bluuebunny/crossref_metadata_2025_split huggingface dataset:
CXCR4 Gene Dosage Is Critical for HSC Engraftment
Authors: McDermott David H. , Jacobs Paejonette , Liu Qian , Gao Jiliang , Murphy Philip M. 
Published: October 2019

Abstract
Introduction: Warts, Hypogammaglobulinemia, Infections and Myelokathexis Syndrome (WHIMS) is an autosomal dominant immunodeficiency resulting from gain-of-function mutations in the chemokine receptor CXCR4. We recently described a unique WHIMS patient who underwent spontaneous genetic and phenotypic reversion at approximately age 30 after being severely affected as a child. Her reversion was due to a single catastrophic genetic event known as chromothripsis (chromosome shattering) resulting in the deletion of one copy of 163 genes in addition to her mutant copy of CXCR4 on chromosome 2. This event was traced to a hematopoietic stem cell (HSC) that had spontaneously repopulated her bone marrow; however, which of the genes was responsible and the mechanism required further investigation.
Methods: Mouse models of CXCR4 haploinsufficiency (Cxcr4+/o) and WHIMS (Cxcr4+/S338X) were used in competitive bone marrow repopulation experiments transplanting whole bone marrow cells or purified HSC. Recipient mice were treated with / without lethal irradiation prior to transplant. Genome editing with TALENs and CRISPR-Cas9 technology was used to target CXCR4 for deletion in human cell lines.
Results: Cxcr4 haploinsufficiency markedly enhanced HSC engraftment potential in recipient WHIM mice whether the donor HSC were purified from whole bone marrow cells or not, and whether the recipient was conditioned by lethal irradiation or not. Enhanced engraftment by Cxcr4 haploinsufficient donor HSC also occurred in wild-type mouse recipients, but to a lesser extent, and was also HSC intrinsic. Genome editing experiments have been successful at deleting one or both copies of CXCR4 in human cell lines in up to 40% of treated cells, and in reducing CXCR4 surface expression.
Conclusion: While CXCR4 was already understood to be important in HSC biology, this patient and subsequent murine experiments have proven that the gene dosage of CXCR4 is a critical factor affecting HSC engraftment. Genome editing is a promising technology for deleting one copy of CXCR4, ideally the WHIM allele,in autologous HSC as a strategy to cure WHIM syndrome.

Disclosures
McDermott: US National Institutes of Health: Employment, Patents & Royalties: pending. Jacobs:US National Institutes of Health: Employment, Patents & Royalties: pending. Liu:US National Institutes of Health: Employment, Patents & Royalties: pending. Gao:US National Institutes of Health: Employment, Patents & Royalties: pending. Murphy:US National Institutes of Health: Employment, Patents & Royalties: pending.
Inflammatory Plasma Proteins Predict Disease Severity and Response to Therapy in Patients with LCH
Authors: Zinn Daniel , Lin Howard , Shih Albert , Scull Brooks , Cantu Miguel Dario , Abhyankar Harshal , Chakraborty Rikhia , Lim Karen Phaik Har , Peters Tricia L. , Lira Sergio , Tsz-Kwong Chris , McClain Kenneth , Merad Miriam , Allen Carl 
Published: October 2019

