One for the Gene Engineers

Of all the possible benefits promised by the controversial new work with recombinant DNA (TIME cover, April 18), none has been more widely publicized than the mass production of insulin by re-engineered bacteria. If these tiny insulin factories could indeed be created in the laboratory, they would yield a virtually unlimited supply of the hormone, which is of vital importance to many diabetics. Last week scientists at the University of California in San Francisco reported that they had taken an important first step toward that goal. Using the bold new technology, they not only gave a bacterium potential insulin-making capability but also got the bug to reproduce millions of precise carbon copies of itself, all with the same new characteristic.

The work bodes well for the world's millions of diabetics. The insulin for their daily shots is for the most part extracted from cow and pig pancreases obtained from slaughterhouses. But some diabetics develop strong allergic reactions to animal insulin. Both for this reason and because of the increasing demand for the hormone, which the body needs to turn sugar into energy, drug companies seeking alternative sources have pinned some of their hopes on recombinant DNA technology. By inserting the human insulin gene into the DNA of the common intestinal bacterium Escherichia coli, they could, in theory, endow the bug with the capacity to make human insulin.

In the achievement announced last week, Biochemists Howard Goodman and William Rutter and their colleagues did not work with human genes. Under the safety guidelines adopted by the National Institutes of Health (to lessen the risk of accidentally producing an E. coli that might be harmful), such less readily available material would have required a far more stringent level of physical containment in the lab than any yet available. Instead, they experimented with insulin genes from rats. Placing this foreign DNA inside enfeebled E. coli, they were delighted to find that the genetic material was replicated every time the bacteria divided. But the scientists do not yet know whether the rat genes --in the language of molecular biology --actually expressed themselves, that is, produced insulin.

No matter; the experimenters are convinced that they will soon be able to "switch on" the genes. Said Rutter: "I'd be surprised if it took more than a year or two." The production of human insulin will probably take much longer. Yet meanwhile, the experiments themselves should help scientists clarify the complex chemistry of insulin and better understand diabetes--which is not a single disease, as was once thought by doctors, but a variety of metabolic disorders that may afflict as many as 10 million people in the U.S. alone.

The newest triumph of genetic engineering may also influence the actions of Congress, which is now considering legislation to regulate recombinant DNA research. Goodman undoubtedly echoed the views of many of his fellow scientists on the subject when he said, "It's a dangerously anti-intellectual precedent to make laws against an unknown harm."

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