How Are Stem Cells Like Wine Grapes?
Silicon Valley started in a small garage across the way from Stanford University by one man named Hewlett and another named Packard. There’s an historic plaque on that garage now, and a worldwide industry surrounds it. Stem cell research has just as much potential.
Last week, I mentioned that I was a believer, that I have seen things happen in stem cell research that others haven’t. Collaborating with Renee Reijo Pera, PhD at Stanford, we have been developing adult stem cells that would not involve embryos, or viruses, and that would not be rejected from the body. It all started when we put our heads together and thought hard about how sperm are made and how stem cells are grown. From this line of thinking, we concluded that the adult human testicle would be a great place to create a stem cell. Why? Because the first thing a developing embryo does as it begins to grow is to set aside cells and designate them as “germ” or reproductive cells. Much later on in fetal life, other tissues develop. So, germ cells are special and very closely related to embryonic stem cells; that is, they are very “stem like.”
The next problem, and a big one at that, was how to take adult stem cells and “reprogram” them to become embryonic-like stem cells. This took the better part of four years to figure out. And, like your grandmother’s great apple pie, the secret is in the recipe. Indeed, we found that just the right combination of feeder layers (a layer of cells in a petri dish which help the stem cells to develop) and bathing solutions were instrumental in nurturing these rare testis stem cells to become embryonic-like in a laboratory dish. I developed a lot of respect and a certain fondness for these rare and special cells through this process of discovery. The care lavished on them reminds me of winemakers and their finicky pinot noir vines, which require the right conditions and care to produce their transcendent fruit. Both require a delicate touch.
So, slowly, with persistence, we were able to generate a very “stem like” adult germ cell in a dish starting from a testicle. We showed that, like a real embryonic stem cell, this cell could begin to form the different layers of the body, including nerve, in a dish. What is still not clear from all of this work is exactly what kinds of body tissues can be made from this cell. Can we make an entire heart? How about a clavicle? Or can we just make sperm? This is what the next four years of research are for. In any case, this discovery may help to bypass the whole moral debate surrounding embryonic stem cells. There would also be no viruses to worry about, nor tissue rejection issues to dodge, because your body would simply be rebuilding itself.
Understand that this research is still in its infancy, but it’s a whole new world of medicine, where whole organs may be regrown, and sight and fertility restored. With more time, this kind of research may be as earthshaking as the discovery of antibiotics a century ago. Stem cell research is likely to be even more transformative than this. May the wonder and awe from scientific discovery never end.