Tumour Pathology 5

Question 1

What is carcinogenesis due to?

Answer 1

Geographic and environment factors

Age

Heredity

Question 2

What are the 2 categories of normal genes that can be disrupted and cause cancer?

Answer 2

Tumour suppressor genes (anti-oncogenes)

Proto-oncogenes

Question 3

What are tumour suppressor genes?

Answer 3

Normal growth inhibitor genes that regulate:

Mitosis (Rb)

Apoptosis (p53)

DNA repair

Question 4

What are anti-oncogenes also known as?

Answer 4

Tumour suppressor genes

Question 5

What does p53 regulate?

Answer 5

Apoptosis

Question 6

What is a key event in tumour formation?

Answer 6

Uncontrolled proliferation, due to cell cycle dysfunction, due to loss of tumour suppressor gene function

Question 7

What are other mutations that can directly impact the performance of pRb?

Answer 7

CKD4

Cyclin D

CDKIs

Question 8

What does absent or inactive pRb do?

Answer 8

Releases the brake on the cell cycle, causing cell proliferation

Question 9

What are the causes of retinoblastomas?

Answer 9

Sporadic

Inherited

Question 10

What are examples of inherited predispositions to cancer?

Answer 10

Familial retinoblastoma

Familial adenomatous polyposis of colon

Multiple endocrine neoplasia

Neurofibromatosis

Van Hippel-Lindou Syndrome

Question 11

What are some known inherited mutations of anti-oncogenes?

Answer 11

APC

p53

Rb

p16

BRCA1/2

Question 12

What does an inherited mutation of APC cause?

Answer 12

FAP colon cancer

Question 13

What does an inherited mutation of Rb cause?

Answer 13

Retinoblastoma

Question 14

What does an inherited mutation of p16 cause?

Answer 14

Malignant melanoma

Question 15

What does an inherited mutation of BRCA1/2 cause?

Answer 15

Breast cancer

Question 16

What is the function of APC?

Answer 16

Signal transduction

Question 17

What is the function of p16?

Answer 17

Cell cycle/apoptosis after DNA damage

Question 18

What is the function of Rb?

Answer 18

Cell cycle regulation

Question 19

What is the function of p16?

Answer 19

Inhibits CDKs

Question 20

What is the function of BRCA1/2?

Answer 20

DNA repair

Question 21

What are proto-oncogenes?

Answer 21

Normal genes coding for normal proteins that regulate growth

Question 22

What are some functions of proto-oncogenes?

Answer 22

Growth factors

Growth factor receptors

Signal transduction

Question 23

What are oncogenes derived from?

Answer 23

Proto-oncogenes

Question 24

What are oncogenes activated by?

Answer 24

Alteration of proto-oncogene structure

Dysregulation of proto-oncogene expression

Question 25

What can cause an alteration of proto-oncogene structure?

Answer 25

Point mutation Chromosome rearrangements and translocation

Question 26

What do oncogenes generate?

Answer 26

Active oncogene products

Question 27

What are active oncogene products?

Answer 27

Growth factors Growth factor receptors Proteins involved in signal transduction Nuclear regulatory proteins Cell cycle regulators

Question 28

How many copies of an oncogene do you need to cause cause?

Answer 28

Only one, not two

Question 29

What is the process of viral carcinogenesis?

Answer 29

1) Virus inserts genome near a host proto-oncogene 2) Viral promoter or other transcription regulation element cause proto-oncogene overexpression

Question 30

What is the relationship between reteroviruses and carcinogenesis?

Answer 30

Reteroviruses insert an oncogene into host DNA causing cell division

Question 31

What are some viruses that are known to cause cancer?

Answer 31

HPV Hepatisis B EBV

Question 32

What cancer does HPV cause?

Answer 32

Cervical cancer

Question 33

What cancer does Hepatitis B cause?

Answer 33

Liver

Question 34

What cancer does EBV cause?

Answer 34

Burkitt lymphoma

Question 35

What is the process of chemical carcinogenesis?

Answer 35

1) Chemicals react with DNA to form covalently binded products known as DNA adducts 2) Leads to activation of oncogenes and suppression of tumour suppressor genes

Question 36

What is formed when chemicals bind to DNA in chemical carcinogenesis?

Answer 36

DNA adducts

Question 37

How many steps are necessary for carcinogenesis?

Answer 37

More than one step, a series of mutations is required

Question 38

How does the number of mutations change as time goes on?

Answer 38

Mutations accumulate