Researchers have developed a new way to make embryonic-like stem cells by soaking them in genetically engineered proteins, a new step toward using ordinary cells to treat disease.
An international team led by the Scripps Research Institute in California said on Thursday it is the safest method yet found to transform ordinary skin cells into what are called induced pluripotent stem cells, or iPS cells.
They reported their finding, made using mouse cells, in the journal Cell Stem Cell.
They have also formed a corporate alliance to sell their technology to other researchers who want to make and work with the cells. "Scientists have been dreaming about this for years," said Sheng Ding of Scripps, who led the research.
The body's master cells
Stem cells are the body's master cells, providing a renewable source of brain, bone, muscle, blood and other cells. These cells make up days-old embryos and in the first few days after conception each one can give rise to all of the cells and tissues in the body.
These embryonic stem cells are sought after and studied by scientists who hope to understand and harness their powers to transform medicine by providing transplants to treat brain diseases, injuries, cancer and perhaps as a source of new organs.
Several teams have been working to find ways to simply make ordinary cells behave like embryonic stem cells - bypassing the need to get them from embryos, a painstaking process that some people also find morally objectionable.
In 2007 researchers figured out it takes only four genes to do this. They have been working ever since to find safe and effective ways to turn on these genes in normal cells, in effect turning back the clock and sending them back into an embryonic-like state.
These newly primitive cells could then be grown in large batches and directed to become the desired cell type - pancreatic cells for diabetes or brain cells for Parkinson's disease, for instance.
Many of the methods so far require the use of a virus to carry the new genes into a cell, and the resulting tissues might be too dangerous to use in people.
Researchers have also used little circles of genetic materials called plasmids to do this, which is safer but still not something that could be done easily in big batches.
Long-lived, primitive cells
Sheng Ding and his company Fate Therapeutics took the four genes needed to make an embryonic stem cell and genetically engineered them with a molecule that would let them get through a cell's outside coat. Then they soaked some mouse cells in this mix. The mouse cells turned into long-lived, primitive cells that look much like embryonic stem cells, they reported.
They differentiated into various cell types, such as beating cardiac muscle cells, neurons, and pancreatic cells, the researchers reported.
Separately, they reported the creation of a program called Catalyst to sell the technology, as well as technology developed by stem cell expert Dr Rudolf Jaenisch of the Whitehead Institute in Massachusetts, who helped found Fate Therapeutics. – (Maggie Fox/Reuters Health, April 2009)
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