Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 8.631
Filtrar
1.
Int J Mol Sci ; 22(13)2021 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-34206957

RESUMO

In recent decades, the conduct of uniform prospective clinical trials has led to improved remission rates and survival for patients with acute myeloid leukaemia and acute lymphoblastic leukaemia. However, high-risk patients continue to have inferior outcomes, where chemoresistance and relapse are common due to the survival mechanisms utilised by leukaemic cells. One such mechanism is through hijacking of the bone marrow microenvironment, where healthy haematopoietic machinery is transformed or remodelled into a hiding ground or "sanctuary" where leukaemic cells can escape chemotherapy-induced cytotoxicity. The bone marrow microenvironment, which consists of endosteal and vascular niches, can support leukaemogenesis through intercellular "crosstalk" with niche cells, including mesenchymal stem cells, endothelial cells, osteoblasts, and osteoclasts. Here, we summarise the regulatory mechanisms associated with leukaemia-bone marrow niche interaction and provide a comprehensive review of the key therapeutics that target CXCL12/CXCR4, Notch, Wnt/b-catenin, and hypoxia-related signalling pathways within the leukaemic niches and agents involved in remodelling of niche bone and vasculature. From a therapeutic perspective, targeting these cellular interactions is an exciting novel strategy for enhancing treatment efficacy, and further clinical application has significant potential to improve the outcome of patients with leukaemia.


Assuntos
Leucemia/tratamento farmacológico , Microambiente Tumoral/efeitos dos fármacos , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/metabolismo , Humanos , Leucemia/patologia , Transdução de Sinais
2.
Molecules ; 26(13)2021 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-34202812

RESUMO

The endocannabinoid system (ECS) is a composite cell-signaling system that allows endogenous cannabinoid ligands to control cell functions through the interaction with cannabinoid receptors. Modifications of the ECS might contribute to the pathogenesis of different diseases, including cancers. However, the use of these compounds as antitumor agents remains debatable. Pre-clinical experimental studies have shown that cannabinoids (CBs) might be effective for the treatment of hematological malignancies, such as leukemia and lymphoma. Specifically, CBs may activate programmed cell death mechanisms, thus blocking cancer cell growth, and may modulate both autophagy and angiogenesis. Therefore, CBs may have significant anti-tumor effects in hematologic diseases and may synergistically act with chemotherapeutic agents, possibly also reducing chemoresistance. Moreover, targeting ECS might be considered as a novel approach for the management of graft versus host disease, thus reducing some symptoms such as anorexia, cachexia, fatigue, anxiety, depression, and neuropathic pain. The aim of the present review is to collect the state of the art of CBs effects on hematological tumors, thus focusing on the essential topics that might be useful before moving into the clinical practice.


Assuntos
Canabinoides/uso terapêutico , Neoplasias Hematológicas , Proteínas de Neoplasias/metabolismo , Receptores de Canabinoides/metabolismo , Neoplasias Hematológicas/tratamento farmacológico , Neoplasias Hematológicas/metabolismo , Neoplasias Hematológicas/patologia , Humanos , Leucemia/tratamento farmacológico , Leucemia/metabolismo , Leucemia/patologia , Linfoma/tratamento farmacológico , Linfoma/metabolismo , Linfoma/patologia
3.
Molecules ; 26(10)2021 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-34070111

RESUMO

Cephalotaxine (CET) is a natural alkaloid with potent antileukemia effects. However, its underlying molecular mechanism has not been well understood. In this study, we verified that CET significantly inhibited the viability of various leukemia cells, including HL-60, NB4, Jurkat, K562, Raji and MOLT-4. RNA-sequencing and bioinformatics analysis revealed that CET causes mitochondrial function change. Mechanism research indicated that CET activated the mitochondrial apoptosis pathway by reducing the mitochondrial membrane potential, downregulating anti-apoptotic Bcl-2 protein and upregulating pro-apoptotic Bak protein. In addition, the autophagy signaling pathway was highly enriched by RNA-seq analysis. Then, we found that CET blocked the fluorescence colocation of MitoTracker Green and LysoTracker Red and upregulated the level of LC3-II and p62, which indicated that autophagy flow was impaired. Further results demonstrated that CET could impair lysosomal acidification and block autophagy flow. Finally, inhibiting autophagy flow could aggravate apoptosis of HL-60 cells induced by CET. In summary, this study demonstrated that CET exerted antileukemia effects through activation of the mitochondria-dependent pathway and by impairing autophagy flow. Our research provides new insights into the molecular mechanisms of CET in the treatment of leukemia.


