BioEd Online

British scientists have been given the green light to clone human embryos for therapeutic purposes. The move should help researchers to understand how diseases such as Alzheimer's, Parkinson's and diabetes arise, and should speed the development of new therapies.

The Human Fertilisation and Embryology Authority has announced that it is to grant the licence to researchers at the Centre for Life in Newcastle on 12 August. It is the first such licence to be issued in Britain, a country that has one of the strongest regulatory systems in the world on cloning.

"We're absolutely thrilled," says reproductive biologist Alison Murdoch from the Newcastle Fertility Centre at Life. "The potential that this area of research offers is immensely exciting and we are keen to take the work we've done so far to the next level."

The licence makes clear the UK's position on therapeutic cloning, ahead of a discussion on human cloning at the United Nations scheduled for October 2004. Member countries could agree to ban both human reproductive and therapeutic cloning.

The UK and other countries including Belgium and Japan, backed by 67 of the world's national science academies, are calling for an agreement to outlaw human reproductive cloning but to permit individual countries to make their own decisions about whether therapeutic cloning should be allowed or not.

Tailor-made cells

Therapeutic cloning is one way to produce embryonic stem cells, which can generate any of the 300 types of cell that make up the adult body. Because stem cells are so versatile, it is hoped they can be used to repair and replace damaged human tissue.

Researchers hope the technique will allow them to avoid problems of rejection, by tailor-making stem cells for individual patients. To do this, a nucleus from a patient's cell is injected into an egg that has had its own nucleus removed. As the resulting embryo develops in culture, stem cells with the patient's DNA can be harvested and injected into the patient.

This differs from reproductive cloning, the technique that yielded Dolly the sheep, as the embryo is not allowed to develop to maturity. Reproductive cloning of human embryos is illegal in Britain and many other countries.

Research boost

"I'm very pleased with this decision," says geneticist Robin Lovell-Badge from London's National Institute for Medical Research. "Using cloning technology to derive embryonic stem cells genetically identical to a patient is potentially very important," says Lovell-Badge. He points out that they can be used "not only to provide a source of cells that may be used to cure patients, but also to allow for genetic disease to be studied and potential drug treatments explored in the laboratory."

The Newcastle team were one of the first UK groups to derive embryonic stem cells from 'spare' human embryos left over from fertility treatments. But such embryos are rare, so the new research, which allows the restricted creation of human embryos, should speed research in the field.

The team is launching a funding appeal to accelerate research and is looking for private sector partners to help Britain stay ahead of international competition. However the researchers caution that it will be at least five years before research of this kind yields any clinical treatments.