23.1 cancer is a group of diseases characterized by cell proliferation
TRANSCRIPT
![Page 1: 23.1 Cancer Is a Group of Diseases Characterized by Cell Proliferation](https://reader030.vdocuments.site/reader030/viewer/2022032612/56649ef15503460f94c02b49/html5/thumbnails/1.jpg)
23.1 Cancer Is a Group of Diseases Characterized by Cell Proliferation
![Page 2: 23.1 Cancer Is a Group of Diseases Characterized by Cell Proliferation](https://reader030.vdocuments.site/reader030/viewer/2022032612/56649ef15503460f94c02b49/html5/thumbnails/2.jpg)
Tumor Formation: A Distinct Mass of Abnormal Cells
• Benign tumor: the tumor remains localized.
• Malignant tumor: tumor cells invade other tissues.
• Metastasis: the tumor cells induce secondary tumors.
![Page 3: 23.1 Cancer Is a Group of Diseases Characterized by Cell Proliferation](https://reader030.vdocuments.site/reader030/viewer/2022032612/56649ef15503460f94c02b49/html5/thumbnails/3.jpg)
Cancer as a Genetic Disease
• The clonal evolution of tumors
• The tumor cells acquire more mutations that allow them to become increasingly more aggressive in their proliferate properties.
![Page 4: 23.1 Cancer Is a Group of Diseases Characterized by Cell Proliferation](https://reader030.vdocuments.site/reader030/viewer/2022032612/56649ef15503460f94c02b49/html5/thumbnails/4.jpg)
![Page 5: 23.1 Cancer Is a Group of Diseases Characterized by Cell Proliferation](https://reader030.vdocuments.site/reader030/viewer/2022032612/56649ef15503460f94c02b49/html5/thumbnails/5.jpg)
Role of Environmental Factors in Cancer
![Page 6: 23.1 Cancer Is a Group of Diseases Characterized by Cell Proliferation](https://reader030.vdocuments.site/reader030/viewer/2022032612/56649ef15503460f94c02b49/html5/thumbnails/6.jpg)
![Page 7: 23.1 Cancer Is a Group of Diseases Characterized by Cell Proliferation](https://reader030.vdocuments.site/reader030/viewer/2022032612/56649ef15503460f94c02b49/html5/thumbnails/7.jpg)
23.2 Mutations in a Number of Different Types of Genes Contribute to Cancer
![Page 8: 23.1 Cancer Is a Group of Diseases Characterized by Cell Proliferation](https://reader030.vdocuments.site/reader030/viewer/2022032612/56649ef15503460f94c02b49/html5/thumbnails/8.jpg)
Oncogenes and Tumor-Suppressor Genes
• Oncogene: dominant-acting stimulatory genes that cause cancer
• Proto-oncogenes: responsible for basic cellular functions in normal cells; when mutated, they become oncogenes.
![Page 9: 23.1 Cancer Is a Group of Diseases Characterized by Cell Proliferation](https://reader030.vdocuments.site/reader030/viewer/2022032612/56649ef15503460f94c02b49/html5/thumbnails/9.jpg)
Tumor-Suppressor Genes
Inhibit cancer and recessive acting; when mutated, normal cells become cancerous.
