment Integrin receptors sense association between the cell and the extracellular matrix The Ras protein, an apparent component of the downstream signaling cascade, functions as a G protein Synopsis and prospects Key concepts Thought questions Additional reading

119

6.11 6.12

121 123

6.13

126 129 132

Chapter 7

135

Tumor Suppressor Genes 7.1

141 7.2 147 7.3 150 153 156 158 158

7.4

7.5 7.6

Chapter 6 7.7

Cytoplasmic Signaling Circuitry Programs Many of the Traits of Cancer 6.1 6.2 6.3

6.4

6.5

A signaling pathway reaches from the cell surface into the nucleus The Ras protein stands in the middle of a complex signaling cascade Tyrosine phosphorylation controls the location and thereby the actions of many cytoplasmic signaling proteins SH2 groups explain how growth factor receptors activate Ras and acquire signaling specificity A cascade of kinases forms one of three important signaling pathways downstream ofRas

A second pathway downstream of Ras controls inositol lipids and the Akt/PKB kinase A third Ras-regulated pathway acts through Ral, a distant cousin of Ras The Jak-STAT pathway allows signals to be transmitted from the plasma membrane directly to the nucleus Cell adhesion receptors emit signals that conv~rge with those released by growth factor receptors The Wnt-~-catenin pathway contributes to cell proliferation G-protein-coupled receptors can also drive normal and neoplastic proliferation Four other signaling pathways contribute in various ways to normal and neoplastic proliferation Synopsis and prospects Key concepts Thought questions Additional reading

159

7.8

161

7.9

164

7.10 7.11

166 7.12 171

173

7.13

Cell fusion experiments indicate that the cancer phenotype is recessive The recessive nature of the cancer cell phenotype requires a genetic explanation The retinoblastoma tumor provides a solution to the genetic puzzle of tumor suppressor genes Incipient cancer cells invent ways to eliminate wild-type copies of tumor suppressor genes The Rb gene often undergoes loss of heterozygosity in tumors Loss-of-heterozygosity events can be used to find tumor suppressor genes Many familial cancers can be explained by inheritance of mutant tumor suppressor genes Promoter methylation represents an important mechanism for inactivating tumor suppressor genes Tumor suppressor genes and proteins function in diverse ways The NF1 protein acts as a negative regulator of Ras signaling Ape facilitates egress of cells from colonic crypts Von Hippel-Lindau disease: pVHL modulates the hypoxic response Synopsis and prospects Key concepts Thought questions Additional reading

176 183

185

186 189 191

193 197 204 207 207

209 210 213

214

216

219 221 224

226 232 233 235 241 247 252 253 253 XV

List of Headings 9.9

Chapter 8 pRb and Control of the Cell Cycle Clock 8.1 8.2

8.3

8.4 8.5 8.6

8.7

8.8 8.9

8.10 8.11 8.12 8.13

External signals influence a cell's decision to enter into the active cell cycle Cells make decisions about growth and quiescence during a specific period in the G1 phase Cyclins and cyclin-dependent kinases constitute the core components of the cell cycle clock Cyclin-Cdk complexes are also regulated by Cdk inhibitors Viral oncoproteins reveal how pRb blocks advance through the cell cycle pRb is deployed by the cell cycle clock to serve as a guardian of the restriction point gate E2F transcription factors enable pRb to implement growth-versus-quiescence decisions A variety of mitogenic signaling pathways control the phosphorylation state of pRb The Myc oncoprotein perturbs the decision to phosphorylate pRb and thereby deregulates control of cell cycle progression TGF -~ prevents phosphorylation of pRb and thereby blocks cell cycle progression pRb function and the controls of differentiation are closely linked Control of pRb function is perturbed in most if not all human cancers Synopsis and prospects Key concepts Thought questions Additional reading

255 9.10 256 9.11 261 9.12 262

9.13

268

9.14

273

277

9.1 9.2 9. 3 9.4 9.5 9.6 9.7 9.

X\'1

Papovaviruses lead to the discovery of p53 p53 is discovered to be a tumor suppressor gene Mutant versions of p53 interfere with normal p53 function p53 protein molecules usually have short lifetimes A variety of signals cause p53 induction D A damage and deregulated growth ignals cause p53 stabilization ~Idrn2 and ARF battle over the fate of p53 _,1.RF and p53-mediated apoptosis protect again t cancer by monitoring intracellular ignaling

