bluuebunny/crossref_metadata_2025_split huggingface dataset:
Epigenetic Signaling Is Required for HoxA9-Based Leukemic Transformation.
Authors: Chaubey Aditya , Velu Chinavenmeni S. , Horman Shane , Jegga Anil , Guzman Monica L. , Risner Laurie , Zeleznik-Le Nancy J. , Jordan Craig T. , Carroll Martin , Gebelein Brian , Grimes H. Leighton 
Published: October 2019

Abstract
Abstract 3966
Poster Board III-902
Since oncogenic activation of HoxA9 is induced by multiple chromosomal translocations affecting MLL1 (11q23)(e.g. MLL-Af9) or Nup98 (11p15)(e.g. Nup98-HoxA9 or Nup98-Nsd1), the function of the HoxA9 transcription factor is of critical interest in human acute myeloid leukemia (AML). HoxA9 forms heterodimeric DNA binding complexes with members of the Pbx and/or Meis family of homeodomain proteins. Importantly, the direct transcriptional targets of endogenous HoxA9 that mediate transformation remain largely unknown. The Growth factor independent-1 (Gfi1) transcriptional repressor is known to induce granulopoiesis and inhibit myeloid progenitor proliferation. GFI1 is mutated in patients with severe congenital neutropenia (SCN). SCN patients are at increased risk for AML. In a transcriptional circuit conserved to Drosophila, we have recently shown that Gfi1 represses HoxA9, Meis1 and Pbx1 expression, that Gfi1 and HoxA9 demonstrate dramatic epistatic relationships, and that Gfi1 loss of function is potently preleukemic. Our new bioinformatic, biochemical and expression data reveal microRNA genes to be targets of endogenous HoxA9 versus Gfi1 antagonism. Moreover, these miR are activated by Hox-signaling leukemia oncoproteins. Next, in both murine leukemia models and primary human AML samples, antagomir-mediated inhibition of microRNA function specifically disrupts oncogenic signaling by HoxA9, Nup98-HoxA9 and MLL-Af9 (but not AML-ETO which does not signal through HoxA9). In vivo, antagomir treatment blocked MLL-Af9-initiated leukemia lethality. These data establish microRNA genes as functional downstream targets of endogenous HoxA9, and implicate epigenetic signaling as critical client/mediators of Hox-based leukemia oncoproteins.

Disclosures:
No relevant conflicts of interest to declare.
Connecticut Attorney General Blumenthal's Citizen Petition Regarding Thalidomide-Associated VTE Redux: Patient Safety Concerns Still Persist.
Authors: McKoy June M. , Boen Monica , Deleon Dianne , Feliciano Josephine , Courtney D. Mark , Bennett Charles L. 
Published: October 2019

Abstract
Abstract 3990
Poster Board III-926

Background
In 2005, the first ever Citizen Petition filed by a State Attorneys General, Attorney General Richard Blumenthal, requested that the FDA adopt 6 measures to improve VTE prophylaxis and patient safety of thalidomide (thal). While 4 recommendations were accepted, the FDA refused to mandate a Phase IV randomized, controlled trial designed to identify the best VTE prophylaxis stating that substantial data already existed, but no specific prophylaxis was identified. We review the progress of this safety concern pre- and post-FDA approval of thal in 2006, specifically for the use of multiple myeloma patients. Similar safety concerns apply to lenalidomide.

Methods
A literature search was performed from 2006 to 2009 through Pubmed and Ovid using the key words “thalidomide,” “lenalidomide,” “thrombosis,” and “multiple myeloma.” High dose thal was defined as higher than 200mg/d, low dose thal as 200mg/d or lower, and high dose dexamethasone (dex) as higher than 20mg/d and low dose dex as 20mg/d and lower.

Results
See table

Conclusion
Since 2006, we have found information on 2657 patients with no prophylaxis, 539 patients with thal/dex with prophylaxis, and 2210 patients with len/dex with prophylaxis. VTE rates remain high, except for the low dose thal and/or low dose dex group. Overall, optimal VTE prophylaxis remains an enigma. Current recommendations for VTE prophylaxis are not supported by empirical data. Against this backdrop, Blumenthal's team should consider resubmitting their safety request.

