bluuebunny/crossref_metadata_2025_split huggingface dataset:
Myeloid Malignancies Induced by Alkylating Agents in Nf1 Mice
Authors: Mahgoub Nidal , Taylor Brigit R. , Beau Michelle M. Le , Gratiot Mary , Carlson Katrin M. , Atwater Susan K. , Jacks Tyler , Shannon Kevin M. 
Published: October 2019

Abstract
Therapy-related acute myeloid leukemia and myelodysplastic syndrome (t-AML and MDS) are severe late complications of treatment with genotoxic chemotherapeutic agents. Children with neurofibromatosis type 1 (NF1) are predisposed to malignant myeloid disorders that are associated with inactivation of the NF1 tumor suppressor gene in the leukemic clone. Recent clinical data suggest that NF1 might be also associated with an increased risk of t-AML after treatment with alkyating agents. To test this hypothesis, we administered cyclophosphamide or etoposide to cohorts of wild-type and heterozygousNf1 knockout mice. Cyclophosphamide exposure cooperated strongly with heterozygous inactivation of Nf1 in myeloid leukemogenesis, while etoposide did not. Somatic loss of the normalNf1 allele correlated with clinical disease and was more common in 129/Sv mice than in 129/Sv × C57BL/6 animals. Leukemic cells showing loss of heterozygosity at Nf1 retained a structural allele on each chromosome 11 homolog. These studies establish a novel in vivo model of alkylator-induced myeloid malignancy that will facilitate mechanistic and translational studies.
ASHAP: A Regimen for Cytoreduction of Refractory or Recurrent Hodgkin’s Disease
Authors: Rodriguez J. , Rodriguez M.A. , Fayad L. , McLaughlin P. , Swan F. , Sarris A. , Romaguera J. , Andersson B. , Cabanillas F. , Hagemeister F.B. 
Published: October 2019

Abstract
Patients with Hodgkin’s disease, which is either refractory or recurs after frontline chemotherapy with MOPP (mechlorethamine, vincristine, procarbazine, and prednisone), ABVD (doxorubicin, bleomycin, vinblastine, and dacarbazine), or both regimens, generally have a poor prognosis. High-dose chemotherapy with autologous marrow or stem cell rescue (ABMT) is now a widely used salvage strategy in these patients. In this study, our objective was to determine the response rate to ASHAP (Adriamycin = doxorubicin, Solumedrol = methylprednisolone, High-dose Ara-C = cytosine arabinoside, and Platinum = cisplatinum), in a group of patients with Hodgkin’s disease with such poor risk characteristics. The treatment was intended as a brief tumor reducing program before ABMT. Fifty-six patients with diagnosed relapsed or primary refractory Hodgkin’s disease underwent this treatment. The program consisted of the administration of two cycles of ASHAP chemotherapy (doxorubicin 10 mg/m2/d intravenous (IV) continuous infusion (CI) over 24 hours, days 1 to 4; methylprednisolone 500 mg/d IV over 15 minutes daily for 5 days; cisplatinum 25 mg/m2/d IV CI over 24 hours, days 1 to 4; cytosine arabinoside 1.5 g/m2/d IV over 2 hours on day 5). After two courses of ASHAP the patients were evaluated for response, including a gallium scan test. Patients with progressive disease were taken off the study. Those with responding or stable disease received a third course of ASHAP, followed by consolidative treatment with ABMT. There were 19 complete responses (34% CR), 20 partial responses (36% PR), and 17 treatment failures, including 8 with minor responses and 9 with disease progression. Thus, in total there were 39 responses out of 56 patients (CR + PR = 70%). Myelosuppression was the main toxicity. There were no deaths due to toxicity. At this time, 23 patients are alive. There were 31 deaths due to disease progression and 2 due to other causes. The initial response to ASHAP before subsequent ABMT consolidation treatment correlated with survival. All 17 patients in whom ASHAP failed to achieve a response have died. The presence of B symptoms at relapse, and a duration of response to the last regimen of ≤6 months, predicted a poor response to ASHAP. A short program of treatment with ASHAP is an effective tumor debulking approach in patients previously treated with both or either ABVD and MOPP, before ABMT.
The Myeloid-Lymphoid Initiating Cell (ML-IC) Assay Assesses the Fate of Multipotent Human Progenitors In Vitro
Authors: Punzel M. , Wissink S.D. , Miller J.S. , Moore K.A. , Lemischka I.R. , Verfaillie C.M. 
Published: October 2019

