THE SCIENCE BEHIND STEM CELL RESEARCH
The bioethics surrounding the revolutionary new embryonic stem cell research has been described in a prior presentation, entitled "The ‘Ethics’ Behind Embryonic Stem Cell Research." Having discussed the grave moral implications of stem cell research, I would like to present the scientific facts as I have extensively researched them since serious research began in the late 1990s. However, before engaging in a meaningful discussion on the current avenues of stem cell investigations, the basic procedure of embryonic stem cell research should be clearly understood. In essence, here`s how the system works: A week-old human embryo is a fluid-filled ball with 100 to 200 stem cells clustered inside at one end, like a mess of peas at the bottom of a pot. Dubbed by researchers the "queen of all cells," each one of these cells has the potential to become any specialized cell in the body. Scientists are racing to find the biochemical triggers that direct stem cells. In one hormone environment they could yield skin for burn victims, for example, or functioning neurons for Alzheimer`s patient. Another cocktail of growth factors could stimulate them to become insulin-producing cells for diabetics, or they could be trained to grow a whole human heart or liver for transplant.
There Are Several Ethical Sources of Stem Cells
Current cutting edge research make it clear that many irresponsible claims about the unique promise of embryonic stem cells must now be abandoned. Indeed, breakthroughs in stem cell research reported just in the last six to nine months take one's breath away. The exaggerated claim that we must destroy human embryos to advance medical progress is not only morally obtuse but now scientifically irresponsible. There is an abundance of alternative ethical sources of stem cells, negating the push for the nightmarish use and destruction of living human embryos for such research. What will surprise many people is that none of these remarkable achievements relied on the use of stem cells from embryos or the products of abortion. Indeed, all of these experiments involved adult stem cells or undifferentiated stem cells obtained from other non-embryo sources. And one would think that the opportunities for developing successful therapies from stem cells that do not require the destruction of human embryos should be very big news. But where are the headlines? These and other successful experiments have been all but drowned out by breathless stories extolling the miraculous potential of embryonic stem cell research.
Scientists have been able to obtain stem cells, effective for research purposes, from placentas, umbilical cords, bone marrow, human fat tissue and brain cells from human corpses. In fact, in a study published in the journal Cell in May 2001, lead researchers, Dr. Neil Theise of New York University School of Medicine and Dr. Diane Krause of Yale University School of Medicine, show that stem cells derived from adult bone marrow could be the best master cells discovered to date. In an experiment, mice were radiated, destroying their bone marrow and damaging various organs. A single stem cell was then introduced into these mice, which differentiated not only into bone marrow and blood cells, but also into lung, esophagus, stomach, small and large intestine, liver and skin cells. In addition to avoiding the ethical problems of stem cells derived from embryos or aborted baby tissue, stem cells from most of these sources are readily available
Warnings about optimistic predictions concerning embryonic stem cells used in human experiments have come from many highly trusted scientific sources. In an article that contrasts the dearth of results from these "miracle" cells with the plentiful and promising results of research using stem cells from other sources, the December 1, 2000 Science journal confirmed doubts about the cure-all that researchers claim fetal stem cells are. It also named research demonstrating the potential of adult stem cells as the fifth most important scientific advance of 2000. More importantly, it states that studies during that year had proven false earlier assumptions that adult stem cells could not be reprogrammed into other types of cells.
Perhaps even more astonishing, the National Institute of Health`s own National Institute for Neurological Disorders and Stroke has confirmed that patients` own bone marrow stem cells can be directed to generate nerve cells for brain repair. Researchers have found "an unexpected amount of flexibility in older cells," and are excited because "bone marrow cells taken from a patient`s own body would not be rejected by the body's immune system." We've known for some time that bone-marrow stem cells can make more blood, but now we know that these adult stem cells can also make bone, muscle, cartilage, heart tissue, liver, and even brain. Bone marrow and cord blood are already successfully being used clinically. Contrast this with clinical use of embryonic stem cells which is believed to be years away. Current clinical applications of adult stem cells include treatments for cancer, arthritis, lupus, and making new corneas, to name a few.
The February 1, 2001, New England Journal of Medicine reports on successful efforts by Italian and Russian researchers to repair "large bone defects" using adult stem cells. By growing patients' own stem cells and placing them on porous "scaffolds" shaped to bridge the gaps in their bones, researchers were able to restore limb function to three patients with serious bone defects in record time.
