2013-02-18 VIR Tumor Viruses

Question 1

Which RNA viruses are strongly assoc’d with human cancer?
What Family are they in?
What cancers do they cause?

Answer 1

HTLV-1,2 (Human T-cell Leukemia Virus)
—retrovirus family
—causes Cutaneous T-cell lymphoma and adult T-cell leukemia

Hep C
—flavivirus family
—causes hepatocellular carcinoma

Question 2

Which DNA viruses are strongly assoc’d with human cancer?
What Family are they in?
What cancers do they cause?

Answer 2

HPV
—papovaviridae
—causes cervical carcinoma

EBV
—herpesviridae
—Burkitt’s lymphoma; nasopharyngeal carcinoma

Hep B
—Hepadnaviridae
—causes hepatocellular carcinoma

Question 3

What are some ways to detect an oncogenic virus in a tumor?

Answer 3

1. see if a cell-free extract will cause tumor in a) lab animals, b) cell culture
2. Immuno assays (e.g. ELISA, fluoro Abs, W blot)
3. Nucleic acid assay (e.g. PCR, N blot, S blot)
4. check tumor genome itself—will often have incorporated fragment of viral genome

Question 4

What ∆sin morpohology are seen in tumor cells?

Answer 4

• less reg shape

- flat—>rounded

Question 5

What ∆sin biochemistry are seen in tumor cells?

Answer 5

• incr glucose uptake and glycolytic rate
• loss of actin filaments
• secrete a lot of proteinases

Question 6

What ∆s growth occur in tumor cells?

Answer 6

• lose contact inhibition

- reduced GF/serum requirement

Question 7

Which strain(s) of HPV cause most condylomas?

Answer 7

HPV 6b and 11

Question 8

Which strain(s) of HPV cause 75% of cerv carcinomas?

Answer 8

HPV 16 and 18

Question 9

What are the two viral oncogenes in HPV? What do they target?

Answer 9

E6 binds p53 and E7 binds Rb (both tumor suppressor genes)

Question 10

Where is the viral HPV genome in condyloma? Carcinoma?

Answer 10

condyloma - extrachromosomal

carcinoma - integrated

Question 11

Which strain(s) of HPV cause most anal cancer?

Answer 11

HPV 16

Question 12

Generally speaking what do cancer-causing DNA viruses mess with?

Answer 12

tumor suppressor genes