Cancer 'The How'

Question 1

What are the 10 hallmarks of cancer

Answer 1

Avoiding immune destruction
Evading growth suppressors
Angiogenesis (make blood supply)
Replicative immortality
Invasion & metastasis
Genomic instability
Resist cell death
Degranulation energetics
Proliferative signals

Question 2

What is tumour heterogeneity

Answer 2

Different components in every tumour due to genomic instability. Same drug/treatment not work on every tumour

Question 3

Why do neoplastic cells become immortal

Answer 3

Keep proliferating
Abnormal oncogene expression
Inactivate tumour suppressors
Genes inhibiting apoptosis

Question 4

what is a tumour suppressor

Answer 4

Genes inhibit neoplastic growth in normal conditions
Genes can be Caretaker or Gatekeeper

Question 5

What are gatekeeper and caretaker genes

Answer 5

Gatekeeper- Stops damaged cells dividing
Caretaker- Repairs DNA damage

Question 6

What has gatekeeper and caretaker functions & how does it lose this

Answer 6

p53

Loses function from mutations, binding to oncoproteins of viruses and mutants

Question 7

What is an oncogene

Answer 7

Genes which drive neoplastic behaviour of cells. Make oncoproteins

Question 8

What are the 5 groups of oncogenes

Answer 8

Growth factors
Receptors of growth factors
Signalling mediator with- Tyrosine kinase or nucleotide binding activity
Nuclear binding transcription factor

Question 9

What genomic instability terms are in neoplastic cells

Answer 9

Diploid, Polyploidy or aneuploidy

Question 10

What is diploid

Answer 10

Normal amount of DNA, 2 copies each chromosome

Question 11

What is polyploidy

Answer 11

Exact multiples of diploid state in cell tetraploidy=4N octoploidy= 8N

Question 12

What is aneuploidy

Answer 12

Cell contains inexact chromosome numbers- Translocations

Question 13

What is a carcinogen

Answer 13

Environmental agent participating in causing tumours

Question 14

What is a mutagenic carcinogen

Answer 14

Acts on DNA of cells

Question 15

How are carcinogens identified

Answer 15

epidemiological studies
Direct evidence- Chernobyl
Experimental testing e.g animals + cells
Occupational risks

Question 16

What cancer did Chernobyl cause

Answer 16

Thyroid carcinoma

Question 17

What cancer and carcinogen is caused by smoking

Answer 17

Carcinomas- skin, lung and mouth

Aromatic hydrocarbons= carcinogen

Question 18

What carcinogens cause bladder cancer

Answer 18

Aromatic amines in rubber/dye industry and azo dyes from mutagenic

Question 19

What carcinogen causes angiosarcoma

Answer 19

Vinyl chloride in PVC maufacuring

Question 20

What carcinogen causes GI cancers

Answer 20

Nitrosamines in tobacco and cured meats

Question 21

What is HPV in 5 steps

Answer 21

1. Get infected with high risk HPV subtype
2. Virus integrates into host genome
3. E6 viral oncoprotein acts on TP53 making p53
4. E& viral oncoprotein acts on RB coding for retinoblastoma protein
5. Neoplastic cells with integrated viral gene keep replicating

Question 22

What cancers can Epstein Barr Virus (EBV) cause

Answer 22

Lymphomas and carcinomas

Question 23

What lymphomas are EBV associated with

Answer 23

Burkitt (high grade B cell)
Hodgkin
Primary effusion

Question 24

What carcinomas are EBV associated with

Answer 24

Squamous cell carcinomas
Nasopharyngeal Carcinoma- combination with smoking/EBV

Question 25

What cancers can UV light cause

Answer 25

Malignant Melanoma Basal cell carcinoma

Question 26

What is a melanoma

Answer 26

Melanocytes are neural derived cells in basal layer of epidermis producing melanin pigment

Question 27

What is a basal cell carcinoma

Answer 27

Tumour of skin which is 80% of of skin cancers associated with sunburn

Question 28

What is ionising radiation

Answer 28

Radiation which detaches electrons from atoms/molecules like X-ray, nuclear radiation and gamma

Question 29

What tissues are sensitive to carcinogenic effects of ionising radiation

Answer 29

Thyroid Breast Bone

Question 30

Why are epithelial origin carcinomas more prominent in >60 years

Answer 30

As increasing somatic genetic mutation and loss of immune competence

Question 31

Why can diet cause carcinogenesis

Answer 31

Excess adipose tissue has higher levels of growth hormones (oestrogen causes cancer) Processed meats have nitrosamines (chemical carcinogen)

Question 32

What inherited mutation predispose to breast and ovarian cancers

Answer 32

BRCA1 and BRCA2

Question 33

How do neoplastic cells increase chances of invasion

Answer 33

decrease cellular adhesion Increase cellular motility Secrete proteolytic enzymes (damage tissue surrounding)

Question 34

How does metastasis occur

Answer 34

1. Detachment 2. Invades surrounding tissue 3. Intravasation to vessels 4. Evasion host defences 5. Adhere to other endothelium 6. Extravasation of cells from vessel into surrounding new tissue

Question 35

What is metastasis

Answer 35

Process where tumour cells get from site of origin to secondary site

Question 36

What are the routes of metastasis

Answer 36

Haematogenous Lymphatic Trans coelomic (across body cavity)