Sunday, October 16, 2005

Stem Cell Loopholes

When gas mileage regulations were tightened after the energy crisis in the late seventies, the American car companies hired lawyers to challenge the regulations while the Japanese companies hired engineers to find ways to comply. Given that Toyota is on the verge of surpassing GM as the world's largest car company, it seems pretty clear which was the better strategy.

Now, a similar situation exists for stem cell research. In an earlier post, I wrote about some of the ethical questions surrounding the issue. Current US regulations only allow federal funding for human stem cell research on embryonic stem (ES) cells derived from a fixed set of cell lines established prior to August 2001. However, many of these lines have been contaminated and researches would like to create more lines. So while some people are striving for a political solution to obtaining more stem cell lines, another group is looking for a technological fix to ease the ethical and religious concerns.

Two papers appearing in today's Nature advanced online publications, demonstrate possible methods in mice to obtain stem cells without technically destroying an embryo. The first by a group from Advanced Cell Technology, extracts a single cell from a developing blastocyst when it is comprised of 8 cells. They then show that they can create an ES line from this single blastomere that remains viable even after 50 divisions. The second paper from MIT, uses a method called altered nuclear transfer (ANT). This is a means of doing therapeutic cloning without destroying an embryo. Instead of implanting adult cells directly into a donated egg that can become a viable embryo to harvest stem cells, certain developmental genes are first deactivated in the adult cell so that the ensuing blastocyst can never implant in a uterus and hence fully develop.

Both approaches have been embraced and criticized and the New York Times has a synopsis of the reactions. I find both approaches to be rather unsatisfactory and expose the hypocrisy of the whole issue. Evidently, fertility clinics already do single-cell embryo biopsy for genetic screening prior to implantation. Supposedly, it is safe and there have been many successful births from embryos that have had a cell extracted. But I wonder who were the first parents to have had this procedure done on their baby? It sounds like rolling the dice on a life to me. The child may seem normal now but we don't know if there are any long term consequences. ANT seems completely contrived. The altered blastocyst is completely identical to a normal one when the stem cell is extracted. The only difference is that if both happen to be in a uterus, then one can implant and the other can't. However, unless you actually implant it you'll never know. So, if we were to say that we fully intend to alter a nucleus prior to implantation for therapeutic cloning, would that be good enough?

If one wants to have a fully consistent position on stem cells then one can either be for them or against them. There is no middle ground. There are no semantic loopholes. Each cell contains the entire genome so it has all the information to create life. Destroying a cell is thus equivalent to destroying an embryo. If one is against stem cell research then one must be against all genetic and cellular manipulations in humans (and perhaps all animals). That means no in vitro fertilization, no gene therapy, no ultrasound imaging of the fetus and certainly no amniocentesis. One could possibly take it further and say that any biological research that destroys cells should not be performed. People must start accepting that it's the software and not the hardware that defines a human life.

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