Deck 24: Cancer Cells

Question 1

The presence of ________ in the microenvironment of cancer cells acts a potent inhibitor of cell proliferation.

A)IL-1
B)TGF-beta
C)TNF-alpha
D)IL-2
E)INF-gamma

Answer 1

B

Question 2

PAHs (polycyclic aromatic hydrocarbons)found in tobacco smoke preferentially bind to regions within the ________ and trigger base substitutions.

A)GAL-4 gene
B)p53 gene
C)DMBA gene
D)homeogenes
E)viral gene

Answer 2

B

Question 3

Genes that,when present,trigger the development of cancer are known as

A)tumor suppressor genes.
B)oncogenes.
C)proto-oncogenes.
D)apoptosis genes.
E) p53.

Answer 3

B

Question 4

The Ames test is characterized by the use of

A)auxotrophic Salmonella typhimurium.
B)heterotrophic monoploid yeast.
C)autotrophic monoploid yeast.
D)prototrophic Salmonella typhimurium.
E)both choices A and C

Question 5

Judah Folkman used which model to discern the relationship between tumor growth and angiogenesis?

A)rabbit eye
B)thymus tissue
C)bone marrow
D)mouse skin
E)in vitro cells

Question 6

All of the following are ways cancer cells avoid growth and invasion restriction imposed by the immune system except

A)they are heterogeneous groups of cells.
B)cancer cells often respond to density-dependent growth factors.
C)some cancer cells produce leukotoxins.
D)some cancers often "hide" in dense supporting tissue.
E)some cancers produce low levels of surface antigens.

Question 7

In a normal cell,cell death typically occurs in which phase of the cell cycle?

A)G₁
B)S
C)G₂
D)M
E)all of the above

Question 8

A new compound developed in the lab was tested as a DNA mutagen. When the Ames test was performed,the results were numerous bacterial colonies following exposure. This result means

A)the chemical is safe.
B)the chemical is radioactive.
C)the chemical is a carcinogen and a low-level mutagen.
D)the chemical is a mutagen and may also be a carcinogen.
E)the chemical can be moved to human trials.

Question 9

Some ________ influence histone modification reactions.

A)microRNAs
B)histones
C)p53 genes
D)scaffolding proteins
E)tumor suppressors

Question 10

Aneuploidy (the gain or loss of chromsomes)is associated with which protein molecule in cancer cells?

A)pRB
B)p53
C)Myc
D)Blc-2
E)all of the above

Question 11

Telomere integrity in cancer cells is the result of

A)natural cell aging.
B)active telomerase activity.
C)exchange of DNA between chromosomes.
D)viral infection.
E)both choices B and C

Question 12

Which of the following statements regarding cancer is false?

A)Rate of cell division is critical.
B)Balance between differentiation and proliferation is important.
C)As cells become more differentiated, their capacity to divide decreases.
D)Balance in cell growth is achieved when division results in no net gain of cells.
E)In tumor cells, division and differentiation are uncoupled.

Question 13

Which of the following statements is true regarding factors associated with the immortalization of cancer cells?

A)inhibition of growth
B)stimulation of apoptosis
C)telomerase activity
D)tumor-suppressor activation
E)both choices B and D

Question 14

The most frequently encountered category of cancer is

A)carcinoma.
B)sarcoma.
C)lymphoma.
D)leukemia.
E)both choices C and D

Question 15

The individual credited for coining the term cancer is

A)Paget.
B)Hippocrates.
C)Folkman.
D)Rous.
E)Aristotle.

Question 16

Which of the following with regard to cancer cells is false ?

A)Growth is not regulated by growth factors.
B)The cell cycle is disrupted.
C)Most cancer cells die in G₁ phase.
D)Growth is not stopped by high levels of DNA damage.
E)The apoptosis pathway is blocked.

Question 17

A cell that has lost its capacity to grow in vitro as a monolayer is now

A)benign.
B)malignant.
C)transformed.
D)anchorage independent.
E)free ranging.

