bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Enhanced Physical Activity on Hematopoietic Stem Cell Aging in PEPCK-Cmus Transgenic Mice
Authors: Qu William W. , Hakimi Parvin , Berger Nathan A. , Hanson Richard W. 
Published: October 2019

Abstract
Abstract 1297
Hematopoietic stem cells (HSCs) are self-renewing multipotent precursor cells that give rise to all blood cell lineages. As HSCs age, expansion of the pool of HSCs and abnormal production of blood cells occur, resulting in a loss of immune function and an increased incidence of myeloid leukemia. Exercise has been associated with an extended lifespan, yet the connection between HSC fitness and enhanced physical exercise is currently unclear. Transgenic mice that over-express the gene for the cytosolic form of phosphoenolpyruvate carboxykinase (PEPCK-C) in their skeletal muscle (PEPCK-Cmus mice) have remarkable endurance, can run five to six kilometers at a speed of 20 meters per minute without stopping, and have a markedly longer lifespan. We thus determined the effects of enhanced physical activity on HSC aging by measuring the pool size and functional ability of HSCs in both aged PEPCK-Cmus transgenic and control mice. Cell surface immunostaining and flow cytometric analysis were performed to determine the total quantity of HSCs within the bone marrow cell population of both groups of animals. Preliminary studies showed that age-associated expansion of the HSC pool was absent in PEPCK-Cmus mice. However, the efficiency of HSCs to produce B lymphoid progenitors in PEPCK-Cmus mice was surprisingly 11-fold higher than that in control mice while the age-associated skewness of HSC differentiation toward the myeloid lineage was diminished in PEPCK-Cmus mice. Furthermore, reactive oxygen species (ROS), known to be associated with aging when at high levels, were lower in the HSCs of PEPCK-Cmus mice than was noted in the HSCs of control animals. Together, these preliminary data imply that the functional capacity of HSCs is maintained in old PEPCK-Cmus mice when compared to that of the HSCs in control animals of the same age. This suggests that enhanced physical activity may slow HSC aging, possibly attributed in part to decreased ROS levels.

Disclosures:
No relevant conflicts of interest to declare.
The Midostaurin (PKC412) Metabolite CGP52421 Shows Little Growth-Inhibitory Activity Against Against Neoplastic Mast Cells but Retains Inhibitory Effects on IgE-Dependent Activation and Histamine Release
Authors: Peter Barbara , Blatt Katharina , Stefanzl Gabriele , Hadzijusufovic Emir , Dutreix Catherine , Gross Stefan H , Roesel Johannes L , Valent Peter 
Published: October 2019

Abstract
Abstract 1417
The multikinase inhibitor midostaurin (PKC412) is currently tested in clinical trials in patients with advanced systemic mastocytosis (SM). Although clinical symptoms improve in many patients and sometimes the proliferation of neoplastic mast cells (MC) can be kept under control for some time, most patients progress after a variable latency period, even if their mediator-related symptoms are still completely suppressed. In vivo, midostaurin is metabolized to two major and active metabolites, namely CGP62221 and CGP52421. Whereas the in vitro effects of midostaurin on growth and activation of MC are well documented, only little data on effects of midostaurin-metabolites are available. We examined the effects of midostaurin and its pharmacologically relevant metabolites CGP52421 and CGP62221, on IgE-dependent mediator secretion in basophils as well as growth of primary neoplastic MC and the human MC leukemia cell line HMC-1. All three compounds were found to inhibit IgE-dependent secretion of histamine in blood basophils, with comparable IC50 values (<1 μM). Midostaurin and CGP62221 were also found to inhibit the proliferation in HMC-1.1 cells and HMC-1.2 cells with IC50 values ranging between 50 and 250 nM. However, the second metabolite of PKC412, CGP52421, did not produce comparable anti-proliferative effects, even when applied at concentrations up to 1 μM. Corresponding results were obtained when analyzing drug-effects on primary neoplastic MC obtained from two patients, one with indolent SM and one with aggressive SM. Furthermore, whereas midostaurin and CGP62221 induced apoptosis in HMC-1.1 and HMC-1.2 cells as evidenced by light microscopy, caspase 3 staining and TUNEL assay, CGP52421 did not induce apoptosis in neoplastic MC. Finally, midostaurin and CGP62221 were found to induce dephosphorylation of KIT V560G and KIT D816V in HMC-1 cells, whereas no effects of CGP52421 on KIT activation were seen. In drug competition experiments, the metabolite CGP52421 did not interfere with midostaurin- or CGP62221-induced growth inhibition in HMC-1 cells. In conclusion, the pharmacologically relevant midostaurin metabolite CGP52421 inhibits IgE-mediated histamine release but does not efficiently block KIT-dependent proliferation of neoplastic MC. This observation may help to explain clinical responses including improvement of mediator-related symptoms seen in midostaurin-treated patients with advanced SM, and would favor the development of new treatment concepts employing midostaurin as an inhibitor of both MC activation and MC growth in patients with SM.

