Nobel Bioethics

Two of the Nobel Prize winners announced yesterday for Medicine or Physiology have something in common besides their groundbreaking work on how cells copy chromosomes. Elizabeth H. Blackburn and Carol W. Greider both served on presidential bioethics commissions. Blackburn, of the University of California, San Francisco, was a member of the George W. Bush President’s Council on Bioethics. Greider, of Johns Hopkins University School of Medicine, served on Bill Clinton’s National Bioethics Advisory Commission. They shared this year’s Nobel equally with Jack W. Szostak of Massachusetts General Hospital for their discovery of “how chromosomes are protected by telomeres and the enzyme telomerase.”

As members of bioethics commissions, both Blackburn and Greider held progressive views on human embryonic stem cell research, and in Blackburn’s case those views had consequences.

Then-chairman Leon Kass appointed Blackburn to the President’s Council on Bioethics in 2001 as one of the original 18 members. Three years later, her membership on the Council was not renewed. [CORRECTION: This post originally stated, incorrectly, that Blackburn was dismissed from the Council.] In her dissenting opinions to the Council’s 2002 report, “Human Cloning and Human Dignity: An Ethical Inquiry,” she disagreed with the Council’s recommendation for national moratorium on somatic cell nuclear transfer. SCNT is a process of “therapeutic cloning” that could be used to produce lines of human embryonic stem cells. She argued that SCNT research is important, and that a ban would slow stem cell science while patients continued to suffer.

Furthermore, she argued that the Council intentionally omitted from their report the results of pertinent experiments indicating the value of SCNT for treatment of disease. Despite the reassurances she received from Kass and others that the science would be fairly represented, Blackburn has stated that, “the best possible scientific information was not incorporated and communicated clearly in the council’s report, suggesting that the presentation was biased.”

Apparently voicing ideas contrary to those of Kass and President Bush was grounds for terminating her Council service. Dean Clancy, the executive director of the Council, claimed that the non-renewal was not politically motivated. However, Blackburn took the opportunity to openly share her criticisms of the Council in the New England Journal of Medicine and in PLoS Biology. Blackburn recalled that, “In a telephone call from the White House one Friday afternoon in February, I was told that my services were no longer needed. The only explanation I was offered was that ‘the White House has decided to make some changes in the bioethics council.’”

Carol Greider, as a member of the National Bioethics Advisory Commission, lent her input to a 1999 report recommending that the federal government not fund SCNT research at the time, but that “scientific progress and the medical utility of this line of research should be monitored closely.”

Until the discoveries of Blackburn, Greider, and Szostak, it had remained a mystery how a cell’s genes could be replicated without also losing the genetic information contained at the very ends of the chromosomes.

Telomeres are “cap-like” ends of chromosomes, which consist of strands of DNA. When cells divide, copying the genetic material in their chromosomes, telomeres diminish in length. Telomerease is an enzyme that can prevent this erosion, lengthening the life of many cancer cells. The scientists’ work is significant for understanding aging and cancer.

The aging process (and eventual death) of a cell, which corresponds with the shortening of its chromosomes and resultant inability to carry out its specified function, is caused by diminished levels of telomerase. One might therefore hypothesize that the key to a cell’s “immortality” lies in the maintenance of optimally high levels of telomerase—yet such conditions are the mark of a cell stricken with cancer. Thus, their findings not only advanced our understanding of basic cell operation, but have potentially laid the groundwork for breakthroughs in both anti-cancer and anti-aging research and treatment.

Hannah Zale is an intern with the Progressive Bioethics Initiative at the Center for American Progress.

Tags: bioethics, nobel, stem cells

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