Last year, researchers in the US and Japan shocked the world of cell biology by successfully transforming regular adult cells (like skin cells) into the equivalent of embryonic stem cells without needing to use or harm human embryos. The technique has since spread like wildfire in the field, not only because it avoids ethical problems (and therefore political controversy and public funding restrictions) but also because it is a great deal easier and cheaper than working with embryos and seems so far to yield the same results. Researchers all over the world have been trying and tinkering with the technique to improve its efficiency, to eliminate the need to use genetically engineered viruses to reprogram the cells, and to look for other applications of the lessons this new technique suggests about how cells function.
Today, the journal Nature announced an extremely important—and again frankly quite shocking—new advance discovered as a result of this flurry of work. A team at Harvard has succeeded in directly reprogramming one type of adult cell into another, without even the need for the intermediary step of reprogramming to a pseudo-embryonic state and only then differentiating to a new developed cell type. In other words, not only do they not need embryos, they don’t even need stem cells at all; they can just turn one type of cell into another directly. What’s more, they’ve done this inside a living animal (a mouse), and not just in a laboratory dish.
Working with a diabetic mouse, the researchers were able to transform regular pancreatic cells into beta cells (the far more rare cells that produce insulin, and are destroyed in diabetes patients) by inserting only three genes into the pancreatic cells. The mouse began to produce insulin, and its blood sugar levels were reduced.
Now mice aren’t men, and the application of this method to human diabetics and patients with other diseases is by no means on the immediate horizon; it may of course never materialize, as diabetic mice have been cured before. You can never be sure, and especially not after just one experiment. But whatever the eventual clinical applications, the implications of the work for cell biology are extraordinary—that sound you hear is PhD-level textbooks being thrown in the garbage all over the world.
The implications for the ethical debate over embryonic stem cell research are also very significant, since this takes the locus of work in the field even further away from the embryo, and suggests yet again, and with greater force, that the outcomes researchers have valued about embryonic stem cell work could very well be achievable without the use of embryos, and without any ethical concerns whatsoever. Science and ethics, as President Bush has so often put it in arguing for his funding policy, need not be at odds, and can be championed together.
So far the best popular press coverage I’ve seen of the study this afternoon is this Washington Post story.