Mice fight the flab
Cancer strategy could be used to treat obesity.
10 May 2004
NADJA NEUMANN
Chubby mice have shaped up with a new slimming aid, based on a technique used in cancer therapy that destroys blood vessels. The researchers say that after clinical trials on humans this may become a useful weapon in the war on obesity.
One promising technique for treating cancer involves starving a tumour of the nutrients it needs to grow. The most effective way to do this is by killing off the blood vessels that supply the cancer cells. This technique is currently being evaluated in clinical trials.
In the same way, each fat cell relies on a network of capillaries to deliver the chemicals it needs to reproduce and grow. So Mikhail Kolonin and his colleagues from the University of Texas and Baylor College of Medicine, Texas, reasoned that if they could kill off these blood vessels, the fat cells would die too.
To do this, they targeted a molecule called prohibitin. It is present on the surface of fat cells, but not other types of cells, and it helps to regulate the growth of surrounding blood vessels. The researchers took a fragment of protein that binds to prohibitin, and attached it to another protein fragment that is used in cancer therapy to kill blood vessels.
In order to test whether the composite molecule works to destroy fat, the researchers fed two groups of mice a high calorie diet. Once the mice were overweight, the researchers injected the molecule under their skin each day for four weeks. The animals treated with the protein fragment ate less food and lost 30% of their original weight, but remained healthy1.
"It is an approach with great potential," says Peter Carmeliet, a biologist from Flanders Interuniversity Institute for Biotechnology in Belgium. He points out that fat cells grow into much bigger masses than tumours, so this starvation technique could potentially work even better against obesity than cancer.
http://www.nature.com/nsu/040503/040503-14.html