Anti-Obesity Drug May Slow Cancer Growth

March 17, 2004 -- A drug designed to help fight fat may also help fight cancer, a new study shows.

Researchers found Xenical (a drug approved for the treatment of obesity) appears to slow the progression of prostate cancer tumors in mice and may also have similar effects in inhibiting other types of cancer.

The study appears in the March 15 issue of the journal Cancer Research.

"This is a big advance in the sense that we have an approved drug -- approved for one indication -- that has another target and another potential disease indication, prostate cancer," says researcher Jeffrey Smith, PhD, associate scientific director for technology at the Burnham Institute in La Jolla, Calif., in a news release.

Xenical Has Unexpected Side Effect

Researchers have long suspected that the metabolism of a cancerous cell is different than a healthy one, and those differences in metabolism contribute to cancer progression.

In the study, researchers used a screening technique to identify active targets that affect metabolism in cells and also screen for things that might inhibit them.

When researchers compared normal prostate cells with cancerous ones, the screen found that the prostate cancer cells were affected by an increase in an enzyme called fatty acid synthase. This enzyme converts dietary carbohydrate to fat.

The screen also identified Xenical as an inhibitor of this enzyme.

When researchers tested this principle in mice, they found that Xenical was able to slow tumor growth in mice with prostate cancer. These experiments also showed that Xenical had no effect on healthy prostate cancer cells and no other significant side effect. The drug appeared to work targeting fatty acid synthase alone.

Other screening tests showed that fatty acid synthase activity was also higher in breast and colon cancer cells.

If more studies confirm these effects, researchers say the results indicate that new treatments for a variety of cancers may be possible based on inhibiting this enzyme with Xenical or a new drug with a similar effect.