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Virus and Cancer

Virus and Cancer. Viruses are usually not complete carcinogens in human cancers Tumor viruses establish chronic infections in humans Cancer is an accidental side of viral replication strategy. Two classes of genes.

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Virus and Cancer

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  1. Virus and Cancer

  2. Viruses are usually not complete carcinogens in human cancers • Tumor viruses establish chronic infections in humans • Cancer is an accidental side of viral replication strategy

  3. Two classes of genes • Oncogenes: These are stimulatory for growth, cause cancer when hyperactive. • Tumor-suppressor genes: genes that inhibit cell growth and cause cancer when turned off.

  4. How do Virus get involved? • Virus can either carry a copy of one of these genes or can alter expression of the cell’s copy.

  5. What is a virus? • Non-living particle • Consisting of proteins and nucleic acid, either DNA or RNA at its core A Virus

  6. RNA • Can not replicate on its own, uses host machinery to replicate. • Entrance is gained through receptors on the cells. • Once inside, viral RNA is reverse read to make a segment of DNA Reverse Transcriptase

  7. Viral Replication 4 steps 1. Attachment and entrance 2. Synthesis of proteins 3. Assembly of new virus 4. Release of new virus particles (lytic or lysis) http://schoolworkhelper.net/viral-replication-lytic-cycle/

  8. Virus to Cancer • DNA Tumor viruses 2 life styles • A permissive cell: all viral parts are replicated • Lysis and death of cell • A non-permissive cell: DNA integrated into the cell chromosome randomly. • Only parts are expressed • No progeny released.

  9. How the virus works in two disorders • Hepatitus C • Cervical Cancer

  10. P53 (tumor suppressor) P53 gene P53 gene P53 gene Papilloma Hepatitis C P53 P53 P53 Papilloma proteolysis P53 DNA Stops replication replication replication

  11. Hepatitus C • Viral proteins interact with p53 and lead to cell proliferation and prevents apoptosis • Transfers by blood • Liver damage, such as cirrhosis, or scarring of the liver • Liver failure • Need for a liver transplant • Liver cancer • Death

  12. Human Papillomavirus • DNA Virus • 8 kilobases long • >100 types of HPV • Cause warts – benign • Malignant carcinomas • epidermodysplasiaverruciformis • Autosomal recessive mutation • leads to abnormal uncontrolled virus replication. • Penile, uterine, cervical, canal carcinomas http://www.ansci.wisc.edu/jjp1/ansci_repro/misc/project_websites_07/tue07/HPV_Vaccine/What%20is%20HPV.html

  13. HPV

  14. Cervical Cancer • New cases 2012 US: 12,170 • Deaths: 4,220 • average age at death 57 yrs • Incidence rate: • 8.1 per 100,000 women • Hispanics 11.8 per 100,000 women • Lifetime Risk for women born today- 1 in 147. • All statistics from the National Cancer Institute, Surveillance Epidemiology and End Results.

  15. Symptoms

  16. Diagnosis

  17. Treatment • Precancerous lesions • Cryosurgery (freezing) • Leep- loop electrosurgical excision procedure. • Laser vaporization • Cancerous tissue • Surgery • Radiation • Chemotherapy

  18. New Treatment: Guardacil • From the U of Rochester • HPV Vaccine • Protects against 4 types of HPV • “2 types of HPV that cause about 75% of cervical cancer cases, and 2 more types that cause 90% of genital warts cases. In boys and young men ages 9 to 26, GARDASIL helps protect against 90% of genital warts cases” • (Guardacil.com)

  19. How a vaccine works

  20. Cutting edge research • Penn Medicine, University of Pennsylvania • Immunotherapy program • Personalizing approach that boosts the bodies own immune system to attach tumors. • Using the patients own tumor proteins in a vaccine. http://www.uphs.upenn.edu/obgyn/research/ovarian_clinical.htm

  21. Conclusion • Virus can show up in the DNA of a host, damaging the cell cycle, causing uncontrolled growth of a cell. • Virus that are carcinogenic are passed in body fluids. • Be safe. • Consider a vaccine to help prevent cervical cancer.

  22. References Hunt, R. 2009. Microbiology and Immunology on-line, University of South Carolina School of Medicine. http://pathmicro.med.sc.edu/lecture/retro.htm Howlader N, Noone AM, Krapcho M, Neyman N, Aminou R, Altekruse SF, Kosary CL, Ruhl J, Tatalovich Z, Cho H, Mariotto A, Eisner MP, Lewis DR, Chen HS, Feuer EJ, Cronin KA (eds). SEER Cancer Statistics Review, 1975-2009 (Vintage 2009 Populations), National Cancer Institute. Bethesda, MD National cancer institute. National institute of health. http://www.cancer.gov/cancertopics/pdq/treatment/cervical/Patient/page2 Ovarian Research. Penn Medicine, University of Pennsylvania. Available at http://www.uphs.upenn.edu/obgyn/research/ovarian_clinical.htm

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