AbstractHematopoietic stem cells (HSC) are cells with self-renewing multilineage differentiation potential. Although engraftment in xenogeneic recipients can be used to measure human HSC, these assays do not allow assessment of individual progenitors. We developed an in vitro assay that allows the identification of a single human bone marrow progenitor closely related to HSC, which we termed “Myeloid-Lymphoid Initiating Cell,” or ML-IC, because it is capable of generating multiple secondary progenitors that can reinitiate long-term myeloid and lymphoid hematopoiesis in vitro. The assay is done in contact with murine AFT024 fetal liver stromal cells and with Flt3-Ligand, stem cell factor, and interleukin-7. In this assay, 0.2% to 1.7% of Lin−/34+/DRdim cells could generate 1 to 3 long-term culture initiating cells (LTC-IC) as well as 1 to 4 NK-IC after 4 to 6 weeks. In addition, this assay measures contribution of net-progenitor conservation and net-progenitor proliferation over time, providing insight in the fate of individual LTC-IC and NK-IC. This assay will prove useful to enumerate the number of very primitive human progenitors with multilineage differentiation potential, as well as to evaluate future ex vivo culture conditions.
T20/DP178, an Ectodomain Peptide of Human Immunodeficiency Virus Type 1 gp41, Is an Activator of Human Phagocyte N-Formyl Peptide Receptor
Authors: Su Shao Bo , Gong Wang-hua , Gao Ji-Liang , Shen Wei-Ping , Grimm Michael C. , Deng Xiyun , Murphy Philip M. , Oppenheim Joost J. , Wang Ji Ming 
Published: October 2019

AbstractHuman immunodeficiency virus type 1 (HIV-1) envelope protein gp41 mediates viral fusion with human host cells. The peptide segment T20/DP178, located in the C-terminus of the ectodomain of gp41, interacts with the N-terminal leucine zipper-like domain on gp41 to establish the fusogenic conformation of the virus. Synthetic T20/DP178 peptide is highly efficacious in inhibiting HIV-1 infection in vitro by disrupting the transformation of fusogenic status of viral gp41; thus, it has been proposed for clinical trial. We report that synthetic T20/DP178 is a chemoattractant and activator of human peripheral blood phagocytes but not of T lymphocytes. We further demonstrate that T20/DP178 specifically activates a seven-transmembrane, G-protein–coupled phagocyte receptor for N-formylated chemotactic peptides, formyl peptide receptor (FPR). Moreover, synthetic T20/DP178 analogs lacking N-terminal amino acids acted as FPR antagonists. Our results suggest that gp41 peptides regulate phagocyte function via FPR and identify a novel mechanism by which HIV-1 may modulate innate immunity.
Physical Interaction Between Retinoic Acid Receptor and Sp1: Mechanism for Induction of Urokinase by Retinoic Acid
Authors: Suzuki Yasuhiro , Shimada Jun , Shudo Koichi , Matsumura Masatoshi , Crippa Massimo P. , Kojima Soichi 
Published: October 2019

