bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adenosine Signaling in Priapism and Novel Therapies
Authors: Ning Chen , Wen Jiaming , Zhang Yujin , Juneja Harinder S. , Qi Lin , Kellems Rodney E. , Xia Yang 
Published: October 2019

Abstract
Abstract 1006

Objective:
Priapism is abnormal prolonged penile erection occurring without sexual interest. The condition is prevalent among men with sickle cell disease (SCD). Priapism is a urological emergency which needs early intervention to avoid the risks of penile fibrosis and eventual erectile dysfunction. Due to poorly understood pathogenesis of priapism no effective approaches to manage the disorder. Recent studies have revealed excess adenosine (Ado) in priapism via Ado A2B receptor (ADORA2B), suggesting novel therapeutic possibilities. Here, we aim to conduct preclinical studies to assess the efficacy and safety of Ado-based therapy in priapism.

Materials and Methods:
ADA-deficient mice (ADA−/−) and SCD Berkeley mice are two independent priapism animal models. We treated both mice with polyethylene glycol-modified ADA (PEG-ADA) to lower penile adenosine level or PSB1115, a selective ADORA2BR antagonist. The erectile function are measured by the changes of intracavernosal pressure (ICP) induced by cavernous nerve stimulation (CNS). Penile fibrosis is evaluated by histological studies and RT-PCR analysis of fibrotic marker gene. In vitro human microvascular endothelial cells (HMECs) were used to determine mechanism underlying ADORA2B-induced priapism.

Results:
Both ADA−/− and SCD mice with elevated Ado levels in penile tissue displayed priapic feature defined by prolonged and heightened erectile in response to CNS. Chronic reduction of accumulation of penile Ado levels by PEG-ADA enzyme therapy or PSB1115 corrected the priapic feature in both priapic animal models and further prevented progression of penile fibrosis. Significantly, both HIF-1α and eNOS mRNA level were elevated but reversed by PSB1115 treatment in penile tissues of ADA−/− mice and SCD mice. Finally, we provide in vitro direct evidence that PSB1115 treatment or siRNA knockdown HIF-1α in HMECs significantly reduced Ado-induced eNOS mRNA, implicating that ADORA2B-mediated HIF-1α induction contributes to elevated eNOS mRNA and underlies Ado-mediated priapism.

Conclusions:
PEG-ADA and PSB1115 are effective and safe to treat priapism and exacerbation of the disease by decreasing penile Ado levels or interfering its signaling. This study provides direct preclinical evidence for the novel and general utility of PEG-ADA enzyme therapy or ADORA2B antagonists for priapism and sets up a solid foundation for future clinical trials to assess the usefulness of Adobased therapeutics to treat priapism.

Disclosures:
No relevant conflicts of interest to declare.
Thrombin Inhibition Prevents Against Severe Atherosclerosis Progression in Prothrombotic Mice
Authors: Spronk Henri M.H. , Borissoff Julian I , Soehnlein Oliver , Koenen Rory , van Oerle Rene , Heeneman Sylvia , Daemen Mat J.A.P. , Esmon Charles T , Degen Jay L. , Weiler Hartmut , van Ryn Joanne , Cate Hugo Ten 
Published: October 2019

Abstract
Abstract 103

Background:
Besides its well-known role in initiation and propagation of thrombus formation, thrombin may have multiple pro-atherogenic actions.

Hypothesis:
Pharmacologic thrombin inhibition attenuates the onset and progression of atherosclerosis and favors plaque stability in hypercoagulable mice prone to aggressive atherosclerosis development.

