bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Zinc Finger Transcription Factor Egr-1 Activates Macrophage Differentiation in M1 Myeloblastic Leukemia Cells
Authors: Krishnaraju Kandasamy , Hoffman Barbara , Liebermann Dan A. 
Published: October 2019

AbstractWe previously have shown that the zinc finger transcription factor Egr-1 blocked granulocytic differentiation of HL-60 cells, restricting differentiation along the monocytic lineage. Egr-1 also was observed to block granulocyte colony-stimulating factor (G-CSF)–induced differentiation of interleukin-3 (IL-3)–dependent 32Dcl3 hematopoietic precursor cells, endowing the cells with the ability to be induced by granulocyte-macrophage colony-stimulating factor (GM-CSF) for terminal differentiation along the macrophage lineage. To better understand the function of Egr-1 as a positive modulator of monocytic differentiation, in this work we have studied the effect of ectopic expression of Egr-1 on the murine myeloblastic leukemic cell line M1, which is induced for differentiation by the physiological inducer IL-6. It is shown that, unlike in HL-60 and 32Dcl3 cells, ectopic expression of Egr-1 in M1 cells resulted in activation of the macrophage differentiation program in the absence of differentiation inducer. This included the appearance of morphologically differentiated cells, decreased growth rate in mass culture, and cloning efficiency in soft agar, and expression of endogenous c-myb and c-myc mRNAs was markedly downregulated. Untreated M1Egr-1 cells also exhibited cell adherence, expression of Fc and C3 receptors, and upregulation of the myeloid differentiation primary response genes c-Jun, junD, andjunB and the late genetic markers ferritin light-chainand lysozyme. Ectopic expression of Egr-1 in M1 cells also dramatically increased the sensitivity of the cells for IL-6–induced differentiation, allowed a higher proportion of M1 cells to become terminally differentiated under conditions of optimal stimulation for differentiation, and decreased M1 leukemogenicity in vivo. These findings demonstrate that the functions of Egr-1 as a positive modulator of macrophage differentiation vary, depending on the state of lineage commitment for differentiation of the hematopoietic cell type.© 1998 by The American Society of Hematology.
Saturation Mutagenesis of the β Subunit of the Human Granulocyte-Macrophage Colony-Stimulating Factor Receptor Shows Clustering of Constitutive Mutations, Activation of ERK MAP Kinase and STAT Pathways, and Differential β Subunit Tyrosine Phosphorylation
Authors: Jenkins Brendan J. , Blake Timothy J. , Gonda Thomas J. 
Published: October 2019

AbstractThe high-affinity receptors for human granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-3 (IL-3), and IL-5 are heterodimeric complexes consisting of cytokine-specific  subunits and a common signal-transducing β subunit (hβc). We have previously demonstrated the oncogenic potential of this group of receptors by identifying constitutively activating point mutations in the extracellular and transmembrane domains of hβc. We report here a comprehensive screen of the entire hβc molecule that has led to the identification of additional constitutive point mutations by virtue of their ability to confer factor independence on murine FDC-P1 cells. These mutations were clustered exclusively in a central region of hβc that encompasses the extracellular membrane-proximal domain, transmembrane domain, and membrane-proximal region of the cytoplasmic domain. Interestingly, most hβc mutants exhibited cell type-specific constitutive activity, with only two transmembrane domain mutants able to confer factor independence on both murine FDC-P1 and BAF-B03 cells. Examination of the biochemical properties of these mutants in FDC-P1 cells indicated that MAP kinase (ERK1/2), STAT, and JAK2 signaling molecules were constitutively activated. In contrast, only some of the mutant β subunits were constitutively tyrosine phosphorylated. Taken together, these results highlight key regions involved in hβc activation, dissociate hβc tyrosine phosphorylation from MAP kinase and STAT activation, and suggest the involvement of distinct mechanisms by which proliferative signals can be generated by hβc.© 1998 by The American Society of Hematology.
DNA-Dependent Protein Kinase Activity Correlates With Clinical and In Vitro Sensitivity of Chronic Lymphocytic Leukemia Lymphocytes to Nitrogen Mustards
Authors: Muller Catherine , Christodoulopoulos Garyfallia , Salles Bernard , Panasci Lawrence 
Published: October 2019

