In 1971, Dr Judah Folkman published the “angiogenic hypothesis” suggesting that
ID: 174981 • 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. propose different strategies to develop a potential anticancer drug.
Explanation / Answer
Anticancer drugs are chemicals designed in such a way so as to inhibit the growth of cancer. Different strategies to develop a potential anticancer drug are:
Gleevec1:
This is a small-molecule. This molecule targets ‘Bcr-Abl’ fusion.
‘Bcr’ stands for ‘Breakpoint cluster region’; it is present on chromosome no.22. On the other hand, ‘Abl’ gene is present on chromosome no.9. Fusion of these two genes results in tyrosine kinase signaling cascade activation, which finally leads to unlimited cell division.
Gleevac targets Bcr–Abl fusion onco-protein, and hampers its activity. This anticancer drug has proved to be extremely useful in chronic myeloid leukemia.