The ability of a population of fibroblasts to migrate along the surface of a tissue culture dish depends on adhesion between the cell surface and the extracellular matrix molecules coating the dish. The dish is coated with laminin, and the only cell-surface protein capable of binding laminin is a cell-adhesion protein called an integrin. Integrins are integral plasma-membrane proteins that function as heterodimers. Under these conditions the rate at which a fibroblast can migrate along the laminin coated culture dish is proportional to the strength of adhesion between the cell and the laminin substrate. The table below lists the rate of cell migration observed for fibroblasts genetically engineered to generate the indicated phenotypes. One explanation for the effect of overexpression of the cytoplasmic domain of the integrin beta subunit is that this domain normally functions to bind a cytoplasmic factor necessary for integrin function. Which of the following would be the most informative experiment to identify the cytoplasmic factor?

#Question id: 1535

#Unit 4. Cell Communication and Cell Signaling

Following statements are regarding to cancer stem cell (CSCs).

a. A representative subpopulation of cancer cells with peculiar molecular aspects that resemble some of those typical of normal stem cells.

b. These cells are capable of replenishing the repertoire of identical cancer cells.

c. These cells cannot create heterogeneous progeny that differentiate into more mature cells.

d. These cells show extraordinary proliferative potential.

e. These cells show excessive programmed cell death.

Which of the following combination is correct?

#Question id: 1534

#Unit 4. Cell Communication and Cell Signaling

Cadherin proteins help animal cells stick (adhere) to each other. Choose which statement about cadherin in cancer cells that are metastasizing (spreading) throughout a patient's body is most likely correct.

#Question id: 1533

#Unit 4. Cell Communication and Cell Signaling

Why might using retroviral vectors for gene therapy increase the patient's risk of developing cancer?

#Question id: 1532

#Unit 4. Cell Communication and Cell Signaling

For a particular microarray assay (DNA chip), cDNA has been made from the mRNAs of a dozen patients' breast tumor biopsies. Which of the following types of evidence will researchers be looking for in order to determine if the cells are cancerous?

#Question id: 1530

#Unit 4. Cell Communication and Cell Signaling

What are the differences and similarities between the transforming genes of retroviruses and those of DNA tumor viruses?

#Question id: 1529

#Unit 4. Cell Communication and Cell Signaling

Which of the following statements are true regarding to gain-of-function and loss-of-function mutations with respect to cancer.