Bone Marrow Stem Cell Therapy Studied

European scientists say excessive stimulation of bone marrow stem cells in mice leads to severe anemia and ultimately death.

The scientists — Claus Nerlov at the European Molecular Biology Laboratory in Monterotondo, Italy, and Achim Leutz at the Max-Delbrueck Center for Molecular Medicine Tumorigenesis and Differentiation in Berlin — say hematopoietic stem cells residing in the bone marrow give rise to all blood cells circulating in the body.

To ensure a lifelong supply of blood cells, those stem cells must continuously self-renew. Previous work revealed stem cells require a signaling molecule called Wnt to activate beta-catenin, a protein involved in self-renewal.

Now research from the two groups of scientists show excessive beta-catenin signals lead, instead, to a loss of stem cells and problems in blood cell development. Mice expressing a mutant form of beta-catenin engineered to be permanently switched on, died at a very young age due to defects in blood cell production.

The study appears in the October issue of the journal Nature Immunology.