bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study on the Membrane Hemopoietic Cytokine Receptor Expression on CD34+ Bone Marrow Cells of the Patients with Myelodysplastic Syndromes
Authors: Shao Zonghong , Li Lijuan , Fu Rong , Wang Huaquan , Yue Lanzhu , Liu Hui , Wang Jun , Wang Honglei , Ruan Erbao , Qu Wen , Liang Yong , Wang Guojin , Wang Xiaoming , Liu Hong , Song Jia , Wu Yuhong , Xing Limin , Guan Jing 
Published: October 2019

Abstract
Abstract 2908

Objectives
This study was to detect if there were abnormalities of membrane hemopoietic cytokine receptor expression on CD34+ bone marrow cells in MDS.

Methods
34 newly diagnosed MDS(12 in low-risk and 22 in high-risk) cases and 32 normal controls were enrolled in this study. Their CD34+CD38+ and CD34+CD38- bone marrow cells and the expressions of stem cell factor receptor(SCF-R),erythropoietin receptor (EpoR), granulocyte colony-stimulating factor receptor (G-CSFR) and thrombopoietin receptor (TpoR) on those cells were measured by flow cytometry.

Results
The mean percentage of CD34+ BMMNCs of MDS cases in high risk[(2.94±4.79)%)] was significantly higher than that of control group[(0.95±1.06)%](P<0.05). The mean percentages of CD34+CD38+ cells were significantly lower in low risk and high risk groups[(86.98±6.83)% and (83.57±9.86)% respectively] than that in control group [(92.41±3.43)%], thus the percentage of CD34+CD38- cells was significantly higher in either low-risk or high-risk group[(13.03±6.84)% and (16.42±9.85)% respectively]than that in control group[(7.59±3.43)%](P<0.05). In control group, the mean percentage of antigen expression of EpoR was significantly lower in CD34+CD38+ cells [(17.72±20.24) %] than that in CD34+CD38- cells [(64.65±21.02)%](P<0.01), The expressions of SCF-R,G-CSFR and TpoR on CD34+CD38- cells were not significantly different from these on CD34+CD38+ cells. The expression of EpoR on CD34+CD38+ cells of low-risk and high-risk MDS groups[(7.01±6.82)% and (7.16±9.45)% respectively] were significantly lower than that of control group[(17.72±20. 24) %] (P<0.05), The expression of G-CSFR on CD34+CD38+ cells of low-risk and high-risk MDS groups[(22.65±12.14)% and (26.50±19.65)% respectively] were significantly lower than that of control group[(45.13±23.41)%](P<0.01). The amount of EpoR on CD34+CD38-cells of low-risk and high-risk MDS groups[(40.18±20.38)% and (28.58±17.00)% respectively] were significantly lower than that of control group[(64.65±21.02)%](P<0.01), The expression of TpoR on CD34+CD38- cells of low-risk and high-risk MDS groups[(4.46±7.45)% and (3.23±4.55)% respectively] were significantly lower than that of control group[(15.33±14.95)%](P<0.01). The incidence of cytopenia of MDS cases with low expression rates of hemopoietic cytokine receptors on CD34+cells were higher than that of MDS with high expression rates of hemopoietic cytokine receptors.

Conclusions
There were abnormalities of differentiation and membrane hemopoietic cytokine receptors expression of CD34+ bone marrow cells in MDS, which were associated with MDS cytopenia and might be useful for MDS diagnosis.

