Bone marrow stromal and endothelial niche cells (BM niche)

The bone marrow stromal and endothelial niche cells represent a complex multicellular microenvironment that regulates hematopoietic stem cell (HSC) homeostasis, including self-renewal, quiescence, and differentiation (Pinho & Frenette, 2019, Nature). This niche is primarily composed of mesenchymal stromal cells (MSCs), osteoblasts, and specialized endothelial cells that form the perivascular and endosteal compartments (Nakamura-Ishizu et al., 2020, Nature Reviews Immunology). These cells produce critical regulatory factors such as CXCL12, stem cell factor (SCF), and various adhesion molecules like VCAM-1 and E-selectin (Ho & Méndez-Ferrer, 2020, Haematologica). In pathological states, particularly hematologic malignancies, the niche is remodeled into a "pro-tumoral" environment that protects malignant cells from apoptosis and chemotherapy-induced stress (Swerdlow et al., 2017, Blood). Therapeutic targeting of the niche involves disrupting these protective interactions to mobilize stem cells for harvest or to sensitize cancer cells to conventional therapies (Baryawno et al., 2019, Cell).

Other names

Bone marrow microenvironmentHematopoietic stem cell nichePerivascular nicheEndosteal nicheBone marrow stroma

Disruption of the CXCL12/CXCR4 signaling axis to induce mobilization of hematopoietic cells; inhibition of cell-adhesion molecules like E-selectin and VLA-4 to prevent marrow homing and chemoresistance; modulation of the cytokine environment to alter niche support for malignant cells.