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Sample records for human erythroleukemia k562

  1. Altered gravity modulates 5-lipoxygenase in human erythroleukemia K562 cells.

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    Maccarrone, M; Putti, S; Finazzi Agro, A

    1998-07-01

    Mammalian lipoxygenases catalyse the first committed step in the so-called "arachidonate cascade", leading to the production of potent bioactive molecules, such as leukotrienes, lipoxins and hepoxilins. Leukotrienes interact with G protein-couple receptors involved in neuronal plasticity and T lymphocyte activation, lipoxins activate leukocytes, hepoxilines control the insulin release and stimulate the phospholipase C. Lipoxygenase (linoleate:oxygen oxidoreductase; E.C. 1.13.11.34; 5-LOX) are responsible for lymphocyte maturation and programmed death (apoptosis) of neuronal cells. Therefore, 5-LOX might be Space relevant, because among the most striking effects of Space enviroment are indeed those on T lymphocyte activation, neuronal cell growth and suspectedly apoptosis. In this study, the possible effects of the force of gravity on the activity and expression of 5-LOX have been investigated by subjecting human erythroleukemia K562 cells to simulated hypogravity or hypergravity.

  2. Effects of 1-beta-D-arabinofuranosylcytosine and phorbol ester on differentiation of human K562 erythroleukemia cells.

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    Watanabe, T; Mitchell, T; Sariban, E; Sabbath, K; Griffin, J; Kufe, D

    1985-06-01

    We have previously demonstrated that 1-beta-D-arabinofuranosylcytosine (ara-C) induces hemoglobin synthesis in human K562 erythroleukemia cells. The present study extends these findings by demonstrating that ara-C treatment of K562 cells results in both increased heme synthesis and accumulation of alpha-, gamma-, epsilon-, and zeta-globin RNA. The results also demonstrate that ara-C enhances K562 cell surface expression of glycophorin. Furthermore, we demonstrate that phorbol ester (12-O-tetradecanoylphorbol-13-acetate; TPA) inhibits the effects of ara-C on heme production, accumulation of globin RNA, and glycophorin expression. The inhibitory effect occurs maximally when K562 cells are treated with TPA before undergoing ara-C-induced commitment to erythroid differentiation. These findings suggest that TPA inhibits an early step in the process required for ara-C to enhance expression of genes involved in the erythroid program.

  3. Complete genome of Phenylobacterium zucineum – a novel facultative intracellular bacterium isolated from human erythroleukemia cell line K562

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    Sun Jie

    2008-08-01

    Full Text Available Abstract Background Phenylobacterium zucineum is a recently identified facultative intracellular species isolated from the human leukemia cell line K562. Unlike the known intracellular pathogens, P. zucineum maintains a stable association with its host cell without affecting the growth and morphology of the latter. Results Here, we report the whole genome sequence of the type strain HLK1T. The genome consists of a circular chromosome (3,996,255 bp and a circular plasmid (382,976 bp. It encodes 3,861 putative proteins, 42 tRNAs, and a 16S-23S-5S rRNA operon. Comparative genomic analysis revealed that it is phylogenetically closest to Caulobacter crescentus, a model species for cell cycle research. Notably, P. zucineum has a gene that is strikingly similar, both structurally and functionally, to the cell cycle master regulator CtrA of C. crescentus, and most of the genes directly regulated by CtrA in the latter have orthologs in the former. Conclusion This work presents the first complete bacterial genome in the genus Phenylobacterium. Comparative genomic analysis indicated that the CtrA regulon is well conserved between C. crescentus and P. zucineum.

  4. DIFFERENTIAL EXPRESSION OF GENES INVOLVED IN METABOLISM BETWEEN TUMORIGENITIC HUMAN LEUKEMIA CELL LINES K562 AND K562-n

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    吕书晴; 许小平; 夏放; 居小萍; 李瑶; 应康; 毛裕民

    2003-01-01

    Objective: To study the molecular mechanism of different tumorigenicity in nude mice of human leukemia cell lines K562-n and K562. Methods: To analyze the genes differently expressed between K562 and K562-n cells by using cDNA microarray technique. Results: Among the 12800 genes detected, some genes involved in material metabolism and material transport were differently expressed between K562-n and K562 cells. These genes include homo sapiens placenta-specific ATP-binding cassette transporter gene, dihydrodiol dehydrogenase gene, hepatic dihydrodiol dehydrogenase gene, NAD-dependent methylene tetrahydrofolate dehydrogenase cyclohydrolase, lysophosphatidic acid acyltransferase, alpha gene, argininosuccinate lyase gene, mitochondrial isocitrtate dehydrogenase, adhesion protein SQM1 gene, dimethylarginine dimethylamino-hydrolase gene, M1 subunit of ribonucleotide reductase and farnesyl pyrophosphate synthetase gene. Conclusion: The high tumorigenicity of K562-n cells is related to the different expression of some genes concerned with cell metabolism and material transpoert.

  5. Analysis of Gene Expression in the K562-n High Tumorigenitic Human Leukemia Cell Line

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    Shuqing Lü; Xiaoping Xu; Fang Xia; JianMin Wang

    2005-01-01

    OBJECTIVE The human leukemia K562-n cell line displays much higher tumorigenic actively in nude mice compared with its parental K562 cell line. The molecular mechanism of the differences in tumorigenicity between K562-n and K562 in nude mice was examined.METHODS The differences in gene expression between K562 and K562-n cells were analyzed by using cDNA microarrays.RESULTS Among the12,800 genes examined, there was a significant difference in expression of 139 genes between K562-n and K562 cells.Eighty-five of these genes have been registered in the GeneBank and 54are unknown. The genes accessible from the GeneBank include:1)oncogenes and tumor-supressor genes; 2) genes related to transcription regulation, the cell cycle and apoptosis; 3) genes related to the cytoskeleton and cytokinetics; 4) genes related to metabolism and transport; 5) genes related to immune function. There were also some differently expressed genes with mixed functions.CONCLUSION There are many genes differentially expressed between K562-n and K562 cells .The high tumorigenicity of the human leukemia K562-n cell line in nude mice might be related to its specific geneexpression profile.

  6. Antitumor Effect of Betulinic Acid on Human Acute Leukemia K562 Cells in vitro

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    吴秋玲; 何静; 方峻; 洪梅

    2010-01-01

    The effects of betulinic acid (BA), a pentacyclic lupane-type triterpene, on the cell viability, cell cycle and apoptosis in human leukemia K562 cells were investigated. The effects of BA on the growth of K562 cells were studied by MTT assay. Apoptosis was assayed through Annexin V/propidium iodide (PI) double-labeled cytometry. The effects of BA on the cell cycle of K562 cells were studied by a PI method. The expression of Bax and capase-3 was detected by using Western blot. The results showed that BA was ...

  7. Heme-binding plasma membrane proteins of K562 erythroleukemia cells: Adsorption to heme-microbeads, isolation with affinity chromatography

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    Majuri, R. (Minerva Foundation Institute for Medical Research, Helsinki (Finland))

    1989-01-01

    Heme-microbeads attached themselves to the surface of viable K562 cells in a manner inhibitable by free hemin, indicating heme-recptor interaction. The microbeads were at first evenly distributed, but after prolonged incubation at 37 deg. C they formed a cap on one pole of the cells indicating clustering of the membrane heme receptors. Membrane proteins were labeled by culturing the cells in the presence of {sup 35}S-methionine and were then solubilized with Triton X-114. The hydrophobic proteins contained about 20% of the total bound label. The solubilized membrane proteins were subsequently adsorbed to a heme-Sepharose affinity gel. According to SDS-electrophorsis and subsequent autoradiography, the immobilized heme captures two proteins or a protein with two polypeptides of 20 000 and 32 000 daltons. The larger of these was only wekly labeled with {sup 35}S. The same two bands were observed if the cell surface proteins were labeled with {sup 125}I by the lactoperoxidase method and the subsequently solubilized membrane proteins were isolated with heme-Sepharose. (author).

  8. Induction of apoptosis in human leukemia K562 cells by cyclic lipopeptide from Bacillus subtilis natto T-2.

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    Wang, C L; Ng, T B; Yuan, F; Liu, Z K; Liu, F

    2007-07-01

    A new cyclic lipopeptide (CLP) purified from Bacillus subtilis natto T-2 dose dependently inhibited growth in human leukemia K562 cells. The results of fluorescent staining indicated that CLP brought about apoptosis in K562 cells. Flow cytometric analysis also demonstrated that CLP caused dose-dependent apoptosis of K562 cells through cell arrest at G1 phase. Western blotting revealed that CLP-induced apoptosis in K562 cells was associated with caspase-3 and poly(ADP-ribose)polymerase (PARP) protein. It is estimated that CLP inhibited proliferation in K562 cells by inducing apoptosis.

  9. The involvement of human-nuc gene in polyploidization of K562 cell line.

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    Cavalloni, G; Danè, A; Piacibello, W; Bruno, S; Lamas, E; Bréchot, C; Aglietta, M

    2000-12-01

    During megakaryocyte differentiation, the immature megakaryocyte increases its ploidy to a 2(x) DNA content by a process called endomitosis. This leads to the formation of a giant cell, the mature megakaryocyte, which gives rise to platelets. We investigated the role of human-nuc (h-nuc), a gene involved in septum formation in karyokynesis in yeast, during megakaryocytic polyploidization. Nocodazole and 12-O-tetradecanoylphorbol-13-acetate (TPA) were used to induce megakaryocytic differentiation in K562 cell line. The ploidy distribution and CD41 expression of treated K562 cells were evaluated by flow cytometry. Using quantitative reverse transcriptase polymerase chain reaction (RT-PCR), we analyzed the h-nuc mRNA expression on treated K562 cells. Mature megakaryocyte-like polyploid cells were detected at day 5-7 of treatment with nocodazole. TPA also had a similar effect on K562 cells, but it was much weaker than that of nocodazole. The analysis of ploidy of nocodazole-treated K562 cells showed that nocodazole preferentially induced polyploidization of K562 cell line with a pronounced increase of the cells 8N at day 7 of culture. Expression of CD41, a differentiation-related phenotype, was significantly induced by TPA after 7 days of treatment, showing that functional maturation was mainly induced by TPA. In contrast, there was no significant increase in CD41 expression in nocodazole-treated K562 cells, suggesting that polyploidization and functional maturation are separately regulated during megakaryocytopoiesis. RT-PCR analysis indicated that h-nuc mRNA increased after 72 hours in the presence of nocodazole, preceding the induction of polyploidization. Our data indicate that h-nuc might play a role in polyploidization during megakaryocytic differentiation via inhibition of septum formation.

  10. Synthesis of new steroidal inhibitors of P-glycoprotein-mediated multidrug resistance and biological evaluation on K562/R7 erythroleukemia cells.

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    de Ravel, Marc Rolland; Alameh, Ghina; Melikian, Maxime; Mahiout, Zahia; Emptoz-Bonneton, Agnès; Matera, Eva-Laure; Lomberget, Thierry; Barret, Roland; Rocheblave, Luc; Walchshofer, Nadia; Beltran, Sonia; El Jawad, Lucienne; Mappus, Elisabeth; Grenot, Catherine; Pugeat, Michel; Dumontet, Charles; Le Borgne, Marc; Cuilleron, Claude Yves

    2015-02-26

    A simple route for improving the potency of progesterone as a modulator of P-gp-mediated multidrug resistance was established by esterification or etherification of hydroxylated 5α/β-pregnane-3,20-dione or 5β-cholan-3-one precursors. X-ray crystallography of representative 7α-, 11α-, and 17α-(2'R/S)-O-tetrahydropyranyl ether diastereoisomers revealed different combinations of axial-equatorial configurations of the anomeric oxygen. Substantial stimulation of accumulation and chemosensitization was observed on K562/R7 erythroleukemia cells resistant to doxorubicin, especially using 7α,11α-O-disubstituted derivatives of 5α/β-pregnane-3,20-dione, among which the 5β-H-7α-benzoyloxy-11α-(2'R)-O-tetrahydropyranyl ether 22a revealed promising properties (accumulation index 2.9, IC50 0.5 μM versus 1.2 and 10.6 μM for progesterone), slightly overcoming those of verapamil and cyclosporin A. Several 7α,12α-O-disubstituted derivatives of 5β-cholan-3-one proved even more active, especially the 7α-O-methoxymethyl-12α-benzoate 56 (accumulation index 3.8, IC50 0.2 μM). The panel of modulating effects from different O-substitutions at a same position suggests a structural influence of the substituent completing a simple protection against stimulating effects of hydroxyl groups on P-gp-mediated transport.

  11. Effects of ginsenoside Rg3 on proliferation and induced differentiation of erythroleukemia cell line K562 in vitro%人参皂甙Rg3在体外对白血病K562细胞增殖和诱导分化的影响

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    肖凤; 刘彬; 张建平; 王伴青; 方木水; 胡玮; 孙续禄; 朱清仙

    2012-01-01

    背景:文献报道人参皂甙Rg3具有抗肿瘤作用,但对白血病作用研究很少.目的:观察人参皂甙Rg3对白血病K562细胞的作用,并探讨其相关机制.方法:以白血病K562细胞为靶细胞,实验分为对照组和人参皂甙Rg3组,人参皂甙Rg3组分别添加10,20,40,80,100 mg/L Rg3.结果与结论:MTT检测结果显示,不同浓度人参皂甙Rg3组K562细胞生长抑制率均显著高于对照组(P < 0.05~0.01).NBT结果显示,人参皂甙Rg3组培养1,2,3 d K562细胞还原率均高于对照组(P < 0.01);人参皂甙Rg3组部分K562细胞体积变小,核仁消失,同时阳性细胞增多,细胞向成熟分化;流式细胞仪检测显示人参皂甙Rg3组培养2 d细胞周期G2期增高了3.84倍.提示人参皂甙Rg3在体外可抑制K562细胞增殖活性,其机制可能与人参皂甙Rg3将K562细胞周期阻滞在G2期,使细胞不能进行正常的有丝分裂,从而抑制细胞增殖有关.%BACKGROUND: Evidence exists that ginsenoside Rg3 can inhibit the growth of carcinoma cells. However, there are fewer studies describing ginsenoside Rg3 effects on leukemia.OBJECTIVE: To investigate the effects of ginsenoside Rg3 on proliferation of erythroleukemia cell line K562 and the underlying mechanism.METHODS: Erythroleukemia cell line K562 was used as target cell. The cells were divided into a control group and an Rg3 group. 10, 20, 40, 80, 100 mg/L Rg3 was added in the Rg3 group.RESULTS AND CONCLUSION: The MTT colorimetric assay indicated that K562 growth inhibition rate was significantly higher in the Rg3 groups than in the control group (P < 0.05-0.01). The nitroblue tetrazolium assay showed that after culture for 1,2, 3 days, the reducing power of K562 cells in the Rg3 group was significantly higher than in the control group (P < 0.01). In the Rg3 group, some K563 cell somas became small, nucleoli disappeared, nitroblue tetrazolium positive cells increased, and cells developed toward maturation. Flow cytometry detection showed

  12. Curcumin inhibits WT1 gene expression in human leukemic K562 cells

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    Songyot ANUCHAPREEDA; Pattra THANARATTANAKORN; Somjai SITTIPREECHACHARN; Prasit CHANARAT; Pornngarm LIMTRAKUL

    2006-01-01

    Aim: Wilms' tumorl (WT1) gene is highly expressed in leukemic blast cells of myeloid and lymphoid origin. Thus, WT1 mRNA and protein serve as promising tumor markers for the detection of leukemia and monitoring of disease progression. The purpose of this study was to investigate the modulating effects of curcumin on WT1 gene expression in the human leukemic cell line K562. Methods: The cytotoxicity of curcumin on the K562 cell line was evaluated by using 3-(4,5-dimethyl-2 thiazoyl)2,5-diphenyl-tetrazolium bromide (MTT) assay. The K562 cell line was treated with a non-cytotoxic dose of curcumin (5,10, or 15 umol/L)for 13 d. The expression levels of WT1 protein and WT1 mRNA were assessed by Western blot analysis and reverse transcription-polymerase chain reaction (RT-PCR), respectively. Results: Curcumin had a cytotoxic effect on K562 leukemic cells with an inhibitory concentration at 50% (IC50) of approximately 20 ug/mL (54.3 umol/L). Non-cytotoxic doses of curcumin, at concentrations of 5,10, and 15 umol/L for 2 d, decreased the level of WT1 protein and WT1 mRNA in the K562 cell line in a dose-dependent manner. Similarly, curcumin at a concentration of 10 umol/L significantly decreased the level of WT1 protein and mRNA in a time-dependent manner. Conclusion: The inhibitory effects of curcumin are associated with a decrease in the levels of both WT1 protein and WT1 mRNA. The current study provides a molecular basis for future clinical trials in leukemic patients. Thus, curcumin could be a promising chemotherapeutic agent for human leukemia.

  13. Differentiation of Erythroleukemia K562 Cells Induced by Piperine%胡椒碱诱导人红白血病细胞株K562的分化

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    宋其芳; 瞿燕春; 郑红波; 张高华; 林鸿刚; 杨金亮

    2008-01-01

    背景与目的:白血病是一种血液系统的恶性肿瘤,诱导分化是治疗白血病非常有效的方法之一.胡椒碱(piperine)是一种从胡椒属植物中提取的生物碱,具有镇静、抗炎、抗肿瘤等多种药理活性.本研究旨在探讨胡椒碱对K562细胞的增殖抑制和诱导分化作用.方法:采用台盼蓝染色计数法绘制生长曲线和流式细胞术检测细胞周期及细胞凋亡.观察胡椒碱对K562细胞增殖的影响;通过观察细胞形态学变化、检测硝基蓝四氮唑(nitroblue tetrazolium,NBT)还原能力、流式细胞术检测细胞表面标志CD33和CD14的变化,探讨胡椒碱对K562细胞的诱导分化作用.结果:20μmol/L和40μmol/L胡椒碱可诱导K562细胞向巨噬细胞和单核系细胞分化.40 μmol/L胡椒碱作用3 d,K562细胞的NBT还原阳性率由(8.5±1.9)%上升到(76.7±5.3)%;20 μmol/L胡椒碱作用3 d,流式细胞术结果显示细胞表面分化抗原CD33的平均荧光强度(mean fluorescence intensity,MFI)下降42.05%(P<0.01),而CD14的MFI则升高了1倍(P<0.01);20 μmol/L以上浓度的胡椒碱对K562细胞的增殖具有抑制作用,其抑制作用随时间的延长或剂量的增加有增强的趋势.结论:胡椒碱可诱导K562细胞向巨噬和单核系细胞分化.

  14. Analysis of the erythroid differentiation effect of flavonoid apigenin on K562 human chronic leukemia cells.

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    Isoda, Hiroko; Motojima, Hideko; Onaga, Shoko; Samet, Imen; Villareal, Myra O; Han, Junkyu

    2014-09-05

    The erythroid differentiation-inducing effect of apigenin and its derivatives on human chronic myeloid leukemia K562 has been reported but the functional group in its structure responsible for the effect has not yet been elucidated. Here, we determined the moiety responsible for the erythroid differentiation induction effect of apigenin by using different flavonoids to represent the functional groups in its structure. In addition, we compared apigenin and apigetrin, a flavonoid similar in structure to apigenin except for the glycoside in its structure. Morphological changes as well as expressions of specific markers in K562 cells treated with apigenin were compared with those treated with apigetrin, flavone, 7-hydroxyflavone, chrysin, luteolin, or naringenin. The anti-proliferative and erythroid differentiation-inducing effect of apigenin and the five flavonoids were then investigated and their effects on the α, β, and γ globin genes expressions were compared using real-time PCR. Results of the comparison between apigenin and apigetrin revealed that the glycoside part of apigetrin does not have a role in the induction of cell differentiation. Based on glycophorin A expression, the potency of the other flavonoids for induction of differentiation, was: apigenin>chrysin>flavone/7-hydroxyflavone>luteolin/naringenin. Results of the analysis of the relationship between the structure and function of the flavonoids suggest that the apigenin-induced K562 cell differentiation was due to the 2-3 double bond and hydroxyl groups in its structure. This is the first study that identified the specific functional group in apigenin that impact the erythroid differentiation effect in K562 cells.

  15. The effect of β-ionone on telomerase activity in the human leukemia cell line K562

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    Zohreh Faezizadeh

    2015-06-01

    Full Text Available Background: Telomerase is highly activated in most human cancer cells, therefore, its inhibition has been proposed as a novel and promising strategy for cancer therapy. Many plant-derived anticancer agents act through inhibition of telomerase activity and induction of apoptosis. β-ionone, a carotenoid compound isolated from Roseaceae, has been reported to possess anticancer properties. The present study was undertaken to examine the mechanism of β-ionone-induced apoptosis in human leukemia cell line K562 with special emphasis on its role in telomerase inhibition. Method: In this study the anti-proliferation effect of β-ionone on K562 cells was evaluated by MTT assay. Apoptosis rate was detected by Hoechst staining and flow cytometry analysis. Telomerase activity was measured by (TRAP ELISA assay. Results: Exposure of K562 cells to β-ionone caused a dose-dependent decrease in proliferation. Flow cytometry analysis and Hoechst staining showed that percentage of apoptotic cells markedly increased with an increase in β-ionone concentration. Compared to control cells, treatment of K562 cells with β-ionone resulted in a significant decrease of telomerase activity. Moreover, a positive correlation was detected between telomerase inhibition and apoptosis induction in the treated K562 cells. Conclusion: Based on these results, β-ionone is an appropriate candidate for inhibiting telomerase activity in K562 cells. Therefore, it may be utilized as a novel drug against some leukemia cell lines.

  16. A DNA-binding protein factor in K562 nuclear extract interacts with positive control region (PCR) in the 5'-flanking sequence of human β-globin gene

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    HUYULONG; YADICHEN; TONGSUN; RUOLANQIAN

    1993-01-01

    It has been known that there are at least three regulatory regions (NCR1. NCR2 and PCR) in the 5'-flanking sequence (from -610 bp to +1 bp) of human β-glohin geneand that the function of PCR is unique to the human erythroleukemia (Ksfi2) ceils. Here we have detected a DNA-binding protein factor (termed NFEa) in K562 ceils. which can bind specifically to the PCR of human β-globin gene. The sequence of the binding site is 5'ACTGATG3' (between -222 bp and -216 bp). The NFEa is erythroidspecific and perhaps specific for K562 cells. It seemed that this factor differed from the erythroid-specific transcriptional factor (NFE-1) ,nsing competition assay. The presence of the NFEa further supported that the funciton of the cis-acting element PCR was specitic for K562 cells. and helps us to understand the mechauism of the regulation of the expression of lmman β-globin gene in the human K562 cells.

  17. Aqueous extract of Crataegus azarolus protects against DNA damage in human lymphoblast Cell K562 and enhances antioxidant activity.

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    Mustapha, Nadia; Bouhlel, Inès; Chaabane, Fadwa; Bzéouich, Imèn Mokdad; Ghedira, Kamel; Hennebelle, Thierry; Chekir-Ghedira, Leila

    2014-02-01

    The present study was carried out to characterize the cellular antioxidant effect of the aqueous extract of Crataegus azarolus and its antigenotoxic potential using human myelogenous cells, K562. The antioxidant capacity of this extract was evaluated by determining its cellular antioxidant activity (CAA) in K562 cells. Also, preceding antigenotoxicity assessment, its eventual genotoxicity property was investigated by evaluating its capacity to induce the DNA degradation of treated cell nuclei. As no genotoxicity was detected at different exposure times, its ability to protect cell DNA against H2O2 oxidative effect was investigated, using the "comet assay." It appears that 800 μg/mL of extract inhibited the genotoxicity induced by H2O2 with a rate of 41.30 %, after 4 h of incubation. In addition, this extract revealed a significant cellular antioxidant capacity against the reactive oxygen species in K562 cells.

  18. Extracts of Medicinal Mushrooms Agaricus bisporus and Phellinus linteus Induce Proapoptotic Effects in the Human Leukemia Cell Line K562

    NARCIS (Netherlands)

    Shnyreva, A.V.; Song, W.; Griensven, van L.J.L.D.

    2010-01-01

    We have studied the effects of Agaricus bisporus and Phellinus linteus ethanol extracts on transcriptional regulation of genes involved in cytokine release and apoptosis in the human leukemia cell line K562. In particular, we applied quantitative real-time PCR (Q-PCR) assays to monitor alterations o

  19. Arecoline-induced death of human leukemia K562 cells is associated with surface up-modulation of TNFR2.

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    Chen, Ying-Jung; Chang, Long-Sen

    2012-05-01

    The goal of the present study is to explore the contribution of tumor necrosis factor-α (TNFα)-related pathway to the cytotoxicity of arecoline on human leukemia K562 cells. Arecoline treatment induced death of K562 cells and increased surface expression of TNFα, TNFR1, and TNFR2. Unlike that of TNFR1 mRNA, transcriptional levels of TNFα and TNFR2 mRNA increased in arecoline-treated cells. Moreover, arecoline-induced down-regulation of ADAM17 maturation was involved in surface up-modulation of TNFR1, TNFR2, and TNFα. Arecoline-elicited increase in intracellular Ca(2+) concentration was responsible for JNK/c-Jun pathway activation and ERK inactivation. Abolition of JNK/c-Jun pathway suppressed arecoline-induced increase in transcriptional level of TNFα and TNFR2 mRNA. TNFα and TNFR2 promoter luciferase activity and chromatin immunoprecipitating analyses revealed that c-Jun increasingly bound with TNFα and TNFR2 promoter upon arecoline treatment. Over-expression of constitutively active MEK1 abolished the effect of arecoline on suppressing ADAM17 maturation. Pretreatment with TNFR2 antibody abrogated arecoline-induced increased susceptibility of K562 cells for the cytotoxicity of TNFα and arecoline-induced cell death. Taken together, our data suggest that up-modulation of TNFR2 surface expression is associated with arecoline-induced death of K562 cells. Copyright © 2011 Wiley Periodicals, Inc.

  20. Caveolin-1 contributes to realgar nanoparticle therapy in human chronic myelogenous leukemia K562 cells.

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    Shi, Dan; Liu, Yan; Xi, Ronggang; Zou, Wei; Wu, Lijun; Zhang, Zhiran; Liu, Zhongyang; Qu, Chao; Xu, Baoli; Wang, Xiaobo

    Chronic myelogenous leukemia (CML) is characterized by the t(9;22) (q34;q11)-associated Bcr-Abl fusion gene, which is an essential element of clinical diagnosis. As a traditional Chinese medicine, realgar has been widely used for the treatment of various diseases for >1,500 years. Inspired by nano-drug, realgar nanoparticles (NPs) have been prepared with an average particle size of processes including tumorigenesis and tumor development. In previous studies, it was found that realgar NPs can inhibit several types of tumor cell proliferation. However, the therapeutic effect of realgar NPs on CML has not been fully elucidated. In the present paper, it was demonstrated that realgar NPs can inhibit the proliferation of K562 cells and degrade Bcr-Abl fusion protein effectively. Both apoptosis and autophagy were activated in a dose-dependent manner in realgar NPs treated cells, and the induction of autophagy was associated with class I phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin pathway. Morphological analysis indicated that realgar NPs induced differentiation effectively in CML cells. Furthermore, it was identified that Cav-1 might play a crucial role in realgar NP therapy. In order to study the effects of Cav-1 on K562 cells during realgar NP treatment, a Cav-1 overexpression cell model was established by using transient transfection. The results indicated that Cav-1 overexpression inhibited K562 cell proliferation, promoted endogenic autophagy, and increased the sensitivity of K562 cells to realgar NPs. Therefore, the results demonstrated that realgar NPs degraded Bcr-Abl oncoprotein, while the underlying mechanism might be related to apoptosis and autophagy, and Cav-1 might be considered as a potential target for clinical comprehensive therapy of CML.

  1. Induction of apoptosis by Cordyceps militaris fraction in human chronic myeloid leukemia K562 cells involved with mitochondrial dysfunction

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    Tian, Tian; Song, Liyan; Zheng, Qin; Hu, Xianjing; Yu, Rongmin

    2014-01-01

    Background: Cordyceps militaris is widely used for various ethno medical conditions including cancer and inflammation complications in traditional Chinese medicine. Objective: To investigate the in vitro antitumor activity of Cordyceps militaris fraction (CMF) and the molecular mechanism underlying the apoptosis it induces in human chronic myeloid leukemia K562 cells. Materials and Methods: CMF was prepared according to our previous report. Cell viability was assessed by MTT assay. The rate of apoptosis, distribution of cell cycle and loss of mitochondrial membrane potential were measured by flow cytometry. Caspase activities were analyzed by Western blot and oxygen consumption rate was recorded using the Oxytherm system. Results: The results demonstrated that CMF triggered growth inhibition in K562 cells with only minor toxicity on a normal human cell line and inhibited the proliferation of K562 cells in a dose- and time-dependent manner with IC50 value of 34.1 ± 2.0 μg/ml after 48 h incubation. This most likely resulted from cell cycle arrest at the S phase and the induction of apoptosis. In addition, CMF induced activation of caspase-3 and subsequent cleavage of poly ADP-ribose polymerase (PARP). The caspase signals may originate from mitochondrial dysfunction, which was supported by the finding of decreased mitochondria transmembrance potential and the lower oxygen consumption rate. Conclusion: CMF possessed the in vitro antitumor effect on K562 cells and CMF-induced apoptosis might be involved by the mitochondrial dysfunction and valuable to research and develop as a potential antitumor agency. PMID:25210321

  2. In vitro anti-telomerase activity of novel lycopene-loaded nanospheres in the human leukemia cell line K562

    Science.gov (United States)

    Gharib, Amir; Faezizadeh, Zohreh

    2014-01-01

    Background: Lycopene, a plant carotenoid, has potent effects against the various types of cancer cells. To date, the effect of lycopene in the free and encapsulated forms on the telomerase activity in human leukemia cell line K562 have not been investigated. The aim of the present study was to prepare a novel lycopene-loaded nanosphere and compare its anti-telomearse activity in K562 cell line with those of free lycopene. Materials and Methods: The lycopene-loaded nanospheres were prepared by nanoprecipitation method. The lycopene entrapment efficacy was measured by high-performance liquid chromatography (HPLC) method. The anti-proliferation effect of the lycopene in the free and encapsulated forms in the different times (0-72 h) and the different doses (0-100 μg/ml) on K562 cell line was studied using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay. The changes of telomerase activity, following treatment with the lycopene in the free and encapsulated forms, were detected using the telomeric repeat amplification protocol-enzyme-linked immunosorbent assay. Results: The entrapment efficacy of lycopene was 78.5% ± 2. Treatment of the K562 cell line with lycopene, in particular in encapsulated form, resulted in a significant inhibition of the cell growth and increasing of percentage of apoptotic cells. It has also been observed that the telomerase activity in the lycopene-loaded nanospheres-treated cells was significantly inhibited in a dose and time-dependent manner. Conclusion: Our data suggest a novel mechanism in the anti-cancer activity of the lycopene, in particular in encapsulated form, and could be provided a basis for the future development of anti-telomerase therapies. PMID:24914298

  3. Mastic oil from Pistacia lentiscus var. chia inhibits growth and survival of human K562 leukemia cells and attenuates angiogenesis.

    Science.gov (United States)

    Loutrari, Heleni; Magkouta, Sophia; Pyriochou, Anastasia; Koika, Vasiliki; Kolisis, Fragiskos N; Papapetropoulos, Andreas; Roussos, Charis

    2006-01-01

    Mastic oil from Pistacia lentiscus var. chia, a natural plant extract traditionally used as a food additive, has been extensively studied for its antimicrobial activity attributed to the combination of its bioactive components. One of them, perillyl alcohol (POH), displays tumor chemopreventive, chemotherapeutic, and antiangiogenic properties. We investigated whether mastic oil would also suppress tumor cell growth and angiogenesis. We observed that mastic oil concentration and time dependently exerted an antiproliferative and proapoptotic effect on K562 human leukemia cells and inhibited the release of vascular endothelial growth factor (VEGF) from K562 and B16 mouse melanoma cells. Moreover, mastic oil caused a concentration-dependent inhibition of endothelial cell (EC) proliferation without affecting cell survival and a significant decrease of microvessel formation both in vitro and in vivo. Investigation of underlying mechanism(s) demonstrated that mastic oil reduced 1) in K562 cells the activation of extracellular signal-regulated kinases 1/2 (Erk1/2) known to control leukemia cell proliferation, survival, and VEGF secretion and 2) in EC the activation of RhoA, an essential regulator of neovessel organization. Overall, our results underscore that mastic oil, through its multiple effects on malignant cells and ECs, may be a useful natural dietary supplement for cancer prevention.

  4. Caveolin-1 contributes to realgar nanoparticle therapy in human chronic myelogenous leukemia K562 cells

    Directory of Open Access Journals (Sweden)

    Shi D

    2016-11-01

    Full Text Available Dan Shi,1,* Yan Liu,1,* Ronggang Xi,1 Wei Zou,2 Lijun Wu,3 Zhiran Zhang,1 Zhongyang Liu,1 Chao Qu,1 Baoli Xu,1 Xiaobo Wang1 1Department of Pharmacy, The 210th Hospital of People’s Liberation Army, 2College of Life Science, Liaoning Normal University, Dalian, Liaoning, 3Department of Pharmaceutics, College of Pharmacy, Harbin Medical University, Harbin, Heilongjiang, People’s Republic of China *These authors contributed equally to this work Abstract: Chronic myelogenous leukemia (CML is characterized by the t(9;22 (q34;q11-associated Bcr-Abl fusion gene, which is an essential element of clinical diagnosis. As a traditional Chinese medicine, realgar has been widely used for the treatment of various diseases for >1,500 years. Inspired by nano-drug, realgar nanoparticles (NPs have been prepared with an average particle size of <100 nm in a previous work. Compared with coarse realgar, the realgar NPs have higher bioavailability. As a principal constituent protein of caveolae, caveolin-1 (Cav-1 participates in regulating various cellular physiological and pathological processes including tumorigenesis and tumor development. In previous studies, it was found that realgar NPs can inhibit several types of tumor cell proliferation. However, the therapeutic effect of realgar NPs on CML has not been fully elucidated. In the present paper, it was demonstrated that realgar NPs can inhibit the proliferation of K562 cells and degrade Bcr-Abl fusion protein effectively. Both apoptosis and autophagy were activated in a dose-dependent manner in realgar NPs treated cells, and the induction of autophagy was associated with class I phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin pathway. Morphological analysis indicated that realgar NPs induced differentiation effectively in CML cells. Furthermore, it was identified that Cav-1 might play a crucial role in realgar NP therapy. In order to study the effects of Cav-1 on K562 cells during

  5. Chaetominine reduces MRP1-mediated drug resistance via inhibiting PI3K/Akt/Nrf2 signaling pathway in K562/Adr human leukemia cells

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Jingyun; Wei, Xing [State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai (China); Shanghai Collaborative Innovation Center for Biomanufacturing Technology, 130 Meilong Road, Shanghai (China); Lu, Yanhua, E-mail: luyanhua@ecust.edu.cn [State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai (China); Shanghai Collaborative Innovation Center for Biomanufacturing Technology, 130 Meilong Road, Shanghai (China)

    2016-05-13

    Drug resistance limits leukemia treatment and chaetominine, a cytotoxic alkaloid that promotes apoptosis in a K562 human leukemia cell line via the mitochondrial pathway was studied with respect to chemoresistance in a K562/Adr human resistant leukemia cell line. Cytotoxicity assays indicated that K562/Adr resistance to adriamycin (ADR) did not occur in the presence of chaetominine and that chaetominine increased chemosensitivity of K562/Adr to ADR. Data show that chaetominine enhanced ADR-induced apoptosis and intracellular ADR accumulation in K562/Adr cells. Accordingly, chaetominine induced apoptosis by upregulating ROS, pro-apoptotic Bax and downregulating anti-apoptotic Bcl-2. RT-PCR and western-blot confirmed that chaetominine suppressed highly expressed MRP1 at mRNA and protein levels. But little obvious alternation of another drug transporter MDR1 mRNA was observed. Furthermore, inhibition of MRP1 by chaetominine relied on inhibiting Akt phosphorylation and nuclear Nrf2. In summary, chaetominine strongly reverses drug resistance by interfering with the PI3K/Akt/Nrf2 signaling, resulting in reduction of MRP1-mediated drug efflux and induction of Bax/Bcl-2-dependent apoptosis in an ADR-resistant K562/Adr leukemia cell line. - Highlights: • Chaetominine enhanced chemosensitivity of ADR against K562/Adr cells. • Chaetominine increased intracellular ADR levels via inhibiting MRP1. • Chaetominine induced apoptosis of K562/Adr cells through upregulation of ROS and modulation of Bax/Bcl-2. • Inhibition of MRP1 and Nrf2 by chaetominine treatment was correlative with blockade of PI3K/Akt signaling.

  6. [Silence potentiates chemosensitivity of K562 cells to SAHA].

    Science.gov (United States)

    Wang, Hou-Cai; Chen, Jing; An, Na; Yu, Teng-Teng; Li, Shou-Yun; Liu, Shuang; Wei, Hui; Rao, Qing; Wang, Min; Wang, Jian-Xiang

    2014-08-01

    Ribosomal protein S27a (RPS27a) can perform extra-ribosomal functions besides imparting a role in ribosome biogenesis and post-translational modifications of proteins. The RPS27a gene has been reported to be over-expressed in breast fibroadenomas, colorectal and renal cancers, advanced-phase chronic myeloid leukemia (CML) and acute leukemia (AL) patients. This study was purposed to explore the function of RPS27a in CML-erythroleukemia cell line K562 cells. RPS27a was silenced by short hairpin RNA (shRNA) in K562 cells. Furthermore, the proliferation changes of K562 cells was detected by MTT method after silencing the RPS27a with suberoylanilide hydroxamic acid (SAHA), then the IC50 of K562-sh1/sh2 and K562-scr cells to SAHA was measured. The results indicated that compared with K562-scr cells, the IC50 of K562-sh1/sh2 to SAHA at 24 h and 48 h decreased (P silence significantly increased the percentage of apoptotic K562-sh1/sh2 cells after incubation with 1 µmol/L, 2 µmol/L and 5 µmol/L SAHA for 24 h and 48 h as compared with that of K562-scr cells (P silence can potentiate sensitivity of K562 cells to SAHA.

  7. 5-(2-Carboxyethenyl) isatin derivative induces G{sub 2}/M cell cycle arrest and apoptosis in human leukemia K562 cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Yao; Zhao, Hong-Ye; Han, Kai-Lin; Yang, Yao; Song, Bin-Bin; Guo, Qian-Nan [Key Laboratory of Industrial Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457 (China); Tianjin Key Laboratory of Industry Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457 (China); Fan, Zhen-Chuan [Key Laboratory of Food Nutrition and Safety (Tianjin University of Science and Technology), Ministry of Education, Tianjin 300457 (China); Obesita and Algaegen LLC, College Station, TX 77845 (United States); Zhang, Yong-Min [Université Pierre et Marie Curie-Paris 6, Institut Parisien de Chimie Moléculaire UMR CNRS 8232, 4 Place Jussieu, 75005 Paris (France); Teng, Yu-Ou, E-mail: tyo201485@tust.edu.cn [Key Laboratory of Industrial Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457 (China); Tianjin Key Laboratory of Industry Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457 (China); Yu, Peng, E-mail: yupeng@tust.edu.cn [Key Laboratory of Industrial Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457 (China); Tianjin Key Laboratory of Industry Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457 (China)

    2014-08-08

    Highlights: • 5-(2-Carboxyethenyl) isatin derivative (HKL 2H) inhibited K562’s proliferation. • HKL 2H caused the morphology change of G{sub 2}/M phase arrest and typical apoptosis. • HKL 2H induced G2/M cell cycle phase arrest in K562 cells. • HKL 2H induced apoptosis in K562 cells through the mitochondrial pathway. - Abstract: Our previous study successfully identified that the novel isatin derivative (E)-methyl 3-(1-(4-methoxybenzyl)-2,3-dioxoindolin-5-yl) acrylate (HKL 2H) acts as an anticancer agent at an inhibitory concentration (IC{sub 50}) level of 3 nM. In this study, the molecular mechanism how HKL 2H induces cytotoxic activity in the human chronic myelogenous leukemia K562 cells was investigated. Flow cytometric analysis showed that the cells were arrested in the G{sub 2}/M phase and accumulated subsequently in the sub-G{sub 1} phase in the presence of HKL 2H. HKL 2H treatment down-regulated the expressions of CDK1 and cyclin B but up-regulated the level of phosphorylated CDK1. Annexin-V staining and the classic DNA ladder studies showed that HKL 2H induced the apoptosis of K562 cells. Our study further showed that HKL 2H treatment caused the dissipation of mitochondrial membrane potential, activated caspase-3 and lowered the Bcl-2/Bax ratio in K562 cells, suggesting that the HKL 2H-causing programmed cell death of K562 cells was caused via the mitochondrial apoptotic pathway. Taken together, our data demonstrated that HKL 2H, a 5-(2-carboxyethenyl) isatin derivative, notably induces G{sub 2}/M cell cycle arrest and mitochondrial-mediated apoptosis in K562 cells, indicating that this compound could be a promising anticancer candidate for further investigation.

  8. Effects of the antitumoural dequalinium on NB4 and K562 human leukemia cell lines. Mitochondrial implication in cell death.

    Science.gov (United States)

    Galeano, Eva; Nieto, Elena; García-Pérez, Ana Isabel; Delgado, M Dolores; Pinilla, Montserrat; Sancho, Pilar

    2005-10-01

    Dequalinium (DQA) is a delocalized lipophylic cation that selectively targets the mitochondria of carcinoma cells. However, the underlying mechanisms of DQA action are not yet well understood. We have studied the effects of DQA on two different leukemia cell lines: NB4, derived from acute promyelocytic leukemia, and K562, derived from chronic myeloid leukemia. We found that DQA displays differential cytotoxic activity in these cell lines. In NB4 cells, a low DQA concentration (2microM) induces a mixture of apoptosis and necrosis, whereas a high DQA concentration (20microM) induces mainly necrosis. However, K562 cell death was always by necrosis as the cells showed a resistance to apoptosis at all time-periods and DQA concentrations assayed. In both cell lines, the cell death seems to be mediated by alterations of mitochondrial function as evidenced by loss of mitochondrial transmembrane potential, O2*- accumulation and ATP depletion. The current study improves the knowledge on DQA as a novel anticancer agent with a potential application in human acute promyelocytic leukemia chemotherapy.

  9. Use of zinc-finger nucleases to knock out the WAS gene in K562 cells: a human cellular model for Wiskott-Aldrich syndrome

    Directory of Open Access Journals (Sweden)

    Miguel G. Toscano

    2013-03-01

    Mutations in the WAS gene cause Wiskott-Aldrich syndrome (WAS, which is characterized by eczema, immunodeficiency and microthrombocytopenia. Although the role of WASP in lymphocytes and myeloid cells is well characterized, its role on megakaryocyte (MK development is poorly understood. In order to develop a human cellular model that mimics the megakaryocytic-derived defects observed in WAS patients we used K562 cells, a well-known model for study of megakaryocytic development. We knocked out the WAS gene in K562 cells using a zinc-finger nuclease (ZFN pair targeting the WAS intron 1 and a homologous donor DNA that disrupted WASP expression. Knockout of WASP on K562 cells (K562WASKO cells resulted in several megakaryocytic-related defects such as morphological alterations, lower expression of CD41ɑ, lower increments in F-actin polymerization upon stimulation, reduced CD43 expression and increased phosphatidylserine exposure. All these defects have been previously described either in WAS-knockout mice or in WAS patients, validating K562WASKO as a cell model for WAS. However, K562WASPKO cells showed also increased basal F-actin and adhesion, increased expression of CD61 and reduced expression of TGFβ and Factor VIII, defects that have never been described before for WAS-deficient cells. Interestingly, these phenotypic alterations correlate with different roles for WASP in megakaryocytic differentiation. All phenotypic alterations observed in K562WASKO cells were alleviated upon expression of WAS following lentiviral transduction, confirming the role of WASP in these phenotypes. In summary, in this work we have validated a human cellular model, K562WASPKO, that mimics the megakaryocytic-related defects found in WAS-knockout mice and have found evidences for a role of WASP as regulator of megakaryocytic differentiation. We propose the use of K562WASPKO cells as a tool to study the molecular mechanisms involved in the megakaryocytic-related defects observed in WAS

  10. Reversal Effect and Mechanisms of Recombinant Human Tumor Necrosis Factor-NC Against the Doxorubicin Resistance in Leukemia K562/Doxorubicin Cells

    Institute of Scientific and Technical Information of China (English)

    ZHOU Jing-hong; CHEN Bo-hua

    2015-01-01

    Objective: To explore the reversal effect and mechanisms of recombinant human tumor necrosis factor-NC (rhTNF-NC) against the doxorubicin (Dox) resistance in chronic myelogenous leukemia (CML) K562/Dox cells. Methods: The chemo-sensitivity of tumor cells dealt with different concentrations of rhTNF-NC to Dox was detected by tetrazolium dye assay (MTT). The intra-cellular Dox accumulation represented by lfuorescence intensity was determined by lfow cytometry (FCM) at the excitation wave length of 488 nm and emission wave length of 550 nm. The expression of multidrug resistance (MDR)-related genes and proteins was analyzed by reverse transcription polymerase chain reaction (RT-PCR) and Western blot assays. Results:After being exposed to gradually increasing concentrations of Dox for 10 consecutive months, K562/Dox cells were more resistant to Dox (nearly 132 times) than Dox-sensitive K562 cells. The IC50 of Dox for K562 and K562/Dox cells were (0.04±0.01) and (5.55±0.08) μmol/L, respectively. When K562/Dox cells were treated with rhTNF-NC at 500, 2 500 or 5 000U/mL, the IC50 of Dox was decreased to (2.22±0.34), (1.41±0.13) and (1.04±0.09) μmol/L, respectively. The concentration-response curves were moved upward by the treatment of rhTNF-NC (P Conclusion: rhTNF-NC can effectively augment the drug accumulation in tumor cells. This is due to the up-regulation of TopoIIα and down-regulation of MDR1, MRP and GSTπ at mRNA expression as well as reduction of P-gp and PKCα expression.

  11. 稳定表达HLA-A*1101蛋白的K562细胞株的建立%Establishment of Stable Subline of K562 Cells Expressing Human Leucocyte Antigen A1101

    Institute of Scientific and Technical Information of China (English)

    查显丰; 周羽竝; 杨力建; 陈少华; 李萡; 闫小娟; 李扬秋

    2011-01-01

    The aim of this study was to establish a stable subline of K562 cells expressing the HLA-A * 1101 protein, which was expected to provide target cells for characterizing the HLA-I restrictive antigen specific cytotoxic T lymphocyte (CTL) effects against chronic myeloid leukemia (CML). The HLA-A* 1101 protein encoding gene was amplified from peripheral blood mononuclear cell (PBMNC) of CML patient by RT-PCR; the 2A peptide linker (D-V-E-X-N-P-G-P) gene was linked to the 3' terminal of the HLA-A' 1101 gene by recombinant PCR, then the recombinant was cloned into the pEGFP-N3 plasmid which contains an enhanced green fluorescent protein gene, and the eukaryotic recombinant expression vector containing HLA-A* 1101-T2A-EGFP transcription box was constructed; the pEGFP-N3 vector and recombinant vector was separately electroporated into K562 cells. The expression of GFP was monitored by fluorescence microscopy, finally stably transfected sublines of K562 cells containing HLA-A' 1101 gene, and of K562 containing pEGFP-N3 vector were obtained by G418 selection; the transcriptional or translational expression of HLA-A' 1101 gene was detected with RT-PCR and flow cytometry respectively. The results indicated that the eukaryotic expression vector HLA-A' 1101-T2A-EGFP plasmid was successfully constructed; after G4I8 selection for 2 months, two sublines of K562 cells (HLA-A'1101 *K562, pEGFP-N3 * K562) expressing GFP were constructed. The expression of HLA-A * AJ101 gene could be determined in HLA-A* 1101 * K562 cell line by RT-PCR,while the pEGFP-N3 * K562 cells could not express HLA-A * A1101 gene. HLA-A* 1101 protein and GFP double positive HLA-A * 1101* K562 cells were upto 88. 5% , which was obviously higher than pEGFP-N3* K562 cells (0. 698% ) by flow cytometric analysis. It is concluded that a simple and effective method to select HLA-A * 1101 * K562 cells has been established and a subline of K562 cell expressing HLA-A* 1101 protein on its cell membrane was successfully

  12. Role of yessotoxin in calcium and cAMP-crosstalks in primary and K-562 human lymphocytes: the effect is mediated by anchor kinase A mitochondrial proteins.

    Science.gov (United States)

    Tobío, Araceli; Fernández-Araujo, Andrea; Alfonso, Amparo; Botana, Luis M

    2012-12-01

    Yessotoxin (YTX) is a marine polyether toxin previously described as a phosphodiesterase (PDE) activator in fresh human lymphocytes. This toxin induces a decrease of adenosine 3',5'-cyclic monophosphate (cAMP) levels in fresh human lymphocytes in a medium with calcium (Ca(2+) ), whereas the contrary effect has been observed in a Ca(2+) -free medium. In the present article, the effect of YTX in K-562 lymphocytes cell line has been analysed. Surprisingly, results obtained in K-562 cell line are completely opposite than in fresh human lymphocytes, since in K-562 cells YTX induces an increase of cAMP levels. YTX cytotoxicity was also studied in both K-562 cell line and fresh human lymphocytes. Results demonstrate that YTX does not modify fresh human lymphocytes viability, whereas in K-562 cells, YTX has a highly cytotoxic effect. It has been described in a previous study that YTX induces a small cytosolic Ca(2+) increase in fresh human lymphocytes but no effect was observed on Ca(2+) pools depletion in these cells. However, our results show that, in K-562 cells, YTX has no effect on cytosolic Ca(2+) levels in a medium with Ca(2+) and induces an increase on Ca(2+) pools depletion followed by a Ca(2+) influx. As far as Ca(2+) modulation is concerned these results demonstrate that YTX has a clear opposite effect in tumoural and fresh human lymphocytes. In addition, intracellular Ca(2+) reservoirs affected by YTX are different than thapsigargin-sensible pools. Furthermore, YTX-dependent Ca(2+) pools depletion was abolished by cAMP analogue (dibutyryl cAMP), phosphodiesterase-4 (PDE4) inhibitor (rolipram), protein kinase A inhibitor (H89) and oxidative phosphorylation uncoupler carbonyl cyanide p-(trifluoromethoxy) (FCCP) treatments. This evidences the crosstalks between Ca(2+) , YTX and cAMP pathways. Also, results obtain demonstrate that YTX-dependent Ca(2+) influx was only abolished by FCCP pre-treatment, which indicates a link between YTX and mitochondria in K-562 cell

  13. Comparative study of DNA damage, cell cycle and apoptosis in human K562 and CCRF-CEM leukemia cells: role of BCR/ABL in therapeutic resistance.

    Science.gov (United States)

    Pytel, Dariusz; Wysocki, Tomasz; Majsterek, Ireneusz

    2006-09-01

    The Philadelphia translocation t(9;22) resulting in the bcr/abl fusion gene is the pathogenic principle of almost 95% of human chronic myelogenous leukemia (CML). Imatinib mesylate (STI571) is a specific inhibitor of the BCR/ABL fusion tyrosine kinase that exhibits potent antileukemic effects in CML. BCR/ABL-positive K562 and -negative CCRF-CEM human leukemia cells were investigated. MTT survival assay and clonogenic test of the cell proliferation ability were used to estimate resistance against idarubicin. DNA damage after cell treatment with the drug at the concentrations from 0.001 to 3 microM with or without STI571 pre-treatment were examined by the alkaline comet assay. We found that the level of DNA damages was lower in K562 cells after STI571 pre-treatment. It is suggested that BCR/ABL activity may promote genomic instability, moreover K562 cells were found to be resistant to the drug treatment. Further, we provided evidence of apoptosis inhibition in BCR/ABL-positive cells using caspase-3 activity colorimetric assay and DAPI nuclear staining for chromatin condensation. We suggest that these processes associated with cell cycle arrest in G2/M checkpoint detected in K562 BCR/ABL-positive compared to CCRF-CEM cells without BCR/ABL expression might promote clone selection resistance to drug treatment.

  14. Involvement of p38 MAPK- and JNK-modulated expression of Bcl-2 and Bax in Naja nigricollis CMS-9-induced apoptosis of human leukemia K562 cells.

    Science.gov (United States)

    Chen, Ying-Jung; Liu, Wen-Hsin; Kao, Pei-Hsiu; Wang, Jeh-Jeng; Chang, Long-Sen

    2010-06-15

    CMS-9, a phospholipase A(2) (PLA(2)) isolated from Naja nigricollis venom, induced apoptosis of human leukemia K562 cells, characterized by mitochondrial depolarization, modulation of Bcl-2 family members, cytochrome c release and activation of caspases 9 and 3. Moreover, an increase in intracellular Ca2+ concentration and the production of reactive oxygen species (ROS) was noted. Pretreatment with BAPTA-AM (Ca2+ chelator) and N-acetylcysteine (NAC, ROS scavenger) proved that Ca2+ was an upstream event in inducing ROS generation. Upon exposure to CMS-9, activation of p38 MAPK and JNK was observed in K562 cells. BAPTA-AM or NAC abrogated CMS-9-elicited p38 MAPK and JNK activation, and rescued viability of CMS-9-treated K562 cells. SB202190 (p38 MAPK inhibitor) and SP600125 (JNK inhibitor) suppressed CMS-9-induced dissipation of mitochondrial membrane potential, Bcl-2 down-regulation, Bax up-regulation and increased mitochondrial translocation of Bax. Inactivation of PLA(2) activity reduced drastically the cytotoxicity of CMS-9, and a combination of lysophosphatidylcholine and stearic acid mimicked the cytotoxic effects of CMS-9. Taken together, our data suggest that CMS-9-induced apoptosis of K562 cells is catalytic activity-dependent and is mediated through mitochondria-mediated death pathway triggered by Ca2+/ROS-evoked p38 MAPK and JNK activation.

  15. Cell proliferation inhibitory effect on human myeloid leukemia K562 of bauhinione from Bauhiniae variegata L.%洋紫荆中菲醌化合物bauhinione对K562细胞的增殖抑制作用

    Institute of Scientific and Technical Information of China (English)

    赵燕燕; 崔承彬; 孙启时

    2007-01-01

    目的 探讨从洋紫荆中分离得到的新的菲醌化合物bauhinione对体外培养的人类慢性骨髓性白血病K562细胞的增殖抑制作用.方法 应用罗丹明B法检测bauhinione对癌细胞K562和tsFT210的抑制作用;采用形态学观察以及流式细胞术(FCM)检测该化合物对K562细胞的细胞周期抑制和诱导凋亡作用;通过倍量稀释法考察该化合物的最小抑制质量浓度及其质量浓度为12.5 mg·L-1时的时效关系.结果 Bauhinione对两种癌细胞的IC50值分别为(24.9±2.1)mg·L-1和(111.36±3.5)mg·L-1,说明K562细胞对bauhinione的作用敏感;Bauhinione对K562细胞的最小抑制质量浓度为6.25 mg·L-1;对K562细胞的增殖抑制作用是通过G2-M期抑制和诱导凋亡实现的,并与时间呈依赖关系.结论 Bauhinione在体外有抑制K562细胞增殖的作用,为洋紫荆的抗癌活性成分之一.

  16. Effects of Thalidomide on the Apoptosis of Human Chronic Myeloid Leukemia K562 Cell Line%沙利度胺对人慢性粒细胞白血病细胞株K562细胞凋亡的影响研究

    Institute of Scientific and Technical Information of China (English)

    张志; 张玉高; 韩丽英; 陈枫

    2012-01-01

    OBJECTIVE: To study the effects of thalidomide on the apoptosis of human chronic myeloid leukemia K562 cell line. METHODS: K.562 cells were divided into control (non-treated) group and thalidomide low-dose, medium-dose and high-dose groups (0.5, 1.0, 2.0 mmol·L-1). After 24 h, 48 h, 72 h and 96 h of treatment, MTT assay was used to determine the cell growth inhibition rate. Morphology of the K562 cells was observed by the Wright-Giemsa staining method. The rate of apoptosis was analyzed by flow cytometry (FCM) with AnnexinV-FITC/PI double-staining method. RESULTS: The growth inhibition rate and apoptosis rate of K562 cells were positively related with the concentration of thalidomide and treatment duration. Compared with control group, the growth inhibition rate of K562 cells in thalidomide groups increased significantly after 72 h and 96 h of treatment (P<0.05), and apoptosis rate of K562 cells increased significantly at 4 time points (P<0.01). After exposure to thalidomide for 72 h, K562 cells underwent typical morphological changes of apoptosis such as dwindling in size. CONCLUSIONS: Thalidomide inhibits the proliferation of K.562 cells in a dose and time-dependent manner to some extent. Thalidomide obviously induces the apoptosis of the K562 cells.%目的:研究沙利度胺对人慢性粒细胞白血病细胞株K562细胞凋亡的影响.方法:将K562细胞分为对照(未加药)组和沙利度胺低、中、高剂量(0.5、1.0、2.0 mmol·L-1)组,加入相应药物分别作用24、48、72、96 h后,MTT法检测各组细胞生长抑制率,Wright-Giemsa染色观察各组细胞形态变化,Annexin V-FITC/PI双染法流式细胞仪检测各组细胞凋亡率.结果:K562细胞的生长抑制10率和凋亡率与沙利度胺浓度和作用时间均呈正相关;与对照组比较,沙利度胺3个剂量组作用72、96h后细胞的生长抑制率明显升高(P<0.05),4个时间点的细胞凋亡率均明显升高(P<0.01).沙利度胺3个剂量组作用72h后,K562

  17. 细胞周期蛋白E2反义脱氧寡核苷酸对K562细胞增殖及凋亡的调控作用%Effect of cyclin E2 antisense oligonucleotide on human leukemic cell line K562

    Institute of Scientific and Technical Information of China (English)

    徐丽粉; 郭晓楠; 刘英芳

    2012-01-01

    Objective To investigate the effect of cyclin E2 antisense oligonucleotide ( ASON) on human leukemic cell line K562. Methods Cyclin E2 ASON was used in vitro culture K562 cell study. MTT assay was used to measure the growth inhibitory effect of transfection of ASON and lipofectamine TM2000. The Mrna expression levels of cyclin E2 were examined by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR). Apopsis was detected by flow cytometry and morphology method. Results Cyclin E2 ASON specifically inhibited K562 cell Mrna expression level as well as the K562 cell proliferation. After transfection with cyclin E2 ASON.K562 cells developed apoptosis. Conclusion Cyclin E2 ASON can specifically inhibit K562 cell Mrna expression levels as well as the K562 cell proliferation. After being transfected with cyclin E2 ASON,K562 cells developed apoptosis. Cyclin E2 gene is likely to be a new target for antisense nucleotides techonology therapy of leukemia.%目的 研究细胞周期蛋白E2 (cyclin E2)反义脱氧寡核苷酸(ASON)对人红白血病细胞K562增殖的调控作用.方法 采用反义技术合成ASON并与K562细胞共培养.用四甲基偶氮唑蓝(MTT)法检测转染ASON和脂质体lipofectamineTM 2000后的细胞活力,逆转录-聚合酶链式反应(RT-PCR)方法检测转染细胞cyclin E2 mRNA表达水平及流式细胞术和形态学观察检测细胞凋亡.结果 Cyclin E2特异的ASON能显著地抑制cyclin E2mRNA水平的表达(F=26.442,P<0.01);白血病细胞的生长明显受抑制(P<0.01),细胞凋亡明显增加.结果 表明反义脱氧寡核苷酸能有效地抑制K562细胞的增殖,抑制K562细胞cyclin E2 mRNA表达上调,并显著地诱导细胞凋亡.结论 脂质体转染cyclin E2的反义寡核苷酸能够有效地抑制K562细胞cyclin E2 mRNA的表达,同时对白血病细胞K562的生长有明显的抑制作用,并可诱导K562细胞凋亡.提示cyclin E2在细胞周期调控中起作用,cyclinE2基因有望

  18. Study of the mechanism on the apoptosis induced in Human leukemia cell line K562 by the combination of indole-3-acetic acid and horseradish peroxidase

    Institute of Scientific and Technical Information of China (English)

    Song Tusheng; Yang Ling; Huang Chen; Liu Liying; Ni Lei; Wang Aiying; Luo Yu

    2007-01-01

    Objective To investigate the mechanisms of apoptosis induced in Human leukemia cell line K562 by the combination of indole-3-acetic acid and horseradish peroxidase. Methods Human leukemia cell line K562 were exposed to indole-3-acetic acid (IAA) at 20, 40, 60, 80 or 100 mol/L and horseradish peroxidase(HRP) at 1.2 g/mL for varying times. MTT assay was applied to detect the cell proliferation. Flow cytometry was performed to detect the arrest of cell cycle. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay was used to measure apoptosis. 2, 7-dichlorofluorescin diacetate (DCFH-DA) uptake was measured to determine free radical by confocal microscope. Content of malondiadehyde (MDA) and activity of superoxide dismutase (SOD) were measured by biochemical methods. Results IAA/HRP initiated growth inhibition of K562 cells in a dose- and time-dependent manner. Flow cytometry revealed that cell cycle arrested at G1/G0 after 24 hours treatment. After 72 hours treatment, apoptotic rate of 100 mol/L IAA group increased to 43.9%, which was 5 times that of control(P<0.01). Content of MDA and activity of SOD increased respectively in treatments compared with control. Meanwhile, IAA/HRP stimulated the formation of free radical, which was increased by IAA concentration-dependently. Conclusion The combination of IAA and HRP can inhibit the growth of Human leukemia cell line K562 in vitro by inducing apoptosis which is associated with the increase of free radical. The combination of IAA and HRP might be a promising chemopreventive and chemotherapeutic agent against human leukemia.

  19. Apoptotic Mechanism of Human Leukemia K562/A02 Cells Induced by Magnetic Ferroferric Oxide Nanoparticles Loaded with Wogonin

    Directory of Open Access Journals (Sweden)

    Miao-Xin Peng

    2016-01-01

    Conclusions: This study demonstrated that MNPs were the effective drug delivery vehicles to deliver wogonin to the leukemia cells. Through increasing cells arrested at G0/G1-phase and inducing apoptosis of K562/A02 cells, MNPs could enhance the therapeutic effects of wogonin on leukemia cells. These findings indicated that MNPs loaded with wogonin could provide a promising way for better leukemia treatment.

  20. Knockdown of HOXA10 reverses the multidrug resistance of human chronic mylogenous leukemia K562/ADM cells by downregulating P-gp and MRP-1.

    Science.gov (United States)

    Yi, Ying-Jie; Jia, Xiu-Hong; Wang, Jian-Yong; Li, You-Jie; Wang, Hong; Xie, Shu-Yang

    2016-05-01

    Multidrug resistance (MDR) of leukemia cells is a major obstacle in chemotherapeutic treatment. The high expression and constitutive activation of P-glycoprotein (P-gp) and multidrug resistance protein-1 (MRP-1) have been reported to play a vital role in enhancing cell resistance to anticancer drugs in many tumors. The present study aimed to investigate the reversal of MDR by silencing homeobox A10 (HOXA10) in adriamycin (ADR)-resistant human chronic myelogenous leukemia (CML) K562/ADM cells by modulating the expression of P-gp and MRP-1. K562/ADM cells were stably transfected with HOXA10-targeted short hairpin RNA (shRNA). The results of reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot analysis showed that the mRNA and protein expression of HOXA10 was markedly suppressed following transfection with a shRNA-containing vector. The sensitivity of the K562/ADM cells to ADR was enhanced by the silencing of HOXA10, due to the increased intracellular accumulation of ADR. The accumulation of ADR induced by the silencing of HOXA10 may be due to the downregulation of P-gp and MRP-1. Western blot analysis revealed that downregulating HOXA10 inhibited the protein expression of P-gp and MRP-1. Taken together, these results suggest that knockdown of HOXA10 combats resistance and that HOXA10 is a potential target for resistant human CML.

  1. Betanin a betacyanin pigment purified from fruits of Opuntia ficus-indica induces apoptosis in human chronic myeloid leukemia Cell line-K562.

    Science.gov (United States)

    Sreekanth, Devalraju; Arunasree, M K; Roy, Karnati R; Chandramohan Reddy, T; Reddy, Gorla V; Reddanna, Pallu

    2007-11-01

    Betalains are water-soluble nitrogenous vacuolar pigments present in flowers and fruits of many caryophyllales with potent antioxidant properties. In the present study the antiproliferative effects of betanin, a principle betacyanin pigment, isolated from the fruits of Opuntia ficus-indica, was evaluated on human chronic myeloid leukemia cell line (K562). The results show dose and time dependent decrease in the proliferation of K562 cells treated with betanin with an IC(50) of 40 microM. Further studies involving scanning and transmission electron microscopy revealed the apoptotic characteristics such as chromatin condensation, cell shrinkage and membrane blebbing. Agarose electrophoresis of genomic DNA of cells treated with betanin showed fragmentation pattern typical for apoptotic cells. Flow cytometric analysis of cells treated with 40 microM betanin showed 28.4% of cells in sub G0/G1 phase. Betanin treatment to the cells also induced the release of cytochrome c into the cytosol, poly (ADP) ribose polymerase (PARP) cleavage, down regulation Bcl-2, and reduction in the membrane potentials. Confocal microscopic studies on the cells treated with betanin suggest the entry of betanin into the cells. These studies thus demonstrate that betanin induces apoptosis in K562 cells through the intrinsic pathway and is mediated by the release of cytochrome c from mitochondria into the cytosol, and PARP cleavage. The antiproliferative effects of betanin add further value to the nutritional characteristics of the fruits of O. ficus-indica.

  2. Carbenoxolone Induces Apoptosis and Inhibits Survivin and Survivin-ΔEx3 Genes Expression in Human Leukemia K562 Cells

    Directory of Open Access Journals (Sweden)

    Z. Sanaat

    2011-12-01

    Full Text Available Background and the purpose of the study: Leukemia is a malignant disorder of the blood progenitor/stem cells which is characterized by abnormal proliferation of white blood cells. Although anti-cancer drugs induce apoptosis in cancerous cells, drug resistance is the significant problem mainly due to over-expression of inhibitors of apoptosis proteins (IAPs such as survivin. In this content, it has been reported that an anti-inflammatory drug, Carbenoxolone (CBX, could induce apoptosis and growth inhibition in several types of cancerous cells. In the present study, effects of CBX on apoptosis and level of the expression of survivin gene and its ΔEx3 splicing variant have were evaluated in K562 cells.Methods: K562 cells were cultured and treated with different concentrations of CBX (50-300 μM at different time intervals (12-48 hrs. Trypan blue exclusion test was used to evaluate cell viability. Fluorescent microscopy (Acridine Orange/Ethidium Bromide double staining and DNA fragmentation assay were used to study apoptosis. The expression level of survivin and its ΔEx3 splice variant were studied by RT- PCR.Results and Major Conclusion: It was found that both growth inhibition and apoptosis occurred in K562 cells. In addition, down-regulation of survivin and survin-ΔEx3 were observed, after 2-4 hrs treatment with 150 μM of CBX. However, the expression level of survivin and its ΔEx3 splice variant increased in subsequent time (6-12 hrs nearly to the level of control cells. From the results of this study, it may be concluded that CBX can be considered as a candidate for further studies in CML treatment, especially in the case of drug- resistant leukemia cells.

  3. Anti-proliferative and apoptotic effects of the derivatives from 4-aryl-4H-chromene family on human leukemia K562 cells.

    Science.gov (United States)

    Aryapour, Hassan; Mahdavi, Majid; Mohebbi, Seyed Reza; Zali, Mohammad Reza; Foroumadi, Alireza

    2012-09-01

    Previous studies suggest that 4-aryl-4H-chromenes are potent apoptosis-inducing agents in various cancer cell lines. In this study, anti-proliferative and apoptotic effects of the derivatives from 4-aryl-4H-chromene family were investigated in the human leukemia K562 cells using [3-(4,5)-dimethyl-2-thiazolyl]-2,5-diphenyl-2H-tetrazolium bromide (MTT) growth inhibition assay. 3-NC was more active among these compounds with IC₅₀ of 65 nM and was selected for further studies. Apoptosis, as the mechanism of cell death, was investigated morphologically by Hoechst 33258 staining, cell surface expression assay of phosphatidylserine by Annexin V/PI technique, caspase-3 activation assay, as well as the formation of DNA ladder. The K562 cells underwent apoptosis upon a single dose (at IC₅₀ value) of the compound, and also increased caspase-3 activity by more than 2.3-fold, following a 72 h treatment. Caspase-9 was also activated which could be detected 48 hours post-treatment. Furthermore, Western blot analysis revealed that the treatment with the compound down-regulated the expression of certain IAP protein, including survivin. These data further suggest that these derivatives from 4-aryl-4H-chromene may provide a novel therapeutic approach for the treatment of leukemia.

  4. Natural and semi-synthetic clerodanes of Croton cajucara and their cytotoxic effects against ehrlich carcinoma and human K562 leukemia cells

    Energy Technology Data Exchange (ETDEWEB)

    Maciel, Maria Aparecida M. [Universidade Federal do Rio Grande do Norte, Natal, RN (Brazil). Dept. de Quimica; Martins, Jenilce R.; Pinto, Angelo C.; Kaiser, Carlos R. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Quimica; Esteves-Souza, Andressa; Echevarria, Aurea [Universidade Federal Rural do Rio de Janeiro, Seropedica, RJ (Brazil). Dept. de Quimica]. E-mail: echevarr@ufrrj.br

    2007-03-15

    The clerodane-type diterpene, trans-dehydrocrotonin (1) the major component of Croton cajucara has shown striking correlation with its therapeutic use in traditional folk medicine. Phytochemical investigations led to the isolation of the metabolites 1, cajucarinolide (6), isocajucarinolide (7), trans-crotonin (2), trans-cajucarin B (3), cis-cajucarin B (4), trans-cajucarin A (5), N-methyltyrosine, vanillic acid and 4-hydroxy-benzoic acid. 6 and 7 were synthesized in good yield by regiospecific oxidation of 1 using singlet-oxygen. All clerodanes were studied for their cytotoxic effects against human K562 leukemia and Ehrlich carcinoma cells. Ehrlich carcinoma assays with IC{sub 50} = 166 {mu}M (1), 164 {mu}M (2), 65 {mu}M (6) and 10 {mu}M (7) related to cell growth inhibitory effects were dose dependent. Furthermore, moderate cytotoxic activity against K562 leukemia cells was observed with IC{sub 50} = 38 {mu}M (3), 33 {mu}M (5), 36 {mu}M (6) and 43 {mu}M (7). The semi-synthetic 2, 6 and 7 showed similar results when compared to the corresponding natural clerodanes. (author)

  5. Quinacrine induces apoptosis in human leukemia K562 cells via p38 MAPK-elicited BCL2 down-regulation and suppression of ERK/c-Jun-mediated BCL2L1 expression

    Energy Technology Data Exchange (ETDEWEB)

    Changchien, Jung-Jung; Chen, Ying-Jung; Huang, Chia-Hui [Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung 804, Taiwan (China); Cheng, Tian-Lu [Department of Biomedical Science and Environmental Biology, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China); Lin, Shinne-Ren [Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China); Chang, Long-Sen, E-mail: lschang@mail.nsysu.edu.tw [Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung 804, Taiwan (China); Department of Biotechnology, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China)

    2015-04-01

    Although previous studies have revealed the anti-cancer activity of quinacrine, its effect on leukemia is not clearly resolved. We sought to explore the cytotoxic effect and mechanism of quinacrine action in human leukemia K562 cells. Quinacrine induced K562 cell apoptosis accompanied with ROS generation, mitochondrial depolarization, and down-regulation of BCL2L1 and BCL2. Upon exposure to quinacrine, ROS-mediated p38 MAPK activation and ERK inactivation were observed in K562 cells. Quinacrine-induced cell death and mitochondrial depolarization were suppressed by the p38MAPK inhibitor SB202190 and constitutively active MEK1 over-expression. Activation of p38 MAPK was shown to promote BCL2 degradation. Further, ERK inactivation suppressed c-Jun-mediated transcriptional expression of BCL2L1. Over-expression of BCL2L1 and BCL2 attenuated quinacrine-evoked mitochondrial depolarization and rescued the viability of quinacrine-treated cells. Taken together, our data indicate that quinacrine-induced K562 cell apoptosis is mediated through mitochondrial alterations triggered by p38 MAPK-mediated BCL2 down-regulation and suppression of ERK/c-Jun-mediated BCL2L1 expression. - Highlights: • Quinacrine induces K562 cell apoptosis via down-regulation of BCL2 and BCL2L1. • Quinacrine induces p38 MAPK activation and ERK inactivation in K562 cells. • Quinacrine elicits p38 MAPK-mediated BCL2 down-regulation. • Quinacrine suppresses ERK/c-Jun-mediated BCL2L1 expression.

  6. Isorhamnetin 3-O-robinobioside from Nitraria retusa leaves enhance antioxidant and antigenotoxic activity in human chronic myelogenous leukemia cell line K562

    Directory of Open Access Journals (Sweden)

    Boubaker Jihed

    2012-08-01

    Full Text Available Abstract Background In this report, the isorhamnetin 3-o-robinobioside and its original extract, the ethyl acetate extract, from Nitraria retusa leaves, were evaluated for their ability to induce antioxidant and antigenotoxic effects in human chronic myelogenous leukemia cell line. Methods Nitraria retusa products properties were carried out by firstly evaluating their effects against lipid peroxidation induced by H2O2, using the thiobarbituric acid reactive substances species (TBARS assay, and proceeding to the assay of cellular antioxidant activity, then doing the comet assay. Results The isorhamnetin 3-o-robinobioside showed a protective effect against lipid peroxidation induced by H2O2. The same natural compound and ethyl acetate extract inhibited oxidation induced by 2,2′-azobis (2-amidinopropane dihydrochloride in human chronic myelogenous leukemia cells with respectively 50% inhibitory concentration values of 0.225 mg/ml and 0.31 mg/ml, reflecting a significant antioxidant potential. The same two products inhibited the genotoxicity induced by hydroxyl radicals in the same human cell line (by 77.77% at a concentration of 800 μg/ml and by 80.55% at a concentration of 1000 μg/ml respectively. Conclusions The isorhamnetin 3- o-robinobioside and its original extract, the ethyl acetate extract, from Nitraria retusa leaves, have a great antioxidant and antigenotoxic potential on human chronic myelogenous leukemia cell line K562.

  7. Identification of coupling DNA motif pairs on long-range chromatin interactions in human K562 cells

    KAUST Repository

    Wong, Ka-Chun

    2015-09-27

    Motivation: The protein-DNA interactions between transcription factors (TFs) and transcription factor binding sites (TFBSs, also known as DNA motifs) are critical activities in gene transcription. The identification of the DNA motifs is a vital task for downstream analysis. Unfortunately, the long-range coupling information between different DNA motifs is still lacking. To fill the void, as the first-of-its-kind study, we have identified the coupling DNA motif pairs on long-range chromatin interactions in human. Results: The coupling DNA motif pairs exhibit substantially higher DNase accessibility than the background sequences. Half of the DNA motifs involved are matched to the existing motif databases, although nearly all of them are enriched with at least one gene ontology term. Their motif instances are also found statistically enriched on the promoter and enhancer regions. Especially, we introduce a novel measurement called motif pairing multiplicity which is defined as the number of motifs that are paired with a given motif on chromatin interactions. Interestingly, we observe that motif pairing multiplicity is linked to several characteristics such as regulatory region type, motif sequence degeneracy, DNase accessibility and pairing genomic distance. Taken into account together, we believe the coupling DNA motif pairs identified in this study can shed lights on the gene transcription mechanism under long-range chromatin interactions. © The Author 2015. Published by Oxford University Press.

  8. Study on the Flavonoid of Huanglian Jiedu Decoction in Reversing MDR of K562/ADM%黄连解毒汤中黄酮成分逆转K562/ADM多药耐药的实验观察

    Institute of Scientific and Technical Information of China (English)

    盛国良; 林潇; 孙付军; 李贵海

    2012-01-01

    目的:观察黄连解毒汤中黄酮成分逆转肿瘤多药耐药的作用,探讨本方逆转肿瘤多药耐药的物质基础.方法:以人慢性粒细胞白血病红白血病细胞株K562的耐阿霉素(adriamycin,ADM)细胞株(K562/ADM)为细胞系,通过MTT实验观察黄芩苷、京尼平苷对K562/ADM细胞ADM的敏感性的影响,计算细胞增殖抑制率、半数抑制浓度(IC50)及耐药逆转倍数,并对细胞内ADM浓度变化进行测定.结果:黄芩苷、京尼平苷均能部分逆转K562/ADM细胞.黄芩苷、京尼平苷的IC50值分别为5.06,6.74 mg·L-1.黄芩苷、京尼平苷的耐药逆转倍数分别为1.95,1.46倍.与相应的对照组相比,K562/ADM细胞经黄芩苷(50 mg·L-1)、京尼平苷(100 mg·L-1)作用后,细胞内ADM的荧光强度高于对照组,其中黄芩苷组提高到3.6%,京尼平苷组提高到1.7%.结论:黄连解毒汤逆转肿瘤多药耐药的物质基础可能与其含有的黄芩苷、京尼平苷有关.%Objective; To observe the effect on the flavoniod of Huanglian Jiedu decoction, and discuss its material base in reversing multiple-drug resistance (MDR) of cancer so as to provide the theory basis for Huanglian Jiedu decoction in clinical practices. Method: MTT assay was adopted to test the sensitivity of baicalin and geniposide to adriamycin ( ADM ) of K562/ADM, the inhibitory rate was calculated, the value of 50% inhibition concentration (IC50) and the multiple of the reversal of drug resistance as well as the change of the concentration of the intracellular ADM were assayed by using ADM K562/ADM of human chronic myelogenous leukemia (CML) erythroleukemia K562 as cell line. Result; Both baicalin and geniposide could partly reverse K562/ADM cell. The value of IC50of baicalin and geniposide was 5. 06 mg - L~ and 6. 74 mg - L-1respectively. The multiple of the reversal of drug resistance of baicalin and geniposide was 1.95 times and 1.46 times. The fluorescence intensity of the intracellular K562/ADM was

  9. 人红白血病细胞株K562上清液对人脐静脉内皮细胞的促增殖作用%Enhancement Effect of K562 Cells Supernatant on Proliferation of Human Umbilical Vein Endothelial Cells

    Institute of Scientific and Technical Information of China (English)

    潘小兵; 曹诗运

    2009-01-01

    目的 研究人红白血病细胞株(K562)上清液对人脐静脉内皮细胞(hUVEC)增殖能力的影响.方法 以hUVEC与K562细胞共培养为K562细胞组,以hUVEC加K562细胞上清液为K562细胞上清液组,以单独培养hUVEC为对照组.采用RT-PCR技术检测各组中hUVEC周期蛋白E(cyclinE)mRNA及周期蛋白依赖性激酶2(CDK2)mRNA的表达情况.结果 K562细胞组、K562细胞上清液组中hUVEC cyclinE mRNA及CDK2 mRNA表达明显增加,与对照组相比差异均有显著性(P<0.01). 结论人白血病肿瘤细胞K562上清液能够促进hUVEC的分裂增殖.

  10. 白血病细胞K562来源的外体对人脐带间充质干细胞作用的研究%Effect of exosomes released from chronic myeloid leukemia K562 cells on human umbilical cord mesenchymal stem cells

    Institute of Scientific and Technical Information of China (English)

    顾建美; 钱晖; 朱伟; 许文荣

    2012-01-01

    目的 探讨白血病细胞株(K562)来源的外体(exosomes)对人脐带间充质干细胞(human umbilical cord mesenchymal stem cells,hucMSCs)的影响.方法 用离心超滤和蔗糖密度梯度超速离心法从K562细胞的培养上清液中分离并纯化exosomes.透射电子显微镜观察其形态;将exosomes与hucMSCs共育,细胞计数板法检测exosomes对hucMSCs增殖的影响;实时荧光定量PCR检测肿瘤相关成纤维细胞(CAFs)相关基因FAP、α-SMA和IL-6的表达;western blot检测exosomes标志性蛋白CD9、CD81及CAFs相关蛋白FAP,α-SMA的表达.结果 透射电镜下观察分离的exosomes呈椭圆或碟状的囊泡结构,直径在30~100 nm;细胞计数板法检测结果表明,不同浓度的exosomes均能抑制hucMSCs细胞增殖且呈剂量依赖性(P均<0.05);荧光定量PCR结果表明,不同浓度的exosomes作用于hucMSCs,其FAP、α-SMA和IL-6表达量明显增加(P均<0.05);western blot 结果表明,exosomes可表达标志性蛋白CD9、CD81,且exosomes作用hucMSCs后FAP、α-SMA蛋白表达量增加.结论 K562细胞来源的exosomes能抑制hucMSCs增殖,且能诱导hucMSCs向CAFs的分化.

  11. Comparative proteomic analysis of differentially expressed proteins between K562 and K562/ADM cells

    Institute of Scientific and Technical Information of China (English)

    SHEN Shao-hua; GU Long-jun; LIU Pei-qing; YE Xin; CHANG Wei-shan; LI Ben-shang

    2008-01-01

    Background Multidrug resistance to chemotherapeutic agents is an important clinical problem during the treatment of leukemia.The resistance process is multifactorial.To realize the totaI factors involved in multidrug resistance,we analyzed the differentially expressed proteins of K562 and K562/ADM cells and we investigated one of the up-regulated proteins(CRKL)using siRNA to determine its role in K562/ADM cells.Methods Altered protein expressions between K562/S(K562 ADM-sensitive cell line)and K562/ADM(K562 multidrug resistant cell line induced by adriamycin)were identified by 2D-DIGE coupled with mass spectrometry. Meanwhile,we confirmed the differential expression of CRKL and Stathmin in both K562 and K562/ADM cells by Western blot analysis.Furthermore,we used RNA interference to silence the CRKL gene expression.Results Among the 9 differentially expressed proteins,3 were up-regulated in K562/ADM cells,while 6 were down-regulated in the K562/ADM cells compared with its parent cell line.The expression of CRKL was up-regulated significantly in K562/ADM cells,and it can be decreased by recombinant lentivirus.Moreover,the multidrug resistance of K562/ADM cells was efficiently reversed by silence of CRKL gene expression.Conclusions The data provided the differentially expressed proteins jn K562 and jts resistant cell line and highlights the power of 2D-DIGE for the discovery of resistance markers in cancer.We found CRKL may be a new protein involved in the multidrug resistanse of leukaemia cells.

  12. In vitro evaluation of the anti-proliferative activities of the wood essential oils of three Cedrus species against K562 human chronic myelogenous leukaemia cells.

