SHARKS AND RAYS ARE PRACtically unique among creatures in their ability to ward off cancerous tumors. Sharp-eyed health-food suppliers took note early, turning dried shark fins into edible tablets. But biologists have also been racing to isolate any fishy compounds that might explain the shark's magical resistance. Now, after scrutinizing dozens of compounds, researchers at California State University in Fresno say they have isolated four substances in shark cartilage that appear to inhibit cancer.
Kin-Ping Wong, dean of Cal State Fresno's School of Natural Sciences, is keeping mum about details until patents are filed. But what the chemicals do is block a mechanism discovered in the mid-1980s at Harvard University: Tumor cells secrete a protein called angiogenin that entices blood vessels to grow close to cancers and nourish them. The shark extracts counteract angiogenin, and the tumor starves. Wong has already begun animal tests, and he hopes to begin human trials next year.