Cancer 2

Question 1

What are the two categories of tumor suppressor genes?

Answer 1

1. proteins that normally restrict cell growth and proliferation
2. proteins that maintain integrity of the genome

Question 2

Describe the hereditary form of Retinoblastoma

Answer 2

loss of function or deletion of one copy of Rb in every cell
have one good copy of the gene, but somatic event occurs and deletes the good copy and tumor forms resulting in a loss of heterozygosity

Question 3

Describe the sporadic (non-hereditary) form of retinoblastoma

Answer 3

non cancerous cells are normal but the cancerous cells have both copies of Rb mutation

Question 4

What is p53? and what is it involved in?

Answer 4

huge tumor suppressor gene
involved in:
1. cell cycle arrest
2. DNA repair
3. apoptosis
4. block of angiogenesis

Question 5

What happens if you lose p53?

Answer 5

1. loss of checkpoint control in cell cycle
2. loss of cell cycle arrest in response to DNA damage
3. loss of DNA repair activities
4. loss of apoptosis in response to DNA damage

Question 6

How is p53 a gene regulatory protein?

Answer 6

1. stimulates transcription of gene encoding CKI (Cdk inhibitory protein) called p21
2. p53 also activates expression of proapoptotic proteins BH123 and BH3 only

Question 7

What happens if viral DNA integrates with host DNA?

Answer 7

interfere with control of cell division in basal cells- malignant tumor develops

Question 8

What can colonoscopies detect?

Answer 8

polyp: a small protruding benign tumor that can develop into colorectal cancer

Question 9

_____ percent of colorectal cancers have point mutation in K-ras

Answer 9

40

Question 10

What is familial adenomatous polyps coli (FAP)?

Answer 10

it is when there are hundreds of small polyps in the colon, and at least one polyp has a high chance of becoming malignant. It is caused by inactivation of tumor suppression gene APC

Question 11

What is the difference between heredity non polyposis colorectal cancer (HPNCC) and colorectal cancer

Answer 11

HPNCC cells have normal # of chromosomes

colorectal cancer cells usually have multiple copies of chromosomes

Question 12

What does chemotherapy do?

Answer 12

stops cell division

Question 13

What is Folkman’s anti angiogenesis therapy?

Answer 13

starve the tumors of new blood vessels to stop cancer growth