bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Phenotype of Human STK4 Deficiency
Authors: Abdollahpour Hengameh , Appaswamy Giridharan , Beier Rita , Schäffer Alejandro A. , Gertz E. Michael , Kreipe Hans H. , Pfeifer Dietmar , Grimbacher Bodo , Lohrmann Sabine , Sherkat Roya , Klein Christoph 
Published: October 2019

Abstract
Abstract 692
Congenital neutropenia syndromes comprise a heterogeneous group of disorders, whose genetic etiology remains often unknown. We describe a consanguineous pedigree with several affected individuals characterized by predisposition to recurrent and chronic bacterial and viral infections. Affected patients had chronic bronchitis/bronchiectasis, recurrent bacterial and herpes simplex skin infections, and disseminated warts associated with human papillomavirus and molluscum contagiosum virus. One patient developed a lymphoproliferative disorder associated with EBV-infection. Patients had congenital neutropenia with fluctuating absolute neutrophil granulocyte counts (180-4000/μl), yet no evidence of cyclic neutropenia. Immunophenotyping of peripheral blood revealed a paucity of peripheral T- and B-cells. Interestingly all patients showed evidences of autoimmunity.
In addition all affected patients had subtle and hemodynamically not relevant cardiac defects such as ASD-II (P1), patent foramen ovale (P2) and patent foramen ovale associated with mitral, tricuspid and pulmonary insufficiency (P3).
Genome-wide genotyping and linkage analysis of the index family yielded a LOD score of 4.3 on a linkage interval on chromosome 20. Candidate gene sequencing revealed a homozygous nonsense mutation in exon 7 of the gene STK4 (formerly MST1). STK4 is the human ortholog of Drosophila Hippo, the central constituent of a highly conserved pathway controlling cell growth and apoptosis. Isolated STK4-deficient lymphocytes and neutrophils of these patients exhibit enhanced loss of mitochondrial membrane potential and increased susceptibility to apoptosis in response to various proapoptotic stimuli. Lymphopenia and congenital neutropenia may therefore be a consequence of increased loss of peripheral lymphocytes and neutrophils, similar to other well defined monogenetic diseases of the immune system. STK4 deficiency is a novel human primary immunodeficiency syndrome and highlights the role of the HIPPO pathway for the development of the human immune and cardiac systems.

Disclosures:
No relevant conflicts of interest to declare.
Modeling Congenital Amegakaryocytic Thrombocytopenia Using Patient-Specific Induced Pluripotent Stem Cells
Authors: Takayama Naoya , Hirata Shinji , Jono-Ohnishi Ryoko , Nakamura Sou , Hirose Sho-ichi , Endo Hiroshi , Nishi Masanori , Hamazaki Yuhei , Kaneko Shin , Ishii Eiichi , Nakauchi Hiromitsu , Kunishima Shinji , Eto Koji 
Published: October 2019

Abstract
Abstract 703
Patient-specific, induced pluripotent stem cells (iPSCs) enable us to study disease mechanisms and drug screening. To clarify the phenotypic alterations caused by the loss of c-MPL, the thrombopoietin (TPO) receptor, we established iPSCs derived from skin fibroblasts of a patient who received curative bone marrow transplantation for congenital amegakarycytic thrombocytopenia (CAMT) caused by the loss of the TPO receptor gene, MPL. The resultant CAMT-iPSCs exhibited mutations corresponding to the original donor skin. Then using an in vitro culture system yielding hematopoietic progenitor cells (HPCs), we evaluated the role of MPL on the early and late phases of human hematopoiesis.
Although CAMT-iPSCs generated CD34+ HPCs, per se, their colony formation capability was impaired, as compared to control CD34+ HPCs. Intriguingly, both Glycophorin A (GPA)+ erythrocyte development and CD41+ megakaryocyte yields from CAMT-iPSCs were also impaired, suggesting that MPL is indispensable for MEP (megakaryocyte erythrocyte progenitors) development. Prospective analysis along with the hematopoietic hierarchy revealed that, in CAMT-iPSCs but not control iPSCs expressing MPL, mRNA expression and phosphorylation of putative signaling molecules downstream of MPL are severely impaired, as is the transition from CD34+CD43+CD41-GPA- MPP (multipotent progenitors) to CD41+GPA+ MEP. Additional analysis also indicated that c-MPL is required for maintenance of a consistent supply of megakaryocytes and erythrocytes from MEPs.
Conversely, complimentary transduction of MPL into CAMT-iPSCs using a retroviral vector restored the defective erythropoiesis and megakaryopoiesis; however, excessive MPL signaling appears to promote aberrant megakaryopoiesis with CD42b (GPIba)-null platelet generation and impaired erythrocyte production.
Taken together, our findings demonstrate the usefulness of CAMT-iPSCs for validation of functionality in the human hematopoiesis system. For example, it appears that MPL is not indispensable for the emergence of HPCs, but is indispensible for their maintenance, and for subsequent MEP development. Our results also strongly indicate that an appropriate expression level of an administered gene is necessary to achieve curative gene correction / therapy using patient-derived iPSCs.

