bluuebunny/crossref_metadata_2025_split huggingface dataset:
The HDAC Inhibitors Trichostatin A (TSA) and Suberoylanilide Hydroxamic Acid (SAHA) Exhibit Multiple Modalities of Benefit for the Vascular Pathology of Sickle Disease.
Authors: Hebbel Robert P , Vercellotti Gregory M. , Pace Betty , Solovey Anna , Kollander Rahn , Abanonu Chine , Nguyen Julia , Vineyard Julie V. , Belcher John D , Abdulla Fuad , Osifuye Shade , Eaton John W. , Kelm Robert , Slungaard Arne 
Published: October 2019

Abstract
Abstract 2586
Poster Board II-562
The chronic, inflammatory vasculopathy of sickle cell anemia accounts for much of the non-infectious morbidity and mortality of this disease. The pathogenesis of vasculopathy involves multiple sub-biologies (sickling, hemolysis, inflammation, adhesion, coagulation, NO deficiency, stasis, and reperfusion injury). Moreover, these various sub-biologies overlap and transactivate each other. So a single modality approach would very likely fail to be effective. For this reason, effective preventative and interventional therapy for sickle vasculopathy will very likely require true multi-modality therapy, preferably with as few drugs as possible. To this end, we have evaluated the histone deacetylase (HDAC) inhibitors TSA and SAHA for beneficial vascular effects in sickle transgenic mouse models. We used the hBERK1 mouse, which displays abnormal endothelial activation even at ambient air; and we used the NY1DD mouse which only acquires significant endothelial activation upon exposure to hypoxia/reoxygenation. Both drugs significantly inhibited the abnormal endothelial expression of tissue factor, predicting beneficial effects for sickle coagulopathy. Both drugs significantly inhibited abnormal endothelial expression of VCAM1, a molecule involved in both adhesion and inflammation sub-biologies. Both drugs worked in both mouse models. For these benefits, both drugs were effective when given as preventative therapy (NY1DD model) or as longer term therapy (hBERK1 model), although previously-established endothelial activation (e.g., the hBERK1 model) required long term (3 weeks) therapy to observe the most significant benefits. TSA markedly inhibited the vascular stasis in the dorsal skinfold chamber model of hBERK1 mice that is seen after their exposure to H/R; SAHA did so in S+SAntilles mice after H/R; our previous studies have implicated VCAM1 and abnormal cell/cell interaction as the etiology of stasis in this model. Both drugs induced gamma globin and levels of HbF in K562 cells in vitro. Both drugs exhibited activity as iron chelators, as detected by absorption spectra in vitro. Since both drugs are hydroxamic acids, they may promote NO formation by the same mechanism that hydroxyurea is said to work, although we did not test this. We suggest that SAHA, which is already approved for other human clinical use, should be considered for testing in a pilot study to determine drug tolerance and in vivo efficacy in sickle subjects.

Disclosures:
No relevant conflicts of interest to declare.
CREB Deficiency: A Potential Critical Factor for Selective GM-CSF Hypersensitivity in Juvenile Myelomonocytic Leukemia.
Authors: Liu Y. Lucy , Malaviarachchi Priyangi A , Lensing Shelly Y. , Castleberry Robert P. , Emanuel Peter Dean 
Published: October 2019

