RESUMO
Acute myeloid leukemia (AML) is a deadly form of leukemia with ineffective traditional treatment and frequent chemoresistance-associated relapse. Personalized drug screening holds promise in identifying optimal regimen, nevertheless, primary AML cells undergo spontaneous apoptosis during cultures, invalidating the drug screening results. Here, we reconstitute a 3D osteogenic niche (3DON) mimicking that in bone marrow to support primary AML cell survival and phenotype maintenance in cultures. Specifically, 3DON derived from osteogenically differentiated mesenchymal stem cells (MSC) from healthy and AML donors are co-cultured with primary AML cells. The AML cells under the AML_3DON niche showed enhanced viability, reduced apoptosis and maintained CD33+ CD34-phenotype, associating with elevated secretion of anti-apoptotic cytokines in the AML_3DON niche. Moreover, AML cells under the AML_3DON niche exhibited low sensitivity to two FDA-approved chemotherapeutic drugs, further suggesting the physiological resemblance of the AML_3DON niche. Most interestingly, AML cells co-cultured with the healthy_3DON niche are highly sensitive to the same sample drugs. This study demonstrates the differential responses of AML cells towards leukemic and healthy bone marrow niches, suggesting the impact of native cancer cell niche in drug screening, and the potential of re-engineering healthy bone marrow niche in AML patients as chemotherapeutic adjuvants overcoming chemoresistance, respectively.
RESUMO
Acute myeloid leukemia (AML) with TP53 mutation is one of the most lethal cancers and portends an extremely poor prognosis. Based on in silico analyses of druggable genes and differential gene expression in TP53-mutated AML, we identified pololike kinase 4 (PLK4) as a novel therapeutic target and examined its expression, regulation, pathogenetic mechanisms, and therapeutic potential in TP53-mutated AML. PLK4 expression was suppressed by activated p53 signaling in TP53 wild-type AML and was increased in TP53-mutated AML cell lines and primary samples. Short-term PLK4 inhibition induced DNA damage and apoptosis in TP53 wild-type AML. Prolonged PLK4 inhibition suppressed the growth of TP53-mutated AML and was associated with DNA damage, apoptosis, senescence, polyploidy, and defective cytokinesis. A hitherto undescribed PLK4/PRMT5/EZH2/H3K27me3 axis was demonstrated in both TP53 wild-type and mutated AML, resulting in histone modification through PLK4-induced PRMT5 phosphorylation. In TP53-mutated AML, combined effects of histone modification and polyploidy activated the cGAS-STING pathway, leading to secretion of cytokines and chemokines and activation of macrophages and T cells upon coculture with AML cells. In vivo, PLK4 inhibition also induced cytokine and chemokine expression in mouse recipients, and its combination with anti-CD47 antibody, which inhibited the "don't-eat-me" signal in macrophages, synergistically reduced leukemic burden and prolonged animal survival. The study shed important light on the pathogenetic role of PLK4 and might lead to novel therapeutic strategies in TP53-mutated AML.
Assuntos
Histonas , Leucemia Mieloide Aguda , Animais , Camundongos , Histonas/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Mutação , Metilação , Nucleotidiltransferases/metabolismo , Leucemia Mieloide Aguda/patologia , Imunidade , PoliploidiaRESUMO
Zebrafish is a widely used model organism for investigating human diseases, including hematopoietic disorders. However, a comprehensive methylation baseline for zebrafish primary hematopoietic organ, the kidney marrow (KM), is still lacking. We employed Oxford Nanopore Technologies (ONT) sequencing to profile DNA methylation in zebrafish KM by generating four KM datasets, with two groups based on the presence or absence of red blood cells. Our findings revealed that blood contamination in the KM samples reduced read quality and altered methylation patterns. Compared with whole-genome bisulfite sequencing (WGBS), the ONT-based methylation profiling can cover more CpG sites (92.4% vs 70%-80%), and exhibit less GC bias with more even genomic coverage. And the ONT methylation calling results showed a high correlation with WGBS results when using shared sites. This study establishes a comprehensive methylation profile for zebrafish KM, paving the way for further investigations into epigenetic regulation and the development of targeted therapies for hematopoietic disorders.
