The Fatal Promise of Cloning

As the cloning debate rages in Washington, there is news from the scientific frontier. It involves cows, but tomorrow it could easily involve humans.

Scientists at Advanced Cell Technology in Worcester, Mass., took a skin cell from Cow A, cloned it (by injecting the nucleus into a cow egg whose nucleus had been removed), then implanted the embryo in the uterus of Cow B. That embryo clone grew into a fetus, which, had it been born, would have been Cow C. But it was not born. The fetus was removed from the uterus and harvested for its tissues. These tissues from the clone were then put back into the original Cow A. Lo and behold, it worked. These cells from the clone were not rejected by Cow A and even organized themselves into functioning tissue (such as a kidney).

An amazing success. This is precisely what the advocates of research cloning are promising. Clone, grow it and then use the cloned tissue to create near identical replacement parts for the original animal and thus presumably put us on the road to curing such human scourges as Alzheimer's disease, Parkinson's, spinal-cord injuries and the like.

Do this in humans, and we might have thousands cured, millions relieved of suffering. Who could possibly stand in the way of this research?

We do, say cloning advocates. We would never countenance such work in humans, they say. Cows, yes, but we would never implant a cloned human embryo in the uterus of a woman and grow it to the stage of a fetus. We solemnly promise to grow human clones only to the blastocyst stage, a tiny 8-day-old cell mass no larger than the period at the end of this sentence, so that we can extract stem cells and cure diseases that way. Nothing more. No fetuses. No implantation. No brave new world of fetal farming.

This is all very nice. But curing with stem cells is extremely complicated. First, you have to tease out the stem cells from the blastocyst. Then you have to keep the stem cells alive, growing one generation after another while retaining their pluripotentiality (their ability to develop into all different kinds of cells). Then you have to take those stem cells and chemically tweak them in complex ways to make them grow into specialized tissue cells--say, neurons for a spinal-cord injury. Then you inject the neurons into the patient and get your cure.

The Advanced Cell Technology cow experiment suggests the obvious short circuit that circumvents this entire Rube Goldberg process: let the cloned embryo grow into a fetus. Nature will then create within the fetus the needed neurons, kidney cells, liver cells, etc., in far more usable, more perfect and more easily available form.

Tempting? No way, the cloning advocates assure us. We will never break that moral barrier. It is one thing to grow a cloned embryo, a tiny mass of cells not yet implanted. It is another thing to grow a cloned human fetus, with recognizable human features and carried in the womb of a woman.

I am skeptical of these assurances. Why? Because just a year or two ago, research advocates were assuring us that they only wanted to do stem-cell research on discarded embryos from fertility clinics but would not create a human embryo in the laboratory just for the purpose of taking it apart for its stem cells.