Proposal may solve stem cell dilemma
■ Creation of a new biological entity could bypass ethical problems of research on human embryos.
By Andis Robeznieks — Posted Jan. 3, 2005
The embryonic stem cell research debate shows no signs of resolution, but a new proposal has been made that could offer a compromise and, in the process, develop new ways of defining "humanity."
The proposal involves creating a new type of biological entity that can produce stem cells but would not rise to the moral status of a human embryo. Reaction has been mixed, but with embryonic stem cell research opponents -- including an influential official of the Catholic church -- expressing interest, both sides might be persuaded to give it another look.
At last month's meeting of the President's Council on Bioethics, council member William B. Hurlbut, MD, a Stanford University consulting professor in human biology, presented a plan to alter a cell's genetic makeup to create an entity that produces embryonic stem cells but would lack the ability to develop into an embryo.
"The chief complaint from one side is that I was proposing to create true embryos with a defect," he said. "The criticism from the other side is, 'Why should science accommodate the private religious views of a small number of people?' "
The answer to that question, he said, is because the United States is a democracy where minority views are respected. The answer to the first complaint is more complicated.
"If we're going to go forward with our new powers over developmental biology, we're going to have to do the hard work of defining what we mean by 'organism,' 'embryo' and 'human being,' " Dr. Hurlbut said.
An opponent of destroying embryos to obtain stem cells, Dr. Hurlbut said the strongest argument for protecting embryos was their potential to become human beings. But the entity he is proposing lacks that potential. In explaining his theory, Dr. Hurlbut argued that, if embryonic stem cells were "coaxed" into becoming a human kidney, "you would just have a human kidney, you don't have 10% of a human being. It's not a moral entity."
The proposal has received some underwhelming responses.
"I applaud the fact that he's trying to find something in this debate that is working toward a moral solution, but I'm not sure he's found that," said Christian Medical Assn. Executive Director David Stevens, MD. "You can call it a 'pre-embryo,' but it's still an embryo." He added that the time spent on Dr. Hurlbut's plan would be better used on adult stem cells.
Charles Jennings, PhD, executive director of the Harvard Stem Cell Institute, said Dr. Hurlbut's proposal would delay scientific advances, could possibly introduce unwanted mutations and would not satisfy moral objections of opponents. "I don't think it will fly with anybody," he said.
Putting ethics first
Dr. Hurlbut's proposal also received mixed reviews from fellow council members. Embryonic stem cell research supporter Michael Gazzaniga, PhD, director of the Center for Cognitive Neuroscience at Dartmouth College, criticized it. "Normally, we generate a word to describe a biologic phenomenon, and here we seem to be tinkering with biologic phenomenon to have it fit the meaning of a word."
But Paul J. Hoehner, MD, of the Christian Medical Assn.'s National Medical Ethics Committee, sees that as a ground-breaking concept.
"Forever, we've developed the science without the ethical thinking and then played catch-up," he said. "Here we start with an ethical opinion and try to adapt the science to fit it."
Dr. Hoehner said he was speaking as an individual and not as a member of the Christian Medical Assn. or its ethics committee. But he said the committee had drafted a statement on the beginning of life that it would present to the CMA House of Delegates in June and that Dr. Hurlbut's proposal "really dovetails well with the ethical concerns" in that statement.
Others opposed to embryonic stem cell research also have said they are willing to look more closely at the proposal, including San Francisco Archbishop William J. Levada. He wrote a letter to President Bush stating that Dr. Hurlbut's proposal "offers hope that there may be a solution to an area of great challenge and controversy."
The letter, which the San Francisco Archdiocese did not release in full, notes that the U.S. Bishops' Committee on Doctrine expressed "interest and encouragement of the proposal."
Council on Bioethics member Robert P. George, DPhil, director of the James Madison Program in American Ideals and Institutions at Princeton University, said animal experiments should begin immediately to test Dr. Hurlbut's theories.
"What it really comes down to is whether we would be creating disabled embryos or a non-embryo source of pluripotent cells," he said. "I want to know the answer to that question, and animal research could determine the answer in short order."