Bone marrow stromal cells promote chemoresistance in acute myeloid leukaemia through P2RX7-mediated antioxidant defence.

Acute myeloid leukaemia (AML) remains a therapeutically challenging malignancy owing to its high relapse rates and chemoresistance, often linked to elevated antioxidant defences. Here, we demonstrate that bone marrow stromal cells (BMSCs) confer chemoresistance in AML by upregulating the purinergic receptor P2RX7. Blocking P2RX7 restored chemosensitivity of AML cells. Mechanistically, BMSC-mediated P2RX7 overexpression induces calcium influx and mitochondrial calcium overload, triggering mitochondrial stress and a compensatory antioxidant response. This process involves mitochondrial phosphoglycerate mutase 5 (PGAM5) transducing reactive oxygen species signals, interfering with Keap1-Nrf2 complex formation and leading to Nrf2 stabilization, thereby enhancing cellular antioxidant defences. These findings identify a vital role of P2RX7 in the BMSC-driven redox adaptation programme that underlies AML chemoresistance and highlight P2RX7 signalling as a potential therapeutic target.