Lifesaving Sponges?

image: Harbor Branch Oceanographic Institution

"You can find lots of different chemical compounds that have lots of different utilities," Wright says. "We have ones that have what look like anti-cancer properties; we have ones with anti-inflammatory activities, so those might be useful in things like arthritis, or dermatological use; we have ones that are anti-infective, so they're antibacterial and there are some that might actually be useful in treating viral diseases as well."

Even after they purify each chemical, the researchers still have a lot more to do, including identifying the chemical's structure and how it works, and testing to see how effective or toxic it may be. They test it first on lab cultures of living cells. "We'll do things to determine if they're toxic to all cells," says Pomponi. "If they're toxic to all cells, then that's probably not going to be something that we'll want to develop, because obviously you don't want to take a drug that's going to kill all of the cells in your body. You just want something that's going to focus on the cancer cells." After that, they test it in animals, and eventually, they patent it and license it out to a drug company for further development and ultimately human testing.

Several of the chemicals they've found are already being tested on humans, but it may be years before each is determined safe. One of the most promising is called discodermolide from the sponge Discodermia. Pharmaceutical company Novartis is conducting a clinical trial of this anti-cancer drug in patients with colon and breast cancer.

Runaway Sponge

While sponges can't run away, one did "disappear" for nearly two decades. In 1984, Pomponi and Wright found a sponge that turned out to have an extremely promising anti-cancer agent. Unfortunately, they had not collected enough of this particular type of sponge to identify the chemical's structure, and when they went back to get more sponge, they couldn't find it again. Luckily, after 19 years of hoping and after carefully identifying the conditions in which this sponge likes to live, they recently found the "missing" sponge again. They plan to finish their analyses of its promising chemical and to get it into human trials as soon as possible.

How important is the ocean in all of this? "I've heard the statistic that about half of the drugs out there today are derived from or based on natural products that came from terrestrial plants or microbes," says Pomponi. "Even though we've done work for about 20 years on marine natural products drug discovery, we really have focused just on a few areas of our world's oceans. There's so much left to explore. For example, marine microorganisms: It's estimated that we know maybe less than a tenth of a percent of all the marine microorganisms that exist and that would be an invaluable resource for drug discovery. We know so little about the oceans, and the oceans have a huge impact on many aspects of our lives— on our climate, on our health, on food, on so many things that affect us."

Pomponi and Wright's research has been published in the December, 2003 issue of the Journal of Natural Products, the October, 2003 issue of Marine Biotechnology, the May, 2003 issue of Bioorganic & Medicinal Chemistry Letters, the February, 2003 issue of Biochemical Pharmacology, among others. It was recently presented at the Oceans 2003 Marine Technology and Ocean Science Conference in San Diego. It was funded by the Harbor Branch Oceanographic Institution, the Gertrude E. Skelly Charitable Foundation, NOAA's Office of Ocean Exploration, the National Science Foundation, the National Institutes of Health, the National Cancer Institute (Part of NIH), the Atlantic Foundation, Novartis Institutes for Biomedical Research and the NOAA Sea Grant College Program.