bluuebunny/crossref_metadata_2025_split huggingface dataset:
BTG1, a Gene Frequently Deleted in Pre-B ALL, Controls Glucocorticoid Receptor-Mediated Gene Expression.
Authors: van Leeuwen Frank N. , van Galen Joost Casper , Kuiper Roland P. , van Emst Liesbeth , Levers Marloes R , Tijchon Esther , Scheijen Blanca , Waanders Esmee , van Reijmersdal Simon V , Gillissen Christian , van Kessel Ad Geurts , Hoogerbrugge Peter M. 
Published: October 2019

Abstract
Abstract 3458
Poster Board III-346

Background
By genome wide profiling we have found that about 10 % of pediatric pre-B ALL cases contain a (single copy) deletion of the B cell translocation gene 1 (BTG1) gene. BTG1 belongs to a family of potential tumor suppressor genes, which include BTG2, BTG3, TOB and TOB2. Proteins encoded by members of this gene family have been implicated in the induction of growth arrest or apoptosis in a variety of model systems. Moreover, BTG1 associates with and regulates the activity of the arginine methyl transferase PRMT1, a coactivator of nuclear receptor-mediated transcription. Hence we hypothesized that loss of BTG1 function, for instance due to deletion, may affect glucocorticoid induced therapy responses in ALL.

Results
Using RNA interference, we find that loss of BTG1 expression decreases sensitivity of pre-B ALL cells to the apoptosis-inducing effects of synthetic GCs about 10,000 fold (Figure). This acquired GC resistance is accompanied by a greater than 10 fold reduction in GR protein expression as well as a (near complete) loss of GC-induced gene expression. Conversely, re-expression of BTG1 restores GC sensitivity by potentiating GC-induced GR expression. By chromatin immunoprecipitations using anti PRMT1 antibodies we show that PRMT1 is recruited to the GR gene promoter in a BTG1-dependent manner, consistent with a role for this arginine methyl transferase in the regulation of GR-mediated gene expression.

Conclusions
Together, our results demonstrate the importance of the BTG1/PRMT1 complex in regulating GR-mediated gene expression and reveal how deregulation of the this complex can give rise to GC resistance. Targeting of these coactivators as part of the GR regulatory circuitry could offer novel opportunities for improving the efficacy of GC based therapies in ALL as well as other hematological malignancies.

Disclosures
No relevant conflicts of interest to declare.
Comparison of Differential Gene Expression Profiles of Relapsed Patients with Acute Promyelocytic Leukemia Treated with Arsenic Trioxide with the Profile of An Arsenic Trioxide Resistant NB4 Cell Line.
Authors: Chendamarai Ezhilarasi , Shaji Ramachandran , Viswabandya Auro , George Biju , Srivastava Alok , Chandy Mammen , Mathews Vikram 
Published: October 2019

