Examples of carcinogenic viruses?
What cancers can EBV cause?
What cancer can HBV and HCV cause?
What cancer can HIV-1 cause?
What cancer can HPVs cause?
Cervix, vulva, vagina, penis, anus carcinomas
What is the mechanism of direct carcinogens?
Introduces viral oncogene into host cell
e.g. HPV E6 & 7, EBV
Modified viral oncogene after integration into host cell
e.g. Merkel cell polyomavirus
What is the mechanism of indirect carcinogens?
Induction of chronic inflammation e.g. Hep C
Prevention of apoptosis e.g. HBVs
Virus induced immunosuppression activates other tumour viruses e.g. HIV
What is the genome type of HPV?
Small dsDNA virus
What two factors drive proliferation in HPV?
E6 & E7
What does E6 act on in HPV?
p53 and stops cell death
What does E7 act on in HPV?
Retinoblastoma (Rb) to cause progression from G1 to S phase of the cell cycle
What does the vaccine Cervarix protect against?
Cervical cancer; HPV16 and HPV18
What does the vaccine Gardasil protect against?
Cervical cancer; HPV6, 11, 16, 18
How do cervical cancer vaccines work?
Prophylactically not therapeutically; they coat the virus with neutralising antibodies which blocks it from binding