Disclosures:
No relevant conflicts of interest to declare.
Residual Vein Thrombosis Improves Screening for Occult Cancer: Results On 537 Patients with Idiopathic Deep Vein Thrombosis.
Authors: Siragusa Sergio , Malato Alessandra , Fulfaro Fabio , Saccullo Giorgia , Caramazza Domenica , Pizzo Giusy , lo Coco Lucio , Gebbia Nicola 
Published: October 2019

Abstract
Abstract 3999
Poster Board III-935

Background
Clinical advantage of extensive screening for occult cancer in patients with idiopathic Deep Vein Thrombosis (DVT) is unknown. We have demonstrated that the Residual Vein Thrombosis (RVT)-based screening for occult cancer improves early detection as well as cancer-related mortality (Siragusa S et al. Blood 2007;110(699):OC). Here we report on final analysis of 537 patients over a period of 8 years.

Objective of the study
We conducted a prospective study evaluating whether a RVT-based screening for cancer is sensitive and influences cancer-related mortality.

Study design
Prospective with two cohorts of DVT patients: the first cohort was monitored for clinical overt cancer only (Group A), while the second (Group B) received complete screening for occult neoplasm and subsequent surveillance.

Materials and methods
Consecutive patients with a first episode of DVT who presented RVT after 3 month of anticoagulation and without signs and/or symptoms for overt cancer. Screening for occult cancer was based on: ultrasound and/or CT scan of the abdomen and pelvis, gastroscopy, colonoscopy or sigmoidoscopy, hemoccult, sputum cytology and tumor markers. These tests were extended with mammography and Pap smear for women and ultrasound of the prostate and total specific prostatic antigen (PSA) for men. All investigations had to be completed within four-weeks from the assessment of RVT. All patients were followed-up for at least 2 years. Incidence and cancer-related mortality was compared between the two groups by survival curves (Kaplan-Mayer) and related Breslow test for statistics.

Results
Over a period of 8 years, 537 patients were included in the analysis: first cohort included 346 patients (Group A), second cohort 191 (Group B). Clinical characteristics between groups were homogenous. During the follow-up, 8.3% of patients developed overt cancer in group A; in group B, 7.8% of patients had diagnosed cancer at the moment of extensive screening while 2 new cases (0.7%) occurred during the follow-up (Table). The sensitivity of this approach was 92.1% (95% confidence intervals 75.2-104.2). Cancer-related mortality was 7.5% in group A and 3.6% in group B (p< 0.001).

Conclusions
The RVT-based screening for occult cancer is highly effective for improving early detection as well as cancer-related mortality in a cohort of 537 patient with DVT of the lower limbs.

Disclosures:
Off Label Use: Hydroxyurea use in myelofibrosis.
Thrombospondin-1 and ADAMTS13 Competitive Binding with VWF Mainly in Both A2 and A3 Domain.
Authors: Wang Anyou , Dong Ningzheng , Ma Zhenni , Zhang Jingyu , Su Jian , Ruan Changgeng 
Published: October 2019

Abstract
Abstract 4008
Poster Board III-944

Introduction
Thrombospondin-1 (TSP1) is one multifunctional glycoprotein belonging to the thrombospondins family. It is mainly synthesized by megakaryocytes, stored in the intermediate zone of platelet -granules, and secreted by platelets upon thrombin activation. TSP1 has been postulated to play an important role in hemostasis for a long time. Recently, in a TSP1 knockout mouse, study showed that TSP1 protected unfolded endothelium-bound and subendothelial VWF from degradation by its plasma protease ADAMTS13, however, concrete mechanism that how to inhitbit ADAMTS13 activity by TSP1 was unclear.

Materials and Methods
we constructed and expressed different domains of human VWF, mainly including D'D3, A1, A2, A3 domain, full-length VWF and ADAMTS13, then investigated the binding effect of TSP1 or ADAMTS13 with these different domains and full-length VWF by enzyme linked immunosorbent assay. We also observed the direct inhibition effect of different concentrations TSP1 on ADAMTS13 activity by Western blot method and residual-collagen binding assay (R-CBA) in denaturing condition and high shear stress condition

Results
We found that ADAMTS13 could interact with the A1, A2, A3 domain and full-length VWF, and TSP1 could bind with the A3 domain. Meanwhile, we observed that TSP1 also had significant interaction with the A2 domain. And TSP1 competed with ADAMTS13 mainly existing in both A2 and A3 domain. The results of Western blot and R-CBA also showed that TSP1 dramatically restrained ADAMTS13 activity, especially at high concentrations, and the inhibitory effect could add up to 50%.

Conclusions
Our study showed that TSP1 played competitive inhibitor role during ADAMTS13 binding and cleaving VWF, and the competitive process maybe mainly exist in both A2 and A3 domain.