    Science.gov (United States)

    Saab, Antoine M; Lampronti, Ilaria; Borgatti, Monica; Finotti, Alessia; Harb, Faouzi; Safi, Samir; Gambari, Roberto

    2012-01-01

    There are four kinds of Cedar: Cedrus libani naturally occurring in Lebanon, Syria and Turkey, Cedrus atlantica in Morocco and Algeria, Cedrus brevefolia in Cyprus Island and Cedrus deodara which is distributed in Himalayan Mountains. Wood essential oils obtained from C. libani, C. atlantica and C. deodara were tested for the inhibition of K562 cell proliferation and for the induction of erythroid differentiation. The wood essential oils of C. libani, C. atlantica and C. deodara inhibited the proliferation of the K562 cell line exhibiting IC(50) values 23.38 ± 1.7, 59.37 ± 2.6 and 37.09 ± 1.4 µg mL(-1), respectively. Meanwhile, C. libani wood oils induced a percentage of erythroid differentiation of 15 ± 2% at concentration 5 µg mL(-1). Cedrus deodara wood oil indicated a percentage of erythroid differentiation of 20 ± 2% at concentration 25 µg mL(-1) and C. atlantica wood oils showed a percentage of erythroid differentiation of 12 ± 1.8% at concentration 10 µg mL(-1).

  13. Apoptosis induced by 3,7-dinitrodibenzobromonium salts in K562 cells

    Institute of Scientific and Technical Information of China (English)

    Ruidong MIAO; Xiaohui XIA; Dongling YANG; Minghua LU; Qin WANG

    2008-01-01

    We evaluated the inhibitory effect of 3,7-dini-trodibenzobromonium salts (cBr) on the proliferation of human chronic myelogenous leukemia K562 cell by trypan blue exclusion test and MTT colorimetric assay.The degree of DNA damage in K562 cells treated with cBr,was detected by isotopic tracer method (3H-TdR).The morphological changes of these K562 cells were examined by fluorescence and electron microscopy.Biochemical characteristics of K562 cells were detected by flow cytome-try and 3H-thymidine incorporation assay.Findings indi-cated that cBr could significantly inhibit cell proliferation and result in DNA damage of K562 cells,cBr is a new type of immunostimulant and can induce cell apoptosis.

  14. Identification of a NF-kB site in the negative regulatory element (εNRAII) of human ε-globin gene and its binding protein NF-κB p50 in the nuclei of K562 cells

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The developmental control of the human ε-globin gene expression is mediated by transcription regulatory elements in the 5' flanking DNA of this gene. Sequence analysis has revealed a DNA motif (GGGGAATTTGCT) similar to NF-κB consensus sequence resides in the negative regulatory element (-3028bp ~ -2902bp, termed ε-NRAII) 5' to the cap site of this gene. NRF DNA fragment (-3010bp ~-2986bp) containing the NF-κB motif similar sequence was synthesized and used in electrophoresis mobility shift assay (EMSA) and competitive analysis. Data showed that a protein factor from nuclear extracts of K562 cells specifically interacted with NRF DNA fragment. The synthetic NF DNA fragment (containing NF-κB consensus sequence) could competed for the protein binding, but MNF DNA fragment (mutated NF-κB motif) could not, suggesting that the binding protein is a member of NF-κB/Rel family. Western blot assay demonstrated that the molecular weight of NF-κB protein in the nuclei of K562 cells is 50ku. We suggested that NF-κB p50 may play an important role in the regulation of human ε-globin gene expression.

  15. Preliminary studies of reversing K562/ADR cell effects of abnormal savda munziq total flavonoids%维药异常黑胆质成熟剂总黄酮逆转K562/ADR细胞株作用机制初步研究

    Institute of Scientific and Technical Information of China (English)

    刘玉; 古丽巴哈·买买提; 严媚; 王学梅

    2016-01-01

    ObjectiveTo probe and analyses whether the abnormal savda munziq total flavonoids (ASMq) has a reverse effect on K562/ADR, the resistant strain to human leukemia doxorubicin. Methods First cultivated K562 and K562/ADR cells, and Chose the cytotoxicity-free dose of ASMq which had a cell inhibition rate less than 10%. Resistance index=IC50(K562/ADR)/IC50(K562)=3.075/ 0.069=44.565 22. Then determined two doses for measuring the reverse multiple. At last, calculated the IC50 of K562, K562/ADR cells and K562/ADR+ASMq cells influenced by ADR.Results IC50(K562)= 0.06, IC50(K562/ADR)=3.075, IC50(K562/ADR+X1)=3.146, IC50(K562/ADR+X2)=3.274. Result fold reversal=IC50(K562/ADR)/IC50(K562/ADR+ASMq). X1 fold reversal=IC50(K562/ADR)/IC50(K562/ ADR+X1)=3.075/3.146=0.977 432, X2 fold reversal=0.939 218. According to the results, the impact of ASMq wasn't evident among the groups.ConclusionsASMq in a small dose doesn’t have an evident impact on reversion of multidrug resistance to K562/ADR. The deeper research need to be done about whether a large dose can make a difference.%目的:探讨维药异常黑胆质成熟剂总黄酮(ASMq)是否对人白血病阿霉素耐药株K562/ADR有逆转作用。方法首先对K562K562/ADR细胞进行培养,选择对K562细胞抑制率<10%的药物浓度为 ASMq 的非细胞毒性剂量,耐药倍数=IC50(K562/ADR)/IC50(K562)=3.075/0.069=44.56522,再确定两个剂量用于逆转倍数的测定(X1,X2)。计算ADR对K562K562/ADR细胞和K562/ADR+ASMq细胞的IC50。结果 IC50(K562)=0.069,IC50(K562/ADR)=3.075, IC50(K562/ADR+X1)=3.146,IC50(K562/ADR+X2)=3.274。逆转倍数=IC50(K562/ADR)/IC50(K562/ADR+ASMq)。X1逆转倍数=IC50(K562/ADR)/IC50(K562/ADR+X1)=3.075/3.146=0.977432,X2逆转倍数=0.939218。由K562K562/ADR、K562/ADR+X1、K562/ADR+X2的IC50和计算出的逆转倍数得出,ASMq在各组之间的作用不明显。结论低剂量的ASMq对K562/ADR

  16. Fangchinoline induces G0/G1 arrest by modulating the expression of CDKN1A and CCND2 in K562 human chronic myelogenous leukemia cells

    Science.gov (United States)

    WANG, YUPING; CHEN, JIE; WANG, LIN; HUANG, YUJI; LENG, YE; WANG, GUIYING

    2013-01-01

    Chronic myeloid leukemia (CML) is a hematopoietic stem cell disease caused by the oncoprotein BCR-ABL, which exhibits a constitutive tyrosine kinase activity. Imatinib mesylate (IM), an inhibitor of the tyrosine kinase activity of BCR-ABL, has been used as a first-line therapy for CML. However, IM is less effective in the accelerated phase and blastic phases of CML and certain patients develop IM resistance due to the mutation and amplification of the BCR-ABL gene. Fangchinoline, an important chemical constituent from the dried roots of Stephaniae tetrandrae S. Moore, exhibits significant antitumor activity in various types of cancers, including breast, prostate and hepatocellular carcinoma. However, the effects and the underlying mechanisms of fangchinoline in CML remain unclear. In the present study, we identified that fangchinoline inhibits cell proliferation in a dose- and time-dependent manner in K562 cells derived from the blast crisis of CML. Additional experiments revealed that fangchinoline induces cell cycle arrest at the G0/G1 phase and has no effect on apoptosis, which is mediated through the upregulation of cyclin-dependent kinase (CDK)-N1A and MCL-1 mRNA levels, as well as the downregulation of cyclin D2 (CCND2) mRNA levels. These findings suggest the potential of fangchinoline as an effective antitumor agent in CML. PMID:23596478

  17. Calcitonin receptor gene expression in K562 chronic myelogenous leukemic cells

    Directory of Open Access Journals (Sweden)

    Pondel Marc D

    2003-04-01

    Full Text Available Abstract Background The peptide hormone calcitonin (CT can significantly effect the proliferation rate of CT receptor (CTR positive human cancer cells. We wish to identify additional human cancers expressing CTRs and assay the effects of CT on their growth rates and signal transduction pathways. Results The expression of the human calcitonin receptor (hCTR gene in the chronic myelogenous leukemia cell line K562 was examined. RT-PCR on total RNA extracted from K562 cells detected the presence of hCTR mRNA. Further analysis demonstrated that multiple hCTR isoforms were present. Incubation of K562 cells with salmon calcitonin (sCT, but not amylin, caused an increase in intracellular levels of cAMP similar to that induced by forskolin treatment. We further demonstrated that butyrate induced erythroid differentiation of K562 cells caused a significant decrease in hCTR mRNA levels. However, phorbol myristate acetate (PMA induced megakaryocytic differentiation of these cells had no significant effect on hCTR mRNA levels. We demonstrated that exposure to various concentrations of sCT had no effect on the cellular proliferation of K562 cells in vitro. Conclusion Chronic myelogenous k562 cells express multiple CTR isoforms. However, CT does not effect K562 proliferation rates. It is likely that the small increase in intracellular levels of cAMP following CT treatment is not sufficient to interfere with cellular growth.

  18. Antiproliferation Effects of Curcumin on the STAT5 Signaling Pathway in K562 Cells

    Institute of Scientific and Technical Information of China (English)

    Yan Chen; Hongli Liu; Weihong Chen

    2005-01-01

    OBJECTIVE Curcumin is the major component of the spice turmeric and the yellow pigment in curry powder. Many studies have shown that curcumin (diferuloylmethane) has significant antiproliferative and apoptotic effects in cancer cells by several mechanisms. Signal transducers and activators of transcription (STAT) proteins are critical in mediating a response in hematopoietic cells. This study was designed to investigate whether curcumin is associated with proteins involved in signal transduction and activation of transcription (STAT) and to investigate the expression of signal transducers and activators of transcription and the significance of the STAT5 signalingpathway of by treating k562 cells and cells from CML patients with curcumin.METHODS The study was divided into the following groups: normal control cells (human bone marrow cells), untreated K562 cells, curcumin treated K562 cells, IFN-γ treated K562 cells, curcumin plus IFN-γ treated K562cells, and CML patient cells with and without curcumin treatment. Cell proliferation was measured by the MTT assay. The expression of STAT5 mRNA was determined by RT-PCR. The expression of the STAT5 protein was assayed by Western-blotting and the expression of STAT5 in K562 cells was examined under confocal laser-scanning microscopy. The expression of STAT5 mRNA of K562 cells was determined with in situ hybridization. EMSA was used to assess the change in binding of STAT5 with DNA in CML patient cells.RESULTS The proliferation of the K562 cells and CML primary cells was decreased in the curcumin-treated group and/or IFN-γ group. The expression of STAT5 mRNA and protein were decreased the curcumin-treated group as compared with the K562 untreated group (P<0.01). STAT5 mRNA and protein expression was decreased in the IFN-γ group compared to the untreated K562 group (P<0.01). Combined use of curcumin with IFN-γ inhibited the proliferation of K562 cells and decreased the expression of STAT5mRNA and protein of the K562

  19. JNK1/c-Jun and p38 alpha MAPK/ATF-2 pathways are responsible for upregulation of Fas/FasL in human chronic myeloid leukemia K562 cells upon exposure to Taiwan cobra phospholipase A2.

    Science.gov (United States)

    Chen, Ku-Chung; Chiou, Yi-Ling; Chang, Long-Sen

    2009-10-15

    Fas and FasL expression upregulation was found in human leukemia K562 cells upon exposure to Naja naja atra phospholipase A(2) (PLA(2)). PLA(2) treatment induced an increase in intracellular Ca(2+) ([Ca(2+)]i) and ROS generation levels, leading to activation of p38 MAPK and JNK. Suppression of both p38 MAPK and JNK abrogated Fas and FasL upregulation. Unlike PLA(2), catalytically inactive PLA(2) treatment did not markedly increase Fas and FasL protein expression, and p38 MAPK activation was exclusively responsible for catalytically inactive PLA(2)-induced increase in Fas and FasL protein expression. Knockdown of p38 alpha MAPK and JNK1 by siRNA proved that p38 alpha MAPK and JNK1 were involved in ATF-2 and c-Jun phosphorylation, respectively. Compared with the p38 alpha MAPK/ATF-2 pathway, the JNK1/c-Jun pathway played a crucial role in Fas/FasL upregulation. Unlike arachidonic acid, lysophosphatidylcholine mimicked the PLA(2) action in inducing Fas/FasL upregulation. Together with the previous finding that c-Jun and ATF-2 are involved in transcriptional regulation of Fas and FasL, our data suggest that PLA(2) induces Fas and FasL upregulation through p38 alpha MAPK/ATF-2 and JNK1/c-Jun pathways in K562 cells, and PLA(2) catalytic activity is involved in this action. (c) 2009 Wiley-Liss, Inc.

  20. siRNA沉默Ikaros基因对K562细胞中γ珠蛋白表达的影响

    Institute of Scientific and Technical Information of China (English)

    马艳; 李冉; 吴新忠; 胡珺; 曾玉

    2012-01-01

    @@ 地中海贫血,即β珠蛋白合成障碍性贫血,简称地贫,是一种单基因缺陷的遗传性疾病,它是由于β珠蛋白多肽链合成减少或缺失,α链与非α链(β、γ、δ)之间不平衡所导致的以红细胞无效生成为特征的血红蛋白病.重型β-地贫常常有严重的临床症状,多采取规则的输血及祛铁治疗,但大多数病人最终还是死于铁过载相关的心脏疾病,平均寿命不满20岁[1].%To interfere the Ikaros gene with siRNA, and observe the expression of y-globin in K562 human erythroleukemia cells. Method, Three siRNA-Ikaros(siRNAl,siRNA2 and siRNA3) were designed and transacted to K562 cells by Lipolectamine 2000. The optimal siRNA se-quence of Ikaros gene silencing was screened by semiquantitative RT-PCR analysis. Real-time quantitative PCR and Western blotting mehtods were used to detect the expression of Ikaros and y-globin mRNA and protein levels alter Ikaros gene silencing. Hemoglobin content of the K562 cells were detected by using benzidine staining method. Results, The transaction rate of K562 cells by the Lipolectamine 2000 could reach up to 58. 7%. SiRNA3 could effectively interfere the expression of Ikaros gene, and the inhibited efficiency could reach up to 86. 7%. SiRNA3 could enhance the expression of y-globin and the hemoglobin content of K562 cells. Conclusion; SiRNA3 can interfere the expression of Ikaros and en-

  1. Mortalin inhibitors sensitize K562 leukemia cells to complement-dependent cytotoxicity.

    Science.gov (United States)

    Pilzer, David; Saar, Moran; Koya, Keizo; Fishelson, Zvi

    2010-03-15

    Mortalin, the mitochondrial hsp70, is a vital constitutively expressed heat shock protein. Its elevated expression has been correlated with malignant transformation and poor cancer prognosis. Cancer cells exhibit increased resistance to complement-dependent cytotoxicity, partly due to their capacity to eliminate the complement membrane attack complex (MAC) from their cell surface. As we have previously reported, mortalin and the complement membrane attack complexes are released in membrane vesicles from complement attacked cells. As shown here, knock down of mortalin with specific siRNA reduces MAC elimination and enhances cell sensitivity to MAC-induced cell death. Similar results were obtained with MKT-077, a cationic rhodacyanine dye that inhibits mortalin. Treatment of human erythroleukemia K562 and colorectal carcinoma HCT116 cells with MKT-077 sensitizes them to cell death mediated by MAC but not by streptolysin O. Pre-treatment of cells with MKT-077 also reduces the extent of MAC-mortalin vesiculation following a sublytic complement attack. In the presence of MKT-077, the direct binding of mortalin to complement C9, the major MAC component, is inhibited. The tumor suppressor protein p53 is a known mortalin client protein. The effect of MKT-077 on complement-mediated lysis of HCT116 p53(+/+) and p53(-/-) cells was found to be independent on the presence of p53. Our results also demonstrate that recombinant human mortain inhibits complement-mediated hemolysis of rabbit erythrocytes as well as zinc-induced C9 polymerization. We conclude that mortalin supports cancer cell resistance to complement-dependent cytotoxicity and propose consideration of mortalin as a novel target for cancer adjuvant immunotherapy.

  2. Study of the mechanism on the apoptosis induced in Human leukemia cell line K562 by the combination of indole-3-acetic acid and horseradish peroxidase

    Institute of Scientific and Technical Information of China (English)

    宋土生; 杨玲; 黄辰; 刘利英; 倪磊; 王爱英; 罗禹

    2007-01-01

    Indole-3-acetic acid(IAA)is an i mportant typeof the plant growth hor mone found in higherplants,and participate inthe regulation of plant celldivision,elongation and differentiation.It is pres-ent in human urine,blood plas ma and central nerv-ous system.IAAis well tolerated in human and isnot oxidized by mammalian peroxidase.Recent re-searches suggest that the combination of IAA andhorseradish peroxidase(HRP)is cytotoxic to mam-malian cells,and could be used as a novel cancertherapy[1-3],while neither IAAn...

  3. [Ginsenoside Rh₂ induces apoptosis and autophagy of K562 cells by activating p38].

    Science.gov (United States)

    Liu, Xiao-Xia; Xia, Jing; Tang, Jia-Feng; Zhou, Ming-Hua; Chen, Di-Long; Liu, Ze-Hong

    2017-01-01

    To study the effect of ginseng saponin Rh₂ in inducing apoptosis of human leukemia K562 cells, and explore its mechanism from the aspect of autophagy pathway. CCK-8 assay was used to examine the growth inhibition of human leukemia cell lines K562 treated with ginsenoside Rh₂; flow cytometry (FCM) was used to detect cell apoptosis; Hoechst staining was used to observe the changes of cell morphological apoptosis; Acridine and MDC staining were used to detect the effects of the Rh₂ on autophagy; Western blot and RT-PCR were used to detect the expression levels of the proteins closely associated with autophagy and apoptosis. In order to study the effect of autophagy in proliferation and apoptosis, we used the autophagy inhibitor (3-MA).CCK-8 indicated that Rh₂ at low concentration could effectively inhibit the proliferation of leukemia cellsin dose- and time-dependent manners in K562 cells; FCM indicated that Rh₂ induced apoptosis; Hoechest staining showed that K562 cells had typical apoptotic morphological changes by treated Rh₂; Acridine and MDC staining showed that Rh₂ enhanced the green fluorescence and a large number of acidic autophagy vesicles were present; Western blot and RT-PCR results showed that Rh₂ increased the expression levels of Beclin-1, LC3A, LC3B, activated Caspase-3 and p-p38 in K562 cells; application of autophagy inhibitors(3-MA) could weaken the inhibition effect of Rh₂ on proliferation and induction effect on apoptosis in K562 cells. Ginsenoside Rh₂ inhibited the proliferation and induced apoptosis probably through activating p-p38, and inducing cell autophagy signaling pathway in K562 cells. Copyright© by the Chinese Pharmaceutical Association.

  4. BME, a novel compound of anthraquinone, down regulated P-glycoprotein expression in doxorubicin-resistant human myelogenous leukemia (K562/DOX) cells via generation of reactive oxygen species.

    Science.gov (United States)

    Wang, Jianhong; Liu, Lu; Cen, Juan; Ji, Biansheng

    2015-09-01

    P-glycoprotein (P-gp)-mediated multidrug resistance (MDR) in tumor cells is still a main obstacle for the chemotherapeutic treatment of cancers. Thus, development of effective MDR reversing agents is an important approach in the clinic. The present study revealed that BME, a novel compound of anthraquinone, elevated intracellular accumulation of the P-gp substrates and reduced concentration resulting in 50% inhibition of cell growth (IC50) values for doxorubicin (DOX) in doxorubicin-resistant human myelogenous leukemia (K562/DOX) cells. Further more, BME was also reported to down regulated P-gp expression accompanying with generation of nontoxic low level of intracellular reactive oxygen species (iROS) and activation of extracellular signal-regulated kinase (ERK)1/2 as well as c-JUN N-terminal kinase (JNK). However, treatment with N-acetyl-cysteine (NAC), U0216 and SP600125 almost abolished actions of the BME mentioned above. These results indicated that the effect of the BME on the P-gp may be involved in generation of nontoxic low level of iROS and activation of ERK1/2 or JNK, which suggested valuable clues to screen and develop P-gp reversing agents.

  5. Binding and endocytosis of monoterbium transferrin by K562 cells

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Using isotopic labeling of human serum apotransferrin, the binding and the endocytosis of monoterbium transferrin (TbC-apotransferrin, TbC-apotransferrin- FeN) by K562 cells, a human leukemic cell line, have been investigated. There are about (8.58±2.41)×105 binding sites per cell surface at 0℃. The association constant for TbC-apo- transferrin binding is 4.1×107 mol-1@L, for TbC-apo- transferrin-FeN 2.7×107 mol-1@L at 0℃. At pH 7.4, upon warming cells to 37℃, endocytosis starts. The rate constants for the endocytosis are about 0.97 min-1 and 0.31 min-1 and the endocytosis ratio reaches 56% and 80% for TbC-apo- transferrin and TbC-apotransferrin-FeN, respectively.

  6. In vitro radiosensitivity of human leukemia cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Weichselbaum, R.R.; Greenberger, J.S.; Schmidt, A.; Karpas, A.; Moloney, W.C.; Little, J.B.

    1981-05-01

    The in vitro radiobiologic survival values (anti n, D/sub 0/) of four tumor lines derived from human hematopoietic tumors were studied. These cell lines were HL60 promyelocytic leukemia; K562 erythroleukemia; 45 acute lymphocytic leukemia; and 176 acute monomyelogenous leukemia. More cell lines must be examined before the exact relationship between in vitro radiosensitivity and clinical radiocurability is firmly established.

  7. SIRT1 is a critical regulator of K562 cell growth, survival, and differentiation.

    Science.gov (United States)

    Duncan, Mark T; DeLuca, Teresa A; Kuo, Hsin-Yu; Yi, Minchang; Mrksich, Milan; Miller, William M

    2016-05-15

    Inhibition of histone deacetylases (HDACi) has emerged as a promising approach in the treatment of many types of cancer, including leukemias. Among the HDACs, Class III HDACs, also known as sirtuins (SIRTs), are unique in that their function is directly related to the cell's metabolic state through their dependency on the co-factor NAD(+). In this study, we examined the relation between SIRTs and the growth, survival, and differentiation of K562 erythroleukemia cells. Using a mass spectrometry approach we previously developed, we show that SIRT expression and deacetylase activity in these cells changes greatly with differentiation state (undifferentiated vs. megakaryocytic differentiation vs. erythroid differentiation). Moreover, SIRT1 is crucially involved in regulating the differentiation state. Overexpression of wildtype (but not deacetylase mutant) SIRT1 resulted in upregulation of glycophorin A, ~2-fold increase in the mRNA levels of α, γ, ε, and ζ-globins, and spontaneous hemoglobinization. Hemin-induced differentiation was also enhanced by (and depended on) higher SIRT1 levels. Since K562 cells are bipotent, we also investigated whether SIRT1 modulation affected their ability to undergo megakaryocytic (MK) differentiation. SIRT1 was required for commitment to the MK lineage and subsequent maturation, but was not directly involved in polyploidization of either K562 cells or an already-MK-committed cell line, CHRF-288-11. The observed blockage in commitment to the MK lineage was associated with a dramatic decrease in the formation of autophagic vacuoles, which was previously shown to be required for K562 cell MK commitment. Autophagy-associated conversion of the protein LC3-I to LC3-II was greatly enhanced by overexpression of wildtype SIRT1, further suggesting a functional connection between SIRT1, autophagy, and MK differentiation. Based on its clear effects on autophagy, we also examined the effect of SIRT1 modulation on stress responses. Consistent

  8. Changes of Proliferation and Apoptosis of K562 Cells after Co-culture with Leukemia Bone Marrow Mesenchymal Stem Cells

    Institute of Scientific and Technical Information of China (English)

    Katja Karjalainen; Carlos E Bueso-Ramos; Hagop M Kantarjian

    2014-01-01

    Objective:To compare the changes of proliferation and apoptosis of K562 cells after co-culture with human leukemia bone marrow mesenchymal stem cells (LMSC). Methods: The prepared cells were randomly divided into SCG group, SCG+0%FBS group, SCG+0%FBS group and CCG+0%FBS group. Cell counting kit-8 (CCK-8) analytic approach was adopted to detect the optical density (OD) of K562 cells in SCG and CCG groups, and the conditions of K562 cell proliferation under different cultured circumstances were compared. Flow cytometer (FCM) was used to detect the changes of K562 cell cycle after co-culture with LMSC, Annexin V/polyimide (PI) lfuorescence labeling method to detect the changes of K562 cell apoptosis after co-culture with LMSC and serum starvation. Results:After co-culture with LMSC, the proliferation of K562 cells was markedly inhibited, and OD in CCG group was conspicuously lower than that in SCG group. Flow cytometer (FCM) detection on cell cycles demonstrated that after co-culture with LMSC, the proportion of cells in gap phases 0~1 (G0~G1) went up notably, whereas that in phase S went down obviously. Besides, the proportion of cells in phases G2~M was on the rise. K562 cell apoptosis in CCG+0%FBS group was more than in SCG+10%FBS group, and less than in SCG+0%FBS group, indicating LMSC had the function of resisting leukemia cell apoptosis. Conclusion: LMSC exerts the effect of inhibiting the proliferation by blocking K562 cell cycles in phases G0~G1, and inhibiting K562 cell apoptosis induced by serum starvation.

  9. Changes of Proliferation and Apoptosis of K562 Cells after Co-culture with Leukemia Bone Marrow Mesenchymal Stem Cells

    Directory of Open Access Journals (Sweden)

    Katja Karjalainen

    2014-06-01

    Full Text Available Objective: To compare the changes of proliferation and apoptosis of K562 cells after co-culture with human leukemia bone marrow mesenchymal stem cells (LMSC. Methods: The prepared cells were randomly divided into SCG group, SCG + 0%FBS group, SCG + 0%FBS group and CCG + 0%FBS group. Cell counting kit-8 (CCK-8 analytic approach was adopted to detect the optical density (OD of K562 cells in SCG and CCG groups, and the conditions of K562 cell proliferation under different cultured circumstances were compared. Flow cytometer (FCM was used to detect the changes of K562 cell cycle after co-culture with LMSC, Annexin V/polyimide (PI fluorescence labeling method to detect the changes of K562 cell apoptosis after co-culture with LMSC and serum starvation. Results: After co-culture with LMSC, the proliferation of K562 cells was markedly inhibited, and OD in CCG group was conspicuously lower than that in SCG group. Flow cytometer (FCM detection on cell cycles demonstrated that after co-culture with LMSC, the proportion of cells in gap phases 0 - 1 (G0 - G1 went up notably, whereas that in phase S went down obviously. Besides, the proportion of cells in phases G2 - M was on the rise. K562 cell apoptosis in CCG + 0%FBS group was more than in SCG + 10%FBS group, and less than in SCG + 0%FBS group, indicating LMSC had the function of resisting leukemia cell apoptosis. Conclusion: LMSC exerts the effect of inhibiting the proliferation by blocking K562 cell cycles in phases G0 - G1, and inhibiting K562 cell apoptosis induced by serum starvation.

  10. The fusarin analogue NG-391 impairs nucleic acid formation in K-562 leukemia cells

    Science.gov (United States)

    The clavicipitaceous fungus Metarhizium robertsii produces the fusarin-like mycotoxin NG-391. We report on the biological effects of NG-391 on K-562 human cancer cells, obtained with radionuclide incorporation assays, along with nucleosome release and caspase assays, respectively. Our data suggests ...

  11. NEW DESIGNED HMBA AGENTS AS INDUCERS OF ERYTHROLEUKEMIA CELL DIFFERENTIATION

    Institute of Scientific and Technical Information of China (English)

    王华力; 张世馥; 周建平; 章静波

    2002-01-01

    Objective.Searching for more potent and less toxic HMBA related agents. Methods.Human erythroleukemia cell K562,murine erythroleukemia cell (MEL) and its sub line MEL DS19 were used as target cells to select a cell line which is the most sensitive to HMBA,then analyzed the activity of inducing differentiation of two new designed HMBA derivatives:HMBPA [hexamethylenebi (3 pyridin) amide] and Co HDTA (ethylenediaminetetra acetic acid cobalt) using cell biology,cytochemical and molecular biology techniques. Results.We found that the MEL DS19 cells were most sensitive to HMBA (benzidine positive,B+ ~76% ).Co HDTA can inhibit the growth of MEL DS19,but induces differentiation just in a small population (B+ 2% ~4.5% ).Between 0.02~5μ mol/L,HMBPA induces 3% ~8% cells committed to differentiation with little inhibition of cell proliferation.1μ mol/L HMBPA and 2mmol/L HMBA together,can obviously increase the percentage of differentiated cell (B+ ~72% ),inhibit DNA synthesis and accelerate β globin transcription. Conclusion.The new HMBA derivatives may provide potential cancer differentiation inducers.

  12. Erythroleukemia cells acquire an alternative mitophagy capability.

    Science.gov (United States)

    Wang, Jian; Fang, Yixuan; Yan, Lili; Yuan, Na; Zhang, Suping; Xu, Li; Nie, Meilan; Zhang, Xiaoying; Wang, Jianrong

    2016-04-19

    Leukemia cells are superior to hematopoietic cells with a normal differentiation potential in buffering cellular stresses, but the underlying mechanisms for this leukemic advantage are not fully understood. Using CRISPR/Cas9 deletion of the canonical autophagy-essential gene Atg7, we found that erythroleukemia K562 cells are armed with two sets of autophagic machinery. Alternative mitophagy is functional regardless of whether the canonical autophagic mechanism is intact or disrupted. Although canonical autophagy defects attenuated cell cycling, proliferation and differentiation potential, the leukemia cells retained their abilities for mitochondrial clearance and for maintaining low levels of reactive oxygen species (ROS) and apoptosis. Treatment with a specific inducer of mitophagy revealed that the canonical autophagy-defective erythroleukemia cells preserved a mitophagic response. Selective induction of mitophagy was associated with the upregulation and localization of RAB9A on the mitochondrial membrane in both wild-type and Atg7(-/-) leukemia cells. When the leukemia cells were treated with the alternative autophagy inhibitor brefeldin A or when the RAB9A was knocked down, this mitophagy was prohibited. This was accompanied by elevated ROS levels and apoptosis as well as reduced DNA damage repair. Therefore, the results suggest that erythroleukemia K562 cells possess an ATG7-independent alternative mitophagic mechanism that functions even when the canonical autophagic process is impaired, thereby maintaining the ability to respond to stresses such as excessive ROS and DNA damage.

  13. Implication of unfolded protein response in resveratrol-induced inhibition of K562 cell proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Bao-Qin; Gao, Yan-Yan; Niu, Xiao-Fang [Department of Biochemistry and Molecular Biology, China Medical University, Shenyang 110001 (China); Xie, Ji-Sheng [Youjiang Medical College for Nationalities, Guangxi 533000 (China); Meng, Xin; Guan, Yifu [Department of Biochemistry and Molecular Biology, China Medical University, Shenyang 110001 (China); Wang, Hua-Qin, E-mail: wanghq_doctor@hotmail.com [Department of Biochemistry and Molecular Biology, China Medical University, Shenyang 110001 (China)

    2010-01-01

    Resveratrol (RES), a natural plant polyphenol, is an effective inducer of cell cycle arrest and apoptosis in a variety of carcinoma cell types. In addition, RES has been reported to inhibit tumorigenesis in several animal models suggesting that it functions as a chemopreventive and anti-tumor agent in vivo. The chemopreventive and chemotherapeutic properties associated with resveratrol offer promise for the design of new chemotherapeutic agents. However, the mechanisms by which RES mediates its effects are not yet fully understood. In this study, we showed that RES caused cell cycle arrest and proliferation inhibition via induction of unfolded protein response (UPR) in human leukemia K562 cell line. Treatment of K562 cells with RES induced a number of signature UPR markers, including transcriptional induction of GRP78 and CHOP, phosphorylation of eukaryotic initiation factor 2{alpha} (eIF2{alpha}), ER stress-specific XBP-1 splicing, suggesting the induction of UPR by RES. RES inhibited proliferation of K562 in a concentration-dependent manner. Flow cytometric analyses revealed that K562 cells were arrested in G1 phase upon RES treatment. Salubrinal, an eIF2{alpha} inhibitor, or overexpression of dominant negative mutants of PERK or eIF2{alpha}, effectively restored RES-induced cell cycle arrest, underscoring the important role of PERK/eIF2{alpha} branch of UPR in RES-induced inhibition of cell proliferation.

  14. Homoharringtonine induces apoptosis of endothelium and down-regulates VEGF expression of K562 cells

    Institute of Scientific and Technical Information of China (English)

    叶琇锦; 林茂芳

    2004-01-01

    Homoharringtonine (HHT) has currently been used successfully in the treatment of acute and chronic myeloid leukemias and has been shown to induce apoptosis of different types of leukemic cells in vitro. Emerging evidence suggests that angiogenesis may play an important role in hematological malignancies, such as leukemia. However, whether HHT can relieve leukemia by anti-angiogenesis is still unknown. We investigated the anti-angiogenesis potential of HHT with the human umbilical vein endothelial cell line (ECV304) and leukemic cell line (K562) in vitro. Cellular proliferation was determined by MTT assay and apoptosis was analyzed by flow cytometry, The mRNA expression of vascular endothelial growth factor (VEGF) was assessed by RT-PCR and VEGF protein production was detected by Western blot. Inhibition of cell proliferation and induction of apoptosis by HHT were discovered in ECV304 cells, and appeared in a dose- and time-dependent manner, Also, treatment with HHT caused down-regulation of VEGF mRNA expression in K562 cells in similar dose- and time-dependent manner and inhibition of VEGF protein production in K562 cells in response to the enhancing concentration of HHT. The results demonstrated that HHT could also induce apoptosis in endothelium and down-regulate VEGF expression in K562 cells. In conclusion, we believe HHT has anti-angiogenesis potential and speculate that HHT might exert its anti-leukemia effects via reduction of angiogenesis.

  15. Signal transduction factors on the modulation of radiosusceptibility in K562 cells

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Kwang Mo; Jeong, Soo Jin [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Youn, Seon Min [College of Medicine, Eulji Univ., Daejeon (Korea, Republic of)

    2003-09-01

    The human chronic myelogenous leukemia cell line, K562, expresses the chimeric bcr-abl oncoprotein, whose deregulated protein tyrosine kinase activity antagonizes the induction of apoptosis via DNA damaging agents. Previous experiments have shown that nanomolar concentrations of herbimycin A [HMA] coupled with X-irradiation have a synergistic effect in inducing apoptosis in the Ph-positive K562 leukemia cell line, but genistein, a PTK inhibitor, is non selective for the radiation-induced apoptosis of p210{sup bcr}/{sup abl} protected K562 cells. In these experiments, the cytoplasmic signal transduction pathways, the induction of a number of transcription factors and the differential gene expression in this model were investigated. K562 cells in the exponential growth phase were used in this study. The cells were irradiated with 0.5-12 Gy, using a 6 MeV Linac (Clinac 1800, Varian, USA). Immediately after irradiation, the cells were treated with 0.25{mu}M of HMA and 25{mu}M of genistein, and the expressions and the activities of ablkinase, MAPK family, NF-KB, c-fos, c-myc, and thymidine kinase1 (TK1) were examined. The differential gene expressions induced by PTK inhibitors were also investigated. The modulating effects of herbimycin A and genistein on the radiosensitivity of K562 cells were not related to the bcr-abl kinase activity. The signaling responses through the MAPK family of proteins, were not involved either. In association with the radiation-induced apoptosis, which is accelerated by HMA, the expression of c-myc was increased. The combined treatment of genistein, with irradiation, enhanced NF-KB activity and the TK 1 expression and activity. The effects of HMA and genistein on the radiosensitivity of the K562 cells were not related to the bcr-abl kinase activity. In this study, another signaling pathway, besides the MAPK family responses to radiation to K562 cells, was found. Further evaluation using this model will provide valuable information for the

  16. trans,trans-2,4-decadienal: cytotoxicity and effect on glutathione level in human erythroleukemia (HEL) cells.

    Science.gov (United States)

    Nappez, C; Battu, S; Beneytout, J L

    1996-01-19

    The effects of trans,trans-2,4-decadienal (DDE), an isomer of a lipid peroxidation product were investigated on the human erythroleukemia cell line (HEL TIB 180). DDE strongly inhibits cell growth and affects cell viability without any differentiating effects. DDE treatment of HEL cells leads to a marked variation of the cellular glutathione level (GSH) and is involved in the beginning of DNA fragmentation.

  17. Piceatannol bolsteres fetal haemoglobin formation in K562 cells via p38 map kinase activation and ERK inactivation

    Directory of Open Access Journals (Sweden)

    AAYUSH KUKREJA

    2015-08-01

    Full Text Available Elevation of the level of fetal haemoglobin (HbF by pharmacological agents is a safe and a promising approach for treating beta thalassemia. In this study, the effect of piceatannol was studied in human erythroleukemic K562 cells for their role in gamma-globin mRNA and HbF induction. The role of p38 mitogen activated protein kinase (MAPK and extracellular regulated protein kinase (ERK signaling pathways were also examined. It was found that piceatannol significantly increased gamma-globin mRNA and HbF levels in dose and time dependent manner in K562 cells. This was determined by enzyme linked immunosorbent assay (ELISA and western blot analysis. Pretreatment with p38 MAPK inhibitor (SB203580 obstructed the stimulatory effect of piceatannol in total and HbF activation. In contrast, no change in HbF level was observed in K562 cells when treated with ERK inhibitor (PD98059. Moreover, piceatannol activated p38 MAPK and inhibited ERK signaling pathways in K562 cells as shown by western blot analysis. Besides, the inhibitor SB203580 inhibited p38 MAPK activation when cells were pre-treated with piceatannol. In summary, piceatannol was found to be a strong inducer of HbF production in K562 cells. The results mark the role of p38 MAPK and ERK signaling as molecular targets for stimulation of HbF synthesis upon treatment with piceatannol.

  18. Lapatinib induces autophagy, apoptosis and megakaryocytic differentiation in chronic myelogenous leukemia K562 cells.

    Directory of Open Access Journals (Sweden)

    Huey-Lan Huang

    Full Text Available Lapatinib is an oral, small-molecule, dual tyrosine kinase inhibitor of epidermal growth factor receptors (EGFR, or ErbB/Her in solid tumors. Little is known about the effect of lapatinib on leukemia. Using human chronic myelogenous leukemia (CML K562 cells as an experimental model, we found that lapatinib simultaneously induced morphological changes resembling apoptosis, autophagy, and megakaryocytic differentiation. Lapatinib-induced apoptosis was accompanied by a decrease in mitochondrial transmembrane potential and was attenuated by the pancaspase inhibitor z-VAD-fmk, indicating a mitochondria-mediated and caspase-dependent pathway. Lapatinib-induced autophagic cell death was verified by LC3-II conversion, and upregulation of Beclin-1. Further, autophagy inhibitor 3-methyladenine as well as autophagy-related proteins Beclin-1 (ATG6, ATG7, and ATG5 shRNA knockdown rescued the cells from lapatinib-induced growth inhibition. A moderate number of lapatinib-treated K562 cells exhibited features of megakaryocytic differentiation. In summary, lapatinib inhibited viability and induced multiple cellular events including apoptosis, autophagic cell death, and megakaryocytic differentiation in human CML K562 cells. This distinct activity of lapatinib against CML cells suggests potential for lapatinib as a therapeutic agent for treatment of CML. Further validation of lapatinib activity in vivo is warranted.

  19. HJC, a new arylnaphthalene lignan isolated from Justicia procumbens, causes apoptosis and caspase activation in K562 leukemia cells.

    Science.gov (United States)

    Luo, Jiaoyang; Kong, Weijun; Yang, Meihua

    2014-01-01

    The aim of this study is to investigate whether HJC, isolated from Justicia procumbens for the first time, can suppress the proliferation and induce apoptosis of human leukemia K562 cells and finally clarify its related mechanism. The chemical structure of HJC was validated by LC-ESI-MS/MS, cytotoxicity was assayed using MTT, and apoptosis was investigated by flow cytometry. These assays indicated that HJC remarkably inhibited the growth in K562 cells by decreasing cell proliferation, reducing the SOD activity, enhancing ROS levels and inducing apoptosis. Activation of caspase-3 indicated that HJC may be inducing intrinsic and extrinsic apoptosis pathways and that HJC-induced apoptosis was caspase-dependent. This study suggests that HJC is a high-potency anti-tumor agent, and it induces apoptosis through a caspase-dependent pathway in human leukemia K562 cells. It also presents a potential alternative to leukemia therapy.

  20. Sonic Hedgehog activation is implicated in diosgenin-induced megakaryocytic differentiation of human erythroleukemia cells.

    Science.gov (United States)

    Ghezali, Lamia; Liagre, Bertrand; Limami, Youness; Beneytout, Jean-Louis; Leger, David Yannick

    2014-01-01

    Differentiation therapy is a means to treat cancer and is induced by different agents with low toxicity and more specificity than traditional ones. Diosgenin, a plant steroid, is able to induce megakaryocytic differentiation or apoptosis in human HEL erythroleukemia cells in a dose-dependent manner. However, the exact mechanism by which diosgenin induces megakaryocytic differentiation has not been elucidated. In this study, we studied the involvement of Sonic Hedgehog in megakaryocytic differentiation induced by diosgenin in HEL cells. First, we showed that different elements of the Hedgehog pathway are expressed in our model by qRT-PCR. Then, we focused our interest on key elements in the Sonic Hedgehog pathway: Smoothened receptor, GLI transcription factor and the ligand Sonic Hedgehog. We showed that Smoothened and Sonic Hedgehog were overexpressed in disogenin-treated cells and that GLI transcription factors were activated. Then, we showed that SMO inhibition using siSMO or the GLI antagonist GANT-61, blocked megakaryocytic differentiation induced by diosgenin in HEL cells. Furthermore, we demonstrated that Sonic Hedgehog pathway inhibition led to inhibition of ERK1/2 activation, a major physiological pathway involved in megakaryocytic differentiation. In conclusion, our study reports, for the first time, a crucial role for the Sonic Hedgehog pathway in diosgenin-induced megakaryocytic differentiation in HEL cells.

  1. BET bromodomain inhibition rescues erythropoietin differentiation of human erythroleukemia cell line UT7

    Energy Technology Data Exchange (ETDEWEB)

    Goupille, Olivier [CEA, Institute of Emerging Diseases and Innovative Therapies, Fontenay-aux-Roses (France); UMR INSERM U.962, University Paris XI, CEA, Fontenay-aux-Roses (France); Penglong, Tipparat [CEA, Institute of Emerging Diseases and Innovative Therapies, Fontenay-aux-Roses (France); UMR INSERM U.962, University Paris XI, CEA, Fontenay-aux-Roses (France); Thalassemia Research Center and Department of Clinical Pathology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University (Thailand); Lefevre, Carine; Granger, Marine; Kadri, Zahra [CEA, Institute of Emerging Diseases and Innovative Therapies, Fontenay-aux-Roses (France); UMR INSERM U.962, University Paris XI, CEA, Fontenay-aux-Roses (France); Fucharoen, Suthat [Thalassemia Research Center and Department of Clinical Pathology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University (Thailand); Maouche-Chretien, Leila [CEA, Institute of Emerging Diseases and Innovative Therapies, Fontenay-aux-Roses (France); UMR INSERM U.962, University Paris XI, CEA, Fontenay-aux-Roses (France); Leboulch, Philippe [CEA, Institute of Emerging Diseases and Innovative Therapies, Fontenay-aux-Roses (France); UMR INSERM U.962, University Paris XI, CEA, Fontenay-aux-Roses (France); Genetics Division, Department of Medicine, Brigham and Women' s Hospital and Harvard Medical School, Boston, MA (United States); Chretien, Stany, E-mail: stany.chretien@cea.fr [CEA, Institute of Emerging Diseases and Innovative Therapies, Fontenay-aux-Roses (France); UMR INSERM U.962, University Paris XI, CEA, Fontenay-aux-Roses (France)

    2012-12-07

    Highlights: Black-Right-Pointing-Pointer UT7 erythroleukemia cells are known to be refractory to differentiate. Black-Right-Pointing-Pointer Brief JQ1 treatment initiates the first steps of erythroid differentiation program. Black-Right-Pointing-Pointer Engaged UT7 cells then maturate in the presence of erythropoietin. Black-Right-Pointing-Pointer Sustained JQ1 treatment inhibits both proliferation and erythroid differentiation. -- Abstract: Malignant transformation is a multistep process requiring oncogenic activation, promoting cellular proliferation, frequently coupled to inhibition of terminal differentiation. Consequently, forcing the reengagement of terminal differentiation of transformed cells coupled or not with an inhibition of their proliferation is a putative therapeutic approach to counteracting tumorigenicity. UT7 is a human leukemic cell line able to grow in the presence of IL3, GM-CSF and Epo. This cell line has been widely used to study Epo-R/Epo signaling pathways but is a poor model for erythroid differentiation. We used the BET bromodomain inhibition drug JQ1 to target gene expression, including that of c-Myc. We have shown that only 2 days of JQ1 treatment was required to transitory inhibit Epo-induced UT7 proliferation and to restore terminal erythroid differentiation. This study highlights the importance of a cellular erythroid cycle break mediated by c-Myc inhibition before initiation of the erythropoiesis program and describes a new model for BET bromodomain inhibitor drug application.

  2. Sonic Hedgehog activation is implicated in diosgenin-induced megakaryocytic differentiation of human erythroleukemia cells.

    Directory of Open Access Journals (Sweden)

    Lamia Ghezali

    Full Text Available Differentiation therapy is a means to treat cancer and is induced by different agents with low toxicity and more specificity than traditional ones. Diosgenin, a plant steroid, is able to induce megakaryocytic differentiation or apoptosis in human HEL erythroleukemia cells in a dose-dependent manner. However, the exact mechanism by which diosgenin induces megakaryocytic differentiation has not been elucidated. In this study, we studied the involvement of Sonic Hedgehog in megakaryocytic differentiation induced by diosgenin in HEL cells. First, we showed that different elements of the Hedgehog pathway are expressed in our model by qRT-PCR. Then, we focused our interest on key elements in the Sonic Hedgehog pathway: Smoothened receptor, GLI transcription factor and the ligand Sonic Hedgehog. We showed that Smoothened and Sonic Hedgehog were overexpressed in disogenin-treated cells and that GLI transcription factors were activated. Then, we showed that SMO inhibition using siSMO or the GLI antagonist GANT-61, blocked megakaryocytic differentiation induced by diosgenin in HEL cells. Furthermore, we demonstrated that Sonic Hedgehog pathway inhibition led to inhibition of ERK1/2 activation, a major physiological pathway involved in megakaryocytic differentiation. In conclusion, our study reports, for the first time, a crucial role for the Sonic Hedgehog pathway in diosgenin-induced megakaryocytic differentiation in HEL cells.

  3. Short communication: Antiproliferative effect of 8 different Lactobacillus strains on K562 cells.

    Science.gov (United States)

    Tuo, Yanfeng; Jiang, Shujuan; Qian, Fang; Mu, Guangqing; Liu, Peng; Guo, Yuanji; Ma, Changlu

    2015-01-01

    Some strains of Lactobacillus genus have antiproliferative activities against cancer cells. However, until now, the exact effector molecules of Lactobacillus strains with anticancer activity have not been identified. The aim of the present study was to explore which fraction of the Lactobacillus cells exerts the highest antiproliferative effect. For this purpose, the heat-killed bacterial cells, bacterial cell wall extract, and genomic DNA of 8 Lactobacillus strains were prepared to assess their antiproliferative activities against human myeloid leukemia cell lines K562. The heat-killed bacterial cells of the 8 lactobacilli strains exerted antiproliferative effect on K562 cells, and the inhibition rates exerted by the heat-killed bacterial cells of the strains G15AL, M5AL, SB31AL, SB5AL, and T3AL were significantly higher than those exerted by the cell walls and genomic DNA of the strains. The bacterial DNA of G15AL exerted higher antiproliferative effect on K562 cells. The exact effector molecules and the effect mechanism of the strains should be further explored for the application of these strains as probiotic strains or bioactive probiotic molecules.

  4. Cytotoxicity of calotropin is through caspase activation and downregulation of anti-apoptotic proteins in K562 cells.

    Science.gov (United States)

    Wang, Shih-Chung; Lu, Mei-Chin; Chen, Hsiu-Lin; Tseng, Hsing-I; Ke, Yu-Yuan; Wu, Yang-Chang; Yang, Pei-Yu

    2009-12-01

    Calotropin is one of cardenolides isolated from milkweed used for medicinal purposes in many Asian countries. Whereas calotropin possesses cytotoxicity against several cancer cells, the mechanisms of action remain unclear. We set out to evaluate the cytotoxic mechanism of calotropin on human chronic myeloid leukemia K562 cells. Calotropin inhibited the growth of K562 cells in a time- and dose-dependent manner by G(2)/M phase arrest. It upregulated the expression of p27 leading to this arrest by downregulating the G2/M regulatory proteins, cyclins A and B, and by upregulating the cdk inhibitor, p27. Furthermore, it downregulated anti-apoptotic signaling (XIAP and survivin) and survival pathways (p-Akt and NFkappaB), leading to caspase-3 activation which resulted in the induction of apoptosis. In all, calotropin exerted its anticancer activity on K562 cells by modulating the pro-survival signaling that leads to induction of apoptosis.

  5. Kefir induces apoptosis and inhibits cell proliferation in human acute erythroleukemia.

    Science.gov (United States)

    Jalali, Fatemeh; Sharifi, Mohammadreza; Salehi, Rasoul

    2016-01-01

    Acute erythroleukemia is an uncommon subtype of acute myeloid leukemia which has been considered to be a subtype of AML with a worse prognosis. Intensive chemotherapy is the first line of treatment. In recent years, the effect of kefir on some malignancies has been experimented. Kefir is a kind of beverage, which obtained by incubation of kefir grains with raw milk. Kefir grains are a symbiotic complex of different kinds of yeasts and bacteria, especially lactic acid bacteria which gather in a mostly carbohydrate matrix, named kefiran. We investigated the effect of kefir on acute erythroleukemia cell line (KG-1) and peripheral blood mononuclear cells (PBMCs). The cell line and PBMCs were treated with different doses of kefir and milk and incubated for three different times. We used Polymixin B to block the lipopolysaccharide and NaOH (1 mol/l) to neutralize the acidic media. Viability was detected by MTT assay. Apoptosis and necrosis were assessed by annexin-propidium iodide staining. Our results showed that kefir induced apoptosis and necrosis in KG-1 cell line. It was revealed that kefir decreased proliferation in erythroleukemia cell line. We did not observe a remarkable effect of kefir on PBMCs. Our study suggested that kefir may have potential to be an effective treatment for erythroleukemia.

  6. File list: NoD.Bld.20.AllAg.K-562 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available NoD.Bld.20.AllAg.K-562 hg19 No description Blood K-562 ERX593133,ERX378356,SRX31877...2,DRX041639,DRX041641,ERX593131,DRX041640,DRX041642,SRX318771 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/NoD.Bld.20.AllAg.K-562.bed ...

  7. Cyclopamine and jervine induce COX-2 overexpression in human erythroleukemia cells but only cyclopamine has a pro-apoptotic effect

    Energy Technology Data Exchange (ETDEWEB)

    Ghezali, Lamia; Leger, David Yannick; Limami, Youness [Université de Limoges, FR 3503 GEIST, EA 1069 “Laboratoire de Chimie des Substances Naturelles”, GDR CNRS 3049, Faculté de Pharmacie, Laboratoire de Biochimie et Biologie Moléculaire, 2 rue du Docteur Marcland, 87025 Limoges Cedex (France); Cook-Moreau, Jeanne [Université de Limoges, FR 3503 GEIST, UMR CNRS 7276 “Contrôle de la réponse immune B et lymphoproliférations”, Faculté de Médecine, 2 rue du Docteur Marcland, 87025 Limoges Cedex (France); Beneytout, Jean-Louis [Université de Limoges, FR 3503 GEIST, EA 1069 “Laboratoire de Chimie des Substances Naturelles”, GDR CNRS 3049, Faculté de Pharmacie, Laboratoire de Biochimie et Biologie Moléculaire, 2 rue du Docteur Marcland, 87025 Limoges Cedex (France); Liagre, Bertrand, E-mail: bertrand.liagre@unilim.fr [Université de Limoges, FR 3503 GEIST, EA 1069 “Laboratoire de Chimie des Substances Naturelles”, GDR CNRS 3049, Faculté de Pharmacie, Laboratoire de Biochimie et Biologie Moléculaire, 2 rue du Docteur Marcland, 87025 Limoges Cedex (France)

    2013-04-15

    Erythroleukemia is generally associated with a very poor response and survival to current available therapeutic agents. Cyclooxygenase-2 (COX-2) has been described to play a crucial role in the proliferation and differentiation of leukemia cells, this enzyme seems to play an important role in chemoresistance in different cancer types. Previously, we demonstrated that diosgenin, a plant steroid, induced apoptosis in HEL cells with concomitant COX-2 overexpression. In this study, we investigated the antiproliferative and apoptotic effects of cyclopamine and jervine, two steroidal alkaloids with similar structures, on HEL and TF1a human erythroleukemia cell lines and, for the first time, their effect on COX-2 expression. Cyclopamine, but not jervine, inhibited cell proliferation and induced apoptosis in these cells. Both compounds induced COX-2 overexpression which was responsible for apoptosis resistance. In jervine-treated cells, COX-2 overexpression was NF-κB dependent. Inhibition of NF-κB reduced COX-2 overexpression and induced apoptosis. In addition, cyclopamine induced apoptosis and COX-2 overexpression via PKC activation. Inhibition of the PKC pathway reduced both apoptosis and COX-2 overexpression in both cell lines. Furthermore, we demonstrated that the p38/COX-2 pathway was involved in resistance to cyclopamine-induced apoptosis since p38 inhibition reduced COX-2 overexpression and increased apoptosis in both cell lines. - Highlights: ► Cyclopamine alone but not jervine induces apoptosis in human erythroleukemia cells. ► Cyclopamine and jervine induce COX-2 overexpression. ► COX-2 overexpression is implicated in resistance to cyclopamine-induced apoptosis. ► Apoptotic potential of jervine is restrained by NF-κB pathway activation. ► PKC is involved in cyclopamine-induced apoptosis and COX-2 overexpression.

  8. The venom of the spider Macrothele raveni induces apoptosis in the myelogenous leukemia K562 cell line.

    Science.gov (United States)

    Liu, Zhonghua; Zhao, Yan; Li, Jing; Xu, Shiyan; Liu, Changjun; Zhu, Yanghui; Liang, Songping

    2012-08-01

    Spider venoms are a rich source of bioactive compounds with therapeutic potential. In traditional Chinese medicine, spiders and spider venoms have been used in the treatment of various ailments. In the present study, the venom of the spider Macrothele raveni potently suppressed cell growth in the myelogenous leukemia K562 cell line in a dose and time-dependent manner with an IC(50) of 5.1 μg/mL. The venom also had a low inhibitory effect on human lymphocytes with an IC(50) of approximately 36.4 μg/mL, indicating that the venom is relatively selective for leukemic cells. Venom treated K562 cells showed typical morphological indicators of apoptosis including condensation of nuclei and fragmentation of DNA. Annexin V-FITC and propidium iodide dual staining further demonstrated that the venom had potent apoptogenic activity. Venom treatment induced caspase 3 and caspase 8 activation in K562 cells and promoted PARP cleavage. The present results indicate that the venom of the spider M. raveni potently and selectively suppresses the growth of K562 cells by inducing apoptosis via caspase 3 and caspase 8 mediated signaling pathways.

  9. Effect of ATRA on the expression of HOXA5 gene in K562 cells and its relationship with cell cycle and apoptosis.

    Science.gov (United States)

    Liu, Wen-Jun; Zhang, Teng; Guo, Qu-Lian; Liu, Chun-Yan; Bai, Yong-Qi

    2016-05-01

    Leukemia is the most common malignant disease in children with high incidence and mortality rates, and a poor treatment effect. The aim of the present study was to examine the changes in the expression of homeobox (Hox) A5 gene and its relationship with cell cycle and apoptosis through the intervention of human K562 myeloid leukemia cell line by all-trans retinoic acid (ATRA), to analyze the role of HOXA5 in the pathogenesis and development process of myeloid leukemia. The optimal concentration of ATRA to be used with K562 cells was determined using a cell counting kit‑8 (CCK‑8). After 24, 72 and 48 h following treatment of K562 cells with 10 µmol/l ATRA, cell cycle events and apoptosis were measured using flow cytometry. HOXA5 mRNA and protein expression in K562 cells was assessed by RT‑PCR and western blot analysis, and the relationship between HOXA5 expression and cell cycle and apoptosis was analyzed. The HOXA5 mRNA and protein expression levels were increased following treatment with ATRA in K562 cells. Apoptosis was increased significantly. The cell cycle was inhibited in G0/G1 phase. Cell proliferation was also inhibited. HOXA5 mRNA and protein expression rates positively correlated with cell apoptosis and the increased percentage and cell cycle of the G0/G1 phase. However, HOXA5 negatively correlated with the reduced percentage of S stage. In conclusion, the expression of HOXA5 in cells was increased following treatment with ATRA in K562 cells, in a time-dependent manner. Additionally, ATRA may inhibit the proliferation of K562 cells and promote apoptosis by upregulating the HOXA5 mRNA and protein expression.

  10. 盐酸千金藤碱逆转K562/ADR细胞多药耐药性及其机制%Correlation between reversing effect of cepharanthine hydrochloride on multidrug resistance and P-glycoprotein expression and function of K562/ADR cells

    Institute of Scientific and Technical Information of China (English)

    彭有梅; 王宁; 王亚峰; 韩立; 张艳; 江金花; 周玉冰; 王庆端

    2012-01-01

    研究盐酸千金藤碱(cepharanthine hydrochloride,CH)逆转K562/ADR细胞多药耐药性及其机制.采用MTT法检测多柔比星(adriamycin,ADR)单用及分别与CH、维拉帕米(verapamil,VER)合用的细胞毒作用;采用流式细胞仪,测定CH对细胞内ADR蓄积、罗丹明123 (Rho123)蓄积和泵出及P糖蛋白(P-gp)表达的影响.结果表明,CH(4 μmol·L-1)使K562/ADR细胞对ADR的敏感性增加7.43倍,逆转活性是VER的3.19倍,但对K562敏感株基本无影响.同时CH浓度依赖性地增加K562/ADR细胞内ADR和Rho123的蓄积,减少Rho123的泵出,抑制P糖蛋白的表达,但对K562细胞均无明显影响.CH在体外逆转肿瘤细胞多药耐药性的作用可能与其抑制P糖蛋白的功能和表达有关.%In this study, cepharanthine hydrochloride (CH) was tested for its potential ability to modulate the expression and function of P-glycoprotein (P-gp) in the multidmg-resistant human chronic myelogenous leukemia cell line K562/ADR. Cytotoxicity of adriamycin (ADR) alone or in combination with CH or verapamil (VER) in K562 and K562/ADR cells was determined by MTT assay. Based on flow cytometric technology, the effect of CH or VER on the uptake and efflux of rhodaminel23 (Rhol23) and the accumulation of ADR in these cells was detected by measuring Rhol23 or ADR-associated mean fluorescence intensity (MFI). The effects of CH and VER on P-glycoprotein (P-gp) expression in K562 and K562/ADR cells were also measured using a flow cytometry with PE-conjugated P-glycoprotein antibody. The results show that CH significantly enhanced the sensitivity of K562/ADR cells to ADR, 4 μmol·L"1 of CH enhanced the sensitivity of K562/ADR cells to ADR by 7.43 folds, the reversal activity was 3.19 times higher than that of verapamil. However, CH had no effect on drug-sensitive K562 cells (P < 0.05). CH increased Rhol23 and ADR accumulation in a concentration-dependent manner (2-8 umol·L-1) and inhibited the efflux of Rhol23 from these cells, but

  11. Comparison of microRNA expression profiles in K562-cells-derived microvesicles and parental cells, and analysis of their roles in leukemia.

    Science.gov (United States)

    Chen, Xiaomei; Xiong, Wei; Li, Huiyu

    2016-12-01

    Microvesicles (MVs) are 30-1,000-nm extracellular vesicles that are released from a multitude of cell types and perform diverse cellular functions, including intercellular communication, antigen presentation, and transfer of proteins, messenger RNA and microRNA (also known as miR). MicroRNAs have been demonstrated to be aberrantly expressed in leukemia, and the overall microRNA expression profile may differentiate normal blood cells vs. leukemia cells. MVs containing microRNAs may enable intercellular cross-talk in vivo. This prompted us to investigate specific variations of microRNA expression patterns in MVs derived from leukemia cells. The present study examined the microRNA expression profile of MVs from chronic myeloid leukemia K562 cells and that of MVs from normal human volunteers' peripheral blood cells. The potential targets of the differentially expressed microRNAs were predicted using computational searches. Bioinformatic analyses of the predicted target genes were performed for further evaluation. The present study analyzed microRNAs of MVs derived from leukemia and normal cells, and characterized specific microRNAs expression. The results revealed that MVs derived from K562 cells expressed 181 microRNAs of the 888 microRNAs assessed. Further analysis revealed that 16 microRNAs were downregulated, while 7 were upregulated in these MVs. In addition, significant differences in microRNA expression profiles between MVs derived from K562 cells and K562 cells were identified. The present results revealed that 77 and 122 microRNAs were only expressed in MVs derived from K562 cells and in K562 cells, respectively. There were 104 microRNAs co-expressed in MVs derived from K562 cells and in K562 cells. Target gene-related pathway analyses demonstrated that the majority of the dysregulated microRNAs were involved in pathways associated with leukemia, particularly the mitogen-activated protein kinase (MAPK) and the p53 signaling pathways. By further conducting

  12. Radioimmunoassay of haemoglobin F in K 562 cells following induction with renin substrate and erythropoietin

    Energy Technology Data Exchange (ETDEWEB)

    Rosenloef, K.; Fyhrquist, F.; Hortling, L.; Groenhagen-Riska, C. (Helsinki Univ. (Finland). Minerva Inst. for Medical Research; Helsinki Univ. (Finland). 4th Dept. of Medicine)

    1985-06-01

    To test the hypothesis of renin substrate (RS: angiotensinogen) being a precursor of erythropoietin (EP), the capacity of RS and EP to induce Hb synthesis was compared in cultured human erythroid leukaemia cells of the K 562 line after prestimulation with haemin. For this purpose a radioimmunoassay for haemoglobin F (HbF) was developed. This assay was shown to be specific for HbF, reproducible, and sensitive for 0.1 ng of HbF. The cells were induced by RS and EP to increased HbF production. Cells stimulated with RS or EP showed increased benzidine staining. These data support the hypothesis that renin substrate is a likely precursor of erythropoietin.

  13. Pentamidine sensitizes chronic myelogenous leukemia K562 cells to TRAIL-induced apoptosis.

    Science.gov (United States)

    Qiu, Geng; Jiang, Jikai; Liu, Xiao-shan

    2012-11-01

    Pentamidine (PMD) is an anti-protozoa drug with potential anticancer activity. Here we show that PMD at clinically achievable plasma drug concentrations slightly inhibited the growth of human leukemia cell lines. PMD close to its therapeutic doses sensitized TRAIL-resistant K562 cells to the cytokine and potentiated TRAIL-induced apoptosis through activation of caspase-8 and -3. When we investigated the underlying mechanism, we observed that treatment with PMD increased DR5 expression at both mRNA and protein levels and down-regulated anti-apoptotic XIAP and Mcl-1 protein levels. This study provides a rationale for a more in-depth exploration into the combined treatment with PMD and TRAIL as a valuable strategy for leukemia therapy.

  14. Cytotoxic and apoptotic effects of different extracts of Artemisia biennis Willd. on K562 and HL-60 cell lines

    Directory of Open Access Journals (Sweden)

    Zahra Tayarani-Najaran

    2017-02-01

    Full Text Available Objective(s: Artemisia is a genus of herbs and small shrubs forms an important part of natural vegetation in Iran. It has been reported that several Artemisia species possess anti-proliferative effects. Considering the value of this genus in anti-cancer researches we have chosen Artemisia biennis for cytotoxic and mechanistic studies. Materials and Methods:In this study we have investigated the cytotoxic and apoptotic effects of petroleum ether, dichloromethane, ethyl acetate, ethanol, and ethanol:water (1:1 v/v extracts of A. biennis Willd. on two cancer human cell lines (K562 and HL-60 and J774 as normal cells. Results: CH2Cl2 extract was found to have the highest anti-proliferative effect on cancer cells. IC50 values obtained in AlamarBlue® assay for CH2Cl2 extract were 64.86 and 54.31 µg/ml on K562 and HL-60 cells respectively. In flow cytometry histogram of the cells treated with CH2Cl2 extract, sub-G1 peak was induced. DNA fragmentation, increased in the level of Bax and cleavage of PARP protein all showed the induction of apoptosis with CH2Cl2 extract after 48 hr contact with cells. Conclusion: The results can corroborate the cytotoxic and apoptotic effects of the CH2Cl2 extract of A. biennis on the K562 and HL-60 cancer cell lines.

  15. Screening and characterization of aptamers of chronic myelognous leukemia K562 cells%慢性髓细胞性白血病K562细胞适体的筛选与鉴定

    Institute of Scientific and Technical Information of China (English)

    刘玲玲; 韩跃武; 祝凯华; 李真真; 韩亚萍; 路艳; 王春霞

    2009-01-01

    目的:筛选并鉴定出慢性髓细胞性白血病(CML)K562细胞的寡核苷酸适体.方法:体外合成长度为88个碱基的随机单链DNA(ssDNA)文库,采用生物素-链霉亲和素磁珠法制备次级文库,以正常人血液中提取的中性粒细胞为反筛细胞,利用指数富集的配基系统进化(SELEX)技术筛选出与CML K562细胞特异结合的适体.将筛选得到的适体回收纯化后连接pGEM-T质粒载体,经蓝白筛选后,随机挑选24个克隆子进行序列测定.采用荧光标记引物法检测ssDNA文库与K562细胞的亲和力,并用Clustal 2.05和DNA sis V 2.5软件对适体序列进行一级结构同源性分析和二级结构预测.结果:经过13轮循环筛选,CML K562细胞适体的A值从0.12上升到1.25,至第13轮A值无明显增高.一级结构分析无同源序列,但可分为6个家族,其中5个家族各自具有保守序列,家族6无保守序列.二级结构分析表明,适体形成的茎环、凸环结构可能是与K562细胞特异性结合的结构基础.结论:利用SELEX技术成功筛选出高亲和性的CML K562细胞适体.%AIM: To screen and characterize oligonucleotide aptamers of chronic myelognous leukemia K562 cells. METHODS: Oligonucleotide aptamers specifically binding to chronic myelog-nous leukemia K562 cells were screened from 88 nt random ssDNA library in vitro syntbesis by SELEX method, sub-library was prepared by biotin-streptavidin magnetic beads and neutro-phils from blood of normal humans were used as anti-sieve cells. The screened aptamters were purified and connected to pGEM-T plasmid vector and 24 clones of random aelection were sequenced after screening by the blue and white. The affinities of the screened aptamers binding to chronic myelognous leukemia K562 cells were detected by fluorescent primers. Homology analyses of the primary structure and secondary structure prediction to the screened aptamters were conducted with Clustal 2.05 and DNA sis V 2.5 software. RESULTS: After

  16. The effect of PG to the expression of p170 on the K562/ADR cells%裴氏升血颗粒含药血清对K562/ADR细胞p170表达的影响

    Institute of Scientific and Technical Information of China (English)

    吴玉强; 薛文翰

    2015-01-01

    目的:观察裴氏升血颗粒(PG)含药血清对人白血病细胞株K562/ADR细胞p170蛋白表达水平的影响。方法:采用MTT法测定不同浓度含药血清对K562细胞系的细胞毒作用,用流式细胞仪检测非细胞毒性浓度含药血清处理后K562/ADR细胞膜表面p170表达变化。结果:不同浓度含药血清对K562/ADR细胞无明显细胞毒作用,非细胞毒性含药血清能明显下调K562/ADR细胞p170蛋白的表达。结论:裴氏升血颗粒能够提高化疗疗效,其机制可能与下调p170蛋白表达有关。%Objective:To investigate the effect of PG herbal serum to the expression level of p170 protein on the human leukemia K562/ADR cells. Methods: Testing the cytotoxic effect of different herbal serum to K562/ADR cells line by MTT method, using Flow cytometry to determine the expressive and functional changes of p170 on K562/ADR cells membrane dealed with the herbal serum at non-cytotoxic concentration. Results:Different herbal serum had no obvious cytotoxic effect to K562/A02 cells, non-cytotoxic concentration of herbal serum can significantly lowered the expression of p170 protein on the K562/ADR cells. Conclusion: PG could improve the curative effect of chemotherapy, and its mechanism may be related to descend the expression of p170.

  17. Changes of gene expression profile in homoharringtonine-induced leukemia multi-drug resistant cell line K562/HHT%高三尖杉酯碱诱导的白血病耐药细胞基因表达谱的变化

    Institute of Scientific and Technical Information of China (English)

    于晓林; 刘永; 陈春燕; 王涓冬; 孔德晓

    2009-01-01

    目的 探讨高三尖杉酯碱(HHT)诱导的人白血病细胞耐药相关分子.方法 在前期建立的HHT诱导的人白血病多药耐药细胞株K562/HHT的基础上,采用基因芯片技术比较K562/HHT细胞、其亲本K562细胞以及用耐药逆转剂米非司酮(RU486)作用后的K562/HHT(K562/HHT/RU486)细胞三者基因表达谱的差异,选择在这三种细胞中呈动态变化的骨髓细胞X染色体上酪氨酸激酶(BMX)基因用RT-PCR和Western blot法在转录和翻译水平进行验证,进而转染BMX基因到K562K562/HHT细胞,观察BMX过表达时这两种细胞内柔红霉素(DNR)含量的变化,确定BMX是否在K562/HHT细胞耐药形成中发挥作用.结果 耐药细胞K562/HHT与其亲本K562细胞相比,共有117个基因表达有显著差异,其中57个基因表达明显上调,60个基因表达明显下调,耐药细胞K562/HHT中多药耐药基因mdr1表达明显上调;K562/HHT/RU486细胞与K562/HHT细胞相比,13个基因表达明显上调,37个基因表达明显下调.这些差异表达的基因涉及耐药、细胞信号传导、细胞分化、细胞增殖、转录调节以及离子转运等.基因NM-001721(BMX)、NM-031459(SESN2)、NM-033642(FGF13)和AL 049309(SFRS12)在两组芯片中的表达均有显著差异.其中BMX基因在K562/HHT细胞中的表达与K562细胞相比,明显上调,在K562/HHT/RU486细胞则较K562/HHT细胞减低.进一步用RT-PCR和Western blot法检测得到了相同的结果.RT-PCR和Western blot证实BMX质粒转染的K562K562/HHT细胞BMX表达均上调,流式细胞术检测到K562K562/HHT细胞内DNR含量荧光强度分别为79.28±4.04和29.84±2.67,均较转染前荧光强度158.52±8.08和58.58±6.53显著减低.结论 BMX在高三尖杉酯碱诱导的人白血病多药耐药细胞株K562/HHT耐药性产生中发挥作用.%Objective To study the resistant related molecules of human leukemia drug resistant K562 cells(K562/HHT) induced by homoharringtonine (HHT). Methods Gene

  18. ZM-66, a New Podophyllotoxin Derivative Inhibits Proliferation and Induces Apoptosis in K562/ADM Cells

    Institute of Scientific and Technical Information of China (English)

    Ling Li; Hong-jie Li; Jian-sheng zhi; Hong Chen; Wen-li Xie

    2014-01-01

    Objective To investigate the anti-tumor effect of ZM-66 on multidrug-resistant leukemic cell line K562/ADM. Methods The K562/ADM cells were treated with varying concentrations (0, 1, 2, 4×10-3 mmol/L) of ZM-66 or etoposide for 24 hours. The proliferation was detected by Sulforhodamine B Sodium Salt (SRB) assay and apoptosis was detected by flow cytometry analysis and fluorescent staining. In addition, the expression levels of p53 and bax genes in K562/ADM cells were detected by RT-PCR analysis. The level of P-glycoprotein (P-gp), P53 and Bax protein in K562/ADM cells were detected by Western blot assay. Results SRB assay demonstrated that etoposide had little inhibitory effect on K562/ADM cells, whereas ZM-66 (1, 2, 4×10-3 mmol/L) had significantly inhibitory effect on K562/ADM cells (all P Conclusion ZM-66 is able to induce cell death by apoptosis in vitro, as a result of the reverse of the apoptosis resistance in drug-resistant K562/ADM cells by modulating expression of key factors associated with apoptosis induction.

  19. Differential impact of bortezomib on HL-60 and K562 cells.

    Science.gov (United States)

    Kliková, Katarína; Štefaniková, Andrea; Pilchová, Ivana; Hatok, Jozef; Chudý, Peter; Chudej, Juraj; Dobrota, Dušan; Račay, Peter

    2015-01-01

    Bortezomib (PS-341, or Velcade), reversible inhibitor of 20S proteasome approved for the treatment of multiple myeloma and mantle cell lymphoma, exhibited a cytotoxic effect toward other malignancies including leukaemia. In this study, we have documented that incubation of both HL-60 and K562 leukaemia cells with nanomolar concentrations of bortezomib is associated with the death of HL-60 cells observed within 24 hours of incubation with bortezomib and the death of K562 cells that were observed after 72 hours of incubation with bortezomib. The relative resistance of K562 cells to bortezomib correlated well with significantly higher expression of HSP27, HSP70, HSP90α, HSP90β and GRP75 in these cells. Incubation of both HL-60 and K562 cells with bortezomib induced a cleavage of HSP90β as well as expression of HSP70 and HSP90β but bortezomib did not affect levels of HSP27, HSP90α, GRP75 and GRP78. The death of both types of cells was accompanied with proteolytic activation of caspase 3 that was observed in HL-60 cells and proteolytic degradation of procaspase 3 in K562 cells. Our study has also pointed to essential role of caspase 8 in bortezomib-induced cleavage of HSP90β in both HL-60 and K562 cells. Finally, we have shown that bortezomib induced activation of caspase 9/caspase 3 axis in HL-60 cells, while the mechanism of death of K562 cells remains unknown.

  20. Berberine-induced apoptosis via decreasing the survivin protein in K562 cell line.

    Science.gov (United States)

    Pazhang, Yaghub; Ahmadian, Shahin; Mahmoudian, Massoud; Shafiezadeh, Mahshid

    2011-12-01

    Berberine is an isoquinoline alkaloid with multiple pharmacological activities, including anti-inflammatory and anti-diarrhea effect, the induction of apoptosis and anti-cancer effect. It has been reported that berberine exerts its anti-inflammatory effect via suppressing nuclear factor-kappa B (NF-κB) expression. Survivin and inducible nitric oxide synthase (iNOS) proteins may contribute to the causal relationship between anti-inflammatory and anti-apoptotic function. To investigate the mechanism of berberine-induced apoptotic activities, the human erythro-myeloblastoid leukemia cell line (K562 cell line) was treated with different concentrations of berberine (25-100 μM). The most significant cellular growth arrest and apoptotic effects were observed in the cells treated with 75 μM of berberine for 72 h. The results indicate that survivin and iNOS protein levels were decreased in berberine-treated cells. However, decrease in the iNOS activity did not affect the cell growth and apoptosis. Moreover, the addition of NO donor, sodium nitroprusside, to culture medium decreased the cell growth in the present cell line, but it seemed that its concentration was too low to induce apoptosis. So despite its production by iNOS in untreated cells, NO does not play a significant role in carcinogenesis in this cell line. These results indicate that the apoptotic activity of berberine may be mediated through the reduction of survivin in K562 cells, but iNOS level and its activity does not play a significant role in berberine-induced apoptosis.

  1. Human platelet/erythroleukemia cell prostaglandin G/H synthase: cDNA cloning, expression, and gene chromosomal assignment

    Energy Technology Data Exchange (ETDEWEB)

    Funk, C.D.; Funk, L.B.; Kennedy, M.E.; Pong, A.S.; Fitzgerald, G.A. (Vanderbilt Univ., Nashville, TN (United States))

    1991-06-01

    Platelets metabolize arachidonic acid to thromboxane A{sub 2}, a potent platelet aggregator and vasoconstrictor compound. The first step of this transformation is catalyzed by prostaglandin (PG) G/H synthase, a target site for nonsteroidal antiinflammatory drugs. We have isolated the cDNA for both human platelet and human erythroleukemia cell PGG/H synthase using the polymerase chain reaction and conventional screening procedures. The cDNA encoding the full-length protein was expressed in COS-M6 cells. Microsomal fractions from transfected cells produced prostaglandin endoperoxide derived products which were inhibited by indomethacin and aspirin. Mutagenesis of the serine residue at position 529, the putative aspirin acetylation site, to an asparagine reduced cyclooxygenase activity to barely detectable levels, an effect observed previously with the expressed sheep vesicular gland enzyme. Platelet-derived growth factor and phorbol ester differentially regulated the expression of PGG/H synthase mRNA levels in the megakaryocytic/platelet-like HEL cell line. The PGG/H synthase gene was assigned to chromosome 9 by analysis of a human-hamster somatic hybrid DNA panel. The availability of platelet PGG/H synthase cDNA should enhance our understanding of the important structure/function domains of this protein and it gene regulation.

  2. INHIBITION OF APOPTOSIS BY bcr-abl FUSION GENE IN K562 CELLS

    Institute of Scientific and Technical Information of China (English)

    WANG Chun-hong; SUN Bing-zhong; YUAN Yue-chuan

    1999-01-01

    Objective: To investigate the effect of bcr-abl fusion gene on CML cell apoptosis. Methods: Apoptosis of exvivo cultured K562 cells were observed after exposure to synthetic 18 mer antisense oligodeoxynucleotide complementary to the bcr-abl junction (b3a2). Results: Apoptosis of K562 cells was significantly increased associated with inhibition of bcr-abl expression. Conclusion: bcr-abl fusion gene formation due to chromosome translocation may be the major mechanism of CML via inhibition of apoptosis.

  3. Effects of arsenic trioxide on the methylation of TMS1 gene in K562 cells

    Institute of Scientific and Technical Information of China (English)

    李洪丽

    2014-01-01

    Objective To detect the methylation status of TMS1gene and its demethylation by arsenic trioxide(As2O2)in K562 cells.Methods K562 cells were treated with different concentrations of As2O2for 48 hours.Methylationspecific PCR(MSP)was used to determine the methylation status of TMS1.RT-PCR and Western blot were used to detect the levels of TMS1 mRNA and protein.

  4. Increased cyclooxygenase-2 and thromboxane synthase expression is implicated in diosgenin-induced megakaryocytic differentiation in human erythroleukemia cells.

    Science.gov (United States)

    Cailleteau, C; Liagre, B; Battu, S; Jayat-Vignoles, C; Beneytout, J L

    2008-09-01

    Differentiation induction as a therapeutic strategy has, so far, the greatest impact in hematopoietic malignancies, most notably leukemia. Diosgenin is a very interesting natural product because, depending on the specific dose used, its biological effect is very different in HEL (human erythroleukemia) cells. For example, at 10 microM, diosgenin induced megakaryocytic differentiation, in contrast to 40 microM diosgenin, which induced apoptosis in HEL cells previously demonstrated using sedimentation field-flow fractionation (SdFFF). The goal of this work focused on the correlation between cyclooxygenase-2 (COX-2) and thromboxane synthase (TxS) and megakaryocytic differentiation induced by diosgenin in HEL cells. Furthermore, the technique of SdFFF, having been validated in our models, was used in this new study as an analytical tool that provided us with more or less enriched differentiated cell fractions that could then be used for further analyses of enzyme protein expression and activity for the first time. In our study, we showed the implication of COX-2 and TxS in diosgenin-induced megakaryocytic differentiation in HEL cells. Furthermore, we showed that the analytical technique of SdFFF may be used as a tool to confirm our results as a function of the degree of cell differentiation.

  5. Arsenic Trioxide Inhibits Proliferation in K562 Cells by Changing Cell Cycle and Survivin Expression

    Institute of Scientific and Technical Information of China (English)

    伍晓菲; 陈智超; 刘仲萍; 周浩; 游泳; 黎纬明; 邹萍

    2004-01-01

    To study the mechanisms involved in the inhibition of chronic myeloid leukemic cells (K562) proliferation induced by arsenic trioxide (As2O3) and to explore the potential role of Survivin, an inhibitor of apoptosis protein, in the regulation of As2O3 induced cell apoptosis, K562 cells were cultured with As2O3 of different concentrations. Cells were collected for proliferation analysis by MTT assay. Cell cycle distribution and cell apoptosis were analyzed by flow cytometry.Expression of Survivin protein and mRNA were detected by flow cytometry and RT-PCR, respectively. Our results showed that As2O3 (2-10 μmol/L) inhibited K562 cells growth effectively, but it did not induce cells apoptosis significantly. The percentage of K562 cells at G2/M phase increased in proportion to As2O3 concentrations, and the expression of Survivin mRNA and content of Survivin protein was up-regulated accordingly. It is concluded that As2 O3 inhibited K562 cells growth by inducing cell cycle arrest mainly at G2/M phase. Over-expression of Survivin gene and protein might be one of the possible mechanisms contributing to K562 cells' resistance to As2O3-induced apoptosis.

  6. The anti-cancer effect of Propranolol in K562 cell line: an in vitro study

    Directory of Open Access Journals (Sweden)

    S Bastani

    2016-03-01

    Full Text Available Introduction: Β-AR receptors are one of the proteins involved in cancer and stress. The therapeutic activity of β-blockers such as propranolol is attributed to the blockade of β1-adrenergic receptors (ARs. In this study, the effect of propranolol on the viability of K562 cell line was examined. Material and methods: In order to assessment of anti-tumoral effects of propranolol, different concentrations of propranolol were prepared. K562 cells were treated with different concentrations of propranolol, then the percentage of inhibitory effect of propranolol on K562 cell viability at different times (24, 48 and 72 hours was estimated by MTT assay. Gel electrophoresis of DNA and DAPI staining were used for apoptosis investigation. Statistical comparisons were performed using two-sample t-test, Nominal significance level of each univariate test was 0.05. Results: Propranolol decreased viability of K562 cell line. The inhibitory effect of propranolol is time- and concentration-dependent, thus in higher concentrations and 72 hours after treatment, the maximum inhibitory effect was observed. (P<0.05. As the results showed, Propranolol induces apoptosis in K562 cell line. Conclusions: With respect to the inhibitory effect of propranolol on cell viability and its apoptotic effect on K562 cell line, this drug may be used for cancer therapy.

  7. The modulation of radiation-induced cell death by genistein in K562 cells:Activation of thymidine kinase 1

    Institute of Scientific and Technical Information of China (English)

    Min Ho JEONG; Young Hee JIN; Eun Young KANG; Wol Soon JO; Hwan Tae PARK; Jae Dong LEE; Yeo Jin YOO; Soo Jin JEONG

    2004-01-01

    Ionizing radiation is one of the most effective tools in cancer therapy. In a previous study, we reported that protein tyrosine kinase (PTK) inhibitors modulate the radiation responses in the human chronic myelogenous leukemia (CML)cell line K562. The receptor tyrosine kinase inhibitor, genistein, delayed radiation-induced cell death, while non-recepter tyrosine kinase inhibitor, herbimycin A (HMA) enhances radiation-induced apoptosis. In this study, we focused on the modulation of radiation-induced cell death by genistein and performed PCR-select suppression subtractive hybridization(SSH) to understand its molecular mechanism. We identified human thymidine kinase 1 (TK1), which is cell cycle regulatory gene and confirmed expression of TK1 mRNA by Northern blot analysis. Expression of TK1 mRNA and TK 1enzymatic activity were parallel in their increase and decrease. TK1 is involved in G1-S phase transition of cell cycle progression. In cell cycle analysis, we showed that radiation induced G2 arrest in K562 cells but it was not able to sustain. However, the addition of genistein to irradiated cells sustained a prolonged G2 arrest up to 120 h. In addition,the expression of cell cycle-related proteins, cyclin A and cyclin B 1, provided the evidences of G1/S progression and G2-arrest, and their relationship with TK1 in cells treated with radiation and genistein. These results suggest that the activation of TK1 may be critical to modulate the radiation-induced cell death and cell cycle progression in irradiated K562 cells.

