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1.
Anticancer Res ; 39(8): 4165-4170, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31366501

RESUMO

AIM: To examine the influence of hypoxia on the in vitro growth of leukaemia cells and the activity of signalling proteins to better understand the pathophysiology of leukaemia cells in human bone marrow. MATERIALS AND METHODS: Six human leukaemia cell lines were cultured under normoxic or hypoxic conditions. Cell growth, recovery of clonogenic cells, and the expression and activation of various signalling proteins were examined. RESULTS: Hypoxia suppressed cell growth and the recovery of clonogenic cells. Moreover, hypoxia up-regulated hypoxia-inducible factor (HIF) 1α and HIF2α expression while suppressing the expression and activation of NOTCH1, mechanistic target of rapamycin kinase (mTOR) activation, and nuclear factor-kappa B (NF-κB) phosphorylation. CONCLUSION: We found that hypoxia up-regulated HIF expression while it suppressed the self-renewal capacity of leukaemia cells, NOTCH activity, and expression of its down-stream signalling molecules, which differs from previous reports mentioning that HIF activates NOTCH signalling. Our findings serve to further elucidate the in vivo pathophysiology of leukaemia cells.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Leucemia/genética , Receptor Notch1/genética , Ciclo Celular/genética , Hipóxia Celular/genética , Linhagem Celular Tumoral , Proliferação de Células/genética , Regulação Leucêmica da Expressão Gênica/genética , Humanos , Leucemia/patologia , NF-kappa B/genética , Fosforilação , Proteínas Proto-Oncogênicas c-akt/genética , Transdução de Sinais/genética , Serina-Treonina Quinases TOR/genética
2.
Int J Nanomedicine ; 14: 4045-4057, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31213814

RESUMO

Background: Quercetin (QUE) shows a potential antileukemic activity, but possesses poor solubility and low bioavailability. Purpose: This article explored the bile salt transport pathway for oral deliver of QUE using cholate-modified polymer-lipid hybrid nanoparticles (cPLNs) aiming to enhance its antileukemic effect. Methods: QUE-loaded cPLNs (QUE-cPLNs) were developed through a nanoprecipitation technique and characterized by particle size, entrapment efficiency (EE), microscopic morphology and in vitro drug release. In vitro cellular uptake and cytotoxicity of QUE-cPLNs were examined on Caco-2 and P388 cells; in vivo pharmacokinetics and antileukemic effect were evaluated using Sprague Dawley rats and leukemic model mice, respectively. Results: The prepared QUE-cPLNs possessed a particle size of 110 nm around with an EE of 96.22%. QUE-cPLNs resulted in significantly enhanced bioavailability of QUE, up to 375.12% relative to the formulation of suspensions. In addition, QUE-cPLNs exhibited excellent cellular uptake and internalization capability compared to cholate-free QUE-PLNs. The in vitro cytotoxic and in vivo antileukemic effects of QUE-cPLNs were also signally superior to free QUE and QUE-PLNs. Conclusion: These findings indicate that cPLNs are a promising nanocarrier able to improve the oral bioavailability and therapeutic index of QUE.


Assuntos
Antineoplásicos/farmacologia , Colatos/química , Lipídeos/química , Nanopartículas/química , Polímeros/química , Quercetina/administração & dosagem , Administração Oral , Animais , Área Sob a Curva , Células CACO-2 , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Liberação Controlada de Fármacos , Sinergismo Farmacológico , Endocitose/efeitos dos fármacos , Humanos , Leucemia/patologia , Camundongos , Nanopartículas/ultraestrutura , Tamanho da Partícula , Quercetina/farmacocinética , Quercetina/farmacologia , Ratos Sprague-Dawley
3.
Talanta ; 200: 378-386, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31036199

