First stem cells taken from cloned embryos

Scientists have made a breakthrough in producing stem cells from cloned human embryos. Researchers in South Korea said that they had for the first time produced cells tailored for an individual patient.

Scientists have made a breakthrough in producing stem cells from cloned human embryos. Researchers in South Korea said that they had for the first time produced cells tailored for an individual patient.

The team produced 31 cloned human embryos by transferring the nucleus from the skin cell of a patient into an egg - taken from a donor - that had its own nucleus removed.

Professor Woo Suk Hwang of Seoul National University, who led the research, said that 18 women donated 185 eggs for the research and 11 patients aged between two and 56 give samples of their skin. From the resulting 31 cloned embryos, the researchers cultured 11 separate "lines" of embryonic stem cells which divided continuously in the laboratory.

The study, published in the journal Science, builds on research last year that resulted in the world's first cloned human embryo. It could lead to effective treatments for a range of devastating conditions, such as Parkinson's disease, spinal cord injuries and diabetes, and might even result in an end to organ transplants.

"This report brings science a giant step forward towards the day when some of humankind's most devastating diseases and injuries can be effectively treated through the use of therapeutic stem cells," Professor Woo said yesterday in London. However, critics argued that the development brought closer the possibility of producing a cloned baby using the same technique, a procedure banned in Britain.

The South Korean scientists emphasised this was not their aim. They instead demonstrated for the first time that the "therapeutic cloning" technique is feasible for both men and women and for the young as well as the old.

The 25-strong team of scientists demonstrated that cloned embryonic stem cells can be derived from the skin cells of men as well as women, and that the donated egg does not have to come from the patient or even someone related to the patient. They also showed that they have improved the efficiency of the process tenfold since last year's announcement, with an average of 17 eggs needed to produce each line of embryonic stem cells, and just 14 eggs when the donors were women under 30.

Professor Gerald Schatten of the University of Pittsburgh School of Medicine, the only non-Korean member of the team, described the breakthrough as a huge leap forward in the understanding and development of stem cell therapies. "What the study shows is that stem cells can be made that are specific to patients regardless of age or sex and that these cells are identical genetic matches to the donor," Professor Schatten said. "If they can be safely used in transplant, the promise for effective treatment - perhaps even cure - of devastating diseases and injuries comes within reach."

Other scientists described the findings as remarkable. Anne McLaren, a distinguished embryologist at Cambridge University, said that the potential for deriving unlimited quantities of embryonic stem cells from patients with chronic diseases promises to revolutionise clinical research into these disorders.

"Some thought that Hwang's success with cloning only worked because it used a woman's egg and the somatic cells surrounding it. But now, good news for men. Some of the cloned lines were derived from men's skin cells," Dr McLaren said.

Professor Ian Wilmut of the Roslin Institute in Edinburgh, who pioneered the cloning technique used by the South Koreans in producing the sheep Dolly, congratulated the team.

"These new observations make a very significant and important step forward toward the use of cells from cloned human embryos for research and therapy," Professor Wilmut said.

Life, the anti-abortion charity, denounced the research yesterday, saying that it brought reproductive cloning a step closer and exploited the young women who would be used as egg donors for such research.