In an article in The New Republic on April 22, 2002, Charles Krauthammer, M.D. explained the cloning process and expressed concerns on why human cloning should not be performed. This is how research cloning works. You take a donor egg from a woman, remove its nucleus, and inject the nucleus of, say, a skin cell from another person. By the right manip-ulation you can trick the egg and the injected nucleus into dedifferentiating—that means giving up all the specialization of the skin cell and returning to its original state as a primordial cell. This cell becomes the equivalent of the fertilized egg in normal procreation, except that instead of having chromosomes from two people, it has chromosomes from one. This cell then behaves precisely like an embryo. It divides and develops. At four to seven days, it forms a “blastocyst” consisting of about 100 to 200 cells. The main objective of cloning researchers would be to pull the stem cells out, grow them in the laboratory, and then try to tease them into becoming specific kinds of cells, such as kidney, heart, brain and so on.

The claimed advantage of using a cloned cell is that there would be no tissue rejection. But there is reason to doubt this claim on scientific grounds. There is some empirical evidence in mice that cloned tissue may be rejected anyway. Thus, adult stem cells offer a promising alternative to cloning because they present no problem of tissue rejection and raise no ethical issues. Examples of these alternatives to human cloning already show significant promise.

University of Minnesota researchers, led by Dr. Catherine Verfaillie, director of the university’s Stem Cell Institute, have announced their success in coaxing adult bone marrow stem cells into becoming functioning liver cells, a discovery revealing the potential of adult stem cells to replace any perceived need to experiment on cells obtained by killing cloned human embryos. According to a report published in the May 15th edition of the Journal of Clinical Investigations, this first-of-its-kind discovery opens the door to a number of potential uses, including treating genetic and other liver diseases and enabling pharmaceutical companies to screen new drugs for liver toxicity and efficiency prior to testing them on humans.

On April 30, Reuters reported another potential medical breakthrough that does not involve human cloning or the killing of human embryos. Scientists from biotech start-up Nucleotech LLC said they have transformed ordinary human skin cells into immune cells in an experiment that, if it can be repeated, might provide all the benefits that are being anticipated from experiments using stem cells or cloning. The objective is to be able to offer patients grow-your-own transplants that could theoretically be used to treat diseases such as immune deficiencies and juvenile diabetes. When you hear claims that a ban on human cloning will prevent medical breakthroughs, remember these results as evidence that adult stem cell research is already making such breakthroughs without the cloning and killing of human embryos.

In some cases use of adult stem cells has already moved beyond the laboratory and offered actual treatments of human patients. One such success has been reported in treating Parkinson’s disease using adult stem cells. Doctors in California took stem cells from a man’s brain. They were able to grow them into neurons that they transplanted back into his brain. The procedure was a first using a human’s adult neural stem cell. Since the surgery, the patient’s hand tremors and other symptoms of Parkinson’s disease have largely disappeared. This achievement suggests endless possibilities, proving once again that the real source of medical success using stem cells will come from adult stem cells, not from cloning and then killing embryos to obtain their stem cells.