bluuebunny/crossref_metadata_2025_split huggingface dataset:
Activation of apoptosis associated with enforced myc expression in myeloid progenitor cells is dominant to the suppression of apoptosis by interleukin-3 or erythropoietin
Authors: Askew DS , Ihle JN , Cleveland JL 
Published: October 2019

Abstract
The inappropriate expression of c-myc in cells deprived of growth factors has recently been implicated in the activation of programmed cell death (apoptosis). The studies described here examine the ability of interleukin-3 (IL-3) or erythropoietin (Epo) to suppress apoptosis that occurs in association with enforced myc expression during cell cycle arrest of a murine IL-3-dependent myeloid progenitor cell line, 32D. G1 arrest was observed when culturing 32D cells to high density in medium supplemented with IL-3, or at subconfluent densities in medium supplemented with Epo. Under both conditions, endogenous c-myc expression was downregulated and viability was maintained. In clones of cells in which c-myc is constitutively expressed from a retroviral vector, enforced c-myc expression was associated with the activation of apoptosis at high cell densities. Similarly, enforced c-myc expression was deleterious to cell survival when these cells were cultured in Epo, as apoptosis was evident within 6 hours. The results support the concept that inappropriate c-myc expression activates apoptosis and that neither IL-3 nor Epo can suppress this program under these conditions.
Targeting of an activated T-cell subset using a bispecific antibody- toxin conjugate directed against CD4 and CD26
Authors: Duke-Cohan JS , Morimoto C , Schlossman SF 
Published: October 2019

Abstract
We have developed a bispecific antibody that recognizes the CD4 and CD26 antigens simultaneously and that was examined for its ability to target CD4+CD26+T cells. These latter cells constitute the activated component of the CD4+ CD29highCD45RO+ memory T-cell subset that provides help for B-cell Ig synthesis and help for responses against recall antigens. The purified bispecific antibody exhibited an estimated dissociation constant (kd) of 2.4 x 10(-9) mol/L, on comparison with 1.1 x 10(-9) mol/L for anti-CD26, and 1.6 x 10(-10) mol/L for anti-CD4. Surface plasmon resonance was used to show the bifunctional capacity of the antibody. On binding 125I-bispecific antibody to phytohemagglutinin (PHA)-activated T cells, 54.4% of the bound antibody was internalized. This was the result of bispecific binding, because monovalent fragments of anti-CD4 and anti-CD26 were not able to modulate antigen or induce internalization using both a fluorescent assay and an 125I-internalization assay. The ability of the bispecific antibody to be internalized was used to deliver a toxin, blocked ricin, specifically to cells that are CD4+CD26+. The inability of monovalent fragments to be internalized formed the basis for our hypothesis that monovalent binding by the bispecific immunotoxin would not result in internalization. Against resting E+ T cells, the bispecific immunotoxin developed a minimal effect. On preactivating the same cells, using phorbol myristate acetate (PMA)/ionomycin on concanavalin A (ConA) or especially PHA, levels of CD26 were upregulated and the immunotoxin effectively inhibited the ability to provide help for B-cell Ig synthesis while leaving intact the CD4-CD26+ and CD4+CD26- populations; an effect observed both functionally and by phenotype. The bispecific antibody proved to be most effective at inhibiting a heterologous mixed leukocyte reaction. We propose that this reagent may form the basis for the rational design of toxins designed to modulate activated T cells from, or directed against, tissue grafts.
Thiotepa, busulfan, and cyclophosphamide: a new preparative regimen for autologous marrow or blood stem cell transplantation in high-risk multiple myeloma
Authors: Dimopoulos MA , Alexanian R , Przepiorka D , Hester J , Andersson B , Giralt S , Mehra R , van Besien K , Delasalle KB , Reading C 
Published: October 2019

