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Flashcards in Outline of disease processes Deck (30)
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1
Q

define cancer

A

disorderly growth of epithelial cells which invade adjacent tissue and spread by the lymphatics and blood vessels to other parts of the body

2
Q

What is the characteristics of cancer cells

A

loss of contact inhibition
Increase in growth factor secretion
increases in oncogene expression
loss of tumour suppressor gene

3
Q

What initiates cancer growth

A

chemical
physical
viral

4
Q

Give example of chemical carcinogens

A

smoking
alcohol
nitrogen mustard - leukemia
aniline dyes - bladder

5
Q

What is a physical carcinogen

A

ionising radiation

6
Q

What is the mechanism of ionising radiation

A

chromosome translocation
gene amplification
oncogene activation

7
Q

Give example of viral carcinogens

A

Herpes virus
Papillomavirus -cervical cancer
reterovirus - leukaemia/lymphoma
Hepatitis B - liver cancer

8
Q

How do growth factors promote cancer

A

bind to cell membrane and regulate cell growth and function by promoting signal transduction pathway

9
Q

What are growth factors composed of

A

polypeptide molecules

10
Q

Growth factor stimulation is either

A

autocrine - GF produce acts on its self
or
paracinre - GF produced act locally or o neighbouring cells

11
Q

What is an example go a growth factor

A

VEGF: vascular endothelial growth factor

12
Q

What do oncogens do

A

promote growth

13
Q

In folicular lymphoma what is the oncogenes

A

BCL2

14
Q

What induces tumour suppressor genes

A

DNA damage and hypoxia

15
Q

What is the most common mutated gene in tumours

A

P53

16
Q

What is the normal function of tumour suppressor genes

A

DNA repair,

promote apoptosis

17
Q

What promotes tumour growth

A

Increase in growth factor secretion
increases in oncogene expression
loss of tumour suppressor gene

18
Q

How do tumours progress

A

metastasis

19
Q

What is the pathway of metastasis

A

nvade basement membrane, moves into surrounding cells/tissues, invade blood vessels, tumours cells arrest in distant organ

20
Q

What process must occur for tumour to surpass 2mm

A

angiogenesis - New blood vessel formation

21
Q

What enzymes are involved with metastasis in the ECM

A

Matrix metalloproteinases (MMPs) eg gelatinases
Plasmin
Cathepsin

22
Q

What is matrix metallaproteinases responsible for

A

degradation of most extracellular matrix proteins

23
Q

What is plasmin responsible for

A

degrading blood plasma proteins

24
Q

what is a cathespin

A

protease

25
Q

Loss of what adhesion mechanisms causes metastasis

A

Cahedrins - transmembrane protein
Integrins - attaches cytoskeleton
CD44 - antigen

26
Q

What is necessary for new blood vessel formation

A

degradation of ECM

27
Q

What does a Anti VEGF antibody prevent

A

Growth factor interacting with receptors prevent transduction signal being sent, therefore tumour lies dormant

28
Q

Why does our immune system not recognise cancer cells

A

PD1 present on T cell binds with PDL-1 ligand on tumour cells and suppress T cell action

29
Q

What may high levels of PD1 or PDL1

protein expression inhibit

A

immune response

30
Q

What kind of process is metastasis

A

organised

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