Abstract
Purpose: Langerhans cell histiocytosis (LCH) is a myeloproliferative disorder with clinical manifestations ranging from single lesions to lethal multi-organ disease, and front-line therapy fails in the majority of patients. No histologic features of LCH lesions have yet been demonstrated to correlate with clinical outcomes.  We hypothesize that function of differentiated CD207+, including interactions with recruited activated lymphocytes, results in plasma protein profiles that reflect disease burden and tissue-specific DC-lymphocyte interactions. Plasma proteins may therefore inform mechanisms of pathogenesis and serve to predict risk and follow disease burden in LCH patients.
Methods: We evaluated inflammatory proteins in the plasma of LCH patients using the Luminex platform. We compared plasma concentrations of 121 analytes in 178 patients with LCH to 90 controls with discovery and validation sets. Comparisons were made based on disease status, age, and clinical risk categories. 152 samples collected from 78 patients at serial time points were also analyzed. Comparisons were made between diagnosis and cure, as well as multiple time points in therapy.
Results: Thirty-one analytes were significantly different between all LCH and controls, including proteins mediating chemotaxis and differentiation of lymphocytes and/or dendritic cells: osteopontin, SDF1A, 6CKine, CCL19, CCL20, sIL4R, IL20, and IL23. Twenty-three analytes were significantly different when comparing adult vs pediatric LCH. When comparing LCH vs control by age groups, 5 were significantly different in adults and 23 were different in children. Eighteen were different in pediatric low risk compared to high risk patients, with the most significant differences in inflammatory proteins including sTNFRI, sTNFRII, TNFa, sIL2Ra, and IL-8. Classifier analysis was able to predict risk organ involvement with a sensitivity of 91.5% and a specificity of 87.5%. Seventeen analytes changed significantly after curative treatment.
Conclusions: Distinct Plasma protein profiles exist in LCH, suggesting pathologic myeloid cells drive the inflammatory pathology of disease. Profiles are vastly different among children and adults with LCH, and differ based on burden of disease, suggesting separate inflammatory pathology. Seven analytes reliably predicted high-risk disease, and analysis of serial samples identified normalization of inflammatory proteins after cure.

Disclosures
Allen: Roche: Consultancy, Other: unpaid; NovImmune: Consultancy, Other: unpaid.
Dynamin 2 (DNM2) and PACSIN2 Regulate Megakaryocyte Demarcation Membrane System Formation and Platelet Production in Concert
Authors: Giannini Silvia , Bender Markus , Pluthero Fred G. , Christensen Hilary , Leung Richard , Lo Richard W. , Kormann Jan , Plomann Markus , Kahr Walter H.A. , Falet Hervé 
Published: October 2019

Abstract
Blood platelets are produced in the bone marrow by megakaryocytes (MKs) in a process that requires extensive intracellular membrane rearrangements. These include the formation of the demarcation membrane system (DMS), the surface-connected membrane extension that invaginates into the cell body and further develops to provide membranes for future platelets. The precise molecular mechanisms responsible for these unique membrane rearrangements remain poorly understood. We have recently shown that Dnm2fl/fl Pf4-Cre mice specifically lacking the large GTPase dynamin 2 (DNM2) in MKs develop severe macrothrombocytopenia due to impaired receptor-mediated endocytosis (RME) (Bender, Giannini et al. Blood. 2015;125(6):1014-1024). Specifically, Dnm2fl/fl Pf4-Cre MKs accumulate arrested endocytic clathrin-coated vesicles that obstruct DMS formation. The actin nucleating factor Arp2/3 complex and polymerized actin clustered with clathrin at sites of impaired RME in Dnm2fl/fl Pf4-Cre MKs. We hypothesized that a DNM2 partner recruits actin-regulatory proteins at sites of RME and investigated the contribution of the F-BAR protein PACSIN2, an internal component of the initiating DMS (Jurak Begonja, Pluthero et al. Blood. 2015;126(1):80-88), in DMS formation and platelet production, as PACSIN2 interacts with DNM2 and actin-regulatory proteins such as N-WASP and filamin A (FlnA). Pacsin2-/- mice developed mild thrombocytopenia with slightly enlarged and shallow platelets. The DMS appeared less well defined and platelet territories were not readily visualized in Pacsin2-/- MKs. Pacsin2-/- Dnm2fl/fl Pf4-Cre mice lacking both PACSIN2 and DNM2 in MKs were further generated to determine the contribution of PACSIN2 in clathrin and actin clustering in Dnm2fl/fl Pf4-Cre MKs. Strikingly, PACSIN2 genetic deletion significantly improved the severe thrombocytopenia of Dnm2fl/fl Pf4-Cre mice. Specifically, PACSIN2 deletion abrogated the accumulation of clathrin and actin clusters, thereby unclogging DMS formation, which appeared as elongated maze-like membrane tubules in Pacsin2-/- Dnm2fl/fl Pf4-Cre MKs. Our results show that DNM2 terminates PACSIN2-dependent actin polymerization that accompanies RME, thereby allowing membrane rearrangements required for DMS formation.

