Take a piece of skin and turn it into a heart, some muscle or a bone or two. Pure fantasy? Not at all. Last week, the Nobel Prize in Medicine was awarded to two scientists who laid the groundwork for this to happen. The field of regenerative medicine is entering its teenage years.
The Nobel Prize for Stem Cells
In 1962, Dr. Gurdon from Cambridge University first took the nucleus of an adult frog cell and injected into another frog egg without a nucleus. Lo and behold, the genetic program switched its duties from an adult cell to a developing egg. In one fell swoop, a maturity process once assumed to be utterly irreversible was found to be entirely reprogrammable. Forty-four years later, Dr. Yamanaka from Kyoto University (and my very own UCSF) found that just 4 small protein factors could accomplish this mammoth task and walk a mature, adult cell back to its primitive or stem cell form. The result: induced pluripotency stem cells (IPSs) and the Nobel in 2012.
Unlike embryonic stem cells that are made from human embryos and are plagued with political, ethical and moral issues surrounding their creation and manipulation, adult IPS cells are very different:
- They are made from adult human cells and involve no embryos.
- They can be “personalized” to contain the genetic material of any individual.
- They can do almost everything a human embryonic stem can do, which is alot.
The potential for IPS cells to become magic bullets to cure many types of diseases is great and is the basis of the field known as regenerative medicine.
Why I Like These Cells
For the last several years in the laboratory, we have been fashioning a working artificial testicle to cure many forms of male infertility. Ultimately, we hope to load the artificial testicle with these same IPSs from infertile men (and maybe women) and create mature sperm (and maybe eggs) outside of the body. Here’s how it might work. Think of a childhood cancer survivor who is cured, survives, but is unable to bear children as an adult due to treatment-induced sterility. Imagine taking a small skin biopsy from that young man, adding the four Yamanaka factors, and creating IPS cells in the lab in a few weeks. Then, envision loading those newly created adult stem cells into the fired up artificial testicle to provide the ideal environment for making wily, wiggly sperm in a dish.
Dreaming of the Day
There is nothing wrong with building castles in the air. But they certainly need to be built with hope, optimism and real solutions, rather than pipe dreams. This year’s Nobel Prize confirmed that these dreams are very much a part of reality. The final element in this puzzle is simple, and well stated by Paulo Coelho: “’Go and get your things,’ he said. ‘Dreams mean work.’”