bluuebunny/crossref_metadata_2025_split huggingface dataset:
Expression of the Epstein-Barr Virus Protein LMP1 Mediates Tumor Regression In Vivo
Authors: Cherney Barry W. , Sgadari Cecilia , Kanegane Chiharu , Wang Frederick , Tosato Giovanna 
Published: October 2019

AbstractBy stimulating the expression of murine IP-10 and Mig, CXC chemokines that inhibit neovascularization and cause damage to established tumor vasculature, human B cells immortalized with Epstein-Barr virus (EBV) can promote an effective antitumor response in athymic mice. In the present study, we examined the potential role of EBV in the induction of this antitumor response. Using a panel of EBV+ and EBV− Burkitt lymphoma (BL) cell lines, a significant correlation was detected between the expression of the EBV latency gene LMP1 and the occurrence of spontaneous tumor regression in athymic mice. Inoculation of LMP1+ and LMP1− BL cells in the same subcutaneous site resulted in tumors that completely regressed in a manner indistinguishable from that induced by EBV-immortalized B cells. EBV-converted BL30 and BL41 sublines infected with B95-8 virus expressed LMP1, generated tumors that frequently regressed spontaneously, and promoted an effective antitumor response against progressively growing tumors. In contrast, the EBV− BL30 and BL41 cell lines and the EBV-converted BL30 and BL41 infected with P3HR-1 virus did not express LMP1 protein, and generated progressively growing tumors in nude mice. When transfected with the LMP1 gene, BL41 cells produced tumors that regressed spontaneously in most cases, and could induce the regression of tumors derived from BL41 cells transfected with vector alone. Tumors induced by LMP1-expressing cells expressed murine IP-10 and Mig and displayed histological evidence of extensive tumor tissue necrosis and vascular damage. We conclude that the EBV protein LMP1 is likely responsible for the antitumor response elicited by EBV-immortalized cells in athymic mice.
Response of Monocyte Iron Regulatory Protein Activity to Inflammation: Abnormal Behavior in Genetic Hemochromatosis
Authors: Recalcati Stefania , Pometta Roberta , Levi Sonia , Conte Dario , Cairo Gaetano 
Published: October 2019

AbstractIn genetic hemochromatosis (GH), iron overload affects mainly parenchymal cells, whereas little iron is found in reticuloendothelial (RE) cells. We previously found that RE cells from GH patients had an inappropriately high activity of iron regulatory protein (IRP), the key regulator of intracellular iron homeostasis. Elevated IRP should reflect a reduction of the iron pool, possibly because of a failure to retain iron. A defect in iron handling by RE cells that results in a lack of feedback regulation of intestinal absorption might be the basic abnormality in GH. To further investigate the capacity of iron retention in RE cells of GH patients, we used inflammation as a model system as it is characterized by a block of iron release from macrophages. We analyzed the iron status of RE cells by assaying IRP activity and ferritin content after 4, 8, and 24 hours of incubation with lipopolysaccharide (LPS) and interferon-γ (IFN-γ). RNA-bandshift assays showed that in monocytes and macrophages from 16 control subjects, IRP activity was transiently elevated 4 hours after treatment with LPS and IFN-γ but remarkably downregulated thereafter. Treatment with NO donors produced the same effects whereas an inducible Nitric Oxide Synthase (iNOS) inhibitor prevented them, which suggests that the NO pathway was involved. Decreased IRP activity was also found in monocytes from eight patients with inflammation. Interestingly, no late decrease of IRP activity was detected in cytokine-treated RE cells from 12 GH patients. Ferritin content was increased 24 hours after treatment in monocytes from normal subjects but not in monocytes from GH patients. The lack of downregulation of IRP activity under inflammatory conditions seems to confirm that the control of iron release from RE cells is defective in GH.
Loss of Imprinting in Disease Progression in Chronic Myelogenous Leukemia
Authors: Randhawa Gurvaneet S. , Cui Hengmi , Barletta Janet A. , Strichman-Almashanu Liora Z. , Talpaz Moshe , Kantarjian Hagop , Deisseroth Albert B. , Champlin Richard C. , Feinberg Andrew P. 
Published: October 2019