Assuntos
Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Mepesuccinato de Omacetaxina/farmacologia , Leucemia/patologia , Mitocôndrias/metabolismo , Apoptose/genética , Autofagia/genética , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Regulação Leucêmica da Expressão Gênica/efeitos dos fármacos , Homeostase/efeitos dos fármacos , Mepesuccinato de Omacetaxina/química , Humanos , Leucemia/genética , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/ultraestrutura , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Transcriptoma/efeitos dos fármacos , Transcriptoma/genética
4.
Int J Mol Sci ; 22(11)2021 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-34072627

RESUMO

BACKGROUND: Glucocorticoids play an essential part in anti-leukemic therapies, but resistance is a crucial event for the prognosis of the disease. Glucocorticoids influence the metabolic properties of leukemic cells. The inherent plasticity of clinically evolving cancer cells justifies the characterization of drug-induced early oncogenic pathways, which represent a likely source of detrimental secondary effects. AIM: The present work aims to investigate the effect of glucocorticoids in metabolic pathways in the CCRF-CEM leukemic cells. Metabolic factors and gene expression profiles were examined in order to unravel the possible mechanisms of the CCRF-CEM leukemic cell growth dynamics. METHODS: CCRF-CEM cells were used as a model. Cells were treated with prednisolone with concentrations 0-700 µM. Cell culture supernatants were used for glucose, lactic acid, LDH, Na+, K+ and Ca++ measurements. Cytotoxicity was determined with flow cytometry. Microarray analysis was performed using two different chips of 1.2 k and 4.8 k genes. Gene Ontology enrichment analysis was applied to find metabolism- and GC-related genes. RESULTS: Higher prednisolone concentrations inhibited glucose uptake, without exhibiting any cytotoxic effects. Glucose consumption did not correlate with the total cell population, or the viable population, indicating that growth is not directly proportional to glucose consumption. Neither of the subpopulations, i.e., viable, necrotic, or apoptotic cells, contributed to this. CONCLUSIONS: Different types of leukemic cells seem to exhibit different patterns of glucose metabolism. Both resistant and sensitive CCRF-CEM cells followed the aerobic pathway of glycolysis. There is probably a rapid change in membrane permeability, causing a general shutdown towards everything that is outside the cell. This could in part also explain the observed resistance. Glucocorticoids do not enter the cell passively anymore and therefore no effects are observed. Based on our observations, ion concentrations are measurable factors both in vitro and in vivo, which makes them possible markers of glucocorticoid cytotoxic action.


Assuntos
Metabolismo Energético/efeitos dos fármacos , Regulação Leucêmica da Expressão Gênica/efeitos dos fármacos , Glucocorticoides/farmacologia , Leucemia/genética , Leucemia/metabolismo , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Biomarcadores , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Biologia Computacional/métodos , Perfilação da Expressão Gênica , Ontologia Genética , Glucocorticoides/uso terapêutico , Glicólise , Humanos , Leucemia/tratamento farmacológico , Leucemia/patologia , Prednisolona/farmacologia , Transcriptoma , Células Tumorais Cultivadas
5.
Anticancer Res ; 41(5): 2397-2402, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33952464

RESUMO

BACKGROUND/AIM: Experimental oncology commonly uses cells as oncological models, providing a framework for the testing of drugs, and investigation of cytotoxicity, mutagenesis and carcinogenesis. Investigations into poly-ADP-ribose polymerase 1 (PARP1) inhibition have become ever more relevant due to its approval as a therapeutic option for tumors with BRCA1/2 DNA repair-associated mutation and the seemingly high PARP expression levels in some tumor subtypes. In this study, we aimed to determine PARP1 gene expression of different hematological cancer-derived cell lineages and compare them to that of normal cell lines. MATERIALS AND METHODS: PARP1 gene expression in seven different neoplastic lineages, representing three different hematological disorders (chronic myeloid leukemia, Burkitt lymphoma and acute lymphoblastic leukemia), was quantified by quantitative real-time polymerase chain reaction. RESULTS: All hematological malignant lineages in this study overexpressed PARP1 when compared to the normal cell line MRC-5, with Burkitt's lymphoma cells having the highest expression values (fold change: 93). CONCLUSION: Overexpression of PARP1 in hematological malignant lineages is a finding of crucial importance to future studies exploring possible cellular oncogenic pathways and supports investigations into the effectiveness of PARP1 inhibitors against hematological disorders.


Assuntos
Regulação Neoplásica da Expressão Gênica , Neoplasias Hematológicas/genética , Oncologia/métodos , Poli(ADP-Ribose) Polimerase-1/genética , Linhagem Celular , Linhagem Celular Tumoral , Neoplasias Hematológicas/patologia , Humanos , Células Jurkat , Células K562 , Leucemia/genética , Leucemia/patologia
6.
Nature ; 594(7862): 265-270, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34040261

RESUMO

Fast and reliable detection of patients with severe and heterogeneous illnesses is a major goal of precision medicine1,2. Patients with leukaemia can be identified using machine learning on the basis of their blood transcriptomes3. However, there is an increasing divide between what is technically possible and what is allowed, because of privacy legislation4,5. Here, to facilitate the integration of any medical data from any data owner worldwide without violating privacy laws, we introduce Swarm Learning-a decentralized machine-learning approach that unites edge computing, blockchain-based peer-to-peer networking and coordination while maintaining confidentiality without the need for a central coordinator, thereby going beyond federated learning. To illustrate the feasibility of using Swarm Learning to develop disease classifiers using distributed data, we chose four use cases of heterogeneous diseases (COVID-19, tuberculosis, leukaemia and lung pathologies). With more than 16,400 blood transcriptomes derived from 127 clinical studies with non-uniform distributions of cases and controls and substantial study biases, as well as more than 95,000 chest X-ray images, we show that Swarm Learning classifiers outperform those developed at individual sites. In addition, Swarm Learning completely fulfils local confidentiality regulations by design. We believe that this approach will notably accelerate the introduction of precision medicine.


