1. Restoration of MYC-repressed targets mediates the negative effects of GM-CSF on RUNX1-ETO leukemogenicity
- Author
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Weng, S, Matsuura, S, Mowery, CT, Stoner, SA, Lam, K, Ran, D, Davis, AG, Lo, M-C, and Zhang, D-E
- Subjects
Genetics ,Pediatric Cancer ,Pediatric ,Hematology ,Rare Diseases ,Cancer ,Childhood Leukemia ,Stem Cell Research - Nonembryonic - Non-Human ,Regenerative Medicine ,Stem Cell Research - Nonembryonic - Human ,Stem Cell Research ,Pediatric Research Initiative ,5.1 Pharmaceuticals ,2.1 Biological and endogenous factors ,Development of treatments and therapeutic interventions ,Aetiology ,Animals ,Basic Helix-Loop-Helix Transcription Factors ,Core Binding Factor Alpha 2 Subunit ,Gene Expression Profiling ,Granulocyte-Macrophage Colony-Stimulating Factor ,Hematopoietic Stem Cells ,Humans ,Leukemia ,Myeloid ,Acute ,Mice ,Myelopoiesis ,Oncogene Proteins ,Fusion ,Proto-Oncogene Proteins ,Proto-Oncogene Proteins c-myc ,RUNX1 Translocation Partner 1 Protein ,Transcription Factors ,Tumor Suppressor Proteins ,Clinical Sciences ,Oncology and Carcinogenesis ,Immunology - Abstract
Granulocyte macrophage-colony-stimulating factor (GM-CSF) signaling regulates hematopoiesis and immune responses. CSF2RA, the gene encoding the α-subunit for GM-CSF, is significantly downregulated in t(8;21) (RUNX1-ETO or RE) leukemia patients, suggesting that it may serve as a tumor suppressor. We previously reported that GM-CSF signaling is inhibitory to RE leukemogenesis. Here we conducted gene expression profiling of primary RE hematopoietic stem/progenitor cells (HSPCs) treated with GM-CSF to elucidate the mechanisms mediating the negative effects of GM on RE leukemogenicity. We observed that GM treatment of RE HSPCs resulted in a unique gene expression profile that resembles primary human cells undergoing myelopoiesis, which was not observed in control HSPCs. Additionally, we discovered that GM-CSF signaling attenuates MYC-associated gene signatures in RE HSPCs. In agreement with this, a functional screen of a subset of GM-CSF-responsive genes demonstrated that a MYC inhibitor, MXI1 (Max interactor 1), reduced the leukemic potential of RE HSPCs and t(8;21) acute myeloid leukemia (AML) cells. Furthermore, MYC knockdown and treatment with the BET (bromodomain and extra terminal domain) inhibitor JQ1 reduced the leukemic potential of t(8;21) cell lines. Altogether, we discovered a novel molecular mechanism mediating the GM-CSF-induced reduction in leukemic potential of RE cells, and our findings support MYC inhibition as an effective strategy for reducing the leukemogenicity of t(8;21) AML.
- Published
- 2017