RESUMO

Zinc oxide (ZnO) based nanostructures owing unique physical properties - high photoluminescence, biocompatibility and other characteristics, therefore, they attract attention as building blocks suitable for biosensor development. In this research as a target we have used human leukemic cell line IM9 (IM9). IM9 was derived from the patient with a multiple myeloma and expressed cluster of differentiation proteins СD19 on the surface of 85-95% here investigated cancer cells. As a control sample healthy human's peripheral blood mononuclear cells (PBMC) were used and the expression of CD19 protein was found only in 5-9% of these cells. Two types of antibodies labeled by fluorescein isothiocyanate (FITC) were used for the labeling of human leukemic cells: FITC-conjugated mouse antibodies against Human CD19 protein (anti-CD19-FITC*) and FITC-conjugated mouse antibodies against Human IgG1 protein (anti-IgG1-FITC*). In order to demonstrate the applicability of zinc oxide nanorods (ZnO-NRs) based platforms three types of ZnO-NRs-based structures were investigated: (i) ZnO-NRs modified by anti-CD19-FITC*; (ii) ZnO-NRs modified by IM9 cells, which were pre-incubated with anti-CD19-FITC*; (iii) ZnO-NRs modified by PBMC cells, which were pre-incubated with anti-CD19-FITC*. It was demonstrated that IM9 cells after specific interaction with anti-CD19-FITC* bind to ZnO-NRs (ZnO-NRs/IM9 +anti-CD19-FITC*) and photoluminescence based signal significantly increase in comparison with that observed in control samples, which contained PBMC cells incubated with anti-CD19-FITC* (ZnO-NRs/PBMC+anti-CD19-FITC*). The photoluminescence results are in good correlation with the data obtained by flow cytometry. This study illustrate that ZnO-NRs exhibit a photoluminescence signal suitable for the determination of anti-CD19-FITC* labeled IM9 cell line at concentrations - from 10 till 500 cells adsorbed per 1 mm2 of ZnO-NRs platform.


Assuntos
Linfócitos B/patologia , Separação Celular , Imunoensaio/métodos , Leucemia/patologia , Nanotubos/química , Óxido de Zinco/química , Biomarcadores/sangue , Células Cultivadas , Citometria de Fluxo , Humanos , Óxido de Zinco/síntese química
4.
Sensors (Basel) ; 19(9)2019 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-31058824

RESUMO

Label-free evaluation and monitoring of living cell conditions or functions by means of chemical and/or physical sensors in a real-time manner are increasingly desired in the field of basic research of cells and clinical diagnosis. In order to perform multi-parametric analysis of living cells on a chip, we here developed a surface plasmon resonance (SPR) imaging (SPRI)-impedance sensor that can detect both refractive index (RI) and impedance changes on a sensor chip with comb-shaped electrodes. We then investigated the potential of the sensor for label-free and real-time analysis of living cell reactions in response to stimuli. We cultured rat basophilic leukemia (RBL)-2H3 cells on the sensor chip, which was a glass slide coated with comb-shaped electrodes, and detected activation of RBL-2H3 cells, such as degranulation and morphological changes, in response to a dinitro-phenol-conjugated human serum albumin (DNP-HSA) antigen. Moreover, impedance analysis revealed that the changes of impedance derived from RBL-2H3 cell activation appeared in the range of 1 kHz-1 MHz. Furthermore, we monitored living cell-derived RI and impedance changes simultaneously on a sensor chip using the SPRI-impedance sensor. Thus, we developed a new technique to monitor both impedance and RI derived from living cells by using a comb-shaped electrode sensor chip. This technique may enable us to clarify complex living cell functions which affect the RI and impedance and apply this to medical applications, such as accurate clinical diagnosis of type I allergy.


Assuntos
Técnicas Biossensoriais , Fenômenos Fisiológicos Celulares , Rastreamento de Células/métodos , Diagnóstico por Imagem/métodos , Animais , Humanos , Leucemia/diagnóstico , Leucemia/patologia , Ratos , Ressonância de Plasmônio de Superfície
5.
Ann Hematol ; 98(8): 1877-1883, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31144019

RESUMO

Secondary poor graft function (sPGF) is defined as secondary cytopenia after initial engraftment of allogeneic stem cell transplantation (allo-SCT). It has been shown to be associated with poor prognosis; however, there are very few reports on the incidence, risk factors, and outcomes of sPGF. Between January 2015 and December 2015, 564 patients, who received transplantation at Peking University People's Hospital, were retrospectively reviewed. Among the 490 patients who achieved initial engraftment of both neutrophils and platelets, 28 patients developed sPGF. The cumulative incidence of sPGF on day 100 was 5.7%. The median time of sPGF was 54.5 (34-91) days after transplantation. Low (< median) CD34+ cell dose (p = 0.019, HR 3.07 (95% CI, 1.207-7.813)), Epstein-Barr Virus (EBV) reactivation (p = 0.009, HR 3.648 (95%CI, 1.382-9.629)), and cytomegalovirus (CMV) reactivation (p = 0.003, HR 7.827 (95%CI, 2.002-30.602)) were identified as independent risk factors for sPGF. There was no significant difference in PGF incidence between the matched sibling donor (MSD) group and haploidentical donor (HID) group (p = 0.44). The overall survival of patients with sPGF at 1 year after transplantation was significantly poorer than that of patients with good graft function (GGF) (50.5% versus 87.2%, p < 0.001). In conclusion, sPGF developed in 5.7% patients after allo-SCT, especially in patients with CMV, EBV reactivation, or infusion with a low dose of CD34+ cells. The prognosis of sPGF is still poor owing to a lack of standard treatment.


