A key gene involved in the production and growth of blood stem cells has been identified. Bmi-1 regulates the activity of normal and cancerous blood stem cells, according to two papers published online by Nature this week.
Mature blood cells are constantly replenished by a reservoir of haematopoietic stem cells (HSCs), found in the liver and bone marrow. Both mouse and human HSCs express the cancer-causing gene Bmi-1, according to Michael Clarke from the University of Michigan, Ann Arbor, and colleagues. Although fetal mice lacking the gene have a normal number of liver HSCs, the number of cells drops after birth. Adult mice lacking the gene are unable to produce new HSCs, and transplanted fetal liver and bone marrow cells from these mice contribute only transiently to blood formation.
In a second paper, Guy Sauvageau and Julie Lessard from the Clinical Research Institute of Montreal, Canada, find that Bmi-1 controls the division of normal and leukaemic HSCs. Leukaemic HSCs lacking Bmi-1 divide less often than their normal counterparts and can die. Introduction of Bmi-1, however, rescues ailing cells.
Division of Hematology/Oncology, University of Michigan, Ann Arbor, MI, USA
Tel: +1 734 764 8195 / 734 647 3428 / 734 645 5484 (cell phone)
Clinical Research Institute of Montreal, Quebec, Canada
Tel: +1 514 987 5797
(C) Nature press release.
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