TCS Daily


Eggs Over Easy? False Dawn for Stem Cell Cures

By Michael Cook - May 25, 2005 12:00 AM

Many people focused on only one word in the banner headlines over news that Korean scientists have successfully cloned 11 embryos and created stem cell lines: cures. Spouses and parents of patients with diabetes, Alzheimer's, Parkinson's and spinal cord damage must have felt elated that their loved ones will no longer have to suffer.

Scientists felt elated, too. The American co-author of the stunning paper in the journal Science, Gerald Schatten, of the University of Pittsburgh, burbled that "in theory, this work could prove to be more significant than the discovery of vaccine or antibiotic".[1] Even his scientific rivals stumbled over each other to congratulate the ingenuity, thoroughness and speed at which Woo-Suk Hwang and his team had worked.

The problem is that the sick and the scientists are rejoicing over two different visions of the future. One believes that cloning embryos will soon yield life-saving cures for devastating diseases and injuries. The other knows that this kind of cloning is basically a research tool for the foreseeable future.

In a number of countries, this news is sure to give heart to supporters of therapeutic cloning at a crucial moment. In California, US$3 billion of funding for a new Institute for Regenerative Medicine is being held up by legal, administrative and financial wrangles. But the news from Seoul will confirm Californian scientists that they are on the right track. In Australia, the Federal Government is about to review the possibility of allowing therapeutic cloning. In Germany Chancellor Gerhard Schröder is expected to announce his support in a speech next month.

So it's important to get this straight now: cures from so-called therapeutic cloning are probably decades away. If ever.

Let's put the central issue of whether the clone is a human being to one side. Other practical and ethical issues make the Koreans' research a non-starter. This is an opinion shared by many scientists, starting with Australia's Alan Trounson, a world expert on embryonic stem cells who will be reviewing projects submitted to the new California institute. He told the journal Nature Medicine earlier this month that "the so-called therapeutic cloning to my mind is a non-event". As a way of creating cures, he observed, "it's just not realistic." He was supported by an American expert, José Cibelli, of Michigan State University, whose tip is that "I can predict that therapeutic cloning is going to be obsolete."[2]

What's the problem?

The first is an economic one: the cost of the cures. The advantage of therapeutic cloning is that it would offer a therapy which is genetically specific to the patient. The disadvantage is that the therapy cannot be used for other patients for that very reason. Unlike conventional drugs, there will be far less scope for economies of scale.

One of the advances made by the Korean team was a ten-fold increase in efficiency. In the experiment which put them on the world map last year, they used 242 human eggs to create a single embryo. By refining their techniques they have now managed to derive cell lines with fewer than 20 human eggs. But it is unlikely that this will put therapeutic cloning remedies on the shelves of every drugstore. Since a woman treated with superovulation drugs yields only about 10 eggs, this means that one or two painful, invasive, and risky IVF cycles will still be needed for her to produce the raw material for a therapy for a single patient. [3] Therapeutic cloning is still going to be medicine for millionaires.

The second issue involves clinical ethics. Will it be possible to avoid exploitation of the donors, whether or not they are remunerated? Egg donation is normally safe, but there can be serious complications, including death. It is not a trivial affair.

So the protocols to protect women donors were an important element in Woo-Suk Hwang's experiment and one to which he gave special attention. The paper published in Science even reproduced the informed consent forms in an effort to convince other scientists that his team's ethical standards were on a par with those of the United States.

Unfortunately, two American bioethicists who reviewed his work in the same issue of Science gave him a D-minus for ethics. David Magnus and Mildred Cho, of Stanford University, are by no means conservatives. But they slated him for failing to describe adequately the risks to participants and for depicting donors as patients. In fact, in their opinion, a good doctor would advise women against exposing themselves to the risk of egg donation. After scrutinising the experiment and the informed consent forms, they concluded that there was abundant potential for abusive exploitation of "vulnerable patients and their friends and family members". [4]

In particular, they highlighted an ethical difficulty which is inherent in the whole therapeutic cloning project at the present time: that the word "therapeutic" is misleading. "It is nearly certain that the clinical benefits of the research are years or maybe decades away," say Magnus and Cho. "This is a message that desperate families and patients will not want to hear." [5]

Moreover, the newspaper hype obscured the fact that Hwang's ideal donors come from a particularly vulnerable group. He has discovered that the best clones come from freshly harvested eggs from fertile women under 30. When eggs from women in their 30s were used, one stem cell line resulted after 30 tries. Younger women produced a stem cell line after only 13 tries, on average. It's easy to see what will result if Hwang's work gets traction: young women selling their eggs to support their children, pay their college tuition or finance overseas holidays.

