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10.11 Tumor Viruses
at 2:40 by Dr. Hagensee
68
Microbiology
Professional
10/11/2011

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Cards

Term
T/F Virus-induced cancers respond to anti-viral medication.
Definition
false
Term
How do you prove that viruses cause human cancer?
Definition
1) strong epidemiologic evience 2) viral elements responsible for cancer are found and expressed in tumor cells 3) virus can cause tumors in-vitro 4) a reasonable mechanism of action has been established
Term
What are Koch's postulates?
Definition
1) MO found in organisms suffering from dz but not in healthy organisms 2) MO isolated and grown 3) cultured MO cause dz in healthy organism 4) MO reisolated from infected organism
Term
What cancer does polyoma virus cause?
Definition
merkel's cell
Term
Up to ___% of all human cancers are related to viruses.
Definition
20
Term
What are the common characteristics of human tumor viruses?
Definition
1) high infection rates, low cancer rates. 2) cancer occurs many years after viral infection 3) virus required for initiation events-allows cells to outlive their usual lifespan. 4) requires other factors (promoters) for cancer
Term
Does HIV cause cancer?
Definition
increased risk of cancer with HIV thought to be due to a lack of immune surveillance and not directly due to HIV.
Term
What population is at a higher risk for viral-induced cancers?
Definition
immune suppressed
Term
HIV + EBV infection in children can cause what type of neoplasm?
Definition
leimyomas and leimyosarcomas
Term
T/F ATLL is usually deadly in 6 months.
Definition
False, can be deadly in 6 months but also can be very mild
Term
What percent of pts with ATLL are seropositive for HTLV-1?
Definition
100%
Term
If there is an ATLL endemic area, you can assume that ___% of the population has HTLV-1.
Definition
30%
Term
What percent of HTLV-1 infected individuals develops cancer?
Definition
1-4%
Term
How long does it take after infection with HTLV-1 to get cancer?
Definition
20-30 years later
Term
What types of cells are infected by HTLV-1?
Definition
CD4+
Term
HTLV-1 causes cancer via a transcription factor called...
Definition
tax
Term
What type of illness does HHV-8 cause upon primary infection?
Definition
infectious mononucleosis-like illness
Term
What virus is associated with primary effusion lymphoma (B cell lymphoma)?
Definition
HHV-8
Term
KS and PEL are more common in patients with HIV or patients who___.
Definition
are transplant recipients
Term
What percent of KS patients have HHV8?
Definition
67-80%
Term
How does HHV-8 cause cancer?
Definition
vCyc causes cellular proliferation
vFLIP, LANA- inhibit cell death
vMip-III- causes angiogenesis
may cause a robust inflammatory immune response (IFN-gamma, IL-1,IL-6) which leads to angiogenesis
Term
What is the treatment for HHV-8?
Definition
HIV anti-retrovirals or reduce immune suppression if possible (intralesional or systemic chemotherapy)
Term
Hep B increases your risk of liver cancer by ___x.
Definition
100
Term
Hep B DNA is found in what percent of HCC?
Definition
85% (most integrated >75%)
Term
How long does it take to get cancer from Hep B?
Definition
more than 30 years
Term
What are the two theories of how hep B causes cancer?
Definition
1) chronic inflammation and cell regeneration
2) x gene
Term
How does the x gene of Hep B cause cancer?
Definition
154 gene is weakly tumorigenic and can activate other genes in the cell such as NFkB, activates ras, JNK, JAK-STAT. Also activates the ERK pathway and binds to CREB
Term
How do you prevent/treat hep B?
Definition
prevent with vaccine. Chronic infection has no cure. HCC can be treated with surgery, chemotherapy.
Term
What percent of hep C infection progresses to chronic disease?
Definition
50%
Term
How does hep C cause cancer?
Definition
1) NS3: N terminus has transforming ability
2) NS5A- regulate proliferation or nothing
Term
How do you prevent/treat hep C?
