Brainscape's Knowledge GenomeTM

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


See full index

MCB II Block 1 > Cancer 4 > Flashcards

Cancer 4 Flashcards

1
Q

What is unique about Nf1

A

there is complete penetrance - they will always present with some signs of disease

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

What does Nf1 stand for

A

neurofibromin

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

What mutation causes NF1

A

loss of function in neurofibromin

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

what does neurofibromin code

A

RasGAP

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

in NF1, describe how disease/cancer is caused

A

pt inherits loss of function mutation in nf1 - if second hit, no RasGAP present, so when Ras is activated there will be prolonged activation b/c nothing will hydrolyze it back to GDP

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

What genes are involved in hereditary breast cancer

A

BRCA1 & BRCA2

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

what is MOI of BRCA1 and BRCA2

A

AD

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

hereditary breast cancer syndrome for breast cancer accoutn for what percent of csaes

A

5%

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

if it is AD breast cancer what will you see

A

earlier age of onset
Multiple & bilateral disease
Multiple affected family members
Other cancers; ovarian, prostate

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

males who inherit BRCA2 or BRCA1 are at risk for what cancer

A

male breast cancer (BRCA2)

prostate

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

females who inherit BRCA2 or BRCA1 are at risk for what cancer

A

breast

ovarian

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

BRCA genes are involved in what pathway

A

DNA repair pathways

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

describe BRCA role in DNA repair

A

can repair double and single stranded DNA breaks

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

what is MOI of hereditary colorectal cancer

A

AD

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

what percent of cancer is colorectal cancer

A

15% of all cases (in USA)

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

what are two types of hereditary colorectal cancer

A

Familial polyposis coli / Familial adenomatous polyposis (FAP
Hereditary non-polyposis colon carcinoma

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

what mutation causes FAP

A

APC

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

what do mutations inherit in FAP

A

one mutation in APC

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

What does FAP stand for

A

Familial adenomatous polyposis (FAP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what are most common mutations for Hereditary non-polyposis colon carcinoma

A

MLH1 & MSH2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is function of MLH1 & MSH2

A

DNA mismatch repair enzyme

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

where are all possible mutations for Hereditary non-polyposis colon carcinoma

A

Mutation MLH1, MLH3, MSH2, MSH6, PMS1, PMS2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

how does cancer occur in FAP

A

second hit occurs - the cells only have on APC, wherever they get second hit cancer will develop

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

loss of APC means what has happened

A

second hit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

loss of APC results in what

A

growth of tumor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

draw out the stages in evolution of cancer, specifically for colon cancer

A

pg 121

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

loss of any gene in cancer suggest it is what

A

tumor suppressor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

gain of function in any gene in cancer suggests it is what

A

oncogene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

what is commonly activated in colorectal cancer

A

Ras

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

what does DCC stand for

A

Deleted in colorectal cancer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

FAP is caused by what

A

loss of funtion mutation in APC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

majority of sporadic colorectal cancer is usually caused by what

A

loss of function mutation in APC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Describe role of beta-catenin and APC

A

Catenin’s link up to cytoskeleton. Catenin involved in cell-cell junctions
If beta catenin is no longer involved in cell-cell junction and it is free in cytoplasm, it can translocate into nucleus and activate TF to transcribe MYC – MYC will transcribe Cyclin D → cell proliferation
APC phosphorylates free beta catenin, when it is phorphorylated targetd for poly-ubiquination and degradation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

draw out APC and beta catenin

A

pg 123

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

what is role of beta catenin

A

adapter protein - cell adhesion

can go into nucleus and stimulate transcription of genes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Wnt pathway occurs where

