BioWorld International Correspondent

LONDON - A human embryonic stem cell line has been grown in the UK for the first time, using five-day-old blastocysts produced by in vitro fertilization, but rejected as unsuitable for implantation after failing screening tests for serious genetic disorders.

The news is seen not only as a scientific success, but also as proof that the UK has a robust ethical and regulatory approach to stem cell research. The research group at King's College in London was one of the first to be granted a license to generate human embryonic stem cells under UK legislation agreed to in 2002.

The researchers produced three stem cell populations from a total of 58 embryos. Two of those were lost at an early stage, but the remaining cell line has been growing for many months and has been characterized. It has been shown to express two molecules unique to human embryonic stem cells, as well as a number of genes commonly found in other stem cells. It is generally difficult to maintain embryonic stem cell lines since they differentiate readily into more mature cells.

The new line, derived by Stephen Minger and Susan Pickering, is likely to be the first embryonic stem cell line to be deposited in the UK Stem Cell Bank. Cell lines in the bank will be available for the use of scientists worldwide.

Minger said, "We are very excited about this development. Human embryonic stem cells [are capable] of giving rise to all the different types of cells in the body. This means their possible therapeutic uses are almost endless."

To date, only a handful of human embryonic stem cell lines have been generated since the first was derived in the U.S. four years ago. The researchers at King's College say it is essential for cell replacement therapy that more lines are grown. However, the area is an ethical minefield, with many countries, including the U.S., refusing to allow public funding of embryonic stem cell research. Last month the European Commission proposed that EU grants would be allowed to generate stem cell lines only from IVF embryos donated before June 27, 2002.

Peter Brande, a member of the King's stem cell team, said, "We are proud of the particular way our lines have been generated. We believe that the derivation has been wholly ethical, as the blastocysts used would otherwise have been discarded." He added that the UK Stem Cell Bank would allow maximum research with the use of as few embryos as possible.

The Stem Cell Bank, which is responsible for managing and supplying ethically approved, quality-controlled adult, fetal and embryonic stem cell lines, is due to open later this year. The bank can be used by academics and industrialists worldwide. Applications to deposit stem cell lines must be approved by the bank steering committee, which will ensure that ethical approvals, donor consents, licenses and accreditation are in place before accepting cell lines for banking, or releasing lines to end users.

The Stem Cell Bank is funded and managed by the Medical Research Council (MRC), which also is leading efforts to coordinate stem cell research globally. At a meeting in London last month, the International Stem Cell Forum, established on the initiative of the MRC, agreed to set international scientific benchmarks on cell line characteristics. Researchers will examine new and existing stem cell lines using standardized tools and procedures, and the resulting data will be posted in a web-based registry of stem cell lines.

The members of the International Stem Cell Forum include the Canadian Institutes of Health Research; the U.S. National Institutes of Health; National University of Singapore; National Health and Medical Research Council, Australia; Academy of Finland; Scientific Council for Medicine of the Swedish Research Council; Israel Academy of Sciences and Humanities; and the U.S. Juvenile Diabetes Research Foundation.

The Forum was set up by the MRC to encourage the sharing of resources and data and to prevent duplication of research.