Disclosures:
No relevant conflicts of interest to declare.
Tissue Factor Pathway Inhibitor Increases Hematopoietic Stem Cell Homing and Engraftment by Glypican-3 Mediated Inhibition of CD26 Activity
Authors: Khurana Satish , Joseph Chacko , Margamuljana Lia , Buckley Shannon , Scouteden Sarah , Verfaillie Catherine M. 
Published: October 2019

Abstract
Abstract 725
Directional migration is an important factor that determines homing of transplanted hematopoietic stem cells (HSC). The SDF-1α-CXCR4 axis is one of the most important determinants of this process. CD26, expressed on various cell types, leads to proteolytic cleavage of SDF-1α, which leads to the inactivation of its chemokine activity. We identified tissue factor pathway inhibitor (TFPI) as an inhibitor of CD26. Culture of murine bone marrow derived c-kit+Lin−Sca-1+ (KLS) cells or human umbilical cord blood derived Lin−CD34+ cells with TFPI significantly inhibited CD26 activity, which resulted in significantly increased migration towards SDF-1α. Moreover, TFPI treatment of murine KLS cells led to significant improvement in homing following intravenous injection and long-term reconstitution upon transplantation in competitive repopulation assays. We found that the effects of TFPI were mediated by the heparan sulphate proteoglycan, Glypican-3 (Gpc3). TFPI directly bound Gpc3; TFPI did not affect CD26 activity, migration or homing of Gpc3−/− KLS cells, but affected Gpc1−/− KLS cells similar to the wild type. Finally, KLS cells from Gpc3−/− but not Gpc1−/− mice homed significantly less following IV injection. Hence, we present a novel molecule that can be used in an HSC specific manner to enhance HSC migration, homing and engraftment.

Disclosures:
No relevant conflicts of interest to declare.
Are Gene Expression Signatures Treatment Specific?
Authors: Shah Parantu K , Minvielle Stephane , Avet-Loiseau Hervé , Li Cheng , Munshi Nikhil C. 
Published: October 2019

Abstract
Abstract 807FN2
Gene expression profiling (GEP) of newly-diagnosed cancer patients is now a routine task in the oncogenomic research using functional genomics platforms like microarray and next generation sequencing. These profiles are then utilized to derive gene expression signatures (GES) that can stratify patients according to survival groups using various statistical methodologies. This is an active area of research with important implications on clinical decision making and patient care. It is important to note that the treatment itself probably plays a major role in influencing outcome in cancer. Therefore, the GES may be specific to a particular treatment and may not be universally applicable in predicting survival of patients treated with different therapeutic regimen.
We evaluated the impact of therapy on GES utilizing two large publicly available gene expression datasets from newly-diagnosed multiple myeloma (MM) patients generated using Affymetrix U133+2 microarrays. The dataset from University of Arkansas Medical Sciences (UAMS; Shaughnessy et al Blood 2007) has gene expression profile (GEP) from 569 patients treated on total therapy (TT)2 and TT3 protocols while the dataset from HOVON-65 trial contains GEO data from 320 patients treated with either the VAD or PAD regimen in equal numbers.
The UAMS dataset was partitioned into training and validation sets. Using a combination of a network inspired univariate ranking procedure and ultra refined methods for variable selection we derived a sparse multivariate survival signature consisting of 40 genes that worked extremely well on the training set (p-value < e-16) as well as the validation set (p-value < e-5). Interestingly we saw the difference of performance between TT2 and TT3 induction arms. The p values were 0.002 for the TT2 induction arm while for the TT3 the p value was 0.02. On applying the signature to the whole HOVON-65 test set our signature worked only moderately well (p-value = 0.003). When the HOVON-65 dataset was split according to the induction treatment arms, the GES worked extremely well (p-value < e-5) in predicting the outcome in patients receiving VAD regimen but had no power to distinguish survival in patients receiving PAD regimen. We have evaluated the results on additional data sets that confirmed our observation from the HOVON study. To our knowledge this is the first clear demonstration of treatment specificity of GES. This data suggest that we may need to derive multiple therapy-specific GES to be applied to the patients to treat the new patient with therapy for which he/she is predicted to have best outcome.

