This past week a paper came out in Nature that reported the successful production of human ES cells using somatic cell nuclear transfer (SCNT) technology.
It is no exaggeration to say that this paper generated massive international media coverage, in part because of the links between this technology and the potential for human cloning, both the potentially positive kind (therapeutic) and the negative (reproductive). Interestingly, most stem cell scientists kind of went “ho hum”.
We did a poll on stem cell scientists’ level of interest in studying these new human ES cells and so far 84% of respondents say they are not interested. Most likely the reason is that the cells are highly abnormal having three instead of the normal two sets of chromosomes.
Of the leading stem cell scientists quoted in the media and of those I have spoken too, most express a generally similar perspective: this paper represents an advance, but it is not a major one. Perhaps this paper is the first one to report this kind of technology at least in part because no one else figured that using an approach without clinical relevance due to the abnormal chromosome number was worth pursuing. I think it is likely others tried this approach, however, and failed because they simply weren’t as technically adept as this team.
Conceptually, the idea that the human oocyte cytoplasm could reprogram a human somatic cell nucleus is cool to have proven, but given all we know and the proven ability to reprogram human somatic cells into iPS cells, pretty much everyone assumed it was possible if one ironed out technical issues.
I think this is a very important paper, but I echo the views of other, more famous stem cell scientists including George Daley, Bob Lanza of ACT, and Miodrag Stojkovic that it is difficult to see the clinical relevance. Lanza was quoted that the method has “no clinical relevance”.
Some readers have asked me why this paper ended up published in Nature if the cells produced are genetically abnormal and do not have clinical relevance.
It is a proof of concept paper and the concept is big, but it provided no major advance in clearing the hurdle of answering the question of why removing the human oocyte nucleus seemingly prevents successful reprogramming. What a fantastically important question.