RESUMO
Epigenetic changes can contribute to development of acute myeloid leukemia (AML), a malignant disease of the bone marrow. A single-nucleotide polymorphism of transcription factor growth factor independence 1 (GFI1) generates a protein with an asparagine at position 36 (GFI1(36N)) instead of a serine at position 36 (GFI1(36S)), which is associated with de novo AML in humans. However, how GFI1(36N) predisposes to AML is poorly understood. To explore the mechanism, we used knock-in mouse strains expressing GFI1(36N) or GFI1(36S). Presence of GFI1(36N) shortened the latency and increased the incidence of AML in different murine models of myelodysplastic syndrome/AML. On a molecular level, GFI1(36N) induced genomewide epigenetic changes, leading to expression of AML-associated genes. On a therapeutic level, use of histone acetyltransferase inhibitors specifically impeded growth of GFI1(36N)-expressing human and murine AML cells in vitro and in vivo. These results establish, as a proof of principle, how epigenetic changes in GFI1(36N)-induced AML can be targeted.
Assuntos
Proteínas de Ligação a DNA/genética , Epigênese Genética , Leucemia Mieloide Aguda/genética , Mutação , Fatores de Transcrição/genética , Substituição de Aminoácidos , Animais , Medula Óssea/patologia , Células da Medula Óssea/metabolismo , Células da Medula Óssea/patologia , Transformação Celular Neoplásica/genética , Códon , Modelos Animais de Doenças , Progressão da Doença , Epigênese Genética/efeitos dos fármacos , Regulação Leucêmica da Expressão Gênica , Predisposição Genética para Doença , Inibidores de Histona Desacetilases/farmacologia , Histona Desacetilases/metabolismo , Humanos , Imunofenotipagem , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/mortalidade , Leucemia Mieloide Aguda/patologia , Camundongos , Camundongos Transgênicos , Modelos Biológicos , Síndromes Mielodisplásicas/tratamento farmacológico , Síndromes Mielodisplásicas/genética , Síndromes Mielodisplásicas/metabolismo , Síndromes Mielodisplásicas/mortalidadeRESUMO
Inherited gene variants play an important role in malignant diseases. The transcriptional repressor growth factor independence 1 (GFI1) regulates hematopoietic stem cell (HSC) self-renewal and differentiation. A single-nucleotide polymorphism of GFI1 (rs34631763) generates a protein with an asparagine (N) instead of a serine (S) at position 36 (GFI1(36N)) and has a prevalence of 3%-5% among Caucasians. Because GFI1 regulates myeloid development, we examined the role of GFI1(36N) on the course of MDS disease. To this end, we determined allele frequencies of GFI1(36N) in four independent MDS cohorts from the Netherlands and Belgium, Germany, the ICGC consortium, and the United States. The GFI1(36N) allele frequency in the 723 MDS patients genotyped ranged between 9% and 12%. GFI1(36N) was an independent adverse prognostic factor for overall survival, acute myeloid leukemia-free survival, and event-free survival in a univariate analysis. After adjustment for age, bone marrow blast percentage, IPSS score, mutational status, and cytogenetic findings, GFI1(36N) remained an independent adverse prognostic marker. GFI1(36S) homozygous patients exhibited a sustained response to treatment with hypomethylating agents, whereas GFI1(36N) patients had a poor sustained response to this therapy. Because allele status of GFI1(36N) is readily determined using basic molecular techniques, we propose inclusion of GFI1(36N) status in future prospective studies for MDS patients to better predict prognosis and guide therapeutic decisions.