18

Question 1

Germline mutation

Answer 1

If a mutation occurs in a cell that go on to make gametes (egg or sperm cells), the mutation can be passed on to the next generation ( e.g. in born errors of metabolism).

Question 2

Somatic mutation

Answer 2

Somatic mutation - occur in other cells and cannot be passed on – can result in caner.

Question 3

Somatic vs Germaine mutation

Answer 3

Question 4

How many cells is the human body made from

Answer 4

37 trillion

Question 5

Cell growth and cell death in cells - balance

Answer 5

• Normally, human cells grow and divide to form new cells as the body needs them.
• When cells grow old or become damaged, they die, and new cells take their place.

Question 6

What is cancer?

Answer 6

Cancer is a collection of related diseases and can start almost anywhere in the body.

Question 7

What are cancers cells? Do they respond to signals?

Answer 7

Cancer cells are cells within a tissue that longer respond to many of the signals that control cellular growth and death. Over time, these cells become increasingly resistant to the controls that maintain normal tissue — and as a result, they divide more rapidly.

Question 8

Do cancer cells do programmed death?

Answer 8

No

Question 9

What happens in the late stages of cancer

Answer 9

In the late stages of cancer, cells break through normal tissue boundaries and metastasize (spread) to new sites in the body

Question 10

What underlies the development of cancer?

Answer 10

Multiple mutation

Question 11

Cancer is the result of….

Answer 11

An accumulation of mutations

Question 12

What are most mutations associated with?

Answer 12

DNA replication

Question 13

The more times a cell decides, the more likely it is to…..

Answer 13

Gain a mutation

Question 14

Why does incidence of cancer increase greatly with age

Answer 14

The more times a cell divides, the more likely it to gain a mutation

Question 15

• Hundreds of _______ encode _____ that normally regulate cell
_____ and _______
• _________ that alter these genes in ______ cells can lead to
________

Answer 15

• Hundreds of genes encode proteins that normally regulate cell growth and division
• Mutations that alter these genes in somatic cells can lead to cancer

Question 16

Mutations may be _____ or result of ______

Answer 16

Mutations may be spontaneous (occur by chance) or the result of exposure to a mutagen (also called carcinogen)

Question 17

Two types of genes cause cancer when mutated

Answer 17

Tumor supressor genes
Once-genes

Question 18

What do tumor suppressor genes fo?

Answer 18

E ncode proteins that normally prevent uncontrolled cell growth e.g.;
• proteins that inhibit cell division
• Prevent other mutations (DNA repair enzymes)

Question 19

What does the lack of tumor suppressor gees do

Answer 19

Lack of these genes can stimulate cell growth - i.e. recessive mutations promote cancer

Question 20

What do oncogenes result form

Answer 20

Mutations that increase gene activity

Question 21

Example of hoe oncogene and tumor supressor mutations lead to cancer

Answer 21

Chronic myeloid leukemia

Question 22

What are once-genes

Answer 22

Encode proteins that promote cell growth
e.g: Proteins that stimulate cell division
Cancer mutations increase the activity of
these genes

Dominant mutations promote cancer

Question 23

Can this cell under go cell division? Why? (Tumor suppressor genes - mutations that decrease gene activity cause cancer)

Answer 23

The cell is prevented from undergoing cell division due to inactivation of E2F transcription factor

Question 24

Can this cell undergo cell division ? Why?

Answer 24

Yes

Signal for cell division results in E2F transcription factor moving in to the nucleus

Cell divison genes can then be expressed

Question 25

What else prevents the E2F being activated? What does it do to the kinase?

Answer 25

P16 binds to kinase preventing it from phosphorylating the RB protein at the wrong time

Question 26

What are the multiple checks that prevent replication happening

Answer 26

• p16 on the kinase
• transcription factor E2F controlled by RB proven

Question 27

What happens here?

Answer 27

Loss of function mutation in RB gene cause activation of the E2F transcription factor

MUST HAVE MUTATION IN BOTH COPIES as recessive

Question 28

What’s happening here?

Answer 28

Loss of function mutation in p16 gene cause activation of the E2F transcription factor

Question 29

Lots of genes important for controlling when and where cells divide

Answer 29

Yes

Question 30

What is a proto-oncogene

Answer 30

A normal gene that when mutated can promote uncontrolled cell growth

Question 31

Answer 31

Question 32

Answer 32

Question 33

Cancer treatments

Answer 33

Surgery: remove cancer cells
Radiation therapy: targeted radiation to kill cancer cells
Chemotherapy: uses dugs that target dividing cells as cancer cells grow rapidly - but also affects normal cells

Question 34

Targeted therapy ;

Answer 34

• drugs that target changes in cancer cells that allow them to grow and divide
• BCR-ABL translocation - not present in any other cells apart from cancer cells
• gleevac inhibits kinase activity of BCR-ABL