bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reduced Folate Carrier Expression in Acute Lymphoblastic Leukemia: A Mechanism for Ploidy but not Lineage Differences in Methotrexate Accumulation
Authors: Belkov Vladimir M. , Krynetski Eugene Y. , Schuetz John D. , Yanishevski Yuri , Masson Eric , Mathew Susan , Raimondi Susana , Pui Ching-Hon , Relling Mary V. , Evans William E. 
Published: October 2019

AbstractMethotrexate (MTX) is one of the most active and widely used agents for the treatment of acute lymphoblastic leukemia (ALL). To elucidate the mechanism for higher accumulation of MTX polyglutamates (MTX-PG) in hyperdiploid ALL and lower accumulation in T-lineage ALL, expression of the reduced folate carrier (RFC) was assessed by reverse transcription-polymerase chain reaction in ALL blasts isolated from newly diagnosed patients. RFC expression exhibited a 60-fold range among 29 children, with significantly higher expression in hyperdiploid B-lineage ALL (median, 11.3) compared with nonhyperdiploid ALL (median, 2.1; P &lt; .0006), but no significant difference between nonhyperdiploid B-lineage and T-lineage ALL. Furthermore, mRNA levels of RFC (mapped by FISH to chromosome 21) were significantly related to chromosome 21 copy number (P = .0013), with the highest expression in hyperdiploid ALL blasts with 4 copies of chromosome 21. To assess the functional significance of gene copy number, MTX-PG accumulation was compared in ALL blasts isolated from 121 patients treated with either low-dose MTX (LDMTX; n = 60) or high-dose MTX (HDMTX; n = 61). After LDMTX, MTX-PG accumulation was highest in hyperdiploid B-lineage ALL with 4 copies of chromosome 21 (P = .011), but MTX-PG accumulation was not significantly related to chromosome 21 copy number after HDMTX (P = .24). These data show higher RFC expression as a mechanism for greater MTX accumulation in hyperdiploid B-lineage ALL and indicate that lineage differences in MTX-PG accumulation are not due to lower RFC expression in T-lineage ALL.
Expression and Function of Leptin Receptor Isoforms in Myeloid Leukemia and Myelodysplastic Syndromes: Proliferative and Anti-Apoptotic Activities
Authors: Konopleva Marina , Mikhail Adel , Estrov Zeev , Zhao Shourong , Harris David , Sanchez-Williams Gisela , Kornblau Steven M. , Dong Joan , Kliche Kay-Oliver , Jiang Shuwei , Snodgrass H. Ralph , Estey Elihu H. , Andreeff Michael 
Published: October 2019

Abstract
The receptor for the gene product of the obesity gene, leptin, was recently reported to be expressed on murine and human hematopoietic progenitor cells. Therefore, we studied the expression of the leptin receptor, OB-R, in normal myeloid precursors, human leukemia cell lines, and primary leukemic cells using reverse-transcriptase polymerase chain reaction. In normal hematopoiesis, OB-R was expressed in CD34+ cells. Normal promyelocytes (CD34−33+ and CD34−13+) expressed only very low levels of the short, presumably nonsignaling isoform. Both the long and short isoforms of OB-R were expressed in 10 of 22 samples from patients with newly diagnosed primary or secondary acute myeloid leukemia (AML), with a higher incidence of the long isoform in primary AML (87.6% v28.6%; P = .01). The incidence of OB-R expression was higher in recurrent than in newly diagnosed AML (P &lt; .001), and samples from four patients with refractory AML showed strong expression of both isoforms. Both OB-R isoforms were also expressed in newly diagnosed and recurrent acute promyelocytic leukemia cells but were essentially absent in samples of chronic or acute lymphocytic leukemia. In vitro growth of myeloid leukemic cell lines and of blasts from 14 primary AMLs demonstrated that recombinant human leptin alone induced low level proliferation, significantly (P &lt; .05) increased proliferation induced by recombinant human granulocyte colony-stimulating factor, interleukin 3, and stem cell factor in a subset of AML and increased colony formation (P &lt; .005). Also, leptin reduced apoptosis induced by cytokine withdrawal in MO7E and TF-1 cells. Serum leptin levels correlated only with body mass index (P &lt; .001) and gender (P = .03). Results confirm the reported expression of leptin receptor in normal CD34+ cells and demonstrate the frequent expression of leptin receptors in AML blasts. While normal promyelocytes lack receptor expression, leukemic promyelocytes express both isoforms. We also demonstrate proliferative effects of leptin alone and in combination with other physiologic cytokines, and anti-apoptotic properties of leptin. These findings could have implications for the pathophysiology of AML.
Synergistic Effects of Prothrombotic Polymorphisms and Atherogenic Factors on the Risk of Myocardial Infarction in Young Males
Authors: Inbal Aida , Freimark Dov , Modan Baruch , Chetrit Angela , Matetzky Shlomi , Rosenberg Nurit , Dardik Rima , Baron Zvia , Seligsohn Uri 
Published: October 2019