Abstract
The pathophysiologic role of the Philadelphia chromosome translocation in chronic myelogenous leukemia (CML) has been known for nearly 20 years. However, the most significant morbidity and mortality in CML are caused by progression to blast crisis, about which comparatively little is known at the molecular level. Genomic imprinting is a chromosomal modification leading to parental-origin–specific gene expression in somatic cells. Recently, we and others have described loss of imprinting (LOI) of the insulin-like growth factor-II gene (IGF2), leading to biallelic rather than monoallelic expression in a wide variety of solid tumors. We have now examined the imprinting status of IGF2 in samples from CML patients in stable phase, accelerated phase, and blast crisis. Five of six stable-phase patients showed normal imprinting, but LOI was found in all six cases of advanced disease (three accelerated phase, three blast crisis), which was statistically highly significant (P < .01). Thus, LOI represents a novel type of genetic alteration in CML that appears to be specifically associated with disease progression.
Inhibition of P-Glycoprotein and Recovery of Drug Sensitivity of Human Acute Leukemic Blast Cells by Multidrug Resistance Gene (mdr1) Antisense Oligonucleotides
Authors: Motomura Sayuri , Motoji Toshiko , Takanashi Minoko , Wang Yan-Hua , Shiozaki Hiroko , Sugawara Isamu , Aikawa Eizou , Tomida Akihiro , Tsuruo Takashi , Kanda Naotoshi , Mizoguchi Hideaki 
Published: October 2019

AbstractTo overcome the problem of multidrug resistance, we investigated the effectiveness of phosphrothioate antisense oligonucleotides (MDR1-AS) in suppressing multidrug resistance gene (mdr1) expression in drug-resistant acute myelogenous leukemia (AML) blast cells and the K562 adriamycin-resistant cell line K562/ADM. The percentage of cells with the mdr1 gene product P-glycoprotein (P-gp) was decreased from 100% to 26% by 20 μmol/L MDR1-AS in the K562/ADM cells, and from 48.1% to 10.2% by 2.5 μmol/L MDR1-AS in the AML blast cells. Western blot analysis also showed a decrease in the amount of P-gp in the MDR1-AS–treated K562/ADM cells. This effect was specific to MDR1-AS, and not observed with sense or random control oligonucleotides. The expression of mdr1 mRNA in K562/ADM and AML blast cells treated with MDR1-AS was decreased compared with the random control. Intracellular rhodamine retention and [3H]daunorubicin also increased after antisense treatment. Chemosensitivity to daunorubicin increased in MDR1-AS–treated blast cells up to 5.9-fold in the K562/ADM cells and 3.0- to 6.4-fold in the AML blast cells. The expression of mdr1mRNA derived from colony cells decreased in the MDR1-AS–treated groups. No inhibitory effect of the oligonucleotides on normal bone marrow progenitors was observed. These findings suggest that MDR1-AS is useful to overcome multidrug resistance in the treatment of leukemia.
Identification of Human and Mouse Hematopoietic Stem Cell Populations Expressing High Levels of mRNA Encoding Retrovirus Receptors
Authors: Orlic Donald , Girard Laurie J. , Anderson Stacie M. , Pyle Louise C. , Yoder Mervin C. , Broxmeyer Hal E. , Bodine David M. 
Published: October 2019

AbstractOne obstacle to retrovirus-mediated gene therapy for human hematopoietic disorders is the low efficiency of gene transfer into pluripotent hematopoietic stem cells (HSC). We have previously shown a direct correlation between retrovirus receptor mRNA levels in mouse HSC and the efficiency with which they are transduced. In the present study, we assayed retrovirus receptor mRNA levels in a variety of mouse and human HSC populations to identify HSC which may be more competent for retrovirus transduction. The highest levels of amphotropic retrovirus receptor (amphoR) mRNA were found in cryopreserved human cord blood HSC. The level of amphoR mRNA in Lin−CD34+ CD38− cells isolated from frozen cord blood was 12-fold higher than the level in fresh cord blood Lin− CD34+ CD38− cells. In mice, the level of amphoR mRNA in HSC from the bone marrow (BM) of mice treated with stem cell factor and granulocyte-colony stimulating factor was 2.8- to 7.8-fold higher than in HSC from the BM of untreated mice. These findings suggest that HSC from frozen cord blood and cytokine-mobilized BM may be superior targets for amphotropic retrovirus transduction compared with HSC from untreated adult BM.
Hypoxia Stimulates Urokinase Receptor Expression Through a Heme Protein-Dependent Pathway
Authors: Graham Charles H. , Fitzpatrick Tania E. , McCrae Keith R. 
Published: October 2019