Disclosures:
Dutreix: Novartis: Employment. Gross:Novartis: Employment. Roesel:Novartis Pharma AG: Employment. Valent:Novartis: Consultancy, Honoraria, Research Funding.
Mir-222-221 Induce Dexamethasone Resistance by Targeting BBC3/PUMA in Human Multiple Myeloma
Authors: Zhao Jian-Jun , Chu Zhangbo , Lin Jianhong , Tai Yu-Tzu , Munshi Nikhil C. , Anderson Kenneth C. , Carrasco Ruben 
Published: October 2019

Abstract
Abstract 1419

ABSTRACT
Dexamethasone is a conventional drug that effectively induces multiple myeloma (MM) cell death at presentation and in relapsed patients and continues to be used against MM alone or in combination with the new therapeutic agents. However, still remain unclear the mechanism of Dexamethasone resistance in clinic. We now report new mechanisms of Dexamethasone resistance implicating microRNAs (miR). MicroRNAs are noncoding small RNAs (18–25nt) that play an important role in the regulation of gene expression. Recently our profiling study in MM1S and MM1R cells has shown that miR-222-221 are highly expressed in MM1R cells as compared with MM1S cells. Our further investigation showed that enforced expression of miR-222-221 could render cells resistant to Dexamethasone and that the resistance to this drug could be partially restored by ectopic expression of PUMA without 3'UTR region. The list of microRNAs regulators for PUMA (BBC3) 3'UTR region in targetscan website includes miR-221 and miR-222. We also found a negative relationship between miR-222-221 levels and therapeutic response in clinical samples by using Q-RT-PCR, IHC and ISH methods. So we propose that miR-222-221 could target PUMA to induce Dexamethasone resistance in MM. Ectopic expression of miR-222-221 in MM1S cells resulted in decreased expression of PUMA protein and mRNA, whereas knockdown expression of miR-222-221 could restore PUMA expression in MM1S cells. Notably, miR-222-221-transfected MM1S cells became resistance to Dexamethasone as compared to vector-treated cells. Further, the knockdown of miR-222-221 sensitizes the MM1R cells to Dexamethasone-induced cell growth arrest and apoptosis. These findings indicate that the miR-222-221 play a significant role in regulation of PUMA expression level and could be potential targets for restoring PUMA expression and response to Dexamethasone therapy in a subset of MM patients. We are currently investigating the role of miR-222-221 in Dexamethasone resistant in vivo using well established mouse xenograft models of MM.