Abstract
Several recent studies evaluated a possible effect of the prothrombotic polymorphisms such as 5,10 methylenetetrahydrofolate reductase (MTHFR) nt 677C → T, factor V (F V) nt 1691G → A (F V Leiden), and factor II (F II) nt 20210 G → A on the risk of myocardial infarction. In the present study, we analyzed the effect of these prothrombotic polymorphisms, as well as apolipoprotein (Apo) E4, smoking, hypertension, diabetes mellitus, and hypercholesterolemia, on the risk of myocardial infarction in young males. We conducted a case-control study of 112 young males with first acute myocardial infarction (AMI) before the age of 52 and 187 healthy controls of similar age. The prevalences of heterozygotes for F V G1691A and F II G20210A were not significantly different between cases and controls (6.3% v 6.4% and 5.9% v 3.4% among cases and controls, respectively). In contrast, the prevalence of MTHFR 677T homozygosity and the allele frequency of Apo E4 were significantly higher among patients (24.1% v 10.7% and 9.4% v5.3% among cases and controls, respectively). Concomitant presence of hypertension, hypercholesterolemia, or diabetes and one or more of the four examined polymorphisms increased the risk by almost ninefold (odds ratio [OR] = 8.66; 95% confidence interval [CI], 3.49 to 21.5) and concomitant smoking by almost 18-fold (OR = 17.6; 95% CI, 6.30 to 48.9). When all atherogenic risk factors were analyzed simultaneously by a logistic model, the combination of prothrombotic and Apo E4 polymorphisms with current smoking increased the risk 25-fold (OR = 24.7; 95% CI, 7.17 to 84.9).The presented data suggest a synergistic effect between atherogenic and thrombogenic risk factors in the pathogenesis of AMI, as was recently found in a similar cohort of women.
Prospective Randomized Multicenter Study Comparing Cyclosporin Alone Versus the Combination of Antithymocyte Globulin and Cyclosporin for Treatment of Patients With Nonsevere Aplastic Anemia: A Report From the European Blood and Marrow Transplant (EBMT) Severe Aplastic Anaemia Working Party
Authors: Marsh J. , Schrezenmeier H. , Marin P. , Ilhan O. , Ljungman P. , McCann S. , Socie G. , Tichelli A. , Passweg J. , Hows J. , Raghavachar A. , Locasciulli A. , Bacigalupo A. 
Published: October 2019

Abstract
We report the results of the first prospective randomized multicenter study of immunosuppressive treatment in patients with previously untreated nonsevere aplastic anemia (AA) as defined by a neutrophil count of at least 0.5 × 109/L and transfusion dependence. Patients were randomized to receive cyclosporin (CSA) alone or the combination of horse antithymocyte globulin ([ATG] Lymphoglobuline; Merieux, Lyon, France) and CSA. The endpoint of the study was the hematologic response at 6 months. One hundred fifteen patients were randomized and assessable with a median follow-up period of 36 months; 61 received CSA and 54 ATG and CSA. In the CSA group, the percentage of complete and partial responders was 23% and 23%, respectively, for an overall response rate of 46%. A significantly higher overall response rate of 74% was found in the ATG and CSA group, with 57% complete and 17% partial responders (P = .02). Compared with CSA alone, the combination of ATG and CSA resulted in a significantly higher median hemoglobin level and platelet count at 6 months. Fewer patients required a second course of treatment before 6 months due to a nonresponse. In the CSA group, 15 of 61 (25%) patients required a course of ATG before 6 months because of disease progression, compared with only 3 of 54 (6%) in the ATG and CSA group. The survival probabilities for the two groups were comparable, 93% (CSA group) and 91% (ATG and CSA group), but at 180 days, the prevalence of patients surviving free of transfusions, which excluded patients requiring second treatment because of nonresponse, death, disease progression, or relapse, was 67% in the CSA group and 90% in the ATG and CSA group (P = .001). We conclude that the combination of ATG and CSA is superior to CSA alone in terms of the hematologic response, the quality of response, and early mortality, and a second course of immunosuppression is less frequently required.
Development of Viral Vectors for Gene Therapy of β-Chain Hemoglobinopathies: Optimization of a γ-Globin Gene Expression Cassette
Authors: Li Qiliang , Emery David W. , Fernandez Magali , Han Hemei , Stamatoyannopoulos George 
Published: October 2019

