Organisms can be cloned through a process called somatic cell nuclear transfer (SCNT), in which the nucleus of a somatic cell from the patient to be cloned is inserted into an enucleated egg, which is then stimulated, resulting in a new embryonic member of the species who is genetically virtually identical to the patient. Researchers have long tried, unsuccessfully, to develop cloned human embryos to the stage at which the derivation of stem cells (thereby killing the embryo) is possible.
In the new research, published in Nature, a team of scientists tinkered with the standard SCNT technique. They inserted the somatic cell nuclei into eggs that had not had their nuclei removed. Thus, the resulting cloned embryos each had 23 extra chromosomes. They were "triploid," a genetic abnormality that prevents a human being from living very long (at most, triploid babies live for some months after birth).
The "breakthrough" is that the researchers successfully derived stem cells from those triploid embryos (destroying the embryos in the process, of course). But those stem cells are useless because they are triploid, so the scientists are hoping in the future to somehow remove the extra set of chromosomes.
Even if they succeed, the merit of this approach is questionable. The main purpose of human cloning research has been to create patient-specific pluripotent stem cells. But we can do that already, and do so ethically, by using direct reprogramming to create induced pluripotent stem cells (iPSCs). Making iPSCs is also much more efficient. According to the Wall Street Journal story, "The [new] technique [reported yesterday] is very inefficient. Dr. Egli and his colleagues said they started with 270 eggs and created 13 early-stage embryos. From these, they obtained only two viable stem cell lines."
Moreover, human pluripotent stem cells -- whether iPSCs or embryonic stem cells derived from either cloned embryos or embryos resulting from in vitro fertilization -- have not been therapeutically useful in any way. Every successful stem cell treatment has used ethically-derived adult stem cells.
Most importantly, the new research is deeply unethical. First, human cloning is wrong in itself, and these researchers are using it to create new human organisms to then kill for their useful parts, which is even worse. In fact, as scientist-blogger Rebecca Taylor writes, "These scientists intentionally created human lives that they knew would have a devastating genetic condition and then destroyed them for cells that they knew could never be used to treat anyone. This is beyond morally offensive, it is downright evil."
Second, egg harvesting poses a real risk to women, and according to the Washington Post:
The research [announced yesterday] was possible because for the first time scientists paid women for their eggs for human embryonic stem cell research, stirring worries about women being exploited and putting their health at risk. At the same time, the researchers made the cells by producing and then destroying mutant embryos, whose moral status immediately became a matter of sharp debate. ...For more on this latest development in embryo-destructive research, see comments from Wesley J. Smith and Dr. David Prentice. Learn why human cloning is wrong here, and learn more about the dangers of human egg harvesting here. Learn more about ethical adult stem cell research -- the only kind that is actually helping patients and saving lives -- here.
A political cross section of scientists, women's health advocates and bioethicists also expressed concern about paying women for the millions of eggs that would be demanded if the work ever led to treatments for common diseases. Egg donation requires risky hormone injections.
