Major advances in the treatment of incurable diseases could arise from new techniques used to clone human embryos. The South Korean scientist who announced a cloning breakthrough warned, however, that those attempting to clone humans will also benefit from his discoveries.
Dr Woo Suk Hwang of Seoul National University addressed a hushed press conference yesterday in Seattle at the American Association for the Advancement of Science annual meeting. The room bristled with television camera crews as his momentous findings were beamed around the world.
Dr Hwang gave details of his much- improved technique which allowed him to produce a plentiful supply of cloned human embryos at what is currently a startling 43 per cent success rate. He then used these clones to harvest embryonic stem cells, cells which potentially have the ability to treat disease by changing into any cell type in the body.
His discoveries are likely to spur fresh international debate on the ethics of any cloning involving human tissues. He admitted, however, that it could also boost the fortunes of renegade groups seeking to clone human beings to order.
"Yes, this technique can't be separated from reproductive cloning and therapeutic cloning," Dr Hwang said. For this reason, every country should now introduce legislation banning any possibility of human cloning, he added.
Dr Hwang's call for an international ban on human cloning was repeated by the editor of Science, Dr Donald Kennedy. He also said that the research did not show that human cloning was possible.
"Nobody has cloned a human here," he told the press conference yesterday. "They have only created a stem cell line. To get from that to an embryo is a big step. This is a recipe only in that catching a turtle is a recipe for turtle soup," he added.
"Our goal is not to clone humans but to understand causes of diseases. Our inspiration is to treat incurable diseases," Dr Hwang told the packed press conference. This research also involved "responsibilities and moral obligations" for the scientists, he added.
Full details of the research were published yesterday by the journal Science. He described to the meeting how his team used existing "somatic cell nuclear transfer" technology used in the creation of Dolly the cloned sheep, but greatly enhanced its success rate.
The team used 242 eggs donated with full consent by Korean women who were not paid for this. Dr Hwang developed new handling techniques to achieve an initial 20 per cent success rate when the cell nucleus was removed from these eggs and replaced by a cell nucleus taken from adult skin cells.
Once the embryos had grown to about 100 cells, they were destroyed to allow the extraction of human stem cells. The experiments were regulated at all times by the South Korean authorities, Dr Hwang added. The researchers then created a self-perpetuating stem cell line that so far has survived 70 cell divisions and could deliver an endless supply of useable stem cells.
Part of the higher success rate could be related to a decision to use adult skin cells from women who donated eggs. None of the skin cells taken from the ears of male volunteers proved successful, he said.
"Our success rate is finally about 43 per cent and we tried both sexes, female and male, but we failed to establish male human embryos. We got the results only with female \." This raises the possibility of a woman producing therapeutic stem cells that would be a perfect genetic match and potentially would not be rejected if given to treat disease. It also suggests that it could be possible for a woman to produce a clone of herself without the contribution of anyone else.