A comparative look at the U.S and British approaches to stem cell research.

• Author: Young, Cynthia Donley

INTRODUCTION

On August 9, 2001, President George W. Bush announced that federal funding of stem cell research would be limited to research involving those cell lines that had been created prior to the date of his announcement. (1) His statement had a significant impact on stem cell research in the United States and brought to mind a number of questions. What are stem cells? Why is this research important? What is the impact of President Bush's restrictions on stem cell research in the United States? To answer the last question, it is useful to examine other countries' and their legislative bodies' approaches to stem cell research. Great Britain, in particular, has a much less restrictive approach to public funding of stem cell research and has even gone so far as to permit the cloning of embryos for research. (2) Many researchers feel that Great Britain's approach is less complicated and leads to more useful results than the United States approach dictated by President Bush. (3)

First, this comment provides a general overview of stem cell research--the types of stem cells, the sources of stem cells, and an analysis of these types and sources--and discusses the ethical issues surrounding this research. (4) This comment will then compare the U.S. and British approaches, analyzing them with a particular focus on various legislative and executive policy choices, the bases for these, and their impacts on the field of stem cell research. (5)

1. OVERVIEW OF STEM CELL RESEARCH

   Stem cells have the ability to give rise to many types of cells in the human body. (6) Although stem cells' full potential remains unclear, researchers believe that these cells will have a remarkable impact on the treatment of various diseases and disorders. (7) In particular, stem cells could be used to generate various cells and tissues for transplantation. (8) For example, researchers hope "to develop heart muscle cells from human pluripotent stem cells and transplant them into the failing heart" muscles of heart attack victims. (9) Preliminary animal studies suggest that this type of research is feasible. (10)

   1. Types of Stem Cells

      Researchers have identified three different types of stem cells: unipotent, multipotent, and pluripotent cells. (11) While pluripotent cells have the potential to give rise to many different cell types, (12) multipotent cells give rise to certain types of cells (e.g., blood and skin stem cells) that perform specific functions, (13) and unipotent cells can give rise only to a single type of cell. (14) Another difference between these cell types is that unipotent and multipotent cells persist throughout life, whereas evidence suggests that pluripotent cells predominantly exist in embryos and fetuses. (15) Pluripotent stem cells also offer a greater potential for medical research, as they can divide indefinitely, self renew, and be stimulated into precursors for many different cell types. (16)

      Stem cell research has a number of potential applications. First, stem cells could provide information about general human development--in particular, the factors that lead to cellular specialization. (17) Second, researchers could test the safety and efficacy of drugs using a human cell line prior to using animal or human subjects. (18) For example, a new medication could be tested on a human cell line modified to incorporate the particular disease that the medication is designed to treat. Third, stem cells could be used to generate cells and tissues to treat diseases and disorders that act to destroy or impair certain cell types and tissues. (19) These "cell therapies" offer great hope to persons suffering from disorders such as "Parkinson's and Alzheimer's diseases, spinal cord injury, stroke, burns, heart disease, diabetes, osteoarthritis and rheumatoid arthritis." (20)

   2. Sources of Stem Cells

      A number of sources of stem cells exist, but vary in terms of their versatility and usefulness. Stem cells can be derived from embryos, fetal tissue, umbilical cord blood, and adult tissue. (21) Fetal stem cells are derived from aborted or stillborn fetal tissue. (22) Embryonic stem cells can come from excess embryos created in fertility clinics for in vitro fertilization, from embryos created specifically for the purpose of research, or from embryos created via somatic cell nuclear transfer (SCNT). (23) With SCNT, the nucleus is removed from a donated egg, replaced with the nucleus from a somatic cell, and then induced to divide into an embryo. (24) This process could reduce rejection problems associated with transplantation of the stem cells, since the replacement nucleus comes from the person to whom the stem cells are given. (25) Embryonic and fetal stem cells typically are pluripotent and offer the greatest research potential, whereas stem cells derived from umbilical cord blood or adult tissues are primarily multipotent or unipotent. (26)

