bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polyphosphate Shortens the Clotting Time of Hemophilic and Anticoagulated Plasma.
Authors: Smith Stephanie A. , Morrissey James H. 
Published: April 2020

Abstract
Introduction: Inorganic polyphosphate (polyP) is a negatively charged polymer of phosphate units linked by high energy phosphoanhydride bonds. Dense granules of human platelets contain abundant polyP which is released in response to thrombin stimulation. We recently reported that polyphosphate is a potent hemostatic regulator, accelerating blood clotting by activating the contact pathway, promoting factor V activation, and abrogating tissue factor pathway inhibitor function. We now report that polyP shortens the clot time of hemophilic plasmas and plasmas containing a variety of anticoagulant drugs.
Methods: Citrated plasmas were obtained from normal donors, patients receiving coumadin, and individuals with severe hemophilia A or B. In some experiments, clinically relevant concentrations of unfractionated heparin, enoxaparin, or argatroban were added to normal plasma. In other experiments, therapeutic concentrations of FIX, FVIII, or FVIIa were added to hemophilic plasma. Clotting was initiated by dilute thromboplastin.
Results: Adding 33 uM polyP to normal plasma shortened clot times at all doses of heparin (by 37–55%), enoxaparin (by 35–57%), and argatroban (by 28–59%; see Figure). PolyP shortened clot times of plasmas from coumadin patients (by 29–39%) with INR values ranging from 1.7 to 4.8. PolyP also shortened the clot times of plasma from patients with hemophilia A (by 54–75%) and B (by 51–79%). PolyP alone shortened clot times of hemophilia A or B plasma equivalent to adding 6 to 15 nM recombinant FVIIa, and the polyP effect was additive to that of FVIIa, FVIII or FIX.
Conclusions: PolyP shortened the in vitro clot time for all plasmas tested and was additive with replacement of missing clotting factors or recombinant FVIIa for hemophilic plasmas. These results suggest that treatment with polyP may be useful for reversal of anticoagulation in patients treated for thrombophilia, or for treatment of bleeding episodes in patients with hemophilia. Furthermore, polyP could potentially reduce the dose of replacement clotting factors or recombinant FVIIa needed to treat bleeding episodes in hemophilia.
Figure Figure
EKLF Is Recruited to the γ-Globin Gene Promoter as a Co-Activator and Is Required for γ-Globin Gene Induction by Short-Chain Fatty Acids.
Authors: Perrine Susan P. , Mankidy Rishikesh , Boosalis Michael S. , Bieker James J. , Faller Douglas V. 
Published: April 2020

Abstract
The erythroid Kruppel-like factor, EKLF, is an essential transcription factor for mammalian β-type globin gene switching, and specifically activates transcription of the adult β-globin gene through binding of its zinc finger domain to the β-globin promoter. We report now that EKLF is also required for activation of the γ-globin gene by short-chain fatty acid (SCFA) derivatives. We found that specific knockdown of EKLF levels by siRNA prevents SCFA induced-expression of an integrated γ-globin promoter in a stably-expressed mLCRβprRluc AγprFluc cassette, and prevents induction of the endogenous γ-globin gene in primary human erythroid progenitors. In chromatin immunoprecipitation (ChIP) assays, EKLF was found to be actively recruited to the endogenous γ-globin gene promoter with exposure of human erythroid progenitors, and hematopoietic cell lines, to SCFA derivatives. The human SWI/WNF complex is a ubiquitous multimeric complex that regulates gene expression by remodeling nucleosomal structure in an ATP-dependent manner. We found that the SWI/SNF complex chromatin-modifying core ATPase BRG1 is also required for γ-globin gene induction by SCFA derivatives. Furthermore, BRG1 is actively recruited to the endogenous γ-globin promoter of human erythroid progenitors with exposure to SCFA derivatives, and this recruitment is dependent upon the presence of EKLF. These findings all demonstrate that EKLF, and the co-activator BRG1, previously demonstrated to be required for definitive or adult erythropoietic patterns of globin gene expression, are co-opted by SCFA derivatives to activate the fetal globin genes. Recently. we also identified a γ-globin-specific repressor complex, consisting of NCoR and HDAC3, which is displaced from the proximal γ-globin promoter by exposure to SCFA derivatives prior to activation of transcription (Blood, 108:3179–86, 2006). Collectively, these studies identify critical activating and repressing cofactors regulating γ-globin gene expression, and provide new targets for therapeutic interventions.
Identification of a Shared CD4+ and CD8+ T Cell Epitope within Human Neutrophil Elastase for Peptide Vaccination in HLA-A02 Negative Leukemia Patients.
Authors: Le Quan , Melenhorst J. Joseph , Hewitt Rachel E. , Hensel Nancy , Barrett A. John 
Published: April 2020

