Stem Cell Research: Why Medicine Should Reject Human Cloning

Abstract

Speculation that the world's first human clone may have been born,1Mayer PW Doc says clone will be born soon. CBS News Web site.Available at: http://www.cbsnews.com/stories/2002/12/27/tech/main534440.shtmlDate: November 27, 2002Google Scholar, 2Ritter M Company claims birth of human clone: experts are skeptical. The Augusta Chronicle Web site.Available at: http://www.augustachronicle.com/stories/122802/tec_clone1.shtmlDate: December 27, 2002Google Scholar combined with reports that human embryos have been cloned for research purposes,3Cibelli JB Lanza RP West MD Ezzell C The first human cloned embryo.Sci Am. 2002; 286: 44-51Crossref PubMed Scopus (40) Google Scholar, 4Cibelli JB Kiessling AA Cunniff K Richards C Lanza RP West MD Rapid communication: somatic cell nuclear transfer in humans: pronuclear and early embryonic development.E-biomed J Regenerative Med. 2001; 2: 25-31Crossref Scopus (148) Google Scholar calls for careful public and professional scrutiny of the critically important matter of human cloning. Human cloning is the asexual production of a human being whose genetic makeup is nearly identical to that of a currently or previously existing individual.5Cloning Human Beings: Report and Recommendations of the National Bioethics Advisory Commission. The President's Council on Bioethics, Rockville, MdJune 1997: 17-18Google Scholar, 6Kass LR Human Cloning and Human Dignity: The Report of the President's Council on BioEthics. PublicAffairs, New York, NY2002Google Scholar Whereas the deliberations of international, national, and state regulatory bodies have, in most cases, favored the prohibition of what has been called reproductive cloning—in which a cloned human embryo is created with the intent that a human clone will be born—they have differed considerably over what has been termed research cloning. Research cloning involves the creation of a cloned human embryo for the purpose of scientific investigation of early human development or for medical research aimed at developing treatments for disease. Because embryonic stem cells are pluripotent, having the capacity to differentiate into the full range of human tissues, some believe that these cells hold the potential to revolutionize medicine by providing a source of replacement tissue that might one day restore the health of persons suffering from a variety of debilitating conditions.7Committee on the Biological Biomedical Applications of Stem Cell Research Board on Life Sciences National Research Council Board on Neuroscience and Behavioral Health Institute of Medicine Stem Cells and the Future of Regenerative Medicine. National Academy Press, Washington, DC2001Google Scholar Transplanted embryonic stem cells derived from a patient's clone may be compatible (as would adultderived stem cells from the patient) with that patient's immune system and hence, in principle, be resistant to immune rejection. Our contention is that human cloning should not be permitted, whether for research or reproductive purposes. While we enthusiastically affirm the importance of medical research and ardently support the goal of healing people, we believe that the harms human cloning would bring to medicine would exceed the anticipated benefits. An overwhelming majority of scientists, health care professionals, policy makers, bioethicists, theologians, and the general public have indicated their opposition to the birth of cloned human beings.6Kass LR Human Cloning and Human Dignity: The Report of the President's Council on BioEthics. PublicAffairs, New York, NY2002Google Scholar, 8Jaenisch R Wilmut I Developmental biology: don't clone humans!.Science. 2001; 291: 2552Crossref PubMed Scopus (102) Google Scholar, 9“Cloning” humans is a turn off to most Americans: embryonic cloning for research is also opposed [Gallup poll analyses]. May 16, 2002.Google Scholar The following concerns have been advanced. Human cloning would be hazardous to the gestating clone and the surrogate mother. The current state of nonhuman animal cloning technology is so rudimentary that the procedure has resulted in a staggeringly high occurrence of severe physical and genetic defects and premature aging in cloned offspring.10Westphal SP Cloned monkey embryos are a “gallery of horrors.”.New Scientist. December 12, 2001; PubMed Google Scholar, 11Wilmut I Are there any normal cloned mammals?.Nat Med. 2002; 8: 215-216Crossref PubMed Scopus (39) Google Scholar Embryologists estimate that a single successful human cloning might come at the cost of hundreds of failed attempts.8Jaenisch R Wilmut I Developmental biology: don't clone humans!.Science. 