bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Optimal Duration of Anticoagulant Therapy In Patients with Cancer-Related Deep Vein Thrombosis: The Advantage of Using Residual Vein Thrombosis (the Cancer-DACUS Study)
Authors: Siragusa Sergio , Malato Alessandra , Mascheroni Doris , Ageno Walter , Bucherini Eugenio , Spadaro Pietro , Imberti Davide , Saccullo Giorgia , Coco Lucio Lo , Rotondo Stefano , Santoro Rita , Micco Pierpaolo Di , Oriana Vincenzo , Urbano Oreste , Prantera Tullio , Recchia Francesco , D'Alessio Andrea , Gallucci Pina , Ghirarduzzi Angelo , Cormaci Oreste , Caracciolo Clementina , Abbadessa Vincenzo 
Published: October 2019

Abstract
Abstract 190
Type and duration of anticoagulation is still matter of debate in cancer patients with acute Deep Vein Thrombosis (DVT) of the lower limbs. Residual Vein Thrombosis (RVT) has been proven to be effective for assessing the optimal duration of oral anticoagulants in non cancer patients (Siragusa S et al Blood 2008:112:511-5). In the present study we evaluate the role of a RVT-based management of anticoagulation with Low-Molecular Weight Heparin in cancer patients with acute DVT.

Materials and Methods.
Patients with active cancer and a first episode of DVT were treated with LMWH for 6 months (the first month at full dosage followed by dose reduction of 25% in the next 5 months). At the end of treatment, they were managed according to RVT findings: those with RVT were randomized to continue anticoagulants for 6 additional months (Group A1) or to stop it (Group A2), while patients without RVT stopped LMWH (Group B). Outcomes were recurrent venous thromboembolism and/or major bleeding; patients were followed up for one year after LMWH discontinuation.

Results.
Over a period of 36 months, 409 patients were evaluated; 62 were excluded (refusal, need for continuing anticoagulation, etc). In total, 347 were included in the study (Table 1). RVT was detected in 242 (69.7%) patients; recurrent events occurred in 21.9% of those randomized to discontinue and 14.2% of those who continued LMWH. In patients without RVT (105, 30.3%), recurrent events occurred in 3 cases (2.8%) (Table 2 and Figure 1). The adjusted Hazard Ratio (HR) for age and sex between RVT groups (Group A2 vs A1) was 1.58 (95% confidence interval [CI], 0.85–2.93; P=.145). The adjusted HR between group A1 versus RVT-negative group (B) was 4.54 (CI 2.3–6.66; P =.028). Five major bleeding events occurred in Group A1 and two events both in Group A2 and B (Table 2). Overall, 89 (25.6%) patients died due to cancer progression after a median follow-up of 10.2 months after heparin withdrawn.

Conclusions.
The Cancer DACUS is the first ever study evaluating an individual marker for assessing duration of anticoagulation in active cancer population. Final results of the study show that absence of RVT identifies a group of patients at low risk for recurrent thrombosis who can safely stop LMWH after 6 months.

Disclosures:
No relevant conflicts of interest to declare.
Hydroxyurea Treatment In 1075 Patients with Essential Thrombocythemia and Occurrence of Extra-Hematological Adverse Events: A Preliminary Report of the Registro Italiano Trombocitemia (RIT)
Authors: Gugliotta Luigi , Papayannidis Cristina , Piccin Andrea , Tieghi Alessia , Vianelli Nicola , Scalzulli Potito Rosario , Candoni Anna , Dragani Alfredo , Patriarca Andrea , Lunghi Monia , Ciancia Rosanna , Martinelli Vincenzo , Liberati Anna Marina , Specchia Giorgina , Imovilli Annalisa , Vannucchi Alessandro M. , Di Gaetano Rosa , Randi Maria Luigia , Passamonti Francesco , Palmieri Fausto , Mazzucconi Maria Gabriella , Mastrullo Lucia , Cimino Giuseppe , Pierri Ivana , Cacciola Emma , Lucchesi Alessandro , Luraschi Annalisa , Martinelli Giovanni , Baccarani Michele 
Published: October 2019

Abstract
Abstract 1973

Background.
Hematological and extra-hematological adverse events associated to Hydroxyurea (HU) treatment in patients with chronic myeloproliferative neoplasms (MPN) are object of particular interest in the Ph-negative MPN since they can significantly limit the HU use.

Objective.
To evaluate the extra-hematological adverse events associated to HU treayment in a large cohort of Essential Thrombocythemia (ET) patients.

