Scientists in the U.S. have successfully transformed ordinary cells into insulin-producing cells in a living mouse and thereby improved the symptoms of diabetes.
The team from Harvard Medical School and the Children's Hospital in Boston say the research represents a major step towards regenerative medicine.
By using a technique called direct reprogramming the scientists have been able to bypass the need for stem cells.
Stem cells are the body's master cells which have in the past been essential in efforts to grow custom-made tissue and organ transplants.
In the reprogramming process the researchers used three genes carried by an ordinary virus to transform mouse exocrine cells.
Exocrine cells make up almost 95 percent of the pancreas, and the process changed them into the far less common insulin-producing beta cells that are destroyed in type 1 or juvenile diabetes.
Lead researcher Dr. Douglas Melton says in theory the same should be possible by using abundant human cells such as liver, skin or fat cells.
Dr. Melton who is a top stem cell expert says the process was easier than first thought as the cells used are very stable and live for the duration of the life of the mouse.
Until now scientists have relied on stem cells to regenerate tissues and organs and in the case of juvenile diabetes, to regenerate the pancreatic cells that are destroyed by the body's immune system.
The cells with the most promise are embryonic stem cells, taken from days-old embryos, but U.S. federal law has place tight limits on funding for such research and the cells are difficult to create.
In 2007 scientists discovered how to reprogram ordinary skin cells by taking them back to an embryonic-like state and these induced pluripotent stem cells are able to be used to study disease and might in the future make tailor-made transplants a reality.
But Melton and his team have gone directly from one type of adult cell to another, and skipped two steps in the process.