WIDESPREAD derision greeted last week鈥檚 announcement by the British
government that it is delaying its decision on whether to allow research into
human cloning for 鈥渢herapeutic鈥� applications.
In any case, the government鈥檚 precautionary approach may be undermined by
loopholes in existing laws, 快猫短视频 has discovered. Research on
cloned cells and tissues can proceed legally in Britain, provided the cells are
initially grown in laboratories abroad.
Therapeutic cloning would use the technique that created Dolly the sheep to
grow cells for transplants that are matched to their recipients鈥攆or
instance to replace the brain cells lost in Parkinson鈥檚 disease. A donated human
egg stripped of its chromosomes would be fused with one of the patient鈥檚 own
cells to create an embryo. This would be allowed to grow for a few days until it
forms a ball of cells called a blastocyst. From this, researchers would extract
the embryonic stem cells that can, in theory, give rise to any of the body鈥檚
tissues (see Figure).
Biologists now need to work out which of the growth
factors that direct embryonic development will produce the desired cells.
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Therapeutic cloning is opposed by 鈥減ro-life鈥� groups because it involves the
destruction of an embryo. But research is already under way in the US, and in
December the two committees that advise the British government on human genetics
and embryology said that the law should be changed to allow therapeutic cloning
in Britain while maintaining the ban on using the technique for human reproduction
(This Week, 12 December 1998, p 5). Last week, however, the
government announced that another six-month study would be needed before it
would consider any such change.
The decision has come under fire from scientists and many media commentators,
with some arguing that the government is running scared of public opinion,
following opposition to its policy on genetically modified food. 鈥淚鈥檓
disheartened,鈥� says Martin Bobrow, a medical geneticist at the University of
Cambridge. 鈥淭hey seem to have been bullied by a vociferous minority.鈥�
But the Human Fertilisation and Embryology Authority, which regulates embryo
research in Britain, says that importing cloned embryonic stem cells would be
perfectly legal. 鈥淏ecause they are not embryos, you wouldn鈥檛 need a licence from
us,鈥� says a spokesman.
One company in Britain, Geron BioMed, is uniquely placed to pursue research
into therapeutic cloning. The company, based at Roslin near Edinburgh, is
licensed to use both the technique that made Dolly and methods of extracting
stem cells. Its parent, Geron of Menlo Park, California, funds the research of
James Thomson, a biologist at the University of Wisconsin. Last year, Thomson
announced that he had isolated embryonic stem cells
(This Week, 14 November 1998, p 6).
Simon Best, managing director of Geron BioMed, told 快猫短视频
that the company would consider making cloned stem cells available to British
researchers. 鈥淚f some of the British collaborators are the right people to do
the work, we would certainly think about it,鈥� he says. However, he points out
that the cells are in very short supply, and may prove difficult to keep alive
while being sent from lab to lab.