bluuebunny/crossref_metadata_2025_split huggingface dataset:
Efficacy and Safety of Recombinant Fusion Protein Linking Coagulation Factor IX with Albumin (rIX-FP) in Previously Treated Patients with Hemophilia B Undergoing Major Orthopedic Surgeries
Authors: Negrier Claude , Lepatan Lynda Mae , Karim Faralzah , Lienhart Anne , Wolko Denise , Voigt Christine , Jacobs Iris C. , Santagostino Elena 
Published: October 2019

Abstract
A fusion protein genetically linking recombinant human coagulation FIX with recombinant human albumin (rIX-FP) has been developed with an improved PK profile, improving hemophilia B treatment by allowing less frequent dosing and FIX consumption for perioperative management. A surgical sub-study was included in 3 Phase III studies, including an on-going Phase IIIb extension study in subjects with hemophilia B, as part of the global PROLONG-9FP clinical program. This report will focus on the use of rIX-FP for perioperative prophylaxis.
Efficacy was evaluated by Investigator assessment (4-point scale), predicted and estimated actual blood loss, and consumption of rIX-FP during the 14-day perioperative period. Safety, including inhibitors to FIX, was assessed. The pre-operative dose of rIX-FP was based on individual incremental recovery, targeting 80-100% FIX activity. FIX activity was monitored at local laboratories to determine repeat doses during the surgical period.
Five major orthopedic surgeries have been assessed to date. Hemostatic response was rated by investigators as excellent or good for all surgeries. A single dose of rIX-FP prior to surgery was sufficient to maintain hemostasis during surgery. Estimated actual blood loss was consistent with predicted blood loss in patients without hemophilia B. The total number of rIX-FP injections ranged from 6-7 over the 14 day post-operative period. The median rIX-FP consumption prior to surgery, Days 1-3, Days 1-7 and Days 8-14 post surgery were 84, 33, 81 and 107 IU/kg, respectively. There were no inhibitors to FIX or antibodies to rIX-FP during the study. The extension study is still ongoing, and additional orthopedic surgeries data may be presented.
These results support the efficacy and safety of rIX-FP for perioperative management in patients with hemophilia B, with prolonged dosing intervals and lower FIX consumption than conventional therapies.

Disclosures
Negrier: CSL Behring: Speakers Bureau. Wolko:CSL Behring: Employment. Voigt:CSL Behring: Employment. Jacobs:CSL Behring: Employment. Santagostino:CSL Behring: Speakers Bureau; Pfizer: Research Funding, Speakers Bureau; Baxter/Baxalta: Speakers Bureau; Biotest: Speakers Bureau; Kedrion: Speakers Bureau; Roche: Speakers Bureau; Octapharma: Speakers Bureau; Biogen/Sobi: Speakers Bureau; Novo Nordisk: Speakers Bureau; Bayer: Speakers Bureau.
A Comparison of Von Willebrand Factor Indexes in Heartmate II Compared to Heartware Left Ventricular Assist Devices
Authors: Gupta Bhanu P , Leoni Juan , Patel Parag , Chen Dong , Blackshear Joseph 
Published: October 2019

Abstract
Background: Von Willebrand factor (VWF) is a multimeric glycoprotein synthesized in endothelium and megakaryocytes. Elevated total VWF antigen has been associated with arterial thrombosis, while in patients with left ventricular assist devices (LVAD), loss of high molecular weight multimers is associated with spontaneous bleeding. We hypothesized that the lower rotational speed of the Heartware LVAD would be associated with less severe disruption of VWF.
Methods: A total of 22 patients were included. We compared samples from a) 17 patients with Heartmate II LVAD (HM II), 76% male, median age 67 (54-73) years, 24% non-white, 45 (33-59) months after implant, with b) 5 patients with Heartware (HW) LVAD, all male, age 64 (59-65) years, 20% non-white, 27 (14-29) months after implant. All patients received warfarin. All HW patients took aspirin, while 82% of HM II patients took aspirin. Samples were analyzed for VWF antigen, activity, platelet function analyzer-100 collagen adenosine diphosphate closure time (PFA) and VWF multimers by gel electrophoresis. Multimers were assessed qualitatively and quantitatively by dividing mers > 15 by mers 2-15 (multimer ratio) and with a normalized multimer ratio (multimer ratio of patient / normal plasma control from the same gel).
Results: Although flow rates did not differ significantly between HM II and HW, 5.2 (4.6-6.5) versus 4.3 (4.2-5.4) liters per minute respectively, rotational speeds were very different, mean 9472 versus 2680 rpms, p<0.0001). There were no differences in hemoglobin, hematocrit, or platelet count at the time of sampling. Qualitative VWF multimers were abnormal in all patients, and PFA was non-clotting in 88% of HM II patients and 80% of HW patients. VWF activity to antigen ratio was not different: HM II 0.68 (0.63-0.74) versus HW 0.70 (0.63-0.71). However, VWF antigen was significantly higher in HM II patients, 199 (174-227) compared to HW, 139 (122-160), p=0.039 and the normalized VWF multimer ratio was significantly lower, suggesting greater loss of high molecular weight multimers in HM II, 0.43 (0.41-0.48) compared to HW, 0.53 (0.48-0.56), p=0.0025 (figure).
Conclusion: The lower rotational speed associated with the Heartware LVAD appears to produce less elevation of VWF antigen, and slightly less loss of VWF high molecular weight multimers compared to the Heartmate II LVAD. Additional studies are needed to describe whether or not lower pump thrombosis rates and rates of spontaneous bleeding are associated with these differences.
Figure 1. Figure 1.