Disclosures:
No relevant conflicts of interest to declare.
Shear-Induced Von Willebrand Factor-Mediated Platelet Glycoprotein Ibα Shedding.
Authors: Cheng Hong , Yan Rong , Li Suping , Yuan Yanhong , Liu Jun , Ruan Changgeng , Dai Kesheng 
Published: October 2019

Abstract
Abstract 4024
Poster Board III-960

Introduction
Shear-induced platelet adhesion through the interaction of glycoprotein (GP) Ibα with von Willebrand factor (VWF) exposed at the injured vessel wall or atherosclerotic plaque rupture is the first step for the physiological hematosis or pathologic thrombus formation in stenosed arteries. However, the role of shear stress in the regulation of platelet function remains poorly defined. Methods: Washed platelets were exposed to VWF-coated surface at different shear conditions, provided by syringe pump connecting with glass capillary or cone-and-plate viscometer. GPIbα shedding was investigated by flow cytometry and western blot.

Results
GPIbα ectodomain was shed from platelets, while a small mass of GPIbα C-terminal peptide around 17 kDa was increased correspondingly. Although GPIbα ectodomain shedding was found under all shear conditions, the extent of GPIbα shedding was maximum at 250/s and dramatically reduced with increased shear rate, which was consistent with the number of stable adhesive platelets. There was a correlation between the levels of platelet adhesion and the extent of GPIbα shedding. Furthermore, GPIbα shedding increased with the concentration of immobilized VWF and time duration (within 1 minute) of constant shear stress. The potential protease(s) and signaling pathway involved in this process were investigated. Pretreatment of platelets with membrane-permeable calpain inhibitors (MDL28170, calpain inhibitor I and II) and metalloproteinase inhibitor (GM6001) abolished shear-induced GPIbα shedding. Though platelets showed partial activation detected by PAC-1 binding, GPIbα shedding was not impacted by apyrase and PGE1. However, integrin αIIbβ3 antibody (SZ-21) and phosphoinositide 3-kinase inhibitors (wortmanine) obviously inhibited GPIbα shedding. Conclusions: These results indicate that shear-induced platelet-VWF interaction results in calpain and metalloproteinase-dependent GPIbα ectodomain shedding. Fluid shear stress and VWF always exist in both the normal circulation of blood and pathological medical conditions, particularly, the interaction of GPIbα with VWF under flow initiates platelet adhesion and thrombus formation. Thus, the current finding that shear-induced the interaction of GPIbα with VWF incurs GPIbα ectodomain shedding not only has physiological implication in understanding the presence of glycocalicin in normal circulation, but also suggests a novel mechanism for the negative regulation of platelet function and the limitation of platelet thrombus growth under pathophysiological flow conditions.

Disclosures:
No relevant conflicts of interest to declare.
Role of Upstream cAMP Response Element (CRE) in γ-Globin Gene Regulation.
Authors: Ramakrishnan Valya , Bhattacharya Kajari , Pace Betty 
Published: October 2019

Abstract
Abstract 4076
Poster Board III-1011
The reactivation of fetal hemoglobin has been shown to ameliorate symptoms of sickle cell disease. Previous work from our laboratory demonstrated that histone deacetylase inhibitors such as Trichostatin A and sodium butyrate activate γ-globin gene expression via p38 MAPK signaling. Using a transient luciferase genetic reporter system, the trans-factors cAMP response element binding protein 1 (CREB1) and activating transcription factor-2 (ATF-2) were shown to trans-activate the Gγ-globin CRE, located upstream at nucleotide -1222. To study this regulatory element in a native chromatin conformation, we cloned the Gγ-globin promoter (-1500 to +36) into pGL4.17 Luc2/neo to produce the pGγLuc2 reporter construct. In addition, three mutant plasmids were created by site directed mutagenesis including the -1225 G/A mutation (pGγLuc2m1), -1227 AC/TG mutations (pGγLuc2m2) and a scrambled G-CRE, 5'-TCTATGTA-3' (pGγLuc2m3S). Each reporter along with the empty vector control (pGL4.17 Luc2/neo) was transfected into K562 cells and five stable lines including KLuc2, KGγLuc2, KGγLuc2(m1), KGγLuc2(m2) and KGγLuc2(m3s) were established using the G418 selectable marker. Luciferase activity in KGγLuc2 was 700-fold higher than the promoterless Kluc2 stable line. When the G-CRE element was mutated, we observed a 70 to 80 % decrease (p<0.05) in luciferase activity in the three mutant lines. Furthermore, a loss of Gγ-promoter inducibility was observed in the mutant lines. Treatment with butyrate (2mM) or Trichostatin A (0.5μM) resulted in a 3-fold increase of luciferase activity for the wild-type KGγLuc2 line while a 5-fold loss of inducibility was observed in the mutant stable lines. These studies support a functional role for the G-CRE in γ-globin transcription. To expand our understanding of p38 MAPK signaling in G-CRE function, siRNA studies were completed. In wild-type K562 cells, p38 siRNA molecules produced a 95% decrease in target p38 MAPK mRNA levels and a concomitant 65% loss of γ-globin expression was observed. This demonstrated that p38 MAPK is required for steady-state γ-globin gene transcription. When p38 MAPK siRNA knockdown was performed in the KGγLuc2 stable line we observed 30% reduction in luciferase activity, while this effect was lost in the mutant stable lines. Additional siRNA studies will be completed in the stable lines to determine if the target trans-factors CREB1 and ATF-2 mediate the effect of p38 MAPK in the context of chromatin. Chromatin immunoprecipitation assay will also be performed to determine in vivo binding to the G-CRE. Elucidating regulatory elements involved in γ-globin gene regulation will provide novel approaches for fetal hemoglobin induction as a treatment for sickle cell disease.

