bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inflammatory Bone Loss Drives Skeletal Deterioration in a Murine Model of Sickle Cell Disease
Authors: Archer David R. , Mulupuri Prasad , Chappa Prasanthi , Vikulina Tatyana , Roser-Page Suzanne , Yamaguchi Masayoshi , Capers Patrice L , Hyacinth Hyacinth I , Hibbert Jacqueline , Weitzmann Neale 
Published: October 2019

Abstract
Abstract 4855
Sickle cell disease (SCD) results from a point mutation in the beta globin gene that leads to the replacement of glutamic acid with a valine at the sixth position of the beta globin chain of hemoglobin. Children with SCD experience delayed skeletal maturation and more than 70% of adult SCD patients' exhibit osteopenia or osteoporosis. The underlying mechanisms responsible are unclear; however in a number of disorders inflammation is established to drive bone loss. Importantly, persistent immune-activation in SCD leads to a chronic inflammatory state that may be pertinent. In this study we characterized the skeletons of four month old Berkeley SCD mice, an animal model that recapitulates key features of SCD including inflammation. We show that as in children with SCD, the skeletons of SCD mice have significantly reduced bone mineral density (BMD). Micro-computed tomography shows that homozygous sickle cell mice were also significantly denuded in cancellous and cortical bone volumes, a consequence of an enhanced pro-osteoclastogenic bone microenvironment. Similarly to animal models of postmenopausal osteoporosis we found a significant increase in T cell activation state and TNFa production in SCD mice, and an elevated expression of receptor activator of NF-kB ligand (RANKL), the key osteoclastogenic cytokine in the bone marrow. Finally, we show a significantly elevated number of monocytes (early osteoclast precursors) that likely further amplifies osteoclastogenesis in the context of elevated RANKL in SCD. Taken together our data validate the Berkeley sickle mouse as a suitable model to explore the mechanisms of bone loss in SCD, and suggest a disruption in the immuno-skeletal interface resulting from chronic inflammation as key to bone loss in SCD.

Disclosures:
No relevant conflicts of interest to declare.
Addition of Hemoglobin Level Into the Prognostic Scoring System Together with White Blood Cell and Platelet Count Provides Better Prognostic Stratification for Overall Survival, Complete Remission Rate and Early Death, but Not for the Relapse Risk in Adult Patients with Acute Promyelocytic Leukemia
Authors: Park Silvia , Jung Chul Won 
Published: October 2019

Abstract
Abstract 4898

Background:
Although the introduction of all-trans retinoic acid (ATRA) and combined chemotherapy improved clinical outcomes of acute promyelocytic leukemia (APL), treatment failure still occur due to early death or disease relapse. The PETHEMA study suggested that the risk adapted stratification of disease into 3 groups (low, intermediate and high risk) according to the white blood cell (WBC; 10×109/L) and platelet counts (40×109/L) could improve treatment outcomes of APL patients. However, this stratification system needs to be validated in an independent cohort of patients. The current study attempted to validate the prognostic significance of WBC count, platelet counts, hemoglobin level and PETHEMA risk stratification system in Asian population and to propose new clinical prognostic system consisting of WBC counts, platelet counts and hemoglobin level.

Methods and patients:
Between 2000 and 2009, total of 156 consecutive patients with APL from 7 institutes in Republic of Korea were retrospectively reviewed. The patients received Idarubicin/ATRA based combination chemotherapy during remission induction, and consolidation therapy was given with idarubicin monotherapy or Idarubicin plus cytarabine. In the new 3 score prognostic model, WBC more than 10×109/L, platelet less than 40×109/L as well as hemoglobin less than 8g/dL were separately considered as an one risk factor, and patients having “0”, “1” and “2 or 3” risk factors fall into a score “0”, “1” and “2”, respectively.

Results:
With median follow-up of 3.8 years, the CR rate following remission induction treatment was 81.4% in overall patients (127 out of 156), and 24 (15.4%) were considered as failures due to early death (ED) within 30 days of APL diagnosis. The 4-year OS, LFS and CIR rate was 73.8±4.1%, 85.7±3.7, and 18.7±3.8%, respectively. Compared to the single variables such as WBC count, platelet count or hemoglobin level, the combined prognostic system such as PETHEMA stratification or CBC score provided better stratification for the prognosis in APL patients. The risk stratification system by PETHEMA could predict OS (p=0.014) and ED (p=0.024), but not CR rates or relapse. However, the proposed 3 score prognostic system could provide better stratification of APL patients in term of the CR rates (p=0.004), OS (p=0.004) and ED (p=0.008), but not of relapse risk.