2001; 291: 2552Crossref PubMed Scopus (102) Google Scholar Even if issues of safety were overcome, which is unlikely apart from unethical human experimentation, compelling ethical objections remain. Human cloning would signify an egregious disrespect for personal autonomy. In forcing on the human clone a selected identity bound to certain, perhaps unfulfilled, expectations placed on the genetic original, cloning would frame that person's life and limit that person's autonomy permanently. Cloning would also encumber that person with profound emotional burdens. The cloned individual would not be born with the special privilege of having a unique genetic identity, but rather would always live in the shadow of the other person whom he or she was intended to duplicate genetically. The social stigma of being known as a clone, combined with confused parentage and expectations of measuring up to the achievements of the genetic original or of “replacing” a deceased loved one, could result in unimaginable psychological turmoil.6Kass LR Human Cloning and Human Dignity: The Report of the President's Council on BioEthics. PublicAffairs, New York, NY2002Google Scholar If cloning became common practice, its deviation from the traditional design and accompanying moral responsibilities of the human family might well disrupt social stability. Moreover, cloning brings to mind images of assemblyline manufacture more suited for the making of replaceable appliances than unique human beings. Deeply held public intuition thus regards the prospect of human cloning to be a repugnant departure from the intimate and richly meaningful process of natural procreation. Unlike other reproductive technologies that assist procreation, cloning seeks to produce a human being with a particular genetic code. It is not technology that we oppose, but rather the misuse of technology that enables some people to exert nearly absolute control over the genetic makeup of others. This substitution of human genetic replication for procreation would constitute a serious affront to human dignity.12Cheshire WP Toward a common language of human dignity.Ethics Med. 2002; 18: 7-10Google Scholar If cloning proceeds along its current path of development, it will foster a grave devaluation of humanity. Whether cloning were to become a widespread or an occasional practice, its acceptance would shift societal attitudes away from appreciating people as distinct individuals and toward a new way of sizing up people as useful or attractive commodities of technology assembled to satisfy others’ expectations. Some will defend human cloning as a right of reproductive liberty that ought never be restricted. However, there exists no inalienable right to engage in human cloning as a means of realizing one's desire for a child, regardless of the particular motivation behind such a desire.13Forsythe CD Human cloning and the constitution.Valparaiso Univ Law Rev. 1998; 32: 469-542PubMed Google Scholar Furthermore, although reproduction is a private matter, development and implementation of genetic technology on which reproductive decisions will be based are matters of definite public interest. No reason has been advanced that is weighty enough to justify overlooking the considerable hazards described herein and resorting to cloning as a means of human reproduction. The disturbing dangers of human cloning to public health and well-being should be of concern to physicians in particular because the menacing key to this Pandora's box is a medical procedure. Proposals to ban human cloning for purposes of reproduction have attracted broad support. However, enacting a ban solely on reproductive cloning, while simultaneously permitting research cloning, would almost certainly fail to achieve its stated objective. For the following reasons, we contend that a partial ban could well result in instances of both types of cloning, leading to a society that most Americans would deem undesirable.14Kilner JF Human cloning.in: Kilner JF Cunningham PC Hager WD The Reproduction Revolution: A Christian Appraisal of Sexuality, Reproductive Technologies, and the Family. WB Eerdmans Publishing Co, Grand Rapids, Mich2000: 124-139Google Scholar First, a partial ban would be unenforceable. If a ban on reproductive cloning only were adopted, enforcement would necessarily entail the legally mandated destruction of human embryos created for research cloning. Such required destruction would not only constitute a form of clear discrimination against a class of human beings based on the means of conception but also would likely be objected to or wholly disregarded by many, particularly by those who desire to implant the embryos. Because the legality of terminating the lives of unborn human beings by abortion is frequently defended as a matter of personal choice, it is difficult to imagine that most Americans would welcome a governmental policy that mandated the destruction of embryonic human life and the punishment of those who defied the law (either by knowingly implanting a cloned human embryo or by giving birth to a human clone).15Kass LR Preventing a brave new world: why we should ban human cloning now.New Repub. 