Stem-cell Debate Mixes Science, Religion And Politics: The FAQs
By Tim Friend
Q: What is a human embryonic stem cell? A: Stem cells are the essence of an embryo, and upon implantation in a womb give rise to all of the different cells, tissues and organs of the human body. Q: Why are scientists and medical organizations so eager to use them for research? A: Scientists hope to harness the power of stem cells and transform them into whatever cell or tissue they desire. If that is possible, stem cells may be developed into replacement therapies for a range of diseases, including Alzheimer’s, Parkinson’s, cancer and juvenile diabetes. So far, scientists report that they have coaxed human embryonic stem cells into becoming brain cells, heart cells, insulin-producing cells and several other types of tissues. Q: Where do embryonic stem cells come from? A: They must be extracted from embryos. Surplus frozen embryos in storage at fertility clinics, which are no longer wanted by the couples that had them created, are the most widely accepted source of embryos by scientists. However, fertility doctors have indicated that they want to create embryos specifically for research using donated sperm and eggs. At least one company has stated that it wants to clone human embryos and use those stem cells for research. Q: Why is the research so controversial? A: The controversy is about whether taxpayer money should be used to fund research that some people find morally wrong. Obtaining stem cells from embryos for research destroys the embryo. The Catholic Church has led the opposition to human embryonic-stem-cell research because of what it calls the “sanctity of life.” Catholic doctrine holds that life begins at conception, so an embryo, even in its earliest stage of development, is regarded as a human life. Destroying an embryo, even for curing disease, is regarded as immoral. Supporters of the research hold a variety of views. Many argue that life begins at a later stage of development. The lines tend to fall along the same fronts as the abortion debate. That life begins at a later stage of development also is the perspective of mainstream Jewish doctrine. It does not grant any legal status to an embryo. Traditionally, the Jewish faith holds that life begins at quickening, or the first time a mother feels the movement of a fetus. The prevailing view among scientists is that it is acceptable to destroy embryos for medical research as long as the embryos are destined to be destroyed anyway. The National Institutes of Health established guidelines during the Clinton administration that would permit federal funding of research on surplus frozen embryos from fertility clinics with the consent of couples that had the embryos created for the purpose of having a baby. Hundreds of thousands, perhaps millions, of surplus embryos are frozen and stored at fertility clinics across the country. When the excess embryos are no longer wanted by a couple, they are usually incinerated. NIH guidelines ban funding of embryos that are created specifically for research. The American Society of Reproductive Medicine, which represents the nation’s fertility doctors, believes it is ethical to create embryos for research. The Jones Institute for Reproductive Medicine in Norfolk, Va., recently announced it had created embryos for research, using eggs and sperm donated by people who were specifically asked to help create embryos for that purpose. The argument of fertility doctors is that this is a more “ethically pure” way to conduct the research than to ask couples who had the embryos created with the expectation of having a baby. Q: How is the debate over human cloning tied into the debate on stem cells? A: Last week, the House of Representatives voted to ban human cloning for any purpose. Some scientists want to clone human embryos and extract those stem cells for research. England officially approved that type of cloning, called therapeutic cloning. Essentially, a patient would clone an embryo of himself and use the stem cells from his own embryo to replace diseased cells in his body. If donated frozen embryos are ever used for therapy, the patient’s immune system would reject the cells. Cloning your own embryo should overcome rejection problems. But that will be illegal if the Senate also votes for the total ban on cloning. Q: Are there any alternatives to human embryonic stem cells for this type of research? A: Opponents of federal funding argue that research should be done on “adult” stem cells and that the cells offer the same hope for developing cellular replacement therapies for diseases. Those are cells that have already “differentiated” into their specific cell or tissue type. They have been found in the brain and blood and certain organs. Stem cell Technology and its possible uses Stem cells from embryos are obtained in three ways: Frozen embryo: Spare frozen embryos come from fertility clinics, donated by infertile couples that no longer need them for pregnancy. Ethical guidelines from the National Institutes of Health recommend research only on these. Fresh embryo: Fresh embryos are being created specifically for research by at least one U.S. fertility clinic. Ethical guidelines ban public funding of research on these. Cloned embryo: Embryos can be created by cloning human cells. Cloning for research is legal in England; the U.S. Congress is considering banning it. The process: A human embryo at five days of development after fertilization is called a blastocyst. It is a ball of cells the size of a pinhead. At six days, the inner cell mass begins to form. This mass contains the stem cells desired for research. The cells give rise to virtually all cells of the human body. If implanted in a womb, they would transform into a fetus. Stem cells are extracted from the blastocyst and put into cultures. The process destroys the embryo and has raised moral and ethical concerns. Scientists say they can trigger stem cells to grow into many different types of tissues, including heart cells that beat in a petri dish. The goal of stem research is to one day use them as sources of replacement cells to treat heart disease, Alzheimer’s, Parkinson’s, diabetes, cancer and others.