HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Reprints/Permissions Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Civin, C. I. Search for Related Content PubMed Articles by Civin, C. I.

Human Pluripotent Stem Cells: Science Fiction Poses No Immediate Dangers

On August 29, Pope John Paul addressed an international conference on transplantation, interrupting his summer retreat for the opportunity to comment on the ethics of stem cell investigations and therapies. The Pope is reported to have "praised science for its dedication to preserving human life" and judged it "morally permissible to conduct research on adult stem cells." But he maintained that the Catholic Church would continue to adamantly oppose "any tampering with embryos, teaching that life begins at the moment of conception... ‘These techniques, insofar as they involve the manipulation and destruction of human embryos, are not morally acceptable, even when their proposed goal is good in itself’"[1].

I am afraid that Pope John Paul's response represented the public's overreaction to scientific fiction as opposed to scientific reality. Earlier in August, President Clinton released new guidelines, which would permit U.S. scientists to utilize NIH grants to support research using stem cells initially obtained without NIH support. Prime Minister Blair went considerably further, allowing UK scientists to utilize government funds to obtain embryonic stem cells from embryos terminated within two weeks of fertilization. We scientists hope that these new guidelines will speed stem cell biology, and several in the scientific community spent major efforts educating the government and the public to reach this point. Thus, we scientists and physicians involved in stem cells and transplantation research had felt that August began as a pretty good month.

We all know that this subject involves a vast ethical and religious territory, which I am not prepared to discuss. But there seem to be some misconceptions involving the state of the science of stem cell biology, which are of immediate interest to the readership of STEM CELLS and are major explicit and implicit factors in this swirling controversy.

Cloning prokaryotes, plants, and non-human animals (such as the famous cow, Dolly) for scientific and commercial purposes is accepted. While such work is likely to also eventually elucidate the principles for cloning humans, the obvious near-term gains, such as feeding the hungry, seem to justify the risk. To create an entire mammal currently requires artificial insemination. If we were able to extend the Dolly experiments directly to humans, most of the embryogenesis of such a cloned human would have to occur in vivo in a human uterus. Clearly, society should fund and otherwise catalyze research and thinking on how to appropriately and effectively regulate cloning of whole humans. Perhaps we could all agree that guidelines, policies and laws should prohibit insemination of humans (or non-human primates) with such embryos, except for the currently accepted purpose of creating full-term newborn children who would grow to independent adulthood.

But what if we could grow, ex vivo, a needed tissue or organ from a fertilized (or unfertilized) human egg, or an early embryonic cell? We might then be able to alter the DNA to substitute donor histocompatibility genes to prevent graft rejection, etc. Although this is what we hope to learn from the current research on human embryonic stem cells, this is a long way off. We do not know even now the tricks necessary to induce human hematopoietic stem cells to self-renew extensively ex vivo, and it can be argued that this is the tissue where stem cell science is furthest along. Some neuronal differentiation has been observed in ex vivo cultures of human embryonic cells, but a great deal more needs to be done to generate functioning cells of the adult nervous system; not to mention the complex anatomic cellular interplay. Nor are we likely to be able to grow a functional kidney, pancreas, liver, heart, or lung from a human embryonic cell in the next few years. I am concerned that, in communicating our excitement about the wonderful and likely long-term gains we can achieve by unleashing scientists to study human embryonic stem cells, we stem cell biologists have confused the public into thinking that we are nearly there. Such gains will take years, perhaps decades. Have we then, in our enthusiasm, overestimated what we can do in the short run, and unintentionally promulgated science fiction rather than science? I think that we have plenty of time to study the ethics of stem cell therapies, much as we have studied the relevant ethics in preparation for proper utilization of scientific information, as we sequenced the human genome.

We have real life examples we can start with. Long-held religious concepts provide starting points, as do the Nuremberg judgments, etc. In addition, I am sure that some parents of children with cancer have had additional children, in part to provide potentially matching hematopoietic stem cells (obtained at birth from cord blood, or after birth from marrow) for transplantation to their ill child. This is verified by a recent New York Times article [2]. Perhaps this has also been done or considered for children needing solid organ transplants. Can the principles involved in these currently acceptable individual family decisions help us to think about the issues around the feared potential issue of "baby farming" solely for the purpose of organ generation?

We have everything to gain by considering and addressing these issues today. Although these are hard issues, we have considerable time to think, debate, and investigate. Surely, we must prevent the Dr. Frankenstein scenario, but that was and still is science fiction. We do not have to stop the science at any point soon. Moreover, this approach of legislatively stopping the discovery science has never provided the solution. Instead, scientists must convince the public of the importance, applicability, and feasibility status of current and near-future discoveries and technologies. Moral responsibilities of scientists must be stressed, so that science can exist within society and be wisely and appropriately regulated by society.

REFERENCES

1. Baker L. Pope tells scientists cloning morally unacceptable. August 29, 2000. Available from: Reuters Health via the internet: http://www.reutershealth.com/frame2/chch.html

2. Grady D. Baby conceived to provide blood cell transplant for his dying sister. N Y Times October 4, 2000; Science.

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Reprints/Permissions Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Civin, C. I. Search for Related Content PubMed Articles by Civin, C. I.