Inorganic arsenic induces necrosis of human CD34-positive haematopoietic stem cells

Inorganic arsenic is a major environmental contaminant known to exert immunosuppressive effects. In this study, we report toxicity of AS(2)O(3), a trivalent inorganic form, toward isolated human hematopoietic CD34+ progenitor cells. Our results demonstrate that low concentrations of AS(2)O(3) (0-1-5 mu M) inhibit in vitro proliferation of CD34+ cells and their differentiation into various hematological cell lineages. These effects were associated with the induction of a necrotic process independent of caspases and likely related to mitochondrial damage. We conclude that As2O3 can impair in vitro human hematopoiesis by decreasing survival of CD34+ progenitor cells. (c) 2008 Wiley Periodicals, Inc.