TOP American researchers might move across the Atlantic if proposed US
legislation banning the creation of cloned human embryos becomes law. Last week,
a spokesman announced that President Bush supports a bill to make human cloning
a federal crime, even for research purposes.
鈥淪cience is global, and there are good labs everywhere,鈥� says David
Greenwood, senior vice-president of stem cell company Geron of California. He
would not say directly whether Geron is considering moving. 鈥淎ll I can say is
that we already have a presence in the UK, and the UK politically is
increasingly receptive to this type of research.鈥�
Most scientists support a ban on reproductive cloning, not least because of
the high risks of abnormalities
(快猫短视频, 19 May, p 14). But they are keen
to work with embryonic stem cells (ESCs), which they believe can be turned into
any type of tissue
(see 鈥淲arning light鈥�).
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ESCs are usually taken from spare human embryos that IVF clinics would
otherwise discard. But you can also create them through 鈥渢herapeutic
cloning鈥濃�攆using cells from a patient with an egg from which the
chromosomes have been removed. ESCs from these cloned embryos could be turned
into tissues for transplant that are an exact match for the patient, preventing
rejection.
Supporters say such research could lead to treatments or even cures for
diseases as diverse as diabetes, Parkinson鈥檚 and AIDS. The trouble is, opponents
see harvesting ESCs as akin to aborting an embryo, and worry that therapeutic
cloning is the first step towards cloning a person.
鈥淭o write off this stem cell research so early would be a tragedy for
millions of people suffering from disease,鈥� says Robert Lanza of Advanced Cell
Technology in Massachusetts. He says ACT has had promising results using ESCs to
rejuvenate the immune systems of ageing cows, an approach that could be help
patients with autoimmune diseases.
However, a ban on therapeutic cloning in the US is unlikely to have any
short-term effect on medicine because so much work still has to be done on
animals before anyone could consider applying it to humans. 鈥淚t鈥檚 regrettable,鈥�
says Alan Colman of PPL Therapeutics in Edinburgh. 鈥淸But] I don鈥檛 think it will
have an immediate impact.鈥� Indeed, some researchers think therapeutic cloning
will always be too expensive and time-consuming to be a practical
treatment.
What could have an immediate effect is a ban on public funding for human ESC
research. Rumours also emerged last week that Bush has decided to revoke rules
passed by President Clinton that would have allowed the government to fund any
ESC research as long as public money wasn鈥檛 used to create or harvest the cells
from the embryos. Soon after Bush took office, he froze those funds pending
review. Last month a group of scientists and actor Christopher Reeve sued the
government to release money for ESC research.
鈥淚t鈥檚 not in the public interest to deny access to [ECSs],鈥� says Brigid Hogan
of Vanderbilt University Medical School in Nashville. 鈥淪ome very good
discoveries could come from stem cell research with public funding.鈥�
Bush officials and opponents of ESC research say that equally promising
results have been achieved with adult stem cells, which aren鈥檛 derived from
embryos. But Lanza says it is too early to rule out any approach. 鈥淲e should
move on all fronts,鈥� he says.