Disclosures:
No relevant conflicts of interest to declare.
A Favorable Outcome In Children with Juvenile Myelomonocytic Leukemia (JMML) with RAS Mutations
Authors: Doisaki Sayoko , Muramatsu Hideki , Hama Asahito , Shimada Akira , Takahashi Yoshiyuki , Kojima Seiji 
Published: October 2019

Abstract
Abstract 2909

Introduction:
Juvenile myelomonocytic leukemia (JMML) is a rare clonal myeloproliferative disorder that affects young children. It is characterized by a specific hypersensitivity of JMML cells to granulocyte-macrophage colony-stimulating factor (GM-CSF) in vitro. The pathogenesis of JMML involves disruption of GM-CSF signal transduction resulting from mutations of the components of the RAS signaling pathway, including NF1, PTPN11, NRAS, and KRAS. Somatic point mutations of the RAS genes at codons 12, 13, and 61 are found in approximately 20% of patients. Although most patients with JMML die due to progressive disease within 12 months unless treated with hematopoietic stem cell transplantation (HSCT), Matsuda et al reported that JMML patients with NRAS or KRAS glycine to serine substitution improved spontaneously. Other groups in Europe did not confirm this observation, and treatment for patients with JMML and RAS mutations is controversial. Therefore, in the present study, we analyze the association between the mutational status of RAS and prognoses of patients with JMML.

Patients and Methods:
Eighty children diagnosed with JMML between 1988 and 2010 were studied retrospectively. We performed a mutational analysis of NRAS, KRAS, PTPN11, and C-CBL genes.

Results:
Seventeen patients (21%) had RAS mutations [NRAS (n = 13) and KRAS (n = 4)], while PTPN11 and C-CBL mutations were found in 28 patients (35%) and 5 patients (6.3%), respectively (Four patients were included in the previous report; Matsuda et al, Blood, 2007). Five children had clinical evidence of NF1 mutations. Among NRAS mutations, G12D and G13D were the most common (n = 6 and n = 5, respectively). Only one patient carried a G12S substitution, which was reported as a favorable mutation. Three patients with KRAS mutations had G13D substitutions. Compared to patients with other mutations or without any aberrations, patients with RAS mutations were significantly younger at diagnosis (median age: 12 months vs. 24 months, p = 0.011), while other known predictive factors such as HbF level and platelet count were not significantly different at diagnosis (median HbF level: 9.1 % vs. 22.2 %, p = 0.295; median platelet count: 27.5 × 109/L vs. 49.0 × 109/L, p = 0.390). Monosomy 7 was observed in seven patients without RAS mutations, and all patients with RAS mutations had normal karyotypes. Among untransplanted patients with RAS mutations, three achieved long-term survival (20, 84, and 209 months after diagnosis). The probability of 5-year overall survival estimated by the Kaplan-Meier method was significantly higher for patients with RAS mutations than for those without (85.7% vs. 30.4%, p = 0.033).

Conclusion:
These results suggest that JMML patients with RAS mutations may be a distinct subgroup with favorable outcomes in spite of other than G12S.

Disclosures:
No relevant conflicts of interest to declare.
Cytogenetic Evolution (CE) In Patients (pts) with Low and Intermediate Risk Myelodysplastic Syndromes (MDS) Is Associated with Poor Prognosis
Authors: Li Liunan , Jabbour Elias , Borthakur Gautam , Faderl Stefan , Kadia Tapan , Ravandi Farhad , Pierce Sherry A. , Wierda William G. , Abruzzo Lynne V. , Kantarjian Hagop , Garcia-Manero Guillermo 
Published: October 2019

Abstract
Abstract 2941

Introduction:
MDS is a spectrum of abnormalities in the proliferation and differentiation of hematopoietic stem cells that result in peripheral cytopenias, bone marrow dysplasia and increased risk of transformation to acute myelogenous leukemia (AML). Cytogenetic abnormalities occur in more than 50% of patients (pts) and have an impact on survival and risk of transformation to AML. CE, or acquisition of additional clonal chromosomal abnormalities, has been reported to occur in 30 to 50% of primary MDS pts. Their impact on prognosis and transformation into AML among pts with low and intermediate risk MDS is not known. In this study, we analyzed the impact of CE on prognosis in lower risk MDS.