9.16

278

325 329

331 332 334 342

346 350 354 355 356

282

Chapter 10 284 288

Eternal Life: Cell Immortalization and Tumorigenesis Normal cell populations register the number of cell generations separating them from their ancestors in the early embryo 10.2 Cancer cells need to become immortal in order to form tumors 10.3 Cell-physiologic stresses impose a limitation on replication 10.4 The proliferation of cultured cells is also limited by the telomeres of their chromosomes 10.5 Telomeres are complex molecular structures that are not easily replicated 10.6 Incipient cancer cells can escape crisis by expressing telomerase 10.7 Telomerase plays a key role in the proliferation of human cancer cells 10.8 Some immortalized cells can maintain telomeres without telomerase 10.9 Telomeres play different roles in the cells of laboratory mice and in human cells 10.10 Telomerase-negative mice show both decreased and increased cancer susceptibility 10.11 The mechanisms underlying cancer pathogenesis in telomerase-negative mice may also operate during the development of human tumors 10.12 Synopsis and prospects Key concepts Thought questions Additional reading

357

10.1 292 296 300 304 305 305

Chapter 9 p53 and Apoptosis: Master Guardian and Executioner

9.15

p53 functions as a transcription factor that halts cell cycle advance in response to DNA damage and attempts to aid in the repair process p53 often ushers in the apoptotic death program p53 inactivation provides advantage to incipient cancer cells at a number of steps in tumor progression Inherited mutant alleles affecting the p53 pathway predispose one to a variety of tumors Apoptosis is a complex program that often depends on mitochondria Two distinct signaling pathways can trigger apoptosis Cancer cells invent numerous ways to inactivate some or all of the apoptotic machinery Synopsis and prospects Key concepts Thought questions Additional reading

307 308 310 311 314 315 317 318

323

358 361 365 368 373 376 381 383 386 388

392 393 397 398 398

List of Headings Chapter 11 Multi-Step Tumorigenesis 11.1 11.2 11.3 11.4

11.5 11.6

11.7 11.8 11.9

11.10 11.11

11.12

11.13

11 .14 11.15 11.16 11.17

11.18

Most human cancers develop over many decades of time Histopathology provides evidence of multi-step tumor formation Colonic growths accumulate genetic alterations as tumor progression proceeds Multi-step tumor progression helps to explain familial polyposis and field cancerization Cancer development seems to follow the rules of Darwinian evolution Tumor stem cells further complicate the Darwinian model of clonal succession and tumor progression A linear path of clonal succession oversimplifies the reality of cancer The Darwinian model of tumor development is difficult to validate experimentally Multiple lines of evidence reveal that normal cells are resistant to transformation by a single mutated gene Transformation usually requires collaboration between two or more mutant genes Transgenic mice provide models of oncogene collaboration and multi-step cell transformation Human cells are constructed to be highly resistant to immortalization and transformation Nonmutagenic agents, including those favoring cell proliferation, make important contributions to tumorgenesis Toxic and mitogenic agents can act as human tumor promoters Chronic inflammation often serves to promote tumor progression in mice and humans Inflammation-dependent tumor promotion operates through defined signaling pathways Tumor promotion is likely to be a critical determinant of the rate of tumor progression in many human tissues Synopsis and prospects Key concepts Thought questions Additional reading

12.2

399

12.3

400

12.4

403

12.5

408

12.6 12.7

412 12.8 413 12.9 416 420 423 12.11 424

12.12

427

12.13

429

470

475 479 483 490 493

499

505 510 511 517

524 525 525

Chapter 13

435

Dialogue Replaces Monologue: Heterotypic Interactions and the Biology of 527 Angiogenesis

439

13.1 441 444

13.2

452

13.3

453 460 461 462

13.4 13.5 13.6

Maintenance of Genomic Integrity and the Development of Cancer 463 Tissues are organized to minimize the progressive accumulation of mutations

466

431

Chapter 12

12.1

12.10

Stem cells are the likely targets of the mutagenesis that leads to cancer Apoptosis, drug pumps, and DNA replication mechanisms offer tissues a way to minimize the accumulation of mutant stem cells Cell genomes are threatened by errors made during DNA replication Cell genomes are under constant attack from endogenous biochemical processes Cell genomes are under occasional attack from exogenous mutagens and their metabolites Cells deploy a variety of defenses to protect DNA molecules from attack by mutagens Repair enzymes fix D NA that has been altered by mutagens Inherited defects in nucleotide-excision repair, base-excision repair, and mismatch repair lead to specific cancer susceptibility syndromes A variety of other DNA repair defects confer increased cancer susceptibility through poorly understood mechanisms The karyotype of cancer cells is often changed through alterations in chromosome structure The karyotype of cancer cells is often changed through alterations in chromosome number Synopsis and prospects Key concepts Thought questions Additional reading

13.7 13.8

464

Normal and neoplastic epithelial tissues are formed from interdependent cell types The cells forming cancer cell lines develop without heterotypic interactions and deviate from the behavior of cells within human tumors Tumors resemble wounded tissues that do not heal Stromal cells are active contributors to tumorigenesis Macrophages represent important participants in activating the tumor-associated stroma Endothelial cells and the vessels that they form ensure tumors adequate access to the circulation Tripping the angiogenic switch is essential for tumor expansion The angiogenic switch initiates a highly complex process