There's a third factor which pushes the use of the embryonic stem cells far into the future -- the safety and efficacy of these new products. As leading stem cell scientists in Britain point out in the British Medical Journal this month, "the premature use of cell therapy could put many patients at risk of viral or prion diseases unless systems are in place".[6] They remind their colleagues of the lessons learned -- and perhaps forgotten -- from the premature application of gene therapy, the devastation of HIV-infected haemophiliacs, hepatitis C spread through blood transfusions and the mysterious emergence of mad cow disease. "Commercial companies are springing up around the world with all the fervour of a new 'biological dotcom' era, but with selective memory loss for the fact that unrealistically high expectations burst that bubble," they write.

A final problem is the specter of human reproductive cloning -- to which nearly all voters are opposed. This taints Hwang's success, just as it has every advance in cloning embryos. His paper in Science piously stated that it did not provide "any encouragement for dangerous human reproductive cloning attempts. Cloned animals have adverse pregnancy outcomes, so regardless of cruel hoaxes, scientific evidence should further dispirit reckless notions regarding human reproductive cloning." [7]

But this is wishful thinking.

The truth is that Hwang's work brings the possibility of reproductive cloning just a little bit closer. And the gathering pace of therapeutic cloning is spiriting, not dispiriting, reckless notions of support for human reproductive cloning. Earlier this month Julian Savulescu, an Australian who is professor of practical ethics at Oxford University, and editor of the influential Journal of Medical Ethics, argued that cloning "will represent one of the greatest scientific advances... Cloning is power and opportunity over our destiny. Eventually artificial reproduction will become safer and more efficient than natural reproduction." [8] There is no shortage of bioethicists who share his views.

And not only bioethicists. James Watson, one of the discoverers of DNA, told a newspaper only a few days ago that there was nothing inherently wrong with cloning. "I'm in favour of anything that will improve the quality of an individual family's way of life," he said.[9]

In fact, stem cell scientists themselves would walk on hot coals before they said the "wrong" word. For instance, the InterAcademy Panel, a global network of national science academies which includes the US National Academy of Sciences and the British Royal Society asserts that reproductive cloning should be banned. But it acknowledges that cloning could become safe some day and that any ban should be "should be reviewed periodically in the light of scientific and social developments"[10]. In other words, "ring us when you've got everything ironed out and we'll make it ethical."

In short, there's no need for us to jump on the therapeutic cloning bandwagon after Hwang's announcement. Apart from the fundamental issue of destroying embryonic human life, there is a raft of other issues which make its success very doubtful. The main thing we have to worry about is resisting the panic of stem cell scientists who have been left in the dust by the Koreans.

Michael Cook is the editor of BioEdge, an international email newsletter on bioethics. Email: mcook@australasianbioethics.org



[1] "Korean scientists envisage long journey to cell treatment." Korea Herald. 21 May 2005. http://www.koreaherald.co.kr/SITE/data/html_dir/2005/05/21/200505210028.asp

[2] "Scientists seek simple remedies to cloning conundrums". Nature Medicine. May 2005, 459.

[3] Gretchen Vogel. "Korean Team Speeds Up Creation Of Cloned Human Stem Cells". Science. 20 May 2005. (Free registration required.)

[5] David Magnus and Mildred K. Cho. "Issues in Oocyte Donation for Stem Cell Research". ScienceExpress. 19 May 2005. Free registration required. http://www.sciencemag.org/cgi/rapidpdf/1114454.pdf

[6] Peter Braude, Stephen L. Minger and Ruth M Warwick. "Stem cell therapy: hope or hype?" BMJ, 21 May 2005. http://bmj.bmjjournals.com/cgi/content/full/330/7501/1159

[7] Woo-Suk Hwang et al. "Patient-Specific Embryonic Stem Cells Derived from Human SCNT Blastocysts". ScienceExpress. 19 May 2005. Free registration required. http://www.sciencemag.org/cgi/rapidpdf/1112286.pdf

[8] Julian Savulescu. Debate in The Times Higher Educational Supplement. 6 May 2005.

[9] "Process holds out hope for childless couples." Guardian (UK), 20 May 2005. http://education.guardian.co.uk/higher/research/story/0,9865,1488424,00.html

[10] InterAcademy Panel. "Statement On Human Cloning". 22 September 2003. http://www4.nationalacademies.org/iap/IAPHome.nsf/weblinks/WWWW-5RHG35/$file/Cloning_Stat_EN.pdf?OpenElement

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