A hormone that regulates blood pressure has been shown to reduce lung cancer tumours in mice and may provide a new way to treat this type of malignancy, a study released on March 15 said.
In experiments on laboratory mice that had been injected with human lung cancer cells, researchers found that the ones treated with the hormone, angiotensin-(1-7), saw their tumours shrink by 30 percent, according to scientists at Wake Forest University School of Medicine.
In contrast, in mice treated with saline, the tumours more than doubled in size over the 28 days of the experiment. The researchers were alerted to the potential anti-cancer properties of the hormone by earlier studies which found that rates of lung cancer were lower in people being treated for high blood pressure with a class of drugs known as ACE inhibitors.
These drugs increase levels of angiotensin-(1-7) in the bloodstream. The hormone helps to lower blood pressure by dilating, or enlarging, blood vessels.
The researchers believe the hormone's anti-cancer effect is due to its reduction of levels of an enzyme called COX-2 or cyclooxgenase-2, which stimulates cell growth.