Assuntos
Metilação de DNA , Hematopoese , Peixe-Zebra , Animais , Ilhas de CpG , Epigênese Genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Sequenciamento por Nanoporos , Análise de Sequência de DNA/métodos , Peixe-Zebra/genética , Hematopoese/genéticaRESUMO
Isocitrate dehydrogenase 2 (IDH2) mutations occur in more than 15% of cytogenetically normal acute myeloid leukemia (CN-AML) but comparative studies of their roles in leukemogenesis have been scarce. We generated zebrafish models of IDH2R172K and IDH2R140Q AML and reported their pathologic, functional and transcriptomic features and therapeutic responses to target therapies. Transgenic embryos co-expressing FLT3ITD and IDH2 mutations showed accentuation of myelopoiesis. As these embryos were raised to adulthood, full-blown leukemia ensued with multi-lineage dysplasia, increase in myeloblasts and marrow cellularity and splenomegaly. The leukemia cells were transplantable into primary and secondary recipients and resulted in more aggressive disease. Tg(Runx1:FLT3ITDIDH2R172K) but not Tg(Runx1:FLT3ITDIDH2R140Q) zebrafish showed an increase in T-cell development at embryonic and adult stages. Single-cell transcriptomic analysis revealed increased myeloid skewing, differentiation blockade and enrichment of leukemia-associated gene signatures in both zebrafish models. Tg(Runx1:FLT3ITDIDH2R172K) but not Tg(Runx1:FLT3ITDIDH2R140Q) zebrafish showed an increase in interferon signals at the adult stage. Leukemic phenotypes in both zebrafish could be ameliorated by quizartinib and enasidenib. In conclusion, the zebrafish models of IDH2 mutated AML recapitulated the morphologic, clinical, functional and transcriptomic characteristics of human diseases, and provided the prototype for developing zebrafish leukemia models of other genotypes that would become a platform for high throughput drug screening.
Assuntos
Leucemia Mieloide Aguda , Peixe-Zebra , Adulto , Animais , Humanos , Peixe-Zebra/genética , Subunidade alfa 2 de Fator de Ligação ao Core/genética , Nucleofosmina , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/tratamento farmacológico , Genótipo , Mutação , Animais Geneticamente Modificados , Isocitrato Desidrogenase/genética , Tirosina Quinase 3 Semelhante a fms/genéticaRESUMO
Aberrant activation of the Hh pathway promotes cell proliferation and multi-drug resistance (MDR) in several cancers, including Acute Myeloid Leukemia (AML). Notably, only one Hh inhibitor, glasdegib, has been approved for AML treatment, and most patients eventually relapse, highlighting the urgent need to discover new therapeutic targets. Hh signal is transduced through the membrane of the primary cilium, a structure expressed by non-proliferating mammalian cells, whose stabilization depends on the activity of HDAC6. Here we describe a positive correlation between Hh, HDAC6, and MDR genes in a cohort of adult AML patients, human leukemic cell lines, and a zebrafish model of Hh overexpression. The hyper-activation of Hh or HDAC6 in zebrafish drove the increased proliferation of hematopoietic stem and progenitor cells (HSPCs). Interestingly, this phenotype was rescued by inhibition of HDAC6 but not of Hh. Also, in human leukemic cell lines, a reduction in vitality was obtained through HDAC6, but not Hh inhibition. Our data showed the presence of a cross-talk between Hh and HDAC6 mediated by stabilization of the primary cilium, which we detect for the first time in zebrafish HSPCs. Inhibition of HDAC6 activity alone or in combination therapy with the chemotherapeutic agent cytarabine, efficiently rescued the hematopoietic phenotype. Our results open the possibility to introduce HDAC6 as therapeutic target to reduce proliferation of leukemic blasts in AML patients.
