Outline of disease processes

Question 1

define cancer

Answer 1

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

Question 2

What is the characteristics of cancer cells

Answer 2

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

Question 3

What initiates cancer growth

Answer 3

chemical
physical
viral

Question 4

Give example of chemical carcinogens

Answer 4

smoking
alcohol
nitrogen mustard - leukemia
aniline dyes - bladder

Question 5

What is a physical carcinogen

Answer 5

ionising radiation

Question 6

What is the mechanism of ionising radiation

Answer 6

chromosome translocation
gene amplification
oncogene activation

Question 7

Give example of viral carcinogens

Answer 7

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

Question 8

How do growth factors promote cancer

Answer 8

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

Question 9

What are growth factors composed of

Answer 9

polypeptide molecules

Question 10

Growth factor stimulation is either

Answer 10

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

Question 11

What is an example go a growth factor

Answer 11

VEGF: vascular endothelial growth factor

Question 12

What do oncogens do

Answer 12

promote growth

Question 13

In folicular lymphoma what is the oncogenes

Answer 13

BCL2

Question 14

What induces tumour suppressor genes

Answer 14

DNA damage and hypoxia

Question 15

What is the most common mutated gene in tumours

Answer 15

P53

Question 16

What is the normal function of tumour suppressor genes

Answer 16

DNA repair,

promote apoptosis

Question 17

What promotes tumour growth

Answer 17

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

Question 18

How do tumours progress

Answer 18

metastasis

Question 19

What is the pathway of metastasis

Answer 19

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

Question 20

What process must occur for tumour to surpass 2mm

Answer 20

angiogenesis - New blood vessel formation

Question 21

What enzymes are involved with metastasis in the ECM

Answer 21

Matrix metalloproteinases (MMPs) eg gelatinases
Plasmin
Cathepsin

Question 22

What is matrix metallaproteinases responsible for

Answer 22

degradation of most extracellular matrix proteins

Question 23

What is plasmin responsible for

Answer 23

degrading blood plasma proteins

Question 24

what is a cathespin

Answer 24

protease

Question 25

Loss of what adhesion mechanisms causes metastasis

Answer 25

Cahedrins - transmembrane protein
Integrins - attaches cytoskeleton
CD44 - antigen

Question 26

What is necessary for new blood vessel formation

Answer 26

degradation of ECM

Question 27

What does a Anti VEGF antibody prevent

Answer 27

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

Question 28

Why does our immune system not recognise cancer cells

Answer 28

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

Question 29

What may high levels of PD1 or PDL1

protein expression inhibit

Answer 29

immune response

Question 30

What kind of process is metastasis

Answer 30

organised