Abstract
Forty patients with multiple myeloma received thiotepa (750 mg/m2), busulfan (10 mg/kg), and cyclophosphamide (120 mg/kg) (TBC) followed by autologous bone marrow or blood stem cell support. Granulocyte-Colony stimulating factor (G-CSF) was administered to accelerate hematopoietic recovery. Sixty-five percent of all patients responded to this treatment. Eighty-eight percent of patients transplanted in partial remission had a further reduction of the myeloma and 53% achieved a complete remission. Forty-eight percent of patients with refractory myeloma responded. All responding patients transplanted during partial remission or with primary refractory myeloma remain free of progression for a period of 4 to 24 months post-transplant, but the remission duration of patients treated in refractory relapse was short (4 months). Five of 24 patients transplanted with marrow and none of 16 receiving blood stem cells died of treatment-related complications. Use of blood stem cells resulted in more rapid granulocyte and platelet recovery. We conclude that TBC is an effective, relatively well tolerated, preparative regimen for patients with multiple myeloma.
Binding of membrane-anchored macrophage colony-stimulating factor (M- CSF) to its receptor mediates specific adhesion between stromal cells and M-CSF receptor-bearing hematopoietic cells
Authors: Uemura N , Ozawa K , Takahashi K , Tojo A , Tani K , Harigaya K , Suzu S , Motoyoshi K , Matsuda H , Yagita H 
Published: October 2019

Abstract
To explore the biologic significance of the membrane-anchored form of macrophage colony-stimulating factor (M-CSF), we examined whether interaction between membrane-bound M-CSF and its receptor mediates intercellular adhesion as well as cell proliferation and differentiation. Human M-CSF receptors were expressed on a murine interleukin-2 (IL-3)-dependent cell line, FDC-P2, by DNA transfection with the c-fms gene (FDC-P2-MCSFR). A human bone marrow-derived stromal cell line, KM102, was used in the cell adhesion assay. The expression of membrane-bound M-CSF on KM102 cells was demonstrated by flow cytometry and immunoblot analysis. After the incubation of parent and transformed FDC-P2 cells on confluent KM102 cells, nonadherent cells were removed and the cells attached to KM102 cells were examined microscopically. Almost all parent FDC-P2 cells were nonadherent, whereas a significant number of FDC-P2-MCSFR cells bound to KM102 cells. The addition of anti-M-CSF or anti-M-CSF receptor neutralizing antibodies dose-dependently inhibited the binding of [3H]-thymidine- labeled FDC-P2-MCSFR cells to KM102 cells. An excess amount of M-CSF also inhibited the binding. On the other hand, the addition of antibodies against some representative adhesion molecules (vitronectin receptor, Pgp-1/CD44, and VLA-4) did not inhibit the adhesion between FDC-P2-MCSFR cells and KM102 cells. These results support the idea that membrane-anchored M-CSF and its receptor may function as mediators of cell-cell adhesion.
Consensus AP-1 and CRE motifs upstream from the human cytotoxic serine protease B (CSP-B/CGL-1) gene synergize to activate transcription
Authors: Hanson RD , Grisolano JL , Ley TJ 
Published: October 2019

Abstract
The human CGL-1/cytotoxic serine protease B gene (CSP-B; also known as granzyme B) is transcriptionally activated during cytotoxic T- lymphocyte maturation. Activation can be mimicked in the PEER T-cell leukemia cell line by treatment with 12-O-tetradecanoylphorbol-13- acetate (TPA) and N6–2′-O-dibutyryladenosine 3′,5′-cyclic monophosphate (bt2cAMP). In this report, we show that a consensus AP-1 element and a consensus cAMP response element (CRE) located 5′ to the CSP-B transcriptional start site are both required for transcriptional activation of the CPS-B promoter in TPA + bt2cAMP-stimulated PEER cells. A 94-bp fragment containing both elements activates a heterologous promoter in an orientation-independent fashion. Several single nucleotide substitutions in the AP-1 site abolish activity of the 94-bp fragment. Several point mutations in the consensus CRE substantially reduce promoter activity, but one CRE mutation increases activity fourfold. Replacement of the CRE with a second copy of the AP- 1 site results in a level of transcriptional activity comparable with that of the wild-type sequence, but replacement of the AP-1 site with a CRE abolishes activity. Neither the AP-1 site nor the CRE can be effectively replaced with an SP-1 site. Deletions between the AP-1 site and the CRE retain full activity only if helical spacing is preserved, suggesting that synergism between these two elements is either the result of cooperative binding of factors to the DNA or of cooperative binding of DNA-bound factors to another protein.
Protection of murine bone marrow by dexamethasone during cytotoxic chemotherapy
Authors: Kriegler AB , Bernardo D , Verschoor SM 
Published: October 2019

