Brainscape's Knowledge GenomeTM

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


See full index

Genetics Of Complex Disease > Breadt Cancer Genetics > Flashcards

Breadt Cancer Genetics Flashcards

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

Why is angiogenesis a requirement for tumorigenesis (1/6 requirements)

A

Tumour needs oxygen aupply

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

What epigentic fsctor causes metastatic breast cancers

A

HDAC increased reduces exp of ecadherins

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

Explain what makes up the breast

A

Lobular units where milk is made then ducts take it down

Epithelial cells make the milk

Myoepithelium surround them as a barrier

Stromal cells also present

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

In situ malignancy is what

A

Where cells are malignant but stay surrounded by myopeithelial cells

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

What is the difference between invasive malignancies and metastatic breast cancer

A

Invasive means they peoentraye the Myoepithelium barrier and spread to breast connective tissues

Metastatic is where they invade other tissues via lymphatic drainage,neural network or vasculature

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

What 3 breast event changes occur eg during mestrual cycle, pregnancy, puberty and lactation

A

Cells will expand, differentiate and then involution occurs to counteract changes

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

What is this controlled by

A

Hormones

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

When is breast cancer risk increased

A

During early and late menopause
Contraceptive pill
Hormone rt for menopause
Phytoestrogens
Zenoestrogens (mimic hormones)

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

Why does oestrogen and progesterone promote mutagenesis

A

Increased cell proliferation

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

Why is pregnancy seen as protective

A

Allows differentiation in mammary gland which is protective

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

What else helps reduce risk

A

Lactation/breastfeeding

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

How can this explain demographic incidence

A

Reduced risk in areas like africa with more pregnancy and breastfeeding

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

What are the sources of oestrogen for pre, post menopausal women and men

A

Pre- ovarian androgens converted

Post- adrenal androgens converted

Men- testicular androgens converted

Converted to estrogens by aromataae

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

Why may obese people have more aromatise and so bigger risk

A

Present in adipose tissue

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

Give examples of anti-oestrogen treatment which could reduce risk

A

Aromatase inhibitors

Serms- antagonist of er binding

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

What do serms like tamoxifen stop

A

Cell proliferation / block cell cycle

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

Explain how the er can affect genes for cell proliferation,apoptosis and differentiation

A

It has tf activity and can interact with other tf in nucleus like ap-1

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

Which genes are usually gained or lost in breast cancers via mutations or epi genetics

A

Loss of tumour suppressors via gene exp or mutation

Gain of oncogenes via mutation in Proto-oncogenes

19
Q

What are proto-oncogenes

A

Genes which when mutated can cause cancer

They usually regulate cell growth

20
Q

What % of breast cancer is hereditary (I.e dominant pattern of inheritance and high penentrance)

A

5%

21
Q

What % does sporadic bc make (ie de novo variants/ mutations)

A

80%

22
Q

What does familial breast cancer mean

A

Runs in family but not Mendelian inheritance- either shared environment, by chance or low risk alleles

23
Q

What are the major hereditary cancer genes (autosomal dominant)

A

Brca 1/2 and they are tumour suppressirs

24
Q

Which brca gets commonly methylated

A

Brca1

25
Q

What are some of their roles

A

Dna damage response
Hr
Cell cycle checkpoint role
Chromatin remodelling

26
Q

What dna repair which is error prone occurs if brca mutated

A

Nhej

27
Q

Why does brca1 allow for hr

A

It interacts with chromatin remodellers like hats and swi/snf to allow for better access for Hr

28
Q

How does brca2 allow for hr

A

It’s brc motifs bind rad51 enzyme for hr and also regulate rad51 activity and availability

29
Q

Which part of brca2 is commonly mutated

A

Brc motifs

30
Q

What happens in late g1 and s and g2/m phases to brca1 for cell cycle regulation

A

Phosphorylated by cdk , atm and atr when dna damage is sensed

= activated dna repair response

31
Q

Which inherited syndrome with tp53 germ line mutation causes frequent breast cancer

A

Li fraumeni syndrome (ad)

32
Q

Which tumour suppressor gene is ad mutated and inherited to cause cowden syndrome and thus high breast cancer risk

A

Pten

33
Q

Which gene is mutated germ line that recognises dna ds breaks in ataxia telangasia

A

Atm gene (phos of brca1)

34
Q

What does chek2 do which is found to have medium penetrance hereditary variants in bc predisposition

A

It is a kinase whcih autophosphorylates and dimerises and activates downstream targets like p53 and brca1 in cell cycle checkpoints

35
Q

Why is brca not so important in sporadic cancer

A

Rare to be somatic mutations

36
Q

What types of studies are used to study breast sporadic cancers

A

Gwas to find snps with associations with risk of breast cancer

37
Q

What was the biggest OR high risk allele but low penetrance

A

Fgfr2

38
Q

are sporadic associations low penetrance

A

Yes except brca

39
Q

How many susceptibility loci found

A

Over 80

40
Q

Which 3 somatic mutations were only ones found in many subtypes of bc eg her2 , luminal a and b

A

Tp53, pik3ca and gata3

41
Q

Why would basal like bc found to be able to be treated by parp inhibitors

A

20% have a variant in brca genes somatic or germline

42
Q

What % of sporadic bc was actually found to be due to germline variants

A

10%

43
Q

Which gene usually screened for germline predisposition

A

Brxa, sometimes p53 is li fraumeni suggested

44
Q

How do parp inhibitors work

A

In healthy cells, both parp and brca used to repair dna eg during radiation

If you block parp from working in cancer cells with mutant brca they can’t repair dna and apoptosis occurs

Genetics Of Complex Disease (17 decks)

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