bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synergistic Interaction of the Histone Deacetylase Inhibitor SAHA with the Proteasome Inhibitor Bortezomib in Mantle Cell Lymphoma.
Authors: Heider Ulrike , Kaiser Martin , Zavrski Ivana , Sterz Jan , Jakob Christian , Fleissner Claudia , Hecht Monica , Kleeberg Lorenz , Braun Christian , Possinger Kurt , Sezer Orhan 
Published: October 2019

Abstract
Mantle cell lymphoma (MCL) is an incurable B cell lymphoma and novel treatment strategies are urgently needed. Proteasome inhibitors, e.g. bortezomib, act by targeting the catalytic 20S core of the proteasome and induce apoptosis in tumor cells. Among other mechanisms, they lead to cytoplasmic accumulation of the IκBa protein, resulting in a reduced NF-κB activity. Histone deacetylase inhibitors (HDAI), e.g. SAHA, promote histone acetylation, chromatin uncoiling, and transcription of a variety of genes. Previous studies have indicated that HDAIs also interfere with NF-κB signaling. Since NF-κB is constitutively activated MCL cells and plays a major role in a variety of cellular processes, we hypothesized synergist effects of bortezomib and HDAI in MCL cells. Human mantle cell lymphoma cell lines (JeKo-1 and Granta-519) were exposed to bortezomib and/ or SAHA for 4 to 48 hours. Cell viability and apoptosis were quantified by the MTT and annexin-V assay, respectively. The effect of the combination of both agents was analyzed using the median effect method of Chou and Talalay. Reactive oxygen species (ROS) were quantified by the fluorophore H2DCFDA. The functional role of ROS generation was assessed using the free radical scavenger N-acetyl-l-cysteine (LNAC). In addition, activated caspases, proteasome- and NF-κB activity were quantified. After 48 hours of incubation, IC50 of SAHA and bortezomib were noted at 0.8μM and 7.7nm in JeKo-1 cells and at 3.9μM and 5.7nm in Granta-519 cells, respectively. Combined incubation resulted in synergistic cytotoxic effects, as indicated by CI values <1. This was accompanied by an increase of caspase-3, -8 and -9 activity. In addition, coexposure of bortezomib and SAHA led to an enhanced ROS generation (5.4 fold in Jeko-1 and 9.2 fold in Granta-519 as compared to untreated controls), while the agents alone only modestly induced reactive oxygen species. LNAC could block the ROS generation and reduced the apoptosis significantly. As expected, bortezomib reduced the NF-κB activity. Interestingly, exposure to SAHA led to an increase of NF-κB activity after 4 hours and a decrease after 24 hours. The combination of both drugs resulted in a decrease of NF-κB activity. Moreover, combined treatment with bortezomib and SAHA resulted in a marked reduction of proteasome activity that was more pronounced than the proteasome inhibition by the single agents. In conclusion, this is the first report giving evidence that SAHA and bortezomib synergistically induce apoptosis in mantle cell lymphoma cells through the generation of reactive oxygen species and disruption of the NF-κB pathway. Our data provide a framework for clinical studies with the combination of both agents in patients with mantle cell lymphoma.
Long-Term Clinical Benefit of Lenalidomide (Revlimid) Treatment in Patients with Myelodysplastic Syndrome and Chromosome Deletion 5q.
Authors: List Alan F. , Dewald Gordon W. , Bennett John M. , Giagounidis Aristoteles , Raza Azra , Feldman Eric J. , Powell Bayard L. , Greenberg Peter L. , Nimer Stephen D. , Zeldis Jerome B. , Wride Kenton , Schmidt Michele , Knight Robert D. 
Published: October 2019

