Once a year, Chris Ireland dives into the South Pacific ocean off Figi looking for little marine critters that have a knack for killing off their neighbors.

Ireland, a professor of medicinal chemistry in the University of Utah's college of pharmacy, hunts for sponges and other invertebrates that secrete toxic chemicals.The same toxins that can control the growth of marine organisms competing for space on crowded coral reefs, Ireland reasons, may also be good at killing human tumors.

"Our emphasis is the treatment of human solid tumors - slow-growing cancers," particularly colon tumors, Ireland explains.

Studies by the National Institutes of Health have shown that sponges and ascidians tend to be especially adept at producing anti-tumor compounds, he says.

Ireland freezes the samples he gathers in the South Pacific and ships them back to the U. where, in collaboration with Louis Barrows of the department of pharmacology and toxicology, he tests extracts in cell cultures. The lab will soon begin animal testing of a half dozen of the more promising extracts.

Three particularly promising anti-tumor compounds, discovered at other research centers, are currently in various phases of clinical trials.