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Copyright (c) by W. H. Freeman and Company Chapter 24 Cancer
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Copyright (c) by W. H. Freeman and Company 24.1 Benign tumors arise with great frequency but pose little risk because they are localized and small Figure 24-1
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Copyright (c) by W. H. Freeman and Company 24.1 Malignant tumors generally invade surrounding tissue and spread throughout the body Figure 24-2 Alterations in cell-cell interactions and the formation of new blood vessels are associated with malignancy
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Copyright (c) by W. H. Freeman and Company 24.1 DNA from tumor cells can transform normal cultured cells Figure 24-3 Cells that continue to grow when normal cells have become quiescent are said to be transformed Transformed cells may exhibit many of the properties of malignant tumor cells normaltransformed
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Copyright (c) by W. H. Freeman and Company 24.1 The identification and molecular cloning of a specific DNA sequence that causes transformation Figure 24-4
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Copyright (c) by W. H. Freeman and Company 24.1 Epidemiology of human cancers indicates that development of cancer requires several mutations Figure 24-5
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Copyright (c) by W. H. Freeman and Company 24.1 The development of colon cancer is characterized by a well-ordered series of mutations Figure 24-6 Inherited mutations in tumor-suppressor genes increase cancer risk
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Copyright (c) by W. H. Freeman and Company 24.1 Overexpression of multiple oncogenes increases tumor formation Figure 24-7
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Copyright (c) by W. H. Freeman and Company 24.1 Cancers originate in proliferating cells Figure 24-8 Formation of differentiated blood cells from hematopoietic stem cells in the bone marrow
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Copyright (c) by W. H. Freeman and Company 24.2 Proto-oncogenes and tumor-suppressor genes: the seven types of proteins that participate in controlling cell growth Figure 24-9
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Copyright (c) by W. H. Freeman and Company 24.2 Gain-of-function mutations convert proto-oncogenes into oncogenes Oncogenes were first identified in cancer-causing retroviruses The Rous sarcoma virus (RSV) contains a gene (src) that is required for cancer-induction but is not required for viral function Normal cells contain a related gene that codes for a protein-tyrosine kinase The normal gene (c-src) is the proto-oncogene, while the viral gene (v-src) is an oncogene that codes for a constitutively active mutant protein-tyrosine kinase Many DNA viruses also contain oncogenes but these have integral functions in viral replication
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Copyright (c) by W. H. Freeman and Company 24.2 Slow-acting carcinogenic retroviruses can activate cellular proto-oncogenes Figure 24-10
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Copyright (c) by W. H. Freeman and Company 24.2 Loss-of-function mutations in tumor- suppressor genes are oncogenic Figure 24-12 The first tumor-suppressor gene was identified in patients with inherited retinoblastoma
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Copyright (c) by W. H. Freeman and Company 24.2 Loss of heterozygosity of tumor-suppressor genes occurs by chromosome mis-segregation or mitotic recombination Figure 24-13
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Copyright (c) by W. H. Freeman and Company 24.3 Virus-encoded activators of growth- factor receptors act as oncoproteins Figure 24-14
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Copyright (c) by W. H. Freeman and Company 24.3 Activating mutations or overexpression of growth-factor receptors can transform cells Figure 24-15
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Copyright (c) by W. H. Freeman and Company 24.3 A chimeric oncoprotein resulting from chromosomal translocation Figure 24-16
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Copyright (c) by W. H. Freeman and Company 24.3 Constitutively active signal-transduction proteins are encoded by many oncogenes Figure 24-17
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Copyright (c) by W. H. Freeman and Company 24.3 Inappropriate expression of nuclear transcription factors can induce transformation Figure 24-18
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Copyright (c) by W. H. Freeman and Company 24.4 Passage from G 1 to S phase is controlled by proto-oncogenes and tumor-suppressor genes Figure 24-19
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Copyright (c) by W. H. Freeman and Company 24.4 Loss of TGF signaling contributes to abnormal cell proliferation and malignancy Figure 24-20
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Copyright (c) by W. H. Freeman and Company 24.5 Mutations in p53 abolish G 1 checkpoint control Figure 24-21 Some human carcinogens cause inactivating mutations in the p53 gene and p53 activity is also inhibited by certain proteins encoded by DNA tumor viruses
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Copyright (c) by W. H. Freeman and Company 24.5 Defects in DNA-repair systems perpetuate mutations and are associated with certain cancers
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Copyright (c) by W. H. Freeman and Company 24.5 Chromosomal abnormalities are common in human tumors Figure 24-22
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Copyright (c) by W. H. Freeman and Company 24.5 Cancer cells may contain localized regions containing multiple copies of a given DNA sequence Figure 24-23
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