2001; 224: 30-39PubMed Google Scholar, 16Andrews LB The Clone Age: Adventures in the New World of Reproductive Technology. Henry Holt & Co, New York, NY1999: 74Google Scholar Such acts of defiance would be viewed by many as the private exercise of a reproductive option entitled to certain protections, effectively circumventing a partial ban. Although we do not believe that people have a right (rooted in reproductive liberty) to create human beings via cloning, we nevertheless maintain that parents should never be forced to destroy their offspring, once created, regardless of their method of origin. Currently, the parents of embryos created via in vitro fertilization (IVF), for example, are given a great measure of decision-making power regarding the fate of their embryos. Some fertility clinics exceed clinical policy requirements in their efforts to determine parents’ wishes regarding stored embryos, and all clinics are obligated to honor decisions both for and against implantation.17Disposition of abandoned embryos: ASRM Ethics Committee report. American Society of Reproductive Medicine, Birmingham, Ala1997Google Scholar Our autonomy-steeped culture would surely have difficulty accepting a policy that would deny people the same choice simply because their embryos were created through cloning. Regardless of their legality, both IVF and reproductive cloning are technologies that lie within the realm of reproduction. Because of the private context of reproduction and the underregulation of the US fertility industry, prohibiting the implantation of cloned human embryos would be a formidable task met with considerable resistance, regardless of whether reproductive cloning is legally permissible. Of importance, although public consensus favors a law prohibiting the reproductive cloning of human beings, continued legislative stalemate on proposals to adopt a comprehensive cloning ban prohibiting both research and reproductive cloning might mean that even reproductive cloning would remain legal. If cloned human embryos were created in the laboratory for research purposes only, the mandate that they not be implanted or otherwise allowed to progress toward birth would prove extremely difficult to uphold. Therefore, the birth of cloned human beings—the very thing that a ban on reproductive cloning should prevent—would likely result. Second, if cloned human embryos were available for research, appeals to compassion within the privacy of the physician-patient relationship would likely lead to their implantation. Consider the following hypothetical scenarios. A cloned human embryo is created with the intent of producing tissue needed to save the life of a seriously ill child. Before the tissue can be obtained, the ill child dies. Her grieving parents, distraught over their tragic loss, request that the embryo be implanted so that they may have another child who is a near genetic duplicate of the daughter whom they so desperately miss. A man agrees to be cloned with the intent of donating the resultant embryo to research. Subsequent to creation of the cloned embryo, he learns that both he and his wife are infertile. Realizing that their prospect for having a genetically related child suddenly appears to be compromised, the man changes his mind and requests that his clone be implanted in his wife instead of donated to research. In such cases, it would be difficult for many physicians to deny the wishes of those desiring to implant a cloned embryo. Third, violations of a partial ban would often go unnoticed. If laboratory creation of cloned human embryos was permitted but implantation of such embryos was banned, it would be infeasible to monitor the fate of each and every cloned embryo. The somatic cell nuclear transfer procedure typically results in the creation of multiple embryos. To prevent a single embryo from being implanted within the private context of the physician-patient relationship would surely prove to be impossible. Moreover, policies that would require genetic testing of every neonate at birth to ensure that he or she is not a clone (and that would penalize the parties responsible for implanting a cloned embryo) would likely be regarded as a violation of privacy. Even if such testing were allowed, it would fail to ensure that reproductive cloning had not occurred because the baby could be a clone of an unknown or unrevealed person, rather than being a near genetic duplicate of one of the parents. As a result, threats to levy fines or inflict other punishments would not always deter those wishing to engage in technology they perceived to be undetectable. Policies that prohibit, and penalize those who request or assist in, the implantation of cloned human embryos would therefore ultimately fail to prevent reproductive cloning once cloned human embryos were produced for research purposes. Fourth, a policy that prohibited cloning for reproduction while permitting cloning for research would actually facilitate the means to achieving the activity it intended