Scientists overcome hurdles to stem-cell alternatives

WASHINGTON — Scientists reported Thursday they had developed a technique that can quickly create safe alternatives to human embryonic stem cells, a major advance toward developing a less-controversial approach for treating a variety of medical problems.

The researchers published a series of experiments showing they can use laboratory-made versions of naturally occurring biological signals to quickly convert ordinary skin cells into cells that appear virtually identical to embryonic stem cells.

Moreover, the same strategy can then coax those cells to change into specific tissues that would be a perfect match for transplantation into patients.

The work, by a team led by Derrick Rossi of Children's Hospital Boston, was praised by other researchers as a breakthrough.

"This paper is a major paper, in my view, in the field of regenerative medicine," said Douglas Melton, who co-directs the Harvard Stem Cell Institute.

In 2007, when scientists first reported they had reprogrammed skin cells into stem cells, it was hailed as an alternative to getting stem cells from embryos, which are then destroyed. Since then, researchers have been working on fine-tuning the method.

Opponents of human-embryonic-stem-cell research seized on the advance as the most convincing evidence yet that alternatives were sufficient, rendering the embryonic-stem-cell approach unnecessary.

Rossi and other researchers, however, said embryonic-stem-cell research was crucial because, among other things, embryonic stem cells are irreplaceable for validating alternatives.

Nevertheless, the announcement, described in a paper in the journal Cell Stem Cell, could mark a pivotal moment in the long, contentious history of embryonic-stem-cell research.

The advance comes as the future of federal funding for embryonic-stem-cell research remains in doubt. A federal judge stunned the field Aug. 23 by ruling that the Obama administration's new more permissive policy for funding the research violated a federal law barring taxpayer dollars from being used for studies that involve destroying human embryos.

The National Institutes of Health (NIH) said it supports research only on cells that have been obtained by privately funded scientists. An appeals court Tuesday let the NIH continue the funding as the case winds through the legal system.

Scientists hope embryonic stem cells will lead to treatments or cures for diabetes, Alzheimer's disease, Parkinson's disease, spinal-cord injuries and a variety of other ailments because they can turn into almost any tissue in the body. But they can be obtained only by destroying days-old embryos, which some people consider equivalent to taking a human life.

Material from The Associated Press is included in this report.