RESUMO
The growth of malignant cells is not only driven by cell-intrinsic factors, but also by the surrounding stroma. Monocytes/Macrophages play an important role in the onset and progression of solid cancers. However, little is known about their role in the development of acute myeloid leukemia, a malignant disease characterized by an aberrant development of the myeloid compartment of the hematopoietic system. It is also unclear which factors are responsible for changing the status of macrophage polarization, thus supporting the growth of malignant cells instead of inhibiting it. We report herein that acute myeloid leukemia leads to the invasion of acute myeloid leukemia-associated macrophages into the bone marrow and spleen of leukemic patients and mice. In different leukemic mouse models, these macrophages support the in vitro expansion of acute myeloid leukemia cell lines better than macrophages from non-leukemic mice. The grade of macrophage infiltration correlates in vivo with the survival of the mice. We found that the transcriptional repressor Growth factor independence 1 is crucial in the process of macrophage polarization, since its absence impedes macrophage polarization towards a leukemia supporting state and favors an anti-tumor state both in vitro and in vivo These results not only suggest that acute myeloid leukemia-associated macrophages play an important role in the progression of acute myeloid leukemia, but also implicate Growth factor independence 1 as a pivotal factor in macrophage polarization. These data may provide new insights and opportunities for novel therapies for acute myeloid leukemia.
Assuntos
Proteínas de Ligação a DNA/fisiologia , Leucemia Mieloide Aguda/patologia , Macrófagos/patologia , Fatores de Transcrição/fisiologia , Animais , Medula Óssea/patologia , Linhagem Celular Tumoral , Movimento Celular , Modelos Animais de Doenças , Progressão da Doença , Humanos , Camundongos , Camundongos Transgênicos , Baço/patologiaAssuntos
Proteínas de Ligação a DNA/genética , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , Proteína 1 Parceira de Translocação de RUNX1/genética , Proteína 1 Parceira de Translocação de RUNX1/metabolismo , Fatores de Transcrição/genética , Biomarcadores Tumorais , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Proteínas de Ligação a DNA/metabolismo , Progressão da Doença , Regulação Leucêmica da Expressão Gênica , Humanos , Leucemia Mieloide Aguda/mortalidade , Leucemia Mieloide Aguda/patologia , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/metabolismo , Prognóstico , Fatores de Transcrição/metabolismoRESUMO
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.