Leukemic stromal hematopoietic microenvironment negatively regulates the normal hematopoiesis in mouse model of leukemia.

Received: 2010­09­10; Accepted: 2010­11­11 Hematopoiesis is a dynamic process resulting in continuous production of mature blood­forming cells from a relatively small population of primitive hematopoietic stem/progenitor cells through diverse proliferative and differentiative events [1­4] . Recent studies have revealed that the normal hematopoiesis requires associative interaction between hematopoietic cells and the cells of the hematopoietic microenvironment which are necessary for the critical maintenance of cell proliferation, maturation, and death [5­10] . Disruption of this fine balance between cell proliferation, cell survival and cell death plays a major role in development of several neoplastic diseases, particularly leukemia. Leukemia is a stem cell disease where normal stem cell function and behavior are lost due to transformation events [11,12] . Leukemia development is a multi­step process characterized by progressive cellular transformation of normal hematopoietic stem/progenitor cells into malignant leukemic clones. These leukemic clones could induce reversible changes in stromal function or composition which results in improved growth conditions for malignant cells (malignancy­induced microenvironment). The functionally abnormal malignant clones become an integral 窑Original Article窑