Disclosures
No relevant conflicts of interest to declare.
The Frequency of Folate Deficiency in Multiple Myeloma Patients
Authors: Wongrakpanich Supakanya , George Gemlyn , Chaiwatcharayut Wikrom , Candelario Nellowe , Mittal Varun , Pomerantz Sherry , Varadi Gabor 
Published: October 2019

Abstract
Background: At the time of being diagnosed with multiple myeloma, more than half of patients will be anemic; therefore, anemia is considered to be an important disease characteristic for multiple myeloma. Folate deficiency is one possible cause of anemia in multiple myeloma patients. The frequency of folate deficiency in multiple myeloma patients is largely unknown.
Objective: The objective of this study is to describe the frequency of serum folate deficiency in patients with multiple myeloma.
Methods: A retrospective chart review study was conducted in Einstein Medical Center, Philadelphia between the dates of 01/01/2004 and 09/25/2014. Of the 216 patients that were reviewed, 175 patients fulfilled the criteria for a diagnosis for multiple myeloma: 1) monoclonal plasma cell in the bone marrow >/= 10% 2) monoclonal protein present in the serum and/or urine 3) at least one of the following: serum calcium > 10.5 mg/l, Creatinine > 2 mg/100 ml, hemoglobin< 10g/100ml, or lytic bone lesions. The relationship between serum folate level and age at diagnosis, gender, race, disease staging defined by International staging system (ISS), percent of bone marrow infiltration, immunoglobulin (Ig) subtypes, number of death and loss to follow up, complete blood count parameters, and other metabolic parameters (glomerular filtration rate, calcium, albumin and beta-2 microglobulin) were analyzed using Chi-Square test or t-tests as appropriate.
Results: Information on folate status was available for 78 consecutive multiple myeloma patients. Of them, 67 patients (85.9%) had a normal serum folate level, and 11 patients (14.1%) had laboratory-defined folate deficiency (serum folate level < 3.5 ng/mL). The mean hemoglobin level in the patients who had low folate level was 9.39 g/dL compared with 10.08 in the patients who had normal folate level (P=0.580). There were no statistical differences between the normal and the folate deficiency group in terms of laboratory parameters, baseline characteristics, staging, treatment modalities, and overall survival. However, the patients who had low folate levels were younger than the patients who had normal folate levels (61.55 years versus 69.88 years, P = 0.028).
Conclusion: Folate deficiency is considered to be a contributing cause of anemia in multiple myeloma patients. The findings from our study may emphasize the need for serum folate measurement and folate replacement therapy in multiple myeloma patients.

Disclosures
No relevant conflicts of interest to declare.
The Frequency of Genetic Anomalies According to Clonal Plasma Cells' Phenotype in Patients with Newly Diagnosed (ND) Multiple Myeloma (MM)
Authors: Garifullin Andrei , Martynkevich Irina , Voloshin Sergei , Kuvshinov Alexei , Martynenko Ludmila , Kleina Elizaveta , Abdulkadyrov Kudrat 
Published: October 2019