AbstractInduction of urokinase plasminogen activator (uPA) by retinoic acid (RA) is the initial event preceding certain subsequent biological changes in vascular endothelial cells. We investigated the molecular mechanism by which RA stimulates the expression of uPA, which lacks a canonical RA receptor (RAR)-responsive element, in bovine and human aortic endothelial cells. Upon stimulation with RA, mRNA levels of RAR and β transiently increased in parallel with the induction of uPA, and this increase was inhibited by cycloheximide. Results of transient transfection of RAR/RXR cDNAs and experiments using specific agonists and antagonists suggested that uPA induction is dependent upon RAR (initially, RAR) with the help of RXR. Deletion analysis of the uPA promoter suggested that RAR/RXR acts on GC box region within the uPA promoter. This was further supported by inhibition of Sp1 binding to this region. Coimmunoprecipitation studies, glutathioneS-transferase pull-down experiment, and mammalian two-hybrid assays suggested a physical interaction between RAR/RXR and Sp1. Furthermore, gel shift studies showed that the binding of Sp1 to the uPA GC box is significantly potentiated in the presence of RARs/RXRs. Finally, Sp1 and RAR/RXR synergistically enhanced the transactivation activity of the uPA promoter. These results suggest that (1) RA induces RARs mainly via RAR and that (2) RAR/RXR physically and functionally interact with Sp1, resulting in a potentiation of uPA transcription.
Identification of Vascular Endothelial Growth Factor (VEGF) Receptor-2 (Flk-1) Promoter/Enhancer Sequences Sufficient for Angioblast and Endothelial Cell-Specific Transcription in Transgenic Mice
Authors: Kappel Andreas , Rönicke Volker , Damert Annette , Flamme Ingo , Risau Werner , Breier Georg 
Published: October 2019

AbstractThe vascular endothelial growth factor (VEGF) receptor-2 (Flk-1) is the first endothelial receptor tyrosine kinase to be expressed in angioblast precursors, and its function is essential for the differentiation of endothelial cells and hematopoietic precursors. We have identified cis-acting regulatory elements of the murineFlk-1 gene that mediate endothelium-specific expression of a LacZ reporter gene in transgenic mice. Sequences within the 5′-flanking region of the Flk-1 gene, in combination with sequences located in the first intron, specifically targeted transgene expression to angioblasts and endothelial cells of transgenic mice. The intronic regulatory sequences functioned as an autonomous endothelium-specific enhancer. Sequences of the 5′-flanking region contributed to a strong, uniform, and reproducible transgene expression and were stimulated by the transcription factor HIF-2. The Flk-1 gene regulatory elements described in this study should allow the elucidation of the molecular mechanisms involved in endothelial cell differentiation and angiogenesis.
Identification of HLA-A2–Restricted T-Cell Epitopes Derived From the MUC1 Tumor Antigen for Broadly Applicable Vaccine Therapies
Authors: Brossart Peter , Heinrich Kathrin S. , Stuhler Gernot , Behnke Lars , Reichardt Volker L. , Stevanovic Stefan , Muhm Alexandra , Rammensee Hans-Georg , Kanz Lothar , Brugger Wolfram 
Published: October 2019

AbstractThe tumor-associated antigen MUC1 is overexpressed on various hematological and epithelial malignancies and is therefore a suitable candidate for broadly applicable vaccine therapies. It was demonstrated that major histocompatibility complex (MHC)-unrestricted cytotoxic T cells can recognize epitopes of the MUC1 protein core localized in the tandem repeat domain. There is increasing evidence now that MHC-restricted T cells can also be induced after immunization with the MUC1 protein or segments of the core tandem repeat. Using a computer analysis of the MUC1 amino acid sequence, we identified two novel peptides with a high binding probability to the HLA-A2 molecule. One of the peptides is derived from the tandem repeat region and the other is derived from the leader sequence of the MUC1 protein, suggesting that, in contrast to previous reports, the MUC1-directed immune responses are not limited to the extracellular tandem repeat domain. Cytotoxic T cells (CTL) were generated from several healthy donors by primary in vitro immunization using peptide-pulsed dendritic cells. The addition of a Pan-HLA-DR binding peptide PADRE as a T-helper epitope during the in vitro priming resulted in an increased cytotoxic activity of the MUC1-specific CTL and a higher production of cytokines such as interleukin-12 and interferon-γ in the cell cultures, demonstrating the importance of CD4 cells for an efficient CTL priming. The peptide induced CTL lysed tumors endogenously expressing MUC1 in an antigen-specific and HLA-A2–restricted fashion, including breast and pancreatic tumor cells as well as renal cell carcinoma cells, showing that these peptides are shared among many tumors. The use of MUC1-derived peptides could provide a broadly applicable approach for the development of dendritic cell-based vaccination therapies.
Fusion of the ets Transcription Factor TEL to Jak2 Results in Constitutive Jak-Stat Signaling
Authors: Ho Jen M.-Y. , Beattie Bryan K. , Squire Jeremy A. , Frank David A. , Barber Dwayne L. 
Published: October 2019

