Developments alter cell-scape

Recent breakthroughs alleviate some early ethical concerns in stem cell research.

Kirk Allison

A wise non-scientist once said, âÄúYou must first define your terms before you can meaningfully discuss them.âÄù The Dec. 12 Minnesota Daily editorial âÄúStem cell research lines multiplyâÄù attempts to do so but misses the mark, leaving out important scientific developments relevant to ethical concerns expressed by prominent embryonic stem cell researchers. First, for clarity, the editorial states, âÄú[f]or anyone not familiar, there are two main types: totipotent embryonic stem cells, which have the ability to become any type of tissue, and pluripotent adult stem cells, which have the ability to become most types of tissue.âÄù This is not accurate in number or kind, leaving the reader without important information for discussing the ethical issues as well as technical possibilities. According to the National Institute of HealthâÄôs Stem Cell Glossary, totipotency involves cells that have âÄúthe ability to give rise to all the cell types of the body plus all of the cell types that make up the extra-embryonic tissues such as the placenta.âÄù Totipotency also includes the possibility of generating a new organism and supporting structures (as with a zygote in twinning). Pluripotency, however, involves stem cells with an ability to produce all types of body tissues as well as self-renew. Until recently, all pluripotent stem cells were embryonic (including those derived from in vitro fertilization clinic embryos such as those indicated in the editorial). A newer source of pluripotent stem cells are induced pluripotent stem cells (iPSCs) and protein-induced pluripotent stem cells (piPSCs). These are reprogrammed from an adult cell, such as a skin cell. The former used a retrovirus to insert first four, then three genes to eliminate a cancer-related factor and to achieve reprogramming. The latter succeeded, using standard recombinant techniques without gene insertion. The editorial writer appears unaware of this breakthrough of great technical and ethical importance; the newer techniques can produce tissue-matched desirable pluripotent stem cells without destroying embryos or requiring embryo cloning. In essence, the method avoids instrumentalizing and commodifying developing human life. The development of these techniques was driven by the ethical concerns of using spare embryos by embryonic stem cell researchers James Thomson, who discovered human embryonic stem cells, and Hinyana Yamanaka in Japan. âÄúWhen I saw the embryo, I suddenly realized there was such a small difference between it and my daughters,âÄù said Dr. Yamanaka, 45, a father of two and now a professor at the Institute for Integrated Cell-Material Sciences at Kyoto University. âÄúI thought, âÄòwe canâÄôt keep destroying embryos for our research. There must be another way.âÄô âÄù It was by attending to the ethical unease that the breakthrough came. In all developments on the pluripotent stem cell front, the science is early and developing. Still a central ethical tension concerning stem cell research and possible future therapies is addressed more effectively by iPSCs than by instrumentalizing even âÄúspareâÄù embryos. Certainly, the University of Minnesota should be prioritizing this line of research. Additionally, nonembryonic pluripotent stem cell sourcing will also avoid creating a future inequity: a market for the oocytes (eggs) required for embryo cloning. The 2005 United Nations Declaration on Human Cloning recognizes not once, but twice, the danger of exploiting poor women in this regard and calls on member nations to adopt policies to prevent such exploitation in the application of the life sciences. Stem cell engineering is certainly an exciting and quickly changing field. There is a great opportunity to catch up on the latest developments from 8 a.m. until 5 p.m., Thursday, Dec. 10 at the symposium âÄúCurrent Stem Cell Therapies: The Engineering Behind Them and Improvements NeededâÄù in the Mississippi Room at Coffman Union. Hosted by the UniversityâÄôs Institute for Engineering in Medicine, registration is free for University students, staff and faculty. Registration is required. Kirk Allison, Director, Program in Human Rights and Health