Angiogenesis Flashcards
4 major stimuli of angiogenesis:
VEGF
Hypoxia
PDGF
Angiopoietins
Where do angiopoetins come from?
**language barrier
Enzyme secreted by endothelial cells which acts on the basement membrane
metalloproteinases (MMPs)
What are the steps involved in new capillary formation, once angiogenic signals have been initiated?
- endothelial cells degrade vascular basement membrane via MMps
- endothelial cells migrate toward stimulus, forming tip cells
- endothelial cell proliferation forms lumen
- two “sprout” lumens fuse, forming a route for blood flow
What is a Folkman’s sprout?
lumen (formed by endothelial cell proliferation) that extends/migrates towards angiogenic signals
The fusion of what structures forms the route for blood flow?
Folkman’s sprout
How does angiogenesis differ from arteriogenesis?
the presence of mural cells
What function does arteriogenesis serve?
alleviates occlusion in major artery
How does arteriogenesis alter vascular structures?
- remodels/thickens vascular walls
2. increases luminal diameter
Angiogenesis or arteriogenesis:
flow mediated
arteriogenesis
What is the role of heparin and heparin sulfates?
VEGF binding
Anti-angiogenesis treats cancer by:
- starve the tumor
- avoid intravasation of metastatic cells
Why are some cancers refractory to anti-VEGF therapies?
Cells in the neovasculature are mimics that are not as responsive to VEGF
Why are anti-VEGF and chemotherapy more effective together?
decreased interstitial pressure promotes chemoagent diffusion
Lymphangiogenesis procedes by similar mechanisms as angiogenesis. Inhibiting this could be another important anti-cancer therapy because:
Anti-lymphangiogenesis to maintain chemo levels, prevent metastases
