In the Middle Ages, the alchemists believed someday they’d find a magical tool that could transmute lead into gold, metals into medicines and plants and animal tissues into powerful elixirs — a panacea that would cure all diseases and prolong life indefinitely.
This week, it appears that the object of their long-ago yearnings has been discovered.
Scientists announced they have reprogrammed the genes of ordinary cells from human skin to make what I'm terming "panacea" cells. These cells can be used to create embryonic-like stem cells that one day could fix many different disorders and diseases that are now beyond cure.
The series of incredible discoveries burst on the scene starting with the announcement last week that a team of scientists in Oregon had successfully cloned monkey embryos, pointing the way to the cloning of humans and offering a method for making repair kits out of the body’s own cells.
Hard on the heels of this announcement came one by Shinya Yamanaka, a leading Japanese genetics researcher, who revealed in the journal Cell that he has successfully extended the technique he used with monkey cells to human cells. By using a virus to create changes, he was able to tweak four genes in adult human cells and get the cells to revert back to an embryo-like state.
The Japanese work coincides with similar findings at the University of Wisconsin published in Tuesday's issue of the journal Science. Under the direction of stem cell pioneers James Thomson and Junying Yu, the group has also gotten cells to act like embryos by tweaking four genes in adult human cells.
Who will get the credit for making the breakthrough discovery that turns adult cells into sources of stem cells? I don’t know. A huge and probably nasty battle is likely to quickly erupt over priority and patenting in this area. Given the potential payoffs involved, the fight will likely keep lots of lawyers busy for years to come.
Why are these discoveries so important? In layman’s terms, the Wisconsin and Japanese teams have discovered a way to not only turn cells into stem cells but, because they can be put back into the body of the person they were developed from, there’s no fear of rejection.
The embryo issue
One more bit of exciting news is that if these techniques hold up, there’s no need to use human embryos as a source of stem cells. In fact, cells produced from human embryos would be less desirable, not just because there is no need to obtain and destroy embryos to get stem cells but also because the reprogrammed panacea stem cells would be genetically the same as the recipients.
In theory, these cells would act just like stem cells made from cloned human embryos making that technique unnecessary as well. That is why cloning pioneer Ian Wilmut, who created Dolly the sheep, announced a few days ago that he is abandoning cloning as a technique for making stem cells.
Still, the reprogrammed panacea cells aren't free of problems or moral dilemmas.
First, the creation of panacea cells uses viruses to get the reprogramming done. Those who have worked with gene therapy know that retroviruses do not always put genetic material where it is supposed to go. That could prove to be a problem, but happily it is a lot easier and far less risky to do gene therapy in cells than it is to do it in human subjects.
Pursue all avenues
Second, it is a bit too soon to stop working on cloning as a technique to generate stem cells. Even though these announcements are momentous, until a reprogrammed panacea cell is used to make stem cells that actually function properly to repair a damaged nerve, spinal cord or heart, all avenues of research must be funded and pursued.
Lastly, some may wonder if a reprogrammed panacea cell acts like an embryo, should it then be classified as a human embryo?
True, a reprogrammed cell cannot implant in the womb but it can do everything else an embryo does. Is this form of genetic engineering a solution to the issue of avoiding human embryo destruction or merely a new route to a similar destination?
My view is that genetically altering body cells creates something that does not have the same moral standing as what is made from a sperm and an egg. That is why I favor continued work to create cloned human embryos as well.
These problems are not likely to impede research with reprogrammed panacea cells for very long. That means that someday we will have one of the key bioethical debates of the 21st century: Is it right to repair ourselves if it means that we live much longer than any human being has ever lived?
Arthur Caplan, Ph.D., is director of the Center for Bioethics at the University of Pennsylvania.