Abstract
Background: Myelodysplastic syndromes (MDS) are hematological disorders characterized by chronic anemia, and are often refractory to cytokine therapy. Two phase 2 studies evaluating lenalidomide in MDS (MDS-001 and MDS-003), demonstrated a high frequency of erythroid response in patients with a chromosome 5q31 deletion (List AF et al., N Eng J Med2005; 352:549–557 and List AF et al., in press). Herein we report on the durability of response with long term follow-up approaching 4 years.
Methods: All enrolled subjects were evaluated for frequency and duration of red blood cell transfusion independence (RBC-TI), change in hemoglobin (Hgb), pathologic and cytogenetic response, and safety.
Results: Ten 5q31- patients achieved a cytogenetic and/or major erythroid response in MDS-001. Four of these patients have maintained a major response for at least 2 years (range 2.2 to 3.7 years). In MDS-003, 99 (67%) of 148 enrolled patients achieved RBC-TI. Of the 99 responders 83 were Low/Int-1, 3 were Int-2/High and 13 were not classified. Median increase in Hgb from baseline to maximum achieved during RBC-TI was 5.4 g/dL (range 1.1, 11.4). The estimated median duration of response was 115.9 weeks, and 52 (53%) of 99 responders remain on study with ongoing RBC-TI response as of 30 June 2006. Duration of response was at least 52 weeks for 63 (64%), 78 weeks for 52 (53%), and 104 weeks for 36 (36%) of 99 responding patients. Variables (or co-variates) associated with longer duration of TI in multivariate analysis included low baseline transfusion requirement (<4 units per 8 wks, p=0.002), 5q- syndrome (p=0.01) and low IPSS (p=0.02) classifications. Among 85 evaluable patients, major cytogenetic responses were achieved in 37 (44%) and minor responses in 24 (28%). Cytogenetic responses occurred in patients with complex karyotypes as well as those with an isolated 5q31 deletion. The frequencies of major and minor cytogenetic responses were similar among patients with and without 5q- syndrome. The most common drug-related adverse events (AE) were Grade 3/4 neutropenia and thrombocytopenia, reported in 87 (59%) and 74 (50%) of 148 patients, respectively although hematologic AEs led to study discontinuation in only 13 (9%) of patients. Pneumonia was the only serious adverse event that occurred in >10% of patients (15/148; 10%). Adverse events were manageable through supportive treatment and dose reduction.
Conclusion: Lenalidomide is an effective treatment in MDS patients with an associated chromosome 5q31 deletion, with RBC-TI and major erythroid response maintained for median duration > 2 years.
Mistargeting of Normal Cells in Anti-CD30 Immunotherapy of Lymphoma Cells Is Blocked by Selective Metalloproteinase Inhibitor.
Authors: Simhadri Vijaya L. , von Strandmann Elke Pogge , Eichenhauer Dennis A. , Ludwig Andreas , Reiners Katrin S. , Engert Andreas , Hansen Hinrich P. 
Published: October 2019

Abstract
CD30 is a transmembrane receptor which is selectively overexpressed on Hodgkin lymphoma and large cell anaplastic lymphoma and therefore an interesting target for antibody-based immunotherapy. However, the receptor is cleaved by metalloproteinases and the ectodomain is released in the environment where it competes with the CD30-based immunotherapy. Moreover, therapeutic anti-CD30 antibodies stimulate this cleavage which results in a loss of target antigen and an enhanced release of the soluble ectodomain (sCD30). In order to improve immunotherapy, we analyzed the mechanism of the release and the function of resulting sCD30. By means of FACS analysis, we demonstrate that sCD30, like membrane-anchored CD30, binds to CD30 ligand (CD153)-expressing cells. Since monoclonal antibodies bind to both CD30 and sCD30, this results in unwanted targeting of these “non-target” cells via sCD30 bridging. To overcome the damage of normal cells in immunotherapy as a consequence of sCD30-binding, we analyzed the mechanism involved in the release of sCD30. Shedding of CD30 can be enhanced by PKC activation involving the disintegrin metalloproteinase ADAM17 but not free cytoplasmic calcium. In contrast, antibody-induced CD30 shedding is calcium-dependent and PKC-independent. Using the ADAM10 inhibitor GI254023X and a ADAM10-deficient cell line generated from embryonically lethal ADAM10−/−mouse we demonstrate that antibody-mediated shedding involves the related metalloproteinase ADAM10. In co-culture experiments, the antibody-induced transfer of sCD30 from the Hodgkin lymphoma cell line L540 to the CD30-negative but CD153-expressing mast cell line HMC-1 was inhibited by GI254023X.
These findings suggest that selective metalloproteinase inhibitors blocking antibody-induced shedding of target antigens could be of therapeutic value to increase the specificity and reduce side-effects of immunotherapy with monoclonal antibodies.
Anti-Adult T-Cell Leukemia Effects of a Novel Synthetic Retinoid, Am80 (Tamibarotene) through Inhibition of NF-κB.
Authors: Nakazato Tetsuro , Ishikawa Chie , Okudaira Taeko , Tomita Mariko , Mori Naoki 
Published: October 2019

Abstract
Adult T-cell leukemia (ATL) is caused by human T-cell leukemia virus type I (HTLV-I) and remains incurable. Retinoid is a collective term for compounds, which bind to and activate retinoic acid receptors (RARα, β, γ and RXRα, β, γ), members of nuclear hormone receptor superfamily. It is involved in cell differentiation, morphogenesis, proliferation, and anti-neoplastic processes. The most important endogenous retinoid is all-trans-retinoic acid (ATRA), which is an RARα, β, and γ ligand. ATRA and its mimics have been in clinical use for treatment of acute promyelocytic leukemia (APL) and adult T-cell leukemia (ATL). Many synthetic retinoids have been developed and attempts to improve their medicinal properties have been made. Among them, a novel synthetic retinoid, Am80 (Tamibarotene) is an RARα- and RARβ-specific (but RARγ- and RXRs-nonbinding) synthetic retinoid that is expected to overcome ATRA resistance, because of several times more potent differentiation activity than ATRA and sustained plasma level during continuous administration due to a lower affinity for cellular retinoic acid binding protein. On this background, we examined the inhibitory effect of Am80 on HTLV-I-infected T-cell lines and primary ATL cells. Am80 showed little growth inhibition of peripheral blood mononuclear cells, but it markedly inhibited the growth of both HTLV-I-infected T-cell lines and primary ATL cells. Am 80 could arrest cells in the G1 phase of the cell cycle and induced apoptosis in HTLV-I-infected T-cell lines. The NF-κB pathway is critical for the immortalization and survival of HTLV-I-infected T cells. Therefore, NF-κB pathway was examined as potential targets of Am80 signaling. Am80 significantly inhibited phosphorylation of IκBα and NF-κB-DNA binding, in conjunction with the reduction of expression of proteins involved in the G1-S cell cycle transition and apoptosis. Furthermore, in animal studies, treatment with Am80 produced partial inhibition of growth of tumors of an HTLV-I-infected T-cell line transplanted subcutaneously in severe combined immunodeficient mice. These findings clearly demonstrate that Am80 is a potential inhibitor of NF-κB in ATL cells, and might be a useful therapeutic agent against ATL.
Survivin Isoforms and HSP90 Are Downregulated in Erythropoiesis during Lineage Specific Differentiation of MDS Hematopoietic Progenitor Cells.
Authors: Hopfer Olaf J. , Komor Martina , Koehler Ina S. , Schulze Matthias , Freitag Claudia , Hoelzer Dieter , Thiel Eckhard , Hofmann Wolf-Karsten 
Published: October 2019

Abstract
Survivin has recently been shown to critically regulate erythroid versus megakaryocytic differentiation in mouse hematopoietic stem cells. Its role in human hematopoiesis has not been fully elucidated yet. To answer the question whether dysregulation of expression of survivin and its protein stabilisator HSP90 contributes to the ineffective erythropoiesis in myelodysplastic syndrome (MDS), we have generated an in vitro model of MDS lineage-specific hematopoietic differentiation by culturing CD34+ cells from healthy donors (n=7) and MDS patients (low risk: RA/n=6, RARS/n=3; high risk: RAEB/n=4, RAEB-T/n=2) with EPO, TPO and GCSF. Cell harvest was at days 0, 4, 7 and 11. Expression analysis of survivin splicing variants (wt, 2a, d3ex) and of HSP90 was done by real time RT-PCR (qPCR) for each lineage at each time point. Furthermore, epigenetic analysis of key regulatory genes by methylation specific PCR and qPCR to detect DNMT1 (maintenance methylation) and DNMT3a and 3b (de novo methylation) expression was performed for each of the experimental conditions. RNA expression of all survivin isoforms and of HSP90 was continously upregulated during normal erythropoiesis. During late megakaryopoiesis of normal hematopoietic stem cells a significant downregulation was seen with elevated expression values for survivin wt and survivin 2b during early thrombopoiesis. In contrast, during MDS erythropoiesis a significant downregulation of expression of all survivin isoforms and HSP90 during late erythropoiesis was observed. Lower expression for survivin wt, survivin 2b and HSP90 was seen during early MDS megakaryopoiesis. Promotor methylation analyisis revealed MDS specific aberrant methylation for survivin, particularly during MDS high risk erythropoiesis (p=0.02). However, expression of DNMT1 was only elevated during erythropoiesis and in low risk MDS. A significant inverse correlation between RNA expression of DNMT enzymes and survivin splicing variants could not be detected. In conclusion our data support the essential role for survivin in regulation of erythropoietic versus megakaryopoietic differentiation of hematopoietic precursor cells. The dysregulation of survivin expression during MDS erythropoiesis may therefore account for the ineffective erythropoiesis known in MDS. Furthermore, downregulation of survivin (protein) stabilisator HSP90 might additionally contribute to this effect. Although an inverse correlation with overexpression of DNMTs and downregulation of survivin splicing variants was not seen, the aberrant survivin promoter methylation during MDS erythropoiesis indicates that epigenetic dysregulation results in low survivin expression.
AML1/ETO and PML/RAR α Can Immortalize Committed Myeloid Progenitor Cells In-Vitro but Not Expand Them In-Vivo.
Authors: Hosen Naoki , Passegue Emmanuelle , Weissman Irving L. 
Published: October 2019