Assuntos
Infecções por Citomegalovirus/virologia , Infecções por Vírus Epstein-Barr/virologia , Doença Enxerto-Hospedeiro/virologia , Transplante de Células-Tronco Hematopoéticas/métodos , Leucemia/terapia , Síndromes Mielodisplásicas/terapia , Ativação Viral/imunologia , Adolescente , Adulto , Idoso , Antígenos CD34/imunologia , Criança , Pré-Escolar , Citomegalovirus/imunologia , Citomegalovirus/patogenicidade , Infecções por Citomegalovirus/diagnóstico , Infecções por Citomegalovirus/mortalidade , Infecções por Citomegalovirus/patologia , Infecções por Vírus Epstein-Barr/diagnóstico , Infecções por Vírus Epstein-Barr/mortalidade , Infecções por Vírus Epstein-Barr/patologia , Feminino , Sobrevivência de Enxerto/fisiologia , Doença Enxerto-Hospedeiro/diagnóstico , Doença Enxerto-Hospedeiro/mortalidade , Doença Enxerto-Hospedeiro/patologia , Transplante de Células-Tronco Hematopoéticas/mortalidade , Células-Tronco Hematopoéticas/imunologia , Células-Tronco Hematopoéticas/virologia , Herpesvirus Humano 4/imunologia , Herpesvirus Humano 4/patogenicidade , Humanos , Leucemia/mortalidade , Leucemia/patologia , Leucemia/virologia , Masculino , Pessoa de Meia-Idade , Síndromes Mielodisplásicas/mortalidade , Síndromes Mielodisplásicas/patologia , Síndromes Mielodisplásicas/virologia , Prognóstico , Estudos Prospectivos , Fatores de Risco , Análise de Sobrevida , Transplante Haploidêntico
6.
Chem Biol Interact ; 306: 29-38, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30954463

RESUMO

Resveratrol, found in variety of plants, is a natural stilbene structure polyphenol. It has various pharmacological effects, such as antioxidation, anti-aging, anti-inflammation, anti-cancer, antiobesity, anti-diabetes, cardioprotection, neuroprotection. Recently, anti-leukemia activities of resveratrol has been studied extensively via its effects on a variety of biological processes involving cell proliferation, apoptosis, autophagy. Current treatments of leukemia mainly rely on intensive chemotherapy or hematopoietic stem cell transplantation, however, these treatments are still with poor survival and high treatment-related mortality. Therefore, it is extremely needed to find relatively non-toxic medicines with minimal side effects but sufficient therapeutic efficacy. Resveratrol is one such potential candidate owing to its reported anti-leukemia effect. In this review, we summarized resveratrol's discovery, sources and isolation methods, administration methods, effects in different types of leukemia, pharmacokinetics and toxicities, aiming to exploit resveratrol as a potential drug candidate for anti-leukemia.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Descoberta de Drogas , Leucemia/tratamento farmacológico , Resveratrol/farmacologia , Antineoplásicos Fitogênicos/efeitos adversos , Antineoplásicos Fitogênicos/química , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Humanos , Leucemia/patologia , Resveratrol/efeitos adversos , Resveratrol/química
7.
Cell Physiol Biochem ; 52(5): 1092-1102, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30977990

RESUMO

BACKGROUND/AIMS: Recent studies indicated that an inhalation treatment of cystic fibrosis mice with acid ceramidase prevents and eliminates infections with Pseudomonas aeruginosa and Stapyhlococcus aureus. Inhalation of acid ceramidase facilitated the elimination of P. aeruginosa in acutely- or chronically-infected mice with cystic fibrosis. Thus, inhalation of acid ceramidase might be a preventive and/or curative treatment for patients with cystic fibrosis suffering from pneumonia. METHODS: We treated cultured epithelial cells or leukemic T-lymphocytes (Jurkat cells) with purified acid ceramidase and determined intracellular signalling events, proliferation and cell survival. Specifically, we measured the activity of AKT, p38-kinase and p70S6-kinase using activation-specific phospho-antibodies in western blot studies. Trypan Blue staining served to analyze proliferation and cell survival. RESULTS: Our studies indicate that treatment of Chang epithelial cells or Jurkat T lymphocytes with purified acid ceramidase results in a dose dependent activation of AKT, p38-kinase and p70S6-kinase, while tyrosine phosphorylation of intracellular proteins remains largely unchanged. Acid ceramidase treatment did not change expression of tight junction proteins such as ZO-1, ZO-2 and occludin. Cellular viability and proliferation were not affected by acid ceramidase treatment. CONCLUSION: Our data suggest that treatment of epithelial cells and lymphocytes with acid ceramidase results in activation of distinct pathways, in particular AKT- and p38K-dependent pathways, while no global activation or cell death was observed.


