WOODY ALLEN: Better have a look at the patient.
SUSAN DENTZER: For decades, the idea of cloning a human being has seemed farfetched, even surreal.
WOODY ALLEN: It's a lot more safe than I thought.
SUSAN DENTZER: Comedian and Director Woody Allen played off that in his 1973 film, "Sleeper."
WOODY ALLEN: We're going to make an attempt to clone the patient directly into his suit, and that way, he'll be completely dressed at the end of the operation. It's a first in cloning. And then we can all just get the hell out of here, without hanging around waiting for him while he suits up.
SUSAN DENTZER: But in 1997, Dolly the sheep was born, and cloning was no longer a laughing matter. Since then, scientists have cloned at least seven other animal species, ranging from mice to rabbits to cows. All are identical, or nearly identical, copies of the animals from which they were cloned. Now, some scientists and physicians are attempting the highly controversial cloning of humans.
Recently, one Italian fertility doctor, Severino Antinori, claimed that three of his female patients were pregnant with cloned human embryos. Although many scientists have dismissed his claim as implausible, several other say they're pursuing the same goal, and will soon produce tangible results.
Last year, the U.S. House of Representatives voted to ban all forms of human cloning. Now, the U.S. Senate plans to take up similar legislation. It would subject anyone who undertook human cloning to as much as ten years in prison and $10 million in fines. Kansas Republican Senator Sam Brownback is a lead sponsor.
SEN. SAM BROWNBACK: The only thing we're banning is the process that Dolly the sheep was created; that there not be a "Dolly the person" created in that same cloning technology. That's the only thing we're banning. We're saying that you can create "Dolly the Lamb," you can create "Copy the Cat," but you can't create "Dolly the Person."
SUSAN DENTZER: President Bush has vowed to sign anti-cloning legislation if it passes the Senate.
PRESIDENT GEORGE W. BUSH: Human cloning is deeply troubling to me, and to most Americans. Life is a creation, not a commodity.
SUSAN DENTZER: But many lawmakers say the real debate over cloning is more complicated. On the one hand, almost no one believes it's safe to use cloning to create a baby, a procedure referred to as reproductive cloning. That's because most scientists fear serious and potentially deadly genetic abnormalities in the babies that would result.
On the other hand, many scientists and medical experts do want to allow for the cloning of individual human cells. That's a process usually referred to as therapeutic cloning, or nuclear transplantation. In effect, researchers use the same basic techniques of cloning, but for a radically different purpose than creating a new human being. Instead, they're trying to create specialized new cells or tissues to treat people with serious diseases. Michael West is president and CEO of Advanced Cell Technology. Last year, the company published research claiming that it had cloned the first human embryos.
MICHAEL WEST, Advanced Cell Technology: The day will come, maybe in our lifetime, when we can use this new technology of regenerative medicine to actually make a whole organ; a complex tissue. Certainly, the first uses of the technology are going to be simple ones: Just to make some cells; cells to cure diabetes; blood cells in the case of cancer.
SUSAN DENTZER: Some lawmakers consider the potential so great that they're backing a rival bill. Their legislation would also ban human reproductive cloning, but it would allow research on therapeutic cloning to proceed. Republican Senator Arlen Specter of Pennsylvania is a lead sponsor of that bill.
SEN. ARLEN SPECTER: The 40 Nobel Laureates who have come forward and have said, "Don't tie the hands of the scientists by making this a criminal offense," say that the potential for curing these maladies is overwhelming, and it ought to be done.
SUSAN DENTZER: To learn more about what is involved in therapeutic cloning, we paid a visit to West and his colleagues at Advanced Cell Technology. On the day we visited the company, its lead scientist, Jose Cibelli, along with his lab assistant, gave us a demonstration of the procedure. On this occasion, they used cells from a cow, rather than cells from humans. To perform cloning, the scientists needed two cells in particular, an egg cell from a female cow and a so-called somatic cell, or body cell, from another one.
JOSE CIBELLI, Advanced Cell Technology: Here what we're going to see in the monitor is the first step, the removal of the DNA from the egg. So that's the egg. The egg is being... you need to hold the egg with suction, and then you go with a needle in... we're already in. And she is now removing the DNA-- that was the maternal DNA.
