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(K1) ETHICAL AND SOCIAL IMPLICATIONS OF STEM CELL RESEARCH. McLaren, Anne1, 1 Wellcome Trust/Cancer Research UK Institute, Cambridge, UK ABSTRACT- Recent research suggests that stem cells hold considerable promise for the treatment and even cure of serious and intractable degenerative diseases. These include neurodegenerative diseases such as Parkinson's, Alzheimer's, Huntington's and multiple sclerosis as well as stroke, ischaemic heart disease, diabetes, rheumatoid arthritis and spinal cord damage. Patients with these relatively common conditions undergo a great deal of physical or mental suffering but often live for many years, so that the total cost to the health service and the community in terms of treatment and long-term care is immense. Even in economic terms therefore, stem cell therapy offers benefit. Stem cells can be derived from adults, aborted foetuses, or early preimplantation embryos. In the adult, most tissues include a population of stem cells, responsible for repair of the tissue throughout life. These stem cells tend to be few in number, hard to isolate, and refractory to multiplication in culture. Recent studies have shown that adult stem cells show much more plasticity than was at one time thought, so that for example haematopoietic stem cells not only give rise to all the different types of blood cell, but can also populate a damaged liver and differentiate into hepatocytes. Stem cells from foetuses, like adult stem cells, seem unlikely to provide a large supply of stable cells capable of providing clinicians with a ready source of whatever cell type the patient requires. Embryonic stem (ES) cells, on the other hand, will proliferate indefinitely in culture and can give rise to many if not all of the tissues of the body. Most research has been carried out on mouse ES cells, but in 1998 human ES cells were reported to have been derived from blastocyst-stage embryos (containing 100-150 cells) donated by couples in IVF clinics who no longer required them for their own infertility treatment. New ES cell lines have since been made in several different parts of the world. Although ES cells hold out great potential for tissue therapy, they also raise serious ethical problems. The ethics of using adult stem cells are similar to those of transplant surgery and new clinical treatments in general. Use of foetal tissue may be unacceptable to those who cannot countenance termination of pregnancy, but most countries have ethical guidelines that regulate such procedures. Embryonic stem cells can only be derived through the destruction of a preimplantation embryo, and for those who feel that the moral value of an early embryo (even one that cannot survive more than a few days) is equal to the moral value of a newborn baby or an adult, ES cell derivation is not ethically acceptable. Others take the view that moral value increases progressively from the one-cell stage up to birth, so that strictly regulated research on early human embryos is acceptable if the research is likely to increase human welfare and decrease suffering. This view implies that research should continue on all types of stem cells, including ES cells, since we cannot judge at the present time which will turn out to be the most effective for any particular clinical condition. KEY WORDS: adult stem cells, embryonic stem cells, stem cell therapy, stem cell ethics |
