7. Tumourigenesis and cancer signalling

Question 1

Definition of neoplasia

Answer 1

new growth

Question 2

defintion of grading

Answer 2

degree of differentiation

Question 3

definition of staging

Answer 3

size and spread of tumour

Question 4

definiton of metaplasia

Answer 4

reversible replacement of one cell type with another

Question 5

what is dysplasia

Answer 5

altered cell maturation, orientation and tissue architecture

Question 6

what is anaplasia

Answer 6

lack of differentiation

Question 7

3 examples of oncogenic viruses

Answer 7

1. human papillomavirus
2. epstein-barr virus
3. hep c and hep b

Question 8

what cancer can human papillomavirus cause?

Answer 8

cervical cancer

Question 9

what cancer can epstein - barr virus cause?

Answer 9

Burkitt’s lymphoma

Question 10

what cancer can Hep B and C cause?

Answer 10

Hepatocellular carcinoma

Question 11

4 examples of familial syndromes

Answer 11

1. Li-fraumeni
2. retinoblastoma
3. breast cancer
4. familial adenomatous polyposis

Question 12

what cancer can li-farumeni causse?

Answer 12

breast, leukaemia, brain tumour

Question 13

what mutation causes Li-Fraumeni syndrome

Answer 13

p53

Question 14

what mutation causes retinoblastoma

Answer 14

pRb - RB1

Question 15

what mutation causes familial adenomatous polyposis

Answer 15

APC gene

Question 16

3 stages of carcinogenesis

Answer 16

1. initation
2. promotion
3. propagation

Question 17

what is initiation?

Answer 17

carcinogen causes non-lethal mutations

Question 18

what is promotion?

Answer 18

cell proliferation - additional mutations accumulate

Question 19

what is progression?

Answer 19

accumulation of mutations lead to invasive phenotype

Question 20

are initiation changes reversible?

Answer 20

yes

Question 21

are promotion changes reverisble ?

Answer 21

proliferion = yes

dna chnages = no

Question 22

3 examples of initiators

Answer 22

1. uV radiation
2. cisplatinum
3. asbestos

Question 23

3 examples of promoters

Answer 23

1. hormones (oest+T)
2. alchol
3. chronic wound

Question 24

3 biological characteristics of tumour cells

Answer 24

1. abnormal proliferation and cell immortalisation
2. abnormal DNA
3. deregulate apoptosis

Question 25

what is polypoloidy - what does it cause?

Answer 25

increase DNA - hyperchromasia

Question 26

what is aneuploidy?

Answer 26

abnormal number of Ch in 1 cell

Question 27

2 main groups of cancer genes

Answer 27

1. tumour suppressor | 2. oncogenes

Question 28

normal function of proto-oncogene?

Answer 28

promote cell growth

Question 29

normal function of tumour suppressor genes

Answer 29

inhibit cell proliferation

Question 30

4 examples of oncogenes

Answer 30

1. cyclin 2. CDK 3. mdm2 4. E2F

Question 31

5 examples of tumour suppressor genes

Answer 31

1. pRB 2. p53 3. p21 4. TGF-b 5. BRCA1 and 2

Question 32

mutations in these 4 genes give rise to dominant active oncogenes

Answer 32

1. GF 2. GF receptor 3. intracellular transducers 4. TF

Question 33

mutations in this protein increases probability of mutations in other protein classes

Answer 33

DNA repair proteins

Question 34

3 ways in which proto-oncogene becomes an oncogene?

Answer 34

1. point mutation 2. gene amplification 3. chromosomal translocation

Question 35

role of p53 - where does it work in the cell cycle?

Answer 35

G1 - cell cycle arrest for repair or apoptosis

Question 36

role of cyclin D/CDK4 and 6 - where does it work in the cell cycle?

Answer 36

G1 - promote cell cycle progression

Question 37

3 examples of CDKIs

Answer 37

p27, p21, p57

Question 38

role of CDKIs - where does it work in the cell cycle?

Answer 38

G1/s and G2/M - cell cycle arrest

Question 39

describe steps in malignancy

Answer 39

1. normal 2. dysplasia 3. carcinoma in situ 4. invasive 5. metastasis

Question 40

what is intraepithlial neoplasia?

Answer 40

abnormality is confined to epithelia

Question 41

6 hallmarks of cancer

Answer 41

1. angiogenesis 2. limitless proliferation 3. tissue invasion and metastasis 4. evading apoptosis 5. self-sufficiency in growth signals 6. insensivitiy to anti-growth signals

Question 42

what is an excisional biopsy?

Answer 42

entire lesion removed

Question 43

what is an incisional biopsy?

Answer 43

large representation sample taken

Question 44

in cytology - what are the samples screened for?

Answer 44

immunological markers which are expressed in specific tumours

Question 45

what is grade 1 ?

Answer 45

well differentiated

Question 46

describe TNM staging

Answer 46

``` t = tumour size n = number of lymph nodes affected m = metastasis ```

Question 47

describe dukes staging

Answer 47

``` a = confined to submucosa/muscle layer b = invasion through muscle layer c = tumour in lymph nodes ```