Outline of Disease Processes

Question 1

What are most cancers (in terms of how many cells they arise from)?

Answer 1

Monoclonal (arise from a single cell)

Question 2

What does monoclonal mean?

Answer 2

Arise from a single cell

Question 3

How do cancer cells divide?

Answer 3

Using the mitosis stages just like normal cells

Question 4

What are the stages of mitosis in cancer cells?

Answer 4

1) Interphase
2) Prophase
3) Metaphase
4) Anaphase
5) Telophase
6) Daughter cells

Question 5

Why do cancer cells have uncontrollable growth?

Answer 5

They have no regulation

Question 6

What are some properties of cancer cell that is different to normal cells?

Answer 6

Loss of contact inhibition

Increase in growth factor secretion

Increase in oncogene expression

Loss of tumour suppresor genes

Question 7

What can you say about tumour suppresor genes in relation to cancer?

Answer 7

Cancer is caused by a loss of tumour suppresor genes

Question 8

What can you say about cancer and oncogene expression?

Answer 8

Increase in oncogene expression leads to cancer

Question 9

What are properties of normal cells that are different to cancer cells?

Answer 9

Oncogene expression is rare

Intermittent or co-ordinated growth factor secretion

Presence of tumour suppressor genes

Question 10

What is carcinogenesis?

Answer 10

The initiation of cancer formation

Question 11

What are the 2 stages of carcinogenesis?

Answer 11

Pre-clinical cancer

Clinical cancer

Question 12

What are the steps of pre clinical cancer in carcinogenesis?

Answer 12

Initiation

Promotion

Tumour growth

Question 13

What happens during clinical cancer in carcinogenesis?

Answer 13

Tumour progression

Question 14

When are cancers detectable?

Answer 14

Only after a certain amount of cells are present

Question 15

What are the causes of cancer seperated into?

Answer 15

Initiation

Promotion

Progression

Question 16

What can initiate cancer?

Answer 16

Chemical

Physical

Viral

Question 17

What is related to the promotion of cancer?

Answer 17

Growth factors

Oncogenes

Question 18

What is related to the progression of cancer?

Answer 18

Metastasis

Question 19

What are some chemicals that can initiate cancer?

Answer 19

Hydrocarbons such as soot and tarts

Analine dyes (cause bladder cancer)

Aflatoxin (causes liver cancer)

Nitrogen mustard (causes leukaemia)

Alcohol and smoking (causes lung, head and neck, and gastrointestinal cancers)

Question 20

What are physical causes of cancer?

Answer 20

Ionising radiation

Mechanisms (chromosome translocation, gene amplification, oncogene activation)

Question 21

What are some mechanisms that are considered a physical cause of cancer?

Answer 21

Chromosome translocation

Gene amplification

Oncogene activation

Question 22

What are some virus causes of cancer?

Answer 22

Herpes virus (causes Burkitt’s lymphoma-cervical cancer)

Hepatitis B (causes liver cancer)

Papilomavirus (causes adult T cell leukaemia/lymphoma)

Question 23

What do oncogenes do?

Answer 23

Promote cells to become cancerous

Question 24

How do oncogenes promote cells to become cancerous?

Answer 24

Transformation genes

Positive regulators of growth

Question 25

What are growth factors that promote cancer growth?

Answer 25

Peptide molecules that: Regulate cell growth and function Bind to cell membrane receptors Stimulate activation of intracellular signal transduction pathways

Question 26

What do polypeptide molecules that are growth factors promoting cancer do?

Answer 26

Regulate cell growth and function Bind to cell membrane receptors Stimulate activation of intracellular transduction pathways

Question 27

What do oncogenes cause in the surrounding cells?

Answer 27

The cells to undergo growth by paracrine stimulation

Question 28

What does not happen in oncogene expression that normally happens?

Answer 28

The feedback loop that stops growth at a certain point

Question 29

What is the most common altered tumour suppresor gene?

Answer 29

P53

Question 30

What is the normal function of P53?

Answer 30

Transcriptional regulator Promotes DNA repair Apoptosis Differentiation

Question 31

What induces P53 to become altered?

Answer 31

DNA damage Hypoxia

Question 32

What is hypoxia?

Answer 32

Deficiency in the amount of oxygen reaching the tissues

Question 33

Why is metastasis not random?

Answer 33

It is a cascade of tumour-host interactions in sequential steps

Question 34

What is the process of invasion and metastasis?

Answer 34

1) Tumour invades through basement membrane 2) Moves into extracellular matrix/connective tissue/surrounding cells 3) Invades blood vessels 4) Spreads to distant tissues/organs

Question 35

What are some enzymes involved in metastasis and what do they do?

Answer 35

Matrix metalloproteinases (MMPs which degrade the extracellular matrix) Cahedrinks, integrins and CD44 (stop cell ahesion so the cancer cell can break away)

Question 36

What is matrix metalloproteinases (MMPs)?

Answer 36

Enzymes that degrade the extracellular matrix

Question 37

What are cahedrins, integrins and CD44?

Answer 37

Enzymes which stop cell adhesion so the cancer cell can break away

Question 38

What is angiogenesis?

Answer 38

The formation of new blood vessels

Question 39

What is angiogenesis a key factor in?

Answer 39

The maintanance and progression of malignant tumours

Question 40

What must happen for a tumour to exceed 2mm in diameter?

Answer 40

New blood vessels must form

Question 41

What is required for new blood vessels to form?

Answer 41

Degradation of the extracellular matrix

Question 42

What are clinical correlations seen in relation to angiogenesis and cancer?

Answer 42

Vessel density Tumour malignancy Metastasis

Question 43

What can prevent tumour growth?

Answer 43

Drugs that can inhibit growth factors

Question 44

What is an example of a growth factor which can be inhibited by drugs?

Answer 44

Vascular endothelial growth factor (VEGF)

Question 46

How does the inhibition of growth factors like vascular endothelial growth factor (VEGF) work?

Answer 46

Drugs block receptors on epithelial cells and prevent binding of VEGF Prevents formation of new blood vessels so the tumour cannot grow

Question 47

Why do immune cells not recognise cancer cells?

Answer 47

They are self

Question 48

In terms of receptors, why do immune cells not kill cancer cells and how can we change this?

Answer 48

PD1 (programmed cell death receptor) is present on T cells Ligand (PDL-1) is on tumour cells Interaction of these two suppreses T cell activation, therapeutic opportunity to block either receptor