A “Need” for Experimental Human Cloning?

Date: 03/18/2002

“Somatic cell nuclear transfer research is essential if we are to achieve our goals in regenerative medicine.”

Thus said Thomas Okarma, president of the Geron Corporation, in his House testimony of June 20, 2001.

It may therefore be a surprise to find that Geron’s own researchers are among those showing that this simply may not be true.

In a March 18 news story in the San Francisco Chronicle, Geron researcher Hans Kierstead says he will soon seek government approval for trials in using embryonic stem cells to repair spinal cord injury. But he says he will use immune-suppression drugs, not embryo cloning, to prevent immune system rejection, having already found success with this approach in animal trials. The Chronicle notes that “Kierstead’s disclosure… undercuts the notion that scientists must use cloning to turn versatile embryonic cells into replacement nerves, muscles or other tissues.”

In fact, whether you support embryonic stem cell research or not, there are many reasons why the claimed “need” for cloning should be greeted skeptically:

1. As Robert Lanza of Advanced Cell Technology (which promotes experimental human cloning) says in the Chronicle article, some tissues such as those of the central nervous system are “immune privileged” – they do not readily reject even foreign tissue.

2. As many researchers are discovering, cells from an early stage of human development may not provoke much of an immune response. For example, studies in using umbilical cord blood stem cells from live births have found that successful treatment with these cells does not require as close a genetic match as other transplants often do.

3. Progress in developing new immune-suppression drugs with fewer side effects is making even adult cell transplants much more successful. For example, over a dozen patients with juvenile diabetes have been successfully treated with adult pancreatic cell implants and a new immunosuppressive drug.

4. Research in treating spinal cord injury and other neurological conditions using the patient’s own adult cells is advancing toward human treatments more rapidly than any protocol using embryonic cells. The most recent celebrated case of progress in treating spinal cord injury involved a young woman from Colorado who has regained some function after being treated with cells from her own adult immune system.

5. As Dr. Stuart Newman of New York Medical College noted in his March 5 Senate testimony, genetically matched cells from cloning may well be useless in treating conditions with a genetic basis such as juvenile diabetes – for these cells will have the same genetic defect that caused the problem in the first place.

6. Due to these factors, as well as advances in genetically tailoring cells without using cloning, “many experts do not now expect therapeutic cloning to have a large clinical impact” – in fact, this whole approach is said to be “falling from favour” among both British and American researchers (P. Aldhous, “Can they rebuild us?”, 410 Nature 622-5 [5 April 2001]).

How, then, can anyone still say that experimental cloning is essential for medical progress?