Assuntos
Proteínas Hedgehog , Inibidores de Histona Desacetilases , Leucemia Mieloide Aguda , Adulto , Animais , Proliferação de Células , Proteínas Hedgehog/metabolismo , Células-Tronco Hematopoéticas , Desacetilase 6 de Histona/metabolismo , Inibidores de Histona Desacetilases/uso terapêutico , Humanos , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/metabolismo , Transdução de Sinais , Peixe-Zebra/metabolismoRESUMO
Internal tandem duplication of Fms-like tyrosine kinase 3 (FLT3/ITD) occurs in about 30% of acute myeloid leukemia (AML) and is associated with poor response to conventional treatment and adverse outcome. Here, we reported that human FLT3/ITD expression led to axis duplication and dorsalization in about 50% of zebrafish embryos. The morphologic phenotype was accompanied by ectopic expression of a morphogen follistatin (fst) during early embryonic development. Increase in fst expression also occurred in adult FLT3/ITD-transgenic zebrafish, Flt3/ITD knock-in mice, and human FLT3/ITD AML cells. Overexpression of human FST317 and FST344 isoforms enhanced clonogenicity and leukemia engraftment in xenotransplantation model via RET, IL2RA, and CCL5 upregulation. Specific targeting of FST by shRNA, CRISPR/Cas9, or antisense oligo inhibited leukemic growth in vitro and in vivo. Importantly, serum FST positively correlated with leukemia engraftment in FLT3/ITD AML patient-derived xenograft mice and leukemia blast percentage in primary AML patients. In FLT3/ITD AML patients treated with FLT3 inhibitor quizartinib, serum FST levels correlated with clinical response. These observations supported FST as a novel therapeutic target and biomarker in FLT3/ITD AML.
Assuntos
Folistatina , Leucemia Mieloide Aguda , Tirosina Quinase 3 Semelhante a fms/genética , Animais , Animais Geneticamente Modificados , Benzotiazóis/farmacologia , Biomarcadores/sangue , Embrião não Mamífero , Folistatina/sangue , Duplicação Gênica , Humanos , Camundongos , Mutação , Transplante de Neoplasias , Compostos de Fenilureia/farmacologia , Inibidores de Proteínas Quinases , Peixe-Zebra/embriologiaRESUMO
BACKGROUND: Patients with relapsed or refractory FLT3 internal tandem duplication (FLT3-ITD)-positive acute myeloid leukaemia have a poor prognosis, including high frequency of relapse, poorer response to salvage therapy, and shorter overall survival than those with FLT3 wild-type disease. We aimed to assess whether single-agent quizartinib, an oral, highly potent and selective type II FLT3 inhibitor, improves overall survival versus salvage chemotherapy. METHODS: QuANTUM-R is a randomised, controlled, phase 3 trial done at 152 hospitals and cancer centres in 19 countries. Eligible patients aged 18 years or older with ECOG performance status 0-2 with relapsed or refractory (duration of first composite complete remission ≤6 months) FLT3-ITD acute myeloid leukaemia after standard therapy with or without allogeneic haemopoietic stem-cell transplantation were randomly assigned (2:1; permuted block size of 6; stratified by response to previous therapy and choice of chemotherapy via a phone-based and web-based interactive response system) to quizartinib (60 mg [30 mg lead-in] orally once daily) or investigator's choice of preselected chemotherapy: subcutaneous low-dose cytarabine (subcutaneous injection of cytarabine 20 mg twice daily on days 1-10 of 28-day cycles); intravenous infusions of mitoxantrone (8 mg/m2 per day), etoposide (100 mg/m2 per day), and cytarabine (1000 mg/m2 per day on days 1-5 of up to two 28-day cycles); or intravenous granulocyte colony-stimulating factor (300 µg/m2 per day or 5 µg/kg per day subcutaneously on days 1-5), fludarabine (intravenous infusion 30 mg/m2 per day on days 2-6), cytarabine (intravenous infusion 2000 mg/m2 per day on days 2-6), and idarubicin (intravenous infusion 10 mg/m2 per day on days 2-4 in up to two 28-day cycles). Patients proceeding to haemopoietic stem-cell transplantation after quizartinib could resume