Abstract
Abstract 2604
Poster Board II-580
Juvenile myelomonocytic leukemia (JMML) is a mixed myelodysplastic /myeloproliferative neoplasm (MDS/MPN) of infancy and early childhood. The pathogenesis of JMML has been linked to dysregulated signal transduction through the NF1/RAS signaling pathway and PTPN11. This dysregulation results in JMML cells demonstrating selective hypersensitivity to GM-CSF in in vitro dose-response assays. Since JMML hematopoietic progenitor cells are selectively hypersensitive to (rather than independent of) GM-CSF, it is rational to hypothesize that the function of the GM-CSF receptor in JMML patients is not constitutively over-active unless stimulated by the cytokine. We previously reported that PTEN is deficient in JMML patients. PTEN expression is up-regulated by Egr-1, which is one of the targets of the cAMP-response-element-binding protein (CREB). CREB, as a transcriptional factor, is expressed ubiquitously and bound to the cAMP-response-element (CRE) of the Egr-1 promoter. After phosphorylation at serine 133, CREB selectively activates the transcription of Egr-1 in response to GM-CSF stimulation in hematopoietic cells. We evaluated the CREB protein level in peripheral blood or bone marrow samples collected from 26 JMML patients. Mononuclear cells (MNCs) were isolated and lysed in lysis buffer at a density of 107/100μl. Protein levels of CREB were evaluated by ELISA and Western-blot. We found that 22/26 (85%) of subjects were substantially CREB deficient while they had constitutively high activity of MAP kinase (Erk-1/2). In comparison to normal controls (n=7), the median level of total CREB protein by ELISA was significantly lower in JMML subjects (0.62 vs 8.85 ng/mg BSA in normal controls; p=0.006). The mechanism that causes CREB deficiency in JMML is under further investigation and further results may be available to present at the meeting. This is the first evidence that CREB, a critical component downstream of the GM-CSF receptor, is highly deficient in the majority of JMML cases.

Disclosures:
No relevant conflicts of interest to declare.
Development of a Novel Treatment Strategy Targeting JAK2 in Acute Myelogenous Leukemia.
Authors: Kojima Shinsuke , Ikezoe Takayuki , Yang Jing , Nshioka Chie , Takeuchi Asako , Isaka Mayuka , Furihata Mutsuo , Yokoyama Akihito 
Published: October 2019

Abstract
Abstract 2619
Poster Board II-595
Somatic mutations in Janus kinase 2 (JAK2) gene activate JAK2/signal transducer and activator of transcriptions (STATs) signaling, leading to proliferation of hematopoietic cells. STAT3 and/or STAT5 were constitutively activated in the majority of patients with acute myelogenous leukemia (AML), although mutation of the JAK2 gene was an extremely rare event in AML. This study performed the immunohistochemichal examination to verify whether JAK2 was activated in AML (n=73, excluding acute promyelocytic leukemia) by utilizing the phosphor-specific antibody against JAK2. p-JAK2 was detectable in all cases examined, although its level varied between each patients (+, n=27; +/−, n=28; −/+, n=18). Statistical examination found that levels of p-JAK2 were correlated with leukocytosis (21.4 × 106/L in patients with high p-JAK2 vs 13.8 × 106/L in those with low p-JAK2, p<0.001) and lower complete remission rate (65.5% in patients with high p-JAK2 vs 83.3% in patients with low p-JAK2, p<0.02). In addition, there was a trend that high expression level of p-JAK2 was associated with poor prognosis in AML patients (median survival time 604 days in patients with high p-JAK2 vs 1431 days in those with low p-JAK2). Moreover, we found that the novel and specific inhibitor of the JAK2 kinase AZ960 potently inhibited the clonogenic growth of freshly isolated CD34+ AML cells from patients (n=6) with IC50 ranging from 0.01 to 0.1 mM. On the other hand, levels of p-JAK2 in CD34+ hematopoietic cells from healthy volunteers (n=3) were lower than those in CD34+AML cells, as measured by FACS, and their colony forming ability was not affected by AZ960. Furthermore, exposure of freshly isolated CD34+ AML cells to AZ960 (0.03–0.1 mM) induced apoptosis as assessed by induction of the cleaved forms of PARP as well as caspase 3, and downregulation of anti-apoptotic protein Bcl-xL. Taken together, JAK2 may be a promising molecular target for treatment of AML. Further studies are warranted to evaluate the efficacy of the JAK2 inhibitor in clinical settings.

