Last Updated

27 Dec 2002

Source: ABC News, April 17, 2002.

Cancer Weapon?

Potential Cure Could Come From Anthrax

By John McKenzie, ABC News

April 17 -- Anthrax is something Americans have come to know and fear.  Last fall, it killed five people and made 13 others sick. The anthrax bacteria are so infectious that health officials wear protective "moon suits" and goggles to avoid direct contact.

Mention the word "anthrax" and many Americans think of bio-terrorism and the mail attacks last fall in Washington, New York and Florida.

But now medical researchers are trying to harness some of the bugs lethal power for use against cancer.

Scientists at the National Institutes of Health in Bethesda, Md., have "disabled" the deadly bacterium and redesigned its toxins to help fight disease -- turning a killer into a lifesaver.

"We've modified the anthrax bacterium so that it's essentially harmless," says NIH research scientist Stephen Leppla. Harmless, but not to certain cancer cells.

Potential Cure

In ground-breaking research published in the Proceedings of the National Academies of Science, scientists found they could cure skin cancer in mice by injecting them with the anthrax "toxin."

The toxin prevents tumors from growing by limiting their blood supply and by also directly destroying the tumor cells themselves. The most recent study used very low doses of the poison, preventing other tissues in the body from being damaged.

"Probably melanoma, colon tumors, and breast cancers are the most susceptible to the effects of anthrax toxin," says Nicholas Duesbery, research scientist at the Van Andel Research Institute, Grand Rapids, Mich.

The concept of using bacterial toxins for therapy isn't entirely new. Last year, a trial reported in the New England Journal of Medicine showed that toxins caused complete remission in 11 out of 16 leukemia patients who had been resistant to standard chemotherapy.

In addition, researchers recently described how they are now re-engineering the poison so that it's safer and more effective, and targets cancer cells exclusively.

"We have changed the anthrax toxin so that it's only activated and toxic once it's in contact with the surface of the cancer cell," says Thomas Bugga, research scientist at the National Institutes of Health.

That means scientists can now use much higher doses, on many more types of cancer.

"The data we have from treating human tumor cells growing in mice are certainly encouraging and we plan to go ahead full speed," adds Bugga.

Scientists say because anthrax is a poison, it will take several more years of testing on animals before the toxin might be tried on humans.

Some experts believe that as more funds are allocated for bioterrorism prevention, new findings will mean more progress towards improved cancer treatment.

And likewise, better understandings of cancer biology could possibly contribute to the homeland security effort.

ABCNEWS.com's Alexa Pozniak and Amy Malick contributed to this report.