Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

cell bio > cancer > Flashcards

cancer Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

define retrovirus

A

their rna genome is reverse transcribed into DNA and inserted in the eukaryotic genome.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is the only retrovirus causing human tumors?

A

the human T cell leukemia/lymphoma virus

example: Hepatitis virus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

whats a dna virus?

A

dna virus can include oncogenes and inorporate them in the host dna
example: HPV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

how does the microbiota play a role in cancer?

A

it can have an anti-tumoral effect or a pro-tumoral effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

define tumor supressor?

A

proteins that inhibit cell growth and proliferation which become inactivated by mutation (loss of function mutatioin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

how can cancer arise?

A

when mutation blocks the activity of a tumor suppressor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what are the 5 major types of tumor suppressors?

A

inhibitors of the cell cycle
receptors and signal transducers inhibiting cell proloferation
checkpoint proteins that stop the cell cycle if dna is damaged
activators of apoptosis
dna repair mechanisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are the checkpoints?

A

g1 checkpoint
g2checkpoint
metaphase checkpoint

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

how does p53 supress cell division?

A

by turning on the cdk inhibitor p21

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what activates p53?

A

dna damage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what does p21 turn off?

A

S-phase CDK

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is micrometastatic?

A

small collection of cancer cells that have been shed from the original tumor and spread to another part of the body through the blood or lymph nodes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

the loss of function mutation needs ?

A

both alleles to be mutated to induce cancer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is loss of heterozygosity mutation?

A

when person with one mutated allele develops a single mutation of the second allele which is enough to induce transformation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

genetic basis of cancer for Rb?

A

Rb blocks G1 phase of cell cycle. Rb+/- predisposes to retinoblastoma if it mutates to its absence Rb-/-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

genetic basis of cancer for APC?

A

APC prevents the expression of proto-oncogene Myc. APC +/- predisposes to colon cancer if it mutates to its absence APC-/-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

genetic basis of cancer for BRCA-1?

A

BRCA-1 blocks cell cycle progression. BRCA+/- predisposes to breast cancer if it mutates to its absence BRCA-/-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

whats hereditary retinoblastoma ?

A

somatic retinal cell has Rb+/- then a somatic mutation occurs leading to Rb-/- which is a homozygous cell that gives rise to tumors in retina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

whats sporadic retinoblastoma?

A

somatic retinal cell first has Rb+ Rb+ then 1st mutation occurs to give heterozygous Rb+/- then 2nd somatic mutation occurs to give Rb-/- leading to tumors in retina

20
Q

what mutation slows down GTPase activity of Ras, which becomes a constitutively active oncoprotein

A

mutation of glycine at position 12

21
Q

what blocks the activity of Bcr-ABl Protein?

A

Gleevec binds the kinase domain and inhibits the enzyme which causes no signal and no leukemia

22
Q

what is the cancer therapy of Gleevec?

A

Treats chronic myelogenous leukemia with philadelphia chromosome. its the first drug targeting a signaling pathway specific of a cancer cell. mutations can make cancer cells resistant to gleevec

23
Q

what is TGFbeta?

A

an inhibitor of cell growth. can promote apoptosis. when it binds to a dimeric receptor with serine/threonine kinase activity, TGF beta activates intracellular messengers Smad proteins.

24
Q

what are smad proteins?

A

smads activate expression of cell cycle inhibitors genes like p15
and PAI - inhibitor of proteases

25
Q

what do mutatioins in TGF beta pathway lead to?

A

increased proliferatioin by blocking p15

increased risk of metastasis by blocking PAI

26
Q

what are cyclins?

A

they promote progression through cell cycle which is induced by growth factors. cyclins bind and activate specific cyclin dependent kinases ( CDKs)

27
Q

what do CDK do?

A

phosphorylate inhibitors of cell cycle like Rb which when Rb is phosphorylated it become inactivated and cells are allowed to proliferate

28
Q

what can inhibit CDK?

A

p15 and p16

29
Q

what is a common cause of cancer involving mutations?

A

1) Over production of cyclins which allow cell cycle progression
2) Loss of Rb or p15/p16 (cell cycle inhibitors) which causes excessive proliferation

30
Q

define carcinogen

A

natural or synthetic chemicals that increase risk of mutations for cancer by DNA mutations grouped in 2 classes

  1. direct acting carcinogens on N and O atoms on DNA
  2. indirect acting carcinogens - chemicals that become reactive after they are modified by cellular enzymes. addition of OH to make the compound more soluble for exretion.
31
Q

list carcinogens

A 
vinyl chloride
benzene
arsenic
asbestos
radium
32
Q

overcooked meat can cause what cancer?

A

colon cancer

33
Q

what are caretaker genes?

A

prevent or repair dna damage. their inactivation increases risk of mutations for tumors

34
Q

how does multidrug cancer therapy help?

A

treating cancer with 2 drugs at a single time shows resistance and do not cure cancer
treating cancer with 2 drugs simultaneously shows cell is not resistant to both drugs and cancer is cured

35
Q

what are the mechanisms of cancer?

A

carcinogens
hormones
viruses
they all genetically damage the cell and cause excessive proliferation

36
Q

define oncogenesis

A

progressive development of a cancer

37
Q

define proto-oncogenes

A

normal regulator of cell growth that becomes an oncogene when a mutation creates excessive activity (gain of function mutation)
example: Ras , EGF receptor, Akt

38
Q

benign vs malignant tumor

A

benign tumor has 1 mutation of epithelial cell

malignant tumor grows and invades other organs

39
Q

what are the 5 types of cancers?

A

carcinoma - derived from epithelial cells
sarcoma - derived from mesoderm (muscle, blood, connective tissue)
Leukemia - derived from white blod cells in bone marrow
lymphhoma - derived from lymphocytes and plasma cells in lymph nodes
Blastomas - cancer cells that lost their differentiation characteristics

40
Q

what are mast cells?

A

white blood cell found in connective tissue

41
Q

what are the hallmarks of cancer?

A

deregulating cellular energetics
avoiding immune destruction
tumor promoting inflammation
genome instability and mutation

42
Q

define angiogensis

A

formation of bew blood vessels to promote the growth of tumor by providing more O2
and open the path to tumor metastasis

43
Q

what gowth factors promot angiogeneis?

A

beta FGF, TGF alpha, and VEGF

44
Q

what is HIF-1 (hypoxia inducible factor)

A

activates glucose anaerobic metabolism to increase survival of cancer cell in hypoxic environment

45
Q

what controls movement of tumor cell?

A

actin cytoskeleton

cell bio (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions