Pathology - Tumor Supressor Genes Flashcards
What are the main tumour supressor genes?
RB
P53
APC
NF-1
BRCA 1 & 2
What is two hit hypothesis ?
Both alleles of TSG needs to be mutated to be turned off
How do you differentiate between sporadic and familial retinoblastoma ?
Sporadic - single eye, late onset
FAMILIAL - both eye, early onset
Which TSG is the governor of proliferation?
RB
When is RB gene inactivated ?
When phosphorylated by CDK-G1
How does RB gene block transcription ?
By binding with E2F
What factors activate and inactive RB
GROWTH FACTORS - INACTIVATES
GROWTH INHIBITORS - ACTIVATE
Which gene is the guardian of the Genome ?
TP53
What protien is bind to P53?
MDM2
What does MDM2 does to P53 ?
Actively degrades p53 in healthy cells
What happens to MDM2 in mutated cells or damaged cells ?
Increase in P14
MDM2 unbinds p53
Increases in P21
Which TSG causes Li fraumeni syndrome ?
p53
Which gene is called to gatekeeper of colonic neoplasia?
APC
What disease does APC mutation cause ?
Familial Adenomatous Polyposis (FAP)
What is the indication of colon cancer related to Polyps ?
1000 of Polyps = 100% colon cancer
What does APC do in a cell ?
Actively degrades Beta Catenin
What does APC do in a healthy cell ?
APC is inactive
APC forms a multicomplex with B-catenin
Increases transcription
What is the function of TSG Neurofibromin (NF-1)?
INACTIVATES RAS
INCREASES GAP
What causes Neurofibromatis type 1?
Mutation in NF-1
What does mutations in BRACA 1 AND 2 INDICATE ?
BREAST CANCER
What is the function of TGF-B?
GROWTH INHIBITON
What are the chromosomes on some important TSG?
RB-13q
P53-17q
BRACA 1 -17q
BRACA 2-13q
APC- 5q
