The substance, artemisinin, is derived from the wormwood plant and has been used in China since ancient times to treat malaria. Earlier work by Henry Lai and Narendra Singh, both UW bioengineers, indicated that artemisinin alone could selectively kill cancer cells while leaving normal cells unharmed.

The new compound appears to vastly improve that deadly selectivity, according to a new study that appeared in a recent issue of the journal Life Sciences. In addition to Lai and Singh, co-authors include Tomikazu Sasaki and Archna Messay, both UW chemists.

"By itself, artemisinin is about 100 times more selective in killing cancer cells as opposed to normal cells," Lai said. "In this study, the new artemisinin compound was 34,000 times more potent in killing the cancer cells as opposed to their normal cousins. So the tagging process appears to have greatly increased the potency of artemisinin's cancer-killing properties."

The compound has been licensed to Chongqing Holley Holdings and Holley Pharmaceuticals, its U.S. subsidiary, to be developed for possible use in humans. Although the compound is promising, officials say, potential use for people is still years away.

In the study, researchers exposed human leukemia cells and white blood cells to the compound. While the leukemia cells quickly died, the white blood cells remained essentially unharmed.

The trick to the compound's effectiveness, according to Lai, appears to be in taking advantage of how cancer cells function.

Because they multiply so rapidly, most cancer cells need more iron than normal cells to replicate DNA. To facilitate that, cancer cells have inlets on their surface, known as transferrin receptor
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Contact: Rob Harrill
rharrill@u.washington.edu
206-543-2580
University of Washington
8-Feb-2005