More Data But No Answers on Powers of Adult Stem Cells

摘要

A new study may provide ammunition in the politically charged debate on stem cell research, but it is unlikely to provide any definitive answer on the key issue of whether adult stem cells can develop into many kinds of tissue. Several years ago, a handful of researchers claimed that bone marrow cells transplanted into radiation-treated recipients were able to do more than just regenerate the blood system. Progeny from the cells seemed to appear in other tissues as well, including lung, liver, and skin, raising excitement that a multipotent stem cell might lurk in adult bone marrow. Such a cell, some hoped, might be used instead of stem cells from embryos to repair damaged tissues or help the body heal itself. The best evidence seemed to come from transplants in which male cells, containing Y chromosomes, would appear in the tissues of female recipients (Science, 21 June 2002, p. 2126).