Abstract
Progress toward gene therapy of β-chain hemoglobinopathies has been limited in part by poor expression of globin genes in virus vectors. To derive an optimal expression cassette, we systematically analyzed the sequence requirements and relative strengths of theAγ- and β-globin promoters, the activities of various erythroid-specific enhancers, and the importance of flanking and intronic sequences. Expression was analyzed by RNase protection after stable plasmid transfection of the murine erythroleukemia cell line, MEL585. Promoter truncation studies showed that theAγ-globin promoter could be deleted to −159 without affecting expression, while deleting the β-globin promoter to −127 actually increased expression compared with longer fragments. Expression from the optimal β-globin gene promoter was consistently higher than that from the optimal Aγ-globin promoter, regardless of the enhancer used. Enhancers tested included a 2.5-kb composite of the β-globin locus control region (termed a μLCR), a combination of the HS2 and HS3 core elements of the LCR, and the HS-40 core element of the -globin locus. All three enhancers increased expression from the β-globin gene to roughly the same extent, while the HS-40 element was notably less effective with theAγ-globin gene. However, the HS-40 element was able to efficiently enhance expression of a Aγ-globin gene linked to the β-globin promoter. Inclusion of extended 3′ sequences from either the β-globin or the Aγ-globin genes had no significant effect on expression. A 714-bp internal deletion ofAγ-globin intron 2 unexpectedly increased expression more than twofold. With the combination of a −127 β-globin promoter, anAγ-globin gene with the internal deletion of intron 2, and a single copy of the HS-40 enhancer, γ-globin expression averaged 166% of murine -globin mRNA per copy in six pools and 105% in nine clones. When placed in a retrovirus vector, this cassette was also expressed at high levels in MEL585 cells (averaging 75% of murine -globin mRNA per copy) without reducing virus titers. However, recombined provirus or aberrant splicing was observed in 5 of 12 clones, indicating a significant degree of genetic instability. Taken together, these data demonstrate the development of an optimal expression cassette for γ-globin capable of efficient expression in a retrovirus vector and form the basis for further refinement of vectors containing this cassette.
One-Day Ex Vivo Culture Allows Effective Gene Transfer Into Human Nonobese Diabetic/Severe Combined Immune-Deficient Repopulating Cells Using High-Titer Vesicular Stomatitis Virus G Protein Pseudotyped Retrovirus
Authors: Rebel Vivienne I. , Tanaka Mayumi , Lee Jeng-Shin , Hartnett Sheila , Pulsipher Michael , Nathan David G. , Mulligan Richard C. , Sieff Colin A. 
Published: October 2019

Abstract
Retrovirus-mediated gene transfer into long-lived human pluripotent hematopoietic stem cells (HSCs) is a widely sought but elusive goal. A major problem is the quiescent nature of most HSCs, with the perceived requirement for ex vivo prestimulation in cytokines to induce stem cell cycling and allow stable gene integration. However, ex vivo culture may impair stem cell function, and could explain the disappointing clinical results in many current gene transfer trials. To address this possibility, we examined the ex vivo survival of nonobese diabetic/severe combined immune-deficient (NOD/SCID) repopulating cells (SRCs) over 3 days. After 1 day of culture, the SRC number and proliferation declined twofold, and was further reduced by day 3; self-renewal was only detectable in noncultured cells. To determine if the period of ex vivo culture could be shortened, we used a vesicular stomatitis virus G protein (VSV-G) pseudotyped retrovirus vector that was concentrated to high titer. The results showed that gene transfer rates were similar without or with 48 hours prestimulation. Thus, the use of high-titer VSV-G pseudotyped retrovirus may minimize the loss of HSCs during culture, because efficient gene transfer can be obtained without the need for extended ex vivo culture.
Long-Term Culture of Human CD34+ Progenitors With FLT3-Ligand, Thrombopoietin, and Stem Cell Factor Induces Extensive Amplification of a CD34−CD14− and a CD34−CD14+ Dendritic Cell Precursor
Authors: Arrighi Jean-François , Hauser Conrad , Chapuis Bernard , Zubler Rudolf H. , Kindler Vincent 
Published: October 2019

