Embryos that have died during test-tube baby attempts, cells taken from embryos without harming them or even recharged adult skin cells might provide alternatives to embryonic stem cells for research, White House ethics advisers say.
Any one of the alternatives might provide a way for the compelling research to go forward without upsetting ethical concerns, the President’s Council on Bioethics said in a report released Thursday.
The report comes out as Congress begins to revisit the issue of whether to loosen or tighten restrictions on embryonic research. Both sides of the debate fired volleys this week as rival bills wended their way toward votes.
At issue are one kind of stem cell — those taken from days-old human embryos. These master cells are “pluripotent,” meaning they have the ability to grow into any kind of tissue or cell in the body. The cells offer the promise of personalized treatments for diseases like juvenile diabetes.
“Much of the ethical controversy over stem cells derives from the fact that, until now, the only way to obtain human pluripotent stem cell lines has been to derive them from living human embryos by a process that necessarily destroys the embryos,” the council said in its report.
“If a way could be found to derive such stem cell lines without creating and destroying human embryos, a good deal of that ethical controversy would subside.”
Will alternatives succeed?
The group, made up of bioethicists, researchers, legal experts and others, suggested four alternatives to creating embryos using cloning technology or using embryos left over from fertility clinic work.
“Stem cells might be obtainable from dead embryos; from living embryos, by nondestructive biopsy; from bioengineered embryo-like artifacts; and from reprogrammed adult somatic cells,” the report reads.
Somatic cells could range from skin cells to blood cells. Dead embryos would include those unsuccessfully thawed at fertility clinics. “Nondestructive biopsy” refers to studies showing that it might be possible to take a cell or two from an embryo without destroying it and grow those in laboratories.
Bioengineered cells would be genetically altered so they could never become an actual human being. Reprogramming adult cells remains the goal of many stem cell researchers, who would like to be able to take a cell from a patient and change its genetic instructions so that it can form a batch of the desired tissue.
“It remains to be seen whether any of these proposals will succeed scientifically, and more discussion is surely required on some of the ethical issues we have identified,” the council said.
Sean Tipton, a spokesman for the American Society of Reproductive Medicine and the Coalition for the Advancement of Medical Research, agreed on that point.
“We would agree that you ought to pursue all the alternatives, he said. “But we think scientific merit ought to drive those decisions.”
He said research using live human embryos still held the most promise.
“We think embryonic stem cell research is the ethical alternative,” Tipton said. “We think that medical ethics ought to apply to living patients with diseases, not just tissues in a lab.”
Since 1995, Congress has banned the use of federal funds for research that would destroy an embryo. President Bush expanded that slightly in 2001 but still limited the use of federal funds for research to a few stem cell lines.
Rival bills in both the House and the Senate would either explicitly encourage federal funding or ban privately funded research. Supporters and opponents do not fall cleanly along party lines or lines drawn by the abortion debate.