SUSAN DENTZER: The egg cell's nucleus, containing the DNA, was drawn up into a tiny glass tube, and discarded. Then the lab assistant began the next step, the actual cloning, or bringing in the new DNA from the other animal.
JOSE CIBELLI: And what you do is you take a somatic cell from the animal-- in the case of a patient, you take a somatic cell from the skin of a patient-- and she can go back through the same hole, making a hole that's... see, in the tip of that needle she has the somatic cell. And then the next step would be to give this an electrical pulse, and the two cells would fuse.
SUSAN DENTZER: The result was an egg with a completely new set of genetic instructions, in other words, a new embryo no bigger than a grain of sand. From here, the cloned embryo would be incubated in a chemical solution. By day four or five, it would develop into what's called a blastocyst, a still tiny embryo of up to several hundred cells. That's the point at which the two different processes-- therapeutic cloning and reproductive cloning-- completely diverge.
In reproductive cloning, the blastocyst is transferred into a female's uterus, in the hope that it will implant and then develop into a fetus. But in therapeutic cloning, some key cells are removed from the blastocyst, and the embryo is effectively destroyed. The cells that are removed are embryonic stem cells, the building block cells that ultimately develop into all the highly specialized cells and tissues of the human body.
And since these particular stem cells would come from cloned embryos, they'd have the additional advantage of being genetically identical to the animal that had been cloned. That means they could ultimately develop into other cells or tissues that the immune system of the grown animal would be unlikely to reject.
MICHAEL WEST: In a sense, it's a cellular time machine, a way of taking a patient's cell, maybe a skin cell, back in time to make these primitive embryonic cells that are your own cells. So we would have a way of, I think, transforming medicine, a way of making any cell or tissue available to treat disease that are your own cells.
SUSAN DENTZER: But critics of therapeutic cloning say that a tiny human embryo would still have to be destroyed in the process. Dr. Kevin Fitzgerald is a Catholic priest, and a researcher in cancer genetics at Georgetown University.
DR. KEVIN FITZGERALD, Georgetown University: This is how human organisms begin. And if it's a human organism, it's a human life, and can you snuff out a human life, destroy a human life in order to benefit others? My question is, is it worth that sacrifice? And I believe the answer is no.
SUSAN DENTZER: Peter Mombaerts is a therapeutic cloning researcher at New York's Rockefeller University. Mombaerts says the payoff could be huge. He sites the example of Parkinson's Disease, the chronic nervous system condition marked by tremors and a shuffling gate.
PETER MOMBAERTS, Rockefeller University: Nerve cells that produce dopamine are those cells that are lost in patients that develop Parkinson's Disease. One can partially or completely restore normal function by transplanting dopamine-producing cells. Just one cell type put in the right place of the brain is sufficient to reverse the symptoms.
SUSAN DENTZER: In a study published recently in the journal Science, Mombaerts and several colleagues showed that embryonic stem cells created from cloned mice could be developed into nerve cells that produce dopamine. So it's not beyond imagination that one day, human dopamine- producing cells produced through cloning could be injected into the brains of Parkinson's patients to help arrest or cure their disease.
Still, for opponents of cloning, that's hardly enough reason to cross ethical and moral boundaries. Fitzgerald argues that scientists are pursuing other research that could lead to innovative ways to regenerate cells or tissues, but without the troubling aspects of therapeutic cloning.
DR. KEVIN FITZGERALD: If all these other avenues are being pursued at the moment without the same kind of controversy and social sort of destruction, then perhaps we should be emphasizing those, and holding this off for a while and saying, "well, wait a minute, let's see how this sorts out."
SUSAN DENTZER: As for alternatives to therapeutic cloning, Senator Brownback cites new findings that suggest potential for treatments based on stem cells from adults, rather than from human embryos.
SEN. SAM BROWNBACK: These are in your bodies, these are in my bodies, we have them in our fat tissue, we have them in our blood stream, we have them in our bone marrow. We could invest some millions of dollars in adult stem cells, that's already giving human clinical applications.
SUSAN DENTZER: The Senate is expected to debate and vote on anti-cloning legislation soon.