  8. ESTABLISHMENT OF K562/ADM/VER CELL SUBLINE RESISTANT TO VERAPAMIL AND ITS RESISTANT MECHANISM

    Institute of Scientific and Technical Information of China (English)

    谢佐福; 周冬梅; 林贤东; 林声; 吴允昆

    2001-01-01

    Objective: To understand whether verapamil (VER) resistance development in the multidrug-resistant cell line and its mechanism. Methods: K562/ADM/VER cell subline resistant to verapamil was established through a gradual increase of VER concentration in the media. MTT method was used to assay resistance to VER, cross resistance to dipyriamole (DPM), cyclosporin A (CsA) in the cells, and HPLC and spectrofluorometer to detect intracellular accumulation of VER or ADM respectively, as well as S-P immunocytochemical technique for detection of genes expression. Results: It were observed that 7.9-fold increase in VER resistance, significantly reduced intracellular accumulation of VER or ADM and also develop across resistance to DPM and CsA in K562/ADM/VER cells, compared with its parent cell, K562/ADM. High-level of p-glycoprotein(pgp), middle-level of p53, p16, was present in two cell lines without expression of GSTPI, C-myc, C-myc, C-fos and C-erbB-2. Bc1-2 protein expression was found only in K562/ADM cells. Conclusion: K562/ADM cells were capable of being induced to develop resistance to VER.

  9. PENGARUH EKSTRAK JAMU TERHADAP AKTIVITAS SEL NATURAL KILLER DALAM MELISIS ALUR SEL LEUKIMIA (K-562 SECARA IN VITRO [The Effects of Commercial “Jamu” Extracts on Natural Killer Cell Activity in Lysing Leukemic Cell Line (K-562 in vitro

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    Elisa Veronica D.C. 2

    2002-04-01

    Full Text Available Natural killer (NK cell consitutes white blood cells which specifically functions in lysing tumor and virus invected cells. In this research, a commercial “Jamu” was tested to observe its effect on NK cells activity against leukemic cell lines (K562 in vitro. Jamu was extracted with hot water, diluted and added into cell cultures consisted of a mixture of human peripheric limphocyte cells, as the source of the effector NK cells, and K562 cell line i.e., the target cells which were cell line derived from human leukemia and had been labelled with H3-thymidine. The mixture of the cells were made by culturing the two cells at the ratio of 50:1 and 100 : 1, respectively. The results showed that lysing activity of NK cells in the presence of “Jamu” water extract measured as lysing percentage and lysing index increased only slightly, which were not statiscally significant. It should be considered that the test used in this research represents only a part of the lysing mechanism by NK cells against the target cells. An in vivo test for a period of time will be recessary to elucidate ffurther this NK cell activity.

  10. The role of DNA methylation in catechol-enhanced erythroid differentiation of K562 cells

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    Li, Xiao-Fei; Wu, Xiao-Rong; Xue, Ming; Wang, Yan; Wang, Jie; Li, Yang; Suriguga,; Zhang, Guang-Yao; Yi, Zong-Chun, E-mail: yizc@buaa.edu.cn

    2012-11-15

    Catechol is one of phenolic metabolites of benzene in vivo. Catechol is also widely used in pharmaceutical and chemical industries. In addition, fruits, vegetables and cigarette smoke also contain catechol. Our precious study showed that several benzene metabolites (phenol, hydroquinone, and 1,2,4-benzenetriol) inhibited erythroid differentiation of K562 cells. In present study, the effect of catechol on erythroid differentiation of K562 cells was investigated. Moreover, to address the role of DNA methylation in catechol-induced effect on erythroid differentiation in K562 cells, methylation levels of erythroid-specific genes were analyzed by Quantitative MassARRAY methylation analysis platform. Benzidine staining showed that exposure to catechol enhanced hemin-induced hemoglobin accumulation in K562 cells in concentration- and time-dependent manners. The mRNA expression of erythroid specific genes, including α-globin, β-globin, γ-globin, erythroid 5-aminolevulinate synthase, erythroid porphobilinogen deaminase, and transcription factor GATA-1 genes, showed a significant concentration-dependent increase in catechol-treated K562 cells. The exposure to catechol caused a decrease in DNA methylation levels at a few CpG sites in some erythroid specific genes including α-globin, β-globin and erythroid porphobilinogen deaminase genes. These results indicated that catechol improved erythroid differentiation potency of K562 cells at least partly via up-regulating transcription of some erythroid related genes, and suggested that inhibition of DNA methylation might be involved in up-regulated expression of some erythroid related genes. -- Highlights: ► Catechol enhanced hemin-induced hemoglobin accumulation. ► Exposure to catechol resulted in up-regulated expression of erythroid genes. ► Catechol reduced methylation levels at some CpG sites in erythroid genes.

  11. In vitro effect of imatinib mesylate loaded on polybutylcyanoacrylate nanoparticles on leukemia cell line K562.

    Science.gov (United States)

    Hasandoost, Leyla; Akbarzadeh, Azim; Attar, Hossein; Heydarinasab, Amir

    2017-05-01

    The study aimed to prepare imatinib mesylate-loaded polybutylcyanoacrylate (PBCA) nanoparticles and evaluate their efficacy on leukemia cell line K562. The formulation was prepared by miniemulsion polymerization technique. Nanoparticles were characterized by dynamic light scattering (DLS), spectrophotometry, Fourier transform infrared spectroscopy (FTIR), dialysis membrane, and 3-(4,5-dimethylthiazol-2-Yl)-2,5-diphenyltetrazolium bromide (MTT) techniques. Nanoscale particles with high encapsulation efficiency (86%) and physical entrapment of drug were observed. In addition, nanoparticles showed suitable drug retention capability and potentiate the cytotoxicity effects of imatinib mesylate. Findings of study suggested PBCA nanoparticles are promising carrier for imatinib mesylate delivery to leukemia cell line K562.

  12. Construction and characterization of hGM-CSF-expressing K-562 cell line

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Objective The whole process of vaccine preparation is time-consuming and technically challenging. Here the hGM-CSF-engineered K-562 cell line was constructed to simplify tumor vaccine preparation process. Methods The eukaryocyte expressing plasmid pcDNA3.1/GM-CSF was first constructed and its accuracy was verified through sequencing. The pcDNA3.1/GM-CSF was transfected into COS-7 cells to verify GM-CSF expression and cytokine activity using TF-1 cell line. Then the plasmid was transfected into K-562 cell li...

  13. K562 cells display different vulnerability to H₂O₂ induced oxidative stress in differing cell cycle phases.

    Science.gov (United States)

    Akcakaya, Handan; Dal, Fulya; Tok, Sabiha; Cinar, Suzan-Adin; Nurten, Rustem

    2015-02-01

    Oxidative stress can be defined as the increase of oxidizing agents like reactive oxygen and nitrogen species, or the imbalance between the antioxidative defense mechanism and oxidants. Cell cycle checkpoint response can be defined as the arrest of the cell cycle functioning after damaging chemical exposure. This temporary arrest may be a period of time given to the cells to repair the DNA damage before entering the cycle again and completing mitosis. In order to determine the effects of oxidative stress on several cell cycle phases, human erytroleukemia cell line (K562) was synchronized with mimosine and genistein, and cell cycle analysis carried out. Synchronized cells were exposed to oxidative stress with hydrogen peroxide (H2O2) at several concentrations and different times. Changes on mitochondria membrane potential (ΔΨm) of K562 cells were analyzed in G1, S, and G2 /M using Rhodamine 123 (Rho 123). To determine apoptosis and necrosis, stressed cells were stained with Annexin V (AnnV) and propidium iodide (PI) for flow cytometry. Changes were observed in the ΔΨm of synchronized and asynchronized cells that were exposed to oxidative stress. Synchronized cells in S phase proved resistant to the effects of oxidative stress and synchronized cells at G2 /M phase were sensitive to the effects of H2O2 -induced oxidative stress at 500 μM and above.

  14. A new 2-aminosteroid induces cellular differentiation and upregulates the expression of MafB and Egr-1 genes respectively in HL-60 and K562 leukemia cells

    Institute of Scientific and Technical Information of China (English)

    HE Qun; LI Qiong; YUAN Lin-bo; HE Jun

    2005-01-01

    Background In previous work, we suggested that some 2-aminosteroids inhibited proliferation and induced differentiation of both human and murine leukemia cells. Here, we reported the actions of another new 2-aminosteroid designated as H89712 on human leukemia cells. Methods Cell colony counting and MTT assay were used to determine proliferation. Cell morphology, histochemical staining, UV detection and cytometry were used to determine differentiation. RT-PCR was used to detect gene expression. Standard statistical method was used to analyze data.Results H89712 inhibited proliferation of HL-60 leukemia cells and the inhibition percentage in MTT assay was 18% at the dose of 10-8 mol/L and 65% at the dose of 10-5 mol/L, respectively. The inhibition for HL-60 in colony assay was 23% at the dose of 10-8 mol/L and 96% at the dose of 10-5 mol/L, respectively. H89712 also induced HL-60 cells toward macrophage-like differentiation. It was verified by flow cytometry that the percentage of positive CD14 expression in differentiated HL-60 cells was about 9 times higher than that of the control at the dose of 10-8 mol/L and 20 times higher than that of the control at the dose of 10-5 mol/L respectively, and this action involved upregulation of MafB gene in HL-60 leukemia cells. On the other hand, H89712 inhibited proliferation of K562 leukemia cells and the inhibition of K562 leukemia cells in MTT assay was shown by 34% at the dose of 10-8 mol/L and 88% at the dose of 10-5 mol/L respectively. The inhibition of K562 leukemia cells in colony assay was 53% at the dose of 10-8 mol/L and 100% at the dose of 10-5 mol/L respectively. H89712 also induced K562 cells toward erythroid-like differentiation and it was verified by flow cytometry that the percentage of positive CD71 expression in differentiated K562 cells was about 9 times higher than that of the control at the dose of 10-8 mol/L and 16 times higher than that of the control at the dose of 10-5 mol/L respectively. This action

  15. Clonal Expansion and Cytotoxicity of TCRVβ Subfamily T Cells Induced by CML and K562 Cells

    Institute of Scientific and Technical Information of China (English)

    YupingZHang; YangqiuLi; ShaohuaChen; LijianYang; GengxinLuo; XueliZhang

    2004-01-01

    OBJECTIVE To investigate the anti-leukemia effect, the distribution and clonal expansion of TCRVβ subfamily T cells in T cells from cord blood and adult peripheral blood induced by CML cells and K562 cells in vitro. METHODS Peripheral blood T cells from one adult donor and 3 cases of cord blood were stimulated with CML cells and K562 cells and further amplified by a suspended T cell-bulk culture,in order to induce CML specific cytotoxic T lymphocytes. The induced T cells were further analyzed for the specific cytotoxicity in CML by LDH assay, the phenotype identification by indirect immunofiuorescence technique and the distribution and clonal expansion of TCRVβ subfamily by using reverse transcriptase-polymerase chain reaction (RT-PCR) and genescan analysis, respectively. RESULTS Oligoclonal and oligoclonal tendency T cells with higher specific cytotoxicity from cord blood and adult peripheral blood could be induced by stimulation with CML cells and K562 cells. CONCLUSIONS Specific cytotoxic T cells for an anti-CML effect could be induced by CML cells and K562 cells .The induced T cells which have the characteristic of specific cytotoxicity against CML cells may come from the clonal expansion of TCRVβ subfamily T cells.

  16. Electrochemical K-562 cells sensor based on origami paper device for point-of-care testing.

    Science.gov (United States)

    Ge, Shenguang; Zhang, Lina; Zhang, Yan; Liu, Haiyun; Huang, Jiadong; Yan, Mei; Yu, Jinghua

    2015-12-01

    A low-cost, simple, portable and sensitive paper-based electrochemical sensor was established for the detection of K-562 cell in point-of-care testing. The hybrid material of 3D Au nanoparticles/graphene (3D Au NPs/GN) with high specific surface area and ionic liquid (IL) with widened electrochemical windows improved the good biocompatibility and high conductivity was modified on paper working electrode (PWE) by the classic assembly method and then employed as the sensing surface. IL could not only enhance the electron transfer ability but also provide sensing recognition interface for the conjugation of Con A with cells, with the cell capture efficiency and the sensitivity of biosensor strengthened simultaneously. Concanavalin A (Con A) immobilization matrix was used to capture cells. As proof-of-concept, the paper-based electrochemical sensor for the detection of K-562 cells was developed. With such sandwich-type assay format, K-562 cells as model cells were captured on the surface of Con A/IL/3D AuNPs@GN/PWE. Con A-labeled dendritic PdAg NPs were captured on the surface of K-562 cells. Such dendritic PdAg NPs worked as catalysts promoting the oxidation of thionine (TH) by H2O2 which was released from K-562 cells via the stimulation of phorbol 12-myristate-13-acetate (PMA). Therefore, the current signal response was dependent on the amount of PdAg NPs and the concentration of H2O2, the latter of which corresponded with the releasing amount from cells. So, the detection method of K-562 cell was also developed. Under optimized experimental conditions, 1.5×10(-14) mol of H2O2 releasing from each cell was calculated. The linear range and the detection limit for K-562 cells were determined to be 1.0×10(3)-5.0×10(6) cells/mL and 200 cells/mL, respectively. Such as-prepared sensor showed excellent analytical performance with good fabrication reproducibility, acceptable precision and satisfied accuracy, providing a novel protocol in point-of-care testing of cells.

  17. H-ferritin-regulated microRNAs modulate gene expression in K562 cells.

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    Flavia Biamonte

    Full Text Available In a previous study, we showed that the silencing of the heavy subunit (FHC offerritin, the central iron storage molecule in the cell, is accompanied by a modification in global gene expression. In this work, we explored whether different FHC amounts might modulate miRNA expression levels in K562 cells and studied the impact of miRNAs in gene expression profile modifications. To this aim, we performed a miRNA-mRNA integrative analysis in K562 silenced for FHC (K562shFHC comparing it with K562 transduced with scrambled RNA (K562shRNA. Four miRNAs, namely hsa-let-7g, hsa-let-7f, hsa-let-7i and hsa-miR-125b, were significantly up-regulated in silenced cells. The remarkable down-regulation of these miRNAs, following FHC expression rescue, supports a specific relation between FHC silencing and miRNA-modulation. The integration of target predictions with miRNA and gene expression profiles led to the identification of a regulatory network which includes the miRNAs up-regulated by FHC silencing, as well as91 down-regulated putative target genes. These genes were further classified in 9 networks; the highest scoring network, "Cell Death and Survival, Hematological System Development and Function, Hematopoiesis", is composed by 18 focus molecules including RAF1 and ERK1/2. We confirmed that, following FHC silencing, ERK1/2 phosphorylation is severely impaired and that RAF1 mRNA is significantly down-regulated. Taken all together, our data indicate that, in our experimental model, FHC silencing may affect RAF1/pERK1/2 levels through the modulation of a specific set of miRNAs and add new insights in to the relationship among iron homeostasis and miRNAs.

  18. Dopamine inhibits proliferation, induces differentiation and apoptosis of K562 leukaemia cells

    Institute of Scientific and Technical Information of China (English)

    HE Qun; YUAN Lin-bo

    2007-01-01

    Background Dopamine exerts its effects mainly in nervous system through D1, D2 or D3 receptors. There are few reports dealing with the effects of dopamine on leukaemia cells. However, some dopamine agonists or antagonists do show biological effects on some types of leukaemia cells. Here, we report the effects of dopamine on the proliferation,differentiation and apoptosis of K562 leukaemia cells.Methods Proliferation was determined by MTT assay and cell counting both in liquid and semisolid cultures.Differentiation was verified by morphology, benzidine staining and flow cytometry. Apoptosis was checked by Hoechst 33258 staining and flow cytometry. The two groups were untreated group and treated group (dopamine 10-9 mol/L-10-4mol/L).Results In liquid culture, MTT assay and colony assay, dopamine inhibited proliferation of K562 cells. Inhibition rate was 29.28% at 10-6 mol/L and 36.10% at 10-5 mol/L after culture for 5 days in MTT assay. In benzidine staining and CD71 expression, dopamine induced K562 cells toward erythroid differentiation by increased 155% at 10-6 mol/L and by 171% at 10-5 mol/L after culture for 5 days in benzidine staining. In Hoechst 33258 staining and flow cytometry,dopamine induced K562 cells toward apoptosis. The sub G1 peak stained by PI was 14.23% at 10-4 mol/L dopamine after culture for 3 days compared with the control (0.81%) in flow cytometry.Conclusion Dopamine inhibites proliferation and induces both differentiation and apoptosis of K562 leukaemia cells.

  19. H-Ferritin-Regulated MicroRNAs Modulate Gene Expression in K562 Cells

    Science.gov (United States)

    Biamonte, Flavia; Zolea, Fabiana; Bisognin, Andrea; Di Sanzo, Maddalena; Saccoman, Claudia; Scumaci, Domenica; Aversa, Ilenia; Panebianco, Mariafranca; Faniello, Maria Concetta; Bortoluzzi, Stefania; Cuda, Giovanni; Costanzo, Francesco

    2015-01-01

    In a previous study, we showed that the silencing of the heavy subunit (FHC) offerritin, the central iron storage molecule in the cell, is accompanied by a modification in global gene expression. In this work, we explored whether different FHC amounts might modulate miRNA expression levels in K562 cells and studied the impact of miRNAs in gene expression profile modifications. To this aim, we performed a miRNA-mRNA integrative analysis in K562 silenced for FHC (K562shFHC) comparing it with K562 transduced with scrambled RNA (K562shRNA). Four miRNAs, namely hsa-let-7g, hsa-let-7f, hsa-let-7i and hsa-miR-125b, were significantly up-regulated in silenced cells. The remarkable down-regulation of these miRNAs, following FHC expression rescue, supports a specific relation between FHC silencing and miRNA-modulation. The integration of target predictions with miRNA and gene expression profiles led to the identification of a regulatory network which includes the miRNAs up-regulated by FHC silencing, as well as91 down-regulated putative target genes. These genes were further classified in 9 networks; the highest scoring network, “Cell Death and Survival, Hematological System Development and Function, Hematopoiesis”, is composed by 18 focus molecules including RAF1 and ERK1/2. We confirmed that, following FHC silencing, ERK1/2 phosphorylation is severely impaired and that RAF1 mRNA is significantly down-regulated. Taken all together, our data indicate that, in our experimental model, FHC silencing may affect RAF1/pERK1/2 levels through the modulation of a specific set of miRNAs and add new insights in to the relationship among iron homeostasis and miRNAs. PMID:25815883

  20. Induction of cellular senescence by doxorubicin is associated with upregulated miR-375 and induction of autophagy in K562 cells.

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    Ming-Yu Yang

    Full Text Available BACKGROUND: Cellular senescence is a specialized form of growth arrest that is generally irreversible. Upregulated p16, p53, and p21 expression and silencing of E2F target genes have been characterized to promote the establishment of senescence. It can be further aided by the transcriptional repression of proliferation-associated genes by the action of HP1γ, HMGA, and DNMT proteins to produce a repressive chromatin environment. Therefore, senescence has been suggested to functions as a natural brake for tumor development and plays a critical role in tumor suppression and aging. METHODOLOGY/PRINCIPAL FINDINGS: An in vitro senescence model has been established by using K562 cells treated with 50 nM doxorubicin (DOX. Since p53 and p16 are homozygously deleted in the K562 cells, the DOX-induced senescence in K562 cells ought to be independent of p53 and p16-pRb pathways. Indeed, no change in the expression of the typical senescence-associated premalignant cell markers in the DOX-induced senescent K562 cells was found. MicroRNA profiling revealed upregulated miR-375 in DOX-induced senescent K562 cells. Treatment with miR-375 inhibitor was able to reverse the proliferation ability suppressed by DOX (p<0.05 and overexpression of miR-375 suppressed the normal proliferation of K562 cells. Upregulated miR-375 expression was associated with downregulated expression of 14-3-3zeta and SP1 genes. Autophagy was also investigated since DOX treatment was able to induce cells entering senescence and eventually lead to cell death. Among the 24 human autophagy-related genes examined, a 12-fold increase of ATG9B at day 4 and a 20-fold increase of ATG18 at day 2 after DOX treatment were noted. CONCLUSIONS/SIGNIFICANCE: This study has demonstrated that in the absence of p53 and p16, the induction of senescence by DOX was associated with upregulation of miR-375 and autophagy initiation. The anti-proliferative function of miR-375 is possibly exerted, at least in part

  1. The differentiation effect of low-dose cytosine arabinoside is disturbed in PU.1-knockdown K562 cells.

    Science.gov (United States)

    Nakano, Hiroko; Yanagita, Akane; Takahashi, Shinichiro

    2014-07-01

    We recently demonstrated by using PU.1-knockdown K562 (K562 PU.1KD) cells stably expressing PU.1 short inhibitory RNAs and PU.1-overexpressing K562 (K562 PU.1OE) cells, that therapeutic concentrations of 5-aza-2'-deoxycytidine (5-azadC) induce erythroid differentiation of these cells and that the PU.1 expression level is closely associated with the differentiating and apoptotic effects of 5-azadC on K562 cells. In this study, we investigated whether the effects of low-dose cytosine arabinoside (Ara-C), which is another erythroid differentiation inducer in K562 cells, is associated with the expression level of PU.1 in these cells. As a result, we demonstrated that the effect of Ara-C on cell viability and differentiation, as determined by the WST-8 assay and β-globin mRNA expression analysis, respectively, was suppressed in K562 PU.1KD cells compared to their controls. Collectively, these findings suggest that sufficient expression of PU.1 is indispensable for the erythroid differentiation of K562 cells.

  2. An Efficient Method for Electroporation of Small Interfering RNAs into ENCODE Project Tier 1 GM12878 and K562 Cell Lines.

    Science.gov (United States)

    Muller, Ryan Y; Hammond, Ming C; Rio, Donald C; Lee, Yeon J

    2015-12-01

    The Encyclopedia of DNA Elements (ENCODE) Project aims to identify all functional sequence elements in the human genome sequence by use of high-throughput DNA/cDNA sequencing approaches. To aid the standardization, comparison, and integration of data sets produced from different technologies and platforms, the ENCODE Consortium selected several standard human cell lines to be used by the ENCODE Projects. The Tier 1 ENCODE cell lines include GM12878, K562, and H1 human embryonic stem cell lines. GM12878 is a lymphoblastoid cell line, transformed with the Epstein-Barr virus, that was selected by the International HapMap Project for whole genome and transcriptome sequencing by use of the Illumina platform. K562 is an immortalized myelogenous leukemia cell line. The GM12878 cell line is attractive for the ENCODE Projects, as it offers potential synergy with the International HapMap Project. Despite the vast amount of sequencing data available on the GM12878 cell line through the ENCODE Project, including transcriptome, chromatin immunoprecipitation-sequencing for histone marks, and transcription factors, no small interfering siRNA-mediated knockdown studies have been performed in the GM12878 cell line, as cationic lipid-mediated transfection methods are inefficient for lymphoid cell lines. Here, we present an efficient and reproducible method for transfection of a variety of siRNAs into the GM12878 and K562 cell lines, which subsequently results in targeted protein depletion.

  3. Multidrug resistance in tumour cells: characterisation of the multidrug resistant cell line K562-Lucena 1

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    VIVIAN M. RUMJANEK

    2001-03-01

    Full Text Available Multidrug resistance to chemotherapy is a major obstacle in the treatment of cancer patients. The best characterised mechanism responsible for multidrug resistance involves the expression of the MDR-1 gene product, P-glycoprotein. However, the resistance process is multifactorial. Studies of multidrug resistance mechanisms have relied on the analysis of cancer cell lines that have been selected and present cross-reactivity to a broad range of anticancer agents. This work characterises a multidrug resistant cell line, originally selected for resistance to the Vinca alkaloid vincristine and derived from the human erythroleukaemia cell K562. This cell line, named Lucena 1, overexpresses P-glycoprotein and have its resistance reversed by the chemosensitisers verapamil, trifluoperazine and cyclosporins A, D and G. Furthermore, we demonstrated that methylene blue was capable of partially reversing the resistance in this cell line. On the contrary, the use of 5-fluorouracil increased the resistance of Lucena 1. In addition to chemotherapics, Lucena 1 cells were resistant to ultraviolet A radiation and hydrogen peroxide and failed to mobilise intracellular calcium when thapsigargin was used. Changes in the cytoskeleton of this cell line were also observed.A resistência a múltiplos fármacos é o principal obstáculo no tratamento de pacientes com câncer. O mecanismo responsável pela resistência múltipla mais bem caracterizado envolve a expressão do produto do gene MDR-1, a glicoproteína P. Entretanto, o processo de resistência tem fatores múltiplos. Estudos de mecanismos de resistência m��ltipla a fármacos têm dependido da análise de linhagens celulares tumorais que foram selecionadas e apresentam reatividade cruzada a uma ampla faixa de agentes anti-tumorais. Este trabalho caracteriza uma linhagem celular com múltipla resistência a fármacos, selecionada originalmente pela resistência ao alcalóide de Vinca vincristina e derivado

  4. In vitro radiosensitivity of human leukemia cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Weichselbaum, R.R.; Greenberger, J.S.; Schmidt, A.; Karpas, A.; Moloney, W.C.; Little, J.B.

    1981-05-01

    The in vitro radiobiologic survival values (n, D0) of four tumor lines derived from human hematopoietic tumors were studied. These cell lines were HL50 (n . 1.3, D0 . 117 rad(1.17 Gy)), promyelocytic leukemia; K562 (n . 1.4, D0 . 165 rad(1.65 Gy)), erythroleukemia; 45 (n . 1.1, D0 . 147 rad(1.47 Gy)), acute lymphocyte leukemia; and 176 (n . 4.0, D0 . 76 rad(0.76 Gy)), acute monomyelogenous leukemia. More cell lines must be examined before the exact relationship between in vitro radiosensitivity and clinical radiocurability is firmly established.

  5. The application of the human beta-globin gene locus control region and murine erythroleukemia cell system to the expression and pharmacological characterization of human endothelin receptor subtypes.

    Science.gov (United States)

    Davies, A; Whiting, E; Bath, C; Tang, E; Brennand, J

    1995-06-01

    The cDNAs encoding both A and B subtypes of the human endothelin receptor have been inserted into mammalian cell expression vectors that utilize the human globin gene, locus control region. These constructs have been introduced into murine erythroleukemia cells and inducible high level expression of the receptors has been achieved (approximately 1.5-pM/mg membrane protein and approximately 13,500 binding sites/cell for both receptor subtypes). Cell lines expressing these receptors were obtained on a rapid time scale (3-4 weeks), facilitated by the need for the analysis of only small numbers of cell clones/receptor (approximately 6). Competitive binding assays with endothelin-1 gave IC50s of 130 +/- 30 pM for endothelin-A receptor and 160 +/- 30 pM for endothelin-B receptor. Similar studies with the different isoforms of endothelin, sarafatoxin-S6b and -S6c, BQ123 and BQ3020, all gave the expected selectivity profiles. The IC50s for all compounds were in close agreement with those reported for native receptors. Thus, this expression system, which has several advantages over other described expression systems, is capable of rapidly providing large quantities of receptor for detailed pharmacological analyses or drug screening. In addition, the expressed receptors display the expected pharmacological profiles in the absence of any complicating, competing interactions from other subtypes or binding sites.

  6. Safranal, a Crocus sativus L constituent suppresses the growth of K-562 cells of chronic myelogenous leukemia. In silico and in vitro study.

    Science.gov (United States)

    Geromichalos, George D; Papadopoulos, Theophanis; Sahpazidou, Despina; Sinakos, Zacharias

    2014-12-01

    Crocin, a main constituent of Crocus sativus L (saffron), has been found to inhibit the growth of K-562 human chronic myelogenous leukemia (CML) cells expressing Bcr-Abl protein tyrosine kinase activity. The aim of our study is to investigate the ability of the bioactive saffron's constituents, crocin (CRC) and safranal (SFR), to inhibit the Bcr-Abl protein activity employing an in silico approach, as well as the in vitro effect of these compounds on K-562 growth and gene expression of Bcr-Abl. In silico molecular docking studies revealed that mostly SFR can be attached to Bcr-Abl protein, positioned inside the protein's binding cavity at the same place with the drug used in the treatment of CML, imatinib mesylate (IM). The predicted polar interactions and hydrophobic contacts constructing a hydrophobic cavity inside the active site, explain the observed inhibitory activity. Cytotoxicity experiments showed that SFR and CRC mediate cytotoxic response to K562 cells. In vitro studies on the expression of Bcr-Abl gene revealed that SFR and in a lesser degree IM inhibited the expression of the gene, while in contrast CRC induced an increase. The ultimate goal was to evaluate the existence of a potential antitumor activity of saffron's constituents SFR and CRC.

  7. Niflumic acid affects store-operated Ca(2+)-permeable (SOC) and Ca (2+)-dependent K (+) and Cl (-) ion channels and induces apoptosis in K562 cells.

    Science.gov (United States)

    Kucherenko, Yuliya V; Lang, Florian

    2014-07-01

    Non-steroidal anti-inflammatory drugs (NSAIDs) are known to induce apoptosis in a variety of cancer cells. However, the precise mechanisms by which NSAIDs facilitate apoptosis in tumor cells are not clear. In the present study, we show that niflumic acid (NA), a member of the fenamates group of NSAIDs and Cl(-) and Ca(2+)-activated Cl(-) (CAC) channels blocker, induced apoptosis (by ~8 %, 24 h treatment) and potentiated (by 8-10 %) apoptotic effect of endoplasmic reticulum Ca(2+) mobilizer thapsigargin (Tg) in human erythroleukemic K562 cell line. The whole-cell patch clamp and Fluo-3 flow cytometric experiments confirmed an inhibitory effect of NA (100 and 300 µM) on store-operated (SOC) channels. We also found that NA-blocked CAC channels were activated by acute application of Tg (2 µM) in K562 cells. NA blockage of CAC channels was accompanied by activation of Ca(2+)-activated K(+) (SK4) channels. The observed effects of NA were not connected with COX-2 inhibition since 100-nM NA (IC50 for COX-2 inhibition) did not induce either apoptosis or affect the channels activity. We conclude that inhibition of SOC channels plays a major role in NA-induced apoptosis. Increased apoptotic levels in Tg-treated K562 cells in the presence of NA may be due to the blockage of CAC and stimulation of SK4 channels in addition to SOC channels inhibition.

  8. Musashi2 modulates K562 leukemic cell proliferation and apoptosis involving the MAPK pathway

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Huijuan; Tan, Shi; Wang, Juan; Chen, Shana; Quan, Jing; Xian, Jingrong; Zhang, Shuai shuai; He, Jingang; Zhang, Ling, E-mail: lingzhang@cqmu.edu.cn

    2014-01-01

    The RNA-binding protein Musashi2 (Msi2) has been identified as a master regulator within a variety of stem cell populations via the regulation of translational gene expression. A recent study has suggested that Msi2 is strongly expressed in leukemic cells of acute myeloid leukemia patients, and elevated Msi2 is associated with poor prognosis. However, the potential role of Msi2 in leukemogenesis is still not well understood. Here, we investigated the effect of Msi2 knockdown on the biological properties of leukemic cells. High expression of Msi2 was found in K562 and KG-1a leukemic cell lines, and low expression was observed in the U937 cell line. We transduced K562 cells with two independent adenoviral shRNA vectors targeting Msi2 and confirmed knockdown of Msi2 at the mRNA and protein levels. Msi2 silencing inhibited cell growth and caused cell cycle arrest by increasing the expression of p21 and decreasing the expression of cyclin D1 and cdk2. In addition, knockdown of Msi2 promoted cellular apoptosis via the upregulation of Bax and downregulation of Bcl-2 expression. Furthermore, Msi2 knockdown resulted in the inactivation of the ERK/MAPK and p38/MAPK pathways, but no remarkable change in p-AKT was observed. These data provide evidence that Msi2 plays an important role in leukemogenesis involving the MAPK signaling pathway, which indicates that Msi2 may be a novel target for leukemia treatment. - Highlights: • Knockdown of Msi2 inhibited K562 cell growth and arrested cell cycle progression. • Knockdown of Msi2 induced K562 cell apoptosis via the regulation of Bax and Bcl-2. • The MAPK pathway was involved in the process of Msi2-mediated leukemogenesis. • Our data indicate that Msi2 is a potential new target for leukemia treatment.

  9. Proteomic analysis of nuclear matrix proteins during arsenic trioxide induced apoptosis in leukemia K562 cells

    Institute of Scientific and Technical Information of China (English)

    WANG Zi-hui; YU Ding; CHEN Yan; HAO Jian-zhong

    2005-01-01

    Background Arsenic trioxide (As2O3) has been identified as a very potent anti-acute leukemic agent. However its role in apoptosis needs to be elucidated. As2O3 interferes with the proliferation and survival of tumor cells via a variety of mechanisms. Drug-target interactions at the level of nuclear matrix (NM) may be critical events in the induction of cell death by As2O3. This study dealt with As2O3-target interactions at the level of NM in chronic myelogenous leukemia cell line K562 by proteomics. Methods K562 cells were cultured in MEM and treated with different concentrations of As2O3. The nuclear matrix proteins were analyzed by high-resolution two-dimensional gel electrophoresis and computer-assisted image analysis. Results As2O3 significantly inhibited the growth of chronic myelogenous leukemia cell line K562 at low concentrations. While more than 200 protein spots were shared among the nuclear matrices, about 18 distinct spots in the nuclear matrices were found characteristic for As2O3 treated cells. Conclusions: As2O3 induces apoptosis in K562 cells in a dose and time-dependent manner. Our results demonstrated that for the detection of the onset of apoptosis, the alteration in the composition of nuclear matrix proteins was a more sensitive indicator than nucleosomal DNA fragmentation test. These results indicated that As2O3 might be clinically useful in the treatment of chronic myelogenous leukemia. The changes of nuclear matrix proteins in the treated cells can be used as a useful indicator for this treatment.

  10. IBTK Differently Modulates Gene Expression and RNA Splicing in HeLa and K562 Cells

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    Giuseppe Fiume

    2016-11-01

    Full Text Available The IBTK gene encodes the major protein isoform IBTKα that was recently characterized as substrate receptor of Cul3-dependent E3 ligase, regulating ubiquitination coupled to proteasomal degradation of Pdcd4, an inhibitor of translation. Due to the presence of Ankyrin-BTB-RCC1 domains that mediate several protein-protein interactions, IBTKα could exert expanded regulatory roles, including interaction with transcription regulators. To verify the effects of IBTKα on gene expression, we analyzed HeLa and K562 cell transcriptomes by RNA-Sequencing before and after IBTK knock-down by shRNA transduction. In HeLa cells, 1285 (2.03% of 63,128 mapped transcripts were differentially expressed in IBTK-shRNA-transduced cells, as compared to cells treated with control-shRNA, with 587 upregulated (45.7% and 698 downregulated (54.3% RNAs. In K562 cells, 1959 (3.1% of 63128 mapped RNAs were differentially expressed in IBTK-shRNA-transduced cells, including 1053 upregulated (53.7% and 906 downregulated (46.3%. Only 137 transcripts (0.22% were commonly deregulated by IBTK silencing in both HeLa and K562 cells, indicating that most IBTKα effects on gene expression are cell type-specific. Based on gene ontology classification, the genes responsive to IBTK are involved in different biological processes, including in particular chromatin and nucleosomal organization, gene expression regulation, and cellular traffic and migration. In addition, IBTK RNA interference affected RNA maturation in both cell lines, as shown by the evidence of alternative 3′- and 5′-splicing, mutually exclusive exons, retained introns, and skipped exons. Altogether, these results indicate that IBTK differently modulates gene expression and RNA splicing in HeLa and K562 cells, demonstrating a novel biological role of this protein.

  11. Targeting catalase but not peroxiredoxins enhances arsenic trioxide-induced apoptosis in K562 cells.

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    Li-Li Song

    Full Text Available Despite considerable efficacy of arsenic trioxide (As2O3 in acute promyelocytic leukemia (APL treatment, other non-APL leukemias, such as chronic myeloid leukemia (CML, are less sensitive to As2O3 treatment. However, the underlying mechanism is not well understood. Here we show that relative As2O3-resistant K562 cells have significantly lower ROS levels than As2O3-sensitive NB4 cells. We compared the expression of several antioxidant enzymes in these two cell lines and found that peroxiredoxin 1/2/6 and catalase are expressed at high levels in K562 cells. We further investigated the possible role of peroxirdoxin 1/2/6 and catalase in determining the cellular sensitivity to As2O3. Interestingly, knockdown of peroxiredoxin 1/2/6 did not increase the susceptibility of K562 cells to As2O3. On the contrary, knockdown of catalase markedly enhanced As2O3-induced apoptosis. In addition, we provide evidence that overexpression of BCR/ABL cannot increase the expression of PRDX 1/2/6 and catalase. The current study reveals that the functional role of antioxidant enzymes is cellular context and treatment agents dependent; targeting catalase may represent a novel strategy to improve the efficacy of As2O3 in CML treatment.

  12. Differential expression and alternative splicing of cell cycle genes in imatinib-treated K562 cells.

    Science.gov (United States)

    Liu, Jing; Lin, Jin; Huang, Lin-Feng; Huang, Bo; Xu, Yan-Mei; Li, Jing; Wang, Yan; Zhang, Jing; Yang, Wei-Ming; Min, Qing-Hua; Wang, Xiao-Zhong

    2015-09-01

    Cancer progression often involves the disorder of the cell cycle, and a number of effective chemotherapeutic drugs have been shown to induce cell cycle arrest. The purpose of this study was to comprehensively investigate the effects of imatinib on the expression profile of cell cycle genes in the chronic myeloid leukemia (CML) K562 cell line. In addition, we also investigated alternative splicing of the cell cycle genes affected by imatinib, since an important relationship has been shown to exist between RNA splicing and cell cycle progression. Exon array analysis was performed using total RNA purified from normal and imatinib-treated K562 cells. We identified 185 differentially expressed genes and 277 alternative splicing events between the two cell groups. A detailed analysis by reverse transcription-PCR (RT-PCR) of key genes confirmed the experimental results of the exon array. These results suggested that treatment of K562 cells with imatinib shifts the expression and alternative splicing profiles of several cell cycle-related genes. Importantly, these findings may help improve imatinib treatment strategies in patients with CML and may be useful for imatinib resistance research and CML drug development.

  13. Isolation of flavonoids from onion skins and their effects on K562 cell viability

    Directory of Open Access Journals (Sweden)

    Guo-Qing Shi

    2016-04-01

    Full Text Available To investigate the anti-proliferative activity of flavonoids from onion skins, extraction by 50% ethanol (v/v, soxhlet polar fractionation, pH gradient separation, thin-layer chromatography, and recrystallization methods were used to isolate and purify flavonoids from dry onion skins. Anti-proliferative activities of some flavonoids obtained on leukemia K562 cell line were deter-mined by MTT assay. Results showed that flavonoids of onion skins were mainly in form of quercetin, kaempferol, isorhamnetin, apigenin-7-O-β-D-glucopyranoside, quercetin-3-O-β-D-glucopyranoside, kaempferol-7-O-β-D-glucopyranoside and rutin. Quercetin and kaempferol decreased K562 cell viability, and quercetin had stronger effect. However, isorhamnetin and rutin exhibited certain proliferation-promoting effects. It suggests that ortho hydroxyl groups on B ring of onion flavonoids might be the key structural elements of their cytotoxic effects on K562 cells, and hydroxyl groups in position 3 or carbonyl groups in position 4 might be one of the structural effect elements.

  14. PEGylated dendritic nanoarchitechture improves mean survival time of BDF1mice bearing myelogenous k -562 leukemia

    Institute of Scientific and Technical Information of China (English)

    Ramadoss Karthikeyan; Pureti Madhu Kumar; Palanirajan Vijayaraj Kumar

    2013-01-01

    Objective:To developing and exploring the use ofPEGylated poly(propylene imine) dendritic architecture for the delivery of an anti leukemic activity ofPrednisolone.Methods:For this study,PEGylated poly(propylene imine) dendritic architecture was synthesized and loaded with Prednisolone and targeted to the ascetic form of myelogenous leukemia k-562 cellines in hybrid miceBDF1, was used as tumor model.Theantileukemic activity was assessed by use of the criterionT/C%, whereT was the mean survival time(MST, days) of the drug treated mice, bearing k-562 leukemia andC- the mean survival time(MST, days) of untreated control animals, bearing the same leukemia cellines.Results:An antileukemic activity of the studiedPrednisolone loaded PEGylatedPolypropyleneimine(PPI) dendrimer was found to have increasing the mean survival time of the k-562 myelogenous leukemia cellines bearingBDF1 mice.The criterion“increase of life span”(ILS%) reached maximally270.1% for the drug loaded dendrimer.Conclusion:The studied dendrimer withPrednisolone showed lower toxicity with improved antileukemic activity in comparison with freePrednisolone.The further experiments in this field are in progress, aiming to design better dendritic formulations, with potential clinical use.

  15. The role of catechol-O-methyltransferase in catechol-enhanced erythroid differentiation of K562 cells

    Energy Technology Data Exchange (ETDEWEB)

    Suriguga,; Li, Xiao-Fei; Li, Yang; Yu, Chun-Hong; Li, Yi-Ran; Yi, Zong-Chun, E-mail: yizc@buaa.edu.cn

    2013-12-15

    Catechol is widely used in pharmaceutical and chemical industries. Catechol is also one of phenolic metabolites of benzene in vivo. Our previous study showed that catechol improved erythroid differentiation potency of K562 cells, which was associated with decreased DNA methylation in erythroid specific genes. Catechol is a substrate for the catechol-O-methyltransferase (COMT)-mediated methylation. In the present study, the role of COMT in catechol-enhanced erythroid differentiation of K562 cells was investigated. Benzidine staining showed that exposure to catechol enhanced hemin-induced hemoglobin accumulation and induced mRNA expression of erythroid specific genes in K562 cells. Treatment with catechol caused a time- and concentration-dependent increase in guaiacol concentration in the medium of cultured K562 cells. When COMT expression was knocked down by COMT shRNA expression in K562 cells, the production of guaiacol significantly reduced, and the sensitivity of K562 cells to cytotoxicity of catechol significantly increased. Knockdown of COMT expression by COMT shRNA expression also eliminated catechol-enhanced erythroid differentiation of K562 cells. In addition, the pre-treatment with methyl donor S-adenosyl-L-methionine or its demethylated product S-adenosyl-L-homocysteine induced a significant increase in hemin-induced Hb synthesis in K562 cells and the mRNA expression of erythroid specific genes. These findings indicated that O-methylation catalyzed by COMT acted as detoxication of catechol and involved in catechol-enhanced erythroid differentiation of K562 cells, and the production of S-adenosyl-L-homocysteine partly explained catechol-enhanced erythroid differentiation. - Highlights: • Catechol enhanced hemin-induced hemoglobin accumulation. • COMT-catalyzed methylation acted as detoxication of catechol. • COMT involved in catechol-enhanced erythroid differentiation.

  16. The role of catechol-O-methyltransferase in catechol-enhanced erythroid differentiation of K562 cells.

    Science.gov (United States)

    Suriguga; Li, Xiao-Fei; Li, Yang; Yu, Chun-Hong; Li, Yi-Ran; Yi, Zong-Chun

    2013-12-15

    Catechol is widely used in pharmaceutical and chemical industries. Catechol is also one of phenolic metabolites of benzene in vivo. Our previous study showed that catechol improved erythroid differentiation potency of K562 cells, which was associated with decreased DNA methylation in erythroid specific genes. Catechol is a substrate for the catechol-O-methyltransferase (COMT)-mediated methylation. In the present study, the role of COMT in catechol-enhanced erythroid differentiation of K562 cells was investigated. Benzidine staining showed that exposure to catechol enhanced hemin-induced hemoglobin accumulation and induced mRNA expression of erythroid specific genes in K562 cells. Treatment with catechol caused a time- and concentration-dependent increase in guaiacol concentration in the medium of cultured K562 cells. When COMT expression was knocked down by COMT shRNA expression in K562 cells, the production of guaiacol significantly reduced, and the sensitivity of K562 cells to cytotoxicity of catechol significantly increased. Knockdown of COMT expression by COMT shRNA expression also eliminated catechol-enhanced erythroid differentiation of K562 cells. In addition, the pre-treatment with methyl donor S-adenosyl-L-methionine or its demethylated product S-adenosyl-L-homocysteine induced a significant increase in hemin-induced Hb synthesis in K562 cells and the mRNA expression of erythroid specific genes. These findings indicated that O-methylation catalyzed by COMT acted as detoxication of catechol and involved in catechol-enhanced erythroid differentiation of K562 cells, and the production of S-adenosyl-L-homocysteine partly explained catechol-enhanced erythroid differentiation.

  17. A Subpopulation of the K562 Cells Are Killed by Curcumin Treatment after G2/M Arrest and Mitotic Catastrophe

    Science.gov (United States)

    Martinez-Castillo, Macario; Bonilla-Moreno, Raul; Aleman-Lazarini, Leticia; Meraz-Rios, Marco Antonio; Orozco, Lorena; Cedillo-Barron, Leticia; Cordova, Emilio J.

    2016-01-01

    Curcumin is extensively investigated as a good chemo-preventive agent in the development of many cancers and particularly in leukemia, including treatment of chronic myelogenous leukemia and it has been proposed as an adjuvant for leukemia therapies. Human chronic myeloid leukemia cells (K562), were treated with 20 μM of curcumin, and we found that a subpopulation of these cells were arrested and accumulate in the G2/M phase of the cell cycle. Characterization of this cell subpopulation showed that the arrested cells presented nuclear morphology changes resembling those described for mitotic catastrophe. Mitotic cells displayed abnormal chromatin organization, collapse of the mitotic spindle and abnormal chromosome segregation. Then, these cells died in an apoptosis dependent manner and showed diminution in the protein levels of BCL-2 and XIAP. Moreover, our results shown that a transient activation of the nuclear factor κB (NFκB) occurred early in these cells, but decreased after 6 h of the treatment, explaining in part the diminution of the anti-apoptotic proteins. Additionally, P73 was translocated to the cell nuclei, because the expression of the C/EBPα, a cognate repressor of the P73 gene, was decreased, suggesting that apoptosis is trigger by elevation of P73 protein levels acting in concert with the diminution of the two anti-apoptotic molecules. In summary, curcumin treatment might produce a P73-dependent apoptotic cell death in chronic myelogenous leukemia cells (K562), which was triggered by mitotic catastrophe, due to sustained BAX and survivin expression and impairment of the anti-apoptotic proteins BCL-2 and XIAP. PMID:27832139

  18. [Ginsenoside Rh₂-induced inhibition of histone deacetylase 6 promotes K562 cells autophagy and apoptosis in vivo].

    Science.gov (United States)

    Liu, Ze-Hong; Chen, Di-Long; Jiang, Rong; Chen, Yi; Xiong, Wei; Wang, Fen; Shi, Xue-Ping; Li, Hai-Xing; Li, Jing

    2016-02-01

    To study the in vivo inhibition effect of ginsenoside Rh₂ on humanleukemia cells, and explore its mechanism from autophagy and apoptosis aspects, human leukemia K562 cells allograft tumor models were applied, and after administration of ginsenosides Rh₂ by gavage, the tumor diameter, volume and inhibitory rate were measured, and the anti-tumor activity of ginsenosides Rh₂ was observed. The levels of HAT and HDAC in tumor tissues were detected by chemical colorimetry assay, and expressions of HDAC1, HDAC2, HDAC3, HDAC4, HDAC5 and HDAC6 were detected by Western blotting assay. The expression levels of vital genes closely associated with autophagy and mRNA expressions of HDAC6 and Hsp90 were detected by Real time-PCR. HE staining was used to observe apoptosis, and immunohistochemistry was used to detect the protein expressions of HDAC6, Hsp90 and activated caspases 3. The results showed that ginsenoside Rh₂ could inhibit the growth of k562 cells allograft tumor, with a tumor inhibition rate up to 53.10%. Ginsenoside Rh₂ could significantly decrease HDAC activity and decrease the expressions of HDAC1, HDAC2 and HDAC6, and inhibit the expressions of HDAC6 and HSP90, increase the expressions of vital autophagy genes (beclin-1, LC3A and LC3B). Histopathological results showed that ginsenosides Rh₂ could significantly increase the tumor apoptosis. Therefore, ginsenoside Rh₂ had good anti-tumor effect in vivo, and the mechanism maybe associated with regulating autophagy and apoptosis through HDAC6 and Hsp90 pathways and inhibiting the in vivo proliferation of tumor cells. Copyright© by the Chinese Pharmaceutical Association.

  19. 蛇毒组分对K562阿霉素敏感株和耐药株的抑制作用%Snake venom components inhibits growth of K562 adriamycin-sensitive and-resistant strains

    Institute of Scientific and Technical Information of China (English)

    杨昌山; 何慧华; 董伟华

    2013-01-01

    目的:通过对中华眼镜蛇毒进行分离和各组分的初筛,寻找逆转K562对阿霉素耐药的活性成分KD-Ⅲ-1,为今后研究肿瘤耐药性奠定工作基础。方法:通过凝胶分离得到的蛇毒组分分别作用于K562对阿霉素耐药株K562/A和敏感株K562/S,筛选有效活性组分;通过荧光探针Rh123测定P-gp蛋白活性和PI染色进一步确定该组分的逆转K562/A的耐药活性。结果:分别给予2μg/mL阿霉素( Adr)和各浓度蛇毒组分处理24 h后,可以发现蛇毒组分对阿霉素敏感株K562/S和耐药株K562/A都有明显的抑制作用,并呈现出剂量-效应关系。1μg/mL蛇毒组分处理组与2μg/mL蛇毒处理组抑制作用明显;在药物持续作用48 h后对K562/A的活性仍有抑制作用在0.5、1、2μg/mL的蛇毒组分组表现的更加明显。通过Rho外排实验发现蛇毒粗毒组平均荧光强度(MFI)与阴性对照组没有明显差异,而2.5μg/mL蛇毒组分组的MFI明显降低,与对照组相比具有统计学意义(P<0.05)。2.5μg/mL蛇毒粗毒和分离组分分别对K562/S敏感株和K562/A耐药株作用3 h后,K562/S的PI染色阳性率明显升高,而K562/A的PI染色阳性率并没有明显升高。结论:蛇毒组分KD-Ⅲ-1对K562/A和K562/S细胞均有明显抑制的作用,抑制作用可能与诱导凋亡有关。%Objective:To explore the active ingredient, KD-Ⅲ-1, for reversal of K562 resistance to adriamycin ( Adr) via separation and primary screening of individual components of cobra venom, thus offering the sound basis for future study on tumor drug resistance. Methods: The K562 Adr-resistant strains, K562/A, and -sensitive strains, K562/S, were incubated with isolated snake venom components derived from gel separation, for exploration of the effective component. The P-gp protein activity was measured by the fluorescent probe Rh123, and the PI staining was applied to determine the resistance reversal capacity of the components

  20. 60 Coγ射线辐射致LyGDI断裂对K562细胞的延迟性凋亡作用%Delayed K562 cell apoptosis promoted by cleaved LyGDI after 60Co γ-rays irradiation

    Institute of Scientific and Technical Information of China (English)

    孙华丽; 段卫明; 邵彦彦; 肖海楠; 周新文

    2010-01-01

    目的 采用不同剂量的60 Coγ射线照射人红白血病细胞系K562,探究鸟苷酸解离抑制因子-2(LyGDI)在细胞延迟性死亡中的作用以及其调控机制.方法 细胞流式仪PI单染检测细胞周期,藻红B染色观察细胞的凋亡,Western blot分析LyGDI和Rac1蛋白的表达,免疫荧光检测Rac1蛋白在细胞内的分布.结果 K562细胞被阻滞在G2/M期的百分率为71.3%,K562细胞早期凋亡率较低,8 Gy60Co γ射线照射后24 h,凋亡率为14%,呈现出延迟性的细胞凋亡;K562细胞在4 Gy的γ射线照射24 h后,可见LyGDI发生断裂,总的Rac1蛋白表达未发生明显变化,但其在细胞内的分布发生改变,Rac1转移至细胞膜上与少量核内分布,Rac1脱离LyGDI而激活.结论 LyGDI具有增加细胞延迟性凋亡的作用,其断裂使Rac1转移至细胞膜上,诱导Rac1的激活,从而促进了细胞的凋亡.%Objective To elucidate the function and regulatory mechanism of LyGDI involved delayed cell death in the human K562 cells and HL-60 cells induced by 60Co γ-rays. Methods Erythrosine B cells staining was used to count the apoptosis rate. PI staining and flow cytometry were applied to check the cell cycle. The expression of LYGDI and Rac1 was resolved by Western blot by using monoclonal antibody of LyGDI and Racl. The distribution of Racl protein in cells was observed with immunofluorescence by using the confocal microscope. Results The K562 cells showed G2/M phase arrest and the percent age was 71.3%. The apoptosis rate was very low at early post-irradiation stage in the K562 cells. The apoptosis rate was 14% in the K562 cells at 24 h post-irradiation with 8 Gy of γ-rays, and delayed cell apoptosis was present. LyGDI was cleaved in the K562 cells irradiated by 4 Gy 60 Co γ-rays after 24 hours post-irradiation. The expression of Racl protein was not altered at all, but the distribution was changed in the irradiated cells while the Racl protein moved to cell membrane and a little in cell

  1. Stat5 Exerts Distinct, Vital Functions in the Cytoplasm and Nucleus of Bcr-Abl+ K562 and Jak2(V617F+ HEL Leukemia Cells

    Directory of Open Access Journals (Sweden)

    Axel Weber

    2015-03-01

    Full Text Available Signal transducers and activators of transcription (Stats play central roles in the conversion of extracellular signals, e.g., cytokines, hormones and growth factors, into tissue and cell type specific gene expression patterns. In normal cells, their signaling potential is strictly limited in extent and duration. The persistent activation of Stat3 or Stat5 is found in many human tumor cells and contributes to their growth and survival. Stat5 activation plays a pivotal role in nearly all hematological malignancies and occurs downstream of oncogenic kinases, e.g., Bcr-Abl in chronic myeloid leukemias (CML and Jak2(V617F in other myeloproliferative diseases (MPD. We defined the mechanisms through which Stat5 affects growth and survival of K562 cells, representative of Bcr-Abl positive CML, and HEL cells, representative for Jak2(V617F positive acute erythroid leukemia. In our experiments we suppressed the protein expression levels of Stat5a and Stat5b through shRNA mediated downregulation and demonstrated the dependence of cell survival on the presence of Stat5. Alternatively, we interfered with the functional capacities of the Stat5 protein through the interaction with a Stat5 specific peptide ligand. This ligand is a Stat5 specific peptide aptamer construct which comprises a 12mer peptide integrated into a modified thioredoxin scaffold, S5-DBD-PA. The peptide sequence specifically recognizes the DNA binding domain (DBD of Stat5. Complex formation of S5-DBD-PA with Stat5 causes a strong reduction of P-Stat5 in the nuclear fraction of Bcr-Abl-transformed K562 cells and a suppression of Stat5 target genes. Distinct Stat5 mediated survival mechanisms were detected in K562 and Jak2(V617F-transformed HEL cells. Stat5 is activated in the nuclear and cytosolic compartments of K562 cells and the S5-DBD-PA inhibitor most likely affects the viability of Bcr-Abl+ K562 cells through the inhibition of canonical Stat5 induced target gene transcription. In HEL

  2. [Inhibitory effect of all-trans retinoic acid combined with SBA-Na on K562 and Kasumi-1 cell lines in vitro].

    Science.gov (United States)

    Chang, Cheng; Guo, Bo; Zhang, Lin; Zhu, Hong-Li; Lu, Xue-Chun; Fan, Hui; Li, Su-Xia; Yang, Bo; Liu, Yang; Zhai, Bing; Yang, Yang; Ran, Hai-Hong; Lin, Jie

    2013-08-01

    This study was aimed to investigate the effect of all-trans retinoic acid (ATRA) combined with SBA-Na on the biologic activities of human leukemia K562 and Kasumi-1 cell lines and their mechanism. The ATRA solution of 10(-6) mol/L (W1), 10(-4) mol/L (W2) and the SBA-Na solution of 100 µg/ ml (Z1) and 200 µg/ml (Z2) were prepared respectively. The K562 and Kasumi-1 cells were treated with W1, W2, Z1, Z2, W1 + Z1 and W2 + Z2 respectively, at same time, the blank control was set up. The cell morphology and growth in different treated groups were observed under light microscope. The CCK-8 method was used to detect the proliferation ability of cells, the cell growth curves were drawn, the inhibitory rate of cells was calculated. The flow cytometry with PI single staining and PI/Annexin V double stainings was used to detect the change of cell cycle and apoptosis of 2 cell lines treated with different drugs. The RQ-PCR was used to detect the change of Cyclin A mRNA expression in K562 cells. The results showed both ATRA and SBA-Na displayed inhibitory effect on cell proliferation, and the combination of these two drugs had stronger effect. As compared with the control group, the cell cycle distribution were changed obviously, and the apoptosis increased more significantly in treated groups, especially in group of ATRA combined with SBA-Na. The Cyclin A mRNA expression was up-regulated in Z1 group, while Cyclin A mRNA expression was down-regulated in other groups. It is concluded that both ATRA and SBA-Na can inhibit the proliferation of K562 and Kasumi-1 cell lines and promote their apoptosis. This effect may be stronger when both drugs combined. For K562 cells, the inhibitory effect may be accomplished through down-regulation of Cyclin A mRNA.

  3. Forced FOG1 expression in erythroleukemia cells: Induction of erythroid genes and repression of myelo-lymphoid transcription factor PU.1.

    Science.gov (United States)

    Fujiwara, Tohru; Sasaki, Katsuyuki; Saito, Kei; Hatta, Shunsuke; Ichikawa, Satoshi; Kobayashi, Masahiro; Okitsu, Yoko; Fukuhara, Noriko; Onishi, Yasushi; Harigae, Hideo

    2017-02-16

    The transcription factor GATA-1-interacting protein Friend of GATA-1 (FOG1) is essential for proper transcriptional activation and repression of GATA-1 target genes; yet, the mechanisms by which FOG1 exerts its activating and repressing functions remain unknown. Forced FOG1 expression in human K562 erythroleukemia cells induced the expression of erythroid genes (SLC4A1, globins) but repressed that of GATA-2 and PU.1. A quantitative chromatin immunoprecipitation (ChIP) analysis demonstrated increased GATA-1 chromatin occupancy at both FOG1-activated as well as FOG1-repressed gene loci. However, while TAL1 chromatin occupancy was significantly increased at FOG1-activated gene loci, it was significantly decreased at FOG1-repressed gene loci. When FOG1 was overexpressed in TAL1-knocked down K562 cells, FOG1-mediated activation of HBA, HBG, and SLC4A1 was significantly compromised by TAL1 knockdown, suggesting that FOG1 may require TAL1 to activate GATA-1 target genes. Promoter analysis and quantitative ChIP analysis demonstrated that FOG1-mediated transcriptional repression of PU.1 would be mediated through a GATA-binding element located at its promoter, accompanied by significantly decreased H3 acetylation at lysine 4 and 9 (K4 and K9) as well as H3K4 trimethylation. Our results provide important mechanistic insight into the role of FOG1 in the regulation of GATA-1-regulated genes and suggest that FOG1 has an important role in inducing cells to differentiate toward the erythroid lineage rather than the myelo-lymphoid one by repressing the expression of PU.1.

  4. Animal experimental study of inhibitory effect of suicide genes on K562 cell neoplasia%自杀基因抑制K562细胞成瘤的动物实验研究

    Institute of Scientific and Technical Information of China (English)

    万德胜; 姜义荣; 陈万宁

    2008-01-01

    目的 探讨自杀基因胞嘧啶脱氨酶(CD)和胸苷激酶(TK)在小鼠体内对K562细胞的抑制作用.方法 将在慢病毒介导下已转染CDgly TK的K562细胞种植于裸鼠皮下,观察其成瘤情况和对前体药物[环氧鸟苷(GCV)、5-氟胞嘧啶(5-FC)]的敏感性.结果 种植K562细胞和K562/CDg1y TK细胞的裸鼠分别在(7.0±1.2)和(7.1±0.9)d后长出肉眼可见的瘤块.两组裸鼠生存期分别是(52.2±5.3)和(54.2±3.7)d,差异无统计学意义(P>0.05);接种K562/CDgly TK细胞的小鼠经GCV和5-FC处理后,其裸鼠分别在(26.9±1.7)、(25.7±1.9)d后肉眼可见肿瘤生长,对照组接种K562细胞后(6.9±1.7)d生长出肉眼可见肿瘤,两者差异有统计学意义(P<0.01).结论 自杀基因在体内对K562细胞有明显的抑制作用,能增强前体药物GCV和5-FC对肿瘤细胞的药物作用.

  5. Monocytic differentiation of K562 cells induced by proanthocyanidins from grape seeds.

    Science.gov (United States)

    Wang, Min; Wang, Li; Pan, Xiao-Jing; Zhang, Hong

    2012-01-01

    Grape seeds procyanidins can inhibit the proliferation of some cancer cell lines and have strong antioxidant activity. The purpose of this study was to investigate whether grape seeds procyanidins affect the proliferation and redifferentiation in K562 cells. The sulforhodamine B colorimetric assay and trypan blue staining were used to measure cell proliferation and survival. Morphological changes, NBT reductive activity, and surface antigens were used to detect redifferentiation of K562 cells. Intracellular reactive oxygen species (iROS) were detected by a fluorescent probe. Grape seeds procyanidins inhibited cell proliferation but the treatment did not appreciably increase lethality. After treatment with grape seeds procyanidins, a typical differentiated morphology was observed. The positive rate of CD11b and CD14 cells and NBT reductive activities increased significantly. As antioxidants, grape seeds procyanidins can induce arrest in the phase G1 and decrease iROS formation. All results indicate that the antioxidant grape seeds procyanidins are likely to induce monocytic differentiation in leukemia cells, mostly through decreasing iROS formation and inducing phase G1 arrest.

  6. The Ethanol Extract of Fructus trichosanthis Promotes Fetal Hemoglobin Production via p38 MAPK Activation and ERK Inactivation in K562 Cells

    Directory of Open Access Journals (Sweden)

    Hui Li

    2011-01-01

    Full Text Available Pharmacological stimulation of fetal hemoglobin (HbF expression may be a promising approach for the treatment of beta-thalassemia. In this study, the effects of Fructus trichosanthis (FT were investigated in human erythroleukemic K562 cells for their gamma-globin mRNA and HbF-induction activities. The role of signaling pathways, including extracellular regulated protein kinase (ERK and p38 mitogen-activated protein kinase (MAPK, was also investigated. It was found that the ethanol extract of FT significantly increased gamma-globin mRNA and HbF levels, determined by real-time reverse transcription polymerase chain reaction and enzyme linked immunosorbent assay, respectively, in dose- and time-dependent manner. Total Hb (THb levels were also elevated in the concentrations without cytotoxicity (<80 μg mL−1. Pre-treatment with p38 MAPK inhibitor SB203580 blocked the stimulatory effects of FT extract in total and HbF induction. In contrast, no change in HbF was observed when treated with ERK inhibitor PD98059. Furthermore, FT ethanol extract activated p38 MAPK and inhibited ERK signaling pathways in K562 cells, as revealed in western blotting analysis. In addition, SB203580 significantly abolished p38 MAPK activation when the cells were treated with FT. In summary, the ethanol extract of FT was found to be a potent inducer of HbF synthesis in K562 cells. The present data delineated the role of ERK and p38 MAPK signaling as molecular targets for pharmacologic stimulation of HbF production upon FT treatment.

  7. EFFECT OF BcL-2 ANTISENSE DRUG WITH DIFFERENT STRUCTURE ON THE BIOLOGICAL FUNCTION OF K562 CELLS

    Institute of Scientific and Technical Information of China (English)

    雷小勇; 张洹; 何冬梅

    2004-01-01

    Objective: To study the differences and similarities of the antisense drugs with different structures on the biological functions of K562 cells. Methods: Cytotoxic effects were measured by use of a cell viability assay. Flow cytometric analysis and agarose gel electrophoresis of DNA fragmentation were also performed. The expression level of protein was assayed by immunofluorescence using fluoresce isothiocyanate label. Results: PNA targeting the coding region of the Bcl-2 messenger RNA could effectively inhibit K562 cell viability, down-regulate the synthesis of the Bcl-2 protein and increase cell apoptosis. By 72 h after the Bcl-2 antisense PNA treatment, K562 cells showed more reduction in the level of Bcl-2 protein compared with cells treated with the antisense ODN. After treatment with 10μmol/L of Bcl-2 antisense PNA or antisense ODN for 72 h, apoptotic rates of K562 cells were 13.15±1.13 and 11.72±1.12, respectively. Furthermore, there was significant difference in the percentage of apoptotic cells between antisense PNA group and antisense ODN group. Conclusion: The results suggest that antisense PNA targeting the coding region of Bcl-2 mRNA has better antisense effects than the antisense oligonucleotides on inducing apoptosis of K562 cells.

  8. Transferred BCR/ABL DNA from K562 extracellular vesicles causes chronic myeloid leukemia in immunodeficient mice.

    Directory of Open Access Journals (Sweden)

    Jin Cai

    Full Text Available Our previous study showed that besides mRNAs and microRNAs, there are DNA fragments within extracellular vesicles (EVs. The BCR/ABL hybrid gene, involved in the pathogenesis of chronic myeloid leukemia (CML, could be transferred from K562 EVs to neutrophils and decrease their phagocytic activity in vitro. Our present study provides evidence that BCR/ABL DNAs transferred from EVs have pathophysiological significance in vivo. Two months after injection of K562 EVs into the tail vein of Sprague-Dawley (SD rats, they showed some characteristics of CML, e.g., feeble, febrile, and thin, with splenomegaly and neutrophilia but with reduced neutrophil phagocytic activity. These findings were also observed in immunodeficient NOD/SCID mice treated with K562 EVs; BCR/ABL mRNA and protein were found in their neutrophils. The administration of actinomycin D, an inhibitor of de novo mRNA synthesis, prevented the abnormalities caused by K562 EVs in NOD/SCID mice related to CML, including neutrophilia and bone marrow hyperplasia. As a specific inhibitor of tyrosine kinases, imatinib blocked the activity of tyrosine kinases and the expression of phospho-Crkl, induced by the de novo BCR/ABL protein caused by K562 EVs bearing BCR/ABL DNA. Our current study shows the pathophysiological significance of transferred tumor gene from EVs in vivo, which may represent an important mechanism for tumorigenesis, tumor progression, and metastasis.

  9. The Effects of Royal Jelly on In-Vitro Cytotoxicity of K562 Cells and Peripheral Blood Mononuclear Cells

    Directory of Open Access Journals (Sweden)

    SE Hosseini

    2014-02-01

    Full Text Available Abstract Background & aim: Royal jelly, secreted by worker bees, has different biological activities on cells and tissues. The aim of this study was to evaluate the effects of royal jelly on peripheral blood mononuclear cells and on the tumor category of K562 cell line. Methods: In the present experimental study, three subjects were selected separately with three repetitions. K562 (104 cells and PBMC (105 cells with different concentrations of royal jelly (5, 10, 25, 50 and 100 mg/ml were cultured under standard conditions for 48 and 72 h separately. The fatality rate on PBMC cells and K562 cancer cells was evaluated by using MTT (Tetrazolium Dye-Reduction Assay. The number of viable cells in PBMC that were exposed for 48 hours with Royal Jelly was evaluated by trypan blue staining. Data were analyzed by ANOVA. Results: The royal jelly had no cytotoxicity effect on PBMC cells but at concentration of 50 and 100 mg/mL the cytotoxicity effect were observed on k562 cells whereas, at 10 and 25 mg/ml the number of PBMC viable cells increased. Conclusion: Due to the lack of lethality of royal jelly on PBMC cells and PBMC cell viability and an increase in the fatality rate of cancer cells in the future, royal jelly can be used as a potential candidate for treatment of leukemia. Keywords: Royal jelly, K562, peripheral blood mononuclear cell

  10. Phenylalanine sensitive K562-D cells for the analysis of the biochemical impact of excess amino acid.

    Science.gov (United States)

    Sanayama, Yoshitami; Matsumoto, Akio; Shimojo, Naoki; Kohno, Yoichi; Nakaya, Haruaki

    2014-11-06

    Although it is recognized that the abnormal accumulation of amino acid is a cause of the symptoms in metabolic disease such as phenylketonuria (PKU), the relationship between disease severity and serum amino acid levels is not well understood due to the lack of experimental model. Here, we present a novel in vitro cellular model using K562-D cells that proliferate slowly in the presence of excessive amount of phenylalanine within the clinically observed range, but not phenylpyruvate. The increased expression of the L-type amino acid transporter (LAT2) and its adapter protein 4F2 heavy chain appeared to be responsible for the higher sensitivity to phenylalanine in K562-D cells. Supplementation with valine over phenylalanine effectively restored cell proliferation, although other amino acids did not improve K562-D cell proliferation over phenylalanine. Biochemical analysis revealed mammalian target of rapamycin complex (mTORC) as a terminal target of phenylalanine in K562-D cell proliferation, and supplementation of valine restored mTORC1 activity. Our results show that K562-D cell can be a potent tool for the investigation of PKU at the molecular level and to explore new therapeutic approaches to the disease.

  11. Inhibitory Effects of Phellinus Linteus Intracellular Polysaccharide on the Proliferation of Leukemic Cells K562%桑黄胞内多糖对白血病细胞K562的增殖抑制效应研究

    Institute of Scientific and Technical Information of China (English)

    史新强; 沈业寿; 卫自; 马金宝; 合肥

    2007-01-01

    背景与目的:观察桑黄胞内多糖(PLIP)对体外培养的人白血病细胞K562的增殖抑制作用,并初步探讨其作用机制.材料和方法:采用MTT法及台盼蓝拒染法测定细胞增殖抑制率和生长曲线,Hoechst-PI双荧光染色,流式细胞术和DNA琼脂糖凝胶电泳检测细胞凋亡.结果:PLIP在25 μg/ml、50 μg/ml、100 μg/ml、200 μg/ml、400 μg/ml、800 μg/ml剂量时均能显著抑制K562细胞增殖(P<0.05),其中400 μg/ml剂量时抑制率最高,达52.55%,半数抑制浓度(IC50)为262.36 μg/ml,流式细胞仪检测PLIP在100 μg/ml、200 μg/ml、400 μg/ml剂量时K562细胞凋亡率分别为5.72%、13.57%、19.39%,并能诱导K562细胞出现凋亡所具有的形态学及生化特征.结论:PLIP对体外培养的人白血病细胞K562生长增殖具有明显的抑制作用,其作用机制可能与诱导K562细胞凋亡和影响细胞周期有关.

  12. Anti - K562 cells effect mediated by dendritic cells derived from cord blood pulsed with exosomes%Exosomes致敏的脐血树突细胞介导的抗K562细胞作用

    Institute of Scientific and Technical Information of China (English)

    卜宁; 李奇灵; 孙秉中; 张涛; 冯琦; 乔庆大

    2006-01-01

    目的分离K562细胞释放的exosomes,致敏脐血树突细胞(dendritic cell,DCs),观察其对细胞毒性T淋巴细胞(cytotoxic Tlymphocytes,CTLs)的激活效应.方法离心超滤和蔗糖密度梯度离心法分离K562细胞释放的exosomes,固相免疫电镜法(SPIEM)制备exosomes的HSP70、ICAM-1及ABL免疫电镜标本.常规方法从脐血单个核细胞诱导DCs并分离T细胞,将K562细胞来源的exosomes冲击或未冲击的DCs与T细胞共培养.MTT比色法检测体外细胞毒活性.结果K562细胞分泌的exosomes为直径50~100nm的膜性微囊.Exosomes致敏的脐血DCs激活CTLs的能力显著高于肿瘤冻融抗原致敏的DCs组,在效靶比为50:1时,两组CTLs对K562细胞的杀伤率为(68.4%vs35.3%,P<0.05).结论K562细胞分泌的exosomes负载脐血DCs后活化CTLs,有抗肿瘤活性.

  13. Molecular cross talk between Notch1, Shh and Akt pathways during erythroid differentiation of K562 and HEL cell lines.

    Science.gov (United States)

    Roy, Anita; Haldar, Srijan; Basak, Nandini Pal; Banerjee, Subrata

    2014-01-01

    Erythropoiesis is a tightly regulated process dependent on extrinsic signals conveyed by the bone marrow niche. The signalling pathways thus activated or repressed do not act in isolation; rather an intricate cross talk among these pathways ensues homoeostasis within the erythroid compartment. In this study, we describe the effects of two such signalling pathways namely the Notch1 and the Shh pathway on erythropoiesis in immortalised K562 and HEL cell lines as well as the cross talk that ensues between them. We show that while activation of the Notch1 pathway inhibits differentiation of erythroid lineage cell lines as well as in in-vitro primary erythroid cultures from the human CD34(+) cells; Shh pathway favours erythroid differentiation. Further, the Notch1 pathway activates the Akt pathway and constitutively active Akt partially mimics the effect of Notch1 activation on erythropoiesis. Moreover, the Notch1, Akt and Shh pathways were found to cross talk with each other. In this process, activation of Notch1 was found to down regulate the Shh pathway independent of Akt activation. Significantly, Notch1 not only down regulated the Shh pathway, but also inhibited recombinant Shh mediated erythropoiesis. Our study thus reveals an intricate crosstalk among the Notch1, Shh and Akt pathways wherein Notch1 emerges as a key regulator of erythropoiesis.

  14. ERK2-Pyruvate Kinase Axis Permits Phorbol 12-Myristate 13-Acetate-induced Megakaryocyte Differentiation in K562 Cells.

    Science.gov (United States)

    Chaman, Noor; Iqbal, Mohammad Askandar; Siddiqui, Farid Ahmad; Gopinath, Prakasam; Bamezai, Rameshwar N K

    2015-09-25

    Metabolic changes that contribute to differentiation are not well understood. Overwhelming evidence shows the critical role of glycolytic enzyme pyruvate kinase (PK) in directing metabolism of proliferating cells. However, its role in metabolism of differentiating cells is unclear. Here we studied the role of PK in phorbol 12-myristate 13-acetate (PMA)-induced megakaryocytic differentiation in human leukemia K562 cells. We observed that PMA treatment decreased cancer-type anabolic metabolism but increased ATP production, along with up-regulated expression of two PK isoforms (PKM2 and PKR) in an ERK2-dependent manner. Interestingly, silencing of PK (PKM2 and PKR) inhibited PMA-induced megakaryocytic differentiation, as revealed by decreased expression of megakaryocytic differentiation marker CD61 and cell cycle behavior. Further, PMA-induced ATP production reduced greatly upon PK silencing, suggesting that PK is required for ATP synthesis. In addition to metabolic effects, PMA treatment also translocated PKM2, but not PKR, into nucleus. ERK1/2 knockdowns independently and together suggested the role of ERK2 in the up-regulation of both the isoforms of PK, proposing a role of ERK2-PK isoform axis in differentiation. Collectively, our findings unravel ERK2 guided PK-dependent metabolic changes during PMA induction, which are important in megakaryocytic differentiation.

  15. ERK2-Pyruvate Kinase Axis Permits Phorbol 12-Myristate 13-Acetate-induced Megakaryocyte Differentiation in K562 Cells*

    Science.gov (United States)

    Chaman, Noor; Iqbal, Mohammad Askandar; Siddiqui, Farid Ahmad; Gopinath, Prakasam; Bamezai, Rameshwar N. K.

    2015-01-01

    Metabolic changes that contribute to differentiation are not well understood. Overwhelming evidence shows the critical role of glycolytic enzyme pyruvate kinase (PK) in directing metabolism of proliferating cells. However, its role in metabolism of differentiating cells is unclear. Here we studied the role of PK in phorbol 12-myristate 13-acetate (PMA)-induced megakaryocytic differentiation in human leukemia K562 cells. We observed that PMA treatment decreased cancer-type anabolic metabolism but increased ATP production, along with up-regulated expression of two PK isoforms (PKM2 and PKR) in an ERK2-dependent manner. Interestingly, silencing of PK (PKM2 and PKR) inhibited PMA-induced megakaryocytic differentiation, as revealed by decreased expression of megakaryocytic differentiation marker CD61 and cell cycle behavior. Further, PMA-induced ATP production reduced greatly upon PK silencing, suggesting that PK is required for ATP synthesis. In addition to metabolic effects, PMA treatment also translocated PKM2, but not PKR, into nucleus. ERK1/2 knockdowns independently and together suggested the role of ERK2 in the up-regulation of both the isoforms of PK, proposing a role of ERK2-PK isoform axis in differentiation. Collectively, our findings unravel ERK2 guided PK-dependent metabolic changes during PMA induction, which are important in megakaryocytic differentiation. PMID:26269597

  16. Separation and purification and in vitro anti-proliferative activity of leukemia cell K562 of Galium aparine L. petroleum

    Directory of Open Access Journals (Sweden)

    Guoqing Shi

    2016-05-01

    Full Text Available To explore material basis of in vitro anti-proliferative activity of leukemia cell K562 of petroleum ether phase of product resulting from Galium aparine L. 60% ethanol extraction, the experiment adopts column chromatography combined with thin layer preparation, isolates and purifies petroleum ether, conducts structural identification of obtained single compound and applies MTT method for viability assay of in vitro anti-proliferative activity of leukemia cell K562. Experimental results show that G. aparine L. petroleum ether contains mainly β-sitosterol, daucosterol and dibutyl phthalate and other substances. Under experimental conditions, the three could inhibit the proliferation of leukemia cell K562 with dose-effect and time-effect relationship, of which dibutyl phthalate has strongest activity. Dibutyl phthalate with excellent activity, β-sitosterol with rich content and moderate effect should be the main contributor to its biological activity.

  17. 地西他滨对NB4及K562细胞增殖和凋亡的影响%Effects of Decitabine on Proliferation and Apoptosis of NB4 and K562 Cells

    Institute of Scientific and Technical Information of China (English)

    韩新爱; 曾慧兰; 韩艳萍; 孙尔维

    2013-01-01

    本研究旨在观察去甲基化药物地西他滨(DAC)对NB4及K562细胞增殖和凋亡的影响.用台盼蓝染色法检测DAC对NB4及K562细胞的增殖抑制作用;流式细胞术检测不同浓度DAC作用后细胞周期的变化和CD11b的表达水平;瑞氏染色法观察药物作用后细胞形态变化;DNA梯形片段电泳分析细胞凋亡.结果表明,DAC显著抑制NB4及K562细胞的增殖(P<0.05),且呈浓度和时间依赖性,DAC作用NB4及K562细胞72 h的半数抑制浓度(IC50)分别为0.113 μmol/L和0.138 μmol/L;不同浓度DAC作用72 h后,0.15 μmol/L DAC处理组两种细胞株G0/G1期细胞比例均显著增高,而S期细胞比例降低(P<0.05);两种细胞株的髓系分化抗原CD11b表达水平均升高(P<0.05);两种细胞株经不同浓度DAC处理48 h后,0.15μmoVL DAC处理组均出现典型的凋亡梯形DNA条带.结论:DAC抑制NB4及K562细胞增殖,诱导细胞分化,促进细胞凋亡;DAC对NB4细胞作用更明显.%This study was aimed to investgate the effects of decitabine (DAC) on proliferation and apoptosis of leukemia NB4 and K562 cells. The proliferation inhibition of DAC on NB4 and K562 cells was detected by Trypan blue staining. After treatment of DAC at different concentrations, the changes of cell cycle and CD11b expression was determined by flow cytometry. The cell morphological changes were observed by Wright's staining. The DNA ladder was used to detect cell apoptosis. The results indicated that DAC significantly inhibited the proliferation of NB4 and K562 cells in dose-and time-dependent manner. The median inhibitory concentration (IC50) of DAC-treated NB4 and K562 cells for 72 h was 0.113 μmol/L and 0.138 μmol/L, respectively. After treating these two cell lines with DAC at different concentration for 72 h, the cell ratio in G0/G1 phase significantly increased, while the cell ratio in S phase obviously decreased in 0. 15 μmol/L DAC group (P < 0. 05 ). The expression levels of myeloid

  18. The Difference of Sensitivity between BXPC-3 and K562 Cells by Treatments with Combination of Indole-3-acetic Acid and Horseradish Peroxidase

    Institute of Scientific and Technical Information of China (English)

    BEN Yali; LIU Deli; ZHU Dali; ZHU Derui; LUO Qin

    2006-01-01

    The difference of sensitivity to indole- 3-acetic acid ( IAA ) combined with horseradish peroxidase (HRP) in K562 and BXPC- 3 cells was investigated. The cell proliferation was determined by MTT assay. The cell cycle and apoptosis of K562 and BXPC- 3 cells were examined by a fluorescence flow cytometer (FCM) and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) respectively. The experimental results show that IAA and HRP could inhibit BXPC- 3 cell proliferation greatly compared with K562 cell during the first 48 h . The cell cycle was arrested predominantly at G2/ M phase in K562 and BXPC- 3 cells. The cell apoptosis of K562 and BXPC- 3 was induced by IAA/ HRP. There was a significant difference between the two cell lines since BXPC- 3 cells were more sensitive than K562 cells by treatments with combination of IAA and HRP.

  19. Growth-inhibiting Effect of Patrinia Scabra Bunge Lignanoid on K562 Cells%糙叶败酱总木脂素对K562细胞体外生长的影响

    Institute of Scientific and Technical Information of China (English)

    陈茹; 赵健雄; 王学习; 李世刚; 王惠娟

    2007-01-01

    目的:探讨糙叶败酱提取物总木脂素对K562细胞体外生长的影响及作用机制.方法:采用四甲基偶氮唑盐比色法(monotetrazolium test,MTT)测定糙叶败酱总木脂素对K562细胞生长的影响;采用电镜技术对其进行形态学观察;采用流式细胞仪对其进行DNA含量分析,检测经药物作用后的细胞凋亡率.结果:糙叶败酱总木脂素对K562细胞生长有明显的抑制作用,抑制作用随药物浓度增加及作用时间延长而有加强趋势,细胞经糙叶败酱总木脂素作用96h,IC50 21.16μg/mL.电镜下观察到经糙叶败酱总木脂素作用48h后,一部分K562细胞体积变小,胞浆浓缩,胞核染色质聚集或边集,核碎裂,凋亡小体形成,呈典型的凋亡形态特征.流式细胞仪可检测到经糙叶败酱总木脂素诱导K562细胞48h后产生明显的亚二倍体峰,细胞凋亡率为10.1%.结论:糙叶败酱总木脂素可抑制K562细胞的生长,作用的机制与其诱导K562细胞凋亡有关.