Question 18

A tumor is actively producing both VEGF and FGF,factors associated with angiogenesis. However,no network of blood vessels to the tumor has been established in spite of the fact that blood vessels are nearby. This observation most likely suggests that

A)the VEGF and FGF are not functional.
B)angiogenesis inhibitors are in greater concentration.
C)only one of the molecules is active, not both.
D)angiostatin is not produced by the cancer cells.
E)the tumor is metastatic.

Question 19

The ploidy of cells characteristic of an aneuploid is best represented by which of the following?

A)2n + 1
B)n
C)2n
D)4n
E)both choices B and C

Question 20

The group of proteins associated with the binding of cells to the extracellular matrix are the

A)integrins.
B)monolins.
C)MHC.
D)matrix metalloproteins.
E)RAS proteins.

Question 21

The normal RB gene functions as

A)an activator of transcription.
B)a proto-oncogene.
C)an activator of translation.
D)a cell surface receptor.
E)an inhibitor of transcription.

Question 22

The branch of medicine that investigates the occurrence and distribution of diseases is

A)immunology.
B)physiology.
C)pathology.
D)epidemiology.
E)gene therapy.

Question 23

Familial adenomatous polyposis coli (APC)is characterized by a small deletion in chromosome 5. In which cells is this deletion present in affected individuals?

A)somatic cells
B)germline cells
C)colon polyps
D)colon epithelial cells
E)all cells

Question 24

Hereditary retinoblastoma is the result of a(n)________ in the RB gene of chromosome 13 in both homologues.

A)insertion
B)duplication
C)inversion
D)point mutation
E)deletion

Question 25

Which of the following viruses has not been determined to be associated with a particular type of cancer?

A)mimivirus
B)hepatitis B virus
C)Epstein-Barr virus
D)human papilloma virus
E)hepatitis C virus

Question 26

Which of the following is not a mechanism whereby proto-oncogenes are converted to oncogenes?

A)point mutation
B)gene amplification
C)translocation
D)deletion
E)silent mutation

Question 27

The correct order of events in metastasis of a cancer is

A)invasion → angiogenesis → transport → new site
B)transport → invasion → angiogenesis → new site
C)transport → angiogenesis → invasion → new site
D)angiogenesis → invasion → transport → new site
E)angiogenesis → transport → invasion → new site

Question 28

The promotion phase of carcinogenesis refers to

A)enhanced levels or exposures to a carcinogen
B)metabolic oxidation by a P₄₅₀ cytochrome
C)normal cell progression to a precancerous cell
D)precancerous cell progression to a cancerous cell
E)the amount of DNA damage in a cell

Question 29

During microscopic examination of potential cancer cells,some of the cells are graded as anaplastic. This means they

A)divide slowly.
B)are easily identified to tissue of origin.
C)are poorly differentiated.
D)respond well to chemotherapy.
E)are not aggressive.

Question 30

Most cancers are

A)environmentally triggered.
B)the result of life style.
C)inherited.
D)viral infections.
E)both choices A and B

Question 31

The first documentation of a viral infection causing oncogenesis was established with

A)Rous sarcoma virus in chickens.
B)Epstein-Barr virus in Burkitt's lymphoma.
C)hepatitis B in liver cancer.
D)HIV in humans.
E)human papilloma virus in cervical cancer.

Question 32

With regard to cancer cells in the process of metastasis to secondary sites,which of the following statements is not correct?

A)If they enter via lymphatics, cancer cells may multiply in regional lymph nodes.
B)Many cells from the primary mass may enter circulation.
C)The population of cancer cells in the bloodstream is monoclonal.
D)Very few cancer cells survive the bloodstream.
E)The population of cancer cells is heterogeneous.

Question 33

The difference between benign and malignant tumors is that

A)benign tumors have not lost growth control.
B)benign tumors do not stimulate angiogenesis.
C)benign tumors have not spread to other sites.
D)malignant tumors are adherent.
E)benign tumors are cancers, while malignant tumors are not.

