A group of promising cancer-fighting
compounds derived from a substance used in ancient Chinese
medicine will be developed for potential use in humans, the
University of Washington announced today.
The UW TechTransfer Office has signed a licensing agreement
with Chongqing Holley Holdings, a Chinese company, and Holley
Pharmaceuticals, its U.S. subsidiary.
The compounds, all developed through the research of UW
scientists Henry Lai and Narendra Singh of the Department of
Bioengineering and Tomikazu Sasaki of the Department of
Chemistry, make use of a substance known as artemisinin, found
in the wormwood plant and used throughout Asia since ancient
times to treat malaria.
Although the compounds are promising, potential medical
applications are still years away, officials say.
"We are very excited about the UW's discovery and an
opportunity to develop an artemisinin-based cancer drug,"
Kevin Mak, chief scientist at Holley, said. "The technology is
very promising, but it's in its early stages. Further research
and clinical trials are needed."
The company, located in Chongqing, China, has been in the
artemisinin business for more than 30 years, and is a world
leader in farming, extracting and manufacturing artemisinin,
its derivatives and artemisinin-based anti-malaria drugs,
Lai said he became interested in artemisinin about 10 years
ago. The chemical helps control malaria because it reacts with
the high iron concentrations found in the single-cell malaria
parasite. When artemisinin comes into contact with iron, a
chemical reaction ensues, spawning charged atoms that chemists
call "free radicals." The free radicals attack the cell
membrane and other molecules, breaking it apart and killing
Lai said he began to wonder if the process might work with
"Cancer cells need a lot of iron to replicate DNA when they
divide," Lai explained. "As a result, cancer cells have much
higher iron concentrations than normal cells. When we began to
understand how artemisinin worked, I started wondering if we
could use that knowledge to target cancer cells."
Perhaps the most promising of the methods licensed involves
the use of transferrin, to which the researchers bind
artemisinin at the molecular level. Transferrin is an
iron-carrying protein found in blood, and is transported into
cells via transferrin receptors on a cell's surface.
Iron-hungry cancer cells typically have significantly more
transferrin receptors on their surface than normal cells,
which allows them to take in more of the iron-carrying
protein. That, according to Lai, is what seems to make the
compound so effective.
"We call it a Trojan horse because a cancer cell recognizes
transferrin as a natural, harmless protein and picks up the
tagged compound without knowing that a bomb -- artemisinin --
is hidden inside."
Once inside the cancer cell, the iron is released and
reacts with the artemisinin. That makes the compound both
highly toxic and, because of cancer's rapacious need for iron,
highly selective. Surrounding, healthy cells are essentially
"Our research in the lab indicated that the
artemisinin-tagged transferrin was 34,000 times more effective
in selecting and killing the cancer cells than normal cells,"
Lai said. "Artemisinin alone is 100 times more effective, so
we've greatly enhanced the selectivity."
For more information, contact Lai at (206) 543-1071 or firstname.lastname@example.org.
The Holley contact is Michael Liu, (714) 606-8415 or email@example.com.