Disclosures:
No relevant conflicts of interest to declare.
Indirubin-3-Monoxime Induces Apoptosis and Autophagy in Human Lymphocytic Leukemia Cells and Human Chronic Myelogenous Leukemia Cells.
Authors: Lee Ming-Yang , Chuang Jing-Jing , Liu Yi-Wen 
Published: October 2019

Abstract
Abstract 4106

Introduction
Indirubin-3-monoxime (IO) is the active ingredient of Danggui Longhui Wan, a mixture of plants that is used in traditional Chinese medicine. It is a potent inhibitor of cyclin-dependent kinases (CDKs), especially CDK2. In clinical studies demonstrated that indirubin did not cause major side effects in patients with chronic myelogenous leukemia. However, the functional action of indirubin on acute lymphoblastic leukemia (ALL) is still unclear. In the present study, we investigated that cytotoxic effect and mechanism study of IO in human acute lymphocytic leukemia cell line JM1 and human chronic myeloid leukemia cell line K562. We also analyzed the viability influence of IO in normal human granulocytes and lymphocytes.

Materials & Methods
After the treatment of IO, cell viability of JM1 and K562 cells was determined by WST-1 assay. The influence of IO on cell-cycle distribution was analyzed by FACScan. To identify which cell death types were induced during IO treatment we measured the caspase-3 activity for analysis the induction of apoptosis; evaluated the LDH release in the necrotic analysis and the expression level of LC3-II was determined by Western blotting analysis for autophagic cell death. Furthermore, we also analyzed the toxicity of IO in normal human granulocytes and lymphocytes by the treatment dose of IO with value of IC50.

Results
IO significantly affected the cell viability on JM1 but also on K562 cells in a dose dependent manner. The G2/M phase of cell cycle was arrested and sub-G1 proportion was relative increased. In addition, the finding showed that IO initiated caspase-3-dependent apoptosis in JM1 and K562 cells. The expression of autophagosome-incorporated LC3-II protein was also clearly increased once cells treated with IO. However, the necrotic phenomenon through measuring LDH release from K562 and JM1 cells could not be observed. Excitingly, by the treatment dose of IO with value of IC50, the cell viability of lymphocytes was marginally affected, whereas the cell cytotoxitity of granulocytes was not induced.

Conclusions
IO has the ability to induce potent cytotoxic effect on K562 and JM1 cells. The cell death after IO treatment is mainly caused by apoptosis and autophagy, not by necrosis. This effect is also associated with interrupted cell cycle. Importantly, IO has few or little cytotoxic effect on human lymphocytes and granulocytes. The results suggest that IO might be useful for clinical anti- ALL treatment.

Disclosures:
No relevant conflicts of interest to declare.
Surgery Treatment and Pathological Results of Patients of Malignant Hematological Disorders Complicated with Lung Diseases.
Authors: Tang Xiaowen , Huang Haoyue , Zhan Shenghua , Sun Xingwei , Shi Xiaolan , Sun Aining , Shen Zhenya , Kang Suya , Depei Wu , Jin Zhengming , Qiu Huiying , Miao Miao , Fu Chengcheng , Han Yue , Chen Suning , Xue Shengli , Ma Xiao 
Published: October 2019

Abstract
Abstract 4107

Objectives
To determine the pulmonary pathological changes in patients of hematological malignancies with pulmonary complications using surgical or thoracoscopic technologie.

