RNA Terminal Uridylyl-Transferases Are Druggable Vulnerabilities in AML, but are Dispensable for Normal Hematopoiesis [RNA-seq]

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 pre-clinical TUT4/7 inhibitor promotes cell death in AML patient samples 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 lifespan 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.