Disclosures
No relevant conflicts of interest to declare.
Comparison of Rethrombosis-Free Survival in Children Versus Adults Suffering from Antithrombin-, Protein C- and Protein S-Deficiency: An Observational Multicenter Cohort Study
Authors: Limperger Verena , Kenet Gili , Heller Christine , Knoefler Ralf , Kurnik Karin , Klostermeier Ulrich C , Mesters Rolf , Goldenberg Neil A , Young Guy , Nowak-Gottl Ulrike 
Published: October 2019

Abstract
Background: Venous thromboembolism [TE] is a multifactorial disease and antithrombin [ATD]-, protein C [PCD]- or protein S [PSD]-deficiency constitutes a major risk factor. Since screening for thrombophilia is controversial, individuals at high risk for recurrence who benefit from screening need to be identified. Primary study objective was to determinethe individual recurrence risk in children compared to adults with TE with respect to their thrombophilia status.
Methods: In 142 consecutively enrolled TE patients (children n=85; adults n=57) with ATD, PCD or PSD after exclusion of six children with purpura fulminans due to homozygous PCD or PSD we calculated i) the cumulative recurrence rates (CRR) at 1, 5 and 10 year following the first TE onset and, ii) in addition, the absolute recurrence risk (ARR) per 100 patient years (%).
Results: At first TE onset in univariate analysis a higher rate of unprovoked TE was found in children, whereas adults presented with a higher rate of a positive TE family history and a higher rate of recurrence: 40 out of 136 patients showed a second TE after withdrawal of anticoagulation (AC) or insufficient AC [n=6]. Two events in children were fatal [pulmonary embolism]. The overall CRR at 1, 5 and 10 years was 10.9%, 20.4% and 29.2% with total ARR [95% CIs] of 5.3 [3.4-7.8] in adults compared to 2.1 [1.0-5.3] in children [p=0.004]. Whereas the ARR was no different between adults and children in ATD patients [5.1 versus 4.7; p=0.85] and in symptomatic PCD subjects [3.9 versus 1.6; p=0.17], adults with PSD showed a higher ARR compared to children [6.3 versus 0.1; p=0.001]. Positive family TE history did not predict recurrence.
Conclusion: Given the high ARR of 5.3% in adults and 2.1% in children we suggest screening for ATD, PCD and PSD in adult and pediatric TE patients. The high rate of ARR should be taken into account when initiating future therapeutic trials. Duration and intensity of AC should be carefully reevaluated in patients with ATD, PCD or PSD.

Disclosures
Young: Baxter, Grifols: Consultancy, Honoraria. Nowak-Gottl:Bayer, LFB: Membership on an entity's Board of Directors or advisory committees.
Bloodspot: A Web Resource Facilitating the Analysis of Transcriptional Programs in Normal and Malignant Hematopoiesis
Authors: Bagger Frederik Otzen , Sasivarevic Damir , Sohi Sina Hadi , Laursen Linea Gøricke , Pundhir Sachin , Winther Ole , Rapin Nicolas , Porse Bo T 
Published: October 2019

