Good Old Aspirin

[Tom]

October 2, 2006

Aspirin combats tumor growth by inhibiting new blood vessel formation

A report published in the October, 2006 issue of The FASEB Journal (Federation of American Societies for Experimental Biology) revealed that aspirin, already recognized as being protective against some cancers due to its cyclooxygenase (Cox) enzyme inhibiting ability, has another tumor-fighting weapon in its arsenal: the ability to directly reduce angiogenesis, or the formation of new blood vessel growth. Without this ability, tumors are unable to grow.

Researchers at the University of Newcastle in England compared the effects of varying concentrations of aspirin, salicylate (the natural form of aspirin), and the selective Cox inhibitors SC560 and Celecoxib on the proliferation, viability and angiogenesis of cultured endothelial cells. They found while therapeutic concentrations of aspirin and salicylate had no effect on cell viability or proliferation, there was a significant reduction in angiogenesis. This effect was seen even at the lowest concentrations of aspirin and salicylate used, but was not observed with the selective Cox inhibitor drugs, either separately or in combination, suggesting that the the antiangiogenic effect of aspirin is via a Cox-independent mechanism.

While a very high concentration of aspirin resulted in apoptosis (programmed cell suicide) of the cells, the effect was not seen at doses approximating to systemic pharmacological concentrations. "It is clear that low therapeutic doses of aspirin have a direct inhibitory effect on the ability of endothelial cells to undergo angiogenesis and that this may contribute to the antineoplastic effects claimed for aspirin in a wide range of tissue types," the authors conclude.

Gerald Weissmann, MD, who is Editor-in-Chief of The FASEB Journal, stated, "Aspirin has always been touted as a 'wonder drug, and this study shows that we are still learning about the many actions of this amazing drug."