The paper by Magill and Neaves in this issue of the Journal attempts to rebut the "natural potency" position, based on recent advances in direct reprogramming of somatic cells to yield "induced pluripotent stem" (iPS) cells. As stated by the authors, the natural potency position holds that because "a human embryo directs its own integral organismic function from its beginning . . . there is a whole, albeit immature, and distinct human organism that is intrinsically valuable with the status of (...) inviolability and deserving full moral respect" (p. 26). The authors boldly assert that "The recent production of iPS . . . highlights a prima facie absurdity for the natural potentiality argument" (p. 29). Yet the argument against natural potency is both logically flawed and based on a characterization of the scientific evidence that is factually inaccurate. (shrink)

The recent successful conversion of adult cells into induced pluripotent stem (iPS) cells through direct reprogramming opens a new chapter in the study of disease and the development of regenerative medicine. It also provides a historic opportunity to turn away from the ethically problematic use of embryonic stem cells isolated through the destruction of human embryos. Moreover, because iPS cells are patient specific, they render therapeutic cloning unnecessary. To maximize therapeutic benefit, adult stem cell research will need to be pursued (...) in parallel with studies using iPS cells. Among the four alternative methods presented by the President’s Council on Bioethics, direct reprogram- ming is the most ethically acceptable. Nonetheless, iPS cells are tainted by their association with the human embryonic stem cell lines, derived in the past, which will be required for their validation. This concern is one that can be resolved. Human iPS cells will serve to stem the tide of human embryonic stem cell research, changing it and diverting stem cell research in a more ethical direction. (shrink)

Direct reprogramming of human skin cells makes available a source of pluripotent stem cells without the perceived evil of embryo destruction, but the advent of such a powerful biotechnology entangles stem cell research in other forms of moral complicity. Induced pluripotent stem cell (iPSC) research had its origins in human embryonic stem cell research and the projected biomedical applications of iPS cells almost certainly will require more embryonic stem cell research. Policies that inhibit iPSC research in order to avoid moral (...) complicity are themselves complicit in preventable harms to patients. Moral complicity may be unavoidable, but a Blue Ribbon Panel charged with assessing the need for additional embryonic stem cell lines may ease a transition from embryonic stem cell research to clinical applications of iPS cells. (shrink)