Hope or Horror?

Texas Physicians Choose Hope in Backing Therapeutic Cloning

Texas Medicine Logo(1)

Public Health Feature -- July 2004  

By  Ken Ortolon
Senior Editor  

Will stem cell research give physicians new ways to treat disease? Or threaten society with the horror of humans created solely for their stem cells and the prospect of designer babies? That was the debate reignited in February when South Korean researchers revealed that they had successfully harvested stem cells from a cloned human embryo.

Some in Congress want all embryonic stem cell research banned. USA Today reports that 33 state legislatures are considering laws supporting, funding, or condemning embryonic stem cell research.

But supporters say stem cell research and so-called "therapeutic cloning" should be embraced because of their great potential for creating new cures for disease. They urge lifting a ban on federal funding of embryonic stem cell research before the United States falls behind other nations.

Meanwhile, several private institutions, including Harvard University, are moving forward with stem cell research without federal money.

In May, Texas physicians joined the fray. The Texas Medical Association House of Delegates voted to support research on both embryonic and adult stem cells and to support therapeutic cloning in biomedical research. However, the house also decided to oppose cloning for producing a human child. Corpus Christi clinical geneticist Raymond C. Lewandowski Jr., MD, says abandoning or limiting research on any type of stem cells would be "premature and ill-advised since we haven't seen what the potential of any of them really is yet." 

Measuring the Potential  

The new policy the house approved was recommended by the TMA Council on Scientific Affairs in consultation with the Board of Councilors. The policy, based largely on an American Medical Association Council on Scientific Affairs report, supports biomedical research on multipotent stem cells, including embryonic, adult, and umbilical cord blood stem cells. It also supports somatic cell nuclear transfer (SCNT) technology, or therapeutic cloning, for biomedical research; opposes cloning specifically for producing a child; and encourages public support for federal funding for research involving pluripotent stem cells.

Dr. Lewandowski, a member of the council and primary author of the report, says the research community does not support reproductive cloning.

"No one within the organization or within the legitimate scientific community believes that human cloning should ever occur."

Therapeutic cloning is another matter, however.

In its report, the council concluded that all types of stem cells show great potential for therapeutic application, but embryonic stem cells have the maximum potential.

"In most cases, to be useful in research and eventually medical therapies, these cells must be able to be grown in tissue culture, maintain genetic stability for at least eight months, and have the ability to differentiate into any organ type," the report states. "Under some circumstances, freshly collected stem cells may be useful without cultures. Stem cells from embryonic tissue clearly possess all of these potentials. It is not currently known if stem cells derived from adult tissues have these potentials."

There are four potential sources for embryonic stems cells. They are embryos created for reproduction that went unused and are stored by fertility clinics, SCNT, parthenogenesis, and more than 70 embryonic stem cell lines that existed before President Bush's August 2001 ban on federal funding. While the 70 stem cell lines can be used in government-funded research, only 13 are available to U.S. researchers. Parthenogenesis involves selecting eggs at a point in their maturation cycle when they still have their full complement of genes and artificially stimulating them to induce cell division. It has been successful in rodent embryos, but not in humans. 

Building a Better Cell  

SCNT involves removing the nucleus from an egg and replacing it with a nucleus from an adult cell. This "new cell" then forms a blastocyst from which stem cells can be harvested.

The council concluded that embryonic stem cells created through SCNT are better for therapeutic purposes because they can be administered to the nucleus donor without eliciting an immune response.

O. Edwin McClusky, MD, former chair of the Council on Scientific Affairs, and Albert Sanders, MD, former chair of the Board of Councilors, say those panels backed embryonic stem cell research, including SCNT, because of its tremendous promise in treating a wide range of diseases.

While acknowledging concerns that "some rogue" scientist might attempt to use SCNT to produce a human child, Dr. Sanders says the Board of Councilors feels the risk versus the reward is worthwhile.

"If you've got appropriate safeguards on it and complete agreement that cloning leading to production of a child is wrong, then I think you can keep a lid on it so that it's only used for valid research."

The Council on Scientific Affairs began examining the issue of therapeutic cloning last summer, and its report was vetted with several other TMA councils and committees, TMA physician leaders, and some physicians known to hold pro-life positions prior to approval by the full council at TMA's Winter Conference in February. The council received little negative feedback, and the House of Delegates approved the policy without debate.

Where's the Therapy?  

However, not all physicians support the policy. New Braunfels family physician Beverly B. Nuckols, MD, spoke against it before a House of Delegates reference committee. She said therapeutic cloning is a misnomer because it provides no therapy for the organism that is the subject of the research.

She believes embryonic stem cell research violates a physician's first duty to "do no harm," and destroying a human embryo, even one created artificially through SCNT, amounts to taking a human life.

"I don't believe any human has a right to kill another human and, by species definition, these embryos are human beings, Homo sapiens . I believe we need to draw the line now as to whether humans are to be killed by other humans for the benefit of a third or fourth person, or whether we're going to say no, humans will not be killed by other humans unless that person is a direct danger to another."

AMA policy says cloning for biomedical research is "consistent with medical ethics."

Ken Ortolon can be reached at (800) 880-1300, ext. 1392, or (512) 370-1392; or by email at Ken Ortolon.  

July 2004 Texas Medicine Contents
Texas Medicine Main Page