By Fr. George Welzbacher
December 2, 2007
Back in 1998 Dr. James Thomson of the University of Wisconsin at Madison announced that a research team of which he was captain had extracted stem cells from human embryos. The unprecedented availability of such stem cells as raw material for research seemed to offer all but limitless promise of scientific advance. The dark side was that in the process of extraction the human embryos were destroyed. Thus was precipitated an ethical debate of immense significance, the basic issue, being: is it morally permissible deliberately to destroy innocent human life so that good may come, the good in question being the securing of undifferentiated cells that have the capacity to turn into any desired type of specialized cell that the researcher wishes to study, with the ultimate aim of repairing diseased human organs. Though today, nine years later, the progress thus far achieved in curing disease from the study of human embryonic stem cells has been essentially zero, intense political pressure has been brought to bear to spend billions of state tax dollars in California and elsewhere (including Minnesota) to push full speed ahead with the destruction of human embryos in the name of humanitarian compassion. President Bush's resolute use of his power of veto over the allocation of federal funds to support research involving the ongoing destruction of human embryos is worthy of note and praise.
The man who headed the Madison research team back in 1998, Dr. James Thomson, has himself expressed misgivings about the ethical rectitude of what he and his team had done. As quoted by New York Times science reporter Gina Kolata in the November 22nd, 2007 issue of the Times, Dr. Thomson has declared: "If human embryonic stem cell research does not make you at least a little bit uncomfortable, you have not thought about it enough." Nevertheless he became the advocate of killing human embryos so that good might come.
Dr. Thomson must therefore have felt considerable relief when his Madison laboratory was able to announce on Tuesday, November 20th, that a team directed by Dr. Junying Yo, under Dr. Thomson's general supervision, was one of two teams-the other team was led by Dr. Shinya Yamanaka of Japan's Kyoto University-that have scored Through the insertion of four genes into the adult cells via a retrovirus a scientific triumph: the securing of human stem cells not from human embryos but from adult skin cells through a process of "reprogramming".the cells in question were turned back into their primitive pluripotent state. Thus human stem cells can now be obtained WITHOUT THE DESTRUCTION OF HUMAN EMBRYOS. As the distinguished priest- scientist Father Tad Pacholezyk exclaimed: 'This is the day we have been wailingfor!'"
This is indeed a historic moment in the battle for the recognition of the sacred and thus inviolable character of innocent human life. The importance of this breakthrough cannot be exaggerated.
I would therefore like to share with you the account of this triumph that appeared in The Wall Street Journal for November 23rd. The report was written by Maureen Condic and Markus Grompe. Dr. Condic is professor of neurobiology and anatomy at the University of Utah. Dr. Grompe, M.D., is professor of molecular and medical genetics at Oregon Health and Science University and director of the Oregon Stem Cell Center. Both are senior fellows of the Westchester Institute for Ethics & the Human Person.
* * * * *Stem-Cell Breakthrough
By.- Maureen Condic and Markus Grompe
For almost a decade now, embryonic stem cells (ESCs) have been heralded as a panacea for a range of ailments-from neurological disorders such as Parkinson's to failing organs in cancer patients. These remarkable cells do have the potential to bring medical advances: They can turn into every cell type of the body, and can provide a potentially unlimited supply of transplantable cells.
The trouble has been that ESC research came with a heavy price-the cells could only be obtained by destroying human embryos. This ignited an intensely polarized debate between those opposed to embryo-destructive research and others who thought that the therapeutic potential of the work justified the use of human embryos.
From early on, however, there were voices- Stanford University's William B. Hurlbut, a member of the President's Council on Bioethics, foremost among them-suggesting that this moral and political dispute could have a solution that was both scientifically and ethically acceptable: that science could solve the dilemma it created.
Now that hope appears to have been dramatically realized, and the landscape has radically changed. Two major scientific papers published this week in Science and Cell magazines unveil a proven way to generate patient-matched, human pluripotent stem cells.without human cloning, or animal eggs. Researchers have generated "induced pluripotent state" cells with the properties of human embryonic stem cells by direct "reprogramming" of adult cells. They produced cells like those derived from embryos, but without an ethical controversy.
Reprogramming now allows us to exploit the advantages of embryonic stem cells without destroying human embryos. Here's how it works: Adult cells are obtained from a skin biopsy by a procedure no more painful than a blood draw. The skin cells are grown in culture and then treated with a combination of our reprogramming factors, inserted into the adult cells with a gene-therapy virus. Within two to three weeks, the combined effect of these factors converts some of the adult skin cells into induced pluripotent state cells (iPSCs).
Remarkably, iPSCs have all the relevant properties that make embryonic stem cells so attractive: They grow indefinitely and can produce all cell types. The senior scientist of the American team is James Thomson, who first described human embryonic stem cells in 1998. Thus his conclusion that iPSCs are virtually identical to embryo-derived stem cells carries special weight.
The induced pluripotent cells are actually superior to embryo-derived stem cells in one critica respect.- They are patient-specific and hence will not be rejected by the immune system of the person from whom they are derived. The ability to generate embryonic stem cells matched to a particular person was the main reason for efforts to produce human embryos by so- called therapeutic cloning. Now even the scientist who generated "Dolly" the sheep and developed mammalian cloning, Ian Wilmut from Scotland, has concluded that direct reprogramming is a superior method for this purpose. He recently announced that he is abandoning cloning research and is focusing his efforts on direct reprogramming.
It should be cautioned that this astonishing breakthrough will not produce immediate cures. The therapeutic potential of all human pluripotent stem cells, including those generated by direct reprogramming, remains uncertain. The risk for tumor formation (a feature common to all pluripolent stem cells) is a grave concern, and the risk may be higher in iPSCs than in embryo-derived stem cells, because the genes used for reprogramming remain inserted in the cell.
In addition, the efficient conversion of pluripotent stem cells to transplantable cells that will be useful in the clinic is not yet possible for any human cell type, although much progress has been made. Thus, no immediate therapies should be expected from human pluripotent stem cell-based therapy, either embryo derived or IPSC.
Still, pluripotent stem cells have very important uses apart from therapy, and here iPSCs are clearly superior to embryo-derived ESCs. Pluripotent stem cells can be used to study "developmental biology in a dish. " They enable researchers to observe how human organs and tissues form. The insights garnered from such studies are likely to lead to the development of new drugs and strategies which can benefit human health.
Direct reprogramming techniques make it possible to generate pluripotent cells from specific individuals, including those with particular diseases. It will be possible to make iPSCs from children with Fanconi's anemia, a devastating genetic disease, and to study the effects of candidate drugs on the formation of human blood. These kinds of experiments are now immediately possible and likely will be the first practical application of iPSCs.
The exciting finding that patient-specific pluripolent stem cells can be generated easily and efficiently through direct reprogramming, without the use of human eggs or the generation of human embryos, is a tremendous leap forward. Science has provided a resolution to the ethical and political debate, and all parties emerge victorious. Scientists have access to an ethically uncompromised source of pluripotent stem cells for research, patients may ultimately benefit from therapies using these cells, and all citizens are spared the corrosive effects of ongoing cultural warfare over embryo-destructive research.
This new finding offers the best possible outcome to a debate that for too long pitted science and ethics against each other.