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Washington: Scientists have transformed one type of fully developed adult cell directly into another inside a living animal, a startling advance that could lead to cures for a variety of illnesses including diabetes and heart diseases.
Through a series of painstaking experiments involving mice, biologists at Harvard pinpointed three crucial molecular switches that, when flipped, completely convert a common cell in the pancreas into the more precious insulin-producing ones that diabetics need to survive.
The experiments, detailed in the journal Nature, raise the prospect that patients suffering from not only diabetes but also heart disease, strokes and many other ailments could eventually have some of their cells reprogrammed to cure their afflictions without the need for drugs, transplants or other therapies.
"It's kind of an extreme makeover of a cell," said Douglas A. Melton, co-director of the Harvard Stem Cell Institute, who led the research. "The goal is to create cells that are missing or defective in people. It's very exciting."
The work was hailed as a welcome development even by critics of research involving embryonic stem cells. "I'm stunned," said Robert Lanza, chief scientific officer of Advanced Cell Technology in Worcester, Massachusettss, a developer of stem cell therapies. "It introduces a whole new paradigm for treating disease."
Melton has already started experimenting with human cells in the laboratory and hopes that within a year he can start planning the first studies involving people with diabetes. "I would say within five years, we could be ready to start human trials," Melton said. "It was a mixture of work, luck and guessing," Melton said.
Systematic mice study
The scientists systematically studied cells from the pancreas of adult mice, slowly winnowing the list of genes necessary to make a "beta" cell that produces insulin.
After narrowing the candidate genes to nine, the researchers genetically engineered viruses known as adenoviruses to ferry the genes into other pancreatic cells, known as exocrine cells, which normally secrete enzymes to help digest food. That finally enabled the researchers to identify the three crucial genes needed to take control of the rest of the cell's genes to convert an exocrine cell into a beta cell.
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