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1.
Article in Chinese | WPRIM | ID: wpr-880025

ABSTRACT

OBJECTIVE@#To investigate the antileukemia activity of phosphatidylinositol-3 kinase (PI3K) inhibitor ZSTK474 on human leukemia cell line U937.@*METHODS@#MTT, soft agar assay, flow cytometric analysis and western blot were used to detect the effect of ZSTK474 on U937 cell proliferation, tumorigenicity, cell cycle, cell apoptosis and phosphorylation levels of the key factor of PI3K/AKT pathway. Chou-Talalay method was used to evaluate the combination of ZSTK474 with Cytarabine or Homoharringtonine.@*RESULTS@#PI3K inhibitor ZSTK474 could inhibit the proliferation and tumorigenicity of U937 cell, induce G@*CONCLUSION@#ZSTK474 can inhibit the pathway of PI3K/AKT, ZSTK474 alone or in combination with Homoharringtonine shows potential antileukemia activity on U937 cells.


Subject(s)
Apoptosis , Cell Line, Tumor , Cell Proliferation , Glycogen Synthase Kinase 3 beta , Humans , Phosphatidylinositol 3-Kinases , Proto-Oncogene Proteins c-akt , Triazines , U937 Cells
2.
Journal of Experimental Hematology ; (6): 1019-1027, 2021.
Article in Chinese | WPRIM | ID: wpr-888513

ABSTRACT

OBJECTIVE@#To detect the expression of different transcripts of lactamase β(LACTB) gene in leukemic cell lines.@*METHODS@#NCBI website and DNAstar software were used to detect the Bioinformatics analysis of LACTB. The expression of different transcripts of LACTB gene in leukemic cell lines (THP-1, HL60, K562, U937, Jurkat and Raji) was detected by reverse transcription PCR (RT-PCR), DNA and clone sequencing; the expression of different transcripts of LACTB gene in leukemic cell lines was detected by Quantitative Real-time PCR.@*RESULTS@#There were a variety of splicing isomers in LACTB, and it could produce a variety of protein isomers with conserved N-terminal and different C-terminal, moreover, there were many splice isoforms of LACTB in leukemia cell lines, and there were different expression patterns in different cell lines, including XR1, V1, V2 and V3. The expression of total LACTB showed high in HL60 cells, while low in Raji cells, and the difference was statistically significant (P<0.05). The V1 was high expression in U937 cells but low in Raji cells, and the difference was statistically significant (P<0.05). V2 was high expression in HL60 cells but lowly in Raji cells, and the difference was statistically significant (P<0.05). The expression of V3 was low in THP-1 cells, which was significantly different as compared with that in normal bone marrow (P<0.05).@*CONCLUSION@#The reaserch found that there are many splice isomers of LACTB in leukemic cell lines, and there are different expression patterns in different cell lines.


Subject(s)
Alternative Splicing , HL-60 Cells , Humans , Leukemia/genetics , Membrane Proteins/genetics , Mitochondrial Proteins/genetics , RNA Splicing , U937 Cells , beta-Lactamases/genetics
3.
Acta bioquím. clín. latinoam ; 54(3): 321-331, set. 2020. ilus, graf
Article in Spanish | LILACS | ID: biblio-1130606

ABSTRACT

Los flavivirus transmitidos por mosquitos son una amenaza actual y emergente en todo el mundo. Dentro de este género, el virus Encefalitis San Luis (VESL) causa una forma severa de enfermedad neuroinvasiva donde la respuesta inmune es un componente crucial de la defensa del huésped. En este trabajo se investigó la interacción entre VESL y células de la inmunidad innata, en un modelo de infección in vitro de monocitos humanos (células U937) con cepas de distinta virulencia y condiciones epidemiológicas de aislamiento (CbaAr-4005 y 78V-6507). Se evaluó la capacidad de infectar y replicar del virus, como también el efecto citopático y la cinética de viabilidad de monocitos durante la infección. Los resultados demostraron la susceptibilidad de los monocitos a la infección, replicación y muerte por ambas cepas virales. Sin embargo, se hallaron diferencias significativas entre ellas. La cepa epidémica y de mayor virulencia CbaAr-4005 registró una tasa de infección y replicación superior a la de la cepa endémica y de menor virulencia 78V-6507. Se comprobó también que el VESL indujo la muerte de monocitos humanos, dependiendo del tiempo post-infección (pi) y de la cepa. Así, CbaAr-4005 provocó a partir del día 3 pi el doble de mortalidad celular que 78V-6507. Además, en los monocitos infectados se observaron alteraciones de parámetros morfológicos que podrían relacionarse con el tipo de mecanismo de muerte celular asociado a la infección por VESL.


Mosquitoes borne Flavivirus infections are an actual and emergent worldwide threat to human health. Within this genus, Saint Louis Encephalitis Virus (SLEV) causes a severe neuroinvasive disease where immune response is crucial for host survival. In this study the interaction between SLEV and innate immune cells was evaluated. An in vitro infection model with human monocytes (U937 cells) and strains with variations in virulence and isolation conditions (CbaAr-4005 and 78V-6507) were used. Infection capacity, replication capacity, cytopathic effect and monocyte viability kinetics were measured. The results showed susceptibility to infection and replication to both strains. However, significant differences were found among them. CbaAr-4005, the epidemic and more virulent strain, showed higher infection and replication ratios compared to 78V-6507. SLEV infection that induces cell death of human monocytes was also found in a post-infection time and in a strain dependent manner. Since day 3 post-infection, twice the mortality in CbaAr-4005 infected cells was observed. Furthermore, infected monocytes showed alterations in morphologic parameters that could be related with apoptosis mechanisms associated to SLEV infections.


