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Carcinogenesis

Carcinogenesis. Format. Introduction What is carcinogenesis Carcinogens Stages of carcinogenesis Multistep theory of carcinogenesis Conclusion. Introduction. Normal cell has Protooncogenes - RAS Tumour supressor genes – P53, RB p. Definition.

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Carcinogenesis

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  1. Carcinogenesis

  2. Format • Introduction • What is carcinogenesis • Carcinogens • Stages of carcinogenesis • Multistep theory of carcinogenesis • Conclusion

  3. Introduction Normal cell has Protooncogenes - RAS Tumoursupressor genes – P53, RB p

  4. Definition • Carcinogenesis / tumourigenesis/oncogenesis • Process by which normal cells are transformed into cancer cells

  5. Carcinogens • A carcinogen is any substance, radionuclide, or radiation that is an agent directly involved in causing cancer. This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes . • Co-carcinogensarechemicals that do not necessarily cause cancer on their own, but promote the activity of other carcinogens in causing cancer.

  6. Types of carcinogens • Carcinogens can be classified as genotoxic or nongenotoxic.  • Genotoxins cause irreversible genetic damage or mutations by binding to DNA. Genotoxins include chemical agents like N-nitroso-N-methylurea (NMU) or non-chemical agents such asultraviolet light and ionizing radiation. Certain viruses can also act as carcinogens by interacting with DNA. • Nongenotoxins do not directly affect DNA but act in other ways to promote growth. These include hormones and some organic compounds • Chemical carcinogens • Physical carcinogens • Biological carcinogens

  7. Chemical carcinogens • Arsenic and its products • Asbestos • Benzene • Cadmium • Chromium • Engine exhaust gas • Ethylene oxide • Radon • Vinyl chloride

  8. Carcinogens in tobacco Tobacco contains • Nitrosamines • Polycyclic aromatic hydrocarbons • Nitrosoproline • Nitrosodicthanolamine • Polonium Tobacco smoke contains • Carbon monoxide • Thiocynate • Hydrogen cynide • Nicotine

  9. Physical carcinogens •  Low-energy waves •  Higher-energy radiation

  10. Oral cancer • Denture irritation • Sharp tooth • Chronic cheek bite

  11. Biological carcinogens • HPV • HSV1 & 2

  12. Other risk factors • Age • Immunity • Habits • Harmones • Genetic suseptibility

  13. Stages

  14. Multistep theory

  15. Conclusion

  16. Thank you

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