[MPWG] Researchers Blend Folk Treatment, High Tech for Promising Anti ...

[Sonya]

*Researchers* Blend Folk Treatment, High Tech for Promising Anti *...* 
<http://www.newswise.com/articles/view/509720/>
Newswise (press release) - USA
Newswise -- *Researchers* at the University of Washington have blended 
the past with the present in the fight against cancer, synthesizing a 
promising new *...

http://www.newswise.com/articles/view/509720/


Source: University of Washington Released: Tue 08-Feb-2005, 16:10 ET
Researchers Blend Folk Treatment, High Tech for Promising Anti-cancer 
Compound


Newswise — Researchers at the University of Washington have blended the 
past with the present in the fight against cancer, synthesizing a 
promising new compound from an ancient Chinese remedy that uses cancer 
cells' rapacious appetite for iron to make them a target.

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 receptors, in greater 
numbers than other cells. Those receptors allow quick transport into the 
cell of transferrin, an iron-carrying protein found in blood.

In creating the compound, researchers bound artemisinin to transferrin 
at the molecular level. The combination of the two ingredients appears 
to fool the cancer cell.

"We call it a Trojan horse because the cancer cell recognizes 
transferrin as a natural, harmless protein," Lai said. "So the cell 
picks up the compound without knowing that a bomb – artemisinin – is 
hidden inside."

Once inside the cell, the artemisinin reacts with the iron, spawning 
highly reactive chemicals called "free radicals." The free radicals 
attack other molecules and the cell membrane, breaking it apart and 
killing the cell.

According to Lai, that process is what initially piqued his interest in 
artemisinin about 10 years ago. The wormwood extract was used centuries 
ago in China, but the treatment became lost over time. In the 1970s, it 
was rediscovered as part of an ancient manuscript containing medical 
remedies, including a recipe that used a wormwood extract. The medical 
community soon discovered that the extract, artemisinin, worked well 
against malaria, and it is currently used for that purpose throughout 
Asia and Africa.

Artemisinin combats malaria because the malaria parasite collects high 
iron concentrations as it metabolizes hemoglobin in the blood. As 
science began to understand how artemisinin functioned, Lai said, he 
began to wonder if the process had implications for cancer treatment.

"I started thinking that maybe we could use this knowledge to 
selectively target cancer cells," he said. "So far, the outlook appears 
good."

The next step in development under the Holley licensing agreement will 
likely be testing in animals and, if that pans out, human trials to 
gauge the compound's effectiveness. The current study was funded by the 
Artemisinin Research Foundation and Chongqing Holley Holdings.


The article is available on-line at 
http://www.sciencedirect.com/science. Click the "journals" button and 
look under Life Sciences, Volume 76, Issue 11. The article is No. 9 on 
the Web page (page 1267-1279).




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