AbstractTo study constitutive Janus kinase signaling, chimeric proteins were generated between the pointed domain of the etstranscription factor TEL and the cytosolic tyrosine kinase Jak2. The effects of these proteins on interleukin-3 (IL-3)–dependent proliferation of the hematopoietic cell line, Ba/F3, were studied. Fusion of TEL to the functional kinase (JH1) domain of Jak2 resulted in conversion of Ba/F3 cells to factor-independence. Importantly, fusion of TEL to the Jak2 pseudokinase (JH2) domain or a kinase-inactive Jak2 JH1 domain had no effect on IL-3–dependent proliferation of Ba/F3 cells. Active TEL-Jak2 constructs (consisting of either Jak2 JH1 or Jak2 JH2+JH1 domain fusions) were constitutively tyrosine-phosphorylated but did not affect phosphorylation of endogeneous Jak1, Jak2, or Jak3. TEL-Jak2 activation resulted in the constitutive tyrosine phosphorylation of Stat1, Stat3, and Stat5 as determined by detection of phosphorylation using activation-specific antibodies and by binding of each protein to a preferential GAS sequence in electrophoretic mobility shift assays. Elucidation of signaling events downstream of TEL-Jak2 activation may provide insight into the mechanism of leukemogenesis mediated by this oncogenic fusion protein.
Sphingosine Blocks Human Polymorphonuclear Leukocyte Phagocytosis Through Inhibition of Mitogen-Activated Protein Kinase Activation
Authors: Raeder Evelin M.B. , Mansfield Pamela J. , Hinkovska-Galcheva Vania , Kjeldsen Lars , Shayman James A. , Boxer Laurence A. 
Published: October 2019

AbstractIn the present study, we investigated the mechanism by which sphingosine and its analogues, dihydrosphingosine and phytosphingosine, inhibit polymorphonuclear leukocyte (PMN) phagocytosis of IgG-opsonized erythrocytes (EIgG) and inhibit ERK1 and ERK2 phosphorylation. We used antibodies that recognized the phosphorylated forms of ERK1 (p44) and ERK2 (p42) (extracellular signal-regulated protein kinases 1 and 2). Sphingoid bases inhibited ERK1 and ERK2 activation and phagocytosis of EIgG in a concentration-dependent manner. Incubation with glycine, N,N′-[1,2-ethanediylbis(oxy-2,1-phenylene)]bis[N-[2-[(acetyloxy)methoxy]-2-oxoethyl]]-bis[(acetyloxy)methyl]ester (BAPTA,AM), an intracellular chelator of calcium, failed to block either phagocytosis or ERK1 and ERK2 phosphorylation, consistent with the absence of a role for a calcium-dependent protein kinase C (PKC) in ERK1 and ERK2 phosphorylations. Western blotting demonstrated that sphingosine inhibited the translocation of Raf-1 and PKCδ from PMN cytosol to the plasma membrane during phagocytosis. These data are consistent with the interpretation that sphingosine regulates ERK1 and ERK2 phosphorylation through inhibition of PKCδ, and this in turn leads to inhibition of Raf-1 translocation to the plasma membrane. Consistent with this interpretation, the sphingosine-mediated inhibition of phagocytosis, ERK2 activation, and PKCδ translocation to the plasma membrane could be abrogated with a cell-permeable diacylglycerol analog. The increase in the diacylglycerol mass correlated with the translocation of PKCδ and Raf-1 to the plasma membrane by 3 minutes after the initiation of phagocytosis. Additionally, the diacylglycerol analog enhanced phagocytosis by initiating activation of PKCδ and its translocation to the plasma membrane. Because PMN generate sufficient levels of sphingosine by 30 minutes during phagocytosis of EIgG to inhibit phagocytosis, it appears that sphingosine can serve as an endogenous regulator of EIgG-mediated phagocytosis by downregulating ERK activation.
Proliferation and Survival of Mammary Carcinoma Cells Are Influenced by Culture Conditions Used for Ex Vivo Expansion of CD34+Blood Progenitor Cells
Authors: Spyridonidis A. , Bernhardt W. , Behringer D. , Köhler G. , Azemar M. , Pflug A. , Henschler R. 
Published: October 2019

