for National Geographic News
Two teams of scientists have given human skin cells many of the properties of embryonic stem cells—a development that could ease political, ethical, and medical concerns over the highly controversial research topic.
Like embryonic stem cells, the new cells—known as induced pluripotent cells—are capable of developing into most types of cells in the body. But the new lines can be created without the use of an embryo.
Such cells could conceivably also be custom-made for any adult, sidestepping issues of cell rejection.
"The advantage of using [such] reprogrammed skin cells is that any cells developed for therapeutic purposes can be customized to the patient," James Thompson, who led one of the studies, said in a prepared statement.
"They are probably more clinically relevant than embryonic stem cells," added Thompson, a biologist at the University of Wisconsin, Madison.
Embryonic stem cell work has long been mired in controversy. Such cells may lead to medical treatments such as tissue and organ replacement, but harvesting the cells typically requires the destruction of an embryo.
Since 2001 the United States government has restricted public funding to a limited number of embryonic stem cell lines, a move many U.S. scientists say has stifled their work.
The race to create induced pluripotent cells in humans began last year, when scientists at Kyoto University in Japan announced they had inserted genes into cells from the tails of mice and reprogrammed them into cells with properties of embryonic stem cells. (Related: "Mouse Testicles Yield Promising Stem Cells" [March 24, 2006].)
Thompson and his colleagues today announced they had finally translated the research to humans by using viruses to ferry four genes—OCT4, SOX2, NANOG, and LIN28—into skin cells. The full findings appear in this week's issue of the journal Science.
In a second study, appearing today in the journal Cell, the Kyoto team announced that they have also given human cells taken from skin and connective tissues stem cell properties.
Using the same technique as that of Thompson but with a slightly different combination of genes, the Japanese researchers report they were able to reprogram 10 cells out of every 50,000.
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