Harvard's Cell `Makeover' May Spur Diabetes Therapy

Using biological alchemy, Harvard University researchers turned one type of cell found in the pancreas of mice into the variety that secretes the hormone insulin.

If the technique can be used safely in humans, one day it can treat diabetes, which occurs when the body either can't produce, or else makes too little of, the insulin needed to process blood sugar. The same approach might be used to make heart, brain, or liver cells from other existing cells and treat diseases in those organs, said a stem-cell scientist who wasn't involved in the findings.

The research team in Cambridge, Massachusetts. The scientists injected viruses bearing three genes into the mice, transforming a common pancreatic cell known as an exocrine cell into the much rarer beta cell that makes insulin. Their findings were published in the journal Nature.

Melton said he aims to refine the technique, show that it can be done safely, and begin human clinical trials within two to five years in diabetes patients.

``We were able to flip the cell from one state into another, what one of the younger students in my lab calls an extreme makeover,'' Melton said yesterday in a conference call with reporters.

The Harvard researchers are calling the process direct reprogramming.

The research says that every cell in a person or animal contains DNA with the complete set of genetic instructions required to create that individual. By turning select genes on and off, scientists can transform existing cells so they start looking and acting like others.

Melton and his team spent three years searching for so- called transcription factors, which control proteins that in turn switch other genes on and off. They started with 1,100 candidate genes and narrowed the field to 28 that are involved in forming the part of the pancreas where beta cells are found.

Finally, they settled on nine genes they guessed might be involved and began a trial-and-error process, injecting them into the pancreases of mice and eliminating one at a time. Finally, they found that just three genes were needed and that 20 percent of the exocrine cells they injected turned into beta cells.

Cleopatra Duque