New life to stem cells?
Nature of the problem: Human embryonic stem (ES) cells, which can become any cell in the body, could be used to study or treat diabetes, Parkinson's, and many other diseases. But because collecting ES cells requires the destruction of embryos, opponents say ES research amounts to murder. As a result, the United States allows federal funding only for 21 lines of ES cells, all of which were isolated before 2001. Proponents of ES-cell research note that thousands of surplus embryos are wasted at fertility clinics each year, along with the ES cells they contain.
Scope of the problem: Despite the funding limits, ES-cell research has advanced in the past 10 years. On Aug. 19, scientists grew ES cells into type O-negative red blood cells, which can be used in virtually all blood transfusions. Eventually, factory-made blood from ES cells could address chronic blood shortages.
In 2007, the discovery of a technique to derive ES-cell look-alikes from skin cells rather than embryos suggested a way to sidestep the controversy over ES cells. In July, Harvard University researchers used this new technique to grow stem cells, and then nerve cells, from skin cells from a patient with the nerve disease ALS. Using these lab-made neurons, scientists hope to understand the death of neurons in ALS, and perhaps create replacement cells to treat the fatal disease.
Yet as scientists continue to investigate stem cells that do not require the use of embryos, ES cells remain the gold standard for understanding how cells change and develop, and ES-cell research must continue, says James Thomson of the University of Wisconsin-Madison, who first isolated human ES cells in 1998.
The big questions: The embryonic stem cells that are eligible for federal funding are old and unsafe for use in the clinic. Continuing to limit ES-cell research could cost the United States its leadership in this phenomenal "made in USA" technology. Do you intend to loosen restrictions on funding for research on ES cells, and if so, how would you do that in a ethical manner?
Megan Anderson, project assistant; Terry Devitt, editor; S.V. Medaris, designer/illustrator; David Tenenbaum, feature writer; Amy Toburen, content development executive