Disclosures:
No relevant conflicts of interest to declare.
Germline Mitochondrial DNA Mutations As a Novel First Event in Childhood Myelodysplastic Syndrome
Authors: de Vries Andrica , Zwaan Christian M. , Beverloo H. Berna , Wagner Anja , Lankester Arjan , te Boekhorst Peter , de Coo Rene , Schoonderwoerd Kees , Smeets Bert , Polychronopoulou Sophia , Pieters Rob , van den Heuvel Marry M. 
Published: October 2019

Abstract
Abstract 1711

Introduction:
Mutations in the mitochondrial DNA (mtDNA) have been found in 50–60% of adult MDS patients, with an increasing frequency with rising age and ahigher incidence in more advanced MDS. In general, cells contain different amounts of mitochondria which can simultaneously harbour wildtype and mutated mtDNA. Co-existence of normal and mutant mtDNA is referred to as heteroplasmy, whereas the existence of only mutated mtDNA is called homoplasmy. As yet no information is available on the role of mtDNA mutations in pediatric MDS. We recently identified a family with (germline) mtDNA mutations and childhood MDS. We hypothesized that mtDNA mutations, catalyzed by ATP deficiency, reflect the genetic instability of the stem cells that facilitates that the development of MDS clone initiation and subsequent clonal evolution to acute myeloid leukemia triggered by type I and II events.

Methods:
Based on our findings in the above mentioned cases we analyzed the role of mtDNA mutations in the index family, in combination with studying oxidative phosphorylation, as well as in an extended cohort of 19 childhood MDS patients, including sporadic primary, therapy-related and familial MDS, using Mito-Chip (Affymetrix) and direct sequencing validation approach. To investigate whether the mutations were germline or somatic, in a subset of patients, germline mtDNA mutation analysis was performed.

Results:
In 14/19 of the pediatric MDS patients non-recurrent mtDNA mutations were found. Mt-mutational status was not correlated with the different WHO subgroups of childhood MDS. Heteroplasmic mutations were only found as somatic events, whereas. germline mutated cases were solely homoplasmic.

Conclusion:
We describe the first family in which germline mtDNA mutations trigger the devlopment of MDS, and show for the first time, that also in sporadic MDS cases, germline homoplasmic mutations may genetically predispose for developping childhood proliferative myeloid disease.

Disclosures:
No relevant conflicts of interest to declare.
Analysis of Efficacy and Costs of Antifungal Prophylaxis in Patients Undergoing Chemotherapy for Acute Leukemia: “Real Life” Evaluation
Authors: Bertz Hartmut , Drognitz Kathrin , Proskurin Tatjana , Lubbert Michael 
Published: October 2019

Abstract
Abstract 2081

Background:
Antifungal prophylaxis (AP) and therapy (AT) are increasing the costs during treatment for acute myeloid leukemia (AML). Efficacy of AP, empirical (EMP) and diagnostic tool led pre-emptive (PRE) AT still need to be evaluated and improved.

Methods:
In 2010 we performed a prospective study analysing all consecutive patients (pts) treated for AML in terms of AP/AT, choice and costs of the applied diagnostic procedures and EMP or PRE AT. All pts received regular lung CT scans, Galactomannan (Gal) and ß D-glucan (ß-D) tests. AP switched every three months between posaconazole (P) and fluconazole (F) to evaluate P-prophylaxis. Planned EMP consisted mainly of liposomal Amphotericin (LAMB) 1 mg/kg and planned PRE of LAMB 3 mg/kg.

Results:
In 37 pts. 86 cycles (cs) of induction (IND; n=51)/consolidation (CONS; n=35) chemotherapy have been documented. F 200mg/d as AP was given in 46 and P 600mg/d in 40 cs. EMP or PRE was initiated in 9+9 /46 cs (IND n=14; CONS n=4) of F (39%) and in 8+9 / 40 cs of P (42.5%; p=n.s.) (IND n=14; CONS n=3); EMP/PRE AT consisted mainly of LAMB 1 (n=12) or LAMB 3 (n=17) with no further antifungal drug escalation in 26/29 cs (89.6%); in 4 cs toxicity led to modification after 10 days in median of LAMB. 23/121 CT scans (19%; 119€ each), 31/277 ß-D (11%; 55€ each) and 13 / 440 GAL tests (3 %; 9€ each) were positive resulting in mean diagnostic costs of 372 €/c. In only 5/86 cs (6%) all 3 and in 7/86 cs (8%) 2 procedures showed positive results simultaneously. No proven, 10 probable (P and F AP: n=5 each) and 7 possible fungal infections (P n=5; F n=2) were detected. No patient died due to IFI, 3/37 pts. due to AML and none experienced > grade 3 toxicity by antifungal therapy.