Conclusions:
This retrospective study suggested that the proposed 3 score prognostic system could provide better stratification of APL patients in term of the CR rates, OS and ED, but not of the relapse risk. Prospective study with a single protocol will be needed to reach a clean conclusion of better clinical prognostic stratification of APL patients.

Disclosures:
No relevant conflicts of interest to declare.
Immunophenotyping Features in Acute Myeloid Leukemia (AML) with NPM1+ and/or FLT3+
Authors: Topcuoglu Pervin , Dalva Klara , Bozdag Sinem Civriz , Arslan Onder , Ozcan Muhit , Ilhan Osman , Akan Hamdi , Beksac Meral , Gurman Gunhan 
Published: October 2019

Abstract
Abstract 4908
Immunophenotyping Features in Acute Myeloid Leukemia (AML) with NPM1 and/or FLT-3 Positive
Pervin Topçuoglu, Klara Dalva, Sinem Civriz Bozdag, Önder Arslan, Muhit Özcan, Osman Ýlhan, Hamdi Akan, Meral Beksaç, Günhan Gürman

Aim:
We aimed to evaluate immunophenotypical (IP) features in AML pts with NPM1+ and/or FLT3+ except on acute promyelocytic leukemia.

Patients&Method:
Between Nov 2009 and Feb 2011, we retrospectively analyzed IP features by flow cytometry (FCM) in 51 pts (46M;17F) with new diagnosed AML. Median age was 46 years (range: 14–71 ys). The mutations of NMP1 and FLT-3 TKD&ITD were determined by the methods of RQ-PCR or RFLP, respectively in the samples of bone marrow (n=31) or periheral blood (n=20) at the diagnosis. Antigenic expression of leukemic cells was analyzed by four-color FCM (FITC, PE, PerCP&APC) based by Nomdedeu et al researh (Leuk res 2011; 35:163) (Table-1).

Results:
We detected NMP1+ mutation in 16 patients. Of these, three were associated with mutations of FLT3-ITD (n=2) or -TKD (n=1). Twelve patients had FLT3+ (9 ITD or 3 TKD). More than half of the patients without any mutation were CD15+/CD34+/HLA-DR+ and 11.5% for CD34 negative. Similarly, the patients with FLT-3 positive were mostly CD34+ as the pts w/o any mutations. Contrary, most of the pts with NMP1+ were CD34 negative (56.3%) (Table 1). When evaluated the complete IP in leukemic cells, the expression of CD123 was significantly marked in the patients with NPM1+ and/or FLT3+ than those w/o mutations (p=0.008). While the co-expression of CD7 and CD117 was found in 67% of the pts w/o any mutations, 30% of the pts with NMP1 and/or FLT-3 ITD (p=0.01). CD56 expression was detected in more pts with NMP1+ than those with FLT-3+ (40% vs 8%, p=0.04). Besides, CD36 expression was positive in the all pts with FLT3-ITD than TKD+ (p=0.005). More intensive CD33 expression was seen in NMP1+ pts. The expression of CD64 was similar in all three mutations.

Conclusion:
Though NMP1 mutation was associated more CD34+ cells, more FLT3+ pts had CD34 positivity. The expression of CD123 was especially associated with the mutations. Aberrant expression of CD56 was in more pts with NPM1+, but CD36 for FLT3-ITD. These data might be a step for a study aiming to show a correlation between the type of mutations combined with IP features of leukemic cells and clinical characteristics or disease course of AML pts.

Disclosures:
No relevant conflicts of interest to declare.
Allogeneic Hematopoietic Stem Cell Transplantation for Blastic Plasmacytoid Dendritic Cell Neoplasm
Authors: Zhou Hongsheng , Zhang Xian , Yu Guopan , Deng Yongjian , Jiang Qianli , Fan Zhiping , Sun Jing , Liu Qifa 
Published: October 2019

Abstract
Abstract 4938

Background
Blastic plasmacytoid dendritic cell neoplasm is a rare malignancy that typically follows a highly aggressive clinical course,formerly known as blastic natural killer (NK)-cell lymphoma and CD4+/CD56+ hematodermic neoplasm. Here we report 2 cases of blastic plasmacytoid dendritic cell neoplasm that underwent allogeneic stem cell transplantation.