Abstract
Abstract 3460
Poster Board III-348
Arsenic trioxide (ATO) has proven efficacy in the management of patients with acute promyelocytic leukemia (APL). Approximately 20% of patients treated with an ATO based regimen relapse. The long term remission rate with ATO in relapsed patients is significantly inferior to that seen in newly diagnosed cases. The biological mechanisms of resistance to ATO in these patients have not been evaluated. We undertook a gene expression profile study to address the potential mechanisms of resistance in patients with relapsed APL. The study included 8 patients at diagnosis and 8 patients at relapse from whom total RNA was extracted from bone marrow mononuclear cells with > 90% promyelocytes (enriched with lineage depletion cocktail as required). This was then subjected to a one color 44K Agilent cDNA array. Data was normalized, filtered and analyzed using Gene Spring software (Ver.10). Using unpaired t-Test, 1744 genes were identified to be differentially expressed (>2 fold) between samples at diagnosis and at relapse. Out of the 865 up regulated genes, the collagen family genes COL5A1 and COL2A1, haematopoietic lineage specific genes CD34 and TdT, C-Lectin family COLEC1 and TRIM15 were found to be 10 fold higher in relapse. About 880 genes were down regulated in relapse which included ABCA1, LEP, TUSC1 and XIST. We generated an ATO resistant NB4 cell line by chronic and gradual exposure to ATO over a period of 1 year. Gene expression profile of naïve and resistant NB4 cell lines arrayed in replicates were obtained. Comparison of relapsed patients and the ATO resistant NB4 cell line data revealed 51 genes were up regulated and 41 were down regulated commonly and in the same direction between these 2 groups in comparison to newly diagnosed patients and naïve NB4 cell line. By gene ontology (GO) analysis of these 92 common genes using Biointerpreter software the following biological processes were identified, namely; differentiation (47 genes), cell adhesion (14 genes), cell proliferation (17 genes), transcription factors and gene regulation (33 genes), apoptosis (11 genes), ECM remodeling (10 genes) and cell migration (5 genes). Of interest in the up-regulated gene list were anti-apoptotic gene BAG4, cell adhesion genes COL2A1 and JAM3 and differentiation gene COLEC11. The prominent down regulated genes included the ABC transporter family gene ABCA1, TNF receptor super family gene TNFRSF14 and the aldehyde dehydrogenase family gene ALDH8A1. These data provide the first evidence of the possible mechanisms of resistance to ATO in APL but needs further evaluation and validation.

Disclosures
No relevant conflicts of interest to declare.
Patients with Severe Factor XI Deficiency Have a Reduced Incidence of Venous Thromboembolism.
Authors: Salomon Ophira , Zivelin Ariella , Tamarin Ilia , Steinberg David M. , Varon David , Seligsohn Uri 
Published: October 2019

Abstract
Abstract 3491
Poster Board III-428
Patients with severe factor XI deficiency (level ≤15U/dL) were recently found to be protected against ischemic stroke but not against myocardial infarction (Blood 2008, 111:4113). Regarding venous thrombosis, several clinical and experimental observations suggest that factor XI deficiency might confer protection. Thus, only 2 patients with severe factor XI deficiency have been reported with unprovoked venous thromboembolism, and protection against FeCl3 Cinduced thrombosis in the vena cava was observed in factor XI deficient mice (J Thromb Haemost 2006, 4:1982). Other studies established that an increased level of factor XI is associated with an increased risk of venous thromboembolism. In the present study, we investigated whether patients with severe factor XI deficiency are protected against venous thromboembolism. We interviewed 222 unrelated patients with severe FXI deficiency and reviewed their medical charts. In the cohort, there were 126 females and 96 males aged 20-94 years of whom 137 were 50 years or older. The expected incidence rates of venous thromboembolism in the general population for males and females at different age groups were extracted from a population-based study of venous thromboembolism (J Thromb Haemost 2007,5:692). The expected incidence rate of venous thromboembolism in the factor XI deficiency cohort was 4.67 (2.37 in females and 2.30 in males), while the observed incidence rate was 0/222. This difference was statistically significant taking into account age and sex by the Poisson test (p=0.036). The prevalence of the common inherited thrombophilias was examined in 194 of the 222 patients. Seven (3.6%) patients harbored factor V Leiden, and 17 (8.8%) harbored the prothrombin G20210A mutation; the corresponding proportions in the general Israeli population are 3.9% for factor V Leiden, and 5.4% for prothrombin G20210A mutation. Thus, there was no decreased prevalence of the common thrombophilias in the factor XI deficient cohort. Collectively, the data suggest that patients with severe factor XI deficiency are protected against venous thromboembolism.

Disclosures:
No relevant conflicts of interest to declare.
Type of Factor VIII Product as Inhibitor Risk Factor in Patients with Severe Hemophilia A and Null Mutations.
Authors: Mancuso Maria Elisa , Mannucci Pier Mannuccio , Rocino Angiola , Garagiola Isabella , Tagliaferri AnnaRita , Margaglione Maurizio , Santagostino Elena 
Published: October 2019

Abstract
Abstract 3500
Poster Board III-437

Aim
This retrospective study evaluates the interactions of known determinants of the inhibitor risk in severe and moderate hemophiliacs followed-up at 3 Italian Hemophilia Centers.

