8. Control of GI progression by oncogenes and tumour suppressor genes

Question 1

What mutation do proto-oncogenes have in cancers and what is the result of this?

Answer 1

Gain of function mutation - allows unregulated cell proliferation and survival

Question 2

What mutation do tumour suppressor genes have in cancers and what is the result of this?

Answer 2

Loss of function mutation - unregulated cell proliferation and survival

Question 3

What mutation do caretaker genes have in cancers and what is the result of this?

Answer 3

Loss of function - allows mutations to accumulate

Question 4

What is the G2/M transition controlled by?

Answer 4

DNA replication checkpoint AND DNA damage checkpoint

Question 5

What is the M/A transition controlled by?

Answer 5

Spindle assembly checkpoint

Question 6

What does the restriction point ensure?

Answer 6

That cells do not enter the cell cycle from G0 until they receive the appropriate proliferation signal

Question 7

What is the G1/S transition controlled by ?

Answer 7

DNA damage checkpoint