Methods and Results:
Hypercoagulability in TMPro/Pro:ApoE−/− mice resulted in severe atherosclerotic burden formation compared to ApoE−/− mice (389.1*103 μm2 vs. 187.0*103 μm2, p<0.0005). Pro-coagulant mice showed larger necrotic cores, decreased plaque collagen content, vast stenosis (up to 90%) and enhanced outward remodeling. Hypercoagulability markedly increased systemic and vascular inflammation, represented by significantly higher CXCL1, MCP-1 and G-CSF plasma levels, pronounced neutrophilia, enhanced Ly6G+ cells arrest to carotid plaques, increased neutrophil recruitment (IHC/Intravital Microscopy), massive intraplaque hemorrhage and spontaneous plaque ruptures. Genetically diminished prothrombin levels (FII-/WT:ApoE−/− mice) caused a significant decrease in atherosclerosis (72.5*103 μm2 vs. 128.4*103 μm2, p<0.01) with a pronounced stable phenotype with less/smaller necrotic cores, thicker fibrous caps and abundant collagen and vascular smooth muscle cell content. Ly6G+ cell intraplaque recruitment was reduced and white blood cell counts and IL-6 levels (3.8±1.66 vs. 8.8±5.34 pg/mL, p<0.05) were diminished compared to control mice. Remarkably, administration of the oral direct thrombin inhibitor Dabigatran etexilate or the anticoagulant activated protein C (APC) in TMPro/Pro:ApoE−/− mice reduced lesions formation by > 80%, suppressed leukocyte recruitment, enhanced plaque stability, whereas numerous pro-inflammatory cytokines were diminished to levels comparable to non-atherosclerotic mice.

Conclusion:
These data establish a pivotal role for thrombin generation in controlling the level of inflammation related to atherosclerosis development in ApoE−/− mice. The potential clinical impact of long term administration of novel classes of anticoagulants on atherosclerosis merits further study.

Disclosures:
Weiler: BloodCenter of Wisconsin: Patents & Royalties. van Ryn:Boehringer Ingelheim Pharma GmbH & Co KG: Employment.
TMEM16F Ion Channel Regulates Calcium-Dependent PS Exposure, Hemostasis, and Thrombosis
Authors: Kim Andrew Y. , Yang Huanghe , David Tovo , Tien Jason , Coughlin Shaun R , Jan Yuh Nung , Jan Lily 
Published: October 2019

Abstract
Abstract 1111
Collapse of membrane lipid asymmetry is a hallmark of blood coagulation. TMEM16F of the TMEM16 family that includes TMEM16A/B Ca2+-activated Cl− channels (CaCCs) is linked to Scott Syndrome with deficient Ca2+-dependent lipid scrambling. We generated TMEM16F-knockout mice that exhibit bleeding defects associated with platelet deficiency in Ca2+-dependent phosphatidylserine exposure and procoagulant activity, and lack a Ca2+-activated cation current in the platelet precursor megakaryocytes. TMEM16F channels permeate both monovalent and divalent cations including Ca2+, and exhibit synergistic gating by Ca2+ and voltage. We further pinpointed a residue in the putative pore region important for the cation versus anion selectivity of TMEM16F-SCAN and TMEM16A-CaCC channels. This study thus identifies a novel Ca2+-activated channel permeable to Ca2+ and critical for Ca2+-dependent scramblase activity.

Disclosures:
No relevant conflicts of interest to declare.
The Hsa-Let-7a miRNA Enhances Ara-C Induced Apoptosis in Human Acute Myeloid Leukemia Cells
Authors: Chen Ye , Jacamo Rodrigo , Konopleva Marina , Garzon Ramiro , Croce Carlo M. , Andreeff Michael 
Published: October 2019