Conclusions:
Recommended posaconazole AP showed no advantage compared to F but strikingly higher expenses (mean cost 2438 € vs. 24 €/c). LAMB as primary AT showed very convincing clinical results. These results underline that clinical signs/judgement and CT scan are still the leading, inexpensive decision tools for starting AT. Our consequences are stop of P as AP and of regular GAL/ß-D testing. This project is supported with a grant by GILEAD.

Disclosures:
Bertz: MSD: Membership on an entity's Board of Directors or advisory committees; GILEAD: Research Funding.
FLT3-ITD-Associated Accumulation of Dendritic Cell Precursors, Depletion of Mature Dendritic Cells and Abnormal Cytokine Production in Acute Myeloid Leukemia: Analyses At Diagnosis, Remission and Relapse
Authors: Stripecke Renata , Rickmann Mareike , Sundarasetty Bala Sai , Ganser Arnold 
Published: October 2019

Abstract
Abstract 2525
FLT3-ITD is a frequent (30%) mutation in AML, conferring proliferative advantage, self-renewability and blocking of myeloid differentiation. We had previously shown that ITD+ AML blasts show an accumulation of cells with characteristics of mixed-lineage dendritic cell (DC) precursors, but the effects of FLT3-ITD on the mature dendritic cell compartment and cytokine profile had not been previously described.
The frequency of different DC types in peripheral blood has been established for healthy donors (HD) such as Pan myeloid DCs (Lin−/DR+/CD11c+: 0.5 ± 0.3% frequency in HD), Pan plasmacytoid DCs (Lin−/DR+/CD123+: 0.15 ± 0.08% in HD), mature myeloid DCs type-1 (CD19−/CD14−/BDCA-1+: 0.35 ± 0.17% in HD), mature myeloid DCs type-2 (CD19−/CD14−/BDCA-3+: 0.04 ± 0.02% in HD), and mature plasmacytoid DCs (CD19−/CD14−/BDCA-2: 0.23 ± 0.2% in HD). In this study, we analyzed the frequency of DCs in diagnostic samples of 12 ITD+ compared with 22 ITD- AML patients, and in sub-cohorts of ITD+ patients in remission and relapse.
We demonstrate that ITD+ patients at diagnosis showed a significantly higher frequency of mixed-lineage DC precursors (Lin−/DR+/CD11c+/CD123+: 13 ± 12%) than ITD- patients (5 ± 4.8%) whereas the frequency of all types of mature DCs was lower for ITD+ patients compared with ITD- patients. Analyses of remission samples (collected at 3–15 months after first diagnosis) revealed a regression of the mixed-lineage DC precursors, but the frequency of mature DCs in ITD+ patients remained consistently lower than for the ITD- or HD cohorts.
Remarkably, for one ITD+ patients who eventually relapsed (at 15 months), a gradual reduction in the frequency of BDCA-1 and BDCA-2 positive DCs was clearly noticeable at 9 months after diagnosis, at a time point when the ITD mutation was not yet detectable by RT-Q-PCR, whereas relapse was correlated with the resurgence of the mixed lineage CD11c+/CD123+ DC population (17% of PBMCs) and reduction in the frequency of BDCA-1 (0.07%) and BDCA-2 positive DCs (0.1%).
Luminex analyses of several cytokines secreted by the PBMCs from 6 ITD+ patients showed that samples collected at diagnosis expressed lower levels of inflammatory and homeostatic cytokines than in remission, such as TNF-alpha (36.67 vs. 101.22 pg/ml, p-value: 0.22), IL-6 (35.27 vs. 119.15 pg/ml, p-value: 0.19), IL-7 (2.84 vs. 16.27 pg/ml, p-value: 0.07) and IL-8 (5682.59 vs. 10108.98 pg/ml, p-value: 0.07).
This is the first clinical evidence that FLT3-ITD undetectable minimal residual disease may affect the differentiation of DCs, potentially subverting the normal inflammatory and homeostatic immune reconstitution and thus hampering the anti-leukemia immune surveillance.