Assuntos
Ceramidase Ácida/farmacologia , Células Epiteliais/metabolismo , Leucemia/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Proteínas de Neoplasias/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fibrose Cística/tratamento farmacológico , Fibrose Cística/metabolismo , Fibrose Cística/patologia , Células Epiteliais/patologia , Humanos , Células Jurkat , Leucemia/patologia
8.
Tumour Biol ; 41(4): 1010428319846803, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31018830

RESUMO

Mesenchymal stem cells have therapeutic properties that are related to their potentials for trans-differentiation, immunomodulation, anti-inflammatory, inhibitory effect on tumor proliferation, and induction of apoptosis. This study was performed to analyze the role of mesenchymal stem cells as an alternative for cellular signaling growth factors involved in the pathogenesis of leukemogenesis in rats. Treatment of rats with 7,12-dimethyl benz [a] anthracene induced leukemogenesis appeared as a significant decrease in hematological parameters with concomitant significant increase in bone marrow oxidative and inflammatory indices (transforming growth factor beta and interleukin-6) in comparison with normal groups. On the contrary, Western immunoblotting showed a significant increase in the signaling growth factors: PI3K, AKT, mTOR proteins and a significant decrease in PTEN in 7,12-dimethyl benz [a] anthracene-treated group. In addition, a significant increase in the transcript levels of B cell lymphoma-2 protein gene in the 7,12-dimethyl benz [a] anthracene group, while that of C-X-C motif chemokine receptor-4 and B cell lymphoma-2 protein associated x-protein were significantly downregulated compared to controls. Meanwhile, therapeutic mesenchymal stem cells treatment predict a significant improvement versus 7,12-dimethyl benz [a] anthracene group through the modulation of growth factors that confront bone marrow dysplasia. In the same direction treatment of 7,12-dimethyl benz [a] anthracene group with mesenchymal stem cells, it induced apoptosis and increased the homing efficacy to bone marrow. In conclusion, mesenchymal stem cells improve hematopoiesis and alleviate inflammation, and modulated PI3K/AKT signaling pathway contributed to experimental leukemogenesis.


Assuntos
Leucemia/terapia , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais , Proteína Oncogênica v-akt/genética , 9,10-Dimetil-1,2-benzantraceno/toxicidade , Animais , Apoptose/genética , Células da Medula Óssea/patologia , Diferenciação Celular/genética , Proliferação de Células/genética , Modelos Animais de Doenças , Humanos , Leucemia/induzido quimicamente , Leucemia/genética , Leucemia/patologia , PTEN Fosfo-Hidrolase , Fosfatidilinositol 3-Quinases/genética , Ratos , Transdução de Sinais , Serina-Treonina Quinases TOR/genética , Fator de Crescimento Transformador beta/genética
9.
Int J Mol Sci ; 20(5)2019 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-30818762

RESUMO

The non-redundant histone methyltransferase SETD2 (SET domain containing 2; KMT3A) is responsible for tri-methylation of lysine 36 on histone H3 (H3K36me3). Presence of the H3K36me3 histone mark across the genome has been correlated with transcriptional activation and elongation, but also with the regulation of DNA mismatch repair, homologous recombination and alternative splicing. The role of SETD2 and the H3K36me3 histone mark in cancer is controversial. SETD2 is lost or mutated in various cancers, supporting a tumor suppressive role of the protein. Alterations in the SETD2 gene are also present in leukemia patients, where they are associated with aggressive disease and relapse. In line, heterozygous SETD2 loss caused chemotherapy resistance in leukemia cell lines and mouse models. In contrast, other studies indicate that SETD2 is critically required for the proliferation of leukemia cells. Thus, although studies of SETD2-dependent processes in cancer have contributed to a better understanding of the SETD2⁻H3K36me3 axis, many open questions remain regarding its specific role in leukemia. Here, we review the current literature about critical functions of SETD2 in the context of hematopoietic malignancies.


Assuntos
Dano ao DNA , Histona-Lisina N-Metiltransferase/metabolismo , Leucemia/genética , Transcrição Genética , Animais , Carcinogênese/genética , Carcinogênese/patologia , Humanos , Leucemia/patologia , Leucemia/terapia , Mutação/genética
10.
Chem Biol Interact ; 304: 131-138, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-30890322