Methods
clinical data up to inhibitor development or 150 exposure days (EDs) were collected in 393 patients with Factor VIII <5% (FVIII <1%: 331, 84%) and median age of 27 years (interquartile range, IQR:15-36) first treated with plasma-derived (pdFVIII, 70%) or recombinant products (rFVIII, 30%). Exposure to blood components for more than 4 days was an exclusion criterion.

Results
the F8 genotype was known in 334 patients (85%), 57% with null mutations (nonsense mutations, inversions and large deletions). Inhibitors (titer ≥ 0.6 BU/ml on at least two consecutive occasions and FVIII recovery <66% of expected) were detected in 112 patients (28%) after a median of 17 EDs (IQR:10-29), being high responding (HR, peak titer ≥ 5 BU/ml) in 23% and transient in 7%. Table 1 shows the crude and adjusted hazard ratios of potential determinants of inhibitor development in this cohort. Intensive treatment was defined as treatment duration ≥ 3 consecutive days at a dose ≥ 50 IU/kg/day. Sub-analyses were performed in 272 patients who never switched class of product (pdFVIII and rFVIII) and in 314 patients who did not started prophylaxis (≥ 1 regular infusion per week): in both cases the use of rFVIII at first exposure was associated with an increased inhibitor risk (adjusted hazard ratio 5.1, 95%CI 1.5-16.9 and 4.1, 95%CI 1.8-9.4, respectively). Similar results were obtained also excluding 103 patients (26%) who were first exposed to blood components (adjusted hazard ratio 3.5, 95%CI 1.5-7.9). Interestingly, patients with null mutations treated with rFVIII had a higher inhibitor risk than those first treated with pdFVIII (adjusted hazard ratio 3.3, 95%CI 1.4-7.6), while no difference was found in patients with non null mutations treated with rFVIII (hazard ratio 1.4, 95%CI 0.5-3.7). These results were confirmed including only high-responding inhibitors in the analysis.

Conclusions
our results show the influence of the interaction between type of FVIII product and F8 genotype on inhibitor risk, being the use of rFVIII associated with an higher risk in patients with null mutations. In our cohort this association was confirmed also after adjustment for the other known genetic and environmental risk factors of inhibitor development.

Disclosures:
No relevant conflicts of interest to declare.
Higher Plasma Cell Burden Predicts for Early Death In Patients with AL Amyloidosis
Authors: Chee Cheng E. , Rajkumar S. Vincent , Gertz Morie Abraham A , Lacy Martha , Zeldenrust Steven , Kumar Shaji , Hayman Suzanne R. , Buadi Francis , Russell Stephen , Kyle Robert , Greipp Philip R. , Dispenzieri Angela 
Published: October 2019

Abstract
Abstract 1893

Background:
Recent data has shown that the level of immunoglobulin free light chain (FLC) is a prognostic factor for patients with AL amyloidosis. Approximately 25% of patients with AL amyloidosis have coexistent multiple myeloma (MM) with myeloma-related end-organ damage and patients may also present with 310% plasma cells (PC) in the bone marrow (BM) in the absence of any MM features. The goal of this study was to determine the effect of increased BM plasmacytosis in the absence of MM end-organ damage on early mortality.

Methods:
We performed a retrospective study of 263 consecutive patients with AL amyloidosis seen at Mayo Clinic within 30 days of diagnosis from July 2002 – April 2009, to compare the effect of PC burden among those who died within 90 days of diagnosis (n=88) and those who survived more than 90 days after diagnosis (n=175). Only those patients with documented BM PC were included in this study. MM end-organ damage was defined according to the CRAB criteria.