Assuntos
Blockchain , Tomada de Decisão Clínica/métodos , Confidencialidade , Conjuntos de Dados como Assunto , Aprendizado de Máquina , Medicina de Precisão/métodos , COVID-19/diagnóstico , COVID-19/epidemiologia , Surtos de Doenças , Feminino , Humanos , Leucemia/diagnóstico , Leucemia/patologia , Leucócitos/patologia , Pneumopatias/diagnóstico , Aprendizado de Máquina/tendências , Masculino , Software , Tuberculose/diagnóstico
7.
Int J Mol Sci ; 22(6)2021 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-33802972

RESUMO

Leukaemia is a malignant disease of the blood. Current treatments for leukaemia are associated with serious side-effects. Plant-derived polyphenols have been identified as potent anti-cancer agents and have been shown to work synergistically with standard chemotherapy agents in leukaemia cell lines. Polyphenols have multiple mechanisms of action and have been reported to decrease cell proliferation, arrest cell cycle and induce apoptosis via the activation of caspase (3, 8 and 9); the loss of mitochondrial membrane potential and the release of cytochrome c. Polyphenols have been shown to suppress activation of transcription factors, including NF-kB and STAT3. Furthermore, polyphenols have pro-oxidant properties, with increasing evidence that polyphenols inhibit the antioxidant activity of glutathione, causing oxidative DNA damage. Polyphenols also induce autophagy-driven cancer cell death and regulate multidrug resistance proteins, and thus may be able to reverse resistance to chemotherapy agents. This review examines the molecular mechanism of action of polyphenols and discusses their potential therapeutic targets. Here, we discuss the pharmacological properties of polyphenols, including their anti-inflammatory, antioxidant, anti-proliferative, and anti-tumour activities, and suggest that polyphenols are potent natural agents that can be useful therapeutically; and discuss why data on bioavailability, toxicity and metabolism are essential to evaluate their clinical use.


Assuntos
Leucemia/tratamento farmacológico , Polifenóis/uso terapêutico , Animais , Autofagia/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Humanos , Leucemia/patologia , Modelos Biológicos , Polifenóis/química , Polifenóis/farmacologia , Espécies Reativas de Oxigênio/metabolismo
8.
Int J Nanomedicine ; 16: 2849-2877, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33883895

RESUMO

Background: Exosomes are endosome-derived nano-sized vesicles that have emerged as important mediators of intercellular communication and play significant roles in various diseases. However, their applications are rigorously restricted by the limited secretion competence of cells. Therefore, strategies to enhance the production and functions of exosomes are warranted. Studies have shown that nanomaterials can significantly enhance the effects of cells and exosomes in intercellular communication; however, how palladium nanoparticles (PdNPs) enhance exosome release in human leukemia monocytic cells (THP-1) remains unclear. Therefore, this study aimed to address the effect of PdNPs on exosome biogenesis and release in THP-1 cells. Methods: Exosomes were isolated by ultracentrifugation and ExoQuickTM and characterized by dynamic light scattering, nanoparticle tracking analysis system, scanning electron microscopy, transmission electron microscopy, EXOCETTM assay, and fluorescence polarization. The expression levels of exosome markers were analyzed via quantitative reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay. Results: PdNP treatment enhanced the biogenesis and release of exosomes by inducing oxidative stress, endoplasmic reticulum stress, apoptosis, and immunomodulation. The exosomes were spherical in shape and had an average diameter of 50-80 nm. Exosome production was confirmed via total protein concentration, exosome counts, acetylcholinesterase activity, and neutral sphingomyelinase activity. The expression levels of TSG101, CD9, CD63, and CD81 were significantly higher in PdNP-treated cells than in control cells. Further, cytokine and chemokine levels were significantly higher in exosomes isolated from PdNP-treated THP-1 cells than in those isolated from control cells. THP-1 cells pre-treated with N-acetylcysteine or GW4869 showed significant decreases in PdNP-induced exosome biogenesis and release. Conclusion: To our knowledge, this is the first study showing that PdNPs stimulate exosome biogenesis and release and simultaneously increase the levels of cytokines and chemokines by modulating various physiological processes. Our findings suggest a reasonable approach to improve the production of exosomes for various therapeutic applications.


