Scientists attempt customizing stem cells

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CAMBRIDGE, Mass., March 8 (UPI) -- Using three approaches that include embryonic stem cells and gene therapy, scientists say they have opened a new avenue to creating customized cellular treatments for genetic disorders, according to a study released Friday.

Embryonic stem cell research could offer a variety of potential new therapies to treat a host of genetic and chronic diseases -- such as diabetes or Alzheimers disease -- because these immature cells have the capability of being developed into any types of cells in the body needed to fight a particular condition.

What makes these findings unique is that it is one of the first times scientists were able to successfully program an embryonic stem cell to become a particular cell type to treat an illness -- in this case it was immune system cells that were needed.

"This is first report that the (cell) differentiation process has been controlled enough," co-researcher William Rideout told United Press International. "It puts some substance behind the hype."

In the past, scientists have been able to concoct these cell mixtures to create different kinds of cells, such as muscle, blood and immune system cells. But there has been little success in taking these cells to the next step -- transplanting them into an animal to treat an illness.

At the Whitehead Institute for Biomedical Research, researchers combined embryonic stem cells, gene therapy and nuclear transplantation -- transplanting the nucleus of a cell containing the genetic code into an egg cell.

Scientists used the nuclei from the skin cells of a mouse with an immune disorder. These skin cells, which contained genetic information, were transplanted into a mouse egg. The egg was grown to a point where it reached the embryonic phase. Researchers then extracted and isolated these immature cells or stem cells, to be transplanted back into the mouse with the genetic immune disorder.

Gene therapy was used separately to correct a defective copy of the gene that was causing the immune disorder. Each gene has two copies.

This cellular therapy, complemented by the gene therapy, triggered the immune system to start producing its own immune cells. The cells were not rejected, as is often the case with tissue-to-tissue transplantation, because they were harvested from the mouse's own genetic material. However, immune system function was only partially restored in this animal.

Rideout said the findings indicate this approach could one day work in treating genetic blood disorders such as sickle cell anemia. The findings were published Friday on the Web cite of the journal Cell.

There is a lot of hype surrounding stem cell research because of the possibilities in a wide range of treatments. Though this is a promising first step, Dr. Nelson Chao, director of the bone marrow transplant program at Duke University Medical Center in Durham, N.C., and an expert of stem cell research, said there still is a very long way to go before therapies can be made available to people.

"I think that the problem is the cells we have in our body don't act in isolation," Chao told UPI.

When scientists extract and isolate these stem cells, they are not going to behave the same in the laboratory as they would in a natural body surrounded by other cells. That is the crux of what makes stem cells so difficult to manipulate, Chao explained.

"The ability to transfer these nuclei, I think, is very important, but the translation from a petri dish to a mouse and a mouse to a human is really a long step," he said.

Despite these roadblocks, Chao remains optimistic.

"I think that's the way the whole field is trying to go, to be able to design the kind of cells one could use to treat different diseases," he said. "All this stuff is pointing to the fact we're going to get there."

(Reported by Katrina Woznicki in Washington)