![Page 10: 23.1 Cancer Is a Group of Diseases Characterized by Cell Proliferation](https://reader030.vdocuments.site/reader030/viewer/2022032612/56649ef15503460f94c02b49/html5/thumbnails/10.jpg)
![Page 11: 23.1 Cancer Is a Group of Diseases Characterized by Cell Proliferation](https://reader030.vdocuments.site/reader030/viewer/2022032612/56649ef15503460f94c02b49/html5/thumbnails/11.jpg)
![Page 12: 23.1 Cancer Is a Group of Diseases Characterized by Cell Proliferation](https://reader030.vdocuments.site/reader030/viewer/2022032612/56649ef15503460f94c02b49/html5/thumbnails/12.jpg)
![Page 13: 23.1 Cancer Is a Group of Diseases Characterized by Cell Proliferation](https://reader030.vdocuments.site/reader030/viewer/2022032612/56649ef15503460f94c02b49/html5/thumbnails/13.jpg)
![Page 14: 23.1 Cancer Is a Group of Diseases Characterized by Cell Proliferation](https://reader030.vdocuments.site/reader030/viewer/2022032612/56649ef15503460f94c02b49/html5/thumbnails/14.jpg)
![Page 15: 23.1 Cancer Is a Group of Diseases Characterized by Cell Proliferation](https://reader030.vdocuments.site/reader030/viewer/2022032612/56649ef15503460f94c02b49/html5/thumbnails/15.jpg)
Genes That Control the Cycle of Cell Division
•Checkpoints that halt cell division•Initiators that act as signals to begin cell divsion
![Page 16: 23.1 Cancer Is a Group of Diseases Characterized by Cell Proliferation](https://reader030.vdocuments.site/reader030/viewer/2022032612/56649ef15503460f94c02b49/html5/thumbnails/16.jpg)
![Page 17: 23.1 Cancer Is a Group of Diseases Characterized by Cell Proliferation](https://reader030.vdocuments.site/reader030/viewer/2022032612/56649ef15503460f94c02b49/html5/thumbnails/17.jpg)
• Signal-transduction pathways• A cascade of intracellular reactions
• DNA repair genes• Genes that regulate telomerase• Inappropriate activation of telomerase may
lead to cancer.• Genes that promote vascularization and the
spread of tumors
![Page 18: 23.1 Cancer Is a Group of Diseases Characterized by Cell Proliferation](https://reader030.vdocuments.site/reader030/viewer/2022032612/56649ef15503460f94c02b49/html5/thumbnails/18.jpg)
23.3 Changes in Chromosome Number and Structure Are Often Associated with Cancer
• Example:
A reciprocal translocation between chromosome 9 and 22 causes chronic myelogenous leukemia.
![Page 19: 23.1 Cancer Is a Group of Diseases Characterized by Cell Proliferation](https://reader030.vdocuments.site/reader030/viewer/2022032612/56649ef15503460f94c02b49/html5/thumbnails/19.jpg)
![Page 20: 23.1 Cancer Is a Group of Diseases Characterized by Cell Proliferation](https://reader030.vdocuments.site/reader030/viewer/2022032612/56649ef15503460f94c02b49/html5/thumbnails/20.jpg)
23.4 Viruses Are Associated with Some Cancers
• Retroviruses cause cancer by
• mutating and rearranging proto-oncogenes
• inserting strong promoters near proto-oncogenes
![Page 21: 23.1 Cancer Is a Group of Diseases Characterized by Cell Proliferation](https://reader030.vdocuments.site/reader030/viewer/2022032612/56649ef15503460f94c02b49/html5/thumbnails/21.jpg)
![Page 22: 23.1 Cancer Is a Group of Diseases Characterized by Cell Proliferation](https://reader030.vdocuments.site/reader030/viewer/2022032612/56649ef15503460f94c02b49/html5/thumbnails/22.jpg)
![Page 23: 23.1 Cancer Is a Group of Diseases Characterized by Cell Proliferation](https://reader030.vdocuments.site/reader030/viewer/2022032612/56649ef15503460f94c02b49/html5/thumbnails/23.jpg)
23.5 Changes in DNA Methylation Are Often Associated with Cancer
• Epigenetic process:
• Reversible genetic alterations
![Page 24: 23.1 Cancer Is a Group of Diseases Characterized by Cell Proliferation](https://reader030.vdocuments.site/reader030/viewer/2022032612/56649ef15503460f94c02b49/html5/thumbnails/24.jpg)
23.6 Colorectal Cancer Arises Through the Sequential Mutation of a Number of Genes
![Page 25: 23.1 Cancer Is a Group of Diseases Characterized by Cell Proliferation](https://reader030.vdocuments.site/reader030/viewer/2022032612/56649ef15503460f94c02b49/html5/thumbnails/25.jpg)