Amniotic fluid may be new stem cell source

Stem cell researchers reacted with enthusiasm to a report saying scientists have found stem cells in amniotic fluid...

Stem cell researchers reacted with enthusiasm to a report saying scientists have found stem cells in amniotic fluid, a discovery that would allow them to sidestep the controversy over destroying embryos for research.

Researchers at Wake Forest University and Harvard University reported on Sunday that the stem cells they drew from amniotic fluid donated by pregnant women hold much the same promise as embryonic stem cells. The researchers said they were able to extract stem cells from the fluid, which cushions babies in the womb, without harming the mother or foetus. They said they were able to turn their discovery into several different tissue cell types 8211; including brain, liver and bone.

However, Dr Anthony Atala, head of Wake Forest8217;s regenerative medicine institute and the senior researcher on the project, said the scientists do not know the exact number of different cell types that can be made from the amniotic fluid stem cells.

The cells from amniotic fluid 8220;can clearly generate a broad range of important cell types, but they may not do as many tricks as embryonic stem cells,8221; said Dr Robert Lanza, chief scientist at the stem cell company Advanced Cell Technology. 8220;Either way, I think this work represents a giant step forward for stem cell research.8221;

Dr George Daley, a Harvard University stem cell researcher, said the finding raises the possibility that in the future expectant parents will be able to freeze amnio stem cells for tissue replacement in a sick child without fear of immune rejection. Nonetheless, Daley said, the discovery shouldn8217;t be used as a replacement for human embryonic stem cell research.

Atala said the research reported in the scientific journal Nature Biotechnology expands far beyond similar work. At a heart research conference in November, Swiss researcher Simon Hoerstrup claimed that he had 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. 8220;Our hope is that these cells will provide a valuable resource for tissue repair and for engineered organs as well,8221; Atala said.

It took Atala8217;s team seven years of research to determine the cells they found were truly stem cells that 8220;can be used to produce a broad range of cells that may be valuable for therapy.8221; Atala said that the new research has found even more promising stem cells with the potential to turn into many more medically useful replacement parts.

Story continues below this ad

The hallmark of human embryonic stem cells, which are created in the first days after conception, possesses 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 restricted federal funding for the embryo work since 2001, leading many scientists to search for alternative stem cell sources.

The advance is the latest in the regenerative medicine field that has sprung from Atala8217;s lab in Winston-Salem, NC. Atala8217;s team had 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 mothers.

8211;PAUL ELIAS