Joined: 16 Mar 2004
|Posted: Mon Oct 23, 2006 10:33 am Post subject: Ultimate aim is to find ways to rewind the clock in old age
|Ultimate aim is to find ways to rewind the clock in old age
by Nigel Hawkes
AMERICAN scientists who have created human stem cells without damaging the embryos used in the process may have achieved more of a public relations than a scientific coup.
That sounds disparaging, but it is not. Science is not always a simple matter of facts and arguments. Stem cells raise strong passions because they involve tinkering with life.
To the Religious Right in the US and the Bush Administration, that is morally unacceptable. In their view one life — even one consisting of a few cells — cannot be sacrificed to save another.
The team at Advanced Cell Technology seems to have vaulted neatly over this objection by showing that it is possible to create stem cells and leave the embryo intact.
Scientifically, the technique seems to offer a smaller benefit. For those untroubled by the ethics of experimenting on embryos, which includes almost all Europeans, there are easier and more effective ways to create stem-cell lines.
Millions of embryos created for in vitro fertilisation are destined to be destroyed in any case. Ultimately, a couple’s hunger for a family is either satisfied or not; in either case, any spare embryos that have been created will not be retained for ever.
Nor is there any obvious way that stem-cell lines created as a by-product of pre-implantation genetic diagnosis would be useful. Perhaps they might be retained as the baby grows, gets old and begins to suffer from degenerative diseases; but this could as easily be done by retaining stem cells from the cord blood.
Ultimately, the aim of stem-cell research is not to build up a potential set of spares from the earliest moments of life, but to devise ways of rewinding the clock in old age. If adult cells from the skin, for example, can be turned back into stem cells and then encouraged to redevelop into whatever is desired — new brain cells, or new muscle cells for a failing heart — then stem-cell therapy might have a role in the clinic.
To achieve this, the only imaginable route at present is therapeutic cloning, which involves using the nuclei of the skin cells to create a genetic copy of the patient and harvesting from its embryo the stem cells needed to make brain or heart. The latest advance would make that possible without destroying the cloned embryo. But allowing a cloned embryo to mature to term would be reproductive cloning, which is everywhere abhorred.
It is also possible to argue, as Professor John Harris, of the University of Manchester, did yesterday, that if a single cell can create stem-cell lines it is totipotent — that is, it has the power to create all the organs of the body.
If so, how does it differ from an embryo? Opponents of embryo research could argue that destroying this single cell to make a cell line is as sinful as destroying an entire embryo.
That said, however, the new research does offer at least a chance of opening the spigots of US federal research funding into embryonic stem cells. And that might ultimately make possible an understanding of stem cells sufficiently complete to enable the use of adult stem cells without the need for thera- peutic cloning.
It is, as they say, a big ask. But science never got anywhere by thinking small.
This story was first posted on 24th August 2006.