Disclosures:
No relevant conflicts of interest to declare.
Aberrant DNA Methylation in Childhood Acute Lymphoblastic Leukemia as a Potential Biomarker Reflecting Disease Status.
Authors: Kwon Seung Yeon , Won Sung Chul , Kim Hyo Sun , Jeung Hei-Cheul , Rha Sun Young , Park Kyu Hyun , Song Jaewoo , Lyu Chuhl Joo 
Published: October 2019

Abstract
Abstract 2637
Poster Board II-613

Background:
Aberrant DNA methylation of promoter-associated cystosine-guanine (CpG) islands is known to play an important role in leukemogenesis and has been reported to have association with poor prognosis in acute lymphoblastic leukemia (ALL). In adult, residual methylation at clinical remission status in patients with acute myeloid leukemia and Philadelphia chromosome-positive ALL showed significant association with poor prognosis in recent studies. We analyzed 47 patients with childhood ALL to evaluate the change of methylation status from the time of diagnosis to the time at morphologic remission.

Methods:
We analyzed the methylation status of CDH1, p16 and DAPK genes at the time of diagnosis and at the time of morphologic remission in 47 patients using methylation specific polymerase chain reaction method with genomic DNA extracted from bone marrow (BM) aspirates. All patients were treated with standard chemotherapy and after 4 weeks, every patient achieved morphologic complete remission. Methylation status of above three genes were also analyzed with the same method in 10 BM aspirate samples from healthy BM donor for comparison.

Results:
CDH1 was methylated in 30 (64%) patients, p16 in 2 (4%) patients and DAPK in 6 (13%) patients at the time of diagnosis. Thirty three (70%) patients had methylation at least one gene, and 5 (11%) had methylation of 2 genes. None of the healthy BM donors showed methylation of above genes. At the time of morphologic remission, all patients who had aberrant DNA methylation of any gene at the time of diagnosis had no detectable residual methylation showing complete resolution of aberrant DNA methylation of examined genes. Clinical prognostic factors including initial white blood cell count, immunophenotype and presence of specific translocations (TEL-AML1, BCR-ABL, E2A-PBX1) did not show any association with initial methylation status. Age was the only factor which showed correlation with methylation status; patients under 2 year old showed significantly low frequency of methylation of above three genes (p <0.001).

Conclusion:
Since aberrant DNA methylation of CDH1, p16 and DAPK genes were found in 70% of pretreatment ALL patients and none in healthy BM donor showing complete resolution of methylation at morphologic remission status, we cautiously suggest aberrant DNA methylation as a potential biomarker reflecting disease status in childhood ALL.

Disclosures:
No relevant conflicts of interest to declare.
Contribution of Deregulated miRNAs to the Phenotypic Characteristic of Hodgkin Lymphoma.
Authors: Ping Tan Lu , Kroesen Bart-Jan , Tiacci Enrico , Duns Gerben , Seinen Erwin , Sibon Ody , Kok Klaas , Poppema Sibrand , Van Den Berg Anke 
Published: October 2019

