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Cloned human embryo stem cell breakthrough

12 February 2004
By BioNews
Appeared in BioNews 245

Scientists in South Korea have extracted and grown stem cells from cloned, early human embryos, a breakthrough in 'therapeutic cloning' research. Using a modified version of the technique used to clone Dolly the sheep, the team, based at the Seoul National University, created 30 cloned human embryos. The researchers extracted stem cells from 20 of these, from which they managed to grow one human embryo stem cell (ES cell) line. They have also shown that these cells can grow into different embryo tissues in the laboratory, and into adult tissues when transplanted into mice. Their work, which will be published in the journal Science, has been hailed as 'a landmark paper' by other scientists, and could pave the way for research into new treatments for many diseases.

The stem cells present in very early embryos are the body's 'master' cells, capable of growing into any type of tissue. Since the unveiling of Dolly the cloned sheep, in February 1997, scientists have been investigating the possibility of using stem cells from cloned, early human embryos to develop tissue-matched therapies for diseases such as Parkinson's disease and diabetes: an approach known as therapeutic cloning.

To create Dolly, scientists at the Roslin Institute in Scotland used a technique called SCNT (somatic cell nuclear transfer), which involved transferring the nucleus of an adult sheep mammary gland cell into a donor egg stripped of its own genetic material. Since then, many other species of animal have been cloned using this technique, or modified versions of it. But creating SCNT embryos from humans (or any primate) has proved very difficult, although several groups have managed to isolate embryo stem cells from IVF embryos. Such cells are being used to carry out research into new therapies, although if used in human patients, they would face rejection by the body's immune system. Stem cells isolated from a person's own cloned (or reprogrammed) body cells would be an exact genetic match, however, and would not face transplant rejection problems.

Scientists at the US firm Advanced Cell Technology (ACT) first reported the creation of cloned human embryos in November 2001, but the team, lead by Dr Robert Lanza, did not manage to extract any stem cells from them. Commenting on the new research, Lanza said: 'you now have the cookbook, you have a methodology that's publicly available'. The South Korean team, lead by Drs Woo Suk Hwang and Shin Yong Moon, carried out their work on 247 unfertilised eggs donated by 16 women. The researchers removed the genetic material from 176 of them, choosing those at the most suitable stage of development. They removed the nuclei of these eggs, and replaced them with the genetic material from cumulus cells (cells that surround a developing egg), taken from each of the egg donor women, so that each clone was an exact genetic copy. 'They had an incredible amount of eggs and an opportunity to perfect the protocols; they tried 14 different protocols' said Dr Jose Cibelli, formerly of ACT. Their method yielded blastocysts (five or six day old embryos that contain ES cells) around 26 per cent of the time.

The discovery will provide scientists with a 'unique opportunity' to study human disease, says stem cell scientist Ron McKay. However, the Editor-in-chief of Science, Donald Kennedy, cautions that 'it may be years yet before embryonic stem cells can be used in transplantation medicine'. The breakthrough is also likely to reignite the debate over regulating attempts to clone human beings, whilst allowing therapeutic cloning research to continue.

Clone breakthrough may lead to gene cures, say scientists
The Guardian |  12 February 2004
Evidence of a pluripotent human embryonic stem cell line derived from a cloned blastocyst
Science |  12 February 2004
Scientists clone 30 human embryos
BBC News Online |  12 February 2004
Scientists create human embryos through cloning
The New York Times |  11 February 2004
7 January 2006 - by BioNews 
An investigation into the work of South Korean stem cell scientist Woo Suk Hwang and his team has concluded that they did not create any cloned embryo stem (ES) cell-lines genetically-matched to patients, as reported in their much-feted Science paper of last year. The revelations have sent shockwaves through the...
9 December 2005 - by BioNews 
The University of Pittsburgh has begun an investigation into research carried out by Korean stem cell scientist Woo Suk Hwang and his former collaborator Gerald Schatten. The celebrated paper, published by Science earlier this year, described the derivation of 11 cloned human embryonic stem (ES) cell-lines from patients with diabetes...
24 November 2005 - by BioNews 
Woo Suk Hwang - head of the South Korean team that obtained the world's first embryonic stem (ES) cells from cloned human embryos - has quit his public positions after admitting that some eggs used in the work were provided by junior researchers and paid donors. The shock resignation follows a statement...
21 November 2005 - by BioNews 
The future of an international consortium aiming to advance human embryo stem (ES) cell research is looking increasingly uncertain, following allegations that its South Korean head, Woo Suk Hwang, used eggs donated by a junior researcher to create cell lines. On 12 November, Gerald Schatten, from Pittsburgh University in the...
14 November 2005 - by BioNews 
A leading American stem cell researcher has abruptly ended his 20 month long collaboration with the team of South Korean scientists famous for creating the world's first human embryonic stem (ES) cell lines from cloned embryos. The same team announced in May that it had managed to derive the world's...
19 January 2004 - by BioNews 
Scientists at the Institute for Frontier for Medical Sciences at Kyoto University in Japan have produced the country's first human embryo stem (ES) cells. Project leader Norio Nakatsuji says that his team has produced enough cells to meet current research needs in Japan, and are now awaiting government approval before...
14 August 2003 - by BioNews 
Researchers at King's College in London have succeeded in growing the UK's first human embryo stem cell-line, it was reported last week. 'We are very excited about this development' said team leader Stephen Minger, adding that human embryonic stem cells 'are capable of giving rise to all the different types...
26 November 2001 - by BioNews 
Scientists in the US announced yesterday that they had created a cloned human embryo for the first time. Their work was part of research into therapeutic cloning - creating cells or tissue for transplant from a person's own cloned embryo and subsequently lessening the risk of rejection. The research team also...
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