Abstract

Eradicating leukemia stem cells (LSCs) and overcoming tyrosine kinase inhibitor (TKI) resistance is urgent for chronic myeloid leukemia (CML) treatment. We find that F-box protein 3 (FBXO3) is highly upregulated in CD34 + CML stem cells from TKI-resistant patients and identify it as an innovative CML-LSC marker via single-cell RNA sequencing (scRNA-seq). FBXO3 deficiency induces apoptosis and reduces proliferation of CML cell lines and LSCs in vitro and in vivo , with minimal effects on normal CD34 + hematopoietic stem cells (HSCs). Mechanistically, FBXO3 interacts with DUSP9 to promote its ubiquitination and activate the MAPK pathway, critical for CML cell activity. DUSP9 knockdown partially reverses FBXO3-deficiency-mediated LSC elimination. Furthermore, FBXO3 inhibitor monotherapy or combination with imatinib effectively eradicates CML-LSCs, overcomes TKI resistance, and spares normal hematopoiesis. Collectively, our findings highlight FBXO3’s role in CML progression and support combining FBXO3 inhibitors with TKIs for durable LSC elimination.