Cancer of Genetics

Question 1

define clonal

Answer 1

tumor that originated from common ancestral cell that accumulated numerous specific mutations

Question 2

what are characteristic of many types of cancers?

Answer 2

reciprocal chromosomal translocations

Question 3

what type of mutations give a growth advantage to tumor cells?

Answer 3

driver mutations

Question 4

what type of mutations have no direct contribution to cancer phenotype?

Answer 4

passenger mutations

Question 5

cancer stem cell hypothesis predicts that

Answer 5

every cell in a tumor has the potential to form a new tumor

Question 6

what indicates that cancer develops from accumulation of several mutagenic events in a single cell?

Answer 6

age-related incidence with cancer

Question 7

carcinogens are

Answer 7

cancer-causing agents

Question 8

tumorigenesis is the

Answer 8

development of a malignant tumor

Question 9

genomic instability of cancer cells is characterized by

Answer 9

somatic point mutations

chromosomal effects

Question 10

list some examples of chromosomal effects

Answer 10

translocation, aneuploidy, DNA amplification. deletions

Question 11

epigenetics is the study of

Answer 11

heritable changes in gene expression that DO NOT alter DNA sequences

Question 12

what are some examples of epigenetic modifications?

Answer 12

• DNA methylation

- histone acetylation and phosphorylation

Question 13

cancer cells contain altered

Answer 13

DNA methylation patterns, and histone modifications

Question 14

cells are stimulated to re-enter the cell cycle by the presence of

Answer 14

external growth factors

Question 15

define signal transduction

Answer 15

process of transmitting growth signals from external environment to cell nucleus

Question 16

where are the 3 cell cycle checkpoints?

Answer 16

1. G1/S
2. G2/M
3. M

Question 17

what are the 2 classes of proteins that controls progress through the cell cycle?

Answer 17

kinases

cyclin-dependent kinases

Question 18

caspases are

Answer 18

proteases responsible for initiating apoptosis and digesting intracellular components

Question 19

what are the steps in apoptosis?

Answer 19

• nuclear DNA becomes fragmented
• disruption of internal cellular structures
• dissolution of cell into spherical apoptotic bodies
• engulfing of bodies by phagocytic

Question 20

proto-oncogenes are genes that

Answer 20

stimulate cell growth and division

Question 21

tumor-repressor genes are genes that

Answer 21

regulate cell cycle checkpoints or initiate apoptosis

Question 22

proto-oncogenes…

Answer 22

• signal transduction molecules that stimulate cell division

- cell-cycle regulators that move cell through cell cycle

Question 23

what is an example of a proto-oncogene?

Answer 23

ras gene

Question 24

ras gene regulates

Answer 24

cell growth and division

Question 25

when both alleles of a tumor-suppressor gene are inactivated the cells become

Answer 25

tumorigenic

Question 26

what is the most frequently mutated gene found in 50% of all cancers?

Answer 26

TP53

Question 27

what percentage of metastatic cells become metastatic tumors?

Answer 27

0.01%

Question 28

to metastasize from primary tumor cancer cells have to

Answer 28

digest components of the EM and basal lamina

Question 29

what glycoprotein is responsible for cell to cell adhesion?

Answer 29

E-cadherin

Question 30

most inherited cancer-susceptibility alleles occur in

Answer 30

tumor-suppressor genes

Question 31

familial adenomatous polyposis is a

Answer 31

genetic predisposition to cancer

Question 32

what percentage of human cancers are associated with viruses?

Answer 32

15%

Question 33

any agent that damages DNA has the potential to be

Answer 33

carcinogenic