Back in August, I and several others in the scientific community expressed skepticism over Nature paper (subscription required) describing a new technique billed by the media as generating “ethically sound” stem cells. The technique involved removing a single cell from an eight-cell blastula and using this cell to derive a line of stem cells while allowing the remaining cells to grow and develop normally, without any apparent damage to the embryo. This “watered down” approach to generating stem cells didn’t seem to convince other scientists, and it apparently (although not surprisingly) didn’t go far enough for the hardcore anti-research religious extremists.
This topic has resurfaced again this week, as a newly-revised paper, authored by Klimanskaya et al., appears in the current issue of Nature. (It was originally an advanced online publication on August 23rd.) The new version is almost identical to the original, except for a few minor changes described in an addendum and a new supplementary information document. The changes, in addition to adding more information, serve primarily to tone down some of the paper’s conclusions, particularly the ones that led to its initial overhype in the media. These changes seem appropriate, and probably should have been in the original version.
I’ll stress as I did before that my main problem here was with the media coverage of the paper, not so much with the paper itself. However, my initial skepticism remains. For a detailed account of the scientific issues/questions at play here, read Jake’s initial post on the issue at Pure Pedantry. For a brief summary, though, here’s what I originally wrote:
When it comes down to it, this technique appears unsatisfactory for ending the current debate either way you look at it. If the technique is validated, and it can in fact produce 100% totipotent embryonic stem cell lines without harming the original embryo, this would mean that the cell used to generate the stem cell line would itself be capable of developing into a human embryo under the right conditions. Since the opposition to embryonic stem cell research generally takes the very narrow view that a fertilized egg is the moral equivalent of a fully grown and developed human being, this probably won’t due much to appease these opponents. Remember, these people prefer to let the extra embryos generated by in vitro fertilization procedures go to waste, instead of using them to generate much needed human embryonic stem cell lines.
On the other hand, if the technique is demonstrated to be significantly less effective than traditional means of harvesting human embryonic stem cells–as seems to be the case–then it is not an acceptable alternative. Although this method shows more promise that some of the other alternatives previously proposed, including creating genetically-altered embryos incapable of completing development, it remains imperative that we continue to try to make the case for the accepted and proven techniques of generating human embryonic stem cells. Instead of giving in to religious zealots, we should instead make sure the ethical debate is fully informed.
I still stand by this argument, and I think it’s been borne out in reality pretty well, especially since The Southern Baptist Convention eventually expressed its opposition to the technique.