  20. Antizyme1基因转染对K562细胞增殖与凋亡的影响%The Effect of Antizymel Transfection on Cell Proliferation and Cell Apoptosis in K562 Cells

    Institute of Scientific and Technical Information of China (English)

    姜立; 马文丽; 李晋; 彭翼飞; 徐兵; 郑文岭

    2007-01-01

    目的: 研究鸟氨酸脱羧酶抗酶蛋白对人红白血病K562细胞增殖、三氧化二砷( As2O3)诱导凋亡时的影响.方法: 定点突变技术构建缺失frameshift位点的pEGFP-N1-AZ1-mutation重组表达载体.脂质体法转染K562细胞,通过G418筛选获得稳定表达antizyme1的K562pAZ1m细胞系.采用不同浓度的As2O3处理细胞,通过MTT法检测细胞增殖,流式细胞术分析细胞周期及凋亡变化.并通过RT-PCR方法检测antizyme1转染对cyclin D1和survivin基因表达的影响.结果:获得稳定表达antizyme1的K562pAZ1m细胞株后,其增殖能力明显减慢.cyclin D1基因表达降低,细胞主要停滞于G0/G1期.在 As2O3的诱导作用下,细胞凋亡增多,survivin基因表达降低.结论:AZ1基因能够抑制K562细胞增殖,通过对cyclin D1的负调控使细胞周期停滞于G0/G1期.并可能通过下调survivin表达来加强 As2O3对其的诱导凋亡作用.

  1. Apoptosis induced by (di-isopropyloxyphoryl-Trp)2-Lys-OCH3 in K562 and HeLa cells

    Indian Academy of Sciences (India)

    Feng Liu; Shi-Ying Liu; Ping Xu; Zhen-Hua Xie; Guo-Ping Cai; Yu-Yang Jiang

    2008-03-01

    According to the method used in our laboratory, our group synthesized (DIPP-Trp)2-Lys-OCH3. It inhibited the proliferation of K562 and HeLa cells in a dose- and time-dependent manner with an IC50 of 15.12 and 42.23 M, respectively. (DIPP-Trp)2-Lys-OCH3 induced a dose-dependent increase of the G2/M cell population in K562 cells, and S cell population in HeLa cells; the sub-G0 population increased dramatically in both cell lines as seen by PI staining experiments using a FACS Calibur Flow cytometer (BeckmanCoulter, USA). Phosphatidylserine could significantly translocate to the surface of the membrane in (DIPP-Trp)2-Lys-OCH3-treated K562 and HeLa cells. The increase of an early apoptotic population was observed in a dose-dependent manner by both annexin-FITC and PI staining. It was concluded that (DIPP-Trp)2-Lys-OCH3 not only induced cells to enter into apoptosis, but also affected the progress of the cell cycle. It may have arrested the K562 and HeLa cells in the G2/M, S phases, respectively. The apoptotic pathway was pulsed at this point, resulting in the treated cells entering into programmed cell death. (DIPP-Trp)2-Lys-OCH3 is a potential anticancer drug that intervenes in the signalling pathway.

  2. Quantitative Proteomic Analysis of Bromotetrandrine and Tetrandrine in K562 Cell Line Using 18O-labeling Method

    Institute of Scientific and Technical Information of China (English)

    TAN Ying; GE Zhi-qiang; LIU Chang-xiao

    2012-01-01

    Objective To compare quantitative proteomic analysis of bromotetrandrine (W198) which was a Class Ⅰ new antitumor drug in China and tetrandrine (Tet) in K562 cell line using 18O-labeling method.Methods To illustrate its mechanism,a shotgun quantitative proteomic strategy employing 2D LC-MS-MS and trypsin catalyzed 18O-labeling quantification was carried out in this study.Compared to normal chronic leukemia cell line K562 and K562 induced by Tet,the proteomic changes of K562 induced by W198 were investigated.In order to validate the quantitation by the 18O-labeling,the analysis was done on an equivalent sample composed of the same amount of labeled and unlabeled proteins from normally cultured cells to act as a reference to the comparative sample.Results A threshold of ± 2-fold change for deciding whether a protein concentration was changed was settled for the following experiments.Comparing the 105 identified soluble proteins' expression levels of the apoptosis starting up K562 cells after W198 induction with the normally cultured cells,16 proteins were found with significantly altered expression levels after W198 treatment.Eight proteins were up-expressed including HMGB2,peroxiredoxin-2,and eIF4A-I,etc.Eight proteins were down-expressed including TCP-1,GRP94,GST-π,and SFGHs,etc.Compared to K562 induced by Tet,eight proteins of K562 were found with significantly altered expression levels after W198 treatment.Five proteins were up-expressed including HSP 90-β and 40S ribosomal protein S15a,etc.Three proteins were down-expressed including phosphoglycerate kinase 1,isoform 5 of interleukin enhancer-binding factor 3,etc.Conclusion The 18O-labeling MS-MS-based method is ideal as a discovery tool,but it is not suitable for validation using a large number of samples.Other more effective methods,such as Western blotting should be used for further validation of candidate cancer proteins discovered from 18O-labeling samples.In total,105 soluble proteins were discovered

  3. [Enhancement of reversing drug resistance of K562/A02 cells to adriamycin by ultrasound-induced cavitation].

    Science.gov (United States)

    Chen, Bao-An; Meng, Qing-Qi; Wu, Wei; Gao, Feng; Shao, Ze-Ye; Ding, Jia-Hua; Gao, Chong; Sun, Xin-Chen; Cheng, Hong-Yan; Sun, Yun-Yu; Wang, Jun; Cheng, Jian; Zhao, Gang; Song, Hui-Hui; Bao, Wen; Ma, Yan; Wang, Xue-Mei

    2008-12-01

    This study was aimed to investigate the effects of low frequency and power ultrasound combined with adriamycin on apoptosis of drug-resistant leukemia cell line K562/A02 in vitro, to find out the parameters of optimal exposure, and to explore the possible mechanism reversing drug-resistance of K562/A02 cells. The K562/A02 cells in logarithmic growth phase were used in experiments. The experiments were divided into 4 groups: group control, group adriamycin (A02) alone, group ultrasound (US) alone and group A02+US. The trypan blue dye exclusion test and MTT assay were used to determine the cell viability; Wright's staining was used to detect the apoptosis; the flow cytometry was used to analyze the drug concentration, and the scanning electron microscopy was used to observe the changes of cell surface. The results showed that the significant differences in cell viability, intracellular adriamycin concentration and changes of cell membrane were found between ultrasound-treated and untreated cells in the presence of various concentration of adriamycin. The exposure to ultrasound at 20 kHZ, 0.25 W/cm2 for 60 seconds could obviously decrease LC50 of adriamycin to K562/A02 cells, while the exposure to ultrasound at 20 kHZ, 0.05 W/cm2 for 60 seconds could kill K562/A02 cells at once. After being treated by low frequency ultrasound, the small holes with diameter about 1-2 microm in the cell surface appeared. The ultrasound increased the adriamycin concentration in the cells, accelerated the formation of apoptotic bodies, and promoted apoptosis of adriamycin-resistant cells. It is concluded that the ultrasound at optimal parameters enhances inhibitory effect of adriamycin on drug-resistant cell line, thereby reverses drug-resistance of drug-resistant cell line through sound-hole effect in tumor cells resulting from ultrasound induced cavitation.

  4. H ferritin silencing induces protein misfolding in K562 cells: A Raman analysis

    KAUST Repository

    Zolea, Fabiana

    2015-10-09

    The redox state of the cell is involved in the regulation of many physiological functions as well as in the pathogenesis of several diseases, and is strictly dependent on the amount of iron in its catalytically active state. Alterations of iron homeostasis determine increased steady-state concentrations of Reactive Oxygen Species (ROS) that cause lipid peroxidation, DNA damage and altered protein folding. Ferritin keeps the intracellular iron in a non-toxic and readily available form and consequently plays a central role in iron and redox homeostasis. The protein is composed by 24 subunits of the H- and L-type, coded by two different genes, with structural and functional differences. The aim of this study was to shed light on the role of the single H ferritin subunit (FHC) in keeping the native correct protein three-dimensional structure. To this, we performed Raman spectroscopy on protein extracts from K562 cells subjected to FHC silencing. The results show a significant increase in the percentage of disordered structures content at a level comparable to that induced by H2O2 treatment in control cells. ROS inhibitor and iron chelator were able to revert protein misfolding. This integrated approach, involving Raman spectroscopy and targeted-gene silencing, indicates that an imbalance of the heavy-to-light chain ratio in the ferritin composition is able to induce severe but still reversible modifications in protein folding and uncovers new potential pathogenetic mechanisms associated to intracellular iron perturbation.

  5. Hemin-dependent induction and internalization of CD38 in K562 cells.

    Science.gov (United States)

    Yalcintepe, Leman; Ercelen, Sebnem; Adin-Cinar, Suzan; Badur, Selim; Tiryaki, Demir; Bermek, Engin

    2003-10-01

    The cell surface antigen, CD38, is a bifunctional ecto-enzyme, which is predominantly expressed on hematopoietic cells during differentiation. In the present study, it is shown that hemin treatment of K562 cells gives rise to induction of enzymatic activities inherent to CD38. GDP-ribosyl cyclase activity, an indicator of CD38, increased initially in response to hemin in a time-dependent manner, reached a maximum level on the 5th day and, thereafter, declined sharply to the initial level. The increase in NAD(+) glycohydrolase and ADP-ribose uptake activities followed a similar time course. However, the decline in the latter activities after the 5th day of induction appeared to be rather slow in contrast to GDP-ribosyl cyclase activity. The time course of these changes was well correlated with the FACScan findings obtained by use of anti-CD38 monoclonal antibody. SDS-PAGE and Western blot analyses by use of the monoclonal antibody OKT10 revealed a transient hemin-dependent appearance of a 43 kDa membrane protein with maximum signal intensity on the first 4 days of incubation. There was subsequently a gradual decrease on the 5th day, concomitant with a reciprocal increase in activity of the internalized protein fraction. The results together indicated that hemin-induced expression of CD38 was followed by its down-regulation.

  6. STAT3 contributes to NK cell recognition by modulating expression of NKG2D ligands in adriamycin-resistant K562/AO2 cells.

    Science.gov (United States)

    Cai, Xiaohui; Lu, Xuzhang; Jia, Zhuxia; Zhang, Xiuwen; Han, Wenmin; Rong, Xiao; Ma, Lingdi; Zhou, Min; Chen, Baoan

    2015-11-01

    Leukemic cells can survive after chemotherapy by acquisition of multidrug resistance genes, but other phenotypes related to escape from immune recognition remain elusive. Adriamycin-resistant K562/AO2 cells are less susceptible to elimination by NK cells compared with wild type K562 cells due to lower expression of NKG2D ligands. Treatment of K562/AO2 cells with STAT3 inhibitor VII resulted in reduced expression of multidrug resistance gene P-glycoprotein, and up-regulation of NKG2D ligands on K562/AO2 cells. Meanwhile, K562/AO2 cells treated with STAT3 inhibitor proliferated less and were more susceptible to killing by NK cells than untreated K562/AO2 cells. The enhanced cytotoxicity of NK cells against K562/AO2 cells was partly blocked by treatment of NK cells with anti-NKG2D antibodies. These data suggest that STAT3 contributes to NK cell recognition by modulating NKG2D ligands in K562/AO2 cells, which may a mechanism by which cells survive and cause relapse of leukemia.

  7. Mechanism of ginseng polysaccharide on apoptosis and cell cycle in leukemia K562 cells%人参多糖对K562细胞凋亡与细胞周期的影响及其机制

    Institute of Scientific and Technical Information of China (English)

    刘艺; 陈地龙; 何轩; 姜蓉; 王建伟; 左国伟; 魏强; 赵亮; 李静

    2012-01-01

    Objective To investigate the mechanism of ginseng polysaccharide (GPS) on the cell cycle and apoptosis in leukemia K562 cells. Methods Leukemia K562 cells in logarithmic phase with density of 7 x 108L-1 were incubated with (GPS group) and without (control group) 400 mg/L GPS, respectively. The effects of GPS on K562 cell cycle and apoptosis were determined by flow cytometry ( FCM). The mRNA expression of ERK was detected by RT-PCR. The distributions and protein expressions of ERK, p-ERK, NF-kB and cyclin D, were detected by immunohistochemical staining and Western blotting. Results Compared with the control group, the apoptosis rate of the K562 cells in the GPS group significantly increased after treatment for 24, 48 and 72 h (P 0. 05), but the differences of p-ERK, NF-kB and cyclin D, were statistically significant between the GPS group and the control group ( P < 0. 05). Conclusion GPS can induce cell cycle arrest in G0/G1 phase and cell apoptosis of K562 cells in a time-dependent manner, probably through inhibiting ERK/NF-kB signaling pathway and thus reducing cyclin D, expression.%目的 探讨人参多糖(ginseng polysaccharide,GPS)诱导白血病细胞K562凋亡和周期阻滞的机制.方法 取对数生长期的K562细胞,调整密度为7×108/L,空白对照组予以常规培养;GPS组加入400 mg/L GPS.流式细胞仪测定细胞的凋亡率及细胞周期分布变化;RT-PCR检测细胞ERK表达的变化.免疫组化的方法检测细胞中p-ERK、NF-κB、Cyclin D1蛋白定位及表达量的变化.Western blot检测细胞中ERK、p-ERK、NF-κB、Cyclin D1蛋白的变化.结果 与对照组比较,K562细胞在400mg/L GPS的作用下,体外培养24、48、72 h后,GPS组细胞凋亡率显著增高(P<0.05),周期分布检测结果显示,与对照组相比,GPS组K562细胞G0/G1期细胞数量呈时间依赖性增多(P<0.05),G2+M、S期细胞数量则明显减少(P<0.05).RT-PCR检测结果显示,400 mg/L GPS处理48 h组ERK mRNA的表

  8. 核苷类似物对K562细胞的抗增殖和诱导分化作用%Nucleoside analog inhibiting proliferation and inducing differentiation of K562 cells

    Institute of Scientific and Technical Information of China (English)

    居小萍; 王健民; 周虹; 夏放; 袁有忠

    2001-01-01

    目的:探讨核苷类似物阿昔洛韦(ACV)、更昔洛韦(GCV)对人白血病细胞的抗增殖和诱导分化作用.方法:将ACV、GCV分别加入K562细胞培养4 d,测定其活细胞数目、克隆形成率、联苯胺染色阳性率,观察光镜形态、组织化学染色,并进行流式细胞分析、端粒酶检测.结果:在ACV、GCV的作用下,K562细胞的增殖受抑,生长分数降低,并且向具有合成血红蛋白能力的细胞分化.结论:核苷类似物ACV、GCV对K562细胞具有抑制增殖和诱导分化作用,该结果为慢性粒细胞白血病的治疗提示了新的途径.

  9. 糙叶败酱总木脂素对K562细胞基因表达的影响%EFFECT OF PATRINIA SCABRA BUNGE LIGNANS ON GENE EXPRESSION PROFILING OF K562 CELLS

    Institute of Scientific and Technical Information of China (English)

    高佩媛; 程卫东

    2008-01-01

    [目的]研究糙叶败酱总木脂素对白血病K562细胞基因表达的影响.探讨糙叶败酱治疗白血病的药理作用机制.[方法]分别提取药物治疗组表模型组K562细胞总RNA, Cy3和Cy5荧光标记,反转录分别合成cDNA探针后,与基因表达谱芯片杂交,ScanArray Lite扫描仪扫描芯片,Quantarray软件分析表达信号.[结果]总木脂素处理前后比较差异表达的基因共有147个,其中表达上调的有68个,表达下调的有79个.[结论]糙叶败酱总木脂素对K562细胞基因表达具有调控作用,从分子水平阐释了糙叶败酱治疗白血病的药理作用机制.

  10. The GATA1s isoform is normally down-regulated during terminal haematopoietic differentiation and over-expression leads to failure to repress MYB, CCND2 and SKI during erythroid differentiation of K562 cells

    Directory of Open Access Journals (Sweden)

    Halsey Christina

    2012-08-01

    Full Text Available Abstract Background Although GATA1 is one of the most extensively studied haematopoietic transcription factors little is currently known about the physiological functions of its naturally occurring isoforms GATA1s and GATA1FL in humans—particularly whether the isoforms have distinct roles in different lineages and whether they have non-redundant roles in haematopoietic differentiation. As well as being of general interest to understanding of haematopoiesis, GATA1 isoform biology is important for children with Down syndrome associated acute megakaryoblastic leukaemia (DS-AMKL where GATA1FL mutations are an essential driver for disease pathogenesis. Methods Human primary cells and cell lines were analyzed using GATA1 isoform specific PCR. K562 cells expressing GATA1s or GATA1FL transgenes were used to model the effects of the two isoforms on in vitro haematopoietic differentiation. Results We found no evidence for lineage specific use of GATA1 isoforms; however GATA1s transcripts, but not GATA1FL transcripts, are down-regulated during in vitro induction of terminal megakaryocytic and erythroid differentiation in the cell line K562. In addition, transgenic K562-GATA1s and K562-GATA1FL cells have distinct gene expression profiles both in steady state and during terminal erythroid differentiation, with GATA1s expression characterised by lack of repression of MYB, CCND2 and SKI. Conclusions These findings support the theory that the GATA1s isoform plays a role in the maintenance of proliferative multipotent megakaryocyte-erythroid precursor cells and must be down-regulated prior to terminal differentiation. In addition our data suggest that SKI may be a potential therapeutic target for the treatment of children with DS-AMKL.

  11. Apoptosis induced by(DIPP-L-Leu)2-L-Lys-OCH3 in K562 cells

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Apoptosis as a mechanism of deleting cells from tissues plays an important role in physiological and varieties of pathological situations, especially cancer conditions. In order to search for tumor cells apoptosis inducers, the inhibition effects on K562 cells of N-phosphoryl dipeptide methyl esters were studied by MTT assays, and (DIPP-L-Leu)2- L-Lys-OCH3 was the compound which had the best activity. From the studies of the typical apoptotic morphologic changes, DNA agarose gel electrophoresis, and flow cytometry analysis, it could be concluded that (DIPP-L-Leu)2- L-Lys-OCH3 could induce apoptosis of K562 cells in a dose-dependent manner, and the IC50 was 22.66 mol/L according to MTT assays.

  12. Different photodynamic effect between continuous wave and pulsed laser irradiation modes in k562 cells in vitro

    Science.gov (United States)

    Klimenko, V. V.; Bogdanov, A. A.; Knyazev, N. A.; Rusanov, A. A.; Dubina, M. V.

    2014-10-01

    Photodynamic therapy is a cancer treatment method is used primarily continuous mode laser radiation. At high power density irradiation occurs intense consumption of molecular oxygen and this caused hypoxic tumor tissue, which leads to inefficiency PDT. In this paper, pulsed and continuous irradiation modes during PDT photosensitizer Radachlorin were compared. A mathematical model for the generation of singlet oxygen 1O2 in tumor cells during photodynamic therapy with tissue oxygenation was developed. Our study theoretically and experimentally demonstrates the increased singlet oxygen generation efficiency in a pulsed irradiation mode compared to continuous wave mode with the same power density 20mW/cm2. Experimental in vitro showed that pulsed irradiation mode mostly induces apoptosis k562 tumor cells at irradiation doses of k562 1.25 - 2.5J/cm2 while the continuous mode induced necrosis.

  13. Experimental study on K562 cells and hematopietic stemcells with Fuzheng-Quxie Tablet%扶正祛邪丹对K562细胞株及造血干细胞的影响

    Institute of Scientific and Technical Information of China (English)

    王展翔; 许勇钢; 麻柔; 杨经敏; 刘锋; 郑金福; 廖军鲜

    2001-01-01

    目的:研究扶正祛邪丹对K562细胞株和小鼠造血干细胞的影响,探讨扶正祛邪丹治疗骨髓增生异常综合征的疗效机理。方法:扶正祛邪丹含药兔血清培养K562细胞株,用流式细胞仪检测P53蛋白表达、细胞活力、细胞凋亡与细胞周期;用造血干细胞培养法观察扶正祛邪丹对BALB/C小鼠骨髓造血干细胞增殖的影响。结果:扶正祛邪丹对K562细胞株P53蛋白表达有抑制作用,对红系造血祖细胞有促进作用。不能诱导细胞凋亡,对细胞增殖周期无明显影响,对小鼠骨髓粒系造血干细胞无明显促进作用。结论:扶正祛邪丹促进红系造血干细胞增殖,降低P53蛋白表达,可能为其主要疗效机理。%Objective:To study the mechanism of Fuzheng Quxie Tablet (FZQXD) in treating myelodysplastic syndromes (MDS).Methods: The in vitro effect of FZQXD on K562 cell line and hematopietic stem cells were studied with flow cytometery and cell cultuer.Results:FZQXD inhibited P53 protein expression,markedly promoted the proliferation of colony forming unit-erythrocytes(CFU-E).no effect on K562 cell in inducing apoptosis and cell-cycle.Conclusions:That FZQXD slightly inhibited P53 protein expression and markedly promoted the proliferation of colony forming unit-erythrocytes (CFU-E) might be one of the mechanisms in treating myelodysplastic syndromes.

  14. Modification of antioxidative and antiapoptotic genes expression in irradiated K562 cells upon fullerenol C60(OH)24 nanoparticle treatment.

    Science.gov (United States)

    Stankov, Karmen; Borisev, Ivana; Kojic, Vesna; Rutonjski, Lazar; Bogdanovic, Gordana; Djordjevic, Aleksandar

    2013-01-01

    Recent data established the prospective applications for fullerenol (C60(OH)24) nanoparticle (FNP) in many fields, such as antioxidants, neuroprotective agents, and potential anti-radiation drugs. Leukemia cell sensitization to apoptosis induced by ionizing radiation is achieved by upregulation of ROS production and/or downregulation of antioxidative enzymes. Therefore, our aim was to analyze the potential role of fullerenol nanoparticle in modulation of the leukemic cellular response to irradiation. We used the qRT-PCR to analyze the expression level of mRNA for 11 genes in irradiated and FNP pre-treated irradiated K562 cells, and compared the gene expression level with the overall cell survival. Our results of the improved cell survival in FNP-treated irradiated cells and significant overexpression of anti-apoptotic Bcl-2 and Bcl-xL and cytoprotective genes such as GSTA4, MnSOD, NOS, CAT and HO-1 genes, may indicate that FNP exerts cytoprotective function in K562 leukemic cells, rendering K562 cells more tolerant to radiotherapy.

  15. Evaluation of Morpholino Antisense Oligos’ Role on BCR-ABL Gene Silencing in the K562 Cell Line

    Directory of Open Access Journals (Sweden)

    Bahman Delalat

    2010-01-01

    Full Text Available Objective: Chronic myeloid leukemia (CML develops when a hematopoietic stem cellacquires the BCR/ABL fusion gene. This causes these transformed hematopoietic cellsto have a greater than normal proliferation rate. Scientists attempt to improve the CMLtreatment process by silencing the BCR/ABL oncogene. In this work, we used morpholinoantisense oligos to silence the BCR/ABL oncogene.Materials and Methods: In this study, the K562 was used as a BCR/ABL fusion-genepositive cell line and the Jurkat cell line as a control. We explored the inhibiting capacityof morpholino antisense oligos in the the expression of the BCR/ABL oncogene andstudied their p210 BCR/ABL suppression, inhibition of cell proliferation and stimulation ofapoptosis in the K562 cells after 24 and 48 hours. Endo-Porter was used for delivery ofmorpholino antisense oligos into cell cytosols. Meanwhile, flow cytometric analysis wasperformed in order to determine the appropriate concentration of morpholino antisenseoligos.Results: Prolonged exposure of the K562 cell line to the morpholino antisense oligostargeted against the BCR-ABL gene showed proliferation inhibition as its main feature.After western blotting, we found that complete silencing of BCR/ABL was achieved, butflow cytometric analysis showed no broad apoptosis.Conclusion: The results indicate that the Morpholino antisense oligo is able to inhibitp210 BCR/ABL; however, it cannot induce broad apoptosis due to co-silencing of BCR.

  16. A new disposable electrode for electrochemical study of leukemia K562 cells and anticancer drug sensitivity test.

    Science.gov (United States)

    Yu, Chunmei; Zhu, Zhenkun; Wang, Li; Wang, Qiuhong; Bao, Ning; Gu, Haiying

    2014-03-15

    Developing cost-effective and simple analysis tools is of vital importance for practical applications in bioanalysis. In this work, a new disposable electrochemical cell sensor with low cost and simple fabrication was proposed to study the electrochemical behavior of leukemia K562 cells and the effect of anticancer drugs on cell viability. The analytical device was integrated by using ITO glass as the substrate of working electrodes and paper as the electrolytic cell. The cyclic voltammetry of the K562 cells at the disposable electrode exhibited an irreversible anodic peak and the peak current is proportional to the cell number. This anodic peak is attributed to the oxidation of guanine in cells involving two protons per transfer of two electrons. For the drug sensitivity tests, arsenic trioxide and cyclophosphamide were added to cell culture media. As a result, the electrochemical responses of the K562 cells decreased significantly. The cytotoxicity curves and results obtained corresponded well with the results of CCK-8 assays. In comparison to conventional methods, the proposed method is simple, rapid and inexpensive. More importantly, the developed sensor is supposed to be a single-use disposable device and electrodes were prepared "as new" for each experiment. We think that such disposable electrodes with these characteristics are suitable for experimental study with cancer cells or other types of pathogens for disease diagnosis, drug selection and on-site monitoring.

  17. [Effects of compound Zhe-Bei granule (CZBG) combined with doxorubicin on expression of membrane transport proteins in K562/A02 cell xenografts].

    Science.gov (United States)

    Li, Dong-Yun; Zheng, Zhi; Hou, Li; Jiang, Miao; Dong, Qing; Tian, Shao-Dan; Ma, Wei; Chen, Ju; Wang, Jing; Chen, Xin-Yi

    2010-02-01

    This study was purposed to investigate the effects of compound Zhe-Bei granule (CZBG) combined with doxorubicin on expressions of P-gp, MRP, LRP in K562/A02 cell xenografts. Tumor xenograft model were established by injecting the multidrug resistant cell line K562/A02 in the axillary flank of BALB/c-nu-nu mice. CZBG-intragastric administration and doxorubicin-intraperitoneal injection in combination were given to the BALB/c-nu nude mice. The tumor xenografts were made into slice after the dissection, and the expression of P-gp, MRP, LRP in K562/A02 tumor xenografts in mice were investigated by immunohistochemical technique. The integral optical density (IOD) of P-gp, MRP, LRP in K562/A02 tumor xenografts were measured by Image Pro Plus 6.0. The results showed that as compared with the doxorubicin alone, the combination of the doxorubicin and CZBG with high, middle and low dosage could decrease IOD of P-gp, MRP in K562/A02 tumor xenografts with statistical significance (p < 0.05). The LRP expression in K562/A02 tumor xenografts was not observed in five groups. It is concluded that the combination of CZBG with doxorubicin decreases the expressions of P-gp, MRP in K562/A02 tumor xenografts of mice.

  18. Effect of NF-κB signaling pathway on the formation of multidrug resistance in K562/A02 cells%NF-κB信号通路的激活对白血病细胞K562/A02多药耐药的影响

    Institute of Scientific and Technical Information of China (English)

    孙海英; 李德志; 徐开林; 李振宇; 曾令宇; 鹿群先

    2009-01-01

    目的 研究K562细胞株及其耐药细胞株K562/A02 NF-κ B活性的差异性表达,探讨白血病多药耐药(MDR)发病机制.方法 用MTT法检测K562/A02的耐药倍数,观察细胞生长的形态学变化,PI单染法检测K562/S、K562/A02细胞周期分布,并用RT-PCR方法榆测mRNA的表达、流式细胞仪检测P糖蛋白(P-gp)表达及其功能,Western blotting方法检测细胞核NF-κB p65表达,比较K562K562/A02白血病耐药细胞株之间的差异性.结果 与K562细胞不同,耐药细胞株K562/A02细胞生长特性发生改变,旱半贴壁生长,与K562/S细胞相比,K562/A02细胞的G0/G1期、S期比例增高,G2/M期细胞比例减低,差异有统计学意义(P<0.05),凋亡细胞比例差异无统计学意义(P>0.05),且检测到mdrl mRNA及细胞膜P-gp表达增高以及细胞核内NF-κB p65表达明显增加.结论 NF-κ B信号通路的激活即NF-κ B p65细胞核内转位可能参与了白血病MDR的形成.%Objective To explore the different expression of NF-κB in both K562 and its multidrug resistant cell line K562/A02 and discuss the mechanism of muhidrug resistance(MDR). Methods To detect the growing feature of the cells. Flow cytometry was used to analys the difference between the distribution profile of K562/S and K562/A02 cell. MTT colorimetry was used to determine the cytotoxic effect of adramycin, and expression of mdrl gene was detected by semi-quantitative reverse transcriptase poly-merase chain reaction (RT-PCR) in K562 and K562/A02 cells. FACS was used to determine the expression and function of glycoprotein (P-gp) on the cell membrane. Western blotting was used to determine the NF-κB p65protein in nueleus. Results There was a difference between K562 and K562/A02 cells growed in a halfadherent way rather than suspending ones, there were increases in the percentage number of cells at G0/G1 and S phases(P <0.05). This was mirrored by a decreasing number of cells within the G2/M phase(P<0.05). Butthere was

  19. Up-regulation of NKG2D ligand ULBP2 by matrine in K562 cells and the underlying molecular mechanisms

    Institute of Scientific and Technical Information of China (English)

    马玲娣

    2014-01-01

    Objective To probe matrine acting on natural killer cell(NK)activating receptor NKG2D ligands expression in CML cell line K562 and its underlying molecular mechanism.Methods The expression of NKG2D ligands(major histocompatibility complex class I chain-related molecule A or B(MICA/B),UL16-binding proteins(ULBP)1,2,and 3 on K562 cells were analyzed before and after treated with matrine by FCM.The cytotoxic sensitivity of K562 to NK cell was detected by FCM after

  20. Stat5 Exerts Distinct, Vital Functions in the Cytoplasm and Nucleus of Bcr-Abl{sup +} K562 and Jak2(V617F){sup +} HEL Leukemia Cells

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Axel [Georg-Speyer-Haus, Institute for Tumor Biology and Experimental Therapy, Frankfurt am Main 60596 (Germany); Borghouts, Corina [Ganymed Pharmaceuticals AG, Mainz 55131 (Germany); Brendel, Christian [Boston Children’s Hospital, Division of Hematology/Oncology, Boston, MA 02115 (United States); Moriggl, Richard [Ludwig Boltzmann Institute for Cancer Research (LBI-CR), Vienna 1090 (Austria); Delis, Natalia; Brill, Boris; Vafaizadeh, Vida; Groner, Bernd, E-mail: Groner@em.uni-frankfurt.de [Georg-Speyer-Haus, Institute for Tumor Biology and Experimental Therapy, Frankfurt am Main 60596 (Germany)

    2015-03-19

    Signal transducers and activators of transcription (Stats) play central roles in the conversion of extracellular signals, e.g., cytokines, hormones and growth factors, into tissue and cell type specific gene expression patterns. In normal cells, their signaling potential is strictly limited in extent and duration. The persistent activation of Stat3 or Stat5 is found in many human tumor cells and contributes to their growth and survival. Stat5 activation plays a pivotal role in nearly all hematological malignancies and occurs downstream of oncogenic kinases, e.g., Bcr-Abl in chronic myeloid leukemias (CML) and Jak2(V617F) in other myeloproliferative diseases (MPD). We defined the mechanisms through which Stat5 affects growth and survival of K562 cells, representative of Bcr-Abl positive CML, and HEL cells, representative for Jak2(V617F) positive acute erythroid leukemia. In our experiments we suppressed the protein expression levels of Stat5a and Stat5b through shRNA mediated downregulation and demonstrated the dependence of cell survival on the presence of Stat5. Alternatively, we interfered with the functional capacities of the Stat5 protein through the interaction with a Stat5 specific peptide ligand. This ligand is a Stat5 specific peptide aptamer construct which comprises a 12mer peptide integrated into a modified thioredoxin scaffold, S5-DBD-PA. The peptide sequence specifically recognizes the DNA binding domain (DBD) of Stat5. Complex formation of S5-DBD-PA with Stat5 causes a strong reduction of P-Stat5 in the nuclear fraction of Bcr-Abl-transformed K562 cells and a suppression of Stat5 target genes. Distinct Stat5 mediated survival mechanisms were detected in K562 and Jak2(V617F)-transformed HEL cells. Stat5 is activated in the nuclear and cytosolic compartments of K562 cells and the S5-DBD-PA inhibitor most likely affects the viability of Bcr-Abl{sup +} K562 cells through the inhibition of canonical Stat5 induced target gene transcription. In HEL cells

  1. [Influence of polypeptide extract from scorpion venom on PI3K and p-Akt signaling protein expression and cell proliferation of K562 cells].

    Science.gov (United States)

    Yu, Wen-Jun; Yang, Wen-Hua; Yang, Xiang-Dong; Shi, Zhe-Xin; Wang, Xing-Li; Hao, Zheng; Zhang, Jia

    2012-08-01

    This study was aimed to investigate the effect of polypeptide extract from scorpion venom (PESV) on PI3K, p-Akt signal protein regulating K562 cell apoptosis and its mechanism. The K562 cells were cultured with PESV for different time, the cell growth curve was determined by MTT method, the levels of PI3K and p-Akt proteins were detected by Western blot. The results showed that as compared with control group, the apoptosis rate of K562 cells treated with PESV increased, the levels of PI3K and p-Akt expression decreased. It is concluded that the PESV inhibits the proliferation and promotes the apoptosis of K562 cells probably through suppressing the expression of PI3K and p-Akt signal proteins.

  2. Effects of K562 cells with over-expression of MHC class Ⅰ chain-related protein A on phagocytosis of dendritic cells%K562细胞过表达MHCⅠ类相关抗原A对树突状细胞吞噬功能的影响

    Institute of Scientific and Technical Information of China (English)

    张跃; 邵小青; 陈贝; 季明春; 龚卫娟

    2012-01-01

    Objective To observe how apoptosed K562 cells with over-expression of MHC class I chain-related protein A (MICA) affects phagocytic function of dendritic cells. Methods At first a K562 cell line with ectopic MICA expression, called K562-MICA, was generated by gene trans-fection and G418 screen. Both K562 and K562-MICA cells were stained with fluorescent CFSE, treated with mitomycin C, and then co-cultured with THP1 cells or dendritic cells derived from peripheral blood monocytes overnight. Phagocytic activities were evaluated through detection of percentage of ap-optotic cells by flow cytometry. Meanwhile, some activating receptors on THP1 cells and NKG2D expression on DC were measured by flow cytometry. Finally NKG2D neutralizing antibody was added to cell co-culture system to observe whether phagocytosis of DC would be varied correspondingly. Results K562-MICA cells stimulated THP1 cell to enhance expression of CD86 and MICA, but had no effects on HLA-DR and NKG2D expression. Compared with K562 cells, apoptotic bodies from K562-MICA cells were more susceptible to be uptake by DC. Apoptosed K562-MICA cells induced DC to increase NKG2D expression. In addition, NKG2D antibody could significantly inhibit phagocytosis of DC. Conclusion MICA over-expression on K562 cells promoted phagocytic function of DC, and the function depended on NKG2D expression on DC.%目的 观察过表达MHC Ⅰ类相关抗原A(MICA)的K562细胞,体外经诱导凋亡后,对树突状细胞(DC)吞噬功能的影响.方法 首先利用脂质体介导的基因转染技术和G418筛选过程,建立稳定表达MICA的K562细胞(K562-MICA).其次分别取K562K562-MICA细胞经CFSE标记,并用丝裂霉素C诱导凋亡,与单核细胞系THP1或外周血单核细胞来源的DC共孵育过夜,流式细胞术检测2种细胞吞噬凋亡小体的活性.同时检测THPI细胞表面相关活化性受体的表达,以及DC表面NKG2D受体的情况.最后,在细胞共培养体系中加入NKG2D抗体,观

  3. The best time of cytotoxicity for extracted cell wall from Lactobacillus casei and paracasei in K562 cell line

    Directory of Open Access Journals (Sweden)

    Riki M

    2013-02-01

    Full Text Available Background: The aim of this study was to evaluate the effect of extracted cell walls from Lactobacillus casei and Lactobacillus paracasei as probiotic bacteria (isolated from common carp intestine on K562 and the role of cell concentration on the results of MTT [3-(4,5-Dimethylthiazol-2-yl2,5- Diphenyl tetrazolium Bromide] test.Methods: For this purpose, bacteria were cultured in specific medium (MRS broth at anaerobic condition for 24-48 hour. After incubation period culture medium was centri-fuged, then the cells were washed twice with PBS buffer to remove additional medium. Finally, collected bacterial cell disrupted by Sonication and cell walls were separated from other components by centrifugation. After that, different concentrations of cell walls (500, 1000, 2000 and 4000 µg/ml were prepared in RPMI medium for each bacteria, separately. Then anticancer properties of the cell walls were determined in vitro at 12, 24, 48 and 72 h, also the effect of K562 concentration was assayed with MTT technique.Results: The results showed extracted cell wall from both probiotic statistically (P=0.098 have anti turmeric properties in K562 and their properties will arise in relation with concentration. As well as, we found that the number of cell had not any affect on the result of MTT assay.Conclusion: We conclude that the cytotoxicity property of extracted cell wall is related in the type of bacteria, but this anticancer property would warrant further study on the clinical application of extracted cell wall.

  4. PESV对K562细胞BCR/ABL融合基因及凋亡调控因子Bcl-2、Bad表达的影响%The Effects of PESV on the Expression of BCR/ABL Fusion Gene and Bcl-2, Bad of Apoptosis Regulators on the K562 Cells

    Institute of Scientific and Technical Information of China (English)

    于文俊; 杨文华; 杨向东; 史哲新; 王兴丽; 郝征; 张佳

    2012-01-01

    Objective: To investigate the PESV of K562 cells BCR / ABL fusion gene and apoptosis regulators bcl-2 and bad expression. Methods: K562 cells were cultured in vitro, by PESV for different times, the apoptosis rate by flow cytometry, fluorescence quantitative RT-PCR detection of BCR / ABL, Bcl-2, Bad mRNA level changes. Results: Compared with the control group, PESV treated K562 cells, apoptosis increased, BCR / ABL fusion gene reduced expression, anti-apoptotic gene Bcl-2 mRNA expression decreased, pro-apoptotic gene Bad mRNA expression. Conclusion: PESV reduced in K562 cells can reduce the BCR / ABL fusion gene, may regulate the expression of Bcl-2 and Bad, inhibit proliferation of K562 cells and promote their apoptosis.%目的:探讨PESV对K562细胞BCR/ABL融合基因及凋亡调控因子bcl-2和bad表达的影响.方法:将体外培养K562细胞,经PESV处理不同时间后,流式细胞术检测细胞凋亡率,荧光定量RT-PCR检测BCR/ABL、Bcl-2、Bad mRNA水平变化.结果:与对照组相比,PESV处理后K562细胞,凋亡率增加,BCR/ABL融合基因表达降低,抗凋亡相关基因Bcl-2 mRNA表达降低,促凋亡基因Bad mRNA表达增加.结论:PESV能降低降低K562细胞BCR/ABL融合基因的表达,可能通过调节Bcl-2和Bad表达,抑制K562细胞增殖,促进其凋亡.

  5. Effects of phenolic alkaloids from Menispermum dauricum on inducing the multidrug resistance cell line K562/MDR1 to apoptosis and reversing their multidrug resistance%蝙蝠葛酚性碱诱导多药耐药细胞系K562/MDR1凋亡及逆转耐药性的研究

    Institute of Scientific and Technical Information of China (English)

    何志一; 刘相辉; 刚宏林

    2010-01-01

    目的:探讨蝙蝠葛酚性碱(phenolic alkaloids from Menispermum dauricum,PAMD)诱导多药耐药(multidrug resistance,MDR)细胞系K562/MDR1凋亡及逆转耐药性的作用.方法:四甲基偶氮唑蓝(MTT)比色法检测K562/S及K562/MDR1细胞对不同浓度PAMD的敏感性,并计算半数抑制浓度(IC50).膜联蛋白V (Annexin V)-异硫氰酸荧光素(FITC)+碘化丙啶(PI)双参数检测细胞凋亡百分率变化,分析在PAMD的作用下,两种细胞对伊马替尼(IM,STI571)敏感性的变化.结果:PAMD可诱导两种细胞凋亡,其低剂量72 h时对K562/S和K562/MDR1细胞的凋亡率分别为(10.92±1.03)%和(8.12±0.98)%,并可提高伊马替尼对K562/MDR1的凋亡率.PAMD可显著逆转K562/MDR1细胞对伊马替尼的耐药性,其逆转倍数为2.22.结论:PAMD对K562/S和K562/MDR1细胞具有诱导凋亡作用,同时具有逆转白血病细胞株K562/MDR1多药耐药性、回归靶位的作用.

  6. 夜香树花甾体皂苷抑制K562细胞增殖及对PI3K/AKt信号通路的调控%Inhibitory Effect of the Steroid Saponins from the Flowers of Cestrum Nocturnum,Linn(SSFCN) on Proliferation of Leukemia K562 Cells and PI3K/AKt Pathway Regulation

    Institute of Scientific and Technical Information of China (English)

    罗发军; 赵世元; 钟振国

    2013-01-01

    目的 探讨夜香树花甾体皂苷(SSFCN)抑制K562细胞增殖及作用机制.方法 夜香树花用有机溶剂提取、分离并鉴定SSFCN,体外培养K562细胞,采用MTT比色法测定抑制率;流式细胞仪分析细胞周期、琼脂糖凝胶电泳检测DNA图谱的变化,Western blot 法检测用SSFCN处理的K562细胞AKt磷酸化水平的变化.结果 SSFCN能显著抑制人白血病细胞K562的生长,作用后细胞生长有明显凋亡特征性改变,凋亡率呈时间和剂量依赖性.60 mg/L 的SSFCN作用K562细胞24 h后,流式细胞仪检测出现亚G1峰及DNA电泳呈梯形条带.Western blot 结果表明,SSFCN处理K562细胞72 h后,K562细胞p-AKt磷酸化水平明显下调.结论 SSFCN具有抑制K562细胞增殖和促进凋亡的作用,SSFCN通过抑制K562细胞PI3K/AKt信号通路,从而抑制K562细胞增殖.

  7. Synergistic effect of magnetic nanoparticles of Fe3O4 with gambogic acid on apoptosis of K562 leukemia cells

    Directory of Open Access Journals (Sweden)

    Baoan Chen

    2009-11-01

    Full Text Available Baoan Chen1,*, Yiqiong Liang1,*, Weiwei Wu1, Jian Cheng1, Guohua Xia1, Feng Gao1, Jiahua Ding1, Chong Gao1, Zeye Shao1, Guohong Li1, Wenji Chen1, Wenlin Xu2, Xinchen Sun3, Lijie Liu4, Xiaomao Li5, Xuemei Wang61Department of Hematology; 3Department of Oncology, The Affiliated Zhongda Hospital, Clinical Medical School, Southeast University, Nanjing, People’s Republic of China; 2Department of Hematology, The Affiliated People’s Hospital, Jiangsu University, Zhenjiang, People’s Republic of China; 4Institution of Physiology, Southeast University, Nanjing, People’s Republic of China; 5Department of Physics, University of Saarland, Saarbruechen, Germany; 6State Key Lab of Bioelectronics (Chien-Shiung Wu Laboratory, Southeast University, Nanjing, Peoples Republic of China; *These authors have contributed equally to this workAbstract: Gambogic acid (GA has a significant anticancer effect on a wide variety of solid tumors. Recently, many nanoparticles have been introduced as drug-delivery systems to enhance the efficiency of anticancer drug delivery. The aim of this study was to investigate the potential benefit of combination therapy with GA and magnetic nanoparticles of Fe3O4 (MNPs-Fe3O4. The proliferation of K562 cells and their cytotoxicity were evaluated by MTT assay. Cell apoptosis was observed and analyzed by microscope and flow cytometry, respectively. Furthermore, realtime polymerase chain reaction and Western blotting analyses were performed to examine gene transcription and protein expression, respectively. The results showed that MNPs-Fe3O4 dramatically enhanced GA-induced cytotoxicity and apoptosis in K562 cells. The typical morphological features of apoptosis treated with GA and MNPs-Fe3O4 were observed under an optical microscope and a fluorescence microscope, respectively. The transcription of caspase-3 and bax gene in the group treated with GA and MNPs-Fe3O4 was higher than that in the GA-alone group or MNPs-Fe3O4-alone group, but

  8. SIRT1 enhances drug resistance of CML K562 cells%SIRT1增强人慢性粒系白血病K562细胞耐药性

    Institute of Scientific and Technical Information of China (English)

    毛蓓蓓; 宋崴; 吕湘; 陈厚早; 刘德培

    2011-01-01

    Objective To explore the function of SIRT1 in drug resistance of chronic myelogenous leukemia (CML) K562 cells. Methods K562 cells stably expressing dominate negative SIRT1-H363Y or SIRT1 shRNA were treated with H2O2 and etoposide. Cleaved caspase3, BAX and -γ-H2A. X signals were detected by Western blot; MCF-7 and 293A cells overexpressing wild type SIRT1 were treated with H2O2 and etoposide. Γ-H2A. X was detected by Western blot. Results SIRT1-H363Y and SIRT1 shRNA expression in K562 cells could enhance the cleavage of caspase3 and the expression of BAX, but inhibit the formation ofy-H2A. X induced by H2O2(control vs SIRT1-H363 Y: 0. 54 ± 0. 03 vs 0. 23 ± 0. 01) ( P < 0. 01) and etoposide (control vs SIRT1-H363 Y: 1. 36 ± 0. 20 vs0.68±0. 14) (P<0. 05); (control vs S1RT1 RNAi: 0. 68 ±0. 06 vs 0.44 ±0. 04) (P <0. 01). On the contrary, overexpression of wild type SIRT1 in MCF-7 and 293 A cells promotes the formation of 7-H2A. X (MCF-7: 0.26±0.04 vs0.46±0.02)(P<0.01);(293A: 0 vs 0. 42 ±0. 09) (P <0. 05). Conclusions SIRT1 may enhance the drug resistance and signal for DNA repair in K562 cells.%目的 研究Ⅲ类去乙酰化酶SIRT1对人慢性粒系白血病K562细胞耐药性的影响及其机制.方法 分别将酶活性缺失突变型SIRT1-H363Y和SIRT1 shRNA表达质粒转染K562细胞,G418筛选稳定克隆后用H2O2和依托泊甙(etoposide)处理细胞,Western blot检测caspase3剪切,BAX表达及DNA损伤标志物H2A.X磷酸化;在MCF-7和293A中过表达野生型SIRT1,检测H2O2和etoposide处理后的H2A.X磷酸化.结果 K562细胞中SIRT1-H363Y表达和SIRT1干扰均能促进H2O2和etoposide诱导的caspase3剪切及BAX表达,并显著抑制H2O2诱导的H2A.X磷酸化(对照vs SIRT1-H363Y:0.54 +0.03vs0.23±0.01)(P<0.01)和etoposide(对照vs SIRT1 H363Y:1.36±0.20vs0.68±0.14)(P <0.05);(对照vs SIRT1 RNAi:0.68±0.06vs0.44±0.04)(P<0.01);在MCF-7和293A细胞中,野生型SIRT1过表达能明显增加etoposide诱导的H2A

  9. Characterization of cancer stem-like cells in a novel STI571-resistant chronic myeloid leukemia cell line%K562多药耐药细胞系中肿瘤干细胞样细胞对伊马替尼耐药机制的初步研究

    Institute of Scientific and Technical Information of China (English)

    Baijun Fang; Yongping Song; Yanli Zhang; Quande Lin; Xudong Wei

    2007-01-01

    Objective: To characterize a novel chronic myeloid leukemia (CML) cell line and to further elucidate the mechanisms of resistance to STI571. Methods: A novel K562 cell line (K562NP16) was achieved after exposure of the K562 cells to VP16. A small subpopulation (K562NP16 SP) that was capable of excluding Hoechst 33342 in the K562NP16 cell line was isolated by flow cytometry sorting. The rest of the K562NP16 cells were classified as non-SP K562NP16. The mechanisms involved in K562NP16 SP cells which became resistant to STI571 were studied. Results: The levels of Bcr-Abl and Abl proteins were similar in the K562 cell line and in non-SP K562NP16 and K562NP16 SP cells. The multidrug-resistant gene 1 (MDR1) expression of the 170 kDa P-glycoprotein (P-gp) was detected in K562NP16 non-SP and K562NP16 SP cells but not in K562 cells. The expression levels of P-gp in the two K562NP16 cell lines were similar. Compared with non-SP K562/VP16, the K562NP16 SP cells were more resistant to STI571. This resistance could hardly be reversed by many multidrug resistance inhibitors. In addition, in vivo study showed that the K562NP16 SP cells induced tumorigenesis in mice, while the K562NP16 non-SP cells failed to do so. Conclusion: A novel K562 cell line, K562NP16, was generated. A small side population K562NP16 SP cells, had high resistance to STI571 treatment and more tumorigenic than the K562 cells. It may represent the cancer stem cells of the K562NP16 cell line.

  10. Isolation and purification of antibacterial peptides with anti- K562 activity from the Tenebrio molitor Linnaeus larvae%黄粉虫幼虫抗肿瘤细胞K562抗菌肽的分离纯化

    Institute of Scientific and Technical Information of China (English)

    刘颜岗; 程璟侠; 赵瑞君; 樊宏英

    2009-01-01

    目的 从黄粉虫幼虫体内分离纯化具有抗肿瘤细胞K562的抗菌肽.方法 通过超声诱导黄粉虫幼虫大量表达抗菌肽.然后经过研磨、离心、固相萃取、反相高效液相色谱分离纯化黄粉虫幼虫抗菌肽,采用四甲基偶氮噻唑蓝(MTY)比色法和光镜观察法筛选对K562有杀伤作用的抗菌肽.结果 离心上清液上样固相萃取柱,经10%、30%、80%的乙腈水溶液洗脱,只有80%的乙腈水溶液分离组分有活性(P<0.01).该活性组分经反相高效液相色谱纯化后分离出5个具有抗肿瘤活性的峰物质,这5个峰活性都较强(P<0.01),其中峰9、峰4能初步确定为抗菌肽,其他3种有待于进一步的实验证明.结论 黄粉虫幼虫体内存在抗肿瘤细胞K562的抗菌肽和抗菌物质,而且不止一种.%Objective To isolate and purify the antimicrobial peptides with anti-tumor cell K562 activity from the Tenebrio molitor Linnaeus larvae. Methods Antimicrobial peptides of Tenebrio molitor L.larvae induced by ultrasonic waves were isolated and purified by trituration, centrifugalization, solid phase extraction (SPE) and reversed-phase high-performance liquid chromatography (RP-HPLC). Then the antimicrobial peptides with anti-K562 activity were sieved by MTT colorimetric method and light microscope observation. Results Supematant eluted with 10%, 30%, 80% acetonitrile (ACN) in aqueous solution by solid phase extraction, of which, only 80% was active (P<0.01). Five anti-tumor peaks appeared after purification by RP-HPLC, which all had strong activity (P<0.01). Only 9 and 4 peaks could initially identified as antimicrobial peptides, the others still need to be proved. Conclusion There are antimicmbial peptides and anti-hacterial substances which have anti-KS62 activity in the Tenebrio molitor L.larvae, and more than one.

  11. Voltage-Gated K+ Channel, Kv3.3 Is Involved in Hemin-Induced K562 Differentiation.

    Science.gov (United States)

    Song, Min Seok; Choi, Seon Young; Ryu, Pan Dong; Lee, So Yeong

    2016-01-01

    Voltage-gated K+ (Kv) channels are well known to be involved in cell proliferation. However, even though cell proliferation is closely related to cell differentiation, the relationship between Kv channels and cell differentiation remains poorly investigated. This study demonstrates that Kv3.3 is involved in K562 cell erythroid differentiation. Down-regulation of Kv3.3 using siRNA-Kv3.3 increased hemin-induced K562 erythroid differentiation through decreased activation of signal molecules such as p38, cAMP response element-binding protein, and c-fos. Down-regulation of Kv3.3 also enhanced cell adhesion by increasing integrin β3 and this effect was amplified when the cells were cultured with fibronectin. The Kv channels, or at least Kv3.3, appear to be associated with cell differentiation; therefore, understanding the mechanisms of Kv channel regulation of cell differentiation would provide important information regarding vital cellular processes.

  12. siRNA Delivery Improvement by Co-formulation of Different Modified Polymers in Erythroleukemic Cell Line K562

    Directory of Open Access Journals (Sweden)

    Mazdak Ganjalikhani hakemi

    2013-09-01

    Full Text Available Objective(s: siRNA may be a very promising tool for treatment of various diseases especially in cancer therapy due to high specificity. One of the main hurdles applications of siRNAs in vivo is optimization of the delivery strategy, especially the carrier systems. The aim of this study was to optimize siRNA delivery into suspended erythroleukemic cell line K562. Materials and Methods: We applied polyethyleneimine (PEI and oligoethyleneimine (OEI derivatives alone or their co-formulation with different agents such as chloroquine (a drug known to alter lysosomal pH and thus to inhibit lysosomal degradation of macromolecules, DOPE (lipophilic agent, succinic acid (introduction of negatively charged to polymer and transferrin (the ligand of transferring receptor which is over-expressed in many types of tumors and hematopoietic cells. Results: In this study it was shown that utilizing a combination of 70% OEI-HA10 (ten hexyl acrylate residues per one OEI chain plus 30% of transferin-PEI with Luc-siRNA was highly effective for transfecting K562 cell. This co-formulation silenced luciferase activity up to 70% after short time without any significant inhibition in the luciferase activity in siCONTROL wells. Conclusion: In conclusion, the combination of modified PEI with transferrin and OEI by hexyl acrylate may increase siRNA delivery and reduce toxicity in hematopoietic suspended cells.

  13. The biocompatibility of materials used in printed circuit board technologies with respect to primary neuronal and K562 cells.

    Science.gov (United States)

    Mazzuferi, Manuela; Bovolenta, Roberta; Bocchi, Massimo; Braun, Tanja; Bauer, Joerg; Jung, Erik; Iafelice, Bruno; Guerrieri, Roberto; Destro, Federica; Borgatti, Monica; Bianchi, Nicoletta; Simonato, Michele; Gambari, Roberto

    2010-02-01

    Printed circuit board (PCB) technology can be used for producing lab-on-a-chip (LOAC) devices. PCBs are characterized by low production costs and large-scale development, both essential elements in the frame of disposable applications. LOAC platforms have been employed not only for diagnostic and/or analytical purposes, but also for identification and isolation of eukaryotic cells, including cancer and stem cells. Accordingly, the compatibility of the employed materials with the biological system under analysis is critical for the development of LOAC devices to be proposed for efficient and safe cell isolation. In this study, we analyzed the in-vitro compatibility of a large set of materials and surface treatments used for LOAC development and evaluation with quasi-standard PCB processes. Biocompatibility was analyzed on hippocampal primary cells (a model of attached cell cultures), in comparison with the reference K562 cell line (a model of cells growing in suspension). We demonstrate here that some of the materials under study alter survival, organization, morphology and adhesion capacity of hippocampal cells, and inhibit growth and differentiation of K562 cells. Nonetheless, a subset of the materials tested did not negatively affect these functions, thus demonstrating that PCB technology, with some limitations, is suitable for the realization of LOAC devices well compatible at least with these preparations. (c) 2009 Elsevier Ltd. All rights reserved.

  14. Synthesis, Crystal Structure and Inhibition of N-2-Thiophenesulfonyl-α-L-phenylalanine Ethyl Ester on K562 Cell Proliferation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The title compound N-2-thiophenesulfonyl-α-L-phenylalanine ethyl ester has been synthesized. Complete assignments were achieved by IR, MS, 1H NMR and single-crystal X-ray diffraction analyses. Using MTT assay, the inhibitory rate of the title compound on K562 cells (chronic myeloid 1eukemic cells) was measured and the result of preliminary bioassay showed that the title compound possesses antiproliferation effects on K562 cells. In order to investigate the relationship between structure and activity of the target compound, we report its crystal structure and biological behavior in the present paper. Crystallographic data: C15H17NO4S2, Mr = 339.42, monoclinic, space group P21, flack = -0.15(12), a = 5.7916(10), b = 11.5078(19), c = 12.924(2) (A), β = 97.781(3)°, Z = 2, V = 853.4(2) (A)3, Dc = 1.321 g/cm3, F(000) = 356, -7≤h≤7, -10≤k≤14, -15≤l≤15, R = 0.0628, wR = 0.1540 and μ(MoKα) = 0.327 mm-1. The molecule comprises a benzene and a thiofuran rings, and the intramolecular N(1)-H(1A)…O(1) makes a five-membered ring of O(1)-C(6)-C(5)-N(1)-H(1A).

  15. A novel erythroid differen tiation related gene EDRF2 inhibited α-globin gene expression in K562 cells

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In previous studies, we found that EDRF2 was an erythroid differentiation related factor, whose expression was markedly upregulated during erythroid differentiation. It suggested that this factor played a role in erythropoiesis.By using rapid amplification of cDNA ends technology, we cloned EDRF2 gene 5 '- and 3 '-cDNA ends successfully.Transfection and Northern blot analysis demonstrated that EDRF2 inhibited mRNA expression of α-globin gene, while did not regulate γ-globin gene expression. Gel shift assay confirmed that DNA-binding activity of erythroid specific transcription factors GATA-1, NF-E2 and AP1 was not af fected by either forced overexpression or artificial down regulation of EDRF2 gene in K562 cells. However, we de tected that the negative regulator of expression of GATA-1 transcription factor was increased in EDRF2 overexpressed K562 cells. These results strongly suggested that EDRF2 was involved in α-globin gene expression and erythroid differen tiation and served as a negative regulator of PU.1 transcrip tion factor.

  16. YCD/5-FC自杀基因治疗系统对K562B白血病细胞杀伤作用的小鼠体内实验研究%Study on the in vivo killing activity of YCD/5-FC gene therapy system on K562B cells

    Institute of Scientific and Technical Information of China (English)

    张雨生; 王健民; 周虹; 翟勇平

    2002-01-01

    目的了解酵母菌胞嘧啶脱氨酶/5-氟胞嘧啶(YCD/5-FC)系统在体内对转基因高致瘤性K562细胞(K562B细胞)的杀伤效应.方法以高滴度逆转录病毒转染K562B细胞并筛选出阳性转染克隆YCD-K562B;12只SCID小鼠分为治疗及对照组,在小鼠左右两侧近前肢处腹部皮下注射YCD-K562B及K562B细胞,成瘤后治疗组腹腔注射500 mg/kg 5-FC共10 d,对照组腹腔注射生理盐水,观察瘤体相对体积变化及病理变化.结果瘤细胞接种第21天,瘤体相对体积分别为:YCD-K562B+5-FC组2.922±0.581,YCD-K562B+生理盐水组24.434±4.790,K562B+5-FC组22.701±2.350,K562B+生理盐水组24.460±1.670;YCD-K562B+5-FC组与YCD-K562B+生理盐水组相比差异非常显著(P=0.000*!1),K562B+5-FC组及K562B+生理盐水组相比,差异无显著性(P=0.096),表明5-FC对转YCD基因的K562B白血病细胞有明显的杀伤效应,而对未转基因细胞的生长无影响;YCD-K562B+5-FC 组瘤体于瘤细胞接种后第12~第15天(5-FC治疗的第3~第6天)有所缩小(最小的相对体积为0.681),病理检查可见5-FC治疗组瘤体有以小动脉血管为中心的坏死.结论 YCD/5-FC系统在体内对转YCD基因K562B细胞有明显的杀伤效应.

  17. 茅莓及其含药血清对K562白血病细胞抑制作用的实验研究

    Institute of Scientific and Technical Information of China (English)

    许晓峰; 张学进; 冯健; 姜铁军; 付天红; 高瑞兰

    2011-01-01

    目的:观察茅莓及其含药血清体内及体外对K562细胞的抑制增殖作用.方法:通过建立荷白血病瘤裸鼠模型,观察不同浓度的茅莓水煎液对荷白血病瘤裸鼠瘤体体积、重量、组织病理学改变的影响;通过半固体琼脂培养观察不同浓度的茅莓含药血清对K562细胞集落生长的抑制作用;通过MIT法观察不同浓度的含药血清对K562白血病细胞的抑制增殖作用.结果:茅莓水煎液高、中、低剂量组瘤体体积、瘤重均较模型对照组明显减少;茅莓水煎液组及阿糖胞苷(Am-c)组光镜下可见多个坏死灶,瘤细胞肿胀、破裂,细胞核溶解,消失等现象.终浓度为10%和20%的含药血清做琼脂半固体集落培养,显示随着浓度增加,K562细胞集落形成明显减少,抑制作用呈剂量依赖性,MTT法显示终浓度10%和20%含药血清能明显抑制K562细胞增殖.结论:茅莓在荷白血病瘤裸鼠体内具有显著抑制瘤体生长的作用,在一定浓度下,其含药血清对K562细胞也有明显的抑制增殖作用.%Objective: To observe the inhibition of Japanese raspberry herb and its serum containing herb on proliferation of K562 leukemia cells in vivo and vitro.Methods: Models of K562 - bearing mice were built by subcutaneous vaccination K562 leukemia cells, mice were divided into model, positive and raspberry low, middle, high groups, each group was given corresponding medicine after vaccination 5 days, observing the changes of tumor volume, weight and histopathology in each group mice after treated 14days. Observing the inhibition of different concentration serum containing raspberry on proliferation of K562 leukemia cells by MTT in vitro.Results: The volume and weight of tumor in raspberry groups were obviously reduced, there were significant difference between each treated group and model group; the histopathology results showed that necroses of tumor cells in each dose raspberry group and Ara C group were more than

  18. Myc induced miR-144/451 contributes to the acquired imatinib resistance in chronic myelogenous leukemia cell K562

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Li, E-mail: liuli029@yahoo.cn [Department of Hematology, Tangdu Hospital, The Fourth Military Medical University, Xi' an 710038 (China); Wang, Sitao; Chen, Renan; Wu, Yanlan; Zhang, Bei; Huang, Siyong; Zhang, Jingyi; Xiao, Fang; Wang, Meng; Liang, Yingmin [Department of Hematology, Tangdu Hospital, The Fourth Military Medical University, Xi' an 710038 (China)

    2012-08-24

    Highlights: Black-Right-Pointing-Pointer Increased c-myc expression in imatinib resistant CML cells. Black-Right-Pointing-Pointer c-myc contributes the imatinib resistance in CML cells. Black-Right-Pointing-Pointer c-myc transcriptionally reduces the expression of miR-144/451 in K562R cells. Black-Right-Pointing-Pointer Restoration of miR-144/451 reverses the resistance of K562R cells to imatinib. -- Abstract: Imatinib resistance remains the big hurdle for CML therapy. Previous study reveals that c-myc is important for bcr-abl CML cell proliferation, while its role in imatinib resistance is largely unknown. In this study, we first found that c-myc expression is upregulated in imatinib resistant K562R cells, which in turn enhances the expression of miR-144/451. Knockdown of c-myc or restoration of miR-144/451 in the K562R cells sensitizes K562R cells to imatinib therapy. Our study here reveals an regulatory pathway between myc and miR-144/451 and highlights that targeting either myc or miR-144/451 might be valuable for eliminating the imatinib resistant CML cells.

  19. Effects of Huangqi (Hex) on Inducing Cell Differentiation and Cell Death in K562 and HEL Cells

    Institute of Scientific and Technical Information of China (English)

    Xaio-Dong CHENG; Chun-Hui HOU; Xue-Jun ZHANG; Heng-Yue XIE; Wei-Ying ZHOU; Lei YANG; Shu-Bing ZHANG; Ruo-Lan QIAN

    2004-01-01

    Huangqi(Astragalus membranaceus),a traditional Chinese medicine,has been used to ameliorate side effects of cancer chemotherapy in China.However,little is known about its molecular mechanisms.Here we show that induction ofK562 or HEL cells with 1.5 mg/mi of Huangqi(Hex)(Components extracted from Huangqi)for 3-5 d results in the expression of ?-globin gene in both cell lines and leads to terminal differentiation.Moreover,the apoptosis in HEL cells can be induced by increasing concentration of Huangqi(Hex)to 4.5 mg/ml for 3-5 d.Upregulation ofApaf-1,caspase-3 and acetylcholinesterase(AChE)in HEL cells may playa crucial role in the process of apoptosis.The prospect of inducing expression of adult(β)globin gene and apoptosis selectively in cancer cells is obviously attractive from a therapeutic point of view.

  20. β-carotene treatment alters the cellular death process in oxidative stress-induced K562 cells.

    Science.gov (United States)

    Akçakaya, Handan; Tok, Sabiha; Dal, Fulya; Cinar, Suzan Adin; Nurten, Rustem

    2017-03-01

    Oxidizing agents (e.g., H2 O2 ) cause structural and functional disruptions of molecules by affecting lipids, proteins, and nucleic acids. As a result, cellular mechanisms related to disrupted macro molecules are affected and cell death is induced. Oxidative damage can be prevented at a certain point by antioxidants or the damage can be reversed. In this work, we studied the cellular response against oxidative stress induced by H2 O2 and antioxidant-oxidant (β-carotene-H2 O2 ) interactions in terms of time, concentration, and treatment method (pre-, co-, and post) in K562 cells. We showed that co- or post-treatment with β-carotene did not protect cells from the damage of oxidative stress furthermore co- and post-β-carotene-treated oxidative stress induced cells showed similar results with only H2 O2 treated cells. However, β-carotene pre-treatment prevented oxidative damage induced by H2 O2 at concentrations lower than 1,000 μM compared with only H2 O2 -treated and co- and post-β-carotene-treated oxidative stress-induced cells in terms of studied cellular parameters (mitochondrial membrane potential [Δψm ], cell cycle and apoptosis). Prevention effect of β-carotene pre-treatment was lost at concentrations higher than 1,000 μM H2 O2 (2-10 mM). These findings suggest that β-carotene pre-treatment alters the effects of oxidative damage induced by H2 O2 and cell death processes in K562 cells.

  1. Evaluation of Synergetic Anticancer Activity of Berberine and Curcumin on Different Models of A549, Hep-G2, MCF-7, Jurkat, and K562 Cell Lines

    Directory of Open Access Journals (Sweden)

    Acharya Balakrishna

    2015-01-01

    Full Text Available Ayurvedic system of medicine is using Berberis aristata and Curcuma longa herbs to treat different diseases including cancer. The study was performed to evaluate the synergetic anticancer activity of Berberine and Curcumin by estimating the inhibition of the cell proliferation by cytotoxicity assay using MTT method on specified human cell lines (A549, Hep-G2, MCF-7, Jurkat, and K562. All the cells were harvested from the culture and seeded in the 96-well assay plates at seeding density of 2.0 × 104 cells/well and were incubated for 24 hours. Test items Berberine with Curcumin (1 : 1, Curcumin 95% pure, and Berberine 95% pure were exposed at the concentrations of 1.25, 0.001, and 0.5 mg/mL, respectively, and incubated for a period of 48 hours followed by dispensing MTT solution (5 mg/mL. The cells were incubated at 37 ± 1°C for 4 hours followed by addition of DMSO for dissolving the formazan crystals and absorbance was read at 570 nm. Separate wells were prepared for positive control, controls (only medium with cells, and blank (only medium. The results had proven the synergetic anticancer activity of Berberine with Curcumin inducing cell death greater percentage of >77% when compared to pure curcumin with <54% and pure Berberine with <45% on average on all cell line models.

  2. CRISPR/Cas9-Directed Reassignment of the GATA1 Initiation Codon in K562 Cells to Recapitulate AML in Down Syndrome

    Directory of Open Access Journals (Sweden)

    Kevin M. Bloh

    2017-06-01

    Full Text Available Using a CRISPR/Cas9 system, we have reengineered a translational start site in the GATA1 gene in K562 cells. This mutation accounts largely for the onset of myeloid leukemia in Down syndrome (ML-DS. For this reengineering, we utilized CRISPR/Cas9 to generate mammalian cell lines that express truncated versions of the Gata1s protein similar to that seen in ML-DS, as determined by analyzing specific genetic alterations resulting from CRISPR/Cas9 cleavage. During this work, 73 cell lines were clonally expanded, with allelic variance analyzed. Using Tracking of Indels by DEcomposition (TIDE and Sanger sequencing, we defined the DNA sequence and variations within each allele. We found significant heterogeneity between alleles in the same clonally expanded cell, as well as among alleles from other clonal expansions. Our data demonstrate and highlight the importance of the randomness of resection promoted by non-homologous end joining after CRISPR/Cas9 cleavage in cells undergoing genetic reengineering. Such heterogeneity must be fully characterized to predict altered functionality inside target tissues and to accurately interpret the associated phenotype. Our data suggest that in cases where the objective is to rearrange specific nucleotides to redirect gene expression in human cells, it is imperative to analyze genetic composition at the individual allelic level.

  3. Involvement of CD147 on multidrug resistance through the regulation of P-glycoprotein expression in K562/ADR leukemic cell line

    Directory of Open Access Journals (Sweden)

    Aoranit Somno

    2016-01-01

    Full Text Available The relationship between P-gp and CD147 in the regulation of MDR in leukemic cells has not been reported. This study aimed to investigate the correlation between CD147 and P-gp in the regulation of drug resistance in the K562/ADR leukemic cell line. The results showed that drug-resistant K562/ADR cells expressed significantly higher P-gp and CD147 levels than drug-free K562/ADR cells. To determine the regulatory effect of CD147 on P-gp expression, anti-CD147 antibody MEM-M6/6 significantly decreased P-gp and CD147 mRNA and protein levels. This is the first report to show that CD147 mediates MDR in leukemia through the regulation of P-gp expression.

  4. Influence of Polypeptide Extract from Scorpion Venom on PI3K and p-Akt Signaling Protein Expression and Cell Proliferation of K562 Cells%蝎毒多肽提取物对K562细胞PI3K和p-Akt信号蛋白表达及细胞增殖的影响

    Institute of Scientific and Technical Information of China (English)

    于文俊; 杨文华; 杨向东; 史哲新; 王兴丽; 郝征; 张佳

    2012-01-01

    This study was aimed to investigate the effect of polypeptide extract from scorpion venom (PESV) on PDK, p-Akt signal protein regulating K562 cell apoptosis and its mechanism. The K562 cells were cultured with PESV for different time, the cell growth curve was determined by MTT method, the levels of PDK and p-Akt proteins were detected by Western blot. The results showed that as compared with control group, the apoptosis rate of K562 cells treated with PESV increased, the levels of PDK and p-Akt expression decreased. It is concluded that the PESV inhibits the proliferation and promotes the apoptosis of K562 cells probably through suppressing the expression of PDK and p-Akt signal proteins.%本研究旨在探讨蝎毒多肽提取物(PESV)对人慢性髓系白血病细胞系K562细胞凋亡调控的PI3K和p-Akt信号蛋白的影响及作用机制.将体外培养的K562细胞,经PESV处理不同时间后,通过MTT法检测细胞增殖曲线,Western blot法检测PI3K及p-Akt蛋白水平变化.结果表明,与对照组相比,PESV处理后K562细胞凋亡率增加,PI3K及p-Akt蛋白表达降低.结论:PESV可能通过抑制凋亡调控的PI3K、p-Akt信号蛋白,抑制K562细胞增殖,促进细胞凋亡.

  5. Diatrizoate, Iopromide and Iotrolan Enhanced Cytotoxicity of Daunorubicin in Multidrug Resistant K562/adr Cells: Impaired the Mitochondrial and Inhibited the P-Glycoprotein Function

    Directory of Open Access Journals (Sweden)

    Nitaya S.N. Ayudhya

    2009-01-01

    Full Text Available Multidrug resistance was an obstacle in cancer chemotherapy because the cells decreased their intracellular drug accumulation by energy-dependent compounds efflux pumps such as P-glycoprotein (P-gp. This study observed some iodinated radiographic contrast media, diatrizoate, iopromide and iotrolan affected the cellular energetic state and the kinetics of P-gp in drug-sensitive K562 and drug resistant K562/adr cell lines using spectrophotometer and spectrofluorometer. By colorimetric MTT assay, it was found that contrast media (0-3500 µM had no effect on both K562 and K562/adr cell viabilities, but in co-treatment with daunorubicin (DNR, diatrizoate decreased cell viability in K562/adr cells by decreasing ICso of DNR from 610.7 ±74.5 nM to 360±108.9 nM. The change in cellular energetic state was studied using rhodamine B as a probe to estimate mitochondrial membrane potential (ΔΨm. The results showed that 3500 µM diatrizoate decreased ΔΨm from 162.2±0.3 mV to 86.9±9.9 mV in K562/adr cells. The kinetics of P-gp-mediated efflux of DNR could be reduced by diatrizoate from 0 (no inhibition to 0.65±0.11. This inhibition could be partially prevented in co-incubation with 20 nM concanamycin A or 10 µM cytochalasin B. Among the three molecules, diatrizoate showed the best efficiency. It could be proposed for further studies that diatrizoate could be used as MDR identification or MDR imaging and also acted as MDR sensitizing agent in cancer treatments.

  6. Regulation of HtrA2 on WT1 gene expression under imatinib stimulation and its effects on the cell biology of K562 cells.

    Science.gov (United States)

    Zhang, Lixia; Li, Yan; Li, Xiaoyan; Zhang, Qing; Qiu, Shaowei; Zhang, Qi; Wang, Min; Xing, Haiyan; Rao, Qing; Tian, Zheng; Tang, Kejing; Wang, Jianxiang; Mi, Yingchang

    2017-09-01

    The aim of the present study was to investigate the regulation of Wilms Tumor 1 (WT1) by serine protease high-temperature requirement protein A2 (HtrA2), a member of the Htr family, in K562 cells. In addition, the study aimed to observe the effect of this regulation on cell biological functions and its associated mechanisms. Expression of WT1 and HtrA2 mRNA, and proteins following imatinib and the HtrA2 inhibitor 5-[5-(2-nitrophenyl) furfuryl iodine]-1, 3-diphenyl-2-thiobarbituric acid (UCF-101) treatment was detected with reverse transcription-quantitative polymerase chain reaction and western blot analysis. Subsequent to treatment with drugs and UCF-101, the proliferative function of K562 cells was detected using MTT assays, and the rate of apoptosis was detected using Annexin V with propidium iodide flow cytometry in K562 cells. The protein levels in the signaling pathway were analyzed using western blotting following treatment with imatinib and UCF-101. In K562 cells, imatinib treatment activated HtrA2 gene at a transcription level, while the WT1 gene was simultaneously downregulated. Following HtrA2 inhibitor (UCF-101) treatment, the downregulation of WT1 increased gradually. At the protein level, imatinib induced the increase in HtrA2 protein level and concomitantly downregulated WT1 protein level. Subsequent to HtrA2 inhibition by UCF-101, the WT1 protein level decreased temporarily, but eventually increased. Imatinib induced apoptosis in K562 cells, but this effect was attenuated by the HtrA2 inhibitor UCF-101, resulting in the upregulation of the WT1 protein level. However; UCF-101 did not markedly change the proliferation inhibition caused by imatinib. Imatinib activated the p38 mitogen activated protein kinase (p38 MAPK) signaling pathway in K562 cells, and UCF-101 affected the activation of imatinib in the p38 MAPK signaling pathway. Imatinib inhibited the extracellular signal-related kinase (ERK1/2) pathway markedly and persistently, but UCF-101

  7. 地西他滨对K562细胞γ-珠蛋白基因表达及细胞增殖的影响%Effects of Decitabine on γ-globin Gene Expression and Proliferation in K562 Cells

    Institute of Scientific and Technical Information of China (English)

    谢冬梅; 赖永榕; 刘容容; 谭滨彬; 杨高晖

    2012-01-01

    目的 研究地西他滨对K562细胞γ-珠蛋白基因表达及细胞增殖的影响,探讨药物治疗β-地中海贫血的新思路.方法 分别用不同浓度(0 nmol/L、50 nmol/L、100 nmol/L、200 nmol/L、300 nmol/L)地西他滨作用于K562细胞24 h、48 h、72 h,用CCK-8检测药物对K562细胞存活率的影响,采用流式细胞术检测细胞凋亡率,采用实时荧光定量RT-PCR检测γ-珠蛋白基因表达.结果 地西他滨对K562细胞生长有抑制作用,作用后细胞凋亡率增加,γ-珠蛋白基因表达显著提高(P<0.05).结论 地西他滨可以提高K562细胞γ-珠蛋白基因表达.%Objective To investigate the effects of decitabine on γ-globin gene expression( HBG ) and proliferation in K562 cells,and provide a new way for β-thalassemia gene therapy. Methods K562 cells were treated with different concentrations of decitabine( 0 nmol/L,50 nmol/L,100 nmol/L,200 nmol/L,300 nmol/L ) for 24 h,48 h,72 h,respectively. The survival of K562 cells was examined by cell counting kit-8( CCK8 ),the Annexin V +/PI- cells were detected by flow cytometry( FCM ). Real-time quantitative reverse transcription polymerase chain reaction( RT-PCR ) was applied to detect the expression of γ-globin gene. Results K562 cells were inhibited by decitabine,and the significant increase in apoptosis and expression of γ-globin gene was found( P < 0.05 ). Conclusion Decitabine can improve γ-globin gene expression in K562cell.

  8. Effect of Thalidomide on Apoptosis of K562 Cells and its Vascular Endothelial Growth Factor Secretion%不同浓度沙利度胺对K562细胞凋亡及血管内皮生长因子分泌的影响

    Institute of Scientific and Technical Information of China (English)

    张玉高; 韩丽英; 陈枫; 赵华

    2011-01-01

    Objective To investigate the effect of thalidomide on apoptosis of k562 cells and its vascular endothelial growth factor secretion. Methods K562 cells were cultured in vitro with 0. 5, 1.0. And 2. 0 mmol/L thalidomide for 24, 48, 72, and 96 hours. Morphology of the K562 cells was observed by the Wright-Giemsa staining method. Methylthiazolyl tetrozolium (MTT) assay was used to determine the cell growth. The rate of apoptosis was analyzed by flow cytometry (FCM) with annexin V-fluorescein isothiocyanate/propidium iodide (AnnexinV-FITC/PI) double-staining method. Agarose gel electrophoresis was used to detected Deoxyribonucleic acid Ladder (DNA Ladder). The concentration of VEGF was quantified by the enzyme-linked immunosorbent assay (ELISA). Results Cultured for 24 or 48 hours, thalidomide had no effect on the proliferation of the K562 cells. But after cultured for 72 hours, thalidomide began to inhibit the growth of the K562 cells at the concentration of 1. 0 and 2. 0 mmol/L (P< 0. 001). After cultured for 96 hours, the proliferation of the K562 cells was inhibited too at the concentration of 0. 5 mmol/L thalidomide (P<0. 001). Thus, thalidomide inhibited the growth of the K562 cells with a dose-and time-dependent manner to some extent. After exposure to thalidomide for 72 hours, K562 cells underwent typical morphological changes of apoptosis such as vaculization, the budding of cytoplasm, chromatin condensation, margination, shrunken nucleus and apoptotic body. The results of flow cytometry showed that thalidomide could obviously increase the rates of the apoptosis of K562 cells (P<0. 001). After treated with thalidomide for 72 hours,DNA was extracted for Agarose gel electrophoresis and typical DNA ladder strips were observed. The secretion of VEGF was inhibited when exposure to thalidomide for 48 hours(P<0. 001), and there was negative correlation between VEGF.concentrations and apoptotic rates(r=- 0. 789). Conclusions Thalidomide could inhibite the growth of the

  9. PESV对K562细胞PI3K、p-Akt通路抑制作用的研究

    Institute of Scientific and Technical Information of China (English)

    于文俊; 杨文华; 杨向东; 史哲新; 王兴丽; 郝征; 张佳

    2012-01-01

    目的 探讨PESV对人慢性粒细胞白血病细胞系K562细胞凋亡调控的PI3K、p - Akt信号蛋白的影响及作用机制方法 将体外培养K562细胞,经PESV处理不同时间后,通过MTT检测细胞生长曲线,Western blot检测PI3K及p- Akt蛋白水平变化.结果 与对照组相比,PESV处理后K562细胞,凋亡率增加,PI3K及p- Akt表达降低.结论 PESV可能通过抑制凋亡调控的PI3K、p- Akt信号蛋白,从而达到抑制K562细胞系增殖,促进细胞凋亡的作用.

  10. Upregulation and activation of caspase-3 or caspase-8 and elevation of intracellular free calcium mediated apoptosis of indomethacin-induced K562 cells

    Institute of Scientific and Technical Information of China (English)

    张广森; 周光飚; 戴崇文

    2004-01-01

    Background A nonsteroidal anti-inflammatory drug, indomethacin, has been shown to have anti-leukemic activity and induce leukemic cell opoptosis. This study was to elucidate the mechanism of indomethacin-induced K562 cell apoptosis.Methods K562 cells were grown in RPMI 1640 medium and treated with different doses of indomethacin (0 μmol/L, 100 μmol/L, 200 μmol/L, 400 μmol/L, 800 μmol/L) for 72 hours. The cells were harvested, and cell viability or apoptosis was analyzed using MTT assay and AO/EB stain, combining laser scanning confocal microscopy (LSCM) technique separately. For the localization and distribution of intracellular caspase-3 or caspase-8 protein, immunofluorescence assay was carried out. To reveal the activation of caspase-3 or caspase-8 in indomethacin-treated cells, Western blot detection was used. The change in intracellular free calcium was determined by Fluo-3/ Am probe labeling combined with LSCM. Results Indomethacin could lead to K562 cell apoptosis and inhibit cell viability in a concentration-dependent manner. An increased expression of intracellular caspase-3 or caspase-8 was observed at higher doses of indomethacin (400-800 μmol/L). Western blot results showed upregrulation and activation in both caspase-3 and caspase-8 protein. Under indomethacin intervention, the levels of intracellular free calcium showed a significant increase. Blocking the activity of cyclooxygenase did not abolish the effects of indomethacin on K562 cell apoptosis.Conclusions Activation and upregulation of caspase-3 or caspase-8 protein were responsible for Indomethacin-induced K562 cell apoptosis. Variation of intracellular free calcium might switch on the apoptotic pathway and the proapoptotic effect of indomethacin might be cyclooxygenase-independent.