Abstract
For most leukemia the target cells of transforming mutations are still unknown. Here, we studied the developmental origin of t(8;21)-acute myeloid leukemia (AML), t(15;17)-acute promyelocytic leukemia (APL), and t(9;22)-chronic myeloid leukemia (CML). Purified mouse hematopoietic stem cells (HSCs) and various committed myeloid progenitor cells were retrovirally transduced with AML1/ETO, PML/RARα, or p210 BCR/ABL and subjected to in-vitro serial replating assay and in-vivo transplantation. Myeloid progenitors were efficiently immortalized in-vitro by AML1/ETO or PML/RARα as assayed in serial replating assays. However, following transplantation into lethally irradiated mice, neither AML1/ETO- nor PML/RARα-transduced myeloid progenitors were expanded in-vivo, although cells carrying the fusion gene DNA persisted well beyond their non-transduced control progenitors. In addition, 10 months after the transplant with transduced myeloid progenitor cells, PML/RARα but not AML1/ETO mRNA expression was still detected in committed myeloid progenitors, although PML/RARα-expressing cells were still not expanded. This finding demonstrates the ability of PML/RARα to increase the lifespan of committed myeloid progenitor cells both in-vitro and in-vivo and suggest that t(15;17)-APL could possibly evolve from persisting progenitor-derived cells. In contrast, BCR/ABL-expressing myeloid progenitors disappeared within 3 months post transplantation. Analysis of mice transplanted with transduced-HSCs demonstrated that AML1/ETO induced the accumulation of the most immature subset of HSCs (Lin-/c-kit+/Sca-1+/Flk-2-), while in contrast PML/RARα induced HSCs disappearance in most (5 out of 6) cases. In addition, we demonstrate that p210 BCR/ABL could induce the development of a CML-like disease from transduced HSCs (6 out of 16 cases), which is compatible with previous report. Together, these results suggest the existence of novel pre-leukemic stem cells (pre-LSCs) entities. Slowly expanding pre-LSCs could be generated from HSCs transformed by the expression of AML1/ETO. Persisting pre-LSCs could be generated from myeloid progenitors transformed by the expression of PML/RARα. These pre-LSC populations could mediate the early phases of t(8;21)-AML and t(15;17)-APL pathogenesis and could represent novel key targets for anti-leukemia therapies.
Comprehensive In Vivo Analysis of p300 Hematopoietic Tumor Suppressor Functions.
Authors: Kimbrel Erin A. , Rebel Vivienne I. , Kung Andrew L. 
Published: October 2019

Abstract
Characterization of chromosomal translocations in leukemias has led to a better understanding of the causes of disease, as well as to new cures. The transcriptional co-activators p300 and CBP are not only targets of translocations, but perturbation of their normal function is central to the transforming effects of most translocation oncogenes in acute myelogenous leukemia. In our prior studies, we demonstrated that genetic inactivation of p300 or CBP function resulted in perturbed hematopoietic differentiation, and the development of hematologic malignancies. However, given the large size and many functional domains of p300/CBP, it has been difficult to determine which specific domains and activities are necessary for them to suppress hematologic tumor formation. We have now developed a novel forward-genetic mouse model that allows us to systematically evaluate p300 structure-function and determine which functional domain mediates hematologic tumor suppression in vivo. By systematically mutating functional domains within p300 and expressing the mutants in embryonic stem (ES) cells, we have been able to generate a series of chimeric mice lines, each expressing a particular mutation in p300. Our current work entails the careful examination of the peripheral blood and bone marrow for each mouse line in order to determine the importance of specific p300 domains for the suppression of hematologic malignancies that arise in the absence of p300. Moreover, this study is helping us gain insight into the mechanisms responsible for the establishment and maintenance of normal, functional stem and progenitor cell populations. This information will be important for elucidating the transcriptional programs that are likely disrupted in leukemias, thus revealing molecular mechanisms that can be used to direct the development of new cures.
Exploiting the Tr3 Interaction with Bcl-2 as a Novel Therapeutic Strategy of Cancer and Leukemia Therapy.
Authors: Zhai Dayong , Sergienko Eduard , Kitada Shinichi , Luciano Frederic , Satterswait Arnold C. , Zhang Xiaokun , Reed John C. 
Published: October 2019