Results:
In those who died <90 days after diagnosis and patients who lived beyond 90 days, the proportion of patients with 310% BM PC were 57% and 55%, respectively. Overall survival (OS) was significantly shorter in the early mortality group when there was 310% BM PC present at diagnosis (25 vs. 54 days, p=0.006), but this was not observed in the group who survived beyond 90 days (Figure 1). In patients with 310% BM PC, troponin-T, ejection fraction (EF), and hemoglobin (Hgb) were significantly worse in the early mortality cohort but patients who survived beyond 90 days had significant increase in intraventricular septal (IVS) thickness and beta-2 microglobulin (Table 1). As expected, patients with 310% BM PC in both cohorts had significantly higher serum M-spike and involved FLC (Table). The same cohort of patients were analyzed substituting MM-related end-organ damage for 310% BM PC and similar results were observed with the exception of uric acid and calcium being significantly higher in the early mortality cohort with MM (results not shown).

Conclusion:
This study demonstrated that an excess of early—but not late—deaths occur in AL amyloidosis patients with 310% BM PC at diagnosis. In our cohort, this finding can be attributed to higher troponin-T levels, indicating more severe cardiac involvement as observed by worse cardiac function. These findings warrant additional investigation.

Disclosures:
Lacy: Celgene: Research Funding. Kumar:Celgene: Consultancy, Research Funding; Millennium: Research Funding; Merck: Consultancy, Research Funding; Novartis: Research Funding; Genzyme: Consultancy, Research Funding; Cephalon: Research Funding. Dispenzieri:Celgene: Honoraria, Research Funding; Binding Site: Honoraria.
Strong Antibody Responses Against a Unique Region of CT-Antigen SSX-2 Are Induced After Allogeneic Stem Cell Transplantation and Correlate with Clinical Remission In Patients with Multiple Myeloma
Authors: Kobold Sebastian , Luetkens Tim , Cao Yanran , Eberhardt Corinna , Tams Sinje , Bartels Britta Marlen , Bartels Katrin , Meyer Sabrina , Haag Friedrich , Bokemeyer Carsten , Zander Axel R. , Kröger Nicolaus , Atanackovic Djordje 
Published: October 2019

Abstract
Abstract 1900
Cancer-testis (CT) antigens show an expression restricted to malignancies and the human germline among healthy tissues and, therefore, represent attractive targets for cancer vaccines. CT antigen SSX-2 is expressed in about 20% of multiple myeloma patients (MM), however, little is known about the occurrence of spontaneous humoral immune responses against SSX-2 in these patients. Moreover, no information is available regarding the functionality of anti-SSX2 antibody responses and a possible impact on the course of the disease. Screening 1098 peripheral blood samples and 200 bone marrow samples of 194 MM patients, as well as 100 healthy donors serving as controls, we found six patients (3%) to present with SSX-2 specific antibodies. When we mapped the target epitopes using overlapping peptides for the whole SSX-2 sequence, we found the antibodies to be exclusively directed against amino acids 81–90. Remarkably, all antibodies were of the IgG3 subtype. In addition, SSX-2 antibodies were strictly antigen-specific and represented potent activators of the complement system. Correlating the antibody responses with clinical events, we found that the majority (5 out of 6) of seropositive patients had been antibody-negative before allogeneic stem cell transplantation (alloSCT) and had only developed anti-SSX2 antibodies after transplantation. Donor-derived antibody responses increased with depth of remission and, in case of recurrence of the disease, dropped to low or undetectable levels. Our data suggest that alloSCT is able to induce immune responses against myeloma specific SSX-2 antigen which is of low immunogenicity under normal conditions. Such antibody responses are of an effective phenotype and seem to correlate with protection from disease recurrence. To further characterize the biological role of transplantation-induced anti-SSX2 immune responses, we will analyze our patients for the presence of SSX-2-specific T cells which might be induced together with serological responses in the framework of an integrated immune response. Active immunotherapy might contribute to amplifying and shaping anti-SSX2 immune responses in myeloma patients, particularly after alloSCT.