Abstract
Decades of studies on developing cells in human and murine haematopoiesis have resulted in a large number of gene-expression datasets that may answer questions regarding normal and aberrant blood formation. To researchers and clinicians with limited bioinformatics experience, these data remain available, yet largely inaccessible. Current resources provide information about gene-expression patterns but disregard key aspects such as genetic co-regulation of genes, and the effects on patient survival.
Here, we present a new web-based resourced termed, BloodSpot, which provides a) a comprehensive representation of gene-expression throughout haematopoiesis, b) a single gene-based Kaplan-Meier analysis and c) a novel, simpler, yet more informative, type of expression plot. Significantly, users can compare their own expression profiles to normal haematopietic populations within the statistical framework of Bloodspot. We illustrate the potential of key features in BloodSpot to identify new putative C/EBPa targets.
Accessible at http://servers.binf.ku.dk/bloodspot/

Disclosures
No relevant conflicts of interest to declare.
ER71/ETV2 Is Essential for Hematopoietic Regeneration after Injury
Authors: Xu Canxin , Choi Kyunghee , Lee Tae-Jin , Sakurai Nagisa 
Published: October 2019

Abstract
Hematopoietic stem and progenitor cell (HSPC) expansion and regeneration is requisite for effective hematopoietic transplantation and recovery from anticancer chemotherapy drug induced bone marrow injury. In chemotherapy-mediated hematopoietic injury model, we found that key developmental genes that are critical for HSPC generation were upregulated in HSPCs when treated with 5-FU. ETS transcription factor Er71/ETV2 is essential for the development of endothelial and blood cells during mammalian embryogenesis. Here, we generated different tissue specific Er71 conditional knockout (CKO) mice as well as transgenic mice that coexpress Er71, GATA2 and Scl (EGS) in a doxycycline inducible manner to investigate the Er71 role in adult hematopoiesis. While Vav-Cre; Er71 CKO and Tie2-Cre; Er71 CKO mice did not display any hematopoietic defects in homeostatic conditions, Vav-Cre; Er71 CKO bone marrow was significantly compromised in hematopoietic reconstitution potential compared to controls. In addition, Vav-Cre; Er71 CKO and Tie2-Cre; Er71 CKO but not VECadherin-Cre; Er71 CKO mice showed reduced HSPC proliferation and deficient HSPC and myeloid cell recovery after 5-FU injury. On the other hand, temporal Er71, GATA2 and Scl (EGS) coexpression promoted HSPC proliferation, hematopoietic reconstitution potential and regeneration after 5-FU injury. These results demonstrate that hematopoietic Er71 is critical for HSPC expansion and regeneration. Future studies warrant Er71 application for in vitro hematopoietic stem cell expansion and bone marrow regeneration in response to hematopoietic injury.

Disclosures
No relevant conflicts of interest to declare.
PRMT1-Mediated Methylation of DUSP4 Determines Megakaryocyte-Erythroid Lineage Choice By Regulating p38 Signaling
Authors: Su Hairui , Tran Ngoc-Tung , Guo Han , Luo Minkui , Zhao Xinyang 
Published: October 2019

Abstract
Protein arginine methyltransferase 1 (PRMT1) expression level is correlated with short survival rate of acute myeloid leukemia patients. PRMT1 contributes to leukemogenesis via direct interaction with leukemic fusion proteins such as AML1-ETO and MLL-EEN. Our previous studies have shown that PRMT1 blocks megakaryocyte (MK) terminal differentiation. Inhibition of PRMT1 enzymatic activity promotes apoptosis and differentiation of acute megakaryocytic leukemia (AMKL) cells. To understand the molecular mechanisms of PRMT1-mediated leukemogenesis, we apply bioorthognal profiling of protein methylation technology to identify PRMT1 substrates. A dual specificity protein phosphatase, DUSP4 was found a PRMT1 substrate. In literature, high expression of DUPS4 is linked to idiopathic CD4 lymphopenia and silencing of DUSP4 expression causes chemo-resistance in solid tumors and abnormal innate immune response to parasitic infections. To understand the role of DUSP4 in megakaryocytic differentiation, we ectopically expressed DUSP4 and found that it enhances megakaryocyte development. In liquid culture system, DUSP4 knockdown in human CD34+ cells crippled MK differentiation induced by TPO. In TPO+EPO culture system, DUSP4 knockdown in human CD34+ cells gave rise to more erythroid cells (CD71+) at the expense of MK cells (CD41+). Therefore, DUSP4 is essential for MK differentiation. To understand how PRMT1-mediated methylation of DUSP4 blocks MK differentiation, we mapped the DUSP4 methylation site. We found that the DUSP4 methylation mutant has a longer half-life compared to DUSP4 wild type. Further studies confirmed that DUSP4 protein stability is controlled by methylation-induced ubiquitylation.
Although DUSP4 has been shown to dephosphorylate ERK, JNK and p38 kinases in overexpression systems, we found that during megakaryocytic differentiation DUSP4 specifically targets p38. These results are consistent with the findings in literature that p38 is required for erythroid differentiation, while ERK is required for megakaryocytic differentiation. Therefore, DUSP4 is responsible for turning off p38 signaling pathway, which pushes cells to erythroid lineage. Furthermore, we found that DUSP4 is associated with chromatin and dephosphorylates histone H3S10; while the methylation mutant DUSP4 locates in cytoplasm, therefore can still dephosphorylate p38 but not H3S10. Given that H3S10 phosphorylation may play a critical role in endomitosis, we also studied whether overexpression of DUSP4 antagonize aurora kinase activity to promote megakaryocytic differentiation in AMKL cell lines, containing OTT-Mal translocation or trisomy 21/down syndrome. We have tested an array of PRMT1 inhibitors to boost DUSP4 activity for potential curative therapy using AMKL leukemia mouse models. Our data support the notion that targeting PRMT1-DUSP4 pathway is a valid therapeutic approach for AMKL.

