Stem Cell Research: An NPR Special Report
A 'Virtual Roundtable' on Federal Funding
Micheline Mathews-Roth, MD, associate professor of medicine, Harvard Medical School:
Stem cells -- unspecialized cells which can form many different specialized cells in the body and can also reproduce themselves -- are obtained by: 1) opening up 5 to 7 day old human embryos and collecting the "inner cell mass" cells (embryonic stem cells); 2) dissecting the bodies of aborted or miscarried fetuses of 5 to 9 weeks of age and collecting the "germinal ridge" cells (fetal stem cells); 3) collecting blood from the placenta and umbilical cord after birth (umbilical cord stem cells); and 4) collecting blood or bone marrow cells, or taking biopsies from various tissues and organs of children and adults (adult stem cells).
I oppose the use of embryonic stem cells because to obtain those cells it is necessary to kill a growing human being. We know from embryology that a new life begins with the formation of the zygote, the cell formed from the union of egg and sperm in fertilization -- this is scientific fact, not religious doctrine. What makes us human is not our looks or mental attributes, but the human chromosomes and genes which we have in our cells from the zygote stage throughout our life. We should not condone killing a member of our species, even for a good reason.
The suggestion that we use leftover embryos from fertility clinics because "they are going to be destroyed anyway" is discrimination against a class of human beings -- the very young. We should offer these extra embryos to infertile couples to implant and allow them to be born, and not kill them either by experimentation or by disposal. The fact that a high percentage of young embryos dies early in their development certainly does not justify our deliberately killing embryos.
Additionally, the use of embryonic or fetal stem cells can result in immunological rejection reactions to the transplanted tissues or cells made from the stem cells, as in patients receiving transplanted organs. Also, teratomas (multi-tissue tumors) can form in recipients of both embryonic and fetal stem cells. People with diseases who might be helped by receiving embryonic stem cells need to ask themselves if they want to obtain benefit at the price of taking another human life, and also incur these potential risks.
I encourage the use of adult stem cells, because no one is killed in the process of obtaining them. Also, since adult stem cells will come from the person needing the transformed cells, they will present no rejection problems, nor do they form teratomas. Adult stem cells seem to be as versatile as embryonic stem cells: For example, adult bone-marrow stomal cells can be transformed into many different cell types, including bone, muscle, liver, brain, nerve and heart muscle cells. Dr. Donald Orlic stated on NBC News on March 30, 2001: "We are currently finding that these adult stem cells can function as well, perhaps even better than, embryonic stem cells." In advocating the use of adult stem cells only, we are thus not depriving our patients of the possibility of cures.
I suggest the government do the following: 1) prohibit studies on human embryonic stem cells and human fetal stem cells, because of the dangers of teratoma formation and tissue rejection, and because of the killing involved in obtaining them; 2) encourage and fund research on human adult stem cells: and 3) encourage and fund research on animal -- especially mouse and primate -- embryonic, fetal and adult stem cells. Such studies will accurately determine the real potential of the various kinds of stem cells, and eventually lead to clinical studies in which no humans are killed to obtain stem cells, and no patients are harmed from receiving them.
Micheline Mathews-Roth, MD, is an associate professor of medicine at Harvard Medical School and a physician at Brigham & Women's Hospital.
Douglas Johnson, legislative director, National Right to Life Committee
Ihor Lemischka, associate professor, Department of Molecular Biology, Princeton University
Daniel Perry, executive director, Alliance for Aging Research
David A. Prentice, founding member, Do No Harm: The Coalition of Americans for Research Ethics
Arti K. Rai, assistant professor, University of Pennsylvania Law School