Dysregulated innate immune signaling cooperates with RUNX1 mutations to transform an MDS-like disease to AML (RNA-Seq)

Dysregulated innate immune signaling is linked to preleukemic conditions and myeloid malignancies like MDS and AML. However, it is unknown whether sustained innate immune signaling contributes to malignant transformation. Here we show that cell-intrinsic innate immune signaling driven by miR-146a deletion (miR-146aKO), a commonly deleted gene in MDS and AML, cooperates with mutant RUNX1 (RUNX1mut) to initially induce marrow failure and features of MDS. However, miR-146aKO HSPCs expressing RUNX1mut eventually progress to a fatal AML. miR-146aKO HSPCs exhaust during serial transplantation, while expression of RUNX1mut restored their hematopoietic cell function. Thus, HSPCs exhibiting dysregulated innate immune signaling require a second hit to develop AML. Inhibiting the dysregulated innate immune pathways with a TRAF6-UBE2N inhibitor suppressed leukemic miR-146aKO/RUNX1mut HSPCs, highlighting the necessity of TRAF6-dependent cell-intrinsic innate immune signaling in initiating and maintaining AML. These findings underscore the critical role of dysregulated cell-intrinsic innate immune signaling in driving preleukemic cells toward AML progression.