Genetic Basis of Cancer Flashcards
What two consequential characteristics of neoplasia facilitate acquisition of cancer properties?
Genomic instability endow cancer cells with genetic alterations to drive tumor progression
Inflammation response by innate cells has tumor-promoting consequences
What are oncogenes?
Genes that have a stimulatory effect on cells typically through GoF mutation
What are tumor suppressor genes?
Genes whose products normally negatively regulate cell proliferation
LoF mutation
Both copies must be non-functional to contribute to cancer progression
What is the inheritance pattern of retinoblastoma?
Autosomal Dominant with incomplete penetrance
What is Loss of Heterozygosity?
Loss of information of one allele
What is Knudson’s Hypothesis?
In familial Rb, only one mutation event is needed to make a cell without Rb product
In sporadic form, two mutations in the same cell are needed
What is the cause of familial adenomatous polyposis?
Germline mutations in the adenomatous polyposis coli gene (APC)
Autosomal dominant
What is the most common type of inherited breast cancer?
Hereditary breast and ovarian cancer syndrome (HBOC)
What is the cause of HBOC?
Mutations in BRCA1 and BRCA2
What is Cowden syndrome?
Characterized by multiple tumor-like growths and an increased risk of certain cancers
Develop hamartomas - small non-cancerous growths
What is hereditary nonpolyposis colorectal cancer syndrome?
Lynch syndrome
Early age onset colorectal cancer and endometrial cancer
Caused by mutations is DNA mismatch repair genes
What is Li-Fraumeni Syndrome?
Rare genetic condition characterized by increased risk to develop multiple types of cancer
Caused by TP53 mutation
What is Von Hippel-Lindau disease?
Multisystem disorder characterized by abnormal growth of blood vessels called hemangioblastomas
Mutation in VHL gene
What is the difference between BRCA1 tumors and BRCA2 tumors?
BRCA1 tumors tend to be more agressive
Tumor biology is different depending on inherited or sporadic occurrence
What is the significance of the I1307K mutation in the APC gene?
Does not impune the function of the protein or the gene itself
Decreases the stability of the gene by increasing the risk of somatic mutations as a result of slippage during replication
