In 1971, Dr Judah Folkman published the “angiogenic hypothesis” suggesting that
ID: 96622 • Letter: I
Question
In 1971, Dr Judah Folkman published the “angiogenic hypothesis” suggesting that a tumor cannot grow beyond 1–2 millimeters without the development (angiogenesis) of new blood vessels that provide access to oxygen and nutrients. During the 1990s, it was discovered that vascular endothelial growth factor (VEGF) stimulates the proliferation and migration of the cells that form blood vessels, leading to the formation of new blood vessels. VEGF binds to receptor tyrosine kinases (RTKs) on the cell surface and causes the RTKs to dimerize and become active, thereby initiating an intracellular signaling cascade that stimulates cell division and inhibits apoptosis. Many cancer cells secrete high levels of VEGF. Increased VEGF expression in a tumor is correlated with a poor medical outcome for the patient. Some evidence suggests that blocking VEGF-dependent signaling may prevent the formation of new blood vessels and lead to the death of immature blood vessels without disturbing mature blood vessels. You work for a biotechnology company that seeks to create anticancer drugs that prevent the growth of tumors and/or cause tumors to shrink, while leaving normal cells relatively untouched. After learning about VEGF, you have a bright idea for a new mechanism of action for a potential anticancer drug. What is your idea?
Explanation / Answer
ANSWER:
The VEGF supports formation of new blood vessels. Thus, it accelerates the angiogenesis in a developing cancer. Also, the VEGF inhibits apoptosis due which further assists in the tumor progression.
Thus, my idea of the new anticancer drug would involve a mechanism which reduces the expression of this VEGF gene.
If the VEGF gene product is not available for the formation of blood vessels, it would cease the angiogenesis process required for the cancer progression. This would not affect the normal cells since they have already developed an adequate amount of blood vessels. Only the tumor cells need to be targeted with this new anticancer drug to hault the tumor growth.