AbstractCurrent in vitro culture systems allow the generation of human dendritic cells (DCs), but the output of mature cells remains modest. This contrasts with the extensive amplification of hematopoietic progenitors achieved when culturing CD34+ cells with FLT3-ligand and thrombopoietin. To test whether such cultures contained DC precursors, CD34+ cord blood cells were incubated with the above cytokines, inducing on the mean a 250-fold and a 16,600-fold increase in total cell number after 4 and 8 weeks, respectively. The addition of stem cell factor induced a further fivefold increase in proliferation. The majority of the cells produced were CD34−CD1a− CD14+(p14+) and CD34−CD1a−CD14−(p14−) and did not display the morphology, surface markers, or allostimulatory capacity of DC. When cultured with granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-4 (IL-4), both subsets differentiated without further proliferation into immature (CD1a+, CD14−, CD83−) macropinocytic DC. Mature (CD1a+, CD14−, CD83+) DCs with high allostimulatory activity were generated if such cultures were supplemented with tumor necrosis factor- (TNF). In addition, p14− cells generated CD14+ cells with GM-CSF and TNF, which in turn, differentiated into DC when exposed to GM-CSF and IL-4. Similar results were obtained with frozen DC precursors and also when using pooled human serum AB+ instead of bovine serum, emphasizing that this system using CD34+ cells may improve future prospects for immunotherapy.
Acquisition of p16INK4Aandp15INK4BGene Abnormalities Between Initial Diagnosis and Relapse in Children With Acute Lymphoblastic Leukemia
Authors: Maloney Kelly W. , McGavran Loris , Odom Lorrie F. , Hunger Stephen P. 
Published: October 2019

Abstract
Although numerous somatic mutations that contribute to the pathogenesis of childhood acute lymphoblastic leukemia (ALL) have been identified, no specific cytogenetic or molecular abnormalities are known to be consistently associated with relapse. Thep16INK4A (p16), which encodes for both p16INK4A and p19ARF proteins, andp15INK4B (p15) genes are inactivated by homozygous deletion and/or p15 promoter hypermethylation in a significant proportion of cases of childhood ALL at the time of initial diagnosis. To determine whether alterations in these genes play a role in disease progression, we analyzed a panel of 18 matched specimen pairs collected from children with ALL at the time of initial diagnosis and first bone marrow relapse for homozygous p16 and/orp15 deletions or p15 promoter hypermethylation. Four sample pairs contained homozygous p16 and p15 deletions at both diagnosis and relapse. Among the 14 pairs that werep16/p15 germline at diagnosis, three ALLs developed homozygous deletions of both p16 and p15, and two developed homozygous p16 deletions and retained p15germline status at relapse. In two patients, p15 promoter hypermethylation developed in the interval between initial diagnosis and relapse. In total, homozygous p16 deletions were present in nine of 18 cases, homozygous p15 deletions in seven of 18 cases, and p15 promoter hypermethylation in two of eight cases at relapse. These findings indicate that loss of function of proteins encoded by p16 and/or p15 plays an important role in the biology of relapsed childhood ALL, and is associated with disease progression in a subset of cases.
A CD4-Independent Interaction of Human Immunodeficiency Virus-1 gp120 With CXCR4 Induces Their Cointernalization, Cell Signaling, and T-Cell Chemotaxis
Authors: Missé Dorothée , Cerutti Martine , Noraz Nelly , Jourdan Patrick , Favero Jean , Devauchelle Gérard , Yssel Hans , Taylor Naomi , Veas Francisco 
Published: October 2019

AbstractThe gp120 envelope glycoprotein of human immunodeficiency virus-1 (HIV-1) interacts with the CXCR4 chemokine receptor, but it is not known whether gp120 activates CXCR4-mediated signaling cascades in the same manner as its natural ligand, SDF1. We assessed the effects of wild-type gp120 and a mutant gp120 that interacts with CXCR4 but not CD4 on CD4−/CXCR4+ cells and CD4+/CXCR4+ cells, respectively. Under both experimental conditions, the interaction of CXCR4 and gp120 resulted in their CD4-independent cointernalization. Both molecules were translocated into early endosomes, whereas neither protein could be detected in late endosomes. Binding of gp120 to CXCR4 resulted in a CD4-independent phosphorylation of Pyk2 and an induction of chemotactic activity, demonstrating that this interaction has functional consequences. Interestingly, however, whereas SDF1 activated the ERK/MAP kinase pathway, this cascade was not induced by gp120. Together, these results suggest that the pathology of HIV-1 infection may be modulated by the distinct signal transduction pathway mediated by gp120 upon its interaction with CXCR4.
Neutrophil Activation and Hemostatic Changes in Healthy Donors Receiving Granulocyte Colony-Stimulating Factor
Authors: Falanga A. , Marchetti M. , Evangelista V. , Manarini S. , Oldani E. , Giovanelli S. , Galbusera M. , Cerletti C. , Barbui T. 
Published: October 2019

