Angiogenesis inhibitor

An angiogenesis inhibitor is a substance that inhibits angiogenesis (the growth of new blood vessels). It can be endogenous or come from outside as drug or a dietary component. Every solid tumor (in contrast to liquid tumors like leukemia) needs to generate blood vessels to keep it alive once it reaches a certain size. Usually, blood vessels are not built elsewhere in an adult body unless tissue repair is actively in process. The angiostatic agent "endostatin" and related chemicals can suppress the building of blood vessels, preventing the cancer from growing indefinitely. In tests with patients, the tumor became inactive and stayed that way even after the endostatin treatment was finished. The treatment has very few side effects but appears to have very limited selectivity. Other angiostatic agents like thalidomide and natural plant-based substances are being actively investigated.

Endogenous

Exogenous

Exogenous angiogenesis inhibitors may be drugs or a dietary components. Some of them are endogenous as well.

Drugs

Known inhibitors include the drug bevacizumab which binds vascular endothelial growth factor (VEGF), inhibiting its binding to the receptors that promote angiogenesis.

Research and development in this field has been driven largely by the desire to find better cancer treatments. Tumors can grow only if they form new blood vessels. By stopping the growth of blood vessels, scientists hope to shut off the means by which tumors can extend themselves and spread inside the body. In animal studies, angiogenesis inhibitors have successfully stopped the formation of new blood vessels.

The pharmaceutical thalidomide is such an antiangiogenic agent. When pregnant women take an antiangiogenic agent, the developing fetus will not form blood vessels properly and thereby stop the proper development of fetal limbs and circulatory systems. The results of the late 1950s and early 1960s when pregnant women were given the drug were children with tiny flippers for arms and legs.

In addition to their use as anti-cancer drugs, angiogenesis inhibitors are being investigated for their use as anti-obesity agents, as blood vessels in adipose tissue never fully mature, and are thus destroyed by angiogenesis inhibitors.

Matrix metalloproteinase inhibitors that may be antiangiogenic are "batimastat" and marimastat.

Diet

Some common components of the Oriental diet (and to a much lesser extent, the Western diet) also act as mild angiogenesis inhibitors. In particular, the following foodstuffs contain significant inhibitors and have been suggested as part of a healthy diet for this and other benefits:

* Soy products such as tofu and tempeh, (which contain the inhibitor "genistein") [cite journal
author=Farina HG, Pomies M, Alonso DF, Gomez DE |title=Antitumor and antiangiogenic activity of soy isoflavone genistein in mouse models of melanoma and breast cancer |journal=Oncol. Rep. |volume=16 |issue=4 |pages=885–91 |year=2006 |month=Oct |pmid=16969510 |doi= |url=http://www.spandidos-publications.com/or/article.jsp?article_id=or_16_4_885]
* Green tea (catechins)Fact|date=December 2007
* Red Wine (resveratrol) - Suggested only in moderationFact|date=December 2007

References

External links

* [http://www.cancer.gov/cancertopics/factsheet/Therapy/angiogenesis-inhibitors Angiogenesis Inhibitors in the Treatment of Cancer] - from the National Cancer Institute
* [http://www.newscientist.com/article/mg18224425.400.html New Scientist on their use as fat-reducing drugs] - from New Scientist, 10 April 2004
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