elo 174 slide viruses and cancer

12/4/2010

VIRUSES AND CANCER
Bidasari Lubis
Child Heatlh Departement University of
Sumatera Utara - Medan

Introduction
• Relationship between human oncogenic
viruses and cancer werw established mostly
in last quarter of the 20th century.
• Virus infection : second major preventable
cancer risk factor after tobacco use
• Immunization program againts HBV in
Taiwan, Gambia succesfully lowered HCC .
• HPV vaccine (2006) reduced death cervical
cancer by 75%

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Introduction
Virus implicated 15% of all cancer:
1. Nasopharyngeal carcinoma
2. Burkitt’s lymphoma
3. Cervical carcinoma
4. T-cell leukemia
5. Hepatocellular carcinoma
6. Kaposi’s sarcoma

Observation viruses may cause cancer

• 1908:Vilhelm Ellerman and Oluf Bang
• 1911:Peyton Rous

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Human oncogenic viruses

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Hepatitis B virus (HBV)
Hepatitis C virus (HCV)
Human Papilloma virus (HPV)
Epstein-Barr Virus (EBV)
Kaposi’s sarcoma – associated
Herpesvirus (KSHV)
• Human T-cell Leukemia virus-1 (HTLV-1)

Mechanisms of virus –induced cellular
transformation
The oncogenic mechanism used by different
viruses differ significantly.
1. Perturbation of signaling pathways
2. Deregulation of the cell cycle

3. Escape of apoptosis
4. Immrotalization of cells
5. Induction of genetic instability
6. Insertional mutagenesis
7. Induction of chronic inflammation

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