530

536 537 548 551

556 563 567 XVll

List of Headings 13.9

Angiogenesis is normally suppressed by physiologic inhibitors 13.10 Certain anti-angiogenesis therapies hold great promise for treating cancer 13.11 Synopsis and prospects Key concepts Thought questions Additional reading

15.2 571 15.3 574 581 585 585 586

15.4 15.5 15.6

Chapter 14 Moving Out: Invasion and Metastasis 14.1

14.2

14.3

14.4 14.5

14.6 14.7

14.8 14.9

14.10 14.11 14.12 14.13

Travel of cancer cells from a primary tumor to a site of potential metastasis depends on a series of complex biological steps Colonization represents the most complex and challenging step of the invasionmetastasis cascade The epithelial-mesenchymal transition and associated loss of E-cadherin expression enable carcinoma cells to become invasive The epithelial-mesenchymal transition is often induced by stromal signals EMTs are programmed by transcription factors that orchestrate key steps of embryogenesis Extracellular proteases play key roles in mvas1veness Small Ras-like GTPases control cellular processes including adhesion, cell shape, and cell motility Metastasizing cells can use lymphatic vessels to disperse from the primary tumor A variety of factors govern the organ sites in which disseminated cancer cells form metastases Metastasis to bone requires the subversion of osteoblasts and osteoclasts Metastasis suppressor genes contribute to regulating the metastatic phenotype Occult micrometastases threaten the long-term survival of cancer patients Synopsis and prospects Key concepts Thought questions Additional reading

587

15.7 15.8

589 15.9 594 15.10 597 605

615

15.11

15.12

621 15.13 624

15.14

631 15.15 634

15.16

638

15.17

642 15.18 645 646 652 653 653

15.19 15.20 15.21

Chapter 15 Crowd Control: Tumor Immunology and Immunotherapy

15.22

655 15.23

15.1

C\.\lli

The immune system functions in complex ways to destroy foreign invaders and abnormal cells in the body's tissues

656

The adaptive immune response leads to antibody production Another adaptive immune response leads to the formation of cytotoxic cells The innate immune response does not require prior sensitization The need to distinguish self from non-self results in immune tolerance Regulatory T cells are able to suppress major components of the adaptive immune response The immunosurveillance theory is born and then suffers major setbacks Use of genetically altered mice leads to a resurrection of the immunosurveillance theory The human immune system plays a critical role in warding off various types of human cancer Subtle differences between normal and neoplastic tissues may allow the immune system to distinguish between them Immune recognition of tumors may be delayed until relatively late in tumor progresswn Tumor-specific transplantation antigens often provoke a potent immune response Tumor-associated transplantation antigens may also evoke anti-tumor immunity Cancer cells can evade immune detection by suppressing cell surface display of tumor antigens Cancer cells protect themselves from NK -mediated attack Tumor cells launch counterattacks on immunocytes C ancer cells become intrinsically resistant to various forms of killing used by the immune system Cancer cells attract regulatory T cells to fend off attacks by other lymphocytes Passive immunization with Herceptin can be used to kill breast cancer cells Passive immunization with antibody can be used to treat B-cell tumors Passive immunization can be achieved by transfer of immunocytes from one individual to another Patients' immune systems can be mobilized to attack their tumors Synopsis and prospects Key concepts Thought questions Additional reading

659 663 666 668

669 669

673

675

681

683 685 687

689 695 697

701 703 704 708

713 714 720 722 723 724

List of Headings

__

,

apter 16 "e Rational Treatment of Cancer 1 ,.....

'"!

_J . ..J..

.2

,

___ J

:oA :6.5

16.6

16.7

16.8

16.9 16.10 16.11

16.12 16.13 16.14 16.15

16.16

T he development and clinical use of effective therapies will depend on accurate diagnosis of disease Successful anti-cancer drugs can elicit several responses from tumor cells Functional considerations dictate that only a subset of the defective proteins in cancer cells are attractive targets for drug development The biochemistry of proteins also determines whether they are attractive targets for intervention Pharmaceutical chemists can generate and explore the biochemical properties of a wide array of potential drugs Drug candidates must be tested on cell models as an initial measurement of their utility in whole organisms Studies of a drug's action in laboratory animals are an essential part of pre-clinical testing Promising candidate drugs must be subjected to rigorous and extensive clinical trials in Phase I trials in humans Phase TI and III trials provide credible indications of clinical efficacy Tumors often develop resistance to initially effective therapy Gleevec development has paved the way for the development of many other highly targeted compounds EGF receptor antagonists may be useful for treating a wide variety of tumor types Proteasome inhibitors yield unexpected therapeutic benefit A sheep teratogen may be useful as a highly potent anti-cancer drug mTOR, a master regulator of cell physiology, represents an attractive target for anti-cancer therapy Synopsis and prospects: Challenges and opportunities on the road ahead Key concepts Thought questions Additional reading

725

727 732

734

737

744

747

748

751 752

755

757 765 769 776

782 787 794 795 795

XIX