Abstract
Background. Genetic anomalies (GA) are primary link of pathogenesis in MM. GA lead to formation of clonal plasma cells, which has different phenotype.
Aim. To estimate the incidence of GA and their correlation with clonal plasma cells' phenotype in patients with ND MM. Methods. We analysed 22 patients with ND MM (median age 57 years, range 38-80; male/female - 1:1.75). Cytogenetic analysis was performed on bone marrow samples using standard GTG-method. Metaphase FISH analysis was performed according to the manufacturer's protocol using DNA probes: LSI 13(RB1)13q14, IGH/CCND1, IGH/FGFR3, LSI TP53 (17q13.1). 8-color immunophenotypic by flow cytometry using antibody to CD45, CD38, CD138, CD56, CD19, CD20, CD27 and CD117 antigenes.
Results. Translocation t(11;14) was detected in 3/14 (21.4%) patients, del(13q) - 2/14 (14.3%), t(11;14) - 3/14 (21.4%), hypodyploidy - 1/20 (5%), del(17р) - 0% patients. Clonal plasma cells' phenotype CD38+CD138+CD45- was detected in 100%. Expression CD56+ was revealed in 11/22 (50%) patients, CD19+ in 9/22 (40.9%), CD117+ in 5/22 (22.7%), CD20+ in 1/22 (4.5%), CD27+ in 1/22 (4.5%). The frequency of GA didn't depend on clonal plasma cells' phenotype and was 27.3%(3/11) in CD56+ phenotype, 23.8%(5/21) - CD20-, 23.8%(5/21) - CD27-, 23.5%(4/17) - CD117-, 23%(3/13) - CD19-, 22.2%(2/9) - CD19+, 20%(1/5) - CD117+, 18.2%(2/11) - CD56-, 0%(0/1) - CD20+, 0%(0/1) - in CD27+ phenotype. Patients of standard risk group according to mSMART 2.0 with GA had CD19-negative plasma cells' phenotype vs. CD19-positive phenotype in patients of intermediate and high-risk groups (p<0.05). 3-years overall survival in standard risk group with CD19- phenotype was 92,3%, CD19+ - 77,7% (p>0.05).
Conclusion . Identification of GA, which has adverse forecast, correlates with CD19+ plasma cells phenotype. The combined definition of plasma cells phenotype and GA can improve the system of risk stratification in MM.

Disclosures
No relevant conflicts of interest to declare.
Cytometric Response in Multiple Myeloma Cells to Low and Standard Doses of Bortezomib
Authors: Beffermann Nicole , Ocqueteau Mauricio , Ramirez Pablo , Galleguillos Mauricio , Sarmiento Mauricio 
Published: October 2019

Abstract
Bortezomib is a very useful drug in the treatment of multiple myeloma (MM) patients. Used in combination with other antineoplastic drugs it has a well documented impact in progression free survival (PFS) and overall survival (OS) of any age patients, elegible or not for hematopoietic cell transplant. Standard dose (1,3 mg/m2) is used in almost all patients and low dose (0,7-0,8mg/m2) is reserved to patients with kidney disease and neuropathy.
However, bortezomib doses used in phase 1 and 2 initial studies were described between 0,7 and 1,3 mg/m2 and were equally effective.
The aim of this study was to evaluate the cytometric response of MM naive patients to two different bortezomib doses.
We retrospectively analyzed the flow cytometry of fourty eight patients with naive MM treated with VCD scheme (Bortezomib-Cyclophosphamide-Dexametasone), without kidney failure nor neuropathy, of whom 21 received low doses of bortezomib (0.8mg/m2) and 27 standard doses (1.3 mg/m2). Flow cytometry was analyzed at diagnosis and at the end of treatment according to the expression of several clusters of differentiation (CD), establishing the presence of plasmoblastic myeloma clones (>95% of plasma cells with immunophenotype CD19 (-) CD56(+) CD45(-) CD38(+) and restriction of intra cytoplasmatic kappa and or lambda light chains) and normal mature plasma cells (CD19(+) CD56(-) CD45 (+) CD38 (++) with a policlonal expression of kappa/lambda light chains). Cytometric complete response was defined as normalization of the immunophenotype of plasma cells and absence of pathological cells.
We found no statistical differences between the 2 groups in flow cytometric response (p>0.1), as shown in figure 1.
This retrospective analysis suggests that lower doses of bortezomib could have similar effects in disease control, at least in cytometric response, to standard doses. Further studies should be made to evaluate clinical response and overall survival in patients treated with low doses compared to standard doses of bortezomib. In our country high costs of new generation antineoplastic drugs makes it necessary to find less expensive and equally effective schemes in order to make these well known beneficial treatments available to a greater number of patients.

