Other bioethicists have tried to avoid a moral controversy
Stanford bioethicist William Hurlbut's proposal for growing the equivalent of embryonic stem cells without creating a human embryo is not the only possible way to avoid the moral controversy that has surrounded the cells.
In Worcester, Advanced Cell Technology is reviving work on a technique called parthenogenesis, in which an egg cell is stimulated to begin developing without being fertilized by sperm. Though this method of reproduction occurs commonly in insects, it does not occur naturally in mammals. But ACT scientists succeeded in getting an egg from a monkey to grow to the point where scientists could harvest embryonic stem cells. Because such a parthenote, as it is called, typically does not survive more than a few days, some scientists hope that it will not be seen as a potential life meriting ethical protection. Researchers at ACT were close to showing the technique can be made to work with human eggs when the program had to be stopped for lack of funding, according to Dr. Robert Lanza, the company's medical director. This month, he said, the company restarted its program and the work is underway.
In China, a scientist reported that she was able to derive human embryonic stem cells by taking a nucleus from a human cell and placing it in the egg cell of a rabbit. Since this process could never lead to a viable being, some researchers see this as a way around ethical objections, but the scientist's work has not been replicated -- and combining human and animal cells raises other moral concerns.
Scientists know how to remove a single cell from an embryo without destroying the embryo. Some have suggested that it might be possible to use this single cell to create a new line of embryonic stem cells.
Looking ahead, some speculate that scientists could discover a way to reverse the normal process of development, coaxing an adult cell to become an embryonic stem cell with the potential to become any other cell. Unlike other approaches, this would not require the use of human eggs.
-- Gareth Cook