Patients and Methods
Case one was recognized as acute lymphocyte leukemia and then was revised to BPDC at recurrence, and another initially presented with typical cutaneous involvement and was promptly diagnosed by biopsy. After induction/re-induction and subsequent consolidation chemotherapy, 2 cases of BPDC received HLA identical-sibling donor allogeneic stem cell transplantation (Allo-HSCT) after BU/Cy, TBI/Cy+VP-16 conditioning regimen, respectively. Both achieved rapid hematopietic recovery in 2 weeks. Multi-color labeling flow cytometry was performed to monitor minimal residual disease (MRD) and the patient received donor lymphocyte infusion (DLI) to control primary malignancy as MRD-triggered or preventive strategy.

Results
Case 1 survived refractory acyclovir-resistant Epstein-Barr virus viremia after rituximab treatment, but failed in DLI-related grade IV graft versus host disease (GVHD) mixed with thrombotic microangiopathy (TMA) on 1 year post-transplantation. Case 2 died from relapse.

Conclusion:
Allo-HSCT seems to be a promising treatment for aggressive BPDC aided with MRD monitoring and MRD-triggered DLI. GVHD mixed with TMA deserves more attention for treatment of refractory GVHD.

Disclosures:
No relevant conflicts of interest to declare.
Lymphomatoid Granulomatosis: A Clinicopathologic Study of a Series of Cases in a Single Institution
Authors: Chavez Julio C , Zhang Ling , Sagatys Elizabeth M. , Sokol Lubomir , Moscinski Lynn , Sotomayor Eduardo M. , Shah Bijal D. 
Published: October 2019

Abstract
Abstract 4960

Introduction:
Lymphomatoid granulomatosis is a rare lymphoproliferative disorder with a proclivity for extranodal involvement, including the lungs, brain, kidney, liver, and skin. It usually affects middle-age adults, with male predominance (M:F ratio >2:1). Its association with EBV (Epstein Barr Virus) infection has been described.

Objectives:
To present our experience of 8 cases of lymphomatoid granulomatosis at Moffitt Cancer Center (MCC) in the last 10 years. Results: We collected the data of 8 cases of lymphomatoid granulomatosis that were diagnosed and treated at MCC from January 2000 to January 2011. The median follow up was 7.5 months. Five out 8 (63%) cases were males. The median age was 65. 3/8 (12.5%) had a performance status (PS) more than 2. 4/8 (50%) of cases had elevated LDH. All patients (100%) had an Ann Arbor Stage IVE. The IPI (International Prognostic Index) was more than high-intermediate in 6/8 (75%) cases. 4/8 (50%) of cases were positive for EBV. 6/8 (75%) have received chemotherapy to date, most commonly R+CHOP. The median time to progression was 8.6 months (1-8 months) following the first treatment and was shorter after the second treatment (4.8 months). 2/8 (25%) are disease free after chemotherapy, all remaining patients have active disease. 2/8 (25%) have died at 7 and 13 months after diagnosis.

Conclusions:
Lymphomatoid granulomatosis is a rare lymphoproliferative disease. In our experience it presents as an advanced and high risk disease. Interestingly, EBV was found in only 50% of cases. The overall response to standard chemotherapy is suboptimal and further strategies are needed for optimal management. These might include aggressive chemotherapy and up front stem cell transplantation.

Disclosures:
No relevant conflicts of interest to declare.
A PML–PPAR-δ Pathway for Fatty Acid Oxidation Regulates Hematopoietic Stem Cell Maintenance Through the Control of Asymmetric Division.
Authors: Ito Keisuke , Carracedo Arkaitz , Arai Fumio , Ala Ugo , Avigan David , Schafer Zachary , Evans Ron M. , Suda Toshio , Lee Chih-Hao , Pandolfi Pier Paolo 
Published: October 2019