Disclosures
No relevant conflicts of interest to declare.
Replication Associated Stress in the Fetal Stem Cell Pool of FA Mice Can be Rescued By Pharmacologic Inhibition of Constitutively Activated P38 MAPK
Authors: Yoon Youngme , Kamimae-Lanning Ashley N. , Storm Kelsie , Goloviznina Natalya A , Kurre Peter 
Published: October 2019

Abstract
Fanconi Anemia (FA) is a rare, recessively heritable disorder with prominent failure of hematopoiesis. The physiologic role of FA proteins has not been fully resolved to date. While several existing model systems delineate its role in DNA damage response caused by alkylating agents, aldehydes, and inflammatory cytokines, all rely on experimental induction. We previously demonstrated the in utero onset of hematopoietic failure in mice with genetic disruption of Fancc. Herein, we found significant deficits in the fetal liver (FL) hematopoietic stem and progenitor cell (HSPC) pool in Fancd2 mice. Both AA4.1+ Sca-1+ Lin- expressing progenitors (ASL) and CD48- CD150+ Lin- Sca-1+ (SLAM) cells were decreased in frequency in Fancd2-/- versus WT FL. Similarly, we observed a significant decrease in progenitor colony formation and deficits in primary and secondary transplantation among Fancd2-/- FL compared to WT. Fancd2-/- FL cells were characteristically sensitive to mitomycin C and had significantly fewer SLAM cells in the G0 phase of cell cycle and elevated p21 expression, indicating canonical P53 activation. Consistent with prior reports by other groups on embryonic stem cells and our own Fancc-/- FL studies, we found neither exaggerated frequency of apoptotic cells, nor transcriptional induction of Puma or Noxa. We hypothesized that the observed deficits in developmental HSPC pool expansion reflect replication-associated stress. At the transcriptional level, we found activation of the DNA damage response via Rad51 and Prkdc, corroborated by immunofluorescent imaging of Rad51 foci as well as comet assays in FL cells. Next, we tested P38 MAPK as a stress response previously found to confer repopulation deficits in postnatal BM failure among Fancc and Fanca mice; here, our experiments revealed baseline (unprovoked) activation of phospho-p38 and rescue of Fancd2-/- progenitor colony formation using a pharmacological inhibitor, SB203580. Results were further strengthened by transplantation, revealing increased Fancd2-/- donor chimerism after in vivo administration of SB203580. The gains in donor chimerism persisted even after cessation of drug administration. These results suggest that replication-associated stress in the rapidly cycling fetal Fancd2-/- HSPC pool evokes a cellular stress response that constrains physiological expansion. Our work emphasizes the prenatal onset of hematopoietic failure and reveals pharmacological rescue by inhibition of constitutively active P38 MAPK. Furthermore, FA fetal hematopoiesis is an original model of unprovoked hematopoietic failure that allows the study of physiologic role of FA proteins in HSPC.

