Cancer Bio Flashcards
Gene amplifications can take the form of double-minutes or homogeneously staining regions (HSRs), both of which can be detected by FISH. What is the difference between these two?
Double-minutes - extrachromosomal material
HSRs - intrachromasomal amplification
What is Li-Fraumeni syndrome?
germline missense mutation of p53
What familial cancer syndrome is caused by mutation in the APC tumor suppressor gene?
Familial adenomatous polyposis
Mutation in which tumor suppressor gene causes familial gastric cancer?
E-cad
Ras proteins (ie H-ras, K-ras, N-ras) are the most frequently mutated oncogene family in human cancers. What are they?
GTP-binding signal transducers
What is the most important regulator of G1–>S transition?
Rb - blocks progression into S by sequestering E2F
Binding of Fas to FasL induces recruitment of the initiator procaspase __.
Procaspase 8
What are the effector caspases?
3,6,7
Mitochondrial-dependent cell death is achieved through activation of initiator caspase __.
Caspase 9 - intrinsic pathway
Release of cytochrome c from the mitochondria is regulated by the _____ protein family.
Bcl-2
What impact does telomere shortening have in normal cells? In p53 deficient cells?
normal –> senescence
p53 deficient –> genomic instability –>accelerated tumorigenesis
What is the most important growth factor for stimulation of neoangiogenesis?
VEGF2
What is the function of VHL protein?
Targets HIF for ubiquitin-mediated degradation
What is the function of thrombospondin (TSP-1)?
antiangiogenic
What happens to expression of E-CAD and NCAM as cells become more invasive?
Loss/decreased expression
Mutation in MSH and PMS genes can cause hereditary nonpolyposis colon cancer. What cellular pathway do these genes participate in?
Mismatch repair
What is microsatellite instability?
Mutation in the endogenous repeat sequences throughout the genome
Ataxia telangiectasia leads to increased radiosensitivity. What is a hallmark of AT cells following ionizing radiation?
Failure to arrest in S phase
“radioresistant DNA synthesis”
What is recQ and when in the cell cycle is it most highly expressed?
Family of DNA helicase proteins, expressed in S phase
Function to monitor DNA replication fork for damage
Mutation of recQ helicases lead to what 3 syndromes?
Bloom syndrome (BLM)
Werner syndrome
Rothmund-Thompson syndrome
How are cytokine signals propagated intracellularly?
JAK signaling pathways
