Chapter 7 pt 3 Flashcards
What is NF1
a tumor suppressor that encodes neurofibromin 1, a GTPase that inhibits RAS signaling
NF1
Germline mutuation
Sporadic mutation
cant make inhibiting GTPase => increase in RAS signaling
- germline LOF => many benign neurofibromas, optic nerve gliomas and malignant peripheral nerve sheath tumors
- sporadic mutation: neublastoma, juvenile myeloid leukemia
What is NF2
encodes neurofibromin 2 (merlin), a cytoskeleton like protein in cell to cell junctions
NF2
Germline mutuation
Sporadic mutation
- germline LOF => neurofibromitosis type 2 => high risk for benign bilateral acoustic schwannomas
- Sporadic=> schwannoma and mengiomas
What is PTCH1
PTCH 1 is a tumor supressor then encodes PATCH receptor
SHH ligand binds to PATCH receptor.
When SHH is bound => stops supresses cell prolferation
When SHH is not bound => supressing proliferation
thus, mutation in PTCH1 => Patch receptor cannot bind SHH
PTCH1
Germline mutuation
Sporadic mutation
Germline mutation: LOF => gorlin syndrome => high risk for basal cell carcinoma and medulloblastoma
Sporadic: basal cell carcinoma and medulloblastoma
In what cancers do you often see a mutated PTCH1 gene?
- Basal cell carcinoma
2. Medulloblastom
What is VHL?
VHL is a tumor supressor that encodes a part of the ubiquitin ligase that breaks down HIF (hypoxia induced factor)
increased VHL => low HIF
VHL
Germline mutuation
Sporadic mutation
- Germline mutation: LOF => high HIF => increase nuclear translocations => increase cell growth and proliferation => Von Hippel Lindau syndrome => increase chance of getting [renal cell carcinoma, pheochromacytoma, hemangioblastomas, retinal angiomas]
- Sporadic => renal cell carcinomas
What is von-Lippau syndrome
Occurs when we have a mutation in VHL => increase in HIF => increase in translocation => increase in cell growth and proliferation =>
increase risk for
- renal cell carcinoma
- pheochromacytoma
- retinal angioma
- hemangioblastomas
What mutations do we often see in sporadic renal cell carcinomas?
aquired biallelic VHL LOF mutations
CDH1 is what
a tumor supressor that encodes E-cadherin
CDH1 encodes E-cadherin.
What does E-cadherin do?
- inhibits growth of epithelial cells via contact
2. Bind and sequesters B-catenin => prevent invasion and metastasis
How does E-cadherin contribute to malignancy
Loss of E-cadherin=>
- promote growth of epithelial cells
- will not bind and sequester B-catenin => bind to TCF TF in the nucleus => invasion and metastasis
CDH1
germline muation
sporadic mutation
G: LOF => famial gastric cancer
Sporadic: gastric carcinoma and lobular breast cancer
BRCA 1 and BRCA 2
tumor supressor that encode Breast Cancer 1 and Breast Cancer 2 => repair dsDNA breaks
BRCA1 and BRCA2
Germline mutuation
Sporadic mutation
G:
- familial breast and ovarian carcinoma
- carcinoma of male breasts
- chronic lymphocytic leukemia (BRCA2 only)
Sporadic mutations are RARE
mutation of BRCA 2 will cause what that a mutation in BRCA 1 will not cause
chronic lymphocytic leukemia
What is MSH
MSH 2 and 6 are tumor supressor genes that code for proteins that REPAIR MISMATCHED DNA
MSH
Germline mutuation
Sporadic mutation
G: hereditary nonpolyposis colon carcinoma
S: colonic and endometrial carcinoma.
What is WNT1
WHT1 is a tumor supressor then is needed for normal development of
- kidneys
- gonads
What gene is WNT1 on
Chr11q13
WNT1
Germline mutuation
Sporadic mutation
G: LOF Familial Wilms tumor (pediatric kidney cancer)
S: Wilms tumor and leukemias
What are characteristsics of familial tumors
bilateral
multicentric