Amniotic Fluid Yields Stem Cells Article

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Report: Amniotic fluid yields stem cells

By PAUL ELIAS, AP

Scientists reported Sunday they had found a plentiful source of stem

cells in the fluid that cushions babies in the womb and produced a

variety of tissue types from these cells — sidestepping the

controversy over destroying embryos for research.

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Researchers at Wake Forest University and Harvard University

reported the stem cells they drew from amniotic fluid donated by

pregnant women hold much the same promise as embryonic stem cells.

They reported they were able to extract the stem cells without harm

to mother or fetus and turn their discovery into several different

tissue cell types, including brain, liver and bone.

" Our hope is that these cells will provide a valuable resource for

tissue repair and for engineered organs as well, " said Dr.

Atala, head of Wake Forest's regenerative medicine institute and

senior researcher on the project.

It took Atala's team some seven years of research to determine the

cells they found were truly stem cells that " can be used to produce

a broad range of cells that may be valuable for therapy. "

However, the scientists noted they still don't know exactly how many

different cell types can be made from the stem cells found in

amniotic fluid. They also said that even preliminary tests in

patients are years away.

Still, Atala said the research reported in the scientific journal

Nature Biotechnology expands far beyond similar work discussed at a

heart research conference in November. There, Swiss researcher Simon

Hoerstrup said he managed to turn amniotic fluid stem cells into

heart cells that could be grown into replacement valves. Hoerstrup

has yet to publish his work in a scientific journal.

Atala said the new research has found even more promising stem cells

with the potential to turn into many more medically useful

replacement parts.

" We have other cell lines cooking, " Atala said.

The hallmark of human embryonic stem cells, which are created in the

first days after conception, is the ability to turn into any of the

more than 220 cell types that make up the human body. Researchers

are hopeful they can train these primordial cells to repair damaged

organs in need of healthy cells.

However, many people, including President Bush, oppose the

destruction of embryos for any reason. The Bush administration has

severely restricted federal funding for the embryo work since 2001,

leading many scientists to search for alternative stem cell sources.

The cells from amniotic fluid " can clearly generate a broad range of

important cell types, but they may not do as many tricks as

embryonic stem cells, " said Dr. Lanza, chief scientist at the

stem cell company Advanced Cell Technology. " Either way, I think

this work represents a giant step forward for stem cell research. "

It's the latest advance in the so-called regenerative medicine field

that has sprung from Atala's lab in Winston-Salem, N.C. In April,

Atala and his colleagues rebuilt bladders for seven young patients

using live tissue grown in the lab.

In the latest work, Atala's team extracted a small number of stem

cells swimming among the many other cell types in the amniotic

fluid. One of the more promising aspects of the research is that

some of the DNA of the amnio stem cells contained Y chromosomes,

which means the cells came from the babies rather than the pregnant

moms.

Dr. Daley, a Harvard University stem cell researcher, said

that finding raises the possibility that someday expectant parents

can freeze amnio stem cells for future tissue replacement in a sick

child without fear of immune rejection.

Nonetheless, Daley said the discovery shouldn't be used as a

replacement for human embryonic stem cell research.

" While they are fascinating subjects of study in their own right,

they are not a substitute for human embryonic stem cells, which

allow scientists to address a host of other interesting questions in

early human development, " said Daley, who began work last year to

clone human embryos to produce stem cells.

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On the Net:

Wake Forest regenerative medicine institute: http://www.wfirm.org/

Nature Biotechnology: http://www.nature.com/nbt/index.html