MISUSE OF SCIENCE ABOUNDS

By Richard Doerflinger

In the public debate on human cloning, March came in like a lion--featuring what many would consider lyin' by proponents. False and misleading claims characterized congressional testimony as well as commentary made about new articles in prestigious journals.

The onslaught began with a March 5 Senate hearing. Actor Christopher Reeve, rendered quadriplegic by a riding accident, cited examples of beneficial research that he claimed would be blocked by a ban on the cloning of human embryos for stem cell research. He also spoke dismissively of progress toward treatment of spinal cord injury using non-embryonic cells.

But in fact, the promising research Reeve cited had nothing to do with cloning. Worse yet (for those who believe in accuracy), the most promising example he cited of a new spinal cord injury treatment uses adult cells from patients' own bodies!

Reeve further declared that treatment of his condition will require "remyelination" of his nerve cells (rebuilding the protective sheath that usually coats functioning neural fibers). Reeve insisted that only embryonic stem cells can provide this.

But as the founder of an organization that funds spinal cord injury research, Reeve should be aware that this last claim is demonstrably false. Studies done at Yale and the University of Wisconsin -- not to mention studies from France, England, and Japan -- have shown great progress in achieving remyelination by other means, usually using adult stem cells.

Finally, Reeve said that all scientists agree there is "no hope" for a cure for ALS (Lou Gehrig's disease) without embryonic stem cells and cloning. But the existence of such an alleged scientific consensus would surely be a surprise to the national ALS Association. The group just announced $1 million in funding for 11 new projects in ALS research, none of which uses embryonic cells.

Reeve's testimony was followed by another media campaign on March 8 when the results of an allegedly groundbreaking study were given advance release on the web site of the journal Cell. Newswire services such as the Associated Press uncritically announced that scientists had "demonstrated" the benefits of "therapeutic cloning" by partially correcting a genetically based immune system defect in mice.

But in truth, the much-ballyhooed study itself recounts an almost complete failure, not a triumph. It also comes, as the respected coalition "Do No Harm" has pointed out, "years after 'remedied' adult stem cells -- not embryonic stem cells -- were used to cure human infants of severe combined immunodeficiency syndrome, in the first successful clinical trials in human gene therapy."

Here's what really happened.

Researchers first cloned mice with a preexisting immune defect. Since the clones were genetically identical, the stem cells harvested from the embryonic clones possessed the same defect. Researchers then used gene therapy to fix the defective gene in the stem cells, in the hope of creating a healthy immune system. They injected these genetically repaired stem cells into the original mice.

Later testing showed that this had no effect. Ironically, the doctored cells were more readily accepted by mice with normal immune systems -- that is, by mice who had no need of treatment.

The researchers ultimately found success only by using a new Rube Goldberg variation on their original technique. They used the genetically repaired stem cells from the cloned embryo to make yet another embryo, which they grew to live birth so they could harvest healthy stem cells from its bone marrow for transplantation into the original mouse. Only these adult stem cells from a live-born mouse were completely successful in treating the immune-deficient mouse.

Opponents of a genuine ban on human cloning insist that they oppose "reproductive cloning" (that is, allowing cloned human embryos to be born alive) but support "therapeutic cloning" (killing these embryos for their stem cells). If the research reported in Cell is a model for human "therapeutic cloning," patients or their spouses will have to give birth to a cloned baby to obtain his or her stem cells. Therapeutic cloning will be done by performing reproductive cloning!

This point, however, was lost on the Associated Press and other news outlets. Also lost on them was the fact, as mentioned above, that there is already a far more successful treatment for humans with severe combined immune deficiency.

This procedure, developed in France, takes out some of the child's own adult bone marrow stem cells, repairs the genetic defect in these cells, and then implants them back in the child to build up a new immune system. Several children have been cured, and are walking around outside their sterile "bubbles," because of this first great success in human gene therapy.

But to read the new press reports, you would never know that embryonic research is producing dead mice while adult stem cells are giving us cured children.

Christopher Reeve and other cloning proponents are clearly frustrated at such advances in adult stem cell research, which may show embryo cloning to be unnecessary for medical progress. So proponents next launched a new frontal attack on such

morally acceptable research, using a twisted interpretation of two studies which appeared in the online edition of the journal Nature on March 13.

The studies reportedly were designed to learn more about the mechanism by which adult stem cells sometimes "transdifferentiate" to form cells of many different types. For example, researchers (including researchers funded by Christopher Reeve's foundation) have found that under certain circumstances adult bone marrow stem cells can produce useful nerve tissue. Human trials are being prepared for use of bone marrow stem cells to help repair damaged heart muscle, which has already been a success in animals.

The studies in Nature explored this phenomenon. Oddly enough, researchers mixed adult stem cells with embryonic stem cells to promote transdifferentiation.

Instead of forming healthy cells of different types, the adult and embryonic cells tended to "fuse" with each other to form tetraploid cells (cells that have twice the usual number of chromosomes). Such cells could be dangerous and even lead to tumor formation.

The obvious conclusions of this study would seem to be: (1) you'd better not mix adult and embryonic stem cells, and (2) this may be one mechanism by which embryonic stem cells tend to form tumors when placed into animals, since all animals (including humans) already contain adult stem cells.

Instead, the "spin" placed on the data (faithfully followed by the Associated Press and some other news outlets) was this: There is a terrible problem with adult stem cells that may make them unfit for human use, so we should rely on embryonic stem cells for treatments!

But that conclusion is, to put it mildly, absurd. Adult stem cells are working and "transdifferentiating" in our bodies all the time without making tumors.

The new findings are more plausibly attributed to the uncontrollable tendencies of embryonic stem cells. We surely can't draw conclusions about the superiority of embryonic over adult cells by finding problems in a mixture of both.

Real cures for devastating diseases will only be slowed, or set aside altogether, if such attacks on promising and morally acceptable research continue. Here, as in other campaigns for the destruction of human life, truth is the first casualty. If we let them get away with it, human casualties -- embryonic and adult -- will follow.

Richard Doerflinger is the Deputy Director of the Secretariat for Pro-Life Activities, U.S. Conference of Catholic Bishops.