Polycomb Group Protein BMI1 In Leukemia Development and Progression:Blocking the Cell Differentiation

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 2150-2150
Author(s):  
Hong-jie Shen ◽  
Xin Ding ◽  
Jian-nong Cen ◽  
Yuan-yuan Wang ◽  
Xiao-fei Qi ◽  
...  
Keyword(s):  
Fluorescence Intensity ◽  
Sodium Butyrate ◽  
Mean Fluorescence Intensity ◽  
Erythroid Differentiation ◽  
Mean Value ◽  
Polycomb Group ◽  
Myelogenous Leukemia ◽  
Transcriptional Level ◽  
Group Protein ◽  
The Mean

Abstract Abstract 2150 BMI1 is the most frequently altered PcG group protein observed in cancer and is useful in predicting prognosis as a biomarker in some malignant blood diseases including myelodysplastic syndromes (MDS) and chronic myelogenous leukemia (CML). However, the role and effect of BMI1 in these diseases is not clear. We have found that BMI1 expression in MDS CD34+ cells (n=13) was correlated with IPSS (R2=0.514,P=0.013). The MDS patient with overexpressed BMI1 shortly after diagnosis displayed a disease progression: one case of MDS-RA progressed to MDS-RAEB and two cases of MDS-RAEB transformed to AML, in company with more serious cytopenia in one or more lineages of bone marrow cells. A similar situation was found in CML. As the CML-CP patients (n=181) accelerated to CML-BP (n=27),the hemoglobin level as well as WBC and Plt counts markedly decreased (p<0.05), whereas the BMI1 transcriptional level in CML-BP (n=12) was much higher than that in CML-CP (n=26) detected by qRT-PCR (p<0.05). To further explore the role of BMI1 in malignant myeloid transformation, we cloned BMI1 cDNA ORF and transfected it into K562 by MSCV retroviral vector. The BMI1 protein expression in transfectant subclones was about three-folds of the untransfected control. NBT assay demonstrated that the differentiation induced by 20nm/L TPA for 72 hours in transfected cell were less than that in control cells. The percentage of NBT positive cells in K562, K562-MSCV, K562- BMI1SC1 and K562-BMI1SC2 were 51±7%, 60±8%, 27±6%, 33±7% (n=3), respectively. In addition, the immunophenotype of CD11b, CD13, CD15, CD33, CD34, CD64 and HLA-DR in TPA-treated cells detected by FCM found that only the mean fluorescence intensity of CD15 in transfected cells was obviously lower than that in control. The mean value of CD15 in K562, K562-MSCV, K562-BMI1SC1, K562-BMI1SC2 were 3.38, 3.25, 2.42, 2.54, respectively. The benzidine staining showed BMI1 transfected K562 treated by 40mm/L sodium butyrate for 72 hours had slower erythroid differentiation compared to that in control cells. The benzidine positive cell in K562, K562-MSCV, K562-BMI1SC1, K562-BMI1SC2 were 28±4%, 31±5%, 10±4%, 9±5% (n=3), respectively. We also found that the mean fluorescence intensity of GPA and CD71 were lower in BMI1 transfected cell compared to control after sodium butyrate treatment. The mean value of GPA in K562, K562-MSCV, K562-BMI1SC1, K562-BMI1SC2 were 36.4, 32.1, 20.6, 16.2 and the mean of CD71 were 3.07, 3.13, 2.8, 1.32, respectively. These in vitro results suggested that overexpression of BMI1 can inhibit cell myelomonocytoid and erythroid differentiation. In summary, we conclude that polycomb group BMI1 may contribute to clonal myeloid transformation by blocking multiple lineage differentiation and potentiating the stemness of the leukemia-initiating cells via possible epigenetic mechanisms. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Chronic Myelogenous Leukemia– Initiating Cells Require Polycomb Group Protein EZH2

