Adult stem cells show promise in new study

Researchers at the University of Minnesota are claiming an influential skeptic as a new believer in the discovery of special adult stem cells and their potential for life-saving treatments and transplants.

In research released today, a U-led team of scientists reports using these human stem cells, which are derived from adult bone marrow, to re-create immune systems in mice.

"The cells not only survived when transplanted, but they completely repopulated the blood system of the mice," said Dr. Catherine Verfaillie, the director of the U's stem cell institute. She first discovered these adult stem cells in 2001 and their potential to create numerous other types of cells in the body.

Co-authoring the study was Dr. Irv Weissman, a Stanford University researcher who often has voiced hesitation about the potential of these cells, called multipotent adult progenitor cells, or MAPCs. The study was published in the Journal of Experimental Medicine.

Weissman said these stem cells showed some limitations in the latest research, "but it is still remarkable that they can give rise to blood cells.''

While only achieved in mice, the discovery raises the hope that MAPCs can be used one day to improve transplants and treatments for cancers and blood disorders. Verfaillie said it was significant in the latest study that the stem cells only created blood cells and not any other types of cells or tumors.

Stem cells are often called the master cells of the body because of their ability to grow other cells and tissues. Early research suggested that only stem cells from early human embryos were versatile enough to create numerous different cell types.

Verfaillie's work has challenged that notion and suggests that some adult stem cells are as versatile and potent as embryonic stem cells. While some politicians offered her progress as evidence that embryonic research isn't needed, Verfaillie maintains that both types of research are necessary.

President Bush is among the politicians who oppose embryonic research when it requires the destruction of human embryos. He has restricted federal funding only to embryonic research using existing cell lines, but some lawmakers are seeking to remove those limits this year.

Weissman has been a leading researcher nationally in embryonic stem cells and also has held leadership positions and benefited financially from companies involved with embryonic research.