Os Flavivírus transmitidos por mosquitos são uma ameaça atual e emergente no mundo todo. Nesse gênero, o vírus Encefalite Saint Louis (VESL) causa uma forma grave de doença neuroinvasiva onde a resposta imune é um componente crucial da defesa do hospedeiro. Neste trabalho nos investigamos a interação entre VESL e células de imunidade inata em um modelo de infecção in vitro de monócitos humanos (células U937) com estirpe de diferentes virulências e condições epidemiológicas de isolamento (CbaAr-4005 e 78V-6507). Foi avaliada a capacidade do vírus de infectar e replicar , assim como o efeito citopático e a viabilidade cinética dos monócitos durante a infecção. Os resultados demonstraram a suscetibilidade dos monócitos à infecção, replicação e morte por ambas as estirpes virais. No entanto, foram detectadas diferenças significativas entre eles. A estirpe epidémica e de maior virulenta CbaAr-4005 teve uma maior taxa de infecção e replicação do que a estirpe endémica e menos virulenta 78V-6507. Foi comprovado também que o VESL induziu a morte de monócitos humanos, dependendo do tempo pós-infecção (pi) e da estirpe. Assim, a CbaAr-4005 causou a partir do dia 3 pi o dobro da mortalidade celular o que a 78V- 6507. Além disso, alterações nos parâmetros morfológicos foram observadas nos monócitos infectados que poderiam estar relacionadas ao tipo de mecanismo de morte celular associado à infecção pelo VESL.


Subject(s)
Humans , Male , Female , Virulence , Flavivirus Infections , U937 Cells , Encephalitis , Encephalitis Virus, St. Louis , Encephalitis Viruses/growth & development , Flavivirus , Patient Isolation , Viruses , In Vitro Techniques , Kinetics , Cells , Disease , Incidence , Causality , Mortality , Apoptosis , Reference Parameters , Culicidae
4.
Article in Chinese | WPRIM | ID: wpr-829035

ABSTRACT

OBJECTIVE@#To investigate the effects of high dose vitamin C on proliferation and apoptosis of acute myeloid leukemia (AML) cell lines including HL-60, U937 and primary CD34 leukemia cells in AML.@*METHODS@#CD34 cells were sorted by using immunomagnetic cell sorting system, then the primary CD34 leukemia cells, including HL-60 and U937 cell lines were cultured in vitro. Cells in each group were treated with different concentrations of vitamin C, the survival rate of cells was determined by MTT assay, the apoptosis rate of cells was evaluated by Annexin V/PI double staining, the expression of apoptotic proteins-including cleaved caspase 3, cleaved caspase-9 and cleaved PARP were detected by Western blot.@*RESULTS@#The proliferation of HL-60 and U937 cells could be inhibited by high dose vitamin C, which showed a concentration-dependent manner (r=-0.9664; r=-0.9796). HL-60 and U937 cells were treated with different concentrations of vitamin C (8 and 20 mmol/L) for 24 hours, respectively, it was found that with the increasing of vitamin C concentration, cell apoptosis rate was significantly increased (r=0.9905; r=0.9971), and the expression of apoptosis related proteins including cleaved caspase 3, cleaved caspase-9 and cleaved PARP was aslo significantly increased with the increasing of concentration. In addition, it was found that with or without the mutation of TET2, high dose vitamin C could inhibit the proliferation (r=-0.9719; r=-0.9699) and promote the apoptosis (r=0.9998; r=0.9901) of primary CD34 leukemia cells in AML, which showed a dose-dependent manner, but it showed no effect on the proliferation (r=-0.2032) and apoptosis (r=0.1912) of normal CD34 cells.@*CONCLUSION@#High dose vitamin C can inhibit the proliferation and promote the apoptosis of acute myeloid leukemia cells, and selectively kill primary CD34 leukemia cells in AML.


Subject(s)
Apoptosis , Ascorbic Acid , Cell Proliferation , HL-60 Cells , Humans , Leukemia, Myeloid, Acute , U937 Cells
5.
Article in English | WPRIM | ID: wpr-764300

ABSTRACT

BACKGROUND: The roots of Scutellaria baicalensis Georgi (Labiatae) have been widely used in traditional medicine for treatment of various diseases. In this study, we investigated the effects of ethanol extracts of S. baicalensis roots (EESB) on the growth ofn human leukemia U937 cells. METHODS: The effect of EESB on cell viability was measured by the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay. Apoptosis was determined using 4,6-diamidino-2-phenyllindile staining and flow cytometry. The effects of EESB on the expression of regulatory proteins of apoptosis and phosphatidyl inositol 3-kinase (PI3K)/Akt signaling were determined by Western blotting. Caspase activity and mitochondrial membrane potential (MMP) were measured using flow cytometric analysis.


