Times Online Q&A

Times Online December 16, 2005
Q&A: human cloning controversy

Mark Henderson, science correspondent for The Times (left), analyses the controversy around Dr Hwang Woo-suk, a pioneer of stem cell research, who today admitted making mistakes in his research

Who is Dr Hwang Woo-suk?

Before the current controversy erupted over his work, Hwang was widely seen as the world's foremost pioneer of human therapeutic cloning.

In February 2004, his team published the details of the first cloned human embryo, beating rivals in the US and the UK, and he appeared to have topped that achievement with his now disputed Science paper of May this year.

In that research, Hwang purported to have created 11 "lines" or colonies of embryonic stem (ES) cells from clones of real patients with diseases such as Parkinson's and diabetes.

The achievement was widely acclaimed as critical to the future of this technology - these ES cells would be genetically identical to the patients, and could thus potentially be transplanted without fear of rejection to treat their conditions. The work also had important implications for research, as it would allow the production of stem cells that accurately model genetic diseases.

What has he admitted to today?

Not very much. He has admitted that some of the photographs of the 11 lines he submitted to Science were duplicates, so that images of all 11 did not appear in the paper. He has also said that six of the 11 lines have now died, because of a fungal infection, and that they are not therefore now available to independent researchers to check.

Hwang, however, rejected allegations from his colleague Roh Sung Il that he had actively fabricated data to make it look as if he had made more ES cell lines than was actually the case. Roh has charged that nine of the lines were essentially fictional, and that even the other two have yet to have their authenticity verified.

Hwang has also told the journal Science, which published the work, that he wishes to retract it. Science will agree to this only if all the co-authors concur, or if its own investigations reveal fatal flaws in the research.

How serious are the errors he says he has made?

The duplication of photographs is an important matter, as it gave a misleading impression about the number of stem cell lines that had been shown to be created. However, on its own, this does not invalidate the work and it may well have been an honest mistake. Most independent experts think it strange that Hwang should want to withdraw the paper purely because of this mistake.

More serious is the charge that the DNA profiles of the ES cell lines do not actually match those of the patients from which they are supposed to have been cloned. If this is proven, it would mean that he had not in fact produced true clones, and might even be guilty of outright scientific fraud.

Another problem would emerge if Dr Roh is right, and none of the 11 lines still exists in a form that allows independent scientists to test them. This week, a group of experts led by Ian Wilmut, the creator of Dolly the sheep, suggested that Hwang submit the cells for independent tests to verify his claims, but if he is unable to do this it would be difficult for him to clear his name.

Will this cast doubt over his other research? What about Snuppy?

No evidence has emerged to date that casts doubt on his 2004 human clone or the creation of Snuppy, the first cloned dog, which Hwang announced earlier this year. If he is proved to have fabricated data, however, scientists will start to question his other research too. Many will feel that if he has cheated once, he may have done so on other occasions as well.

How bad a setback is this for stem cell research as a whole?

It is something of a disaster. Religious groups who oppose therapeutic cloning and the use of embryonic stem cells have already seized on Hwang's troubles to accuse the entire field of being founded on hype and not science.

Scientists reject this, but they are worried about the effect on public opinion. Many feel that the problems make it all the more important that countries like Britain and the US support cloning and ES research enthusiastically, so that they can control the scientific and ethical parameters in which it is attempted.