Disclosures
No relevant conflicts of interest to declare.
FOXR1 Activation in B-Cell Lymphoma
Authors: Quentmeier Hilmar , Pommerenke Claudia , Nagel Stefan , Hauer Vivien , Zaborski Margarete , Amini Rose Marie , Berglund Mattias , Geffers Robert , Drexler Hans G 
Published: October 2019

Abstract
Several recurrent chromosomal aberrations targeting 11q23 have been described in diffuse large B-cell lymphoma (DLBCL). Here, we describe a novel fusion between RPS25 and FOXR1, two neighboring genes on 11q23 in the DLBCL cell line U-2932. RNAseq identified the fusion mRNA and genomic cloning localized the breakpoint to intron 2/3 of RPS25 and to the promoter region of FOXR1 (bp -3532). The cell line consists of two genetically distinct clones that represent subclones of the patients tumor.1 We confirmed RPS25/FOXR1 fusion in the patients DNA and in one of the two cell line subclones suggesting that the fusion had occurred at some later stages of tumor development. Physiological FOXR1 expression is restricted to the early stages of embryogenesis. Ectopic expression as result of 11q23 intrachromosomal deletion-fusion had so far only been described in neuroblastoma.2 In-frame fusions with the 5´ genes MLL and PAFAH1B2 led to the overexpression of FOXR1.2 In accordance with the notion that also in DLBCL a constitutively expressed 5´ gene (RPS25) might be responsible for the ectopic expression of FOXR1, FOXR1 levels were 1000x higher in the fusion-positive than in the fusion-negative U-2932 subclone. Expression array analyses showed that the RPS25/FOXR1 positive U-2932 subclone had the highest FOXR1 expression level of 55 B-lymphoma cell lines tested, three log-scales higher than the average expression level. Santo et al.2 reported that FOXR1 acts as negative regulator of fork-head box factor-mediated transcription and suggested a possible role in tumorigenesis. We describe for the first time that FOXR1 fusions also occur in lymphoma. In-silico analyses show that the aberrant expression of FOXR1 is rare, but recurrent in various forms of lymphoma. Given the potential oncogenic role of FOXR1, cell line U-2932 with one FOXR1-positive and one FOXR1-negative subclone appear to be a promising model for functional analysis of FOXR1-mediated cellular events.
1 Quentmeier H, Amini RM, Berglund M, et al. U-2932: two clones in one cell line, a tool for the study of clonal evolution. Leukemia. 2013;27(5):1155-1164.
2 Santo EE, Ebus ME, Koster J, et al. Oncogenic activation of FOXR1 by 11q23 intrachromosomal deletion-fusions in neuroblastoma. Oncogene 2012;31(12):1571-1581.

Disclosures
No relevant conflicts of interest to declare.
Epigenetic Reprogramming of Cis-Regulatory Sites By R882-Mutated DNMT3A Potentiates Aberrant Stem Cell Gene Program and Acute Leukemia Development
Authors: Lu Rui , Wang Ping , Parton Trevor , Zheng Deyou , Wang Gang Greg 
Published: October 2019

Abstract
DNA Methyltransferase 3A (DNMT3A) is frequently mutated in various hematopoietic malignancies; however, the underlying oncogenic mechanisms remain elusive. Here, we establish ex vivo and in vivo leukemogenic models recapitulating synergy between a DNMT3A 'hotspot' mutation (i.e., DNMT3AR882H) and kinase activation, which include a leukemia-initiating stem cell (LSC) model. We show that DNMT3AR882H cooperates with constitutively activated RAS (NRAS G12D) in transforming murine hematopoietic stem/progenitor cells (HSPCs) ex vivo and inducing acute leukemias in vivo. Genome-wide transcriptome profiling analysis of these models reveals that DNMT3AR882H potentiates aberrant transactivation of 'stemness' gene expression programs, notably a set of transcription factors Meis1, Hox-A, Mn1 and Mycn. Further examination by ChIP-Seq and enhanced Reduced Representation Bisulfite Sequencing (eRRBS) demonstrate that R882-mutated DNMT3A enzymes directly binds to cis-regulatory elements of these genes and induces focal CpG hypomethylation reminiscent of what was seen in human leukemias bearing DNMT3A R882 mutation. Furthermore, DNMT3AR882H-induced DNA hypomethylation facilitates gene enhancer/promoter activation and recruitment of Dot1l-associated transcription elongation machineries. Lastly, with these established leukemogenic model systems, we also demonstrate profound differences between R882-mutated and wild-type DNMT3A in mediating oncogenic transformation, epigenetic dysregulation and gene mis-regulation. Collectively, these findings not only mechanistically explain clonal and malignant hematopoiesis found associated with DNMT3A mutation but also establish targeting transcription elongation machineries as novel therapeutic avenues for DNMT3A-mutated hematological malignancies.

Disclosures
No relevant conflicts of interest to declare.