Disclosures:
No relevant conflicts of interest to declare.
Aberrant Expression of Regulatory miRNAs and Transcripts for IRS-PI3K Growth and Survival Signaling In Waldenstrom's Macroglobulinemia
Authors: Hunter Zachary , Cao Yang , Lewicki Megan , Sun Jenny , Tseng Hsiuyi , Hanzis Christina , Brodsky Philip , Manning Robert , Xu Lian , Yang Guang , Zhou Yangsheng , Liu Xia , Jiang Jingrui , Patterson Christopher , Treon Steven P. 
Published: October 2019

Abstract
Abstract 1912

Background:
Waldenstrom's Macroglobulinemia (WM) is a rare low grade non-Hodgkin's lymphoma characterized by the accumulation of IgM secreting lymphoplasmacytic cells in (LPC) the bone marrow, an elevated serum IgM, and frequently accompanied with hyperviscosity syndrome. The insulin receptor substrates (IRS) are important mediators of the insulin like receptor family and PI3K signaling leading to PKC and AKT activation.

Methods:
TaqMan low density arrays were used to evaluate the relative levels of 667 miRNAs in 11 WM patient and 5 age matched healthy donor (HD) CD19+ bone marrow cells. The results of this screen were validated using individual stem loop RT-PCR assays. Additional mRNA targets were identified using an existing gene expression profiling (GEP) data set of 22 WM patients and 8 HD using the Affymetrix U133 plus 2 platform. GEP findings were validated using an independent cohort of 18 WM patients and 7 HD.

Results:
Aberrant miRNAs identified were miR-21 (+3.27 fold p=0.035), miR-29c (+3.17 fold; p=0.003), miR-155 (+5.53 fold; p=0.082), miR-9* (-3.94 fold; p=0.001), miR-27b (-4.94 fold; p=0.001), miR-126 (-21.52 fold; p=0.006), miR-126* (-25.55 fold; p=0.039), miR-145 (-34.27 fold; p<0.001), miR-223 (-24.25 fold; p=0.041), and miR-886-5p (-3.01 fold; p=0.004). Importantly, 5 of these 10 miRNAs targeted members of the IRS-PI3K signaling pathway, a pathway important for growth and survival of WM cells: miR-29c (PIK3R1); R-155 (SHIP1); miR-21 (PTEN); miR-145 (IRS1); miR-126 (IRS1 and PIK3R2), and predict for increased protein levels for PIK3R2 and IRS1 with lower protein levels for PIK3R1, PTEN and SHIP1. Moreover, GEP and confirmatory RT-PCR revealed down-regulation of the IRS-PI3K pathway members IRS2 (-2.0 fold; p=0.004) and PIK3R1 (-2.0 fold; p=0.04).

Conclusions:
The results of this demonstrate aberrant expression of regulatory miRNAs and transcripts for IRS-PI3K growth and survival signaling in WM, and provide support for the development of IRS/PI3K targeted therapeutics in WM.

Disclosures:
No relevant conflicts of interest to declare.
Association of Age with Fluorescence In Situ Hybriditization (FISH) Abnormalities In Multiple Myeloma Patients Reveals Higher Rate of Igh Translocations Among Older Patients
Authors: Butler Charles M , Alge Joseph L , Stuart Robert K , Costa Luciano J 
Published: October 2019

Abstract
Abstract 1913

Introduction:
Molecular cytogenetic evaluation of chromosome abnormalities has proven to be an important tool to determine prognosis in newly diagnosed multiple myeloma (MM) patients. The majority of MM patients will have one or more cytogenetic abnormality detectable by fluorescence in situ hybridization (FISH). Deletion of 17p13, t(4;14)(p16;q32) and t(14;16)(q23;q32) define high-risk MM, while abnormalities common in standard risk MM are hyperdiploid karyotype and t(11;14)(q13;q32). The prognostic importance of deletion of 13q14 detected by FISH is controversial with worse outcome noted in some but not all series. Even though a strong correlation between age and patter of chromosome abnormalities has been demonstrated in other hematologic malignancies (e.g. acute leukemias), such association has not been clearly defined in MM. We utilized a cohort with high frequency of young patients to further explore the correlation between FISH abnormalities and age in MM.

