Turning skin cells into embryonic stem cells
Last blog I talked about how I may have to be cloned to get my own embryonic stem (ES) cells. I was willing to deal with all of the associated ethical baggage because these sorts of cells would be so useful. They'll help cure many of my future ailments without my body rejecting these ES cells because they'll be made from my DNA.
This week a report has come out in Nature that may let me have my cake and eat it too (at least a few years from now). Scientists in Japan report that they can turn mouse skin cells into ES cells. And two other labs were able to repeat the result.
This is a really big deal. If we can get this to work in people, scientists can concentrate on finding cures. Instead of trying to find the money to do their research.
Two of the big opponents to ES cell research are the Catholic Church and the U.S. federal government. Neither is opposed to this line of research because it doesn't create and destroy a fetus.
This new procedure also eliminates some technical hurdles. For example, no one has actually successfully cloned a person. Now we won’t have to in order to make personalized ES cells.
Also, cloning requires lots of unfertilized eggs which are not easy to get. And harvesting them has its own set of ethical problems as well.
So how'd they do it? Scientists have been trying to figure out for a long time what genes are important for making a cell go embryonic. (Incidentally, you need to use embryonic stem cells to figure this out.) After a lot of work, they narrowed the number of genes in mice down to four. Just four.
So the scientists put those four genes into a mouse skin cell and selected cells that got all four genes. After a couple of weeks, they had ES cells. From a mouse's skin cell.
They then put these cells into a mouse embryo to see if these newly made ES cells could turn into different cell types. And they could. The mouse pups had parts that came from the original fetus and parts from the changed skin cell. This chimera was proof positive that these were indeed ES cells.
Of course we aren't to the Promised Land yet. One of the genes seems to cause cancer and killed around 20% of the mice. And we don't know if the same 4 genes work in people. And they haven't got the whole thing to work in people yet either.
But this work shows that it is possible to turn a skin cell into an ES cell. At least in a mouse. Eventually by continuing to work with human ES cells, they'll figure out how to get it to work in people too.
Dr. Barry Starr is a Geneticist-in-Residence at The Tech Museum of Innovation in San Jose, CA.