Overview

• Princeton-led researchers show metastatic breast cancer co-opts erythroblast island macrophages that normally recycle iron for red blood cell production.
• The commandeered cells divert iron from erythroblasts and block their final enucleation step, stalling red blood cell maturation and producing anemia.
• Tumor cells switch on a GATA1-driven erythroid program and make β-globin/hemoglobin to endure the bone marrow’s low-oxygen conditions.
• Depleting these iron-recycling macrophages in mouse models curtailed breast cancer growth in bone, indicating their role in sustaining metastasis.
• Similar macrophages and elevated β-globin were identified in human bone metastases from lung and kidney cancers, suggesting broader relevance and pointing to preclinical therapeutic avenues.