Human stem cells created without need for embryos

Ordinary skin cells from the face of a 36-year-old woman and the foreskin of a newborn were turned into stem cells and may have the power to become any cell in the body, according to reports in the journals Science and Cell.
The technique by U.S. and Japanese researchers may shift the ethics debate by ending use of embryos and leapfrog studies by hundreds of companies, including Geron Corp. and Advanced Cell Technology Inc. It may allow human tissue to be more easily created and help drugmakers test how compounds interact with diseased cells, said Ian Wilmut, who cloned Dolly the sheep.
The scientific teams each inserted four genes into the skin cells, switching on a process that converted them into a form equivalent to embryonic stem cells. The cells were then changed into heart, brain, muscle, fat and cartilage cells by one team using proven methods for growing tissue from embryonic cells.
“It will revolutionize the way in which we study and treat human disease,” Wilmut, who was not involved in the research, said in a telephone interview from his home in Edinburgh, Scotland. The biologist, who ushered in a new era of exploration and ethical conflict with Dolly a decade ago, said he’s shifting his research to work on reprogramming stem cells.
Scientists have grown embryonic stem cell colonies, called lines, from human embryos discarded by fertility clinics. The cells have the ability to grow almost limitlessly, and with chemical and genetic stimulation, can become virtually any cell in the body. Because embryos are killed to extract the cells, their use has been controversial and limited.
Scientific efforts to create embryonic stem cells by combining the genes of patients with egg cells donated by women have been slowed by the lack of donors.
The new method was first perfected in mice last year by Shinya Yamanaka of Kyoto University. He began years ago testing combinations of genes that are unusually active in embryonic stem cells. After mixing and matching, he found a combination of four genes that could bestow embryonic characteristics on stem cells.
Now that the technique has been established in human cells, it may eliminate the push for so-called therapeutic cloning of human embryos as a way to create stem cells that genetically match a person, said Wilmut, who predicted Yamanaka’s work would earn him a Nobel Prize.
“We decided some weeks ago that we were not going to pursue” human cloning, Wilmut said. “It seems more likely that you’d get an effective or reliable source of stem cells from the Yamanaka procedure.” •