RNA terminal uridylyl transferases are druggable vulnerabilities in AML but are dispensable for normal hematopoiesis

Acute myeloid leukemia (AML) is an aggressive hematological malignancy arising from hematopoietic stem and progenitor cells (HSPCs). Current treatments often fail to eradicate AML; therefore, new therapeutic strategies are essential. Here, we reveal that RNA terminal uridylyl transferase enzymes 4 and 7 (TUT4/7) are druggable therapeutic targets, whose genetic deletion suppresses AML growth, induces apoptosis, and improves the survival in leukemic mouse models. Notably, a preclinical TUT4/7 inhibitor promotes cell death in samples from patients with AML and synergizes with venetoclax. Mechanistically, TUT4/7 inactivation suppresses mevalonate pathway gene expression, compromising the cholesterol synthesis pathway. Current AML therapies often cause severe hematopoietic toxicity. Although Tut4/7 deletion results in inflammatory activation throughout the hematopoietic system, this is permissive to a normal life span and Tut4/7 deficiency does not compromise HSPC function. Together, these findings identify TUT4/7 as druggable targets, whose inactivation suppresses AML while sparing normal hematopoiesis. In combination with venetoclax, this represents a promising therapeutic strategy.