Were claims of the first human embryo premature?

http://www.sciam.com/explorations/2001/122401clone/

December 24th, 2001
By Gary Stix

On November 25, 2001, a Massachusetts biotechnology company, Advanced Cell Technology (ACT), reported in an online journal—e-biomed: The Journal of Regenerative Medicine—that it had cloned the first human embryos. In a concurrent article in the January Scientific American, the researchers explained that their results could "represent the dawn of a new age in medicine by demonstrating that the goal of therapeutic cloning is within reach." Therapeutic cloning—in contrast to reproductive cloning, intended to create a baby—would produce the stem cells needed to treat diabetes, paralysis and other currently incurable conditions.

Many leading scientists, however, say the work should never have been published, because the research failed on several accounts to achieve its goals. First, ACT didn’t produce any stem cells. But more fundamentally, some investigators questioned the company’s basic assertion about having actually cloned a human embryo. In the experiment, the ACT researchers injected cumulus cells into eggs that had their nuclei removed. (Cumulus cells nurture eggs in the ovary.) The investigators hoped that the cumulus cells’ DNA would launch the process of early embryonic development that leads to a hollow sphere called a blastocyst, which would contain stem cells. Among the eight eggs injected with cumulus cells, two divided until they became four-cell embryos, and one proceeded until it reached six cells. Eleven other eggs injected with the nucleus of a skin cell failed to develop.

According to some biologists, a cloned embryo would attain its true status as an embryo only when the DNA from the cumulus cell transferred into the egg began transcription (in which its genes begin to issue instructions to make proteins for embryonic development). An egg contains genetic material (RNA) and proteins that were made during the formation of the egg within the ovary and can support development up to the eight-cell stage without any signals from the DNA in the nucleus. Thus, the ACT experiment may have been "running on fumes, purely directed by RNA and supported by proteins that were present in the egg," says John Eppig, a developmental and reproductive biologist at Jackson Laboratory in Bar Harbor, Me. Eppig adds that "there’s no published information on a cloned human embryo. Whether someone has done it and not published it, your guess is as good as mine. This [result] is not it." (There was one previous claim of multicell embryo clones, but the findings were not published.)

Eppig is not alone. "They did not present in their paper any evidence that the nuclei that they transferred into the eggs were biologically active," notes Brigid Hogan, a developmental biologist at Vanderbilt University and a member of a National Academy of Sciences panel examining the scientific and medical aspects of human cloning. "So therefore, strictly speaking, they cannot say they generated a cloned embryo." She goes on to say, "If that had been [about anything but] human embryos, it would have never gotten accepted in any journal whatsoever, and I’m not the only one that thinks that. I mean, they should have kept quiet until they got some results that were worth publishing." Rudolf Jaenisch, a cloning expert at the Whitehead Institute for Biomedical Research at the Massachusetts Institute of Technology, concurred: "It’s shocking to me that this would be published and that they would have attempted to publish; it’s the total failure of an experiment."

Paul Berg, professor emeritus of biology at Stanford University and a Nobel laureate, also expressed his outrage: "It was anything but a reportable result. I have not heard a single person in this field who hasn’t rolled his eyes and been extremely puzzled of what the motive for it was. Anyone who wasn’t totally naive would have predicted that this would have raised a firestorm among the people who were trying to prohibit this research." Harry Griffin, assistant director at the Roslin Institute, which cloned Dolly the sheep, also questioned whether the work should have been published. But Griffin asserts that, even if the work eventually proves a success, it would be impractical as a routine technique for cell therapy. "The suggestion that the cloning of an embryo would revolutionize stem cell therapy by providing a route for routine immunocompatible cell transplants is simply naive. Such a treatment might be possible for a small number of patients, but there are five million suffering from Parkinson's disease in the U.S. alone. There is, in our view, no way that individual embryos can be created to provide individual treatment for this number of people—it would be incredibly costly, and there are simply not enough human eggs available."

Not everyone was as harsh, however. Peter Braude, head of the division of women and children’s health at Guy’s and St. Thomas’s School of Medicine in London, says that this paper is the first publication that reports having "put donor nuclei into recipient eggs and demonstrated cleavage. They have yet to demonstrate that they have gene activation of the new nucleus, for which they may be criticized as being premature. But with their having put this up online, it is up to the scientific community to either repeat it or refute it." Braude also said he would have difficulty repeating the experiment from the methodology reported by ACT. But he bridled at the suggestion that ACT should have waited until they could publish on stem cells developed through these methods, given the difficulty that researchers have encountered in obtaining stem cells by any methodology. "If people are saying that they ought to have made stem cells as well, I think they’re asking a tall order. It strikes me that they may be the stem cell people who are struggling on those grounds as well. I don’t know of anybody who has good-quality stem cell lines that are out in the public domain."

Michael D. West, the president and chief executive of ACT, says that his group has adopted an approach that resembles that of Bob Edwards, the British scientist whose research resulted in 1978 in the first test-tube baby. Edwards published each step of his studies. That, in West’s view, helped to foster openness about a controversial procedure. "The reason we decided to publish this was purely because we’re promoting the idea of human therapeutic cloning, and we felt it was important to be transparent about where we’re at and publish frequently," West says." He explains further that "when we were sure that we had gotten this far and had these results, we felt there was a publishable paper there."

