Current methods of generating embryonic stem cells involve removing the cells from a roughly five-day-old embryo, destroying the embryo in the process. Because of moral concerns about the destruction of an embryo, US president George W Bush has refused federal funding for the creation of new stem cell lines.
The new method draws on a technique called pre-implantation genetic diagnostics, or PGD, used by in-vitro fertility clinics to check for genetic defects in the embryo. In this technique, one of the embryo’s eight cells is removed; the remaining cells are able to grow into a viable embryo for implantation and might, therefore, overcome the administration’s restrictions on funding. According to the Nature paper, the single removed cell can divide to produce a line of normal embryonic stem cells.
While this new method may hold promise for the field of stem cells research, stem cell experts at Stanford have expressed some concerns over the announcement.
“From the scientific perspective, never believe anything until it’s replicated several times. That’s not an accusation of fraud, but science is full of honestly nonreplicable findings. It has to be able to be replicated reliably,” commented Hank Greely, professor of law and chair of the Stanford Center for Biomedical Ethics steering committee.
“On the ethics side,” he continued, “first it needs to be determined whether these cells can actually be done with embryos subject to pre-implantation genetic diagnosis without jeopardizing the viability of those embryos. This paper does not speak to that at all. They did not use PGD, though the authors say that is the way it should be done. The second ethics point is that some of the people who oppose research on embryos won’t view this as protecting an embryo, but as turning it into two embryos and killing the second. It will be interesting to see how much of the embryo-rights movement’s opposition might be weakened by this.”
Dr Irving Weissman, director of the Stanford Institute for Stem Cell Biology and Regenerative Medicine, also expressed concern that the newly created stem cell lines would mirror the genetic background of people undergoing IVF treatment. He said that he hopes to see stem cell lines from people with genetic disorders, such as diabetes, cystic fibrosis or Parkinson’s disease. Creating stem cells from the cells of people with those diseases would allow researchers to study how the disease develops and how the cells respond to drug treatments.
“While the work by Advanced Cell Technologies is very interesting and might be a potentially interesting additional way of procuring and developing embryonic stem cells, it is deeply misguided to think of this as a solution to the ethical controversy over human embryonic stem cell research,” added Dr David Magnus, director of the Stanford Center for Biomedical Ethics.