2016 ◽  
Vol 6 (11) ◽  
pp. 1237-1247 ◽  
Author(s):  
Huafeng Xie ◽  
Cong Peng ◽  
Jialiang Huang ◽  
Bin E. Li ◽  
Woojin Kim ◽  
...  
Keyword(s):  
Chronic Myelogenous Leukemia ◽  
Polycomb Group ◽  
Myelogenous Leukemia ◽  
Polycomb Group Protein ◽  
Group Protein

Eradication of Chronic Myelogenous Leukemia By Inactivation of the Polycomb Group Protein EZH2

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 778-778 ◽  
Author(s):  
Huafeng Xie ◽  
Cong Peng ◽  
Jun Qi ◽  
Giullia Cheloni ◽  
Partha Das ◽  
...  
Keyword(s):  
Mouse Model ◽  
Chronic Myelogenous Leukemia ◽  
Polycomb Group ◽  
Chromosome 9 ◽  
Myelogenous Leukemia ◽  
Definitive Treatment ◽  
Polycomb Group Protein ◽  
Term Survival ◽  
Group Protein

Abstract Chronic myelogenous leukemia (CML) is a stem-cell driven malignancy caused by BCL/ABL, the oncoprotein derived from the Philadelphia chromosome 9/22 translocation. Although tyrosine kinase inhibitors (TKIs) are highly effective in managing chronic phase CML, challenges remain, including acquisition of TKI resistance, toxicities of long-term TKI administration and third-generation TKIs, and persistence of leukemia initiating cells (LICs). Reliable curative chemotherapy remains elusive. Alternative approaches to definitive treatment of CML would enhance current management. We report here that the Polycomb group protein EZH2, a catalytic subunit of Polycomb repressive complex 2 (PRC2), is a potential target for curative chemotherapy for CML. EZH2 is overexpressed in LICs, compared to normal hematopoietic stem cells (HSCs), and is sustained by BCR/ABL signaling, as TKIs suppress EZH2 expression in CML cells. Removal of EZH2 in an engineered mouse model prevents CML initiation and development. Moreover, Ezh2 is also required for maintenance of established CML. In a tamoxifen-inducible EZH2 deletion mouse model, conditional inactivation of EZH2 eradicates existing disease induced by wild-type BCR/ABL or the gatekeeper T315I mutant, and leads to long-term survival. Importantly, EZH2 inactivation also eliminates phenotypic and functional LICs. Relevance of the genetic studies in mice is supported by shRNA knockdown and EZH2-inhibitor treatment of human CML cell lines and primary samples, which leads to cell cycle inhibition, apoptosis, and reduced colony formation. Effects of EZH2 loss in CML are context-specific, as EZH2 is dispensable for HSCs, in part due to decreased EZH1 expression in CML LICs compared to normal HSCs. EZH1 expression decreases even further in LICs upon the loss of EZH2. Thus, loss of EZH2 in CML LICs creates a scenario resembling complete inactivation of PRC2, which is essential for the maintenance of HSCs. EZH2-dependence of CML LICs raises prospects for curative chemotherapy based on addition of EZH2 inhibitors to conventional TKI administration. Disclosures No relevant conflicts of interest to declare.

Expression of the cell adhesion molecules on leukocytes that demarginate during acute maximal exercise

1999 ◽  
Vol 86 (3) ◽  
pp. 970-976 ◽  
Author(s):  
Stephan F. van Eeden ◽  
John Granton ◽  
Jennifer M. Hards ◽  
Barbara Moore ◽  
James C. Hogg
Keyword(s):  
Fluorescence Intensity ◽  
Mean Fluorescence Intensity ◽  
Maximal Exercise ◽  
Flow Cytometric Analysis ◽  
Cycle Ergometer ◽  
Phenotypic Characteristics ◽  
Flow Cytometric ◽  
The Mean ◽  
Low Levels