quizartinib after haemopoietic stem-cell transplantation. The primary endpoint was overall survival in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, number NCT02039726, and follow-up is ongoing. FINDINGS: Between May 7, 2014, and Sept 13, 2017, 367 patients were enrolled, of whom 245 were randomly allocated to quizartinib and 122 to chemotherapy. Four patients in the quizartinib group and 28 in the chemotherapy group were not treated. Median follow-up was 23·5 months (IQR 15·4-32·3). Overall survival was longer for quizartinib than for chemotherapy (hazard ratio 0·76 [95% CI 0·58-0·98; p=0·02]). Median overall survival was 6·2 months (5·3-7·2) in the quizartinib group and 4·7 months (4·0-5·5) in the chemotherapy group. The most common non-haematological grade 3-5 treatment-emergent adverse events (within ≤30 days of last dose or >30 days if suspected to be a treatment-related event) for quizartinib (241 patients) and chemotherapy (94 patients) were sepsis or septic shock (46 patients [19%] for quizartinib vs 18 [19%] for chemotherapy), pneumonia (29 [12%] vs eight [9%]), and hypokalaemia (28 [12%] vs eight [9%]). The most frequent treatment-related serious adverse events were febrile neutropenia (18 patients [7%]), sepsis or septic shock (11 [5%]), QT prolongation (five [2%]), and nausea (five [2%]) in the quizartinib group, and febrile neutropenia (five [5%]), sepsis or septic shock (four [4%]), pneumonia (two [2%]), and pyrexia (two [2%]) in the chemotherapy group. Grade 3 QT prolongation in the quizartinib group was uncommon (eight [3%] by central reading, ten [4%] by investigator report); no grade 4 events occurred. There were 80 (33%) treatment-emergent deaths in the quizartinib group (31 [13%] of which were due to adverse events) and 16 (17%) in the chemotherapy group (nine [10%] of which were due to adverse events). INTERPRETATION: Treatment with quizartinib had a survival benefit versus salvage chemotherapy and had a manageable safety profile in patients with rapidly proliferative disease and very poor prognosis. Quizartinib could be considered a new standard of care. Given that there are only a few available treatment options, this study highlights the value of targeting the FLT3-ITD driver mutation with a highly potent and selective FLT3 inhibitor. FUNDING: Daiichi Sankyo.
Assuntos
Benzotiazóis/uso terapêutico , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/mortalidade , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/mortalidade , Compostos de Fenilureia/uso terapêutico , Terapia de Salvação , Adulto , Idoso , Benzotiazóis/farmacologia , Feminino , Humanos , Leucemia Mieloide Aguda/genética , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/genética , Compostos de Fenilureia/farmacologia , Taxa de Sobrevida , Sequências de Repetição em Tandem , Tirosina Quinase 3 Semelhante a fms/antagonistas & inibidores , Tirosina Quinase 3 Semelhante a fms/genéticaRESUMO
Information arising from next generation sequencing of leukemia genome has shed important light on the heterogeneous and combinatorial driver events in acute myeloid leukemia (AML). It has also provided insight into its intricate signaling pathways operative in the disease pathogenesis. These have also become biomarkers and targets for therapeutic intervention. Emerging evidence from in vitro drug screening has demonstrated its potential value in predicting clinical drug responses in specific AML subtypes. However, the best culture conditions and readouts have yet to be standardized and the drugs included in these screening exercises frequently revised in view of the rapid emergence of new therapeutic agents in the oncology field. Testing of leukemia cell functions, including BCL2 profiling, has also been used to predict treatment response to conventional chemotherapy and hypomethylating agents as well as BCL2 antagonist in small patient cohorts. These platforms should be integrated into future clinical trials to develop personalized treatment of AML.