AbstractThe objective of this study is to investigate the role of DNA-dependent protein kinase (DNA-PK) in the chronic lymphocytic leukemia (CLL) lymphocyte response to nitrogen mustard therapy. DNA-PK is a nuclear serine/threonine kinase that functions in DNA double-strand break repair and in the joining process in recombination mechanisms. In a series of 34 patients with B-CLL, either untreated (n = 16) or resistant to chlorambucil (n = 18), the kinase activity of the complex, as determined by its capacity to phosphorylate a peptide substrate in vitro, is increased in the resistant samples as compared with the untreated ones (24.4 ± 2.6 arbitrary units [a.u.] [range, 12.7 to 55.8 a.u.] versus 8.1 ± 2.8 a.u. [range, 0.9 to 44.5 a.u.], respectively (P < .0001]), independent of other clinical and biological factors. Linear regression analysis shows an excellent correlation between the level of DNA-PK activity and the inherent in vitro sensitivity of CLL lymphocytes to chlorambucil (r = .875, P =.0001). The regulation of DNA-PK activity was associated with increased DNA-binding activity of its regulatory subunit, the Ku heterodimer, in resistant samples. These results suggest that this activity is a determinant in the cellular response to chlorambucil and participates in the development of nitrogen mustard–resistant disease. The increase in DNA-PK activity might contribute to the enhanced cross-link repair that we previously postulated to be a primary mechanism of resistance to nitrogen mustards in CLL.
Transduction of Murine Bone Marrow Cells With an MDR1 Vector Enables Ex Vivo Stem Cell Expansion, but These Expanded Grafts Cause a Myeloproliferative Syndrome in Transplanted Mice
Authors: Bunting Kevin D. , Galipeau Jacques , Topham David , Benaim Ely , Sorrentino Brian P. 
Published: October 2019

AbstractAttempts to expand repopulating hematopoietic cells ex vivo have yielded only modest amplification in stem cell numbers. We now report that expression of an exogenous human multi-drug resistance 1 (MDR1) gene enables dramatic ex vivo stem cell expansion in the presence of early acting hematopoietic cytokines. Bone marrow cells were transduced with retroviral vectors expressing either the MDR1 gene or a variant of human dihydrofolate reductase (DHFR), and then expanded for 12 days in the presence of interleukin-3 (IL-3), IL-6, and stem cell factor. When these cells were injected into nonirradiated mice, high levels of long-term engraftment were only seen with MDR1-transduced grafts. To verify that expansion of MDR1-transduced repopulating cells had occurred, competitive repopulation assays were performed using MDR1 expanded grafts. These experiments showed progressive expansion of MDR1-transduced repopulating cells over the expansion period, with a 13-fold overall increase in stem cells after 12 days. In all of the experiments, mice transplanted with expanded MDR1-transduced stem cells developed a myeloproliferative disorder characterized by high peripheral white blood cell counts and splenomegaly. These results show that MDR1-transduced stem cells can be expanded in vitro using hematopoietic cytokines without any drug selection, but enforced stem cell self-renewal divisions can have adverse consequences.
The Importance of Diagnostic Cytogenetics on Outcome in AML: Analysis of 1,612 Patients Entered Into the MRC AML 10 Trial
Authors: Grimwade David , Walker Helen , Oliver Fiona , Wheatley Keith , Harrison Christine , Harrison Georgina , Rees John , Hann Ian , Stevens Richard , Burnett Alan , Goldstone Anthony 
Published: October 2019

AbstractCytogenetics is considered one of the most valuable prognostic determinants in acute myeloid leukemia (AML). However, many studies on which this assertion is based were limited by relatively small sample sizes or varying treatment approach, leading to conflicting data regarding the prognostic implications of specific cytogenetic abnormalities. The Medical Research Council (MRC) AML 10 trial, which included children and adults up to 55 years of age, not only affords the opportunity to determine the independent prognostic significance of pretreatment cytogenetics in the context of large patient groups receiving comparable therapy, but also to address their impact on the outcome of subsequent transplantation procedures performed in first complete remission (CR). On the basis of response to induction treatment, relapse risk, and overall survival, three prognostic groups could be defined by cytogenetic abnormalities detected at presentation in comparison with the outcome of patients with normal karyotype. AML associated with t(8;21), t(15;17) or inv(16) predicted a relatively favorable outcome. Whereas in patients lacking these favorable changes, the presence of a complex karyotype, −5, del(5q), −7, or abnormalities of 3q defined a group with relatively poor prognosis. The remaining group of patients including those with 11q23 abnormalities, +8, +21, +22, del(9q), del(7q) or other miscellaneous structural or numerical defects not encompassed by the favorable or adverse risk groups were found to have an intermediate prognosis. The presence of additional cytogenetic abnormalities did not modify the outcome of patients with favorable cytogenetics. Subgroup analysis demonstrated that the three cytogenetically defined prognostic groups retained their predictive value in the context of secondary as well as de novo AML, within the pediatric age group and furthermore were found to be a key determinant of outcome from autologous or allogeneic bone marrow transplantation (BMT) in first CR. This study highlights the importance of diagnostic cytogenetics as an independent prognostic factor in AML, providing the framework for a stratified treatment approach of this disease, which has been adopted in the current MRC AML 12 trial.
Regulation of the c-jun Gene in p210 BCR-ABL Transformed Cells Corresponds With Activity of JNK, the c-jun N-Terminal Kinase
Authors: Burgess Gem S. , Williamson Elizabeth A. , Cripe Larry D. , Litz-Jackson Sara , Bhatt Jay A. , Stanley Kurt , Stewart Mark J. , Kraft Andrew S. , Nakshatri Harikrishna , Boswell H. Scott 
Published: October 2019

