Drug derived from ocean sponge boosts Taxol's performance

[Melinda]

Lung cancer killer gets a powerful ally

Drug derived from ocean sponge boosts Taxol's performance, researchers find

By LEE BOWMAN

SCRIPPS HOWARD NEWS SERVICE

A new drug derived from an ocean sponge dramatically enhances the performance of the powerful cancer killer Taxol, according to a new study.

The drug, called discodermolide, was isolated from a marine sponge. Combined with Taxol, the drug reduced the proliferation of human lung cancer cells in a lab setting by 41 percent, reports an international team led by Mary Ann Jordan, an adjunct professor and research biologist at the University of California-Santa Barbara.

The combined drugs also induced programmed cell death in the lung tumors.

Administered alone, discodermolide reduced cancer-cell growth by only 10 percent; and Taxol alone by just 16 percent.

"Our results indicate that Taxol and discodermolide have the potential to improve cancer patients' responses and reduce undesirable side effects when the two drugs are administered together," Jordan said.

Lung cancer is the leading cause of cancer death in the United States, with 171,000 new cases diagnosed each year and 157,000 people dying, according to the American Cancer Society.

For the study, published today in the journal Cancer Research and sponsored by the National Institutes of Health, Jordan worked with scientists at the University of the Mediterranean in Marseille, France, and the Albert Einstein College of Medicine in New York City.

Both drugs act to disrupt the ability of cancer cells to duplicate genetic material and divide.

Specifically, they act to interfere with structures inside cells called microtubules, bundles of protein that help maintain the cell's shape and move components around inside the cell.

The tubes normally are rather instable, growing longer or shorter to meet the needs of the cells at particular times.

Discodermolide and Taxol make the microtubules more stable.

Alone, each reduced the dynamic instability of the microtubules by 24 percent. In concert, the drugs altered the dynamics of the structures by 71 percent, according to the study.

By altering the stability of the bundles, the drugs limit the ability of cancer cells to divide.

Cancer cells stuck in this stage of cell cycle cannot duplicate, and ultimately die, thus reducing the growth of tumors.

While Taxol has been widely employed against cancer for more than a decade, human safety studies on the sponge-derived drug are now under way, with further tests of effectiveness in cancer patients still to come.

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