Material and Methods.
One thousand and seventy-five out of the 2005 ET patients registered in the RIT were treated with HU and are the object of this report. The patients, 641 females (59.6%) and 434 males (40.4%), diagnosed according to the PVSG or WHO criteria in 54 hematological centers of the RIT, started treatment with HU as first (92%) or second (8%) line, at median age of 65 years.The mean duration of HU treatment was 3.3 years. The HU treatment was withdrawn in 221 (20.5%) patients after a mean of 3.0 years.The administered dose of HU was 0.25–3.0 g/day (median 1), and a mean cumulative dose was 1113 g. The extra-hematological adverse events (EHAEs) observed during the HU treatment were distinguished in HU related AEs (HU-EHAEs), ET related AEs (ET-EHAEs) and HU or ET unrelated AEs (U-EHAEs).Results. During the HU treatment (3587 pt-y) 378 EHAEs were reported in 207 (19.3%) patients, being the HU-EHAEs 244 (6.8/100 pt-y) in 170 (15.8%) patients. In detail, the HU-EHAEs were: dermatological in 108 (48.3%) cases (38 hyperpigmentation, 26 leg ulcers, 22 maculo-papular rash, 10 lichenoid eruptions, 5 skin cancer, 4 alopecia); gastro-intestinal in 80 (32.8%) cases (37 nausea/vomiting, 30 diarrhea, 13 gastro-intestinal intolerance); systemic in 35 (14.3%) cases (28 fever, 7 fatigue); neurological in 19 (7.8%) cases (headache); miscellanea in 2 (0.8%) cases.

Conclusion.
This preliminary analysis in 1075 ET patients of the Registro Italiano Trombocitemia (RIT) treated with HU shows that the extra-hematological adverse events referred to the HU (HU-EHAEs) occurred with not negligible rate (6.8/100 pt-y) and need to be object of attention in the management of ET patients.

Disclosures:
No relevant conflicts of interest to declare.
A Germinal Center- Derived B Cell Lymphoma Model
Authors: Phan Ryan T , Nguyen Khang , Romero Sonia , Nicolson Alice , Nham Phillipp , Nguyen Dany V. 
Published: October 2019

Abstract
Abstract 2008
Most human B-cell lymphomas represent mature phenotypes of germinal center (GC) or post-GC origin and are frequently associated with chromosomal translocations, often involving the rearrangement of immunoglobulin (Ig) loci to various cellular oncogenes, leading to oncogenic activation. The mechanisms underlying these processes, however, are not well understood. Several studies suggest that these genetic lesions arise from errors of physiologic DNA rearrangements in GC B cells, namely class switch recombination (CSR) and somatic hypermutation (SHM). Here we report the generation of a mouse model in which DNA breaks are physiologically instituted in mature B cells, yet inefficiently repaired via specific deletion of DNA repair gene XRCC4 in GC B cells, thus effectively creating an in vivo environment for errors in DNA rearrangements. These activated B cells exhibit significant increased chromosomal IgH locus breaks and reduced CSR. In p53-deficient background, these mice develop B-cell lymphoma from 5.5 to 16 months. These clonally developed tumors characteristically harbor chromosomal translocations and phenotypically resemble mature phenotypes. Many of these tumors bear mutated V genes, suggesting that those cells have transited through GC. Thus, this mouse model mimics human B-cell lymphoma and might be useful for the development of therapeutic interventions in B-cell lymphoma.

Disclosures:
No relevant conflicts of interest to declare.
An Important Role for Rac1 and RhoA In Regulating Platelet Microparticle Formation and Phosphatidylserine Exposure
Authors: Delaney Michael Keegan , Liu Junling , Zheng Yi , Du Xiaoping 
Published: October 2019

Abstract
Abstract 2023
Platelets activated by physiological agonists such as thrombin and collagen shed procoagulant microparticles (MPs) and externalize the procoagulant phospholipid phosphatidylserine (PS), both of which are critical to hemostasis and play an important role in inflammation. To date, the signaling mechanisms that regulate agonist-induced MP formation and PS exposure in platelets remain unclear. In this study, we demonstrate that the small GTPases Rac1 and RhoA play important roles in regulating the procoagulant activity of platelets. Rac1 null (-/-) mouse platelets or human platelets treated with the Rac1 inhibitor NSC23766 (NSC) displayed a significant defect in MP formation and PS exposure induced by various agonists. Furthermore, Rac1-/- platelets and NSC-treated human platelets displayed a defect in procoagulant activity as demonstrated by a prolonged coagulation time following recalcification of citrated PRP. The stimulatory role of Rac1 in platelet MP formation and PS exposure is distinct from the known function of Rac1 in facilitating platelet granule secretion and secretion-dependent amplification of platelet aggregation, because supplementation of the granule content ADP rescued the defect in platelet aggregation caused by Rac1 inhibition, but failed to rescue the defect in MP formation caused by Rac1 inhibition. In contrast to Rac1, RhoA plays an inhibitory role in regulating platelet procoagulant activity, because treatment of platelets with the Rho inhibitor C3-toxin (C3) significantly enhanced agonist-induced MP formation, PS exposure, and procoagulant activity. The enhancing effect of C3 on platelet procoagulant activity is not caused by an overall enhancement of platelet activation because C3 significantly inhibited platelet secretion and aggregation. Thus, our data demonstrates that while Rac1 and RhoA both play important stimulatory roles in platelet granule secretion and aggregation, they play opposing roles in MP formation and PS exposure in platelets. Rac1 is important for stimulating platelet MP formation, PS exposure, and procoagulant activity, which is antagonized by RhoA.

