Efforts to create embryonic stem cells using cloning techniques should be put on hold for the time being, according to the Center for Genetics and Society, a public interest group.
“The successes in cell reprogramming suggest that scientists can achieve the goals of cloning-based stem cell research by other means,” said Marcy Darnovsky, associate executive director for the organization. “Given its risks and lack of progress, it’s time to put research cloning on the back burner. If the new techniques don’t deliver on their promise, then the cloning issue can be revisited.”
Some stem cell scientists have for years sought to use cloning to derive disease-specific and patient-specific stem cell lines. Two research teams recently reported they had isolated such cells without cloning.
Jesse Reynolds, a policy analyst at the Center, has said cloning-based stem cell research lays the technical groundwork for reproductive cloning of humans and requires enormous numbers of fresh eggs—whose extraction poses health risks to women. After years of work, no researcher has created a clonal human embryo viable enough to yield stem cells, she said, adding that at this point, the risks outweigh possible benefits.
Most embryonic stem cell research uses embryos left over from IVF procedures, but cloning requires unfertilized eggs, which are hard to obtain and preserve. Two weeks ago the first stem cell lines were derived from a primate—a rhesus monkey—but this required hundreds of eggs.
Darnovsky says researchers who continue to insist on cloning are needlessly painting themselves in a corner.
“At this point, those who say we should pursue all possible avenues of research are dismissing the risks to women who would provide the eggs they would need for their experiments,” she said. “They’re also downplaying the potential for reproductive cloning, especially given the absence of a US law against it.”
In response to the successes of cell reprogramming, leading cloning researcher Ian Wilmut said he is abandoning that avenue of work in favor of the new methods, noting new techniques provide new options.
“Now that we can take embryo politics out of the stem cell issue, we can begin to address some of the pressing regulatory challenges raised by emerging biotechnologies,” he said. Wilmut favors national and international bans on reproductive cloning, and comprehensive federal policies regulating other powerful new genetic technologies.
The Center is a policy research and advocacy organization, which supports embryonic stem cell research under conditions of responsible societal oversight and regulation.