A

occurs at bottom of crypts of colorectum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

what does Wnt pathway normally do

A

normally inhibits APC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

draw out Wnt pathway

A

pg 125

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

what does Wnt activate

A

frizzled

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

what does frizzled activate

A

dishevelled

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

when beta catenin goes ito nucleus it transcribes what

A

MYC (and therefore cyclin D)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

proliferation of cells at bottom of crypt is normal or abnormal

A

normal

the stromal cells at bottom secrete Wnt

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

in colorectal cancer what happens regarding crypt

how is this different from what normally happens

A

the cells migrate up crypt and continue proliferating at top of crypt and tumors will form.
(normally the cells differentiate as they go up the crypt and they stop proliferating. there is Wnt signaling at bottom of crypt therefore inactive APC at bottom of crypt)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

in 90% of sporadic colorectal cancer where is mutation

A

APC → accumulation of beta-catenin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

heterozygous FAP mean what

A

pts have FAP -

46
Q

at what age should heterozygous FAP undergo routine colonoscopies

A

15

47
Q

what is total colectomy

A

entire colorectum is removed

48
Q

HNPCC stands for what

A

Hereditary non-polyposis colon carcinoma

49
Q

Hereditary non-polyposis colon carcinoma is also known as what

A

Lynch syndrome

50
Q

males who inherit HNPCC have what risk of colorectal cancer

A

90%

51
Q

females who inherit HNPCC have what risk of colorectal cancer

A

70%

52
Q

What is function of MLH1, MLH3, MSH2, MSH6, PMS1, PMS2

A

DNA repair

53
Q

microsatellite instablitiy

A

repeats change length as cells go through division

54
Q

what is result of loss of function of DNA repair

A

lots of replication errors, microsatellites and microsattelite repeats
replication slippage

55
Q

a result of homozygous cells (loss of both allels for DNA repair) results in what

A

accumulation of point mutations

replication slippage

56
Q

replication slippage

A

when it is replicated won’t be replicated exactly

57
Q

when gel has more than one band, what does it indicate

A

slippage
it means as cell replicates the daughter cells will have different size allele (so each individual cell has two alleles) and that continues. THe PCR reaction extracts from a few cells, so a bunch of different sized alleles who up.

58
Q

What does RER + stand for

A

replication error positive phenotype

59
Q

what does RER+ mean

A

microsattellite instability

60
Q

why is there slippage

A

the cell had a second hit, so DNA mismatch repair enzyme has been lost, causes microsattelite instability

61
Q

what is the initial event that causes HNPCC

A

loss of function of DNA mismatch repair due to second hit

62
Q

p15 and p16 are what

A

INKs (inhibitor of kinase)

inhibit CDK4

63
Q

why is there loss of function of TGFBR2 in HNPCC

A

within coding sequence, it has 10 adenines - slippage likely, if there is slippage will cause deletion which causes frameshift and loss of fuction

64
Q

loss of function of TGF beta receptor

A

not cause of colorectal cancer

65
Q

what is initiation of cancer of HNPCC

A

loss of function of DNA repair enzyme

66
Q

Draw out TGFBR2 pathway

A

pg 138

67
Q

Change in bowel habits; frequency , consistency, bleeding, mucus
Feeling of incomplete defecation (tenesmus), reduction in diameter of stool (rectal ca.)
Melena (upper GI ca.)
Bowel obstruction causing pain, bloating & vomiting of stool-like material.
A tumour in the abdomen, felt by patients or their doctors
smptoms of what

A

colon cancer

68
Q

almost complete obstruction of bowel what will happen

A

vomitting of stool like material

69
Q

if colorectal cancer causes invasion of bladder what will happen

A

haematuria (blood)

70
Q

colorectal cancer invades vagina what symptom

A

causing pungeant vaginal discharge.

= late events & large tumour

71
Q

symptoms of liver metastases

A

Jaundice
Pain in the abdomen, usually epigastric
hepatomegaly

72
Q

constitutional (systemic symptoms) of colorectal cancer

A

Unexplained weight loss, (most common symptom, caused lack of appetite)
Anemia, fatigue, palpitations
Clinically, pallor and blood tests will confirm the low Hb level.

73
Q

what vaccine has been developed against colon cancer

A

TroVax

74
Q

what is common therapy of colon cancer

A

surgical removal of part with cancer followed by chemotherapy

75
Q

what does TroVax do?