Abstract
Abstract 1286
CXCR4 surface expression has been reported as an important prognostic marker in AML patients. Our group previously reported that targeting the SDF-1α/CXCR4 axis by CXCR4 inhibition could overcome the resistance of AML cells to chemotherapy both in vitro and in vivo. To further explore the mechanism of targeting CXCR4, we first performed a microRNA microarray platform and revealed that hsa-let-7a as one of the most significantly degraded microRNA in OCI-AML3 cells treated with SDF-1α. Moreover, hsa-let-7a was highly elevated when the OCI-AML3 cells were treated with CXCR4 antagonist. To investigate the role of hsa-let-7a in leukemia cells, we first attempted to transfect human hsa-let-7a mimic into the OCI-AML3 cells by electroporation. When exposed to chemotherapy agent AraC (2.5μM, 48 hours), the hsa-let-7a overexpressed cells exhibited 2 more folds of apoptosis than negative controls (Annexin V positive percentage: 69.8% ± 9.4 % vs 23.2% ± 2.7%, p<0.01). Next, we suppressed CXCR4 in OCI-AML3 cells with lenti-virus delivered CXCR4 shRNA (CXCR4-shRNA-OCI3) to test whether CXCR4 regulates the hsa-let-7a expression. The CXCR4-shRNA-OCI3 cells had ∼70% lower of the cell surface CXCR4 expression as evaluated by Flow cytometry (PE-conjugated 12G5 anti-CXCR4 antibodies) and ∼60% less of migration to SDF-1α compared with the vector control cells. Using RT-PCR, we observed that hsa-let-7a level was elevated in the CXCR4-shRNA-OCI3 cells (∼2.3 folds of level in the NS-shRNA-OCI3 cells). As expected, hsa-let-7a target BCLXL were significantly decreased in CXCR4-shRNA-OCI3 cells in both mRNA and protein levels, which lead to higher sensitivity to AraC treatment (Annexin V positive percentage: 48.1% ± 5.1 % vs NS-shRNA-OCI3 cells 19.1% ± 2.7%, p<0.01). To investigate whether the CXCR4 surface expression is associated with the hsa-let-7a level in patient samples, we collected bone marrow samples from AML patients after informed consent. Mononuclear cells were separated by ficoll and stained with CXCR4 antibody for cell sorting. We observed CXCR4 high expression subpopulation had significantly lower level of hsa-let-7a. c-Myc and BCLXL protein levels were much lower in CXCR4 low expression subpopulation, and it may explain that low CXCR4 expression on AML cells correlated with a better prognosis, resulting in a longer relapse-free and overall survival. Collectively, our results support that CXCR4 antagonists could mobilize AML cells from the protective stromal microenvironments and make them more susceptible to conventional therapy. These findings also showed hsa-let-7a plays an important role in AML cell chemoresistance, and suggested a new mechanism that microRNA is involved in SDF-1α/CXCR4 signaling pathway.

Disclosures:
No relevant conflicts of interest to declare.
Comparison of the Transforming Effect of Different SYK Oncogenes in Vivo Reveals TEL-SYK As Inducer of an MDS/MPS Overlap Syndrome in Mice
Authors: Sprissler Clara , Maurer Helga , Jumaa Hassan , Veelken Hendrik , Dierks Christine 
Published: October 2019

Abstract
Abstract 1310
The spleen tyrosin kinase (SYK) was shown to be overexpressed in various human hematologic malignancies like B-cell lymphomas and acute myeloid leukemias. There are two known translocations involving the SYK kinase: ITK-SYK and TEL-SYK. ITK-SYK was identified in unspecified peripheral T-cell lymphomas, whereas the TEL-SYK fusion had been discovered in a patient with myelodysplastic syndrome (MDS).

Methods:
All SYK containing oncogenes, ITK-SYK, TEL-SYK and SYK wt, were cloned into a pMSCV-IRES-GFP retroviral vector. All oncogenes and a GFP control vector were overexpressed in bone marrow of 5-flurouracil-pretreated mice and oncogene containing bone marrow was transplanted into irradiated recipient mice. Disease development was monitored over 1 year. Additionally the three SYK oncogenes were overexpressed in a myeloid (32D), B-lymphoid (BaF3) and T-cell lineage (Jurkat) to monitor cell context specific differences in cell signaling.

Results:
Here, we demonstrate that the overexpression of 3 SYK containing oncogenes, SYK wt, TEL-SYK and ITK-SYK in a murine bone marrow transplantation model induces the development of 3 different hematologic (pre)diseases. While ITK-SYK exclusively induced T-cell lymphomas in mice, we found that the TEL-SYK fusion induced an MDS/MPS overlapsyndrom. The mice developed an anemia and thrombopenia with signs of dysplasia of megakaryocytes and the erythroid lineage in the bone marrow and spleens. In addition those mice showed a strong expansion of the myeloid lineage, with leucocytosis in the peripheral blood mainly consisting of differentiated neutrophils. The bone marrow shows expansion of differentiated myeloid cells, but also myeloid progenitors and expansion of HSCs. Interestingly, also SYK wt induced a relative expansion of the myeloid compartment without inducing a leucocytosis or a lethal disease indicating a premalignant myeloproliferative state. Only TEL-SYK was able to induce IL-3 independent growth of BaF3- and 32D cells and could activate STAT5, STAT6, ERK, PLCγ2 and SLP76 in those cell lines. SYK and ITK-SYK were able to activate PLCγ2 and SLP76, but no STAT transcription factors. STAT5 activation by TEL-SYK was detectable also in vivo, which might indicate STAT5 as the major driver of TEL-SYK induced transformation.
Our results demonstrate, that the various SYK oncogenes can induce different hematologic diseases in mice and reveales TEL-SYK as the first oncogene inducing an MDS/MPS overlap syndrome in mice.

