Multistep carcinogenesis

Question 1

Tumourigenesis definition

Answer 1

development of a tumour

Question 2

Metastasis definition

Answer 2

spread of cancer cells to other parts of the body

Question 3

What changes in cell behaviour suggest carcinogenesis

Answer 3

nuclei expansion (DNA takes up most of nuclear space)
cell division is abnormal (eg. dividing too fast)
reduced apoptosis
tumour angiogenesis and invasion (cancer cells acquire own blood supply)
cancer cells may move to distant sites (metastasis)

Question 4

When do proto-oncogenes become oncogenes?

Answer 4

proto-oncogenes that are mutated and become overactive are termed oncogenes (they now have n active role in carcinogenesis)

Question 5

Tumour suppressor genes function

Answer 5

prevent abnormal cell division

Question 6

Is a single driver mutation enough to cause cancer?

Answer 6

no
cancer development is multistep process that involved the accumulation of sufficient driver mutations

Question 7

Driver mutation causes

Answer 7

reactive oxygen species
background radiation
toxin exposure

Question 8

What are the distinct phenotypic stages of tumourigenesis in colorectal cancer?

Answer 8

1) polyps
2) small benign tumours called adenomas
3) malignant tumour