The pulmonary vascular bed is an important reservoir for the marginated pool of leukocytes that can be mobilized by exercise or catecholamines. This study was designed to determine the phenotypic characteristics of leukocytes that are mobilized into the circulation during exercise. Twenty healthy volunteers performed incremental exercise to exhaustion [maximal O2consumption (V˙o2 max)] on a cycle ergometer. Blood was collected at baseline, at 3-min intervals during exercise, atV˙o2 max, and 30 min after exercise. Total white cell, polymorphonuclear leukocyte (PMN), and lymphocyte counts increased with exercise toV˙o2 max( P < 0.05). Flow cytometric analysis showed that the mean fluorescence intensity of L-selectin on PMN (from 14.9 ± 1 at baseline to 9.5 ± 1.6 atV˙o2 max, P < 0.05) and lymphocytes (from 11.7 ± 1.2 at baseline to 8 ± 0.8 atV˙o2 max, P < 0.05) decreased with exercise. Mean fluorescence intensity of CD11b on PMN increased with exercise (from 10.2 ± 0.6 at baseline to 25 ± 2.5 atV˙o2 max, P < 0.002) but remained unchanged on lymphocytes. Myeloperoxidase levels in PMN did not change with exercise. In vitro studies showed that neither catecholamines nor plasma collected atV˙o2 maxduring exercise changed leukocyte L-selectin or CD11b levels. We conclude that PMN released from the marginated pool during exercise express low levels of L-selectin and high levels of CD11b.

scholarly journals The Average IFN-γSecreting Capacity of Specific CD8+T Cells Is Compromised While Increasing Copies of a Single T Cell Epitope Encoded by DNA Vaccine

2012 ◽  
Vol 2012 ◽  
pp. 1-6
Author(s):  
Yanmin Wan ◽  
Jing Wang ◽  
Haizhu Zhou ◽  
Zhidong Hu ◽  
Xiaonan Ren ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Fluorescence Intensity ◽  
Cd8 T Cells ◽  
Mean Fluorescence Intensity ◽  
Cell Epitope ◽  
Cell Receptor ◽  
T Cell Epitope ◽  
The Mean

Previous studies suggested that both the frequency and the mean fluorescence intensity (MFI) of cytokine secreting T cells could be of great value for immunogenicity evaluation of a vaccine. In this study, by constructing epitope-based DNA vaccines encoding a previously identified CD8+T cell epitope, we investigated the influence of multiplying epitope copies on both the frequency and the MFI of specific IFN-γsecreting CD8+T cells. We found that frequencies of specific CD8+T cell could be improved by multiplying epitope copies, while the MFI of IFN-γsecreted by epitope-specific CD8+T cells decreased synchronously. And further analysis showed that the decrease of MFI was not caused by the functional avidity variation of CD8+T cell receptor.

scholarly journals Positive influence of aminosilanes on anti-EpCAM antibody immobilization on a glass surface

2021 ◽  
Vol 9 (2) ◽  
pp. 93-99
Author(s):  
Paula Kamińska ◽  
Karolina Buszka ◽  
Przemysław Pietras ◽  
Maciej Zabel ◽  
Michał Nowicki ◽  
...  
Keyword(s):  
Fluorescence Intensity ◽  
Glass Surface ◽  
Mean Fluorescence Intensity ◽  
Positive Influence ◽  
Contact Angles ◽  
Binding Activity ◽  
Antibody Immobilization ◽  
Glass Slides ◽  
The Mean ◽  
Detection Of Biomolecules

Abstract Immobilization of antibodies has a number of promising applications, including detection of biomolecules and cells. Well-oriented antibodies are required to bind them effectively. To eliminate the problem of random antibodies’ orientation, the surface of the device can be modified with silanes. This study aimed at elucidating if selected aminosilanes were able to bind antibodies in the appropriate orientation and thus retain their binding activity. Silanization of glass slides was performed using three amino-functional trialkoxysilanes – A, AE, and AEE. The immunofluorescent reaction was used to evaluate the potential of the silanized glass surface to bind anti-EpCAM antibodies. The affinity of selected anti-EpCAM HEA125 antibodies labeled with fluorochrome to tested silanized surfaces was evaluated by measuring the mean fluorescence intensity (MFI) in each analyzed area. The presented silanes effectively bound antibodies. Higher fluorescence intensity was noticed in the case of silane-coated glass slides in comparison to unmodified ones. The differences in the contact angles also confirmed this result. In the case of silane A, the fluorescence intensity reflected the amount of bound antibodies. However, there was no such a relation in the case of the silanes AE and AEE. Although our research gave promising results, the usefulness of selected silanes needs to be confirmed by further studies using cancer cells. Running title: Aminosilanes as enhancers of antibody immobilization

scholarly journals Acute exposure to paraquat affects the phenotypic differentiation of substantia nigra microglia in rats

