Chapter 10 Self-check questions

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

Angiopoietins and ephrins are classes of drugs that block the action of VEGF.

Angiopoietins and ephrins are needed before VEGF can initiate angiogenesis.

Angiopoietins and ephrins inhibit the action of VEGF.

Angiopoietins and ephrins are important after initiation for vessel maturation.

. Which of the following statements about angiogenic vessels are false?

The vessels express different integrin receptors compared to mature vessels.

The vessels sprout from mature blood vessels.

The vessels are straight and stable.

The vessels are tortuous and leaky.

. What is the main aim of anti-angiogenic therapy?

To target tumor cells directly.

To increase cellular response to pro-angiogenic signals.

To prevent the formation of new blood vessels.

To directly induce apoptosis in tumor cells.

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

Angiogenesis only occasionally occurs in adults and so drug resistance does not occur in the clinic

Anti-angiogenic drugs are associated with some side effects such as hemorrhage..

Multi-targeted small molecule tyrosine kinase inhibitors are more effective compared to single-targeted anti-angiogenic drugs.

A different response may be observed between two different types of cancer.

. Which one of the following statements is false?

Tumors can only form new blood vessels by angiogenesis.

Angiogenesis is needed to provide nutrients and oxygen to both primary and metastatic tumors.

Circulating endothelial cells derived from the bone marrow can contribute to the tumor vasculature.

Tumor cells can act as endothelial cells and form vascular-like structures.

. During normoxic conditions, degradation of HIFα is signaled by the addition of:

Phosphate by a kinase.

Ubiquitin via VHL.

A hydroxyl group by a hydroxylase.

VEGF by a transcription factor.

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

By responding to a concentration gradient of VEGF via VEGFR-2.

By being pushed forward by stalk cells.

By inhibiting the expression and release of DLL4.

By producing and releasing VEGF and growing towards the tumor.

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

Ras is only activated in the EGF pathway.

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

The RAF–MEK–MAPK cascade is only activated in the EGFR pathway.

Only dimerization of the VEGFR receptor triggers autophosphorylation.

. Conditions of hypoxia stimulate angiogenesis via the hypoxia-inducible-factor-1α alpha (HIF-1α). Which one of the following statements is true?

Under hypoxic conditions, the enzyme prolyl 4-hydroxylase is inactivated and allows VEGF to induce the transcription of the HIF-1α gene.

Under hypoxic conditions, HIF-1α is covalently modified and targeted for degradation.

Under hypoxic conditions, the enzyme prolyl 4-hydroxylase is activated and this leads to angiogenesis.

Under hypoxic conditions, the enzyme prolyl 4-hydroxylase is inactivated and allows HIF-1α 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 VEGFR.

Antibodies targeted against VEGF and VEGFR.

Kinase inhibitors targeted against endothelial-specific integrins.

Peptide-Fc fusion proteins targeted against angiopoietins.

. The finding that the effectiveness of chemotherapy was improved if administered with anti-angiogenic drugs was initially puzzling. The hypothesis of vessel normalization has been proposed to explain this observation. Which of the following would not be a consequence of vessel normalization?

Normalized vessels would improve the delivery of immune cells and decrease immunosuppression.

Normalized vessels would improve delivery of chemotherapies.

Normalized vessels are tortuous and leaky.

Normalized vessels lead to a decrease in hypoxia.

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