Cancer Genetics Flashcards Preview

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Flashcards in Cancer Genetics Deck (54)
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1
Q

How do cancer cells arise?

A

Cell growth is highly regulated

2
Q

When cells are derailed how are new cells produced?

A

uncontrolled proliferation

3
Q

What is the difference between cell masses of tumours or neoplasms?

A

Tumours - cancerous

Neoplasms - new growth

4
Q

What does transformation mean?

A

Process of changes within a cell that lead to a neoplasm

5
Q

What are 2 types of neoplasm?

A

Benign - localised

Metastatic - spread

6
Q

What are familial cancers?

A

Inherited in families - high penetrance in genes

7
Q

What are sporadic cancers?

A

Acquired in ones life time - combo of low pentrance genes

8
Q

What are cancer cells in situ?

A

Clonal

9
Q

What part of chromosomes are associated with cancer?

A

Aberrations

10
Q

What are mutagens?

A

Exposure to chemicals that damage DNA

11
Q

What type of infection can lead to cancer?

A

oncovirus

12
Q

What is carciogenesis?

A

Process of inducing cancer

13
Q

Which 2 genes do mutations arise in?

A

Oncogenes and Tumour surpressor gene

14
Q

What are 4 types of mutations?

A

Single letter change, reverse order, deletion, insertion

15
Q

What type of genetic changes in oncogenes?

A

1 change, gain of unction, stimulate cell growth, myc, ras

16
Q

What type of genetic changes in tumour suppressors?

A

2 genetic changes, loss of function, repress cell entry - pRb, P53

17
Q

What are proto oncogenes?

A

Genes which encode for components of cell signalling pathways

18
Q

What do proto oncogenes promote?

A

Cell growth and division

19
Q

What happens to proto oncogenes when mutated?

A

Become oncogenes - drive cell to divide

20
Q

What do oncogenes trigger?

A

Cell transformation

21
Q

What are viral oncogenes?

A

Copies of a group of genes found in humans

22
Q

What do proto-oncogenes control?

A

Key process in cell growth such as factors, receptors, signalling, transcription

23
Q

When does proto-oncogenes become activated oncogenes?

A

Gain of function by amplification, mutation and chromosomal rearrangement

24
Q

Why is HER 2 an example of oncogene?

A

30% have this, increased her2 receptors on cell surface - amplification

25
Q

Why is Ras an example of oncogene?

A

Signal transducer protein - active and inactive form 1/3 have it

26
Q

Why is VEGF an example of oncogene?

A

Vascular endothelial growth factor - over produce this and sprouts new vessels feeding cancer - target avastin

27
Q

What is theact of cancers creating new blood vessels?

A

Angiogenesis

28
Q

What inhibits angiogensis?

A

Anti angiogenesis - avastin

29
Q

Where do tumour suppressor genes work?

A

At cell cycle check points

30
Q

What are 3 classfications of TSG?

A

Gatekeeper
Caretaker
Landscaper

31
Q

What do Gatekeeper genes do?

A

regulate cell division

32
Q

What do Caretaker genes do?

A

DNA repair

33
Q

What do Landscaper genes do?

A

Modulate stroma for tumour to grow

34
Q

Why are mutations in TSG recessive?

A

Both alleles must be mutated for gene to stop functioning

35
Q

Why is Rb an example of TSG?

A

People can inherit one faulty copy and later in life lose second copy and be cancerous

36
Q

Why is p53 an example of TSG?

A

Known as gaurdian of genome needed for apoptosis

37
Q

Why is BCRA 1 and BRCA 2 an example of TSG?

A

Encode DNA repair enxymes and when mutated can accumulate

38
Q

What does BRCA 1 regulate?

A

Microtubules for taxane resistance

39
Q

How do Viruses assist cancer?

A

Enhance proliferation and predispose cells to cancer - CANT induce IT

40
Q

What does protein does DNA make to inactivate tumour surpressors?

A

Viral proteins - mesotheliomas

41
Q

What does RNA viruses insert for viral promotion?

A

Avian model

42
Q

What do RNA viruses carry to activate oncogene?

A

Avian sarcoma

43
Q

What does HPV E6 /E7 inactivate?

A

P53 and Rb

44
Q

What also inactivates P53 and Rb?

A

SV40 TAg and AdE1a,b - Rb and P53

45
Q

What does two hit hypothesis define?

A

Min number of mutations for tumour to occur

46
Q

For cancer to develop what 6 stuff must cells acquire?

A
External growth signals
Anti-growth signals
Apoptosis
Immortality
Angiogenesis
Metastatic
47
Q

What does FAP lead to?

A

Colon cancer

48
Q

What can transformation process lead to?

A

Neoplasms

49
Q

What are 2 types of neoplasms?

A

Benign or Malignant

50
Q

What facts indicate cancer is genetic?

A

Familial cancers, Oncoviruses, Mutagens

51
Q

What do the Mutations that cause cancer disrupt?

A

Cell cycle checkpoints

52
Q

What aberration causes a gain of function event?

A

Proto-oncogenes to oncogenes

53
Q

What genes prevent uncontrolled cell division?

A

Tumour Suppressor genes

54
Q

How do TSG stop cell division?

A

Deactivated in cancer by recessive mutations in both alleles

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