Scientists voice anger over stem cell vote

Nothing short of a medical revolution is promised if scientists can achieve their stated goal of growing the vital "stem cells" of a cloned human embryo in a test-tube.

Nothing short of a medical revolution is promised if scientists can achieve their stated goal of growing the vital "stem cells" of a cloned human embryo in a test-tube.

This could end the shortage of human organs for transplant operations and launch a new era in medicine, where diseased or defective tissues are mended in situ rather than being cut out and replaced with someone else's organs.

By combining the ability to grow embryonic stem cells in a test-tube with the technique of cloning embryos from adult cells, used to create Dolly the sheep, scientists hope in effect to create individualised "body repair kits" for the time when we fall ill, have a serious accident or grow old.

As the House of Lords debated new rules last night governing the cloning of human embryos, scientists warned that any delay in relaxing the law to allow the extraction of embryonic stem cells threatens to relegate Britain to the second division of medical research. Robin Lovell-Badge, head of developmental genetics at the National Institute of Medical Research, said: "Stem cells have brought hope to literally millions of people who suffer from severe diseases. A vote against embryonic stem cells would genuinely put back research by two years."

Scientists are almost unanimous in their support for the use of embryonic stem cells. Five major investigations into stem cells - involving the Human Fertilisation and Embryology Authority (HFEA), the Human Genetics Advisory Commission, the Nuffield Council on Bioethics and the Royal Society - have called for an extension to existing rules governing such research.

Austin Smith, a stem-cell scientist at Edinburgh University, said: "The key issue is the potential to deliver treatments of diseases that are untreatable or that can only be treated in poorly defined and unsatisfactory ways." He is likely to be among the first to apply for the new research licences.

"We have to consider the patient's rights at this moment. It is not an abstract issue for someone with Parkinson's disease to say that we'll just put this on hold for a couple more years."

The debate has centred on the emotive issue of human cloning, although "reproductive" cloning of babies is to be specifically banned by the Government in primary legislation. However, the argument is really about stem-cell technology, which could lead to untold medical benefits. Stem cells are the undifferentiated "master" cells of the body. They are capable of developing into one of the many types of specialised tissues, ranging from blood and bone to muscles and nerves. Embryos are packed full of stem cells, demonstrating the vital role they play in human development.

Although adults also possess stem cells, these are usually geared towards making a narrower range of tissues. Stem cells in the adult gut are designed to develop into the specialised cells lining the intestines. Those in bone marrow are programmed to make fresh blood cells.

The Catholic Church and other religious groups opposed to the use of human embryos argue that adult stem cells, and those derived from the umbilical cords of newborn babies, could be just as effective as embryonic cells, but few scientists would agree. Dr Lovell-Badge said that, of 1,500 published studies on umbilical-cord stem cells, none had shown it was possible to use the cells for anything other than making blood cells. They would therefore be of little use for treating Parkinson's disease, diabetes or heart disease.

Many experiments on mice have shown that stem cells taken from an early embryo a few days after fertilisation have a remarkable ability to develop into any one of the fully specialised tissue types.

The idea is eventually to grow replacement tissues, or even organs, in a test-tube. "The scope for therapy is considerable," said a report on stem cells by a committee of scientists for the Royal Society. "Organs damaged by trauma or disease do not always need replacing, and repair often would be possible if a suitable source of cells was available," it said.

"Patients suffering from certain degenerative diseases of the brain, liver (hepatitis), pancreas (diabetes), blood (leukaemias), joints (rheumatoid arthritis), heart and kidneys are likely to benefit from stem-cell therapy," the Royal Society concluded.

Cloning comes into the equation because it would allow scientists to grow embryonic stem cells of the same patient who needs them. This is achieved by taking an adult skin cell and injecting its nucleus into an unfertilised egg with its own nucleus removed - the so-called cell nuclear replacement of the Dolly technique. This would overcome the problem of tissue rejection.

The law now allows scientists to research human embryos only if they are less than 14 days old and the aim meets one of five research aims, largely concerned with fertility, reproduction and contraception. The regulations being proposed aim to extend these uses to "increasing knowledge about serious diseases" and "enabling such knowledge to be applied".

The HFEA said it would not consider licensing a scientist who under current rules proposed to create a cloned embryo for stem-cell work. However, it would consider issuing a licence if embryonic stem cells could be used for research into serious diseases such as Parkinson's.