What the stem cell scientists really want.
Oct 3, 2005, Vol. 11, No. 03 • By ROBERT P. GEORGE
THE JOURNAL Science late last month published the results of research conducted at Harvard proving that embryonic stem cells can be produced by a method that does not involve creating or destroying a living human embryo. Additional progress will be required to perfect this technique of stem cell production, but few seriously doubt that it will be perfected, and many agree that this can be accomplished in the relatively near future. At the same time, important breakthroughs have been announced by scientists at the University of Pittsburgh and the University of Texas demonstrating that cells derived harmlessly from placental tissue and umbilical cord blood can be induced to exhibit the pluripotency of embryonic stem cells. ("Pluripotency" is the potential of a cell to develop into multiple types of mature cells.)
One would expect that advocates of embryonic stem cell research would be delighted by these developments. After all, they point to uncontroversial ways to obtain embryonic stem cells or their exact equivalent and to create new stem cell lines that are (unlike lines created by destroying embryos) immediately eligible for federal funding. Yet some advocates seem to be unhappy at the news. Why?
The likely answer is ominous.
Up to now, embryonic stem cell advocates have claimed that they are only interested in stem cells harvested from embryos at the blastocyst (or five-to six-day) stage. They have denied any intention of implanting embryos either in the uterus of a volunteer or in an artificial womb in order to harvest cells, tissues, or organs at more advanced stages of embryonic development or in the fetal stage. Advocates are well aware that most Americans, including those who are prepared to countenance the destruction of very early embryos, are not ready to approve the macabre practice of "fetus farming." However, based on the literature I have read and the evasive answers given by spokesmen for the biotechnology industry at meetings of the President's Council on Bioethics, I fear that the long-term goal is indeed to create an industry in harvesting late embryonic and fetal body parts for use in regenerative medicine and organ transplantation.
This would explain why some advocates of embryonic stem cell research are not cheering the news about alternative sources of pluripotent stem cells. If their real goal is fetus farming, then the cells produced by alternative methods will not serve their purposes.
Why would biomedical scientists be interested in fetus farming? Researchers know that stem cells derived from blastocyst-stage embryos are currently of no therapeutic value and may never actually be used in the treatment of diseases. (In a candid admission, South Korean cloning expert Curie Ahn recently said that developing therapies may take "three to five decades.")
In fact, there is not a single embryonic stem cell therapy even in clinical trials. (By contrast, adult and umbilical cord stem cells are already being used in the treatment of 65 diseases.) All informed commentators know that embryonic stem cells cannot be used in therapies because of their tendency to generate dangerous tumors. However, recent studies show that the problem of tumor formation does not exist in cells taken from cows, mice, and other mammals when embryos have been implanted and extracted after several weeks or months of development (i.e. have been gestated to the late embryonic or fetal stage). This means that the real therapeutic potential lies precisely in the practice of fetus farming. Because the developmental process stabilizes cells (which is why we are not all masses of tumors), it is likely true that stem cells, tissues, and organs harvested from human beings at, say, 16 or 18 weeks or later could be used in the treatment of diseases.
Scientists associated with a leading firm in the embryonic stem cell field, Advanced Cell Technology, recently published a research paper discussing the use of stem cells derived from cattle fetuses that had been produced by cloning (to create a genetic match). Although the article did not mention human beings, it was plain that the purpose of the research was not to cure diseased cows, but rather to establish the potential therapeutic value of doing precisely the same thing with human beings. For those who have ears to hear, the message is clear. I am hardly the first to perceive this message. Slate magazine bioethics writer Will Saletan drew precisely the same conclusion in a remarkable five-part series, the final installment of which was entitled "The Organ Factory: The Case for Harvesting Older Human Embryos."