Can research on adult stem cells be substituted for embryonic stem cell research?
Adult stem cells are multipotent, which means that they can become only a limited number of types of tissues and cells in the body. For example, adult blood-forming stem cells (found in bone marrow) have only been used successfully to treat blood-based diseases such as leukemia and lymphoma. Embryonic stem cells have greater potential to treat a wider variety of diseases because they are pluripotent, which means that they can become almost all types of tissues and cells in the body. Adult stem cells are found in small quantities in adult tissues and umbilical cord blood, and scientists think they do not have the same capacity to produce diverse tissues or multiply as embryonic stem cells. If a patient receives an adult stem cell transplant from a donor, the patient’s body might reject it-a problem that researchers anticipate could be overcome with therapeutic cloning. Adult stem cells may have more genetic abnormalities, which occur naturally during the aging process and with exposure
