cell cycle and cancer

Question 1

eukaryotic cell cycle master controllers are a few protein ___ that contain what 2 subunits

Answer 1

protein kinases
cyclin, catalytic subunit (cyclin-dependent kinase [CDK])

Question 2

cell cycle phases

Answer 2

G1 (first gap)
S (sythesis)
G2 (second gap)
M (miotic - prophase, metaphase, anaphase, telophase)
Go (resting phase)

Question 3

what phases count as interphase and how long does it take vs how long does mitosis last

Answer 3

G1,S,G2 (16-24 hrs)
mitosis - 1-2 hr

Question 4

G1
S
G2
M

Answer 4

G1 - grow, synthesize RNA and proteins for DNA synthesis
S - chromosome replication
G2 - rapid growth and protein synthesis
M - cell division

Question 5

-Initiates mitosis
-Gradual condensation of chromosomes
-Disintegration and eventual disappearance of the nucleolus
-Beginning of formation of miotic spindle
-Centrosomes (pair of microtubule organizing centers) from which microtubules radiate
-Centrosomes gradually move to take up positions at poles of cell
-Separation of centrosomes

Answer 5

Prophase

Question 6

-Enters when nuclear membrane breaks up
-Chromosomes disperse within the cell and attach via kinetochores, to microtubules of the mitotic spindle
-Chromosomes begin to move toward a point midway between the spindle poles
-Chromosomes continue to condense throughout this stage
-Microtubules attach to chromosomes
-Chromosome forms 2 kinetochores at centrosome

Answer 6

Pro-metaphase

Question 7

-Chromosome algin in the metaphase plate
-Chromosome reach maximal condensation
-Chromosomes become arranged at the equatorial plane of the cell
-Chromosome of a divind human cell is most readily analyzed at the metaphase stage of mitosis

Answer 7

Metaphase

Question 8

-Chromatids separate words opposite poles
-Begins abruptly when the chromosomes separate at the centromere
-Sister chromatids of each chromosome now become independent daughter chromosomes, which move to opposite poles of the cell

Answer 8

Anaphase

Question 9

-New nuclear envelop forms
-Chromosomes unfold back into chromatin
-Nucleoli reappearance
-Cell continues to elongate
-Chromosomes begin to decondense from their highly contracted state
-Nuclear membrane begins to reform around each of the 2 daughter nuclei and each nucleus gradually resumes its interphase appearance

Answer 9

Telophase

Question 10

cytokinesis

Answer 10

separation of the 2 daughter cells

Question 11

cell cycle checkpoint in mitosis

Answer 11

anaphase is blocked if chromatids are not properly assembled on mitotic spindle

Question 12

R point

Answer 12

decide to continue or go G0

Question 13

B-CDK1 what phase

Answer 13

M phase

Question 14

D-CDK4/6 what phase

Answer 14

G1 phase

Question 15

E-CDK2 what phase

Answer 15

G1 and S phase

Question 16

A-CDK2 what phase

Answer 16

S phase

Question 17

A-CDK1 what phase

Answer 17

S and G2 phase

Question 18

CDK inhibitors suppress the formation of what

Answer 18

tumors (are tumor suppressor proteins)

Question 19

INK4 proteins (inhibitors of CDk4) affect what

Answer 19

CDK4/6

Question 20

cip/kip proteins affect what

Answer 20

CDK1/2

Question 21

members of INK4 proteins

Answer 21

p16INK4A, p15INK4B, p18INK4C, p19INK4D

Question 22

members of cip/kip proteins

Answer 22

p21CIP1 (or p21Waf1), p27Kip1, p57Kip2

Question 23

mitogens do what to inhibitors

Answer 23

proliferative (inhibits the inhibtors) (favor cell cycle advance)

Question 24

antiproliferative do what to inhibitors

Answer 24

activate inhibitors (block cell cycle)

Question 25

Rb protein initially inhibits what

Answer 25

E2F acitvity

Question 26

stimulation of G0 cells with mitogens induces expression of what

Answer 26

CDK4, CDK6, D-type cyclins, E2F transcription factor

Question 27

in the presence of mitogens, what does cyclin D-CDK4/6 do

Answer 27

phosphorylates Rb protein

Question 28

E2F does what

Answer 28

stimulates gene transcription

Question 29

phosphorylated or unphosphorylated Rb is inhibiting E2F

Answer 29

phosphorylated Rb is not inhibiting E2F

Question 30

Rb is a what type of protein

Answer 30

tumor supressing protein

Question 31

important hallmark of cancer

Answer 31

evading growth supressors

Question 32

what is mutated in several cancers

Answer 32

p53

Question 33

what are the two prototypical tumor suppressor genes

Answer 33

p53 and Rb

Question 34

p21Cip1 is activated by what

Answer 34

p53

Question 35

what is p53 trying to do, and so what happens if its mutated

Answer 35

halt cell cycle if theres damage if its mutated, proliferation keeps going w the damage

Question 36

ATM and ATR are what and do what

Answer 36

protein kinases sense DNA damage and trigger cell cycle arrest

Question 37

how can cancer cells spread

Answer 37

through blood and lymphatic systems

Question 38

what causes sustaining proliferative signaling

Answer 38

growth factors autocrine proliferative stimulation

Question 39

Rb

Answer 39

tumor supressor protein

Question 40

p53

Answer 40

tumor supressor protein

Question 41

TGF-B

Answer 41

antiproliferative protein

Question 42

NF2/Merlin

Answer 42

tumor suppressor protein, orchestrates contact inhibition

Question 43

loss of normal p53 important why

Answer 43

p53 is a critical damage sensor (usually apoptosis would occur)

Question 44

extrinsic apoptosis pathway

Answer 44

bind to cell surface receptors-death receptors (DRs)

Question 45

intrinsic apoptosis pathway

Answer 45

involves damage to nuclear DNA as well as mitochondria triggered by agents such as ROS

Question 46

necrosis

Answer 46

release proinflammatory signals into the surrounding tissue environment, and immune inflammatory cells can be tumor promoting due to fostering angiogenesis, cancer cell proliferation and invasiveness

Question 47

necrotic cells can release