bluuebunny/crossref_metadata_2025_split huggingface dataset:
Yeast Models of Diamond Blackfan Anemia and Shwachman Diamond Syndrome Differ in Their Effect on the Synthesis and Function of Ribosomal Subunits.
Authors: Ellis Steven R , Moore Joseph B. , Liu Johnson M. , Arceci Robert J. , Farrar Jason E. 
Published: April 2020

Abstract
Nucleolar stress is a frequently invoked mechanism used to describe the pro-apoptotic phenotype of cells affected in human diseases linked to abnormalities of the ribosome. However, the diversity of clinical phenotypes observed in these diseases suggests that there may be different types of nucleolar and/or translational stress that stimulate cell death pathways by alternative mechanisms. We have studied yeast models of Diamond Blackfan anemia (DBA) and Shwachman Diamond syndrome (SDS), two inherited bone marrow failure syndromes linked to defects in ribosome synthesis and/or function, to determine potential underlying molecular mechanisms that distinguish these disease models. To date, all genes identified in DBA encode ribosomal proteins. In contrast, SBDS, the gene affected in SDS encodes a protein that associates with 60S subunits, but is not considered a structural component of the ribosome. We have analyzed the translational capacity of cells harboring mutations in RPL33A and SDO1, yeast orthologs of genes affected in DBA and SDS, respectively. Polysome profiles from cells depleted of Rpl33A have a decrease in the amount of free 60S subunits and the presence of half-mer polysomes, as expected for an essential structural component of the 60S subunit. Polysome profiles from cells depleted of Sdo1 also had half-mer polysomes, but in this case there were significant amounts of free 60S subunits evident. Analysis of the intracellular distribution of 60S subunits by fluorescence microscopy revealed significant differences between the two disease models. In the DBA model, there was no evidence of accumulation of incompletely assembled subunits in the nucleolus indicating that rapid degradation. In contrast, in the SDS model there was significant accumulation of 60S subunits in the nucleoplasm. Thus, the two disease models interfere with the biogenesis of 60S subunits through distinct mechanisms. To determine if these mechanistic differences influence protein synthesis, we analyzed the patterns of proteins synthesized in these two disease models. We found that the expression of the 20S replicon was induced in both models, a sign of general translational stress. However, the two models also showed distinct differences in the synthesis of certain proteins. Thus, the mechanisms by which reductions of Rpl33A or Sdo1 influence levels of functional 60S subunits have differential effects on the patterns of proteins synthesized within cells Together these data indicate that the ribosome-based diseases may result from a composite of effects that include both nucleolar stress mechanisms and changes in translational output. The distinct clinical phenotypes observed in these disorders may result from differences in the relative contributions of either of these two mechanisms.
Very Rapid Clearance after a Joint Bleed Knee Can Not Prevent Adverse Effects on Cartilage and Synovial Tissue: A Canine in Vivo Study.
Authors: Jansen Nathalie W.D. , Roosendaal Goris , Wenting Marion , Hazewinkel Herman A.W. , Bijlsma Johannes W.J. , Theobald Matthias , Lafeber Floris P.J.G. 
Published: April 2020

Abstract
Purpose Joint bleeds lead to joint destruction. In vitro exposure of human and canine cartilage to blood results in long lasting severe adverse changes in cartilage. An in vivo joint haemorrhage in the canine knee joint demonstrates similar adverse effects although less outspoken and long-lasting. We investigated the clearance rate of blood from canine knee joints as a possible explanation for this discrepancy.
Methods Blood was injected into the knee joint of Beagle dogs, either 48h, 24h or 15m before termination. The amount of red and white blood cells present in the joint cavity was determined. Chondrocyte activity and cartilage matrix integrity as well as cartilage destructive activity of synovial tissue were determined biochemically. Additionally, synovial tissue was analyzed by use of histochemistry.
Results Fifteen minutes after the injection of autologous blood, the red blood cell count was 5,7*1012/L, comparable to the amount present in whole blood, and gradually decreased (1,6*1012/L at 24 hours) to 0,2*1012/L within 48 hours (less than 5%). The amount of white blood cells increased in the first 24 hours, and was still increased after 48 hours, although less than after 24 hours. The proteoglycan synthesis rate and -release were adversely affected already within 24 hours (−22% and +24% respectively), and these effects were more severe 48 hours post-injection (−34% and +53% resp.). Synovial tissue culture supernatants demonstrate cartilage destructive properties as expressed by an increased release, a decreased synthesis rate, and decreased content of cartilage proteoglycans; increasing with time after the experimental haemorrhage (+207%/+247%; −58%/−62%; −8%/−28% respectively, for 24/48 hours). Evaluation of the synovial tissue revealed at 15 minutes post-injection countless numbers of intact RBC that were almost completely disappared after 48 hours, withonly limited recruitment of macrophages and iron deposition.
Conclusions Blood is cleared very rapidly from the canine knee joint, but in that short time span already has adverse effects on both cartilage and synovial tissue. This rapid clearance can play a role in the discrepancy between long-term in vitro and in vivo effects of blood-induced joint damage since more than 10% v/v blood for 48 hours is needed induced to long-term adverse effects in vitro. Irrespectively, blood has devastating effects on articular cartilage very rapidly, and in this respect it is important to prevent (traumatic) joint haemorrhages and if they occur, to treat them properly.
Identification of ADAMTS13 Peptide Sequences Recognized by Autoantibodies in Patients with Acquired Thrombotic Thrombocytopenic Purpura.
Authors: Yamaguchi Yusuke , Moriki Takanori , Wada Hideo , Matsumoto Masanori , Fujimura Yoshihiro , Nakagawa Terumichi , Igari Atsuko , Ikeda Yasuo , Murata Mitsuru 
Published: April 2020

Abstract
Anti-ADAMTS13 autoantibodies are considered to play pivotal roles in the pathophysiology of acquired thrombotic thrombocytopenic purpura (TTP). They inhibit the ADAMTS13 function resulting in the appearance of ultra-large von Willebrand factor (VWF) multimers. Major binding sites of the autoantibodies were reported to be in the cysteine-rich/spacer domains. To clarify the precise peptide sequences recognized by anti-ADAMTS13 IgG autoantibodies, we constructed a random cDNA fragment library expressing various peptides of ADAMTS13 on the surface of lambda phage and screened the library using purified IgG from 13 TTP patients. Diverse peptide sequences were obtained from almost entire ADAMTS13 domains such as metalloprotease, disintegrin, TSP1-1, cysteine-rich, spacer, TSP1- 2, 3, 4, 5, 7, 8 and CUB1. In particular, we detected an identical 26 amino-acid epitope sequence in the C-terminus of spacer domain from Gly662 to Val687 (sp662–687) shared by 5 TTP patients. Moreover, the peptide sequence was exactly included in one of the VWF binding epitope sites that we previously determined (Blood110 (11), 795a, 2007). We then assessed the impact of specific autoantibody to ADAMTS13 activity measured by FRETS-VWF73 or EIA and ADAMTS13 inhibitor titer in each of TTP patient plasma. However, both of the ADAMTS13 activity and inhibitor titer seemed not correlated with the existence of specific sp662–687 IgG autoantibody. These observations suggest that the autoantibody to sp662–687 may be one specific feature of TTP, although other epitopes are also involved in the pathogenesis of the disorder.
The MiR23A MicroRNA Cluster Is a Target of PU.1 and Promotes Development of Myeloid Cells at the Expense of B Cells
Authors: Owens Kristin S , Kong Kimi Y , Rogers Jason H , Dahl Richard E. 
Published: April 2020

Abstract
The transcription factor PU.1 is an important regulator of hematopoiesis, directing cell fate decision in a dosage dependent manner with higher levels driving monocytic differentiation and lower levels directing B-cell differentiation. The mechanism by which PU.1 controls this process is not fully understood. Here we show that PU.1 is involved in regulating the expression of several microRNAs. MicroRNAs regulate gene expression at a post-transcriptional level by binding target mRNA through the 3′ UTR and either repressing translation or causing degradation of the mRNA itself. We used microarray expression profiling to assess a large group of microRNAs in PUER cells, a PU.1 −/− cell line that differentiates into macrophages when PU.1 activity is restored. Several miRNAs showed changes in expression four days after restoration of PU.1 activity. We focused on a cluster of microRNAs that includes miR-23a, miR27a, and miR24-2, which we call the miR23a cluster. All three miRNAs are coded for on a single pri-miRNA transcript. Northern blot analysis verified the findings of the microarray–that expression of this microRNA cluster is enhanced by PU.1. The promoter for the cluster contains several conserved predicted binding sites for PU.1. Chromatin immunoprecipitation and EMSA has confirmed that PU.1 binds to these sites. In addition, reporter assays show that the mir23a promoter can be activated by PU.1. The 23a cluster appears to be a critical target gene for PU1 to promote myeloid development. Using in vitro hematopoietic cultures we have observed that expressing this cluster in hematopoietic progenitors promotes myeloid development over B cell development. In addition, data from bone marrow transplant assays will be presented demonstrating the role of this cluster in directing hematopoiesis in vivo. Targetscan and miRanda computer algorithms predict several B cell transcription factors as targets of the miRNAs of the 23a cluster. PU.1 potentially activates expression of the 23a cluster to downregulate B cell transcription factors in order to commit cells to the myeloid cell fate.
The Tyrosine Kinase Src Regulates Adhesion and Survival in Waldenström Macroglobulinemia
Authors: Ngo Hai T. , Farag Mena , Jia Xiaoying , Burwick Nicolas , Melhem Molly R. , Leleu Xavier , Runnels Judith , Azab Abdel Kareem , Roccaro Aldo M. , Azab Feda , Sacco Antonio , Quang Phong , Tai Yu-Tzu , Anderson Kenneth C. , Ghobrial Irene M. 
Published: April 2020

Abstract
BACKGROUND: Tyrosine phosphorylation is a central event in the regulation of a variety of biological processes such as cell proliferation, migration, adhesion, and survival. Waldenström Macroglobulinemia (WM) is an incurable lymphoplasmacytic lymphoma with limited options of therapy and characterized by widespread involvement of the bone marrow. We sought to determine whether the protein tyrosine kinase Src regulates adhesion and survival in WM.
METHODS: The WM cell lines BCWM1, WM-WSU, and IgM secreting lymphoma cells lines MEC-1 and RL were used in these studies. Primary CD19+ WM cells were obtained from the bone marrow of patients after informed consent. AstraZeneca Biopharmaceuticals (London, England) provided the Src inhibitor AZD0503 (AZD). Cytotoxicity and DNA synthesis were measured using MTT assay and [3H]-thymidine uptake, respectively. Apoptosis was measured using flow cytometry with Apo 2.7 staining. Western blotting was performed to determine downstream signaling pathways. Migration was performed using the transwell migration assay.
RESULTS: We demonstrated that pSrc is overexpressed in WM cells compared to control B cells. Similarly, phospho-Src protein expression was upregulated in WM cell lines, specifically BCWM.1 but not in WM-WSU. We then showed that pSrc regulates migration and adhesion in response to the chemokine SDF-1, as well as in vivo homing using in vivo flow cytometry. The use of the specific Src inhibitor AZD0530 led to significant inhibition of adhesion and migration in cell lines with pSrc activation, but not in those deficient of Src activation. Similarly, inhibition of Src activity led to significant inhibition of proliferation and survival through inhibition of STAT3, Akt, and ERK/MAPK pathways. The monoclonal antibody rituximab signals through Src kinase, and the combination of AZD0530 and rituximab was synergistic in vitro.
CONCLUSION: Taken together, these studies delineate the role of Src kinase activity in WM and provide the framework for future clinical trials using Src inhibitors in combination with rituximab to improve the outcome of patients with WM.
Confirmation of the Efficacy and Safety of Lenalidomide Oral Monotherapy in Patients with Relapsed or Refractory Diffuse Large-B-Cell Lymphoma: Results of An International Study (NHL-003)
Authors: Czuczman Myron S. , Vose Julie M. , Zinzani Pier Luigi , Reeder Craig B. , Buckstein Rena , Haioun Corinne , Bouabdallah Reda , Polikoff Jonathan , Guo Pingshan , Ervin-Haynes Annette , Pietronigro Dennis , Zeldis Jerome B. , Witzig Thomas E. 
Published: April 2020

Abstract
Introduction: Diffuse large-B-cell lymphoma (DLBCL) is the most common of the non-Hodgkin lymphomas (NHL). Patients with DLBCL who are not cured by treatment with R-CHOP chemotherapy or high-dose chemotherapy with autologous stem cell rescue have a poor prognosis. These patients reflect a clear unmet need in the treatment of DLBCL. A previous sub-analysis of a phase II trial (NHL-002) of lenalidomide in patients with relapsed or refractory DLBCL, demonstrated a 19% overall response rate (ORR) with a 7-month median duration of response (DR). A confirmatory international phase II trial (NHL-003) of single-agent lenalidomide was initiated for patients with relapsed/refractory aggressive NHL that had received at least one prior treatment and had measurable disease. Herein, we report the data from the DLBCL patients enrolled in this trial.
Methods: Patients received 25 mg oral lenalidomide once daily on days 1–21 of every 28-day cycle and continued therapy until disease progression or toxicity. The 1999 IWLRC methodology was used to assess response and progression.
Results: This report focuses on the 73 DLBCL patients that were enrolled and evaluable for response assessment. The median age was 67 (21–87) years and 49 (67%) patients were male. Median time from diagnosis to lenalidomide treatment was 2 (0–18.6) years, and patients had received a median of 3 (1–6) prior treatment regimens. The ORR to lenalidomide was 29% (21/73), with 4% complete response (3/73) and 25% partial response (18/73). Eleven patients (15%) had stable disease. The most common grade 3 or 4 adverse events were neutropenia (32%), thrombocytopenia (15%), asthenia (8%) and anemia (7%).
Conclusion: These results of this international study confirm that lenalidomide is active in heavily pre-treated patients with relapsed or refractory DLBCL with manageable side effects.
Foxp3 Expression Is Induced in Peripheral Blood Mononuclear Cells from Patients with CTCL and GVHD after Extracorporeal Photopheresis
Authors: Ni Xiao , Shiue Lisa , Arias-Mendoza Paola , Aakhus Erin , Hosing Chitra , Duvic Madeleine 
Published: April 2020

Abstract
Anti-tumor immunity mediated by cytotoxic CD8+ T lymphocytes (CTL) is thought to underlie the efficacy of extracorporeal photopheresis (ECP) for cutaneous T cell lymphoma (CTCL). In contrast, induction of immune tolerance mediated by regulatory T cells (Treg) is hypothesized to underlie the effect of ECP for graft-versus-host disease (GVHD). In this translational research study, peripheral blood mononuclear cells (PBMC) from patients (Pt) with Sézary Syndrome (SS), a leukemic form of CTCL, and GVHD pre- and post-ECP were studied for expression of the CTL cytokine IFN-gamma and of the nuclear transcription factor forkhead box P3 (Foxp3), a specific marker of Treg. Total RNA from PBMCs at pre-ECP, 2 day, 1 month, 3 months, and 6 months post- ECP were quantitated by real-time quantitative reverse transcript-PCR (RT-Q-PCR) for Foxp3 and IFN-gamma mRNA expression levels, normalized to endogenous control gene, glyceraldehyde 3-phosphate dehydrogenase (GAPDH). Foxp3 levels at baseline varied but increased at 2 day and 1 month post-ECP in GVHD by 9.5-fold and 27.6-fold, respectively (Fig.1). Similarly,foxp3 also increased in 3 of 4 CTCL patients (Pt#1, #2 and #4). Foxp3 levels rose steadily in clinical responders, Pt#1 and Pt#2, during the treatment course, and highest levels were detected at 6 months post-ECP with 13.1-fold and 17.4-fold increase, respectively. Pt#1 and #2 experienced partial clinical response and decreased circulating tumor cells with ECP. The levels of interferon-gamma had only &lt; 2-fold up or down over the treatment course from baseline among CTCL post-ECP samples. While the level of IFN-gamma was decreased by half at 2 day and 1 month post-ECP in GVHD compared to that in pre-ECP (Fig.2). These results suggest that Tregs (detected by Foxp3) but not IFN-gamma are induced during ECP in responding CTCL patients as in GVHD. ECP might thus have common mechanisms in these two T cell mediated diseases. The study will continue to enroll patients to further study the effects of ECP.
Fig. 1 Foxp3 expression in PBMCs from CTCL and GVHD pre- and post ECP Fig. 1. Foxp3 expression in PBMCs from CTCL and GVHD pre- and post ECP Fig. 2 IFN-gamma expression in PBMCs from CTCL and GVHD pre- and post ECP Fig. 2. IFN-gamma expression in PBMCs from CTCL and GVHD pre- and post ECP
R2: Preliminary Results of a Phase II Study of Lenalidomide and Rituximab in Relapsed/Refractory Indolent Non-Hodgkin’s Lymphoma (NHL)
Authors: DeRook Ian , Odonnell Robert T , Noble B. , Quirch C. , Tuscano Joseph 
Published: April 2020

Abstract
Background: Lenalidomide (Revlimid®) is a potent immune-modulating, anti-angiogenic agent, approved in the USA for treatment of relapsed/refractory multiple myeloma and myelodysplastic syndromes associated with the 5q- chromosomal deletion. Lenalidomide also demonstrates activity as monotherapy in aggressive and indolent NHL, chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), and cutaneous T-cell lymphoma. The current study was designed to evaluate the safety and efficacy of the lenalidomide and rituximab (R2) combination in patients with relapsed/refractory indolent NHL.
Methods: Patients with relapsed/refractory indolent NHL with measurable disease after at least 1 prior treatment regimen were eligible. Lenalidomide was initially administered at a dose of 25mg orally once daily, on days 1–21 on a 28-day cycle, and continued until disease progression. Rituximab 375mg/m2 was infused beginning on day 15 of cycle 1, and repeated weekly for a total of 4 doses. Following development of tumor lysis syndrome (TLS) in two patients, the protocol was amended to reduce the starting dose of lenalidomide to 20mg, and TLS prophylaxis was provided. Response and progression were evaluated using IWLRC methodology.
Results: At the time of this report, 7 patients were enrolled, and 6 had initiated therapy. The median age was 67 (range 54–91) years and 2 were female. Histologies are follicular lymphoma [FL] (n=5), SLL (n=1), and marginal zone lymphoma (n=1). Median time from diagnosis to treatment on study was 7.3 (3.3–19) years and median number of prior treatment regimens was 4 (1–5). All patients had received prior treatment with rituximab. Four patients were evaluable for response, all of whom had rituximab-resistant disease. All four evaluable patients, including two with highly refractory disease, after a median of 2 cycles, exhibited an objective response (1 complete response unconfirmed, 2 partial responses, and 1 minor response). Progression free survival, currently ongoing, is &gt; 102 days. Toxicity included TLS in two refractory patients with FL within the first week of therapy. The most common grade 3 and 4 events were neutropenia, lymphopenia, and hyponatremia.
Conclusion: This is the first study to demonstrate that combination therapy using lenalidomide and rituximab is safe and active in relapsed/refractory indolent NHL. The side effect profile was acceptable with the addition of TLS prophylaxis. With additional analysis, the R2 combination may warrant further study in refractory indolent lymphoma.
HOX-Gene Expression and Inhibition of the Non-Canonical NF-KappaB Pathway in t(7;12) Leukemias
Authors: Wildenhain Sarah , Hauer Julia , Roettgers Silija , Engelmann Hartmut , Novosel Astrid , Binder Vera , Slany Robert K. , Ludwig Wolf-Dieter , Harbott Jochen , Borkhardt Arndt 
Published: April 2020

Abstract
The chromosomal translocation t(7;12) was described recently in MLL negative acute myeloid leukemias of infancy associated with a very poor clinical outcome. The rearrangement involves the genes HLXB9 (7q36) and ETV6 (12p13) with a fusion transcript of exon1/HLXB9 and exon3/ETV6. An alternative in frame splicing variant of exon1/HLXB9 to exon2/ETV6 is also detectable. Leukemic bone marrow samples of 42 infants, diagnosed in Germany with AML, were screened for the fusion transcript HLXB9/ETV6 with RT-PCR. Inclusion criteria were diagnosis of AML, age&lt;2 years, no MLL/AF9, MLL/AF4 or MLL/ENL rearrangement in RT-PCR, no chromosomal 11q23 rearrangement and no trisomy 21. Positive samples were cloned and sequenced. A fusion transcript was found in approx. ~17% of patients. Common features of HLXB9/ETV6 positive leukemias in this cohort are poorly differentiated FAB subtypes, trisomy 19 karyotype of the leukemic cells, coexpression of the T-cell markers CD4 and CD7 as well as high expression of the un-rearranged HLXB9 gene. Quantitative PCR showed no upregulation of HOXA9 and MEIS1 in HLXB9/ETV6 positive patients as reported for MLL+ leukemias. The mechanism of HLXB9/ETV6 induced leukemogenesis remains unknown. We show that in vitro retroviral transduction of murine hematopoietic precursor cells with either HLXB9/ETV6 or HLXB9 or ETV6/RUNX1 was not transforming. Furthermore altered activity of the transcription factor family NF-kappaB has been demonstrated for various types of cancer including acute myeloid leukemias. Therefore we analysed the impact of the HLXB9/ETV6 fusion on the NF-kappaB signaling pathway in a 293T cell-system. HLXB9/ETV6 and HLXB9 showed inhibition of the NF-kappaB dependent transcription signal in a reporter assay, whereas the typical ALL-fusion ETV6/RUNX1 showed no influence. Analysis of nuclear extracts by western blot confirmed, that the inhibition of the NF-kappaB signal is due to a reduced nuclear translocation of the non-canonical NF-kappaB components p52 and RelB, whereas the canonical pathway remains not influenced.
Conclusion: The HLXB9/ETV6 fusion transcript can be found in 17% of infants with MLL-negative AML in a German cohort. HLXB9/ETV6 positive leukemias show no increased expression on HOXA9 and MEIS1, but coexpression of T-cell markers and inhibition of the non-canonical NF-kappaB pathway on protein level. HLXB9/ETV6 did not induce malignant transformation in murine hematopoietic precursor cells.