cancer biology exam two

all of the following are upstream activators of p53 EXCEPT:

DNA repair and oncogenic activation

which one of the following statements is the strict definition of a tumor suppressor gene as stated by Knudson’s Hypothesis?

a gene in which a germline mutation predisposes individuals to cancer

viral proteins interact with p53 and pRB. identify which one of the following is a correct statement.

Adenovirus E1A, papilloma virus E7 and SV40 LgT inactivate RB and adenovirus E1B, papilloma virus E6 and SV40 LgT inactivate p53

which of the following statements about p53 is false?

it was the first oncogene to be identified

which of the following statements about retinoblastoma is false?

the mechanism of action of the Rb gene in cancer does not follow the concept of a tumor suppressor gene described by Knudon’s two-hit hypothesis

which of the following does NOT describe p53 mutations in tumor cells

most involve nonsense or frameshift mutations that lead to inactivated truncated proteins

what is the role of PTEN (phosphate and tensin homolog) on chromosome 10?

dephosphorylation of the membrane lipid PIP3 to form PIP2

which of the following therapeutic drugs target the p53 regulator, MDM2?

nutlins

which one of the following correctly describes the downstream cell effects of p53 paired with a p53 target gene?

cell cycle arrest, apoptosis, DNA repair, inhibition of angiogenesis

which of the following statements regarding Li-Fraumeni syndrome is true?

patients develop multiple primary tumors

which one of the following statements about the Bcl-2 family is false?

the release of important apoptosis mediators from the mitochondria is mediated by the pro-apoptotic members only

which one of the following statements about apoptosis is false?

the aim of conventional chemotherapies is to inhibit apoptosis

which one of the following statements about the apoptosome is correct?

cytochrome C, procaspase8, ATP, and Apaf-1 are components of the

which one of the following statements about apoptosis is false?

it is unregulated cell death characterized by swelling

which one of the following statements is false?

gain of caspase-8 expression is linked with lung cancer

which one of the following statements correctly explains why direct apoptotic inducers may be a better drug strategy than conventional chemotherapy?

they bypass the need to be mutagenic and avoid therapy related leukemias

which one of the statements below about the intrinsic pathway of apoptosis is false?

the intrinsic pathway of apoptosis depends on death factors TNF and Fas

drugs being developed as direct apoptotic inducers include all of the following except:

5-fluorouracil

how does p53 trigger apoptosis?

by inducing the transcription of genes that code for pro-apoptotic proteins

which statement about alternative cell death pathways is false?

drugs that induce alternative cell death pathways are not yet in clinical trials

in the laboratory, scientists can detect apoptosis by which of the following methods?

the TUNEL technique, that uses nick end-labelling

which one of the following statements correctly describes what happens after Wnt ligand binds to Frizzled and LRP?

axin is recruited to the phosphorylated co-receptor LRP and this disrupts the APC, CKI, GSK3B complex

evidence that the Wnt-signaling pathway is important for self-renewal of stem cells in the adult is:

Tcf gene knockout mice show lack of stem cells in the intestine

polycomb group proteins are known as “guardians of stemness”. which statement about polycomb proteins is true?

they repress genes that promote differentiation by epigenetic mechanisms

mutations that activate the hedgehog signaling pathway are characteristic of which one of the following?

basal cell carcinoma

the hedgehog signal transduction pathway culminates with the induction of target genes by which transcription factor?

Gli

which of the following is the correct name for the treatment of acute promyelocytic leukemia by the administration of all-transe retinoic acid?

differentiation therapy

the chromosomal translocation that is associated with acute promyelocytic leukemia results in the PML-RAR fusion protein. Which statement about how this oncoprotein acts is false?

it acts by inducing the EGF pathway

which one of the following statements regarding cancer stem cells is false?

they represent one in a hundred tumor cells in acute myeloid leukemia

which experimental strategy showed that restoration of Apc promotes cell differentiation and re-establishes homeostasis in colorectal cancer in mice?

conditional and reversible control of apc expression by inducible short hairpin RNAs

which one of the following statements about patients with the syndrome, familial adenomatous polyposis is true?

they have a predisposition to developing colon cancer and carry a germline mutation in the APC gene

which one of the following is NOT a valid strategy for the development of new anti-cancer drugs that target cancer stem cells?

tyrosine kinase inhibitors targeted against the Frizzled receptor

“cross seeding’ is a term used to describe a process of metastasis that involves:

the seeding of metastases from subclones from other metastases

the epithelial-mesenchymal transition (EMT) is:

triggered by the transcription factors: snail, slug, and twist

which of the following statements about extravasation is true?

selectin molecules are important for the attachment of tumor cells to the endothelium

which of the following statements about a disseminated tumor cells (DTCs) are false?

all DTCs remain dormant

which of the following statements is false

micrometastases show net growth

there are five important steps involved in metastasis. which one of the lists below gives the correct order in which these stages occur?

invastion, intravasation, transport, extravasation, and metastatic colonization

which one of the following statements about integrins is false?

their cytoplasmic tails exhibit catalytic activity

which of the following evidence does not support the concept of the pre-metastatic niche

breast cancer metastasizes to the lung, one of its closest anatomical organs via the bloodstream

which one of the following are not viable therapeutic strategies that target metastasis?

blocking expression of metastasis suppressor genes

which one of the following statements about transport is true?

one way we can “see” metastasis is by detecting tumor cells in the bloodstream, called circulating tumor cells

VEGF is highly involved in the initiation of angiogenesis. How are angiopoietins and ephrins involved?

angiopoietins and ephrins are important after initiation for vessel maturation

which of the following statements about angiogenic vessels are false?

the vessels are straight and stable

what is the main aim of anti-angiogenic therapy?

to prevent the formation of new blood vessels

which one of the following statements about anti-angiogenic therapy is false?

drug resistance is more likely to happen with anti-angiogenic drugs

which one of the following statements is false?

tumors can only form new blood vessels by angiogenesis

during normoxic conditions, degredation of HIFa is signaled by the addition of:

ubiquitin via VHL

how does a tip cell form at the forefront of angiogenic sprouting?

by responding to a concentration gradient of VEGF via VEGFR-2

the signal transduction pathway of VEGF is similar to that of EGF except:

one molecule of VEGF binds to two VEGF receptors but one molecule of EGF binds to one EGF receptor

conditions of hypoxia stimulate angiogenesis via the hypoxia-inducible-factor-1a (HIF1a). which one of the following statements is true?

under hypoxic conditions, the enzyme prolyl-4-hydroxylase is inactivated and allows HIF-1a to induce transcription of target genes, including VEGF

which one of the strategies listed below has NOT been developed as an anti-angiogenic drug?

kinase inhibitors targeted against endothelial-specific integrins