In his August 9th remarks, President Bush declared that federal funding will be provided for research on pre-existing embryonic stem cell lines but not for harvesting new embryonic cell lines or for research on such lines once they are cultured. He proposed "aggressive federal funding" and "a President's council" to oversee the research. He emphasized the complexity of the moral, ethical, and scientific issues at stake in stem cell research, stating that it raised "fundamental questions about the beginnings of life and the ends of science"(Bush 2001). Perhaps Bush arrived at his "compromise" decision because of the difficulty of resolving a cacophony of conflicting views on stem cell research; in any case, those on either side of the debate are displeased with the decision, seeming to agree only that compromise is inadequate to resolve the issue. Both Richard Doerflinger (National Conference of Catholic Bishops spokesperson), an adamant opposer of embryonic stem cell research, and pro-stem cell research Tony Mazzaschi (Association of American Medical Colleges) agree that Bush's decision "does not resolve the ethical problem, and it doesnt resolve the scientific problem" (Doerflinger in Vogel 2001). While the press plays "spin the Pope" - oversimplifying and manipulating complex messages like John Paul II's warning to value life (Saletan 2001) - and exaggerates the promise of unverified research, we are left to wonder why no viable compromise seems possible and what Mazzaschi means by "ethical paradigms that can't be bridged" (Vogel 2001).

Stem cell Biology

Scientists believe stem cells have the potential to cure diseases affecting millions of Americans each year, including cancer, Alzheimer's disease, heart disease, and diabetes. The goal of regenerative medicine is the restoration of organ function lost to disease or injury. Because stem cells have the potential to mature (differentiate) into many different kinds of cells, they are expected to have great potential for regenerative cures. Eventually, scientists hope to guide stem cell differentiation to create tissues that will replace or boost diseased tissues or organs. Some transplanted stem cells may even secrete drugs or other helpful chemicals. Stem cells can be derived from early-stage embryos called blastocysts, from aborted fetuses, or from adult tissue.

Embryonic stem cells come from the 100-cell blastocyst, a 0.14 millimeter hollow sphere of cells with an inner cell mass, which is formed five to six days after fertilization. As a fetus develops, its cells become more and more differentiated until each cell is completely specialized (e.g. into a liver, nerve, or blood cell). The cells of the inner mass are young and still pluri- or multipotent, which means each cell can differentiate into virtually any tissue type in the body. Embryonic stem cells have the most potential to lead to cures in regenerative medicine because they have demonstrated long-term self-renewal and multipotency (NAS 2001).

Every year, thousands of embryos are created for in vitro fertilization and thousands end up untransferable or abandoned. Scientists can take embryonic stem cells in pure form from these embryos, although it destroys embryos in the process. However, because many couples will continue turning to in vitro fertilization in order to have children, this creation and destruction of embryos will proceed regardless of stem cell research (Chapman et al. 1999).

Embryonic germ cells, which are also stem cells, come from fetuses aborted before the eighth week of pregnancy. After eight weeks of development, the rudiments of all major structures exist. Because the fetus is so far developed, stem cells derived from it are not as plastic as embryonic stem cells, so these fetal cells have potential for developing into fewer tissue types than embryonic cells.

Adult stem cells are undifferentiated cells within differentiated tissue. For example, in the bone marrow, hematopoietic stem cells continually create new blood cells. In the brain, stem cells generate new nerve cells that make new connections when we learn. Researchers have induced hematopoietic stem cells to give rise to liver cells, and it is the plasticity of hematopoietic stem cells that accounts for the success of bone marrow transplants. Harvesting adult stem cells is not as controversial as harvesting embryonic stem and germ cells but it is more difficult. Adult stem cells are rare and difficult to isolate in a pure form-their apparent plasticity in promising experiments may be due to impure samples. Scientists have not been able to maintain adult stem cells in culture for very long before they differentiate. Long-term survival will be necessary if scientists are to maintain a bank of stem cells. Adult stem cells are not as plastic as embryonic stem cells, but they are already "poised to create a particular tissue" and can migrate to injured areas, which may prove advantageous when patients whose injury or disease is localized (NAS 2000).

For a more detailed introduction to the science of stem cells, please see Joshua Tusin's article, Defining Stem Cells, published in the October Issue of JYI (Tusin 2001) and the stem cell reports by the National Academy of Sciences, National Bioethics Advisory Commission, and American Association for the Advancement of Science/Institute for Civil Society (Chapman et al. 1999). A real audio file of the proceedings of the June 22, 2001 NAS meeting which informed the NAS report is also available.

Moral and Ethical Issues

Many people-bioethicists, theologians, scientists, and laymen alike-have qualms about the way stem cells are harvested or even about using them at all in scientific research. Few question the morality of a consenting adult donating tissue. However, taking embryonic stem cells from pre-implantation blastocysts and embryonic germ cells from aborted fetuses is highly controversial because it raises questions about the definition of human life and the potential to become human.