Definition
no vaccine, decrease high-risk behavior
chronic infection: pegylated interferon-alpha + ribavirin (50%) cure rates
HCC: surgery, chemotherapy
Term
What percent of Burkitt's lymphoma is positive in Africa vs. america?
Definition
96% African
30% American
Term
What percent of nasopharyngeal CA is EBV +?
Definition
100%
Term
What percent of hodgkin's disease is EBV+?
Definition
50%
Term
Where is nasopharyngeal ca common and how do you screen for it?
Definition
southern china and certain native americans; measure IgA antibodies against EBV
Term
What percent of pediatric versus young adult cases of Hodgkin's are EBV+?
Definition
pediatric 70%
young adult 15%
Term
T/F EBV related HD is more aggressive.
Definition
true
Term
Who is at risk for hodgkin's disease?
Definition
increased in third world, hispanic, men, and HIV+
Term
What percent of immunoblastic lymphoma is EBV+?
Definition
100%
Term
What patient population gets immunoblastic lymphoma?
Definition
immunosuppressed (T cells): HIV, BMT, renal transplant
Term
What percent of lymphoproliferative disorder is EBV+?
Definition
100%
Term
When do patients get lymphoproliferative disorder?
Definition
post transplant
Term
What's the connection with gastric carcinoma and EBV?
Definition
10% of gastric ca are EBV + and EBV is found in 100% of the cells in the tumor (monoclonal)
Term
What EBV proteins does burkett's lymphoma have?
Definition
EBNA-1
Term
What EBV proteins does Hodgkin's have?
Definition
EBNA1 and LMP1
Term
What EBV proteins does NPC have?
Definition
EBNA-1 and LMP-1
Term
What EBV proteins does Mononucleosis have?
Definition
EBNA-1, EBNA-2, LMP-1
Term
What EBV proteins does PTLD have?
Definition
EBNA-1, EBNA-2, LMP1
Term
How does EBV cause Burkitt's lymphoma?
Definition
75% have c-myc-mu chain translocation
Term
What are EBNAs?
Definition
epstein barr nuclear antigens: activators of B cell regulatory proteins
Term
What is LMP-1?
Definition
late membrane protein 1 (activates other host genes)
Term
What virus can cause merkel cell carcionma?
Definition
polyomavirus
Term
How does polyomavirus cause merkel cell carcinoma?
Definition
large T antigen is mutated in cases of merkel's--> likely leads to cancer
Term
Which HPV strains cause plantar and common warts?
Definition
1,2
Term
Which HPV strains cause condylomata and laryngeal warts?
Definition
6, 11
Term
Which HPV strains cause anogenital malignancies?
Definition
16,18
Term
Cervical cancer is the ____ most common malignancy of women world wide.
Definition
2nd
Term
What is the mortality of cervical cancer?
Definition
35%
Term
How do you detect HPV infection?
Definition
clinical: genital warts, epithelial defects
cellular changes caused by virus via pap
DNA hypridization or PCR
detection of antibody against HPV (laboratory only)
Term
What percent of cervical and anal cancers have HPV DNA? oral cancers?
Definition
90%
33%
Term
Which oncogenic genes of HPV are expressed in tumors?
Definition
E6 and E7
Term
What increases your risk of HPV/HPV cancer?
Definition
increased number of sexual partners, smoking, immune suppression (HIV infection, renal transplant)
Term
What is the funciton of E6?
Definition
E6 ubiquinates p53 so that P53 is tagged for destruction
Term
How does E7 protein from HPV cause cancer?
Definition
binds and inhibits the function of the tumor suppressor gene Rb
Term
How does HPV repress the E2 gene?
Definition
by integrating into the host chromosome at the E2 gene and disrupting it.
Term
T/F E6 and E7 of low risk strains of HPV bind/degrade/suppress p53 and Rb respectively.
Definition
FALSE! they do not because they are low risk
Term
What strains of HPV are in the Merck vaccine Gardasil?
Definition
16,18,6,11
Term
Which HPV strains are in the GSK vaccine Cerverix?
Definition
HPV 16, 18
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