Abstract
Malignant cell contamination in autologous transplants is a potential origin of tumor relapse. Ex vivo expansion of CD34+ blood progenitor cells (BPC) has been proposed as a tool to eliminate tumor cells from autografts. To characterize the influence of culture conditions on survival, growth, and clonogenicity of malignant cells, we isolated primary mammary carcinoma cells from pleural effusions and ascites of patients with metastatic breast cancer and cultured them in the presence of stem cell factor (SCF), interleukin-1β (IL-1β), IL-3, IL-6, and erythropoietin (EPO), ie, conditions previously shown to allow efficient ex vivo expansion of CD34+ BPC. In the presence of serum, tumor cells proliferated during a 7-day culture period and no significant growth-modulatory effect was attributable to the presence of hematopoietic growth factors. When transforming growth factor-β1 (TGF-β1) was added to these cultures, proliferation of breast cancer cells was reduced. Expansion of clonogenic tumor cells was seen in the presence of SCF + IL-1β + IL-3 + IL-6 + EPO, but was suppressed by TGF-β1. Cocultures of tumor cells in direct cellular contact with hematopoietic cells showed that tumor cell growth could be stimulated by ex vivo expanded hematopoietic cells at high cell densities (5 × 105/mL). In contrast, culture under serum-free conditions resulted in death of greater than 90% of breast cancer cells within 7 days and a further decrease in tumor cell numbers thereafter. In the serum-free cultures, hematopoietic cytokines and cellular contact with CD34+ BPC could not protect the tumor cells from death. Therefore, ex vivo expansion of CD34+ BPC in serum-free medium provides an environment for efficient purging of contaminating mammary carcinoma cells. These results have clinical significance for future protocols in autologous progenitor cell transplantation in cancer patients.
Fusion of ETV6 to the Caudal-Related Homeobox Gene CDX2 in Acute Myeloid Leukemia With the t(12;13)(p13;q12)
Authors: Chase Andrew , Reiter Andreas , Burci Linda , Cazzaniga Giovanni , Biondi Andrea , Pickard Julie , Roberts Irene A.G. , Goldman John M. , Cross Nicholas C.P. 
Published: October 2019