Assuntos
Apoptose/efeitos dos fármacos , Estresse do Retículo Endoplasmático , Exossomos/metabolismo , Imunomodulação/efeitos dos fármacos , Leucemia/patologia , Nanopartículas Metálicas/toxicidade , Estresse Oxidativo , Paládio/toxicidade , Acetilcolinesterase/metabolismo , Acetilcisteína/farmacologia , Compostos de Anilina/farmacologia , Antioxidantes/metabolismo , Compostos de Benzilideno/farmacologia , Biomarcadores Tumorais/metabolismo , Caspases/metabolismo , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Citocinas/metabolismo , Dano ao DNA , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Ativação Enzimática/efeitos dos fármacos , Regulação Leucêmica da Expressão Gênica/efeitos dos fármacos , Humanos , Leucemia/sangue , Nanopartículas Metálicas/ultraestrutura , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/patologia , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Tamanho da Partícula , Esfingomielina Fosfodiesterase/metabolismo , Células THP-1
9.
Int J Mol Sci ; 22(4)2021 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-33668652

RESUMO

Leukemia is a hematological malignancy that originates from hematopoietic stem cells in the bone marrow. Significant progress has made in understanding its pathogensis and in establishing chemotherapy and hematopoietic stem cell transplantation therapy (HSCT). However, while the successive development of new therapies, such as molecular-targeted therapy and immunotherapy, have resulted in remarkable advances, the fact remains that some patients still cannot be saved, and resistance to treatment and relapse are still problems that need to be solved in leukemia patients. The bone marrow (BM) niche is a microenvironment that includes hematopoietic stem cells and their supporting cells. Leukemia cells interact with bone marrow niches and modulate them, not only inducing molecular and functional changes but also switching to niches favored by leukemia cells. The latter are closely associated with leukemia progression, suppression of normal hematopoiesis, and chemotherapy resistance, which is precisely the area of ongoing study. Exosomes play an important role in cell-to-cell communication, not only with cells in close proximity but also with those more distant due to the nature of exosomal circulation via body fluids. In leukemia, exosomes play important roles in leukemogenesis, disease progression, and organ invasion, and their usefulness in the diagnosis and treatment of leukemia has recently been reported. The interaction between leukemia cell-derived exosomes and the BM microenvironment has received particular attention. Their interaction is believed to play a very important role; in addition to their diagnostic value, exosomes could serve as a marker for monitoring treatment efficacy and as an aid in overcoming drug resistance, among the many problems in leukemia patients that have yet to be overcome. In this paper, we will review bone marrow niches in leukemia, findings on leukemia-derived exosomes, and exosome-induced changes in bone marrow niches.


Assuntos
Medula Óssea/metabolismo , Comunicação Celular , Exossomos/metabolismo , Leucemia/metabolismo , Microambiente Tumoral , Medula Óssea/patologia , Exossomos/patologia , Humanos , Leucemia/patologia
10.
Anticancer Res ; 41(3): 1429-1438, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33788734

RESUMO

BACKGROUND/AIM: Clinical significance of antitumour drugs is limited by multidrug resistance (MDR). We examined the effect of bioreductive activation of the anthracyclines, doxorubicin (DOX) and pirarubicin (PIRA), by cytochrome P450 reductase (CPR) on triggering apoptosis of leukaemia HL60 cells and their MDR counterparts. MATERIALS AND METHODS: Cell cycle and FAS expression were investigated by flow cytometry. DNA fragmentation was examined by electrophoretic analysis and caspase-3/8 activities were determined colorimetrically. RESULTS: Non-activated and CPR-activated forms of DOX and PIRA (IC90) had similar efficacy in provoking G2/M arrest of sensitive HL60 as well as resistant HL60/VINC and HL60/DOX cells and in causing DNA degradation. Interestingly, HL60/VINC cells were more prone to apoptosis induced by all studied forms of these drugs. However, no change in Fas expression was observed. CONCLUSION: Bioreductive activation of DOX and PIRA does not affect their ability to induce apoptosis of sensitive and resistant HL60 leukaemia cells.


Assuntos
Apoptose/efeitos dos fármacos , Doxorrubicina/análogos & derivados , Doxorrubicina/farmacologia , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Leucemia/patologia , Antineoplásicos/farmacologia , Caspase 3/metabolismo , Caspase 8/metabolismo , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Fragmentação do DNA/efeitos dos fármacos , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos dos fármacos , Células HL-60 , Humanos , Leucemia/metabolismo , NADPH-Ferri-Hemoproteína Redutase/metabolismo
12.
Transplant Cell Ther ; 27(5): 438.e1-438.e6, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33728417

RESUMO

An evidence-based triage plan for cellular therapy distribution is critical in the face of emerging constraints on healthcare resources. We evaluated the impact of treatment delays related to COVID-19 on patients scheduled to undergo hematopoietic cell transplantation (HCT) or chimeric antigen receptor T-cell (CAR-T) therapy at our center. Data were collected in real time between March 19 and May 11, 2020, for patients who were delayed to cellular therapy. We evaluated the proportion of delayed patients who ultimately received cellular therapy, reasons for not proceeding to cellular therapy, and changes in disease and health status during delay. A total of 85 patients were delayed, including 42 patients planned for autologous HCT, 36 patients planned for allogeneic HCT, and 7 patients planned for CAR-T therapy. Fifty-six of these patients (66%) since received planned therapy. Five patients died during the delay. The most common reason for not proceeding to autologous HCT was good disease control in patients with plasma cell dyscrasias (75%). The most common reason for not proceeding to allogeneic HCT was progression of disease (42%). All patients with acute leukemia who progressed had measurable residual disease (MRD) at the time of delay, whereas no patient without MRD at the time of delay progressed. Six patients (86%) ultimately received CAR-T therapy, including 3 patients who progressed during the delay. For patients with high-risk disease such as acute leukemia, and particularly those with MRD at the time of planned HCT, treatment delay can result in devastating outcomes and should be avoided if at all possible.


