Oncogenic Viruses Flashcards
What are two methods that retroviruses can cause cancer in animal models?
1- they contrain oncogenes
2- they can insert their promoter into a chromosome and cause expression of host genes
***mechanism is unknown in HUMANS
How do oncogenic DNA viruses cause cancer?
encode proteins that disturb cell cycle and prevent apoptosis–> inactive p53 or Rb
What are the “oncogenic” viruses that do NOT cause cancer in HUMANS?
SV40 virus, Adenovirus
What virus is linked to squamous cell carcinoma of the cervix, penis, and oropharynx?
HPV
What HPV genes are responsible for its cancer-causing ability? How?
E6–> binds p53 –> degrades ubiquitin pathway
E7–> binds Rb–> prevents interaction with E2 which suppresses E6 and E7
T/F: the HPV vaccine has significantly reduced the prevalence of cervical cancer.
FALSE! no change BUT the vaccines have reduced incidence of CIN
How many HPV vaccines are there? What are they made of?
2 vaccines! made of empty viral capsids
What virus is associated with Burkitt’s lymphoma? Where is it most prevalent?
EBV
Africa
What other cancer is associated with EBV besides Burkitt’s lymphoma? Where is it common?
naso-pharyngeal cancer
ASIA
What does Hepatitis B virus cause?
chronic hepatitis –> cirrhosis –> hepatocellular carcinoma
Which oncogenic virus has a vaccine that has shown to reduce cancer?
Hep B virus vaccine
What oncogene is seen in Burkitt lymphoma?
myc
Name that virus:
RNA virus that causes leukemia and lymphoma
Human T-cell lymphotropic virus (HTLV-1, HTLV-2)
how does HTLV cause cancer?
tax gene causes over expression of IL2 and the receptor for IL2, other proteins dysregulate RNA metabolism
where do you see HTLV commonly?
Caribbean
