Ethics of a New Science

By Claudia Wallis

People who object on moral grounds to research using human embryonic stem cells might be surprised to learn that scientists too are struggling with ethical dilemmas. In the past when a controversial new technology came along--recombinant DNA, for example--the National Institutes of Health (NIH) would set the scientific and ethical standards for research. But with embryonic stem cells (ESCs), the NIH has been hamstrung by President Bush's 2001 order allowing it to fund only research using the limited and imperfect cell lines already in existence--not exactly cutting-edge science. Relegated to a minor role in the field, the NIH thus has not done its usual job of defining the field's perimeters. To the relief of researchers, the National Academy of Sciences stepped in last week with a 131-page set of recommendations. They arrived just in time to be put to use by the new California Institute for Regenerative Medicine, which plans to fund $200 million in human ESC research beginning this summer. Some of the guidelines:

>>> NATIONAL AND LOCAL OVERSIGHT

Labs doing this research should run proposed studies past a review board with community members as well as scientists. A national panel should review the rules as science advances.

>>> NO PAYING FOR HUMAN EGGS

Unlike egg donors at fertility clinics, women who donate eggs for ESC research should not be paid for their services.

>>> LIMITS ON GROWING EMBRYOS

No human embryo should be grown in a lab more than 14 days--when the first primitive streak of a nervous system appears. (This is already common practice for in-vitro-fertilization labs.)

>>> NO TRANSPLANTS INTO LIVING EMBRYOS

Human ESCs may not at present be transplanted into an early human embryo--a promising avenue for therapy but one that raises the specter of bioengineered humans.

>>> SOME TRANSPLANTS INTO ANIMALS ARE O.K. ...

Experiments in which human ESCs are implanted in animals--to study the development and treatment of diseases--should be permitted but tightly regulated by review panels.

>>> ... BUT OTHERS ARE NOT

Certain types of studies with human-animal chimeras should be banned for now. Human ESCs should not be implanted in the embryo of another primate where, potentially, a partly human brain could develop, but implants in mice would be permitted. Animals seeded with human ESCs should not reproduce.

>>> WHERE WE GO FROM HERE

The guidelines aren't binding but will probably be embraced by academic and commercial labs across the U.S., making collaboration easier. Foes of the research, who object that embryos are destroyed to create stem-cell lines, called the document a futile effort to bring moral clarity to an immoral field. --By Claudia Wallis