Adult stem cells not as versatile as embryonic stem cells, say scientists

Brussels, 15 March 2002

Hopes that research on embryonic stem cells can be abandoned in favour of adult stem cells may be unfounded, according to new study results from scientists in the UK and the USA.

Two research groups led by Austin Smith of the University of Edinburgh, UK, and Edward Scott from the University of Florida, USA, have revealed that adult stem cells which appear able to form a diverse range of new tissues may in fact be combining with other cells to form abnormal hybrids. They say that the material created by this process of fusion could be mistaken for new tissue.

The Edinburgh and Florida teams grew adult neural and blood stem cells along with embryonic stem cells. Both groups found that both the neural and blood stem cells seemed to have reverted back to the basic, 'unspecialised' state of the cells alongside them. But it was found upon closer examination that they had in fact simply fused with the embryonic stem cells, and the new cells had twice the amount of chromosomes, or genetic material, as ordinary ones. The effect these hybrid cells could have if introduced into humans is unknown.

Professor Smith told the BBC: 'If nothing else, our study indicates that calls for a halt to embryonic stem cell research are not scientifically justified.'

Although experts disagree on the significance of the findings, they represent a blow to those who oppose the use of embryonic material for research purposes and who claim that adult stem cells show such versatility that there is no need to harvest such cells from embryos.

CORDIS RTD-NEWS/© European Communities, 2001