British scientists grow stem cells from blood

[Guest guest]

http://www.guardian.co.uk/uk_news/story/0,3604,1551272,00.html

Tim Radford, science editor

Thursday August 18, 2005

Guardian

Using technology developed for experiments on the International Space

Station, British scientists have managed to grow human embryonic stem

cells from umbilical cord blood, and turn them into human liver tissue.

This could be the first step towards a worldwide " library " of stem

cells that could provide more than a million different tissue types.

Such a collection, based on stem cells taken at birth and preserved

for decades, would have the capacity to turn into most of the 200 to

300 types of tissue in an adult human. These could one day be used to

treat liver disease, diabetes, strokes and heart conditions.

Researchers in Britain have begun experiments with embryo stem cells,

which have even greater potential. But this research is contentious,

even in Britain, which legally cleared the way for such attempts in

2001. Other teams have tested the promise of adult stem cells, found

in bone marrow and blood.

" We have found a unique group of cells that brings together the

essential qualities of both types of stem cells for the first time, "

said Colin McGuckin of Kingston University. He and colleagues report

in Cell Proliferation today that they screened umbilical cord blood to

get stem cells with the characteristics of an embryo.

The dream is that stem cells could one day be used to grow new organ

tissue or nerve cells and treat diseases for which there is currently

no treatment.

But stem cells are extremely rare. To serve any useful medical

purpose, they must exist in quantity. The challenge is to find a small

number and then culture them, while stopping them from differentiating

into a range of unwanted tissue.

The British team worked with a Texan group to harness a technology,

derived from Nasa research, to multiply the stem cells and then " grow "

liver cells. A bioreactor, designed by one of Nasa's spin-off

companies, was used to simulate the weightlessness of space, and

amplify the original stem cells 168-fold.

" Acquiring stem cells from embryos also has major limitations because

it is difficult to obtain enough cells to transplant, as well as

getting the right tissue type for the patient, " Dr McGuckin said.

" Using cord blood gets over that obstacle because we can produce more

stem cells, and, with a global birth rate of 100 million babies a

year, there is a better chance of getting the right tissue type for

the many patients out there waiting for stem cell therapy. "

In Britain, the US and Europe, agencies have begun to collect and

preserve umbilical cord blood samples at birth. It could be a decade

before the first clinical trials could help treat diseases.

The Kingston team has begun to grow liver tissue in lumps of three

dimensions, using a bioreactor that mimics the freefall of a spacecraft.

" You keep the stem cells in a state of freefall and they never really

get to know where they are, they never really get to know which way is

down, which way is up. You can grow the cells inside three-dimensional

scaffolds into larger and larger amounts of tissue. "

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