Disclosures:
No relevant conflicts of interest to declare.
MLL Fusion Driven Activation of CDK6 Potentiates Proliferation in MLL-rearranged Infant ALL
Authors: van der Linden Marieke Hendrika , Willekes Merel , Van Roon Eddy , Schneider Pauline , Pieters Rob , Stam Ronald 
Published: October 2019

Abstract
Abstract 1426
MLL-rearranged acute lymphoblastic leukemia represents a highly aggressive and clinically unfavorable type of childhood leukemia, displaying unique gene expression signatures. Nevertheless, the overwhelming number of differentially expressed genes made it difficult to elucidate the actual “drivers” of the leukemia. However, recent advances demonstrated that MLL fusion proteins recruit the histone methyltransferase DOT1L, leading to H3K79 methylation. Hence, genomic regions displaying aberrant enrichment of H3K79 methylation are prone to mark genes transcriptionally activated by the MLL fusion protein itself. Based on this concept, two independent studies recently identified gene signatures consisting of genes likely to represent direct MLL fusion targets. Yet, functional validation of such genes so far remains unacknowledged. In the present study we confirmed that CDK6 (cyclin-dependent protein kinase 6) represents a direct target of MLL-AF4 in t(4;11)-positive ALL cells. In contrast to its functional homologue CDK4, ChIP-sequencing analysis showed the presence of both MLL and AF4, as well as H3K79 methylation at the CDK6. Moreover, CDK6 mRNA appeared significantly (p<0.001) higher expressed in primary MLL- rearranged infant ALL patient samples when compared with other childhood ALL subtypes without translocations of the MLL gene. Next, using RNA interference, we performed MLL-AF4 and MLL-ENL knockdown experiments in ALL cell lines bearing these corresponding fusion transcripts, resulting in CDK6 down-regulation, whereas CDK4 expression was unaffected. These results emphasize that CDK6 is indeed a genuine transcriptional target of the MLL fusion protein itself. Moreover, direct knockdown of CDK6 itself significantly inhibited proliferation in MLL-rearranged ALL cells, whereas knockdown of CDK4 virtually had no effect on the cell cycle in these cells.
Taken together we conclude that CDK6 up-regulation in MLL-rearranged ALL is directly mediated by the MLL fusion itself and provides these cells with a proliferation advantage.

Disclosures:
No relevant conflicts of interest to declare.
Incidence, Age, and Gender of Children with Thrombotic Thrombocytopenic Purpura (TTP) Associated with Severe, Acquired ADAMTS13 Deficiency.
Authors: Muthurajah Darrshini S. , George James N. , Vesely Sara K. , Terrell Deirdra R. 
Published: October 2019

Abstract
Abstract 2196

Introduction
TTP associated with severe acquired ADAMTS13 deficiency has been rarely reported among children. Specific aims: [1] To identify all published reports of TTP associated with acquired ADAMTS13 deficiency in children <18 years old and document the age and gender distribution. [2] To document the incidence in the Oklahoma TTP-HUS Registry region of TTP associated with acquired ADAMTS13 deficiency (activity <10%) in children <18 years old.

Methods
Systematic literature review using MEDLINE, PubMed, Embase, Cochrane, and CINAHL databases. Comprehensive search terms for TTP, HUS, and children were combined with the term, ADAMTS13. Bibliographies of selected articles were reviewed. Incidence was calculated using person-years of all children < 18 years old in the Registry region (58 counties) over the 16.5 year period (January 1, 1996 to June 30, 2012) using 2000 census data.

