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Flashcards in Viral Oncogenesis II Deck (35)
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1

What is Merkel Cell Carcinoma (MCC)

highly aggressive neuroendocrine carcinoma of the skin w/ a high propensity of recurrence and metastasis

2

5-year disease-specific survival rate for Merkel Cell Carcinoma (MCC)

60%

3

virus associated with Merkel Cell Carcinoma (MCC)

Merkel cell polyomavirus (MCV)

4

how common is the Merkel cell polyomavirus

rare but incidence is rapidly increasing

5

is Merkel Cell Polyomavirus associated with all Merkel Cell Carcinoma

it is associated with most of it but not all of it; about 20 - 30% of cases of MCC do not have the MCV virus and have a distinct pathoetiology

6

genome that Hep B and C are associated with

Hep B - DNA
Hep C - RNA

7

organ that Hep B and Hep C virus infect

they infect and damage the liver so you get classical symptoms of jaundice and liver enzyme release

8

80% of all Primary Hepatocellular Carcinoma (PHC) can be attributed to what virus

chronic HBV infection

9

prognosis if a pt has PHC

usually fatal -- one of the three most common causes of cancer mortality in the world

10

what type of virus is HBV

Hepadnavirus (class VII)

11

how is HBV spread

blood or needles, sexual contact, and
perinatally

12

median incubation period of HBV

3 months which then icterus symptoms begin

13

what do 5-10% of pts with PHC eventually develop

chronic hepatitis

14

percentage of the world's population that has been infected with HBV and how many die from it annually

1/3 of world infected

1-2 million deaths/year

15

why has the incidence of HBV gone down

vaccination

16

HBV has a tissue tropism for what organ and what happens when in that organ

liver
integrates into the host chromosome and stimulate cell growth

17

oncoprotein associated with HBV

HBx

18

type of virus is Hep C

flavivirus (Class IV so (+) ssRNA)

19

how long does it take for Hep C to develop into cancer

10-50 years (30 years being median)

20

when someone contract HCV acute infection, what are the three fates

-15%: recovery and clearance
-15%: cirrhosis rapid onset
-70%: persistent infection with 40% being asymptomatic and other 30% definitely leading to chronic hepatitis

21

of the 30% of those with HCV that eventually become chronic hepatitis, what is their fate

-6% liver failure
-20% cirrhosis
-4% hepatocellular carcinoma

22

only known retrovirus known to cause cancer in humans

HTLV-1 (RNA tumor virus)

23

what do retroviruses carry with their regular genes

they carry oncogenes that they can integrate at particular sites in the host cell

24

example of fast acting and slow/transacting RNA tumor cancer

fast: acute leukemia or sarcoma
slow: leukemia

25

what is significant about leukemia virus' replication (including HTLV-1)

replication is competent but they cannot transform cells in vitro

26

how long does it take for HTLV-1 to cause cancer

after a long latency period usually about 30 years

27

how does HTLV-1 promote cell growth

in more indirect ways than the oncogene encoding viruses

28

what is associated with myelopathy (tropical spastic paraparesis)

Adult acute T-cell lymphocytic leukemia (ATLL) and HTLV 1

29

is HTLV-1 only associated with neoplastic diseases

no they are also associated with nonneoplastic neurologic disorders

30

what is the importance of HTLV-1 having the tax protein

activates promoters in LTR region and specific cellular genes (promote outgrowth of the cell)