State-Transition Analysis of Time-Sequential microRNA Expression Predicts Development of Acute Myeloid Leukemia

We show that the microRNA transcriptome undergoes a global state transition during the initiation and progression of acute myeloid leukemia, and accurately predicts time to disease development. Overall design: We conducted a longitudinal study in a mouse AML model induced by the Cbfb-MYH11 (CM) oncogene to observe the temporal evolution of the transcriptome from healthy state to leukemia state. In the conditional CM knock-in mouse model (Cbfb+/56MMx1Cre), expression of CM in the adult bone marrow alters normal hematopoietic differentiation creating aberrant pre-leukemic progenitor cells which acquire additional genetic and epigenetic alterations needed for malignant transformation and AML development. We used two independent cohorts of mice as training and validation cohorts. For the training cohort, we collected PBMC from the CM-induced mice (n = 7) and the similarly treated littermate controls (n = 7) before induction (t = 0) and monthly after induction up to 10 months (t = 1-10) or when the mouse developed leukemia and became moribund, whichever event occurred first. Similarly, for the validation cohort, we collected PBMC from CM mice (n=9) or control (n=7) before induction and monthly thereafter up to 6 months. Total RNA was isolated from PBMC using AllPrep DNA/RNA Kit (Qiagen) and subjected to micro RNA-sequencing.