Results
The systematic literature search identified 22 publications reporting 53 children with acquired ADAMTS13 deficiency. Their age and gender are presented in the Figure. Two-thirds of children were ages 9–17 years. Among the 18 children ages 0–8 years, 8 (44%) were girls; among the 35 children ages 9–17 years, 24 (69%) were girls. The relative frequency of the older children was greater than younger children (p=0.02). Although there were more girls than boys reported, the difference was not significant (p=0.13). From January 1, 1995 to June 30, 2012, 72 patients with acquired ADAMTS13 deficiency were enrolled in the Oklahoma TTP-HUS Registry; one patient was less than 18 years old. The calculated incidence for the Oklahoma Registry region was 0.10/106 children/year.

Conclusion
The Oklahoma Registry experience documents for the first time the incidence of TTP associated with acquired ADAMTS13 deficiency in children: 0.10/106 children/year, 6% of our previously calculated incidence rate of 1.74/106/year for all patients with TTP and acquired ADAMTS13 deficiency (J Thromb Haemost 2005;3:1432). The age and gender distribution of children in published case reports suggests that TTP associated with acquired ADAMTS13 deficiency in children is not a distinct juvenile disorder, but more likely a continuum of the spectrum of TTP in adults (J Thromb Haemost 2005;3:1432).

Disclosures:
George: Alexion, Inc.: Consultancy; Baxter, Inc.: Consultancy; Amgen, Inc.: Consultancy, PI of clinical trial involving romiplostim, PI of clinical trial involving romiplostim Other, Research Funding. Terrell:Baxter, Inc.: Consultancy; Amgen, Inc.: Consultancy.
Stromal Cells Expressing Hedgehog-Interacting Protein Are One of the Main Regulators of the Hedgehog Signaling System in Myeloid Neoplasms
Authors: Kobune Masayoshi , Horiguchi Hiroto , Kikuchi Shohei , Iyama Satoshi , Takada Kohichi , Murase Kazuyuki , Ono Kaoru , Kamihara Yusuke , Kawano Yutaka , Hayashi Tsuyoshi , Sato Tsutomu , Miyanishi Koji , Sato Yasushi , Takimoto Rishu , Kato Junji 
Published: October 2019

Abstract
Abstract 3840
Aberrant reactivation of Hedgehog (Hh) signaling has been described in a wide variety of human cancers including cancer stem cells. However, involvement of the Hh signaling system in the bone marrow (BM) microenvironment during the development of myeloid neoplasm is unclear. In this study we assessed the expression of Hh-related proteins in normal human CD34+ cells, CD34+ leukemic/dysplastic cells and BM stromal cells. Both Indian hedgehog (Ihh) and its signal transducer, SMO, were expressed in CD34+ acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) derived cells, suggesting that Ihh could be affected in an autocrine manner. Remarkably, expression of the endogenous Hh signaling inhibitor, human hedgehog-interacting protein (HHIP), in AML/MDS-associated stromal cells was significantly lower than in healthy donor-derived stromal cells. Moreover, HHIP expression level in BM stromal cells highly correlated with their tumor-supporting activity of SMO+ leukemic cells. Demethylating agent 5-aza-dC rescued HHIP expression via demethylation of HHIP gene and reduced the leukemia-supporting activity of AML/MDS-associated stromal cells. This effect of 5-aza-dC was negated by HHIP shRNA transfer into stromal cells. These results indicate that suppression of stromal HHIP expression could be involved in the progression of AML/MDS and 5-aza-dC may improve the protective function of BM stromal cells for AML/MDS.