AbstractGranulocyte colony-stimulating factor (G-CSF) enhances neutrophil functions in vitro and in vivo. It is known that neutrophil-derived products can alter the hemostatic balance. To understand whether polymorphonuclear leukocyte (PMN) activation, measured as PMN degranulation and phenotypical change, may be associated to hemostatic alterations in vivo, we have studied the effect of recombinant human G-CSF (rHuG-CSF) administration on leukocyte parameters and hemostatic variables in healthy donors of hematopoietic progenitor cells (HPCs). Twenty-six consecutive healthy donors receiving 10 μg/kg/d rHuG-CSF subcutaneously for 5 to 7 days to mobilize HPCs for allogeneic transplants were included in the study. All of them responded to rHuG-CSF with a significant white blood cell count increase. Blood samples were drawn before therapy on days 2 and 5 and 1 week after stopping rHuG-CSF treatment. The following parameters were evaluated: (1) PMN activation parameters, ie, surface CD11b/CD18 antigen expression, plasma elastase antigen levels and cellular elastase activity; (2) plasma markers of endothelium activation, ie, thrombomodulin (TM) and von Willebrand factor (vWF) antigens; (3) plasma markers of blood coagulation activation, ie, F1+2, TAT complex, D-dimer; and (4) mononuclear cell (MNC) procoagulant activity (PCA) expression. The results show that, after starting rHuG-CSF, an in vivo PMN activation occurred, as demonstrated by the significant increment of surface CD11b/CD18 and plasma elastase antigen levels. Moreover, PMN cellular elastase activity, which was significantly increased at 1 day of treatment, returned to baseline at day 5 to 6, in correspondence with the elastase antigen peak in the circulation. This change was accompanied by a parallel significant increase in plasma levels of the two endothelial and the three coagulation markers. The PCA generated in vitro by unstimulated MNC isolated from rHuG-CSF–treated subjects was not different from that of control cells from untreated subjects. However, endotoxin-stimulated MNC isolated from on-treatment individuals produced significantly more PCA compared with both baseline and control samples. All of the parameters were decreased or normal 1 week after stopping treatment. These data show that rHuG-CSF induces PMN activation and transiently affects some hemostatic variables in healthy HPC donor subjects. The clinical significance of these findings remains to be established.
Stromal Cell CD9 Regulates Differentiation of Hematopoietic Stem/Progenitor Cells
Authors: Aoyama Keisuke , Oritani Kenji , Yokota Takafumi , Ishikawa Jun , Nishiura Tetsuo , Miyake Kensuke , Kanakura Yuzuru , Tomiyama Yoshiaki , Kincade Paul W. , Matsuzawa Yuji 
Published: October 2019

AbstractCD9 belongs to the transmembrane 4 superfamily, and has been shown to influence cell proliferation, motility, and adhesion. We show here that ligation of CD9 modifies proliferation and/or differentiation of hematopoietic stem/progenitors. Pluripotent EML-C1 hematopoietic cells were cocultured with MS-5 stromal cells in the presence of KMC8.8, an anti-CD9 antibody. Numbers of recovered EML-C1 cells were slightly reduced and the antibody caused the hematopoietic cells to migrate beneath the adherent stromal cell layer. Of particular interest, EML-C1 cells recovered from CD9-ligated cultures had undifferentiated properties. Separate pretreatment of the two cell types with antibody showed that stromal-cell CD9 mediated these responses. Spontaneous expression of erythroid marker was completely blocked and there was a shift towards undifferentiated clonogenic progenitors. Immunoprecipitation studies showed that stromal-cell CD9 associates with the β1 subunit of integrin, as well as a novel 100 kD protein. Antibody cross-linking of cell surface CD9 increased the amount of 100 kD protein that was subsequently coprecipitated with CD9. These observations show that stromal-cell CD9 influences physical interactions with hematopoietic cells and may be one factor that determines the degree of stem cell differentiation.