L06 Viruses and cancer

Question 1

Examples of carcinogenic viruses?

Answer 1

EBV
HBV
HPV
HIV-1

Question 2

What cancers can EBV cause?

Answer 2

Nasopharyngeal carcinoma

Lymphomas

Question 3

What cancer can HBV and HCV cause?

Answer 3

Hepatocellular carcinoma

Question 4

What cancer can HIV-1 cause?

Answer 4

Lymphomas
Cervical cancer
Anal cancer

Question 5

What cancer can HPVs cause?

Answer 5

Cervix, vulva, vagina, penis, anus carcinomas

Question 6

What is the mechanism of direct carcinogens?

Answer 6

Introduces viral oncogene into host cell
e.g. HPV E6 & 7, EBV

or

Modified viral oncogene after integration into host cell
e.g. Merkel cell polyomavirus

Question 7

What is the mechanism of indirect carcinogens?

Answer 7

Induction of chronic inflammation e.g. Hep C
Prevention of apoptosis e.g. HBVs
Virus induced immunosuppression activates other tumour viruses e.g. HIV

Question 8

What is the genome type of HPV?

Answer 8

Small dsDNA virus

Question 9

What two factors drive proliferation in HPV?

Answer 9

E6 & E7

Question 10

What does E6 act on in HPV?

Answer 10

p53 and stops cell death

Question 11

What does E7 act on in HPV?

Answer 11

Retinoblastoma (Rb) to cause progression from G1 to S phase of the cell cycle

Question 12

What does the vaccine Cervarix protect against?

Answer 12

Cervical cancer; HPV16 and HPV18

Question 13

What does the vaccine Gardasil protect against?

Answer 13

Cervical cancer; HPV6, 11, 16, 18

Question 14

How do cervical cancer vaccines work?

Answer 14

Prophylactically not therapeutically; they coat the virus with neutralising antibodies which blocks it from binding