Cancer Flashcards
cause of cancer is usually traced back to a mutation in what 3 classes
proto-oncogenes
tumor suppressors
caretaker genes
proto-oncogenes
control of cell division
caretaker gene function
protect integrity of genome
6 acquired capabilities of cancer cells
self-sufficiency in growth signals insensitivity ot antigrowth signals evade apoptosis limitless repolicative potential sustained angiogensis tissue invasion/metasis
ErbB1/HER1
receptor for epidermal growth factor
function of erbB1 and HER2
protooncogenes
what happens in the mutation that makes ErbB1 an oncogene
gives signal to grow without an appropriate sitmulus
what happens in the muation that makes HER2 an oncogene
point mutation, allows receptor dimerization and autophosphorylation in avsence of ligand
oncogenic forms of Ras behave inw aht manner
dominant
what cancers are mutations in Ras assocaited with
pancreus, large intestine, biliary tract, skin
what class are c-fos adn c-myc
protooncogenes
what auses burkitt’s lumphoma
inppropriate Mc activity
what transloation happens in burkitt’s lymphoma
chormosome 8 to 14
what tends to need to happen for a tumor suppressor gene to be inhbiited
damage to both allels of the gene (recessive)
what tends to need to happen for a proto-oncogene to be inhibited
damage to one allele (dominant)
Rb function
inhbit cell cycle progession
what forms are there of retinoblastoma
hereditary and sporadic
retinoblastoma is an example of what phenomon
two hit
muations in RB1 are assocaited with what kinds of cancers
osteosarcoma
small cell lung
breast
why is p53 usually unstable
assocaited with Mdm2, an E3 ubiquitin ligase
what happens when p53 is phosphorylated by ATM/ATR
displacement of Mdm2, making p53 more stable
what is the gene that iencodes p53
TP53
if DNA damage can’t be repaired what does p53 do
signals apoptosis
what is the active form of p53
homotetramer
what happens if you have a missense muation in a single TP53 allel
produces an inactive protein taht reduces p53 activity within the cell
oncogenic p53 mutations act as what
dominant negative muation
li-fraumeni syndrome is assocaited with waht kinds of cancers
breast, sarcoma, brain
how do you get li-fraumeni syndrome
inherent a muatnt TP53 allel
what does E6 inhbiit
p53
what does E7 inhibit
Rb
NF-1 follows what mechanisms
2-hit
BRCA1-BRCA2 are part of what class
caretaker genes
function of BRCA1/BRCA2
repair of double-stranded DNA breaks
how can increased methylation affect genes
silences
how can loss of methylation affect genes
overproduction
what happens if you have damge to checkpoint mechanisms and teh shortened chromosomes lack telomere sequences
you get breakage/fusion/bridge cycles and chromosomal instability
what happens if you lack telomeres
fusion of sister chromatids at mitosis, get a chromsome with 2 centromeres
waht transcription factor does hypoxia trigger
HIF-1alphabeta
what happens with HIF-1alpha pairs with HIF0-beta
activat VEGF
what does VEGF do
stimualte growth of new blood cessels
function of matrix metalloproteases
break down basement membrane
fucntino of E cadherin
hold epithelial cells tightly together
what happens when you get degration of collagen IV and laminin
stimulate migration
symptom of FAP
get thousands to benign polyps in their colon during young age. eventuallly will get colorectal adenocarcomia
how do you get RAF
muation of APC
function of APC
downregulate growth promoting signals.
what happens when you ahve a muajtion that impairs APC function
constitutively active WNT pathway
what happens in absense of WNT signals
formation of destruction complex
what happens when WNT binds to recpetor
b catenin not destroyed, free beta catenin transolates into nucleus, promotes cellular proliferation
HNPCC symptom
cancers of colon, stomach, small intestine
HNPCC is assocaited with what genes
MSH2, MLH1
function of MSH2
identify DNA containing mismatch errors
function of MLH1
helps repair damaged DNA
what happens when you get defected NSH2/MLH1
muations accumulate in microsatellite repeasts
what is the transloation that heppns in philadelphia chromosome
chromosomes 9 and 22
what happens when chromsones 9 and 22 are translocated
fusion of BCR adn ABL1