AbstractActivity of the c-jun N-terminal kinase (JNK) has been shown in hematopoietic cells transformed by p210 BCR-ABL. However, analysis has not been reported for hematopoietic cells on the consequences of this activity for c-jun promoter regulation within its distinctive proximal 8-base consensus CRE-like element, an element linked to JNK-mediated increase in c-jun transcription. In the present study, regulation of the proximal c-jun promoter was studied in murine myeloid cells transformed by p210 BCR-ABL. Promoter regulation in p210 BCR-ABL transformed cells was compared with regulation of the promoter in nontransformed interleukin-3 (IL-3)–dependent parental cells. The composition of nuclear AP-1 proteins contained within cells with p210 BCR-ABL, and their binding to the c-jun promoter proximal CRE-like element, was compared with the composition and binding of AP-1 proteins in IL-3–treated parental cells without p210 BCR-ABL. The present analysis found fivefold increased c-jun transcription occurring in p210 BCR-ABL transformed murine myeloid cells possessing a corresponding magnitude of increased kinase activity of JNK, compared with IL-3–stimulated parental cells. Augmented JNK activity was accompanied by increased nuclear abundance of c-jun and c-fos proteins that bound specifically to the proximal c-jun promoter CRE element. Also, representative human leukemic cell lines expressing p210 BCR-ABL and possessing abundant kinase activity of JNK, when compared with parental cells that were deficient in JNK activity, had increased c-jun and c-fosproteins. Finally, to show the relevance of these observations in model systems, we studied blast cells from patients with Philadelphia chromosome–positive acute leukemic transformation, and observed comparable activities of JNK catalysis and c-jun/AP-1 protein relative to the cell lines that possessed p210 BCR-ABL and JNK activity. These studies provide a basis for investigating the set of downstream genes which augmented c-jun/AP-1 activity enlists in the process of transformation by p210 BCR-ABL.
Activated Endothelial Cells Induce Apoptosis in Leukemic Cells by Endothelial Interleukin-8
Authors: Terui Yasuhito , Ikeda Masayuki , Tomizuka Hiroshi , Kasahara Tadashi , Ohtsuki Tetsuya , Uwai Masaya , Mori Masaki , Itoh Takehito , Tanaka Miyuki , Yamada Muneo , Shimamura Seiichi , Ishizaka Yukihito , Ikeda Kazuma , Ozawa Keiya , Miura Yasusada , Hatake Kiyohiko 
Published: October 2019

AbstractTumor cells are eradicated by several systems, including Fas ligand-Fas and tumor necrosis factor (TNF)-tumor necrosis factor receptor (TNFR). In the previous study, we purified an apoptosis-inducing factor (AIF) to homogeneity from a medium conditioned by PDBu-treated HL-60 cells. N-terminal sequence analysis showed that AIF is identical to endothelial interleukin-8 (IL-8). A novel apoptosis system, in which endothelial cells participate via endothelial IL-8 release, is identified here. Human umbilical vein cells (VE cells) produce and secrete IL-8 by stimulation of IL-1 and TNF-. Endothelial IL-8, which is secreted from VE cells by stimulation of IL-1 and TNF- , induces apoptosis in myelogenous leukemia cell line K562 cells. Monocyte-derived IL-8 could not induce apoptosis in K562 cells. Moreover, interaction between VE cells and K562 cells induces the release of endothelial IL-8 from VE cells, and the attached K562 cells undergo apoptosis. Moreover, interactions between VE cell and other cell lines, such as HL-60, U937, Jurkat, and Daudi, induce the secretion of endothelial IL-8 and the induction of apoptosis in cell lines. Endothelial IL-8 significantly inhibits tumor growth of intraperitoneal and subcutaneous tumor mass of K562 cells and induces apoptosis in their cells in vivo. Endothelial IL-8 plays an important role in apoptosis involving endothelial cells, which may provide us with a new therapy for hematological malignancies.© 1998 by The American Society of Hematology.
Tissue Distribution and Regulation of Murine von Willebrand Factor Gene Expression In Vivo
Authors: Yamamoto Koji , de Waard Vivian , Fearns Colleen , Loskutoff David J. 
Published: October 2019

