First Human Embryos Are Cloned in U.S.
Private Lab Seeks to Mine Stem Cells for Research
By Rick Weiss
Washington Post Staff Writer
Monday, November 26, 2001; Page A01
Scientists in Massachusetts said yesterday they had succeeded in creating the world's first cloned human embryos, a controversial advance intended to speed the development of new medical therapies but which could also hasten the arrival of the first cloned baby.
The cloned human embryos, made by researchers at Advanced Cell Technology in Worcester, grew for only a few hours -- long enough to form microscopic balls containing just four to six cells each. The creations -- made from the fusion of a single human cell and a human egg -- are still so unformed that some ethicists and scientists remain divided over whether they should be called embryos and to what extent they may deserve special moral standing.
Nonetheless, the work broke enough new scientific and ethical ground to reignite a long-simmering debate over human cloning that had been on the back burner since the Sept. 11 terrorist attacks and ensuing events. The use of federal funds to conduct research on human cloning is now illegal, but privately funded scientists such as those at ACT are under no such restriction. Several members of Congress yesterday vowed to place the legality issue on the top of their agendas.
Michael West, ACT's chief executive, has repeatedly said he has no interest in making cloned human babies. Rather, the goal is to coax cloned embryos to grow for just a few days, then isolate from them embryonic stem cells, which have the capacity to grow into all kinds of human tissues -- a process called therapeutic cloning.
Experiments in animals have suggested that cloned human embryonic stem cells could launch a new era of regenerative medicine in which replacement tissues and perhaps organs could be grown for transplantation into aging or diseased individuals.
"Human therapeutic cloning could be used for a host of age-related deseases," West said in a company statement.
In August, President Bush announced a policy that allows federally financed scientists to conduct research on human embryonic stem cells. But those cells must be retrieved from embryos that were created by in vitro fertilization and had been slated for destruction at fertility clinics. Federally funded stem cell research involving cloned embryos is precluded under the Bush policy.
Some scientists have argued, however, that the best way to make stem cells for transplantation into patients is to grow them from embryos that are clones of those patients. That way the stem cells -- and the tissues made from those stem cells -- would be genetically identical to the patient and, in theory, less likely to be rejected by the patient's immune system.
But that approach has raised ethical concerns because it would require the creation of human embryos with the sole intent of destroying them.
The latest work does not show that stem cells can be derived from cloned human embryos, because the clones did not live past the six-cell stage. Typically an embryo must grow to a mass of a few hundred cells before it gives rise to stem cells.
But the work breaks new scientific ground by demonstrating that a single cell taken from a human adult can be coaxed to turn into what appears to be a healthy young embryo -- a feat until now accomplished only in farm animals and mice. And it breaks new ethical ground by creating the beginnings of a human being from a single parent -- a step that many people have said is, at a minimum, morally precarious.
The only previous report of such an experiment was by South Korean scientists in 1998. But that work was never published in a scientific venue, and some experts have questioned whether it was as successful as the scientists there had reported.
Scientists involved in the latest work said it was justified because they and the company's ethics advisory board had concluded that the creations did not have the same moral standing as conventional human embryos and because the creations had such great potential to reduce human suffering.
"This work sets the stage for human therapeutic cloning as a potentially limitless source of immune-compatible cells for tissue engineering and transplantation medicine," said Robert Lanza, vice president of medical and scientific development at ACT and a principal scientist involved in the work, in a news release. "Our intention is not to create cloned human beings, but rather to make life-saving therapies for a wide range of human disease conditions, including diabetes, strokes, cancer, AIDS, and neurodegenerative disorders such as Parkinson's and Alzheimer's disease."
Some yesterday spoke out in favor of the work. "We believe that reproductive cloning should be prohibited but therapeutic cloning [the cloning of embryos to retrieve their stem cells] should be allowed to go forward with oversight" by the Food and Drug Administration, said Carl Feldbaum, president of the Biotechnology Industry Organization.
But members of Congress and others yesterday warned that they would work to preclude further such studies in this country.