Abstract
Abstract 265
In Hodgkin Lymphoma (HL), the Hodgkin Reed-Sternberg (HRS) cells are a minority of large mono- or multi-nucleated B cells characterized by a loss of B cell phenotype, constitutive NF-kB activation, a disturbed cell cycle and anti-apoptotic features. In this study we investigated the role of deregulated miRNA expression in the pathogenesis of HL. MiRNA in situ hybridization (ISH) in HL tissue was performed to determine expression of miRNAs previously reported to be highly abundant in HL cell lines, in HRS cells. Next we identified the miRNA-targetome of two HL cell lines by immunoprecipitation of RISC in untransfected and transfected cell lines. miRNA ISH confirmed expression of miR-17-5p, miR-24, miR-106a, miR-146a, miR-150, miR-155, miR-181b and miR-210 in HRS cells. Ago2-immunoprecipitation followed by microarray analysis of the co-immunoprecipitated mRNA revealed that the miRNA-targetome of HL comprises of about 2,500 genes. Inhibition of the anti-miR-17 seed family revealed that about 500 of these genes are regulated by miRNAs of the miR-17 seed family. Gene ontology (GO) analysis for the total miRNA-targetome of HL showed a significant enrichment of genes involved in the regulation of cell cycle, apoptosis, immune system development and NF-kB cascade. The miRNA-targetome of HL contained several genes known to be mutated in HRS cells, including A20, FAS, NFKB1A, NFKB1E, PERP and SOCS1. Also, using previously reported gene expression data, we defined a set of genes downregulated in HL cell lines (L428 and L1236) compared to germinal center B cells (GCB) and compared them to the miRNA-targetome of the same cell lines. This resulted in the identification of 149 genes in L428 and 183 genes in L1236 that were subjected to miRNA mediated repression. Unexpectedly, only a few of all the reported inactivated genes in HRS cells that might contribute to loss of B cell phenotype (MYBL1 and CXCR4) were found to be regulated by miRNAs in HL. In conclusion, we confirmed the expression of miRNAs in the HRS cells of HL tissue and identified miRNA repressed genes in HL. Our data indicated that aberrant miRNA expression contributes to the deregulation of apoptosis, cell cycle, and NF-kB pathways but not loss of B cell phenotype in HL.

Disclosures:
No relevant conflicts of interest to declare.
Defective Central Memory CD8+ T Cell Differentiation in the Absence of Eomesodermin.
Authors: Banerjee Arnob , Gordon Scott M. , Intlekofer Andrew M. , Wherry E. John , Reiner Steven L. 
Published: October 2019

Abstract
Abstract 2662
Poster Board II-638
The differentiation of central memory CD8+ T cells after vaccination or primary pathogen encounter is critical for the establishment of long-lasting protection against pathogens including intracellular infectious organisms and malignancies. Unfortunately, the mechanisms of immune memory establishment are unclear, preventing the development of effective vaccines to many emerging pathogens. Naïve CD8+ T cells responding to intracellular pathogens undergo rounds of cell division and progressive differentiation to give rise to terminally differentiated effector cells and memory cells to provide acute and long-lasting immunity, respectively. T-bet and Eomesodermin (Eomes), key transcription factors in this differentiation, share significant DNA binding domain sequence and functional homology, although their distinct expression patterns and non-DNA binding domains suggest potential non-redundant functions. T-bet drives effector and effector-memory differentiation, suppressing the formation of long-lasting central memory CD8+ T cells. We now show that CD8+ T cells responding to acute infection with the lymphocytic choriomeningitis virus (LCMV) display significant heterogeneity in the relative expression levels of T-bet and Eomes on a single cell level. Using mice with a tissue specific deletion of Eomes in T cells, we show defective central-memory differentiation in CD8+ T cells lacking Eomes after infection with LCMV. We observe defects in both long-term persistence and re-expansion on re-challenge, two defining characteristics of central-memory T cells, in memory CD8+ T cells lacking Eomes. These results demonstrate that, in direct contrast to T-bet, Eomes promotes central-memory CD8+ T cell differentiation. Thus, the balance of T-bet and Eomes expression may determine the propensity for CD8+ T cell terminal effector differentation versus long-lived memory differentiation. Our findings demonstrate a crucial role for Eomes in the differentiation of pathogen specific central memory CD8+ T cells which can provide life-long immune protection.

Disclosures:
No relevant conflicts of interest to declare.
Prognostic Value of Angiogenesis Assessment in Chronic Lymphocytic Leukemia: More Data Needed.
Authors: Antic Darko , Cokic Vladan , Fekete Marija Dencic , Perunicic Maja , Mihaljevic Biljana , Boskovic Darinka 
Published: October 2019

Abstract
Abstract 4396

Introduction
The association between angiogenesis and cancer progression in solid tumors has been documented, but its significance in chronic lymphocytic leukemia (CLL) has not been completely evaluated. Vascular endothelial growth factor /VEGF/ is the major pro-angiogenic factor in humans and his transduction pathway may be very active in CLL cells contributes to their enhanced survival. In this context VEGF can be additional tool for predicting the clinical course in early CLL.

Patients and Methods
To predict the risk of disease progression, we analyzed serum levels VEGF (sVEGF) using ELISA tehnique in 33 Binet stage A de novo CLL patients. In addition, We analyzed microvessel density (MVD) of the same patients using immunohistochemical staining with CD34 and vWf. Finally, we explored wheather changes of circulating VEGF concentrations and MVD reflected clinico-biological features of CLL (peripheral blood lymphocytosis (PBL), bone marrow (BM) histology, beta-2 microglobulin (β2m) level, lactat dehidrogenase (LDH) level) and kariotype abnormalities.

Results
The VEGF serum levels (sVEGF) was not significantly elevated (p=0.31) in CLL patients (mean: 70.9 pg/mL; range: 16–483) compared with and age- and sex-matched healthy controls (mean: 44.7 pg/mL; range: 22–69.2). sVEGF level positively correlated with elevated LDH level (p=0.008), but no correlation with other clinico-biological features was found.
Bone marrow MVD was significantly higher (p<0.0001) in CLL patients (mean: 35.91 vessels/field ± 15.71) compared to controls (mean:8.27 vessels/field ±6.19). Also, there was a significant difference between MVD counts according to the antibody used. MVD was higher using CD34 vs vWF (CD34, 35.91 vessels/field ±15.7, vs vWF, 8.15 vessels/field ±4.65, p<0.0001). Bone marrow MVD detected by CD34 was significantlyhigher in patinents with CD38 expression more than 30% (p=0.006). However, no significant MVD differences were detected between CLL subgroups with regard to clinical course, pattern of marrow infiltration, Rai stage and FISH abnormalities.
In univariate analysis sVEGF (p=0.018), Rai substages (p=0.027), PBL (p=0,030), β2m level (p=0.008) and diffuse bone marrow infiltration (p=0.006) were significantly associated with increased risk of disease progression. But, in multivariate analysis only sVEGF (p=0.002) and β2m level (p=0.008) retained their prognostic significance.

Conclusions
Serum VEGF level although not increased in comparasion with healthy controls, may improve the assessment of individual prognosis of patients with early CLL. Assessment of real clinical significance of bone marrow angiogenesis in CLL is required.

Disclosures:
No relevant conflicts of interest to declare.
Treatment of Patients with Autoimmune Cytopenia and Progressive CLL Using Rituximab, Cyclophosphamide, Vincristine, and Prednisone (R-CVP).
Authors: Zent Clive S. , Bowen Deborah , Call Timothy G , Shanafelt Tait D. , Kay Neil E. , Slager Susan L , Schwager Susan , Rabe Kari , Reinalda Megan 
Published: October 2019

Abstract
Abstract 4410

BACKGROUND
Autoimmune cytopenia occurs in 5%-10% of patients with CLL. Treatment for patients with both autoimmune cytopenia and progressive CLL is challenging due to poor tolerance of myelosuppression, and the risk of exacerbation of autoimmune cytopenia by purine analogues.

METHODS
We identified 20 patients from our CLL database of approximately 3000 patients who were treated with a chemoimmunotherapy regimen of rituximab, cyclophosphamide, vincristine, and prednisone (R-CVP) for both autoimmune cytopenia and progressive CLL from January 2000-December 2008 at Mayo Clinic Rochester.

