2.a Pharmacological Targets

Question 1

Name the different treatment approaches of cancer ?

Answer 1

1. Surgery
2. Chemotherapy
3. Personalised therapy
4. Radiotherapy
5. Hormone therapy
6. Bone marrow transplant
7. Immunotherapy

Question 2

Is chemotherapy specific to cancer cells ?

Answer 2

No, can target healthy cells which can have side effects

Question 3

What are the general problems with anti-cancer therapies ?

Answer 3

1. Lack of selectivity and specificity (can target non cancerous cells)
2. Off-target side effects
3. Drug resistance (transporter proteins which can pump up toxic agents)
4. Patient-specific factors (treatment that focuses on general patters of genetic mutations)
5. Problems with cancer diagnosis (non-specific symptoms make it difficult to diagnose, lack of effective bio markers for cancer diagnosis)

Question 4

What is the best treatment from solid tumours ?

Answer 4

Surgery

Question 5

What is debulking in terms of surgery ?

Answer 5

Removing of main bulk of tumour size before chemotherapy treatment started

Question 6

Describe the two delivery forms of radiotherapy

Answer 6

External beam radiotherapy:

• From outside the body using high energy ionising radiation

Internal brachytherapy:

• Radiotherapy fro small radioactive ‘seeds’ placed within the body

Question 7

Are normal cells affected when using radiotherapy ?

Answer 7

Causes damage to the DNA but normal tissues can also be affected.

There is a risk of new cancer development as a result of this

Question 8

How does chemotherapy work ?

Answer 8

Interferes with the cell cycle by inhibiting cellular events that lead to cell division and replication

Question 9

What phases do current chemotherapeutic agents target ?

Answer 9

S phase: responsible for DNA replication (chromosomes replicated by the cell)

M phase: responsible for mitosis (cell division)followed by cytokinesis (cell separation); leads to formation of two identical daughter cells

Question 10

Give an example on how a drug can interrupt the cell cycle ?

Answer 10

Drug A can inhibit DNA synthesis eg preventing uncoiling of DNA, cross links DNA so it is unable to separate

Drug B can inhibit mitosis eg, disrupting spindle fibres, disrupting separation of cells

Question 11

What are the issues with chemotherapy ?

Answer 11

Most cytotoxic chemotherapy drugs trainer cells that are actively multiplying:

• Rapitly dividing cells are susceptible to cell death

Question 12

Give examples of normal cells that are actively susceptible cell death from cytotoxic chemotherapy ?

Answer 12

Brown marrow
Gastrointestinal tract
Hair follicles

Question 13

What are the common side effects (toxicities) associated with chemotherapy agents ?

Answer 13

• Neutropenia, anaemia and thrombocytopenia
  (Knocking out particular white or red blood cells that leads to the above conditions; myelosuppression)
• Increasing risk of infection
• Nausea and vomiting
• Diarrhoea and mucous it is (pain and inflammation of mucus layers that line digestive system)
• Alopecia
• Nephrotoxicity, neurotoxicity, cardiovascular toxicicity

Question 14

What do anti-cancer drugs target ?

Answer 14

Target growth and death

• Apoptosis pathway (Bcl-2)
• oncogene and tumour suppressor (RAS, Scr, p53)
• cell growth and proliferation pathways

Target hormones

• anti-oestrogen signalling (tamoxifen)
• anti-androgen signalling (flutamide)

Targeting cell signalling

• Tryosine kinase inhibitor (EGF, VEGF, HER2/neu)
• angiogenesis inhibitor (bevacizumab)