cell bio test 4 (2018)
bcr-abi
chromosomal translocation
which of the following would be a reasonable threapeutic strategy to inhibit cancer metastasis
overexpress E-cadherin
all the following statements about destruction of cyclins is true except one
ubiquitin targets Cdks
myc
oncogene
Ubiquitin ligase
APC/C
which of the following summary statements is most accurate when describing the role of ATM and ATR kinases
ATM and ATR result in activation of p21 and PUMA respectively
each of the following would inhibit cell progression through the cell cycle except
CAK kinase phosphorylation of the mitotic Cdk/cyclin complex
which of the following forms a dimer that gets displaced from the surface of the mitochondria by EGL-1
CED-4
phosphatase
Cdc14
anaphase to telophase transition
Cdc20
G2-M transition
Cdc25
protease/proteosome
Cdh1
highly invasive cnacer cells usually express less_____a key adhesion moleculeq
E-cadherin
mitogens are added to the medium of cultured human cells that are synchronized in mitosis. the mitogen is washed way after these cells have passed START in the cell cycle. these cells will progress through the cell cycle then arrest in which phase?
G0/G1
Start (restriction point)
G1/S cyclin
which of the following is the correct order of the pathway by which activation of P13-kinase stimulates cell division
PIP3 formation-Akt phosphorylation-Rheb activation TOR activation
cancer cell aneuploidy is most likely directly caused by a defect in which one of the following
RB
which of the following statements about the Rb tumor suppressor protein is correct
Rb binds the transcription factor E2F and thus prevents the cell from entering S phase until a mitogenic signal is received
Metaphase-Anaphase Transition
Sic1
kinase
WEE1
what is the function of E2F
a transcription factor
each of the following statements regarding CD95-stimulated programmed cell death is true except
adaptor proteins stimulate the P13K-Akt pathway
which of the following types of utation cannot give rise to an oncogene
addition of deletion of a base producing a nonsense message and an inactive protein product
in the cell cycle, mitotic CDK is present during
all of the phases of the cell cycle
deletion of CARD domain from Apaf-1
apoptosis is less likely
loss of function mutation in Bax
apoptosis is less likely
FAS dead receptors can cluster without the need for the FAS ligand
apoptosis is more likely
inactivating mutation of Bcl-2
apoptosis is more likely
procaspase 9 can self proteolytically cleave
apoptosisis more likely
what role in regulating the intrinsic pathway a apoptosis is played by the bcl-2 protein family members Bax and Bcl-2
bax stimulates apoptosis while Bcl-2 inhibits apoptosis
which of the following is false about caspases
caspases cleave proteins after arginines
which of the following proteins is a death receptor which triggers the extrinsic pathway of apoptosis
cd95/fas
epigenetic changes in gene expression that can lead to cancer by silencing tumor suppressor genes are mediated by
changes in normal DNA methylation
individuals can inherit a defective APC gene on chromosome 5 from one parent that makes them susceptible to developing familial adenomatous polyposis coli. in which cells is this deletion present in affected individuals
colon epithelial cells
have a gain of function in a proto-oncogene
decrease the probability of cancer
have a gain of function in a tumor suppressor gene
decrease the probability of cancer
organ transplant patients often develop cancers at rates higher than normal. this observation supports the idea that cancer formation is dependent on
evasion of immune surveillance
true or false: APC/C-Cdc20 degrades securin which holds the sister chromatids together, leading to the metaphase to anaphase transition
false
have a loss of function in a proto-oncogene
increase the probability of cancer
each of the following would inhibit cell progression through the cell cycle except
kinase phosphorylation of mitotic Cdk
TRK oncogene
local dna rearrangment
cancer cells secrete an activator of the enzyme _______to degrade basal lamina and extracellular matrix
matrix metalloproteinase
which property of p53 enables it to prevent the development of cancer
p53 prevents the replication of cells with DNA damage
the enzyme_____breaks down the extracellular matrix to facilitate angiogenesis
plasmin
rous sarcoma virus
point mutation
src
proto-oncogene
in which of the following situations would cells die by necrosis not apoptosis
removal of heart muscle cells damaged by oxygen depletion following cardiac infarction
most hereditary forms of breast and ovarian cancer arise in women who inherit a mutant copy of wither the BRCA1 or BRCA2 gene, each of which encodes proteins involved directly in
repairing dna double-strand breaks
which one of the following is true of the G2/M phase transition
requires the destruction of S-cyclins by polyubiquitination and degradation by the proteasome
the first demonstration that cancer could be caused by a virus involved
rous sarcoma virus in chickens
each of the following occurs during apoptosis of a cell except
rupture of the cell membrane releasing cytoplasmic contents for phagocytosis
some cancer cells produce the enzyme ________ which protects the ends of chromosomes during multiple rounds of cell division
telomerase
look closely at the figure and identify the stages of mitosis in the figure. which of the following is the correct listing of stages of mitosis in the figure from A through to D
telophase, prophase, anaphase, prometaphase
mitogens are added to the medium of cultured human cells, with an activating mutation in RAS and that are synchronized in mitosis. the mitogen is washed way after these cells have passed START in the cell cycle.these cells will progress through the cell cycle then arrest in which phase?
the cell cycling just keeps repeating
True or False: Sic1 is polyubiquitinated and targeted for degradation at S-phase by the SCF rather than APC/C which functions during mitosis
true
phosphorylated AKT protein phosphorylates bad proteinsmaking them inactive and preventsapoptosis
true
BRCA1
tumor suppressor gene
p53
tumor suppressor gene
hereditary cancers typically possess loss-of-heterozygosity in
tumor-suppressor genes