Angiogenesis is the formation of new blood vessels, whilst promoting cancer growth and proliferation. The inner lining of cells in these blood vessels called endothelial cells, are what potentiate the growth and uncontrolled division of cancer.
There are 2 types of endothelial cells:
“Quiescent” endothelial cells – rarely divide
“Angiogenic” endothelial cells – divide using a very intricate and complex series of reactions that lead to new blood vessel formation
To be a little more scientific, there are a number of molecules and proteins that act as immune stimulators to promote angiogenesis:
VEGF (vascular endothelial growth factor)
Fibroblast growth factor
Angiopoetins
Endostatin
Thrombospondin
And many more!
On angiogenic endothelial cells, there are certain proteins expressed, that you may not see on the quiescent endothelial cells (remember, endothelial cells are the cells that line the inside of blood vessels). Angiogenic endothelial cells can express receptor proteins for VEGF (Vascular Endothelial Growth Factor).
Some studies have shown that if we can inhibit VEGF, then we can prevent tumour growth and proliferations. Avastin, Sorafenib & Sunitinib and pharmacological agents that have been shown in the past, to be used in many types of cancer including breast cancer, but more studies are still ongoing. There has been some specific research on VEGF targeting in lung cancer, but again not applicable to all cases!
An important point to note regarding angiogenic activators, like VEGF, is that if one type of receptor is blocked via a pharmaceutical agent or by other means, this will upregulate other receptor activators, therefore, not necessarily reducing or mitigating burden of cancer growth overall. This is why it is important to target as many angiogenic receptors as possible during cancer treatments!
Using the example of VEGF shows us the importance of targeting cancer receptors from a variety of angles. Angiogenesis is a complex process and we do need more research in the field of anti-angiogenic receptors in order to make this treatment a standard of care in North America.
Interested in learning more? Please book an introductory 15-minute consult here
Cheers!
Dr. Mawji