Methods:
This is a retrospective analysis of all patients seen at our institution with diagnosis of MM from 2002 to 2010 and for whom comprehensive FISH analysis of MM cells was available. Patients were divided in two groups according to age. The proportions of specific FISH findings were compared between the two groups using chi-square test.

Results:
One hundred patients were identified with a median age of 59 years (range 20–81). We defined two groups containing younger (age < 60 years, N=51) and older patients (age ≥ 60 years, N=49). FISH abnormalities were detected in 66% (99%C.I. 56.7–75.3%) of patients. Older MM patients had a significantly higher incidence of l t(4:14) abnormalities (16.3% vs 3.9% p=0.039) and IgH rearrangements in general (36.7% vs 15.7% p=0.02). There were no significant differences between the two groups for the frequency of any of the remaining FISH abnormalities (see Figure). Similarly, no pattern of association was seen between FISH panel and initial International Staging System.

Conclusions:
Even though there does not seem to be a strong association between age and MM FISH abnormalities, our findings suggest a higher frequency of translocations involving IgH, particularly t(4;14), among older patients. It is unlikely however that the differences in outcomes between younger and older MM patients are due to intrinsic biological differences.

Disclosures:
No relevant conflicts of interest to declare.
Serum/Glucocorticoid-Regulated Kinase 1 (SGK1) Is a Prominent Target Gene of the Transcriptional Response to Cytokines In Multiple Myeloma and Supports the Growth of Myeloma Cells
Authors: Fagerli Unn-Merete , Stühmer Thorsten , Holien Toril , Holt Randi Utne , Bruland Ove , Chatterjee Manik , Shaughnessy John , Mathas Stephan , Sundan Anders , Bargou Ralf C , Dörken Bernd , Borset Magne , Janz Martin 
Published: October 2019

Abstract
Abstract 1915
Multiple myeloma is a paradigm for a malignant disease that exploits external stimuli of the microenvironment for growth and survival. A thorough understanding of the complex interactions between malignant plasma cells and their surrounding requires a detailed analysis of the transcriptional response of myeloma cells to environmental signals. We hypothesized that the intracellular signals evoked by cytokines converge and regulate transcription of a set of genes that are common targets for several growth factors and therefore constitute pivotal mediators of the tumor-promoting effects of autocrine or paracrine stimuli. To identify such targets, we determined the changes in gene expression induced by IL-6, TNFalpha, IL-21 or co-culture with bone marrow stromal cells in myeloma cell lines. Among a limited set of genes that were consistently activated in response to growth factors, a prominent transcriptional target of cytokine-induced signaling in myeloma cells was the gene encoding the serine/threonine kinase SGK1, which is a down-stream effector of PI3-kinase and highly homologous to AKT. We could demonstrate a rapid, strong and sustained induction of SGK1 in the cell lines INA-6, ANBL-6, IH-1, OH-2 and MM.1S as well as in primary myeloma cells. Pharmacologic inhibition of the JAK/STAT pathway abolished STAT3 phosphorylation and SGK1 induction. In addition, shRNA-mediated knock-down of STAT3 reduced basal and induced SGK1 levels, demonstrating the involvement of the JAK/STAT3 signaling pathway in SGK1 induction. Furthermore, down-regulation of SGK1 by shRNAs resulted in decreased proliferation and viability of myeloma cell lines. Our results indicate that SGK1 is a highly cytokine-responsive gene in myeloma cells promoting their growth and survival and represents an attractive candidate for further evaluation as a therapeutic target.

Disclosures:
No relevant conflicts of interest to declare.