Published in Volume 48, Issue 4.
UWMC Professor of Philosophy Mark Brown doesn’t work in a biology laboratory, but his research examining the bioethics of embryonic stem cells has raised important questions for this new frontier.
Scientific Background
Cells having the ability to transform into specialized types of cells are known as stem cells. A stem cell might become heart tissue, skin, or part of your eye, for example. Stem cells can be found in human embryos and in adult tissue. In human embryos, stem cells are present during the blastocyst phase, about four to five days after the development of a zygote, the single cell produced by fertilization. Adult tissues also contain stem cells in tissues such as bone marrow, blood, skin, and several other locations. Adult stem cells allow some tissues to regenerate.
The main difference between adult stem cells and those derived from an embryo is the difference in potential for the cell to differentiate or transform. Human embryonic stem cells are pluripotent, meaning they can transform into many different types of cells. The ability of an adult stem cell to differentiate is more limited and in some cases the cell may only transform into closely related cells. Thus, research has tended to favor using embryonic stem cells, despite rapid growth which could result in tumors. The potential applications for stem cell research include organ and tissue regeneration, brain disease treatment, cell deficiency therapy, blood disease treatment, and development of pharmaceuticals.
Recent research has revived interest in adult stem cells which may be stimulated to function as induced pluripotent stem cells (iPSC), first derived from human adult stem cells in 2007 by UW-Madison cell biologist James Thomson and his Japanese colleague Shinya Yamanaka at Kyoto University in Japan.
The Bioethics of Embryonic Stem Cell Research
In 2009, Brown published a paper in the Kennedy Institute of Ethics regarding recent advances in stem cell research which gained him national notoriety. As a result, he was invited to present a paper at the Stem Cell World Congress in San Francisco in January 2010. There, he became acquainted with other scientists and was invited in December 2010 to the Third Annual World Congress of Regenerative Medicine & Stem Cells in Shanghai, China. After making his presentation at the conference, Brown made contacts with other researchers who were interested in collaborating on projects and was approached by editors of journals who requested that he submit articles. Brown was also invited to several other important events pertaining to stem cell research.
His paper, “Complicity Complications in Induced Pluripotent Stem Cell (iPSC) Research,” drew the attention of many in the scientific community and established Brown as a leading expert. Pluripotent cells can be made available from the direct reprogramming of human skin cells. This technique might avoid the perceived evil of destroying embryos, but introduces other types of moral complicity which Brown explores in his paper.
First, the development of induced stem cells, derived from existing human tissues, occurred within current human embryonic stem cell research programs. Because the latter research entails the destruction of a human embryo, ethical questions were raised in part by religious leaders who believe that life begins at conception. “This new research (iPSC) was built on the back of the previous research, so it’s all part of the same program,” said Brown.
Second, although iPSC research attempts to avoid their use, additional lines of human embryonic cells may be needed to effectively transition to the practical use of iPSC in medicine. To gain insight into how pluripotent cells transform into particular tissues in the human body, researchers need to first examine how the process works in human embryonic cells. Only then does iPSC research hold promise for discovering medical treatments. “The two research activities happen in parallel,” said Brown. He compared the situation to basic experimental design in science. In order to make sense of how a process works when manipulated by a scientist, that process must be understood as it occurs without interference. Thus, human embryonic cells are the control group in this experiment while iPSC research is the variable. To put it another way, iPSC research simulates the natural process that occurs in human embryonic cells. Before that simulation can occur with confidence, the natural process in human embryonic cells must be uncovered. Moral complicity therefore weighs on both areas of research.
Third, the paper advocated the use of an expert panel to assess the ethical implications of using these additional human embryonic stem cells in iPSC research. For example, in the United States, Brown thought this panel could be established by the federal government in the National Institutes of Health. Its purpose would be to determine the degree to which new embryonic stem cells need to be derived in order to develop alternatives. Are there enough embryonic stem cells available for research and if not, how many more will be needed to make the research successful? In answering this question, the panel—and therefore the scientific community—is showing sensitivity to those who think stem cell research is unethical and who would limit research to only that which is necessary. Another purpose of an expert panel is to give a voice to stakeholders in the research process—individuals with religious objections as well as patients advocating research that could potentially impact their treatment.
Brown will continue to pursue the field of bioethics and stem cell research. Brown’s next paper, “No Ethical Bypass for Moral Status in Stem Cell Research,” will be published this spring in the international journal Bioethics. Much of the funding for independent research in bioethics is provided by state and federal governments. The new political mentality recently enacted in U.S government calls for across-the-board cuts in spending, including research programs. However, Brown is optimistic that funding for bioethics will continue because of its important economic and social impact.
Brown attended the University of Kansas where he completed his Ph.D. in philosophy. Beyond bioethics, his research interests include the philosophy of mind and personal identity. Brown has previously published research on dissociative identity disorder. Brown’s interest in bioethics was spurred by teaching a philosophy course in the subject. As he began to explore biothics, the abstract and metaphysical questions that Brown was so familiar with became the real-world concerns affecting the lives of many.
A colony of human embryonic stem cells (center, blue) from the lab of the University of Wisconsin-Madison’s James Thomson. These cells, which arise at the earliest stages of development, are blank slate cells capable of differentiating into any of the 220 types of cells in the human body, and can provide access to cells for basic research and potential therapies. Photo: Clay Glennon/Thomson Lab