Subject(s)
Apoptosis , Blotting, Western , Caspase 8 , Caspase 9 , Cell Survival , Down-Regulation , Ethanol , Flow Cytometry , Humans , Leukemia , Ligands , Medicine, Traditional , Membrane Potential, Mitochondrial , Phosphatidylinositols , Receptors, Death Domain , Scutellaria baicalensis , Scutellaria , U937 Cells , Up-Regulation
6.
Article in Chinese | WPRIM | ID: wpr-771901

ABSTRACT

OBJECTIVE@#To investigate the effect of Pim1 expression up-regulation on cell proliferation, apoptosis, chemotaxis and angiogenesis in acute myeloid leukemia (AML) cell line U937, and to explore the possible molecular mechanism involved, finally to estimate the Pim1 expression in primary AML cells.@*METHODS@#GFP-tagged plasmid for Pim1 overexpression and an empty vector plasmid were constructed, and then a stable Pim1 expressed U937 cell line and a control virus-infected U937 cell line were established by a lentiviral vector system. After confirming Pim1 overexpression in U937 cells, proliferation and apoptosis are determined by CCK-8 Kit and flow cytometry respectively. Transwell chemotaxis assay was used to measure the effect of Pim1 overexpression on AML cells. Flow cytometry and confocal microscopy were applied to detect the influence of Pim1 overexpression on phosphorylated CXCR4 (pCXCR4) and its location. Real-time fluorescence quantitative PCR (qPCR) was used to detect the expression of angiogenesis and adhesion related genes in AML primary cells.@*RESULTS@#The lentivirus-infected AML cell line with Pim1 overex-pression and the control virusinfected AML cell line were established successfully. The Pim1 overexpression could enhance the proliferation and inhibit the cell apoptosis, moreover accompnied with the increasing expression of cyclin D1, phosphorylated BAD (pBAD) and pCXCR4. After SDF-1 α stimuli, Pim1 overexpression induced AML cell chemotaxis accompanied with p-CXCR4 expression and calcium influx increment. Pim1 overexpression has no effect on angiogenesis. Pim1 mRNA expression was significantly higher in AML patients than the healthy people.@*CONCLUSION@#Pim1 plays an important role in the pathogenesis of AML, which not only promotes AML cell proliferation and inhibition of apoptosis, but also enhances the chemotactic ability of leukemia cells, which closely relates with Pim1 phosphorylation of CXCR4 and the increase of intracellular calcium ion influx signals.


Subject(s)
Apoptosis , Cell Proliferation , Humans , Leukemia, Myeloid, Acute , Genetics , Proto-Oncogene Proteins c-pim-1 , Genetics , Signal Transduction , U937 Cells
7.
Article in English | WPRIM | ID: wpr-718961

ABSTRACT

Leucocyte extravasation has been known to play an important role in inflammatory reactions including contact dermatitis. Previous studies suggested that CD99 regulates β1 integrin activity and may be a novel therapeutic target molecule for inflammatory diseases. In this study, the effects of CD99-derived peptide, CD99CRIII3, on inflammatory reactions in contact dermatitis mouse model were investigated. CD99CRIII3 decreased β1-integrin activity in human monocytic U937 cells. CD99CRIII3 inhibited the adhesion of U937 monocytes to human umbilical vein endothelial cells and their extravasation through human umbilical vein endothelial cells. CD99CRIII3 reduced inflammation in the phorbol myristate acetate-induced contact dermatitis mice in a dose-dependent manner. These results indicate that CD99CRIII3 suppresses the extravasation of monocytes and inflammatory reactions in the animal model of the contact dermatitis, suggesting that CD99CRIII3 could be a new drug candidate against inflammatory skin diseases.


Subject(s)
Animals , Dermatitis, Contact , Human Umbilical Vein Endothelial Cells , Humans , Inflammation , Mice , Models, Animal , Monocytes , Myristic Acid , Skin Diseases , U937 Cells
8.
Article in Chinese | WPRIM | ID: wpr-689544

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the effect of all transretinoicacid(ATRA) combined with decitabine (5-Aza-2'-deoxycytidine;DAC) on DNA methylation and gene expression of p16INK4a (p16) and retinoic acid receptor β (RARβ), and to explore their combined anti neoplastic effect on U937 cells and newly diagnose delder acute myeloid leukemia(AML) patients.</p><p><b>METHODS</b>The expression levels of p16 and RARβ were determined by qRT-PCR and Western blot. Methylation-specific PCR was used to analyze their methylation status. WST-1 and flow cytometry were performed to detect growth inhibition, differentiation, apoptosis and cell cycle of U937 cells respectively.</p><p><b>RESULTS</b>The expression p16 and RARβ was down-regulated by promoter hypermethylation in newly diagnose delder AML patients and U937 cells. Combination treatment of ATRA and DAC induced DNA hypomethylation as well as gene expression of p16 and RARβ, which contributed to the growth inhibition, differentiation, apoptosis and cell cycle arrest of U937 cells. In addition for elder AML patients intolerable to standard chemotherapy, the combination regimen of ATRA and DAC showed antineoplastic activity accompamied by up-regulation of p16 and RARβ expression and decrease of bone marrow blast, moreover the parients showed good tolerence to the reginen.</p><p><b>CONCLUSION</b>The regimen of ATRA combined with DAC as the combination therapeutic strategy for inducing differentiation and demethylation possesses the anti-AML potency, and contributes to optimizing the therapeutic strategy for elder AML patients and promoting the clinical prognosis.</p>


Subject(s)
Azacitidine , Decitabine , Humans , Leukemia, Myeloid, Acute , Tretinoin , U937 Cells
9.
Rio de janeiro; s.n; 2018. 45 p. ilus.
Thesis in Portuguese | LILACS, BBO | ID: biblio-1015577