Another study published in the May 3, 2001, issue of the journal Nature shows that stem cells can be extracted "from the brains of dead people." Fred Gage, of the Salk Institute in La Jolla, California notes that the cells extracted from nine cadavers ranging in age from 11 weeks to 71 years, that had been dead for as long as 20 hours, were able to develop into three different types of brain cells, which could then be transplanted to people with disorders such as Parkinson's disease.
One obvious advantage of using our own adult stem cells is that there will be no transplant rejection, since it is our own tissue. By contrast, use of human embryonic stem cells will require lifelong use of drugs to prevent rejection of the tissue. Or, the patient will have to be cloned (a second ethical issue), and that embryo (the patient's twin) sacrificed to obtain the embryonic stem cells for the tissue, essentially creating a human being whose only purpose is to be "harvested".
Unforeseen Problems and Risks Associated with Embryonic Stem Cell Implantation
We have in North America an untrustworthy mainline news media that is deliberately keeping from public knowledge the unforeseen problems and risks associated with embryonic stem cell implantation (the same type of mind set that keeps them from reporting on the indisputable link between breast cancer and abortion). According to the March, 2001, issue of the New England Journal of Medicine, using embryonic stem cells to treat Parkinson's is a kind of medical shell game, with sometimes nightmarish results. Tragic side effects resulted from an experiment involving the insertion of fetal brain cells into the brains of Parkinson's disease patients. The results, in the words of one disheartened researcher, were " utterly devastating," with the unfortunate patients exhibiting permanent uncontrollable movements: writhing, twisting, head-jerking, arm flailing, and constant chewing. One man was so badly affected he no longer can eat, requiring the insertion of a feeding tube.
Even more alarming, a May, 1996, Neurology article disclosed a patient's death caused by an experiment in China in which fetal nerve cells and embryo cells were transplanted into a human Parkinson's patient. After briefly improving, the patient died unexpectedly. His autopsy showed that the tissue graft had failed to generate new nerve cells to treat his disease as had been hoped. Worse, the man's death was caused by the unexpected growth of bone, skin, and hair in his brain, material the authors theorized resulted from the transformation of undifferentiated stem cells into non-neural, and therefore deadly, tissues.
Even some of the most enthusiastic boosters of embryo stem cell research see trouble ahead. For example, University of Pennsylvania bioethicist Glenn McGee admitted to Technology Review, a Massachusetts Institute of Technology publication, "The emerging truth in the lab is that pluripotent stem cells are hard to rein in. The potential that they would explode into a cancerous mass after a stem cell transplant might turn out to be the Pandora's box of stem cell research." Thus, it is very likely that adult tissue-specific stem cells are actually safer than their counterparts culled from embryos since, being extracted from mature cells, they may not exhibit the propensity for uncontrolled differentiation.
While some studies using stem cells taken from embryos to treat Parkinson's-type symptoms in mice may have seemed encouraging, grafts of fetal and embryonic tissue may provoke the body's immune response, leading to rejection of the tissue and potentially death, since once the cells are injected they cannot be extracted.
As one researcher (whose name I can`t) noted regarding human embryonic stem cells: "We thought from the first that problems would arise using human pluripotent stem cells to make replacement tissues," indicating that the early stage cells are both difficult and slow to grow. "More important, there's a risk of tumors. If you're not very careful when coaxing these early cells to differentiate - to form nerve cells and the like - you risk contaminating the newly differentiated cells with the stem cells. Injected into the body, [embryonic] stem cells can produce tumors." No such problems exist with adult stem cells.
Sadly, it most be conceded, embryonic stem cells have been held up as the panacea for disease and a fountain of youth, despite the advantages of adult stem cells both from a scientific and ethical view point.
Why Then the Continued Scientific Support for Federal Funding of Embryonic Stem Cell Experimentations?
After reviewing the recent startling advances in adult stem cell research, the past December 1, 2000, issue of Science (journal which supports destructive embryo research) admits that "easily accessible cells from bone marrow might someday be used to treat a wide range of neurological diseases - without raising the ethical concerns that accompany the use of embryonic cells." And this article admits something even more significant: "In contrast, the human embryonic stem cells and fetal germ cells that made headlines in November 1998 because they can in theory develop into any cell type, have so far produced relatively modest results."