AbstractHypoxia underlies a number of biologic processes in which cellular migration and invasion occur. Because earlier studies have shown that the receptor for urokinase-type plasminogen activator (uPAR) may facilitate such events, we studied the effect of hypoxia on the expression of uPAR by first trimester human trophoblasts (HTR-8/SVneo) and human umbilical vein endothelial cells (HUVEC). Compared with control cells cultured under standard conditions (20% O2), HTR-8/SVneo cells and HUVEC cultured in 1% O2 expressed more uPAR, as determined by flow cytometric and [125I]-prourokinase ligand binding analyses. Increased uPAR expression paralleled increases in uPAR mRNA. The involvement of a heme protein in the hypoxia-induced expression of uPAR was suggested by the observations that culture of cells with cobalt chloride, or sodium 4,5-dihydroxybenzene-1,3-disulfonate (Tiron), an iron-chelating agent, also stimulated uPAR expression, and that the hypoxia-induced uPAR expression was inhibited by adding carbon monoxide to the hypoxic atmosphere. Culture of HTR-8/SVneo cells with vascular endothelial growth factor (VEGF) did not increase uPAR mRNA levels, suggesting that the hypoxia-mediated effect on uPAR expression by these cells did not occur through a VEGF-dependent mechanism. The functional importance of these findings is suggested by the fact that HTR-8/SVneo cells cultured under hypoxia displayed higher levels of cell surface plasminogen activator activity and greater invasion through a reconstituted basement membrane. These results suggest that hypoxia may promote cellular invasion by stimulating the expression of uPAR through a heme protein-dependent pathway.
Prognostic Value of Numerical Chromosome Aberrations in Multiple Myeloma: A FISH Analysis of 15 Different Chromosomes
Authors: Pérez-Simón J.A. , Garcı́a-Sanz R. , Tabernero M.D. , Almeida J. , González M. , Fernández-Calvo J. , Moro M.J. , Hernández J.M. , Miguel J.F. San , Orfão A. 
Published: October 2019

Abstract
Recent observations indicate that chromosome aberrations are important prognostic factors in patients with multiple myeloma (MM) treated with high-dose chemotherapy. Nevertheless, the inherent problems of conventional cytogenetics have hampered the systematic evaluation of this parameter in series of patients treated with conventional chemotherapy. Fluorescence in situ hybridization (FISH) analysis is an attractive alternative for evaluation of numerical chromosomal changes. In the present study, we analyze the relationship between aneuploidies of 15 different chromosomes assessed by FISH and prognosis in a series of 63 patients with MM treated with conventional chemotherapy. After a median follow-up of 61 months (range, 6 to 109), 49% of patients are still alive with a median survival of 33 months. The overall incidence of numerical chromosome abnormalities was 70%. This incidence significantly increased when seven or more chromosomes were analyzed (53 patients), reaching 81%. Trisomies of chromosomes 6, 9, and 17 were associated with prolonged survival (P = .033, P = .035, and P = .026, respectively); by contrast, overall survival (OS) was lower in cases with monosomy 13 (as assessed by deletion of Rb gene,P = .0012). From the clinical point of view, loss of Rb gene was associated with a poor performance status; low hemoglobin levels; high creatinine, C-reactive protein, and lactic dehydrogenase serum levels; high percentage of bone marrow plasma cells (BMPC); extensive bone lytic lesions; and advanced clinical stage. Other chromosome abnormalities such as trisomy of chromosome 9 and 17 were associated with good prognostic features including high hemoglobin levels, early clinical stage, β2microglobulin less than 6 μg/mL, and low percentage of BMPC. A multivariate analysis for OS showed that S-phase PC greater than 3% (P = .010) and β2microglobulin serum levels greater than 6 μg/mL (P = .024), together with monosomy of chromosome 13 (P = .031) and nontrisomy of chromosome 6 (P = .048) was the best combination of independent parameters for predicting survival in patients with MM. According to these results, chromosomal analysis is of great use in patients with MM at diagnosis to have a correct prognostic evaluation for clinical decision making.
Expression of the T-Cell–Specific Tyrosine Kinase Lck in Normal B-1 Cells and in Chronic Lymphocytic Leukemia B Cells
Authors: Majolini M. Bernardetta , D'Elios Mario M. , Galieni Piero , Boncristiano Marianna , Lauria Francesco , Del Prete Gianfranco , Telford John L. , Baldari Cosima T. 
Published: October 2019

AbstractSrc family kinases play a key role in mitogenesis. The exquisitely tissue-specific distribution of different Src family members suggests that a fine tuning of their expression might be a key prerequisite for cell homeostasis. We tested B cells from patients affected by B-cell chronic lymphocytic leukemia (B-CLL) for expression of Src family kinases. The T-cell–specific tyrosine kinase Lck was found to be expressed at significant levels in CLL B-cells. This finding could be accounted for either by ectopic expression of Lck in B-CLL or by specific expression of this kinase in normal B-1 cells, which are believed to be the normal counterpart of CLL B cells. To answer this question B cells from different sources, characterized by a different size of the B-1 subpopulation, were tested for Lck expression. The results show that Lck expression is a feature of CD5+, B-1 cells, suggesting a potential role for Lck in the self-renewal capacity of this B-cell subpopulation and supporting the notion that B-1 cells are the subset undergoing oncogenic transformation in B-CLL. Furthermore, we show that the CD5−, B-2 subpopulation, while normally lacking Lck expression, acquires the capacity to express Lck ectopically upon transformation by EBV.
Comparative Oxidation of Hemoglobins A and S
Authors: Sheng Kuan , Shariff Michelle , Hebbel Robert P. 
Published: October 2019