Disclosures:
No relevant conflicts of interest to declare.
Inhibition of Histone Methylation Arrests Ongoing Graft-Versus-Host Diseases in Mice by Selectively Inducing Apoptosis of Alloreactive Effector T Cells
Authors: He Shan , Wang Jina , Kato Koji , Xie Fang , Varambally Sooryanarayana , Mineishi Shin , Kuick Rork , Mochizuki Kazuhiro , Liu Yongnian , Nieves Evelyn , Mani Ram , Chinnaiyan Arul M. , Marquez Victor E. , Zhang Yi 
Published: October 2019

Abstract
Abstract 820
Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a potentially curative treatment option for patients with hematological malignancies. However, its success is limited by life-threatening graft-versus-host disease (GVHD). Novel approaches are needed to control GVHD. Recent studies have shown the importance of histone methylation in regulating the expression of genes associated with effector T cell differentiation and proliferation. Using several mouse models of allo-HSCT, we report that in vivo administration of the histone methylation inhibitor 3-Deazaneplanocin A (DZNep) arrested ongoing GVHD while preserving graft-versus-leukemia activity (GVL). To assess the therapeutic effect of pharmacologic modulation of histone methylation on GVHD, we administered DZNep to BALB/c mice receiving major histocompatibility-mismatched C57BL/6 mouse T cells 7 days after transplantation, in which GVHD had been fully established. Notably, injection of 12 doses of DZNep controlled the disease in these recipients, with approximately 80% of them surviving long-term without significant clinical signs of GVHD. We found that in vivo administration of DZNep caused selective apoptosis in alloantigen-activated T cells, but did not impair the generation of effector T cells that produced inflammatory cytokines (e.g., TNF-α, IFN-γ and IL-17) and cytotoxic molecules (e.g., granzyme B and Fas ligand). As a result, alloreactive T cells retained potent GVL activity, leading to improved overall survival of the recipients challenged by leukemic cells. These data suggest that DZNep-mediated inhibition of GVHD may be accounted for by reduced number of alloreactive effector T cells. In vitro culture assays showed that DZNep treatment induced apoptosis in T cells activated by anti-CD3/CD28 antibodies but not in naive T cells stimulated by IL-2 or IL-7. This effect was associated with DZNep's ability to selectively reduce trimethylation of histone H3 lysine 27 (H3K27), deplete the histone methyltranferase Ezh2 that specifically catalyzes trimethylation of H3K27, and activate Ezh2-repressed pro-apoptotic gene Bim. Inactivation of Bim partially protected alloreactive T cells from DZNep-mediated apoptosis. Importantly, unlike DNA methylation inhibitors, inhibition of histone methylation by DZNep had no toxicities to hematopoietic cells or impairment on the reconstitution of hematopoiesis and thymopoiesis. Our findings indicate that modulation of histone methylation may have significant implications in the development of novel approaches to treat established GVHD and other T cell-mediated inflammatory disorders in a broad context.

Disclosures:
No relevant conflicts of interest to declare.
Long Term Follow-up of Haploidentical Hematopoietic Stem Cell Transplantation without in Vitro T Cell Depletion for the Treatment of Hematological Malignancies: 9-Year Experience of a Single Center
Authors: Huang Xiao Jun 
Published: October 2019

