BioProject

Apoptosis Repressor with Caspase Recruitment Domain (ARC) was recently found to be highly expressed in solid tumors and in blast cells of patients with acute myeloid leukemia (AML). More...

Apoptosis Repressor with Caspase Recruitment Domain (ARC) was recently found to be highly expressed in solid tumors and in blast cells of patients with acute myeloid leukemia (AML). In this study, we assessed the functional and molecular consequences of loss of ARC on the hematopoietic system. We found, unexpectedly, that deletion of Nol3 (the gene that encodes ARC) in mice leads to development of a myeloproliferative neoplasm (MPN) resembling primary myelofibrosis (PMF). Nol3-/--induced MPN is transplantable into secondary recipient mice and is characterized by anemia, thrombocytopenia, extramedullary hematopoiesis, and bone marrow fibrosis. Despite an overall reduction in bone marrow cellularity Nol3-/- MPN mice have an expanded Thy1+LSK stem cell population with increased cell cycling, in addition to a myelomonocytic differentiation bias. Molecularly, the Nol3-/--induced phenotype is, at least in part, mediated by activation of cyclin-dependent kinases 4 (CDK4) and 6 (CDK6) and MYC. Nol3-/- MPN Thy1+LSK cells show significant molecular similarities with primary CD34+ cells isolated from patients with PMF. Furthermore, we found that Nol3 is deleted in patients with human myeloid malignancies and has decreased expression in a subset of patients with de novo AML. Our results reveal a novel role of Nol3 in normal hematopoiesis and in the pathogenesis of myeloid malignancies. To obtain insight into the molecular mechanism of the Nol3-/- -induced MPN, we performed gene expression profiling on Thy1+LSK bone marrow cells from Nol3+/+ and Nol3-/- MPN mice Overall design: RNA was isolated from Thy1+LSK bone marrow cells from 11-18 month old Nol3+/+ or Nol3-/- MPN mice. Less...