Abstractvon Willebrand factor (vWF) is frequently used as a biochemical marker for endothelial cells (ECs). Despite this, little is known about the relative level of expression and regulation of this hemostatic factor in ECs in different vascular beds in vivo. In the present study, we used quantitative reverse transcription polymerase chain reaction and in situ hybridization analysis to study vWF gene expression in murine tissues. Large differences in the level of vWF mRNA were observed when comparing highly vascularized tissues, with the lung and brain containing 5 to 50 times higher concentrations of vWF mRNA than the kidney and liver. In this regard, ECs of small vessels and some microvessels in the lung and brain expressed abundant vWF mRNA, whereas ECs of similar sized vessels in the liver and kidney expressed relatively low levels. In general, significantly higher levels of vWF mRNA and antigen were demonstrated in ECs of larger vessels compared with microvessels and in venous ECs compared with arterial ECs. Although intraperitoneal administration of endotoxin (or tumor necrosis factor-) increased plasma vWF levels, it had variable effects on the steady-state level of vWF mRNA in murine tissues (ie, it decreased vWF mRNA in many tissues, increased it in others, and had little effect on still others). These results indicate that vWF is differentially expressed and regulated in ECs present in different tissues and within the same vascular bed.© 1998 by The American Society of Hematology.
Fluorescence In Situ Hybridization of Progenitor Cells Obtained by Fluorescence-Activated Cell Sorting for the Detection of Cells Affected by Chromosome Abnormality Trisomy 8 in Patients With Myelodysplastic Syndromes
Authors: Saitoh Kohki , Miura Ikuo , Takahashi Naoto , Miura Akira B. 
Published: October 2019

Abstract
Myelodysplastic syndrome (MDS) is believed to be a stem-cell disorder involving cytopenia and dysplastic changes in three hematopoietic lineages. However, the involvement of pluripotent stem cells and progenitor cells has not been clarified conclusively. To address this issue, we used fluorescence in situ hybridization (FISH) of blood and bone marrow (BM) smears for mature cells and FISH of cells sorted by fluorescence-activated cell sorting for progenitor cells. Seven patients with MDS associated with trisomy 8 were studied. FISH showed +8 in granulocytes, monocytes, and erythroblasts, but not in lymphocytes. Sorted cells of T (CD3+), B (CD19+), and NK cells (CD3−CD56+) from peripheral blood did not contain +8, nor did CD34+ subpopulations from BM including B (CD34+CD19+), T/NK (CD34+CD7+) progenitors, and pluripotent stem cells (CD34+Thy1+). The +8 chromosome abnormality was identified in stem cells only at the level of colony-forming unit of granulocyte-erythrocyte-macrophage-megakaryocyte (CFU-GEMM; CD34+CD33+). It may thus be concluded that cells affected by trisomy 8 in the context of MDS are at the CFU-GEMM level and that cells of lymphoid lineage are not involved. These results provide new insights into the biology of MDS and suggest that intensive chemotherapy and autologous BM transplantation may become important therapeutic strategies.
© 1998 by The American Society of Hematology.
Molecular Identification and Functional Characterization of a Novel Protein That Mediates the Attachment of Erythroblasts to Macrophages
Authors: Hanspal Manjit , Smockova Yva , Uong Quang 
Published: October 2019

AbstractWe have previously identified a novel protein that mediates the attachment of erythroblasts to macrophages in vitro. This attachment promotes terminal maturation and enucleation of erythroblasts (Hanspal and Hanspal, Blood 84:3494, 1994). This protein is referred to here as Emp for erythroblast macrophageprotein. Two immunologically related isoforms of Emp with apparent molecular weights of 33 kD and 36 kD were detected in macrophage membranes. The complete amino acid sequence of the larger isoform of Emp was deduced from the nucleotide sequence of a full-length 2.0-kb cDNA that was isolated from a human macrophage cDNA library using affinity-purified anti-Emp antibodies. Of the 2,005 bp, 1,185 bp encode for 395 amino acids representing 43 kD (the sodium dodecyl sulfate-polyacrylamide gel electrophoresis [SDS-PAGE] molecular mass is 36 kD). Northern blot analysis of human macrophage poly(A) RNA detected a message for Emp of 2.1 kb. The deduced amino acid sequence contains a putative transmembrane domain near the N-terminus. To investigate the structure/function relationships of Emp, recombinant fusion proteins of full-length and truncated Emp were produced in bacteria, COS-7, and HeLa cells. Cell binding assays showed that the N-terminus is exposed on the cell surface. The recombinant Emp functions as a cell attachment molecule when expressed in heterologous cells. Furthermore, we showed that the demise of erythroblasts in the absence of Emp-mediated erythroblast-macrophage association is accompanied by apoptosis. We postulate that Emp-mediated contact between erythroblasts and macrophages promotes terminal maturation of erythroid cells by suppressing apoptosis.© 1998 by The American Society of Hematology.
Sickle Cell Adhesion to Laminin: Potential Role for the 5 Chain
Authors: Lee Sheritha P. , Cunningham Michelle L. , Hines Patrick C. , Joneckis Christopher C. , Orringer Eugene P. , Parise Leslie V. 
Published: October 2019

