mA demethylase-driven reprogramming of leukemia-associated macrophages predicts improved outcomes in acute myeloid leukemia.

[BACKGROUND] N6-methyladenosine (mA) is a dynamic mRNA modification influencing transcript fate and cellular identity, especially in cancer. While oncogenic roles of mA regulators in AML cells are known, their impact on the leukemic immune microenvironment is unclear.

[METHODS] In this study, we constructed a single-cell atlas of macrophages in AML by integrating publicly available scRNA-seq datasets from 129 patient cohorts. Data were batch-corrected using Seurat and Harmony. Macrophage subpopulations were identified, and the expression and activity of 29 mA regulators were analyzed. Pseudotime analysis (Monocle3), cell-cell communication (CellChat), and pathway enrichment (Metascape) analyses were performed to explore mA-related functional programs. Survival analysis was conducted using Kaplan-Meier curves. RT-qPCR was used to verify the correlation between mA regulatory molecules and prognosis.

[RESULTS] Our findings indicated that mA regulators are associated with macrophage fate. Writer-high macrophages showed enhanced proliferation and differentiation, maintaining monocyte-like features. Eraser-high macrophages remodeled macrophage function toward an M1-like, pro-inflammatory and antigen-presenting state. Reader-high macrophages drove macrophages toward an immunosuppressive, M2-like phenotype, while mA-deficient cells exhibit features of functional exhaustion. Survival analysis based on bulk RNA-seq data further revealed that mA-regulated macrophage profiles were associated with distinct prognostic stratification in AML patients. RT-qPCR analysis of macrophages isolated from clinical AML samples further validated these findings, showing that patients with favorable prognosis exhibited significantly higher expression levels of erasers compared to those with poor prognosis.

[CONCLUSION] These results highlight mA system's role in macrophage reprogramming and suggest that targeting mA regulators in macrophages may serve as a potential basis for prognostic stratification and a promising therapeutic strategy in AML.