CD40 promotes AML survival via non-canonical NF-κB signaling and aberrant lipid metabolism.

Despite the identification of several pathogenic drivers, the molecular mechanisms underlying the development of acute myeloid leukemia (AML) remain largely unknown. Therefore, we sought to explore the key genes associated with leukemia and identified cluster of differentiation 40 (CD40) as a key mediator linked to the incidence and progression of AML. Higher levels of CD40 were detected in patients with AML compared to healthy donors. Moreover, elevated CD40 expression was associated with lower overall survival rates. Furthermore, anti-CD40 antibody significantly induced apoptosis and enhanced drug sensitivity in human AML cell lines. Conversely, ex vivo treatment of primary AML samples with a CD40 agonist significantly decreased cell apoptosis and drug sensitivity. In Kasumi-1 AML cells, CD40 knockout (KO) significantly impaired the engraftment ability of leukemia cells and reduced the leukemia burden in NSG mice compared to wild-type mice. RNA sequencing showed that differentially expressed genes were significantly enriched in the nuclear factor-kB (NF-kB) signaling pathway in CD40-KO cells, which was confirmed through Western blotting. Untargeted metabolomic analysis revealed 179 metabolites with differential expression between WT and CD40 KO cells. Subsequent analysis revealed significant changes in the main metabolic pathways, particularly the biosynthesis of unsaturated fatty acids and lipid metabolism. A targeted metabolomics study of fatty acid metabolism demonstrated that cis-5, 8, 11, 14, 17-eicosapentaenoic acid (EPA) was markedly downregulated in CD40-KO cells compared to wild-type cells. Remarkably, EPA reversed the apoptosis and cell cycle arrest induced by CD40 deletion, simultaneously reducing the drug sensitivity of CD40-KO cells. Together, our study highlights the potential of CD40 as a target in the treatment of AML.