AbstractSickle red blood cell (RBC) adhesion to the endothelium and to exposed, underlying subendothelial proteins is believed to contribute to vascular occlusion in sickle cell disease. Laminin, a major component of the subendothelium, supports significant adhesion of sickle, but not normal RBCs. The purpose of this study was to define the adhesive region for sickle RBCs within a human laminin preparation using a flow adhesion assay designed to mimic physiologic flow through postcapillary venules. Because sickle RBCs did not adhere to the common laminin contaminants entactin or collagen type IV, neither of these proteins are likely to contribute to the observed adhesion to laminin. Known adhesive regions of laminin neither supported nor inhibited sickle RBC adhesion to laminin, suggesting a mechanism of adhesion previously uncharacterized in other laminin adhesion studies. Moreover, sickle RBCs did not adhere to mouse EHS laminin or to human laminin-2 (merosin), eliminating the 1, 2, β1, and γ1 chains as mediators of sickle cell adhesion. The monoclonal antibody 4C7, which binds at or near the G-domain of the laminin 5 chain, significantly inhibited sickle RBC adhesion. These results suggest that an adhesive region for sickle RBCs is contained within the laminin 5 chain.© 1998 by The American Society of Hematology.
Role of CD28 in Acute Graft-Versus-Host Disease
Authors: Yu Xue-Zhong , Martin Paul J. , Anasetti Claudio 
Published: October 2019

AbstractBecause CD28-mediated T-cell costimulation has a pivotal role in the initiation and maintenance of T-cell responses, we tested the hypothesis that CD28 is critical for the development of graft-versus-host disease (GVHD). We compared the in vivo effects of CD28−/− T cells transplanted from B6 donor with the CD28 gene deleted by homologous recombination with those of CD28+/+ T cells transplanted from wild-type C57BL/6 (B6) donor. Fifty million CD28−/− or CD28+/+ splenocytes from B6 mice were transplanted into unirradiated (B6 × DBA/2)F1 (BDF1) recipients. Unlike CD28+/+, CD28−/− T cells from B6 mice had lower levels of proliferation and interleukin-2 production, had a limited ability to generate cytotoxic T lymphocytes against the recipient, and did not induce immune deficiency, despite survival in the recipient for at least 28 days. The ability to prevent rejection was reduced by the absence of CD28, because as many as 1.0 × 107 CD28−/− CD8+ cells were needed to prevent rejection of major histocompatibility complex (MHC) class-I incompatible marrow in sublethally irradiated (550 cGy) bm1 recipients, whereas 8.0 × 105 CD28+/+CD8+ T cells were sufficient to produce a similar effect, indicating that CD28 on donor CD8+ cells helps to eliminate host immunity. Two million CD4+CD28−/− or CD28+/+ T cells were transplanted into sublethally irradiated (750 cGy), MHC class-II incompatible (B6 × bm12)F1 recipients. With CD28−/−cells, 44% of the recipients died at a median of 20 days compared with 94% at a median of 15 days with CD28+/+ cells (P &lt; .001). Two million CD8+CD28−/− or CD28+/+ T cells were transplanted into sublethally irradiated (750 cGy), MHC class-I incompatible (B6 × bm1) F1 recipients. With CD28−/−cells, 25% of the recipients died at a median of 41 days compared with 100% at a median of 15 days with CD28+/+ cells (P &lt; .001). (B6 × bm12)F1 and (B6 × bm1)F1 mice surviving after transplantation of CD28−/− cells recovered thymocytes, T cells, and B cells in numbers and function comparable with that of irradiation-control F1 mice. We conclude that CD28 contributes to the pathogenesis and the severity of GVHD. Our results suggest that the severity of GVHD could be decreased by the administration of agents that block CD28 function in T lymphocytes.© 1998 by The American Society of Hematology.