Saturday, December 04, 2004

Advances in Embryonic Stem Cells

It is unfortunate that so many Americans are unaware that there are two types of stem cells, and only one type has been shown to have any theraputic benefit at all. Embryonic stem cells are taken from otherwise normally developing embryos, however it is necessary to kill the embryos to harvest them. No one has ever identified any theraputic benefit for such cells, and only an amoral monster could argue that it is acceptable to destroy a human embryo for a purpose that provides no benefit to anyone.

Adult stem cells are taken from adult tissue, and there have been several promising experiments with them. No one is injured when adult stem cells are harvested. I argue that instead of wasting their time and effort lobbying for the federally-funded murder of additional embryos, advocates for stem-cell research should spend their money financing adult stem-cell research.

Given these caveats, I did find interesting the article in today's Washington Post that discusses two approaches to harvesting embryonic stem cells that do not involve the destruction of human beings. I laud the members of this bioethics committee for looking into other options. Unfortunately, at least one of these approaches remains morally unacceptable.

The first approach discussed involves watching embryos who have been produced as part of an IVF program. Some 40% of such embryos cease to divide after a few days, indicating that they are morally equivalent to adults who have experienced "brain death," still metabolizing, thus "alive" in some sense, yet not in any sustainable or meaningful way. Curiously enough, just as one can harvest a liver or heart from a brain-dead adult, it remains possible in some cases to harvest embryonic stem cells from such embryos. The "ethicists" in this article seem to believe that no-one could have an ethical objection to such harvesting. They are close to the truth, but sadly blind to their error.

While I would be hard-pressed to argue that the harvesting of embryonic stem cells from such embryos is immoral, I must point out that the creation of such embryos for IVF is certainly immoral. It may not be immoral on the same scale as intentionally killing an embryo is, but the distinction is much like arguing that rape is not as bad as murder. The statement may be true, but it hardly makes an effective argument for encouraging rapists. The reason I make this analogy is that just as rape is an offense against the dignity of a human being, in-vitro fertilization is an offense against the dignity of the child. Every human being has the right to be conceived as part of loving relations between married parents, and within the womb of his mother. Anything less offends the dignity of that child. Therefore, while the harvesting of stem cells from deceased embryos is not a sin, creating those embryos in-vitro in the first place most certainly is. It is no more moral to profit from the immoral actions of others in this case than it would be to make use of the scientific research of Josef Mengele (Nazi torturer).

The second approach is a bit more complex, but strikes me as potentially more promising from a moral standpoint. In this approach, an adult cell is taken and certain genes (I suspect homeobox genes) are disabled. The nucleus is then evacuated from an ovum, and the nucleus from the disabled adult cell is inserted. This is the same process that is used for cloning. The same electro-chemical stimulation as is used in cloning is provided. However, with these genes disabled, what would be produced is not an embryo, but a tumor cell known as a teratoma. Embryonic stem cells could then be harvested from this teratoma, and their disabled genes reactivated.

Curiously enough, it is this second approach that garnered objections from the bioethics panel. "What you propose, really, is to build a weird genetic hybrid. . . . Is that right?" was the objection. I can understand the concern, but it's hard to see exactly how this is reasonable ethical objection, since human life is neither created nor destroyed in the process.

One question this proposal raises for me, however, is whether embryonic stem cells could be harvested from naturally-occuring teratomas. These tumors, while rare, appear naturally. I have heard of them being used as the basis for "cell lines." Wouldn't these cell lines also be pluripotent, as embryonic stem cells are?

These ideas still need some work, but I hope this is the start of a more ethical treatment of human embryos.


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