Chapter 9 Self-check questions

. "Cross-seeding" is a term used to describe a process of metastasis that involves:

the seeding of metastases from subclones from the primary tumor.

one primary tumor seeding two or more other metastases

the seeding of metastases from one cell or subclone.

the seeding of metastases from subclones from other metastases.

. The Epithelial-Mesenchymal Transition (EMT) is:

characterized by the production of differentiated-like cells.

induced by the transcription factors: HGF and TGFβ

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

characterized by high E cadherin expression.

. Which of the following statements about extravasation is true?

Strong evidence suggests that cancer cells pass directly through endothelial cells in a process called transcellular transendothelial migration.

The steps of extravasation use exactly the same mechanisms compared with intravasation.

It is the entry of a tumor cell into a blood or lymphatic vessel.

Selectin molecules are important for the attachment of tumor cells to the endothelium.

. Which of the following statements about disseminated tumor cells (DTCs) are false?

DTCs are cells that have spread from a primary tumor but have not yet become a successful metastatic colony.

Therapeutic agents that may be able to prevent the reactivation of dormant DTCs are in clinical trials.

All DTCs remain dormant.

DTCs may be induced to enter a state of quiescence by factors such as those from stable blood vessels.

. Which one of the following statements is false?

Micrometastases show net growth.

Metastatic colonization requires the growth of new blood vessels.

Loss of function of metastasis-suppressor genes results in an increase in metastatic capability.

A class of microRNAs that suppress metastasis have been identified and are called metastasis-suppressor microNAs.

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

Invasion, extravasation, transport, intravasation, and metastatic colonization.

Invasion, transport, intravasation, extravasation, and metastatic colonization.

Invasion, intravasation, transport, extravasation, and metastatic colonization.

Metastatic colonization, intravasation, transport, extravasation, and invasion.

. Which one of the following statements about integrins is false?

Their cytoplasmic tails exhibit catalytic activity.

They mediate cell-ECM interactions and intracellular signal transduction.

Many ligands for integrin receptors contain the amino acid sequence RGD (Arginine, Glycine, and Aspartate).

Their binding to suitable ECM ligands inhibits anoikis.

. Which of the following evidence does not support the concept of the pre-metastatic niche:

Conditioned media from one tumor type can redirect the location of metastatic colonization of another tumor type.

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

Green-labeled bone marrow cells arrive at a future site of metastasis before red-labeled tumor cells as a result of factors from the primary tumor.

Tumor-derived exosomes may act as systemic factors that 'educate' bone-marrow derived cells to mobilize to future sites of metastasis.

. Which one of the following are not viable therapeutic strategies that target metstasis:

Blocking EMT by using tyrosine kinase inhibitors against c-MET.

Blocking expression of metastasis suppressor genes.

Inhibiting metalloproteinases.

Inducing tumor cell dormancy and preventing metastatic niche formation.

. Which 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.

Transport through the bloodstream can be bidirectional with some cells moving with and some against blood flow.

Tumor cells never get trapped in capillary vessels as they are too small to do so.

Most tumor cells that enter the bloodstream are successful in setting up a metastatic colony.

. All of the following are ways to induce EMT in cultured epithelial cells except:

Transfect cells with the E-cadherin gene.

Treat with HGF to activate the MET receptor

Treat cells with TGF-b growth factor.

Transfect cells with genes that code for TWIST or SNAIL

. An approved drug that targets bone metastasis is:

Avastin, a monoclonal antibody that targets VEGFR

Metalloproteinase inhibitor (MPI) ipilimumab

Denosumab, a humanized monoclonal antibody that binds to RANKL

Imatinib, a tyrosine kinase inhibitor that targets Abl

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