Drugs Stimulate Growth of New Blood Vessels By Mimicking Growth Factor
New research indicates that besides lowering levels of harmful cholesterol, the drugs may also promote the growth of new blood vessels, which may not necessarily be such a great thing. Although this effect may help to prevent heart attacks and other forms of heart disease, it may have the potential to promote cancer as well.
Tests in human cell samples and in rabbits, show that the cholesterol-lowering drug simvastatin (Zocor) seems to activate a pathway through which cells communicate and act very similar to a naturally-occurring growth factor, according to Dr. Kenneth Walsh, of Tufts University School of Medicine in Boston, Massachusetts.
Researchers suspect that the drug interacts with a molecule called protein kinase Akt/PKB, which helps regulate blood vessel development properly.
Simvastatin produced similar effects on the growth of new blood vessels, a process called angiogenesis, as does vascular endothelial growth factor (VEGF), a substance essential for healthy blood vessels, according to Dr. Walsh. "The same pathway is being activated by statins as VEGF," he said.
But if statins do promote angiogenesis, the effects may not always be helpful, Dr. Michael Simons, of Beth Israel Deaconess Medical Center in Boston points out in an editorial that accompanies the study.
For example, statins might increase the growth of blood vessels in cancerous tumors, Simons notes. However, even though statins are some of the most widely used prescription drugs, these and other potential harmful effects have not been reported, which calls into question their vessel-promoting abilities, Dr. Simons adds.
Nature Medicine September, 2000;6:965-966, 1004-1010.