ABSTRACT

O objetivo do trabalho foi investigar o efeito de diferentes soluções químicas auxiliares, em concentrações subcitotóxicas, na expressão de citocinas pró e anti-inflamatórias, quando em contato com células da linhagem de linfoma humano, diferenciadas em macrófagos, human macrophage-like (U937), através da adição de 125ng/mL de PMA. As concentrações, citotóxica e subcitotóxica, de cada solução, foram determinadas de acordo com padrão ISO, utilizando-se fibroblastos de camundongos (L929). As células L929 foram cultivadas em meio MEM completo e mantidas em placas de 96 poços. As células foram então colocadas em contato com as diluições das soluções químicas auxiliares (a partir das concentrações recomendadas para uso, NaOCL 5,25%; CHX 2%; Quitosana 0,2%; HEBP 18%; GSE de Vitis vinífera, 6,5%), por 24 horas a 37ºC em estufa de CO2. Em seguida, o meio de cultivo contendo 1mg/mL de MTT foi adicionado aos poços em triplicata, para avaliação da viabilidade celular e determinação das concentrações citotóxicas (30% de morte das células L929) e subcitotóxicas (15% de morte) por regressão linear por meio do programa GraphPad Prism versão 6.0. As concentrações subcitotóxicas foram colocadas em contato com as células human macrophage-like (U937) por 60 min. Os sobrenadantes da pré-incubação (controles sem substâncias químicas auxiliares), e incubação com as soluções químicas auxiliares em meio DMEM completo foram congelados em freezer ultrafrio (­ 80ºC) e avaliados para as concentrações de dezessete citocinas através do kit Bio-Plex Pro Human Th17 Cytokine Panel® pelo método Luminex®. Foi possível obter valores de expressão de 7 citocinas pró-inflamatórias: IL-1ß, TNFα, IL-6, IL-17A, IL-17F, IL-22 e IL-23. As substâncias com maior atividade citotóxica (padrão ISO para morte celular) foram em ordem de grandeza, a quitosana, a CHX, o NaOCl, o HEBP e o GSE de Vitis vinifera. As concentrações subcitotóxicas das soluções químicas auxiliares, CHX e NaOCl, induziram ao aumento da maioria das citocinas pró-inflamatórias, exceto para a IL-6. Quanto a IL-1ß, a quitosana e a CHX, estas foram as que mais induziram a expressão pelas células U937 (P<0,05),enquanto o NaOCl induziu maior expressão de TNFα (P>0,05). Dentre as citocinas relacionadas ao fenótipo Th17, a CHX foi a que mais induziu a expressão de IL-17A (P<0,05), IL-17F e IL-23, seguido do NaOCl(P<0,05). O NaOCl induziu maior expressão de IL22 seguido da CHX (p<0,05). Quanto a IL-6, todas as substâncias modularam a sua expressão pelas células U937(p>0.05). O HEBP atuou como um excelente modulador da expressão de citocinas pró-inflamatórias, induzindo a redução da expressão de todas as citocinas testadas (P<0,05). O GSE de Vitis vinifera, apesar de ser o menos citotóxico não apresentou diferença estatística para o controle em nenhuma das situações avaliadas, exceto para a redução da IL-6 (assim como o HEBP e a quitosana) (p<0,05). A quitosana comportou-se de forma similar ao GSE de Vitis vinífera (p>0,05) exceto para a IL-1ß. Conforme observado, as substâncias químicas auxiliares são capazes de induzir a expressão de citocinas pró-inflamatórias diversas. O HEBP foi o agente químico que melhor modulou a expressão de citocinas pró-inflamatórias.


The aim of this investigation was to analyze the effect of different chemical endodontic solutions, in subcytotoxic concentrations, on the expression of pro and anti-inflammatory cytokines when in contact with human lymphoma lineage differentiated into human macrophages, human macrophage-like (U937), by the addition of 125ng/ml PMA. The cytotoxic and subcytotoxic concentrations of each solution were determined according to ISO standard using mouse fibroblasts (L929). L929 cells were cultured in complete MEM medium and maintained in 96-well plates. Dilutions of the auxiliary chemical solutions, from the recommended concentrations for use: NaOCL 5,25%; CHX 2%; Chitosan 0.2%; Etidronic acid 18% and Grape seed extract, Vitis vinifera, 6.5%, were carried out in complete MEM medium, and placed in contact with the cells for 24 hours at 37ºC in CO2 cell incubator, in triplicate. Thereafter, the culture medium containing 1 mg/mL MTT was added to the wells. Cytotoxic concentrations (30% death of L929 cells) and subcytotoxic (15% death) were determined by linear regression using GraphPad Prism version 6.0. Subcytotoxic concentrations were obtained in complete DMEM medium and maintained in contact for 60 min. with U937 cells. Controls without chemical substances were also performed. Supernatants from the pre-incubation, incubation with the chemical solutions and complete DMEM were removed, frozen in ultra-cold freezer (-80ºC) and evaluated for the concentrations of 17 cytokines through the Bio-Plex Pro Human Th17 Cytokine Panel® kit by Luminex®. The substances with higher cytotoxic activity were in order of magnitude: chitosan, CHX, NaOCl, etidronic acid and Vitis vinifera extract. The values of 7 pro-inflammatory cytokines: IL-1ß, TNFα, IL-6, IL-17A, IL-17F, IL-22 and IL-23 were obtained. Subcytotoxic concentrations of the irrigant agents (chlorhexidine and NaOCl) generally induced the increase of most pro-inflammatory cytokines, except for IL-6. Chitosan and CHX were the agents that most induced the expression of IL-1ß by U937 cells, whereas NaOCl induced higher TNFα expression (P> 0,05). Among the cytokines related to the Th17 phenotype, CHX was the agent that induced the highest expression of IL-17A (P <0,05), IL-17F and IL-23, followed by NaOCl (P<0,05). NaOCl induced the highest expression of IL22 followed by CHX. All of the substances modulated the expression of IL-6 by U937 cells (P >0,05). HEBP was an excellent modulator of the expression of pro-inflammatory cytokines, inducing the reduction of the expression of all cytokines tested. Vitis vinifera extract, despite being the least cytotoxic agent, did not present statistical differences compared to the control for any of the evaluated cytokines, except for the reduction of IL-6 (as well as etidronic acid and chitosan) (P<0,05). Chitosan, except for IL-1 ß, was very similar to the Vitis vinifera (P>0,05) extract. As observed, the auxiliary substances (especially the irrigants) are capable of inducing the expression of various pro-inflammatory cytokines. Etidronic acid was the chemical that modulated the expression of pro-inflammatory cytokines.