"Relatively modest" is really a euphemism here. The results reported by the Geron Corporation at last November`s neuroscience meeting in New Orleans are deeply disturbing. Their researchers reported that when they transplanted human embryonic stem cells into rats' brains, the cells "did not readily differentiate into brain cells. "Instead, "they stayed in a disorganized cluster, and brain cells near them began to die.
Earlier reports that these embryonic cells might not be easy to control - that they might produce tumors or other harmful growths when transplanted into patients - had been dismissed by some embryo research enthusiasts. Now the leading corporation funding embryonic stem cell research in the United States, which has more experience in this field than anyone else and has aggressively lobbied and testified for federal funding, has confirmed these reports. The Science article noted that "Geron researchers seem no closer than other groups to devising therapeutic uses for [embryonic] stem cells."
This article further notes that human embryonic cells have proved much harder to grow in culture than once thought -- much "trickier" to keep alive than the mouse embryonic cells which had raised some researchers' hopes. This is especially ironic because embryo research advocates have denied that adult stem cells can be grown to produce sufficient quantities of cells for transplants. Now adult stem cells are proving easier to grow than many thought, and embryonic cells proving far more difficult.
All of this raises intriguing questions: Why is federal funding for embryo and fetal research pushed so hard and so publicly - while adult stem cell and other alternative therapies are damned with faint praise? Why do the media applaud fetal stem cell experiments and provide abundant coverage of stories promoting the use of embryos, while they mention uncontroversial research not requiring the destruction of human life as an afterthought, if that? Indeed, why do some scientists assert that alternative stem cell research offers but uncertain hope, while they promote embryo and fetal tissue research as the keys to the Great Cure - as the Holy Grail of 21st century medical research? Why go down the ethically flawed and controversial path of fetal stem cells, when adult stem cells offer such tremendous hope for treating every disease that research using embryos and fetal tissue seeks to improve? I`m still scratching my head for an answer to these questions.
In my view, the ultimate purpose of promoting federal funding for embryo experiments over adult stem cell research, particularly among many in the bioethics movement, is to open the door to the eugenic manipulation of the human genome. Once embryos can be exploited for their stem cells to promote human welfare, what is to stop scientists from manipulating embryos to control and direct human evolution, equally for the purpose of improving the human future? Indeed, some of those who are pushing the hardest for non-discretionary federal funding for human embryo research are scientists and bioethicists well known as favoring eugenics. For example, among many others, Nobel prize winner Dr. James D. Watson, a co-discoverer of the DNA helix, has written that newborns should not be considered "alive" for three days, to permit genetic screening. He believes newborns who fail to pass genetic muster should be discarded, much as the ancient Romans left unwanted babies outdoors to die of exposure.
Professor Peter Singer, formerly deputy director of the Centre for Human Bioethics at Australia's Monash University, now Professor of bioethics and human values at prestigious Princeton University, recently said that in cases where parents and doctors agree that a baby's disabilities are incompatible with a decent quality of life, it would be kinder to end the baby's life deliberately, rather than leave it to die. He suggests giving a lethal injection would be appropriate. This icon of the bioethics community argued years ago that: 1) the life of a healthy pig or a dog has superior value to that of an infant with a birth abnormality; 2) "Killing a defective infant is not morally equivalent to killing a person. Sometimes it is not wrong at all; 3) "No infant, defective or not, has a strong claim to life as a person." As a thinker, this man is consistent, clear, and as subtle as a tank rolling over a wheelchair. Yet, sadly, these are the type of people fueling the promotion of unfettered stem cell research among the research and media elites that, objective scientific assessment tells us, is unlikely to produce the therapeutic benefits its supporters have told us to anticipate!
As any objective study of the current scientific literature indicates, ethically palatable adult stem cells are showing much more promise than embryonic cells. In fact, they are already being used clinically, making good on the potential that embryonic stem cells still only promise. The proponents of embryonic stem cell experiments may want to believe otherwise, but they cannot deny that the cutting-edge research being done now uses adult stem cells as a source for tissue. For this reason, we should focus our presently scarce public resources with laser-like intensity on the incredible potential of adult and alternative sources of stem cells. We can pursue the cure of disease in morally acceptable ways. In the case of stem cell research, the choice between medical progress and moral principle is truly a false dilemma.
New Brunswick, Canada
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