#5 Oncogenesis Flashcards
Oncoviruses are necessary but NOT _____for cancer devo.
sufficient
Many/most people infected with a given virus do not devo the cancer that the virus can cause
Viral cancers appear in context of ________infections. Occur many years to decades after acute infection
persitant/chronic
Immune system can play a _____ or a prote______ctive role in virally induced oncogenesis
deleterious
protective
see human visus associated cancers in association with
immunosuppresion/chronic inflammation
How viruses causes indirect cancer
Chronic infection causes cirrhosis, inflammation, tissue damage, high levels of cell division to increase chance of mutation to derail growth control
How do viruses directly cause cancer
stimulate cells to enter S phase and make viral proteins to contineu to direct cell to ovvride normal controls on growth
How can we tell if a cancer we’re seeing epidemiologically is viral related
we’ll see it in an immunosuppresed population
aggressive skin cancer in elderly/immunocompormised
Merkel Cell carcinoma
Mech of merkel cell carcinoma
common deletion renders virus unable to complete replication cycle; persistnat infecction
common deletion renders virus unable to complete replication cycle; persistnat infecction
Merkel cell carcinoma
Papillomaviurs is member of:
genome:
infectects:
papovavirus
dsDNA
mucosal/epithelial~ hands/feet/genital
this has ~100 sub types with 1/3 infecting genital strand
papillomavirus
E1 and E2 of HPV mediate:
E1 and E2 mediate replication and transcription of viral DNA
E4 of HPV will:
E4 distrupts cytokeratins to facilitate virus egress~ helps virus out of the tissue
L1 and L2 of HPV
compose the capid
distrupts cytokeratins to facilitate virus egress~ helps virus out of the tissue
E4
mediate replication and transcription of viral DNA
E1 and E2
E5, 6, and 7 of HPV
intersect with key elements of cellular growth control, are associated with oncogenesis
E5 in HPV
stimulates constituitive GF replicating signal thus the cell no longer needs the GF receptor to signal replication
stimulates constituitive GF replicating signal thus the cell no longer needs the GF receptor to signal replication
E5
E6 and E7 in HPV
neutralize major ‘brakes’ that regulate cell cyle—p53 and Rb—thus uncouple cell division from key regulatory controls
neutralize major ‘brakes’ that regulate cell cyle—p53 and Rb—thus uncouple cell division from key regulatory controls
E6 and E7
Cousre of HPV
Inocculation of epitherlium→ hand/foot/throat or cervix→ Local multiplication→ wart
–resulotion(latency) OR –cell transformation
Life cycle of papillomavirus is tied to the differenation state of
keratinocytes
Stage of HPV virions fucking you up
a. Early gene expression in the basal layer of E1, E2, E6 and E7
b. Late gene expression and viral genome amplication: in the spinous layer
c. Virion assembly and release in the cornified layer
a. Early gene expression in the_____ layer of E1, E2, E6 and E7
basal
Late gene expression and viral genome amplication: in the ____ layer
spinous
Virion assembly and release in the _____layer
cornified
HPV stimulation of cell cycle causes cell in _______ to replicate
stratum spinosum
the spinosum is spitting out hpv