RESUMO
Cytokines provide signals that regulate immature normal and acute myeloid leukemia (AML) cells in the bone marrow microenvironment. We here identify interleukin 4 (IL4) as a selective inhibitor of AML cell growth and survival in a cytokine screen using fluorescently labeled AML cells. RNA-sequencing of the AML cells revealed an IL4-induced upregulation of Stat6 target genes and enrichment of apoptosis-related gene expression signatures. Consistent with these findings, we found that IL4 stimulation of AML cells induced Stat6 phosphorylation and that disruption of Stat6 using CRISPR/Cas9-genetic engineering rendered cells partially resistant to IL4-induced apoptosis. To evaluate whether IL4 inhibits AML cells in vivo, we expressed IL4 ectopically in AML cells transplanted into mice and also injected IL4 into leukemic mice; both strategies resulted in the suppression of the leukemia cell burden and increased survival. Notably, IL4 exposure caused reduced growth and survival of primary AML CD34+CD38- patient cells from several genetic subtypes of AML, whereas normal stem and progenitor cells were less affected. The IL4-induced apoptosis of AML cells was linked to Caspase-3 activation. Our results demonstrate that IL4 selectively induces apoptosis of AML cells in a Stat6-dependent manner-findings that may translate into new therapeutic opportunities in AML.
Assuntos
Apoptose , Interleucina-4/metabolismo , Leucemia Mieloide Aguda/metabolismo , Fator de Transcrição STAT6/metabolismo , Animais , Apoptose/efeitos dos fármacos , Apoptose/genética , Biomarcadores , Linhagem Celular Tumoral , Citocinas/metabolismo , Citometria de Fluxo , Expressão Gênica , Células-Tronco Hematopoéticas , Humanos , Interleucina-4/farmacologia , Leucemia Mieloide Aguda/genética , Camundongos , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismoAssuntos
Antineoplásicos/uso terapêutico , Benzamidas/uso terapêutico , Fusão Gênica , Leucemia/genética , Piperazinas/uso terapêutico , Pirimidinas/uso terapêutico , Receptor de Fator Estimulador de Colônias de Macrófagos/genética , Análise de Sequência de RNA , Humanos , Mesilato de Imatinib , Leucemia/tratamento farmacológico , Fatores de Transcrição MEF2/genética , Receptor beta de Fator de Crescimento Derivado de Plaquetas/genéticaRESUMO
BACKGROUND: Little is known about the asthma candidate gene neuropeptide S receptor 1 (NPSR1) in relation to environmental exposures, but recent evidences suggest its role as an effect modifier. OBJECTIVES: To explore the interaction between NPSR1 polymorphisms and environmental exposures related to farming lifestyle and to study the in vitro effects of lipopolysaccharide (LPS) stimulation on NPSR1 expression levels. METHODS: We studied 3113 children from PARSIFAL, a European cross-sectional study on environmental/lifestyle factors and childhood allergy, partly focused on children brought up on a farm. Information on exposures and outcomes was primarily obtained from parental questionnaires. Seven tagging polymorphisms were analysed in a conserved haplotype block of NPSR1. Multivariate logistic regression was used to evaluate a multiplicative model of interaction. NPSR1 protein and messenger RNA (mRNA) levels in monocytes were measured after LPS stimulation by fluorescence activated cell sorting (FACS) and quantitative real-time polymerase chain reaction (PCR). RESULTS: A strong interaction was seen between current regular contact to farm animals and several NPSR1 polymorphisms, particularly rs323922 and rs324377 (p<0.005), with respect to allergic symptoms. Considering the timing of initiation of such current regular farm animal contact, significant interactions with these and two additional polymorphisms (SNP546333, rs740347) were revealed. In response to LPS, NPSR1-A protein levels in monocytes were upregulated (p = 0.002), as were NPSR1-A mRNA levels (p = 0.02). CONCLUSIONS: The effect of farm animal contact on the development of allergic symptoms in children is modified by NPSR1 genetic background.