- BIOETHICS FORUM ESSAY
Clarifying the President’s Council’s Clarification of the Obama Stem Cell Policy
Recently, ten members of George W. Bush’s President’s Council on Bioethics published a statement on Bioethics Forum in which they attempted to clarify the ethical stakes in President Obama’s new federal stem cell policy. This statement is likely to be remembered as one of the authors’ final pronouncements as members of the PCB. It is fitting, therefore, that in their swan song they tried to defend much of the hard work they produced in their past seven years of service to this country. And for that I am deeply sympathetic. However, I am greatly disappointed by their overreaching claims and potentially misleading analyses. They advance three general claims about President Obama’s permissive stem cell policy, and each claim is seriously flawed.
First, they claim that the Obama policy cannot accurately be described as “lift[ing] the ban on federal funding for promising embryonic stem cell research.” They argue that the Bush policy granted federal funds for the very first time for human embryonic stem cell research, as long as the lines were derived before August 9, 2001. Therefore, far from banning stem cell research per se, President Bush actually enabled it (subject to some constraints). But this analysis is only half correct. As everyone knows, the second half of the Bush policy involved a categorical prohibition – a ban – on all federal funding for research on stem cell lines derived after that date. What the Obama policy does is allow federal funding for stem cell research involving new stem cell lines created after that date. In other words, President Obama lifted the ban that constituted the second half of the Bush policy. Obviously President Obama’s actions left the first half of the Bush policy untouched; there will continue to be federal funds available for research on Bush’s stem cell lines. Therefore, to put the matter in its fullest context, saying that President Obama “lifted the ban on federal funding for promising embryonic stem cell research” is logically, factually, and semantically correct.
I do not wish to dwell on this minor issue, however. Far more disappointing is the ten PCB members’ suggestion that Bush’s policy compromise was actually succeeding in allowing stem cell science to advance without violating the moral convictions of people opposed to embryonic stem cell research. According to most stem cell scientists, patient advocacy groups, and even top-ranking NIH officials involved in stem cell research funding, federally sponsored stem cell research using Bush’s stem cell lines is woefully inadequate to advance American stem cell science. The Bush stem cell lines were derived more than eight years ago using old-fashioned techniques and have since then accrued many serious genetic abnormalities. The U.S. cannot hope to compete in the international stem cell race using only jalopy-grade stem cells. To say that the Bush compromise is good enough for American stem cell science is an insult to the researchers and to our fellow citizens who have pinned their hopes on the success of this field.
Second, they suggest that the Obama policy is an unnecessary step backwards both scientifically and ethically, since new “alternative” methods for deriving pluripotent stem cells have been developed that do not involve the destruction of human embryos. The most notable new method is the development of induced pluripotent stem (iPS) cells. The ten PCB members go on to point out that they had published a white paper in 2005 in which they had recommended this and other alternative methodologies for advancing stem cell science. Given the wording of this paragraph, it is difficult to ignore their apparent insinuation that their 2005 white paper, together with the restrictive Bush policy, had some influence on these recent developments. Whether or not they intended to imply this is difficult to determine for certain. In any case, it must be pointed out that the first steps in the iPS cell breakthrough began in Japan three years prior to the publication of the PCB’s 2005 white paper. The study leader and iPS cell pioneer, Shinya Yamanaka, has told me he was inspired by a nonfederally funded study conducted at Harvard in 2002 in which somatic cells were fused to human embryonic stem cells and subsequently began to develop pluripotent characteristics. In other words, Yamanaka’s team in Japan is deeply indebted to nonfederally funded advances in human embryonic stem cell research. To suggest otherwise is to attempt to rewrite stem cell history.
There are other ways in which iPS cells and human embryonic stem cell research are inexorably tied. It is a mistake to try to separate the two and to single out iPS cells as being capable of advancing without new forms of human embryonic stem cell research. As leading iPS cell researchers (including Yamanaka) and I have argued in a major stem cell journal, the use of human embryonic stem cells is absolutely essential in increasing our understanding of iPS cells. The point can be put succinctly: If you are going to make an artificial version of a human embryonic stem cell, you had better know everything you can learn about the real deal. And we are far from knowing everything there is to know about embryonic stem cells. More research is needed on new embryonic stem cell lines in order to know what both embryonic stem cells and iPS cells are capable of doing. It is bizarre that these PCB members cited the Nicholas Wade article in the New York Times as supporting their contention that iPS cell research has made human embryonic stem cell research unnecessary. That article concludes with the following statement: “Despite the new interest in reprogrammed stem cells, human embryonic stem cells are still worth studying, both to track the earliest moments in disease and to help assess the behavior of the reprogrammed cells.” The thrust of the article does not appear to support the PCB members’ views.
