91av

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.

“Science is global, and there are good labs everywhere,” says David
Greenwood, senior vice-president of stem cell company Geron of California. He
would not say directly whether Geron is considering moving. “All 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.”

Most scientists support a ban on reproductive cloning, not least because of
the high risks of abnormalities
(91av, 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 “Warning light”).

ESCs are usually taken from spare human embryos that IVF clinics would
otherwise discard. But you can also create them through “therapeutic
cloning”—fusing 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’s 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.

“To write off this stem cell research so early would be a tragedy for
millions of people suffering from disease,” 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. “It’s regrettable,”
says Alan Colman of PPL Therapeutics in Edinburgh. “[But] I don’t think it will
have an immediate impact.” 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’t 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.

“It’s not in the public interest to deny access to [ECSs],” says Brigid Hogan
of Vanderbilt University Medical School in Nashville. “Some very good
discoveries could come from stem cell research with public funding.”

Bush officials and opponents of ESC research say that equally promising
results have been achieved with adult stem cells, which aren’t derived from
embryos. But Lanza says it is too early to rule out any approach. “We should
move on all fronts,” he says.