Assuntos
COVID-19 , Transplante de Células-Tronco Hematopoéticas , Imunoterapia Adotiva , Pandemias , SARS-CoV-2 , Tempo para o Tratamento , Adulto , Idoso , Aloenxertos , Amiloidose/terapia , Anemia Aplástica/terapia , COVID-19/complicações , COVID-19/epidemiologia , COVID-19/transmissão , Defesa Civil , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/prevenção & controle , Progressão da Doença , Prática Clínica Baseada em Evidências/organização & administração , Feminino , Transplante de Células-Tronco Hematopoéticas/estatística & dados numéricos , Humanos , Controle de Infecções/métodos , Transmissão de Doença Infecciosa do Profissional para o Paciente , Leucemia/mortalidade , Leucemia/patologia , Leucemia/terapia , Masculino , Pessoa de Meia-Idade , Doenças Mieloproliferativas-Mielodisplásicas/mortalidade , Doenças Mieloproliferativas-Mielodisplásicas/terapia , Neoplasia Residual , Neoplasias/mortalidade , Neoplasias/terapia , Cidade de Nova Iorque/epidemiologia , Alocação de Recursos , Tempo para o Tratamento/estatística & dados numéricos , Transplante Autólogo , Triagem/organização & administração , Adulto Jovem
13.
Front Immunol ; 12: 607836, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33717090

RESUMO

Wiskott-Aldrich Syndrome, WAS/WAVE, is a rare, X-linked immune-deficiency disease caused by mutations in the WAS gene, which together with its homolog, N-WASP, regulates actin cytoskeleton remodeling and cell motility. WAS patients suffer from microthrombocytopenia, characterized by a diminished number and size of platelets, though the underlying mechanism is not fully understood. Here, we identified FLI1 as a direct transcriptional regulator of WAS and its binding partner WIP. Depletion of either WAS or WIP in human erythroleukemic cells accelerated cell proliferation, suggesting tumor suppressor function of both genes in leukemia. Depletion of WAS/WIP also led to a significant reduction in the percentage of CD41 and CD61 positive cells, which mark committed megakaryocytes. RNAseq analysis revealed common changes in megakaryocytic gene expression following FLI1 or WASP knockdown. However, in contrast to FLI1, WASP depletion did not alter expression of late-stage platelet-inducing genes. N-WASP was not regulated by FLI1, yet its silencing also reduced the percentage of CD41+ and CD61+ megakaryocytes. Moreover, combined knockdown of WASP and N-WASP further suppressed megakaryocyte differentiation, indicating a major cooperation of these related genes in controlling megakaryocytic cell fate. However, unlike WASP/WIP, N-WASP loss suppressed leukemic cell proliferation. WASP, WIP and N-WASP depletion led to induction of FLI1 expression, mediated by GATA1, and this may mitigate the severity of platelet deficiency in WAS patients. Together, these results uncover a crucial role for FLI1 in megakaryocyte differentiation, implicating this transcription factor in regulating microthrombocytopenia associated with Wiskott-Aldrich syndrome.


Assuntos
Proteínas do Citoesqueleto/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteína Proto-Oncogênica c-fli-1/metabolismo , Trombopoese/genética , Proteína da Síndrome de Wiskott-Aldrich/metabolismo , Síndrome de Wiskott-Aldrich/etiologia , Síndrome de Wiskott-Aldrich/metabolismo , Animais , Sequência de Bases , Biomarcadores , Linhagem Celular , Sequenciamento de Cromatina por Imunoprecipitação , Modelos Animais de Doenças , Suscetibilidade a Doenças , Regulação da Expressão Gênica , Humanos , Leucemia/genética , Leucemia/metabolismo , Leucemia/patologia , Camundongos , Camundongos Knockout , Regiões Promotoras Genéticas , Proteína Proto-Oncogênica c-fli-1/genética , Transdução de Sinais
14.
J Biochem Mol Toxicol ; 35(6): 1-10, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33724660