A

causes tumor associated antigen

boosts immune system to attack the tumor associated antigens

76
Q

loss of what is found in many cancers

A

p53

77
Q

loss of what is frequently found in sporadic cancers

A

Rb

78
Q

draw out external signal to RAS/MYC pathway

A

pg 145

79
Q

how can one have loss of Rb

A

Mutation / LOH / down-regulation by ↑miRNA (mi-R106a)

80
Q

Are BRCA1 and BRCA2 involed in sporadic breast cancer? explain

A

No

it is unusual, usually the hereditary gene is also involved in sporadic cancer

81
Q

describe CGH and cancer

A

stain chromosomes
extract DNA from tumor cells and label DNA with green fleurocohrome. Label DNA from normal cells with red. take equal amounts and hybridize them onto metaphase spread. where it shows green it means it is amplified
red = more normal DNA than tumor so it is deleted.
yellow = equal amounts

82
Q

in majority of cases in sporadic colorectal cancer mutation where

A

APC

83
Q

if sporadic colorectal cancer doesn’t have APC mutation, where is mutation

A

beta catenin

84
Q

SMAD4 loss of function in colorectal and also what other cancer

A

pancreatic

85
Q

what is PTEN

A

tumor suppressor gene - it’s phosphatase that normally removes one of the phosphates from PIP3 reverting it back to PIP2 - it prevents activation of PKB

86
Q

PTEN prevents

A

activation of PKB

87
Q

Lose PTEN in cancer what happens

A

lose ability to block pathway - so the pathway is overactive in cancer cells

88
Q

Draw PTEN pathway

A

151

89
Q

WT-1 is normally involved in what

A

regulates mesenchymal to epithelial transition - involved in renal differentiation
when there is wound epithelial cells look like mesenchymal - after it is healed supposed to go back to epithelial. in cancer it doesn’t go back

90
Q

loss of WT-1 results in what cancer

A

wilms tumor

91
Q

chromosome instability syndromes describe

A

not hereditary cancer syndromes
risk of developing cancer
AR conditions - very rare

92
Q

xeroderma pigmentosum where is mtuation

A

in nucleotide excision repair - gene does not work correctly.

93
Q

if pt is exposed to UV radiation with xeroderma pigmentosum

A

thymine dimers

thymine dimers can’t be repaired

94
Q

NER stands for what

A

nucleotide excision repari

95
Q

in order for pts to present XP they have to inherit

A

bad copy from both parents

96
Q

treatment of XP

A

reduced exposure

97
Q

what are symptoms of XP

A

Severe sunburn & blistering following sun exposure

Thin & dry skin, early development of freckles

98
Q

Ataxia Telangiectasia - what does this word mean

A

loss of balance and dilation of blood vessels

99
Q

what gene mutated in ataxia telangiectasia

A

ATM

100
Q

what does ATM stand for

A

ataxia telangiectasia, mutated)

101
Q

what does ATM do

A

kinase that can phosphorylated p53 (this stabilizes it)

it responds to damage

102
Q

what happens to Wnt signaling at top of crypt in colon

A

there isn’t Wnt signaling

103
Q

Wnt signaling pathway normally:

A

inhibits APC complex, allowing beta catenin to stimulate proliferation (at bottom of crypt)

104
Q

in 10% of sporadic colorectal cancer, where is mutation

A

APC tumor suppressor is w.t. but is hypermethylated (epigenetics! so still loss of function)
or
point mutation in beta catenin

105
Q

replication splippage leads to what

A

microsattelite instability

106
Q

In 12% of sporadic colorectal cancer there is loss of which mismatch repair genes?

A

MLH1, MSH2

107
Q

In 70% oof sporadic colorectal cancer there is a loss of expression of what

A

DCC

108
Q

In 15% of sporadic colorectal cancer there is loss of what

A

SMAD4

109
Q

What does SMAD4 signal?

A

downstream TGFBR2 growth inhibitory pathway

110
Q

Draw out TGF/SMAD pathway

A

pg 150

111
Q

loss of heterozygosity = (what should I htink of it as)

A

second hit

losing w.t. gene

MCB II Block 1 (12 decks)

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