  11. Jellyfish extract induces apoptotic cell death through the p38 pathway and cell cycle arrest in chronic myelogenous leukemia K562 cells

    Science.gov (United States)

    Kwak, Choong-Hwan; Abekura, Fukushi; Park, Jun-Young; Park, Nam Gyu; Chang, Young-Chae; Lee, Young-Choon; Chung, Tae-Wook; Ha, Ki-Tae; Son, Jong-Keun

    2017-01-01

    Jellyfish species are widely distributed in the world’s oceans, and their population is rapidly increasing. Jellyfish extracts have several biological functions, such as cytotoxic, anti-microbial, and antioxidant activities in cells and organisms. However, the anti-cancer effect of Jellyfish extract has not yet been examined. We used chronic myelogenous leukemia K562 cells to evaluate the mechanisms of anti-cancer activity of hexane extracts from Nomura’s jellyfish in vitro. In this study, jellyfish are subjected to hexane extraction, and the extract is shown to have an anticancer effect on chronic myelogenous leukemia K562 cells. Interestingly, the present results show that jellyfish hexane extract (Jellyfish-HE) induces apoptosis in a dose- and time-dependent manner. To identify the mechanism(s) underlying Jellyfish-HE-induced apoptosis in K562 cells, we examined the effects of Jellyfish-HE on activation of caspase and mitogen-activated protein kinases (MAPKs), which are responsible for cell cycle progression. Induction of apoptosis by Jellyfish-HE occurred through the activation of caspases-3,-8 and -9 and phosphorylation of p38. Jellyfish-HE-induced apoptosis was blocked by a caspase inhibitor, Z-VAD. Moreover, during apoptosis in K562 cells, p38 MAPK was inhibited by pretreatment with SB203580, an inhibitor of p38. SB203580 blocked jellyfish-HE-induced apoptosis. Additionally, Jellyfish-HE markedly arrests the cell cycle in the G0/G1 phase. Therefore, taken together, the results imply that the anti-cancer activity of Jellyfish-HE may be mediated apoptosis by induction of caspases and activation of MAPK, especially phosphorylation of p38, and cell cycle arrest at the Go/G1 phase in K562 cells. PMID:28133573

  12. 人参皂苷对K562细胞增殖与分化相关基因表达的影响%The effect of ginsenoside on mRNA expression of proliferation and differentiationrelated genes in K562 cells

    Institute of Scientific and Technical Information of China (English)

    危建安; 胡永珍; 韩凌

    2011-01-01

    Objective To explore the potential mechanisms of ginsenosides on K562 cell proliferation and differentiation. Methods Relative quantification RT-PCR with SYBR Green dye was used to determine the expression of Lif, Ccndl, Mdm2, Erbb2 ,p53 and myc mRNA in K562 cells treated with ginsenoside (20 μg/mL) at 36 h. Results mRNA expression of Lif was significantly up-regulated(P < 0.05 ), and that of myc was markedly down-regulated (P < 0.05) in K562 cells when treated with traginsenoside。 mRNA levels of Mdm2,Erbb2 and Ccndl were not significantly changed after treatment of ginsenoside (P > 0. 05 ). mRNA expression of p53 was very weak in K562 cells, so that was not statistically analysed. Conclusion The effect of ginsenoside on proliferative inhibition and differential induction of K562 cells is related to up-regulation of Lif mRNA and down - regulation of myc mRNA respectively.%目的 探讨人参皂苷影响K562细胞增殖、分化的可能分子机制.方法 采用real-time PCR技术和SYBR Green染料法检测人参皂苷(20 μg/mL)作用于K562细胞36 h时间点Lif、Ccnd1、Mdm2、Erbb2、p53和myc等6个基因mRNA相对表达水平.结果 人参皂苷能显著促进K562细胞Lif mRNA的表达(P<0.05),对myc mRNA表达有显著抑制作用(P<0.05),对Mdm2、Erbb2和Ccnd1等mRNA表达无显著影响.结论 人参皂苷对K562细胞的诱导分化和增殖抑制作用可能分别与Lif mRNA表达上调和mycmRNA表达下调相关.

  13. 苦参碱对K562细胞端粒酶hTERT-mRNA表达及其酶活性影响作用的研究%Effects of Matrine on hTERT-mRNA Expression and Telomerase Activity in K562 Cells

    Institute of Scientific and Technical Information of China (English)

    李旭芬; 张苏展; 郑树; 张行

    2001-01-01

    目的:观察苦参碱对K562细胞hTERT-mRNA表达及端粒酶活性的影响作用,并明确两者的相关性。方法:以0.1~2mg/ml苦参碱处理K562细胞48h后,RT-PCR检测其hTERT-mRNA表达,同时行TRAP-PCR-ELISA端粒酶活性检测。结果:K562细胞为一强端粒酶活性细胞株,在浓度分别为0.1、05、10、20mg/ml苦参碱作用后,K562细胞hTERT-mRNA表达明显受抑,同时伴有端粒酶活性下降,抑制率分别为0.%、13.%、91.7%和98.6%。结论:苦参碱可降低K562细胞hTERT-mRNA表达,同时伴端粒酶活性下降;端粒酶活性强度与hTERT-mRNA表达有关。%Objective:This study was designed to investigate the effects of matrine on hTERT-mRNA expression and telomerase activity in K562 cells and their relationship. Methods: The hTERT-mRNA expression was determined by RT-PCR assay in untreated and matrine-treated K562 cells, and telomerase activity was analyzed by TRAP-PCR-ELISA assay. Results: The hTERT-mRNA expression of K562 cells was significantly inhibited when treatment with matrine, while telomerase activity was decreased. Conclusion: Matrine can inhibit the hTERT-mRNA expression and telomerase activity of K562 cells. Telomerase activity might be related to the expression of hTERT-mRNA.

  14. Human NK cells maintain licensing status and are subject to killer immunoglobulin-like receptor (KIR) and KIR-ligand inhibition following ex vivo expansion.

    Science.gov (United States)

    Wang, Wei; Erbe, Amy K; Alderson, Kory A; Phillips, Emily; Gallenberger, Mikayla; Gan, Jacek; Campana, Dario; Hank, Jacquelyn A; Sondel, Paul M

    2016-09-01

    Infusion of allogeneic NK cells is a potential immunotherapy for both hematopoietic malignancies and solid tumors. Interactions between killer immunoglobulin-like receptors (KIR) on human NK cells and KIR-ligands on tumor cells influence the magnitude of NK function. To obtain sufficient numbers of activated NK cells for infusion, one potent method uses cells from the K562 human erythroleukemia line that have been transfected to express activating 41BB ligand (41BBL) and membrane-bound interleukin 15 (mbIL15). The functional importance of KIRs on ex vivo expanded NK cells has not been studied in detail. We found that after a 12-day co-culture with K562-mbIL15-41BBL cells, expanded NK cells maintained inhibition specificity and prior in vivo licensing status determined by KIR/KIR-ligand interactions. Addition of an anti-CD20 antibody (rituximab) induced NK-mediated antibody-dependent cellular cytotoxicity and augmented killing of CD20+ target cells. However, partial inhibition induced by KIR/KIR-ligand interactions persisted. Finally, we found that extended co-cultures of NK cells with stimulatory cells transduced to express various KIR-ligands modified both the inhibitory and activating KIR repertoires of the expanded NK cell product. These studies demonstrate that the licensing interactions known to occur during NK ontogeny also influence NK cell function following NK expansion ex vivo with HLA-null stimulatory cells.

  15. Effect of magnetic nanoparticles of Fe3O4 and 5-bromotetrandrine on reversal of multidrug resistance in K562/A02 leukemic cells

    Directory of Open Access Journals (Sweden)

    Jian Cheng

    2009-09-01

    Full Text Available Jian Cheng1*, Weiwei Wu1*, Bao-an Chen1, Feng Gao1, Wenlin Xu2, Chong Gao1, Jiahua Ding1, Yunyu Sun1, Huihui Song1, Wen Bao1, Xinchen Sun3, Cuirong Xu1, Wenji Chen1, Ningna Chen1, Lijie Liu4, Guohua Xia1, Xiaomao Li5, Xuemei Wang61Department of Hematology, 3Department of Oncology, The Afiliated Zhongda Hospital, Southeast University, Nanjing, People’s Republic of China; 2Department of Hematology, The First People’s Hospital of Zhengjiang, Zhenjiang, People’s Republic of China; 4Institution of Physiology, 6State Key Lab of Bioelectronics (Chien-Shiung Wu Laboratory, Southeast University, Nanjing, People’s Republic of China; 5Department of Physics, University of Saarland, Saarbruechen, Germany; *These authors have contributed equally to this workAbstract: This study aims to evaluate the multidrug resistance (MDR reversal activity by magnetic nanoparticles of Fe3O4 (MNPs-Fe3O4 and 5-bromotetrandrine (BrTet MDR cell line K562/A02 solitarily or symphysially. The proliferation of K562 and K562/A02 cells and the cytotoxicity on peripheral blood mononuclear cells (PMBCs were evaluated by MTT assay. Cellular accumulation of daunorubicin (DNR was analyzed by flow cytometry. Real-time polymerase chain reaction and Western blotting analyses were performed to examine the mRNA and protein levels of mdr1, respectively. The results showed that the combination of MNPs-Fe3O4 and BrTet with effective concentrations significantly increased cytotoxicity against MDR cell line K562/A02. Both BrTet and MNPs-Fe3O4 increased the intracellular DNR accumulation in the K562/A02 cell line, and downregulated the level of mdr1 gene and expression of P-glycoprotein. Furthermore, the combination did not have significant cytotoxicity in PMBCs. We propose that MNPs-Fe3O4 conjugated with DNR and BrTet probably have synergetic effects on MDR reversal.Keywords: magnetic nanoparticles of Fe3O4, 5-bromotetrandrine, multidrug resistance K562/A02

  16. Time-series analysis in imatinib-resistant chronic myeloid leukemia K562-cells under different drug treatments.

    Science.gov (United States)

    Zhao, Yan-Hong; Zhang, Xue-Fang; Zhao, Yan-Qiu; Bai, Fan; Qin, Fan; Sun, Jing; Dong, Ying

    2017-08-01

    Chronic myeloid leukemia (CML) is characterized by the accumulation of active BCR-ABL protein. Imatinib is the first-line treatment of CML; however, many patients are resistant to this drug. In this study, we aimed to compare the differences in expression patterns and functions of time-series genes in imatinib-resistant CML cells under different drug treatments. GSE24946 was downloaded from the GEO database, which included 17 samples of K562-r cells with (n=12) or without drug administration (n=5). Three drug treatment groups were considered for this study: arsenic trioxide (ATO), AMN107, and ATO+AMN107. Each group had one sample at each time point (3, 12, 24, and 48 h). Time-series genes with a ratio of standard deviation/average (coefficient of variation) >0.15 were screened, and their expression patterns were revealed based on Short Time-series Expression Miner (STEM). Then, the functional enrichment analysis of time-series genes in each group was performed using DAVID, and the genes enriched in the top ten functional categories were extracted to detect their expression patterns. Different time-series genes were identified in the three groups, and most of them were enriched in the ribosome and oxidative phosphorylation pathways. Time-series genes in the three treatment groups had different expression patterns and functions. Time-series genes in the ATO group (e.g. CCNA2 and DAB2) were significantly associated with cell adhesion, those in the AMN107 group were related to cellular carbohydrate metabolic process, while those in the ATO+AMN107 group (e.g. AP2M1) were significantly related to cell proliferation and antigen processing. In imatinib-resistant CML cells, ATO could influence genes related to cell adhesion, AMN107 might affect genes involved in cellular carbohydrate metabolism, and the combination therapy might regulate genes involved in cell proliferation.

  17. Carbon monoxide induced erythroid differentiation of K562 cells mimics the central macrophage milieu in erythroblastic islands.

    Directory of Open Access Journals (Sweden)

    Shlomi Toobiak

    Full Text Available Growing evidence supports the role of erythroblastic islands (EI as microenvironmental niches within bone marrow (BM, where cell-cell attachments are suggested as crucial for erythroid maturation. The inducible form of the enzyme heme oxygenase, HO-1, which conducts heme degradation, is absent in erythroblasts where hemoglobin (Hb is synthesized. Yet, the central macrophage, which retains high HO-1 activity, might be suitable to take over degradation of extra, harmful, Hb heme. Of these enzymatic products, only the hydrophobic gas molecule--CO can transfer from the macrophage to surrounding erythroblasts directly via their tightly attached membranes in the terminal differentiation stage.Based on the above, the study hypothesized CO to have a role in erythroid maturation. Thus, the effect of CO gas as a potential erythroid differentiation inducer on the common model for erythroid progenitors, K562 cells, was explored. Cells were kept under oxygen lacking environment to mimic BM conditions. Nitrogen anaerobic atmosphere (N₂A served as control for CO atmosphere (COA. Under both atmospheres cells proliferation ceased: in N₂A due to cell death, while in COA as a result of erythroid differentiation. Maturation was evaluated by increased glycophorin A expression and Hb concentration. Addition of 1%CO only to N₂A, was adequate for maintaining cell viability. Yet, the average Hb concentration was low as compared to COA. This was validated to be the outcome of diversified maturation stages of the progenitor's population.In fact, the above scenario mimics the in vivo EI conditions, where at any given moment only a minute portion of the progenitors proceeds into terminal differentiation. Hence, this model might provide a basis for further molecular investigations of the EI structure/function relationship.

  18. PESV干预K562细胞PI3K/Akt信号通路凋亡调控的研究%Study on PI3K/Akt messenger passage and apoptosis controlling in PESV-preconditioned K562 cells

    Institute of Scientific and Technical Information of China (English)

    张蕾; 杨文华; 于文俊; 郝征; 张佳

    2012-01-01

    [Objective] To investigate the effect of PESV on the expression of massage protein PI3K / Akt, apoptosis regulators Bcl-2 and Bad expression in K562 cells. [Methods] In vitro cultured K562 cells preconditioned with PESV for different times were determined for cell apoptosis rate with cytoflowmeter, the level of P13K and p-AKT protein with Western blot and Bcl-2, Bad mRNA level by realtime fluorescence quantitative RT-PCR. [Results] Compared with the control group, the apoptosis rate of PESV treated K562 cells was significantly increaseds, the expression of PI3K and p-Akt and anti-apoptosis-related gene Bcl-2 mRNA was decreased; the expression of pro-apoptotic gene Bad mRNA was increased. [Conclusion] PESV may regulate the expression of Bcl-2 and Bad, inhibit the proliferation of K562 cells and promote their apoptosis by reducing the expression of PI3K and Akt signaling protein.%[目的]探讨PESV对K562细胞PI3K/Akt信号蛋白及凋亡调控因子Bcl-2和Bad表达的影响.[方法]将体外培养K562细胞,经PESV处理不同时间后,流式细胞术检测细胞凋亡率,Western blot检测PI3K及p-Akt蛋白水平变化,实时荧光定量RT-PCR检测Bcl-2、Bad mRNA水平变化.[结果]与对照组相比,PESV处理后K562细胞凋亡率显著增加,PI3K及p-Akt表达降低,抗凋亡相关基因Bcl-2 mRNA表达降低,促凋亡基因Bad mRNA表达增加.[结论]PESV可能通过降低PI3K、Akt信号蛋白表达,调节Bcl-2和Bad表达,抑制K562细胞增殖,促进其凋亡.

  19. Experimental study on K562 cell apoptosis induced by steroid saponins extracted from the flowers of Cestrum nocturnum Linn%夜香树花甾体皂苷诱导K562细胞凋亡机制研究

    Institute of Scientific and Technical Information of China (English)

    赵世元; 黄之虎; 叶海洪; 钟振国; 张明艳; 李彩萍

    2013-01-01

    目的 研究夜香树花甾体皂苷对人白血病细胞K562的增殖抑制作用和凋亡诱导影响.方法 用MTT法检测夜香树花甾体皂苷对K562细胞的增殖抑制作用;Wright's染色观察细胞形态学改变;应用流式细胞仪检测细胞周期和凋亡率.Annexin V/PI双标记法、TUNEL法检测细胞凋亡特点;采用Western blotting法检测Caspase-3、线粒体和胞浆中细胞色素C表达.结果 夜香树花甾体皂苷对K562细胞生长具有显著的抑制作用,并呈剂量-时间依赖性,夜香树花甾体皂苷可阻滞K562细胞周期于G0/G1期,经夜香树花甾体皂苷处理后的K562细胞Annexin V+/P-细胞显著增加,TUNEL细胞涂片可见强烈荧光效应.夜香树花甾体皂苷可诱导K562细胞线粒体细胞色素C释放和Caspase-3活化.结论 夜香树花甾体皂苷可有效抑制K562细胞增殖,诱导K562细胞凋亡,与作用剂量和作用时间呈正相关,这一过程可能与夜香树花甾体皂苷损伤线粒体和激活Caspase-3有关.

  20. 人参多糖对人白血病细胞株K562细胞信号转导的调控%Effect of GPS on JAK2-STAT5, NF-κB signal transduction pathways in K562 cells

    Institute of Scientific and Technical Information of China (English)

    谢冰松; 李静; 陈地龙; 王亚平; 王建伟

    2009-01-01

    目的:研究人参多糖(GPS)对人红白血病细胞株(K562)信号转导的调控.方法:采用细胞体外培养技术,免疫细胞化学、Western Blot检测GPS诱导后K562细胞蛋白酪氨酸激酶JAK2、核因子NF-κB p65和信号传导及转录激活因子5(STAT5)的表达,免疫沉淀法检测GPS对K562细胞JAK2磷酸化的影响,RT-PCB技术检测GPS诱导后K562细胞c-myc,p53表达的变化.结果:免疫细胞化学和Western Blot检测GPS诱导后K562细胞,JAK2蛋白表达明显增强,随着剂量的加大、时间的延长更加明显[(12.33±2.05)vs(88.18±13.57)];NF-κB p65[(79.48±9.56)vs(6.98±1.45)]和STAT5[(71.56±16.28)vs(10.23±2.16)]蛋白表达明显减弱;GPs(40 mg/L)作用K562细胞6 d后,加入GM-CSF继续刺激5~10 min,JAK2酪氨酸磷酸化增强,而刺激20 min后JAK2酪氨酸磷酸化明显减弱.GPS(40 mg/L)诱导K562细胞3,6 d后.c-myc mRNA明显减弱[(196±12)vs(136±11)],而p53 mRNA无明显变化[(202±16)vs(181±16)].结论:GPS激活了酪氨酸蛋白激酶JAK2,促进其磷酸化,同时抑制STAT5,NF-κB信号转导途径,下调原癌基因c-myc表达,促进K562细胞凋亡与分化.

  1. Proteins pattern alteration in AZT-treated K562 cells detected by two-dimensional gel electrophoresis and peptide mass fingerprinting

    Directory of Open Access Journals (Sweden)

    Mignogna Giuseppina

    2006-03-01

    Full Text Available Abstract In this study we report the effect of AZT on the whole protein expression profile both in the control and the AZT-treated K562 cells, evidenced by two-dimensional gel electrophoresis and peptide mass fingerprinting analysis. Two-dimensional gels computer digital image analysis showed two spots that appeared up-regulated in AZT-treated cells and one spot present only in the drug exposed samples. Upon extraction and analysis by peptide mass fingerprinting, the first two spots were identified as PDI-A3 and stathmin, while the third one was proved to be NDPK-A. Conversely, two protein spots were present only in the untreated K562 cells, and were identified as SOD1 and HSP-60, respectively.

  2. SENYAWA BIOAKTIF RIMPANG JAHE (Zingiber officinale Roscue MENINGKATKAN RESPON SITOLITIK SEL NK TERHADAP SEL KANKER DARAH K-562 IN VITRO [Ginger Root Bioactive Compounds Increased Cytolitic Response of Natural Killer (NK Cells Against Leucemic Cell Line K-562 In Vitro

    Directory of Open Access Journals (Sweden)

    Fransiska Rungkat Zakaria 2

    2006-08-01

    Full Text Available Natural killer (NK cell, a kind of lymphocyte cells, plays an important role in attacking infectious, immature, and cancer cell. Its function could be modulated by food bioactive compounds. This experiment was conducted to investigate the effects of ginger root bioactive compounds such as oleoresin, gingerol, and shogaol on cytolitic response of NK cell in vitro. Lymphocyte cells were isolated by centrifugation on ficoll-hypaque density (1,77 ?0,001 g/ml method. Leukemic cells line K-562 as target cells(TC labelled by [3H]-timidin, together with lymphocyte as effector cell (EC were cultured in two ratio levels of EC : TC equal to 1:50 and 1:100, and two culture conditions, for 4 hours, respectively. Paraquate dichloride (1,1-dimethyl-4,4-bipyridilium dichloride 3 mM was used to induce stress oxidative circumstance. Cytolytic capacity of NK cells was determined by percentage of TC lysed by NK cells, in normal and oxidative stress conditions. Statistical analysis showed that the effects of ginger bioactive compounds on cytolytic response of NK cell depended on the culture conditions, as shown by cultures in the presence of oleoresin, and gingerol, but not shogaol. In the lymphocyte culture without stress oxidative, oleoresin, gingerol and shogaol compounds increased significantly cytolytic response of NK cells cultured at a ratio of TC : EC equal to 1:50, with the highest increament of 65 % at oleoresin concentration of 50 ?g/ml. However, in culture at a ratio of TC : EC equals to 1:100, only oleoresin at a concentration of 50 ?g/ml increased significantly cytolytic response of NK cells with the highest increament of 8 %. Shogaol did not affect significantly NK cells cytolytic response. Under stress oxidative conditions, shogaol increased significantly cytolytic response of NK cells cultured at a ratio of TC:EC equal to 1:50, but the highest increament of 56 % , was by oleoresin at concentration of 50 ?g/ml. Meanwhile, oleoresin and gingerol did

  3. Mechanistic Evaluation for Mixed-field Agglutination in the K562 Cell Study Model with Exon 3 Deletion of A1 Gene.

    Science.gov (United States)

    Chen, Ding-Ping; Tseng, Ching-Ping; Lin, Chi-Jui; Wang, Wei-Ting; Sun, Chien-Feng

    2015-01-01

    In the case of blood type B3 with typical mixed-field agglutination of RBCs in the presence of anti-B or anti-AB antibody, a number of genetic alternations have been reported. It is well known that the IVS3+5G→A mutation in the B gene destroys the consensus of the splice donor site leading to exon 3 skipping during mRNA splicing. The lack of exon 3 likely causes a short stem region, producing an unstable B3 protein, and is concomitant with a decrease in B3 protein expression. Whether the phenomenon also appears in the type A blood group is of question. In this study, we evaluate whether exon 3 deletion in the blood type A gene also results in mixed-field phenotype. Site-directed mutagenesis was used to generate cDNA encoding A1 gene with exon 3 deletion. The cDNA was stably expressed in K562 cells. The expression of A antigen was compared with expression in parental K562 cells that did not express A antigen and in the stable K562 cell line expressing A(1) cDNA by flow cytometry analyses. The expression of A antigen in A1 stable cells and parental K562 cells was set as 100% and 0%, respectively. The mean relative percentage of A antigen expression for the cells of A1 with exon 3 deletion was 59.9% of A1 stable cells. Consistent with the observations of B3, which is B gene with exon 3 deletion, mixed field agglutination was observed for the cells expressing A1 with exon 3 deletion. Exon 3 deletion results in mixed field phenotype in both type A and B RBCs. However, the degree of antigen expression change for exon 3 deletion in A gene was less severe when compared with the deletion occurred in B gene.

  4. 半夏醇提取液逆转多药耐药细胞系K562/A02的耐药性%Reversal of Multirug Resistance in K562/A02 Cell by Alcoholic Extract of Pinellia ternate

    Institute of Scientific and Technical Information of China (English)

    彭向前; 冯玮; 张文会

    2012-01-01

    Objective; To investigate the effect and mechanism of alcoholic extract of Pinellia ternate at non-cytotoxic concentration (inhibit rate≤ 5% ) reversing the multidrug resistant (MDR) leukemia cell lines K562/A02. Method; Cells were seeded into 72-well plates at 2 x 108/L with varying concentrations (2.5, 5, 10, 20, 40 μg o L-1 ) of P. ternate for 72 h, MTT colorimetry was used to determine the cytotoxic effect of alcoholic extract of P. ternate and the sensibility to adriamycin of K562/A02 cell line. Flow cytometry was used to determine the expressive and functional changes of glycoprotein-170 (pl70) on the cell membrane dealed with alcoholic extract of P. ternate at non-cytotoxic concentration. And daunorubicin concentration in the cells was detected by flow cytometry. The statistical treatment with SPSS 16. 0 was applied to deal with all the experimental data. Result: Alcoholic extract of P. ternate had definite cytotoxic effect on K562/A02, the non-cytotoxic dose of oxymatrine was 6. 5 μg ·L-1 . Non-cytotoxic dose of alcoholic extract of P. ternate can significantly decrease theq medium inhibition concentration ( IC50 ) value of K562/ADM cell line to adriamycin ( ADM ) . The IC50 was obviously reduced from (30. 9 ±0. 11) μg·L-1 to (10.1 ±0.21) μg·L-1 , alcoholic extract of P. ternate at non-cytotoxic concentration could partly reverse MDR of K562/A02 (3.06times) , and could descend the expression of pl70 from 91.21% to 45.12% (P < 0. 01 ) . The exosmosis test of daunorubicin showed that intracellular concentration of chemotherapeutics concentration increased evidently. Conclusion; Alcoholic extract of P. ternate is able to partly reverse MDR of K562/A02 cell line could descend the expression of P1 70, and can restrain the function of pumping chemotherapeutics out of the cell and enhance the efficient intracellular concentration of chemotherapeutics which can kill leukemia cells of multidrug resistance, and partly reversed MDR of K562/A02.%目的:观

  5. Development and characterization of K562 cell clones expressing BCL11A-XL: Decreased hemoglobin production with fetal hemoglobin inducers and its rescue with mithramycin

    Science.gov (United States)

    Finotti, Alessia; Gasparello, Jessica; Breveglieri, Giulia; Cosenza, Lucia Carmela; Montagner, Giulia; Bresciani, Alberto; Altamura, Sergio; Bianchi, Nicoletta; Martini, Elisa; Gallerani, Eleonora; Borgatti, Monica; Gambari, Roberto

    2015-01-01

    Induction of fetal hemoglobin (HbF) is considered a promising strategy in the treatment of β-thalassemia, in which production of adult hemoglobin (HbA) is impaired by mutations affecting the β-globin gene. Recent results indicate that B-cell lymphoma/leukemia 11A (BCL11A) is a major repressor of γ-globin gene expression. Therefore, disrupting the binding of the BCL11A transcriptional repressor complex to the γ-globin gene promoter provides a novel approach for inducing expression of the γ-globin genes. To develop a cellular screening system for the identification of BCL11A inhibitors, we produced K562 cell clones with integrated copies of a BCL11A-XL expressing vector. We characterized 12 K562 clones expressing different levels of BCL11A-XL and found that a clear inverse relationship does exist between the levels of BCL11A-XL and the extent of hemoglobinization induced by a panel of HbF inducers. Using mithramycin as an inducer, we found that this molecule was the only HbF inducer efficient in rescuing the ability to differentiate along the erythroid program, even in K562 cell clones expressing high levels of BCL11A-XL, suggesting that BCL11A-XL activity is counteracted by mithramycin. PMID:26342260

  6. Thiosemicarbazone p-Substituted Acetophenone Derivatives Promote the Loss of Mitochondrial Δψ, GSH Depletion, and Death in K562 Cells

    Science.gov (United States)

    Pessoto, Felipe S.; Yokomizo, Cesar H.; Prieto, Tatiana; Fernandes, Cleverton S.; Silva, Alan P.; Kaiser, Carlos R.; Basso, Ernani A.; Nantes, Iseli L.

    2015-01-01

    A series of thiosemicarbazone (TSC) p-substituted acetophenone derivatives were synthesized and chemically characterized. The p-substituents appended to the phenyl group of the TSC structures were hydrogen, fluor, chlorine, methyl, and nitro, producing compounds named TSC-H, TSC-F, TSC-Cl, TSC-Me, and TSC-NO2, respectively. The TSC compounds were evaluated for their capacity to induce mitochondrial permeability, to deplete mitochondrial thiol content, and to promote cell death in the K562 cell lineage using flow cytometry and fluorescence microscopy. TSC-H, TSC-F, and TSC-Cl exhibited a bell-shaped dose-response curve for the induction of apoptosis in K562 cells due to the change from apoptosis to necrosis as the principal mechanism of cell death at the highest tested doses. TSC-Me and TSC-NO2 exhibited a typical dose-response profile, with a half maximal effective concentration of approximately 10 µM for cell death. Cell death was also evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, which revealed lower toxicity of these compounds for peripheral blood mononuclear cells than for K562 cells. The possible mechanisms leading to cell death are discussed based on the observed effects of the new TSC compounds on the cellular thiol content and on mitochondrial bioenergetics. PMID:26075034

  7. Thiosemicarbazone p-Substituted Acetophenone Derivatives Promote the Loss of Mitochondrial Δψ, GSH Depletion, and Death in K562 Cells

    Directory of Open Access Journals (Sweden)

    Felipe S. Pessoto

    2015-01-01

    Full Text Available A series of thiosemicarbazone (TSC p-substituted acetophenone derivatives were synthesized and chemically characterized. The p-substituents appended to the phenyl group of the TSC structures were hydrogen, fluor, chlorine, methyl, and nitro, producing compounds named TSC-H, TSC-F, TSC-Cl, TSC-Me, and TSC-NO2, respectively. The TSC compounds were evaluated for their capacity to induce mitochondrial permeability, to deplete mitochondrial thiol content, and to promote cell death in the K562 cell lineage using flow cytometry and fluorescence microscopy. TSC-H, TSC-F, and TSC-Cl exhibited a bell-shaped dose-response curve for the induction of apoptosis in K562 cells due to the change from apoptosis to necrosis as the principal mechanism of cell death at the highest tested doses. TSC-Me and TSC-NO2 exhibited a typical dose-response profile, with a half maximal effective concentration of approximately 10 µM for cell death. Cell death was also evaluated using the 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay, which revealed lower toxicity of these compounds for peripheral blood mononuclear cells than for K562 cells. The possible mechanisms leading to cell death are discussed based on the observed effects of the new TSC compounds on the cellular thiol content and on mitochondrial bioenergetics.

  8. Effects of a new retinoic acid derivative ATPA on the proliferation and differentiation of leukemia cell line K562%新型维甲酸衍生物ATPA对白血病细胞株K562增殖及分化的影响

    Institute of Scientific and Technical Information of China (English)

    洪凡青; 陈飞虎; 王璐; 陈慧慧; 吴菲; 吴繁荣; 汪渊

    2011-01-01

    目的:本研究探讨新型维甲酸衍生物4-氨基-2-三氟甲基苯基依曲替酸酯(4-amino-2-trifluoromethyl-phenyl acitretinate,ATPA)对白血病K562细胞体外增殖和分化的作用.方法:用不同浓度的ATPA作用白血病K562细胞后,在体外通过MTT法检测和绘制细胞生长曲线来分析细胞增殖;瑞特染色法观察细胞形态学改变;氯化硝基四氮唑蓝(nitroblue tetrazolium chloride,NBT)还原实验分析细胞的分化指标;采用FCM法检测细胞表面分化抗原及细胞周期的变化.结果:ATPA呈浓度依赖性抑制K562细胞增殖,明显的抑制作用从药物作用48 h后开始出现,在72 h后作用更明显.倒置显微镜下观察发现ATPA作用后K562细胞形态趋向成熟,NBT阳性细胞率增加;G0/G1期细胞表达量增加,S期细胞表达量减少,呈G0/G1期阻滞;细胞表面分化抗原CD71表达减少.结论:ATPA对白血病K562细胞具有抑制增殖和一定的诱导分化作用.%Objective: To explore the effects of 4-amino-2-trifluoromethyl-phenyl acitretinate (ATPA)on the proliferation and differentiation of K562 leukemia cells in vitro.Methods: After K562 leukemia cells were treated with ATPA at different concentrations, cell proliferation was assessed by MTT and cell growth curve.Morphologic changes of cells were observed under an inverted microscope (oilimmersion lens) after Wright's staining.Nitroblue tetrazolium (NBT) reduction test was used to analyze cell differentiation indices.The cell cycle and the expression of the specific cell surface maturation marker CD71 were analyzed by flow cytometry (FCM).Results: The growth of K562 cells treated with ATPA was inhibited in a dose-dependent manner.The distinct inhibitory effect appeared after treatment with ATPA for 48 h, but the effect was more significant after 72 h.Morphology of K562 cells treated with ATPA was observed to be mature under an inverted microscope.NBT reduction test indicated that ATPA could increase the percentage of NBT

  9. Survivin反义寡核苷酸对5-FU诱导人红白血病细胞系K562凋亡的影响%Survivin antisense oligodeoxy-nucleotid enhances 5-FU- induced apoptosis of leukemic cell line K562

    Institute of Scientific and Technical Information of China (English)

    靳秋月; 王瑞珉; 谢红; 陈立军

    2006-01-01

    [目的]探讨survivin反义寡核苷酸(Antisense Oligodeoxy-nucleotid,ASODN)对5-FU(5-氟尿嘧啶)诱导人红白血病细胞系K562细胞凋亡的影响.[方法]体外培养K562细胞,合成survivin ASODN并经脂质体转染至K562细胞内,MTT法观察survivin ASODN组、5-FU组及5-FU联合survivin ASODN的细胞毒作用,Hoechst33342/PI双荧光染色观察各组细胞核形态,镜下计算各组细胞凋亡率.[结果]400、600、800、1000nmol/L survivin ASODN处理K562细胞44h后,IC50为800 nmol/L;与单独使用survivin ASODN或5-FU相比,5-FU联合800 nmol/L survivin ASODN后细胞生长明显受到抑制(P<0.01);Hoechest33342/PI双荧光染色可观察到survivin ASODN组、5-FU组及5-FU联合survivin ASODN组均出现明显核固缩、凝集等细胞凋亡表现.镜下细胞计数,survivin ASODN组、5-FU组及5-FU联合survivin ASODN组细胞凋亡率分别为54.55%、53.85%、86.70%.[结论]Survivin ASODN可增强K562细胞对5-FU的敏感性.

  10. Reversal in multidrug resistance by magnetic nanoparticle of Fe3O4 loaded with adriamycin and tetrandrine in K562/A02 leukemic cells

    Directory of Open Access Journals (Sweden)

    Baoan Chen

    2008-06-01

    Full Text Available Baoan Chen1,5, Qian Sun1,5, Xuemei Wang2, Feng Gao1, Yongyuan Dai1, Yan Yin1, Jiahua Ding1, Chong Gao1, Jian Cheng1, Jingyuan Li2, Xinchen Sun1, Ningna Chen1, Wenlin Xu3, Huiling Shen3, Delong Liu41Department of Hematology, Zhongda Hospital, Southeast University, Nanjing, China; 2State Key Lab of Bioelectronics(Chien-Shiung Wu Laboratory, Southeast University, Nanjing 210096, China; 3Department of Hematology, The First People’s Hospital of Zhenjiang, Zhenjiang, China; 4Westchester Medical Center, New York Medical College, NY, USA; 5These authors have contributed equally to this work.Abstract: Drug resistance is a primary hindrance for efficiency of chemotherapy. To investigate whether Fe3O4-magnetic nanoparticles (Fe3O4-MNPs loaded with adriamycin (ADM and tetrandrine (Tet would play a synergetic reverse role in multidrug resistant cell, we prepared the drug-loaded nanoparticles by mechanical absorption polymerization to act with K562 and one of its resistant cell line K562/A02. The survival of cells which were cultured with these conjugates for 48 h was observed by MTT assay. Using cells under the same condition described before, we took use of fluorescence microscope to measure fluorescence intensity of intracellular ADM at an excitation wavelength of 488 nm. P-glycoprotein (P-gp was analyzed with flow cytometer. The expression of mdr1 mRNA was measured by RT-PCR. The results showed that the growth inhibition efficacy of both the two cells increased with augmenting concentrations of Fe3O4-MNPs which were loaded with drugs. No linear correlation was found between fluorescence intensity of intracellular adriamycin and augmenting concentration of Fe3O4-MNPs. Tet could downregulate the level of mdr-1 gene and decrease the expression of P-gp. Furthermore, Tet polymerized with Fe3O4-MNPs reinforced this downregulation, causing a 100-fold more decrease in mdr1 mRNA level, but did not reduce total P-gp content. Our results suggest that Fe3O4-MNPs

  11. Cytotoxic effect of Spirulina platensis extracts on human acute leukemia Kasumi-1 and chronic myelogenous leukemia K-562 cell lines

    Directory of Open Access Journals (Sweden)

    Flor Yohana Flores Hernandez

    2017-01-01

    Conclusions: The cytotoxicity exhibited by Spirulina extract to cancer cell lines might be due to the presence of phytopigments (carotenoids, chlorophyll, phycocyanin as well as polysaccharides that were reported previously as constituents of the extract. So crude extracts of Spirulina can be used as a source to develop anticancer drugs.

  12. Potential Role of Nucleophosmin(NPM1)Gene Mutations in K562 Leukemia Cell Invasion Phenotype%NPM1突变基因调控K562白血病细胞侵袭表型的相关机制

    Institute of Scientific and Technical Information of China (English)

    陈先春; 覃凤娴; 谭诗; 张慧娟; 邵会媛; 张伶

    2011-01-01

    Objective To investigate the role of CXCR4 and Angs in the invasion phenotype in vitro of leukemic cells with NPM1 mutations, and further study the effect of NPM1 mutations on leukemia infiltration. Methods The pEGFPC1-NPM1-mA plasmid vector was transfected into K562 cells. The cells stably expressing NPM1-mA protein were established, named as K562-mA. The expressions of CXCR4 and Ang-1/2 mRNA were assayed by quantitative Real-Time PCR ( qRT-PCR ). The expression of CXCR4 protein was assayed by Western blot and flow cytometry. Results Compared with control groups, CXCR4 mRNA and protein expression levels were significantly increased in K562-mA group. The expression of Ang-1 mRNA was markedly decreased, whereas Ang-2 mRNA expression was increased in K562-mA group. Conclusion CXCR4 and Ang-1/2 may play important roles in the invasion phenotype of leukemic cells with NPM1 mutations in vitro.%目的 探讨CXCR4、Angs在NPM1突变参与调控的白血病细胞浸润转移中的作用,以期进一步明确NPM1突变在白血病浸润转移中的调控机制.方法 通过基因转染构建稳定表达NPM1突变蛋白的K562白血病细胞株(K562-mA).qRT-PCR检测各组细胞CXCR4、Ang-1/2的mRNA表达水平;Western免疫印迹和流式细胞仪分别检测细胞CXCR4总蛋白和膜蛋白的表达.结果 建立了稳定表达NPM突变基因的K562-mA细胞株.与未处理组和空载体转染组相比,K562-mA细胞CXCR4的mRNA和蛋白表达水平显著增高;Ang-1 mRNA表达水平明显降低、Ang-2 mRNA表达水平明显增高.结论 CXCR4、Ang-1/2可能在NPM1突变调控白血病细胞的浸润转移中发挥重要作用.

  13. Cis-vaccenic acid induces differentiation and up-regulates gamma globin synthesis in K562, JK1 and transgenic mice erythroid progenitor stem cells

    Science.gov (United States)

    Aimola, Idowu A.; Inuwa, Hajiya M.; Nok, Andrew J.; Mamman, Aisha I.; Bieker, James J.

    2017-01-01

    Gamma globin induction remains a promising pharmacological therapeutic treatment mode for sickle cell anemia and beta thalassemia, however Hydroxyurea remains the only FDA approved drug which works via this mechanism. In this regard, we assayed the γ-globin inducing capacity of Cis-vaccenic acid (CVA). CVA induced differentiation of K562, JK1 and transgenic mice primary bone marrow hematopoietic progenitor stem cells. CVA also significantly up-regulated γ-globin gene expression in JK-1 and transgenic mice bone marrow erythroid progenitor stem cells (TMbmEPSCs) but not K562 cells without altering cell viability. Increased γ-globin expression was accompanied by KLF1 suppression in CVA induced JK-1 cells. Erythropoietin induced differentiation of JK-1 cells 24 h before CVA induction did not significantly alter CVA induced differentiation and γ-globin expression in JK-1 cells. Inhibition of JK-1 and Transgenic mice bone marrow erythroid progenitor stem cells Fatty acid elongase 5 (Elovl5) and Δ9 desaturase suppressed the γ-globin inductive effects of CVA. CVA treatment failed to rescue γ-globin expression in Elovl5 and Δ9-desaturase inhibited cells 48 h post inhibition in JK-1 cells. The data suggests that CVA directly modulates differentiation of JK-1 and TMbmEPSCs, and indirectly modulates γ-globin gene expression in these cells. Our findings provide important clues for further evaluations of CVA as a potential fetal hemoglobin therapeutic inducer PMID:26879870

  14. DNA damage, lysosomal degradation and Bcl-xL deamidation in doxycycline- and minocycline-induced cell death in the K562 leukemic cell line.

    Science.gov (United States)

    Fares, Mona; Abedi-Valugerdi, Manuchehr; Hassan, Moustapha; Potácová, Zuzana

    2015-07-31

    We investigated mechanisms of cytotoxicity induced by doxycycline (doxy) and minocycline (mino) in the chronic myeloid leukemia K562 cell line. Doxy and mino induced cell death in exposure-dependent manner. While annexin V/propidium iodide staining was consistent with apoptosis, the morphological changes in Giemsa staining were more equivocal. A pancaspase inhibitor Z-VAD-FMK partially reverted cell death morphology, but concurrently completely prevented PARP cleavage. Mitochondrial involvement was detected as dissipation of mitochondrial membrane potential and cytochrome C release. DNA double strand breaks detected with γH2AX antibody and caspase-2 activation were found early after the treatment start, but caspase-3 activation was a late event. Decrement of Bcl-xL protein levels and electrophoretic shift of Bcl-xL molecule were induced by both drugs. Phosphorylation of Bcl-xL at serine 62 was ruled out. Similarly, Bcr/Abl tyrosine kinase levels were decreased. Lysosomal inhibitor chloroquine restored Bcl-xL and Bcr/Abl protein levels and inhibited caspase-3 activation. Thus, the cytotoxicity of doxy and mino in K562 cells is mediated by DNA damage, Bcl-xL deamidation and lysosomal degradation with activation of mitochondrial pathway of apoptosis. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  15. Genetically re-engineered K562 cells significantly expand and functionally activate cord blood natural killer cells: Potential for adoptive cellular immunotherapy.

    Science.gov (United States)

    Ayello, Janet; Hochberg, Jessica; Flower, Allyson; Chu, Yaya; Baxi, Laxmi V; Quish, William; van de Ven, Carmella; Cairo, Mitchell S

    2017-02-01

    Natural killer (NK) cells play a significant role in reducing relapse in patients with hematological malignancies after allogeneic stem cell transplantation, but NK cell number and naturally occurring inhibitory signals limit their capability. Interleukin-15 (IL-15) and 4-1BBL are important modulators of NK expansion and functional activation. To overcome these limitations, cord blood mononuclear cells (CB MNCs) were ex vivo expanded for 7 days with genetically modified K562-mbIL15-41BBL (MODK562) or wild-type K562 (WTK562). NK cell expansion; expression of lysosome-associated membrane protein-1 (LAMP-1), granzyme B, and perforin; and in vitro and in vivo cytotoxicity against B-cell non-Hodgkin lymphoma (B-NHL) were evaluated. In vivo tumor growth in B-NHL-xenografted nonobese diabetic severe combined immune deficient (NOD-scid) gamma (NSG) mice was monitored by tumor volume, cell number, and survival. CB MNCs cultured with MODK562 compared with WTK562 demonstrated significantly increased NK expansion (thirty-fivefold, p cell numbers (p cells to enhance B-NHL targeting in vitro and in vivo. Copyright © 2016 ISEH - International Society for Experimental Hematology. Published by Elsevier Inc. All rights reserved.

  16. Antagonistic effects of black tea against gamma radiation-induced oxidative damage to normal lymphocytes in comparison with cancerous K562 cells.

    Science.gov (United States)

    Ghosh, Debjani; Dey, Subrata Kumar; Saha, Chabita

    2014-11-01

    The potential of naturally occurring antioxidants to reduce the cellular oxidative damage induced by ionizing radiation has been studied for more than a decade for their pharmacological application during cancer treatment. It is already known that radioprotective efficacy of phytochemicals might influence various end points of radiation damage. Flavonoids are well-known natural radioprotectors, and their biological effects depend upon their chemical structure. In the present study, radioprotective effect of black tea rich in flavonoids was evaluated against gamma radiation-induced oxidative damage on normal lymphocytes and compared with erythroleukemic K562 cells. Pre-treatment with black tea extract (BTE) significantly reduced radiation-induced loss of cell viability, generation of reactive oxygen species, mitochondrial dysfunction, activation of caspase-3 and apoptosis in normal lymphocytes compared to K562 cells. BTE also regulates the activity of endogenous antioxidant enzymes. The changes in the mRNA expression of bax, bcl2, p53 and Nrf2 were also followed to evaluate regulation of radiation-induced apoptosis by BTE. These findings suggest that black tea may have the potential of a natural radioprotective agent which can be used as adjunct with radiation during cancer treatment.

  17. MAPK/ERK信号通路调节K562细胞中mdr1基因的诱导性表达%The mitogen-activated protein kinase pathway regulates the induced expression of mdr1 gene in K562 cells

    Institute of Scientific and Technical Information of China (English)

    罗文娟; 许文林; 吕旭晶; 邱志远; 陈巧云; 王法春

    2009-01-01

    Objective To investigate the effect of mitogen-activated protein kinase(MAPK)pathway on the transcriptional expression of mdr1 gene induced by doxorubicin ( DOX)and study the transcription regulation of mdr1 gene.Methods K562 cells were treated with DOX(0.01 μg/ml)with the initial concentration of 0.01 μg/ml for 24 hours,then change the culture media without DOX.K562 cells were cultured until the its status wag recovered.Subsequently the cells were treated with DOX(0.02μg/ml)for 24 hours again.The concentration of DOX was increaged until 0.05 μg/ml by following the protocol above.K562 cells were collected at the concentration of 0.01 μg/ml,0.03μg/ml and 0.05μS/ml DOX.Expression of mdr1 gene were examined by reverse transcription-polymerase chain reaction(RT-PCR).Pglycoprotein(P-gP)wag detected by flow cytometry.Western blot wag performed to detect ERK and P-ERk.K562 cells were pretreated with MAPK inhibitor PD98059 for 1 hour.and then DOX was added.RT-PCR and FCM were used to detect the expression of mdr1 mRNA and P-gp.Results When K562 cells were exposured to DOX.the phosphorylation of ERK wag increaged.the mdr1 gene wag highly expressed as well as its corresponding protein P-gp.When the concentration of DOX was 0.05μg/ml,the expression of mdr1 gene and P-gp were increased over 5 fold.When K562 cells were pretreated with MAPK inhibitor PD98059,the expression of mdr1 gene induced by DOX(the concentration was 0.03 μg/ml and 0.05 μg/m1)was effectively inhibited by(74.1±0.11)%and(70.2±0.14)%respectively.Conclusions DOX could induce the expression of mdr1 gene in K562 cells accompanied by the activation of MAPK/ERK pathway.The block of activation of ERK could inhibit the induced expression of mdr1 gene.%目的 观察多柔比星(doxorubicin,DOX)诱导K562细胞mdr1基因表达过程中丝裂原活化蛋白激酶(mitogen-activated protein kinase,MAPK)/细胞外信号调节激酶(ERK)信号通路的作用,探讨mdr1基因的转录调控机制.方法

  18. Salinomycin inhibits proliferation and induces apoptosis of Gleevec-resistant chronic myeloid leukemic cell line K562/Glv%盐霉素抑制耐格列卫的人慢性粒细胞白血病细胞株K562/Glv增殖并诱导其凋亡

    Institute of Scientific and Technical Information of China (English)

    徐霜清; 祝爱珍; 刘成成; 许婷婷; 陈小宇; 刘革修

    2012-01-01

    AIM: To study the effect of salinomycin on inhibiting proliferation and inducing apoptosis of Gleevec - resistant chronic myeloid leukemia cell line K562/Glv. METHODS: The inhibitory effect of salinomycin on the growth of K562/Glv cells was detected by CCK - 8 assay in vitro. Flow cytometry was used to observe apoptosis, mitochondria membrane potential ( △Ψm ), reactive oxygen species ( ROS ) and the concentration of intracellular Ca 2+ ( [ Ca 2+ ) in K562/Glv cells. The activity of caspase - 3 , - 8 and - 9 was measured by the method of colorimetry. The levels of cyto-chrome C, Bcl - 2, Bax, (3 - catenin and phosphorylated low - density lipoprotein receptor - related protein 6 ( p - LRP6 ) were determined by Western blotting. RESULTS: Salinomycin inhibited the growth of K562/Glv cells in a dose — dependent manner. Salinomycin at concentration of 0. 2 μmol/L inhibited the growth of the cells with the inhibitory rate of ( 36.70 ± 2. 31 )% . The cell apoptotic rate was ( 19. 66 ± 2. 23 )% . Salinomycin at concentration of 0. 2 μmol/L decreased the level of △Ψm, and increased the levels of ROS, cytochrome C and [ Ca 2+]i in the cells. Salinomycin also increased the activity of caspase — 3, — 8 and — 9 in the cells, reduced the ratio of Bel — 2/Bax, and attenuated the levels of (3 — catenin and p — LRP6. CONCLUSION: Salinomycin induces the apoptosis of Gleevec - resistant myeloid leukemia cell line K562/Glv via Bcl - 2/Bax and mitochondria - dependent pathways, and inhibits the cell growth through Wnt signal pathway.%目的:探讨盐霉素对耐格列卫的人慢性粒细胞白血病细胞株K562/Glv抑制增殖和诱导凋亡的作用及其机制.方法:采用CCK-8的方法检测盐霉素对K562/Glv细胞生长的抑制作用;流式细胞术检测细胞凋亡、活性氧、细胞内Ca2+浓度([Ca2+]i)和线粒体膜电位(ΔΨm);比色法检测caspase-3、-8和-9活性;Western blotting 分析细胞色素C、Bcl-2、Bax、β-catenin和磷酸化

  19. Human NK cells of mice with reconstituted human immune system components require preactivation to acquire functional competence.

    Science.gov (United States)

    Strowig, Till; Chijioke, Obinna; Carrega, Paolo; Arrey, Frida; Meixlsperger, Sonja; Rämer, Patrick C; Ferlazzo, Guido; Münz, Christian

    2010-11-18

    To investigate human natural killer (NK)-cell reactivity in vivo we have reconstituted human immune system components by transplantation of human hematopoietic progenitor cells into NOD-scid IL2Rγ(null) mice. We demonstrate here that this model allows the development of all NK-cell subsets that are also found in human adult peripheral and cord blood, including NKp46(+)CD56(-) NK cells. Similar to human cord blood, NK cells from these reconstituted mice require preactivation by interleukin-15 to reach the functional competence of human adult NK cells. Mainly the terminally differentiated CD16(+) NK cells demonstrate lower reactivity without this stimulation. After preactivation, both CD16(+) and CD16(-) NK cells efficiently produce interferon-γ and degranulate in response to stimulation with NK cell-susceptible targets, including K562 erythroleukemia cells. NK-cell lines, established from reconstituted mice, demonstrate cytotoxicity against this tumor cell line. Importantly, preactivation can as well be achieved by bystander cell maturation via poly I:C stimulation in vitro and injection of this maturation stimulus in vivo. Preactivation in vivo enhances killing of human leukocyte antigen class I negative tumor cells after their adoptive transfer. These data suggest that a functional, but resting, NK-cell compartment can be established in immune-compromised mice after human hematopoietic progenitor cell transfer.

  20. 黄芪多糖和丁酸钠联合用药对K562细胞胎儿血红蛋白合成的作用%Combined Use of Astragalus Polysaccharide with Sodium Butyrate in Induction of Fetal Hemoglobin Synthesis on K562 Cells

    Institute of Scientific and Technical Information of China (English)

    曹祥; 钱新华; 徐梅佳; 陈佳; 郭丽珊

    2011-01-01

    目的 探讨黄芪多糖(APS)和丁酸钠(NaB)联合用药对人K562细胞胎儿血红蛋白(HbF)合成的作用,为临床联合用药治疗β-珠蛋白生成障碍性贫血(β-地贫)提供实验依据.方法 以K562细胞为模型,低剂量APS和NaB联合用药诱导的细胞为实验组,低剂量APS、NaB单药和常规剂量 NaB单药诱导的细胞分别为阳性对照组1、2、3,未加药组细胞为对照组4,采用联苯胺染色和Western blot技术分析药物作用K562细胞96 h后红系分化和HbF表达.结果 1.实验组对细胞生长的抑制作用显著弱于对照组3(P<0.05).2.APS和NaB联合作用K562细胞的最佳剂量组合为APS 2.50 g·L-1+NaB 250 μmol·L-1.3.联苯胺染色结果显示实验组联苯胺染色阳性率于48 h显著升高,96 h达高峰,与各对照组比较差异均有统计学意义(F=966.630,P<0.05),作用可维持至144 h.4.Western blot结果显示实验组和对照组3诱导K562细胞后HbF合成分别增加至对照组4的(1.82±0.16)倍和(1.57±0.08)倍(F=26.569,P<0.05),实验组HbF表达水平显著高于对照组3(P<0.05).结论 APS和 NaB低剂量联合用药诱导HbF表达增强,作用维持时间长,细胞毒性低,有望成为β-地贫的一种新的治疗方案.%Objective To provide an experimental basis for clinical combination therapy of β - thalassemia through investigating the effects of combined use of low - dose astragalus polysaccharide(APS) and sodium butyrate(NaB) in the induction of fetal hemoglobin(HbF)synthesis on K562 cells.Methods K562 cells were chosen as the cell model, cells treated with low - dose APS combined with NaB were taken as the experimental group,while low -dose APS,low -dose NaB and regular-dose NaB were set up as the positive control group 1,2,3 and untreated cells as the control group 4.Benzidine staining and Western blot were used to analyze erythroid differentiation and HbF expression in K562 cells after getting treated with drugs for 96 h.Results 1.The K562 cell inhibiting

  1. Apoptosis Induced by Microbubble-Assisted Acoustic Cavitation in K562 Cells: The Predominant Role of the Cyclosporin A-Dependent Mitochondrial Permeability Transition Pore.

    Science.gov (United States)

    Zhao, Lu; Feng, Yi; Shi, Aiwei; Zong, Yujin; Wan, Mingxi

    2015-10-01

    Acoustic cavitation of microbubbles has been described as inducing tumor cell apoptosis that is partly associated with mitochondrial dysfunction; however, the exact mechanisms have not been fully characterized. Here, low-intensity pulsed ultrasound (1 MHz, 0.3-MPa peak negative pressure, 10% duty cycle and 1-kHz pulse repetition frequency) was applied to K562 chronic myelogenous leukemia cells for 1 min with 10% (v/v) SonoVue microbubbles. After ultrasound exposure, the apoptotic index was determined by flow cytometry with annexin V-fluorescein isothiocyanate/propidium iodide. In addition, mitochondrial membrane potential (ΔΨm) was determined with the JC-1 assay. Translocation of apoptosis-associated protein cytochrome c was evaluated by Western blotting. We found that microbubble-assisted acoustic cavitation can increase the cellular apoptotic index, mitochondrial depolarization and cytochrome c release in K562 cells, compared with ultrasound treatment alone. Furthermore, mitochondrial dysfunction and apoptosis were significantly inhibited by cyclosporin A, a classic inhibitor of the mitochondrial permeability transition pore; however, the inhibitor of Bax protein, Bax-inhibiting peptide, could not suppress these effects. Our results suggest that mitochondrial permeability transition pore opening is involved in mitochondrial dysfunction after exposure to microbubble-assisted acoustic cavitation. Moreover, the release of cytochrome c from the mitochondria is dependent on cyclosporin A-sensitive mitochondrial permeability transition pore opening, but not formation of the Bax-voltage dependent anion channel complex or Bax oligomeric pores. These data provide more insight into the mechanisms underlying mitochondrial dysfunction induced by acoustic cavitation and can be used as a basis for therapy. Copyright © 2015 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  2. Synthesis and Evaluation of Haloacetyl, α-Bromoacryloyl and Nitrooxyacetyl Benzo[b]furan and Benzo[b]thiophene Derivatives as Potent Antiproliferative Agents Against Leukemia L1210 and K562 Cells

    Science.gov (United States)

    Romagnoli, Romeo; Baraldi, Pier Giovanni; Carrion, Maria Dora; Cara, Carlota Lopez; Casolari, Alberto; Hamel, Ernest; Fabbri, Enrica; Gambari, Roberto

    2010-01-01

    Identification of novel and selective anticancer agents remains an important and challenging goal in pharmacological research. In search of new compounds with strong antiproliferative activity and simple molecular structure, we have synthesized three different series of compounds in which different substituents were linked to the 3-amino position of the 2-(3′, 4′, 5′-trimethoxybenzoyl)-benzo[b]furan or benzo[b]thiophene ring system. These substituents, corresponding to acetyl/haloacetyl, α-bromoacryloyl and nitrooxyacetyl moieties had different electrophilic properties. The benzoheterocycle parent structures were selected because of their reported bioactivities. Compounds bearing a methoxy group at the 6-position of the benzo[b]furan skeleton, were identified as potent antiproliferative agents against the human chronic myelogenous K562 and murine L1210 leukemia cell lines. Comparison of positional isomers indicated that moving the methoxy group from the 6- to the 5- or 7-position yielded inactive compounds. The effects of a selected series of compounds on cell cycle progression correlated well with their strong antiproliferative activity and inhibition of tubulin polymerization. The analysis of structure-activity relationships observed in the series of compounds described here may represent a platform for the design of more active molecules. PMID:20676361

  3. Erythroid induction of K562 cells treated with mithramycin is associated with inhibition of raptor gene transcription and mammalian target of rapamycin complex 1 (mTORC1) functions.

    Science.gov (United States)

    Finotti, Alessia; Bianchi, Nicoletta; Fabbri, Enrica; Borgatti, Monica; Breveglieri, Giulia; Gasparello, Jessica; Gambari, Roberto

    2015-01-01

    Rapamycin, an inhibitor of mTOR activity, is a potent inducer of erythroid differentiation and fetal hemoglobin production in β-thalassemic patients. Mithramycin (MTH) was studied to see if this inducer of K562 differentiation also operates through inhibition of mTOR. We can conclude from the study that the mTOR pathway is among the major transcript classes affected by mithramycin-treatment in K562 cells and a sharp decrease of raptor protein production and p70S6 kinase is detectable in mithramycin treated K562 cells. The promoter sequence of the raptor gene contains several Sp1 binding sites which may explain its mechanism of action. We hypothesize that the G+C-selective DNA-binding drug mithramycin is able to interact with these sequences and to inhibit the binding of Sp1 to the raptor promoter due to the following results: (a) MTH strongly inhibits the interactions between Sp1 and Sp1-binding sites of the raptor promoter (studied by electrophoretic mobility shift assays, EMSA); (b) MTH strongly reduces the recruitment of Sp1 transcription factor to the raptor promoter in intact K562 cells (studied by chromatin immunoprecipitation experiments, ChIP); (c) Sp1 decoy oligonucleotides are able to specifically inhibit raptor mRNA accumulation in K562 cells. In conclusion, raptor gene expression is involved in mithramycin-mediated induction of erythroid differentiation of K562 cells and one of its mechanism of action is the inhibition of Sp1 binding to the raptor promoter.

  4. Studies on the Anti-tumor Action of active components of Menispermum dauricum to leukemia K562 cells%蝙蝠葛活性成分对人白血病K562细胞株抗肿瘤作用的研究

    Institute of Scientific and Technical Information of China (English)

    杨万山; 孙抒; 汪俊颖; 全宗学

    2014-01-01

    目的 研究蝙蝠葛活性成分体外对人白血病K562细胞株的抑制增殖和诱导凋亡作用.方法 应用MTT法检测蝙蝠葛活性成分对体外培养的人白血病K562细胞株的抑制增殖作用的影响及细胞毒活性;通过倒置显微镜对细胞进行形态学观察;通过免疫细胞化学S-P法测定凋亡关键效应酶Caspase-9、Caspase-8和Caspase-3的表达情况.结果 (1)MTT比色法结果表明,蝙蝠葛活性成分对人白血病K562细胞株的增殖抑制作用呈剂量依赖性(P<0.01);(2)倒置显微镜观察:蝙蝠葛活性成分20 μg/ml作用后早期细胞出现凋亡形态学变化:细胞膜鼓泡、凋亡小体形成等;作用晚期细胞发生膜破裂坏死;(3)免疫细胞化学结果表明:蝙蝠葛活性成分作用后加药组Caspase-9、Caspase-8和Caspase-3表达增加,与对照组相比较均有显著差异(P<0.01).结论 蝙蝠葛活性成分对人白血病K562细胞株具有抑制增殖和诱导凋亡作用.

  5. 喷他脒增强K562细胞对肿瘤坏死因子相关凋亡诱导配体诱导凋亡敏感性%Pentamidine sensitizes leukemia K562 cells to TRAIL-induced apoptosis

    Institute of Scientific and Technical Information of China (English)

    刘小珊; 蒋纪恺

    2007-01-01

    背景与目的:肿瘤坏死因子相关凋亡诱导配体(TRAIL)是一种理想的抗肿瘤药物,但许多肿瘤细胞常对TRAIL诱导凋亡耐受.本研究探讨了喷他脒增强白血病K562细胞对TRAIL诱导凋亡敏感性.方法:利用光镜形态学和Annexin V FITC/PI 双标记凋亡细胞的流式细胞仪(FACS)测定两种方法观察喷他脒预处理K562细胞并继用TRAIL后凋亡的发生.应用蛋白印迹方法观察此过程中半胱氨酸-天冬氨酸蛋白酶(Caspase)-3,-8和聚ADP核糖聚合酶(PARP)等3种蛋白的蛋白剪切与X连锁凋亡抑制蛋白(XIAP)蛋白表达的改变.结果:在10 μg/ml喷他脒作用K562细胞20 h,K562细胞未发生凋亡,继用200 ng/ml TRAIL 作用4 h后,光镜和Annexin V FITC/PI 双标记流式细胞仪方法均观察到细胞发生明显凋亡,并出现了Caspase-3,-8和PARP蛋白剪切,两者单独作用则无明显细胞凋亡发生.另外,喷他脒明显降低了XIAP表达.结论:喷他脒联合TRAIL可能成为肿瘤治疗的一种新策略.

  6. 三磷酸腺苷生物发光法在白血病细胞株K562化疗药物敏感实验中应用探讨%A study of the application of an ATP-bioluminescence assay in chemosensitivity test of leukemic cell line K562

    Institute of Scientific and Technical Information of China (English)

    储德勇; 李炜如; 廖清奎

    2003-01-01

    目的:探讨三磷酸腺苷生物发光法(ATP-BLA法)在白血病细胞药敏实验中的可行性.方法:采用ATP-BLA法,用液体闪烁记数仪检测ATP标准品以及白血病细胞株K562在不同细胞浓度、药物浓度、培养时间下的荧光发光值.结果:ATP标准品浓度、K562细胞浓度的对数与荧光发光值的对数具极好的线性关系(P<0.001);药敏实验时,结束细胞培养的时间以第4 d为宜,药物浓度的选择以1×PPC为最佳.结论:ATP-BLA法在白血病药敏试验中是可行的,有一定的临床应用价值,值得进一步研究.

  7. Bcl-2 antisense oligodeoxynucleotide increases the sensitivity of HL60 and K562 cells to daunorubicin%Bcl-2反义核酸增强HL-60、K562细胞对柔红霉素敏感性的研究

    Institute of Scientific and Technical Information of China (English)

    雷小勇; 张洹; 何冬梅

    2003-01-01

    目的:研究bcl-2反义寡核苷酸作用后,白血病细胞株HL60、K562细胞对柔红霉素(DNR)敏感性的影响.方法:MTT法测HL60、K562细胞中DNR的半数抑制率(IC50);免疫荧光标记观测细胞Bcl-2蛋白水平;用Hoechest33258和碘化丙锭双染色法及流式细胞仪检测细胞凋亡.结果:靶向bcl-2 mRNA蛋白编码区反义寡核苷酸(AS-ODN1)和靶向翻译起始区的反义寡核苷酸(AS-ODN2)分别与DNR联合作用于HL60细胞后DNR的IC50值分别为0.124±0.011、0.149±0.012,分别与不加寡核苷酸组DNR的IC50值(0.173±0.021)或无义寡核苷酸联用DNR的IC50值(0.180±0.023)相比有显著差异,P<0.05.AS-ODN1和AS-ODN2分别与DNR联合作用于K562细胞后DNR的IC50值分别为0.078±0.007、0.079±0.008,分别与不加寡核苷酸组DNR的IC50值(0.106±0.011)或无义寡核苷酸联用DNR的IC50值(0.107±0.012)相比有显著差异,P<0.05.AS-ODN1和AS-ODN2分别与DNR同时作用于HL60或K562细胞后抑制Bcl-2蛋白表达及诱导细胞凋亡率分别与单用DNR或无义寡核苷酸联用DNR相比有显著差异,P<0.05.与AS-ODN2比较,AS-ODN1提高HL60细胞对DNR的敏感性作用要强些(P<0.05).结论:靶向bcl-2 mRNA蛋白编码区反义寡核苷酸和靶向翻译起始区的反义寡核苷酸能增强HL60和K562细胞对DNR的敏感性.

  8. Resveratrol Increases Anti-Proliferative Activity of Bestatin Through Downregulating P-Glycoprotein Expression Via Inhibiting PI3K/Akt/mTOR Pathway in K562/ADR Cells.

    Science.gov (United States)

    Wang, Li; Wang, Changyuan; Jia, Yongming; Liu, Zhihao; Shu, Xiaohong; Liu, Kexin

    2016-05-01

    Multidrug resistance (MDR) is a major obstacle in the clinical therapy of hematological malignancies. P-glycoprotein (P-gp) overexpression results in reduction of intracellular drug concentration with a consequence that the cytotoxicity of anti-tumor drugs is decreased, which leads to MDR in K562/ADR cells. In this study, we found that resveratrol enhanced the anti-proliferative activity of bestatin in K562/ADR cells. Co-treatment with resveratrol, IC50 values of bestatin in K562/ADR cells significantly decreased and activation of caspase-3 and caspase-8 increased, which indicated that resveratrol potentiated bestatin-induced apoptosis. Resveratrol increased the intracellular concentration of bestatin through inhibiting P-gp function and downregulating P-gp expression at mRNA and protein levels, which increased anti-proliferative activity of bestatin in K562/ADR cells. Resveratrol decreased the phosphorylation of Akt and mTOR but did not affect the phosphorylations of JNK or ERK1/2. These results demonstrated that resveratrol could increase the anti-proliferative activity of bestatin through downregulating P-gp expression via suppressing the PI3K/Akt/mTOR signaling pathway.

  9. 下调PPP2R5C表达对K562细胞TP53相关通路基因表达的影响

    Institute of Scientific and Technical Information of China (English)

    沈琦[1,2; 张新友[1; 李扬秋[2,3

    2016-01-01

    目的:利用基因芯片技术研究RNA干扰下调PPP2R5C对K562细胞中TP53通路相关基因表达的影响。方法:Affymetrix U133 plus 2.0基因表达谱芯片检测核转染PPP2R5C-siRNA991和SC对照组的K562细胞,应用Genespring GX 11.0软件分析差异基因相关信号通路变化情况。结果:基因芯片分析TP53信号通路紧密相关的22个基因,发现全部基因发生了差异表达,其中上调基因有8个,下调基因有14个。明显上调的基因有EP300、CCND1、BRCA2和USP7,而明显下调的基因则有MDM4、ESR1、ATM、CDK2、CDKN1A、TP53和CDKN2A。结论:下调K562细胞PPP2R5C基因时,在一定程度上选择性调节与细胞增殖密切相关的TP53信号通路相关基因的表达,从而抑制K562细胞增殖,促进了K562细胞凋亡。

  10. Data in support of transcriptional regulation and function of Fas-antisense long noncoding RNA during human erythropoiesis

    Directory of Open Access Journals (Sweden)

    Olga Villamizar

    2016-06-01

    Full Text Available This paper describes data related to a research article titled, “Fas-antisense long noncoding RNA is differentially expressed during maturation of human erythrocytes and confers resistance to Fas-mediated cell death” [1]. Long noncoding RNAs (lncRNAs are increasingly appreciated for their capacity to regulate many steps of gene expression. While recent studies suggest that many lncRNAs are functional, the scope of their actions throughout human biology is largely undefined including human red blood cell development (erythropoiesis. Here we include expression data for 82 lncRNAs during early, intermediate and late stages of human erythropoiesis using a commercial qPCR Array. From these data, we identified lncRNA Fas-antisense 1 (Fas-AS1 or Saf described in the research article. Also included are 5′ untranslated sequences (UTR for lncRNA Saf with transcription factor target sequences identified. Quantitative RT-PCR data demonstrate relative levels of critical erythroid transcription factors, GATA-1 and KLF1, in K562 human erythroleukemia cells and maturing erythroblasts derived from human CD34+ cells. End point and quantitative RT-PCR data for cDNA prepared using random hexamers versus oligo(dT18 revealed that lncRNA Saf is not effectively polyadenylated. Finally, we include flow cytometry histograms demonstrating Fas levels on maturing erythroblasts derived from human CD34+ cells transduced using mock conditions or with lentivirus particles encoding for Saf.

  11. 携SH2-Caspase8融合基因重组腺病毒的构建及对K562细胞增殖的影响%Construction of recombinant adenovirus carrying SH2-Caspase8 fusion gene and its effect on proliferation in K562 cells

    Institute of Scientific and Technical Information of China (English)

    刘双凤; 胡晶; 曹唯希; 史静; 彭智; 王海霞; 李亚娟; 冯文莉

    2011-01-01

    Objective To construct the recombinant adenovirus carrying SH2-Caspase8 fusion gene and its mutant to observe its inhibitory effect on proliferation of K562 cells. Methods SH2-Caspase8 fusion gene was amplified by RT-PCR and splicing PCR, and cloned into the shuttle plasmid pAdTrack-CMV of adenovirus. The shuttle plasmid pAdT-SC-EGFP was constructed and identified by double-enzyme digestion and DNA sequencing, and transformed into ultra-competent pAdEasy-BJ5183 after Pme Ⅰ digestion. Defective replication recombinant adenovirus plasmid pAdE-SC-EGFP and its mutant were generated by homologous recombination and further transfected into AD293 cells to package recombinant adenovirus after Pac Ⅰ digestion. Recombinant adenovirus plasmid AdE-SC-EGFP was identified by PCR and Western blotting, respectively, and amplified for the measurement of its titers. Results PCR, enzyme digestion and DNA sequencing showed that the shuttle and recombinant plasmids of adenovirus, pAdT-SC-EGFP and pAdE-SC-EGFP, were successfully constructed. PCR and EGFP expression confirmed that the recombinant plasmid of adenovirus, pAdE-SC-EGFP, was successfully packaged. After amplification, its titer was 1.5 ×l012pfu/ml. Western blot analysis displayed the expression of target protein. MTT and colony formation test could inhibit the proliferation of K562 cells. Conclusion Recombinant adenovirus plasmid, AdE-SC-EGFP, carrying SH2-Caspase8 fusion gene and its mutant, has been successfully constructed, and can significantly inhibit the proliferation of BCR-ABL positive K562 cells in vitro.%目的构建并鉴定携SH2 -Caspase8融合基因的重组腺病毒AdE-SC-EGFP及其突变体,观察其对K562细胞增殖的抑制作用。方法采用RT-PCR、重叠PCR扩增SH2-Caspase8融合基因,克隆至腺病毒穿梭载体pAdTrack-CMV中,构建穿梭质粒pAdT-SC-EGFP,进行酶切和测序鉴定。将PmeⅠ酶切后的穿梭质粒转化pAdEasy-BJ5183感受态,通过细菌内同源重组产

  12. Growth inhibition and apoptosis induction of Scutellaria luteo-coerulea Bornm. & Sint. on leukemia cancer cell lines K562 and HL-60

    Directory of Open Access Journals (Sweden)

    Mahsa Motaez

    2015-10-01

    Full Text Available Objective: Scutellaria (Lamiaceae has been implicated for medicinal purposes both in modern and traditional medicine. Some species of the genus Scutellaria has extensively been studied for anticancer activity. Scutellaria luteo-coerulea (S. luteo-coerulea is one of the Iranian species of the genus Scutellaria. Materials and Methods: In the present study, cytotoxic and apoptogenic properties of CH2Cl2, EtOAc, n-BuOH, and H2O fractions of S. luteo-coerulea were investigated on K562. Moreover, HL-60. DNA fragmentation in apoptotic cells were determined by propidium iodide (PI staining (sub-G1 peak. Results: Scutellaria luteo-coerulea inhibited the growth of malignant cells in a dose-dependent manner. Among solvent fractions of S. luteo-coerulea, the CH2Cl2 fraction was found to be the most cytotoxic one among others. Sub-G1 peak in flow cytometry histogram of treated cells suggested the induction of apoptosis in S. luteo-coerulea. Conclusion: Scutellaria luteo-coerulea could be a novel candidate for further analytical elucidation in respect to fine major components responsible for the cytotoxic effect of the plant also clinical evaluations.

  13. Integrative genomic analysis in K562 chronic myelogenous leukemia cells reveals that proximal NCOR1 binding positively regulates genes that govern erythroid differentiation and Imatinib sensitivity.

    Science.gov (United States)

    Long, Mark D; van den Berg, Patrick R; Russell, James L; Singh, Prashant K; Battaglia, Sebastiano; Campbell, Moray J

    2015-09-01

    To define the functions of NCOR1 we developed an integrative analysis that combined ENCODE and NCI-60 data, followed by in vitro validation. NCOR1 and H3K9me3 ChIP-Seq, FAIRE-seq and DNA CpG methylation interactions were related to gene expression using bootstrapping approaches. Most NCOR1 combinations (24/44) were associated with significantly elevated level expression of protein coding genes and only very few combinations related to gene repression. DAVID's biological process annotation revealed that elevated gene expression was uniquely associated with acetylation and ETS binding. A matrix of gene and drug interactions built on NCI-60 data identified that Imatinib significantly targeted the NCOR1 governed transcriptome. Stable knockdown of NCOR1 in K562 cells slowed growth and significantly repressed genes associated with NCOR1 cistrome, again, with the GO terms acetylation and ETS binding, and significantly dampened sensitivity to Imatinib-induced erythroid differentiation. Mining public microarray data revealed that NCOR1-targeted genes were significantly enriched in Imatinib response gene signatures in cell lines and chronic myelogenous leukemia (CML) patients. These approaches integrated cistrome, transcriptome and drug sensitivity relationships to reveal that NCOR1 function is surprisingly most associated with elevated gene expression, and that these targets, both in CML cell lines and patients, associate with sensitivity to Imatinib.

  14. Effect of STAT5 decoy oligodeoxynucleotides on expression profile of apoptosis-related genes in K562 cells by cDNA microarray%cDNA芯片检测STAT5诱骗核苷酸对K562细胞凋亡相关基因的影响

    Institute of Scientific and Technical Information of China (English)

    曾建明; 冯文莉; 王小中; 史梅; 涂植光; 黄宗干

    2006-01-01

    目的:转录因子STAT5在慢性粒细胞白血病(chronic myeloid leukemia,CML)中组成性激活,并与CML细胞恶性表型密切相关,本研究用cDNA芯片检测方法探讨诱骗核苷酸(decoy ODNs)抑制STAT5对白血病K562细胞株凋亡相关基因的影响.方法:分别提取decoy ODNs处理前后的K562细胞总RNA,逆转录合成Cy3、Cy5标记的cDNA探针,与人14K基因表达谱cDNA芯片(V2.0)杂交,扫描获得数据后,用Genespring软件分析对照组和实验组的差异表达基因,半定量RT-PCR验证cDNA芯片结果.结果:2张cDNA芯片检测重复性良好(R=0.9799).在13 824个标记的基因中,检出413个上调基因,其中包括:TIAF1、GAB1、GYPA、DAPK3、TNFRSF1B、IRF1和PML等在内的18个凋亡相关基因;在检出的332个下调基因中,发现PIM1、CCND2、CCND1、MYC和BCL2L1等在内的11个凋亡相关基因;部分基因经半定量RT-PCR证实与cDNA芯片结果一致.结论:Decoy ODNs抑制STAT5信号通路后可引起K562细胞多种凋亡相关基因的变化,本实验为进一步研究STAT5信号通路所调控的凋亡相关基因提供了依据.

  15. Study on Taxol in Inhibiting Human Leukemia Cell Proliferation and Inducing Apoptosis

    Institute of Scientific and Technical Information of China (English)

    赵小英; 张晓红; 徐磊; 张行

    2004-01-01

    Objective: To explore the effects of Taxol in inhibiting human leukemia k562 cell proliferation and inducing apoptosis in vitro. Methods: Human leukemia K562 cells were treated with Taxol of different concentrations for 12-72 hrs. Cell proliferation was evaluated by MTT assay and morphological changes of apoptosis were examined by microscopy. Cell apoptosis was determined by flow cytometry (FCM) and DNA gel electrophoresis. Results: Growth of K562 cells was inhibited by Taxol with an IC50 value of 0.84 μg/mi.Typical nuclear condensation and apoptosis bodies were observed as early as 24 hrs after a 0.5 μg/ml Taxol treatment; Apoptotic rate of the Taxol-treated K562 cells increased from 3.7% to 24.0% in 24 hrs. No DNA ladder was observed by DNA gel electrophoresis. Conclusion: Taxol could inhibit K562 cell growth and induce apoptosis in vitro.

  16. 蝎毒多肽提取物对白血病细胞株K562/A02荷瘤鼠耐药性的影响%Reversion Impact of Peptide Extract from Scorpion Venom on Multidrug-resistance of Leukemia Stem Cell Line K562/A02 in vivo

    Institute of Scientific and Technical Information of China (English)

    杨向东; 杨文华; 刘宝山; 伊学军; 高宏; 姚芳; 王兴丽; 闫理想

    2016-01-01

    目的 探讨蝎毒多肽(peptide extract from scorpion venom,PESV)逆转白血病干细胞(leukemiastem cells,LSC)在体内多药耐药(multidrug resistance,MDR)的分子机制.方法 以多药耐药的K562/A02细胞株成模白血病BALB/c裸鼠为例,成模鼠随机分为6组:模型对照组、阿霉素(ADM)组、PESV组、ADM+PESV(H)组、ADM+PESV(M)组、ADM+PESV(L)组.模型对照组给予等体积0.9%氯化钠溶液腹腔注射,其余各组予相应剂量ADM和(或)PESV腹腔注射,连续给药14天.第21天观察各组裸鼠移植瘤生长情况,分别检测瘤块中LSC:细胞膜上P-gp的表达,细胞质中ALDH、PI3K的变化及细胞核中MDR1、NF-κB的活性.结果 K562/A02细胞经免疫磁珠分选前后的CD34+CD38-细胞比率和IC50值分别为31.5%、(60.33±10.68)μg/ml和92.8%、(58.33±9.72)μg/ml,分选后细胞干性显著提高,而耐药性无差异性损失;各组造模裸鼠成瘤率100%.瘤体中LSC:流式细胞仪检测细胞膜上P-gp表达结果:检测对照组89.8%、ADM组91.9%、PESV组88.4%、ADM+PESV(H)组53.9%、ADM+PESV(M)组78.0%、ADM+PESV(L)组78.7%;半定量RT-PCR检测MDRl mRNA的表达:PESV组>ADM+PESV(L)组> ADM+PESV(M)组>ADM+PESV(H)组>ADM组;免疫组织化学检测ALDH,显示灰度值ADM组>PESV组>ADM+PESV(H)组>ADM+PESV(M)组>ADM+PESV(L)组;Western blot检测PI3K分子与Elisa检测NF-κB因子结果一致,在ADM组、PESV组表达上调,在ADM+PESV组中表达下调,下调强度与PESV剂量呈正相关.结论 PESV具有下调白血病干细胞膜上P-gp,细胞质内ALDH、PI3K及细胞核中MDR1、NF-κB的表达水平,增强了白血病K562/A02干细胞在体内对ADM的敏感度,逆转其多药耐药特性.

  17. Prokaryotic Expression and Purification of sCAR-TSP-1, and Induced Apoptosis in Leukemic Cells k562%融合蛋白sCAR-TSP-1原核表达纯化及诱导白血病细胞K562凋亡的研究

    Institute of Scientific and Technical Information of China (English)

    梁天祥; 谌贺宽子; 陈磊; 武虎; 唐斌

    2012-01-01

    According to thrombospondin-l(TSP-l) amino acid sequence(RFYWMWK), to the ade-novirus receptor sCAR as template, the 8 amino acids corresponding gene nucleotide amplified by PCR from sCAR, sCAR-TSP-1, connected to the expression vector pQE30, is transformed into E. coli M15 obtained after engineering bacteria. The strain induced by IPTG, efficient expression with histidine label in the form of inclusion body of the fusion protein sCAR-TSP-1. Inclusion body after urea denaturation dissolved, PBS dilution refolding, Ni ion affinity chromatography purification, and obtains the target proteia SDS-PAGE analysis shows, there is an obvious specificity protein band. At the same time, the experimental results show that the fusion protein in sCAR-TSP-1 cells of leukemia cell K562 has obvious apoptosis.%根据thrombospondin-1( TSP-1)氨基酸序列(RFYVVMWK),以已有的腺病毒受体sCAR为模板,将8个氨基酸对应基因核苷酸通过PCR扩增于sCAR之后,得到sCAR-TSP-1,连接到表达载体pQE30上,转化大肠杆菌M15后获得工程茵.该菌株经IPTG诱导后,高效表达出带有组氨酸标签以包涵体形式存在的融合蛋白;sARTSP-1.包涵体经过尿素变性溶解、PBS稀释复性、Ni离子亲和层析柱纯化,获得目的蛋白.SDS-PAGE分析表明,有一条明显的特异性蛋白条带.同时细胞实验结果表明融合蛋白sCAR-TSP-1对白血病细胞K562有明显凋亡作用.

  18. Amplification of the E2F1 transcription factor gene in the HEL erythroleukemia cell line

    DEFF Research Database (Denmark)

    Saito, M; Helin, K; Valentine, M B;

    1995-01-01

    and overexpressed in HEL erythroleukemia cells and translocated to other chromosomes in several established human leukemia cell lines. This study provides the first evidence of gene amplification involving a member of the E2F family of transcription factors. We propose that E2F1 overexpression in erythroid......The E2F transcription factor plays an important regulatory role in cell proliferation, mediating the expression of genes whose products are essential for inducing resting cells to enter the cell cycle and synthesize DNA. To investigate the possible involvement of E2F in hematopoietic malignancies...... progenitors may stimulate abnormal cell proliferation by overriding negative regulatory signals mediated by tumor suppressor proteins such as pRb....

  19. Ptpmt1 induced by HIF-2α regulates the proliferation and glucose metabolism in erythroleukemia cells

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Qin-Qin [High Altitude Medicine of Ministry of Chinese Education and Research Center for High Altitude Medicine, Qinghai University, Xining, 810001 (China); Qinghai Provincial People' s Hospital, Xining (China); Xiao, Feng-Jun; Sun, Hui-Yan [Department of Experimental Hematology, Beijing Institute of Radiation Medicine, Beijing, 100850 (China); Shi, Xue-Feng [High Altitude Medicine of Ministry of Chinese Education and Research Center for High Altitude Medicine, Qinghai University, Xining, 810001 (China); Qinghai Provincial People' s Hospital, Xining (China); Wang, Hua; Yang, Yue-Feng; Li, Yu-Xiang [Department of Experimental Hematology, Beijing Institute of Radiation Medicine, Beijing, 100850 (China); Wang, Li-Sheng, E-mail: wangls@bmi.ac.cn [Department of Experimental Hematology, Beijing Institute of Radiation Medicine, Beijing, 100850 (China); Ge, Ri-Li, E-mail: geriligao@hotmail.com [High Altitude Medicine of Ministry of Chinese Education and Research Center for High Altitude Medicine, Qinghai University, Xining, 810001 (China)

    2016-03-18

    Hypoxia provokes metabolism misbalance, mitochondrial dysfunction and oxidative stress in both human and animal cells. However, the mechanisms which hypoxia causes mitochondrial dysfunction and energy metabolism misbalance still remain unclear. In this study, we presented evidence that mitochondrial phosphatase Ptpmt1 is a hypoxia response molecule that regulates cell proliferation, survival and glucose metabolism in human erythroleukemia TF-1 cells. Exposure to hypoxia or DFO treatment results in upregulation of HIF1-α, HIF-2α and Ptpmt1. Only inhibition of HIF-2α by shRNA transduction reduces Ptpmt1 expression in TF-1 cells under hypoxia. Ptpmt1 inhibitor suppresses the growth and induces apoptosis of TF-1 cells. Furthermore, we demonstrated that Ptpmt1 inhibition reduces the Glut1 and Glut3 expression and decreases the glucose consumption in TF-1 cells. In additional, Ptpmt1 knockdown also results in the mitochondrial dysfunction determined by JC1 staining. These results delineate a key role for HIF-2α-induced Ptpmt1 upregulation in proliferation, survival and glucose metabolism of erythroleukemia cells. It is indicated that Ptpmt1 plays important roles in hypoxia-induced cell metabolism and mitochondrial dysfunction. - Highlights: • Hypoxia induces upregulation of HIF-1α, HIF-2α and Ptpmt1; HIF-2a induces Ptpmt1 upregulation in TF-1 cells. • PTPMT-1 inhibition reduces growth and induces apoptosis of TF-1 cells. • PTPMT1 inhibition downregulates Glut-1, Glut-3 expression and reduces glucose consumption.

