Metastatic myeloma?

摘要

Evidence suggests that multiple myeloma cells are constantly invading new regions within the bone marrow through induced systemic re-circulation. In this issue of Blood, Azab and colleagues demonstrate that regional bone marrow hypoxia promotes the dissemination of myeloma cells in a manner similar to solid tumor metastasis. This spread is mediated by a hypoxia-induced epithelial-to-mesenchymal cell transition (EMT)-like phenotype. Multiple myeloma is an exclusively bone marrow-localized malignancy generating from normal plasma cell differentiation. Plasma cell maturation involves migration of pre-germinal center (GC) B cells from the bone marrow to secondary lymphoid organs and return to the bone marrow as mature plasma cells. Post-GC homing is mediated by CXCR4-induced homing to CXCL12/SDF-1-rich regions of bone marrow niche. Within the bone marrow plasma cell adherence to ECM, bone marrow stromal cells (BMSCs) and other juxtaposed cells lead to the production of crucial factors for bone marrow homeo-stasis.