Disclosures:
No relevant conflicts of interest to declare.
ERK1/2 Pathway Is Required for Differentiation of AML Triggered by Anti-CD44 Monoclonal Antibodies
Authors: Al-Madhoun Nour Y. , Gadhoum Samah Zeineb , Merzaban Jasmeen S. 
Published: October 2019

Abstract
Abstract 4334
Acute myeloid leukemia (AML) is a heterogeneous disease characterized by accumulation of immature hematopoietic cells due to a blockage in myeloid differentiation at various stages. Since the current chemotherapy rarely eradicates the leukemic clones entirely, differentiation induction therapy has evolved. Previous experiments have shown that ligation of CD44, a cell surface glycoprotein strongly expressed on all AML cells, with anti-CD44 monoclonal antibodies (mAbs) could reverse the differentiation blockage of leukemic blasts and inhibit their proliferation in most AML subtypes, rendering CD44 a promising target for AML therapy. However, the underlying molecular mechanisms of the induction of differentiation by anti-CD44 mAbs have not been fully elucidated. Here, we investigated the signaling pathways triggered during anti-CD44 mAb (A3D8)-induced granulocytic differentiation of HL60, a human leukemic cell line commonly used as a model of human AML type2/3.
Extracellular signal regulated kinase (ERK1/2) pathway plays a major role in the regulation of differentiation and proliferation for myeloid cells and has been reported to be aberrantly activated in AML. In our studies, we observed an increase of ERK1/2 phosphorylation by mitogen-activated ERK kinase (MEK) following A3D8 treatment. The use of U0126 (a MEK inhibitor) significantly abrogated the anti-CD44 induced granulocytic differentiation of HL60 cells, suggesting that ERK1/2 is critical for the induction of differentiation via CD44 in AML-M2/3. Our work provides the first evidence for the importance of the ERK pathway in granulocytic differentiation via CD44 and adds a new argument to the use of CD44 in differentiation therapy of AML.

Disclosures:
No relevant conflicts of interest to declare.
New Characteristics of Translocation in Anaplastic Large T-Cell ALK-Positive Lymphoma
Authors: Gorenkova Liliya , Kravchenko Sergei , Misurin Andrei , Vinogradova Yulia , Penskaya Ekaterina , Gemdjian Eduard G. , Savchenko Valeri G. 
Published: October 2019

Abstract
Abstract 4419

Background
ALK-Positive Anaplastic Large Cell Lymphoma (ALCL ALK+) represent 5–15% of all non-Hodgkin in children and 5% in adults and characterized by the specific chromosome translocations, which lead to the break of gene ALK. Currently describe 9 translocations. All of them have no prognostic significance.

Purpose
We present a case of ALCL ALK+ with a new chromosomal rearrangement involving locus gene 2p23 and poor response to therapy.
Case presentation. A 24-year old woman presented to our clinic with a month history of right axillar tumor 20×9 sm. Full examination reveals B-symptoms, the involvement of the mammary gland, generalized lymphadenopathy and splenomegaly.
The diagnosis ALCL ALK+ was made on the base of CD30 and ALK expression and ALK gene rearrangement. Cytogenetic analysis showed a normal karyotype including a new translocation t(2;8)(p23;q22). In our centre we provided the pilot study of the efficacy of the protocol NHL BFM-90 in adult ALCL ALK+. Overall five-year survival rate is 90%±6% (n=25).
The patient was treated according to the program, branch K3 (6 cycles AA-BB-C-AA-BB-C, the dose of methotrexate 5 g/m2). The remission was achieved after 4 cycle. CNS prophylaxis was made in the first cycle of the chemotherapy (intrathecal administration of methotrexate 15 mg, cytarabine 30 mg and dexamethasone 4 mg).
A weak after the last cycle of the chemotherapy the patient complained of intensive headache. Neuroleukemia was diagnosed (100 cells in μl large anaplastic cells expressed CD30, ALK, and have ALK rearrangement). Full examination revealed no other tumor lesions. The patient was treated with 10 intrathecal administration of methotrexate, ara-C and dexamethasone. The normalization of the cerebrospinal fluid was after the 7th lumbar puncture. Currently the patient is treated following chemotherapy program for relapsed lymphomas.

Conclusions
we presented a case of primary progressive course of ALCL ALK+ with a new chromosomal rearrangement t(2;8)(p23;q22). To the best of our knowledge and after literature search this appears to be a new cytogenetic abnormality in ALCL ALK+. It was the first case of progression of ALCL ALK+ on the intensive program NHL BFM-90 in adults in our experience. So we propose that this translocation may be associated with unfavorable prognosis. Further trials and study of pathogenesis of t(2;8)(p23;q22) to confirm our observation.

Disclosures:
No relevant conflicts of interest to declare.