Tuesday, October 28, 2008

Cancer cure in a sponge? Institute tests synthetic version of substance

By Robyn Shelton, Medicine & Health / Cancer

As one of their first projects in Florida, scientists at the Burnham Institute for Medical Research in Orlando have created a man-made version of the substance.

Previous research showed the compound could zap the cancer cells in lab tests. Now the goal is to improve on nature to make it more potent, yet less toxic, so it someday can be tested as a drug for patients.

"The sponge itself only has very tiny quantities of the material," said Gregory Roth, Burnham's director of medicinal chemistry and exploratory pharmacology. "By making it synthetically, we can get larger quantities to do the kind of testing we need."

Roth's laboratory is working on the project with Harbor Branch Oceanographic Institution at Florida Atlantic University, which discovered the substance's cancer-fighting abilities in routine testing of deep-sea creatures.

Many sponges produce a variety of compounds themselves or harbor microorganisms that churn them out. Scientists don't always know what the substances do in nature, though they likely repel predators or serve as chemical signals, said Amy E. Wright, who directs Harbor Branch's biomedical-marine-research program.

The sponge - called Aphrocallistes Beatrix - lives on the cold-water reef that lies deep under the ocean off Florida's coast.

Wright's team uses a submersible vehicle that can dive 3,000 feet to collect a variety of sponges, soft corals and other organisms. The sponge was ground up and made into a solution tested with various cancer cells. It showed the most promise with colon and pancreatic cells, which together are expected to kill about 83,000 Americans this year.

Scientists rate a substance's cancer-fighting ability by the amount needed to wipe out 50 percent of the tumor cells in a lab test.

"This compound is about as potent as the best drug that's currently used for pancreatic cancer," Wright said.

Her team collects sea life on regular expeditions. A chemist in Roth's laboratory, Jennifer Hoffman, went with Harbor Branch on a recent dive. Sitting in the four-person submersible vehicle, Hoffman could see shrimp, squid and other creatures swimming in the lights as they traversed the dark, cool waters. The sub is equipped with a robotic arm that can pluck sponges off the coral and place them in containers.

Hoffman, who previously worked for the Pfizer drug company, said more work is needed before the compound even can be considered for human testing.

"It takes a lot of time and a lot of effort by many different people to develop a drug," said Hoffman, a senior research associate with Burnham. "But we know the compound is active, so we'll be making little changes to it and see if we can improve upon it."

Original here

No comments: