MicroRNA-155 is a direct target of Meis1, but not a driver in acute myeloid leukemia

OBJECTIVE: The microRNA miR-155 is upregulated by Hoxa9 and Meis1, and accelerate the onset of acute myeloid leukemia (AML) together with Hoxa9 but through largely unknown molecular mechanisms. To further resolve these mechanisms, we performed a gene expression profiling, in the context of Hoxa9 leukemogenesis with our without overexpression of miR-155. RESULTS: Gene expression profiling of a Hoxa9 preleukemic cell line transduced with miR-155 leads to differential expression of multiple genes, including a set not previously implicated as miR-155 targets. Murine bone marrow cells transduced with Hoxa9-GFP + empty MIY vector were compared to Hoxa9+miR-155 and harvest for mRNA expression array. Three independent experiments were performed for each of the different conditions included in the study. Cells from were also transplanted into lethally irradiated mice to test for their transforming and leukemic potential.