Ethics and Stem Cells
Stem cells show potential for many different areas of health and medical research, and studying them can help us understand how they transform into the dazzling array of specialized cells that make us what we are. Some of the most serious medical conditions, such as cancer and birth defects, are caused by problems that occur somewhere in this process. A better understanding of normal cell development will allow us to understand and perhaps correct the errors that cause these medical conditions.
Research on one kind of stem cell—human embryonic stem cells—has generated much interest and public debate. Pluripotent stem cells (cells that can develop into many different cell types of the body) are isolated from human embryos that are a few days old. Pluripotent stem cell lines have also been developed from fetal tissue (older than 8 weeks of development). As science and technology continue to advance, so do ethical viewpoints surrounding these developments. It is important to educate and explore the issues, scientifically and ethically.
For More Information:
The following links to other Internet sites are offered only for the convenience of World Wide Web users. The NIH is not responsible for the availability or content of these external sites, nor does the NIH endorse, warrant, or guarantee the products, services, or information described or offered at these other Internet sites.
- Presidential Commission on Bioethics The Presidential Commission for the Study of Bioethical Issues advises President Obama on bioethical issues that may emerge from advances in biomedicine and related areas of science and technology.
- National Academy of Sciences Guidelines for Human Embryonic Stem Cell Research The National Academy of Sciences developed its first set of ethical standards for stem cell research in 2005. The guidelines were updated in 2007, 2008, and 2010.
- The Kennedy Institute of Ethics at Georgetown University Library & Information Services allows searches of books, newspapers, journal articles, and other materials on bioethical issues.
- Stem Cell Research and Applications: Monitoring the Frontiers of Biomedical Research (300K PDF; get Adobe Reader) The American Association for the Advancement of Science (publisher of Science magazine) and the Institute for Civil Society produced this report addressing stem cells and ethics.
- The Ethics of Human Embryonic Stem Cell Research The International Society for Stem Cell Research provides this information as a public service to those wishing to discuss stem cell ethics.
- Bioethics Advisory Committee (BAC) Singapore Addresses the ethical, legal, and social issues arising from biomedical sciences research.
- EuroStemCell has developed a factsheet on the ethical issues around embryonic stem cell research.
Stem cell Ethics, Moral Values, and US Law
Scientists and society as a whole must consider the ethical implications of stem cell research. Different ethical issues are raised by the wide range of stem cell research activities. In 2005, the National Academies published guidelines for scientists who do research with human embryonic stem cells to encourage responsible and ethically sensitive conduct in their work. Although the guidelines are not expressly legally binding, many researchers have voluntarily adopted them as a guide to what constitutes appropriate conduct in human embryonic stem cell research. Yet for some people, such guidelines are inadequate because they aim to govern a practice that they see as intrinsically unethical. As the science advances, it is essential that scientists; religious, moral, and political leaders; and society as a whole continue to evaluate and communicate about the ethical implications of stem cell research.
The National Academies’ Guidelines for Human Embryonic Stem Cell Research In order to provide all scientists—those working in universities and private companies and with both public and private funding—with a common set of scientific and ethical guidelines, the National Academies published the Guidelines for Human Embryonic Stem Cell Research in 2005. The report outlines the need for institutional oversight mechanisms for monitoring all human embryonic stem cell research and provides specific guidance regarding the derivation of new stem cell lines.
Under the guidelines, certain activities, such as experimenting on human embryos by inserting stem cells into them, are not permitted. The guidelines also require that all egg, sperm, and blastocyst donations follow appropriate informed consent and confidentiality procedures. Because the ethical and technical questions associated with human embryonic stem cell research are likely to change as science advances, in 2006, the National Academies established a panel of experts to monitor and review scientific developments and changing ethical, legal, and policy issues and to prepare periodic reports to update the guidelines as needed. Learn more about this ongoing activity.
Is an Embryo a Person?
The controversy over embryonic stem cell research touches on some of the same fundamental questions that society has grappled with in the debates over contraception, abortion, and in vitro fertilization. The questions at the center of the controversy concern the nature of early human life and the legal and moral status of the human embryo.
