Embryonic Stem Cells: High on Hype Low on Hope


Universe column for August 21st 2005

by David Alton

We are told ad nauseam that unless scientists are allowed to work unfettered creating embryonic stem cells, preferably from cloned human embryos, we will never be able to cure most of the diseases which beset mankind. The long list includes diabetes, Alzheimer’s, Parkinson’s, Motor Neurone, and many other genetic and degenerative conditions, plus a host of acquired disorders such as spinal cord trauma.

Tragically, many desperate patients actually believe that these cures are already up and running, or at the very least just around the corner. In reality, progress is extremely slow and many vital scientific questions are still unanswered.

Will the hype ever turn into hope, let alone produce successful therapies? The Market is always a good indicator: the aggressive venture capitalist, Sir Chris Evans of Merlin Biosciences, with 180 trials in the pipeline, is forced to concede that at best embryonic stem cells are still about ten years away from the market.

A key US-player, William Haseltine, of Human Genome Sciences, says that ‘the routine utilization of human embryonic stem cells for medicine is 20 to 30 years hence. The timeline to commercialisation is so long that I simply would not invest.’

Other scientists are even more cautious. Despite decades of embryo stem cell research using the animal research model, we have not begun to overcome the risk of tumour formation or tissue rejection.

We have limited knowledge about genetic stability, let alone epigenetic influences. Our knowledge of the feeder materials required to keep the cells alive and healthy is minimal. There are considerable worries that some materials being used (rodent derived for example) may actually introduce dangerous pathogens into the cell lines.

‘Nobody knows for sure what components are necessary to ensure pluripotency and proliferation,’ states Miodrag Stojkovic, recipient of the Newcastle cloning licence.

James Thompson, the Wisconsin developmental biologist who first isolated embryonic stem cells in 1998, is equally cautious. In a June TV interview he declared that he thought current prospects for transplantation cures from stem cell lines were unrealistic, that existing stem-cell lines are not suited to such applications, and that he does not believe that there is need to resort to therapeutic cloning, certainly not right now and perhaps never.

And our own Professor Lord Winston, also this June, in his Gresham Special Lecture, reiterates the opinion of Thompson. ‘There is a real risk with stem cells that we are raising expectations that they will be much more successful than they are likely to be.’

But from the outset I have argued that our concerns should not simply be those of pragmatic science.

The UK may not have accepted the right to life of the embryo when writing its 1990 fertility laws – although Italy has chosen to do so – but we certainly established that the human embryo was at least worthy of “special respect.” Does embryonic stem cell research and cloning fulfil that guarantee?

I read in Nature Biotechnology, June, that a UK embryonic stem cell line was created from 11 human embryos. After further enquiry I discovered that, in reality, during the whole project, between the end of 2000 and mid 2003, some 898 human embryos were destroyed in order to produce the successful cell line. A second project, undertaken by the same team, involved fewer embryos (228) but has not yet created a viable stem cell line.

Over a thousand human embryos destroyed and just one stem cell line to show for it. For a line of research which may well be going nowhere. Is this really what Parliament meant by “special respect”?

There is not space to look at how stem cells obtained from umbilical cord blood, bone marrow, and other post-natal sources, are ethically uncontroversial, and are rushing ahead in the race to provide therapies for many of the above disease targets. I suggest a visit to the website www.stemcellresearch.org to assess the state of play in the adult versus the embryo stem cell debate. It is a complete victory for the adult stem cell. And it illustrates how good science is at its best when it marches hand in hand with good ethics.