RESUMO
BACKGROUND: Previous studies achieved low microbial detection rates in lymphoma patients with interstitial pneumonia (IP) after chemotherapy. However, the metagenomic next-generation sequencing (mNGS) is a comprehensive approach that is expected to improve the pathogen identification rate. Thus far, reports on the use of mNGS in lymphoma patients with chemotherapy-related IP remain scarce. In this study, we summarized the microbial detection outcomes of lymphoma patients with chemotherapy-related IP through mNGS testing of bronchoalveolar lavage fluid (BALF). METHODS: Fifteen lymphoma patients with chemotherapy-related IP were tested for traditional laboratory microbiology, along with the mNGS of BALF. Then, the results of mNGS and traditional laboratory microbiology were compared. RESULTS: Of the 15 enrolled patients, 11 received rituximab and 8 were administered doxorubicin hydrochloride liposome. The overall microbial yield was 93.3% (14/15) for mNGS versus 13.3% (2/15) for traditional culture methods (P ≤ 0.05). The most frequently detected pathogens were Pneumocystis jirovecii (12/15, 80%), Cytomegalovirus (4/15, 26.7%), and Epstein-Barr virus (3/15, 20%). Mixed infections were detected in 10 cases. Five patients recovered after the treatment with antibiotics alone without glucocorticoids. CONCLUSION: Our findings obtained through mNGS testing of BALF suggested a high microbial detection rate in lymphoma patients with IP after chemotherapy. Notably, there was an especially high detection rate of Pneumocystis jirovecii. The application of mNGS in patients with chemotherapy-related IP was more sensitive.
RESUMO
Lysine methyltransferase G9a regulates the transcription of multiple genes by primarily catalyzing mono- and di-methylation of histone H3 lysine 9, as well as several non-histone lysine sites. An attractive therapeutic target in treating leukemia, knockout studies of G9a in mice have found dramatically slowed proliferation and self-renewal of acute myeloid leukemia (AML) cells due to the attenuation of HoxA9-dependent transcription. In this study, a series of compounds were identified as potential inhibitors through structure-based virtual screening. Among these compounds, a new G9a inhibitor, DCG066, was confirmed by in vitro biochemical, and cell based enzyme assays. DCG066 has a novel molecular scaffold unlike other G9a inhibitors presently available. Similar to G9a's histone substrate, DCG066 can bind directly to G9a and inhibit methyltransferase activity in vitro. In addition to suppressing G9a methyltransferase activity and reducing histone H3 methylation levels, DCG066 displays low cytotoxicity in leukemia cell lines with high levels of G9a expression, including K562. This work presents DCG066 as an inhibitor of G9a with a novel structure, providing both a lead in G9a inhibitor design and a means for probing the functionality of G9a.
Assuntos
Descoberta de Drogas , Histona-Lisina N-Metiltransferase/antagonistas & inibidores , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/farmacologia , Animais , Apoptose/efeitos dos fármacos , Azepinas/metabolismo , Ligação Competitiva , Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Histona-Lisina N-Metiltransferase/química , Histona-Lisina N-Metiltransferase/metabolismo , Humanos , Células K562 , Camundongos , Simulação de Acoplamento Molecular , Conformação Proteica , Quinazolinas/metabolismo , Bibliotecas de Moléculas Pequenas/metabolismoRESUMO
Interstitial leukocyte migration plays a critical role in inflammation and offers a therapeutic target for treating inflammation-associated diseases such as multiple sclerosis. Identifying small molecules to inhibit undesired leukocyte migration provides promise for the treatment of these disorders. In this study, we identified vibsanin B, a novel macrocyclic diterpenoid isolated from Viburnum odoratissimum Ker-Gawl, that inhibited zebrafish interstitial leukocyte migration using a transgenic zebrafish line (TG:zlyz-enhanced GFP). We found that vibsanin B preferentially binds to heat shock protein (HSP)90ß. At the molecular level, inactivation of HSP90 can mimic vibsanin B's effect of inhibiting interstitial leukocyte migration. Furthermore, we demonstrated that vibsanin B ameliorates experimental autoimmune encephalomyelitis in mice with pathological manifestation of decreased leukocyte infiltration into their CNS. In summary, vibsanin B is a novel lead compound that preferentially targets HSP90ß and inhibits interstitial leukocyte migration, offering a promising drug lead for treating inflammation-associated diseases.
