Thursday, November 02, 2006

 

DIABETES ARTICLES - Firm Reports Stem Cell Use for Making of Insulin

DIABETES ARTICLES

Firm Reports Stem Cell Use for Making of Insulin

Scientists at a small California biotechnology company reported yesterday that they had developed a process to turn human embryonic stem cells into pancreatic cells that can produce insulin and other hormones.

The work by the company, Novocell, based in San Diego, is a step toward using embryonic stem cells to replace the insulin-producing cells that are destroyed by the body’s immune system in people with Type 1, or juvenile, diabetes. Years of research remain, however, before a therapy developed from this approach can be put to use.

Embryonic stem cells can potentially be turned into any type of tissue in the body, and scientists are trying to figure out how to form various types.

Other researchers have previously reported turning various types of human or animal stem cells into cells that produce insulin. But the new work, published online yesterday by the journal Nature Biotechnology, represents a significant advance, some experts said.

“It provides some very strong evidence that it will be possible to make insulin-producing pancreatic beta cells from human E.S. cells in a culture dish,” Dr. Mark A. Magnuson, a professor at Vanderbilt University, wrote in an e-mail message. He said the scientists at Novocell had achieved an efficiency of cell conversion and insulin production in “orders of magnitude higher than anything previously accomplished.”

Dr. Magnuson, however, also said that in laboratory experiments the cells had not varied their insulin production much in response to the level of glucose, a key requirement for a beta cell. So more work is needed.

Emmanuel Baetge, the chief scientific officer at Novocell and the senior author of the paper, said the cells were “not fully mature” but rather seemed similar to the beta cells in a human fetus. Those cells also do not respond to glucose, a capability gained after the baby is born.

He said the insulin-producing cells had been derived by taking the embryonic stem cells and adding and subtracting various growth factors in a series of stages that mimicked the process that cells in an embryo go through to become a pancreatic cell. The process takes 16 to 20 days, he said.

Dr. Baetge said that the company hoped to begin testing its cells in animals in 2008 and that if all went well to begin clinical trials in human patients in 2009. Such timeline projections by companies often prove overly optimistic.

Doctors are already experimenting with transplanting cells from the pancreases of deceased organ donors into people with Type 1 diabetes. In some cases, the transplants relieve the recipients of the need to give themselves daily injections of insulin. But the effect wears off for most patients by two years.

Donated pancreases are scarce, so scientists hope to use stem cells to create insulin-producing cells. People with Type 1 diabetes and their families were among the biggest backers of the effort to create a $3 billion program of stem cell research in California. The program’s chairman, the real estate developer Robert N. Klein, has a son with diabetes.

by Andrew Pollack at New York Times





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