Ch. 23 Cancer

Question 1

Cancer

Answer 1

a group of disorders characterized by cell proliferation

Question 2

metastasis

Answer 2

advanced tumors shed cells that travel to other parts of the body

Question 3

Tumor growth

Answer 3

cells divide rapidly and constantly (crowd normal cells and rob nutrients)

Question 4

Tumor suppressor genes

Answer 4

mutated recessive-acting inhibitory genes that cause cancer; cell division may be stimulated when inhibitory genes are made inactive

Question 5

Oncogenes

Answer 5

mutated dominant-acting stimulatory genes that cause cancer- (have a stimulatory affect on the cell cycle)

Question 6

Proto-oncogenes

Answer 6

oncogene prior to mutation; normal cellular gene responsible for basic ceullar function; when mutated they may become an oncogene

Question 7

DNA repair genes

Answer 7

mutations in DNA-repair genes can increase the likelihood of acquiring mutations in these genes

Question 8

If one or more required mutations are inherited…

Answer 8

less mutations would be required to produce cancer: Knudson’s Multistep Model

Question 9

Most tumors arise from __________mutations

Answer 9

somatic mutations

Question 10

The 1st mutation cell…

Answer 10

predisposed to proliferate faster

Question 11

The 2nd mutation causes…

Answer 11

cells to divide rapidly

Question 12

3rd mutation cell…

Answer 12

undergoes structural changes

Question 13

The 4th mutation causes

Answer 13

cells to divide uncontrollably and invade outher tissue (malignant)

Question 14

The rate of clonal evolution depends on…

Answer 14

the frequency with which new mutations arise

Question 15

telomerase

Answer 15

activation of telomerase allows cells to divide indefinitely

Question 16

Apoptosis genes

Answer 16

genes involved in signaling programmed cell death are often mutated

Question 17

Vascularization genes

Answer 17

genes that stimulate angiogenesis are often overexpressed

Question 18

cell adhesion genes

Answer 18

genes involved in intercellular interactions and attachment

Question 19

miRNAs

Answer 19

microRNAs are often misregulated

Question 20

kinase

Answer 20

an enzyme that adds a phosphate to a protein

Question 21

Cyclin-dependent kinases

Answer 21

kinases that control key events of the cell cycle

Question 22

CDKs are functional only when associated with a ______

Answer 22

cyclin (another protein)

Question 23

Cyclin appears

Answer 23

at specific points in the cell cycle

Question 24

The retinoblastoma protein helps control…

Answer 24

the progression through G1/S checkpoint

Question 25

When RB binds to E2F does it activate or inactivate it

Answer 25

keeps it inactive

Question 26

During G1…

Answer 26

concentrations of cyclin D and E increase and they combine with their CDK

Question 27

After the cyclins binds to the CDK…

Answer 27

The CDK phosphorylate the RB, which inactivates it and it releases E2F which then stimulates transcription of genes

Question 28

people _______ for a tumor-suppressor gene are predisposed to cancer

Answer 28

heterozygous

Question 29

loss of heterozygosity for a tumor-suppressor gene often leads to

Answer 29

cancer

Question 30

hormones (some) and growth factors bind to ____, and initiate a

Answer 30

cell surface receptors that transmit the message into the cell; signal transduction pathway

Question 31

in the Ras signal transduction pathway, inactive Ras binds to

Answer 31

GDP

Question 32

in the Ras signal transduction pathway, active Ras binds to

Answer 32

GTP

Question 33

What happens in the Ras signal transduction pathway

Answer 33

bind of growth factor causes conformational change and phosphorylation, adaptor molecules bind to receptor and link to Ras, Ras binds GTP and is activated

Question 34

What happens at the end of the Ras signal transduction pathway

Answer 34

activated MAP kinase moves to nucleus and activates TFs that stimulate transcription of cell cycle genes

Question 35

Burkitt’s Lymphoma

Answer 35

a recurring reciprocal translocation between the q-arms of chromosomes 8 and 14

Question 35

What genetic testing would you use to find Burkitt’s Lymphoma

Answer 35

fluorscence in situ hybridization

Question 36

The Philadelphia Chromosome is an example of

Answer 36

a translocation that leads to a fusion protein