Assuntos
Movimento Celular/efeitos dos fármacos , Diterpenos/farmacologia , Encefalomielite Autoimune Experimental/imunologia , Encefalomielite Autoimune Experimental/metabolismo , Proteínas de Choque Térmico HSP90/metabolismo , Leucócitos/efeitos dos fármacos , Leucócitos/imunologia , Animais , Linhagem Celular , Sistema Nervoso Central/efeitos dos fármacos , Sistema Nervoso Central/imunologia , Sistema Nervoso Central/metabolismo , Sistema Nervoso Central/patologia , Diterpenos/administração & dosagem , Encefalomielite Autoimune Experimental/tratamento farmacológico , Encefalomielite Autoimune Experimental/patologia , Feminino , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Humanos , Leucócitos/metabolismo , Camundongos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos , Medula Espinal/efeitos dos fármacos , Medula Espinal/imunologia , Medula Espinal/metabolismo , Medula Espinal/patologia , Peixe-ZebraRESUMO
The M2 subtype Acute Myeloid Leukemia (AML-M2) with t(8;21) represents an unmet challenge because of poor clinical outcomes in a sizable portion of patients. In this study,we report that FTY720 (Fingolimod), a sphingosine analogue and an FDA approved drug for treating of multiple sclerosis, shows antitumorigenic activity against the Kasumi-1 cell line, xenograft mouse models and leukemic blasts isolated from AML-M2 patients with t(8;21) translocation. Primary investigation indicated that FTY720 caused cell apoptosis through caspases and protein phosphatase 2A (PP2A) activation. Transcriptomic profiling further revealed that FTY720 treatment could upregulate AML1 target genes and interfere with genes involved in ceramide synthesis. Treatment with FTY720 led to the elimination of AML1-ETO oncoprotein and caused cell cycle arrest. More importantly, FTY720 treatment resulted in rapid and significant increase of pro-apoptotic ceramide levels, determined by high-performance liquid chromatography-electrospray ionization tandem mass spectrometry based lipidomic approaches. Structural simulation model had also indicated that the direct binding of ceramide to inhibitor 2 of PP2A (I2PP2A) could reactivate PP2A and cause cell death. This study demonstrates, for the first time, that accumulation of ceramide plays a central role in FTY720 induced cell death of AML-M2 with t(8;21). Targeting sphingolipid metabolism by using FTY720 may provide novel insight for the drug development of treatment for AML-M2 leukemia.
Assuntos
Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Ceramidas/metabolismo , Leucemia Mieloide Aguda/tratamento farmacológico , Propilenoglicóis/uso terapêutico , Esfingolipídeos/metabolismo , Esfingosina/análogos & derivados , Animais , Caspases/metabolismo , Linhagem Celular , Subunidade alfa 2 de Fator de Ligação ao Core/genética , Cloridrato de Fingolimode , Regulação Leucêmica da Expressão Gênica/efeitos dos fármacos , Humanos , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/patologia , Camundongos Nus , Modelos Moleculares , Proteínas de Fusão Oncogênica/genética , Proteína Fosfatase 2/metabolismo , Proteína 1 Parceira de Translocação de RUNX1 , Esfingosina/uso terapêuticoRESUMO
We previously reported a fusion protein NUP98-IQCG in an acute leukaemia, which functions as an aberrant regulator of transcriptional expression, yet the structure and function of IQCG have not been characterized. Here we use zebrafish to investigate the role of iqcg in haematopoietic development, and find that the numbers of haematopoietic stem cells and multilineage-differentiated cells are reduced in iqcg-deficient embryos. Mechanistically, IQCG binds to calmodulin (CaM) and acts as a molecule upstream of CaM-dependent kinase IV (CaMKIV). Crystal structures of complexes between CaM and IQ domain of IQCG reveal dual CaM-binding footprints in this motif, and provide a structural basis for a higher CaM-IQCG affinity when deprived of calcium. The results collectively allow us to understand IQCG-mediated calcium signalling in haematopoiesis, and propose a model in which IQCG stores CaM at low cytoplasmic calcium concentrations, and releases CaM to activate CaMKIV when calcium level rises.
Assuntos
Calmodulina/metabolismo , Proteínas de Peixe-Zebra/metabolismo , Animais , Proteína Quinase Tipo 4 Dependente de Cálcio-Calmodulina/metabolismo , Proliferação de Células , Técnicas de Silenciamento de Genes , Proteínas de Choque Térmico HSP70/metabolismo , Hematopoese , Peixe-Zebra , Proteínas de Peixe-Zebra/genéticaRESUMO
DNA methyltransferases (DNMTs) are the key enzymes for genome methylation, which plays an important role in epigenetically regulated gene expression and repression. Mouse models with conditional knockout of the DNA methyltransferase 1 (DNMT1) and DNA methyltransferase 3A (DNMT3A) genes have revealed a role of DNA methylation in mediating the self-renewal and differentiation of normal hematopoietic stem cells (HSCs) and the leukemia stem cells (LSCs). Recently, various mutations of DNMT3A and other DNA methylation regulators have been identified in hematologic malignancies. Functional analysis of these mutations may lead to a better understanding of the disease mechanisms, and even the discovery of new biomarkers and/or drug targets, as well as more rational design of therapeutic regimens. Moreover, DNMTs inhibitors as epigenetic drugs have already been approved by US Food and Drug Administration for clinical use and some clinical trials are currently underway in patients with myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML). This review focuses on the biology of DNMTs with regard to epigenetic regulation, HSC renewal/differentiation, and drug discovery for targeted therapy, and delineates the latest studies that have been conducted to unfold the relationship between aberrant DNMTs and hematologic malignancies.