Assuntos
Antineoplásicos/uso terapêutico , Leucemia Mieloide Aguda/tratamento farmacológico , Medicina de Precisão/métodos , Animais , Antineoplásicos/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , Terapia de Alvo Molecular/métodos , Proteínas Proto-Oncogênicas c-bcl-2/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Transdução de Sinais/efeitos dos fármacosRESUMO
BACKGROUND: Diamond-Blackfan anemia (DBA) was the first ribosomopathy associated with mutations in ribosome protein (RP) genes. The clinical phenotypes of DBA include failure of erythropoiesis, congenital anomalies and cancer predisposition. Mutations in RPL5 are reported in approximately 9 ~ 21 % of DBA patients, which represents the most common pathological condition related to a large-subunit ribosomal protein. However, it remains unclear how RPL5 downregulation results in severe phenotypes of this disease. RESULTS: In this study, we generated a zebrafish model of DBA with RPL5 morphants and implemented high-throughput RNA-seq and ncRNA-seq to identify key genes, lncRNAs, and miRNAs during zebrafish development and hematopoiesis. We demonstrated that RPL5 is required for both primitive and definitive hematopoiesis processes. By comparing with other DBA zebrafish models and processing functional coupling network, we identified some common regulated genes, lncRNAs and miRNAs, that might play important roles in development and hematopoiesis. CONCLUSIONS: Ribosome biogenesis and translation process were affected more in RPL5 MO than in other RP MOs. Both P53 dependent (for example, cell cycle pathway) and independent pathways (such as Aminoacyl-tRNA biosynthesis pathway) play important roles in DBA pathology. Our results therefore provide a comprehensive basis for the study of molecular pathogenesis of RPL5-mediated DBA and other ribosomopathies.
Assuntos
Anemia de Diamond-Blackfan/genética , Regulação para Baixo/genética , Perfilação da Expressão Gênica , Ribossomos/metabolismo , Proteínas de Peixe-Zebra/genética , Peixe-Zebra/genética , Animais , Modelos Animais de Doenças , Regulação para Baixo/efeitos dos fármacos , Embrião não Mamífero/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Redes Reguladoras de Genes/efeitos dos fármacos , Hematopoese/efeitos dos fármacos , Hematopoese/genética , Hemoglobinas/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Morfolinos/farmacologia , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Transcriptoma/efeitos dos fármacos , Transcriptoma/genética , Proteínas de Peixe-Zebra/metabolismoRESUMO
Superoxide anion radical (O2(â¢-)) is undoubtedly the most important primary reactive oxygen species (ROS) found in cells, whose formation and fate are intertwined with diverse physiological and pathological processes. Here we report a highly sensitive and selective O2(â¢-) detecting strategy involving O2(â¢-) cleavage of an aryl trifluoromethanesulfonate group to yield a free phenol. We have synthesized three new O2(â¢-) fluorescent probes (HKSOX-1, HKSOX-1r for cellular retention, and HKSOX-1m for mitochondria-targeting) which exhibit excellent selectivity and sensitivity toward O2(â¢-) over a broad range of pH, strong oxidants, and abundant reductants found in cells. In confocal imaging, flow cytometry, and 96-well microplate assay, HKSOX-1r has been robustly applied to detect O2(â¢-) in multiple cellular models, such as inflammation and mitochondrial stress. Additionally, our probes can be efficiently applied to visualize O2(â¢-) in intact live zebrafish embryos. These probes open up exciting opportunities for unmasking the roles of O2(â¢-) in health and disease.
Assuntos
Alcanossulfonatos/química , Fluoresceínas/química , Corantes Fluorescentes/química , Macrófagos/química , Superóxidos/análise , Peixe-Zebra/embriologia , Alcanossulfonatos/síntese química , Animais , Linhagem Celular , Sobrevivência Celular , Fluoresceínas/síntese química , Corantes Fluorescentes/análise , Corantes Fluorescentes/síntese química , Células HCT116 , Humanos , Concentração de Íons de Hidrogênio , Macrófagos/citologia , Camundongos , Estrutura MolecularRESUMO
Immunocompromised mice, such as the nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice, have been widely used to examine the self-renewal and differentiation potential of human hematopoietic stem cells (HSCs) in vivo. However, the efficiency of human HSC engraftment remains very low. Here, we report that NOD/SCID mice had higher levels of reactive oxygen species (ROS) in their bone marrow (BM) than other commonly used mouse strains (C57BL/6 and BALB/C). Treatment with the antioxidant N-acetyl-l-cysteine (NAC) decreased ROS levels in the BM of NOD/SCID mice. Furthermore, the NAC-treated mice displayed a significant increase in human HSC engraftment and multilineage hematopoietic differentiation in the mice. In comparison with the control mice, NAC-treated recipients displayed a 10.8-fold increase in hematopoietic engraftment in the injected tibiae. A beneficial effect of NAC for human hematopoietic engraftment was also observed in an additional immunodeficient mouse strain, namely NOD.Cg-Prkdc(scid)Il2rg(tm1Wjl)/SzJ (NOD/SCID/γc(-/-) or NSG). Thus, this study uncovers a previously unappreciated negative effect of ROS on human stem cell engraftment in immunodeficient mice.