RESUMO

Non-apoptotic cell-death induction is a potential strategy for cancer treatment. Cytoplasmic vacuolation-associated cell death represents a novel type of non-apoptotic cell-death. Here, we showed that isobavachalcone (IBC), a naturally occurring chalcone compound, selectively induced cell death with massive cytoplasmic vacuolation in some leukemic cells but not in normal peripheral blood cells. Although the IBC-induced cell death displayed certain apoptotic changes, the caspase inhibitor Z-VAD-FMK did not significantly suppress IBC-induced cell death. IBC-induced vacuoles are acidic in nature, as revealed by neutral red staining. However, these vacuoles could not be labeled by lysosome or mitochondrial trackers. Moreover, the knockdown of several autophagy-related genes, such as LC3, Beclin-1, and ATG7, did not inhibit IBC-induced vacuolation. Transmission electron microscope examination revealed that these vacuoles mainly derived from the endosome. Surprisingly, Vacuolar-type H + -ATPase inhibitors, weak bases, such as chloroquine and AKT inhibitors, markedly abrogated vacuolization but enhance IBC-induced cell death, suggesting that IBC-induced vacuolation and cell death go into different direction and the vacuolization is a protective action rather than a part of the death mechanism. In conclusion, by using IBC as a chemical probe, we provide new characteristics of methuosis-like cell death. Inducing methuosis-like cell death may represent a novel strategy to combat leukemia.


Assuntos
Antineoplásicos/farmacologia , Chalconas/farmacologia , Leucemia/tratamento farmacológico , Leucemia/patologia , Apoptose/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Células HEK293 , Humanos
11.
Eur Biophys J ; 48(3): 267-275, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30903263

RESUMO

We introduce a simple, label-free cytometry technique, based on the spatio-temporal fluctuation analysis of pixel gray levels of a cell image utilizing the Gray Level Information Entropy (GLIE) function. In this study, the difference in GLIE random fluctuations and its biophysical etiology in a comparison cell model of leukemic Jurkat cells and human healthy donor lymphocytes was explored. A combination of common bright field microscopy and a unique imaging dish wherein cells are individually held untethered in a picoliter volume matrix of optical chambers was used. Random GLIE fluctuations were found to be greater in malignant Jurkat cells than in benign lymphocytes, while these fluctuations correlate with intracellular vesicle Mean Square Displacement (MSD) values and are inhibited by myosin-2 and adenosine triphosphate (ATP) inhibitors. These results suggest that the incoherent active forces acting on the cytoskeleton which cause mechanical dissipative fluctuation of the cytoskeletal and related intracellular content are the biophysical cellular mechanism behind the GLIE random fluctuation results. Analysis of the results in Jurkat cells and normal lymphocytes suggests the possible potential of this simple and automated label-free cytometry to identify malignancy, particularly in a diagnostic setup of multiple cell examination.


Assuntos
Citometria de Fluxo/instrumentação , Leucemia/patologia , Linfócitos/citologia , Trifosfato de Adenosina/metabolismo , Humanos , Células Jurkat
12.
Pharmacol Rep ; 71(2): 248-256, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30822618

RESUMO

BACKGROUND: Sodium dichloroacetate (DCA) is an agent with anticancer properties against solid tumors. DCA also seems to have antileukemic activity. In order to affirm it we investigate the effect of DCA on cell viability and apoptotic gene expression profiles in leukemia cell lines: CEM/C1, CCRF/CEM, HL-60, HL-60/MX2. METHODS: Cell viability was assessed by trypan blue staining. The expression of 93 genes involved in the process of apoptosis was determined by real-time PCR method using Taqman Low Density Array (TLDA). RESULTS: CEM/C1, CCRF/CEM, HL-60, HL-60/MX2 cells were exposed to DCA for 24 h. The sensitivity of each cell line to DCA is different and depends on the concentration. CEM/C1 was the most sensitive with an half-maximal inhibitory concentration (IC50) value of 30 mM, while HL-60/MX2 was the most resistant with an IC50 value of 75 mM. Exposure of leukemia cells to DCA causes differences in gene expression profiles which cannot indicate that any particular pathway of apoptosis is initiated. However, the presence of 388 statistically significant correlations between expression pattern of gens was determined. CONCLUSION: We showed that DCA causes a decrease in viability of leukemia cells. The decline depends on DCA concentration. The induction of any particular apoptosis pathway is not shown in cells after DCA treatment. For that reason, studies on the molecular mechanism of cell death after exposure to DCA should be continued.


