Cancer Center goes exotic

By Cara Miller

Arizona Daily Wildcat

Traditional Chinese plants may soon be used in non-traditional treatment methods for cancer patients.

A University of Arizona Cancer Center research team is testing extracts from over 2,000 traditional Chinese plants for possible anti-cancer activity.

"Exotic plants are some of the best sources for potential new drugs," said Garth Powis, pathology professor and principal investigator for the project. "Many of them have been in use for 3,000 years and have been shown to be relatively safe for human use."

Powis said over 120 plant-

derived drugs are currently in clinical use, and of these, 80 percent have come from folk remedies or traditional medicines.

"Plants have been used by Indians and immigrants for medicinal purposes, and in China there is a long, long history of plant use," he said.

To date, over 5,000 different plant-based products are being sold as drugs in China, he said.

Powis said the team has investigated about 1,000 different plants from the U.S. and Europe and have just recently screened 40 Chinese plants. Overall, they will examine more than 2,000 plants.

Bill Remers, pharmaceutical sciences professor, said he usually researches more traditional drugs, but agreed that plant research has been a very fruitful avenue.

"One of the most exciting new anti-cancer drugs is derived from plants," he said.

While most current anti-cancer drugs target DNA, Dr. Powis' laboratory is investigating the mechanisms that control the function of specific genes in the cancer cell.

A cancer cell receives stimuli through receptors. Those receptors then send a signal to the cell's nucleus, via signaling pathways, where the cell's genes are located. The messages then tell the nucleus to turn specific genes on and off.

"Some cancers occur when the signaling pathways become permanently turned on," Powis said.

He said his goal is to develop efficient cancer-fighting drugs that will block the signals sent through the targeted pathways without destroying the cell.

"We know there is a limitation in current drugs because we are limited in our ability to cure cancer," Powis said. "Current therapy is only curing about 12 percent of patients. We need new types of drugs."

Remers agreed that more approaches are needed.

"It's a relatively new concept," he said. "But it's very interesting and new directions should be probed."

The group will also be investigating the anti-cancer capabilities of other Chinese home remedies such as snake and scorpion extracts.

"A good proportion of the Chinese rely on traditional medicine and take stews and extracts as preventative medicine or as remedies," Powis said.

The research is being funded by a National Cooperative Drug Discovery Grant from the National Cancer Institute. The grant, now in its fifth year, annually provides researchers with $750,000.

Eli Lilly and Company is providing the research teams with the ability to test promising new drugs in animal models and to develop the drugs to the point of clinical trials.

"There has been almost 50 years of cancer discovery, but we need new approaches," Powis said. "Now we will be combining the old with the new."

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