Abstract Introduction & Background: MicroRNA expression is dysregulated in many human
cancers, including hematologic malignancies. Among hematologic malignancies, acute
myeloid leukemia (AML) carries a particularly poor prognosis, leading to over 10,000 deaths
each year. The most common genetic aberration in AML is a gain-of-function mutation in the
FMS-like tyrosine kinase 3 (FLT3) receptor. FLT3 internal tandem duplication (ITD) occurs
in~ 25% of all AML diagnoses, and confers a negative prognosis. MicroRNA expression has …

FLT3-ITD+ acute myeloid leukemia (AML) accounts for∼ 25% of all AML cases and is a
subtype that carries a poor prognosis. microRNA-155 (miR-155) is specifically
overexpressed in FLT3-ITD+ AML compared with FLT3 wild-type (FLT3-WT) AML and is
critical for the growth of FLT3-ITD+ AML cells in vitro. However, miR-155's role in regulating
FLT3-ITD–mediated disease in vivo remains unclear. In this study, we used a genetic mouse
model to determine whether miR-155 influences the development of FLT3-ITD–induced …