Legal and Ethical Issues

Legislative bodies around the world are grappling with the questions regarding the legal regulation or prohibition of stem cell research. In the United States since 2001—by presidential directive of George Bush—only those ES cell lines that were already established can be used for research that is funded by the federal government. At that time, it was thought that some sixty or so viable cell lines would be available. However, as of mid-2005, only fifteen to twenty of these cell lines existed, and these had been largely contaminated with, for example, the mouse feeder cells on which they had been cultured. Worldwide at this time, fewer than 150 lines have been created. In the United States, there currently are no laws prohibiting such re­search. However, it must be done through private or state funding. Such is California's Institute of Regenerative Medicine, for which voters approved $3 billion in funds for startup work. As of March 2007, this institute had decided to fund several groups after an extensive peer review process.⁴ Scientists are concerned that the United States may lose its leadership role in this science to other countries. On April 11, 2007, the U.S. Senate passed the Human Cloning Ban and Stem Cell Research Protection Act of 2007; the House of Representatives then passed the bill by a wide margin. As the title indicates, although the ban on cloning human beings continues, the act holds that the federal government should provide funds for stem cell research. The Senate vote was sixty-three to thirty-four, with three more senators abstaining but in support. Nevertheless, the vote in favor was

408 PART TWO ■ ETHICAL ISSUES

one vote short of that required to override an expected presidential veto. In June 2007, George W. Bush vetoed the bill as he had done the previous year.⁵

To overcome certain ethical concerns about the moral status of the early embryo, some people have suggested that adult stem cells be used. These exist in bone marrow and purportedly in other parts of the body such as the brain, skin, fat, and muscle.⁶ The use of these cells seems to work in some cases. For example, "German doctors reported having repaired a large gap in a young girl's skull using a combination of bone graft and stem cells derived from her own fatty tissue."⁷ Adult stem cells have also been used to treat heart failure patients, either by forming new heart muscle cells or by stimulating their production.⁸ These adult stem cells may be part of the body's natural "repair mechanism."⁹ However, at most, adult stem cells can be used to produce or spur the development of only a limited number of types of related tissues. They are multipotent rather than pluripotent. Moreover, they do not seem to be as vigorous as the ES cells. Recently, researchers have found evidence that stem cells might be pres­ent and obtainable from amniotic fluid. It would be a plentiful source and not as problematic as those obtained from embryos. Again, however, although they have elements in common with embryonic stem cells, it is not clear yet whether these amniotic stem cells would have the same potency as those taken from embryos.¹⁰

Another line of research is inspired by the newt, a small amphibian. If it loses a limb, the newt can regenerate a new one. The idea would be to see if certain already differentiated body cells could be reprogrammed in such a way that they could be c/e-differentiated—in other words, they might be brought back to a state closer to that of ES cells. Even further, this type of research might lead to a better understanding of the body's "innate capacity for regeneration" such as in wound healing.''

Because there is no federal funding in the United States for this type of research, there are also no ethical guidelines. To supply these, the National Academy of Sciences (NAS) has recently proposed a set of such recommendations for voluntary use by researchers. This set is modeled on the type of

self-regulation that scientists proposed for recom­binant DNA research in 1975, guidelines later adopted by the National Institutes of Health (NIH). These guidelines are particularly relevant for stem cell research in which the tissues and organs that might be developed would need to be tested first in animals. This may lead to the creation of chimeras, animals with some human cells or organs. This research is for medical purposes, not to produce the centaur and mermaids of mythology. In fact, doctors are already using pig heart valves that have some human cells to treat heart patients. While recommending that such testing be allowed, the NAS also recommended that (1) chimeraic ani­mals not be allowed to mate because, if the cells invaded the sperm and eggs, this could lead to a human being conceived; (2) human stem cells not be allowed to become part or all of an animal's brain and not be injected into other primates; (3) the embryo should not be allowed to develop for more than fourteen days; and (4) women who donate eggs not be paid in order to avoid financial inducement.¹²

Recently, a task force of the International Society for Stem Cell Research published its own guidelines for embryonic stem cell research. They were developed by ethicists and scientists and legal experts from fourteen countries. They are much like those of the NAS in the United States but do allow some research on chimeraic animals— those that could carry human gametes—but only if it passes the review of an oversight committee. They also sought to justify the fourteen-day limit for embryo development, arguing that it is not until this point with the development of a "primitive streak" that the embryo "has begun to initiate organogenesis."¹³

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