Subject(s)
Humans , Root Canal Irrigants/pharmacology , Cytokines , U937 Cells , Sodium Hypochlorite , In Vitro Techniques , Chlorhexidine , Etidronic Acid , Chitosan , Grape Seed Extract
10.
Biol. Res ; 50: 42, 2017. tab, graf
Article in English | LILACS | ID: biblio-950888

ABSTRACT

BACKGROUND: Fresh frozen plasma (FFP) administration may increase the risk of nosocomial infections in parallel with the development of immune modulation. This could be driven by soluble mediators, possibly influencing the in vitro activation of human U937 monocyte cells, in a manner dependent on the age of the donors. METHODS: FFP donors were stratified into groups of 19-30 years, 31-40 years or 41-50 years, and U937 cells were cultured with FFP (alone or plus lipopolysaccharide-LPS) for 24 h. Both in FFP and supernatants, TNF, IL-1ß, IL-6, and IL-10 levels were measured by ELISA. Additionally, CD11B, TLR2, and CASP3 gene expression were measured by qtPCR in U937 cells. Total phagocytic activity was also assayed. RESULTS: Elevated IL-10, but low TNF and IL-1ß levels were measured in FFP from individuals aged 19-40 years, whereas in individuals aged 41-50 years FFP were characterized by equalized TNF and IL-10 levels. Elevated IL-6 levels were found in all FFP samples, especially in those from the oldest individuals. FFP stimulation was associated with striking modifications in cytokine production in an age-dependent way. Exposure to FFP attenuates the response to LPS. TLR2 and CD11B expression were enhanced regardless of the age of plasma donors, although CASP3 expression was increased only when FFP from individuals aged 19-40 years were tested. Phagocytosis decreased after exposure to FFP regardless of donor age. CONCLUSION: Our results suggest that soluble mediators in FFP may modulate the functioning of monocytes. Interestingly, this effect appears to be partially influenced by the age of donors.


Subject(s)
Humans , Male , Female , Adult , Middle Aged , Young Adult , Plasma/immunology , Blood Donors , Monocytes/immunology , Cytokines/immunology , U937 Cells/immunology , Enzyme-Linked Immunosorbent Assay , Monocytes/physiology , Age Factors , Interleukin-6/metabolism , Tumor Necrosis Factor-alpha/metabolism , Interleukin-10/metabolism , Interleukin-1beta/metabolism
11.
Article in Chinese | WPRIM | ID: wpr-263971

ABSTRACT

<p><b>OBJECTIVE</b>To explore the effect of DAPK overexpression on the biological behaviors and caspase-3 expression in HL-60 cells.</p><p><b>METHODS</b>The expression of DAPK mRNA was detected by RT-PCR leukemia cell lines K562, Molt4, U937, and HL-60 cells. HL-60 cells were transfected by a eukaryotic expression vector pReceiver-M29-DAPK via LipofectamineTM 2000, and the impact of DAPK overexpression on cell apoptosis, cell cycle, cell differentiation and caspase-3 expression were analyzed.</p><p><b>RESULTS</b>DAPK mRNA expression was positive in K562, Molt4 and U937 cells but negative in HL-60 cells. Significantly increased cell apoptosis was observed in pReceiver-M29-DAPK-transfected HL-60 cells by flow cytometry and Hoechst33342 staining. The cell cycle distribution and differentiation showed no significant changes after the transfection. The expression of caspase-3 was significantly increased in the cells after transfection.</p><p><b>CONCLUSION</b>DAPK gene overexpression promotes apoptosis of HL-60 cells without affecting the cell cycle and differentiation. Caspase-3 may be involved in the regulation of cell apoptosis.</p>


Subject(s)
Apoptosis , Caspase 3 , Metabolism , Cell Cycle , Cell Differentiation , Cell Line, Tumor , Death-Associated Protein Kinases , Metabolism , HL-60 Cells , Humans , RNA, Messenger , Metabolism , Transfection , U937 Cells
12.
Chinese Journal of Hematology ; (12): 119-123, 2016.
Article in Chinese | WPRIM | ID: wpr-234019

