Designing Our Descendants: The Promises and Perils of Genetic Modifications

8 The Moral Impasse in Human Embryo Research: Bypasses in the Making?

c h a p t e r e i g h t The Moral Impasse in Human Embryo Research Bypasses in the Making? John Fletcher, Ph.D. In some cases, new technology creates a bypass around a seemingly intractable moral impasse. For example, before it was possible to diagnose death by neurological criteria, justifiable caution blocked the way to saving lives by transplanting organs from brain-injured patients presumed to be dead. This caution was due to uncertainty about whether patients on ventilators whose hearts were still beating were truly dead.1 Diagnosis of death by neurological criteria (clinical signs assisted by encephalography) bypassed this obstacle and provided a technical solution to satisfy the rule that an organ donor must be certi fiably dead before any procedures related to transplantation could begin.Furthermore , this advance optimized chances of success by reducing ischemic damage to the donor organ, which could be perfused right up to time of surgery .2 This chapter discusses the potential of two technology-assisted ways around the controversy over human embryo research (HER), which is a moral problem that divides our society and its politics. These bypasses may be in the making . Please note the emphasis on “may.” The first could fail to prove itself and the second is very futuristic. These technologies could also evolve into other possibilities. This chapter examines the following questions: How viable are hopes that there may be ways around HER? What morally defensible alternatives exist if these hopes do not materialize? Two Bypasses in the Making? Stem cells are unique inasmuch as they renew themselves and give rise to specialized types of cells in the human body (e.g., blood, bone, muscle, neural, etc.). Stem cells found in the human embryo are pluripotent (i.e., infinitely renewable and the progenitors of most of the cells functioning in the human body). These characteristics make scientists and patients hope that cell lines grown from embryonic stem cells will be an ideal source of therapy for diseases caused by cell wasting or cell death. Human embryonic stem cells (ESCs) in current research3 are almost universally derived from clinically unused embryos donated by couples in infertility treatment. The act of deriving ESCs for research destroys the embryo. Communities or persons holding that embryos have the same right not to be killed accorded to a living fetus or individual obviously regard such an act as morally wrong. Without belaboring all sides of the moral debate about HER, if there were a way to avoid the use of ESCs for research and treatment, it would greatly reduce social conflict. The first possibility for a bypass is using cell lines grown from adult stem cells (ASCs) or other less morally problematic alternatives, such as embryonic germ cells (EGCs) derived from fetal tissue after elective abortion. If these sources prove effective in therapy,then using ESCs may become unnecessary.Opponents of embryo research make this argument, and some argue that advances in ASC research have already rendered ESC research unnecessary.4 On the other hand, the prevailing consensus in the scientific community is that this judgment is entirely premature and that the better course is to pursue parallel research with all three types of cells. As the most current and comprehensive scientific review of the entire field of human stem cell research concludes: “Predicting the future of stem cell applications is impossible, particularly given the very early stage of the science of stem cell biology.To date,it is impossible to predict which stem cells— those derived from the embryo, the fetus, or the adult—or which methods for manipulating the cells, will best meet the needs of basic research and clinical applications . The answers clearly lie in conducting more research.”5 This judgment reflects no change in the prevailing view in the scientific communityasreportedbyVogelmorethanayearearlier :“mostscientistscautionthat 106 John Fletcher research on both adult and embryonic stem cells is too premature to compare the potential of the two.”6 I will argue below that the only morally defensible way to create a bypass of HER in stem cell research is to proceed with parallel studies of cell lines grown from these three sources to determine their properties and their preclinical promise as cell replacement therapies. Several outcomes are possible: one source may be clearly superior in all cases; each source may be effective for specific diseases; or none...