Disclosures:
No relevant conflicts of interest to declare.
EBV Copy Number Variation in Twins Discordant for Young Adult Hodgkin Lymphoma
Authors: Cozen Wendy , Hwang Amie , Marshall Vickie , Mack Thomas M , Whitby Denise 
Published: October 2019

Abstract
Abstract 2631

Background:
Epstein-Barr Virus (EBV) is a risk factor for some types of Hodgkin lymphoma (HL). Host response to the virus may play a role in pathogenesis and is in part determined by genetic factors. Therefore, using only traditional unrelated controls may not be appropriate.

Methods:
We compared EBV DNA copy number in peripheral blood mononuclear cells (PBMCs) collected from 63 young adult HL patients in remission and their unaffected co-twins, and 43 spouse controls. Viral load was measured with TaqMan quantitative PCR assays, tested in triplicate and reported as viral copies per million cells. Samples positive in all 3 replicates were classified as positive, and those positive in 1–2 samples were classified as qualitative positive (QP). EBV copy number was log-transformed for some analyses. A binomial proportion test was used to compare EBV copy number in cases and their unaffected co-twins (n=50 like-sex pairs). Conditional (case vs. unaffected co-twin) and unconditional logistic regression (case and unaffected co-twin vs. spouse controls) were used to estimate the effect of EBV copy number on risk as a categorical (positive, QP, or negative) or continuous variable (SAS 9.1). Unconditional logistic regression analyses were adjusted for sex and age.

Results:
26% of case, 18% of unaffected co-twins and 9% of spouse controls had positive EBV copy number measurements. Like-sex young adult HL cases had higher EBV copy numbers compared to their unaffected co-twins (P = 0.04). When EBV copy number was considered as a categorical variable, both cases and monozygotic unaffected co-twins were more likely to be positive compared to controls (cases v. controls: Odds Ratio [OR] = 3.2, 95% confidence intervals [CI] = 0.9, 11.1; unaffected co-twins v. controls: OR= 3.6, 95% CI= 0.9, 14.6). However, there was little difference between dizygotic unaffected co-twins and controls (OR= 0.7, 95% CI = 0.5, 5.5).

Conclusions:
That young adult HL cases had higher EBV DNA copies than their unaffected co-twins implies that an acquired pre-disease factor or disease affect altered the host response to EBV. However, that both cases and unaffected co-twins had higher EBV DNA copies compared to controls suggests that there is also a heritable component to the host response to EBV.
HL cases > co-twins (acquired or disease effect)
HL cases and co-twins > controls (heritable effect)

Disclosures:
No relevant conflicts of interest to declare.
Immunoregulation of Human Myeloid Dendritic Cells and Monocytes by Vascular Endothelial Growth Factor,
Authors: Sanchez Washington Yamandu , Wang Ran , Wilkinson Andrew , Khalil Dalia , Hart Derek NJ , Catley Laurence , Vuckovic Slavica 
Published: October 2019

