A team from Advanced Cell Technologies (and other research centers) reports in Cell Stem Cell today that they have created colonies of human embryonic stem cells without harming the embryos from which the cells were derived. (ACT reported an earlier version of this technique, which involves removing one cell from an embryo, last year — today’s paper seems to describe a more efficient version.) The yardstick they used for harm in this case was fertility clinic embryos, which also often have one cell removed, though it’s usually for genetic testing (preimplantation genetic diagnosis, or PGD, is the technical term). As Rick Weiss reports in the Washington Post, the embryos used by ACT to generate the stem cell colonies had a survival rate as good as or better than that of fertility clinic embryos — whether they were underwent PGD or not.

So, given the seeming lack of harm, NIH should be able to fund this kind of research, right? Actually, no. From that Washington Post article:

That means the work should be eligible for federal financing under President Bush’s six-year-old policy of funding only stem cell research that does not harm embryos, said study leader Robert Lanza, chief scientific officer at Advanced Cell Technology in Worcester.

But that is not likely, said Story Landis, who heads the National Institutes of Health stem cell task force, which oversees grants for studies on the medically promising cells.

The embryos Lanza used, which were donated for research, appear not to have been damaged, Landis acknowledged. However, she said, “it is impossible to know definitively” that the embryos were not in some subtle way harmed by the experiment. And “no harm” is the basis of the Bush policy, she said.

Landis said the only way to prove that the technique does not harm embryos would be to transfer many of them to women’s wombs and see if the resulting babies were normal. But it would be unethical to do that experiment, she said, so the question cannot be answered.

That standard has Lanza fuming. By all scientifically recognized measures, he said, the embryos — currently frozen in suspended animation because they were donated for research and not to make babies — are normal, he said.

“I think the burden of proof lies with the NIH and the Bush administration to show that an embryo was harmed,” Lanza said.

-Greg Dahlmann

(via Jim Fossett)