RESUMO

Among cancers, leukemia is a multistep progression that involves genetic modifications of normal hematopoietic progenitor cells to cancerous cells. In recent times, leukemia cases and their mortality rate have increased rapidly. Therefore, the immense need for a therapeutic approach is crucial that can control this type of cancer. Phyllanthin is a lignan compound constituent from the Phyllanthus species and has numerous beneficial effects as a dietary component. The present study aims to determine the impact of phyllanthin on the MOLT-4 cytotoxic effect. MOLT-4 cells and MS-5 cells were cultured at different concentrations of phyllanthin (5, 10, 25, 50, 75, and 100 µM/ml), and the viability was assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. The level of reactive oxygen species, the membrane potential of mitochondria, apoptosis by 2',7'-dichlorofluorescin-diacetate (DCF-DA), rhodamine, acridine orange (AO)/ethidium bromide (EB), 4',6-diamidino-2-phenylindole (DAPI)/propidium iodide (PI) staining, gene expression of signaling molecules, and protein levels were assessed by reverse-transcription polymerase chain reaction and western blot analysis. Phyllanthin did not show toxicity toward MS-5 cells and significantly decreased the cell viability of MOLT-4 cells with an IC50 value of 25 µM/ml. Also, phyllanthin induced the production of reactive oxygen species and led to the loss of mitochondrial membrane potential. AO/EB and DAPI/PI staining fluorescent image confirmed the induction of apoptosis by phyllanthin treatment. The messenger RNA (mRNA) expression of cell cycle regulator cyclin D1, antiapoptotic gene Bcl-2, NF-κB, and TNF-α decreased, but the proapoptotic Bax mRNA expression was increased. The phosphorylated protein levels of p-PI3K1/2, p-ERK1/2, and p-AKT were decreased, whereas the levels of p-p38 and p-JNKT1/2 increased. Our results confirmed that phyllanthin inhibits the MOLT-4 cells, increases apoptosis, and inhibits MOLT-4 migration and cell invasion. Therefore, phyllanthin can be used as a potential target for leukemia treatment.


Assuntos
Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Leucemia/metabolismo , Lignanas/farmacologia , MAP Quinase Quinase 4/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos , Linhagem Celular Tumoral , Humanos , Leucemia/tratamento farmacológico , Leucemia/patologia
15.
Ann Clin Lab Sci ; 51(1): 120-123, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33653790

RESUMO

OBJECTIVE: The value of bronchoalveolar lavage (BAL) in the diagnosis of pulmonary diseases of diverse etiologies is widely accepted. Cytospin and cell-block preparations for cytomorphological (CM) evaluation and for immunohistochemical studies are the standard method to evaluate BAL, though it may be time-consuming. Flow cytometric (FC) evaluation, on the other hand, has a short turnaround time, and is a useful methodology to differentiate reactive processes from hematological neoplasms, or detect a small aberrant population in an inflammatory background. BAL specimens provide an excellent source for FC studies. CASE REPORTS: We describe two cases of critically ill patients with no history of hematolymphoid neoplasms, who presented with non-specific symptoms. Abnormal pulmonary imaging studies prompted bronchoscopic evaluation and collection of BAL during the initial evaluation. FC analysis of the BAL fluid aided to the early diagnosis of aggressive NK cell leukemia and adult T cell leukemia/lymphoma, respectively. CONCLUSIONS: Flow cytometric immunophenotyping in addition to the CM assessment increases the diagnostic value and provides timely diagnosis from BAL specimens, which is especially important for critically ill patients.


Assuntos
Lavagem Broncoalveolar/métodos , Citometria de Fluxo/métodos , Leucemia/diagnóstico , Idoso , Líquido da Lavagem Broncoalveolar/citologia , Estado Terminal , Detecção Precoce de Câncer/métodos , Feminino , Neoplasias Hematológicas/patologia , Humanos , Células Matadoras Naturais/metabolismo , Leucemia/patologia , Leucemia-Linfoma de Células T do Adulto/diagnóstico , Leucemia-Linfoma de Células T do Adulto/patologia , Pulmão/patologia , Pneumopatias/diagnóstico , Masculino , Pessoa de Meia-Idade
16.
Proc Natl Acad Sci U S A ; 118(6)2021 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-33542097

RESUMO

The chimeric transcription factor E2A-PBX1, containing the N-terminal activation domains of E2A fused to the C-terminal DNA-binding domain of PBX1, results in 5% of pediatric acute lymphoblastic leukemias (ALL). We recently have reported a mechanism for RUNX1-dependent recruitment of E2A-PBX1 to chromatin in pre-B leukemic cells; but the subsequent E2A-PBX1 functions through various coactivators and the general transcriptional machinery remain unclear. The Mediator complex plays a critical role in cell-specific gene activation by serving as a key coactivator for gene-specific transcription factors that facilitates their function through the RNA polymerase II transcriptional machinery, but whether Mediator contributes to aberrant expression of E2A-PBX1 target genes remains largely unexplored. Here we show that Mediator interacts directly with E2A-PBX1 through an interaction of the MED1 subunit with an E2A activation domain. Results of MED1 depletion by CRISPR/Cas9 further indicate that MED1 is specifically required for E2A-PBX1-dependent gene activation and leukemic cell growth. Integrated transcriptome and cistrome analyses identify pre-B cell receptor and cell cycle regulatory genes as direct cotargets of MED1 and E2A-PBX1. Notably, complementary biochemical analyses also demonstrate that recruitment of E2A-PBX1 to a target DNA template involves a direct interaction with DNA-bound RUNX1 that can be further stabilized by EBF1. These findings suggest that E2A-PBX1 interactions with RUNX1 and MED1/Mediator are of functional importance for both gene-specific transcriptional activation and maintenance of E2A-PBX1-driven leukemia. The MED1 dependency for E2A-PBX1-mediated gene activation and leukemogenesis may provide a potential therapeutic opportunity by targeting MED1 in E2A-PBX1+ pre-B leukemia.