Abstract 839FN2
Many patients who require allogeneic hematopoietic stem cell transplantation (allo-HSCT) lack a human leukocyte antigen (HLA)-matched donor. Recently, we developed a new strategy named GIAC protocol for HLA-mismatched/haploidentical transplantation from family donors that combines granulocyte-colony stimulating factor (G-CSF) primed bone marrow (G-BM) and peripheral blood stem cells (PBSC) without in vitro T-cell depletion (TCD). For the past nine years, promising results for HLA-mismatched allo-HSCT without in vitro TCD have been achieved at our institute using this protocol. From May 2002 to December 2010, 820 patients, including 206 in high-risk group, underwent transplantation from haploidentical family donors. Eight-hundred and eleven patients (99%) achieved sustained, full donor chimerism. The incidence of grade 2–4 acute graft-versus-host disease (GVHD) was 42.9%, and that of grades 3 and 4 was 14.0% which was not associated with the extent of HLA disparity.Figure 1Cumulative incidence of acute GVHD grade 2–4 according to HLA disparity.Figure 1. Cumulative incidence of acute GVHD grade 2–4 according to HLA disparity.Figure 2Probability of LFS after haploidentical HSCT according to disease stage (p =.001).Figure 2. Probability of LFS after haploidentical HSCT according to disease stage (p =.001).

Disclosures:
No relevant conflicts of interest to declare.
Small Molecule Inhibition of SIRT Activity: A Novel Therapeutic Approach for Acute Myeloid Leukemia
Authors: Nawrocki Steffan T , Espitia Claudia M , Kelly Kevin R. , Bornmann William G. , Carew Jennifer S 
Published: October 2019

Abstract
Abstract 84
New therapeutic strategies are urgently needed to improve clinical outcomes for patients with acute myeloid leukemia (AML), which is an extremely aggressive disease with very few long-term survivors. The sirtuin deacetylases (SIRTs) are critical regulators of genes that are essential for longevity, cell growth, tumor suppression, and apoptosis. Elevated SIRT expression has been reported in several types of cancer and may promote pathogenesis and drug resistance by increasing the lifespan and survival capacity of malignant cells. Our preliminary analysis of SIRT expression indicated that SIRT1 was consistently expressed at significantly higher levels in AML cell lines and primary AML blasts as compared with normal controls. In order to investigate the potential role of SIRT1 as a regulator of AML pathogenesis, we utilized shRNA to stably knockdown its expression in MV4-11 and KG-1 AML cells. Cells with targeted SIRT1 knockdown displayed an altered gene expression profile as compared with non-targeted controls. Moreover, antagonizing SIRT1 expression significantly impeded the progression of AML in a xenograft mouse model. A number of deacetylase inhibitors have been clinically evaluated for cancer therapy. However, disrupting SIRT function as an anticancer strategy remains to be rigorously investigated as none of these previously studied drugs significantly inhibit the activity of this class of NAD+-dependent deacteylases. Tenovin-6 is a novel small molecule SIRT inhibitor. We investigated the efficacy and pharmacodynamic effects of tenovin-6 in AML cell lines, primary blasts from patients with AML, and mouse models. Treatment with tenovin-6 induced apoptosis and dramatically diminished AML clonogenic survival. Tenovin-6 promoted a dose-dependent increase in the acetylated levels of the SIRT-regulated gene p53 in AML cells and triggered the induction of several p53 transcriptional targets including p21 and PUMA. Targeted knockdown of PUMA with shRNA significantly reduced the pro-apoptotic effects of tenovin-6, indicating that it is a critical mediator of its anti-leukemic activity. Notably, administration of tenovin-6 to mice implanted with AML cells was well-tolerated and led to a highly significant reduction in disease burden and increase in overall survival. Our collective findings demonstrate that SIRT1 is a promising novel therapeutic target in AML. Further investigation aimed to elucidate the safety, efficacy, and mechanism of action of tenovin-6 is warranted.

Disclosures:
No relevant conflicts of interest to declare.
Changes in Survival in Acute Myeloblastic Leukemia by Racial and Ethnic Group: Greater Improvement for Non-Hispanic Whites and Increase in the Disparity for Minority Patients in the Early 21st Century
Authors: Pulte Dianne , Redaniel Maria Theresa , Brenner Hermann , Jansen Lina , Jeffreys Mona 
Published: October 2019

Abstract
Abstract 844

Background:
Acute myeloblastic leukemia (AML) is a potentially curable disease but treatment is intense, prolonged, and expensive. Survival has improved for adults age less than 75 with AML in the early 21st century1, but it is unknown whether people of all ethnic and racial backgrounds have benefitted equally. Here, we examine changes in survival in patients with AML by racial and ethnic group between 1993–97 and 2003–07.

