There are 2 main categories of oncogenic viruses DNA and RNA. One of the first viruses to be recognized was the Rous ___ virus. This virus was noted to contain a mutated version of which normal gene? This virus caused the development of ____ (type of tumors) in what species? This virus is what type of virus (DNA or RNA)?
Rous sarcoma virus v-src Sarcomas Chickens RNA/retrovirus
The process of recombination of cellular and viral retroviral genes in front of a cellular oncogene is called ____.
Transduction
For the following viruses, say whether they are DNA or retroviruses (RNA).
- Hepatitis B Virus.
* Assoc with what tumor type?
* What animal has also been shown to induce tumor formation by this virus
* In this animal what gene is often affected? - Hepatits C Virus.
- HTLV
- HIV
* What subcategory of virus does this belong to? - Adenovirus
- Epstein Barr Virus
* Associated w/ what cancer type? - FeLV
- Papillomavirus (HPV)
* Assoc with what cancer type?
* How does it cause tumor formation?
- Hepatitis B - DNA
* Assoc w HCC
* Woodchuck hepatitis virus
* Myc affected in woodchuck! - Hepatitis C - same family as W. Nile
- HTLV - retrovirus (Adult T cell leukemia)
- HIV - RNA (lentivirus)
- Adenovirus - DNA (used for vax bc very immunogenic but cn be used repeatedly dt IR)
- Epstein Barr - Burkitt’s LSA - B cell LSA w/ translocation bt c-myc and IgG heavy chain or light chain. Results in deregulation of c-myc expression (overexpressed since near IgG locus)
- FeLV - retrovirus
- HPV - DNA
* Cervical carcinoma
* Targets p53 for degradation (via ubiquitin pathway) leading to decrease p53 functional in the cells leading to decreased tumor surveillance and t/f tumor production
In Hodgkin’s LSA,
What is malignant cell type?
What other cells commonly seen in association w/ these (ie. what cell is classic hallmark and what other group of non-cancerous cells are often seen in association w/ this diagnosis)
Hodgkin’s is a malignant mononuclear B cell LSA.
Other malignant cells include the multi-nuclear Reed Sternberg cells. These two cell types are set amongst background of reactive non-malignant lymphs.
RSCs are generally non-B/non-T and have escaped apoptosis
Retroviruses have 3 main genes. Describe their functions:
ENV - envelope protein - a glycoprotein w/in the envelope that surrounds the core of the virus
GAG - makes the nuclecapsid core which contains 2 IDENTICAL single strands of viral RNA that are linked together at the 5’ ends
POL - reverse transcriptase enzyme (polymerase)
There are 2 main categories of retroviruses - acute and chronic.
Explain the difference bt these 2 groups and give 1 example of each
Acute transforming viruses - rapidly transforming viruses. Contain viral oncogenes. Are replication deficient and need a competent partner in order to replicate. No introns present so transformation can occur quickly.
Ex: Feline Sarcoma Virus - affects signaling
Chronic or slowly transforming retroviruses do not have oncogenes. They transform by inserting the viral genome into chromosomal DNA (INSERTIONAL MUTAGENESIS) - proviral integration into normal genome leads to activation of oncogene in the normal genome or inactivation of a TSG - not as random as previously thought…which is why can see same mutation in multiple individuals.
Ex: Avian Leukemia Virus - induces B cell LSA by transforming myc (FeLV, Mouse Mammary tumor virus)
