Medicine from the Sea

From slime to sponges, scientists are plumbing the ocean's depths for new medications to treat cancer, pain and other ailments

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Tropical waters pose their own hazards. Bill Gerwick, who refers to the blue-green algae he studies as “pond scum,” says that his specimens prefer the same cloudy bays favored by stinging jellyfish, saltwater crocodiles and sharks. His colleague, Phil Crews, a natural products chemist at the University of California at Santa Cruz, finds people more threatening. In New Guinea in 1999, villagers, fearing that the scientists were invading fishing grounds off their island, attacked Crews with spears and slingshots. Another time, a machine-gun-wielding gang of young Indonesian soldiers boarded Crews’ research vessel and demanded money. “Basically,” Crews says, “we came up with enough cash.”

He has identified more than 800 compounds in tropical sponges. One promising source of cancer-fighting substances are the compounds called bengamides, after Fiji’s Beqa (pronounced “Benga”) Lagoon, where Crews collected the original specimens. Gerwick has isolated a substance he christened kalkitoxin, from an algae collected off the Caribbean island of Curaçao; he says it has potential as a treatment for some neurodegenerative disorders and possibly cancer, as well as pain control.

Technology is opening the deep sea to bioprospecting. In the past, biologists hoping to collect samples from waters as deep as 3,000 feet could do little more than sink trawl nets and hope for the best, says Amy Wright, an organic chemist at Harbor Branch Oceanographic Institution in Fort Pierce, Florida. But since 1984, Wright has collected from inside the Johnson-Sea-Link I and II, deep-water submersibles equipped with robotic claws and high-powered vacuums. They have enabled her to gather delicate sea fans and a host of other organisms intact, mainly from the Atlantic and the Caribbean. “It’s always a surprise,” she says. Acompound from a Caribbean sponge, Discodermia, “is now in clinical trials for the treatment of pancreatic and other cancers.”

The deep sea has turned up leads in the quest for oceanic pharmaceuticals. ASan Diego-based biotechnology firm, Diversa, announced two years ago that its scientists had sequenced the genome of Nanoarchaeum equitans, an unusual organism collected from a seafloor vent north of Iceland. The organism, smaller and simpler and with less DNA than any known bacterium, is being studied as a possible minuscule, living factory for the production of marine chemicals. “We can use what we learn from Nanoarchaeota to figure out something very basic: which genes are essential and which we can do without,” says Michiel Noordewier, a researcher at Diversa. “This is the smallest genome ever found.”

Suddenly a squadron of bluefish, converging in a feeding frenzy, thrashed out of the waves and began snapping at the swells’ surfaces—a reminder of the astonishing variety of marine life around the Gulf of Mexico oil platforms. A few minutes later, the divers surfaced one at a time and clambered onto the deck—just in time. What looked like a shark fin had flashed in the water 100 feet off starboard. They hauled the specimen bag out of the water and onto a table.

What spilled out of the laundry-basket-size bag was mind-boggling. Amid a matrix of varicolored, agglutinated barnacles—their shells opening and closing, working overtime in the air—grew tiny tube worms; strands of telesto coral, branching like miniature caribou antlers; and hydroids, filter-feeding organisms resembling ferns. Juan López- Bautista, the expedition’s algae expert, picked through the tangled mass with long tweezers, teasing out flywing-shaped specks of purple and green. Each tiny dot, he said, probably contains several algae species. Tiny crabs, brittle stars, shrimplike amphipods and delicate, green marine worms wriggled from the muddy gunk. Something bigger wriggled into view. Rainey quickly stepped back. Abright red bristleworm, a centipede-like creature spiked with poison-tipped spines poking out from its six-inch-long body, dropped onto the deck. “Don’t touch that,” he said. “It will hurt like hell. At the very least.” He snared the bristleworm with long tweezers and gingerly placed it in a jar, saying: “We’re going to grind up your gut and see what kind of microbes you have.”

The research team failed to find one creature they had particularly sought: the bryozoan Bugula neritina, a tiny, tentacled aquatic organism that looks like a piece of moss the size of a quarter. It yields a compound currently being tested as a cancer drug; the compound originally was identified by George Pettit, an organic chemist at Arizona State University, who collected the bryozoans off western Florida. He found that compounds from the Bugula demonstrated anticancer properties, and in 1981 he isolated a compound he christened bryostatin. Lab tests have found that it attacks various malignancies. It is currently undergoing advanced human trials in the United States, Canada and the United Kingdom.

More than two decades after Pettit’s discovery, scientists at Harvard and in Japan have synthesized small amounts of the complex molecule, which is in great demand. Researchers in California have discovered populations of Bugula growing on West Coast oil platforms. The team was hoping to find a Bugula source in the Gulf. But not today.

Early the next morning, as the day dawned clear, the spree floated in a calm sea alongside 82-A, a big platform lying 27 miles out in clear blue water. We could see the divers 20 feet down. A Portuguese man-of-war floated by; schools of feeding fish, extending on all sides for perhaps half an acre, flashed at the surface. Afour-foot-long barracuda cruised in to investigate. Then the divers began to resurface; within minutes, everyone had climbed aboard. The take this time was also dazzling—extravagant pink conchs, spiny pureblack sea urchins the size of half dollars, and mats of what the biologists call “scunge,” gooey conglomerations of bacteria and algae.

The next platform, lying also in blue water, offered up bell-like corals, tiny purple-and-white octopuses and—at last—a few strands of seemingly unimpressive reddish mossy stuff, possibly the much-sought bryozoan Bugula neritina. “We’ll have to wait until we get back to the lab,” said Rainey. “Alot of these things look alike.”


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