stem cells anc cancer?

[Guest guest]

It's interesting how different people see the future of medicine

(discussions on this list). Here's another article I read today that

may be of value to the discussion:

http://www.guardian.co.uk/genes/article/0,2763,1464781,00.html

 

Stem cells cancer fear

 

Colin Blackstock

Thursday April 21, 2005

 

Guardian

Stem cells that have been grown to cure disease might have the reverse

effect and turn cancerous if they are allowed to develop for too long

outside the body.

 

Two new studies have shown that adult stem cells, such as those taken

from bone marrow, can be harmful if they are allowed to divide for too

long.

 

Scientists already know of a possible cancer risk from stem cells

taken from very early embryos, but the new research shows adult stem

cells are safe only if the number of times they are allowed to divide

outside the body is limited.

 

Researchers at the Autonomous University of Madrid grew human stem

cells extracted from fat tissue for up to eight months.

 

In that time the cells divided between 90 and 140 times. When they

were transplanted into animals, the oldest cells formed cancers.

 

Antonio Bernad, who is leading the research team, told the New

Scientist magazine that pioneering treatments which already test bone

marrow stem cells in humans should be safe because the cells are grown

outside the body for a short time.

 

" In normal conditions in clinical applications we think the cells are

pretty safe, but we must be careful, he said. " The key is not to grow

them for too long. "

 

A Danish research team found that the reason stem cells become

cancerous may be because after a time they start to make an enzyme

that activates the " fuse " on chromosomes which normally limits the

number of times cells can divide.

 

If the division of stem cells is unlimited, they will eventually turn

cancerous.

 

Robert Lanza, of Advanced Cell Technology, a US stem cell company,

said the research highlighted the need for rigorous safety measures.

He told the New Scientist: " Both these papers reinforce the potential

danger of using stem cells. "