Abstract
Abstract 3212
Vascular endothelial growth factor (VEGF), produced by many tumours including multiple myeloma (MM), has been reported to regulate the function of myeloid cells inducing myeloid-derived suppressor cells that suppress T cell responses. Little is known about the effect of VEGF on human myeloid cells including myeloid dendritic cells (MDC) and monocytes during their lifespan in bone marrow (BM) and peripheral blood (PB). We analysed the capacity of rhVEGF165 to regulate. MDC (CD11c+CD16+MDC and CD11c+CD16−MDC) and CD14+ monocytes that reside in the BM of humanised (hu)NOD/SCID mice or in peripheral blood (PB) of adult healthy subjects.
The CD11c+CD16−MDC and monocytes located in the femur, tibia and pelvic bones had elevated VEGFR-1 and VEGFR-2 surface expression compared to those located in the vertebrae and skull. Surface expression of VEGFR-1 and VEGFR-2 was negligible on CD11c+CD16+MDC, CD11c+CD16−MDC and monocytes in PB, however, VEGFR-1 mRNA was detected in CD11c+CD16+MDC and monocytes, and VEGFR-1 and VEGFR-2 mRNA in CD11c+CD16−DC. Treatment with rhVEGF165 had no effect on maturation status of MDC and monocytes residing in BM and PB, as measured by MHC-class II, CD40, CD86, CD83 expression. However, rhVEGF165 treatment regulated the capacity of MDC and monocytes to stimulate T cell responses by inducing several disparate outcomes, enhancing the capacity of CD11c+CD16−MDC, diminishing the capacity of monocytes and no effect on CD11c+CD16+MDC.
Our data suggests that the paradigm of VEGF-induced myeloid-derived suppressor cells is not as simple as originally predicted and it is likely that VEGF regulates myeloid cells to varying degrees depending on their developmental status.

Disclosures:
No relevant conflicts of interest to declare.
Positron Emission Tomography Status and Tandem High-Dose Therapy Favorably Influence Outcome of Patients with Relapsed and/or Refractory Hodgkin Lymphoma
Authors: Devillier Raynier , Coso Diane , Castagna Luca , Brenot-Rossi Isabelle , Anastasia Antonella , Chitit Arturo , Schiano Jean Marc , Santoro Armando , Chabannon Christian , Balzarotti Monica , Blaise Didier , Bouabdallah Reda 
Published: October 2019

Abstract
Abstract 335
The cure of relapsed or refractory Hodgkin Lymphoma (HL) still remains a challenge. High dose chemotherapy followed by autologous stem cell transplantation (ASCT) is the standard of care but almost half of patients relapse after ASCT and have poor outcome. Predictive factors including an interval from end of first line therapy to relapse shorter than 12 months, an Ann-Arbor stage III or IV at relapse, and relapse in previously irradiated field are currently used to identify patients with poor outcome. Development of 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) assessment improves evaluation of response both in first line and salvage treatments. The aim of our study is first to confirm the predictive value of PET status before ASCT and then to compare ASCT strategy (single versus tandem) in patients with relapsed and/or refractory HL. We here report a series of 111 consecutive patients with relapsed and/or refractory HL who achieved at least partial remission (PR) at PET evaluation after one line of salvage chemotherapy and who underwent single or tandem ASCT. PET response assessment showed 85 (77%) patients in CR (PET- group) and 26 (23%) in PR (PET+ group). Five-year overall (OS) and progression free survival (PFS) were 81% and 64% respectively. There were significant differences in 5-year PFS (79% versus 23%, p<0.001) and 5-year OS (90% versus 55%, p=0.001) between PET- and PET+ groups respectively. This predictive value remained significant in both favorable/intermediate and unfavorable subgroups. In PET+ subgroup analysis, tandem ASCT dramatically improved 5-years PFS, from 0% to 43% (p=0.034) compared to single ASCT. Multivariate analysis showed that PET status (HR: 5.26 [2.57–10.73]) and tandem ASCT (HR: 0.39 [0.19–0.78]) but not relapse risk (HR: 1.77 [0.80–3.92]) significantly influenced PFS, while only PET status significantly influenced OS (HR: 4.03 [1.38–11.75]). Our results suggest that I) PET status before ASCT must be considered as a strong and significant prognostic factor influencing outcome and identifying high risk patients for more intensive strategy II) Tandem ASCT improved outcome compared to single ASCT, especially for PET+ patients.

Disclosures:
No relevant conflicts of interest to declare.