Oncogenic Viruses
| Auteur: | Microbiology and Immunology on-line University of South Carolina |
| Tags: | Foto's/dia's Lessen/cursussen Leerboek Video's Virussen Hoger onderwijs Middelbaar onderwijs Engels Algemene microbiologie |
| Bron: | http://pathmicro.med.sc.edu/lecture/RETRO.HTM 
Melding defecte link. |
Viruses that cause cancer and the mechanisms by which they do so: DNA cancer viruses (polyoma, herpes, papilloma, hepatitis, adenovirus). RNA cancer viruses (retroviruses) To learn which viruses can cause cancer in humans To learn how cells become transformed by the virus To learn the differences between DNA and RNA tumor viruses To understand how RNA viral oncogenes result in cell transformation Cancers are the result of a disruption of the normal restraints on cellular proliferation. It is apparent that the number of ways in which such disruption can occur is strictly limited and there may be as few as forty cellular genes in which mutation or some other disruption of their expression leads to unrestrained cell growth. There are two classes of these genes in which altered expression can lead to loss of growth control: (a) Those genes that are stimulatory for growth and which cause cancer when hyperactive. Mutations in these genes will be dominant. These genes are called oncogenes. (b) Those genes that inhibit cell growth and which cause cancer when they are turned off. Mutations in these genes will be recessive. These are the anti-oncogenes or tumor-suppressor genes. Viruses are involved in cancers because they can either carry a copy of one of these genes or can alter expression of the cell's copy of one of these genes. To understand the discovery of cellular proto-oncogenes To learn how cellular oncogenes may cause cancer in the absence of a virus To learn understand how these discoveries led to the discovery of anti-oncogenes To understand how the discovery of anti-oncogenes showed how DNA viruses may cause cancer
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