Disclosures
No relevant conflicts of interest to declare.
Direct Comparison of Wharton Jelly and Bone Marrow Derived Mesenchymal Stromal Cells to Enhance Engraftment of Cord Blood CD34+ Transplants
Authors: van der Garde Mark , Van Pel Melissa , Millan Rivero Jose , de Graaf-Dijkstra Alice , Slot Manon , Kleinveld Yoshiko , Watt Suzanne , Roelofs Helene , Zwaginga Jaap Jan 
Published: October 2019

Abstract
Co-transplantation of CD34+ hematopoietic stem and progenitor cells (HSPC) and mesenchymal stromal cells (MSC) enhances HSPC engraftment. For these applications, MSC are mostly obtained from bone marrow. However, MSC can also be sourced from Wharton's jelly (WJ) of the human umbilical cord, which as a 'waste product', is cheaper to acquire and without significant burden to the donor. Here, we evaluated the ability of WJ MSC to enhance HSPC engraftment. First, we compared cultured human WJ MSC with human bone marrow-derived MSC (BM MSC) for in vitro marker expression, immunomodulatory capacity and differentiation into three mesenchymal lineages. Although we confirmed that WJ MSC have a more restricted differentiation capacity, both WJ MSC and BM MSC expressed similar levels of surface markers and exhibited similar immune inhibitory capacities. Co-transplantation of either WJ MSC or BM MSC with CB CD34+ cells into NOD-SCID mice showed faster recovery of human platelets and CD45+ cells in the peripheral blood and a 3-fold higher engraftment in the BM, blood and spleen six weeks after transplantation when compared to transplantation of CD34+ cells alone. Upon co-incubation, both MSC sources increased the expression of adhesion molecules on CD34+ cells, although SDF-1-induced migration of CD34+ cells remained unaltered. Interestingly, there was an increase in CFU-GEMM when CB CD34+ cells were cultured on monolayers of WJ MSC in the presence of exogenous thrombopoietin, and an increase in BFU-E when BM MSC replaced WJ MSC in such cultures. Our results suggest that WJ MSC is likely to be a practical alternative for BM MSC to enhance CB CD34+ cell engraftment.

Disclosures
No relevant conflicts of interest to declare.
Effect of RNAi-Mediated Knockdown of MCM7 on Human Leukemia Cells and Its Mechanism
Authors: Tian Liang , Chen Baoan , Liu Juan , Cheng Jian , Xia Guohua 
Published: October 2019

Abstract
Background: MCM7 is one of the subunits of the MCM2-7 complex that are essential for DNA replication licensing and control of cell cycle progression. It also participates in mRNA transcription and DNA damage regulation. It is found that MCM7 was highly expressed in many cancer cells including Leukemia. Thus, lentivirus-mediated siRNA targeting MCM7 was used to suppress its endogenous expression in K562 cells and develop a novel therapeutic strategy for leukemia.
Method: Lentivirus-mediated siRNA targeting MCM7 were designed and infected K562 cells. Down-regulation of MCM7 mRNA and protein expression in K562 cells were determined by Real-time PCR and Western blot analysis. The proliferation of the transfected K562 cells was assessed by CCK8 assay. Cell cycle progression and apoptosis were calculated by flow cytometry. The related protein levels of the transfected K562 cells were detected by Western blot. The stably transfected K562 cells were injected into nude mice. The transplanted tumors were measured and weighed, then Western blot and Immunocytochemistry were used to evaluated the expression of the proteins for mechanism.
Results: The mRNA and protein expression of MCM7 in the stably transfected K562 cells decreased with the percentage of 92.3±1.88 and 91.18%±0.93 respectively. Compared with control and negative control groups, the proliferative rate of K562 cells was significantly reduced after LV-MCM7-RNAi infection. The cell cycle progression of K562 cells was blocked, with a massive increase in the percentage of cells in the G0/G1 phase and decrease in S phase. The apoptosis rate of the transfected K562 cells was significantly higher. PLK1 and pPLK1 protein were down-regulated in response to MCM7 inhibition; P53 and bax protein were up-regulated simultaneously. In vivo, the tumor size and weight dramatically decreased in the MCM7-RNAi group than in negative control group. PLK1, pPLK1 proteins in transplanted tumors were down- regulated and P53,bax were up-regulated correspondingly.
Conclusions: Lentivirus-mediated MCM7 shRNA has effectively down regulated the expression of MCM7 gene on mRNA and protein levels. Moreover, the silence of MCM7 has led to the significant decrease in proliferation, blocking the cell cycle progression of K562 cells in vitro. Simultaneity, the apoptosis of the leukemia cell was enhanced. Both of the functions above cause the inhibition of the tumor growth in nude mice. Overall, these results suggest that the proliferation and cell cycle of K562 cells could be regulated by silencing MCM7 gene which is a promising gene therapeutic method to treat gastric cancer.

