The drug losartan, which is commonly used to treat high blood pressure, can reduce tumour formation in mice reports a study published in Nature Communications this week. These findings suggest that this drug could in the future prove useful for the treatment of cancers in humans.
Tumour blood vessels provide cancer cells with nutrients and are ultimately responsible for the delivery of anti-cancer agents. Rakesh Jain and colleagues demonstrate that the environment surrounding cancer cells places physical stresses on these cancer blood vessels, which can restrict blood flow and reduce the ability of chemotherapeutics to penetrate into tumours. They find that treatment with the angiotensin II antagonist - losartan - which is widely used to treat hypertension, reduced the production of proteins and complex sugars in the tumour environment that compress tumour blood vessels. This is turn alleviated the constriction of blood vessels and aided the delivery of the chemotherapy drug 5-flurouracil to tumours in these mice. When pancreatic or breast tumour bearing mice were treated in combination with losartan and 5-fluoruracil, the average survival time increased in comparison to administration of 5-fluoruracil alone.