Growth Factors - Another target for Meso treatment

Sunday, December 25, 2005

A growth factor is a substance that triggers the growth of some type of cells. There are nerve growth factors, bone growth factors and blood vessel growth factors. These small molecules help maintain a healthy balance between normal growth and development of the body and out of control growth.

Cancer is all about out of control growth taking over essential functions. In mesothelioma, a hard rind of overgrowth covers the outside of the lungs and gradually impairs their function.

One area of active research is with a certain growth factor called VEGF or vascular endothelial growth factor. For some reason Mesothelioma cells produce receptors for this growth factor and seem to be stimulated to grow by VEGF, possibly because VEGF stimulates new blood vessel growth. It stands to reason that growth might be slowed if VEGF can be inhibited in some way.

Several methods are under investigation. The first involves actually suppressing the body's production of VEGF using various drugs. Some studies have indicated that the common class of antihypertensive drugs called ACE (Angiotensin converting enzyme) inhibitors may have just this type of effect and slow the growth of mesothelioma. Another technique that could be utilized would be to target cells with large numbers of VEGF receptors and attach a sort of microscopic warhead. An engineered molecule would consist of an analog of VEGF which would bind to the VEGF receptor. Attached would be a chemotherapy drug that would be delivered directly to the cell when it was bound to the receptor.

VEGF is only one of many biologically active molecules that appear to contribute to the growth of mesothelioma. With new investigative techniques in basic science our understanding of these complex systems is moving forward rapidly. Each new discovery is another step toward developing new effective therapies for meso and many other diseases.

This though provoking paper on Cancer and Inflammation discusses the role of the angiotensin system in cancer and discusses how ACE inhibitors may affect cancer using a number of different mechanisms.

On the speculation front, nicotine is known to be a potent upregulator of ACE expression. Perhaps this might account for some of the synergistic effect smoking and asbestos exposure have on mesothelioma development. I'm not aware if anyone has looked at this angle before.