Stem-cell research is critical to developing treatments for Alzheimer's and other diseases. But debate grows over whether use of human embryos is really necessary.

Rep. Dennis Hastert of Illinois announced that the budget of the National Institutes of Health (NIH) will more than double, from $13.6 billion in 1998 to $27.3 billion in 2003.

However, as advancements in medical science leap toward providing better treatments, or even cures, new questions of morality and medical ethics abound.

Perhaps no field is fraught with more dynamic possibility and moral concern than "stem-cell" research.

Stem cells are the basis for every type of cell in the body. Many scientists believe they hold the key to developing treatments for autoimmune diseases, Alzheimer's, Parkinson's and various forms of paralysis.

In brief, there are three types of stem cells - pluripotent, which give rise to most, but not all, tissues in an organism; totipotent, which have unlimited capabilities (i.e., a fertilized egg); and multipotent, which give rise to specialized cells (i.e., blood cells).

It long has been believed that pluripotent cells are the most useful for research because they can be coaxed to form a variety of cells. But these are embryonic stem cells "harvested" from aborted fetuses or embryos taken from a mother for in-vitro fertilization.

The use of aborted human tissue has made stem-cell experiments morally controversial. Federal funding of embryonic stem-cell research has been illegal since Rep. Jay Dickey, R-Ark., attached an amendment to the fiscal 1996 Labor, Health and Human Services and Education appropriations bill prohibiting it. But privately funded research of this kind is not prohibited.

The prohibition was challenged in 1999 by the Clinton administration, which wrote new NIH guidelines permitting embryonic stem-cell research by federal agencies - provided stem cells were extracted with private funds. Clinton's Department of Health and Human Services (HHS) also took the position that replication of embryonic cells did not constitute cloning because there was no "embryo."

The legality of these guidelines, which encourage research that creates a market for human embryonic cells, will be decided after the conclusion of a review process established by HHS Secretary Tommy Thompson, whose recent congressional testimony did not tip the hat in either direction. An HHS spokesman tells Insight "no specific date has been set" for completing the review process, but both sides anticipate a summer decision.

In early March, a group of 80 Nobel laureates sent a letter to President George W. Bush urging his support of the Clinton guidelines. But more than 20 congressmen responded with a letter calling Bush's attention to "revolutionary nonembryonic human stem-cell research" being conducted by a joint U.S. Navy/NIH research team.

Meanwhile, the public view of embryonic stem-cell research has been colored by celebrities, such as Parkinson's sufferer Michael J. Fox, creating the perception that to oppose this research is to oppose funding to cure terrible diseases.

"The key here is a lot of people say, 'Well, you are against all stem-cell research.' That is not true. ... What the media do not cover enough of are the success stories of the alternative research and some of the negatives which have been associated with the embryonic stem-cell research," says David Prentice, a professor of life sciences at Indiana State University and an adjunct professor of medical and molecular genetics at the University of Indiana School of Medicine.

In that March 14 letter to Bush, for instance, the congressmen concluded, "Mr. President, we wanted to alert you to the fact that successful stem-cell research does not necessitate the use of human embryos and has already achieved a remarkable degree of success."

Writing in the prestigious medical journal The Lancet, Neil Scolding of the Institute of Clinical Neurosciences at the University of Bristol in England argued that "the rapid progress made in research with stem cells from adults and the clear evidence of the potential therapeutic value of these stem cells make it misleading to suggest that arguing against legalizing embryo research is to deny sufferers hope, or to prevent scientific or therapeutic progress."

One key breakthrough in adult stem-cell work came in October 1997 when the journal Nature Medicine published results from a University of South Florida (USF) study.

Researchers found that when Sertoli cells from rat testes were implanted into rat brains, Parkinson's symptoms decreased, providing hope the process could be duplicated in humans. At a Feb. 18, 2001, meeting of the American Association for the Advancement of Science, USF researchers once again relayed positive news about their effort.

In the study, funded in part by the state of Florida, researchers showed umbilical-cord stem cells could be reprogrammed to act as brain cells, such as neurons, and may speed recovery in the brains of stroke victims.

Unlike the Parkinson's study using embryonic stem cells, scientists injected the cells into the blood rather than directly into the brain.

Stem cells were removed from umbilical cords, transformed into immature nerve cells and injected into the bloodstreams of rats that had suffered strokes.

Acknowledging the potential of stem cells taken from umbilical-cord blood, Chute notes: "There is a high concentration of very potent stem cells within cord blood, which could be easily attained at delivery. The biggest problem is that it is a small sample, so if you are thinking of applying it to adults, there may not be enough of a sample."

Although proponents argue the pluripotency of embryonic stem cells make research with them more valuable, studies have established that the rapid growth of embryonic cells injected into the body can produce tumors. Meanwhile, a study conducted by California-based Geron seeking to produce brain cells from embryonic stem cells not only failed to do so, but actually killed brain cells.

Contestants in this debate appear to be familiar, but the stem-cell issue is not mere mimicry of the abortion controversy. For instance, the pro-choice United Methodist Church argues against using embryonic materials in such research - based on concern about a slippery slope leading to human cloning. Before dismissing those fears, it is advisable to examine the precedent being set in the United Kingdom.

insightmag.com

Comment by David Stevens, M.D.
(Christian Medical Association Executive Director)

This report adds another study to the pro-life side of the ledger. Those strongly advocating embryonic stem cell research maintain that it has greater potential, but the data tells another story.

Almost all the positive accomplishments in stem cell use have been made with adult stem cells. In cases where the cells can be harvested from the patient who later receives them, adult stem cells don't threaten the recipient's immune system.

If federal funds are not diverted to embryonic stem cell research, adult stem cell therapeutics will become a reality much sooner.