Abstract
Abstract 2327
Stem-cell function is an exquisitely regulated process. Thus far, the contribution of metabolic cues to stem-cell function has not been well understood. Here we have established a new assay for the assessment of asymmetric division in hematopoietic stem cells (HSCs), and identify a previously unknown promyelocytic leukemia (PML)–peroxisome proliferator-activated receptor δ (PPAR-δ)–fatty-acid oxidation (FAO) pathway for the maintenance of HSCs and the control of asymmetric cell division.
HSCs exist in a quiescent state in the bone marrow niche and are the source of all hematological progenitors and differentiated cells throughout the lifespan of an organism. One of the central tasks of stem-cell biology is to define the modes and mechanisms that regulate the self-renewal and commitment of stem cells, as alterations in this equilibrium have a substantial effect on hematopoietic homeostasis and maintenance. It has been suggested that asymmetric division of HSCs ensures that a fraction of daughter cells retain features of stem cells while replenishing the committed compartment of hematopoietic progenitors. Therefore, identifying the factors that regulate this process would be of great biological and therapeutic relevance.
The PML tumor-suppressor gene, originally cloned at the break point of the t(15;17) chromosomal translocation of acute promyelocytic leukemia, has a key role in the maintenance of HSCs. However, how PML exerts its crucial function in the biology and maintenance of HSCs has not been established. In this study, we will present a new metabolic pathway downstream of PML, which can be regarded as a fine-tuning rheostat essential for HSC maintenance and their asymmetric division.
Specifically, we find that loss of PPARδ or inhibition of mitochondrial FAO induces loss of HSC maintenance both in vitro and in vivo, whereas treatment with PPARδ agonists improved HSC maintenance. We demonstrate that PML exerts its essential role in HSC maintenance through regulation of PPAR signaling and FAO. Mechanistically, we show that the PML–PPAR δ–FAO pathway controls the asymmetric division of HSCs. Deletion of the Ppard or Pml genes as well as inhibition of FAO results in the symmetric commitment of HSC daughter cells, whereas PPARδ activation increases asymmetric cell division, and rescues the defect exhibited by Pml-deficient HSCs, therefore ensuring the correct maintenance of the HSC population.
Thus, our findings identify a metabolic switch for the control of HSC cell fate with potential therapeutic implications.

Disclosures:
Avigan: Curetech: Research Funding; Celgene: Research Funding; Genzyme: Membership on an entity's Board of Directors or advisory committees.
The Role of Bone Marrow T Cells in Regulating Hematopoietic Stem Cell Function.
Authors: Brandao Claudia , de Bruin Alexander M. , Nolte Martijn A. 
Published: October 2019

Abstract
Abstract 2349
After immune activation, effector/memory T cells, including virus-specific CD8 T cells, are known to migrate to the bone marrow (BM), where they can be maintained by the production of IL-15 by the stroma; however, it is not yet known whether these T cells also have a function at this site. Since depletion of T cells from allogenic BM grafts compromises HSC engraftment, we hypothesize that T cells can directly influence the balance between differentiation and self-renewal of hematopoietic stem cells (HSCs). To test the ability of T cells to affect hematopoiesis, we performed co-cultures of HSCs and T cells isolated from murine BM. We found that T cells localized in the BM are able to enhance HSC differentiation as well as their self-renewal capacity. This feature is specific for BM central memory (CM) CD8 T cells, since other T cell subsets are not able to affect HSCs to the same extent. Moreover, depletion of CM CD8 T cells from the total BM T cell pool abrogates the impact on HSC differentiation and self-renewal, indicating that this particular T cell population is both sufficient and required for the observed effects. BM CM CD8 T cells do not affect quiescence of HSCs, but do enhance their proliferative capacity, and we found that supernatant from CM CD8 T cells is sufficient for this effect. Interestingly, competitive transplantation assays showed that HSCs cultured with CM CD8 T cells-derived supernatant contribute much better to leukocyte formation than medium-treated HSCs. This effect is seen in both the myeloid and lymphoid compartment, indicating that CM CD8 T cells are able to release soluble factors that support and enhance the multilineage reconstitution capacity of HSCs. Functional studies with blocking antibodies or knock-out mice showed that the supernatant-mediated effect is not caused by the hematopoietic cytokines IL3, IL6, IL21, GM-CSF, RANTES, TNFα or IFNγ. Preliminary data indicate that this feedback mechanism of the immune system on the hematopoietic process in the bone marrow is also present in the human situation, since autologous BM T cells increase the numbers of human HSCs, as well as their differentiation capacity.
Overall, these findings demonstrate that T cells have an important function in the BM and that especially CD8 TCM cells can directly influence HSC homeostasis. We postulate that this feedback mechanism of the immune system on the hematopoietic process in the BM is particularly relevant during viral infection, as the efficient migration of virus-specific CD8 T cells to the BM could well benefit the replenishment of the HSC/progenitor cell compartment and restoration of blood cell numbers that got lost upon infection.

