The Politics of Stem Cells

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APPENDIX E

Stem cells are undifferentiated "master cells" in the body that can develop into differentiated tissues, such as bone, muscle, nerve, or skin. Stem cell research may lead to exponential improvements in the treatment of many terminal and debilitating conditions, from cancer to Parkinson's to Alzheimer's to diabetes to heart disease. Indeed, breakthroughs in stem cell research reported just in the last six months take one's breath away:

Italian scientists have generated muscle tissue using rat stem cells, a discovery that may have significant implications for organ transplant therapy.

University of South Florida researchers report that rats genetically engineered to have strokes were injected with rat stem cells that "integrated seamlessly into the surrounding brain tissue, maturing into the type of cell appropriate for that area of the brain." The potential for stem cell treatments to alleviate stroke symptoms such as slurred speech and dizziness-therapy that would not require surgeryhas the potential to dramatically improve the treatment of many neurological diseases.

* The group of scientists who achieved worldwide fame for cloning Dolly the sheep have successfully created heart tissue using cow stem cells. The experiment demonstrated that stem cells could be transformed into differentiated bodily tissues, offering great impetus to further research.

Scientists at Enzo Biochem, Inc., inserted anti-HIV genes into human stem cells. The stem cells survived, grew, and developed into a type of white blood cell that is affected adversely by HIV infection. In the laboratory, these treated cells blocked HIV growth. The next step is human trials, in which stem cell therapy will be attempted using bone marrow transplantation techniques currently effective in the treatment of some cancers.

What will surprise many people is that none of these remarkable achievements relied on the use of stem cells from embryos or the products of abortion. Indeed, all of these experiments involved adult stem cells or undifferentiated stem cells obtained from other non-embryo sources. The rat muscle tissue in the first example was generated using adult rat brain cells. The brain tissue generated in the Florida research was obtained using human stem cells found in umbilical cord blood-material usually discarded after birth and a potentially inexhaustible source of stem cells, since 4 million babies are born in the United States alone each year. Dolly's creators obtained cow heart tissue by reprogramming adult cow skin tissue back into its primordial stem cell state and thence to cardiac cells. The exciting HIV experiments were conducted using stem cells found in the patients' own bone marrow, spleen, or blood.

The opportunities for developing successful therapies from stem cells that do not require the destruction of human embryos should be very big news. But where are the headlines? These and other successful experiments have been all but drowned out by breathless stories extolling the miraculous potential of embryonic stem cell research. How many readers are aware, for example, that French doctors recently transformed a heart patient's own thigh muscle into contracting muscle cells? When these cells were injected into the patient's damaged heart, they thrived and, in association with bypass surgery, substantially improved the patient's heartbeat. Such research is now on the fast track, offering great hope for cardiac patients everywhere.

With all of the hype surrounding embryo research, it is important to note that embryo stem cell research-and its first cousin, fetal tissue experiments-may not actually produce the therapeutic benefits its supporters have told us to anticipate. Such worries are not mere speculation. The March 8, 2001, New England Journal of Medicine reported tragic side effects from an experiment involving the insertion of fetal brain cells into the brains of Parkinson's disease patients. …