Abstract
Corticosteroids have the ability to suppress the production of growth factors and cytokines and are thus implicated in the negative regulation of hematopoiesis. We have shown that the corticosteroids, prednisolone and dexamethasone, were able to effectively protect progenitor cells in four strains of mice against cell-cycle-specific antimetabolic chemotherapy agents. The highest levels of protection against 5-fluorouracil (FU; 200 mg/kg) were achieved when two or three intraperitoneal injections of dexamethasone were administered between - 7 and +3 hours at a dose of 7.5 mg/kg/injection (optimal dose) or by continuous infusion between -4 and +20 hours. This protective effect is manifested as an increase in the number of high proliferative potential colony-forming cells that survive in the bone marrow 3 days after treatment with FU from between 0.5% and 11% to between 10% and 34% of normal. The bone marrow progenitors and blood cell numbers return to normal from 3 to 5 days and 1 to 2 days earlier, respectively. Less dexamethasone than prednisolone is required to give an equivalent protective effect, which is consistent with their anti-inflammatory potency. These findings are further evidence of the negative regulatory role played by corticosteroids, and indicate that the treatment schedules of corticosteroids during cancer therapy need to be reexamined to obtain the maximum benefit from their use.
Isolation and characterization of the human interleukin-9 receptor gene
Authors: Chang MS , Engel G , Benedict C , Basu R , McNinch J 
Published: October 2019

Abstract
To better understand the regulation of interleukin-9 (IL-9) receptor expression, we have isolated the genomic clone of the human IL-9 receptor based on its sequence homology with a human IL-9 receptor cDNA isolated from the human megakaryocyte cell line UT-7. The entire genomic structure has been determined. The human IL-9 receptor gene consists of 10 exons spread over approximately 13.7 kb of DNA. The nucleotide sequence of the coding region from the genomic DNA is identical to our cDNA clone. Several blocks of transcriptional control sequence have been identified at the 5′ noncoding region of the IL-9 receptor gene that may play an important role in the regulation of the IL-9 receptor gene. A fusion gene containing 659 bp of human IL-9 receptor 5′ noncoding region linked to the firefly luciferase gene directed expression of luciferase activity in human embryonic kidney 293 cell line, but not in the mouse fibroblast cell line NIH3T3 cells.
Idiotypic vaccination against human B-cell lymphoma. Rescue of variable region gene sequences from biopsy material for assembly as single-chain Fv personal vaccines
Authors: Hawkins RE , Zhu D , Ovecka M , Winter G , Hamblin TJ , Long A , Stevenson FK 
Published: October 2019

Abstract
Idiotypic determinants on neoplastic B cells could provide tumor antigens for vaccination of patients with B-cell tumors. Because this approach requires an individual vaccine for each patient, simple methods for obtaining idiotypic antigen are desirable. Using polymerase chain reaction (PCR) with family-based V-gene and J-region primers, the variable region genes of heavy and light chains (VH and VL) of Ig have been obtained from biopsy material from 13 patients with B-cell tumors. In each case, analysis of random clones derived from the PCR product showed repeated, clonally-related sequences, whereas normal lymphoid tissue generated no repeated sequences. In 3/3 cases, the repeated sequences were found to be the same as those in a tumor-derived hybridoma. Mutational patterns in the V-genes differed among the tumors, with follicular lymphoma tending to be more highly mutated. The individual VH and VL sequences have been assembled with a flexible linker sequence to encode single-chain Fv (scFv). The scFv sequences can be cloned into bacterial expression vectors to produce protein, or into vectors suitable for direct vaccination using naked DNA. In a model system, expressed scFv protein retained all idiotypic determinants defined by a panel of five anti-idiotypic monoclonal antibodies (MoAbs). Similarly, expressed scFv proteins from two patients were shown to react with anti-idiotypic antibodies. This approach allows production of potential vaccines from surgical biopsies within 2 to 3 weeks.
Similar patterns of V kappa gene usage but different degrees of somatic mutation in hairy cell leukemia, prolymphocytic leukemia, Waldenstrom's macroglobulinemia, and myeloma
Authors: Wagner SD , Martinelli V , Luzzatto L 
Published: October 2019

