Synthetic Poisons That Kill Cancer But Not People
The combination of a natural poison and scientists' ingenuity may result in a new class of potent cancer drugs. In 1987, researchers found that certain types of soil bacteria produce substances, called enediynes, that are downright "diabolical," says chemist K.C. Nicolaou of the Scripps Research Institute in La Jolla, Calif.
The molecular equivalent of a Trojan horse, the substances innocently enter cells and home in on their genes. Then, when activated by a chemical signal, they turn deadly, destroying the genes--and the cells. Because the enediynes are such powerful assassins, scientists immediately wondered if they could fight cancer. But the poisons have a fatal flaw: They kill normal as well as tumor cells. Researchers set out to make synthetic enediynes, hoping to target only tumors.
Nicolaou's team appears to have succeeded by fashioning an enediyne that's more potent in killing leukemia and other cancers than are such current drugs as vinblastin and taxol. Yet, in lab and animal experiments described on May 22 in Science magazine, it didn't harm normal cells. The researchers don't know exactly why, but they're convinced that man-made enediynes will be important in the anticancer battle.