Delivering on the promise of human stem‐cell research. What are the real barriers?

The therapeutic potential of human embryonic stem cells (hESCs) is one of the most controversial and hotly debated areas of scientific research. The stem‐cell debate largely revolves around the ethical implications of two techniques that involve the manipulation of human embryos: the derivation of pluripotent hESC lines from surplus embryos created for the purposes of assisted reproductive technology (ART), and the use of somatic cell nuclear transfer (SCNT) to generate a blastocyst from an enucleated egg and an adult somatic cell in order to produce an hESC line that will be immunologically compatible with the donor of the nucleus. The most common argument against hESC research is that both techniques involve the destruction of human life, which, according to opponents, begins at conception. Ironically, these same people often support in vitro fertilization (IVF) technologies, despite the fact that IVF clinics routinely discard surplus embryos, which are the main source of hESC lines. As this view has rarely been decisive in the public debate, opponents have reinforced their argument by claiming that hESC research is unnecessary because adult stem cells (ASCs) have the same therapeutic potential as hESCs. Advocates of hESC research counter that ASCs will never be pluripotent or sufficiently able to expand into stable cell lines, which are required for both basic and applied research to develop cures against a range of devastating illnesses, such as Alzheimer and Parkinson diseases, or to repair spinal cord injuries. This ethical controversy has been regarded as a major barrier to research, but here we argue that its impact has been less damaging than previously thought. In fact, the debate—and the media coverage and public interest that it has created—might have been beneficial for stem‐cell research. In addition, the ethical arguments against hESC research have overshadowed other potentially important legal, regulatory, political and …