Those in the Judeo-Christian and Islamic traditions find themselves, as Elliot Dorff writes, torn between the charge of their scriptures to both "work in the world and preserve it" (NBAC 2000). They must carefully consider whether or not stem cell research's potential to do good work in the world (healing the sick) comes at the price of a violation of the sanctity of creation. Religious people are performing careful, personal exploration of such issues, for as Father Tully, director of St. Bartholomew's Church in New York says, "the days when people were hanging on to the pronouncements of a denomination-if they ever did-are passing"(Niebuhr 2001). Religious leaders cannot speak for everyone in their faith, for there is no complete consensus about stem cells within any religious tradition.

The National Bioethics Advisory Commission provides advice and recommendations on human biology research to government agencies based on bioethics and applications. Its report, "Ethical Issues in Stem Cell Research" (NBAC 2000), has a section dedicated to statements by scholars and leaders in Judeo-Christian and Islamic religious groups which the following heavily draws upon. Unfortunately, perspectives from any other religions (e.g. Sikhism, Hinduism, and Buddhism) are lacking in the published literature.


Jewish and Islamic Perspectives

Jewish and Islamic views on stem cells (with exceptions) are clearer-cut than Christian ones because of tenets in Jewish law and Shari`a (Muslim law). Jewish law allows life-saving abortion and the fetus is considered part of the mother's body until 40 days after fertilization. Also, Jewish tradition allows that "an illicit act does not necessarily result in prohibition to use the product of that act" - hence, any aborted fetus may be used in research. The technology of taking stem cells from aborted fetuses, then, is "morally neutral." An embryo created in a petri dish is not considered human because it is not in the womb; therefore, taking stem cells from a pre-implantation blastocyst is morally neutral as well. According to Shari`a, ensoulment takes place 120 days after fertilization (the majority of both Sunni and Shi`ite Muslims make this distinction) but with the qualification that abortion should only be performed for health reasons; all Muslims maintain the sanctity of fetal life after 120 days. Abdulaziz Sachedina says that "most modern Muslim opinions speak of a moment beyond the blastocyst stage when a fetus turns into a human being" with moral status. Stem cell technology, then, is morally neutral according to the Muslim tradition. However, both Judaism and Islam warn against human arrogance. Papers submitted to NBAC by Jewish and Muslim scholars all stipulate that though the technology may be neutral, "it gains its moral valence on the basis of what we do with it" - i.e., who benefits from it and whether we use it for cures or "for enhancement": attempting to improve on God's creation.


Orthodox, Catholic, and Protestant Perspectives

Matthew 10:8 calls on the twelve apostles to heal: "cure the sick, raise the dead, cleanse lepers, cast out demons." Christians must balance this charge and the sentiment expressed by Protestant theologian Karl Barth: "No community... is really strong if it will not carry its very weakest members."

In the Greek Orthodox tradition (according to Father Demopulos of Holy Trinity Greek Orthodox Church), we are all "potential human persons" who are "struggling toward theosis," a process of becoming God, which "begins with the zygote." Demopulos writes that because pre-implantation blastocysts "were not going to be implanted... cannot mitigate the fact that they should not have been created." The use of stem cells from spontaneous miscarriages and adult stem cells, however, is moral (Ibid.).

Although many members of the media, such as the Associated Press and the Today show, have reported otherwise, the Pope has made no statement about banning or funding stem cell research (Saletan 2000). He merely called on Americans to "reject practices that devalue and violate human life at any stage from conception until natural death."

"Discerning which technologies 'devalue' human life, and how to 'reject' them," writes William Saletan, "is - pending further clarity from His Holiness..." Margaret Farley of Yale University believes that the Catholic tradition can be used either to support or condemn stem cell research, while Edmund Pellegrino of Georgetown University absolutely condemns it because in his understanding of Catholicism, "human life is a continuum from the one-cell stage to death."

Protestants' views of the situation are even more varied, with theologian Gilbert Meilaender calling on us to protect the embryo, "the weakest and least advantaged of our fellow human beings," while Ronald Cole-Turner of the Pittsburgh Theological Seminary is open even to the use of cloning (somatic cell nuclear transfer) to create embryos for their stem cells.

A June 2000 ABC news poll (Langer 2001) showed a fairly even split among evangelical white protestants, with 50% in support of the research and 40% opposed. This poll also showed 54% of Catholics in favor of stem cell research. However, ABC News also notes that the framing of the question has a large impact on a poll's results. For example, a poll by the anti-research National Conference of Catholic Bishops which said that "live embryos would be destroyed" for "experiments" showed 70% of people opposed, while a pro-research poll which didn't mention embryos but did list "deadly diseases" the research could treat garnered the support of 77% of people.


