Nuclear NAD homeostasis governed by NMNAT1 prevents apoptosis of acute myeloid leukemia stem cells.

Metabolic dysregulation underlies malignant phenotypes attributed to cancer stem cells, such as unlimited proliferation and differentiation blockade. Here, we demonstrate that NAD metabolism enables acute myeloid leukemia (AML) to evade apoptosis, another hallmark of cancer stem cells. We integrated whole-genome CRISPR screening and pan-cancer genetic dependency mapping to identify and as AML dependencies governing NAD biosynthesis. While both and were required for AML, the presence of NAD precursors bypassed the dependence of AML on but not , pointing to as a gatekeeper of NAD biosynthesis. Deletion of reduced nuclear NAD, activated p53, and increased venetoclax sensitivity. Conversely, increased NAD biosynthesis promoted venetoclax resistance. Unlike leukemia stem cells (LSCs) in both murine and human AML xenograft models, was dispensable for hematopoietic stem cells and hematopoiesis. Our findings identify NMNAT1 as a previously unidentified therapeutic target that maintains NAD for AML progression and chemoresistance.