to prevent. To permit research cloning as a legitimate activity of science would undoubtedly result in an increased number of human clone births. Ongoing embryological research is poised to overcome many of the remaining technical obstacles to human cloning. Some experts estimate that the successful and efficient production of healthy cloned human embryos suitable for implantation might be months or at most a few years away.18Boiani M Eckardt S Schöler HR McLaughlin KJ Oct4 distribution and level in mouse clones: consequences for pluripotency.Genes Dev. 2002; 16: 1209-1219Crossref PubMed Scopus (456) Google Scholar, 19Solter D Cloning v. clowning.Genes Dev. 2002; 16: 1163-1166Crossref PubMed Scopus (7) Google Scholar If this methodology is perfected and IVF practitioners are trained in its use, the implantation of cloned human embryos would no longer be the distant prospect of a few laboratories in possession of specialized resources but could become a simple and brief procedure within reach of most fertility clinics that perform intracytoplasmic sperm injection or other labor-intensive forms of fertilization. If the goal is to avoid instances of human reproductive cloning, as advocates of a partial ban fervently assert, then a law designed to prevent a requisite activity occurring over a period of months or years should be regarded as preferable to a law forbidding the implantation of cloned human embryos that could be accomplished in only minutes. Many existing US laws offer precedents. For example, to prevent private citizens from developing nuclear weapons, current laws ban the unlicensed possession of plutonium and enriched uranium.20Atomic Energy Act, 42 USC §2077 and 42 USC §2014 (aa) (1954).Google Scholar It would be foolhardy to distribute plutonium widely and then expect people not to engage in the production and use of nuclear weaponry because it is easier to withhold the means to produce a weapon than it is to prevent its production and use. Even persons who do not find research cloning to be morally objectionable may nevertheless oppose cultivating the industry due to the inevitability that cloned human beings would be born if the development of technology for research cloning were not banned.21Associated Press Sen. Smith changes stance on stem cells.Northwest News Channel 8 Web site. May 6, 2002; Google Scholar Fifth, a partial ban would eliminate only the language of reproductive cloning. To speak of a distinction between “reproductive” cloning and “research” cloning is to neglect an important commonality between both forms of cloning. Regardless of intent, both generate in the same manner a human embryo. Therefore, both methods of human cloning are reproductive in that they give rise to new individual human lives.22Langman J Medical Embryology. 4th ed. Williams & Wilkins, Baltimore, Md1981: 1Google Scholar A partial ban clearly understood would not truly be a ban against cloning but against the implantation—and hence the survival—of human clones. The choice of language applied to cloning should recognize that, on biologic grounds alone, the human embryo is a living human organism. Structurally, the embryo is genetically complete. What is necessary for continued growth is suitable nurture and environment, 2 conditions that live human beings need as much in their adult stage as in their embryonic stage. Metabolically, at every cell division the embryo copies the complete human genome with nearly perfect fidelity and, in transcribing his or her genetic code, has begun the journey toward actualization of all the functional capacities that uniquely typify a being of the species Homo sapiens. Some well-intentioned thinkers will defend research cloning and human embryo research in general on the grounds that, rather than being fully present at conception, human worth develops gradually as the nervous system reaches a stage of maturation when certain functional capacities are demonstrable. We consider such a gradualist view to be an inadequate account of the value of human life. To suppose that human life consists only in functional capacities is to mistake the detection of life for its existence. Life ontologically precedes biologic function, and one must first be a human being to develop and possess human capacities. Similarly, although some have argued that the embryo fertilized in vitro must enter the womb to count as human, we maintain that the moral status of a human being is independent of age or geographical location. A gradualist view can also run counter to the widely accepted belief that diminished or less developed capacities may obligate increased care or protection. Some of the very people who would gain from the alleged benefits of research cloning are themselves in a state of functional decline due to degenerative disease. If one accepts the gradualist criterion that moral worth depends on one's stage of development or function, then, by the same logic, individuals who