A Japanese research team has discovered a way to render somatic cells (in this case, blood cells) pluripotent, simply by bathing them in acid for under a half-hour. The pluripotent cells were generated in a mouse model, and when injected into a mouse embryo, contributed to all three of the developing embryo's tissue-types. They also exhibited stem-cell like growth capacity when cultivated with growth factors. The team are calling their creation STAP stem-cells, for "stimulus-triggered acquisition of pluripotency." The new method involved no nuclear transfer and no introduction of transcription factors.
If the method works in humans, it could be the key to practical regenerative medicine. A person in need of replacement pancreatic cells, for example, might be able to give blood or other tissue to scientists who could then, very quickly, create pluripotent cells from them, and then develop these into replacement tissue which would not be rejected by the recipients body.
This story in the New Scientist has a lot of excellent detail, but includes a side allegation that an unnamed collaborator of the researchers permitted some STAP cells to grow into "spherical clusters" and then implanted one of these into a mouse uterus. According to the story, a researcher's "understanding" was that the collaborator's experiment resulted in the creation of an embryo. The unnamed collaborator hasn't commented. This would be a big deal, as it would indicate that STAP stem-cells were actually STAT stem cells (totipotent, not just pluripotent), and it would constitute an embryonic cloning without nuclear transfer.
But this is still reprogrammed cells, aka induced pluripotent (iPSC) which haven't made it to human trial stage yet. Our own mesenchymal stem cells are what are already in human trials today. They are more effective if expanded in a lab. Here's the headcount on how many trials like this have been published, all showing safety, and signs of efficacy. http://www.patientsforstemcells.org/education/how-safe-are-stem-cells/
ReplyDeleteI note that your site declares that human iPS cells are the least safe of stem-cell types. Since there have been no trials in humans yet, there is no basis for that conclusion. iPS cells may indeed be just as safe as mesenchymal stem cells, when derived from the person they'll be used to treat. More importantly, there is no "choice" to be had between research on and use of MSCs and iPS cells; they have different functions and will likely be useful for different clinical purposes.
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