ABSTRACT

<p><b>OBJECTIVE</b>To explore the role of CXCR4/STAT3 in mesenchymal stromal cell (MSC)-mediated drug resistance of AML cells.</p><p><b>METHODS</b>AML cell lines U937 and KG1a and primary AML cells were co-cultured with MSC from bone marrow of healthy donors. The AML cell lines cultured alone were used as control. Apoptosis induced by mitoxantrone was measured by flow cytometry. Expression of CXCR4 and STAT3 protein were detected by Western blot. After incubated with STAT3 inhibitor Cucurbitacin I or CXCR4 antagonist AMD3100, the apoptosis of AML cells induced by mitoxantrone was evaluated.</p><p><b>RESULTS</b>Apoptosis of AML cells (U937 and KG1a) and primary AML cells induced by mitoxantrone significantly decreased in cocultured group than that of control group [U937 cells: (20.08±1.53)% vs (45.33 ± 1.03)% , P=0.004; KG1a cells: (25.60 ± 1.82)% vs (40.33 ± 3.29)% , P=0.020]. Expression of phosphorylated STAT3 and CXCR4 protein in AML cells were upregulated in cocultured group. After addition of Cucurbitacin I into the co-culture system, the apoptosis rate of primary AML cells significantly increased. Similar results of the apoptosis rates were also detected when the inhibitor of CXCR4 AMD3100 was added to overcome the stromal cell-mediated drug resistance. Besides, the expression of p-STAT3 in AML cells after incubated with AMD3100 decreased significantly.</p><p><b>CONCLUSIONS</b>AML cells cocultured with MSC leads to the up-regulation of phosphorylated STAT3 and CXCR4 proteins, which resulted in AML cells resistance to chemotherapeutic drugs. Therefore targeting STAT3 or CXCR4 could be a new therapeutic strategy of AML.</p>


Subject(s)
Acute Disease , Apoptosis , Coculture Techniques , Drug Resistance, Neoplasm , Flow Cytometry , Gene Expression Regulation, Leukemic , Heterocyclic Compounds , Humans , Leukemia , Metabolism , Mesenchymal Stem Cells , Cell Biology , Receptors, CXCR4 , Metabolism , STAT3 Transcription Factor , Metabolism , Signal Transduction , U937 Cells , Up-Regulation
13.
Article in English | WPRIM | ID: wpr-728679

ABSTRACT

Adhesion events of monocytes represent an important step in inflammatory responses induced by chemokines. The β1-integrin CD29 is a major adhesion molecule regulating leukocyte migration and extravasation. Although several adhesion molecules have been known as regulators of CD29, the molecular interactions between CD29 and its regulatory adhesion molecules (such as CD98 and CD147) have not been fully elucidated. Therefore, in this study, we examined whether these molecules are functionally, biochemically, and cell-biologically associated using monocytic U937 cells treated with aggregation-stimulating and blocking antibodies, as well as enzyme inhibitors. The surface levels of CD29, CD98, and CD147 (but not CD43, CD44, and CD82) were increased. The activation of CD29, CD98, and CD147 by ligation of them with aggregation-activating antibodies triggered the induction of cell-cell adhesion, and sensitivity to various enzyme inhibitors and aggregation-blocking antibodies was similar for CD29-, CD98-, and CD147-induced U937 cell aggregation. Molecular association between these molecules and the actin cytoskeleton was confirmed by confocal microscopy and immunoprecipitation. These results strongly suggest that CD29 might be modulated by its biochemical and cellular regulators, including CD98 and CD147, via the actin cytoskeleton.


Subject(s)
Actin Cytoskeleton , Antibodies , Antibodies, Blocking , Chemokines , Enzyme Inhibitors , Immunoprecipitation , Leukocytes , Ligation , Microscopy, Confocal , Monocytes , U937 Cells
14.
Article in Chinese | WPRIM | ID: wpr-337962

ABSTRACT

<p><b>OBJECTIVE</b>To study the proliferation and apoptosis of tetramethylpyrazine (TMP) on leukemic U937 cells and its possible mechanism.</p><p><b>METHOD</b>The inhibitory effect of TMP on the proliferation of U937 cells was detected by CCK-8 assay. The cell apoptosis and cycle distribution were examined by the flow cytometry. The mRNA expressions of bcl-2 and P27 were determined by the Real-time PCR. Western blot was carried out to detect bcl-2, caspase-3, cyclin E1, CDK2 and P27 expressions.</p><p><b>RESULT</b>TMP inhibited the proliferation of U937 cells in a dose-and-time dependent manner, with IC50 value of 160 mg x L(-1) at 48 h. In addition, TMP could induce the apoptosis of U937 cells and block the cell cycle in G0/G1 phase. According to the results of Real-time PCR and Western blot, TMP could down-regulate the expression of apoptosis-related molecule bcl-2, cycle-related protein cyclin E1 and CDK2 and up-regulate caspase-3 and P27.</p><p><b>CONCLUSION</b>TMP shows the effects in inhibiting the proliferation of leukemic U937 cells and inducing the apoptosis. Its mechanism may be related to the impacts on the cell cycle distribution, down-regulation of the bcl-2 expression, which finally activates caspase-3, starts the apoptosis path and causes the cell apoptosis.</p>


Subject(s)
Apoptosis , Cell Cycle , Cell Proliferation , Cyclin-Dependent Kinase 2 , Humans , Leukemia , Drug Therapy , Proto-Oncogene Proteins c-bcl-2 , Pyrazines , Pharmacology , Therapeutic Uses , U937 Cells
15.
Article in Chinese | WPRIM | ID: wpr-329181