are ill or disabled (eg, those with Alzheimer disease, Parkinson disease, or spinal cord injury) would have an uncertain claim to full human worth because of their loss of function. From the gradualist perspective, the widely held belief in human equality grounded in a common basis for dignity vanishes. Because material traits alone are an unsatisfactory guide to assessing human moral status, no empirical description of a human being, no matter how exact, can fully grasp the magnificent complexity of the individual within. Drawing from their experience in responding to human frailty and suffering, physicians understand this well. The practice of medicine teaches that the meaning of human joy cannot be fully explained by a map of molecules in motion, or the tears of human suffering by the trickling of neurotransmitters. Thus, human dignity, which medicine recognizes as being irreducible to mere physical characteristics, cannot be denied on material grounds to a portion of the biologic life span. To discount the emergence of human dignity at the very beginning of life—when life, although just barely measurable yet has distinctly begun—would be a serious error. Language that undermines the humanity of early human life inevitably exposes other vulnerable classes of humanity to the risk of similar devaluation. Regrettably, medicine has witnessed throughout history the tragic consequences that ensue when a certain subgroup of human beings is denied the full status of humanity for the purpose of research or economic gain. A ban on human cloning for both research and reproductive purposes would be the most effective and ethically responsible safeguard against the birth of human beings via cloning. Once human embryos were developed to the stage at which stem cells are present, a primary objective of research cloning, they would also be suitable for implantation.23Smith WJ Cloning and Congress: no ban is better than a phony ban.The Weekly Standard. July 1, 2002; Google Scholar Then, as we have illustrated, the birth of cloned human embryos would be only a short step away; once a cloned human embryo was implanted in a woman's body, no responsible public policy would mandate the termination of pregnancy. Advocates of a less than comprehensive ban may respond to the preceding arguments by pointing out that all legal bans function imperfectly. Although it is of course true that no law functions perfectly (eg, people continue to murder even though homicide is illegal), a society serious about prohibiting a certain act should adopt laws that will reduce, to the greatest extent possible, the likelihood of that act occurring. Although a comprehensive ban on human cloning may indeed fail to prevent all instances of reproductive cloning, prohibiting not only the implantation but also the creation of cloned human embryos would prove to be a far more effective mechanism for securing a society free from reproductive cloning. A comprehensive cloning ban is also the only policy consistent with the priority medicine should place on the value of human life. Historically, extracorporeal human embryos have been afforded certain protections24Consolidated Appropriations Act. §510, Pub L No. 108-7 (2003).Google Scholar that have received broad support. For example, many present-day proponents of embryo and stem cell research dependent on the destruction of already existing human embryos created during IVF procedures recoil at the prospect of deliberate creation and sacrifice of human embryos.25Krauthammer C Research cloning? No.Washington Post. May 10, 2002; : A37Google Scholar A substantial proportion of the public is also opposed to the creation and destruction of cloned human embryos for research purposes.26Poll on American support of human cloning. Stop Human Cloning, Washington, DCApril 22, 2002Google Scholar, 27Cloning opposed, stem cell research narrowly supported: public makes distinctions on genetic research. The Pew Research Center for the People & the Press and The Pew Forum on Religion & Public Life, Washington, DCApril 9, 2002Available at: http://www.pewtrusts.com/pdf/vf_pew_research_religion_cloning.pdfGoogle Scholar In 1994, the National Institutes of Health proposed that the federal government begin funding research in which human embryos were created for destructive experimentation. This proposal was greeted with nearly universal condemnation from the public, various professional communities, and the major news media.28Embryos: drawing the line [editorial].Washington Post. October 2, 1994; (sect C:): 6Google Scholar, 29Embryo research is inhuman [editorial].Chicago Sun-Times. October 10, 1994; : 25Google Scholar President William J. Clinton appropriately chose not to grant federal funding for the creation of embryos for research, and Congress went one step further in passing an amendment prohibiting funding for all research harmful to human embryos.24Consolidated Appropriations Act. §510, Pub L No. 108-7 (2003).Google Scholar When opposition to this amendment has been voiced by members of Congress, bipartisan support for its prohibition against creating human embryos for destructive research has remained undiminished.30Lowey N 142 Congressional Record at H7343. July 11, 1996. Quoted in: Americans oppose cloning human embryos for research.Available at: www.nrlc.org/Killing_Embryos/factsheetcloning.htmlGoogle Scholar The National Bioethics Advisory Commission's report on cloning human beings,5Cloning Human Beings: Report and Recommendations of the National Bioethics Advisory Commission. The President's Council on Bioethics, Rockville, MdJune 1997: 17-18Google Scholar the National Institutes of Health guidelines for embryonic stem cell research,31National Institutes of Health. National Institutes of Health Guidelines for Research Using Human Pluripotent Stem Cells. 65 Federal Register 51976-51981 (2000).Google Scholar and the Stem Cell Research Act of 200132Amendment to the Stem Cell Research Act of 2001: Referred to the Committee on Health, Education, Labor, and Pensions 107th Cong, 1st Sess (April 5, 2001) (statement of Arlen Specter, senator).Google Scholar all explicitly proscribed the special creation of embryos for research purposes. More recently, the President's Council on Bioethics unanimously rejected human cloning for purposes of reproduction, while pronouncing a majority recommendation for a moratorium on human cloning for biomedical research.6Kass LR Human Cloning and Human Dignity: The Report of the President's Council on BioEthics. PublicAffairs, New York, NY2002Google Scholar In addition to constituting a break with US legal tradition and much of public sentiment, research cloning violates existing ethical guidelines designed to protect human subjects. The Nuremberg Code (1945) stipulates that, “No experiment should be conducted where there is an a priori reason to believe that death or disabling injury will occur….”33Annas GJ Grodin MA The Nazi Doctors and the Nuremberg Code: Human Rights in Human Experimentation. Oxford University Press, New York, NY1992: 2Google Scholar This fundamental principle of nonmaleficence is reflected also in the Declaration of Helsinki (1964, latest revision 2000), the Belmont Report (1979), and the Council of Europe's Convention on Human Rights and Biomedicine (1996), which represent the accumulated wisdom of a half century of reflection on the grave consequences of conscripting nonconsenting human beings for destructive research. Of importance, these moral codes do not exempt human beings at the beginning or end of life as somehow not being under the protection due all human subjects. To the contrary, these codes demand even greater degrees of protection for the most vulnerable of human subjects, eg, children. We maintain that cloned human embryos, as human beings, likewise are vulnerable human subjects and are worthy of such protections.34Smith T Ethics in Medical Research: A Handbook of Good Practice. Cambridge University Press, Cambridge, England1999: 278Google Scholar, 35Ramsey Colloquium The inhuman use of human beings: a statement on embryo research.First Things. 1995; 49: 17-21PubMed Google Scholar Although a strong lobby to legalize research cloning has been formed by certain scientists, biotechnology firms, and patient advocacy groups, the fact remains that the prospect of creating and destroying human embryos for research purposes has, for valid reasons, been consistently opposed in both the legal and the ethical arenas. It is incumbent on advocates of research cloning who wish to overturn wellestablished ethical standards to make and defend a sufficient and compelling case. No convincing case has been presented that provides substantive arguments for rejecting the existing set of governing principles that has been carefully formulated and deeply etched into the prevailing ethos of our culture. A policy allowing research cloning would therefore run counter to US jurisprudence regarding the treatment of human embryos and to the intent of ethical codes designed to protect human subjects in research. Of note, a noncomprehensive ban permitting research cloning would establish, for the first time in US history, a class of human beings created for the sole purpose of experiments that will destroy them and whom ironically it is a crime not to destroy. In recognition of this fact, and of research cloning's inherent potential for reproductive applications, the burden of proof must lie on those who wish to justify such a momentous break with legal and ethical precedent. We assert that no such justification has been offered, as defended in the subsequent section. In justifying a policy promoting the creation and subsequent destruction of cloned human embryos, advocates of research cloning have frequently turned to the rationale of utility. Utilitarianism in its classic form advocates acting in whatever ways will result in the “greatest good for the greates