Fluorescent Fish Aids Medical Research

TAIPEI, Taiwan (AP) -- Taiwanese researchers claimed Wednesday that they have developed an alternative to laboratory mice for testing new medicines -- using fluorescent fish to show the impact of experimental drugs on cancerous tumors.

Wu Jen-leih of Taipei's Academia Sinica headed a team that took a gene that makes jelly fish fluoresce and transplanted it into the livers of zebra fish that were then later implanted with cancer cells for testing.

The gene highlighted the cancerous tissue with a special tint.

This allowed the scientists to monitor cancer development in the fish's liver through a special microscope and evaluate the impact of drugs.

Wu said fluorescent zebra fish can test experimental drugs for cancers in less time and at less cost than conventional laboratory mice.

He said zebra fish were chosen because the structure and function of their internal organs resemble those of humans, and they react similarly to cancerous tissue.

Wu claimed that his team was the first in the world to use zebra fish in such a way. Two years ago a U.S. team used the fish to isolate lymphoma, he said.

It takes about 68 weeks to implant liver cancer in a mouse, he said, but only six weeks in zebra fish. In addition, Wu said, a zebra fish can lay hundreds of eggs in a week, compared to a dozen or two by a mouse -- producing a larger test sample in a shorter amount of time.

"The fish works better than mice in the laboratories," he said. "Real time images enable us to monitor how the internal organs grow, are affected by tumors and heal after treatment."

But Wu maintained fluorescent zebra fish can only be used for prescreening the impact of drugs. He said drugs found effective in the fish will then be tested on mice to comply with requirements made by most countries.

--Annie Huang

Associated Press

Amazing Images: Science & Nature Photos from Our Readers

Credit: AP Photo/Taiwan Academia Sinica, HO