  20. Antitumor activity of 6-(cyclohexylamino)-1, 3-dimethyl-5(2-pyridyl)furo[2,3-d]pyrimidine-2,4(1H,3H)-dione and Its Ti(IV), Zn(II), Fe(III), and Pd(II) complexes on K562 and Jurkat cell lines.

    Science.gov (United States)

    Shabani, Fahmideh; Ghammamy, Shahriar; Mehrani, Khayroallah; Teimouri, Mohammad Bagher; Soleimani, Masoud; Kaviani, Saeid

    2008-01-01

    (6-(cyclohexylamino)-1,3-dimethyl-5(2-pyridyl)furo[2,3-d]pyrimidine-2,4(1H,3H)-dione) abbreviated as CDP was synthesized and characterized. Ti(IV), Zn(II), Fe(III), and Pd(II) metal complexes of this ligand are prepared by the reaction of salts of Ti(IV), Zn(II), Fe(III), and Pd(II) with CDP in acetonitrile. Characterization of the ligand and its complexes was made by microanalyses, FT-IR, (1)H NMR, (13)C NMR, and UV-Visible spectroscopy. All complexes were characterized by several techniques using elemental analysis (C, H, N), FT-IR, electronic spectra, and molar conductance measurements. The elemental analysis data suggest the stoichiometry to be 1:1 [M:L] ratio formation. The molar conductance measurements reveal the presence of 1:1 electrolytic nature complexes. These new complexes showed excellent antitumor activity against two kinds of cancer cells that are K562 (human chronic myeloid leukemia) cells and Jurkat (human T lymphocyte carcinoma) cells.

  1. Development of K562 cell clones expressing β-globin mRNA carrying the β039 thalassaemia mutation for the screening of correctors of stop-codon mutations

    Science.gov (United States)

    Salvatori, Francesca; Cantale, Vera; Breveglieri, Giulia; Zuccato, Cristina; Finotti, Alessia; Bianchi, Nicoletta; Borgatti, Monica; Feriotto, Giordana; Destro, Federica; Canella, Alessandro; Breda, Laura; Rivella, Stefano; Gambari, Roberto

    2013-01-01

    Nonsense mutations, giving rise to UAA, UGA and UAG stop codons within the coding region of mRNAs, promote premature translational termination and are the leading cause of approx. 30 % of inherited diseases, including cystic fibrosis, Duchenne muscular dystrophy and thalassaemia. For instance, in β039-thalassaemia the CAG (glutamine) codon is mutated to the UAG stop codon, leading to premature translation termination and to mRNA destabilization through the well-described NMD (nonsense-mediated mRNA decay). In order to develop an approach facilitating translation and, therefore, protection from NMD, aminoglycoside antibiotics have been tested on mRNAs carrying premature stop codons. These drugs decrease the accuracy in the codon–anticodon base-pairing, inducing a ribosomal read-through of the premature termination codons. Interestingly, recent papers have described drugs designed and produced for suppressing premature translational termination, inducing a ribosomal read-through of premature but not normal termination codons. These findings have introduced new hopes for the development of a pharmacological approach to the therapy of β039-thalassaemia. In this context, we started the development of a cellular model of the β039-thalassaemia mutation that could be used for the screening of a high number of aminoglycosides and analogous molecules. To this aim, we produced a lentiviral construct containing the β039-thalassaemia globin gene under a minimal LCR (locus control region) control and used this construct for the transduction of K562 cells, subsequently subcloned, with the purpose to obtain several K562 clones with different integration copies of the construct. These clones were then treated with Geneticin (also known as G418) and other aminoglycosides and the production of β-globin was analysed by FACS analysis. The results obtained suggest that this experimental system is suitable for the characterization of correction of the β039-globin mutation causing

  2. Development of K562 cell clones expressing beta-globin mRNA carrying the beta039 thalassaemia mutation for the screening of correctors of stop-codon mutations.

    Science.gov (United States)

    Salvatori, Francesca; Cantale, Vera; Breveglieri, Giulia; Zuccato, Cristina; Finotti, Alessia; Bianchi, Nicoletta; Borgatti, Monica; Feriotto, Giordana; Destro, Federica; Canella, Alessandro; Breda, Laura; Rivella, Stefano; Gambari, Roberto

    2009-07-09

    Nonsense mutations, giving rise to UAA, UGA and UAG stop codons within the coding region of mRNAs, promote premature translational termination and are the leading cause of approx. 30% of inherited diseases, including cystic fibrosis, Duchenne muscular dystrophy and thalassaemia. For instance, in beta(0)39-thalassaemia the CAG (glutamine) codon is mutated to the UAG stop codon, leading to premature translation termination and to mRNA destabilization through the well-described NMD (nonsense-mediated mRNA decay). In order to develop an approach facilitating translation and, therefore, protection from NMD, aminoglycoside antibiotics have been tested on mRNAs carrying premature stop codons. These drugs decrease the accuracy in the codon-anticodon base-pairing, inducing a ribosomal read-through of the premature termination codons. Interestingly, recent papers have described drugs designed and produced for suppressing premature translational termination, inducing a ribosomal read-through of premature but not normal termination codons. These findings have introduced new hopes for the development of a pharmacological approach to the therapy of beta(0)39-thalassaemia. In this context, we started the development of a cellular model of the beta(0)39-thalassaemia mutation that could be used for the screening of a high number of aminoglycosides and analogous molecules. To this aim, we produced a lentiviral construct containing the beta(0)39-thalassaemia globin gene under a minimal LCR (locus control region) control and used this construct for the transduction of K562 cells, subsequently subcloned, with the purpose to obtain several K562 clones with different integration copies of the construct. These clones were then treated with Geneticin (also known as G418) and other aminoglycosides and the production of beta-globin was analysed by FACS analysis. The results obtained suggest that this experimental system is suitable for the characterization of correction of the beta(0

  3. Crosstalk between the Smad and the Mitogen-Activated Protein Kinase Pathways is Essential for Erythroid Differentiation of Erythroleukemia Cells Induced by TGF-β, Activin, Hydroxyurea and Butyrate.

    Science.gov (United States)

    Akel, Salem; Bertolette, Daniel; Ruscetti, Francis W

    2013-04-22

    The role of crosstalk between the Smad and the MAPK signaling pathways in activin-, transforming growth factor-β (TGF-β)-, hydroxyurea (HU) - and butyrate-dependent erythroid differentiation of K562 leukemic cells was studied. Treatment with all four inducers caused transient phosphorylation of Smad2/3 and MAPK proteins including ERK, p38 and JNK. Use of specific inhibitors of p38, ERK and JNK MAPK proteins, and TGF-β type I receptor indicated that differentiation induced by each of these agents involves activation of Smad2/3 and p38 MAPK, and inhibition of ERK MAPK. Also, treatment of cells with an inhibitor of protein serine/threonine phosphatase, okadaic acid (OA), induced phosphorylation of Smad2/3, and p38 MAPK, coincident with its induction of erythroid differentiation. Specific inhibition of TGF-β type I receptor kinase activity not only abolished TGF-β/activin effects but also prevented Smad2/3 activation and erythroid differentiation induced by OA, HU and butyrate. The TGF-β type I receptor kinase inhibitor blocked OA-induced differentiation but not p38 MAPK phosphorylation demonstrating that signals from both pathways are needed. As previously observed, addition of ERK1/2 MAPK inhibitors upregulated Smad2/3 phosphorylation and enhanced differentiation, but these effects were dependent on signals from the TGF-β type I receptor. These data indicate that activation of both Smad2/3 and p38 MAPK signaling pathways is a prerequisite to induce erythroid differentiation of erythroleukemia cells by activin, TGF-β, HU, OA and butyrate.

  4. Characterization of cells resistant to the potent histone deacetylase inhibitor spiruchostatin B (SP-B) and effect of overexpressed p21waf1/cip1 on the SP-B resistance or susceptibility of human leukemia cells.

    Science.gov (United States)

    Kanno, Syu-Ichi; Maeda, Naoyuki; Tomizawa, Ayako; Yomogida, Shin; Katoh, Tadashi; Ishikawa, Masaaki

    2012-09-01

    We previously showed that the B cell leukemia cell line NALM-6 had the highest susceptibility among a number of leukemia cell lines to spiruchostatin B (SP-B), a potent histone deacetylase (HDAC) inhibitor. We also showed that SP-B-induced cytotoxicity depended on induction of apoptosis that was mediated by p21waf1/cip1 expression. In the present study, we generated and characterized a stable, SP-B-resistant NALM-6 cell line (NALM-6/SP-B) by continuous exposure to SP-B, starting with a low SP-B concentration. NALM-6/SP-B cells were also more resistant to FK228, which has a similar chemical structure to SP-B, and were slightly more resistant to the P-gp substrates doxorubicin and vincristine than parental cells, but displayed similar susceptibility to other HDAC inhibitors and to paclitaxel as the parental cells. There was little change in the basal mRNA expression of HDAC1, p53, Bax, Bcl-2, Fas, caspase-3, c-Myc and MDR1 in NALM-6/SP-B compared to parental cells, but the mRNA expression of p21waf1/cip1 was decreased. The introduction of an exogenous p21waf1/cip1 expression vector restored SP-B induction of NALM-6/SP-B cell apoptosis. Moreover, overexpressed p21waf1/cip1 enhanced SP-B induction of the apoptosis of the human erythroleukemia leukemia cell line K562 which is less susceptible to SP-B than NALM-6 cells. These results suggest that downregulation of p21waf1/cip1, which is a characteristic feature of NALM-6/SP-B cells, was important for their resistance to SP-B, and that this SP-B resistance could be overcome by the introduction of exogenous p21waf1/cip1. Furthermore, introduction of p21waf1/cip1 to other leukemia cells such as K562 may enhance their susceptibility to SP-B. This is the first report of the characterization of SP-B-resistant cells and of the effect of overexpressed p21waf1/cip1 on the resistance or susceptibility of human leukemia cells to SP-B.

  5. NF-Y recruits both transcription activator and repressor to modulate tissue- and developmental stage-specific expression of human γ-globin gene.

    Directory of Open Access Journals (Sweden)

    Xingguo Zhu

    Full Text Available The human embryonic, fetal and adult β-like globin genes provide a paradigm for tissue- and developmental stage-specific gene regulation. The fetal γ-globin gene is expressed in fetal erythroid cells but is repressed in adult erythroid cells. The molecular mechanism underlying this transcriptional switch during erythroid development is not completely understood. Here, we used a combination of in vitro and in vivo assays to dissect the molecular assemblies of the active and the repressed proximal γ-globin promoter complexes in K562 human erythroleukemia cell line and primary human fetal and adult erythroid cells. We found that the proximal γ-globin promoter complex is assembled by a developmentally regulated, general transcription activator NF-Y bound strongly at the tandem CCAAT motifs near the TATA box. NF-Y recruits to neighboring DNA motifs the developmentally regulated, erythroid transcription activator GATA-2 and general repressor BCL11A, which in turn recruit erythroid repressor GATA-1 and general repressor COUP-TFII to form respectively the NF-Y/GATA-2 transcription activator hub and the BCL11A/COUP-TFII/GATA-1 transcription repressor hub. Both the activator and the repressor hubs are present in both the active and the repressed γ-globin promoter complexes in fetal and adult erythroid cells. Through changes in their levels and respective interactions with the co-activators and co-repressors during erythroid development, the activator and the repressor hubs modulate erythroid- and developmental stage-specific transcription of γ-globin gene.

  6. High concentrations of L-ascorbic acid specifically inhibit the growth of human leukemic cells via downregulation of HIF-1α transcription.

    Directory of Open Access Journals (Sweden)

    Hiroshi Kawada

    Full Text Available We examined the antileukemic effects of high concentrations of L-ascorbic acid (high AA on human leukemic cells. In vitro, high AA markedly induced apoptosis in various leukemic cell lines by generating hydrogen peroxide (H2O2 but not in normal hematopoietic stem/progenitor cells. High AA significantly repressed leukemic cell proliferation as well as neoangiogenesis in immunodeficient mice. We then noted that in leukemic cells, HIF-1α transcription was strongly suppressed by high AA and correlated with the transcription of VEGF. Our data indicate that exposure to high AA markedly increased the intracellular AA content of leukemic cells and inhibited the nuclear translocation of NF-κB, which mediates expression of HIF-1α. We next generated K562 cells that overexpressed HIF-1α (K562-HIF1α cells and assessed the mechanistic relationship between inhibition of HIF-1α transcription and the antileukemic effect of high AA. The ability of high AA to induce apoptosis was significantly lower in K562-HIF1α cells than in K562 cells in vitro. We found that expression of HIF-1α-regulated antiapoptotic proteins of the Bcl-2 family, such as Mcl-1, Bcl-xL, and Bcl-2, was significantly suppressed by high AA in K562 cells, but was sustained at higher levels in K562-HIF1α cells, regardless of high AA exposure. Moreover, repression of cell proliferation and neoangiogenesis by high AA was completely abrogated in mice receiving transplants of K562-HIF1α cells. These results indicate that, along with H2O2 generation, downregulation of HIF-1α transcription plays a crucial role in growth inhibition of human leukemic cells by high AA.

  7. 15. APPLICATION OF THE ALKALINE COMET ASSAY IN HUMAN BIOMONITORING: INTERNAL STANDARD AND GLOBAL REPAIR PHENOTYPE

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@An internal standard, composed of untreated an ethy1 methane sulfonate treated K562 cells was validated for its application in comet analysis of human biomonitoring samples. Firstly, the different levels of variability which may influence the damage levels of the internal standards were assessed. Three experimenters performed the comet assay with cells coming from the same set of untreated

  8. A Portrait of Ribosomal DNA Contacts with Hi-C Reveals 5S and 45S rDNA Anchoring Points in the Folded Human Genome.

    Science.gov (United States)

    Yu, Shoukai; Lemos, Bernardo

    2016-12-31

    Ribosomal RNAs (rRNAs) account for >60% of all RNAs in eukaryotic cells and are encoded in the ribosomal DNA (rDNA) arrays. The rRNAs are produced from two sets of loci: the 5S rDNA array resides exclusively on human chromosome 1, whereas the 45S rDNA array resides on the short arm of five human acrocentric chromosomes. The 45S rDNA gives origin to the nucleolus, the nuclear organelle that is the site of ribosome biogenesis. Intriguingly, 5S and 45S rDNA arrays exhibit correlated copy number variation in lymphoblastoid cells (LCLs). Here we examined the genomic architecture and repeat content of the 5S and 45S rDNA arrays in multiple human genome assemblies (including PacBio MHAP assembly) and ascertained contacts between the rDNA arrays and the rest of the genome using Hi-C datasets from two human cell lines (erythroleukemia K562 and lymphoblastoid cells). Our analyses revealed that 5S and 45S arrays each have thousands of contacts in the folded genome, with rDNA-associated regions and genes dispersed across all chromosomes. The rDNA contact map displayed conserved and disparate features between two cell lines, and pointed to specific chromosomes, genomic regions, and genes with evidence of spatial proximity to the rDNA arrays; the data also showed a lack of direct physical interaction between the 5S and 45S rDNA arrays. Finally, the analysis identified an intriguing organization in the 5S array with Alu and 5S elements adjacent to one another and organized in opposite orientation along the array. Portraits of genome folding centered on the ribosomal DNA array could help understand the emergence of concerted variation, the control of 5S and 45S expression, as well as provide insights into an organelle that contributes to the spatial localization of human chromosomes during interphase. © The Author(s) 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  9. Increase of microRNA-210, decrease of raptor gene expression and alteration of mammalian target of rapamycin regulated proteins following mithramycin treatment of human erythroid cells.

    Directory of Open Access Journals (Sweden)

    Nicoletta Bianchi

    Full Text Available Expression and regulation of microRNAs is an emerging issue in erythroid differentiation and globin gene expression in hemoglobin disorders. In the first part of this study microarray analysis was performed both in mithramycin-induced K562 cells and erythroid precursors from healthy subjects or β-thalassemia patients producing low or high levels of fetal hemoglobin. We demonstrated that: (a microRNA-210 expression is higher in erythroid precursors from β-thalassemia patients with high production of fetal hemoglobin; (b microRNA-210 increases as a consequence of mithramycin treatment of K562 cells and human erythroid progenitors both from healthy and β-thalassemia subjects; (c this increase is associated with erythroid induction and elevated expression of γ-globin genes; (d an anti-microRNA against microRNA-210 interferes with the mithramycin-induced changes of gene expression. In the second part of the study we have obtained convergent evidences suggesting raptor mRNA as a putative target of microRNA-210. Indeed, microRNA-210 binding sites of its 3'-UTR region were involved in expression and are targets of microRNA-210-mediated modulation in a luciferase reporter assays. Furthermore, (i raptor mRNA and protein are down-regulated upon mithramycin-induction both in K562 cells and erythroid progenitors from healthy and β-thalassemia subjects. In addition, (ii administration of anti-microRNA-210 to K562 cells decreased endogenous microRNA-210 and increased raptor mRNA and protein expression. Finally, (iii treatment of K562 cells with premicroRNA-210 led to a decrease of raptor mRNA and protein. In conclusion, microRNA-210 and raptor are involved in mithramycin-mediated erythroid differentiation of K562 cells and participate to the fine-tuning and control of γ-globin gene expression in erythroid precursor cells.

  10. Secretory products from thrombin-stimulated human platelets exert an inhibitory effect on NK-cytotoxic activity

    DEFF Research Database (Denmark)

    Skov Madsen, P; Hokland, P; Hokland, M

    1987-01-01

    decreased the NK-cytotoxicity by 40% +/- 4.3%, indicating the existence of secreted products from platelets as a source of NK-inhibiting substances. In contrast, no direct cytotoxic effect of these secretory products on the target cells (K562) was seen. Thus, normal human platelets, when stimulated...

  11. GATA-1 Inhibits PU.1 Gene via DNA and Histone H3K9 Methylation of Its Distal Enhancer in Erythroleukemia.

    Directory of Open Access Journals (Sweden)

    Pavel Burda

    Full Text Available GATA-1 and PU.1 are two important hematopoietic transcription factors that mutually inhibit each other in progenitor cells to guide entrance into the erythroid or myeloid lineage, respectively. PU.1 controls its own expression during myelopoiesis by binding to the distal URE enhancer, whose deletion leads to acute myeloid leukemia (AML. We herein present evidence that GATA-1 binds to the PU.1 gene and inhibits its expression in human AML-erythroleukemias (EL. Furthermore, GATA-1 together with DNA methyl Transferase I (DNMT1 mediate repression of the PU.1 gene through the URE. Repression of the PU.1 gene involves both DNA methylation at the URE and its histone H3 lysine-K9 methylation and deacetylation as well as the H3K27 methylation at additional DNA elements and the promoter. The GATA-1-mediated inhibition of PU.1 gene transcription in human AML-EL mediated through the URE represents important mechanism that contributes to PU.1 downregulation and leukemogenesis that is sensitive to DNA demethylation therapy.

  12. GATA-1 Inhibits PU.1 Gene via DNA and Histone H3K9 Methylation of Its Distal Enhancer in Erythroleukemia.

    Science.gov (United States)

    Burda, Pavel; Vargova, Jarmila; Curik, Nikola; Salek, Cyril; Papadopoulos, Giorgio Lucio; Strouboulis, John; Stopka, Tomas

    2016-01-01

    GATA-1 and PU.1 are two important hematopoietic transcription factors that mutually inhibit each other in progenitor cells to guide entrance into the erythroid or myeloid lineage, respectively. PU.1 controls its own expression during myelopoiesis by binding to the distal URE enhancer, whose deletion leads to acute myeloid leukemia (AML). We herein present evidence that GATA-1 binds to the PU.1 gene and inhibits its expression in human AML-erythroleukemias (EL). Furthermore, GATA-1 together with DNA methyl Transferase I (DNMT1) mediate repression of the PU.1 gene through the URE. Repression of the PU.1 gene involves both DNA methylation at the URE and its histone H3 lysine-K9 methylation and deacetylation as well as the H3K27 methylation at additional DNA elements and the promoter. The GATA-1-mediated inhibition of PU.1 gene transcription in human AML-EL mediated through the URE represents important mechanism that contributes to PU.1 downregulation and leukemogenesis that is sensitive to DNA demethylation therapy.

  13. DIFFERENTIATION AND MALIGNANT SUPPRESSION INDUCED BY MOUSE ERYTHROID DIFFERENTIATION AND DENUCLEATION FACTOR ON MOUSE ERYTHROLEUKEMIA CELLS

    Institute of Scientific and Technical Information of China (English)

    韩代书; 赵青; 葛晔华; 周建平; 马静; 陈克铨; 薛社普

    2002-01-01

    Objective. To investigate the roles of mouse erythroid differentiation and denueleation factor (MEDDF), a novel factor cloned in our laboratory recently, in erythroid terminal differentiation.Methods. Mouse erythroleukemia (MEL) cells were transfected with eukaryotic expression plasmid pcD-NA-MEDDF. Then we investigated the changes on characteristics of cell growth by analyzing cells growth rate,mitotic index and colony-forming rate in semi-solid medium. The expressions of c-myc and β-globin genes were analysed by semi-quantitative RT-PCR.Results. MEL ceils transfected with pcDNA-MEDDF showed significant lower growth rate, mitotic index,and colony-forming rate in semi-solid medium ( P<0.01 ). The percentage of benzidine-positive cells was 32.8% after transfection. The expression of β-globin in cells transfected with pcDNA-MEDDF was 3.43 times higher than that of control (MEL transfected with blank vector, pcDNA3. 1 ), and the expression of c-myc decreased by 66.3%.Conclusions. MEDDF can induce differentiation of MEL cell and suppress its malignancy.

  14. Spi-1/PU.1 activates transcription through clustered DNA occupancy in erythroleukemia.

    Science.gov (United States)

    Ridinger-Saison, Maya; Boeva, Valentina; Rimmelé, Pauline; Kulakovskiy, Ivan; Gallais, Isabelle; Levavasseur, Benjamin; Paccard, Caroline; Legoix-Né, Patricia; Morlé, François; Nicolas, Alain; Hupé, Philippe; Barillot, Emmanuel; Moreau-Gachelin, Françoise; Guillouf, Christel

    2012-10-01

    Acute leukemias are characterized by deregulation of transcriptional networks that control the lineage specificity of gene expression. The aberrant overexpression of the Spi-1/PU.1 transcription factor leads to erythroleukemia. To determine how Spi-1 mechanistically influences the transcriptional program, we combined a ChIP-seq analysis with transcriptional profiling in cells from an erythroleukemic mouse model. We show that Spi-1 displays a selective DNA-binding that does not often cause transcriptional modulation. We report that Spi-1 controls transcriptional activation and repression partially through distinct Spi-1 recruitment to chromatin. We revealed several parameters impacting on Spi-1-mediated transcriptional activation. Gene activation is facilitated by Spi-1 occupancy close to transcriptional starting site of genes devoid of CGIs. Moreover, in those regions Spi-1 acts by binding to multiple motifs tightly clustered and with similar orientation. Finally, in contrast to the myeloid and lymphoid B cells in which Spi-1 exerts a physiological activity, in the erythroleukemic cells, lineage-specific cooperating factors do not play a prevalent role in Spi-1-mediated transcriptional activation. Thus, our work describes a new mechanism of gene activation through clustered site occupancy of Spi-1 particularly relevant in regard to the strong expression of Spi-1 in the erythroleukemic cells.

  15. Monocytoid differentiation of freshly isolated human myeloid leukemia cells and HL-60 cells induced by the glutamine antagonist acivicin.

    Science.gov (United States)

    Nichols, K E; Chitneni, S R; Moore, J O; Weinberg, J B

    1989-10-01

    Previously we showed that starvation of HL-60 promyelocytic leukemia cells for a single essential amino acid induced irreversible differentiation into more mature monocyte-like cells. Although not an essential amino acid, glutamine is important in the growth of normal and neoplastic cells. The glutamine analogue, alpha S,5S-alpha-amino-3-chloro-4,5-dihydro-5-isoxazoleacetic acid (acivicin) inhibits several glutamine-utilizing enzymes and therefore depletes cells of certain metabolic end products. The current study was designed to examine in vitro the effects of acivicin on growth and differentiation of several established human myeloid leukemia cell lines, including the HL-60 cell line, and of freshly isolated cells from patients with acute nonlymphocytic leukemia (ANLL). Four-day culture of HL-60 cells with acivicin at concentrations of 0.1 to 10.0 micrograms/mL (0.56 to 56 nmol/L) decreased cell growth by 33% to 88% as compared with untreated control cells. Viability of cells was greater than 92% for untreated cells and 93% to 41% for acivicin-treated cells. Cells treated with acivicin differentiated along a monocytic pathway as shown by increased H2O2 production and alpha-naphthyl butyrate esterase (NSE) content. Differentiation was time and dose dependent, and was irreversible. Changes in H2O2 production and NSE content were partially abrogated by co-culture with 10 mmol/L exogenous cytidine and guanosine but not by co-culture with other nucleosides or glutamine. At these concentrations of acivicin, differentiation was associated with expression of the N-formyl-methyl-leucyl-phenylalanine-receptor (FMLP-R) on 8% to 29% of cells as compared with 8% for control cells. Acivicin potentiated the differentiating effects of interferon-gamma, tumor necrosis factor, dihydroxyvitamin D3, dimethylsulfoxide, and retinoic acid. Culture of cells from the U937 (monoblastic), K562 (erythroleukemia), and KG-1 (myeloblastic) cell lines resulted in decreased growth and viability

  16. A natural-like synthetic small molecule impairs bcr-abl signaling cascades and induces megakaryocyte differentiation in erythroleukemia cells.

    Directory of Open Access Journals (Sweden)

    Silvia Turroni

    Full Text Available Over the past years, we synthesized a series of new molecules that are hybrids of spirocyclic ketones as complexity-bearing cores with bi- and ter-phenyls as privileged fragments. Some of these newly-shaped small molecules showed antiproliferative, pro-apoptotic and differentiating activity in leukemia cell lines. In the present study, to investigate more in depth the mechanisms of action of these molecules, the protein expression profiles of K562 cells treated with or without the compounds IND_S1, MEL_T1, IND_S7 and MEL_S3 were analyzed using two-dimensional gel electrophoresis coupled with mass spectrometry. Proteome comparisons revealed several differentially expressed proteins, mainly related to cellular metabolism, chaperone activity, cytoskeletal organization and RNA biogenesis. The major results were validated by Western blot and qPCR. To attempt integrating findings into a cellular signaling context, proteomic data were explored using MetaCore. Network analysis highlighted relevant relationships between the identified proteins and additional potential effectors. Notably, qPCR validation of central hubs showed that the compound MEL_S3 induced high mRNA levels of the transcriptional factors EGR1 and HNF4-alpha; the latter to our knowledge is reported here for the first time to be present in K562 cells. Consistently with the known EGR1 involvement in the regulation of differentiation along megakaryocyte lineage, MEL_S3-treated leukemia cells showed a marked expression of glycoprotein IIb/IIIa (CD41 and glycoprotein Ib (CD42, two important cell markers in megakaryocytic differentiation, together with morphological aspects of megakaryoblasts and megakaryocytes.

  17. 逆转录病毒介导的HO-1基因在尼洛替尼诱导K562/A02耐药细胞凋亡中的作用%The effect of retrovirus-mediated HO-1 gent on chronic myeloid leukemia resistance cell KS62/A02 apoptosis induced lay nilotinib

    Institute of Scientific and Technical Information of China (English)

    陈埕; 王季石; 秦东; 杨远; 于艳艳; 方琴

    2012-01-01

    目的 研究逆转录病毒介导的血红素加氧酶-1(HO-1)基因在尼洛替尼(Nilotinib,AMN107)诱导慢性髓性白血病(CML)耐药细胞凋亡中的作用.方法 制备高病毒滴度的逆转录病毒载体pQCXIP-EGFP-HO-1,建立稳定转染HO-1基因的K562/A02细胞.采用RT-PCR鉴定K562/A02细胞中HO-1基因的表达.RT-PCR和Western blot法检测AMNl07作用24 h后K562/A02细胞中HO-1 mRNA和蛋白的表达,采用MTT法观察细胞增殖变化,通过实时荧光定量PCR(RQ-PCR)法检测bcr-abl融合基凶的表达.通过流式细胞术检测细胞凋亡和细胞周期分布.结果 成功构建重组逆转录病毒载体,并建立稳定转染HO-1基因的K562/A02细胞系;证实转基冈组细胞HO-1 mRNA显著表达.AMN107作用3组细胞后,转基因组细胞HO-1 mRNA和蛋白的表达明显高于转空载体组和未转染组,差异有统计学意义(P<0.05);MTT法检测显示AMN107处理后细胞增殖受抑.而转基因组细胞存活率明显高于转空载体组和未转染组,差异有统计学意义(P<0.05);RQ-PCR法检测结果显示,10 ILLmol/L AMNl07抑制bcr-abl基因的表达,但转基因组的bcr-abl基因表达水平(Ct值18.15±0.18)高于转空载体组(20.32±0.20)和未转染组(20.51±0.21),差异有统计学意义(P<0.05);流式细胞术检测结果显示10 μmol/L AMNl07作用24 h后,转基因组、转空载体组、未转染组细胞凋亡率分别为(17.26±0.23)%、(39.47±0.17)%、(41.84±0.09)%.未加药转基因组、未加药未转染组细胞凋亡率分别为(3.74±0.03)%、(5.91±0.08)%;细胞周期分析结果显示经AMNl07处理后,Go/G1期和S期细胞明显减少,细胞阻滞在G2/M期,而转基因细胞组细胞周期改变不如转空载体组、未转染组明显.结论 AMN107可抑制CML耐药细胞增殖且诱导细胞凋亡,HO-1基因在CML耐药细胞凋亡过程中起保护作用,与促进CML耐药细胞的生长有关.

  18. The sequential addition of ribosomal proteins during the formation of the small ribosomal subunit in Friend erythroleukemia cells.

    Science.gov (United States)

    Todorov, I T; Noll, F; Hadjiolov, A A

    1983-03-15

    Nucleolar '80-S' and '40-S' preribosomes (containing 45-S and 21-S pre-rRNA, respectively), as well as cytoplasmic ribosomes, were isolated from Friend erythroleukemia cells. The presence of structural ribosomal proteins in the isolated particles was studied by using antisera against individual rat liver small ribosomal subunit proteins. The analysis is based on the established crossreactivity between rat and mouse ribosomes [F. Noll and H. Bielka (1970) Mol. Gen. Genet. 106, 106-113]. The identification of the proteins was achieved by two independent immunological techniques: the passive haemagglutination test and the enzyme immunoassay of electrophoretically fractionated proteins, blotted on nitrocellulose. All 17 proteins tested are present in cytoplasmic ribosomes. A large number of proteins (S3a, S6, S7, S8, S11, S14, S18, S20, S23/24 and S25) are present in the '80-S' preribosome. Only two proteins (S3 and S21) are added during the formation of the '40-S' preribosome in the nucleolus. Four proteins (S2, S19, S26 and S29) are added at later, possibly extranucleolar, stages of ribosome formation. The results obtained provide evidence for the sequential addition of proteins during the formation of the small ribosomal subunit in Friend erythroleukemia cells.

  19. INTERNALIZATION OF ANTIMICROBIAL PEPTIDE ACIPENSIN 1 INTO HUMAN TUMOR CELLS

    Directory of Open Access Journals (Sweden)

    E. S. Umnyakova

    2016-01-01

    Full Text Available Search for new compounds providing delivery of drugs into infected or neoplastic cells, is an important direction of biomedical research. Cell-penetrating peptides are among those compounds, due to their ability to translocate through membranes of eukaryotic cells, serving as potential carriers of various therapeutic agents to the target cells. The aim of present work was to investigate the ability of acipensin 1, an antimicrobial peptide of innate immune system, for in vitro penetration into human tumor cells. Acipensin 1 is a cationic peptide that we have previously isolated from leukocytes of the Russian sturgeon, Acipenser gueldenstaedtii. Capability of acipensin 1 to enter the human erytroleukemia K-562 cells has been investigated for the first time. A biotechnological procedure for producing a recombinant acipensin 1 peptide has been developed. The obtained peptide was conjugated with a fluorescent probe BODIPY FL. By means of confocal microscopy, we have shown that the tagged acipensin 1 rapidly enters into K-562 cells and can be detected in the intracellular space within 5 min after its addition to the cell culture. Using flow cytometry technique, penetration kinetics of the labeled peptide into K-562 cells (at nontoxic micromolar concentrations has been studied. We have observed a rapid internalization of the peptide to the target cells, thus confirming the results of microscopic analysis, i.e, the labeled acipensin was detectable in K-562 cells as soon as wihin 2-3 seconds after its addition to the incubation medium. The maximum of fluorescence was reached within a period of approx. 45 seconds, with further “plateau” at the terms of >100 seconds following cell stimulation with the test compound. These data support the concept, that the antimicrobial peptides of innate immunity system possess the features of cell-penetrating peptides, and allow us to consider the studied sturgeon peptide a promising template for development of new

  20. Phytochemicals and Cytotoxicity of Launaea procumbens on Human Cancer Cell Lines

    Science.gov (United States)

    Rawat, Preeti; Saroj, Lokesh M.; Kumar, Anil; Singh, Tryambak D.; Tewari, SK.; Pal, Mahesh

    2016-01-01

    Background: The plant Launaea procumbens belongs to the family Asteraceae and traditionally used in the treatment rheumatism, kidney, liver dysfunctions and eye diseases. In the present study Phytochemical analysis and fractions of methanolic extract of L. procumbens leaves were tested in vitro for their cytotoxicity. Objectives: Phytochemical analysis and cytotoxic activity of methanolic extract and fractions of Launaea procumbens against four cancer cell lines K562, HeLa, MIA-Pa-Ca-2 and MCF-2 by SRB assay. Materials and Methods: Powdered leaves of Launaea procumbens were extracted sequentially with hexane, ethyl acetate, butanol and water by cold extraction. Phytochemical analysis and cytotoxicity assay were carried out for these fractions using SRB assay against four human cancer cell lines, namely leukemia (K562), cervix (HeLa), pancreatic (MIA-Pa-Ca-2) and breast (MCF-7). Results: Ethyl acetate extract exerts potent cytotoxicity against human leukemia (K562), cervix (HeLa) and breast (MCF-7) cell lines IC50 value of 25.30±0.50, 19.80±0.10 and 36.90±4.90 μg/ml respectively. Moderately cytotoxic effect found in hexane extract IC50 value of 41±8 and 48.20±0.50 μg/ml against leukemia (K562), and breast (MCF-7) cancer cell line respectively. The Chemical composition analyzed by GC-MS showed considerable differences in solvent fractions of Launaea procumbens. Conclusion: This study revealed the cytotoxic potential of ethyl acetate and hexane fractions of L. procumbens leaves on different cancer cell lines. SUMMARY Ethyl acetate and Hexane fractions of Launaea procumbens plant exhibit cytotoxicity. Among the different fractions Ethyl acetate showed relatively higher cytotoxicity.Ethyl acetate found more cytotoxic against leukemia (K 562), cervix (HeLa) and breast (MCF-7) cancer cell lines. Moderete cytotoxicity found in hexane fraction against leukemia (K 562) and breast (MCF-7) cancer cell line.GC-MS results showed L. procumbens is a rich source of 1-H

  1. RETROVIRAL MEDIATED EFFICIENT TRANSFER ANDEXPRESSION OF MULTIPLE DRUG RESISTANCE GENE TO HUMAN LEUKEMIC CELLS

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective: To investigate retroviral-mediated transfer and expression of human multidrug resistance (MDR) gene MDR1 in leukemic cells. Methods: Human myeloid cells, K562 and NB4, were infected by MDR retrovirus from the producer PA317/HaMDR, and the resistant cells were selected with cytotoxic drug. The transfer and expression of MDR1 gene was analyzed by using polymerase chain reaction (PCR), flow cytometry (FCM) and semisolid colonies cultivation. Results: The resistant cells, K562/MDR and NB4/MDR, in which integration of the exogenous MDR1 gene was confirmed by PCR analysis, displayed a typical MDR phenotype. The expression of MDR1 transgene was detected on truncated as well as full-length transcripts. Moreover, the resistant cells were P-glycoprotein postiive at 78.0% to 98.7% analyzed with FCM. The transduction efficieny in K562 cells was studied on suspension cultures and single-cell colonies. The transduction was more efficient in coculture system (67.9%~ 72.5%) than in supernatant system (33.1%~ 46.8%), while growth factors may improve the efficiency. Conclusion: Retrovirus could allow a functional transfer and expression of MDR1 gene in human leukemia cells, and MDR1 might act as a dominant selectable gene for coexpression with the genes of interest in gene therapy.

  2. Midazolam Induces Cellular Apoptosis in Human Cancer Cells and Inhibits Tumor Growth in Xenograft Mice

    Science.gov (United States)

    Mishra, Siddhartha Kumar; Kang, Ju-Hee; Lee, Chang Woo; Oh, Seung Hyun; Ryu, Jun Sun; Bae, Yun Soo; Kim, Hwan Mook

    2013-01-01

    Midazolam is a widely used anesthetic of the benzodiazepine class that has shown cytotoxicity and apoptosis-inducing activity in neuronal cells and lymphocytes. This study aims to evaluate the effect of midazolam on growth of K562 human leukemia cells and HT29 colon cancer cells. The in vivo effect of midazolam was investigated in BALB/c-nu mice bearing K562 and HT29 cells human tumor xenografts. The results show that midazolam decreased the viability of K562 and HT29 cells by inducing apoptosis and S phase cell-cycle arrest in a concentration-dependent manner. Midazolam activated caspase-9, capspase-3 and PARP indicating induction of the mitochondrial intrinsic pathway of apoptosis. Midazolam lowered mitochondrial membrane potential and increased apoptotic DNA fragmentation. Midazolam showed reactive oxygen species (ROS) scavenging activity through inhibition of NADPH oxidase 2 (Nox2) enzyme activity in K562 cells. Midazolam caused inhibition of pERK1/2 signaling which led to inhibition of the anti-apoptotic proteins Bcl-XL and XIAP and phosphorylation activation of the pro-apoptotic protein Bid. Midazolam inhibited growth of HT29 tumors in xenograft mice. Collectively our results demonstrate that midazolam caused growth inhibition of cancer cells via activation of the mitochondrial intrinsic pathway of apoptosis and inhibited HT29 tumor growth in xenograft mice. The mechanism underlying these effects of midazolam might be suppression of ROS production leading to modulation of apoptosis and growth regulatory proteins. These findings present possible clinical implications of midazolam as an anesthetic to relieve pain during in vivo anticancer drug delivery and to enhance anticancer efficacy through its ROS-scavenging and pro-apoptotic properties. PMID:24008365

  3. Effects of TFAR19 gene on the in vivo biorheological properties and pathogenicity of mouse erythroleukemia cell line MEL

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    After injecting VP16, MEL cells and MEL-TF19 cells into the body of mice, with those injected with the same dose of saline as the control group, we observed the mice for their blood pictures, histological changes of the liver and spleen, and the hemorhelogical indexes within 4 weeks. The results indicated that after injecting MEL cells, the mice entered into a pathological status similar to erythroleukemia, which had the following exhibitions: the tissue structures of the liver and spleen were damaged, a mass of proerythroblasts, basophil erythroblasts and polychromatophilic erythroblasts could be observed on the smears of the bone marrow and spleen, and the deformability and orientation ability of erythrocytes were both depressed. The pathogenicity of MEL-TF19 cells carrying TFAR19 gene was obviously lower than that of MEL cells, and the MEL-TF19 cells even lost their faintish pathogenicity under the apop-tosis-inducing effect of the chemotherapeutic reagent. The outcome from the animal experiments suggests that the TFAR19 gene suppresses the pathogenicity of MEL cells to the mice, and the effect may be better exerted with the synergy of the chemotherapeutic reagent.

  4. Herpes simplex virus types 1 and 2 induce shutoff of host protein synthesis by different mechanisms in Friend erythroleukemia cells.

    Science.gov (United States)

    Hill, T M; Sinden, R R; Sadler, J R

    1983-01-01

    Herpes simplex virus type 1 (HSV-1) and HSV-2 disrupt host protein synthesis after viral infection. We have treated both viral types with agents which prevent transcription of the viral genome and used these treated viruses to infect induced Friend erythroleukemia cells. By measuring the changes in globin synthesis after infection, we have determined whether expression of the viral genome precedes the shutoff of host protein synthesis or whether the inhibitor molecule enters the cells as part of the virion. HSV-2-induced shutoff of host protein synthesis was insensitive to the effects of shortwave (254-nm) UV light and actinomycin D. Both of the treatments inhibited HSV-1-induced host protein shutoff. Likewise, treatment of HSV-1 with the cross-linking agent 4,5',8-trimethylpsoralen and longwave (360-nm) UV light prevented HSV-1 from inhibiting cellular protein synthesis. Treatment of HSV-2 with 4,5',8-trimethylpsoralen did not affect the ability of the virus to interfere with host protein synthesis, except at the highest doses of longwave UV light. It was determined that the highest longwave UV dosage damaged the HSV-2 virion as well as cross-linking the viral DNA. The results suggest that HSV-2 uses a virion-associated component to inhibit host protein synthesis and that HSV-1 requires the expression of the viral genome to cause cellular protein synthesis shutoff.

  5. The distribution of calmodulin and Ca2+—activated calmodulin in cell cycle of mouse erythroleukemia cells

    Institute of Scientific and Technical Information of China (English)

    YouJinsong; LiSuwen; 等

    1990-01-01

    Cell proliferation is accompanied with changing levels of intracellular calmodulin (CaM) and its activation.Prior data from synchronized cell population could not actually stand for various CaM levels in different phases of cell cycle.Here,based upon quantitative measurement of fluorescence in individual cells,a method was developed to investigate intracellular total CaM and Ca2+-activated CaM contents. Intensity of CaM immunoflurescence gave total CaM level,and Ca2+-activated CaM was measured by fluorescence intensity of CaM antagonist trifluoperazine (TFP).In mouse erythroleukemia (MEL) cells,total CaM level increased from G1 through S to G2M,reaching a maximum of 2-fold increase,then reduced to half amount after cell division.Meanwhile,Ca2+-activated CaM also in creased through the cell cycle(G1,S,G2M).Increasing observed in G1 meant that the entry of cells from G1 into S phase may require CaM accumulation,and,equally or even more important,Ca2+-dependent activation of CaM.Ca2+-activated CaM decreased after cell division.The results suggested that CaM gene expression and C2+-modulated CaM activation act synergistically to accomplish the cell cycle progression.

  6. Effects of TFAR19 gene on the in vivo biorheological properties and pathogenicity of mouse erythroleukemia cell line MEL

    Institute of Scientific and Technical Information of China (English)

    GU Li; TANG ZhiYu; HE DongQi; KA WeiBo; SUN DaGong; WEN ZongYao

    2007-01-01

    After injecting VP16, MEL cells and MEL-TF19 cells into the body of mice, with those injected with the same dose of saline as the control group, we observed the mice for their blood pictures, histological changes of the liver and spleen, and the hemorhelogical indexes within 4 weeks. The results indicated that after injecting MEL cells, the mice entered into a pathological status similar to erythroleukemia, which had the following exhibitions: the tissue structures of the liver and spleen were damaged, a mass of proerythroblasts, basophil erythroblasts and polychromatophilic erythroblasts could be observed on the smears of the bone marrow and spleen, and the deformability and orientation ability of erythrocytes were both depressed. The pathogenicity of MEL-TF19 cells carrying TFAR19 gene was obviously lower than that of MEL cells, and the MEL-TF19 cells even lost their faintish pathogenicity under the apoptosis-inducing effect of the chemotherapeutic reagent. The outcome from the animal experiments suggests that the TFAR19 gene suppresses the pathogenicity of MEL cells to the mice, and the effect may be better exerted with the synergy of the chemotherapeutic reagent.

  7. Human Wharton's jelly mesenchymal stem cell secretome display antiproliferative effect on leukemia cell line and produce additive cytotoxic effect in combination with doxorubicin.

    Science.gov (United States)

    Hendijani, Fatemeh; Javanmard, Shaghayegh Haghjooy; Sadeghi-aliabadi, Hojjat

    2015-06-01

    Mesenchymal stem cell (MSC) therapy moves toward clinic progressively. Recent evidences establish anticancer effect of mesenchymal stem cells. However multiple factors including type of cancer, MSC source, study design, and animal model play role in final outcome. Wharton's jelly - a newly approved source of MSCs - possesses superiorities to bone marrow as the conventional source; therefore investigation of its medical effects can produce beneficial results. In this survey we examined cytotoxic and proapoptotic effect of human Wharton's jelly MSC secretome on K562 human leukemia cells. MSCs were isolated from human Wharton's jelly of umbilical cord by explant culture method, then characterized according to ISCT criteria (morphology and plastic adherence, surface antigenicity and differentiation potential). MSC secretome was collected and its cytotoxic and proapoptotic effects on K562 cells in combination with doxorubicin were evaluated using BrdU cell proliferation assay and Annexin V-PI staining. Our results showed antiproliferative effect of mesenchymal stem cell secretome on K562 cancer cells, the effect was also added to cytotoxic effect of doxorubicin without induction of drug resistance. Human Wharton's jelly derived mesenchymal stem cells exerted cytotoxic effect on leukemia cells. Addition of that effect to anticancer effect of chemotherapeutic agents can leads to cytotoxic drug dose reduction and diminished side effects. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Cytotoxic effects induced by combination of heliantriol B2 and dequalinium against human leukemic cell lines.

    Science.gov (United States)

    Gurovic, M Soledad Vela; Lanza, A María Díaz; Adánez, María del Carmen Boyano; Omaña, M Cristina Estañ; Gómez, Irene Gañán; Murray, A Paula; López, Pilar Sancho

    2011-04-01

    Natural occurring compounds are considered an important source of antitumoral agents. In the present study, the cytotoxic potential of three pentacyclic triterpenes isolated from Chuquiraga erinacea (Asteraceae), against the human leukemic cell lines NB4 and K562 was assessed. Heliantriol B2 (HB2) showed the highest cytotoxic activity after 24 h treatment showing IC(50) values of 1.98 ± 0.12 µm and 3.52 ± 0.14 µm for NB4 and K562 cells, respectively. This activity was higher than that of the reference compound dequalinium (DQA). Apoptosis and necrosis induced by HB2 in both NB4 and K562 cell lines were analysed by Annexin V/PI labeling. Mitochondrial alterations including reactive oxygen species (ROS) production and mitochondrial transmembrane potential (ΔΨm) were also tested. The results demonstrated that HB2 induced cell death by apoptosis and necrosis and showed enhanced cytotoxic effects in combination with DQA. Besides, HB2 induced ROS overproduction in NB4 cells and a slight decrease of ΔΨm. Consequently, our findings prompt further studies on the HB2 mechanism of action and its selectivity to tumor cells in order to assess the potential of HB2 as an agent for cancer treatment.

  9. The apoptosis of HEL cells induced by hydroxyures

    Institute of Scientific and Technical Information of China (English)

    GUICHANGYUN; CHUJIANG; 等

    1997-01-01

    Hydroxyurea has been used to synchronize cultured cells to S-phase and used to treat patients with sicklecell anemia.Recently,we found that hydroxyurea can induce the apoptosis of HEL(human erythroleukemia) cells.The induced HEL cells showed ultrastructurally chromatin condensation with regular crescents at the nuclear edges and apoptotic bodies.However,the cells of K562,another human erythroleukemia cell line,did not show such morphological changes.Under fluoroscope,the HEL cells after induction of ten displayed a clear reduction in nuclear diameter and nuclear chromatin cleavage and condensation and the presence of nuclear ring and apoptotic bodies.Analysis with flow cytometry showed that the percentage of apoptotic cells is about 30-40% after HEL cells were induced by hydroxyurea for 3 days.DNA ladder can be observed by electrophoretic analysis.

  10. Differential cytotoxic effects of Annona squamosa seed extracts on human tumour cell lines: Role of reactive oxygen species and glutathione

    Indian Academy of Sciences (India)

    B V V Pardhasaradhi; Madhurima Reddy; A Mubarak Ali; A Leela Kumari; Ashok Khar

    2005-03-01

    Annonaceous acetogenins are a new class of compounds that have been reported to have potent pesticidal, parasiticidal, anti-microbial, cell growth inhibitory activities. In this study, organic and aqueous extracts from the defatted seeds of Annona squamosa (custard apple) were tested on different human tumour cell lines for antitumoural activity. While organic and aqueous extracts induced apoptosis in MCF-7 and K-562 cells, they failed to do so in COLO-205 cells. Treatment of MCF-7 and K-562 cells with organic and aqueous extracts resulted in nuclear condensation, DNA fragmentation, induction of reactive oxygen species (ROS) generation and reduced intracellular glutathione levels. In addition downregulation of Bcl-2 and PS externalization by Annexin-V staining suggested induction of apoptosis in MCF-7 and K-562 cells by both the extracts through oxidative stress. On the contrary, COLO-205 cells showed only PS externalization but no change in ROS and glutathione levels. These observations suggest that the induction of apoptosis by A. squamosa extracts can be selective for certain types of cancerous cells.

  11. Spi-1, Fli-1 and Fli-3 (miR-17-92 oncogenes contribute to a single oncogenic network controlling cell proliferation in friend erythroleukemia.

    Directory of Open Access Journals (Sweden)

    Samer Kayali

    Full Text Available Clonal erythroleukemia developing in susceptible mice infected by Friend virus complex are associated with highly recurrent proviral insertions at one of three loci called Spi-1, Fli-1 or Fli-3, leading to deregulated expression of oncogenic Spi-1 or Fli-1 transcription factors or miR-17-92 miRNA cluster, respectively. Deregulated expression of each of these three oncogenes has been independently shown to contribute to cell proliferation of erythroleukemic clones. Previous studies showed a close relationship between Spi-1 and Fli-1, which belong to the same ETS family, Spi-1 activating fli-1 gene, and both Spi-1 and Fli-1 activating multiple common target genes involved in ribosome biogenesis. In this study, we demonstrated that Spi-1 and Fli-1 are also involved in direct miR-17-92 transcriptional activation through their binding to a conserved ETS binding site in its promoter. Moreover, we demonstrated that physiological re-expression of exogenous miR-17 and miR-20a are able to partially rescue the proliferation loss induced by Fli-1 knock-down and identified HBP1 as a target of these miRNA in erythroleukemic cells. These results establish that three of the most recurrently activated oncogenes in Friend erythroleukemia are actually involved in a same oncogenic network controlling cell proliferation. The putative contribution of a similar ETS-miR-17-92 network module in other normal or pathological proliferative contexts is discussed.

  12. Spi-1, Fli-1 and Fli-3 (miR-17-92) oncogenes contribute to a single oncogenic network controlling cell proliferation in friend erythroleukemia.

    Science.gov (United States)

    Kayali, Samer; Giraud, Guillaume; Morlé, François; Guyot, Boris

    2012-01-01

    Clonal erythroleukemia developing in susceptible mice infected by Friend virus complex are associated with highly recurrent proviral insertions at one of three loci called Spi-1, Fli-1 or Fli-3, leading to deregulated expression of oncogenic Spi-1 or Fli-1 transcription factors or miR-17-92 miRNA cluster, respectively. Deregulated expression of each of these three oncogenes has been independently shown to contribute to cell proliferation of erythroleukemic clones. Previous studies showed a close relationship between Spi-1 and Fli-1, which belong to the same ETS family, Spi-1 activating fli-1 gene, and both Spi-1 and Fli-1 activating multiple common target genes involved in ribosome biogenesis. In this study, we demonstrated that Spi-1 and Fli-1 are also involved in direct miR-17-92 transcriptional activation through their binding to a conserved ETS binding site in its promoter. Moreover, we demonstrated that physiological re-expression of exogenous miR-17 and miR-20a are able to partially rescue the proliferation loss induced by Fli-1 knock-down and identified HBP1 as a target of these miRNA in erythroleukemic cells. These results establish that three of the most recurrently activated oncogenes in Friend erythroleukemia are actually involved in a same oncogenic network controlling cell proliferation. The putative contribution of a similar ETS-miR-17-92 network module in other normal or pathological proliferative contexts is discussed.

  13. The 5‘—flanking cis—acting elements of the human ε—globin gene associates with the nuclear matrix and binds to the nuclear matrix proteins

    Institute of Scientific and Technical Information of China (English)

    YANZHIJIANG; RUOLANQIAN

    1998-01-01

    The nuclear matrix attachment regions(MARs) and the binding nuclear matrix proteins in the 5'-flanking cisacting elements of the human ε-globin gene have been examined.Using in vitro DNA-matrix binding assay,it has been shown that the positive stage-specific regulatory element (ε-PREII,-446bp- -419bp) upstream of this gene could specifically associate with the nuclear matrix from K562 cells,indicating that ε-PREII may be an erythroidspecific facultative MAR.In gel mobility shift assay and Southwestern blotting assay,an erythroid-specific nuclear matrix protein (ε-NMPk) in K562 cells has been revealed to bind to this positive regulatory element (ε-PREII).Furthermore,we demonstrated that the silencer (-392bp- -177bp) upstream of the human ε-globin gene could associate with the nuclear matrices from K562,HEL and Raji cells.In addition,the nuclear matrix proteins prepared from these three cell lines could also bind to this silencer,suggesting that this silencer element might be a constitutive nuclear matrix attachment region(constitutive MAR).Our results demonstrated that the nuclear matrix and nuclear matrix proteins might play an important role in the regulation of the human ε-globin gene expression.

  14. Human Platelet Antigen Genotyping and Expression of CD109 (Human Platelet Antigen 15 mRNA in Various Human Cell Types

    Directory of Open Access Journals (Sweden)

    Sang Mee Hwang

    2013-01-01

    Full Text Available CD109 gene encodes a glycosylphosphatidylinositol-linked glycoprotein found in a subset of platelets and endothelial cell, and human platelet antigen (HPA 15 is found on CD109. We evaluated the HPA genotype and/or the CD109 mRNA expression on two peripheral blood stem cells (PBSC, two peripheral bloods (PB, 12 granulocyte products, natural killer (NK-92, B-lymphocyte (CO88BV59-1, K-562 leukemia cell line, human embryonic stem cell (hESC, and human fibroblasts (HF. HPA genotyping was performed by SNaPshot assay and CD109 mRNA expression was evaluated by real-time PCR with SYBR green and melting curve analysis. Genotype HPA-15a/-15a was found in PBSC#1 and two granulocyte products, and HPA-15a/-15b was found in PBSC#2, eight granulocyte products, NK-92, K-562, hESC, and HF, and HPA-15b/-15b was found in two granulocyte products. CD109 mRNA expression was highly increased in HF and increased in CD34+ and CD34− PBSCs and some granulocyte products, compared to the PB. However, the increase of expression level varied among the PBSC and granulocyte products. The CD109 mRNA expression of NK-92, K-562, hESC, and CO 88BV59-1 was not detected. HPA genotype was evaluated in various cells and the expression of CD109, which contains HPA 15, was different among cell lines and high in HF and PBSCs.

  15. The role of WDR5 in silencing human fetal globin gene expression

    Science.gov (United States)

    Xu, Zhen; He, Yinghong; Ju, Junyi; Rank, Gerhard; Cerruti, Loretta; Ma, Chi; Simpson, Richard J.; Moritz, Robert L.; Jane, Stephen M.; Zhao, Quan

    2012-01-01

    Background Histone H3 lysine 4 (K4) methylation has been linked with transcriptional activity in mammalian cells. The WD40-repeat protein, WDR5, is an essential component of the MLL complex that induces histone H3 K4 methylation, but the role of WDR5 in human globin gene regulation has not yet been established. Design and Methods To study the role of WDR5 in human globin gene regulation, we performed knockdown experiments in both K562 cells and primary human bone marrow erythroid progenitor cells (BMC). The effects of WDR5 knockdown on γ-globin gene expression were determined. Biochemical approaches were also employed to investigate WDR5 interaction molecules. Chromosomal marks in the globin locus were analyzed by ChIP. Results We found that WDR5 interacted with protein arginine methyltransferase 5 (PRMT5), a known repressor of γ-globin gene expression, and was essential for generating tri-methylated H3K4 (H3K4me3) at the γ-globin promoter in K562 cells. Enforced expression of WDR5 in K562 cells reduced γ-globin gene expression, whereas knockdown of WDR5 increased γ-globin gene expression in both K562 cells and primary human bone marrow erythroid progenitor cells. Consistent with this, both histone H3 and H4 acetylation at the γ-globin promoter were increased, while histone H4R3 and H3K9 methylation were decreased, in WDR5 knockdown cells compared to controls. We found that WDR5 interacted with HDAC1 and a PHD domaincontaining protein, ING2 (inhibitor of growth), an H3K4me3 mark reader, to enhance γ-globin gene transcriptional repression. In human BMC, levels of WDR5 were highly enriched on the γ-promoter relative to levels on other globin promoters and compared to the γ-promoter in cord blood erythroid progenitors, suggesting that WDR5 is important in the developmental globin gene expression program. Conclusions Our data are consistent with a model in which WDR5 binds the γ-globin promoter in a PRMT5-dependent manner; H3K4me3 induced at the

  16. Modulation of P-glycoprotein by Stemona alkaloids in human multidrug resistance leukemic cells and structural relationships.

    Science.gov (United States)

    Umsumarng, Sonthaya; Pitchakarn, Pornsiri; Yodkeeree, Supachai; Punfa, Wanisa; Mapoung, Sariya; Ramli, Rosdayati Alino; Pyne, Stephen G; Limtrakul, Pornngarm

    2017-10-15

    Multidrug resistance (MDR) is a major reason for the failure of chemotherapy in the treatment of cancer patients. P-gp over-expression in MDR cancer cells is a multifactorial phenomenon with biochemical resistance mechanisms. Stemofoline (STF), isolated from Stemona bukillii, has been reported to be an MDR reversing compound. This study investigated whether other Stemona alkaloids that had been purified from Stemonaceae plants exerted MDR modulation activity. MTT assay was performed to determine the MDR reversing property of the alkaloids. Modulation of P-gp function by these compounds was investigated using cell cycle analysis and P-gp fluorescent substrate accumulation assays. P-gp expression was determined by Western blot analysis. We preliminarily examined the safety of these compounds in normal human fibroblasts and human peripheral blood mononuclear cells (PBMCs) using the MTT assay, and in red blood cells (human and rat) through in vitro hemolysis assays. Three of the eight alkaloids tested, isostemofoline (ISTF), 11Z -didehydrostemofoline (11Z-DSTF) and 11E-didehydrostemofoline (11E-DSTF), enhanced the chemotherapeutic sensitivity of MDR leukemic K562/Adr cells, which overexpressed P-gp. The P-gp functional studies showed that these three alkaloids increased the accumulation of P-gp substrates, calcein-AM (C-AM) and rhodamine123 (Rho 123) in K562/Adr cells, while this effect was not seen in drug sensitive parental K562 cells. Whereas, the alkaloids did not alter P-gp expression as was determined by Western blotting analysis. The alkaloids reversed MDR via the inhibition of P-gp function. For pharmaceutical safety testing, the alkaloids were found to be not toxic to normal human fibroblasts and PBMCs. Moreover, the effective compounds did not induce hemolysis in either human or rat erythrocytes. These compounds may be introduced as potential candidate molecules for treating cancers exhibiting P-gp-mediated MDR. Copyright © 2017 Elsevier GmbH. All rights

  17. Myricetin is a novel inhibitor of human inosine 5′-monophosphate dehydrogenase with anti-leukemia activity

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Huiling; Hu, Qian; Wang, Jingyuan; Liu, Zehui; Wu, Dang [Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237 (China); Lu, Weiqiang, E-mail: wqlu@bio.ecnu.edu.cn [Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, 500 Dongchuan Road, Shanghai 200241 (China); Huang, Jin, E-mail: huangjin@ecust.edu.cn [Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237 (China)

    2016-09-02

    Human inosine 5′-monophosphate dehydrogenase (hIMPDH) is a rate-limiting enzyme in the de novo biosynthetic pathway of purine nucleotides, playing crucial roles in cellular proliferation, differentiation, and transformation. Dysregulation of hIMPDH expression and activity have been found in a variety of human cancers including leukemia. In this study, we found that myricetin, a naturally occurring phytochemical existed in berries, wine and tea, was a novel inhibitor of human type 1 and type 2 IMPDH (hIMPDH1/2) with IC{sub 50} values of 6.98 ± 0.22 μM and 4.10 ± 0.14 μM, respectively. Enzyme kinetic analysis using Lineweaver-Burk plot revealed that myricetin is a mix-type inhibitor for hIMPDH1/2. Differential scanning fluorimetry and molecular docking simulation data demonstrate that myricetin is capable of binding with hIMPDH1/2. Myricetin treatment exerts potent anti-proliferative and pro-apoptotic effects on K562 human leukemia cells in a dose-dependent manner. Importantly, cytotoxicity of myricetin on K562 cells were markedly attenuated by exogenous addition of guanosine, a salvage pathway of maintaining intracellular pool of guanine nucleotides. Taking together, these results indicate that natural product myricetin exhibits potent anti-leukemia activity by interfering with purine nucleotides biosynthetic pathway through the suppression of hIMPDH1/2 catalytic activity. - Highlights: • Myricetin, a common dietary flavonoid, is a novel inhibitor of hIMPDH1/2. • Myricetin directly binds with hIMPDH1/2 and induces cell cycle arrest and apoptosis of leukemia cells. • The cytotoxicity of myricetin on K562 cells is markedly attenuated by exogenous addition of guanosine.

  18. Pycnogenol induces differentiation and apoptosis in human promyeloid leukemia HL-60 cells.

    Science.gov (United States)

    Huang, W W; Yang, J S; Lin, C F; Ho, W J; Lee, M R

    2005-06-01

    Pycnogenol, rich of many phytochemicals of medical value, is a commercialized nutrient supplement extracted from the bark of European coastal pine. In this study, we investigated the anti-tumor effects of Pycnogenol on HL-60, U937 and K562 human leukemia cell lines. We found that Pycnogenol inhibited cell proliferation dose- and time-dependently, and the IC(50)s of Pycnogenol on HL-60, U937 and K562 cells were 150, 40 and 100 microg/ml, respectively. When HL-60 cells were incubated with low concentrations of Pycnogenol (50, 100 and 125 microg/ml) for 24 h, a prominent G0/G1 arrest was observed, followed by gradual accumulation of sub-G0/G1 nuclei. At 48 h of treatment, 50-70% of HL-60 cells differentiated, as evidenced by morphological changes, NBT reduction, induction of NSE activity, and increases of cell surface expression of CD11b. However, results from Annexin V/PI staining, DAPI staining and DNA fragmentation assay indicated that Pycnogenol induced HL-60, U937 and K562 cell apoptosis at their respective IC(50)s after 24 h of treatments. Pretreatment of z-DEVD-fmk, a caspase-3 specific inhibitor, not only decreased caspase-3 activity but also reduced the percentage of apoptotic cells induced by Pycnogenol. This indicated that caspase-3 activation was involved in Pycnogenol induced-apoptosis. In conclusion, Pycnogenol induced differentiation and apoptosis in leukemia cells. Our data suggest that Pycnogenol could serve as a potent cancer chemopreventive or chemotherapeutic agent for human leukemia.

  19. Effect of decitabine in combination with modified CAG regimen in 4 cases of acute erythroleukemia%地西他滨联合改良CAG方案治疗急性红白血病4例

    Institute of Scientific and Technical Information of China (English)

    张琪; 杨华; 牛建花; 朱成英; 朱海燕; 姚子龙; 于力; 靖彧

    2013-01-01

    目的:了解地西他滨联合阿柔比星(Acla)+阿糖胞苷(Ara-C)+重组人粒细胞刺激因子(G-CSF)的方案(DCAG)治疗急性红白血病(AML-M6)的疗效及不良反应。方法应用地西他滨联合CAG方案化疗,治疗4例急性红白血病患者:地西他滨20 mg/m2,1次/d,5 d;重组人粒细胞刺激因子300μg,1次/d,使用时间为化疗前1 d至中性粒细胞恢复;阿糖胞苷10 mg/m2,1次/12小时,5 d;阿柔比星20 mg,第1、3、5天使用。观察疗效及不良反应。结果4例急性红白血病患者中,2例完全缓解(CR),2例部分缓解(PR),治疗过程中不良反应轻微,病人可耐受。结论 DCAG方案治疗急性红白血病缓解率好,不良反应轻,可以作为急性红白血病诱导化疗的备选方案。%Objective To investigate the effect and side effect of decitabine in combination with Acla + Ara-C + G-CSF regimen on acute erythroleukemia.Methods Four patients with acute erythroleukemia were treated with decitabine in combination with CAG regimen. The effect and side effect of decitabine (20 mg/m2, once a day for 5 days), G-CSF (300μg, once a day from the day before chemotherapy to leukocyte recovery), Ara-C (10 mg/m2, twice a day for 5 days), Acla (20 mg on days 1, 3, and 5) were observed. Results Of the 4 cases of acute erythroleukemia, 2 were completely recovered, 2 were partially recovered with mild adverse reactions during treatment.Conclusion The effect of decitabine in combination with CAG regimen on acute erythroleukemia is good with mild adverse reactions, and can thus be used an alternative regimen for acute erythroleukemia.

  20. CLONING PROMOTER OF HUMAN SATB1 GENE AND EFFECT OF ATRA AND CoCl2 ON ITS ACTIVITY

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Objective To explore the structure and activity of SATB1 promoter in different cells, ATRA and CoCl2 effect on its activity. Methods Using luciferase system to assay the promoter activity of human SATB1 gene, three luciferase reporter vectors were constructed which driven by different regions of 5' untranslated sequence from human SATB1 gene, called pGL3-SP2946-luc, pGL3-SP1718-luc and pGL3-SP751-luc, and transfected into Jurkat T, K562, U937 and Hela cells transiently using lipofectinamine, the expression activity was detected at different dosage of ATRA and CoCl2 treatment for different time course. Results The reporter gene expression from SATB1 promoter were high activity in U937 cell, moderate in Jurkat T cell, low activity in K562 cell and showed no obvious activity in Hela cell, the reporter gene expression from pGL3-SP751-luc kept on the higher lever in Jurkat T, K562 and U937 cells than the other two vectors. We also found that the repressive effect of CoCl2 on SATB1 's mRNA expression and the relative luciferase expression from pGL3-SP751-luc in U937 cell was down-regulated obviously by ATRA and CoCl2 in the concentration- and time-dependent manners. Conclusion SATB1 promoter drives gene expression with cell-specificity and its core promoter region maybe exist in the - 751 ~ - 9bp of 5' untranslated region of human SATB1 gene. Combined with the experiment result we found before that SATB1 was down-regulated by ATRA in U937, the results imply that STAB1 maybe is down-regulated by ATRA and CoCl2 through its promoter in the differentiation of myeloid cell line-U937.

  1. Protein kinase clk/STY is differentially regulated during erythroleukemia cell differentiation: a bias toward the skipped splice variant characterizes postcommitment stages

    Institute of Scientific and Technical Information of China (English)

    Ana GARC(I)A-SACRIST(A)N; María J.FERN(A)NDEZ-NESTOSA; Pablo HERN(A)NDEZ; Jorge B.SCHVARTZMAN; Dora B.KRIMER

    2005-01-01

    Clk/STY is a LAMMER protein kinase capable to phosphorylate serine/arginine-rich (SR) proteins that modulate premRNA splicing.Clk/STY alternative splicing generates transcripts encoding a full-length kinase and a truncated catalytically inactive protein.Here we showed that clk/STY,as well as other members of the family (e.g.clk2,clk3 and clk4),are up-regulated during HMBA-induced erythroleukemia cell differentiation.mRNAs coding for the full-length and the truncated forms were responsible for the overall increased expression.In clk/STY,however,a switch was observed for the ratio of the two alternative spliced products.In undifferentiated cells the full-length transcript was more abundant whereas the transcript encoding for the truncated form predominated at latter stages of differentiation.Surprisingly,overexpression of clk/STY did not alter the splicing switch upon differentiation in MEL cells.These results suggest that clk/STY might contribute to control erythroid differentiation by a mechanism that implicates a balance between these two isoforms.

  2. Cloning and characterization of polyA- RNA transcripts encoded by activated B1-like retrotransposons in mouse erythroleukemia MEL cells exposed to methylation inhibitors.

    Science.gov (United States)

    Tezias, Sotirios S; Tsiftsoglou, Asterios S; Amanatiadou, Elsa P; Vizirianakis, Ioannis S

    2012-02-01

    We have previously identified a DNA silent region located downstream of the 3'-end of the β(major) globin gene (designated B1-559) that contains a B1 retrotransposon, consensus binding sites for erythroid specific transcription factors and shares the capacity to act as promoter in hematopoietic cells interacting with β-globin gene LCR sequences in vitro. In this study, we have cloned four new non-polyA RNA transcripts being detected upon blockade of murine erythroleukemia (MEL) cell differentiation to erythroid maturation by methylation inhibitors and demonstrated that two of them share high structural homology with sequences of B1 element found within the B1-559 region. Although it is not clear yet whether and how these RNAs interfere with induction of erythroid maturation, these data provide evidence for the first time showing that methylation inhibitors can activate silent repetitive DNA sequences in MEL cells and may have implications in cancer chemotherapy using demethylating drugs as antineoplastic agents.

  3. Caspase-independent apoptosis in Friend's erythroleukemia cells: role of mitochondrial ATP synthesis impairment in relocation of apoptosis-inducing factor and endonuclease G.

    Science.gov (United States)

    Comelli, Marina; Genero, Nadia; Mavelli, Irene

    2009-02-01

    Mitochondria have emerged as the central components of both caspase-dependent and independent apoptosis signalling pathways through release of different apoptogenic proteins. We previously documented that parental and differentiated Friend's erythroleukemia cells were induced to apoptosis by oligomycin and H(2)O(2) exposure, showing that the energy impairment occurring in both cases as a consequence of a severe mitochondrial F(0)F(1)ATPsynthase inactivation was a common early feature. Here we provide evidence for AIF and Endo G mitochondrio-nuclear relocation in both cases, as a component of caspase-independent apoptosis pathways. No detectable change in mitochondrial transmembrane potential and no variation in mitochondrial levels of Bcl-2 and Bax are observed. These results point to the osmotic rupture of the mitochondrial outer membrane as occurring in response to cell exposure to the two energy-impairing treatments under conditions preserving the mitochondrial inner membrane. A critical role of the mitochondrial F(0)F(1)ATP synthase inhibition in this process is also suggested.

  4. Eos negatively regulates human γ-globin gene transcription during erythroid differentiation.

    Directory of Open Access Journals (Sweden)

    Hai-Chuan Yu

    Full Text Available BACKGROUND: Human globin gene expression is precisely regulated by a complicated network of transcription factors and chromatin modifying activities during development and erythropoiesis. Eos (Ikaros family zinc finger 4, IKZF4, a member of the zinc finger transcription factor Ikaros family, plays a pivotal role as a repressor of gene expression. The aim of this study was to examine the role of Eos in globin gene regulation. METHODOLOGY/PRINCIPAL FINDINGS: Western blot and quantitative real-time PCR detected a gradual decrease in Eos expression during erythroid differentiation of hemin-induced K562 cells and Epo-induced CD34+ hematopoietic stem/progenitor cells (HPCs. DNA transfection and lentivirus-mediated gene transfer demonstrated that the enforced expression of Eos significantly represses the expression of γ-globin, but not other globin genes, in K562 cells and CD34+ HPCs. Consistent with a direct role of Eos in globin gene regulation, chromatin immunoprecipitaion and dual-luciferase reporter assays identified three discrete sites located in the DNase I hypersensitivity site 3 (HS3 of the β-globin locus control region (LCR, the promoter regions of the Gγ- and Aγ- globin genes, as functional binding sites of Eos protein. A chromosome conformation capture (3C assay indicated that Eos may repress the interaction between the LCR and the γ-globin gene promoter. In addition, erythroid differentiation was inhibited by enforced expression of Eos in K562 cells and CD34+ HPCs. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that Eos plays an important role in the transcriptional regulation of the γ-globin gene during erythroid differentiation.

  5. Expression of Glycosylphosphatidylinositol-Anchored CD59 on Target Cells Enhances Human NK Cell-Mediated Cytotoxicity1

    OpenAIRE

    2006-01-01

    NK cell-mediated cytotoxicity of target cells is the result of a balance between the activating and inhibitory signals provided by their respective ligand-receptor interactions. In our current study, we have investigated the significance of CD59 on human target cells in modulating this process. A range of CD59 site-specific Abs were used in NK cytotoxicity blocking studies against the CD59-expressing K562 target cell line. Significantly reduced cytotoxicity was observed in the presence of Abs...

  6. Resveratrol-induced transcriptional up-regulation of ASMase (SMPD1) of human leukemia and cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Mizutani, Naoki [Department of Pathophysiological Laboratory Science, Nagoya University Graduate School of Medicine, Nagoya (Japan); College of Life and Health Sciences, Chubu University, Kasugai (Japan); Omori, Yukari [Department of Pathophysiological Laboratory Science, Nagoya University Graduate School of Medicine, Nagoya (Japan); Kawamoto, Yoshiyuki; Sobue, Sayaka; Ichihara, Masatoshi [College of Life and Health Sciences, Chubu University, Kasugai (Japan); Suzuki, Motoshi [Division of Molecular Carcinogenesis, Nagoya University Graduate School of Medicine, Nagoya (Japan); Kyogashima, Mamoru [Department of Microbiology and Molecular Biology, Nihon Pharmaceutical University, Saitama (Japan); Nakamura, Mitsuhiro [Department of Drug Information, Gifu Pharmaceutical University, Gifu (Japan); Tamiya-Koizumi, Keiko [College of Life and Health Sciences, Chubu University, Kasugai (Japan); Nozawa, Yoshinori [Tokai Gakuin University, Kakamigahara (Japan); Murate, Takashi, E-mail: murate@isc.chubu.ac.jp [College of Life and Health Sciences, Chubu University, Kasugai (Japan)

    2016-02-19

    Resveratrol (RSV) is a plant-derived phytoalexin present in plants, whose pleiotropic effects for health benefits have been previously reported. Its anti-cancer activity is among the current topics for novel cancer treatment. Here, effects of RSV on cell proliferation and the sphingolipid metabolism of K562, a human leukemia cell line, were analyzed. Some experiments were also performed in HCT116, a human colon cancer cell line. RSV inhibited cell proliferation of both cell lines. Increased cellular ceramide and decreased sphingomyelin and S1P by RSV were observed in RSV-treated K562 cells. Further analysis revealed that acid sphingomyelinase mRNA and enzyme activity levels were increased by RSV. Desipramine, a functional ASMase inhibitor, prevented RSV-induced ceramide increase. RSV increased ATF3, EGR1, EGR3 proteins and phosphorylated c-Jun and FOXO3. However, co-transfection using these transcription factor expression vectors and ASMase promoter reporter vector revealed positive effects of EGR1 and EGR3 but not others. Electrophoresis mobility shift assay (EMSA) and Chromatin immunoprecipitation (ChIP) assay demonstrated the direct binding of EGR1/3 transcription factors with ASMase 5′-promoter. These results indicate that increased EGR1/3 and ASMase expression play an important role in cellular ceramide increase by RSV treatment. - Highlights: • Resveratrol inhibited cell proliferation of K562 and HCT116 cells. • Resveratrol increased cellular ceramide and decreased sphingomyelin and S1P. • ASMase mRNA and activity were increased with resveratrol. • ASMase inhibition suppressed RSV-induced ceramide accumulation. • Increased ASMase transcription was at least partially due to EGR family proteins.

  7. Apoptosis induction in human leukemic cells by a novel protein Bengalin, isolated from Indian black scorpion venom: through mitochondrial pathway and inhibition of heat shock proteins.

    Science.gov (United States)

    Gupta, Shubho Das; Gomes, Antony; Debnath, Anindita; Saha, Archita; Gomes, Aparna

    2010-01-27

    Scorpion venom possesses protein toxins having numerous biological activities, some of which are potentially anticancerous. Previously we had reported antiproliferative activity of the venom of Indian black scorpion, Heterometrus bengalensis Koch. Here we have isolated and purified a novel protein named Bengalin (72kDa) from the venom, responsible for antiproliferative and apoptogenic activities against human leukemic cells U937 (histiocytic lymphoma) and K562 (chronic myelogenous leukemia). N-terminal sequence of first 20 amino acids of Bengalin was G-P-L-T-I-L-H-I-N-D-V-H-A-A/R-F-E-Q/G-F/G-N-T. Bengalin induced cell growth inhibition at IC(50) values of 3.7 and 4.1 microg/ml for U937 and K562 cells respectively did not significantly affect normal human lymphocytes. Inhibition of U937 and K562 cell proliferation occurred by apoptosis as evidenced from damaged nuclei, cell cycle arrest at sub G1 phase, increase of early apoptotic cells, augmentation of DNA fragmentation and also a reduction of telomerase activity. Further insights revealed that Bax:Bcl2 ratio was elevated after Bengalin treatment. Moreover Bengalin elicited loss of mitochondrial membrane potential (MMP) which commenced cytochrome c release in cytosol, decreased heat shock protein (HSP) 70 and 90 expression, activated caspase-9, caspase-3 and induced poly(ADP-ribose) polymerase (PARP) cleavage. We have also determined that HSP70 and 90 inhibitions correlated with Bengalin induced antiproliferation, caspase-3 upregulation, apoptogenesis and increased DNA fragmentation. These results hypothesize that Bengalin might provide a putative molecular mechanism for their anticancer effect on human leukemic cells which might be mediated by mitochondrial death cascade. Inhibition of HSPs might also play a crucial role in induction of apoptosis.

  8. Experiment list: SRX069159 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available al_provider=ATCC || cell=K562 || cell organism=Human || cell description=leukemia || cell karyotype=cancer || cell lineage=The contin...uous cell line K-562 was established by Lozzio and Lozzi

  9. Experiment list: SRX069222 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available al_provider=ATCC || cell=K562 || cell organism=Human || cell description=leukemia || cell karyotype=cancer || cell lineage=The contin...uous cell line K-562 was established by Lozzio and Lozzi

  10. Experiment list: SRX037116 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available al_provider=ATCC || cell=K562 || cell organism=Human || cell description=leukemia || cell karyotype=cancer || cell lineage=The contin...uous cell line K-562 was established by Lozzio and Lozzi

  11. A comparison of cytotoxicity of some phosphoramides against K562 cell line

    Directory of Open Access Journals (Sweden)

    niloufar Dorosti

    2012-03-01

    Conclusion: Since hydrogen bonds play a key role in biology processes, these results suggest that increase in the hydrogen bonds of derivatives bearing urea moiety (4-6 may be increase cytotoxicity of these compounds. Moreover, the 3-NO2 group showed higher anti-cancer activity than two other positions owing to possibility electronic and steric effects.

  12. Co-induction of c-fos and junB during the latent period preceding commitment of Friend erythroleukemia cells to differentiation.

    Science.gov (United States)

    Francastel, C; Mazouzi, Z; Robert-Lézénès, J

    1992-09-01

    Chemically induced differentiation of Friend murine erythroleukemia cells (F-MELC) is a multistep process with a latent period of about 12 h preceding irreversible commitment to terminal maturation. To gain understanding of the early genetic response of F-MELC to the dimethyl sulfoxide (DMSO) inducer of F-MELC differentiation, we have investigated by Northern blot analysis the expression of fos and jun family genes that encode components of the transcription factor AP-1 complex. Our results show that c-jun mRNA is not detected at any time in untreated and DMSO-treated F-MELC. In contrast, DMSO-induced differentiation of F-MELC is associated with an early and transient induction of c-fos and junB mRNAs by 2 to 8 h treatment while in presence of dexamethasone, an inhibitor of F-MELC commitment, c-fos mRNA is not detected and junB mRNA remains at basal levels. junD mRNA is detected at low levels in untreated F-MELC and remains unchanged during DMSO treatment. Furthermore, DMSO treatment in a F-MELC cell line resistant to DMSO-differentiation does not result in an early induction of c-fos and junB mRNAs. Taken together, these results indicate that the DMSO-induced F-MELC differentiation is accompanied by an early co-induction of c-fos and junB during the latent period preceding the commitment to erythroid maturation.

  13. A Metabolic Biofuel Cell: Conversion of Human Leukocyte Metabolic Activity to Electrical Currents

    Directory of Open Access Journals (Sweden)

    Cui X Tracy

    2011-05-01

    Full Text Available Abstract An investigation of the electrochemical activity of human white blood cells (WBC for biofuel cell (BFC applications is described. WBCs isolated from whole human blood were suspended in PBS and introduced into the anode compartment of a proton exchange membrane (PEM fuel cell. The cathode compartment contained a 50 mM potassium ferricyanide solution. Average current densities between 0.9 and 1.6 μA cm-2 and open circuit potentials (Voc between 83 and 102 mV were obtained, which were both higher than control values. Cyclic voltammetry was used to investigate the electrochemical activity of the activated WBCs in an attempt to elucidate the mechanism of electron transfer between the cells and electrode. Voltammograms were obtained for the WBCs, including peripheral blood mononuclear cells (PBMCs - a lymphocyte-monocyte mixture isolated on a Ficoll gradient, a B lymphoblastoid cell line (BLCL, and two leukemia cell lines, namely K562 and Jurkat. An oxidation peak at about 363 mV vs. SCE for the PMA (phorbol ester activated primary cells, with a notable absence of a reduction peak was observed. Oxidation peaks were not observed for the BLCL, K562 or Jurkat cell lines. HPLC confirmed the release of serotonin (5-HT from the PMA activated primary cells. It is believed that serotonin, among other biochemical species released by the activated cells, contributes to the observed BFC currents.

  14. Simvastatin induces NFκB/p65 down-regulation and JNK1/c-Jun/ATF-2 activation, leading to matrix metalloproteinase-9 (MMP-9) but not MMP-2 down-regulation in human leukemia cells.

