Deck 7: Tumor Suppressor Genes

Question 1

Which of the following statements about NF1 is FALSE?

A)It regulates Ras signaling through positive feedback control mechanisms.
B)Cells lacking NF1 have higher levels of GTP-bound Ras.
C)NF1 is known as a Ras-GAP.
D)B and C.
E)None of the above.

Answer 1

It regulates Ras signaling through positive feedback control mechanisms.

Question 2

Which of the following genes is NOT classified as a tumor suppressor?

A)MGMT
B)p16^INK4A
C)PTEN
D)VHL
E)None of the above

Answer 2

MGMT

Question 3

of heterozygosity

Answer 3

E

Question 4

Sporadic cases of retinoblastoma require

A)One inactivating somatic mutation in one copy of Rb.
B)Two somatic inactivating mutations,one in each of the two copies of Rb.
C)One somatic mutation in Rb,leading to its activation.
D)Two somatic mutations in a copy of Rb,leading to its activation.
E)None of the above.

Answer 4

Two somatic inactivating mutations,one in each of the two copies of Rb.

Question 5

When a normal cell and a cancer cell were fused,the resulting hybrids lost the ability to form tumors in mice.This suggests that

A)The cancer cell alleles are dominant over the normal cell alleles.
B)The cancer cell alleles are recessive to the normal cell alleles.
C)The normal and cancer cell alleles are co-dominant.
D)The original tumor formed as a result of infection by a tumor virus.
E)None of the above.

Question 6

The APC protein

A)Is essential for degrading β-catenin.
B)Causes increased activation of β-catenin.
C)Helps to regulate cell motility.
D)A and C.
E)None of the above.

Question 7

Single nucleotide polymorphism markers SNPs)are found approximately how far apart across the genome?

A)Every 1 megabase
B)Every 10 megabases
C)Every 1 kilobase
D)Every 10 kilobases
E)None of the above

Question 8

You are studying cancer cells,and hypothesize that you have found a previously unidentified tumor suppressor gene.Which of the following results would support your hypothesis?

A)You have found loss of heterozygosity in the locus containing your gene in a number of human lung cancer samples.
B)You have identified a gain-of-function mutation in this gene that results in the transformation of normal cells.
C)Functional analysis has revealed that the wild-type form of the gene that you have identified serves to drive proliferation.
D)B and C.
E)None of the above.

Question 9

Which of the following is TRUE of methylation in cancer cells?

A)Overall levels of methylation throughout the cancer cell genome often increase.
B)There is an increase in DNA methyltransferase enzyme activity.
C)Areas of CpG islands are hypomethylated.
D)Areas of CpG islands become methylated inappropriately.
E)None of the above.

Question 10

You are studying a cell line in which the loss of just one copy of a tumor suppressor gene provides a growth advantage for the cells.This would be an example of genetic

A)Haplosufficiency.
B)Heteroinsufficiency.
C)Haploinsufficiency.
D)Unilateral mutation.
E)None of the above.

Question 11

HIF-1α levels may go up when

A)Oxygen conditions are at normal physiologic levels.
B)Cells are experiencing hypoxic conditions.
C)Oxygen levels are high.
D)HIF-1α is bound to pVHL.
E)C and D.

Question 12

Inactivation of tumor suppressor genes can occur as the result of

A)Somatic mutation.
B)Promoter demethylation.
C)Loss of heterozygosity.
D)A and C.
E)None of the above.