2021 ◽  
Author(s):  
Wendi Zhang ◽  
Xiaobei Fan ◽  
Zhuo Fan ◽  
Bailin Wu ◽  
Mengchao Wang ◽  
...  
Keyword(s):  
Nervous System ◽  
Substantia Nigra ◽  
Western Blotting ◽  
Fluorescence Intensity ◽  
Mean Fluorescence Intensity ◽  
Early Stage ◽  
Exposure Dose ◽  
Phenotypic Differentiation ◽  
The Mean ◽  
Lung And Kidney

Abstract The toxicity of paraquat (PQ), a bipyridine cationic herbicide, to the lung and kidney has been widely recognized, but the acute toxic effects of PQ on the nervous system have received little attention. The aim of this study was to explore changes in the phenotypic differentiation of microglia in rats caused by acute PQ exposure. We found that acute PQ exposure induced pyknosis, edema and apoptosis in substantia nigra neurons. The results of immunohistochemistry and western blotting showed that the number of activated microglia increased, the number of microglia branches decreased and the length became shorter in the early stage of exposure to 25 mg/kg PQ. We then compared the mean fluorescence intensity of iNOS and ARG1. In the early stage of acute 25 mg/kg PQ exposure, the number of M1 phenotypes of microglia increased; in contrast, in the early stage of acute 45 mg/kg PQ exposure, the number of M2 phenotypes of microglia increased. On the 69th day, the expression of iNOS and ARG1 increased in the 25 mg/kg and 45 mg/kg PQ exposure groups. In sum, changes in microglia phenotypic differentiation were related to exposure dose and exposure time.

Long-period modulated superstructures in Pd-12.5 at.%Ce and Pd-15 at.%Ce alloys

1990 ◽  
Vol 48 (4) ◽  
pp. 164-165
Author(s):  
Noriyuki Kuwano ◽  
Masaru Itakura ◽  
Kensuke Oki
Keyword(s):  
Electron Microscopy ◽  
Mean Value ◽  
Heavy Elements ◽  
Arc Furnace ◽  
X Ray ◽  
Long Period ◽  
Ultra High Purity ◽  
Heat Treated ◽  
Atomic Scattering ◽  
The Mean

Pd-Ce alloys exhibit various anomalies in physical properties due to mixed valences of Ce, and the anomalies are thought to be strongly related with the crystal structures. Since Pd and Ce are both heavy elements, relative magnitudes of (fcc-fpd) are so small compared with <f> that superlattice reflections, even if any, sometimes cannot be detected in conventional x-ray powder patterns, where fee and fpd are atomic scattering factors of Ce and Pd, and <f> the mean value in the crystal. However, superlattices in Pd-Ce alloys can be analyzed by electron microscopy, thanks to the high detectability of electron diffraction. In this work, we investigated modulated superstructures in alloys with 12.5 and 15.0 at.%Ce.Ingots of Pd-Ce alloys were prepared in an arc furnace under atmosphere of ultra high purity argon. The disc specimens cut out from the ingots were heat-treated in vacuum and electrothinned to electron transparency by a jet method.