Abstract
Human Neutrophil Elastase (HNE) is aberrantly expressed by myeloid leukemia cells and contains the antigenic PR1 peptide sequence inducing HLA-A*0201 restricted cytotoxic T cells (CTL) against leukemic cells. Our previous studies demonstrated that full length HNE protein can induce both CD4+ and CD8+ T cell responses in healthy individuals including HLA- A*0201 negative individuals, indicating an immunogenic potential of HNE beyond the PR1 peptide (Fujiwara H et al Blood 2004). To identify new HNE epitopes, a peptide matrix consisting of 15mers overlapping by 11 amino acids spanning HNE was screened using peripheral blood mononuclear cells (PBMC) from patients with acute myeloid leukemias (AML). Peptide candidates predicted using syfpeithi predictive algorithms were evaluated by measuring responses to candidate epitopes. We found a novel HNE peptide E17 (HNE: 65–80), recognized by both CD4+ and CD8+ T cells in an HLA-A (11, 31) patient with AML. E17 induced significant proliferation of CD4+ T cells 3.2X and CD8+ T cells 4.6X above background, as measured by CFSE flow cytometry-based proliferation assay. E17 induced IFN-g expression in CD4+ T cells 7.4X and in CD8+ T cells 2.5X above background in flow cytometric assay (see figure). E17 (HNE: 65–80) peptide induced IFN-g mRNA expression 3 hours after peptide treatment of PBMC, as measured by quantitative Real-Time RT-PCR assay. Finally, we showed by flow cytometry that E17 induced cell surface expression of CD137 in CD4+ T cells 2.4X and CD8+ T cells 1.7X above background 8 hours after peptide treatment of the cells. Antigen-driven surface expression of CD137 was used to isolate peptide E17 antigen-specific T cells, for further in vitro expansion and characterization of the T cell response. Thus we have identified a shared CD4+ and CD8+ T cell epitope in HNE, inducing the proliferation and effecter functions in CD4+ and CD8+ T cells. Since this epitope (HNE: 65–80) recruits both helper and cytotoxic T cells, it is well suited for peptide vaccine applications. This study provides the rationale for using the novel E17 (HNE: 65–80) peptide to vaccinate patients with myeloid leukemias.
Figure Figure
Numerous Genomic Abnormalities in AML with Normal Karyotype.
Authors: Akagi Tadayuki , Ogawa Seishi , Yamamoto Go , Nannya Yasuhito , Sanada Masashi , Kawamata Norihiko , Miller Carl W. , Dugas Martin , Schnittger Susanne , Haferlach Torsten , Haferlach Claudia , Koeffler H. Phillip 
Published: April 2020

Abstract
Acute myeloid leukemia (AML) is a clonal hematopoietic malignant disease; about 45–50% of AML samples have no detectable chromosomal abnormality. We wanted to determine if alterations of the genome were present in these AML samples using a sensitive technique and to determine what were these common abnormalities. Thirty-seven normal karyotype AMLs were analyzed with high-density single-nucleotide polymorphism microarray (250K SNP-chip) using the new algorithm AsCNAR (allele-specific copy-number analysis using anonymous references). Nineteen samples (51%) showed either one or more genomic abnormalities including duplication, deletion and loss of heterozygosity with normal copy number [we call this somatic uniparental disomy (UPD)]. Importantly, 12 patients (32%) had UPD, causing duplication of either mutant FLT3 (2 cases), mutant JAK2 (1 case) or mutant AML1/RUNX1 (1 case); and each of these samples had loss of the normal allele. Ten patients (27%) had small copy number changes including deletions of either NF1, ETV6/TEL, or the CDKN2A (p16/INK4A and p14/ARF) and CDKN2B (p15/INK4B) gene complex; these genes can normally function as tumor suppressor genes. mRNA microarray analysis was done on all samples. One case clearly showed a relationship between chromosomal changes and mRNA expression levels: loss or gain of chromosomes leading to decrease or increase mRNA expression of genes; however, in general a loss or gain of a gene could not be detected by microarray analysis. This study suggests that at least one half of AML patients with normal karyotype have readily identifiable genomic abnormalities as found by SNP-chip and AsCNAR. Especially notable is the high frequency of UPD. This technique may become a routine, rapid, robust technique for prognostic stratification of patients and to screen for novel therapeutic targets.
PKCδ Regulates Retinoic Acid-Induced Myeloid Cell Differentiation through Eukaryotic Initiation Factor Alpha (eIF2α).
Authors: Ozpolat Bulent , Akar Ugur , Barria Magaly , Lopez-Berestein Gabriel 
Published: April 2020