Disclosures:
No relevant conflicts of interest to declare.
DNMT3A Mutation Leads to Hematopoietic Dysregulation.
Authors: Xu Jie , Zhang Wei-na , Zhen Tao , Li Yang , Shi Jing-yi , Mi Jian-qing , Wang Yue-ying , Chen Sai-juan , Chen Zhu 
Published: October 2019

Abstract
Abstract 2382
Epigenetic modification process is required for the development of hematopoietic cells. DNA methyltransferase DNMT3A, responsible for de novo DNA methylation, was newly reported to have a high frequency of mutations in hematopoietic malignancies. Conditional knock-out of DNMT3A promoted self-renewal activity of murine hematopoietic stem cells (HSCs). However, the role of mutated DNMT3A in hematopoiesis and its regulative mechanism of epigenetic network mostly remain unknown. Here we showed that the Arg882His (R882H) hotspot locus on DNMT3A impaired the normal function of this enzyme and resulted in an abnormal increase of primitive hematopoietic cells. In both controlled in vivo and in vitro assays, we found that the cells transfected by R882H mutant promoted cell proliferation, while decreased the differentiation of myeloid lineage compared to those with wild type. Analysis of bone marrow (BM) cells from mice transduced by R882H reveals an expansion of Lin−Sca-1+C-kit+ populations and a reduction of mature myeloid cells. Meanwhile, a cluster of upregulated genes and downregulated lineage-specific differentiation genes associated with hematopoiesis were discovered in mice BM cells with R882H mutation. We further evaluated the association of mutated DNMT3A and HOXB4 which was previously detected to be highly expressed in clinical samples carrying R882 mutation. Compared with wildtype DNMT3A, R882H mutation disrupted the repression of HOXB4 by largely recruiting tri-methylated histone 3 lysine 4 (H3K4). Taken together, our results showed that R882H mutation disturbed HSC activity through H3K4 tri-methylation, and transcriptional activation of HSC-related genes.

Disclosures:
No relevant conflicts of interest to declare.
GLI1 Directly Regulates the Transcription of AKT Genes in Diffuse Large B-Cell Lymphoma.
Authors: Agarwal Nitin K , Qu Changju , Kunkalla Kranthi , Liu Yadong , Vega Francisco 
Published: October 2019

Abstract
Abstract 2399
Activation of the Hedgehog (Hh)/glioma-associated oncogene (GLI) pathway has been found in a growing number of malignancies. We have provided evidence that canonical Hh signaling is required for cell survival and proliferation of DLBCL cell lines. To confirm the pathogenic role of GLI1 in DLBCL, we established GLI1 knock down DLBCL cell lines (OCI-Ly19, HBL-1 and BJAB) using a lentiviral shRNA system and performed cell viability and apoptosis assays. Cell viability assays demonstrated that GLI1 knockdown DLBCL cells experienced a statistically significantly decrease in the number of viable cells in comparison with control cells harboring scramble shRNA. To examine whether decreases number of cell viability in GLI1 knock down cells were due to apoptosis, we performed annexin V and PI assays. We observed marked increase of apoptosis in GLI1 knock down DLBCL cells versus controls (2.5 fold increase for OCI-Ly10, and 5 fold for HBL1 and BJAB). To investigate the mechanism by which GLI1 regulates tumorigenesis and cell survival, we searched for whole genome GLI1-target genes in DLBCL cells using CHIP sequencing technique and identified AKT genes as potential targets of GLI1. Using pharmacological and silencing approaches, we observed that Hh signaling modulates the expression of AKT genes in DLBCL cells. We further identified two putative binding sites for GLI1 in the AKT1 promoter region and confirmed their functionality using chromatin immunoprecipitation, luciferase reporter and site-directed mutagenesis assays. To investigate whether there is any correlation between AKT1 and GLI1 mRNA expression in human DLBCL tumors, we performed quantitative real-time PCR analyses in 17 frozen DLBCL specimens including apharesis samples from pleural effusions. The real time PCR analysis revealed a strong Spearmen correlation coefficient (R2=0.9) between GLI1 and AKT1 mRNA expression. In summary, we provide evidence of the role of GLI1 in the pathobiology of DLBCL and demonstrated a cross talk, at the transcriptional level, between Hh signaling and AKT in DLBCL. A link between these 2 pathways at the trasncriptional level was not previoulsy documented. This finding is of clinical interest as AKT has a key role in lymphoma cell survival and constitutive activation of AKT has been described in DLBCL.

Disclosures:
No relevant conflicts of interest to declare.