Disclosures:
No relevant conflicts of interest to declare.
Hepcidin Independent Anemia of Inflammation
Authors: Rivera Seth , Vaulont Sophie , Shprung Dana , Limbrick Donald , Ganz Tomas 
Published: October 2019

Abstract
Abstract 2050
Anemia of inflammation (AI, anemia of chronic disease) is a common complication of a wide variety of inflammatory conditions including infections and connective tissue diseases. Because the iron regulatory protein hepcidin is increased during inflammation and overexpression of hepcidin recapitulates many of the features of AI, hepcidin is currently believed to be the primary mediator of AI. Furthermore, Sasu and colleagues showed that blocking hepcidin could improve AI (Blood, Vol. 115, No. 17, pp. 3616-24). To test whether hepcidin is indeed necessary for the development of AI, we used two models of AI in hepcidin knockout mice. The first model, using heat-killed Brucella abortus to model brucellosis, is the same as that used by Sasu and colleagues. The second model uses complete Freund's adjuvant to model Mycobacterial disease. We showed that absence of hepcidin did not protect against the development of anemia. Furthermore, we show that this was an iron restricted anemia arguing that iron sequestration can occur independent of hepcidin. This study indicates that hepcidin may not be the central mediator in all AI. Future research will be needed to determine why the anti-hepcidin treatment used by Sasu and colleagues was able to improve the anemia.

Disclosures:
Ganz: Intrinsic Life Sciences: Employment, Membership on an entity's Board of Directors or advisory committees.
Gvhd Increases Apoptosis of CD8+, but Not CD4+, T Cells Expanded by Vaccines but Is Not Dependent on Fas Ligand
Authors: Capitini Christian M. , Guimond Martin , Fry Terry J 
Published: October 2019

Abstract
Abstract 2098
Donor lymphocyte infusions (DLIs) administered following allogeneic blood and marrow transplantation (alloBMT) can enhance T cell reconstitution through homeostatic peripheral expansion (HPE), but can also cause graft-versus-host-disease (GVHD). Vaccines are a strategy to skew T cells toward a “third-party” tumor antigen, but it is not clear if the effects of GVHD on vaccine-responding T cells is equivalent to the effects on alloantigen-reactive polyclonal T cells. Previous work by others has demonstrated “bystander” effects of GVHD causing activation-induced cell death through the Fas pathway on polyclonal T cells; however, the impact of GVHD on T cells expanded by a vaccine expressing a third-party nonalloantigen remains unclear. T cell depleted (TCD) minor histocompatibility antigen (mHA)-mismatched alloBMT (CD45.1+ B6 –> CD45.1+/CD45.2+ B6 × C3H.SW) was followed by a CD45.1+ B6 DLI on day +14 to induce GVHD. CD45.2+ B6 Rag2-/- T cell receptor transgenic (TCRTg) CD4+ or CD8+ T cells specific for epitopes derived from the male histocompatibility antigen complex (HY) were administered on day +28 with an HY-expressing male dendritic cell vaccine to determine the impact of the allogeneic environment on the persistence, proliferation and survival of vaccine-responding T cells. Despite the fact that syngeneic and allogeneic recipients had similar degrees of lymphopenia, the absolute number of CD4+ and CD8+ TCRTg T cells was decreased 5 and 7 days respectively after adoptive transfer and vaccination in alloBMT recipients compared to syngeneic recipients (p < 0.05). To determine the mechanism of decreased persistence of the TCRTg T cells, proliferation was measured by assessing dilution of CFSE and apoptosis was measured by FACS analysis for Annexin V. Importantly, since both the CD4+ and CD8+ TCRTg T cells do not undergo HPE, all proliferation has to be antigen-driven. Neither CD4+ nor CD8+ TCRTg T cells proliferated in the absence of HY vaccine following alloBMT, confirming lack of bystander proliferation. Interestingly, both CD4+ (p < 0.01) and CD8+ (p < 0.05) TCRTg T cells undergo less vaccine-induced proliferation after alloBMT compared to syngeneic recipients. The amount of CD8+ TCRTg T cell apoptosis following vaccination was higher in allogeneic recipients (p < 0.05), but there was no difference in CD4+ TCRTg T cell apoptosis. Surprisingly, using a DLI from Fas ligand-deficient B6 (gld) donors on day +14 was sufficient to induce GVHD but did not prevent CD8+ TCRTg T cell apoptosis. Thus, diminished vaccine responses during GVHD appear to result in part from impaired CD8+ and CD4+ T cell vaccine-driven proliferation, but there is an additional contribution on CD8+ T cell apoptosis that is not dependent on recognition of alloantigen or the Fas-Fas ligand pathway.