Assuntos
Carcinogênese/genética , Proteínas de Homeodomínio/metabolismo , Leucemia/genética , Leucemia/patologia , Subunidade 1 do Complexo Mediador/metabolismo , Proteínas de Fusão Oncogênica/metabolismo , Transcrição Genética , Linfócitos B/patologia , Carcinogênese/patologia , Pontos de Checagem do Ciclo Celular , Proliferação de Células/genética , Sobrevivência Celular , Subunidade alfa 2 de Fator de Ligação ao Core/metabolismo , DNA de Neoplasias/metabolismo , Regulação para Baixo/genética , Regulação Leucêmica da Expressão Gênica , Genes Neoplásicos , Humanos , Ligação Proteica , Estabilidade Proteica
17.
Biochimie ; 184: 8-17, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33556471

RESUMO

Acquired drug-resistance, often involving downregulation or mutations in the target protein, is a major caveat in precision medicine. Understanding mechanisms of resistance to therapeutic drugs may unravel strategies to overcome or prevent them. We previously identified phorbol ester (PE) compounds such as TPA that induce Protein Kinase δ (PKCδ), thereby suppressing leukemogenesis. Here we identified erythroleukemia cell lines that resist PEs and showed that reduced PKCδ protein expression underlies drug resistance. Reduced level of PKCδ in resistant cell lines was due to its phosphorylation followed by protein degradation. Indeed, proteasome inhibition prevented PE-induced loss of PKCδ. Accordingly, a combination of TPA and the proteasome inhibitor ALLN significantly suppressed leukemia in a mouse model of leukemia. PKCδ downregulation by TPA was independent of the downstream MAPK/ERK/P38/JNK pathway. Instead, expression of ubiquitin-associated and SH3 domain-containing protein b (Ubash3b) was induced by TPA, which leads to PKCδ protein dephosphorylation and degradation. This specific degradation was blocked by RNAi-mediated depletion of Ubash3b. In drug-sensitive leukemic cells, TPA did not induce Ubash3b, and consequently, PKCδ levels remained high. A PE-resistant cell line derived from PE-treated sensitive cells exhibited very low PKCδ expression. In these drug resistance cells, a Ubash3b independent mechanism led to PKCδ degradation. Thus, PE compounds in combination with proteasome or specific inhibitors for Ubash3b, or other factors can overcome resistance to TPA, leading to durable suppression of leukemic growth. These results identify Ubash3b as a potential target for drug development.


Assuntos
Carcinogênese/efeitos dos fármacos , Regulação para Baixo/efeitos dos fármacos , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Regulação Leucêmica da Expressão Gênica/efeitos dos fármacos , Leucemia/enzimologia , Proteínas de Neoplasias/metabolismo , Proteína Quinase C-delta/biossíntese , Proteínas Tirosina Fosfatases/metabolismo , Acetato de Tetradecanoilforbol/farmacologia , Carcinogênese/genética , Carcinogênese/metabolismo , Linhagem Celular Tumoral , Humanos , Leucemia/genética , Leucemia/patologia , Proteínas de Neoplasias/genética , Proteína Quinase C-delta/genética , Proteínas Tirosina Fosfatases/genética
18.
Nat Commun ; 12(1): 223, 2021 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-33431820

RESUMO

Enhancers are DNA sequences that enable complex temporal and tissue-specific regulation of genes in higher eukaryotes. Although it is not entirely clear how enhancer-promoter interactions can increase gene expression, this proximity has been observed in multiple systems at multiple loci and is thought to be essential for the maintenance of gene expression. Bromodomain and Extra-Terminal domain (BET) and Mediator proteins have been shown capable of forming phase condensates and are thought to be essential for super-enhancer function. Here, we show that targeting of cells with inhibitors of BET proteins or pharmacological degradation of BET protein Bromodomain-containing protein 4 (BRD4) has a strong impact on transcription but very little impact on enhancer-promoter interactions. Dissolving phase condensates reduces BRD4 and Mediator binding at enhancers and can also strongly affect gene transcription, without disrupting enhancer-promoter interactions. These results suggest that activation of transcription and maintenance of enhancer-promoter interactions are separable events. Our findings further indicate that enhancer-promoter interactions are not dependent on high levels of BRD4 and Mediator, and are likely maintained by a complex set of factors including additional activator complexes and, at some sites, CTCF and cohesin.