Question 34

Changes in an organism that are the result of changes in gene action(s)are known as

A)diseases.
B)epigenetic.
C)silencing.
D)micro-RNA mediated.
E)all of the above

Question 35

The viral oncogene associated with the Rous sarcoma virus is

A)RAS.
B)p53.
C)ERBB-2.
D)SIS.
E)SRC.

Question 36

Some compounds are themselves not carcinogens,but their metabolic activity on the compound produces intermediates that are carcinogenic. This process is known as

A)precarcinogenesis.
B)carcinogen activation.
C)metabolic carcinogenesis.
D)plasminogen activation.
E)DNA mutagenesis.

Question 37

Which of the following is not a category for the gene product for an oncogene?

A)growth factor receptor
B)nonreceptor protein kinase
C)transcription factor
D)glycolytic enzyme
E)growth factor

Question 38

Using polyethylene glycol,a cancer cell and a normal cell are fused. The resulting hybrid behaves like a normal cell. The best reason for this observation is the

A)recombination between cancer and normal chromosomes.
B)removal of environmental triggers.
C)presence of tumor suppressor genes and gene products.
D)exposure to polyethylene glycol.
E)both choices A and C

Question 39

Which scientist(s)was/were awarded a Nobel prize 50 years after discovering viral oncogenesis?

A)Rous
B)Epstein and Barr
C)Burkitt
D)Folkman
E)Kaposi

Question 40

In some forms of breast cancer,estrogen is a(n)

A)initiator.
B)promoter.
C)progressor.
D)inhibitor.
E)mutagen.

Question 41

Some cancer cells produce the enzyme ________,which avoids stimulating apoptosis based on the number of cell divisions.

Question 42

________ are cancers that originate in epithelial cells and comprise 90% of all cancers.

Question 43

How are cancer cells able to evade the immune system and thus able to proliferate seemingly uncontrolled?

Question 44

Overexpression of ________ lead to the development of cancer in mice,and variations in their structure or amounts have been documented in various types of cancer cells.

Question 45

________ and ________ have been demonstrated to trigger DNA mutation associated with particular geographical cancers.

Question 46

A ________ is a cancer of blood cells in which the cells proliferate in the bloodstream.

Question 47

Changes in gene action that are often associated with cancer cells are known as ________ changes.

Question 48

Based on your knowledge of cancer and carcinogenesis,address the following:
a)What type of mutation would be directly expressed,and therefore dominant,in the development of cancer? Why?
b)What type of mutation would be expressed as a recessive trait in the development of cancer? Why?
c)Based upon your previous answers,how would you treat these situations using a gene therapy approach?

Question 49

The ________ virus in chickens was the first association between viral infection and cancer.

Question 50

Increased ________ concentrations degrade the basal lamina and extracellular matrix and activate matrix metalloproteinases.

Question 51

How does genetic instability arise,and how might you test your hypothesis?

Question 52

Epidemiologists at the CDC in Atlanta,GA,have called you in to investigate an increased incidence of leukemia in a remote region of Africa. Shortly after arriving,an RNA virus was isolated from patients and found to induce leukemia in mice. At this point you don't know the mechanism or viral gene product associated with the development of leukemia. One of your lab assistants has isolated a variant of the virus and reports that this variant is missing a portion (20%)of the genome of the original virus. Furthermore,this variant does not induce leukemia in mice.
a)How would you determine which portion of the genome is associated with the development of leukemia?
b)How would you determine the viral mechanism and product associated with the development of leukemia?

Question 53

A key adhesion molecule is ________,which decreases cell adherence when present in insufficient quantities.

Question 54

________ is the direct migration and penetration of cancer cells into neighboring tissues.

Question 55

How does the tumor microenvironment influence the growth,invasion,and metastasis of tumor cells? Design an experiment that allows you to test your hypothesis.

Question 56

In actively dividing cancer cells,________ often results,as three or more poles may be present during mitosis.

Question 57

An ________ is the result of an alteration of gene expression rather than a mutation of a gene.

Question 58

The enzyme ________ breaks down the extracellular matrix to facilitate angiogenesis.