Disclosures:
No relevant conflicts of interest to declare.
Urokinase Receptor (uPAR)-Dependent Integrin Redistribution Represents a Central Mechanism for Growth Factor Induced Endothelial Cell Migration
Authors: Novotny Rene , Unseld Matthias , Poettler Marina , Zielinski Christoph , Binder Bernd , Prager Gerald 
Published: October 2019

Abstract
Abstract 2119
Tumor angiogenesis is induced when the net balance of pro- and antiangiogenic molecules is tipped in favor of angiogenesis, the so called ‘angiogenic switch’. Recently, we described a mechanism how VEGF induces pro-urokinase (pro-uPA) activation, which led to uPAR-complex formation and internalization of beta-1 integrins into the endosomal compartment via LDLR-proteins such as ApoER2 or VLDLR. Thereby, uPAR plays a central role for VEGF-induced endothelial cell migration.
Here, we describe that uPAR-induced integrin internalization and redistribution to the leading edge is not only limited to VEGF-induced endothelial cell migration, but plays a central role for others angiogenic growth factors such as fibroblast growth factor-2 (FGF-2), hepatocyte growth factor (HGF) as well as epidermal growth factor (EGF). Furthermore, we found that a hitherto undescribed binding site on domain 3 of uPAR for direct LDLR-protein interaction is required and sufficient for uPAR-dependent integrin redistribution. Interference with the uPAR/integrin internalization either by the Receptor Associated Protein (RAP) or a specific LDLR-binding site mimicking peptide (P1), the migratory response of endothelial cells towards the growth factors VEGF, HGF, FGF-2, or EGF was almost blocked (20.24% ± 4.56%). Consistently, expression of a mutated uPAR lacking interaction site for LDLR-proteins in uPAR-/- endothelial cells via a retroviral construct led to reduced invasive response towards angiogenic growth factors in vitro as well as in a Matrigel plug in vivo assay.
From these data we conclude that uPAR/LDLR-protein interaction represents a central molecule in growth factor-induced endothelial cell behavior, which might open a new avenue for therapeutic intervention.

Disclosures:
No relevant conflicts of interest to declare.
Association of HLA-G Haplotype Risk Model with Overall Survival In Acute Myeloid Leukemia Patients
Authors: Volbracht Anja , Novotny Juergen R , Ochsenfarth Crista , Switala Magdalena , Frey Ulrich , Horn Peter A , Duehrsen Ulrich , Rebmann Vera , Nuckel Holger 
Published: October 2019

Abstract
Abstract 2169

Introduction:
The human leukocyte antigen G (HLA-G) molecule exhibits limited tissue distribution and exerts multiple immunosuppressive functions. Thus, HLA-G expression in tumor cells favors tumor immune escape and tumor progression. The HLA-G gene polymorphism is extremely restricted in comparison to the classical HLA antigens. However, specific HLA-G polymorphisms in exons 3, 4, 5, 7 and parts of the 3′UTR encode for different haplotypes/alleles. Because of the prognostic role of HLA-G in cancer, especially in B-CLL, we investigated here the role of the HLA-G haplotypes in acute myeloid leukemia (AML).

Methods:
Genotyping was performed on the basis of examining exons 3, 4, 5, 7 and parts of the 3′UTR by pyrosequencing in 166 patients with AML. In total, we found 17 different haplotypes in the cohort.

