PLAYING GOD... by Mina Radhakrishnan

So goes the creation myth, prevalent in every culture that still exists today. In some, man is a mistake, an aberration allowed to live on the earth. In others, he is the ultimate goal and the earth was created solely for the purpose of giving him a place to stand. But in every story, there is this one common thread - namely, that he was created by a higher power. From Mayan to Indian to every civilization that succeeded them, man came into being by the gods. The Egyptians believed that Ra-Atun rose from the waters of the Nile to bring forth man's ancestors. The Babylonians believed that Marduk killed Omorka and from her blood, created all that is. Although this may be no more than superstition and myth, what explanation can a scoffing scientist offer? No more than a great vat of primordial soup.

How man came to be is still somewhat of a mystery, but the lack of clues surrounding his origin has not stopped man from exploring how he can be made. As he learns more about his "stuff", his essential being, he comes ever closer to crossing the line that only the gods had previously dared to navigate. In this age, man is accused of playing God. And for the first time, he may actually be able to fulfill that role.

As science expands, even more new fields of inquiry clamor to be explored. Of all these possible avenues, few are more fascinating or more controversial than that of stem cell research. Since 1998, when a group of scientists at University of Wisconsin-Madison first successfully isolated and cultured human embryonic stem cells, the issue has been prominently featured in the media; recently, even more so since President Bush's decision to allow federal funding for stem cell research. However, this media barrage is actually one of the greatest obstacles to further research in the field. Media tends to fold complicated issues into the simple cases of good and bad, when in fact it is impossible to do so. The impact of media on the masses is an equally controversial topic, but we must concede that it exists. The news media is supposed to be an unbiased source of information, but complete objectivity is, at best, rare. Opinions based on facts cobbled together from CNN and The New York Times are the standard. While one may argue that this is better than an opinion based on gut feeling, it has oft been proven that a little knowledge is a dangerous thing.

If we can view the issue with the clarity that science demands, then we may consider ourselves capable of professing an opinion. To do this, there are concepts that must be defined, distinctions that need to be drawn, and questions that must be asked.

What is a stem cell?

Human development first begins when the male sperm cell fertilizes the female egg cell. This union of two cells has the capacity to form an entire human being. In the first moments of life, this is what's known as a totipotent cell. Totipotent cells are undifferentiated and can become any kind of cell. These embryonic stem cells can be regenerated when cultured, and can be manipulated to produce specific cells, such as blood, muscle or bone cells. These cells, when placed in a women's uterus, can develop into a fetus.

Within a few days of forming, the primitive zygote continues to multiply and begins to form a hollow spherical bunch of cells called a blastocyst. The blastocyst contains an inner and outer layer of cells. The outer layer forms the placenta and other tissues to support the emerging fetus, which is actually created by the inner layer of cells. These inner cells form almost all of the different cells in the human body, and are called pluripotent cells.

The important distinction between totipotent and pluripotent cells is that unlike totipotent cells, pluripotent cells by themselves cannot develop into a fetus. They would not grow if they were simply placed in the woman's uterus, because they lack the ability to produce the cells for fetal development. The blastocyst is still dividing, and breaks into more specialized layers, which are now classified as multipotent cells, since they cannot develop into the same wide range of cells as the pluripotent or totipotent cells. As the embryo grows, cells become more and more specialized, which results in the term multipotent cells. Finally, with a few exceptions, adult cells reproduce only their specific type of cell.

How are stem cells obtained?

Embryonic stem cells can be obtained in various ways. So far, researchers have used three main methods. Of these methods, two extract pluripotent cells, while the third extracts totipotent cells.

1. Dr. James Thompson and his colleagues did pioneering research in this field at the University of Wisconsin-Madison. Their method isolated cells from the inner mass of the blastocyst of a newly formed embryo, thus cultivating pluripotent stem cell lines. The embryos were obtained from in vitro fertilization clinics with the consent of donor couples who were informed about the purpose of this research. The embryos were only those not necessary to fulfill the clinical need of embryos for infertility treatments.
2. Other researchers obtained pluripotent stem cells from embryos after the donors had independently made a decision to terminate their pregnancy. Cells were taken from the embryos that were supposed to develop into fetuses.
3. Finally, the most controversial of the three methods was publicized by the Jones Institute for Reproductive Medicine. The researchers at the Jones Institute created hundreds of embryos purely for the purpose of research. The Institute made no attempt to hide their research, and in fact, titled their paper, "Use of human gametes obtained from anonymous donors for the production of human embryonic stem cell

What are their applications? The potential of this research is enormous. At a basic level, we can understand more about the development of the human body. Beyond this, there is the field of drug research and pharmacology. Instead of the long study and testing before a potentially useful drug can be introduced on the market, drugs can be applied directly to human embryonic stem cells, thus eliminating the need for years of testing. At a more visionary level, the ability to restore any type of cell could be the ultimate panacea. From Parkinson's disease to diabetes to the debilitating Alzheimer's, the embryonic stem cell holds the promise of the complete regeneration of the human body. Where does the controversy lie? When embryonic stem cells are extracted, that organism is for all practical purposes a biological cadaver. If stem cells are extracted from a totipotent cell, those cells no longer have the ability to develop into a fetus. If stem cells are extracted from pluripotent cells, those cells are no longer able to regenerate a fetus even in the presence of the placenta. They can be coaxed in a laboratory to produce whatever cells are needed, but on their own, are no longer prospects for life. The question that we must ask now is the one that is perpetually being debated. At what point does consciousness appear? When does a mass of cells go from being just that to an actual "human being"? There are no easy answers to these questions. In fact, there may not even be a universal answer. But, if we keep in mind that science represents clarity, then obscurity comes only from the perspective of ignorance.

Microscopic 5x view of a colony of undifferentiated human embryonic stem cells. The embryonic stem cell colonies are the rounded, dense masses of cells. (Courtesy of University of Wisconsin-Madison.)

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