West cites papers in other journals that have detailed findings about other animals at an early stage of embryonic development—in particular, he pointed to a research group led by Don Wolf of the Oregon Regional Primate Research Center, who published a paper last year on parthenogenesis (coaxing an unfertilized egg to become an embryo) and cloning in rhesus monkeys in the Biology of Reproduction, a well-established journal. The cloned monkey embryos, West says, died at an earlier stage than did the embryos in the ACT experiment. Wolf, however, disagreed with West’s assessment of his work: "I guess I just would ask him whether he would ever consider submitting this [human cloning] manuscript to the Biology of Reproduction," Wolf says. "It would have been laughed off the stage. I mean it’s so inadequate in terms of the number of experiments that were conducted and the failure of the experiments that were conducted."

William Haseltine, editor in chief of e-biomed and chairman of the biotechnology company Human Genome Sciences, defended the decision to publish. "It was a small but significant first step," he says of the research. The paper, Haseltine describes, went through a standard review process in which "two or more" reviewers," not including him, vetted the paper over the course of about three weeks. He refuses to identify the reviewers, saying only that they did not include editorial board members from ACT.

Haseltine also criticizes scientists for voicing their skepticism in the press, instead of writing letters to the journal or attempting to replicate the results: "It is nonscientific and not acceptable for people to make those comments to the press in the form of sound bites where they can’t be judged." He says that scientists may have made such sharp comments partly because of "deep frustration" over the prohibition against any federally funded research that destroys human embryos: "There are those who would express frustration that they think they can do the work better and indeed it is possible they could, but [they] cannot do it." He also blames Scientific American and U.S. News and World Report, which released their articles at the same time as e-biomed, for the subsequent frenzy. "Part of the public furor," Haseltine says, "was generated by the weight that the Scientific American publication also gave to this story and of course U.S. News and World Report."

Scientific American editor in chief John Rennie says that he and staff editors debated whether to publish the article. "I think that we were disappointed that it wasn’t a more clear-cut demonstration of an embryo that was further along," Rennie says. The likelihood of intense public interest in the result as the first documented human cloning demonstration justified the decision, he explained. "It was also our intention to continue to follow the story and provide other points of view on this, including dissenting ones," Rennie elaborates.

Haseltine has complained that his journal was not kept informed that Scientific American was preparing an article to be released concurrently. But ACT has been in the middle of press spats before. In 1998 it made a claim in the New York Times and on a CBS broadcast that it had created an embryo by fusing the nucleus of a human skin cell with a cow egg that had its nucleus removed. West says he just wanted to probe public reaction to the bizarre research. But critics say that the study, which has never been published, was intended to tie into the swell of press attention that attended the publications of research on the first isolation of human embryonic stem cells. At the time, stem cell researcher John Gearhart said ACT’s claims reminded him of the spurious findings about cold fusion.

Critics of the ACT paper say that the dispute has not helped the case for therapeutic cloning. "In a controversial area you should have at least one part clean and scrutinized, which is the scientific part, and then you can go to the public and discuss all the other considerations like ethical and moral, ideological and religious," remarks M.I.T.’s Jaenisch. The U.S. House of Representatives has already voted to ban cloning, whether for therapeutic or reproductive purposes. Last December the Senate declined to take up a measure to place a moratorium on the procedure, but the debate will resume in 2002.

"I think the debate was progressing, and it was progressing in a fairly orderly manner; things were moving ahead," says Vanderbilt’s Hogan. "People were working behind the scenes to make sure that everyone was aware of the biology. People like me were going around giving talks to Rotary clubs and oncology nurses and students, and then this comes out and everybody panicked."

These results may also mislead the public, says one observer. "When relatively underdeveloped science gets touted, first and foremost, patient hopes get raised," says University of Pennsylvania bioethicist Arthur Caplan. "So a lot of people say, ‘Hey, I want this research to proceed because I’m dying and I’m very sick.’ But it’s cruel to offer something everybody knows is going to take a minimum of 10 years."

For his part, West says that the publication has created a healthy awareness about the cloning debate. "This paper," he says, "has certainly made it clear to the U.S. Congress and the U.S. public in general that there may be therapeutic use for nuclear transfer [cloning] that’s entirely distinct from cloning a human being. One does not make a pregnancy."

During a December Senate hearing, West stated that he would be disappointed if ACT couldn’t obtain cloned stem cells within six months. In an interview, Jose B. Cibelli, the ACT researcher who performed the cloning procedure, also said, "Give me 200 human eggs, and I’ll give you cloned human stem cells." Whether such musings prove to be prescience or braggadocio remains to be seen. But one thing that does seem certain is that, one way or another, ACT will find a way to keep its research endeavors squarely in the public eye.

SPEAKING PARTHENOGENETICALLY

In addition to their claim of human cloning, researchers at ACT got six of 22 human eggs to form into balls of cells called blastocysts through a process known as parthenogenesis—in which unfertilized eggs are chemically tricked into becoming embryos. Although none of the blastocysts contained stem cells, a new study at ACT suggests that producing them is possible in primates. In an upcoming issue of Science, ACT is scheduled to report harvesting stem cells from monkey blastocysts and prompting them to turn into cultures of beating-heart cells, gut epithelial tissue, nerve cells that made dopamine, and other cell types.

MIRED IN IRE

Not everyone at e-biomed, the online journal that accepted ACT’s cloning paper, was happy with its publication. John Gearhart of Johns Hopkins University, an editorial board member and a pioneer in stem cell research, told the BBC that he was going to resign from the board over the matter. "I feel very embarrassed and very chagrined by this publication," he said in the BBC interview. In December the publisher, Mary Ann Liebert, was planning to meet with Gearhart and said she hoped he would change his mind.