Assuntos
Acetilcisteína/uso terapêutico , Antioxidantes/uso terapêutico , Medula Óssea/efeitos dos fármacos , Transplante de Células-Tronco Hematopoéticas , Células-Tronco Hematopoéticas/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Acetilcisteína/farmacologia , Animais , Antioxidantes/farmacologia , Medula Óssea/metabolismo , Feminino , Hematopoese/efeitos dos fármacos , Transplante de Células-Tronco Hematopoéticas/métodos , Células-Tronco Hematopoéticas/citologia , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Camundongos SCID , Transplante HeterólogoRESUMO
BACKGROUND: Diamond-Blackfan anemia (DBA) is a class of human diseases linked to defective ribosome biogenesis that results in clinical phenotypes. Genetic mutations in ribosome protein (RP) genes lead to DBA phenotypes, including hematopoietic defects and physical deformities. However, little is known about the global regulatory network as well as key miRNAs and gene pathways in the zebrafish model of DBA. RESULTS: In this study, we establish the DBA model in zebrafish using an RPS24 morpholino and found that RPS24 is required for both primitive hematopoiesis and definitive hematopoiesis processes that are partially mediated by the p53 pathway. Several deregulated genes and miRNAs were found to be related to hematopoiesis, vascular development and apoptosis in RPS24-deficient zebrafish via RNA-seq and miRNA-seq data analysis, and a comprehensive regulatory network was first constructed to identify the mechanisms of key miRNAs and gene pathways in the model. Interestingly, we found that the central node genes in the network were almost all targeted by significantly deregulated miRNAs. Furthermore, the enforced expression of miR-142-3p, a uniquely expressed miRNA, causes a significant decrease in primitive erythrocyte progenitor cells and HSCs. CONCLUSIONS: The present analyses demonstrate that the comprehensive regulatory network we constructed is useful for the functional prediction of new and important miRNAs in DBA and will provide insights into the pathogenesis of mutant rps24-mediated human DBA disease.
Assuntos
Anemia de Diamond-Blackfan/genética , Perfilação da Expressão Gênica , Transcriptoma , Anemia de Diamond-Blackfan/metabolismo , Animais , Análise por Conglomerados , Modelos Animais de Doenças , Células Precursoras Eritroides/metabolismo , Regulação da Expressão Gênica , Técnicas de Inativação de Genes , Redes Reguladoras de Genes , Hematopoese/genética , Células-Tronco Hematopoéticas/metabolismo , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Morfolinos/genética , Morfolinos/metabolismo , Fenótipo , Proteínas Ribossômicas/deficiência , Proteínas Ribossômicas/genética , Proteínas Ribossômicas/metabolismo , Transdução de Sinais , Proteína Supressora de Tumor p53 , Peixe-Zebra/genéticaRESUMO
Although CEBPA mutations are among the most common genetic abnormalities in acute myeloid leukemia (AML), the transformation mechanism remains largely obscure. In this issue of Cancer Cell, Zhang and colleagues report that SOX4 is a direct target and crucial mediator of C/EBPα mutants in AML, revealing a potential therapeutic avenue.