Disclosures
No relevant conflicts of interest to declare.
Mortality Associated with Venous Thromboembolism in Hospitalized Pediatric Patients: A Single Tertiary Care Institute Experience
Authors: Chadha Raminder , Goel Ruchika , Takemoto Clifford M. 
Published: October 2019

Abstract

Background: Hospital-associated venous thromboembolism (HA-VTE) is a major cause of morbidity and mortality in adults; there is a paucity of data about mortality risk in children.
Objective: To determine clinical factors associated with mortality in children with HA-VTE.
Methods: We conducted retrospective chart review of patients <=21 years with HA-VTE admitted to the Johns Hopkins Hospital from 1992-2013. ICD-9 codes were used to identify cases with deep venous thrombosis and pulmonary embolism; diagnosis was verified by reviewing hospital records and radiologic imaging. HA-VTE was defined as 1) VTE diagnosed ≥48 hours after hospital admission or 2) VTE diagnosed within 90 days of hospital discharge. Univariate and conditional multivariable logistic regression analyses with backward elimination were used to estimate the risk factors for mortality and adjusted Odds Ratios (adjOR) calculated.
Results: Of 330 HA-VTE cases, there were 55 deaths (16.7%); 18 deaths (5.5%) were attributable to VTE. Median follow up was 2.9 years. Within 30 days of VTE diagnosis, all-cause mortality was 4.2% and VTE-attributable mortality was 1.8%. Acute systemic infection (adjOR 11.3; 95%CI 4.7-26.8) and malignancy (adjOR 3.9; 95%CI 1.6-9.5) were associated with increased adjusted odds of all-cause mortality (Table 1). For deaths specifically attributable to VTE, acute systemic infection (adjOR 18.6; 95%CI 4.9-71.4) was associated with increased adjusted odds of mortality.
Conclusion: The majority of VTE-attributable deaths occurred over 30 days from VTE diagnosis. Acute systemic infection was a significant predictor of VTE-related mortality in HA-VTE. Further studies are warranted to identify additional risks for VTE-related mortality to develop prevention strategies.
Table 1. Odds Ratio Estimates of All-cause Mortality in Hospital Associated Venous Thromboembolism in Children in a Tertiary Care Hospital. Putative Risk Factor Odds Ratio 95% WaldConfidence Limits *Systemic Infection 11.3 4.7 26.8 Cancer 3.9 1.6 9.5 Pulmonary Embolism 0.7 0.3 2.0 Age (each year increase) 0.9 0.9 1.1 Male gender versus female 0.7 0.3 1.5 Central Venous Catheter 1.4 0.6 3.2 Hospital readmission within 90 days 1.5 0.6 3.7 *Meningitis, abscess, pneumonia, osteomyelitis, bacteremia, fungemia, and pyelonephritis

Disclosures
Takemoto: Novo Nordisk: Research Funding; Mast Therapeutics: Speakers Bureau.