The iPS cell advance is indeed an exciting new development in stem cell science. PCB members like iPS cells in part because “they are patient-specific stem cells that are less likely to be rejected by their recipients.” But one must be extremely careful at this point not to overstate their potential for direct therapeutic use. PCB members and the general public should be made aware of two potential drawbacks. First, in order for iPS cells and their direct derivatives to be approved for therapeutic use, each patient-specific batch will have to conform to FDA regulations for both biologic product development and gene transfer research. Because each patient-specific iPS cell line will have to meet two rounds of very high FDA standards (and rightly so), the end result of these tough regulatory requirements might make it financially and logistically impractical to attempt to develop patient-specific iPS cell therapies using the patient’s own cells. Second, iPS cells are the most heavily manipulated human cells of all time. Extraordinary interventions are necessary to drive somatic cells back in developmental time – and then to drive the newly dedifferentiated cell down a particular developmental pathway toward specialization. A patient’s iPS cells and their derivatives may end up losing their immune compatibility along the way. Only further iPS cell research can answer this lingering concern, and that research will likely depend on lessons learned from the use of new, genetically unmanipulated human embryonic stem cells and from stem cells derived from other reprogramming methods, such as human research cloning.
Third, members of the PCB criticize President Obama for not clarifying how he will prohibit attempts to produce children from cloned human embryos created for research. They argue that the only way to prohibit human reproductive cloning would be “to prohibit, by law, the implantation of cloned embryos for the purpose of producing children. To do so, however, the government would find itself in the unsavory position of designating a class of embryos that it would be a felony not to destroy.”
However, it is not at all clear why a ban on human reproductive cloning would force the government into such a strange position. Banning human reproductive cloning can be grounded in a host of other reasons that do not involve creating a “second class” of human embryos. Here are just a few.
- Animal studies show that cloned offspring have a 3% to 5% chance of surviving gestation, and among those that do, all have developmental problems. Furthermore, there have been no successes in primate reproductive cloning, and the threat of harm to human and nonhuman primate cloned offspring may be even higher than it is in the case of domestic species. Thus, a ban on human reproductive cloning could be justified on the basis of safety to the potential child and the gestating mother tout court.
- Stem cell scientists want to derive stem cells from disease-specific cloned human embryos to compare them to disease-specific iPS cells and normal embryonic stem cells. The fear that someone will want to gestate these disease-specific cloned embryos to produce a child is a concern that strains credulity. Assuming human reproductive cloning is possible (a very big if), the resulting child created from a research embryo would have a serious genetic disease on top of all the developmental risks associated with reproductive cloning. Again, safety considerations provide the justification for banning reproductive uses of research cloned embryos.
- Cloned human embryos created for stem cell research purposes must be used for the research project articulated in the study protocol and in the informed consent documents signed by the human materials donors. To use cloned human embryos outside of the approved research protocol would violate all of these legal agreements and could be banned on those grounds alone. Embryos created for research purposes must be used for their intended purpose.
A ban on reproductive cloning may be a good idea just to ensure that nobody pursues this line of reproductive and developmental (not stem cell) science. This is a policy worth considering under any presidential administration. If anything, a ban now would have the happy effect of preventing embryo protectionists from being forced into an uncomfortable position: According to the value commitments of some PCB members and other embryo protectionists, if a healthy (or only moderately diseased) cloned human embryo were created, it should be gestated and brought into full being, just like any other human embryo. Philosophical consistency demands that embryo protectionists protect the lives of all human embryos, even if they are produced by cloning. This is a strange logical entailment, and I hope embryo protectionists never have to contend with it.
As the Obama stem cell policy moves forward, it is my hope that the scientific and ethical complexities of all forms of stem cell research are fully appreciated and explored. To do this, one needs a firm grasp of the technical realities and limitations of the science underlying the social debate. But as the recent statement from these PCB members shows, some commentators still have a long way to go on this score.
Insoo Hyun teaches bioethics at Case Western Reserve University’s School of Medicine. He chairs the Ethics and Public Policy Committee of the International Society for Stem Cell Research and cochairs the ISSCR’s Task Force on Guidelines for the Clinical Translation of Stem Cells.