AbstractThe mutant hemoglobin S (HbS) previously was reported to undergo accelerated autooxidation during incubation in vitro. However, subsequent observations have raised the possibility that this might be explained by adventitious association of molecular iron with HbS, rather than reflecting an inherent property of HbS. Using purified HbA and HbS obtained from genotypic HbAS donors, we found that the observed oxidation rate of HbS, but not of HbA, is indeed exaggerated by adventitious iron. This result suggests a preferential partitioning of molecular iron to HbS over HbA, which was further supported by experimentation. However, after elimination of this effect, there still remains a significant increase in inherent autooxidation rate for HbS. Physiologic oxidants (superoxide, peroxide, hydroxyl radical) and various Fe(III) chelates all stimulate oxidation of oxyHb, but they do so equivalently for HbA and HbS. Nevertheless, these mechanisms also would contribute to excessive biologic oxidation of HbS because the cytoplasm of sickle red blood cells, unlike that of normal cells, would be exposed to abnormal amounts of oxidants and low–molecular-weight iron compounds.
Blockade of Human P2X7 Receptor Function With a Monoclonal Antibody
Authors: Buell G. , Chessell I.P. , Michel A.D. , Collo G. , Salazzo M. , Herren S. , Gretener D. , Grahames C. , Kaur R. , Kosco-Vilbois M.H. , Humphrey P.P.A. 
Published: October 2019

AbstractA monoclonal antibody (MoAb) specific for the human P2X7receptor was generated in mice. As assessed by flow cytometry, the MoAb labeled human blood-derived macrophage cells natively expressing P2X7 receptors and cells transfected with human P2X7 but not other P2X receptor types. The MoAb was used to immunoprecipitate the human P2X7 receptor protein, and in immunohistochemical studies on human lymphoid tissue, P2X7receptor labeling was observed within discrete areas of the marginal zone of human tonsil sections. The antibody also acted as a selective antagonist of human P2X7 receptors in several functional studies. Thus, whole cell currents, elicited by the brief application of 2′,3′-(4-benzoyl)-benzoyl-ATP in cells expressing human P2X7, were reduced in amplitude by the presence of the MoAb. Furthermore, preincubation of human monocytic THP-1 cells with the MoAb antagonized the ability of P2X7 agonists to induce the release of interleukin-1β.
Susceptibility Alleles for Aberrant B-1 Cell Proliferation Involved in Spontaneously Occurring B-Cell Chronic Lymphocytic Leukemia in a Model of New Zealand White Mice
Authors: Hamano Yoshitomo , Hirose Sachiko , Ida Akinori , Abe Masaaki , Zhang Danqing , Kodera Sanki , Jiang Yi , Shirai Jun , Miura Yuko , Nishimura Hiroyuki , Shirai Toshikazu 
Published: October 2019

AbstractB-cell chronic lymphocytic leukemia (B-CLL) and autoimmune disease are a related event, and genetic factors are linked to both diseases. As B-CLL is mainly of B-1 cell type that participates in autoantibody production, genetically-determined regulatory abnormalities in proliferation and/or differentiation of B-1 cells may determine their fate. We earlier found that, in H-2–congenic (NZB × NZW) F1 mice, while H-2d/z heterozygosity predisposes to autoimmune disease, H-2z/z homozygosity predisposes to B-CLL. Studies also suggested the involvement of non–H-2-linked NZW allele(s) in leukemogenesis. Using H-2–congenic NZW and B10 mouse strains, their F1 and backcross progeny, we have now identified three major NZW susceptibility loci for abnormal proliferation of B-1 cells, which form the basis of leukemogenesis; one H-2–linked locus on chromosome 17 and the other two non–H-2-linked loci, each on chromosome 13 and chromosome 17. Each susceptibility allele functioned independently, in an incomplete dominant fashion, the sum of effects determining the extent of aberrant B-1 cell frequencies. The development of leukemia was associated with age-related increase in B-1 cell frequencies in the blood. Thus, these alleles probably predispose B-1 cells to accumulate genetic alterations, giving rise to B-CLL. Potentially important candidate genes and correlation of the findings with autoimmune disease are discussed.
Thrombopoietin Production Is Inhibited by a Translational Mechanism
Authors: Ghilardi Nico , Wiestner Adrian , Skoda Radek C. 
Published: October 2019