Abstract
Overactivity of eukaryotic initiation factor-alpha (eIF2α) has been shown to be oncogenic and induces malignant transformation. Here we investigated the regulation and the role of eIF2α in the terminal differentiation of myeloid leukemia cells. We found that all-trans-retinoic acid (ATRA) and other granulocytic differentiation inducers, such as dimethylsulfoxide and arsenic trioxide inhibited activity of eIF2α by inducing serine 51 phosphorylation in promyelocytic leukemia cells (NB4). In contrast, activity of eIF2α was unaffected during ATRA-induced monocytic differentiation of U937 and THP-1 myelomonocytic cells and phorbol 12-myristate 13-acetate-induced monocytic/macrophagic differentiation of NB4 cells. Knockdown of eIF2α by RNA interference (siRNA) significantly inhibited (p&lt;0.05) ATRA-induced differentiation, indicating that eIF2α is critical for the induction of granulocytic differentiation. ATRA-induced eIF2α phosphorylation was correlated with the expression and activity/phosphorylation (Thr505 and Ser643) of protein kinase Cδ (PKCδ) and eIF2a kinase PKR (Thr446). The specific PKCδ inhibitor Rottlerin significantly reduced phosphorylation of eIF2α, activity of PKR and blocked ATRA-induced granulocytic differentiation of NB4 cells (p&lt;0.05). Knockdown of PKCδ by siRNA decreased PKR activity and increased eIF2α activity while knockdown of PKR increased eIF2α activity. We also observed that PKCδ regulates eIF2a activity in normal CD34+ bone marrow progenitor cells and breast and pancreatic cancer cell lines. Furthermore, we found that eIF2α regulated the expression and activity of important targets of ATRA, including c-myc, p21Waf1/Cip1, DAP5, GADD153, ATF-2, TG2, and p-P70S6K. In conclusion, our findings indicate that ATRA-induced granulocytic differentiation of myeloid leukemia cells is regulated by PKCδ through the activity of eIF2α, revealing a novel mechanism of granulocytic cell differentiation.
Figure Figure
CD3+/CD56+ Cells, but Not Natural Killer T Cells, Are Increased in Peripheral Blood of Untreated Patients with Leukemia.
Authors: Le Dieu Rifca , Taussig David , MacDougal Finlay , Lister Andrew , Gribben John G. 
Published: April 2020

