3-cancer principles

Question 1

cancer is

Answer 1

a disorder of growth regulation

Question 2

how does cancer progress

Answer 2

-single abnormal cell that develops a heritable change that is passed on to progeny
-over generations, mutations accumulate and give them a growth advantage
-give them the ability to invade surrounding tissues

Question 3

what are driver mutations?

Answer 3

mutations that contribute to the dev. of a malignant phenotype

Question 4

4 classes of normal regulatory genes that are targets of cancer causing mutations

Answer 4

1. growth promoting proto oncogenes
2. growth inhibiting tumor suppressor genes
3. genes that regulate apoptosis
4. genes involved in dna repair

Question 5

first driver mutation is the

Answer 5

initiating mutation

Question 6

how are tumors selected

Answer 6

-a single cell undergoes mutations that give it a selective advantage over its neighbors
-the offspring are clones with the lesion

Question 7

as new mutations occur and the cells continue to be subjected to selection pressure, tumors become more and more

Answer 7

heterogenous

Question 8

tumors are heterogenous , consisting of multiple

Answer 8

sub populations of cells with distinct properties

Question 9

cell fate is dictated by

Answer 9

external and internal signals

Question 10

stages of cell cycle

Answer 10

G1, S, G2, M , G0

Question 11

what phase decides if the cell grows or goes into non replicating state

Answer 11

G1

Question 12

during G1 phase, cells respond to

Answer 12

mitogenic signals and antimitogenic signals

Question 13

once cell passes R, it is no longer controlled by

Answer 13

external signals

Question 14

if a mistake is detected at a checkpoint, progress is either

Answer 14

halted
or cell undergoes apoptosis

Question 15

CDKs are only active when bound to

Answer 15

cyclin

Question 16

at each step of the cell cycle,

Answer 16

a specific cyclin CDK complex phosphorylates the proteins to execute the next step

Question 17

protein Rb is a key regulatory protein at

Answer 17

R point

Question 18

absence of mitogenic signals, Rb forms a complex with

Answer 18

E2F transcription factors which control expression of genes needed for entry to S phase

Question 19

For a cell to pass R, Rb must be

Answer 19

phosphorylated

Question 20

Rb is phosphorylated in response to

Answer 20

mitogenic signals

Question 21

In response to growth factor stimulation,

Answer 21

-MAP kinase phosphorylates TFs that lead to expression of myc which inc expression of cyclin D
-cyclin D-CDK4/6 complex phosphorylates Rb which release grip on E2F
-allows transcription of genes needed to pass through S

Question 22

If DNA damage present, progression is

Answer 22

halted until damage repaired

Question 23

p53 is a key regulator of the cell’s response

Answer 23

to dna damage and other dangers

Question 24

signaling between tumor cells and their neighbors promotes

Answer 24

tumor progression

Question 25

what are the hallmarks of cancer

Answer 25

1. sustaining proliferative signaling
2. deregulating cellular energetics
3. evading growth suppressors
4. resisting cell death
5. enabling replicative immortality
6. inducing angiogenesis
7. activating invasion and metastasis
8. avoiding immune destruction

Question 26

the most critical feature of cancer cells

Answer 26

ability to divide independent of normal regulatory mechanisms

Question 27

cells need two signals to proliferate

Answer 27

1. to promote growth of the cell
2. to drive progression through the cell cycle

Question 28

enabling characteristics of hallmarks

Answer 28

1. genomic instability
2. tumor promoting inflammation

Question 29

genomic instability enables

Answer 29

carcinogenesis

Question 30

tumors consist of 2 basic components

Answer 30

1. neoplastic cells
2. stroma

Question 31

the stroma consitutes the

Answer 31

tumor microenvironment