Embryonic stem cells are occupying the minds of most US senators. While it is most pleasing to see cell biology in the limelight, ES cells present the political elite in Washington with one of the thorniest ethical debates in recent history. The pro-life lobby is caught between its ethical convictions and an increasing realization that the US is loosing ground to stem cell boom countries such as South Korea.
Enter Senate majority leader Bill Frist. The staunch pro-lifer recently demonstrated a change of heart that was true to his medical background: in a milestone speech to the Senate on 29 July, he firmly rebuked president Bush's threat to veto H.R.810, a bill passed in the House by a large bipartisan majority that would lift the ban on federal funding for research on ES cells derived after the 2001 freeze on 22 cell lines. In particular, the bill would allow the use of ES cells derived from frozen embryos left over from fertility treatment. After consulting with several scientists, Frist accepted the medical promise of embryonic over adult stem cells and argued for disbanding with the stifling limitations imposed on research by the handful of lines that are all but useless for clinical work. Frist rightly argues that close oversight has to be guaranteed to prevent financial incentives and to clarify who decides the fate of the leftover embryos. The predicted outcome of Frist's speech is a broader swing of the Senate behind bill S.471 when it reconvenes this month, which may be sufficient to overturn president Bush's promised veto.
Support for the bill is important, but it does not solve the ongoing stalemate on somatic cell nuclear transfer. Others have proposed ethically more palatable ways around the issue of the sanctity of embryonic life. Notably, William Hurlbut, who serves on the President's Council on Bioethics, suggests 'altered nuclear transfer', in which mutations in developmentally relevant genes would prevent embryonic development past early stages sufficient to yield ES cells. While initially attractive, this concept is marred with problems such as how to find a gene appropriate for human development that will not interfere with any other aspects of biology, as well as the difficulty in defining a generally acceptable transition point at which an embryo acquires moral status (discussed in N. Engl. J. Med. 351, 2791). A more promising suggestion is the use of parthenogenesis, which has been shown to work in other primates. While alternatives should continue to be explored and a strong research focus on adult stem cells should be encouraged, it is important not to nip the nascent but promising science of ES cell research in the bud. Instead the focus should be on a truly global and enforceable ban on reproductive cloning (Nature Cell Biol. 7, 323; 2005).
S.471 is an important first step and cell biologists would do well to discuss the issues and alternatives openly with senators at every opportunity before their crucial vote on this and related bills in September.
View background material on Connotea: http://www.connotea.org/user/bpulverer/tag/Embryonic%20stem%20cells.