Tuesday, August 22, 2006

A Lesson for Our Time - Greatly Multiplying the Potential of Adult Stem Cells

The most hotly debated bioethical issue for the past five years has been the acquisition of stem cells. These cells can transform into a wide variety of human cell types, and so can be used to cure disease. For this reason, a large sector of the medical research community has insisted on the need to harvest stem cells from human embryos. Others have insisted that growing embryos for this purpose is both immoral and inhuman.

Embryonic and Adult Stem Cells

Some aspects of this debate are unlikely to be settled by rational argument. The passion of the medical research community for embryonic experimentation is not always in proportion to the real need for stem cells. Early on, scientists discovered that they can gather stem cells from adult bone marrow and umbilical cord blood, and they have already used such cells to develop cures for more than fifty diseases. By contrast, embryonic stem cell research has not produced a single cure. Yet the demand for embryonic stem cells continues to increase. One may reasonably speculate that this demand is fueled in part by an unrestrained passion for the domination of nature.

Nonetheless, there remains a legitimate interest in tapping the full power of embryonic stem cells, which have a greater ability to differentiate than adult stem cells. Unlike other body cells, stem cells in general have a capability of self-renewal through division. Some stem cells are “unipotent”, which means they can divide and develop into just one type of specialized cell. Adult stem cells are generally “multipotent”, which means they can divide and differentiate into any of a number of closely related cell types. Embryonic stem cells are “pluripotent”, which means they can divide and differentiate into a far wider range of cell types. Even more powerful are “totipotent” stem cells, the kind that are produced from the initial union of a sperm and an egg. A single totipotent cell is the material component of the newly conceived human person, capable of producing every kind of cell necessary to human development.

Technology and Morality

Because of the promise of pluripotent cells, especially when genetically similar to the cells of a particular medical patient, there is inevitable interest in harvesting them when they first appear in embryonic development (at the blastocyst stage). But the moral problem is obvious. Harvesting such cells not only uses parts of a person’s body without his consent, but kills the person in the process. This moral scenario becomes even grimmer when embryos are actually grown and killed for this purpose. Even if the cells could be removed without harming the embryo, or removed only from already dead embryos, the procedure would raise grave moral questions, in effect placing an unwholesome premium on body parts from which the unscrupulous might be all too quick to profit. As things are, however, we do not have the luxury of debating these lesser concerns. To put it bluntly, harvesting embryonic stem cells kills babies.

Yet it may now be possible to convert adult cells into pluripotent stem cells in a way which meets the most stringent moral tests. The most well-known method proposed for doing this is Altered Nuclear Transfer - Oocyte Assisted Reprogramming (ANT-OAR). This theory behind this initiative has been carefully articulated to put the latest scientific research at the service of the best theological and philosophical understanding. All three disciplines are necessary. From theology, we learn the special reverence due to the human person, a reverence which is derived from Revelation and characteristic only of Judeo-Christian societies. From philosophy, we learn when a collection of cells has the potential to be a human person and when it does not. And from science, we learn technologies to solve material problems. [snip] Read More at CatholicCulture.org

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