Lecture 24 - Cancer

Question 1

Name the 8 acquired capabilities of cancer cells

Answer 1

1. self sufficiency in growth signals
2. apoptosis evasion
3. anti-growth signal insensitivity
4. limitless replicative potential
5. sustained angiogenesis
6. tissue invasion & metastasis
7. metabolic reporgramming
8. evade immune destruction

Question 2

describe size restriction arrest

Answer 2

A cell is trapped in a blood vessel due to its size

Question 3

name a possible consequence of size restriction arrest

Answer 3

cell undergoes extravasation to the perivascular position

Question 4

name and describe the two types of cancer growths in the perivascular position

Answer 4

cooptive- localise in close proximity to each other and divide - does not guarantee survival
angiogenic- increased vasculature to the tumour to provide support

Question 5

what do anchoring junctions link to

Answer 5

actin filaments

Question 6

what are cadherins and what do they bind to

Answer 6

cadherins mediate adhesion between neighbouring cellsbinds to p120ctn, which binds to alpha catenin, which binds to f-actin. beta catenin also binds to alpha catenin. cadherins connect actin filaments of two neighbouring cells together

Question 7

describe the role of beta catenin

Answer 7

beta catenin is a cell growth upregulator in the nucleus. is bound to alpha catenin to prevent over-upregulation. excess free beta catenin is directed to the ubiquitin/proteosome pathway for degredation by complexing with an apc. this binding allows beta catenin phosphorylation by gsk3, targetting it for degredation

Question 8

what is confluence and what is its relation to tumours

Answer 8

confluence is the point when cells stop dividing after using up the surrounding space due to contact inhibition. tumours ignore this and continue to divide.

Question 9

what degrades e-cadherin

Answer 9

mmp3

Question 10

true or false

the adhesion belt is continuous in epithelial cells

Answer 10

true, non-epithelial cell adhesion belts are not continuous

Question 11

what is intravasation?

Answer 11

intravasation is tumour cell entry from the blood stream

Question 12

what is extravasation?

Answer 12

extravasation is tumour cell exit from the blood stream

Question 13

true or false

healthy cells grow well with no agar plate contact

Answer 13

false, tumour cells grow well, healthy cells do not