September 4, 2001

Health

Wisconsin Scientists Produce

Blood Cells From Stem Cells

By ANTONIO REGALADO

Staff Reporter of THE WALL STREET JOURNAL

Providing some of the first evidence that stem cells from embryos can be coaxed to form specific tissue types in the laboratory, scientists at the University of Wisconsin have turned embryonic stem cells into oxygen-carrying red blood cells and other components of human blood.

In theory, embryonic stem cells have the potential to form unlimited quantities of human cells for transplant treatments, including blood for transfusions or bone marrow to treat cancer patients. Now that President Bush has given a limited go-ahead for federal funding of stem-cell research, the pace of efforts to produce useful tissues is expected to accelerate.

The project to grow blood from stem cells began soon after Wisconsin scientists first isolated the primitive cells from embryos in 1998, said Dan S. Kaufman, a doctor at the University of Wisconsin Hospital and Clinics in Madison and the study's lead author.

Reporting Tuesday in the journal Proceedings of the National Academy of Sciences, the Wisconsin scientists describe how they incubated embryonic stem cells alongside bone-marrow cells from laboratory mice for several weeks. The mouse cells provided chemical cues that encouraged a small percentage of humanstem cells to grow into blood-system cells, including white and red blood cells.

Experts who have performed similar work using stem cells from mouse embryos during the past decade said the study confirmed their own results. Norman N. Iscove, a researcher at the Ontario Cancer Institute in Toronto , said the Wisconsin report "does not advance the fundamental science" but the paper is a milestone, because "every time biology in another species is confirmed in humans, it is kind of an event."

He said scientists have yet to prove that blood-system cells created in the laboratory are useful in treating disease, such as restoring the damaged immune system of a leukemia patient who has received radiation treatment. Dr. Iscove said such transplants haven't succeeded in experiments on mice, despite years of effort, because the lab-grown cells fail to thrive. However, he held out the possibility that human stem cells could behave differently.

Dr. Kaufman said he is working on an experiment to grow human bone marrow cells and then transplant them into mice. For the time being, he said, "We are a long way off from anything clinically useful."

Stem-cell work at Wisconsin is being conducted in an off-campus laboratory with private financial support. "While all this was swirling in Washington I have been working on this paper," said Dr. Kaufman, who said he expects colleagues soon will publish strong results on how to grow nerves from stem cells as well.

Write to Antonio Regalado at antonio.regalado@wsj.com