Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MCD - IE > CANCER- angiogenesis > Flashcards

CANCER- angiogenesis Flashcards

1
Q

what does angiogenesis mean?

A

formation of new blood vessels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what triggers the release of angiogenic factors?

A

hypoxia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are the inhibitors of angiogenesis?

A

extracellular matrix:
thrombospondin-1
angiostatin
endostatin

soluble factors:
sVEGF-R
IL-10
IL-12
TNF-a

avB3- receptor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

whjat are the activators of angiogenesis?

A 
GF:
VEGF family 
FGF family
TGF beta
PDGF

soluble factors:
IL-6
factor XIII
TNF- a

cell surface receptor avB3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

outline the multistep process of sprouting angiogenesis

A
  1. tip/stalk cell selection;
  2. tip cell navigation and
    stalk cell proliferation;
  3. branching coordination;
  4. stalk elongation, tip cell
    fusion, and lumen
    formation;
  5. perfusion and vessel
    maturation.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what happens in the absence of oxygen?

A

the HIF-a does not bind to the von hippel-lindau protein. HIF goes into the nucleus, binds to the DNA that codes for the gene responsible for angiogenesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what does VEGF bind to?

A

it binds to a cell on the vessel and turns it into a tip cell.

by doing this it tells the surrounding cells to become stalk cells and support the tip cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is tip cell selection regulated by?

A

the Notch pathway

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is the Notch pathway?

A

essential for development and basic functioning of cells

ligand and receptor on two different cells bind
this binding causes the cleavage of the intercellular domain of notch

this can go into the nucleus and binds to the transcription factor RBP-J

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

when might angiogenesis occur?

A

embryonic development, wound healing and in the menstrual cycle.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what controls gene regulation?

A

HIF – Hypoxia-Inducible Transcription Factor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what controls levels of HIF

A

pVHL – protein Von Hippel-Lindau tumour suppressor gene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what happens in the presence of oxygen in relation to HIF and pVHL?

A

pVHL adds a hydroxyproline group to HIF and HIF is degraded by a proteasome.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what are the 5 families of VEGF?

A

VEGF-A/B/C/D and Placental GF (PlGF)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what are the TK receptors?

A

VEGFR-1/2/3; and co-receptors neuropilin (Nrp1, Nrp2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is required for the angiogenic sprouting outgrowth and guidance?

A
  • Myeloid cells are recruited to support and guide the sprout (stimulated by Ang-II).
  • Macrophages have a large role in angiogenesis anastomosis:

o Macrophages carve out tunnels in the ECM for subsequent capillary infiltration.

o Tissue-resident macrophages associate with the tip-cells during anastomosis to support the structure.

17
Q

what is the importance of platelets in angiogenesis?

A

full of regulators of angiogenesis, both inhibitory and stimulatory

18
Q

what controls contact inhibition?

A

the tight junctions and adherens

19
Q

what cells are important for the stability of blood neovessels

A

mural cells (pericytes) which surround the capillary cells

20
Q

what do the mural cells produce?

A

angiopoietin 1 which promotes survival, anti inflammation and tight junctions

the signalling pathway uses the angiopoietin-Tie 2 ligand receptor system

21
Q

what is angiogenesis driven by?

A

PIP cells and VEGF

22
Q

what is an anti VEGF drug? and how is it effective?

A

avastin

blocking the VEGF pathway means it blocks tumour angiogenesis so the tumour cannot get the nutrients it requires to grow

23
Q

what is the angiogenic switch?

A

up to a certain size tumour cells can grow and survive without vasculature as they can get their requirements from the surrounding environment

but there is a point above which tumours require their own vessel network- this is the angiogenic switch

tumours release angiogenic factors
-eg VEGF
so they can grow.

24
Q

how are tumour blood vessels different?

A 
irregularly shaped
dilated
tortuous
not organised into definitive venuoles 
leaky and haemorrhagic
25
Q

give examples of some pro angiogenic growth factors that cancer associated fibroblasts secrete

A

VEGFA
FGF2
CXCL12
PDGFC

26
Q

what are the side effects of avastin?

A 
GI perforation
hypertension
proteinuria
venous thrombosis
haemorrhage 
wound healing complications
27
Q

why is avastin not as effective as anticipated?

A

VEFG is essential not only for angiogenesis but also for endothelial survival

28
Q

what are the potential mechanisms of resistance to anti-VEGF therapy in cancer?

A

by blocking the tumour vasculature it causes hypoxia which may stimulate the tumour to release other angiogenic factors or increase tumour invasiveness

tumour vessels may be less sensitive to VEGF inhibition due to vessel lining by tumour cells

MCD - IE (21 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions