Cancer Genetics

Question 1

How do cancer cells arise?

Answer 1

Cell growth is highly regulated

Question 2

When cells are derailed how are new cells produced?

Answer 2

uncontrolled proliferation

Question 3

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

Answer 3

Tumours - cancerous

Neoplasms - new growth

Question 4

What does transformation mean?

Answer 4

Process of changes within a cell that lead to a neoplasm

Question 5

What are 2 types of neoplasm?

Answer 5

Benign - localised

Metastatic - spread

Question 6

What are familial cancers?

Answer 6

Inherited in families - high penetrance in genes

Question 7

What are sporadic cancers?

Answer 7

Acquired in ones life time - combo of low pentrance genes

Question 8

What are cancer cells in situ?

Answer 8

Clonal

Question 9

What part of chromosomes are associated with cancer?

Answer 9

Aberrations

Question 10

What are mutagens?

Answer 10

Exposure to chemicals that damage DNA

Question 11

What type of infection can lead to cancer?

Answer 11

oncovirus

Question 12

What is carciogenesis?

Answer 12

Process of inducing cancer

Question 13

Which 2 genes do mutations arise in?

Answer 13

Oncogenes and Tumour surpressor gene

Question 14

What are 4 types of mutations?

Answer 14

Single letter change, reverse order, deletion, insertion

Question 15

What type of genetic changes in oncogenes?

Answer 15

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

Question 16

What type of genetic changes in tumour suppressors?

Answer 16

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

Question 17

What are proto oncogenes?

Answer 17

Genes which encode for components of cell signalling pathways

Question 18

What do proto oncogenes promote?

Answer 18

Cell growth and division

Question 19

What happens to proto oncogenes when mutated?

Answer 19

Become oncogenes - drive cell to divide

Question 20

What do oncogenes trigger?

Answer 20

Cell transformation

Question 21

What are viral oncogenes?

Answer 21

Copies of a group of genes found in humans

Question 22

What do proto-oncogenes control?

Answer 22

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

Question 23

When does proto-oncogenes become activated oncogenes?

Answer 23

Gain of function by amplification, mutation and chromosomal rearrangement

Question 24

Why is HER 2 an example of oncogene?

Answer 24

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

Question 25

Why is Ras an example of oncogene?

Answer 25

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

Question 26

Why is VEGF an example of oncogene?

Answer 26

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

Question 27

What is theact of cancers creating new blood vessels?

Answer 27

Angiogenesis

Question 28

What inhibits angiogensis?

Answer 28

Anti angiogenesis - avastin

Question 29

Where do tumour suppressor genes work?

Answer 29

At cell cycle check points

Question 30

What are 3 classfications of TSG?

Answer 30

Gatekeeper Caretaker Landscaper

Question 31

What do Gatekeeper genes do?

Answer 31

regulate cell division

Question 32

What do Caretaker genes do?

Answer 32

DNA repair

Question 33

What do Landscaper genes do?

Answer 33

Modulate stroma for tumour to grow

Question 34

Why are mutations in TSG recessive?

Answer 34

Both alleles must be mutated for gene to stop functioning

Question 35

Why is Rb an example of TSG?

Answer 35

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

Question 36

Why is p53 an example of TSG?

Answer 36

Known as gaurdian of genome needed for apoptosis

Question 37

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

Answer 37

Encode DNA repair enxymes and when mutated can accumulate

Question 38

What does BRCA 1 regulate?

Answer 38

Microtubules for taxane resistance

Question 39

How do Viruses assist cancer?

Answer 39

Enhance proliferation and predispose cells to cancer - CANT induce IT

Question 40

What does protein does DNA make to inactivate tumour surpressors?

Answer 40

Viral proteins - mesotheliomas

Question 41

What does RNA viruses insert for viral promotion?

Answer 41

Avian model

Question 42

What do RNA viruses carry to activate oncogene?

Answer 42

Avian sarcoma

Question 43

What does HPV E6 /E7 inactivate?

Answer 43

P53 and Rb

Question 44

What also inactivates P53 and Rb?

Answer 44

SV40 TAg and AdE1a,b - Rb and P53

Question 45

What does two hit hypothesis define?

Answer 45

Min number of mutations for tumour to occur

Question 46

For cancer to develop what 6 stuff must cells acquire?

Answer 46

``` External growth signals Anti-growth signals Apoptosis Immortality Angiogenesis Metastatic ```

Question 47

What does FAP lead to?

Answer 47

Colon cancer

Question 48

What can transformation process lead to?

Answer 48

Neoplasms

Question 49

What are 2 types of neoplasms?

Answer 49

Benign or Malignant

Question 50

What facts indicate cancer is genetic?

Answer 50

Familial cancers, Oncoviruses, Mutagens

Question 51

What do the Mutations that cause cancer disrupt?

Answer 51

Cell cycle checkpoints

Question 52

What aberration causes a gain of function event?

Answer 52

Proto-oncogenes to oncogenes

Question 53

What genes prevent uncontrolled cell division?

Answer 53

Tumour Suppressor genes

Question 54

How do TSG stop cell division?

Answer 54

Deactivated in cancer by recessive mutations in both alleles