Exam 3: Angiogenesis Flashcards
What are the activators and inhibitors of Angiogenesis?
Activator = VEGF Inhibitors = Endostatin and Angiostatin
What is VEGF? And what is its function?
Vascular Endothelial Growth Factor
It is the most potent angiogenic stimulator
Describe the characteristics of: Inhibitors of Angiogenesis
More stable
Can be distributed into the blood stream
What is the main function of Endostatin and Angiostatin in mice?
Cause tumors to shrink and disappear
What therapy did not work on humans, but did in mice?
Anti-angiogenesis did not work
Many drugs used on mice don’t have the same effects on humans
What are the two FDA approved drugs for Angiogenesis?
Avastin - Monoclonal Antibody for VEGF
Sutinib (and Sorafenib) - VEGFR tyrosine kinase inhibitors
Why does an abnormal leaky tumor vasculature benefit tumor progression?
Excessive activity of VEGF causes endothelial cells in blood vessels to separate and that Leakiness of blood vessels makes it easier for cancer cells to access the blood stream and metastasize.
Tumor cells need access to blood supply in order to metastasize. If there is a leak in the blood vessels its easier for the tumor cells to access that supply, then grow and spread.
Why does Leaky tumor vasculature make Chemotherapy harder?
Because Tumor have a high hydrostatic pressure. (high fluid pressure)
It resist effective delivery of drugs from the blood stream to the tumor
Why are angiogenesis inhibitors still used on Humans?
The drugs might reduce excessive VEGF activity
restore a more appropriate balance between angiogenic activators and inhibitors
can restore a normal tumor vascular capable of delivering chemo drugs effectively