Abstract
To compare V kappa gene usage and the amount of somatic mutation in rearranged Ig genes from patients with lymphoproliferative disorders, we have polymerase chain reaction-amplified and sequenced a total of 26 V kappa genes from a total of 55 cases. Six sequences were obtained both from six cases of prolymphocytic leukemia (PLL) and from nine cases of hairy cell leukemia (HCL). Seven sequences were obtained both from 11 cases of Waldenstrom's macroglobulinemia (WM) and 29 cases of multiple myeloma (MM). Eleven different germline genes have been used in this series, indicating a wide but nonrandom usage of germline Ig gene rearrangements in these disorders. Comparison of the nucleotide sequences of V kappa genes obtained from B-cell malignancies with germline V kappa genes shows that somatic mutation is rare in PLL and HCL and common in WM and MM. Analysis of the pattern of mutations suggests that WM and MM are derived from B cells that have been selected by antigen at a relatively late stage of differentiation.
Chromosomal assignment of genes involved in glycosylphosphatidylinositol anchor biosynthesis: implications for the pathogenesis of paroxysmal nocturnal hemoglobinuria
Authors: Ware RE , Howard TA , Kamitani T , Chang HM , Yeh ET , Seldin MF 
Published: October 2019

Abstract
Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired clonal hematologic disorder that affects both sexes equally. The biochemical defect in PNH resides in the incomplete enzymatic assembly of glycosylphosphatidylinositol (GPI) anchors used for surface protein attachment. In all PNH patients tested to date, the biosynthetic defect occurs at the addition of N-acetyl-glucosamine to the phosphatidylinositol molecule (class A defect). A human cDNA, Piga, that repairs cell lines with the class A GPI-anchor biosynthetic defect has been recently cloned. Mapping of Piga to the X chromosome suggests that a single acquired mutation within Piga could alter GPI-anchor synthesis and result in PNH. However, this finding does not explain why all PNH patients have the class A defect. In the current study, the chromosomal assignment of Piga, as well as of Pigf and Pigh, two additional genes involved in GPI-anchor biosynthesis, has been established using a mouse interspecific backcross mapping technique. In contrast to Piga, both human and mouse Pigf and Pigh genes map to autosomes. The location of Pigf and Pigh suggests that mutations on both alleles of these autosomal genes would be necessary to produce PNH. This helps to explain the predominant class A defect in PNH.
Flow cytometric assessment of human MIC2 expression in bone marrow, thymus, and peripheral blood
Authors: Dworzak MN , Fritsch G , Buchinger P , Fleischer C , Printz D , Zellner A , Schollhammer A , Steiner G , Ambros PF , Gadner H 
Published: October 2019

Abstract
The cell-surface expression of the MIC2 antigen defined by the monoclonal antibody 12E7 was investigated on human leukocytes in bone marrow (BM), thymus, and peripheral blood (PB) using multiparameter flow cytometry and cell sorting. In contrast to preceding reports, we found that the MIC2 antigen is not restricted to T cells and monocytes. We show that it is also expressed in the B cell and in the granulocytic lineage, the levels of expression being related to distinct maturational stages. CD34+ cells of BM were found to express the antigen at high levels. Along the granulocytic maturation pathway from CD34+CD33+ blasts to mature granulocytes, MIC2 densities appeared progressively reduced with a considerable decline at the myelocyte stage. In B lymphopoiesis, the earliest CD34+ CD10+ B-cell precursor (BCP) cells, further subdivided by expression of CD19, displayed the highest MIC2 density of BM leukocytes. All later BCP stages showed lower MIC2 expression levels, with a remarkable reduction concomitant with loss of the CD34 antigen at the CD10+CD20- surface mu-chain- stage, and a subsequent slight upregulation along with maturation to CD10-CD20high surface mu-chain+ BCPs. The brightest MIC2 expression of all cells tested was displayed by the most immature thymic T-lineage cells characterized by the antigenic profile CD34weakor- CD7++ surface CD3-CD1a(weak) CD4weak CD8-or weak. Common thymocytes stained slightly less intense with 12E7, whereas all subsequent stages of T-lineage cells in thymus, PB, or BM showed markedly reduced MIC2 levels. Mature peripheral CD4+ as well as CD8+ T cells displayed a bimodal distribution of MIC2. In the CD4+ population, the distinct MIC2 levels were related to the well-studied functional subdivision by differential expression of CD45 isoforms, the helper-inducer/memory subset showing higher MIC2 expression than helper-suppressor/naive CD4+ T cells. Similarly high MIC2 densities were found on CD16+ natural killer cells and on CD14+ monocytes, whereas mature peripheral B cells exhibited low or intermediate expression, and granulocytes exhibited no or only dim expression. These results document that the MIC2 antigen (1) is expressed on all leukocyte lineages; (2) is differentially expressed during T- and B-lymphoid, as well as granulocytic maturation; (3) shows highest expression in the most immature lymphocytic and granulocytic developmental stages; and (4) is also differentially expressed on functional T-cell subsets. We speculate that these observations imply a functional significance of MIC2 in the network of hematopoietic adhesion pathways.
Limited value of myeloablative therapy for late multiple myeloma
Authors: Alexanian R , Dimopoulos M , Smith T , Delasalle K , Barlogie B , Champlin R 
Published: October 2019