Common Ground

There is consensus within and among the religious groups represented in the NBAC report that we must be careful to avoid arrogance. Though they disagree on what constitutes "ill use," all would warn us "to be discerning so that we do not commit outrages by putting a gift of God to ill use" (Demopulos in NBAC 2000). A common concern of all the reports by the NBAC, the AAAS/ISC, and the NAS is the need for social justice. Cole-Turner asks, "How will the benefits be shared equally?" (NBAC 2000) while the AAAS/ICS report suggests that public funding for stem cell research would ensure greater access to eventual cures.

The Case for Public Funding

• What causes stem cells to remain undifferentiated?
• What signals a cell to start or stop dividing?
• What genetic and environmental signals affect differentiation?
• What physiological properties guide functional integration of new tissues into existing organs?

The Problem of Complicity and The Case Against Public Funding

Stem Cells from Adults and Spontaneous Abortions: A Compromise?

Many of those who oppose research on embryos and aborted fetuses call on scientists to work only with stem cells from miscarriages and adult tissues because they are morally less problematic (NAS 2001). However, there is little evidence that adult stem cells can substitute for embryonic stem cells: much of the successful work on adult stem cells has not been done with human cells. Much research that used human cells used hematopoietic stem cells and is not generalizable to other types of adult stem cells. Adult stem cells are difficult to grow in culture, and their potential to differentiate into many tissue types (plasticity) has not been established (Ibid.). Sixty percent of miscarriages are the "result of fetal anomalies" and 20% have "specific chromosomal abnormalities," which would most likely adversely affect the usefulness of their stem cells (Chapman et al. 1999).

Embryonic stem cell research is more promising. Embryonic stem cells, which are easier to culture, have demonstrated long-term self-renewal in culture and significant plasticity. Research on stem cells from adults and spontaneous abortions will proceed more slowly and be less likely to yield cures:

"Access to embryonic stem cells is likely to ultimately determine the rate at which scientists make progress in this field. In fact, the successful cultivation of postnatal and adult sources of stem cells for regenerative medicine is likely to advance more rapidly if the study of embryonic stem cells proceeds and cells from different sources can be compared (NAS 2001)."

Problems Posed by President Bush's Decision

President Bush, having weighed the moral problems posed by religious and bioethical thought, and having given the issues much "thought, prayer and considerable reflection," chose to value the "potential for life" of early embryos above their potential to cure. Bush's decision on stem cell research does not allocate funding for harvesting new embryonic cell lines or for research on new lines as they are cultured-only for research on sixty pre-existing cell lines, which scientists fear will not be enough to produce viable tissue for transplantation.

Although the NAS report does not directly evaluate Bush's decision because the report was "in review" before Bush's decision was announced, its implications are clear. Assuming privately-financed embryonic stem cell harvesting reaches optimal levels, research on those lines will attain much less than optimal levels without federal funds because only the private sector will be able to perform the research. According to the NAS report, research on new cell lines is crucial to moving forward in regenerative medicine because most existing lines are probably not viable. Human cells acquire about one mutation per division; these mutations accumulate in cell lines in culture, and stem cells are no exception. Extant stem cell lines have been cultured in a medium containing cow serum and grown on a layer of mouse embryonic fibroblasts, which secrete growth factors and sustain the stem cells in an undifferentiated state. These cells can be used for some basic research but not for cures. If they were injected into humans, they might spread animal viruses and other infections picked up in the growth medium. Because of mutations and the risk of infection, there is no reason to assume the existing cell lines are optimal (NAS 2001).

Assuming these lines are even safe, sixty lines will not suffice to move towards regenerative medical cures because there is not enough genetic variation among them. This lack of variation may become a significant pitfall to transplanting stem cells or their products. Unless there is a close match between the transplant and the recipient tissues, transplant rejection occurs. With only 60 tissue lines to choose from (unless the private sector comes through with a multiplicity of lines), transplants would be unviable or would rely heavily on life-threatening immunosuppressive drugs to prevent rejection.

The Future of Stem Cell Research

Applied stem cell research has the potential to cure diseases that affect millions of Americans. However, the research is controversial because some stem cells are derived from aborted fetuses and embryos left over from in vitro fertilization, which are destroyed in the process. Many people are strongly opposed to stem cell research for moral reasons, although there is no strong consensus on the issue within American religious groups.

President Bush's policy decision on stem cell research limits federal funding to research performed on pre-existing stem cell lines. Pro-research advocates are disappointed with the decision because with only private funds for derivation of and research on new lines, the pace of stem cell research will be slow and potential cures far off. Bush's decision also dismayed many anti-research advocates who feel that the use of embryonic stem cells derived from pre-implantation blastocysts is immoral whether or not the lines existed before the August 9th decision.

Public dialogue about stem cell research is healthy and necessary. Stem cell research has the potential to revolutionize how we treat disease and injuries; it will eventually have wide-ranging effects on public health and perhaps even on how we see man in relation to personal religious or ethical beliefs. The debate about stem cell research has only just begun.