Assuntos
Apoptose/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ácido Dicloroacético/farmacologia , Leucemia/tratamento farmacológico , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Ácido Dicloroacético/administração & dosagem , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células HL-60 , Humanos , Concentração Inibidora 50 , Leucemia/patologia , Reação em Cadeia da Polimerase em Tempo Real
13.
Nature ; 568(7750): 112-116, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30918399

RESUMO

Chimeric antigen receptors (CARs) are synthetic antigen receptors that reprogram T cell specificity, function and persistence1. Patient-derived CAR T cells have demonstrated remarkable efficacy against a range of B-cell malignancies1-3, and the results of early clinical trials suggest activity in multiple myeloma4. Despite high complete response rates, relapses occur in a large fraction of patients; some of these are antigen-negative and others are antigen-low1,2,4-9. Unlike the mechanisms that result in complete and permanent antigen loss6,8,9, those that lead to escape of antigen-low tumours remain unclear. Here, using mouse models of leukaemia, we show that CARs provoke reversible antigen loss through trogocytosis, an active process in which the target antigen is transferred to T cells, thereby decreasing target density on tumour cells and abating T cell activity by promoting fratricide T cell killing and T cell exhaustion. These mechanisms affect both CD28- and 4-1BB-based CARs, albeit differentially, depending on antigen density. These dynamic features can be offset by cooperative killing and combinatorial targeting to augment tumour responses to immunotherapy.


Assuntos
Antígenos de Neoplasias/imunologia , Antígenos de Neoplasias/metabolismo , Leucemia/imunologia , Receptores de Antígenos Quiméricos/imunologia , Linfócitos T/imunologia , Linfócitos T/metabolismo , Evasão Tumoral/imunologia , Ligante 4-1BB/imunologia , Animais , Antígenos CD28/imunologia , Citotoxicidade Imunológica , Feminino , Imunoterapia Adotiva , Leucemia/patologia , Masculino , Camundongos , Camundongos Endogâmicos NOD , Recidiva Local de Neoplasia/imunologia , Linfócitos T/citologia
14.
Nat Commun ; 10(1): 1347, 2019 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-30902969

RESUMO

The BCL6 Corepressor (BCOR) is a component of a variant Polycomb repressive complex 1 (PRC1) that is essential for normal development. Recurrent mutations in the BCOR gene have been identified in acute myeloid leukaemia and myelodysplastic syndrome among other cancers; however, its function remains poorly understood. Here we examine the role of BCOR in haematopoiesis in vivo using a conditional mouse model that mimics the mutations observed in haematological malignancies. Inactivation of Bcor in haematopoietic stem cells (HSCs) results in expansion of myeloid progenitors and co-operates with oncogenic KrasG12D in the initiation of an aggressive and fully transplantable acute leukaemia. Gene expression analysis and chromatin immunoprecipitation sequencing reveals differential regulation of a subset of PRC1-target genes including HSC-associated transcription factors such as Hoxa7/9. This study provides mechanistic understanding of how BCOR regulates cell fate decisions and how loss of function contributes to the development of leukaemia.


Assuntos
Carcinogênese/metabolismo , Carcinogênese/patologia , Diferenciação Celular , Leucemia/patologia , Células Mieloides/patologia , Proteínas Repressoras/deficiência , Animais , Proliferação de Células , Regulação Leucêmica da Expressão Gênica , Células-Tronco Hematopoéticas/metabolismo , Histonas/metabolismo , Proteínas de Homeodomínio/metabolismo , Leucemia/genética , Lisina/metabolismo , Camundongos Endogâmicos C57BL , Mutação/genética , Complexo Repressor Polycomb 1/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Fatores de Transcrição/metabolismo , Transcrição Genética , Ubiquitinação
15.
Mol Cell Probes ; 44: 37-43, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30731134

RESUMO

AIM: Studies have reported that micro (miR)-486-5p plays a crucial part in the progression of leukemia, however, to the best of our knowledge, few studies have been conducted on its mechanism in leukemia. In this study, the mechanism of miR-486-5p in leukemia cells was pointed out and its possible target genes were analyzed for the purpose of providing new therapeutic strategies for treating leukemia patients. METHODS: MiRNA expression of Leukemia cells (K562, Kasumi-1, and THP-1) and primary leukocytes was detected by Real-time Quantitative polymerase chain reaction(qPCR). The activity of the cells was assessed using the Cell Counting Kit-8 (CCK-8). Apoptotic cells were analyzed by a flow cytometer (FCM). Caspase-3 activation in leukemia cells was determined by Western blot. Targetscan 7.2 was used to predict the potential targets of miR-486-5p and further confirmed by dual-luciferase reporter assay. RESULT: miR-486-5p was significantly down-regulated in leukemia cells. The over-expression of miR-486-5p notably increased the apoptosis and caspase-3 activity in leukemia cells. There was a predicted interaction site for miR-486-5p in the FOXO1 3'-UTR. Furthermore, this study showed that FOXO1 was significantly up-regulated in leukemia cells, the growth of which was depressed by the up-regulation of miR-486-5p. CONCLUSION: miR-486-5p may inhibit the proliferation of leukemia cells and induce apoptosis through targeting FOXO1.