Partition Coefficient Ratios and Tumour Perfusion Studied with 85mKr and 133Xe

1987 ◽  
Vol 26 (06) ◽  
pp. 253-257
Author(s):  
M. Mäntylä ◽  
J. Perkkiö ◽  
J. Heikkonen
Keyword(s):  
Partition Coefficient ◽  
Partition Coefficients ◽  
Regional Blood Flow ◽  
Blood Perfusion ◽  
Compartmental Analysis ◽  
Malignant Tumour ◽  
Mean Value ◽  
Perfusion Rate ◽  
Biological Variables ◽  
The Mean

The relative partition coefficients of krypton and xenon, and the regional blood flow in 27 superficial malignant tumour nodules in 22 patients with diagnosed tumours were measured using the 85mKr- and 133Xe-clearance method. In order to minimize the effect of biological variables on the measurements the radionuclides were injected simultaneously into the tumour. The distribution of the radiotracers was assumed to be in equilibrium at the beginning of the experiment. The blood perfusion was calculated by fitting a two-exponential function to the measuring points. The mean value of the perfusion rate calculated from the xenon results was 13 ± 10 ml/(100 g-min) [range 3 to 38 ml/(100 g-min)] and from the krypton results 19 ± 11 ml/(100 g-min) [range 5 to 45 ml/(100 g-min)]. These values were obtained, if the partition coefficients are equal to one. The equations obtained by using compartmental analysis were used for the calculation of the relative partition coefficient of krypton and xenon. The partition coefficient of krypton was found to be slightly smaller than that of xenon, which may be due to its smaller molecular weight.

Detection of Soluble Fibrin Monomer Complexes in Blood by Means of Protamine Sulphate Test

1968 ◽  
Vol 20 (01/02) ◽  
pp. 044-049 ◽  
Author(s):  
B Lipiński ◽  
K Worowski
Keyword(s):  
Human Subjects ◽  
Coronary Thrombosis ◽  
Mean Value ◽  
Healthy Human ◽  
Protamine Sulphate ◽  
Soluble Fibrin ◽  
Fibrin Monomer ◽  
Dog Plasma ◽  
The Mean ◽  
Precipitable Protein

SummaryIn the present paper described is a simple test for detecting soluble fibrin monomer complexes (SFMC) in blood. The test consists in mixing 1% protamine sulphate with diluted oxalated plasma or serum and reading the optical density at 6190 Å. In experiments with dog plasma, enriched with soluble fibrin complexes, it was shown that OD read in PS test is proportional to the amount of fibrin recovered from the precipitate. It was found that SFMC level in plasma increases in rabbits infused intravenously with thrombin and decreases after injection of plasmin with streptokinase. In both cases PS precipitable protein in serum is elevated indicating enhanced fibrinolysis. In healthy human subjects the mean value of OD readings in plasma and sera were found to be 0.30 and 0.11, while in patients with coronary thrombosis they are 0.64 and 0.05 respectively. The origin of SFMC in circulation under physiological and pathological conditions is discussed.

Detection of Circulating Tissue Factor and Factor VII in a Normal Population

1996 ◽  
Vol 75 (05) ◽  
pp. 772-777 ◽  
Author(s):  
Sybille Albrecht ◽  
Matthias Kotzsch ◽  
Gabriele Siegert ◽  
Thomas Luther ◽  
Heinz Großmann ◽  
...  
Keyword(s):  
Tissue Factor ◽  
Normal Population ◽  
Mean Value ◽  
Factor Vii ◽  
Significant Difference ◽  
Age Dependent ◽  
The Mean ◽  
Highly Correlated ◽  
And Gender

SummaryThe plasma tissue factor (TF) concentration was correlated to factor VII concentration (FVIIag) and factor VII activity (FVIIc) in 498 healthy volunteers ranging in age from 17 to 64 years. Immunoassays using monoclonal antibodies (mAbs) were developed for the determination of TF and FVIIag in plasma. The mAbs and the test systems were characterized. The mean value of the TF concentration was 172 ± 135 pg/ml. TF showed no age- and gender-related differences. For the total population, FVIIc, determined by a clotting test, was 110 ± 15% and the factor VIlag was 0.77 ± 0.19 μg/ml. FVII activity was significantly increased with age, whereas the concentration demonstrated no correlation to age in this population. FVII concentration is highly correlated with the activity as measured by clotting assay using rabbit thromboplastin. The ratio between FVIIc and FVIIag was not age-dependent, but demonstrated a significant difference between men and women. Between TF and FVII we could not detect a correlation.

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