    Science.gov (United States)

    Chen, Ying-Jung; Chang, Long-Sen

    2014-12-15

    The aim of the present study was to explore the signaling pathways associated with the effect of simvastatin on matrix metalloproteinase-2 (MMP-2)/MMP-9 expression in human leukemia K562 cells. In sharp contrast to its insignificant effect on MMP-2, simvastatin down-regulated MMP-9 protein expression and mRNA levels in K562 cells. Simvastatin-induced Pin1 down-regulation evoked NFκB/p65 degradation. Meanwhile, simvastatin induced JNK-mediated c-Jun and ATF-2 activation. Over-expression of Pin1 suppressed simvastatin-induced MMP-9 down-regulation. Treatment with SP600125 (a JNK inhibitor) or knock-down of JNK1 reduced MMP-2 expression in simvastatin-treated cells. Simvastatin enhanced the binding of c-Jun/ATF-2 with the MMP-2 promoter. Down-regulation of c-Jun or ATF-2 by siRNA revealed that c-Jun/ATF-2 activation was crucial for MMP-2 expression. Suppression of p65 activation or knock-down of Pin1 by shRNA reduced MMP-2 and MMP-9 expression in K562 cells. Over-expression of constitutively active JNK1 rescued MMP-2 expression in Pin1 shRNA-transfected cells. Simvastatin treatment also suppressed MMP-9 but not MMP-2 expression in human leukemia U937 and KU812 cells. Taken together, our data indicate that simvastatin-induced p65 instability leads to MMP-9 down-regulation in leukemia cells, while simvastatin-induced JNK1/c-Jun/ATF-2 activation maintains the MMP-2 expression underlying p65 down-regulation. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Apoptosis Induction in Human Leukemia Cell Lines by Gold Nanoparticles Synthesized Using the Green Biosynthetic Approach

    Directory of Open Access Journals (Sweden)

    Farideh Namvar

    2015-01-01

    Full Text Available Gold nanoparticles were grown on Sargassum muticum water extract (S-GNPs using the green biosynthetic approach. The nanoparticles were characterized using UV-visible spectroscopy, zeta potential, and transmission electron microscopy (TEM. The resulting S-GNPs were spherical and crystalline with a size of <10 nm. The in vitro anticancer activity was demonstrated in human leukemia cell lines. The cancer cells were treated with different concentrations of S-GNPs, and calorimetric (MTT assay used for the cytotoxicity test, which resulted in an IC50 value of 4.22 ± 1.12, 5.71 ± 1.4, 6.55 ± 0.9, and 7.29 ± 1.7 μg/mL for each of the K562, HL-60, Jurkat, and CEM-ss cells, respectively. Thus, the K562 was selected for the next experiments. Furthermore, apoptosis induction was confirmed by Hoechst 33342, annexin V staining, and caspase-3/-9 activity tests. The cell cycle analysis exhibited a significant increase in the accumulation of S-GNPs treated cells at the sub-G1 phase, demonstrating the induction of apoptosis by S-GNPs. The nature of the inhibition of cancer cell growth by S-GNPs could open the way for further research in the design of green synthesis therapeutic agents, particularly in nanomedicine, for the treatment of cancer.

  16. Triptolide Inhibits Cyclooxygenase-2 and Inducible Nitric Oxide Synthase Expression in Human Colon Cancer and Leukemia Cells

    Institute of Scientific and Technical Information of China (English)

    Xiangmin TONG; Shui ZHENG; Jie JIN; Lifen ZHU; Yinjun LOU; Hangping YAO

    2007-01-01

    Triptolide (TP), a traditional Chinese medicine, has been reported to be effective in the treatment of autoimmune diseases and exerting antineoplastic activity in several human tumor cell lines. This study investigates the antitumor effect of TP in human colon cancer cells (SW114) and myelocytic leukemia (K562), and elucidates the possible molecular mechanism involved. SW114 and K562 cells were treated with different doses of TP (0, 5, 10, 20, or 50 ng/ml). The cell viability was assessed by 3-[4,5-dimethylthiazol2-yl]-2,5-diphenyltetrazolium bromide (MTT). Results demonstrated that TP inhibited the proliferation of both tumor cell lines in a dose-dependent manner. To further investigate its mechanisms, the products prostaglandin E2 (PGE2) and nitric oxide (NO) were measured by enzyme-linked immunosorbent assay (ELISA). Our data showed that TP strongly inhibited the production of NO and PGE2. Consistent with these results, the expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) was up-regulated both at the mRNA level and the protein expression level, as shown by real-time RT-PCR and Western blotting. These results indicated that the inhibition of the inflammatory factor COX-2 and iNOS activity could be involved in the antitumor mechanisms of TP.

  17. Induction of apoptosis and inhibition of proliferation in human tumor cells treated with extracts of Uncaria tomentosa.

    Science.gov (United States)

    Sheng, Y; Pero, R W; Amiri, A; Bryngelsson, C

    1998-01-01

    Growth inhibitory activities of novel water extracts of Uncaria tomentosa (C-Med-100) were examined in vitro using two human leukemic cell lines (K562 and HL60) and one human EBV-transformed B lymphoma cell line (Raji). The proliferative capacities of HL60 and Raji cells were strongly suppressed in the presence of the C-Med-100 while K562 was more resistant to the inhibition. Furthermore, the antiproliferative effect was confirmed using the clonogenic assay, which showed a very close correlation between C-Med-100 concentration and the surviving fraction. The suppressive effect of Uncaria tomentosa extracts on tumor cell growth appears to be mediated through induction of apoptosis which was demonstrated by characteristic morphological changes, internucleosomal DNA fragmentation after agarose gel electrophoresis and DNA fragmentation quantification. C-Med-100 induced a delayed type of apoptosis becoming most dose-dependently prominent after 48 hours of exposure. Both DNA single and double strand breaks were increased 24 hours after C-Med-100 treatment, which suggested a well-established linkage between the DNA damage and apoptosis. The induction of DNA strand breaks coupled to apoptosis may explain the growth inhibition of the tumor cells by Uncaria tomentosa extracts. These results provide the first direct evidence for the antitumor properties of Uncaria tomentosa extracts to be via a mechanism of selective induction of apoptosis.

  18. Discovery of 3H-Benzo[4,5]thieno[3,2-d]pyrimidin-4-ones as Potent, Highly Selective, and Orally Bioavailable Inhibitors of the Human Protooncogene Proviral Insertion Site in Moloney Murine Leukemia Virus (PIM) Kinases

    Energy Technology Data Exchange (ETDEWEB)

    Tao, Zhi-Fu; Hasvold, Lisa A.; Leverson, Joel D.; Han, Edward K.; Guan, Ran; Johnson, Eric F.; Stoll, Vincent S.; Stewart, Kent D.; Stamper, Geoff; Soni, Nirupama; Bouska, Jennifer J.; Luo, Yan; Sowin, Thomas J.; Lin, Nan-Horng; Giranda, Vincent S.; Rosenberg, Saul H.; Penning, Thomas D.; (Abbott)

    2010-02-19

    Pim-1, Pim-2, and Pim-3 are a family of serine/threonine kinases which have been found to be overexpressed in a variety of hematopoietic malignancies and solid tumors. Benzothienopyrimidinones were discovered as a novel class of Pim inhibitors that potently inhibit all three Pim kinases with subnanomolar to low single-digit nanomolar K{sub i} values and exhibit excellent selectivity against a panel of diverse kinases. Protein crystal structures of the bound Pim-1 complexes of benzothienopyrimidinones 3b (PDB code 3JYA), 6e (PDB code 3JYO), and 12b (PDB code 3JXW) were determined and used to guide SAR studies. Multiple compounds exhibited potent antiproliferative activity in K562 and MV4-11 cells with submicromolar EC{sub 50} values. For example, compound 14j inhibited the growth of K562 cells with an EC{sub 50} value of 1.7 {micro}M and showed K{sub i} values of 2, 3, and 0.5 nM against Pim-1, Pim-2, and Pim-3, respectively. These novel Pim kinase inhibitors efficiently interrupted the phosphorylation of Bad in both K562 and LnCaP-Bad cell lines, indicating that their potent biological activities are mechanism-based. The pharmacokinetics of 14j was studied in CD-1 mice and shown to exhibit bioavailability of 76% after oral dosing. ADME profiling of 14j suggested a long half-life in both human and mouse liver microsomes, good permeability, modest protein binding, and no CYP inhibition below 20 {micro}M concentration.

  19. Hemoglobin switching in man and chicken is mediated by a heteromeric complex between the ubiquitous transcription factor CP2 and a developmentally specific protein.

    Science.gov (United States)

    Jane, S M; Nienhuis, A W; Cunningham, J M

    1995-01-03

    The human stage selector protein (SSP) has been implicated in the developmental regulation of the globin genes. Binding of SSP to the stage selector element (SSE) in the proximal gamma-globin promoter is integral to the competitive silencing of a linked beta-promoter in embryonic/fetal stage erythroleukemia (K562) cells. We now report the biochemical purification of SSP from K562 cell nuclear extract and demonstrate that the ubiquitously expressed transcription factor CP2 is pivotal to, but not sufficient for, SSP binding activity. Although addition of anti-CP2 antiserum disrupts the formation of the SSP-SSE complex in the electrophoretic mobility shift assay (EMSA), recombinant CP2 fails to bind to the SSE. Binding of CP2 to the SSE requires a heterodimeric partner present in K562 cells. We have defined the molecular weight of the partner protein as 40-45 kDa in UV and protein cross-linking experiments. An element analogous to the human SSE has previously been demonstrated in the chicken beta A-gene-promoter. The effects of this element are dependent on the binding of the chicken stage selector protein, NF-E4. Comparative studies between human CP2 and chicken NF-E4 demonstrate homology between the protein complexes. SSP binds to the chicken SSE and formation of this complex is ablated by the addition of anti-CP2 antiserum or a monoclonal antibody to NF-E4. Western analysis of partially purified NF-E4 using anti-CP2 antiserum or the NF-E4 monoclonal antibody both demonstrate a dominant band at 66 kDa. Similarly, the NF-E4 antibody recognizes the 66 kDa human CP2 protein in Western analysis of the SSP-SSE complex.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Regulation of synthesis and activity of NAD(+)-dependent 15-hydroxy-prostaglandin dehydrogenase (15-PGDH) by dexamethasone and phorbol ester in human erythroleukemia (HEL) cells

    Energy Technology Data Exchange (ETDEWEB)

    Xun, C.Q.; Ensor, C.M.; Tai, H.H. (Univ. of Kentucky, Lexington (USA))

    1991-06-28

    Dexamethasone stimulated 15-PGDH activity in HEL cells in a time and concentration dependent manner. Increase in 15-PGDH activity by dexamethasone was found to be accompanied by an increase in enzyme synthesis as revealed by Western blot and (35S)methionine labeling studies. In addition to dexamethasone, other anti-inflammatory steroids also increased 15-PGDH activity in the order of their glucocorticoid activity. Among sex steroids only progesterone increased significantly 15-PGDH activity. 12-0-Tetradecanoylphorbol-13-acetate (TPA) also induced the synthesis of 15-PGDH but inhibited the enzyme activity. It appears that TPA caused a time dependent inactivation of 15-PGDH by a protein kinase C mediated mechanism.

  1. Mean diameter of nucleolar bodies in cultured human leukemic myeloblasts is mainly related to the S and G2 phase of the cell cycle

    Directory of Open Access Journals (Sweden)

    K Smetana

    2009-08-01

    Full Text Available Mean diameter of nucleolar bodies (nucleoli without the perinucleolar chromatin per cell was studied in human leukemic myeloblasts represented by K 562 and Kasumi 1 cell lines which originated from chronic and acute myeloid leukaemia. The measurement of mean diameter of nucleolar bodies in specimens stained for RNA was very simple. Such approach eliminated the variability of the perinucleolar chromatin discontinuous shell which might influence the measured nucleolar size as suggested by earlier studies. Ageing of K 562 myeloblasts produced a significant decrease of cells in S+G2 phase of the cell cycle accompanied by a significant reduction of mean diameter of nucleolar bodies (MDNoBs per cell. In contrast, treatment of Kasumi 1 myeloblasts with histone deacetylase inhibitor - Trichostatin A - produced a large incidence of resistant cells in S+G2 phase which were characterised by a large increase of MDNoBs. Thus, MDNoBs in leukemic myeloblasts might be a helpful tool to estimate the incidence of cells in the S+G2 phase at the single cell level in smear preparations when the number of cells is very small.

  2. [Mitochondria-targeted antioxidant SkQR1 selectively protects MDR-negative cells against ionizing radiation].

    Science.gov (United States)

    Fetisova, E K; Antoshina, M M; Cherepanynets, V D; Izumov, D S; Kireev, I I; Kireev, R I; Lyamzaev, K G; Riabchenko, N I; Chernyak, B V; Skulachev, V P

    2014-01-01

    Radioprotection appeared to be an important problem of today due to atom energetic development and utilization of radiation material in the industry, science and medicine. It has been shown that mitochondrial targeted antioxidant SkQR1 could attenuate radiation injury of human erythroleukemia K562 cells. Pretreatment with SkQR1 before irradiation decreased DNA double strand breaks formation, diminished the number of chromosomal aberrations and suppressed delayed ROS production. Prevention of oxidative stress and normalization of mitochondrial function by mitochondria-targeted antioxidants may be a potential therapeutic strategy not only against immediate consequences of radiation, but, either against its late consequences such as genomic instability. SkQR1 did not protect against radiation-induced damage the K562 subline with high level of multidrug resistance (MDR) due to SkQR1 extrusion with Pgp 170 MDR pump. We suggest that mitochondria-targeted antioxidants might be used for selective protection of normal cells against radiation-induced damage without interference with radiotherapy of MDR-positive tumors.

  3. Marijuana effects on immunity: suppression of human natural killer cell activity of delta-9-tetrahydrocannabinol.

    Science.gov (United States)

    Specter, S C; Klein, T W; Newton, C; Mondragon, M; Widen, R; Friedman, H

    1986-01-01

    Delta-9-tetrahydrocannabinol (THC), the major psychoactive component of marijuana, was tested for its ability to modulate human natural killer (NK) cell function. THC was toxic for peripheral blood lymphocytes at 20 micrograms/ml but not at 10 micrograms/ml or less. This component of marijuana also was inhibitory for NK activity against K562, a human tumor cell line at concentrations down to 5 micrograms/ml when pre-incubated with the effector cells. Suppression of NK function was dependent upon the concentration of THC and the length of time of pre-incubation but was independent of the ratio of effector to target cells. Prostaglandins were not involved in suppression of NK activity.

  4. The cytotoxic effects of a novel IH636 grape seed proanthocyanidin extract on cultured human cancer cells.

    Science.gov (United States)

    Ye, X; Krohn, R L; Liu, W; Joshi, S S; Kuszynski, C A; McGinn, T R; Bagchi, M; Preuss, H G; Stohs, S J; Bagchi, D

    1999-06-01

    Grape seed proanthocyanidins are natural antioxidants which possess a broad spectrum of chemoprotective properties against free radicals and oxidative stress. In this study, we have assessed the cytotoxicity of a novel IH636 grape seed proanthocyanidin extract (GSPE) against MCF-7 human breast cancer cells, A-427 human lung cancer cells, CRL-1739 human gastric adenocarcinoma cells and K562 chronic myelogenous leukemic cells at 25 and 50 mg/lit concentrations for 0-72 h using cytomorphology and MTT cytotoxicity assay. In addition, we compared the effects on normal human gastric mucosal cells and normal J774A.1 murine macrophage cells with the effects on the cancer cell lines. Concentration- and time-dependent cytotoxic effects of GSPE were observed on the MCF-7 breast cancer, A-427 lung cancer and gastric adenocarcinoma cells. Following incubation of the MCF-7 cells with 25 mg/lit of the GSPE approximately 6.5, 30 and 43% inhibitions in cell growth were observed at 24, 48 and 72 h of incubation, respectively, while incubation of the MCF-7 cells with 50 mg/lit of the GSPE resulted in 11, 35 and 47% inhibition in cell growth at these same points, respectively. Similar results were observed in the A-427 and gastric adenocarcinoma cells. GSPE exhibited no cytotoxicity toward the neoplastic K562 myelogenous leukemic cells. However, GSPE enhanced the growth and viability of the normal human gastric mucosal cells and J774A.1 murine macrophage cells. These data demonstrate that GSPE exhibited cytotoxicity towards some cancer cells, while enhancing the growth and viability of the normal cells which were examined.

  5. Amsacrine suppresses matrix metalloproteinase-2 (MMP-2)/MMP-9 expression in human leukemia cells.

    Science.gov (United States)

    Liu, Wen-Hsin; Chen, Ying-Jung; Chien, Jen-Hung; Chang, Long-Sen

    2014-05-01

    This study explores the suppression mechanism of amsacrine (4-(9-Acridinylamino)-N-(methanesulfonyl)-m-anisidine hydrochloride) on matrix metalloproteinase-2 (MMP-2) and MMP-9 expression in human leukemia cells. Amsacrine attenuated cell invasion with decreased MMP-2/MMP-9 protein expression and mRNA levels in U937, Jurkat, HL-60, K562, KU812, and MEG-01 cells. Moreover, amsacrine reduced both MMP-2/MMP-9 promoter luciferase activity and MMP-2/MMP-9 mRNA stability in leukemia cells. Studies on amsacrine-treated U937 cells revealed that amsacrine-elicited ROS generation induced JNK and p38 MAPK activation but reduced the phospho-ERK level. Amsacrine-induced ERK inactivation and p38 MAPK/JNK activation were demonstrated to suppress MMP-2/MMP-9 promoter luciferase activity and promote MMP-2/MMP-9 mRNA decay, respectively. p38 MAPK/JNK activation led to up-regulation of protein phosphatase 2A catalytic subunit α (PP2Acα) in amsacrine-treated U937 cells. Okadaic acid (PP2A inhibitor) treatment increased MMP-2/MMP-9 mRNA stability in amsacrine-treated cells, whereas PP2Acα over-expression increased MMP-2/MMP-9 mRNA decay. Amsacrine-induced MMP-2/MMP-9 down-regulation was also related to PP2Acα up-regulation on Jurkat, HL-60, K562, KU812, and MEG-01 cells. Collectively, our data indicate that amsacrine induces MMP-2/MMP-9 down-regulation via simultaneous suppression of genetic transcription and mRNA stability in human leukemia cells.

  6. Perifosine induces protective autophagy and upregulation of ATG5 in human chronic myelogenous leukemia cells in vitro

    Institute of Scientific and Technical Information of China (English)

    Yin TONG; Yan-yan LIU; Liang-shun YOU; Wen-bin QIAN

    2012-01-01

    Aim:The efficacy of the Akt inhibitor perifosine against chronic myeloid leukemia (CML)cells and its mechanisms of action are unknown.In this study,the cytotoxic effects of perifosine on CML and acute myeloid leukemia (AML)cell lines were compared to elucidate the mechanisms underlying the differences.Methods:Human AML cell lines Kasumi-1 and HL-60,and the CML cell line K562 were used.Cell viability was quantitated using MTT assay.Apoptosis was determined using Annexin V-FITC/propidium iodide and Hoechst staining,which were followed by flow cytometry and fluorescence microscopy analysis,respectively.Caspase pathway activation and the expression of autophagy-related genes were examined using Western blot.Autophagy was studied using electron microscopy,the acridine orange staining method,and GFP-LC3 was examined with fluorescence microscopy.Results:In contrast to AML cell lines,the CML cell lines K562 and K562/G (an imatinib-insensitive CML cell line)were resistant to perifosine (2.5-20 μmol/L)in respect to inhibiting cell growth and inducing apoptosis.Perifosine (2.5,5,and 10 μmol/L)inhibited Akt and its phosphorylation in AML cells,but not in CML cells.Treatment with perifosine (20 μmol/L)resulted in autophagy in CML cells as shown by the increased formation of acidic vesicular organelles and the accumulation of LC3-II.Treatment of CML cells with perifosine (5,10,and 20 μmol/L)dose-dependently upregulated AGT5,but not Beclin 1 at the protein level.Furthermore,inhibition of autophagyby chloroquine (40 nmol/L)significantly suppressed the cell growth and induced apoptosis in CML cells treated with perifosine (20 μmol/L).Conclusion:Our results show that CML cell lines were resistant to the Akt inhibitor perifosine in vitro,which is due to perifosine-induced protective autophagy and upregulation of ATG5.

  7. Proteolysis by sourdough lactic acid bacteria: effects on wheat flour protein fractions and gliadin peptides involved in human cereal intolerance.

    Science.gov (United States)

    Di Cagno, Raffaella; De Angelis, Maria; Lavermicocca, Paola; De Vincenzi, Massimo; Giovannini, Claudio; Faccia, Michele; Gobbetti, Marco

    2002-02-01

    Sourdough lactic acid bacteria were preliminarily screened for proteolytic activity by using a digest of albumin and globulin polypeptides as a substrate. Based on their hydrolysis profile patterns, Lactobacillus alimentarius 15M, Lactobacillus brevis 14G, Lactobacillus sanfranciscensis 7A, and Lactobacillus hilgardii 51B were selected and used in sourdough fermentation. A fractionated method of protein extraction and subsequent two-dimensional electrophoresis were used to estimate proteolysis in sourdoughs. Compared to a chemically acidified (pH 4.4) dough, 37 to 42 polypeptides, distributed over a wide range of pIs and molecular masses, were hydrolyzed by L. alimentarius 15M, L. brevis 14G, and L. sanfranciscensis 7A. Albumin, globulin, and gliadin fractions were hydrolyzed, while glutenins were not degraded. The concentrations of free amino acids, especially proline and glutamic and aspartic acids, also increased in sourdoughs. Compared to the chemically acidified dough, proteolysis by lactobacilli positively influenced the softening of the dough during fermentation, as determined by rheological analyses. Enzyme preparations of the selected lactobacilli which contained proteinase or peptidase enzymes showed hydrolysis of the 31-43 fragment of A-gliadin, a toxic peptide for celiac patients. A toxic peptic-tryptic (PT) digest of gliadins was used for in vitro agglutination tests on K 562 (S) subclone cells of human myelagenous leukemia origin. The lowest concentration of PT digest that agglutinated 100% of the total cells was 0.218 g/liter. Hydrolysis of the PT digest by proteolytic enzymes of L. alimentarius 15M and L. brevis 14G completely prevented agglutination of the K 562 (S) cells by the PT digest at a concentration of 0.875 g/liter. Considerable inhibitory effects by other strains and at higher concentrations of the PT digest were also found. The mixture of peptides produced by enzyme preparations of selected lactobacilli showed a decreased agglutination

  8. Extraction and Detection of mRNA from a Single K562 Cell Based on the Functionalized Superparamagnetic Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    ZHU,Long-Zhang; YU,Ping-Guo; SHEN,He-Bai; JIA,Neng-Qin; LONG,De-Hong; ZHOU,Hai-Qing

    2008-01-01

    A novel and promising method was developed to extract mRNA from a single cell based on the functionalized superparamagnetic nanoparticles.The oligo(dT)-coupled magnetite nanobeads were synthesized by the reaction of oligo(dT) and thiol-modified γ-Fe2O3 nanoparticles.The single cell was isolated from the massive cultivation according to a semi-quantum approaching technique and then lysed before mRNA separation.The oligo(dT)-coupled magnetite nanobeads were added to the crude lysates and then magnetic separation was preformed to get mRNA.The mRNA amplification through a two-step RT-PCR method was achieved.The agarose gel electrophoresis of PCR products after amplification shows that mRNA could be extracted from a single cell successfully.

  9. A novel in vivo transcription assay demonstrates the presence of globin-inducing trans-acting factors in uninduced Murine Erythroleukemia cells.

    NARCIS (Netherlands)

    N. Wrighton; F.G. Grosveld (Frank)

    1988-01-01

    textabstractWe report the development of a novel in vivo transcription assay for trans-acting factors regulating the human gamma- and beta-globin genes. A cDNA coding for the human tissue-type plasminogen activator (t-PA) was inserted into the globin genes. Simian virus 40 small T-antigen splice and

  10. Inhibition of the Mitochondrial Protease ClpP as a Therapeutic Strategy for Human Acute Myeloid Leukemia.

    Science.gov (United States)

    Cole, Alicia; Wang, Zezhou; Coyaud, Etienne; Voisin, Veronique; Gronda, Marcela; Jitkova, Yulia; Mattson, Rachel; Hurren, Rose; Babovic, Sonja; Maclean, Neil; Restall, Ian; Wang, Xiaoming; Jeyaraju, Danny V; Sukhai, Mahadeo A; Prabha, Swayam; Bashir, Shaheena; Ramakrishnan, Ashwin; Leung, Elisa; Qia, Yi Hua; Zhang, Nianxian; Combes, Kevin R; Ketela, Troy; Lin, Fengshu; Houry, Walid A; Aman, Ahmed; Al-Awar, Rima; Zheng, Wei; Wienholds, Erno; Xu, Chang Jiang; Dick, John; Wang, Jean C Y; Moffat, Jason; Minden, Mark D; Eaves, Connie J; Bader, Gary D; Hao, Zhenyue; Kornblau, Steven M; Raught, Brian; Schimmer, Aaron D

    2015-06-08

    From an shRNA screen, we identified ClpP as a member of the mitochondrial proteome whose knockdown reduced the viability of K562 leukemic cells. Expression of this mitochondrial protease that has structural similarity to the cytoplasmic proteosome is increased in leukemic cells from approximately half of all patients with AML. Genetic or chemical inhibition of ClpP killed cells from both human AML cell lines and primary samples in which the cells showed elevated ClpP expression but did not affect their normal counterparts. Importantly, Clpp knockout mice were viable with normal hematopoiesis. Mechanistically, we found that ClpP interacts with mitochondrial respiratory chain proteins and metabolic enzymes, and knockdown of ClpP in leukemic cells inhibited oxidative phosphorylation and mitochondrial metabolism.

  11. Inhibition of the mitochondrial protease, ClpP, as a therapeutic strategy for human acute myeloid leuekmia

    Science.gov (United States)

    Cole, Alicia; Wang, Zezhou; Coyaud, Etienne; Voisin, Veronique; Gronda, Marcela; Jitkova, Yulia; Mattson, Rachel; Hurren, Rose; Babovic, Sonja; Maclean, Neil; Restall, Ian; Wang, Xiaoming; Jeyaraju, Danny V.; Sukhai, Mahadeo A.; Prabha, Swayam; Bashir, Shaheena; Ramakrishnan, Ashwin; Leung, Elisa; Qia, Yi Hua; Zhang, Nianxian; Combes, Kevin R.; Ketela, Troy; Lin, Fengshu; Houry, Walid A.; Aman, Ahmed; Al-awar, Rima; Zheng, Wei; Wienholds, Erno; Xu, Chang Jiang; Dick, John; Wang, Jean C.Y.; Moffat, Jason; Minden, Mark D.; Eaves, Connie J.; Bader, Gary D.; Hao, Zhenyue; Kornblau, Steven M.; Raught, Brian; Schimmer, Aaron D.

    2015-01-01

    Summary From an shRNA screen, we identified ClpP as a member of the mitochondrial proteome whose knockdown reduced the viability of K562 leukemic cells. Expression of this mitochondrial protease that has structural similarity to the cytoplasmic proteosome is increased in the leukemic cells from approximately half of patients with AML. Genetic or chemical inhibition of ClpP killed cells from both human AML cell lines and primary samples in which the cells showed elevated ClpP expression, but did not affect their normal counterparts. Importantly, Clpp knockout mice were viable with normal hematopoiesis. Mechanistically, we found ClpP interacts with mitochondrial respiratory chain proteins and metabolic enzymes, and knockdown of ClpP in leukemic cells inhibited oxidative phosphorylation and mitochondrial metabolism. PMID:26058080

  12. Monodisperse and LPS-free Aggregatibacter actinomycetemcomitans leukotoxin: Interactions with human β2 integrins and erythrocytes

    DEFF Research Database (Denmark)

    Reinholdt, Jesper; Poulsen, Knud; Brinkmann, Christel Rothe

    2013-01-01

    Aggregatibacter actinomycetemcomitans is a gram-negative, facultatively anaerobic cocco-bacillus and a frequent member of the human oral flora. It produces a leukotoxin, LtxA, belonging to the repeats-in-toxin (RTX) family of bacterial cytotoxins. LtxA efficiently kills neutrophils and mononuclear...... structure. Here, we describe a protocol for the purification of LtxA from bacterial culture supernatant, which does not involve denaturing procedures. The purified LtxA was monodisperse, well folded as judged by the combined use of synchrotron radiation circular dichroism spectroscopy (SRCD) and in silico...... prediction of the secondary structure content, and free of bacterial lipopolysaccharide. The analysis by SRCD and similarity to a lipase from Pseudomonas with a known three dimensional structure supports the presence of a so-called beta-ladder domain in the C-terminal part of LtxA. LtxA rapidly killed K562...

  13. Fucoidan Suppresses the Growth of Human Acute Promyelocytic Leukemia Cells In Vitro and In Vivo.

    Science.gov (United States)

    Atashrazm, Farzaneh; Lowenthal, Ray M; Woods, Gregory M; Holloway, Adele F; Karpiniec, Samuel S; Dickinson, Joanne L

    2016-03-01

    Fucoidan, a natural component of seaweeds, is reported to have immunomodulatory and anti-tumor effects. The mechanisms underpinning these activities remain poorly understood. In this study, the cytotoxicity and anti-tumor activities of fucoidan were investigated in acute myeloid leukemia (AML) cells. The human AML cell lines NB4, KG1a, HL60, and K562 were treated with fucoidan and cell cycle, cell proliferation, and expression of apoptotic pathways molecules were analyzed. Fucoidan suppressed the proliferation and induced apoptosis through the intrinsic and extrinsic pathways in the acute promyelocytic leukemia (APL) cell lines NB4 and HL60, but not in KG1a and K562 cells. In NB4 cells, apoptosis was caspase-dependent as it was significantly attenuated by pre-treatment with a pan-caspase inhibitor. P21/WAF1/CIP1 was significantly up-regulated leading to cell cycle arrest. Fucoidan decreased the activation of ERK1/2 and down-regulated the activation of AKT through hypo-phosphorylation of Thr(308) residue but not Ser(473). In vivo, a xenograft model using the NB4 cells was employed. Mice were fed with fucoidan and tumor growth was measured following inoculation with NB4 cells. Subsequently, splenic natural killer (NK) cell cytotoxic activity was also examined. Oral doses of fucoidan significantly delayed tumor growth in the xenograft model and increased cytolytic activity of NK cells. Taken together, these data suggest that the selective inhibitory effect of fucoidan on APL cells and its protective effect against APL development in mice warrant further investigation of fucoidan as a useful agent in treatment of certain types of leukemia.

  14. Methanolic Extract of Plumbago Zeylanica - A Remarkable Antibacterial Agent Against Many Human and Agricultural Pathogens

    Directory of Open Access Journals (Sweden)

    Mukesh Kumar Singh

    2017-03-01

    Full Text Available Objectives: The current investigation was carried out to determine the cytotoxic and the antimicrobial activities of methanolic extracts of Plumbago zeylanica. Methods: The stems, leaves, and whole plants were air dried and extracted with methanol by using a Soxhlet extractor for 72 hours at 55 - 60°C. The antimicrobial activities were determined from the zones of inhibition, which were measured by using the agar well diffusion method, and the cytotoxicity assays were performed using the 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay method. Results: The methanolic extracts of the stem and the leaves of Plumbago zeylanica were tested against six bacterial species and nine fungal species, and both extracts showed antimicrobial activity in a dose-dependent manner. The leaf extract of Plumbago zeylanica showed maximum antimicrobial activity against both Staphylococcus aureus sub sp aureus and Fusarium oxysporum. The stem extract was found to be more antimicrobial against the Pseudomonas aeruginosa and the Penicillium expansum species. MTT assays were used to test the cytotoxicity of the whole plant extract in the HCT-116 and the K-562 cell lines, and that extract was shown to have weak cytotoxicity in both cell lines. Conclusion: In the present study, the methanolic stem extracts of Plumbago zeylanica were found to possess remarkable antibacterial activities against many human and agricultural pathogens. The extracts were also found to possess significant antifungal activities, but the antifungal activities were less than the antibacterial activities. Finally, the extracts were found to have weak cytotoxicities in the HCT-116 and the K-562 cell lines.

  15. Methanolic Extract of Plumbago Zeylanica - A Remarkable Antibacterial Agent Against Many Human and Agricultural Pathogens

    Science.gov (United States)

    Pandey, Ajit; Sawarkar, Hemant; Gupta, Anshita; Gidwani, Bina; Dhongade, Hemant; Tripathi, Dulal Krishna

    2017-01-01

    Objectives: The current investigation was carried out to determine the cytotoxic and the antimicrobial activities of methanolic extracts of Plumbago zeylanica. Methods: The stems, leaves, and whole plants were air dried and extracted with methanol by using a Soxhlet extractor for 72 hours at 55 - 60°C. The antimicrobial activities were determined from the zones of inhibition, which were measured by using the agar well diffusion method, and the cytotoxicity assays were performed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay method. Results: The methanolic extracts of the stem and the leaves of Plumbago zeylanica were tested against six bacterial species and nine fungal species, and both extracts showed antimicrobial activity in a dose-dependent manner. The leaf extract of Plumbago zeylanica showed maximum antimicrobial activity against both Staphylococcus aureus sub sp aureus and Fusarium oxysporum. The stem extract was found to be more antimicrobial against the Pseudomonas aeruginosa and the Penicillium expansum species. MTT assays were used to test the cytotoxicity of the whole plant extract in the HCT-116 and the K-562 cell lines, and that extract was shown to have weak cytotoxicity in both cell lines. Conclusion: In the present study, the methanolic stem extracts of Plumbago zeylanica were found to possess remarkable antibacterial activities against many human and agricultural pathogens. The extracts were also found to possess significant antifungal activities, but the antifungal activities were less than the antibacterial activities. Finally, the extracts were found to have weak cytotoxicities in the HCT-116 and the K-562 cell lines.

  16. Design of retrovirus vectors for transfer and expression of the human. beta. -globin gene

    Energy Technology Data Exchange (ETDEWEB)

    Miller, A.D.; Bender, M.A.; Harris, E.A.S.; Kaleko, M.; Gelinas, R.E.

    1988-11-01

    Regulated expression of the human ..beta..-globin gene has been demonstrated in cultured murine erythroleukemia cells and in mice after retrovirus-mediated gene transfer. However, the low titer of recombinant viruses described to date results in relatively inefficient gene transfer, which limits their usefulness for animal studies and for potential gene therapy in humans for diseases involving defective ..beta..-globin genes. The authors found regions that interfered with virus production within intron 2 of the ..beta..-globin gene and on both sides of the gene. The flanking regions could be removed, but intron 2 was required for ..beta..-globin expression. Inclusion of ..beta..-globin introns necessitates an antisense orientation of the gene within the retrovirus vector. However, they found no effect of the antisense ..beta..-globin transcription on virus production. A region downstream of the ..beta..-globin gene that stimulates expression of the gene in transgenic mice was included in the viruses without detrimental effects on virus titer. Virus titers of over 10/sup 6/ CFU/ml were obtained with the final vector design, which retained the ability to direct regulated expression of human ..beta..-globin in murine erythroleukemia cells. The vector also allowed transfer and expression of the human ..beta..-globin gene in hematopoietic cells (CFU-S cells) in mice.

  17. Establishment of an acute GVHD animal model in EL9611 erythroleukemia mice%EL9611红白血病小鼠急性GVHD动物模型的建立

    Institute of Scientific and Technical Information of China (English)

    五纳宁; 何善阳; 徐霖; 陈康; 赵湛; 廖冰; 曹开源

    2011-01-01

    AIM: To establish an acute graft - versus - host disease ( GVHD ) model in EL9611 erythroleukemia mice.METHODS: Using C57BL/6 ( H - 2b ) mice as the donor and BALB/c ( H - 2d ) mice as the recipient in allogeneic bone marrow transplantation ( allo - BMT ), the acute GVHD model was established.The mice were divided into leukemia group ( n = 10 ), radiation control group ( leukemic mice given radiation without allo - BMT, n = 4 ), GVHD group ( leukemic mice given radiation + allo - BMT, n = 10 ) and normal control group ( n = 4 ).In leukemia group, 2 × 106/mouse EL9611 erythroleukemic cells were transfused via tail vein into BALB/c mice to build the erythroleukemia model.In GVHD group, 7 days after leukemic cell transfusion, the mice received total dose of 8.0 Gy [60Co]γ of total body irradiation( TBI ), and within 5 h, 2 × 10 C57BL/6 bone marrow cells and 1 × 10 C57BL/6 spleen cells per mouse were transfused via tail vein to build the acute GVHD model in EL9611 erythroleukemia mice.The clinical manifestations of posture , fur, stool and so on were observed.Pathological examination was conducted to examine the changes of liver, spleen, skin, small intestine and peripheral blood.The survival rate was also calculated.RESULTS: ( 1 ) In leukemia group, the mean survival time ( MST ) was ( 14.5 ± 2.1 ) days, or ( 7.5 ± 0.7 ) days when irradiation day was as day 0( P < 0.01 compared with GVHD group ).The death rate was 100% with no spontaneous remission.The dead mice showed splenohepatomegalia [liver weight ( 2.40 ±0.48 ) g, spleen weight ( 0.84 ±0.20 ) g, P <0.01 compared with normal group]and high WBC count [( 3.33 ±0.27 ) × 1010/L prior to death, P <0.05, compared with normal group].Pathological examination showed disorganization of normal tissues and leukemic cell infiltration.( 2 ) In radiation control group, MST was ( 9.0 ± 0.7 ) d, with significant difference as compared with GVHD group and normal group ( P < 0.01 ).The death rate was 100

  18. Single-colour flow cytometric assay to determine NK cell-mediated cytotoxicity and viability against non-adherent human tumor cells.

    Science.gov (United States)

    Thakur, Ajit; Zaman, Abeyat; Hummel, Jeff; Jones, Kim; Hortelano, Gonzalo

    2012-03-01

    A flow cytometry-based cytotoxicity (FCC) assay was developed using a single fluorophore, calcein-acetoxymethyl diacetylester (calcein-AM), to measure NK cell-mediated cytotoxicity. Non-adherent human K562 and U937 target cells were individually labelled with calcein-AM and co-incubated with effector NK cells to measure calcein loss, and therefore calculate target cell cytotoxicity. This FCC assay also provided a measure of sample viability. Notably, cell viability measured by traditional calcein/7-amino-actinomycin D (7-AAD) double labelling and Trypan Blue methods were comparable to the viability calculated using calcein-loss FCC. This FCC assay may also be used with various effector and target cell types and as a multi-parameter tool to measure viability and immunophenotype cells for tissue engineering purposes.

  19. Toxic effects of Microgramma vacciniifolia rhizome lectin on Artemia salina, human cells, and the schistosomiasis vector Biomphalaria glabrata.

    Science.gov (United States)

    de Albuquerque, Lidiane Pereira; Pontual, Emmanuel Viana; Santana, Giselly Maria de Sá; Silva, Luanna Ribeiro Santos; Aguiar, Jaciana dos Santos; Coelho, Luana Cassandra Breitenbach Barroso; Rêgo, Moacyr Jesus Barreto de Melo; Pitta, Maira Galdino da Rocha; da Silva, Teresinha Gonçalves; Melo, Ana Maria Mendonça de Albuquerque; Napoleão, Thiago Henrique; Paiva, Patrícia Maria Guedes

    2014-10-01

    The present study evaluated the toxicity of Microgramma vacciniifolia rhizome lectin (MvRL) to Artemia salina, human tumour cell lines (larynx epidermoid carcinoma Hep-2, NCI-H292 lung mucoepidermoid carcinoma, and chronic myelocytic leukaemia K562), and normal peripheral blood mononuclear cells (PBMCs), as well as to Biomphalaria glabrata embryos and adults. MvRL was toxic to A. salina (LC50=159.9 μg/mL), and exerted cytotoxic effects on NCI-H292 cells (IC50=25.23 μg/mL). The lectin (1-100 μg/mL) did not affect the viability of K562 and Hep-2 tumour cells, as well as of PBMCs. MvRL concentration of 1, 10, and 100 μg/mL promoted malformations (mainly exogastrulation) in 7.8%, 22.5%, and 27.7% of embryos, respectively, as well as delayed embryo development in 42.0%, 69.5%, and 54.7% of embryos, respectively. MvRL at a concentration of 100 μg/mL killed B. glabrata embryos (17.7%) and adults (25%). Further, MvRL damaged B. glabrata reproductive processes, which was evidenced by observations that snails exposed to the lectin (100 μg/mL) deposited fewer eggs than those in the control group, and approximately 40% of the deposited eggs exhibited malformations. Comparison of these results with that from A. salina assay indicates that MvRL is adulticidal at the concentration range which is toxic to environment. In conclusion, the cytotoxicity of MvRL on tumour cell and absence of toxicity to normal cell indicate its potential as chemotherapeutic drug. Also, the study revealed that the lectin is able to promote deleterious effects on B. glabrata embryos at environmentally safe concentrations.

  20. An upstream activator of transcription coordinately increases the level and epigenetic stability of gene expression

    OpenAIRE

    Magis, Wendy; Fiering, Steven; Groudine, Mark; Martin, David I. K.

    1996-01-01

    The mouse metallothionein-I (mMT-I) promoter is activated by the metal response element-binding transcription factor (MTF), which binds metal response elements (MREs) when stimulated with heavy metals. We analyzed eight K562 erythroleukemia cell clones, each carrying a single integrated copy of an mMT-I/β-geo construct, using a system that can independently assess the level of β-geo expression and the rate at which it is silenced. In these clones, basal expression ...

  1. Mobilization of human CD34+ CD133+ and CD34+ CD133(-) stem cells in vivo by consumption of an extract from Aphanizomenon flos-aquae--related to modulation of CXCR4 expression by an L-selectin ligand?

    Science.gov (United States)

    Jensen, Gitte S; Hart, Aaron N; Zaske, Lue A M; Drapeau, Christian; Gupta, Niraj; Schaeffer, David J; Cruickshank, J Alex

    2007-01-01

    The goal of this study was to evaluate effects on human stem cells in vitro and in vivo of an extract from the edible cyanobacterium Aphanizomenon flos-aquae (AFA) enriched for a novel ligand for human CD62L (L-selectin). Ligands for CD62L provide a mechanism for stem cell mobilization in conjunction with down-regulation of the CXCR4 chemokine receptor for stromal derived factor 1. Affinity immunoprecipitation was used to identify a novel ligand for CD62L from a water extract from AFA. The effects of AFA water extract on CD62L binding and CXCR4 expression was tested in vitro using human bone marrow CD34+ cells and the two progenitor cell lines, KG1a and K562. A double-blind randomized crossover study involving 12 healthy subjects evaluated the effects of consumption on stem cell mobilization in vivo. An AFA extract rich in the CD62L ligand reduced the fucoidan-mediated externalization of the CXCR4 chemokine receptor on bone marrow CD34+ cells by 30% and the CD62L+ CD34+ cell line KG1A by 50% but did not alter the CXCR4 expression levels on the CD34(-) cell line K562. A transient, 18% increase in numbers of circulating CD34+ stem cells maximized 1 hour after consumption (P<.0003). When 3 noncompliant volunteers were removed from analysis, the increase in CD34+ cells was 25% (P<.0001). AFA water extract contains a novel ligand for CD62L. It modulates CXCR4 expression on CD34+ bone marrow cells in vitro and triggers the mobilization of CD34+ CD133+ and CD34+ CD133(-) cells in vivo.

  2. The recognition of N-glycans by the lectin ArtinM mediates cell death of a human myeloid leukemia cell line.

    Directory of Open Access Journals (Sweden)

    Fernanda Caroline Carvalho

    Full Text Available ArtinM, a D-mannose-binding lectin from Artocarpus heterophyllus (jackfruit, interacts with N-glycosylated receptors on the surface of several cells of hematopoietic origin, triggering cell migration, degranulation, and cytokine release. Because malignant transformation is often associated with altered expression of cell surface glycans, we evaluated the interaction of ArtinM with human myelocytic leukemia cells and investigated cellular responses to lectin binding. The intensity of ArtinM binding varied across 3 leukemia cell lines: NB4>K562>U937. The binding, which was directly related to cell growth suppression, was inhibited in the presence of Manα1-3(Manα1-6Manβ1, and was reverted in underglycosylated NB4 cells. ArtinM interaction with NB4 cells induced cell death (IC(50 = 10 µg/mL, as indicated by cell surface exposure of phosphatidylserine and disruption of mitochondrial membrane potential unassociated with caspase activation or DNA fragmentation. Moreover, ArtinM treatment of NB4 cells strongly induced reactive oxygen species generation and autophagy, as indicated by the detection of acidic vesicular organelles in the treated cells. NB4 cell death was attributed to ArtinM recognition of the trimannosyl core of N-glycans containing a ß1,6-GlcNAc branch linked to α1,6-mannose. This modification correlated with higher levels of N-acetylglucosaminyltransferase V transcripts in NB4 cells than in K562 or U937 cells. Our results provide new insights into the potential of N-glycans containing a β1,6-GlcNAc branch linked to α1,6-mannose as a novel target for anti-leukemia treatment.

  3. Effect of dioxin on normal and leukemic human hematopoietic cells

    Energy Technology Data Exchange (ETDEWEB)

    Lambertenghi-Deliliers, G.; Soligo, D. [Univ. degli Studi, Milan (Italy). Dipt. die Ematologia, Ospedale Maggiore Policlinico IRCCS; Fracchiolla, N.S. [Ospedale Maggiore Policlinico IRCCS, Milan (Italy). Dipt. di Ematologia; Servida, F. [Fondazione Matarelli, Milan (Italy); Bertazzi, P.A. [Istituti Clinici di Perfezionamento, Milan (Italy). Dipt. di Medicina del Lavoro

    2004-09-15

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) arises from chlorination of phenolic substrates or from partial combustion of organic materials in the presence of chlorine sources. TCDD has a large number of biological effects such as long-lasting skin disease, cardiovascular disease, diabete and cancer. TCDD is the prototypical agonist of the aryl hydrocarbon receptor (AhR), a member of the erb-A family that also includes the receptors for steroids, thyroid hormones, peroxisome proliferators and retinoids. When bound to dioxin, the AhR can bind to DNA and alter the expression of some genes including cytokines and growth factors. In this study, we analyzed the effect of escalating doses of TCDD on human CD34{sup +} progenitor cells from the leukapheresis of normal donors stimulated with G-CSF as well as the human myeloid leukemic cell lines HL60 (promyelocytic leukemia) and K562 (chronic myelogenous leukemia). The possible specific modulation of gene expression induced by the TCDD exposure was then tested by means of microarray analyses.

  4. Distinct Dasatinib-Induced Mechanisms of Apoptotic Response and Exosome Release in Imatinib-Resistant Human Chronic Myeloid Leukemia Cells

    Directory of Open Access Journals (Sweden)

    Juan Liu

    2016-04-01

    Full Text Available Although dasatinib is effective in most imatinib mesylate (IMT-resistant chronic myeloid leukemia (CML patients, the underlying mechanism of its effectiveness in eliminating imatinib-resistant cells is only partially understood. This study investigated the effects of dasatinib on signaling mechanisms driving-resistance in imatinib-resistant CML cell line K562 (K562RIMT. Compared with K562 control cells, exsomal release, the phosphoinositide 3-kinase (PI3K/protein kinase B (Akt/ mammalian target of rapamycin (mTOR signaling and autophagic activity were increased significantly in K562RIMT cells and mTOR-independent beclin-1/Vps34 signaling was shown to be involved in exosomal release in these cells. We found that Notch1 activation-mediated reduction of phosphatase and tensin homolog (PTEN was responsible for the increased Akt/mTOR activities in K562RIMT cells and treatment with Notch1 γ-secretase inhibitor prevented activation of Akt/mTOR. In addition, suppression of mTOR activity by rapamycin decreased the level of activity of p70S6K, induced upregulation of p53 and caspase 3, and led to increase of apoptosis in K562RIMT cells. Inhibition of autophagy by spautin-1 or beclin-1 knockdown decreased exosomal release, but did not affect apoptosis in K562RIMT cells. In summary, in K562RIMT cells dasatinib promoted apoptosis through downregulation of Akt/mTOR activities, while preventing exosomal release and inhibiting autophagy by downregulating expression of beclin-1 and Vps34. Our findings reveal distinct dasatinib-induced mechanisms of apoptotic response and exosomal release in imatinib-resistant CML cells.

  5. Gene expression profiles of human promyelocytic leukemia cell lines exposed to volatile organic compounds.

    Science.gov (United States)

    Sarma, Sailendra Nath; Kim, Youn-Jung; Ryu, Jae-Chun

    2010-05-27

    Benzene, toluene, o-xylene, ethylbenzene, trichloroethylene and dichloromethane are the most widely used volatile organic compounds (VOCs), and their toxic mechanisms are still undefined. This study analyzed the genome-wide expression profiles of human promyelocytic leukemia HL-60 cells exposed to VOCs using a 35-K whole human genome oligonucleotide microarray to ascertain potential biomarkers. Genes with a significantly increased expression levels (over 1.5-fold and p-values p53 signaling pathway, apoptosis, and natural killer cell-mediated cytotoxicity pathway. Functionally important immune response- and apoptosis-related genes were further validated by real-time RT-PCR. The results showed that IFIT1, IFIT2, IFIT3, USP18, INFGR2, PMAIP1, GADD45A, NFKBIA, TNFAIP3, and BIRC3 genes altered their expression profiles in a dose-dependent manner. Similar expressions profiles were also found in human erythromyeloblastoid leukemia K562 cells and in human leukemic monocyte lymphoma U937 cells. In conclusion, both gene expression profiles and gene ontology analysis have elucidated potential gene-based biomarkers and provided insights into the mechanism underlying the response of human leukemia cell lines to VOC exposure.

  6. Production and Characterization of a Murine Monoclonal Antibody Against Human Ferritin

    Science.gov (United States)

    Bayat, Ali Ahmad; Yeganeh, Omid; Ghods, Roya; Zarnani, Amir Hassan; Ardekani, Reza Bahjati; Mahmoudi, Ahmad Reza; Mahmoudian, Jafar; Haghighat-Noutash, Farzaneh; Jeddi-Tehrani, Mahmood

    2013-01-01

    Background Ferritin is an iron storage protein, which plays a key role in iron metabolism. Measurement of ferritin level in serum is one of the most useful indicators of iron status and also a sensitive measurement of iron deficiency. Monoclonal antibodies may be useful as a tool in various aspects of ferritin investigations. In this paper, the production of a murine monoclonal antibody (mAb) against human ferritin was reported. Methods Balb/c mice were immunized with purified human ferritin and splenocytes of hyper immunized mice were fused with Sp2/0 myeloma cells. After four times of cloning by limiting dilution, a positive hybridoma (clone: 2F9-C9) was selected by ELISA using human ferritin. Anti-ferritin mAb was purified from culture supernatants by affinity chromatography. Results Determination of the antibody affinity for ferritin by ELISA revealed a relatively high affinity (2.34×109 M -1) and the isotype was determined to be IgG2a. The anti-ferritin mAb 2F9-C9 reacted with 79.4% of Hela cells in flow cytometry. The antibody detected a band of 20 kDa in K562 cells, murine and human liver lysates, purified ferritin in Western blot and also ferritin in human serum. Conclusion This mAb can specifically recognize ferritin and may serve as a component of ferritin diagnostic kit if other requirements of the kit are met. PMID:24285995

  7. Preliminary Study on Biological Properties of Adult Human Bone Marrow-derived Mesenchymal Stem Cells

    Institute of Scientific and Technical Information of China (English)

    WU Tao; BAI Hai; WANG Jingchang; SHI Jingyun; WANG Cunbang; LU Jihong; OU Jianfeng; WANG Qian

    2006-01-01

    Objective: To establish a method of culture and expansion of adult human bone marrow-derived MSCs in vitro and to explore their biological properties. Methods: Mononuclear cells were obtained from 5 mL adult human bone marrow by density gradient centrifugation with Percoll solution. Adult human MSCs were cultured in Dulbecco's Modified Eagle's Medium with low glucose (LG-DMEM) containing 10% fetal calf serum at a density of 2× 105 cell/cm2. The morphocytology was observed under phase-contrast microscope. The cell growth was measured by MTT method. The flow cytometer was performed to examine the expression of cell surface molecules and cell cycle. The ultrastructure of MSCs was observed under transmission electron microscope. The immunomodulatory functions of MSCs were measured by MTT method. The effects of MSCs on the growth of K562 cells and the dynamic change of HA, Ⅳ-C, LN concentration in the culture supernatant of MSCs was also observed. Results: The MSCs harvested in this study were homogenous population and exhibited a spindle-shaped fibroblastic morphology. The cell growth curve showed that MSCs had a strong ability of proliferation. The cells were positive for CD44,while negative for hematopoietic cell surface marker such as CD3, CD4, CD7, CD13, CD14, CD15, CD19,CD22, CD33, CD34, CD45 and HLA-DR, which was closely related to graft versus host disease. Above 90% cells of MSCs were found at G0/G1 phase. The ultrastructure of MSCs indicated that there were plenty of cytoplasmic organelles. Allogeneic peripheral blood lymphocytes proliferation was suppressed by MSCs and the inhibition ratio was 60.68% (P<0.01). The suppressive effect was also existed in the culture supernatant of MSCs and the inhibition ratio was 9.00% (P<0.05). When lymphocytes were stimulated by PHA, the suppression effects of the culture supernatant were even stronger and the inhibition ratio was 20.91%(P<0.01). Compared with the cell growth curve of the K562 cells alone, the K562

  8. Hexamethylenebisacetamide (HMBA) is a growth factor for human, ovine and porcine thyroid cells.

    Science.gov (United States)

    Fayet, G; Amphoux-Fazekas, T; Aouani, A; Hovsépian, S

    1996-03-01

    Hexamethylenebisacetamide (HMBA) provokes in murine erythroleukemia cells (MELC) a commitment to terminal differentiation leading to the activation of the expression of hemoglobin. HMBA has been tested also in other cells from colon cancer, melanoma or lung cancer. However it has not yet been tested in the thyroid. We demonstrate in this paper that HMBA in kinetics and concentration-response experiments increases the proliferation of human thyroid cells isolated from Graves'-Basedow patients. It also acts like a growth factor for ovine and porcine thyroid cells, respectively, from the OVNIS line and the ATHOS line. This molecule which is a differentiating factor in the MELC system and a growth factor in human thyroid cell cultures represents a potential to get human thyroid cell lines expressing specialized functions.

  9. Ru-indoloquinoline complex as a selective and effective human telomeric G-quadruplex binder

    Science.gov (United States)

    Yu, Hui-juan; Zhao, Ying; Mo, Wei-jie; Hao, Zhi-feng; Yu, Lin

    2014-11-01

    Indoloquinoline and its derivatives have been reported to be a kind of efficient G-quadruplex binder and have been found to interact preferentially to intramolecular G-quadruplex and inhibit telomerase activity in human K562 cells and SW620 cells. In contrast to indoloquinoline derivatives, much less is known about the metal complex based on indoloquinoline or its derivative. In this report, we studied the interaction of ruthenium complex [Ru(bpy)2(itatp)]2+ containing indoloquinoline moiety with human telomeric G-quadruplex DNA (Telo22) and c-myc G-quadruplex DNA (Pu27) by UV-visible (UV-Vis), fluorescence spectroscopy, fluorescent intercalator displacement (FID), thermal denaturation studies and CD spectroscopy. The results suggest that [Ru(bpy)2(itatp)]2+ displays a strong π-π stacking interaction with human telomeric G-quadruplex with a high binding constant (∼107 M-1), but just exhibits moderate binding affinity to c-myc G-quadruplex, thus showing significant selectivity to human telomeric G-quadruplex. The CD titration results indicate that [Ru(bpy)2(itatp)]2+ could effectively convert Telo22 into antiparallel G-quadruplex conformation, while in the c-myc G-quadruplex case, instead of promoting Pu27 to fold into G-quadruplex, [Ru(bpy)2(itatp)]2+ destroys the parallel G-quadruplex structure of Pu27.

  10. High-level expression of human calmodulin in E. coli and its effects on cell proliferation

    Institute of Scientific and Technical Information of China (English)

    Xiao Jun Li; Jian Guo Wu; Jun Ling Si; Da Wen Guo; Jian Ping Xu

    2000-01-01

    Calmodulin (CaM), widely distributed in almost all eukaryotic cells, is a major intracellular calcium receptor responsible for mediating the Ca2 + signal to a multitude of different enzyme systems and is thought to play a vital role in the regulation of cell proliferative cycle[1,2]. Recently, many studies showed that CaM is also present in extracellular fluid such as cell culture media and normal body fluid and has been reported to stimulate proliferation in a range of normal and neoplastic cells, apparently acting as an autocrine growth factor[3-11]. In 1988, Crocker et al reported for the first time that addition of extracellular pure pig brain CaM could promote DNA synthesis and cell [7]proliferation in K562 human leukaemic lymphocytes[7].After that, more and more research was done on extracellular CaM and evidences demonstrated that extracellular CaM could also stimulate cell proliferation in normal human umbilical vein endothelial cells[5], keratinocytes[4], suspension-cultured cells of Angelica Dahurica, etc[6]. CaM is a monomeric protein of 148 amino acids that contains four homologous Ca2 + -binding domains. CaM has been highly conserved throughout the evolution. Only 1 out of 148 amino acids of human CaM is different from that of fish CaM. Complementary DNAs encoding rat, eel, chicken, human, and trypanosome CaM have been cloned.

  11. THE ENHANCED GREEN FLUORESCENT PROTEIN AS A MARKER FOR HUMAN TUMOR CELLS LABELLED BY RETROVIRAL TRANSDUCTION

    Institute of Scientific and Technical Information of China (English)

    傅建新; 王玮; 白霞; 卢大儒; 阮长耿; 陈子兴

    2002-01-01

    Objective: To investigate the feasibility of marking the human tumor cells with enhanced green fluorescent protein (EGFP) in vitro. Methods: The retroviral vector LGSN encoding EGFP was constructed and three human tumor cell lines were infected with LGSN amphotropic virus. Tumor cell lines that stably express EGFP were selected with G418. The integration and expression of EGFP gene were analyzed by polymerase chain reaction, and flow cytometry (FCM). Results: After gene transfection and ping-pong transduction, amphotropic producer line Am12/LGSN was generated with a stable green fluorescence signal readily detectable by FCM in up to 97% of examined cells. The viral titer in the supernatants was up to 8.2×105CFU/ml. After transduction and selection, G418-resistant leukemia K562, mammary carcinoma MCF-7, and bladder cancer 5637 cells were developed, in which the integration of both EGFP and neomycin resistance gene was confirmed by DNA amplification. In comparison with uninfected cells, FCM analysis revealed EGFP expression in up to 90% (range 85.5%~90.0%) of tumor cells containing LGSN provirus. Conclusion: The retroviral vector LGSN can effectively mark the human tumor cells with a stably EGFP expression which may be in studying tumor growth, metastasis and angiogenesis.

  12. CP2 binding to the promoter is essential for the enhanced transcription of globin genes in erythroid cells.

    Science.gov (United States)

    Chae, Ji Hyung; Kim, Chul Geun

    2003-02-28

    We have previously reported that the reduced level of CP2 suppresses the mouse alpha- and beta-globin gene expression and hemoglobin synthesis during terminal differentiation of mouse erythroleukemia (MEL) cells in vitro [Chae et al. (1999)]. As an extension of this study, we demonstrated that human alpha-, epsilon-, and gamma- globin genes were also suppressed by the reduced expression of CP2 in K562 cells. To address how much CP2 contributes in the regulation of globin gene expression, we measured transcriptional activities of the wild type alpha-globin promoter and its various factor-binding sites mutants in erythroid and nonerythroid cells. Interestingly, CP2 site dependent transcriptional activation occurred in an erythroid-cell specific manner, even though CP2 is ubiquitously expressed. In addition, CP2 site mutation within the alpha-promoter severely suppressed promoter activity in differentiated, but not in undifferentiated MEL cells, suggesting that the CP2 binding site is needed for the enhanced transcription of globin genes during erythroid differentiation. When the human beta-globin locus control region was linked to the alpha-promoter, suppression was more severe in the CP2 site mutant in differentiated MEL cells. Overall data indicate that CP2 is a major factor in the regulation of globin expression in human and mouse erythroid cells, and CP2 binding to the globin gene promoter is essential for the enhanced transcription of globin genes in erythroid differentiation.

  13. A human PrM antibody that recognizes a novel cryptic epitope on dengue E glycoprotein.

    Science.gov (United States)

    Chan, Annie Hoi Yi; Tan, Hwee Cheng; Chow, Angelia Yee; Lim, Angeline Pei Chiew; Lok, Shee Mei; Moreland, Nicole J; Vasudevan, Subhash G; MacAry, Paul A; Ooi, Eng Eong; Hanson, Brendon J

    2012-01-01

    Dengue virus (DENV) is a major mosquito-borne pathogen infecting up to 100 million people each year; so far no effective treatment or vaccines are available. Recently, highly cross-reactive and infection-enhancing pre-membrane (prM)-specific antibodies were found to dominate the anti-DENV immune response in humans, raising concern over vaccine candidates that contain native dengue prM sequences. In this study, we have isolated a broadly cross-reactive prM-specific antibody, D29, during a screen with a non-immunized human Fab-phage library against the four serotypes of DENV. The antibody is capable of restoring the infectivity of virtually non-infectious immature DENV (imDENV) in FcγR-bearing K562 cells. Remarkably, D29 also cross-reacted with a cryptic epitope on the envelope (E) protein located to the DI/DII junction as evidenced by site-directed mutagenesis. This cryptic epitope, while inaccessible to antibody binding in a native virus particle, may become exposed if E is not properly folded. These findings suggest that generation of anti-prM antibodies that enhance DENV infection may not be completely avoided even with immunization strategies employing E protein alone or subunits of E proteins.

  14. Engineered human tmpk/AZT as a novel enzyme/prodrug axis for suicide gene therapy.

    Science.gov (United States)

    Sato, Takeya; Neschadim, Anton; Konrad, Manfred; Fowler, Daniel H; Lavie, Arnon; Medin, Jeffrey A

    2007-05-01

    Gene therapy and stem cell transplantation safety could be enhanced by control over the fate of therapeutic cells. Suicide gene therapy uses enzymes that convert prodrugs to cytotoxic entities; however, heterologous moieties with poor kinetics are employed. We describe a novel enzyme/prodrug combination for selectively inducing apoptosis in lentiviral vector-transduced cells. Rationally designed variants of human thymidylate kinase (tmpk) that effectively phosphorylate 3'-azido-3'-deoxythymidine (AZT) were efficiently delivered. Transduced Jurkat cell lines were eliminated by AZT. We demonstrate that this schema targeted both dividing and non-dividing cells, with a novel killing mechanism involving apoptosis induction via disruption of the mitochondrial inner membrane potential and activation of caspase-3. Primary murine and human T cells were also transduced and responded to AZT. Furthermore, low-dose AZT administration to non-obese diabetic/severe combined immunodeficiency (NOD/SCID) mice injected with transduced K562 cells suppressed tumor growth. This novel suicide gene therapy approach can thus be integrated as a safety switch into therapeutic vectors.

  15. Human uroporphyrinogen-III synthase: genomic organization, alternative promoters, and erythroid-specific expression.

    Science.gov (United States)

    Aizencang, G; Solis, C; Bishop, D F; Warner, C; Desnick, R J

    2000-12-01

    Uroporphyrinogen-III (URO) synthase is the heme biosynthetic enzyme defective in congenital erythropoietic porphyria. The approximately 34-kb human URO-synthase gene (UROS) was isolated, and its organization and tissue-specific expression were determined. The gene had two promoters that generated housekeeping and erythroid-specific transcripts with unique 5'-untranslated sequences (exons 1 and 2A) followed by nine common coding exons (2B to 10). Expression arrays revealed that the housekeeping transcript was present in all tissues, while the erythroid transcript was only in erythropoietic tissues. The housekeeping promoter lacked TATA and SP1 sites, consistent with the observed low level expression in most cells, whereas the erythroid promoter contained GATA1 and NF-E2 sites for erythroid specificity. Luciferase reporter assays demonstrated that the housekeeping promoter was active in both erythroid K562 and HeLa cells, while the erythroid promoter was active only in erythroid cells and its activity was increased during hemin-induced erythroid differentiation. Thus, human URO-synthase expression is regulated during erythropoiesis by an erythroid-specific alternative promoter.

  16. Microvesicles released from human embryonic stem cell derived-mesenchymal stem cells inhibit proliferation of leukemia cells.

    Science.gov (United States)

    Ji, Yuan; Ma, Yongbin; Chen, Xiang; Ji, Xianyan; Gao, Jianyi; Zhang, Lei; Ye, Kai; Qiao, Fuhao; Dai, Yao; Wang, Hui; Wen, Xiangmei; Lin, Jiang; Hu, Jiabo

    2017-08-01

    Human embryonic stem cell derived-mesenchymal stem cells (hESC‑MSCs) are able to inhibit proliferation of leukemia cells. Microvesicles released from human embryonic stem cell derived-mesenchymal stem cells (hESC‑MSC‑MVs) might play an important part in antitumor activity. Microvesicles were isolated by ultracentrifugation and identified under a scanning electron microscopy and transmission electron microscope separately. After 48-h cocultured with hESC‑MSCs and hESC‑MSC‑MVs, the number of K562 and HL60 was counted and tumor cell viability was measured by CCK8 assay. The expression of proteins Bcl-2 and Bax were estimated by western blotting. Transmission electron microscope and western blot analysis were adopted to evaluate the autophagy level. Results showed that both hESC‑MSCs and hESC‑MSC‑MVs inhibited proliferation of leukemia cells in a concentration-dependent manner. hESC‑MSC‑MVs reduced the ratio of Bcl/Bax, enhanced the protein level of Beclin-1 and LC3-II conversion, thus upregulating autophagy and apoptosis. In conclusion, microvesicles released from human embryonic stem cell derived-mesenchymal stem cells inhibited tumor growth and stimulated autophagy and excessive autophagy might induce apoptosis.

  17. Epigenetic regulation of transposable element derived human gene promoters.

    Science.gov (United States)

    Huda, Ahsan; Bowen, Nathan J; Conley, Andrew B; Jordan, I King

    2011-04-01

    It was previously thought that epigenetic histone modifications of mammalian transposable elements (TEs) serve primarily to defend the genome against deleterious effects associated with their activity. However, we recently showed that, genome-wide, human TEs can also be epigenetically modified in a manner consistent with their ability to regulate host genes. Here, we explore the ability of TE sequences to epigenetically regulate individual human genes by focusing on the histone modifications of promoter sequences derived from TEs. We found 1520 human genes that initiate transcription from within TE-derived promoter sequences. We evaluated the distributions of eight histone modifications across these TE-promoters, within and between the GM12878 and K562 cell lines, and related their modification status with the cell-type specific expression patterns of the genes that they regulate. TE-derived promoters are significantly enriched for active histone modifications, and depleted for repressive modifications, relative to the genomic background. Active histone modifications of TE-promoters peak at transcription start sites and are positively correlated with increasing expression within cell lines. Furthermore, differential modification of TE-derived promoters between cell lines is significantly correlated with differential gene expression. LTR-retrotransposon derived promoters in particular play a prominent role in mediating cell-type specific gene regulation, and a number of these LTR-promoter genes are implicated in lineage-specific cellular functions. The regulation of human genes mediated by histone modifications targeted to TE-derived promoters is consistent with the ability of TEs to contribute to the epigenomic landscape in a way that provides functional utility to the host genome.

  18. Mesua beccariana (Clusiaceae), a source of potential anti-cancer lead compounds in drug discovery.

    Science.gov (United States)

    Teh, Soek Sin; Cheng Lian Ee, Gwendoline; Mah, Siau Hui; Lim, Yang Mooi; Rahmani, Mawardi

    2012-09-10

    An investigation on biologically active secondary metabolites from the stem bark of Mesua beccariana was carried out. A new cyclodione, mesuadione, along with several known constituents which are beccamarin, 2,5-dihydroxy-1,3,4-trimethoxy anthraquinone, 4-methoxy-1,3,5-trihydroxyanthraquinone, betulinic acid and stigmasterol were obtained from this ongoing research. Structures of these compounds were elucidated by extensive spectroscopic methods, including 1D and 2D-NMR, GC-MS, IR and UV techniques. Preliminary tests of the in vitro cytotoxic activities of all the isolated metabolites against a panel of human cancer cell lines Raji (lymphoma), SNU-1 (gastric carcinoma), K562 (erythroleukemia cells), LS-174T (colorectal adenocarcinoma), HeLa (cervical cells), SK-MEL-28 (malignant melanoma cells), NCI-H23 (lung adenocarcinoma), IMR-32 (neuroblastoma) and Hep-G2 (hepatocellular liver carcinoma) were carried out using an MTT assay. Mesuadione, beccamarin, betulinic acid and stigmasterol displayed strong inhibition of Raji cell proliferation, while the proliferation rate of SK-MEL-28 and HeLa were strongly inhibited by stigmasterol and beccamarin, indicating these secondary metabolites could be anti-cancer lead compounds in drug discovery.

  19. Mesua beccariana (Clusiaceae, A Source of Potential Anti-cancer Lead Compounds in Drug Discovery

    Directory of Open Access Journals (Sweden)

    Soek Sin Teh

    2012-09-01

    Full Text Available An investigation on biologically active secondary metabolites from the stem bark of Mesua beccariana was carried out. A new cyclodione, mesuadione (1, along with several known constituents which are beccamarin (2, 2,5-dihydroxy-1,3,4-trimethoxy anthraquinone (3, 4-methoxy-1,3,5-trihydroxyanthraquinone (4, betulinic acid (5 and stigmasterol (6 were obtained from this ongoing research. Structures of these compounds were elucidated by extensive spectroscopic methods, including 1D and 2D-NMR, GC-MS, IR and UV techniques. Preliminary tests of the in vitro cytotoxic activities of all the isolated metabolites against a panel of human cancer cell lines Raji (lymphoma, SNU-1 (gastric carcinoma, K562 (erythroleukemia cells, LS-174T (colorectal adenocarcinoma, HeLa (cervical cells, SK-MEL-28 (malignant melanoma cells, NCI-H23 (lung adenocarcinoma, IMR-32 (neuroblastoma and Hep-G2 (hepatocellular liver carcinoma were carried out using an MTT assay. Mesuadione (1, beccamarin (2, betulinic acid (5 and stigmasterol (6 displayed strong inhibition of Raji cell proliferation, while the proliferation rate of SK-MEL-28 and HeLa were strongly inhibited by stigmasterol (6 and beccamarin (2, indicating these secondary metabolites could be anti-cancer lead compounds in drug discovery.

  20. Regulation of Cop9 signalosome activity by the EF-hand Ca2+-binding protein tescalcin.

    Science.gov (United States)

    Levay, Konstantin; Slepak, Vladlen Z

    2014-06-01

    The Ca(2+)-binding protein tescalcin is known to be involved in hematopoietic cell differentiation; however, this mechanism is poorly understood. Here, we identify CSN4 (subunit 4 of the COP9 signalosome) as a novel binding partner of tescalcin. The COP9 signalosome (CSN) is a multiprotein complex that is essential for development in all eukaryotes. This interaction is selective, Ca(2+)-dependent and involves the PCI domain of CSN4 subunit. We then investigated tescalcin and CSN activity in human erythroleukemia HEL and promyelocytic leukemia K562 cells and find that phorbol 12-myristate 13-acetate (PMA)-induced differentiation, resulting in the upregulation of tescalcin, coincides with reduced deneddylation of cullin-1 (Cul1) and stabilization of p27(Kip1) - molecular events that are associated with CSN activity. The knockdown of tescalcin led to an increase in Cul1 deneddylation, expression of F-box protein Skp2 and the transcription factor c-Jun, whereas the levels of cell cycle regulators p27(Kip1) and p53 decreased. These effects are consistent with the hypothesis that tescalcin might play a role as a negative regulator of CSN activity towards Cul1 in the process of induced cell differentiation.

  1. PRKAA1/AMPKα1 is required for autophagy-dependent mitochondrial clearance during erythrocyte maturation.

    Science.gov (United States)

    Zhu, Huaiping; Foretz, Marc; Xie, Zhonglin; Zhang, Miao; Zhu, Zhiren; Xing, Junjie; Leclerc, Jocelyne; Gaudry, Murielle; Viollet, Benoit; Zou, Ming-Hui

    2014-09-01

    AMP-activated protein kinase α1 knockout (prkaa1(-/-)) mice manifest splenomegaly and anemia. The underlying molecular mechanisms, however, remain to be established. In this study, we tested the hypothesis that defective autophagy-dependent mitochondrial clearance in prkaa1(-/-) mice exacerbates oxidative stress, thereby enhancing erythrocyte destruction. The levels of ULK1 phosphorylation, autophagical flux, mitochondrial contents, and reactive oxygen species (ROS) were examined in human erythroleukemia cell line, K562 cells, as well as prkaa1(-/-) mouse embryonic fibroblasts and erythrocytes. Deletion of Prkaa1 resulted in the inhibition of ULK1 phosphorylation at Ser555, prevented the formation of ULK1 and BECN1- PtdIns3K complexes, and reduced autophagy capacity. The suppression of autophagy was associated with enhanced damaged mitochondrial accumulation and ROS production. Compared with wild-type (WT) mice, prkaa1(-/-) mice exhibited a shortened erythrocyte life span, hemolytic destruction of erythrocytes, splenomegaly, and anemia, all of which were alleviated by the administration of either rapamycin to activate autophagy or Mito-tempol, a mitochondria-targeted antioxidant, to scavenge mitochondrial ROS. Furthermore, transplantation of WT bone marrow into prkaa1(-/-) mice restored mitochondrial removal, reduced intracellular ROS levels, and normalized hematologic parameters and spleen size. Conversely, transplantation of prkaa1 (-/-) bone marrow into WT mice recapitulated the prkaa1(-/-) mouse phenotypes. We conclude that PRKAA1-dependent autophagy-mediated clearance of damaged mitochondria is required for erythrocyte maturation and homeostasis.

  2. Effect of polo-like kinase 1 gene silence on cell cycle and drug resistance in K562/A02 cell

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ Polo-like kinase 1(PLK1) plays an important role in many cell-cycle-related events.1 At G2/M transition, PLK1 contributes to the activation of cyclinB/Cdc by phosphorylation of Cdc25C, centrosome functional maturation, bipolar spindle formation. In later stage of mitosis, PLK1 is involved in regulating components of the anaphase-promoting complex (APC) for mitotic exit and in the execution of cytokinesis.

  3. Flow Cytometric Measurement of [Ca2+]i and pHi in Conjugated Natural Killer Cells and K562 Target Cells during the Cytotoxic Process1,2

    NARCIS (Netherlands)

    van Graft, Marja; van Graft, M.; Kraan, Yvonne M.; Segers-Nolten, Gezina M.J.; Radosevic, K.; Radosevic, Katarina; de Grooth, B.G.; Greve, Jan

    1993-01-01

    We describe a flow cytometric assay that enables one to follow conjugate formation between cytotoxic cells and their target cells during the cytotoxic process. In addition, the internal calcium concentration ([Ca2+]i) and internal pH (pHi) of the conjugated cells can be monitored and directly

  4. Genome-wide map of regulatory interactions in the human genome.

    Science.gov (United States)

    Heidari, Nastaran; Phanstiel, Douglas H; He, Chao; Grubert, Fabian; Jahanbani, Fereshteh; Kasowski, Maya; Zhang, Michael Q; Snyder, Michael P

    2014-12-01

    Increasing evidence suggests that interactions between regulatory genomic elements play an important role in regulating gene expression. We generated a genome-wide interaction map of regulatory elements in human cells (ENCODE tier 1 cells, K562, GM12878) using Chromatin Interaction Analysis by Paired-End Tag sequencing (ChIA-PET) experiments targeting six broadly distributed factors. Bound regions covered 80% of DNase I hypersensitive sites including 99.7% of TSS and 98% of enhancers. Correlating this map with ChIP-seq and RNA-seq data sets revealed cohesin, CTCF, and ZNF143 as key components of three-dimensional chromatin structure and revealed how the distal chromatin state affects gene transcription. Comparison of interactions between cell types revealed that enhancer-promoter interactions were highly cell-type-specific. Construction and comparison of distal and proximal regulatory networks revealed stark differences in structure and biological function. Proximal binding events are enriched at genes with housekeeping functions, while distal binding events interact with genes involved in dynamic biological processes including response to stimulus. This study reveals new mechanistic and functional insights into regulatory region organization in the nucleus. © 2014 Heidari et al.; Published by Cold Spring Harbor Laboratory Press.

  5. Chromosome conformation capture uncovers potential genome-wide interactions between human conserved non-coding sequences.

    Directory of Open Access Journals (Sweden)

    Daniel Robyr

    Full Text Available Comparative analyses of various mammalian genomes have identified numerous conserved non-coding (CNC DNA elements that display striking conservation among species, suggesting that they have maintained specific functions throughout evolution. CNC function remains poorly understood, although recent studies have identified a role in gene regulation. We hypothesized that the identification of genomic loci that interact physically with CNCs would provide information on their functions. We have used circular chromosome conformation capture (4C to characterize interactions of 10 CNCs from human chromosome 21 in K562 cells. The data provide evidence that CNCs are capable of interacting with loci that are enriched for CNCs. The number of trans interactions varies among CNCs; some show interactions with many loci, while others interact with few. Some of the tested CNCs are capable of driving the expression of a reporter gene in the mouse embryo, and associate with the oligodendrocyte genes OLIG1 and OLIG2. Our results underscore the power of chromosome conformation capture for the identification of targets of functional DNA elements and raise the possibility that CNCs exert their functions by physical association with defined genomic regions enriched in CNCs. These CNC-CNC interactions may in part explain their stringent conservation as a group of regulatory sequences.

  6. Pinoresinol inhibits proliferation and induces differentiation on human HL60 leukemia cells.

    Science.gov (United States)

    Sepporta, Maria Vittoria; Mazza, Teresa; Morozzi, Guido; Fabiani, Roberto

    2013-01-01

    Pinoresinol (PIN), one of the simplest lignans, is the precursor of other dietary lignans that are present in whole-grain cereals, legumes, fruits, and other vegetables. Several experimental and epidemiological evidences suggest that lignans may prevent human cancer in different organs. In this study we investigated the chemopreventive properties of PIN on cell lines derived from different sites either expressing or not the functional tumor suppressor protein p53. It was found that PIN inhibited the proliferation of p53 wild type colon and prostate tumor cells (HCT116 and LNCaP) while in breast cells the inhibition of growth was observed only in p53 mutant cells (MDA-MB-231). A potent antiproliferative activity of PIN was also observed on p53 null cells HL60 (IC50% 8 μM), their multidrug resistant variant HL60R (IC50% 32 μM) and K562. On HL60 cells, PIN caused a block of cell cycle in the G0/G1 phase, induced a weak proapoptotic effect but it was a good trigger of differentiation (NBT reduction and CD11b expression). PIN caused an upregulation of the CDK inhibitor p21(WAF1/Cip1) both at mRNA and protein levels so suggesting that this could be a mechanism by which PIN reduced proliferation and induced differentiation on HL60 cells.

  7. Mechanosensitive channel activity and F-actin organization in cholesterol-depleted human leukaemia cells.

    Science.gov (United States)

    Morachevskaya, Elena; Sudarikova, Anastasiya; Negulyaev, Yuri

    2007-04-01

    This study focuses on the functional role of cellular cholesterol in the regulation of mechanosensitive cation channels activated by stretch in human leukaemia K562 cells. The patch-clamp method was employed to examine the effect of methyl-beta-cyclodextrin (MbetaCD), a synthetic cholesterol-sequestering agent, on stretch-activated single currents. We found that cholesterol-depleting treatment with MbetaCD resulted in a suppression of the activity of mechanosensitive channels without a change in the unitary conductance. The probability that the channel was open significantly decreased after treatment with MbetaCD. Fluorescent microscopy revealed F-actin reorganization, possibly involving actin assembly, after incubation of the cells with MbetaCD. We suggest that suppression of mechanosensitive channel activation in cholesterol-depleted leukaemia cells is due to F-actin rearrangement, presumably induced by lipid raft destruction. Our observations are consistent with the notion that stretch-activated cation channels in eukaryotic cells are regulated by the membrane-cytoskeleton complex rather than by tension developed purely in the lipid bilayer.

  8. Human Liver Stem Cells Suppress T-Cell Proliferation, NK Activity, and Dendritic Cell Differentiation

    Directory of Open Access Journals (Sweden)

    Stefania Bruno

    2016-01-01

    Full Text Available Human liver stem cells (HLSCs are a mesenchymal stromal cell-like population resident in the adult liver. Preclinical studies indicate that HLSCs could be a good candidate for cell therapy. The aim of the present study was to evaluate the immunogenicity and the immunomodulatory properties of HLSCs on T-lymphocytes, natural killer cells (NKs, and dendritic cells (DCs in allogeneic experimental settings. We found that HLSCs inhibited T-cell proliferation by a mechanism independent of cell contact and dependent on the release of prostaglandin E2 (PGE2 and on indoleamine 2,3-dioxygenase activity. When compared with mesenchymal stromal cells (MSCs, HLSCs were more efficient in inhibiting T-cell proliferation. At variance with MSCs, HLSCs did not elicit NK degranulation. Moreover, HLSCs inhibited NK degranulation against K562, a NK-sensitive target, by a mechanism dependent on HLA-G release. When tested on DC generation from monocytes, HLSCs were found to impair DC differentiation and DCs ability to induce T-cell proliferation through PGE2. This study shows that HLSCs have immunomodulatory properties similar to MSCs, but, at variance with MSCs, they do not elicit a NK response.

  9. Human Liver Stem Cells Suppress T-Cell Proliferation, NK Activity, and Dendritic Cell Differentiation.

    Science.gov (United States)

    Bruno, Stefania; Grange, Cristina; Tapparo, Marta; Pasquino, Chiara; Romagnoli, Renato; Dametto, Ennia; Amoroso, Antonio; Tetta, Ciro; Camussi, Giovanni

    2016-01-01

    Human liver stem cells (HLSCs) are a mesenchymal stromal cell-like population resident in the adult liver. Preclinical studies indicate that HLSCs could be a good candidate for cell therapy. The aim of the present study was to evaluate the immunogenicity and the immunomodulatory properties of HLSCs on T-lymphocytes, natural killer cells (NKs), and dendritic cells (DCs) in allogeneic experimental settings. We found that HLSCs inhibited T-cell proliferation by a mechanism independent of cell contact and dependent on the release of prostaglandin E2 (PGE2) and on indoleamine 2,3-dioxygenase activity. When compared with mesenchymal stromal cells (MSCs), HLSCs were more efficient in inhibiting T-cell proliferation. At variance with MSCs, HLSCs did not elicit NK degranulation. Moreover, HLSCs inhibited NK degranulation against K562, a NK-sensitive target, by a mechanism dependent on HLA-G release. When tested on DC generation from monocytes, HLSCs were found to impair DC differentiation and DCs ability to induce T-cell proliferation through PGE2. This study shows that HLSCs have immunomodulatory properties similar to MSCs, but, at variance with MSCs, they do not elicit a NK response.