Assuntos
Apoptose/genética , Proteína Forkhead Box O1/metabolismo , Leucemia/genética , Leucemia/patologia , MicroRNAs/metabolismo , Sequência de Bases , Caspase 3/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Regulação Leucêmica da Expressão Gênica , Humanos , Regulação para Cima/genética
16.
Nat Cell Biol ; 21(3): 328-337, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30778220

RESUMO

Over their lifetime, long-term haematopoietic stem cells (HSC) are exposed to a variety of stress conditions that they must endure. Many stresses, such as infection/inflammation, reactive oxygen species, nutritional deprivation and hypoxia, activate unfolded protein response signalling, which induces either adaptive changes to resolve the stress or apoptosis to clear the damaged cell. Whether unfolded-protein-response signalling plays any role in HSC regulation remains to be established. Here, we report that the adaptive signalling of the unfolded protein response, IRE1α-XBP1, protects HSCs from endoplasmic reticulum stress-induced apoptosis. IRE1α knockout leads to reduced reconstitution of HSCs. Furthermore, we show that oncogenic N-RasG12D activates IRE1α-XBP1, through MEK-GSK3ß, to promote HSC survival under endoplasmic reticulum stress. Inhibiting IRE1α-XBP1 abolished N-RasG12D-mediated survival under endoplasmic reticulum stress and diminished the competitive advantage of NrasG12D HSCs in transplant recipients. Our studies illuminate how the adaptive endoplasmic reticulum stress response is advantageous in sustaining self-renewal of HSCs and promoting pre-leukaemic clonal dominance.


Assuntos
Autorrenovação Celular/genética , Estresse do Retículo Endoplasmático/genética , Endorribonucleases/metabolismo , Células-Tronco Hematopoéticas/metabolismo , Células-Tronco Neoplásicas/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteína 1 de Ligação a X-Box/metabolismo , Adaptação Fisiológica , Animais , Sobrevivência Celular/genética , Endorribonucleases/genética , Leucemia/genética , Leucemia/metabolismo , Leucemia/patologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Proteínas Monoméricas de Ligação ao GTP/genética , Proteínas Monoméricas de Ligação ao GTP/metabolismo , Lesões Pré-Cancerosas , Proteínas Serina-Treonina Quinases/genética , Transdução de Sinais/genética , Proteína 1 de Ligação a X-Box/genética
17.
Cell Mol Life Sci ; 76(13): 2489-2497, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30715556

RESUMO

Adipose tissue (AT) is an extramedullary reservoir of normal hematopoietic stem cells (HSCs). Adipocytes prevent the production of normal HSCs via secretion of inflammatory factors, and adipocyte-derived free fatty acids may contribute to the development and progression of leukemia via providing energy for leukemic cells. In addition, adipocytes are able to metabolize and inactivate therapeutic agents, reducing the concentrations of active drugs in adipocyte-rich microenvironments. The aim of this study was to detect the role of adipocytes in the progression and treatment of leukemia. Relevant literature was identified through a PubMed search (2000-2018) of English-language papers using the following terms: leukemia, adipocyte, leukemic stem cell, chemotherapy, and bone marrow. Findings suggest the striking interplay between leukemic cells and adipocytes to create a unique microenvironment supporting the metabolic demands and survival of leukemic cells. Based on these findings, targeting lipid metabolism of leukemic cells and adipocytes in combination with standard therapeutic agents might present novel treatment options.


Assuntos
Adipócitos/patologia , Antineoplásicos/farmacologia , Medula Óssea/patologia , Resistencia a Medicamentos Antineoplásicos , Leucemia/patologia , Microambiente Tumoral/efeitos dos fármacos , Adipócitos/efeitos dos fármacos , Adipócitos/metabolismo , Animais , Medula Óssea/efeitos dos fármacos , Medula Óssea/metabolismo , Humanos , Leucemia/tratamento farmacológico , Leucemia/metabolismo
18.
Exp Hematol ; 71: 51-60, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30615903

RESUMO

We describe the establishment of an embryoid-body-based protocol for hematopoietic/myeloid differentiation of human induced pluripotent stem cells that allows the generation of CD34+ cells or mature myeloid cells in vitro. Using this model, we were able to recapitulate the defective granulocytic differentiation in patients with severe congenital neutropenia (CN), an inherited preleukemia bone marrow failure syndrome. Importantly, in vitro maturation arrest of granulopoiesis was associated with an elevated unfolded protein response (UPR) and enhanced expression of the cell cycle inhibitor p21. Consistent with this, we found that CD34+ cells of CN patients were highly susceptible to DNA damage and showed diminished DNA repair. These observations suggest that targeting the UPR pathway or inhibiting DNA damage might protect hematopoietic cells of CN patients from leukemogenic transformation, at least to some extent.


