Cloning breakthrough offers hope of new treatments but may help maverick doctors

The scientist behind the world's first cloned human embryo has admitted that his research techniques could help maverick doctors to produce cloned babies.

Woo Suk Hwang, of the Seoul National University in South Korea, said yesterday that he wantedso-called "reproductive cloning" banned worldwide, even though his work has brought it a step closer.

"This technology cannot be separated from reproductive cloning and therapeutic cloning and because of that we think we have to prepare every country to prevent trying reproductive cloning with this technology," Dr Hwang said.

In a report published today in the journal Science, Professor Hwang describes how his team in South Korea has used a similar cloning method to the one that produced Dolly the sheep, but with human cells and eggs. They removed the egg's nucleus, and inserted a nucleus from an adult cell. The egg began to grow like a fertilised embryo. In all, there were 30 embryos.

But rather than implanting it into a woman's womb, the team let the embryos grow to about 100 cells, and then tried to take cells from inside them, to see if they would act as stem cells. These are capable of growing into virtually any specialised tissue, such as heart, muscle or skin. This opens the door tomedical treatments which might replace faulty or dying cells with fresh, working stem cells taken from cloned embryos grown from patients themselves. That is therapeutic cloning - unlike reproductive cloning, which aims to produce babies.

The cloning debate is contested from three incompatible perspectives: those completely against cloning, those in favour of its limited use for medical research, and those who want to produce cloned babies. All are waging political and scientific battles to make sure that their view holds sway.

The views of patient groups might be key in swinging legislators' minds. In theory, embryonic stem cells could treat a range of disorders such as osteoarthritis or Parkinson's disease, by being transplanted to replace damaged or dead cells.

Patient groups welcomed the news, but cautiously. "This is the first time this has been done using human cells and it has been published in a reputable, peer-reviewed journal so that we can have a lot of confidence in the science," said Alistair Kent, director of the Genetic Interest Group in Britain, an alliance of patient organisations.

Roger Pedersen, an American stem-cell expert who left the US in 2001 because of its restrictive position on embryo research, who is now professor of regenerative medicine at Cambridge University, said that the Korean research substantially advanced the prospect of using tissue transplants derived from a patient's own cells. "This will likely accelerate the development of alternative ways of reprogramming human cells, which could in the future diminish the need to use human eggs for this purpose," Professor Pedersen said.

But the initiative was condemned by opponents of cloning. Dr Donald Bruce, director of the Church of Scotland's society, religion and technology project, said it was "irresponsible science". He called for an immediate United Nations ban on reproductive human cloning. Earlier attempts to introduce such a ban through the UN failed because the US, urged on by the religious right, attempted to extend the ban to therapeutic uses. That was resisted by too many countries, including the UK, which in 2002 issued its first licences for therapeutic cloning. Others had different reasons to dislike the work. "Cloning research is impossible to do without exploiting women. It should be banned immediately," said Daniel McConchie, a spokesman for the Centre for Bioethics and Human Dignity in Chicago.

And what about the pro-cloners? Clonaid, the company set up by the Swiss-based Raelian sect, which says humans are cloned versions of aliens, chose yesterday to announce on its website that a sixth cloned child had been born in Australia. The company claimed that the first was born in December 2002, but no proof ever emerged.

Clonaid is the leader - at least in its claims - of the reproductive cloning group. That includes Panos Zavos, an IVF expert based in the US, who has claimed that he has implanted cloned embryos into women; last week he said one had miscarried. The Italian doctor Severino Antinori has been silent for some time after claiming in 2002 he would be first to clone a human. Richard Seed, an American expert who made similar claims, has also failed to find the limelight for a couple of years. Clonaid also says that it has produced eight pregnancies from 20 implantations in its latest round of cloning - a result that, if true, would have scientists flocking to its laboratories to find out its secrets. For the reality is that producing embryos by cloning adult cells is a hit-and-miss affair - and mostly miss.

Professor Hwang's team collected human eggs from 16 unpaid volunteers who had signed "informed consent" agreements to allow their eggs to be used in research. They collected a total of 242 eggs but only managed to generate 30 cloned embryos, of which only 20 were of good enough quality to attempt stem-cell extraction. The researchers said their comparative success was due to using extremely fresh human eggs and using a new technique for extracting the egg nucleus by gently squeezing it out of the cell rather than inserting a microscopic glass tube and sucking it out.

Professor Hwang also revealed that his team has tried to produce a cloned male embryo using skin cells from the ear lobe of a man. He refused to say how many attempts his team made.

Generally, animal cloning has demonstrated that pregnancies from cloned cells are difficult to achieve and unlikely to succeed. Rudolph Jaenisch, a world authority on cloning and professor of biology at the Whitehead Institute in Massachusetts, said the Korean study was the first time anyone had shown unequivocally that it was possible to clone human embryos using the Dolly technique of "cell nuclear transfer".

He added: "It would be unethical to use this research to move to reproductive cloning of a baby because the animal research has shown that all clones are to some extent abnormal.

"They [Antinori and Zavos] are not going to get normal babies, no way," he said.

WHAT ARE THE IMPLICATIONS?

What have these scientists done?

They have used the same cloning technique that produced Dolly the sheep, but stopped the growth when the embryo reached the "blastocyst" stage, at about 100 cells. (An adult has about 50 billion cells.) They showed that those cells could act as "stem cells".

What is a stem cell?

A cell from an adult or an embryo that can grow into an organ or other part of the body. Stem cells arise naturally. There are three kinds: "totipotent", from early embryos, can grow into any part of the body; "pluripotent", from older embryos, can become anything except certain placental tissues; and "multipotent", found after the embryo stage, which have specialised and can only become a particular form, such as bone or skin. Every adult has stem cells in the bone marrow, for example.

The Korean researchers showed that the cells from their embryos were "pluripotent" - able to grow into virtually any other part of the body.

Does this mean they will produce cloned babies?

Not at all. That would require implanting the embryo in a woman, and seeing the pregnancy through to term. In other cloned animals, including Dolly the sheep, mostpregnancies fail, and a number of those which are born - usually by Caesarean section - are malformed or die early.

Although many groups have claimed to have cloned babies, none has produced persuasive evidence, and this result makes it no easier.

What does this mean, then?

It is a small, but very significant, step towards using stem cells in medical operations and being able to regrow lost organs, such as a kidney or perhaps an arm, and to treating illnesses such as Parkinson's disease or Alzheimer's. Some stem cell researchers think the work was unsurprising; but achieving it was important.

What is the next step?

As with all science, someone needs to reproduce the work. Then they need to investigate further how to use stem cells, and exactly how efficient they can be in curing disease, and how to direct their growth to a focused and specific need in medicine.

How soon will I be able to be cured using stem cells grown this way? Will I be able to get a new arm/kidney?

It will be years - if ever - before proven treatments using this technique are available. Some time in the future you might receive them as a treatment for age-related brain disorders such as Parkinson's or Alzheimer's. But it's more likely that your children, or their children, will benefit.