Abstract
TR3 (Nur77) is an orphan member of the retinoid/steroid family of nuclear receptors, which translocates from nucleus to mitochondria where it binds Bcl-2 and converts Bcl-2 from an anti-apoptotic to a pro-apoptotic protein (Li, et al. Science289: 1159, 2000; Lin, et al CELL116: 527, 2004). Because Bcl-2 is pathologically over-expressed in many ca cancers and leukemias, contributing to chemoresistance, we sought to exploit the TR3 interaction with Bcl-2 as a novel therapeutic approach. Mutagenesis studies identified a 9 amino-acid peptide from TR3 that mimics the effects of the full-length protein in terms of binding Bcl-2 and inducing conformational changes that covert Bcl-2 into a killer. A cell-permeable version of this TR3 peptide induced apoptosis of cultured leukemia cell lines (CEM; Jurkat), such that gene transfer-mediated over-expression of Bcl-2 enhanced sensitivity to the TR3 peptide. In contrast, Bcl-2 over-expression rendered these leukemia cells resistant to other inducers of apoptosis, such as the broad-spectrum kinase inhibitor Staurosporine. Mutant TR3 peptides that fail to bind Bcl-2 did not induce apoptosis. To identify chemical compounds that mimic the pro-apoptotic TR3 peptide, a Fluorescence Polarization Assay (FPA) was developed in which FITC-conjugated TR3 peptide binding to Bcl-2 or other appropriate anti-apoptotic Bcl-2-family proteins was measured in high-throughput mode. This high-throughput screening (HTS) assay performs well in 384 well format, with Z′ > 0.75. A chemical library of ~70,000 compounds was screened to identify compounds that displace the TR3 peptide, thus yielding hits that may serve as a potential starting point for drug discovery. Characterization of the properties of these compounds and their analogs will be described. (Supported by NIH grants R01-GM60554 and U54-HG003916).
Isolation of Human Bone Marrow Mesenchymal Stem Cells by a Novel Monoclonal Antibody, ZUC3.
Authors: Lai Xiaoyu , Huang He , Huang Li , Zeng Fenfang 
Published: October 2019

Abstract
Objective: Due to absence of a single definitive marker of mesenchymal stem cells (MSCs) and low incidence in human bone marrow, the primary culture of MSCs, conventionally isolated with its characteristic of adherent, were considered to be heterogeneous containing of several subpopulations, which had currently limited our understanding of their biology and therapeutic applications. In our previous study, a novel murine monoclonal antibody (McAb) ZUC3 was produced by hybridoma technology, which was specifically reactive with human MSCs, while showed negative cross-reactivity when screened against a variety of human tissues. Now, ZUC3 antigen positive MSCs population would be further identified by magnetic-activated cell sorting (MACS).
Methods: Bone marrow were taken from the iliac crest of normal healthy adult volunteers, and mononuclear cells were separated by density gradient centrifugation, then separated into positively- and negatively-labelled fractions with McAb ZUC3 by immunomagnetic activated cell sorting. The purity of positive cells was analyzed by flow cytometry, then ZUC3 antigen positive and negative cells were plated respectively in human MSCs medium consisting of 10% FBS, LG-DMEM. Characteristics of ZUC3 antigen positive cells phenotype was analyzed by flow cytometry, and proliferation and multiple differentiation potential of the cells was observed in vitro.
Results: Flow cytometric analysis showed that ZUC3 antigen expression by cultured MSCs and mononuclear cells derived from bone marrow were 91.31±2.92%, 0.96±0.28% respectively, and western blotting showed the molecular mass of antigen was about 33KD. The purity of the recovered fractions for ZUC3 by MACS was 76.82±6.32%. The positive cells have adhered to culture flask in vitro, and the quantity of adhered cells that had fibroblast-like morphology increased and proliferated during primary expansion period, while the negative cells were observed as round shape cells without any proliferation. It was demonstrated that ZUC3 antigen positive cells continued growth with spindle-shape, extending beyond 30 population doublings in long-term culture. Analyzed by flow cytometry, the culture-expanded positive cells were uniformly positive for CD29, CD44, CD105, CD106, and lack typical hematopoietic antigens such as CD14, CD34, CD45, HLA-DR, which demonstrated that ZUC3 postive cells sorted from bone marrow mononuclear cells by McAb were MSCs. With proper medium, the ZUC3 antigen positive cells could be successfully induced to differentiate into adipocytes, osteoblasts, and neuro-like cells which were positive of neuron markers such as nestin, NSE and NF-M.
Conclusion: ZUC3 McAb was a specific surface marker against human MSCs for cell sorting. The ZUC3 antigen positive cells separated from bone marrow mononuclear cells had potential capacity of high proliferation and multiple differentiation.