Normal and Leukemic Hematopoietic Cells Niche
Pp. 3-9 (7)
Eduardo Magalhaes Rego and Mirela de Barros Tamarozzi
The fate of hematopoietic stem cells (HSCs) is largely regulated by interactions with the bone
marrow environment. In the bone marrow, multiple stem cell niches have been proposed to control different
stem cell behaviors, including mobilization, circulation and homing. Currently, the hematopoietic niche is
conceptually divided into an osteoblastic niche (located near osteoblasts) and a vascular niche (near the
sinusoids). It has been suggested that the osteoblastic niche is responsible for retain stem cells in a quiescent
state maintaining a sufficient stem cells number while the vascular niche has an important role in supporting
proliferation, differentiation, and transendothelial migration of HSCs. These niche’s functions are controlled
by multiple signaling and adhesion molecules. Leukemic stem cells (LSC) are derived from HSCs or
proliferating progenitor cells through the acquisition of stem cell properties including the ability to selfrenewal.
Similar to normal HSCs, LSCs depend upon interactions within a specific niche to maintain and to
support cell growth. This review addresses the interactions between HSC and LSC with their
microenvironment, exploring mechanisms that regulate normal and malignant hematopoiesis.
Hematopoietic Stem Cells (HSCs), Normal HSC, HSC Progeny, Hematopoietic Progenitors,
KIT ligand, Mesenchymal Stem Cells (MSCs), BM HSC, Leukemia Stem Cells, SLAM family, Acute
Department of Internal Medicine, National Institute of Science and Technology on Cell Based Therapy. Medical School of Ribeirao Preto, University of Sao Paulo. Av. Bandeirantes, 3900, CEP 14049- 900, Ribeirao Preto, SP, Brazil.