Methods:
Using cancer registry data from the Surveillance, Epidemiology and End Results (SEER9) Program, we assessed trends in 5-year relative survival for patients with AML by racial and ethnic group, including non-Hispanic whites (nHw), African-Americans (AA), Hispanics, and Asian-Americans (Asian) for the periods 1993–97 and 2003–07. Modelled period analysis was used to obtain the most up-to-date measurements of survival. Because survival varies greatly with age, survival for patients age 15–54 was calculated separately.

Results:
Median age at diagnosis was highest for nHw, lowest for Hispanics. A statistically significant improvement in survival was seen for nHw patients with AML between 1993–97 and 2003–07. Better survival was observed for other racial/ethnic groups, but the differences were small and non-significant (table 1). When only patients age 15–54 were considered, this effect was enhanced and a trend towards shorter survival was observed for AA patients (table 2). In 1993–97, five year relative survival rates were lower for nHw than for other racial or ethnic groups overall and for patients age 15–54 (tables 1 and 2). In 2003–07, nHw had a 5-year relative survival rate that was higher than AA overall and higher than any other ethnic group for ages 15–54 (table 2).

Conclusions:
Significant disparities in survival exist for patients with AML between nHw and people of other ethnic or racial groups and these disparities are increasing, especially in younger patients. The disparity was more notable for patients age 15–54, suggesting that lack of access to aggressive treatment, particularly transplant, may be a factor in the growing disparity. Further research is needed to pinpoint where on the cancer continuum factors determining survival, including diagnosis, treatment, and biological prognostic markers, are worse for people from minority ethnic groups, and hence where interventions may be the most effective.

Disclosures:
No relevant conflicts of interest to declare.
Factor XIII Deficiency Improves Motor Function in Mice Challenged with Experimental Autoimmune Encephalomyelitis, An Established Model of Multiple Sclerosis
Authors: Mullins Eric S. , Talmage Kathryn E. , Kombrinck Keith W. , Miller Whitney M , Palumbo Joseph S. , Degen Jay L. 
Published: October 2019

Abstract
Abstract 858
Multiple sclerosis (MS) is an inflammatory disease characterized by autoimmune demyelination of neurons and axonal damage within the central nervous system, leading to relapsing/remitting neurological deficits, including sensory and motor deficits. MS plaques are characterized by blood-brain barrier disruption leading to perivascular deposition of fibrin that correlates with areas of microglia activation and myelin damage. Consistent with multiple studies showing that hemostatic factors can serve as important modulators of the inflammatory response in vivo, fibrin(ogen) has been identified as a novel regulator of microglial activation and differentiation. Furthermore, fibrin(ogen) has been found, via the αMβ2 binding motif on the γ chain, to play a role in microglial activation in experimental autoimmune encephalomyelitis (EAE), a murine model of MS. However, previous work by our lab, as well as others, suggests that thrombin-mediated proteolysis plays a greater role in driving neuroinflammatory disease than by merely supporting fibrin formation. Our working hypothesis is that thrombin-mediated proteolysis drives autoimmune neuroinflammation through both fibrin(ogen)-dependent and fibrin(ogen)-independent pathways. To test this hypothesis, we have initiated studies of EAE in mice lacking selected thrombin substrates, including protease activated receptors (PARs) and factor XIII (fXIII). Clinical evaluation of loss of motor function in EAE-challenged cohorts of PAR-1-deficient, PAR-4-deficient and WT control mice revealed a similar outcome in all three cohorts, suggesting PARs may have either a modest or a secondary role in EAE-induced neuroinflammatory disease. However, mice with a constitutive deficiency of another thrombin substrate, the fibrin cross-linking transglutaminase fXIII, were found to have a significant amelioration in motor function loss when challenged with EAE. To further explore this phenotype, we have utilized cystamine, a transglutaminase inhibitor, as a pharmacologic complement to the fXIII knockout mice. Mice with cystamine placed in their drinking water during the EAE challenge period also experienced significantly less disease than control mice that did not receive cystamine. This data suggests that (pro)thrombin contributes neuroinflammatory disease by both supporting local fibrinogen polymerization and by activation of fXIII leading to fibrin stabilization. Furthermore, this line of research suggests that more detailed studies of fXIII may reveal novel strategies for limiting or reversing the devastating pathologies associated with multiple sclerosis.

Disclosures:
Mullins: Baxter: Consultancy. Palumbo:Novo Nordisk Corporation: Research Funding.