In yesterday’s column I said that, theoretically, embryonic stem cells could be used to replace cells that are killed by disease — heart cells killed in a heart attack, for example, or brain cells killed by Alzheimer’s disease. If you needed stem cells, what you would ideally want were your own embryonic stem cells. The dilemma: Your own stem cells existed only briefly, long ago, and you couldn’t turn back the clock. That is, until a research breakthrough in 2007 showed that you could.
As we discussed yesterday, embryonic stem cells and all the specialized cells have exactly the same genes within them. However, cells in the eye and stomach, for example, are so very different because different genes are turned on in each type of cell. A Japanese research team decided to see if a unique group of genes was turned on in embryonic stem cells. There were.
Then they asked an audacious question: What would happen if you placed into a fully specialized cell — like a cell in the skin — the activated genes seen in embryonic stem cells? The answer was so remarkable it was honored with the Nobel Prize. The skin cell turned into a cell (called an iPS cell) very much like that person’s long-lost embryonic stem cells. You could turn back the clock!
Since this discovery, scientists have been experimenting with using iPS cells to cure disease in animals. For example, iPS cells created from skin cells in mice have been transformed into specialized healthy blood and nerve cells — curing the mice of the equivalent of sickle cell anemia and Parkinson’s disease.
Other researchers have created iPS cells in order to study what goes wrong in certain diseases, and what treatments would be effective. Take Parkinson’s disease, for example. The cells that die in a person with Parkinson’s disease lie deep in the brain. You can’t just reach in and study them.
But you can take a skin cell from a patient with Parkinson’s disease and turn it into an iPS cell. You can transform that iPS cell into the type of brain cell that dies in Parkinson’s disease. Then you can see what medicines keep that cell from dying. This is being done today, for many diseases.
Of course, I’ve made this remarkable new technique sound simpler and freer of potential complications than it really is. Certain ways of creating iPS cells could possibly turn the cells cancerous. But new discoveries are reducing or eliminating that risk. Also, the technique still is quite inefficient and cumbersome, but new discoveries are making it simpler. Still, it will be some time before this new type of stem cell therapy affects medical practice in a major way.
Perhaps this remarkable breakthrough will achieve its full potential in helping us to understand and cure diseases. If so, it will show again how society benefits when we support the work of curious and talented scientists who seek to understand the basic processes of life.