AbstractThrombopoietin (TPO) is a lineage-dominant hematopoietic cytokine that regulates megakaryopoiesis and platelet production. The major site of TPO biosynthesis is the liver. Despite easily detectable levels of liver TPO mRNA, the circulating TPO serum levels are very low. We have observed that translation of TPO mRNA is inhibited by the presence of inhibitory elements in the 5′-untranslated region (5′-UTR). Alternative promoter usage and differential splicing generate at least three TPO mRNA isoforms that differ in the composition of their 5′-UTR. Using mutational analysis we show that physiologically the translation of these TPO mRNA isoforms is strongly inhibited by the presence of AUG codons, which define several short open reading frames (ORFs) in the 5′-UTR and suppress efficient initiation at the physiologic start site. The two regularly spliced isoforms, which account for 98% of TPO mRNA, were almost completely inhibited, whereas a rare splice variant that lacks exon 2 can be more efficiently translated. Thus, inhibition of translation of the TPO mRNA is an efficient mechanism to prevent overproduction of this highly potent cytokine.
The Viral Chemokine Macrophage Inflammatory Protein-II Is a Selective Th2 Chemoattractant
Authors: Sozzani S. , Luini W. , Bianchi G. , Allavena P. , Wells T.N.C. , Napolitano M. , Bernardini G. , Vecchi A. , D’Ambrosio D. , Mazzeo D. , Sinigaglia F. , Santoni A. , Maggi E. , Romagnani S. , Mantovani A. 
Published: October 2019

AbstractKaposi’s sarcoma (KS) lesions are characterized by a prominent leukocyte infiltrate composed of mononuclear phagocytes and T cells. KS-associated CD4+ and CD8+ cells showed predominantly a type II cytokine profile. The CC chemokine viral macrophage inflammatory protein-II (vMIP-II) encoded by the KS-associated herpes virus 8 was a selective chemoattractant for T helper 2 (Th2 cells) and for monocytes, whereas it was inactive on other leukocytes, including Th1 cells, dendritic cells, and natural killer (NK) cells. vMIP-II was an agonist for CCR8, a chemokine receptor selectively expressed on CD4+ and CD8+ cells with a type II cytokine profile. Hence, vMIP-II has agonist activity for a chemokine receptor (CCR8), which is preferentially expressed on polarized Th2 cells. The capacity of vMIP-II to attract type II T cells selectively is likely to be a component of the virus strategy to subvert the host immune response.
Trivalent Antimonials Induce Degradation of the PML-RAR Oncoprotein and Reorganization of the Promyelocytic Leukemia Nuclear Bodies in Acute Promyelocytic Leukemia NB4 Cells
Authors: Müller Stefan , Miller Wilson H. , Dejean Anne 
Published: October 2019

Abstract
Acute promyelocytic leukemia (APL) is characterized by a specific t(15;17) chromosomal translocation that fuses the genes encoding the promyelocytic leukemia protein (PML) and the retinoic acid receptor  (RAR). The resulting PML-RAR protein induces a block in the differentiation of the myeloid progenitor cells, which can be released by retinoic acid (RA) in vitro and in vivo. The RA-induced differentiation of APL blasts is paralleled by the degradation of the fusion protein and the relocation of wild-type PML from aberrant nuclear structures to its normal localization in nuclear bodies. Recently, arsenic trioxide (As2O3) treatment was proposed as an alternative therapy in APL, because it can induce complete remission in both RA-sensitive and -resistant APL patients. Intriguingly, As2O3 was also shown to induce degradation of the PML-RAR chimera and to reorganize PML nuclear bodies. Here we show that trivalent antimonials also have striking effects on RA-sensitive and RA-resistant APL cells. Treatment of the APL-derived NB4 cells and the RA-resistant subclone NB4R4 with antimony trioxide or potassium antimonyl tartrat triggers the degradation of the fusion protein and the concomitant reorganization of the PML nuclear bodies. In addition, as reported for As2O3, the antimonials provoke apoptosis of NB4 and NB4R4 cells. The mechanism of antimony action is likely to be similar to that of As2O3, notably both substances induce the attachment of the ubiquitin-like SUMO-1 molecule to the PML moiety of PML-RAR. From these data, we propose that, in analogy to As2O3, antimonials might have a beneficial therapeutic effect on APL patients, perhaps with less toxicity than arsenic.