"I believe it will be a big debate, but at the end of the day, I don't think we're going to let the cloning of human embryos go on," said Sen. Richard C. Shelby (R-Ala.) on NBC's "Meet the Press."
"I find it very, very troubling and I think most of the Congress would," added Sen. Patrick J. Leahy (D-Vt.).
Antiabortion religious groups spoke out against the work. "We're moving toward artificially creating human embryos solely to mine them for spare parts -- solely to destroy them for their cells," said Richard Doerflinger of the U.S. Conference of Catholic Bishops.
Cloning involves the creation of an embryo from a single adult cell. In the most commonly used technique -- the one used to create Dolly the sheep, the first cloned mammal -- the adult cell is fused with an egg cell whose own genetic material has been removed.
Through a process that scientists have only recently begun to understand, naturally occurring chemicals inside the egg persuade the newly fused creation to behave like a fertilized egg. It begins to divide, one cell into two and two into four, until it becomes an embryo.
If that embryo is transferred to the womb of a surrogate mother -- as has been done repeatedly in recent years with mice, sheep, goats, cattle and pigs, that clone can develop into a fetus and eventually a newborn -- one that is genetically identical to the adult that donated the original cell. ACT had previously made cloned embryos using donated human cells fused with cow eggs (which are more easily obtained than human eggs), including some the firm said appeared to produce coveted stem cells. But the cross-species combination raised technical and ethical issues that the firm wished to overcome.
According to details released on ACT's Web site -- company officials could not be reached for comment yesterday -- the human embryo cloning work began earlier this year when the company placed ads in the Boston area seeking egg donors. Volunteers were given psychological and medical tests, and a dozen of them were selected to donate eggs.
That process involves weeks of hormone supplements and a minor surgical procedure, which can generate up to about 20 eggs.
Other individuals were asked to donate skin cells -- the cells from which the clones would grow -- and in July the researchers tried to fuse some of those cells with eggs.
After three such attempts failed to generate an early embryo, the researchers took a tip from a University of Hawaii team that had cloned mice using cells other than skin cells as their donor cells. They had used a kind of cell that grows inside the ovaries, and which appears to be amenable to being cloned when fused with an egg.
All told, the researchers went through 71 egg cells from seven volunteers before they got a live embryo to grow. Ultimately they managed to get three early embryos to grow -- two that got to the four-cell stage and one that grew to "at least" six cells, the report said.
All three early embryos apparently died after that. It remains unclear whether they harbored genetic or other defects related to the cloning process that might have prevented them from maturing.
The same research team also used a second technique to try to clone embryos. Using chemicals, they forced some human eggs to start dividing on their own, as though they had been fertilized by sperm.
In those experiments, which involve a process called parthenogenesis, the researchers got six out of 22 eggs to grow into what appeared to be five-day-old embryos -- old enough to contain stem cells. But for reasons that remain unclear, those embryos lacked the inner cell mass that usually contains embryonic stem cells.
Clonaid, a second company, said yesterday it, too, had cloned human embryos and hopes to eventually create fully-developed human clones. Its research has not been published, and Clonaid has not revealed the location of its lab.
Clonaid director Brigitte Boisselier told the Associated Press that its embryos were created by injecting eggs with a variety of other cells, but she refused to give details.
The ACT research is described in a new and relatively unknown on-line scientific journal called E-BioMed: Journal of Regenerative Medicine. The company also arranged special media exclusives through which the work is described in Monday's issue of U.S. News & World Report and in the lay science magazine Scientific American -- a media-savvy arrangement that some experts criticized as an unprofessional means of sharing new scientific data.
One ethicist interpreted the approach as evidence that the company is engaged in a power play to gain hotly contested intellectual property rights to the fledgling technology.
"The ability to make these clones could be very, very important," said Glenn McGee, an ethics professor at the University of Pennsylvania who has criticized ACT's selectively releasing details of its work through the media.
"That's not the way to do science, and everyone in science who works on sensitive issues says so," McGee said.