AbstractThe t(12;13)(p13;q12) is a rare, recurrent translocation reported in a range of hematological malignancies. We have analyzed the molecular basis of this lesion in three patients with acute myeloid leukemia (AML), two of whom were known to have chromosome 12 breakpoints within the ETV6 gene. Fluorescence in situ hybridization (FISH) with ETV6 cosmids indicated that this gene was also disrupted in the third patient, while the normal ETV6 allele was retained. 3′ rapid amplification of cDNA ends (RACE) polymerase chain reaction (PCR) from bone marrow mRNA of this individual identified a novel sequence fused to ETV6 that was homologous to a region just upstream of the mouse CDX2 homeobox gene, the human homologue of which has previously been mapped to chromosome 13q12. PCR primers designed to amplify an ETV6-CDX2 fusion identified two major transcripts from this patient. First, a direct in-frame fusion between exon 2 of ETV6 and exon 2 of CDX2, and second, a transcript that had an additional sequence of unknown origin spliced between these same exons. Surprisingly, apparently normal CDX2 transcripts, usually expressed only in intestinal epithelium, were also detectable in cDNA from this patient. Neither normal nor fusion CDX2 mRNA was detectable in the two other patients with a t(12;13), indicating that this translocation is heterogeneous at the molecular level. Reverse transcription-PCR analysis showed that CDX2 mRNA, but not ETV6-CDX2 mRNA, was strongly expressed in 1 of 10 patients with chronic myeloid leukemia in transformation, suggesting that deregulation of this gene may be more widespread in leukemia. CDX2 is known to regulate class I homeobox genes and its expression in hematopoietic cells may critically alter the balance between differentiation and proliferation.
Notch1-Induced Delay of Human Hematopoietic Progenitor Cell Differentiation Is Associated With Altered Cell Cycle Kinetics
Authors: Carlesso Nadia , Aster Jon C. , Sklar Jeffrey , Scadden David T. 
Published: October 2019

AbstractHematopoiesis is a balance between proliferation and differentiation that may be modulated by environmental signals. Notch receptors and their ligands are highly conserved during evolution and have been shown to regulate cell fate decisions in multiple developmental systems. To assess whether Notch1 signaling may regulate human hematopoiesis to maintain cells in an immature state, we transduced a vesicular stomatitis virus G-protein (VSV-G) pseudo-typed bicistronic murine stem cell virus (MSCV)-based retroviral vector expressing a constitutively active form of Notch1 (ICN) and green fluorescence protein into the differentiation competent HL-60 cell line and primary cord blood–derived CD34+ cells. In addition, we observed endogenous Notch1 expression on the surface of both HL-60 cells and primary CD34+ cells, and therefore exposed cells to Notch ligand Jagged2, expressed on NIH3T3 cells. Both ligand-independent and ligand-dependent activation of Notch resulted in delayed acquisition of differentiation markers by HL-60 cells and cord blood CD34+ cells. In addition, primary CD34+cells retained their ability to form immature colonies, colony-forming unit–mix (CFU-mix), whereas control cells lost this capacity. Activation of Notch1 correlated with a decrease in the fraction of HL-60 cells that were in G0/G1phase before acquisition of a mature cell phenotype. This enhanced progression through G1 was noted despite preservation of the proliferative rate of the cells and the overall length of the cell cycle. These findings show that Notch1 activation delays human hematopoietic differentiation and suggest a link of Notch differentiation effects with altered cell cycle kinetics.
Autoimmune Antibody in a Hemorrhagic Patient Interacts With Thrombin-Activated Factor XIII in a Unique Manner
Authors: Lorand Laszlo , Velasco Pauline T. , Murthy S.N. Prasanna , Lefebvre Phil , Green David 
Published: October 2019

AbstractWithout a prior history of hemorrhagic disease, a 62-year-old man suffered recurrent episodes of bleeding. Solubility of the patient’s clot in 5 mol/L urea indicated a problem with fibrin stabilization. The transamidase activity potential of factor XIII, measured by the incorporation of radioactive putrescine into N,N-dimethylcasein as test substrate, was 62% of control, close to the normal range of values. Examination of the patient’s clot from recalcified plasma by sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that essentially none of the  chains and only about two thirds of the γ chains of fibrin became cross-linked under conditions where both were fully cross-linked in the controls. An antibody to factor XIII was isolated which, although recognizing the recombinant rA2subunits, as well as the virgin A2B2 plasma ensemble, showed a 100-fold greater affinity for the thrombin-activated rA2′ and A2′B2 forms of the zymogen, suggesting that the latter would be its main target during coagulation. Furthermore, the patient’s IgG has an ability, never seen before, for inducing an enzymatically active configuration in the thrombin-activated zymogen in the absence of Ca2+.