Abstract
The utility of myeloablative therapy supported by autologous bone marrow (BM) or blood progenitor cells was assessed in 49 patients with multiple myeloma who had received at least 1 year of prior chemotherapy. Outcomes were compared with those of similar patients who did not receive intensive treatment primarily for socioeconomic reasons. Among patients with disease in resistant relapse despite treatment with vincristine-doxorubicin by continuous infusion with pulse dexamethasone (VAD), a 61% response rate was associated with a median remission time of 5 months. After primary resistance for more than 1 year, 6 of 15 patients responded and the overall survival was similar to that of control patients. For patients with melphalan- resistant disease that responded to VAD, the remission time was similar to that of control patients. Current myeloablative treatments supported by autologous BM or blood stem cells were useful to very few patients with multiple myeloma after the first year of chemotherapy.
Elimination of the O-linked glycosylation site at Thr 104 results in the generation of a soluble human-transferrin receptor
Authors: Rutledge EA , Root BJ , Lucas JJ , Enns CA 
Published: October 2019

Abstract
The transferrin receptor (TfR) is the plasma membrane protein responsible for the binding and internalization of the major iron- transport protein, transferrin. The function of the single O-linked oligosaccharide near the transmembrane domain of the TfR at amino acid Thr 104 is unknown. To elucidate the effect of the O-linked carbohydrate on TfR function, the oligosaccharide was eliminated by replacing Thr 104 with Asp and the mutated cDNA was expressed in a cell line lacking endogenous TfR. Elimination of the oligosaccharide at Thr 104 results in a form of the receptor that is susceptible to cleavage. A 78-kD soluble TfR that can bind transferrin is released into the growth medium. The intact mutant TfR is not grossly altered in its structure and does not differ significantly from the wild-type human receptor in many respects: (1) It shows the same distribution between the plasma membrane and intracellular compartments; (2) the binding constant for transferrin is similar to that of the wild-type TfR; and (3) it is not rapidly degraded. Protein-sequence analysis of the soluble form indicates that the sequence begins at amino acid 101 of the intact receptor. This is the same cleavage site reported for a soluble form of normal receptor found in human serum. Substitution of Gly, Glu, or Met at position 104 also results in increased cleavage of the TfR and suggests that elimination of the O-linked carbohydrate at position 104 enhances the susceptibility of TfR to cleavage and may mimic a naturally occurring process previously described as being related to erythropoiesis.
Clonal, nonconstitutional rearrangements of the MLL gene in infant twins with acute lymphoblastic leukemia: in utero chromosome rearrangement of 11q23
Authors: Gill Super HJ , Rothberg PG , Kobayashi H , Freeman AI , Diaz MO , Rowley JD 
Published: October 2019

Abstract
Rearrangements of chromosome band 11q23 are common in infant leukemias, comprising more than 70% of the observed chromosome abnormalities in children less than 1 year of age. The MLL gene, which is located at the 11q23 breakpoint in infant, childhood, and adult acute leukemias, has been cloned and has homology to the Drosophila trithorax gene. The breakpoints in MLL are restricted to an 8.3-kilobase pair (kb) region of the gene that is involved in translocations with as many as 29 other chromosomal regions in a number of phenotypically distinct acute leukemias. We have detected an identical, clonal, nonconstitutional rearrangement of the MLL gene in peripheral blood cells from a pair of female infants twins with acute lymphoblastic leukemia (ALL) and a t(11;19)(q23;p13.3). The detection of nonidentical IGH rearrangements suggests that the MLL rearrangement took place in a B-cell precursor or hematopoietic stem cell in one twin which was transferred in utero to the other fetus resulting in ALL with an identical aneuploid karyotype in both infants. We speculate that the other MLL-related infant leukemias may also develop in utero, and that the rearrangements may occur consistently in stem cells or early precursor cells, accounting for the frequency of mixed-lineage leukemia in infants.