  10. Antiproliferative activity of methanol extracts of four species of Croton on different human cell lines

    Directory of Open Access Journals (Sweden)

    Jóice P. Savietto

    2013-08-01

    Full Text Available Several species of Croton have been described with biological activities, mainly due to diterpenes, alkaloids and/or other secondary metabolites. These activities account for the traditional use of Croton species to treat certain diseases in South America, Asia and Western Africa. The crude methanol extracts obtained from leaves and steam bark of Croton dichrous Müll. Arg., C. erythroxyloides Baill., C. myrianthus Müll. Arg. and C. splendidus Mart. ex Colla were tested for antiproliferative activity against ten human cancer cell lines. Chemical analyses of all extracts were carried out by GC/MS and HPLC/MS/MS. The leaf extract obtained from C. erythroxyloides showed potent activity against PC-3 (prostate and OVCAR-3 (ovary cell lines. Lupeol is suggested to be involved in such activity. Tiliroside, an acyl-glycosilated flavonoid ubiquitous in all tested extracts, seems to play an important role in the observed moderate activity of most extracts against the leukemia K562 cell lineage.

  11. Selective proliferation of human γδ T cells in vitro

    Institute of Scientific and Technical Information of China (English)

    CHENSONGHUA; AKINORIOKI; 等

    1996-01-01

    The effect of monoethylphosphate (MEP,commercial available or synthesized) together with IL-2 on the selective proliferation of human γδT cells in vitro from peripheral blood mononuclear cells (PBMC) of healthy donors and of cancer patients was investigated.The γδT cells were stimulated by MEP to proliferate in a dose-dependent manner.The effect of synthesized MEP was 10 times greater than that of commercial MEP.When the PBMCs of healthy donors were cultured for 25 d in the medium containing different concentrations of MEP,the total cell number increased about 1000-3000 fold;and the ratio of γδT cells reached to 70-80%.The selective expansion of γδT cells depended on the synergic action of MEP and IL-2.The bulk cultured γδT cells exhibited obvious cytotoxic activities against allogenic tumor cell lines (SQ-5,K562 and Daudi) and autologous tumor cells.The culture system described here not only offers a simple method for obtaining a large number of γδT cells which may become a new effector in the adoptive immunotherapy,but also provides a useful model for the further studies of the structure and function of γδT cells in vitro.

  12. Characterization of human mitochondrial ferritin promoter: identification of transcription factors and evidences of epigenetic control

    Science.gov (United States)

    Guaraldo, Michela; Santambrogio, Paolo; Rovelli, Elisabetta; di Savino, Augusta; Saglio, Giuseppe; Cittaro, Davide; Roetto, Antonella; Levi, Sonia

    2016-09-01

    Mitochondrial ferritin (FtMt) is an iron storage protein belonging to the ferritin family but, unlike the cytosolic ferritin, it has an iron-unrelated restricted tissue expression. FtMt appears to be preferentially expressed in cell types characterized by high metabolic activity and oxygen consumption, suggesting a role in protecting mitochondria from iron-dependent oxidative damage. The human gene (FTMT) is intronless and its promoter region has not been described yet. To analyze the regulatory mechanisms controlling FTMT expression, we characterized the 5‧ flanking region upstream the transcriptional starting site of FTMT by in silico enquiry of sequences conservation, DNA deletion analysis, and ChIP assay. The data revealed a minimal promoter region and identified the presence of SP1, CREB and YY1 as positive regulators, and GATA2, FoxA1 and C/EBPβ as inhibitors of the transcriptional regulation. Furthermore, the FTMT transcription is increased by acetylating and de-methylating agent treatments in K562 and HeLa cells. These treatments up-regulate FtMt expression even in fibroblasts derived from a Friedreich ataxia patient, where it might exert a beneficial effect against mitochondrial oxidative damage. The expression of FTMT appears regulated by a complex mechanism involving epigenetic events and interplay between transcription factors.

  13. The iron-chelating agent picolinic acid enhances transferrin receptors expression in human erythroleukaemic cell lines.

    Science.gov (United States)

    Testa, U; Louache, F; Titeux, M; Thomopoulos, P; Rochant, H

    1985-07-01

    Picolinic acid, a metal chelating molecule, was administered to human erythroleukaemic cell lines (K 562 and HEL) that were grown in serum-containing media. Picolinic acid inhibited both iron uptake and cell growth. Furthermore, picolinic acid was shown to markedly decrease the level of ferritin in the cells. In spite of the inhibition of cell growth, picolinic acid induced a marked increase in the transferrin-binding capacity of the cells. This phenomenon was due to a two-five-fold enhancement of the rate of transferrin receptor biosynthesis. Other iron-chelating compounds, capable of reducing the level of intracellular iron, also elicited a marked enhancement of the transferrin-binding capacity of the cells. However, the addition of iron, as ferric ammonium citrate, in the culture medium elicited a marked increase in the level of ferritin and a strong decrease in the transferrin-binding capacity of the cells. On the basis of these data we propose that a feed-back mechanism is involved in the regulation of transferrin receptors: when the cells accumulate iron they decrease the number of transferrin receptors in order to prevent further accumulation of iron; when no or low iron is available to the cells, the number of transferrin receptors markedly increases as a compensatory mechanism.

  14. The immunomodulatory effects of shark cartilage on the mouse and human immune system

    Directory of Open Access Journals (Sweden)

    ali Sheikhian

    2007-01-01

    Materials and methods: In an experimental study, the effects of different doses of shark cartilage on humoral (antibody titer immune response against sheep red blood cells (SRBC, were measured in mouse. In addition, we evaluated the modulatory effects of the shark cartilage on the natural killer (NK activity of the peritoneal cells of mouse against a tumor cell line called K562, according to the standard methods. The proliferative response of the human peripheral blood mononuclear cells was measured under the influence of shark cartilage. Results: Pure shark cartilage enhanced antibody response against SRBC in vivo. The hemagglutination titer which was 1/147 in the control group (injected with hen cartilage, increased to 1/1355 in the test group. The optimal dose was 100 mg/ml. both type of cartilage had blastogenic effect on peripheral blood mononuclear cells (the blastogenic index was 6.7 and 4.9 for impure shark cartilage and hen cartilage, respectively. NK activity was inhibited completely by pure shark cartilage (the amount of the killing activity of the effector peritoneal cells for the control and test groups against target cells was 25.9% and 5.5% respectively. Conclusion: Shark cartilage has a potent immunomodulatory effect on the specific immune mechanisms and some inhibitory effects on the innate immune mechanisms such as NC activity. Since the specific immunity has a more pivotal role against tumor formation, shark cartilage can be used as a cancer immunotherapeutic.

  15. Antioxidant activity and cytotoxic profie of Chuquiraga spinosa Lessing on human tumor cell lines: A promissory plant from Peruvian flra

    Directory of Open Access Journals (Sweden)

    Oscar Herrera-Calderon

    2017-05-01

    Full Text Available Objective: To determine the phytochemical content, antioxidant activity in vitro and cytotoxicity of crude ethanol extract (CEE, n-hexane fraction (NHF, petroleum ether fraction (PEF, chloroform fraction (CLF and ethyl acetate fraction (EAF of aerial parts of Chuquiraga spinosa (C. spinosa Lessing. Methods: Phytochemical screening was developed by color and precipitated formation. The evaluation of antioxidant activity was assessed using hydroxyl and nitric oxide radical. Total phenolic content (TPC and total flavonoids content (TFC were measured by using standard methods by spectrophotometry. The cytotoxic effect was determined on human tumor cell lines including MCF-7, H-460, HT-29, M-14, HUTU-80, K-562 and DU-145. Results: Phytochemical analysis confirmed the presence of phenols, flavonoids in crude extract and its all fractions. The CEE showed the highest antioxidant activity, for OH and NO radical scavenging tests (IC50 = 15.16 ± 3.45 μg/mL and IC50 = 18.91 ± 1.13 μg/mL, respectively. TPC was found to be the highest in the CEE (121.36 mg of gallic acid equivalent/g of dried extract compared to other fractions. The ranking order of NHF, PEF, CLF, EAF and CEE for TFC was 21.17 < 35.20 < 62.19 < 70.25 < 78.25 mg quercetin equivalent/g of dried extract. The crude ethanolic extract (μg/mL showed a high cytotoxicity on MCF-7 (IC50 = 9.25 ± 0.81, K-562 (IC50 = 7.34 ± 1.00, HT-29 (IC50 = 8.52 ± 2.69, H-460 (IC50 = 5.32 ± 1.05, M-14 (IC50 = 8.30 ± 0.60, DU-145 (IC50 = 7.09 ± 0.09, HUTU-80 (IC50 = 6.20 ± 0.50. Conclusions: The study showed that CEE of the aerial parts of C. spinosa can be measured as a natural source of antioxidant which might be effective towards preventing or slowing oxidative stress related to chronic diseases as well as cytotoxic agent.

  16. Cytotoxic effect of root extract of Tiliacora racemosa and oil of Semecarpus anacardium nut in human tumour cells.

    Science.gov (United States)

    Chakraborty, Sutapa; Roy, Madhumita; Taraphdar, Amit K; Bhattacharya, R K

    2004-08-01

    Tiliacora racemosa and Semecarpus anacardium, the two plants frequently used in Ayurvedic medicine for the treatment of cancerous diseases, have been selected to examine their action in four human tumour cell lines: acute myeloblastic leukaemia (HL-60), chronic myelogenic leukaemia (K-562), breast adenocarcinoma (MCF-7) and cervical epithelial carcinoma (HeLa). In cells grown in appropriate media the ethanol extract of T. racemosa root, the total alkaloids isolated from this organ and S. anacardium nut oil prepared according to the Ayurvedic principle were found to have cytotoxic activity. The alkaloid fraction from T. racemosa had maximum cytotoxicity and was effective against all four cell lines. S. anacardium oil was cytotoxic only in leukaemic cells. These herbal preparations were not cytotoxic towards normal human lymphocytes, suggesting their action is specific for tumour cells. On microscopic examination the cells treated with these agents exhibited characteristic morphological features of apoptosis, such as cell shrinkage, and the formation of apoptotic bodies. Fluorescent staining with propidium iodide revealed distinct chromatin condensation and nuclear fragmentation. The apoptotic index paralleled the cytotoxic parameters, and fragmented DNA extracted free of genomic DNA from treated cells displayed a typical ladder pattern on gel electrophoresis. Apoptosis induced by alkaloids and phenolics, the active principles present in T. racemosa and S. anacardium, respectively, was found to be mediated by the activation of caspases. Copyright (c) 2004 John Wiley & Sons, Ltd.

  17. Decreased Intracellular pH Induced by Cariporide Differentially Contributes to Human Umbilical Cord-Derived Mesenchymal Stem Cells Differentiation

    Directory of Open Access Journals (Sweden)

    Wei Gao

    2014-01-01

    Full Text Available Background/Aims: Na+/H+ exchanger 1 (NHE1 is an important regulator of intracellular pH (pHi. High pHi is required for cell proliferation and differentiation. Our previous study has proven that the pHi of mesenchymal stem cells is higher than that of normal differentiated cells and similar to tumor cells. NHE1 is highly expressed in both mesenchymal stem cells and tumor cells. Targeted inhibition of NHE1 could induce differentiation of K562 leukemia cells. In the present paper we explored whether inhibition of NHE1 could induce differentiation of mesenchymal stem cells. Methods: MSCs were obtained from human umbilical cord and both the surface phenotype and functional characteristics were analyzed. Selective NHE1 inhibitor cariporide was used to treat human umbilical cord-derived mesenchymal stem cells (hUC-MSCs. The pHi and the differentiation of hUC-MSCs were compared upon cariporide treatment. The putative signaling pathway involved was also explored. Results: The pHi of hUC-MSCs was decreased upon cariporide treatment. Cariporide up-regulated the osteogenic differentiation of hUC-MSCs while the adipogenic differentiation was not affected. For osteogenic differentiation, β-catenin expression was up-regulated upon cariporide treatment. Conclusion: Decreased pHi induced by cariporide differentially contributes to hUC-MSCs differentiation.

  18. Comparison of effects of the ethanolic extracts of brazilian propolis on human leukemic cells as assessed with the MTT assay.

    Science.gov (United States)

    Franchi, Gilberto C; Moraes, Cleber S; Toreti, Viviane C; Daugsch, Andreas; Nowill, Alexandre E; Park, Yong K

    2012-01-01

    Propolis is a resinous product collected by honey bees. It was also reported that propolis has a wide variety of biological actions, including antimicrobial activity and antioxidant, anti-inflammatory, and suppressive effects of dioxin toxicity activities. The aim of this study was to compare the in vitro cytotoxic activities of green propolis (G12) and red propolis (G13) in human leukemia cells. These cells were incubated with different concentrations of propolis and 48 hours after the IC(50) was calculated for each cell. The results showed that the red propolis has cytotoxic effect in vitro higher than green propolis. Red propolis was showed to be cytostatic in K562 cells and caused the same amount of apoptosis as its control Gleevec. In conclusion, these results showed that red propolis is more cytotoxic than the green propolis in a variety of human cell lines of leukemia. Red propolis may contain drugs capable of inhibiting cancer cell growth. Therefore, further isolation of respective chemical ingredients from the red propolis (G13) for identification of the activities is necessary.

  19. Comparison of Effects of the Ethanolic Extracts of Brazilian Propolis on Human Leukemic Cells As Assessed with the MTT Assay

    Directory of Open Access Journals (Sweden)

    Gilberto C. Franchi

    2012-01-01

    Full Text Available Propolis is a resinous product collected by honey bees. It was also reported that propolis has a wide variety of biological actions, including antimicrobial activity and antioxidant, anti-inflammatory, and suppressive effects of dioxin toxicity activities. The aim of this study was to compare the in vitro cytotoxic activities of green propolis (G12 and red propolis (G13 in human leukemia cells. These cells were incubated with different concentrations of propolis and 48 hours after the IC50 was calculated for each cell. The results showed that the red propolis has cytotoxic effect in vitro higher than green propolis. Red propolis was showed to be cytostatic in K562 cells and caused the same amount of apoptosis as its control Gleevec. In conclusion, these results showed that red propolis is more cytotoxic than the green propolis in a variety of human cell lines of leukemia. Red propolis may contain drugs capable of inhibiting cancer cell growth. Therefore, further isolation of respective chemical ingredients from the red propolis (G13 for identification of the activities is necessary.

  20. Polyphenols isolated from Allium cepa L. induces apoptosis by suppressing IAP-1 through inhibiting PI3K/Akt signaling pathways in human leukemic cells.

    Science.gov (United States)

    Han, Min Ho; Lee, Won Sup; Jung, Ji Hyun; Jeong, Jae-Hun; Park, Cheol; Kim, Hye Jung; Kim, GonSup; Jung, Jin-Myung; Kwon, Taeg Kyu; Kim, Gi-Young; Ryu, Chung Ho; Shin, Sung Chul; Hong, Soon Chan; Choi, Yung Hyun

    2013-12-01

    Allium cepa Linn is commonly used as supplementary folk remedy for cancer therapy. Evidence suggests that Allium extracts have anti-cancer properties. However, the mechanisms of the anti-cancer activity of A. cepa Linn are not fully elucidated in human cancer cells. In this study, we investigated anti-cancer effects of polyphenols extracted from lyophilized A. cepa Linn (PEAL) in human leukemia cells and their mechanisms. PEAL inhibited cancer cell growth by inducing caspase-dependent apoptosis. The apoptosis was suppressed by caspase 8 and 9 inhibitors. PEAL also up-regulated TNF-related apoptosis-inducing ligand (TRAIL) receptor DR5 and down-regulated survivin and cellular inhibitor of apoptosis 1 (cIAP-1). We confirmed these findings in other leukemic cells (THP-1, K562 cells). In addition, PEAL suppressed Akt activity and the PEAL-induced apoptosis was significantly attenuated in Akt-overexpressing U937 cells. In conclusion, our data suggested that PEAL induced caspase-dependent apoptosis in several human leukemic cells including U937 cells. The apoptosis was triggered through extrinsic pathway by up-regulating DR5 modulating as well as through intrinsic pathway by modulating IAP family members. In addition, PEAL induces caspase-dependent apoptosis at least in part through the inhibition of phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway. This study provides evidence that PEAL might be useful for the treatment of leukemia.

  1. Detection of (Leu-7)-positive cells with NK activity in human gingival tissues from patients with periodontitis

    Energy Technology Data Exchange (ETDEWEB)

    Komiyama, K.; Hirsch, H.Z.; Mestecky, J.; Moro, I.

    1986-03-05

    Natural killer (NK) cells have been identified in peripheral blood, lymphoid tissue and more recently in gut mucosa and may be involved in the regulation of immunoglobulin synthesis. They have assayed gingival tissues obtained from 25 periodontitis patients, for the presence and activity of NK cells. Routine histological techniques demonstrated an inflammatory infiltrate dominated by plasma cells and B lymphocytes. Indirect staining procedures with a biotin-labeled mouse anti-human, Leu-7 antibody revealed the presence of numerous positive cells accompanying the inflammatory cellular infiltrate in perivascular areas. Several specimens demonstrated positive-staining cells in the epithelium as well. Few cells were observed in histologically uninflammed areas. Single cell suspension obtained by collagenase digestion of 5 gingival samples were used in /sup 51/Cr release cytotoxicity assay against K562 cells. Three of the five samples were positive in this assay. The finding of Leu-7-positive cells in areas of intense plasma cell foci but not in uninflammed areas, may support a role for these cells in the regulation of immunoglobulin synthesis in oral mucosal tissues.

  2. Group I PAK inhibitor IPA-3 induces cell death and affects cell adhesivity to fibronectin in human hematopoietic cells.

    Directory of Open Access Journals (Sweden)

    Kateřina Kuželová

    Full Text Available P21-activated kinases (PAKs are involved in the regulation of multiple processes including cell proliferation, adhesion and migration. However, the current knowledge about their function is mainly based on results obtained in adherent cell types. We investigated the effect of group I PAK inhibition using the compound IPA-3 in a variety of human leukemic cell lines (JURL-MK1, MOLM-7, K562, CML-T1, HL-60, Karpas-299, Jurkat, HEL as well as in primary blood cells. IPA-3 induced cell death with EC50 ranging from 5 to more than 20 μM. Similar range was found for IPA-3-mediated dephosphorylation of a known PAK downstream effector, cofilin. The cell death was associated with caspase-3 activation, PARP cleavage and apoptotic DNA fragmentation. In parallel, 20 μM IPA-3 treatment induced rapid and marked decrease of the cell adhesivity to fibronectin. Per contra, partial reduction of PAK activity using lower dose IPA-3 or siRNA resulted in a slight increase in the cell adhesivity. The changes in the cell adhesivity were also studied using real-time microimpedance measurement and by interference reflection microscopy. Significant differences in the intracellular IPA-3 level among various cell lines were observed indicating that an active mechanism is involved in IPA-3 transport.

  3. Synthesis, characterization and the interaction of some new water-soluble metal Schiff base complexes with human serum albumin.

    Science.gov (United States)

    Asadi, Mozaffar; Asadi, Zahra; Sadi, Somaye Barzegar; Zarei, Leila; Baigi, Fatemeh Moosavi; Amirghofran, Zahra

    2014-03-25

    Some new water-soluble Schiff base complexes of Na2[M(L)(H2O)n]; (M=Zn, Cu, Ni, Mn) with a new water-soluble Schiff base ligand where L denotes an asymmetric N2O2 Schiff base ligands; N,N'-bis(5-sulfosalicyliden)-3,4-diaminobenzophenone (5-SO3-3,4-salbenz) were synthesized and characterized. The formation constants of the water soluble Schiff base complexes were calculated by Ketelaar's equation. The theoretical molecular structure for the complexes was computed by using the HF method and the 6-311G basis set. The mechanism of binding of Na2[M(L)(H2O)n] with human serum albumin (HSA) was studied by fluorescence spectroscopic technique. The results of fluorescence titration showed that the intrinsic fluorescence of HSA was quenched by the complexes; which was rationalized in terms of the dynamic quenching mechanism. The values of Stern-Volmer constants, quenching rate constants, binding constants, binding sites and average aggregation number of HSA have been determined. The thermodynamic parameters, were calculated by van't Hoff equation, indicate that the binding is entropy driven and enthalpically disfavored. Based on the Förster theory of non-radiation energy transfer, the efficiency of energy transfer and the distance between the donor (Trp residues) and the acceptor (complex) were obtained. Finally, the growth inhibitory effects of the complexes toward the K562 cancer cell line were measured.

  4. Identification of a novel splice variant of human PD-L1 Mrna encoding an isoform-lacking Igv-like domain

    Institute of Scientific and Technical Information of China (English)

    Xian-hui HE; Li-hui XU; Yi LIU

    2005-01-01

    Aim: To investigate the expression and regulation of PD-1 ligand 1 (PD-L1) in peripheral blood mononuclear cells (PBMC). Methods: The cDNA encoding human PD-L1 precursor was cloned from the total RNA extracted from the resting and phorbol dibutyrate plus ionomycin- or phytohemagglutinin-activated PBMC, by reverse transcription polymerase chain reaction (RT-PCR), and independent clones were sequenced and analyzed. The expression and subcellular localization were examined in transiently transfected cells. The PD-L1 gene expression in different PBMC was also analyzed by RT-PCR. Results: A novel human PD-L1 splice variant was identified from the activated PBMC. It was generated by splicing out exon 2 encoding an immunoglobulin variable domain (Igv)-like domain but retaining all other exons without a frame-shift. Consequently, the putative translated protein contained all other domains including the transmembrane region except for the Igv-like domain. Furthermore, the conventional isoform was expressed on the plasma surface whereas the novel isoform showed a pattern of intmcellular membrane distribution in transiently transfected K562 cells. In addition, the expression pattern of the PD-L1 splice variant was variable in different individuals and in different cellular status. Conclusion: PD-L1 expression may be regulated at the posttranscriptional level through alternative splicing, and modulation of the PD-L1 isoform expression may influence the outcome of specific immune responses in the peripheral tissues.

  5. Experiment list: SRX1091816 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ntibody=First, IP with custom mouse monoclonal BORIS Ab, next IP with custom mous...; ChIP-Seq source_name=Human chronic myelogenous leukemia; lymphoblastoid cells. || cell line=K562 || chip a

  6. Human Prolactin Improves Engraftment and Reconstitution of Human Peripheral Blood Lymphocytes in SCID Mice

    Institute of Scientific and Technical Information of China (English)

    Rui Sun; Jian Zhang; Cai Zhang; Jianhua Zhang; Shujuan Liang; Anyuan Sun; Junfu Wang; Zhigang Tian

    2004-01-01

    Recombinant human prolactin (rhPRL) was administered to huPBL-SCID mice to determine its effects on human immunologic reconsfitution and function. The huPBL-SCID mice were given 10 μg I.p. Injection of rhPRL every other day for a total of 10 injections after huPBL were transferred. The results demonstrated that rhPRL improved the engraftment of lymphocytes into thymus, lymph nodes and spleens, showing that the cellularities of these organs increased although the cellularities tended to vary depending on the donor. The amounts of human T cells (HLA-ABC+/CD3+) increased greatly in thymus (14.2 folds), spleen (4.16 folds) and lymph nodes (40.18 folds) after rhPRL injections. The amounts of human B cells (HLA-ABC+/CD19+) also increased greatly in lymph nodes (42.5 folds) and spleen (5.78 folds). The lymph node cells from the rhPRL-treated huPBL-SCID mice were more sensitive to PHA stimulation ([3H] thymidine incorporation). The supernatant of PHA-stimulated PBL from rhPRL-treated huPBL/SCID chimerism contained more cytokines (IFN-γ and IL-2). The natural cytotoxicity against human sensitive target cells, K562 cells, from spleen and bone marrow of hPBL/SCID chimerism was significantly enhanced by rhPRL administration. The lymph node cells were stimulated with LPS in vitro for 3 days and the lymphocytes from the rhPRL-treated huPBL-SCID mice were more sensitive to mitogen stimulation. Both serum total IgG level and IgM level of rhPRL-treated huPBL/SCID chimerism were increased, and even without DT-rechallenge the base line of DT-specific IgG was elevated after rhPRL treatment in huPBL-SCID mice. Thus, rhPRL stimulation promotes reconstitution of human immune system in huPBL-SCID mice.

  7. Human Prolactin Improves Engraftment and Reconstitution of Human Peripheral Blood Lymphocytes in SCID Mice

    Institute of Scientific and Technical Information of China (English)

    RuiSun; JianZhang; CaiZhang; JianhuaZhang; ShujuanLiang; AnyuanSun; JunfuWang; ZhigangTian

    2004-01-01

    Recombinant human prolactin (rhPRL) was administered to huPBL-SCID mice to determine its effects on human immunologic reconstitution and function. The huPBL-SCID mice were given 10 μg i.p. injection of rhPRL every other day for a total of 10 injections after huPBL were transfered. The results demonstrated that rhPRL improved the engraftment of lymphocytes into thymus, lymph nodes and spleens, showing that the cellularities of these organs increased although the cellularities tended to vary depending on the donor. The amounts of human T cells (HLA-ABC+/CD3+) increased greatly in thymus (14.2 folds), spleen (4.16 folds) and lymph nodes (40.18 folds) after rhPRL injections. The amounts of human B cells (HLA-ABC+/CD19+) also increased greatly in lymph nodes (42.5 folds) and spleen (5.78 folds). The lymph node cells from the rhPRL-treated huPBL-SCID mice were more sensitive to PHA stimulation (〔3H〕thymidine incorporation). The supernatant of PHA-stimulated PBL from rhPRL-treated huPBL/SCID chimerism contained more cytokines (IFN-γ and IL-2). The natural cytotoxicity against human sensitive target cells, K562 cells, from spleen and bone marrow of hPBL/SCID chimerism was significantly enhanced by rhPRL administration. The lymph node cells were stimulated with LPS in vitro for 3 days and the lymphocytes from the rhPRL-treated huPBL-SCID mice were more sensitive to mitogen stimulation. Both serum total IgG level and IgM level of rhPRL-treated huPBL/SCID chimerism were increased, and even without DT-rechallenge the base line of DT-specific IgG was elevated after rhPRL treatment in huPBL-SCID mice. Thus, rhPRL stimulation promotes reconstitution of human immune system in huPBL-SCID mice. Cellular & Molecular Immunology. 2004;1(2):129-136.

  8. Biological Characteristics of Exosomes Secreted by Human Umbilical Cord-derived Mesenchymal Stromal Cells%人脐带间充质干细胞来源外泌体的生物学特性研究

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    目的 探讨正常人脐带间充质干细胞(human umbilical cord mesenchymal stromal cells,hUC-MSCs)分泌的外泌体(exosomes)的免疫调节功能及对恶性肿瘤细胞体外增殖的影响.方法 采用组织贴壁法分离培养hUC-MSCs,收集第3~6代hUC-MSCs上清液,使用超速离心法分离纯化exosomes;通过电子显微镜观察exosomes形态并分析其直径和直径分布范围等特征;采用流式细胞仪检测其表面hUC-MSCs来源的CD44、CD73标志物.将exosomes与正常人外周血单个核细胞共培养,采用MTT检测exosomes对淋巴细胞增殖的影响,ELISA法检测上清液中IL-4和INF-γ的分泌量.选择慢性粒细胞白血病(CML)K562细胞株,加入exosomes共培养,应用MTT法、PI/AnnexinⅤ双染流式法检测exosomes对癌细胞体外生长增殖、凋亡的影响.结果 组织贴壁法成功分离hUC-MSCs,传代后呈长梭状生长.电镜观察分离得到的exosomes为椭圆形膜性小囊泡,经统计得出其直径在6.8~78.1 nm之间,且分布比较集中.流式细胞术测得exosomes高表达黏附分子CD44(54.1%)与干细胞标志物CD73 (31.5%),MTT和ELISA检测结果表明,不同浓度的exosomes均抑制外周血单个核细胞增殖且抑制细胞因子IL-4和INF-γ的分泌,呈现剂量依赖性.体外实验表明exosomes对K562细胞株具有抑制增殖、促进凋亡的作用.结论 hUC-MSCs来源的exosomes具有免疫调节作用及抑制K562细胞增殖的作用.

  9. The in-vitro antiproliferative effect of PRI-2191 and imatinib applied in combined treatment with cisplatin, idarubicin, or docetaxel on human leukemia cells.

    Science.gov (United States)

    Switalska, Marta; Nasulewicz-Goldeman, Anna; Opolska, Aleksandra; Maciejewska, Magdalena; Kutner, Andrzej; Wietrzyk, Joanna

    2012-01-01

    Imatinib mesylate (Gleevec, STI571) is a specific inhibitor of the Bcr/Abl fusion tyrosine kinase that exhibits potent antileukemic effects in chronic myelogenous leukemia. Bcr/Abl-positive K562 and Bcr/Abl-negative HL-60 human leukemia cells were used to investigate the effect of PRI-2191, a calcitriol analog, on the biological effects of imatinib combined with other anticancer drugs. The results show that PRI-2191 enhances the antiproliferative effect of imatinib on HL-60 cells. When these two agents together are applied with either docetaxel or cisplatin, but not with idarubicin, the antiproliferative effect could still be enhanced. Moreover, when the interaction between the chemotherapy agents was antagonistic or additive, PRI-2191 could even shift it to synergism. This effect correlated with an accumulation of HL-60 cells in the G0/G1 phase of the cell cycle and a decrease in the percentage of cells in the G2/M and S stage in the ternary combinations used. PRI-2191 did not influence apoptosis induced by imatinib alone or in ternary combinations with all the chemotherapy agents used. These results may suggest that the stronger antiproliferative effect of the combined treatment with PRI-2191 on HL-60 cells is related to cell cycle arrest rather than to the induction of apoptosis.

  10. Cre/loxP-mediated excision of a neomycin resistance expression unit from an integrated retroviral vector increases long terminal repeat-driven transcription in human hematopoietic cells.

    Science.gov (United States)

    Fernex, C; Dubreuil, P; Mannoni, P; Bagnis, C

    1997-01-01

    Recombinant retroviruses are currently the most attractive vehicles for gene transfer into hematopoietic cells. Retroviral vectors often contain an easily selectable marker gene in addition to the gene of interest. However, the presence and selection for expression of the selectable gene often result in a significant reduction of the expression of the gene of interest in the transduced cells. In order to circumvent this problem, we have developed a Cre/loxP recombination system for specific excision of the selectable expression unit from integrated retroviruses. A retroviral vector, containing both a neomycin resistance expression unit flanked by loxP sites and granulocyte-macrophage colony-stimulating factor cDNA, was used to transduce the human hematopoietic K-562 cell line. Four transduced cell clones were then superinfected with a retrovirus containing a Cre recombinase expression unit. Molecular analyses of 30 doubly transduced subclones showed a strict correlation between cre expression and loxP-flanked selectable cassette excision, thus implying that Cre recombinase activity is very efficient in a retroviral context. Moreover, the excision of the selectable cassette results in a significant increase of granulocyte-macrophage colony-stimulating factor transcription driven by the retroviral promoter. PMID:9311833

  11. Distinct regulatory mechanisms of the human ferritin gene by hypoxia and hypoxia mimetic cobalt chloride at the transcriptional and post-transcriptional levels.

    Science.gov (United States)

    Huang, Bo-Wen; Miyazawa, Masaki; Tsuji, Yoshiaki

    2014-12-01

    Cobalt chloride has been used as a hypoxia mimetic because it stabilizes hypoxia inducible factor-1α (HIF1-α) and activates gene transcription through a hypoxia responsive element (HRE). However, differences between hypoxia and hypoxia mimetic cobalt chloride in gene regulation remain elusive. Expression of ferritin, the major iron storage protein, is regulated at the transcriptional and posttranscriptional levels through DNA and RNA regulatory elements. Here we demonstrate that hypoxia and cobalt chloride regulate ferritin heavy chain (ferritin H) expression by two distinct mechanisms. Both hypoxia and cobalt chloride increased HIF1-α but a putative HRE in the human ferritin H gene was not activated. Instead, cobalt chloride but not hypoxia activated ferritin H transcription through an antioxidant responsive element (ARE), to which Nrf2 was recruited. Intriguingly, cobalt chloride downregulated ferritin H protein expression while it upregulated other ARE-regulated antioxidant genes in K562 cells. Further characterization demonstrated that cobalt chloride increased interaction between iron regulatory proteins (IRP1 and IRP2) and iron responsive element (IRE) in the 5'UTR of ferritin H mRNA, resulting in translational block of the accumulated ferritin H mRNA. In contrast, hypoxia had marginal effect on ferritin H transcription but increased its translation through decreased IRP1-IRE interaction. These results suggest that hypoxia and hypoxia mimetic cobalt chloride employ distinct regulatory mechanisms through the interplay between DNA and mRNA elements at the transcriptional and post-transcriptional levels.

  12. NK cells are strongly activated by Lassa and Mopeia virus-infected human macrophages in vitro but do not mediate virus suppression.

    Science.gov (United States)

    Russier, Marion; Reynard, Stéphanie; Tordo, Noël; Baize, Sylvain

    2012-07-01

    Lassa virus (LASV) and Mopeia virus (MOPV) are closely related Arenaviruses. LASV causes hemorrhagic fever, whereas MOPV is not pathogenic. Both viruses display tropism for APCs such as DCs and macrophages. During viral infections, NK cells are involved in the clearance of infected cells and promote optimal immune responses by interacting with APCs. We used an in vitro model of human NK and APC coculture to study the role of NK cells and to characterize their interactions with APCs during LASV and MOPV infections. As expected, NK cells alone were neither infected nor activated by LASV and MOPV, and infected DCs did not activate NK cells. By contrast, LASV- and MOPV-infected macrophages activated NK cells, as shown by the upregulation of CD69, NKp30, and NKp44, the downregulation of CXCR3, and an increase in NK-cell proliferation. NK cells acquired enhanced cytotoxicity, as illustrated by the increase in granzyme B (GrzB) expression and killing of K562 targets, but did not produce IFN-γ. Contact between NK cells and infected macrophages and type I IFNs were essential for activation; however, NK cells could not kill infected cells and control infection. Overall, these findings show that MOPV- as well as pathogenic LASV-infected macrophages mediate NK-cell activation.

  13. Manipulation of EAT-2 expression promotes induction of multiple beneficial regulatory and effector functions of the human innate immune system as a novel immunomodulatory strategy.

    Science.gov (United States)

    Aldhamen, Yasser A; Seregin, Sergey S; Aylsworth, Charles F; Godbehere, Sarah; Amalfitano, Andrea

    2014-05-01

    The signaling lymphocytic activation molecule (SLAM) receptor-associated adaptor Ewing's sarcoma-associated transcript-2 (EAT-2) is primarily expressed in innate immune cells including dendritic cells (DCs), macrophages and NK cells. A recent human HIV vaccine study confirmed that EAT-2 expression was associated with the enhanced immunogenicity induced by the MRKAd5/HIV vaccine. We previously harnessed the capability of EAT-2 to modulate signaling mediated by SLAM receptors and demonstrated that by incorporating EAT-2 expression into vaccines, one could enhance innate and adaptive immune responses in mice, even in the face of pre-existing immunity to the vaccine vectors. Herein, we investigated the innate immune responses of human cells exposed to EAT-2-over-expressing vaccines. Our results demonstrate that EAT-2 over-expression can significantly alter the kinetics of critical pro-inflammatory cytokine and chemokine responses elaborated by human PBMCs. In addition, enhanced DC maturation and increased monocyte phagocytosis were observed in EAT-2-transduced human cells. We also found that EAT-2 over-expression improved antigen presentation by human cells. Moreover, EAT-2 over-expression increased the anti-tumor activity of human NK cells against K562 tumor cell targets. Many of these responses were extinguished with use of an EAT-2 variant carrying a mutant SH2 domain (R31Q), suggesting a critical role for the interaction between EAT-2 and SLAM receptors in mediating these responses. In conclusion, these results provide evidence that EAT-2 interacts with key components of multiple arms of the human innate immune system, and that this role highlights the potential for targeting EAT-2 functions so as to improve a number of human immunotherapeutic approaches, including vaccine development.

  14. A simple method for obtaining transferrins from human plasma and porcine serum: preparations and properties.

    Science.gov (United States)

    Wu, Lin; Wu, Jinhui; Zhang, Jian; Zhou, Yuanyuan; Ren, Guoyan; Hu, Yiqiao

    2008-05-01

    A simple method was described for the purification of serum transferrin (Tf) from human plasma and porcine serum with relative high yield and purity. The properties including purity, integrity, immunoreactivity and the receptor-binding ability of the proteins were studied by several assays, comprising spectrometry, SDS-PAGE, HPLC, Western blotting, urea electrophoresis, mass spectrometry and cytometry. Analysis from all the different aspects manifested that the proteins were of high purity. The two kinds of Tfs appeared to be iron-saturated as confirmed by their absorbance spectra and urea-PAGE mobility. The specific spectra of absorption of the two Tfs were both at around 465 nm. The relative molecular weights of human Tf (hTf) and porcine Tf (pTf) were determined by SDS-PAGE and further identified by MAIDI-TOF mass spectrometry with a result of 79,707 and 79,258, respectively. Immunoblotting assay showed that pTf could react with the anti-human Tf monoclonal antibody with a less level compared to hTf. FACS assays of their binding activities to Tf receptor-positive cell (K562 cell line) indicated that pTf could be recognized by the hTf receptor and internalized into cells, with a slightly less efficacy than hTf. All special property studies demonstrated that pTf was similar to hTf in physical and chemical characteristics, which gave a hint that pTf could substitute for hTf in some kinds of researches, such as using hTf as a carrier in drug targeting system.

  15. Human platelets repurposed as vehicles for in vivo imaging of myeloma xenotransplants

    Science.gov (United States)

    Dai, Lu; Gu, Ning; Chen, Bao-An; Marriott, Gerard

    2016-01-01

    Human platelets were identified in tumors by Trousseau in 1865, although their roles in tumor microenvironments have only recently attracted the attention of cancer researchers. In this study we exploit and enhance platelet interactions in tumor microenvironments by introducing tumor-targeting and imaging functions. The first step in repurposing human platelets as vehicles for tumor-targeting was to inhibit platelet-aggregation by cytoplasmic-loading of kabiramide (KabC), a potent inhibitor of actin polymerization and membrane protrusion. KabC-Platelets can accumulate high levels of other membrane-permeable cytoxins and probes, including epidoxorubicin, carboxyfluorescein di-ester and chlorin-e6. Finally, mild reaction conditions were developed to couple tumor-targeting proteins and antibodies to KabC-platelets. Fluorescence microscopy studies showed KabC-platelets, surface-coupled with transferrin and Cy5, bind specifically to RPMI8226 and K562 cells, both of which over-express the transferrin receptor. Repurposed platelets circulate for upto 9-days a feature that increases their chance of interacting with target cells. KabC-platelets, surface-coupled with transferrin and Cy7, or chlorin-e6, and injected in immuno-compromised mice were shown to accumulate specifically in sub-cutaneous and intra-cranial myeloma xenotransplants. The high-contrast, in vivo fluorescence images recorded from repurposed platelets within early-stage myeloma is a consequence in part of their large size (φ∼2μm), which allows them to transport 100 to 1000-times more targeting-protein and probe molecules respectively. Human platelets can be configured with a plurality of therapeutic and targeting antibodies to help stage tumor environments for an immunotherapy, or with combinations of therapeutic antibodies and therapeutic agents to target and treat cardiovascular and neurologic diseases. PMID:27049725

  16. Reactivating Fetal Hemoglobin Expression in Human Adult Erythroblasts Through BCL11A Knockdown Using Targeted Endonucleases

    Directory of Open Access Journals (Sweden)

    Carmen F Bjurström

    2016-01-01

    Full Text Available We examined the efficiency, specificity, and mutational signatures of zinc finger nucleases (ZFNs, transcriptional activator-like effector nucleases (TALENs, and clustered regularly interspaced short palindromic repeat (CRISPR/Cas9 systems designed to target the gene encoding the transcriptional repressor BCL11A, in human K562 cells and human CD34+ progenitor cells. ZFNs and TALENs were delivered as in vitro transcribed mRNA through electroporation; CRISPR/Cas9 was codelivered by Cas9 mRNA with plasmid-encoded guideRNA (gRNA (pU6.g1 or in vitro transcribed gRNA (gR.1. Analyses of efficacy revealed that for these specific reagents and the delivery methods used, the ZFNs gave rise to more allelic disruption in the targeted locus compared to the TALENs and CRISPR/Cas9, which was associated with increased levels of fetal hemoglobin in erythroid cells produced in vitro from nuclease-treated CD34+ cells. Genome-wide analysis to evaluate the specificity of the nucleases revealed high specificity of this specific ZFN to the target site, while specific TALENs and CRISPRs evaluated showed off-target cleavage activity. ZFN gene-edited CD34+ cells had the capacity to engraft in NOD-PrkdcSCID-IL2Rγnull mice, while retaining multi-lineage potential, in contrast to TALEN gene-edited CD34+ cells. CRISPR engraftment levels mirrored the increased relative plasmid-mediated toxicity of pU6.g1/Cas9 in hematopoietic stem/progenitor cells (HSPCs, highlighting the value for the further improvements of CRISPR/Cas9 delivery in primary human HSPCs.

  17. Human platelets repurposed as vehicles for in vivo imaging of myeloma xenotransplants.

    Science.gov (United States)

    Dai, Lu; Gu, Ning; Chen, Bao-An; Marriott, Gerard

    2016-04-19

    Human platelets were identified in tumors by Trousseau in 1865, although their roles in tumor microenvironments have only recently attracted the attention of cancer researchers. In this study we exploit and enhance platelet interactions in tumor microenvironments by introducing tumor-targeting and imaging functions. The first step in repurposing human platelets as vehicles for tumor-targeting was to inhibit platelet-aggregation by cytoplasmic-loading of kabiramide (KabC), a potent inhibitor of actin polymerization and membrane protrusion. KabC-Platelets can accumulate high levels of other membrane-permeable cytoxins and probes, including epidoxorubicin, carboxyfluorescein di-ester and chlorin-e6. Finally, mild reaction conditions were developed to couple tumor-targeting proteins and antibodies to KabC-platelets. Fluorescence microscopy studies showed KabC-platelets, surface-coupled with transferrin and Cy5, bind specifically to RPMI8226 and K562 cells, both of which over-express the transferrin receptor. Repurposed platelets circulate for upto 9-days a feature that increases their chance of interacting with target cells. KabC-platelets, surface-coupled with transferrin and Cy7, or chlorin-e6, and injected in immuno-compromised mice were shown to accumulate specifically in sub-cutaneous and intra-cranial myeloma xenotransplants. The high-contrast, in vivo fluorescence images recorded from repurposed platelets within early-stage myeloma is a consequence in part of their large size (φ~2µm), which allows them to transport 100 to 1000-times more targeting-protein and probe molecules respectively. Human platelets can be configured with a plurality of therapeutic and targeting antibodies to help stage tumor environments for an immunotherapy, or with combinations of therapeutic antibodies and therapeutic agents to target and treat cardiovascular and neurologic diseases.

  18. Detection of regulatory SNPs in human genome using ChIP-seq ENCODE data.

    Science.gov (United States)

    Bryzgalov, Leonid O; Antontseva, Elena V; Matveeva, Marina Yu; Shilov, Alexander G; Kashina, Elena V; Mordvinov, Viatcheslav A; Merkulova, Tatyana I

    2013-01-01

    A vast amount of SNPs derived from genome-wide association studies are represented by non-coding ones, therefore exacerbating the need for effective identification of regulatory SNPs (rSNPs) among them. However, this task remains challenging since the regulatory part of the human genome is annotated much poorly as opposed to coding regions. Here we describe an approach aggregating the whole set of ENCODE ChIP-seq data in order to search for rSNPs, and provide the experimental evidence of its efficiency. Its algorithm is based on the assumption that the enrichment of a genomic region with transcription factor binding loci (ChIP-seq peaks) indicates its regulatory function, and thereby SNPs located in this region are more likely to influence transcription regulation. To ensure that the approach preferably selects functionally meaningful SNPs, we performed enrichment analysis of several human SNP datasets associated with phenotypic manifestations. It was shown that all samples are significantly enriched with SNPs falling into the regions of multiple ChIP-seq peaks as compared with the randomly selected SNPs. For experimental verification, 40 SNPs falling into overlapping regions of at least 7 TF binding loci were selected from OMIM. The effect of SNPs on the binding of the DNA fragments containing them to the nuclear proteins from four human cell lines (HepG2, HeLaS3, HCT-116, and K562) has been tested by EMSA. A radical change in the binding pattern has been observed for 29 SNPs, besides, 6 more SNPs also demonstrated less pronounced changes. Taken together, the results demonstrate the effective way to search for potential rSNPs with the aid of ChIP-seq data provided by ENCODE project.

  19. Induction of apoptosis in human leukemia cells by naturally fermented sugar cane vinegar (kibizu) of Amami Ohshima Island.

    Science.gov (United States)

    Mimura, Akio; Suzuki, Yoshihiro; Toshima, Youhei; Yazaki, Shin-ichi; Ohtsuki, Takashi; Ui, Sadaharu; Hyodoh, Fuminori

    2004-01-01

    Naturally fermented vinegar such as Kibizu (sugar cane vinegar in Amami Ohshima, Japan), Kurozu (black rice vinegar in Kagoshima, Japan), Kouzu (black rice vinegar in China) and red wine vinegar in Italy had potent radical-scavenging activity analyzed by DPPH method. For the elucidation of food factor for cancer prevention contained in naturally fermented vinegar, the induction of apoptosis in human leukemia cell HL-60 was investigated with sugar cane vinegar Kibizu. Fraction eluted by 40% methanol from Amberlite XAD 2 chromatography of sugar cane vinegar showed potent radical scavenging activity. The fraction also showed the activity repressing growth of typical human leukemia cells such as HL-60, THP-1, Molt-4, U-937, Jurkat, Raji and K-562. On the other hand, the fraction did not have any growth inhibition activity against human fetal lung cell TIG-1. The most potent radical-scavenging activity and the growth repression activity of the leukemia cell were observed in the same chromatographic fraction of methanol 40%. From cell sorting FACS analyses, electron microscopic observations and cytochemical staining of chromatin and nuclear segments in human leukemia cell HL-60 treated with the active fraction, it was concluded that apoptosis was induced in the leukemia cell by the fraction of sugar cane vinegar and resulted in the repression of growth of the human leukemia cells. Chromatographic fraction of sugar cane juice eluted by 20% methanol showed potent activities of radical-scavenging and growth repression of HL-60. These results led us the consideration that active components in sugar cane juice could be converted to more lipophilic compounds with activity to induce apoptosis in HL-60 by microbial fermentation with yeast and acetic acid bacteria.

  20. Reversion of P-Glycoprotein-Mediated Multidrug Resistance in Human Leukemic Cell Line by Diallyl Trisulfide

    Directory of Open Access Journals (Sweden)

    Qing Xia

    2012-01-01

    Full Text Available Multidrug resistance (MDR is the major obstacle in chemotherapy, which involves multiple signaling pathways. Diallyl trisulfide (DATS is the main sulfuric compound in garlic. In the present study, we aimed to explore whether DATS could overcome P-glycoprotein-(P-gp-mediated MDR in K562/A02 cells, and to investigate whether NF-κB suppression is involved in DATS-induced reversal of MDR. MTT assay revealed that cotreatment with DATS increased the response of K562/A02 cells to adriamycin (the resistance reversal fold was 3.79 without toxic side effects. DATS could enhance the intracellular concentration of adriamycin by inhibiting the function and expression of P-gp, as shown by flow cytometry, RT-PCR, and western blot. In addition, DATS resulted in more K562/A02 cell apoptosis, accompanied by increased expression of caspase-3. The expression of NF-κB/p65 (downregulation was significantly linked to the drug-resistance mechanism of DATS, whereas the expression of IκBα was not affected by DATS. Our findings demonstrated that DATS can serve as a novel, nontoxic modulator of MDR, and can reverse the MDR of K562/A02 cells in vitro by increasing intracellular adriamycin concentration and inducing apoptosis. More importantly, we proved for the first time that the suppression of NF-κB possibly involves the molecular mechanism in the course of reversion by DATS.

  1. Characterization of human mucin (MUC15) and identification of ovine and caprine orthologs

    DEFF Research Database (Denmark)

    Pallesen, Lone Tjener; Pedersen, Lise Refstrup Linnebjerg; Petersen, Torben Ellebæk

    2008-01-01

    expression in placenta, salivary gland, thyroid gland, trachea, esophagus, kidney, testis, and the leukemia K-562 cell line. Furthermore, moderate expression was seen in the pancreas, adult and fetal lung, fetal kidney, lymph node, adult and fetal thymus, and parietal lobe. Structural motifs for interactions...

  2. Flow cytometric evaluation of the effects of 3-bromopyruvate (3BP) and dichloracetate (DCA) on THP-1 cells: a multiparameter analysis

    NARCIS (Netherlands)

    Verhoeven, H.A.; Griensven, van L.J.L.D.

    2012-01-01

    Two human leukemia cells K562 and THP-1, the breast cancer lines MCF-7 and ZR-75-1, and the melanoma line MDA-MB-435S were compared by flowcytometry for their behaviour at increasing levels of 3BP. K562 and THP-1 responded to 3BP by membrane depolarization and increased ROS; MCF-7 and ZR-75-1 showed

  3. Study of Transcription Activity of X-Box Binding Protein 1 Gene in Human Different Cell Lines%人类不同类型细胞中X-盒结合蛋白1转录活性研究

    Institute of Scientific and Technical Information of China (English)

    郭风劲; 宋方洲; 张静; 李婧; 唐勇

    2007-01-01

    Human X-box binding protein 1 (XBP1), an important transcription factor, participates in many signal transduction processes. To further investigate the biological function of XBP1, sequences of XBP1 promoter and its two deletion mutants were first determined using bioinformatic analysis. The report vectors containing XBP1 promoter and its deletion mutants were then constructed, namely, p1-XBP1p, p2-XBP1p, and p3-XBP1p. Each reporter vector was separately transfected into HepG2, L02, K562,SMMC-7721, HSF, and Lipocyte Ito Cell line using FuGENE 6 transfection reagents. The activity of chloramphenicol acetyltransferase (CAT) in each group of transfected cells was detected by ELISA assay, which in turn reflects the transcription activity of the XBP1 gene promoter. The activity involving p3-XBP1p was the highest in HepG2, which was 12.4-fold of that of pCAT3-Basic. The activities of p3-XBP1p in K562 and SMMC-7721 were the second and the third highest, which were 10.9-fold and 10.0-fold of that of the pCAT3-Basic, respectively. The CAT activity in L02 was lower than that in the above-mentioned abnormal cell, and no reporter activity was detected in HSF and Ito Cell. The XBP1 transcription and expression in K562, HepG2 and SMMC-7721 were found to be higher than that in L02, HSF and Ito cells, based on the results of real-time RT-PCR and Western blot. The XBP1 transcription and expression in L02, HSF was lower, whereas that in Ito cells was totally lacking. The result was similar to that of CAT-ELISA. Therefore, the XBP1 gene promoter can drive its downstream gene expression and its activity is cell line-dependent.The core sequence of XBP1 promoter was found between -227bp and 66bp sequence. This sequence was closely associated with the transcriptional activity of XBP1 promoter.%人类X-盒结合蛋白1(X-box binding protein1,XBP1)作为一种重要的转录因子,在细胞中涉及了广泛的信号调控过程.为进一步研究XBP1的生物学功能,首先利用

  4. Inhibition of Leukemic Cell Telomerase Activity by Antisense Phosphorothioate Oligodeoxynucleotides

    Institute of Scientific and Technical Information of China (English)

    HEDongmei; ZHANGYuan

    2002-01-01

    Objective To evaluate the effect of human telomerase reverse transcriptase(hTERT) gene antisense oligodeoxynucleotide (ASON) on telomerase activity in K562 cells.Methods Telomerase activity was detemined by polymerase chain reaction enzyme-linked immunoassay (PCR-ELISA) in K562 cells treated with ASODN and hTERTmRNA expression was detected by reverse transcriptase polymerase chain reaction (RT-PCR). Results The hTERTmRNA level was decreased,and telomerase activity was significantly inhibited when the K562 cells were treated with ASODN for 48 h. Conclusion It is suggested that hTETR ASODN might specifically inhibit telomrase activity of K562 cells at translation level,and it is further proved that hTERT gene has significant correlation with telopmerase activity.

  5. Effects of highly purified anthraquinoid compounds from Aloe vera on sensitive and multidrug resistant leukemia cells.

    Science.gov (United States)

    Grimaudo, S; Tolomeo, M; Gancitano, R; Dalessandro, N; Aiello, E

    1997-01-01

    Folk medicine has attributed antitumor properties to preparations from Aloe vera. We have studied the effects of five purified compounds from the plant on human K562 leukemia and on its multidrug resistant (MDR) variant, K562/R. The glycosides aloin A and B, aloesin and aloeresin were devoid of antitumor activity up to 200 mu M concentrations. Only the aglycone aloe emodin produced reproducible antitumor effects, which, interestingly, were more pronounced in the MDR, P-glycoprotein overexpressing, cell line. Its IC50 was in fact 29 mu M in K562 and 10.5 mu M in K562/R. Aloe emodine caused mainly cytostasis and accumulation of the cells in the S and G(2)-M phases of the cell cycle during the first 48 h of treatment. Thereafter, massive cell death ensued. Research on the antitumor activity of compounds extracted from Aloe vera probably deserves continuation.

  6. Antileukemic activity of the leaf extract of Bischofia javanica blume on human leukemic cell lines

    Directory of Open Access Journals (Sweden)

    Sutharson Lingadurai

    2011-01-01

    Full Text Available Objective : Leaves of Bichofia javanica (BJ have been traditionally used for many ailments including cancer. In the present study, antileukemic activity of the leaf extract was evaluated on human leukemic cell lines. Materials and Methods : Human leukemic cell lines U937, K562, and HL60 were purchased from National Facility for Animal Tissue and Cell Culture, Pune, India. The cells were routinely maintained in RPMI 1640 medium supplemented with 10% heat inactivated fetal calf serum. Cultures were maintained at 37ºC in a humidified atmosphere containing 5% CO 2 in air. The methanol extract of BJ (MEBJ was dissolved in PBS and used at the concentrations of 5, 10, and 15 μg/ml for cell viability and cytotoxicity studies (MTT assay. Cell counts were made in quadruplicate samples at the interval of 24, 48, and 72 h and cytarabine (20 μg/ml served as standard drug. The apoptotic pathway of cytotoxicity was assessed by DNA agarose gel electrophoresis technique and confirmed by fluorescence and confocal microscopic methods at the concentration of 10 μg/ml. Results : MEBJ showed significant cytotoxicity (P<0.001 in leukemic cell lines in the in-vitro cell proliferation assay. IC 50 of MEBJ was very low (3.5 μg/ml at 72 h in the HL60 cell line. The apoptotic pathway of cytotoxicity was observed at 10 μg/ml of MEBJ by the fragmented DNA pattern in the apoptosis assay, chromatin condensation, and apoptotic body formation as revealed in the fluorescence and confocal microscopic studies. Conclusion : The present findings support the ethno-medicinal use of BJ for cancer by mediating through the apoptosis pathway.

  7. Comparison of the uptakes of {sup 99m}Tc-sestamibi and {sup 99m}Tc-tetrofosmin in cancer cell lines expressing multidrug resistance

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Jeong Ah; Chung, Shin Young; Seo, Myeng Rang; Kwak, Dong Suk; Ahm, Byeong Cheol; Lee, Kyu Bo; Lee, Jae Tae [Kyungpook National University School of Medicine, Taegu (Korea, Republic of)

    2003-06-01

    Cellular uptakes of {sup 99m}Tc-sestamibi(MIBI) and {sup 99m}Tc-tetrofosmin into cancer cell lines expressing multidrug resistance(MDR) were investigated and compared. The effects of verapamil and cyclosporin A, well-known multidrug resistant reversing agents, on cellular uptakes of both tracers were also compared. Doxorubicin-resistant HCT15/CL02 human colorectal cell and doxorubicin-resistant K562(Adr) and vincristin-resistant K562(Vcr) human leukemic cells were studied. RT-PCR analysis was used for the detection of mdr1 mRNA expression. MDR-reversal effects with verapamil and cyclosporine A were evaluated at different drug concentrations after incubation with MIBI and tetrofosimin for 1, 15, 30, 45 and 60 min, using single-cell suspensions at 1x10{sup 6} cells/ml incubated at 37 .deg. C. Radioactivity in supernatants and pellets were measured with gamma well counter. The cellular uptakes of MIBI and tetrofosmin in K562(Adr) and K562(Vcr) were lower than those of parental K562 cell. In HCT15/CL02 cells ad K562(Adr) cells, there were no significant difference in cellular uptakes of both tracers, but cellular uptake of MIBI was higher than that of tetrofosmin in K562(Vcr) cells. Coincubation with verapamil resulted in a increase in cellular uptakes of MIBI and tetrofosmin. Verapamil increased cellular uptakes of MIBI and tetrofosmin by HCT15/LC02 cell by 11.9- and 6.8-fold, by K562(Adr) cell by 14.3- and 8-fold and by K562(Vcr) cell by 7- and 5.7-fold in maximum, respectively. Cyclosporin A increased cellular uptakes of MIBI and tetrofosmin by HCT15/CL02 cell by 10- and 2.4-fold, by K562(Adr) cell by 44- and 13-fold and by K562(Vcr) cell by 18.8- and 11.8-fold in maximum, respectively. Taking together, MIBI and tetrofosmin are considered as suitable radiopharmaceuticals for detecting multidrug resistance. However, MIBI seems to be a better tracer than tetrofosmin for evaluating MDR reversal effect of the modulators. Since cellular uptakes of both tracers might

  8. Gain of DNA methylation is enhanced in the absence of CTCF at the human retinoblastoma gene promoter

    Directory of Open Access Journals (Sweden)

    Recillas-Targa Félix

    2011-06-01

    Full Text Available Abstract Background Long-term gene silencing throughout cell division is generally achieved by DNA methylation and other epigenetic processes. Aberrant DNA methylation is now widely recognized to be associated with cancer and other human diseases. Here we addressed the contribution of the multifunctional nuclear factor CTCF to the epigenetic regulation of the human retinoblastoma (Rb gene promoter in different tumoral cell lines. Methods To assess the DNA methylation status of the Rb promoter, genomic DNA from stably transfected human erythroleukemic K562 cells expressing a GFP reporter transgene was transformed with sodium bisulfite, and then PCR-amplified with modified primers and sequenced. Single- and multi-copy integrants with the CTCF binding site mutated were isolated and characterized by Southern blotting. Silenced transgenes were reactivated using 5-aza-2'-deoxycytidine and Trichostatin-A, and their expression was monitored by fluorescent cytometry. Rb gene expression and protein abundance were assessed by RT-PCR and Western blotting in three different glioma cell lines, and DNA methylation of the promoter region was determined by sodium bisulfite sequencing, together with CTCF dissociation and methyl-CpG-binding protein incorporation by chromatin immunoprecipitation assays. Results We found that the inability of CTCF to bind to the Rb promoter causes a dramatic loss of gene expression and a progressive gain of DNA methylation. Conclusions This study indicates that CTCF plays an important role in maintaining the Rb promoter in an optimal chromatin configuration. The absence of CTCF induces a rapid epigenetic silencing through a progressive gain of DNA methylation. Consequently, CTCF can now be seen as one of the epigenetic components that allows the proper configuration of tumor suppressor gene promoters. Its aberrant dissociation can then predispose key genes in cancer cells to acquire DNA methylation and epigenetic silencing.

  9. Effect of carbamate pesticides on perforin, granzymes A-B-3/K, and granulysin in human natural killer cells.

    Science.gov (United States)

    Li, Qing; Kobayashi, Maiko; Kawada, Tomoyuki

    2015-09-01

    We previously found that ziram, a carbamate pesticide, significantly reduced perforin, granzyme A (GrA), granzyme B (GrB), granzyme 3/K (Gr3/K), and granulysin (GRN) levels in NK-92MI cells, a human natural killer (NK) cell line. To investigate whether other carbamate pesticides also show similar toxicity on human NK cells, we conducted further experiments with NK-92CI cells, a human NK cell line, using a more sensitive assay. We previously confirmed that NK-92CI cells express CD56, perforin, GrA, GrB, Gr3/K, and GRN and are highly cytotoxic to K562 cells in a chromium release assay, which are more sensitive to organophosphorus pesticides and ziram than the NK-92MI cell line. NK-92CI cells were treated with ziram, thiram, maneb, or carbaryl at various concentrations for 4-24 h at 37°C in vitro. Thereafter, intracellular levels of perforin, GrA, GrB, Gr3/K, and GRN were determined by flow cytometry. It was found that all carbamate pesticides significantly reduced the intracellular levels of perforin, GrA, GrB, Gr3/K, and GRN in NK-92CI cells in a dose-dependent manner. However, the strength of the effect differed among the pesticides, and the order was thiram > ziram > maneb > carbaryl. In addition, it was also found that the degree of the reductions differed among the five proteins, with perforin more sensitive to pesticides than GRN, GrA, GrB, and Gr3/K, and the order was perforin > GRN > Gr3/K ≒ GrA ≒ GrB. © The Author(s) 2015.

  10. Human Calprotectin: Effect of Calcium and Zinc on its Secondary and Tertiary Structures, and Role of pH in its Thermal Stability

    Institute of Scientific and Technical Information of China (English)

    Reza YOUSEFI; Mehdi IMANI; Susan K ARDESTANI; Ali Akbar SABOURY; Nematollah GHEIBI; Bijan RANJBAR

    2007-01-01

    Calprotectin, a heterodimeric complex belonging to the S100 protein family, has been found predominantly in the cytosolic fraction of neutrophils. In the present study, human calprotectin was purified from neutrophils using two-step ion exchange chromatography. The purified protein was used for circular dichroism study and fluorescence analysis in the presence of calcium and zinc at physiological concentrations,as well as for assessment of its inhibitory activity on the K562 leukemia cell line. The thermal stability of the protein at pH 7.0 (physiological pH) and 8.0 (similar to intestinal pH) was also compared. The results of cell proliferation analysis revealed that human calprotectin initiated growth inhibition of the tumor cells in a dosedependent manner. The intrinsic fluorescence emission spectra of human calprotectin (50 μg/ml) in the presence of calcium and zinc ions show a reduction in fluorescence intensity, reflecting a conformational change within the protein with exposure of aromatic residues to the protein surface that is important for the biological function of calprotectin. The far ultraviolet-circular dichroism spectra of human calprotectin in the presence of calcium and zinc ions at physiological concentrations show a decrease in the α-helical content of the protein and an increase in β- and other structures. Our results also show that increasing the pH level from 7.0 to 8.0 leads to a marked elevation in the thermal stability of human calprotectin, indicating a significant role for pH in the stability of calprotectin in the gut.

  11. Overexpression of P-glycoprotein induces acquired resistance to imatinib in chronic myelogenous leukemia cells

    Institute of Scientific and Technical Information of China (English)

    Xing-Xiang Peng; Amit K. Tiwari; Hsiang-Chun Wu; Zhe-Sheng Chen

    2012-01-01

    Imatinib,a breakpoint cluster region (BCR)-Abelson murine leukemia (ABL) tyrosine kinase inhibitor (TKI),has revolutionized the treatment of chronic myelogenous leukemia (CML).However,development of multidrug resistance(MDR) limits the use of imatinib.In the present study,we aimed to investigate the mechanisms of cellular resistance to imatinib in CML.Therefore,we established an imatinib-resistant human CML cell line (K562-imatinib) through a stepwise selection process.While characterizing the phenotype of these cells,we found that K562-imatinib cells were 124.6-fold more resistant to imatinib than parental K562 cells.In addition,these cells were cross-resistant to second- and third-generation BCR-ABL TKIs.Western blot analysis and reverse transcription-polymerase chain reaction(RT-PCR) demonstrated that P-glycoprotein (P-gp) and MDR1 mRNA levels were increased in K562-imatinib cells.In addition,accumulation of [14C]6-mercaptopurine (6-MP) was decreased,whereas the ATP-dependent efflux of [14C] 6-MP and [3H]methotrexate transport were increased in K562-imatinib cells.These data suggest that the overexpression of P-gp may play a crucial role in acquired resistance to imatinib in CML K562-imatinib cells.

  12. Can cytotoxic activity of anthracyclines be related to DNA damage?

    Science.gov (United States)

    Nishiyama, M; Horichi, N; Mazouzi, Z; Bungo, M; Saijo, N; Tapiero, H

    1990-02-01

    Accumulation, cytotoxicity, and DNA damages produced by doxorubicin (DOX), pirarubicin (THP-DOX), fluoro-doxorubicin (ME2303) or its isolated metabolite M1 have been investigated in human myelogenous leukemia cells, sensitive (K562) and resistant to DOX (K562/DOX). These compounds differed by lipophilicity and/or sugar moiety either with (DOX, THP-DOX) or without (ME2303, M1) amino group. In K562 cells, the cytotoxicity was correlated to DNA single-stranded breaks and the intracellular drug amount of DOX or M1. This was not true when the cells were treated with THP-DOX or ME2303. In addition, THP-DOX produced total DNA protein cross-linking. In K562 cells DNA damage was not repaired, while in K562/DOX repair of DNA damage produced by all drugs could be observed. Although in K562/DOX cells drug accumulation was much reduced, higher intracellular drug concentration was required to induce similar level of cytotoxicity and DNA damage. Thus, cytotoxicity produced by anthracycline is not always associated with DNA damage. Different level of resistance to DOX, THP-DOX, ME2303 or M1 is associated with reduced drug accumulation which varies with the structure.

  13. Comparison of Cytotoxic Activity in Leukemic Lineages Reveals Important Features of β-Hairpin Antimicrobial Peptides.

    Science.gov (United States)

    Buri, Marcus V; Torquato, Heron F Vieira; Barros, Carlos Castilho; Ide, Jaime S; Miranda, Antonio; Paredes-Gamero, Edgar J

    2017-07-01

    Several reports described different modes of cell death triggered by antimicrobial peptides (AMPs) due to direct effects on membrane disruption, and more recently by apoptosis and necrosis-like patterns. Cytotoxic curves of four β-hairpin AMPs (gomesin, protegrin, tachyplesin, and polyphemusin) were obtained from several human leukemic lineages and normal monocytes and Two cell lines were then selected based on their cytotoxic sensitivity. One was sensitive to AMPs (K562) and the other resistant (KG-1) and their effect compared between these lineages. Thus, these lineages were chosen to further investigate biological features related with their cytotoxicities to AMPs. Stimulation with AMPs produced cell death, with activation of caspase-3, in K562 lineage. Increase on the fluidity of plasmatic membrane by reducing cholesterol potentiated cytotoxicity of AMPs in both lineages. Quantification of internal and external gomesin binding to the cellular membrane of both K562 and KG-1 cells showed that more peptide is accumulated inside of K562 cells. Additionally, evaluation of multi-drug resistant pumps activity showed that KG-1 has more activity than K562 lineage. A comparison of intrinsic gene patterns showed great differences between K562 and KG-1, but stimulation with gomesin promoted few changes in gene expression patterns. Differences in internalization process through the plasma membrane, multidrug resistance pumps activity, and gene expression pattern are important features to AMPs regulated cell death. J. Cell. Biochem. 118: 1764-1773, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  14. On the nucleolar size and density in human early granulocytic progenitors, myeloblasts

    Directory of Open Access Journals (Sweden)

    K Smetana

    2009-06-01

    Full Text Available Human myeloblasts were studied in bone marrow of patients suffering from chronic phase of chronic myeloid leukaemia to provide more information on the nucleolar diameter in these early granulocytic progenitors. These cells are a convenient model for such study since the number of myeloblasts in diagnostic bone marrow smears of investigated patients is larger than in not-leukemic persons because of the increased granulopoiesis. The nucleolar diameter was measured in myeloblasts after various cytochemical procedures such as methods for visualisation of RNA, DNA and proteins of AgNORs using digitized images and image processing. The results clearly demonstrated that values of the nucleolar diameter depended on the procedures used for visualising nucleoli. It seems to be also clear that a close relationship exists between the diameter of nucleoli and their number since the larger the number of nucleoli per cell the smaller their mean size. However, one of multiple nucleoli present in the nucleus is usually significantly larger. Moreover, the possibility exists that the variability of nucleolar diameter of leukemic myeloblasts and thus the heterogeneity of these cells might depend on various stages of the cell cycle as supported by nucleolar measurements on aging leukemic myeloblasts (K 562 cells in vitro. Since the staining density of small and large nucleoli did not differ substantially after staining for RNA, it seems to be likely that the nucleolar size is directly related to the total RNA content in myeloblasts. In addition, karyometry combined with RNA cytochemistry still appears to be an useful tool to study nucleoli at the single cell level.

  15. Functional role of human NK cell receptor 2B4 (CD244) isoforms.

    Science.gov (United States)

    Mathew, Stephen O; Rao, Krithi K; Kim, Jong R; Bambard, Nowland D; Mathew, Porunelloor A

    2009-06-01

    2B4 (CD244), a member of the signaling lymphocyte-activation molecule (SLAM/CD150), is expressed on all NK cells, a subpopulation of T cells, monocytes and basophils. Human NK cells express two isoforms of 2B4, h2B4-A and h2B4-B that differ in a small portion of the extracellular domain. In the present investigation, we have studied the functions of h2B4-A and h2B4-B. Our study demonstrated that these two isoforms differ in their binding affinity for CD48, which results in differential cytotoxic activity as well as intracellular calcium release by NK cells upon target cell recognition. Analysis of the predicted 3-D structure of the two isoforms showed conformational differences that could account for their differences in binding affinity to CD48. h2B4-A was able to mediate natural cytotoxicity against CD48-expressing K562 target cells and induce intracellular calcium release, whereas h2B4-B showed no effects. NK-92MI, U937, THP-1, KU812, primary monocytes, basophils and NK cells showed expression of both h2B4-A and h2B4-B whereas YT and IL-2-activated NK cells did not show any h2B4-B expression. Stimulation of NK cells through 2B4 resulted in decreased mRNA levels of both h2B4-A and h2B4-B indicating that down-regulation of 2B4 isoforms may be an important factor in controlling NK cell activation during immune responses.

  16. Induction of apoptosis in human leukemia cells through the production of reactive oxygen species and activation of HMOX1 and Noxa by benzene, toluene, and o-xylene.

    Science.gov (United States)

    Sarma, Sailendra Nath; Kim, Youn-Jung; Song, Mee; Ryu, Jae-Chun

    2011-02-27

    Whereas benzene (BZ) is a well-known human carcinogen, toluene (TOL) and o-xylene (o-XY) are not; however, all three compounds are important environmental pollutants. Although BZ, TOL, and o-XY have been shown to induce apoptosis in vitro, their mechanism of toxicity remains unclear. In this study, we sought to identify the apoptotic pathway(s) activated by BZ, TOL, and o-XY in human HL-60 promyelocytic leukemia cells. Cell cycle analysis by propidium iodide (PI) staining and flow cytometric analyses of Annexin V/PI double-stained cells revealed similar patterns of apoptosis following BZ, TOL, and o-XY exposure. Though reactive oxygen species (ROS) production contributes significantly to BZ metabolite-induced apoptotic cell death, we hypothesized that BZ, TOL, and o-XY can themselves trigger ROS production, leading to the activation of apoptotic signaling. Dose-dependent increases in ROS production and significant tail moments were observed in HL-60 cells exposed to all three compounds. Real-time RT-PCR revealed increased HMOX1 and Noxa expression in BZ-, TOL-, and o-XY-treated HL-60 cells, confirming the results of previous microarray analyses. Similar expression profiles were found in human K562 erythromyeloblastoid leukemia cells and human U937 leukemic monocyte lymphoma cells. Pretreatment with the ROS scavenger N-acetyl cysteine decreased the effects of exposure to BZ, TOL, and o-XY. In summary, this study provides useful insights into the mechanism of BZ-, TOL-, and o-XY-induced apoptosis in leukemia cells. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  17. Purification and functional characterization of a protein: Bombyx mori human growth hormone like protein in silkworm pupa.

    Science.gov (United States)

    Chen, Jianqing; Shu, Tejun; Lv, Zhengbing; Nie, Zuoming; Chen, Jian; Chen, Hao; Yu, Wei; Gai, Qijing; Zhang, Yaozhou

    2014-01-01

    Human growth hormone (hGH) is a peptide hormone secreted by eosinophils of the human anterior pituitary, and a regulatory factor for a variety of metabolic pathways. A 30-kD protein from the pupa stage of silkworm was detected by Western blotting and confirmed by immunoprecipitation based on its ability to bind to anti-hGH antibody. This protein, named BmhGH-like protein, was purified from fresh silkworm pupas through low-temperature homogenization, filtration, and centrifugation to remove large impurity particles. The supernatants were precipitated, resuspended, and passed through a molecular sieve. Further purification by affinity chromatography and two-dimensional electrophoresis resulted in pure protein for analysis by MS MALDI-TOF-MS analysis. An alignment with predicted proteins indicated that BmhGH-like protein consisted of two lipoproteins, which we named hGH-L1 and hGH-L2. These proteins belong to the β-trefoil superfamily, with β domains similar to the spatial structure of hGH. Assays with K562 cells demonstrated that these proteins could promote cell division in vitro. To further validate the growth-promoting effects, hGH-L2 was cloned from pupa cDNA to create recombinant silkworm baculovirus vBmNPV-hGH-L2, which was used to infect silkworm BmN cells at low titer. Flow cytometric analysis demonstrated that the protein shortened the G0/G1 phase of the cells, and enabled the cells to rapidly traverse the G1/S phase transition point to enter S phase and promote cell division. Discovery of hGH-like protein in silkworm will once again arouse people's interest in the potential medicinal value of silkworm and establish the basis for the development of new hormone drugs.

  18. Purification and functional characterization of a protein: Bombyx mori human growth hormone like protein in silkworm pupa.

    Directory of Open Access Journals (Sweden)

    Jianqing Chen

    Full Text Available Human growth hormone (hGH is a peptide hormone secreted by eosinophils of the human anterior pituitary, and a regulatory factor for a variety of metabolic pathways. A 30-kD protein from the pupa stage of silkworm was detected by Western blotting and confirmed by immunoprecipitation based on its ability to bind to anti-hGH antibody. This protein, named BmhGH-like protein, was purified from fresh silkworm pupas through low-temperature homogenization, filtration, and centrifugation to remove large impurity particles. The supernatants were precipitated, resuspended, and passed through a molecular sieve. Further purification by affinity chromatography and two-dimensional electrophoresis resulted in pure protein for analysis by MS MALDI-TOF-MS analysis. An alignment with predicted proteins indicated that BmhGH-like protein consisted of two lipoproteins, which we named hGH-L1 and hGH-L2. These proteins belong to the β-trefoil superfamily, with β domains similar to the spatial structure of hGH. Assays with K562 cells demonstrated that these proteins could promote cell division in vitro. To further validate the growth-promoting effects, hGH-L2 was cloned from pupa cDNA to create recombinant silkworm baculovirus vBmNPV-hGH-L2, which was used to infect silkworm BmN cells at low titer. Flow cytometric analysis demonstrated that the protein shortened the G0/G1 phase of the cells, and enabled the cells to rapidly traverse the G1/S phase transition point to enter S phase and promote cell division. Discovery of hGH-like protein in silkworm will once again arouse people's interest in the potential medicinal value of silkworm and establish the basis for the development of new hormone drugs.

  19. A novel sulfonamide agent, MPSP-001, exhibits potent activity against human cancer cells in vitro through disruption of microtubule

    Institute of Scientific and Technical Information of China (English)

    Zu-long LIU; Wei TIAN; Yong WANG; Shah KUANG; Xiao-min LUO; Qiang YU

    2012-01-01

    Aim:To evaluate the anti-cancer effects of a new sulfonamide derivative,2-(N-(3-chlorophenyl)-4-methoxyphenylsulfonarhido)-N-hydrox-ypropanamide (MPSP-001).Methods:Human cancer cell lines (HepG2,THP-1,K562,HGC-27,SKOV3,PANC-1,SW480,Kba,HeLa,A549,MDA-MB-453,and MCF-7) were examined.The cytotoxicity of MPSP-001 was evaluated using the WST-8 assay.Cell cycle distribution was examined with flow cytometry.Mitotic spindle formation was detected using immunofluorescence microscopy.Apoptosis-related proteins were examined with Western blot using specific phosphorylated protein antibodies.Competitive tubulin-binding assay was performed to test whether the compound competitively bound to the colchicine site.Molecular docking was performed to explore the possible binding conformation.Results:MPSP-001 potently inhibited the growth of the 12 different types of human cancer cells with the IC5o values ranging from 1.9 to 15.7 μmol/L.The compound exerted potent inhibition on the drug-resistant Kb/VCR and MCF-7/ADR cells,as on Kba and MCF-7 cells.In HeLa,HGC-27,A549,and other cells,the compound (5 μmol/L) caused cell cycle arrest at the G2/M phase,and subsequently induced cell apoptosis.In Hela cells,it prevented the mitotic spindle formation.Furthermore,the compound dose-dependently inhibited polymerization of tubulin in vitro,and directly bound to the colchicine-site of β-tubulin.Molecular docking predicted that the compound may form two hydrogen bonds to the binding pocket.The compound showed synergistic effects with colchicine and taxol in blocking mitosis of HeLa cells.Conclusion:MPSP-001 shows a broad-spectrum of anti-tumor efficacy in vitro and represents a novel structure with anti-microtubule activity.

  20. Human NK cells activated by EBV+ lymphoblastoid cells overcome anti-apoptotic mechanisms of drug resistance in haematological cancer cells

    Science.gov (United States)

    Sánchez-Martínez, Diego; Azaceta, Gemma; Muntasell, Aura; Aguiló, Nacho; Núñez, David; Gálvez, Eva M; Naval, Javier; Anel, Alberto; Palomera, Luis; Vilches, Carlos; Marzo, Isabel; Villalba, Martín; Pardo, Julián

    2015-01-01

    Natural killer (NK) cells recognize and eliminate transformed or infected cells that have downregulated MHC class-I and express specific activating ligands. Recent evidence indicates that allogeneic NK cells are useful to eliminate haematological cancer cells independently of MHC-I expression. However, it is unclear if transformed cells expressing mutations that confer anti-apoptotic properties and chemoresistance will be susceptible to NK cells. Allogeneic primary human NK cells were activated using different protocols and prospectively tested for their ability to eliminate diverse mutant haematological and apoptotic-resistant cancer cell lines as well as patient-derived B-cell chronic lymphocytic leukemia cells with chemotherapy multiresistance. Here, we show that human NK cells from healthy donors activated in vitro with Epstein Barr virus positive (EBV+)-lymphoblastoid cells display an enhanced cytotoxic and proliferative potential in comparison to other protocols of activation such a K562 cells plus interleukin (IL)2. This enhancement enables them to kill more efficiently a variety of haematological cancer cell lines, including a panel of transfectants that mimic natural mutations leading to oncogenic transformation and chemoresistance (e.g., overexpression of Bcl-2, Bcl-XL and Mcl-1 or downregulation of p53, Bak/Bax or caspase activity). The effect was also observed against blasts from B-cell chronic lymphocytic leukemia patients showing multi-resistance to chemotherapy. Our findings demonstrate that particular in vitro activated NK cells may overcome anti-apoptotic mechanisms and oncogenic alterations frequently occurring in transformed cells, pointing toward the use of EBV+-lymphoblastoid cells as a desirable strategy to activate NK cells in vitro for the purpose of treating haematological neoplasia with poor prognosis. PMID:25949911

  1. The anti-cancer effect of PC-3 sensitized DC vaccine on human immune reconstruction NOD/SCID mice model bearing human prostate carcinoma%DC疫苗对荷人前列腺癌免疫重建NOD/SCID小鼠的抑瘤作用

    Institute of Scientific and Technical Information of China (English)

    周海滨; 付强

    2016-01-01

    目的 探讨PC-3细胞冻融抗原致敏的树突状细胞(dendritic cells,DC)疫苗(PC-3-DC)对荷人前列腺癌免疫重建NOD/SCID小鼠(hu-PBL-NOD/SCID)的抑瘤作用.方法 采用人外周血淋巴细胞(peripheral blood lymphocytes,PBL)腹腔注射法建立hu-PBL-NOD/SCID小鼠模型,随机分为实验组(PC-3-DC组)和对照组(DC组、PBS组),腹腔分别注射PC-3-DC疫苗、未致敏的DC和PBS.每周1次,共2次,然后接种1×107 PC-3细胞,观察鼠成瘤率、成瘤潜伏期、肿瘤体积以及测定特异性CTL活性.结果 ELISA法可检测到小鼠血清中人IgG水平,hu-PBL-NOD/SCID嵌合模型重建成功,各组小鼠间成瘤率无明显差异,但PC-3-DC组成瘤潜伏期延长,肿瘤生长缓慢,2周后肿瘤体积明显小于DC组和PBS组,差异有统计学意义(P<0.05),实验组脾淋巴细胞对PC-3细胞有特异性杀伤效应,而对K562细胞则无杀伤活性.结论 负载PC-3冻融抗原的DC疫苗可诱导人T淋巴细胞活化增殖,能有效抑制hu-PBL-NOD/SCID小鼠肿瘤的生长.%Objectives To investigate the effect of dendritic cells (DC) stimulated with PC-3 cells lysate inhibiting tumor action in human immune reconstruction NOD/SCID mice model bearing human prostate carcinoma.Methods Human immune reconstruction NOD/SCID mice model was established by intraperitoneal injection of human peripheral blood lymphocytes.The PC-3 DC vaccine,naive DC,PBS were injected respectively,and then they were injected subcutaneously with 1 × 107 PC -3 cells.Tumorigenic rate,latent period,and tumor volume were observed,and specific CTL activity was measured.Results The serum concentration of human lgG in hu-PBL-NOD/SCID mice model was confirmed by ELISA that suggested that the hu-PBL-NOD/SCID mice model was established successfully.Tumorigenic rates were the same among these groups.However,tumors grew slowly in PC-3 DC vaccine groups,and its latent period was prolonged.Tumor volumes were significantly smaller than those in control group

  2. Effects of Serum of the Rats that are Given Arsenical Agents on Human Leukemia Apoptosis and Expression of bcl-2 Gene%注射砒霜大鼠的血清对白血病细胞凋亡及Bcl-2基因表达的影响

    Institute of Scientific and Technical Information of China (English)

    臧运华; 李震; 张丹; 李洁; 高向慧; 李军山

    2003-01-01

    目的:探讨中药砒霜治疗白血病的作用机理.方法:运用血清药理学法孵育人白血病细胞株K562细胞,通过流式细胞术检测注射砒霜大鼠的血清对细胞凋亡及bcl-2基因表达的影响.结果:注射砒霜大鼠的血清能使K562细胞G0-G1期细胞百分数减少,S期细胞百分数增加,Bcl-2表达减少,具有诱导k562细胞凋亡的作用.

  3. Functional Analysis of Multiple Transcription Factor Sites in a Regulatory Element of Human ε-Globin Gene

    Institute of Scientific and Technical Information of China (English)

    Chun-Hui HOU; Jian HUANG; Ruo-Lan QIAN

    2004-01-01

    The developmental control of the human ε-globin gene expression is mediated by transcriptional regulatory elements in the 5' flanking DNA of this gene. A previously identified negative regulatory element (-3028 to -2902 bp, termed ε-NRAII) was analyzed and one putative NF-κB site and two GATA sites locate at -3004 bp, -2975 bp and -2948 bp were characterized. Electrophoresis mobility shift assay (EMSA)showed that the putative NF-κB site was specifically bound by nu