Abstract
Despite recent interest in the use of natural killer T (NKT) cells for cancer immunotherapy, there remains confusion over the phenotype and function of these cells. We observed a population of CD3+/CD56+ cells in the peripheral blood (PB) of patients with acute myeloid leukemia (AML) at diagnosis. We therefore performed more detailed multiparametric flow cytometric analysis on PB from previously untreated patients with AML (n=30), chronic lymphocytic leukemia (CLL) (n=12) and healthy normal volunteers (n=17) to characterize these cells in more detail. Since we were assessing rare cell populations, at least 200,000 events were always acquired from the mononuclear and live cell gates. In healthy individuals CD3+/CD56+ cells comprise 1% to 8.6% (median 2.74%) of PB T cells, but these cells are significantly increased both in percentage of T cells as well as in absolute numbers in the PB of patients with AML (p=0.0009) and CLL (p&lt;0.0001). The percentage of these cells expressing the activation markers CD25 and CD69, is significantly higher in patients with AML (p=0.0007), but not CLL (p=0.67). We next assessed whether there was an increase in true NKT cells identified using anti-CD3 mAb and CD1d molecule loaded with alpha-galactosylceramide tetramer (kindly provided by the NIH tetramer facility). A tetramer consisting of an unloaded CD1d molecule was used as a negative control. Results were confirmed using fluorochrome-labelled antibodies to the T cell receptor chains Valpha24 and Vbeta11. Consistent with previous reports, true NKT cells ranged from undetectable to 1.59% (median 0.03%) of PB T cells in normal individuals. These NKT cells express CD4 or CD8alpha but few express the NK markers CD16 or CD56. There was no significant increase in true NKT cells in percentage or absolute numbers in AML (p=0.56) or CLL (p=0.4), however there are significant differences in subsets of these NKT cells in patients with AML compared with normal individuals. Taken together, these results demonstrate an increase in CD3+/CD56+ cells, but not true NKT cells, in PB of patients with acute and chronic leukemias. CD3+CD56+ cells do not represent NKT cells in health or in disease and true NKT cells require specific characterization. Functional analysis of both CD3+/CD56+ cells as well as true NKT cells in their ability to recognize and lyze AML and CLL cells is underway.
A Chimeric Gene, FIP1L1-RARα, Is Isolated from t(4;17)-Positive Acute Promyelocytic Leukemia; a Report of Cloning and Functional Analysis.
Authors: Kondo Takeshi , Mori Akio , Onozawa Masahiro , Kahata Kaoru , Hashino Satoshi , Tanaka Junji , Imamura Masahiro , Morioka Masanobu , Asaka Masahiro 
Published: April 2020

Abstract
Acute promyelocytic leukemia (APL) comprises 5 to 10% of acute myelogenous leukemia, the leukemia cells of which is characterized by the differentiation block at the stage of promyelocyte. In APL cells, a reciprocal translocation in chromosome 17 is usually observed, and consequently, a retinoic acid receptor alpha (RARα) gene is rearranged. The rearranged RARα gene is fused to another gene, and as a result, the product of newly composed fusion gene provokes the onset of APL. So far, there are five RARα partner genes reported; PML gene in 15q22, PLZF gene in 11q23, NPM gene in 5q35, NuMA gene in 11q13 Stat5b in 17q21. We recently experienced APL case, in which a chromosomal translocation, t(4;17) was observed. FISH analysis of leukemia cells indicated that RARα gene was translocated. To identify the RARα-partner gene, we performed 5′-rapid amplification of cDNA end (RACE) and identified FIP1L1 gene as RARα-partner gene. It is known that FIP1L1 gene is fused to PGDFRα gene in the hypereosinophilic syndrome. DNA sequence revealed that exon 15 of FIP1L1 gene was fused to exon 3 of RARα gene. In previous reports, five X-RARα have the common character;
X-RARα manifests homodimerization. X-RARα suppresses retinoic acid-induced transcription.
We examined that FIP1L1-RARα has these two characters. Transient transfection analysis showed that FIP1L1-RARα has the ability to form homodimer. And luciferase assay suggested that FIP1L1-RARα suppressed the retinoic acid-induced transcriptional activity at the physiological concentration of all-trans retinoic acid (ATRA). And the level of luciferase activity suppressed by FIP1L1-RARα was similar to that suppressed by PML-RARα. And the therapeutic concentration of ATRA activated the significant level of luciferase activity. Thus, in vitro analysis suggested that ATRA treatment could be effective to FIP1L1-RARα-positive APL patients. Consistent with the results of in vitro analysis, ATRA treatment was clinically effective, and the patient achieved complete remission after five weeks of ATRA treatment. Collectively, we suggest that FIP1L1-RAR? is the sixth pathogenic gene of APL.
Etoposide Sensitivity Does Not Predict MLL Rearrangements or Risk of Therapy-Related Acute Myeloid Leukemia.
Authors: Yang Jun , Bogni Alessia , Cheng Cheng , Bleibel Wasim K. , Cai Jean , Fan Yiping , Yang Wenjian , Rocha Jose Claudio , Pei Deqing , Liu Wei , Dolan M. Eileen , Pui Ching-Hon , Relling Mary V. 
Published: April 2020