RESULTS
Autoimmune cytopenia responded in 19 patients (14 CR and 5 PR) with a median time to progression (TTP) of 13.6 months (range 5 – 29). Five patients remain in sustained remission at last follow up (range 15 – 30 months) and 4 patients have had recurrent autoimmune cytopenia requiring re-treatment. Six patients required maintenance corticosteroid therapy after completing R-CVP. Progressive CLL responded to treatment in 17 patients (9 CR/CCR, 8 PR by NCI-WG 1996 criteria) with a median TTP of 6.3 months (range 1-40 months). Fourteen patients have required additional treatment for progressive CLL at a median of 5.4 months (range 4-22 months). Five patients have not required additional treatment for either CLL or autoimmune cytopenia at 15 -30 months after completing treatment. R-CVP treatment toxicity included 3 patients with grade 3-4 infections, 2 with grade 1 peripheral neuropathy, and one with grade 3 drug-induced pneumonitis. No patient required blood cell transfusions after the completion of cycle 1 of therapy.

CONCLUSIONS
Although R-CVP is an effective and tolerable therapy for patients with simultaneous autoimmune cytopenia and progressive CLL requiring therapy, the duration of response is suboptimal. Clinical trials testing alternative treatment strategies are needed for this patient population.

Disclosures:
Zent: Genentech, Bayer, Genzyme, Novartis: Research Funding. Shanafelt:Cephalon: Research Funding; Celgene: Research Funding; Polyphenon Pharma : Research Funding; Hospira: Membership on an entity's Board of Directors or advisory committees, Research Funding; Genentech: Research Funding; Bayer Health Care Pharmaceuticals: Research Funding. Kay:Biogenc-Idec, Celgene, Genentech, genmab: Membership on an entity's Board of Directors or advisory committees; Genentech, Celgene, Hospira, Polyphenon Pharma, Sanofi-Aventis: Research Funding.
The Alemtuzumab Treatment of Refractory to Fludarabine Chronic Lymphocytic Leukemia Patients.
Authors: Kataeva Elena , Golenkov Anatoly , Triphonova Elena , Buravtsova Iolanta 
Published: October 2019

Abstract
Abstract 4415
The aim of this study was to explore the efficiency of treatment with Alemtuzumab (A.) of chronic lymphocytic leukemia (CLL) patients (pts) refractory to Fludarabine(F.).

Meterials and methods
We observed 6 pts (3 male and 3 female). The median age was 56 years old(52-69). 4 of the pts had Rai stage I desease, 1 patient had Rai stage III, 1 had Rai stage IV. We revealed that 4 pts had 17p deletion with high level, 1 patient did not have del 17p, 1 - was not assessed. High level of the expression of CD38+ was determined, the median number was 37,3%(15-82). All pts were pretreated with Chlorambucil, COP, CHOP, FC for 18 months(7-48). All pts were refractory to F. 5 pts received A. monotherapy during median 9 weeks (2-18). Subcutaneous(SQ) A. dose escalation: 3mg-10mg-30mg on days 1,3,5, followed by 30mg Monday, Wednesday and Friday for 17 weeks. 1 patient received 5 courses FluCam(A. 30 mg 1,2,3 days IV after dose escalation 3mg-10mg-30mg, F. 25mg/m2 1,2,3 days). All pts received PCP, herpes and cytomegalovirus(CMV) and fungal prophylaxis as well as CMV viral DNA monitoring.
Responses were based on NCI-WG 1996 criteria. Minimal residual disease (MRD) was measured in peripheral blood and bone marrow aspirate using flow cytometry for CD19+/CD5+/CD23+ lymphocytes.

Results
The efficiency of the treatment of CLL pts was following: 2 pts (33,3%) displayed disease progression(PD) in 2 and 4 weeks of A. monotherapy, 2 pts achived (33,3%) CR in 14 and 16 weeks, 2 pts (33,3%), achived PR, among them 1 patient showed PR after 5 FluCam courses, the other — after 14 weeks of A. monotherapy. At the completion of the study 4 pts (66,6%) had no evidence of MRD by flow cytometry(<0,01%).

Conclusion
Obtained results showed high effectiveness of A. and acceptable toxity, among resistant to F. CLL pts (66,6% responded), the majoority of them had unfavourable del 17p.

Disclosures:
No relevant conflicts of interest to declare.