A new way of producing stem cells that could lead to treatments for illnesses such as diabetes and Parkinson's was revealed by US scientists today.
The advance in cell reprogramming by researchers in Boston is a more efficient way of turning skin cells into stem cells, which avoids the use of embryos.
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.
Embryonic stem cells, which have the ability to morph into any type of cell, continue to be controversial.
Last month, a US judge cut off federal funding for research with them. A different court then ruled last Tuesday that funding could resume while legal arguments proceed.
The reprogramming produces what scientists call iPS cells, for induced pluripotent stem cells.
The technology first used to make them involved disrupting the DNA of the skin cells.
That method would introduce a risk of cancer to any patient who got transplanted tissue derived from the iPS cells. So researchers have been developing alternate methods.
The new approach is more efficient than earlier efforts and avoids tampering with DNA, said Derrick Rossi of Children's Hospital Boston and the Harvard Stem Cell Institute.
He and his colleagues reported the work in a paper published online today by the journal Cell Stem Cell.
Their technique treats skin cells with modified forms of RNA, a chemical cousin of DNA that normally transmits instructions from genes to the protein-making machinery of the cell. Dr Rossi has patented the technique and formed a company to use it.
Experts unconnected with the study praised the work.
The method appears to be highly efficient, which implies the resulting iPS cells will be of good quality, said Marius Wernig, an iPS researcher at Stanford University.
It will take further work to see if the initial promise is borne out, Wernig said. If so, it would be the first practical method for generating iPS cells that could be used for transplant therapies, he said.
"If it turns out to be a very efficient way of generating iPS cells without any genetic modification, then it would be a big advance," he said.
Kathrin Plath of the University of California, Los Angeles, called the work "very impressive" and said it appears to show the best approach so far for making such cells for transplant tissue.
"We will definitely try this method here at UCLA," she said in an e-mail.
Still, further study is needed to confirm the benefits of the new approach, she said.