Assuntos
Proteínas Estimuladoras de Ligação a CCAAT/genética , Regulação Leucêmica da Expressão Gênica , Leucemia Mieloide Aguda/genética , Fatores de Transcrição SOXC/genética , Animais , HumanosRESUMO
Although HCO(3)(-) is known to be required for early embryo development, its exact role remains elusive. Here we report that HCO(3)(-) acts as an environmental cue in regulating miR-125b expression through CFTR-mediated influx during preimplantation embryo development. The results show that the effect of HCO(3)(-) on preimplantation embryo development can be suppressed by interfering the function of a HCO(3)(-)-conducting channel, CFTR, by a specific inhibitor or gene knockout. Removal of extracellular HCO(3)(-) or inhibition of CFTR reduces miR-125b expression in 2 cell-stage mouse embryos. Knockdown of miR-125b mimics the effect of HCO(3)(-) removal and CFTR inhibition, while injection of miR-125b precursor reverses it. Downregulation of miR-125b upregulates p53 cascade in both human and mouse embryos. The activation of miR-125b is shown to be mediated by sAC/PKA-dependent nuclear shuttling of NF-κB. These results have revealed a critical role of CFTR in signal transduction linking the environmental HCO(3)(-) to activation of miR-125b during preimplantation embryo development and indicated the importance of ion channels in regulation of miRNAs.
Assuntos
Bicarbonatos/farmacologia , Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , MicroRNAs/metabolismo , Animais , Regulador de Condutância Transmembrana em Fibrose Cística/deficiência , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Regulação para Baixo , Embrião de Mamíferos/metabolismo , Desenvolvimento Embrionário/efeitos dos fármacos , Humanos , Canais Iônicos/metabolismo , Camundongos , Camundongos Knockout , MicroRNAs/antagonistas & inibidores , NF-kappa B/metabolismo , Transdução de Sinais/efeitos dos fármacos , Proteína Supressora de Tumor p53/metabolismo , Regulação para CimaRESUMO
OBJECTIVE: Myeloid sarcoma (MS) is a rare extramedullary manifestation of acute myeloid leukemia that often presents during remission or disease relapse. With awareness of this clinical entity and the appropriate clinical history, MS can be detected despite its nonspecific radiologic features. CONCLUSION: This article highlights the utility of (18)F-FDG PET/CT, which has high sensitivity in detecting early MS and provides a systemic overview of tumor burden, and its potential role in monitoring of treatment response.
Assuntos
Imagem Multimodal , Tomografia por Emissão de Pósitrons , Sarcoma Mieloide/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Feminino , Fluordesoxiglucose F18 , Humanos , Masculino , Estadiamento de Neoplasias , Compostos Radiofarmacêuticos , Sarcoma Mieloide/patologia , Sensibilidade e EspecificidadeRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Diabetic foot ulceration results in high risk of lower extremity amputation, and represents a significant health care expenditure worldwide. Radix Astragali (RA) and Radix Rehmanniae (RR) are widely used Chinese medicinal herbs in treating diabetes, and have shown positive effects in enhancing wound healing in diabetic foot ulcer animal model. MATERIALS AND METHODS: The angiogenic efficacy of NF3, a simplified 2-herb formula consisting of RA and RR in 2:1 ratio, was investigated. Median lethal concentration (LC50) and median effective concentration (EC50) were determined by treating zebrafish embryos with different concentrations of NF3 from 20 hpf to 72 hpf. The angiogenic activity of NF3 was examined in zebrafish embryos in vivo and by rat aortic ring assay in vitro. Cell cycle analysis of endothelial cells induced by NF3 was analyzed by flow cytometry using transgenic zebrafish Tg(fli1:EGFP). Real-time PCR was used to analyze mRNA expression profiles of selected genes involved in VEGF, FGF and MAPK pathways. RESULTS: NF3 enhanced blood vessel formation as indicated by extra growth of intersegmental vessels in zebrafish embryos, and increased microvessels formation in rat aortic ring. NF3 also enhanced endothelial cells proliferation as shown by increased percentage of cells accumulating in S phase and G2/M phase of the cell cycle. NF3 exposure significantly induced up-regulation of VEGF-A, Flk-1, fgf1 and bRaf expression in zebrafish embryos. CONCLUSIONS: Our results demonstrated that NF3 was effective in promoting angiogenesis in zebrafish embryos and by rat aortic ring assay, which provided scientific basis to support the use of NF3 as potential therapeutics in treating diabetic foot ulceration.