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the expression of ASK1 and PRKCD in the process of monocyte differentiation, and explore their role in functional changes of hypersplenism spleen macrophages (Mφ) in portal hypertension (PH).</p><p><b>METHODS</b>U937 cells were stimulated to differentiate into monocyte/macrophage-like cells by cultivation in PMA and the mRNA expressions of ASK1 and PRKCD were detected by q-PCR and the changes of protein expression were identified by western blot analysis. The secretion of phagocytose related cytokines such as IL-10 and TNF-α were tested by ELISA, and the function of the macrophage-like cells were studied by chicken red blood cell phagocytose test.</p><p><b>RESULTS</b>The expressions of PRKCD and ASK1 mRNA were gradually decreased along with the cell differentiation, while the secretion of TNF-α was increased, IL-10 secretion reached a maximum at 24 h after PAM stimulation, and then gradually fell. The expression of ASK1 and p-ASK1 were rapidly increased compared with the non-stimulated U937 cells, while the expression of PRKCD and p-PRKCD were sightly declined. The phagocytose test show that U937 cells induced with PMA were able to swallow the chicken red blood cell.</p><p><b>CONCLUSION</b>Up-regulated protein expression of ASK1 and p-ASK1 and down-regulated protein expression of PRKCD and p-PRKCD in the process of PMA induced monocyte differentiation, are consist with the expression changes of splenic macrophage phagocytosis in hypersplenism, which leads to increased activity of Mφ.</p>


Subject(s)
Cell Differentiation , Down-Regulation , Humans , Hypersplenism , Hypertension, Portal , Interleukin-10 , Bodily Secretions , MAP Kinase Kinase Kinase 5 , Physiology , Macrophages , Cell Biology , Phagocytosis , Protein Kinase C-delta , Physiology , RNA, Messenger , Tumor Necrosis Factor-alpha , Bodily Secretions , U937 Cells
16.
Journal of Experimental Hematology ; (6): 1535-1539, 2014.
Article in Chinese | WPRIM | ID: wpr-340463

ABSTRACT

This study was aimed to observe the effects of emodin on apoptosis and cell cycle related genes in human myeloid leukemia cell line U937 cells. U937 cells were exposed to 60 µmol/L emodin for 24, 48, 72 h. The expressions of C-MYC, h-TERT, PIM-2, Survivin, wild type P53, P21, TGF β-1 and MCL-1 genes before and after treatment with emodin were determined and quantitated by using reverse transcriptase-polymerase chain reaction (RT-PCR). The results showed that the expressions of C-MYC, h-TERT, PIM-2, Survivin in treated U937 cells decreased, but the expressions of WTp53, P21 and TGFβ1 increased, while the expression of MCL-1 gene had no obvious change. It is concluded that multiple pathways may be involved in the processes of emodin-induced U937 cell apoptosis.


Subject(s)
Apoptosis , Apoptosis Regulatory Proteins , Cell Cycle , Cell Proliferation , Emodin , Pharmacology , Genes, myc , Humans , Reverse Transcriptase Polymerase Chain Reaction , U937 Cells
17.
Journal of Experimental Hematology ; (6): 1561-1566, 2014.
Article in Chinese | WPRIM | ID: wpr-340458

ABSTRACT

The aim of this study was to investigate the effects of H3K27 methylation inhibitor EPZ005687 on the apoptosis, proliferation and cell cycle of U937 cells and normal CD34⁺ cells. The U937 cells and normal CD34⁺ cells were treated with different concentration of EPZ005687 at different time points. The apoptosis rate was determined by Annexin V/PI staining. The cell proliferation and cell cycle was determined using WST-1 assay and 7-AAD assay, respectively. The activity of H3K27 methylation was detected by chemiluminescent immunoassay. The results showed that the EPZ005687 induced an obvious apoptosis of U937 cells. The apoptotic rate was 3.96% ± 0.79%,5.74% ± 0.73%,13.34% ± 1.77% and 25.24% ± 2.55% in U937 cells treated with 0.5, 1, 5 and 10 µmol/L EPZ005687 for 48 hours, respectively. However, EPZ005687 had rare effect on normal bone marrow(NBM) CD34⁺ cells. The apoptotic rate was 3.64% ± 0.62%,4.28% ± 0.99%,6.18% ± 1.19% and 7.56% ± 1.34% after U937 cells were treated with 0.5, 1, 5 and 10 µmol/L EPZ005687 for 48 hours, respectively. EPZ005687 inhibited obviously the proliferation of U937 cells but had weak effect on the proliferation of NBMCD34⁺ cells. The inhibitory effect of EPZ005687 on U937 cells was time-dependent after treated with 0.5, 1, 5 and 10 µmol/L EPZ005687 from 12 to 96 hours. EPZ005687 induced G1 phase blocking (G1%, 64.18% ± 13.27% vs 49.43% ± 12.54%) and decreased the percentage of cells in S phase (9.67% ± 2.61% vs15.26% ± 5.58%) in U937 cells. However, EPZ005687 had no effect on the cell cycle of NBMCD34⁺ cells. In addition, EPZ005687 produced obviously depletion of H3K27 methylation in U937 cells (P < 0.05), but hardly had effect on the H3K27 methylation of NBMCD34⁺ cells. It is concluded that the EPZ005687 inhibites proliferation, induces apoptosis and cell cycle blocking in G1 phase in leukemia cells. This agent may have potential value in clinical application.