   3. Ethical Issues

      1. Source of Stem Cells

         The arguments made against stem cell research depend on the source of the stem cells. Different issues are involved when the stem cells are recovered from surplus embryos obtained from fertility clinics, as opposed to embryos created via SCNT or fetuses from abortion procedures. The predominant opposition to such research tends to have a moral or religious origin rather than a legal or constitutional origin, (27) especially in the United States, where the influences of religious and ethical principles play an influential role in lawmaking. Many politicians are influenced by their religious beliefs or by highly opinionated political action committees. (28) A strong argument exists that an individual's religious and moral values should not play a role in lawmaking. If one accepts this argument, then opponents to stem cell research seem to have little basis for restricting this research.

         1. IVF Embryos

            The use of excess in vitro fertilization (IVF) embryos from fertility clinics as a source of stem cells for medical research raises serious public concern and creates an ethical dilemma in which the benefits of research must be weighed against respect for the potential life of an embryo. (29) The argument against this research is that embryos that could possibly develop into a human life should be protected and preserved--that allowing the destruction of such embryos is comparable to mutilating and killing a child. (30) This argument seems to ignore the fact that fertility clinics only store excess embryos for a limited time before their destruction. No support exists for the idea that preventing research on these embryos would help put an end to the destruction of embryos by fertility clinics.

            Policies limiting research on embryos, with the goal of preserving human life, often rest on the premise that an embryo is a person or a potential person. (31) Indeed, the U.S. Constitution explicitly states that no "person" shall be denied life without due process of law. (32) But for an embryo to receive this protection, it must be considered a person. While some believe that personhood begins at birth, others are of the opinion that human life starts at conception--this view, however, receives little support from U.S. lawmakers. (33) Furthermore, the majority opinion in Roe v. Wade (34) determined that the unborn are not "`persons'" with respect to the law. (35) On the other hand, many jurisdictions safeguard the embryo as if it were a potential person. (36) In these "potential personhood" jurisdictions, opponents to embryonic sources of stem cells have a much stronger case. Even in the United States, though, viable fetuses are often offered some degree of protection. (37)

            Another concern is that doctors in fertility clinics would create more embryos than necessary to be used in their own stem cell research or to sell to other researchers. Regulations governing stem cell research often deal with this concern by including provisions that disallow doctors in fertility clinics from using excess embryos in their own research or from receiving any compensation or incentives for these embryos. (38) These regulations do not stop doctors from using more surreptitious means to perform research on excess embryos or from selling them to other unethical researchers, but these concerns will always exist--even if stem cell research is prohibited. (39)

            Also of concern is that women in conjunction with their doctors will create embryos for the sole purpose of creating a source of stem cells. (40) This worry is especially acute with respect to the use of the resulting tissues for transplantation into a needy patient, especially if that patient is personally related to the donor (e.g. the donor has a child with a life-threatening disease). (41) Many supporters of stem cell research believe the benefit of saving an existing life outweighs the disadvantage of destroying a potential life, especially since embryos are regularly created and destroyed for in vitro fertilization. (42)

         2. Aborted/Miscarried Fetuses

            Another set of concerns arises when an aborted fetus serves as a source for stem cells. Anti-abortion activists are concerned that allowing researchers to use fetal tissue will encourage women who are against abortion--or otherwise undecided--to pursue an abortion. (43) They believe that women will rely on the positive use of the fetus to justify an "immoral act." (44) This argument assumes that women are incapable of making rational or moral decisions when faced with incentives. It is unlikely that a woman who would otherwise choose to keep her baby would instead have an abortion just because the fetal tissue may be used for research that has yet to be proven valuable.

            Apprehension also exists that women would be more likely to abort if offered financial incentives or to support research for a particular disease or disorder from which they or a loved one suffer. (45) Despite the unlikelihood that women contemplating abortion would be swayed by research, federal...