Assuntos
Elementos Facilitadores Genéticos , Regiões Promotoras Genéticas , Transcrição Genética , Fator de Ligação a CCCTC/metabolismo , Carcinogênese/efeitos dos fármacos , Carcinogênese/genética , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Cromatina/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , Proteínas de Ligação a DNA/metabolismo , Glicóis/farmacologia , Histonas/metabolismo , Humanos , Leucemia/genética , Leucemia/patologia , Modelos Genéticos , Ligação Proteica/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-myc/genética , Transcrição Genética/efeitos dos fármacos
19.
Hum Genet ; 140(6): 849-861, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33385171

RESUMO

Mitochondrial (MT) dysfunction is a hallmark of aging and has been associated with most aging-related diseases as well as immunological processes. However, little is known about aging, lifestyle and genetic factors influencing mitochondrial DNA (mtDNA) abundance. In this study, mtDNA abundance was estimated from the weighted intensities of probes mapping to the MT genome in 295,150 participants from the UK Biobank. We found that the abundance of mtDNA was significantly elevated in women compared to men, was negatively correlated with advanced age, higher smoking exposure, greater body-mass index, higher frailty index as well as elevated red and white blood cell count and lower mortality. In addition, several biochemistry markers in blood-related to cholesterol metabolism, ion homeostasis and kidney function were found to be significantly associated with mtDNA abundance. By performing a genome-wide association study, we identified 50 independent regions genome-wide significantly associated with mtDNA abundance which harbour multiple genes involved in the immune system, cancer as well as mitochondrial function. Using mixed effects models, we estimated the SNP-heritability of mtDNA abundance to be around 8%. To investigate the consequence of altered mtDNA abundance, we performed a phenome-wide association study and found that mtDNA abundance is involved in risk for leukaemia, hematologic diseases as well as hypertension. Thus, estimating mtDNA abundance from genotyping arrays has the potential to provide novel insights into age- and disease-relevant processes, particularly those related to immunity and established mitochondrial functions.


Assuntos
Envelhecimento/genética , DNA Mitocondrial/genética , Genoma Mitocondrial , Doenças Hematológicas/genética , Hipertensão/genética , Leucemia/genética , Idoso , Envelhecimento/imunologia , Bancos de Espécimes Biológicos , Índice de Massa Corporal , DNA Mitocondrial/imunologia , Contagem de Eritrócitos , Feminino , Estudo de Associação Genômica Ampla , Doenças Hematológicas/epidemiologia , Doenças Hematológicas/imunologia , Doenças Hematológicas/patologia , Humanos , Hipertensão/epidemiologia , Hipertensão/imunologia , Hipertensão/patologia , Imunidade Inata , Padrões de Herança/imunologia , Leucemia/epidemiologia , Leucemia/imunologia , Leucemia/patologia , Contagem de Leucócitos , Masculino , Pessoa de Meia-Idade , Mitocôndrias/genética , Mitocôndrias/imunologia , Polimorfismo de Nucleotídeo Único , Fumar/genética , Fumar/fisiopatologia , Reino Unido/epidemiologia
20.
Nat Struct Mol Biol ; 28(2): 190-201, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33479542

RESUMO

NUP98 fusion proteins cause leukemia via unknown molecular mechanisms. All NUP98 fusion proteins share an intrinsically disordered region (IDR) in the NUP98 N terminus, featuring repeats of phenylalanine-glycine (FG), and C-terminal fusion partners often function in gene control. We investigated whether mechanisms of oncogenic transformation by NUP98 fusion proteins are hardwired in their protein interactomes. Affinity purification coupled to mass spectrometry (MS) and confocal imaging of five NUP98 fusion proteins expressed in human leukemia cells revealed that shared interactors were enriched for proteins involved in biomolecular condensation and that they colocalized with NUP98 fusion proteins in nuclear puncta. We developed biotinylated isoxazole-mediated condensome MS (biCon-MS) to show that NUP98 fusion proteins alter the global composition of biomolecular condensates. An artificial FG-repeat-containing fusion protein phenocopied the nuclear localization patterns of NUP98 fusion proteins and their capability to drive oncogenic gene expression programs. Thus, we propose that IDR-containing fusion proteins combine biomolecular condensation with transcriptional control to induce cancer.


Assuntos
Núcleo Celular/metabolismo , Proteínas de Homeodomínio , Leucemia , Complexo de Proteínas Formadoras de Poros Nucleares , Proteínas de Fusão Oncogênica , Animais , Expressão Gênica , Regulação Leucêmica da Expressão Gênica , Células HEK293 , Células HL-60 , Proteínas de Homeodomínio/química , Proteínas de Homeodomínio/fisiologia , Humanos , Leucemia/metabolismo , Leucemia/patologia , Camundongos , Células NIH 3T3 , Complexo de Proteínas Formadoras de Poros Nucleares/química , Complexo de Proteínas Formadoras de Poros Nucleares/fisiologia , Proteínas de Fusão Oncogênica/química , Proteínas de Fusão Oncogênica/fisiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...