Subject(s)
Antigens, CD34 , Metabolism , Apoptosis , Cell Cycle , Cell Proliferation , Humans , Indazoles , Pharmacology , Methylation , Pyridones , Pharmacology , U937 Cells
18.
Article in English | WPRIM | ID: wpr-183211

ABSTRACT

BACKGROUND/OBJECTIVES: In this study, the apoptogenic activity and mechanisms of cell death induced by hexane extract of aged black garlic (HEABG) were investigated in human leukemic U937 cells. MATERIALS/METHODS: Cytotoxicity was evaluated by MTT (3-(4, 5-dimethyl-thiazol-2-yl)-2, 5-diphenyl tetrazoliumbromide) assay. Apoptosis was detected using 4,6-diamidino-2-phenyllindile (DAPI) staining, agarose gel electrophoresis and flow cytometry. The protein levels were determined by Western blot analysis. Caspase activity was measured using a colorimetric assay. RESULTS: Exposure to HEABG was found to result in a concentration- and time-dependent growth inhibition by induction of apoptosis, which was associated with an up-regulation of death receptor 4 and Fas legend, and an increase in the ratio of Bax/Bcl-2 protein expression. Apoptosis-inducing concentrations of HEABG induced the activation of caspase-9, an initiator caspase of the mitochodrial mediated intrinsic pathway, and caspase-3, accompanied by proteolytic degradation of poly(ADP-ribose)-polymerase. HEABG also induced apoptosis via a death receptor mediated extrinsic pathway by caspase-8 activation, resulting in the truncation of Bid, and suggesting the existence of cross-talk between the extrinsic and intrinsic pathways. However, pre-treatment of U937 cells with the caspase-3 inhibitor, z-DEVD-fmk, significantly blocked the HEABG-induced apoptosis of these cells, and increased the survival rate of HEABG-treated cells, confirming that HEABG-induced apoptosis is mediated through activation of caspase cascade. CONCLUSIONS: Based on the overall results, we suggest that HEABG reduces leukemic cell growth by inducing caspase-dependent apoptosis through both intrinsic and extrinsic pathways, implying its potential therapeutic value in the treatment of leukemia.


Subject(s)
Apoptosis , Blotting, Western , Caspase 3 , Caspase 8 , Caspase 9 , Cell Death , Electrophoresis, Agar Gel , Flow Cytometry , Garlic , Humans , Leukemia , Receptors, TNF-Related Apoptosis-Inducing Ligand , Survival Rate , U937 Cells , Up-Regulation
19.
Article in English | WPRIM | ID: wpr-812315

ABSTRACT

AIM@#Ursolic acid (UA), a pentacyclic triterpenoid, is used as an anti-inflammatory and anti-cancer agent. There were few studies on the effects of UA on differentiation, and this is the first time to elucidate the potential effect and molecular mechanism of UA on inducing differentiation in the human leukemia cell line U937.@*METHODS@#Wright-Giemsa staining, nitroblue tetrazolium reduction assay and flow cytometric analysis were utilized to demonstrate the differentiation of U937 cells induced by UA. Western blotting and immunofluorescence assay were used to investigate the possible mechanism.@*RESULTS@#It was found that UA could induce the differentiation of U937cells and Akt-activity was significantly increased during differentiation. Additionally, LY294002, a PI3K-Akt inhibitor, could block the differentiation of U937 cells induced by UA.@*CONCLUSION@#UA could induce the differentiation of U937 cells by activating the PI3K/Akt pathway, and it could be a potential candidate as a differentiation-inducing agent for the therapy of leukemia.


Subject(s)
Apoptosis , Cell Proliferation , Humans , Leukemia , Genetics , Phosphatidylinositol 3-Kinases , Genetics , Metabolism , Proto-Oncogene Proteins c-akt , Genetics , Metabolism , Signal Transduction , Triterpenes , Pharmacology , U937 Cells
20.
Biol. Res ; 47: 1-9, 2014. ilus, graf
Article in English | LILACS | ID: biblio-950738

ABSTRACT

BACKGROUND: Tuberculosis (TB) is a respiratory tract disease caused by Mycobacterium tuberculosis infection. M. tuberculosis exploits immune privilege to grow and divide in pleural macrophages. Fibrates are associated with the immune response and control lipid metabolism through glycolysis with ß-oxidation of fatty acids. RESULTS: In this study, we investigated the effect of fibrate pretreatment on the immune response during M. smegmatis infection in U937 cells, a human leukemic monocyte lymphoma cell line. The protein expression of tumor necrosis factor α (TNF-α), an inflammatory marker, and myeloid differentiation primary response gene 88 (MyD88), a toll like receptor adaptor molecule, in the infected group increased at 1 and 6 h after M. smegmatis infection of U937 cells. Acetyl coenzyme A acetyl transferase-1 (ACAT-1), peroxisome proliferator-activated receptor-α (PPAR-α), TNF-α, and MyD88 decreased in U937 cells treated with fibrates at 12 and 24 h after treatment. More than a 24 h pretreatment with fibrate resulted in similar expression levels of ACAT-1 and PPAR-α between infected vehicle control and infected groups which were pretreated with fibrate for 24 h. However, upon exposure to M. smegmatis, the cellular expression of the TNF-α and MyD88 in the infected groups pretreated with fibrate for 24 h decreased significantly compared to that in the infected vehicle group. CONCLUSION: These results suggest that fibrate pretreatment normalized the levels of inflammatory molecules in Mycobacterium smegmatis-infected U937 cells. Further studies are needed to confirm the findings on pathophysiology and immune defense mechanism of U937 by fibrates during M. tuberculosis infection.


Subject(s)
Humans , Inflammation Mediators/metabolism , Mycobacterium smegmatis , Fibric Acids/pharmacology , Macrophages/drug effects , Mycobacterium Infections/metabolism , Acetyl-CoA C-Acetyltransferase/metabolism , Signal Transduction/drug effects , Blotting, Western , Tumor Necrosis Factor-alpha/metabolism , U937 Cells , PPAR alpha/metabolism , Myeloid Differentiation Factor 88/metabolism , Macrophages/metabolism , Macrophages/microbiology
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