Hematopoietic stem cell niche and bone marrow microenvironment (BMM)

The hematopoietic stem cell (HSC) niche and bone marrow microenvironment (BMM) constitute a specialized anatomical and functional system within the bone marrow that governs the life cycle of blood-forming stem cells (Morrison & Scadden, Nature, 2014). This environment is composed of diverse cell types, including osteoblasts, endothelial cells, and mesenchymal stromal cells, alongside a complex extracellular matrix and signaling molecules like CXCL12 and Stem Cell Factor (SCF) (Crane et al., Nature Reviews Cancer, 2017). Its primary biological role is to maintain HSC quiescence, facilitate self-renewal, and regulate differentiation into various blood lineages (Nakamura-Ishizu et al., Blood, 2020). In hematological malignancies, the BMM is often remodeled into a "pro-tumoral" niche that protects cancer cells from apoptosis and chemotherapy-induced stress (Nakamura-Ishizu et al., Blood, 2020). Therapeutic interventions targeting the niche, such as CXCR4 antagonists (e.g., Plerixafor) or E-selectin inhibitors, aim to "flush" malignant cells into the circulation where they are more vulnerable to treatment or to mobilize healthy HSCs for transplantation (FDA Label for Mozobil).

Other names

Bone marrow nicheHematopoietic microenvironmentHSC nicheOsteoblastic nicheVascular niche

Disruption of cell-niche interactions, primarily through the inhibition of the CXCR4/CXCL12 axis or E-selectin-mediated adhesion, to mobilize hematopoietic stem cells into the peripheral blood or to sensitize malignant cells to chemotherapy by removing them from protective microenvironmental signals (Morrison & Scadden, Nature, 2014; FDA Label for Mozobil).