It’s called “reprogramming.”
Another technical term for it is “somatic cell dedifferentiation.” Just get those terms into your vocabulary because they’ll be around for the foreseeable future. As reported in two scientific papers published today, reprogramming is now the future of stem cell research and renders ethically controversial therapeutic cloning obsolete.
Ever since the debate of embryo-destructive stem-cell research began in earnest in 1998 when researchers at the University of Wisconsin first isolated human embryonic stem cells, we’ve known that the best overall answer to the ethical impasse would be a solution that both allows the search for stem-cell related cures to go foreword, while doing so without harming or destroying embryonic human life in the process.
We now have that solution.
Two major scientific papers published today in Science and Cell offer proof of principle research to show that it is possible to generate patient-matched pluripotent stem cells without human cloning and its attendant moral pitfalls: the need to harvest and use human eggs from female donors and the subsequent destruction of cloned human embryos. Both studies used reprogramming of adult human cells to generate stem cells known as “induced pluripotent state cells” (iPSCs) that have all the properties of human embryonic stem cells.
When the President’s Council on Bioethics reported in 2005 on a number of alternative sources of the kinds of cells scientists were after — pluripotent cells, or cells with the capability of giving rise to all human tissue types for eventual therapeutic applications — one of those alternatives was hailed, hands down, as the best all-around solution: cell reprogramming. “We find this proposal to be ethically unproblematic,” wrote the Council members, “and acceptable for use in humans, if and when it becomes scientifically practical.”
In the highly contentious political battle over federal funding for stem-cell research, one cannot help but note that of all the current presidential candidates, only Governor Mitt Romney embraced an unambiguous and principled stance on the alternatives, incorporating them into his proposed domestic policy.
Reprogramming takes normal adult body cells — such as skin cells — and sends each cell’s nucleus back to a pluripotent state. In other words, the reprogrammed cells would then be capable of producing any tissue type in the human body — essentially equivalent in versatility to human embryonic stem cells. The reprogrammed cells would, furthermore, be genetically matched to the person who donated the original body cells. They could then be used to grow tissues for future use in tissue replacement therapies (everything from regeneration of damaged heart tissue to Parkinson’s to spinal-cord injury). A perfect genetic match, these tissues would not be rejected by the donor’s immune system. Most importantly, there would be no embryo created, destroyed, damaged or used in any way at any point in the process.
The papers were published by Shinya Yamanaka of Kyoto University, and by James Thomson of the University of Wisconsin, Madison. A year ago, the journal Cell published Yamanaka’s research in which he reported successes in reprogramming mouse cells by adding four key genes to those cells. His findings were like a shot heard round the stem-cell world. Almost immediately after his work was published, two additional teams of researchers set out to duplicate and, if possible, exceed Yamanaka’s findings.
In articles published on June 7 of this year in the journals Nature and Cell-Stem Cell, the three teams gave what most stem-cell scientists would consider definitive proof that Yamanaka’s four genes can, indeed, reprogram mouse cells to a pluripotent state.
And as if the rapid success in accomplishing that goal were not amazing enough, further astonishment accompanied the news that the second paper was submitted by Thomson himself, the veritable father of human embryonic-stem-cell research. It will remain a happy paradox of history that the very scientist who first isolated human embryonic stem cells in 1998, James Thomson now finds himself making history as a researcher who helps us get beyond the ethical impasse.
But this was not the only paradox making news over the weekend. A portent of news to reach the airwaves today, and a bombshell of a story in itself, the creator of Dolly the sheep, Prof Ian Wilmut, announced his decision to forego therapeutic cloning, just days after U.S. researchers announced a breakthrough in the cloning of primates. Wilmut’s announcement sent shockwaves through the scientific establishment. In an article published in the Telegraph last Saturday, Wilmut revealed that he has decided not to pursue a license to clone human embryos, which he was awarded just two years ago by Britain’s Human Fertilisation and Embryology Authority (HFEA). “This approach” — reprogramming, he was quoted as saying, “represents, the future for stem cell research.” So here we have both the scientist who gave us embryonic-stem-cell research and the scientist who gave us cloning both telling us that the cloning agenda is now obsolete and that the future of robust stem-cell research does not lie in embryos.
Ponder the meaning.
Like the unexpected climax of a romance novel, these historical paradoxes foreshadow a culmination to the ten-year tale of human embryonic-stem-cell research that is remarkably unlike anything we could have imagined. To be sure, a new day has dawned in the world of stem-cell research, thanks to the intellectual honesty and scientific acumen of researchers like Thomson, Wilmut and Yamanaka. The best part, of course, is that, for advocates of embryonic-stem-cell research, as well as for those opposed to embryo-destructive research, and especially for those millions of potential beneficiaries of stem-cell related therapies, the advent of the age of somatic cell reprogramming marks an enormous victory for all of us.
– Father Thomas Berg. L.C. is executive director of the Westchester Institute for Ethics and the Human Person, and member of the ethics committee of New York’s Empire State Stem Cell Board.