Methods
17 hematological malignant patients who underwent surgical treatment were evaluated retrospectively in our study. Pulmonary infection was presented in 14 cases following chemotherapy, and lesions can not be completely absorbed after a broad-spectrum anti-bacterial and anti-fungal treatment. Furthermore, computerized tomographic scanning showed that there remained several kinds of localized lesions. Subsequently, all the 17 patients underwent open lung or thoracoscopic biopsies (lobar, partial, or wedge resection). The pathological changes of all the surgical specimens were examined postoperatively by standard hematoxylin and eosin staining.

Results
Pathological examination confirmed: Aspergillus infection in 9 patients, sub-acute inflammation (fibrosis and hematoma formation) in 3 patients, pulmonary infarction with granulomatous tissue in the periphery in 1 patient, granulomatous inflammation with calcified tubercle in 1 patient, alveolar dilation and hemorrhage, interstitial fibrosis and focal vasculitis in 1 patient, intercostal neurilemmoma in 1 patient, and moderate-differentiated adenocarcinoma accompanied by intrapulmonary metastasis in 1 patient. And several operative complications (1 case of fungal implantation, 3 cases of pleural effusion and adhesions and 2 cases of pulmonary hematoma) were occurred. The coincidence rate of pre- and post-operative diagnosis was 9/14 (64.3%). After surgery, 8 patients were received hematopoietic stem cell transplantation (HSCT, allo-gene or autologous), in which 7 cases were succeeded. Following the effective secondary antifungal prophylaxis,4 of 5 patients of aspergillosis were succeeded in transplantation free from mycotic relapse,just one patient was dead from fungal relapse.

Conclusion
Hematological malignancies with certain pulmonary complications, that is, persistent and/or medical-management-resistant pulmonary infection, hemoptysis, or lung diseases of diagnosis unknown, should be treated in time by surgical resection to effectively eliminate the residual disease and to achieve definitive diagnosis, so as to create a prerequisite condition for the following treatments. Moreover, the secondary antifungal prophylaxis could provide positive roles in protecting patients scheduled for chemotherapy and/or HSCT.

Keywords
hematological malignancies; immunocompromise; pulmonary aspergillosis; pulmonary resection; histopathology ; secondary antifungal prophylaxis

Disclosures:
No relevant conflicts of interest to declare.
CD22 Expression in Pediatric B-Lineage Acute Lymphoblastic Leukemia.
Authors: Jegalian Armin G. , Wayne Alan S. , Kreitman Robert J. , Mussai Francis J. , Pastan Ira , Yuan Constance M. , Stetler-Stevenson Maryalice 
Published: October 2019

Abstract
Abstract 4119
While the majority of pediatric patients with newly diagnosed B-lineage acute lymphoblastic leukemia (ALL) are cured with standard chemotherapy regimens, treatment is associated with multiple toxicities, and ALL remains the most frequent cause of cancer mortality in childhood. CD22, a B-lineage surface glycoprotein involved in B cell signaling and adhesion, is expressed in most cases of B-lineage ALL. We are conducting clinical trials of anti-CD22 immunotoxins [RFB4(dsFv)-PE38] for pediatric ALL. To assess eligibility for such targeted therapy, CD22 expression by ALL cells was studied in peripheral blood and/or bone marrow aspirate samples from 50 patients with relapsed ALL. The level of CD22 expression by ALL cells was quantitated by measuring mean anti-CD22 antibody binding per ALL cell (ABC) under saturating conditions using flow cytometry and the BD Biosciences QuantiBRITE system for fluorescence quantitation. Patients ranged in age from 3 to 22 years (median 10 years) and included 27 males and 23 females. CD22 expression was detected in all samples, and the vast majority of cases demonstrated expression of CD22 in 100% of leukemic blasts. CD22 antigen density in ALL cells varied widely among patients at baseline (range 451 - 14,519; mean 4276; median 3824; standard deviation 2976; see graph). CD22-directed immunotoxin therapy was initiated in 29 of the 50 patients, 19 of whom had samples quantitated for CD22 expression levels both before and after immunotoxin therapy. Most patients exhibited limited variation in the mean number of anti-CD22 molecules bound per ALL cell when comparing multiple specimens. In conclusion, CD22 expression varies widely in pediatric B-lineage ALL and persists despite repeated exposure to CD22-directed therapy.
(MedImmune, LLC, sponsored the clinical studies of anti-CD22 immunotoxin CAT-8015.)

Disclosures:
No relevant conflicts of interest to declare.