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 is a 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 because I have seen things happen in stem cell research that others haven’t. In my collaboration with Renee Reijo Pera, PhD, we have been developing adult stem cells that would not involve embryos, or viruses, and that would not be rejected by the body.
Stem Cell Research
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 line” or reproductive cells. Much later 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.”
Environments Matter
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 have 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 care to produce their transcendent fruit. Both require a delicate touch.
Fruits of Labor
So, slowly, and 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 form the different layers of the body, including nerve, in a dish. What is still not clear from all 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 several years of research are for. In any case, this discovery may help to bypass the whole moral debate surrounding embryonic stem cells as these cells are not embryonic in origin. 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 work may be as earthshaking as the discovery of antibiotics a century ago. Stem cell research could be even more transformative than this. May the wonder and awe from scientific discovery never end.
Update: Since this post was written in 2009, stem cell research has evolved significantly. Human sperm have not been made yet in a dish, but the process of getting there has been simplified. Thanks to CRISPR technology and mRNA technology (think the COVID vaccine), the path from stem cell to sperm is a much clearer one.
Like wine, stem cell research is getting better with age, and it may not be long before it can help men with the most serious fertility problems to become fathers.
