Petri Dish Politics - biomedical revolution

Reason, Dec, 1999 by Ronald Bailey

The next step in stem cell research will occur when biotechnologists learn how to strip off the suppressing proteins from a mature cell's genes and transform it directly into a stem cell without having to use enucleated human eggs. That advance will take human eggs out of the discussion. Once it is possible to make stem cells without eggs, perhaps the moral intuition of many people will shift.

"It may eventually become possible to take a cell from any one of our organs and to expose it to the right set of environmental stimuli and to encourage that cell to return to a more primitive stage in the hierarchy of stem cells," explains Varmus. "Under those conditions, one might in fact generate the cell with as great a potential as a pluripotent cell [capable of becoming many different, but not all, types of tissues] from a very mature cell. One might even in fact imagine generating a cell that is totipotent in that manner." (Again, a totipotent cell is one that could develop into a complete organism if put in the right circumstances.)

Stem cells produced this way would be identical to the human embryonic stem cells that currently must be harvested from embryos. A cell whose suppressor proteins have been stripped off could become a nerve stem cell, a liver stem cell, or a baby - depending on the intentions of the patients and doctors. Researchers are experimenting right now to see if new embryonic stem cells could be formed by introducing the nucleus of an adult cell into an already existing enucleated embryonic stem cell, thus bypassing the need to use human eggs.

One final consideration is that those committed to claims that individual human beings are defined by their DNA must take into account the fact that up until the eight-cell stage any one of an embryo's cells could become a separate embryo and, under the right circumstances, develop into a baby. So until that point are there several persons, or one, in a fertilized human egg? It is now possible after a fertilized egg has first divided into two cells to take one cell and use it to test for genetic diseases. The tested cell could have developed into a baby if placed in a woman's womb. Has the genetic test killed a twin?

Stem cell research opponents might respond that these arguments are just splitting hairs. But there are quite a lot of biochemical hairs to split. And just how you split them determines how you regard the moral status of all types of cells.

Does human uniqueness really reside in our genes? Try this thought experiment. Imagine that transplant surgery has so improved that it is possible to remove your brain and place it safely into another body. So after your brain transplant, is your original body "you"? Or are "you" residing now in a different body? A new body could certainly change "you" in certain ways, since your senses and biochemistry would be different. But humans already affect the operation of their brains by giving themselves different drugs. When people take therapeutic drugs, say Prozac, L-dopamine, or even steroids, we do not believe they become different people.