Assuntos
Transformação Celular Neoplásica/metabolismo , Dano ao DNA , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Leucemia/etiologia , Modelos Biológicos , Neutropenia/congênito , Resposta a Proteínas não Dobradas , Antígenos CD34/metabolismo , Biomarcadores , Células Cultivadas , Reprogramação Celular , Estresse do Retículo Endoplasmático , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/metabolismo , Humanos , Imunofenotipagem , Células-Tronco Pluripotentes Induzidas/patologia , Leucemia/metabolismo , Leucemia/patologia , Neutropenia/etiologia , Neutropenia/metabolismo , Neutropenia/patologia
19.
Int J Mol Sci ; 20(1)2019 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-30626136

RESUMO

Morniga-G, the Gal-specific black mulberry (Morus nigra) lectin, displays high affinity for T (CD176) and Tn (CD175) antigens, frequently expressed at the cancer cell surface. The effects of Morniga-G were investigated on a Tn-positive leukemic Jurkat cell line. The lectin, used in a concentration range between 5⁻20 µg/mL, induced cell death in leukemic Jurkat cells. Microscopic and cytofluorometric analyses indicated that Jurkat cell death was essentially apoptotic, associated with an increase in the ceramide content and a depolarization of the mitochondrial transmembrane potential. This lectin-mediated cell death was inhibited by the pan caspase-inhibitor zVAD. In addition, cleavage of caspases 8, 9, and 3 was observed in Morniga-G-treated Jurkat cells whereas Jurkat cell lines that are deficient in caspase 8⁻10, caspase 9, or FADD, survived to the lectin-mediated toxicity. Furthermore, in the presence of TRAIL- or DR5-blocking mononoclonal antibodies, Jurkat cells became resistant to Morniga-G, suggesting that the lectin triggers cell death via the TRAIL/DR5 pathway. In silico computer simulations suggest that Morniga-G might facilitate both the DR5 dimerization and the building of TRAIL/DR5 complexes. Finally, upon treatment of Jurkat cells with benzyl-GalNAc, an O-glycosylation inhibitor, a decrease in Tn antigen expression associating with a reduced Morniga-G toxicity, was observed. Taken together, these results suggest that Morniga-G induces the cell death of Tn-positive leukemic cells via concomitant O-glycosylation-, caspase-, and TRAIL/DR5-dependent pathways.


Assuntos
Antígenos Glicosídicos Associados a Tumores/metabolismo , Lectinas/farmacologia , Leucemia/patologia , Morus/química , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Caspases/metabolismo , Morte Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Ceramidas/metabolismo , Glicosilação , Humanos , Células Jurkat , Linfócitos/efeitos dos fármacos , Linfócitos/metabolismo , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Agregados Proteicos
20.
Mol Genet Genomic Med ; 7(4): e00591, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30697976

RESUMO

BACKGROUND: Platelet-derived growth factor receptor beta (PDGFRB) rearrangement has been reported in a number of patients with chronic eosinophilic leukemia (CEL), B-acute lymphoblastic leukemia, myeloproliferative neoplasms, and juvenile myelomonocytic leukemia. Here, we report a case of CEL carrying a novel fusion gene involving PDGFRB and GRIP and coiled-coil domain containing 2 (GCC2). PATIENT AND METHODS: A 54-year-old man presenting with a cough and dyspnea was diagnosed with acute eosinophilic pneumonia. Cytogenetic analysis of the bone marrow revealed the presence of t(2;5)(q37;q31). Fluorescence in situ hybridization analysis in the peripheral blood leukocytes revealed the presence of a split signal at PDGFRB gene. Imatinib treatment was effective, and disappearance of t(2;5)(q37;q31) in the bone marrow was confirmed after three months of imatinib therapy. Whole-genome sequencing was performed in peripheral blood leukocytes collected before imatinib therapy. RESULTS: A novel fusion gene between exon 22 of GCC2 and exon 12 of PDGFRB was detected and the presence of GCC2-PDGFRB was confirmed by PCR. CONCLUSION: This is the first case report demonstrating the GCC2 gene as a partner of PDGFRB in the pathogenesis of CEL.


Assuntos
Biomarcadores Tumorais/genética , Proteínas da Matriz do Complexo de Golgi/genética , Síndrome Hipereosinofílica/genética , Leucemia/genética , Proteínas de Fusão Oncogênica/genética , Receptor beta de Fator de Crescimento Derivado de Plaquetas/genética , Células da Medula Óssea/metabolismo , Células da Medula Óssea/patologia , Cromossomos Humanos Par 2/genética , Cromossomos Humanos Par 5/genética , Humanos , Síndrome Hipereosinofílica/patologia , Leucemia/patologia , Masculino , Pessoa de Meia-Idade , Fusão Oncogênica , Translocação Genética
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