Abstract
Therapy-related acute myeloid leukemia (t-AML) can arise from topoisomerase II-directed agents such as etoposide and teniposide, most likely via drug-induced MLL gene fusions. MLL cleavage in its breakpoint cluster region has been linked to apoptosis caused by etoposide and other agents. It has been speculated that the degree of myelotoxicity caused by agents such as etoposide may predispose to t-AML. However, whether drug-induced MLL rearrangements (rMLL) and subsequent leukemogenesis are inextricably linked to the desired drug-induced cytotoxic effects remains a matter of uncertainty. To directly address this question, we compared rMLL in blood samples from and epipodophyllotoxin-related clinical toxicity in children with acute lymphoblastic leukemia (ALL) who did and did not develop t-AML, as well as the level of rMLL in cell lines that were sensitive or resistant to etoposide. In 7 t-AML cases and 7 identically-treated matched controls, rMLL were detectable following etoposide treatment in both cohorts, but at a slightly greater frequency in the former group (P = 0.04, Wilcoxon signed-rank test). However, there was no correlation between the cumulative etoposide dose and the degree of rearrangements (P = 0.5, r2=0.039, Spearman rank correlation). Secondly, etoposide or teniposide-related acute toxicities to the host tissues did not differ between the 14 t-AML cases and the 14 matched controls. The drug-induced reduction in neutrophil and leukocyte counts was not greater among t-AML cases than controls (P&gt;0.17, Wilcoxon signed-rank test), nor was the incidence of infection and gastrointestinal toxicity during epipodophyllotoxin treatment (P&gt;0.22, McNemar’s test). Finally, in 25 human lymphoid cell lines, MLL fusions were more common after etoposide treatment (at equitoxic concentrations) compared to untreated controls (P &lt; 0.0001, paired t test) but did not differ in frequency in etoposide-sensitive versus resistant cell lines (P = 0.91, Mann-Whitney U test). Together, these data indicate that epipodophyllotoxin-mediated leukemogenesis is not directly linked to the cytotoxicity of these agents.
Elderly Patients with Acute Myeloid Leukemia Are Not All the Same: Results of the Prospective DSIL AML96 Trial.
Authors: Schaich Markus Andreas , Aulitzky Walter E. , Bodenstein Heinrich , Bornhaeuser Martin , Illmer Thomas , Schaekel Ulrike , Schmitz Norbert , Schuler Ulrich S. , Soucek Silke , Thiede Christian , Wandt Hannes , Ehninger Gerhard 
Published: April 2020

Abstract
The majority of patients with acute myeloid leukemia (AML) are older than 60 years at diagnosis. However, treatment results for these elderly patients are still unsatisfactory. This is thought to be due to a more aggressive disease, preexisting co-morbidities or a decreased tolerance for intensive treatment approaches. As for younger patients there is growing evidence that elderly AML patients may be divided into prognostic subgroups. So far data on prognostic factors in this group of patients are still sketchy. Between February 1996 and March 2005 a total of 827 elderly AML patients with a median age of 67 (61–87) years were treated within the prospective AML96 trial of the German Study Initiative Leukemia (DSIL). 643 patients had de novo and 184 patients secondary disease. All patients were scheduled to receive a double induction therapy with Daunorubicin and Ara-C (DA3+7). The consolidation therapy consisted of one course of m-Amsacrine and intermediate-dose (10g/m2) Ara-C. 265 (32%) patients reached CR criteria after double induction therapy. Forty-two patients (5%) had only a PR, 307(37%) displayed refractory disease, 126(15%) died during induction therapy and 77(10%) received only one course of induction therapy due to severe toxicity. Out of the 265 patients in CR 120 (45%) patients received the consolidation course. The strongest independent prognostic factors for achieving a CR were less than 10% blasts in the day 15 bone marrow, the presence of a NPM mutation or a low-risk karyotype (p&lt;0.0001 each). The 3-year overall (OS) and relapse-free survival (RFS) rates were 18% for all patients and 17% for all patients in CR, respectively. In the multivariate analysis the strongest prognostic factors for survival were age, LDH and cytogenetics (p&lt;0.0001 each). Using these three parameters a prognostic model for survival was established. Patients older than 70 years with intermediate- or high-risk cytogenetics and a high LDH level at diagnosis (n=213) had a 3-year OS of only 9%, whereas patients with low-risk cytogenetics or patients with intermediate-risk cytogenetics, younger than 70 years and a low LDH level (n=237) had a 3-year OS of 32%. All other patients (n=377) had an intermediate 3-year OS of 15% (p&lt;0.0001). In conclusion, elderly AML patients can be stratified into prognostic groups. AML patients older than 70 years with high LDH levels and intermediate- or high-risk cytogenetics at diagnosis do not profit from conventional chemotherapy.