Researchers turn living cells into insulin-makers

By Maggie Fox, Health and Science Editor

WASHINGTON (Reuters) - Researchers have transformed ordinary cells into insulin-producing cells in a living mouse, improving symptoms of diabetes in a major step towards regenerative medicine.

The technique, called direct reprogramming, bypasses the need for stem cells -- the body's master cells which, until now, have been indispensable to efforts to custom-make tissue and organ transplants.

The researchers used three genes carried by an ordinary virus to transform mouse exocrine cells, which make up about 95 percent of the pancreas, into the scarce insulin-producing beta cells that are destroyed in type 1 or juvenile diabetes.

In theory, the same is possible using abundant human cells such as liver, skin or fat cells, Dr. Douglas Melton and colleagues at Harvard Medical School and Children's Hospital in Boston reported.

"It was easier than one might have thought," Melton, a Howard Hughes Medical Institute researcher and one of the world's top stem cell experts, said in a telephone interview.

"These cells are very stable and live for the life of the mouse."

Scientists had been counting on stem cells to show them how to regenerate tissues and organs -- in the case of juvenile diabetes, to regenerate the pancreatic cells that are mistakenly destroyed by the body's immune system.

"I wake up every day thinking about how to make beta cells," said Melton, whose two children have type 1 diabetes.