PHARM A45/46: Viruses and Cancer Flashcards
What are the common characteristics shared by human tumor viruses?
High infections rate, low cancer rates; cancer occurs after many years after viral infection; virus required for initiation events;viral genomes become integrated into host chromosome as virus initiates cancer development
What phase of the cell cycle do parvoviruses require for replication? What is the exception?
S phase unless the cell is co-infected with an adeno or herpes virus
What is transformation of a cell?
Alteration in a cells properties that leads to immortalization and different growth patterns that result in alteration in the cell cycle
What cellular properties come with transformation?
Loss of anchorage dependence, loss of contact inhibition of growth, and decreased requirements for growth factors
How do herpes viruses interfere with tumor suppressor Rb? HPV? Polyoma viruses?
The virus has E1A that binds to and inhibits pRb; HPV has E7 protein which binds to pRb and releases E2F; Large T inhibits Rb
How does human papilloma virus interfere with p53?
E6 which binds to p53 and tags it with ubiquitin for proteosomal degradation
What kind of cancer is associated with Human T-cell Lymphotrophic Virus Type 1 (HTLV-1)?
Adult T-cell Leukemia/ Lymphoma (ATLL)
What is the characteristic cell morphology of ATL?
Flower cell morphology
True or False: HTLV-1 has no traditional oncoproteins.
True
What is the mechanism by which HTLV-1 increases the likely hood of developing ATL?
Viral Tax protein induces IL-2 and GM-CSF expression stimulating T cells to enter a proliferative phase
What is the most common viral STD?
Papilloma
What kind of cancer is associated with JC virus?
Progressive Multifocal Leukoencephalopathy
What condition is association with BK virus?
Hemmorrhagic cystitis
What condition is potentially a consequence of Merkel cell virus infection?
Merkel cell melanoma
What are the risk factors for developing Merkel cell carcinoma?
Exposure to a lot of sunlight or artificial sunlight, immune system weakened by disease, organ transplant, being older than 50 yrs old, male or white
What types of Papillomavirus causes plantar and common warts?
1 and 2
What type of Papillomavirus causes condylomata (genital warts) and laryngeal warts?
6 and 11
What type of Papillomavirus causes anogenital malignancies?
16 and 18
True or False: HIV can exacerbate infection and development of cancer.
True
What is the 2nd most common malignancy in women world wide?
Cervical
What is the HPV’s preferential target in the vagina?
A narrow transformation zone between the transition from columnar epithelium to the original squamocolumnar
What is L1?
Capsid protein of HPV that is used as a diagnostic PCR target and vaccine target
What are the hallmarks of an abnormal pap smear?
Dyskaryosis, Microvascularization; Perinuclear clearing, and nuclear enlargement
What types of HPV are targeted by Gardasil?
6,11,16,18
During which phase of the alpha herpes viral life cycle does disease present?
Lytic phase
During which phase of the gamma herpes viral life cycle does disease present?
Latency
What is the tropism of EBV and KSHV?
Epithelial cells, endothelial cells, and B cells
How is EBV and KSHV transmitted?
Contact, kissing, sexual
What test is used to differentiate CMV vs. EBV mononucleosis
Monospot test
What population is most susceptible to KSHV-associated cancer?
HIV/AIDS patients
True or False: EBV and KSHV do not produce proteins that activate cell signaling pathways
True
What cell type is the site of latency for viral EBV infection?
B cells
What is EBV-associated mononucleosis characterized by?
Production of heterophile antibodies
What signalling cascae is initiated by the binding of CD40 with CD40L
NFkB and AP-1
All forms of Burkitt’s lymphoma have what type of oncogene?
c-Myc
What EBV protein is found in Burkitt’s Lymphoma tissues?
EBNA1
How does Kaposi’s sarcoma present?
Multiple bluish-black papular nodules on the skin, mucous membranes and viscera
What are the components of CHOMP chemotherapy?
Cyclophosphamide, Hydroxy-daunorubicin, ncovin, Methotrexate, Prednisone
What is rituximab
A mAb against CD20