Results:
The haplotype distributions between 166 AML patients and 190 healthy controls were significantly different in two alleles, arguing that these two haplotypes of HLA-G on the one hand increases (*01:06, p=0.042) and on the other hand decreases (*01:01:12 variante, p=0.0014) the susceptibility for AML. Next a risk model was generated for overall survival (OS) adapted to specific haplotypes/alleles of the HLA-G gene. The favorable group (A) consisted of the alleles *01:06 and *01:01:20 variant at codon 57 G (12 patients), the intermediate group (B) of *01:01:20, *01:04:10, *01:01:30 and *01:01:41 variant at codon 57 A (113 patients) and the unfavorable group (C) of the remaining 11 alleles (41 patients). The OS for patients in group C was significantly (p=0.02) shorter (median OS 613 days) than for those in group B (median OS 961 days) and A (median OS not reached). Multivariate analysis shows a trend that the risk HLA-G model (Hazard ratio (HR) 1.4, p=0.084) was an independent predictor next to the established prognostic factors cytogenetics (HR 2.1, p=0.001), age (HR 1.8, p=0.009), leucocytes (HR 1.6, p=0.026), ECOG stage (HR 1.5, p=0.006) and platelets (HR 2.1, p=0.015). Moreover, the new risk model was able to further subdivide patients with intermediate cytogenetic risk profile (median OS: group A not reached; group B 987 days; group C 624 days; p=0.10).

Conclusion:
Our study is the first study demonstrating that the combination of different alleles of the HLA-G gene is associated with the overall survival in AML patients. This fact emphasizes the extensive role of this gene by the tumor escape mechanism and could be responsible for progress in other cancers.

Disclosures:
No relevant conflicts of interest to declare.
SMAC-Mimetic BV-6 Sensitizes Therapeutic Agents-Induced Apoptosis In AML Cells
Authors: Mak Duncan H , Manton Christa , Andreeff Michael , Carter Bing Z 
Published: October 2019

Abstract
Abstract 2177
The antiapoptotic function of the inhibitors of apoptosis family of proteins (IAPs) is antagonized by mitochondria-released SMAC protein. The IAP-member XIAP suppresses apoptosis by directly binding and inhibiting caspase-9 and caspase-3, while cIAP1, a component of the cytoplasmic signaling complex containing TNF receptor associated factors, suppresses apoptosis via the caspase-8-mediated pathway. BV-6 (Genentech) is a bivalent SMAC-mimetic and has been shown to promote cell death by inducing cIAP autoubiquitination, NF-κB activation, and TNFα-dependent apoptosis. We examined its effect on leukemic cells and found that BV-6 only moderately induced apoptosis. The EC50 was found to be 15.3±5.1 μM at 48 hours in OCI-AML3 cells which are relatively sensitive. We then determined whether BV-6 sensitizes leukemic cells to the HDM2-inhibitor nutlin-3a and to Ara-C. p53 modulates the expression and activity of Bcl-2 family proteins and promotes the mitochondrial-mediated apoptosis. We showed previously that activation of p53 by nutlin-3a sensitizes AML cells to XIAP inhibition induced-death in part by promoting the release of SMAC from mitochondrion (Carter BZ et al., Blood 2010). We treated OCI-AML3 cells with BV-6, nutlin-3a or Ara-C, and BV-6+nutlin-3a or BV-6+Ara-C and found that the combination of BV-6 and nutlin-3a or BV-6 and Ara-C synergistically induced cell death in OCI-AML3 cells with a combination index (CI) of 0.27±0.11 and 0.22±0.05 (48 hours), respectively. To demonstrate that p53 activation is essential for the synergism of BV-6+nutlin-3a combination, we treated OCI-AML3 vector control and p53 knockdown cells with these two agents and found that the combination synergistically promoted cell death in the vector control (CI=0.47±0.15) but not in the p53 knockdown cells, as expected, while BV6+Ara-C was synergistic in both vector control and p53 knockdown cells (CI=0.15±0.03 and 0.08±0.03, respectively, 48 hours). BV-6 induced activation of caspase-8, caspase-9, and caspase-3 and decreased XIAP levels, but did not cause rapid cIAP1 degradation, as reported by others. To assess the contribution of death receptor-mediated apoptosis in BV-6-induced cell death, we treated Jurkat and caspase-8 mutated Jurkat cells (JurkatI9.2) with BV-6 and found that BV-6 induced cell death and significantly potentiated TRAIL-induced apoptosis in Jurkat cells (CI=0.14±0.08, 48 hours). Caspase-8 mutated JurkatI9.2 cells were significantly less sensitive to BV-6 than Jurkat cells and as expected, JurkatI9.2 was completely resistant to TRAIL.
Collectively, we showed that the bivalent SMAC-mimetic BV-6 potentiates p53 activation-, chemotherapy-, and TRAIL-induced cell death, but has only minimal activity by itself in leukemic cells. SMAC-mimetics could be useful in enhancing the efficacy of different classes of therapeutic agents used in AML therapy.

Disclosures:
No relevant conflicts of interest to declare.