Embryonic stem cell research often involves removing the inner cell mass from “excess” blastocysts that are unneeded by couples who have completed their fertility treatment (Learn more). This prevents those blastocysts from continuing to develop. Although such blastocysts would likely be discarded (and thus destroyed) by the clinics in any case, some believe that this does not make it morally acceptable to use them for research or therapeutic purposes. They believe that the life of a human being begins at the moment of conception and that society undermines a commitment to human equality and to the protection of vulnerable individuals if blastocysts are used for such purposes.
Some cultures and religious traditions oppose the use of human life as a means to some other end, no matter how noble that end might be. Other traditions support embryonic stem cell research because they believe that the embryo gains the moral status of a human being only after a few weeks or months of development. Many traditions emphasize obligations to heal the sick and ease suffering—goals for which embryonic stem cell research holds great potential—and favor embryonic stem cell research for this reason. Several religious groups are currently involved in internal discussions about the status of the human embryo and have not yet established official opinions on the matter. Public opinion polls suggest that the majority of both religious and non-religious Americans support embryonic stem cell research, although public opinion seems divided about the creation or use of human blastocysts solely for research.
The Relationship of Stem Cell Research to Reproductive Cloning
Although cloning and stem cell research are often lumped together in the context of ethical debates, the goals and results of the two are very different. The common factor between current attempts at reproductive cloning and stem cell research is a laboratory technique called nuclear transfer.
Using nuclear transfer, scientists can create blastocysts containing stem cells that are “clones” of a single adult cell by inserting the genetic material from an adult cell (for example, a skin cell) into an egg whose nucleus has been removed. Scientists hope that they could derive stem cells from the cells inside such blastocysts and grow replacement tissues that are genetically matched to specific patients, thus offering patients a safer alternative to traditional tissue transplants.
Reproductive cloning, such as the process that was used to create Dolly the sheep, also uses the nuclear transfer technique. However, instead of removing the inner cell mass to derive a stem cell line, the blastocyst is implanted into the uterus and allowed to develop fully. In 2002, the National Academies issued the report Scientific and Medical Aspects of Human Reproductive Cloning, which concluded “Human reproductive cloning should not now be practiced. It is dangerous and likely to fail.”
The Ethics of Human-Animal Chimeras
Chimeras are organisms composed of cells or tissues from more than one individual. Chimeras have been produced for research for many years, but when human and animal cells are mixed in the laboratory, there is a clear need for heightened ethical consideration.
Cells from different organisms can be combined either in the early developmental stages (for example, introducing human cells into a mouse blastocyst to observe certain developmental processes) or after an individual is fully developed (for example, implanting human stem cell-derived pancreatic cells into a mouse to test their ability to function in a living body). Chimeras are considered essential for advancing stem cell research to viable therapies, since no therapy can be tested in humans without research in animals first.
Some people believe that the creation of chimeras involving human cells for medical research is morally acceptable as long as the chimera has no level of human consciousness. Therefore, research in which it is possible for human stem cells to produce part of an animal’s brain should be conducted with great care. The National Academies’ guidelines prohibit the introduction of human cells into the blastocyst of a non-human primate, or the introduction of any animal or human cells into a human blastocyst. The guidelines also prohibit the breeding of human-animal chimeras in the unlikely event that any human genetic material would be contained in their reproductive cells.
Is it legal?
As of the summer of 2006, all forms of stem cell research in the U.S. are legal at the federal level. That is, it is not illegal to make or work with new embryonic stem cell lines. However, the use of federal funds for human embryonic stem cell research is restricted to the cell lines that were available as of August 9, 2001. Therefore, the derivation of new embryonic stem cell lines can only occur when scientists are working with non-federal funding. Some states and private foundations have been supporting this work. Some requirements of federal law, such as human subjects protections, apply to state- and privately funded stem cell research. For a complete discussion of the mechanisms for oversight of stem cell research, see the National Academies’ report Guidelines for Human Embryonic Stem Cell Research.
It is legal to conduct research using blastocysts and to derive new cell lines in most states, with some exceptions. Because stem cell legislation is an area of active debate, please visit the National Conference of State Legislatures to learn about the laws in a particular state.