Methods:
we reviewed 722 pts clinic records of low and intermediate risk MDS pts at MD Anderson Cancer Center (MDACC) from 2000–2010 and conducted a retrospective analysis of all MDS pts with at least two consecutive cytogenetic analysis (365 patients, 50.6%) and compared the cytogenetic evolution group (CE group) with the group without cytogenetic changes (no CE group). Cytogenetic analysis was performed in the Cytogenetics Laboratory at MDACC.

Results:
CE was detected in 200 pts (55%). Characteristics of patients with CE are: median age 65 years (23-91), IPSS int-1 79%, diploid CG 42%, excess blasts 25%. Pts with CE were more frequently female (p=0.005), and had more frequently abnormalities of chromosome 5 and 7 (p<0.001) at baseline. There were no statistically significant difference between these two groups (p>0.05) regarding age, WBC, platelet, hgb, ANC, BM blasts percent, diagnosis (RA or RAEB), and IPSS score. There were more chr.-5/-7, insufficient metaphases, and other abnormalities, but less diploid cases in CE group compared with no CE group (p<0.001). History of malignancy (p=0.001) and prior chemotherapy exposure were also associated with CE (p=0.001), but this was not as strong for radiation exposure (p=0.066). Also, more CE patients required therapy for MDS compared to no CE patients (p=0.039). Progression free survival was significantly extended in no CE patients (p=0.02). Overall survival was a longer in no CE (34.1months), compared with CE group (26.2 months), although this was not statistically significant.

Conclusion:
CE is more commonly observed among pts with high-risk features, and is usually associated with disease progression and resistance. Also, prior malignancy and chemotherapy exposure were associated with CE in this study. This data indicates that genomic instability has a role in disease progression in MDS. Further analysis of CE in MDS is needed.

Disclosures:
No relevant conflicts of interest to declare.
Identification of Prognostic Markers by Gene Expression Profiling In Myelodysplastic Syndrome Hematopoietic Stem Cells
Authors: Pellagatti Andrea , Cazzola Mario , Giagounidis Aristoteles , Perry Janet , Malcovati Luca , Porta Matteo G. Della , Jädersten Martin , Killick Sally , Vyas Paresh , Hellström-Lindberg Eva , Boultwood Jacqueline , Wainscoat James S. 
Published: October 2019

Abstract
Abstract 298
The myelodysplastic syndromes (MDS) are a heterogeneous group of clonal hematopoietic stem cell malignancies that are characterized by ineffective hematopoiesis resulting in peripheral cytopenias and a hypercellular bone marrow. Approximately 40% of patients with MDS will develop an acute myeloid leukemia. It is important to establish prognosis of MDS patients since the treatment options vary from supportive care to bone marrow transplantation. In order to determine the relationship of gene expression levels to prognosis and so identify new molecular markers, we have used gene expression profiling to study the transcriptome of the hematopoietic stem cells of 125 MDS patients with a minimum 12 month follow up. The CD34+ cells obtained from MDS patients and healthy individuals were analyzed using Affymetrix U133 Plus2.0 arrays. The patients were split randomly in a training set (n=84) and a test set (n=41). Supervised principal components analysis was used to identify genes correlated with survival. Using the 84 patients in the training set, the Cox scores were computed for each gene, and the principal components calculated on the genes with the highest Cox scores. The first of the principal components was then used to generate a regression model to predict the survival in the test set. Finally, for each probe set an importance score was calculated equal to its correlation with the supervised principal component predictor. This approach returned a list of 150 top ranked probe sets correlated with survival. Patients in the training set were split into tertiles based on the predictor (low, medium and high score) and patients in the test set were assigned to their predicted class, and Kaplan-Meier plots were generated for both training and test set. The differences in survival for both training and test set were statistically significant (Figure 1). Top ranked genes showing lower expression levels in patients with shorter survival include CDH1, LEF1 and AKAP12/Gravin. Top ranked genes showing higher expression levels in patients with shorter survival include IL23A, WT1 and PTHR2. Figure 2 shows survival of patients divided into tertiles of expression for the individual genes CDH1, LEF1 and WT1. It is probable that the genes identified in this study will become the first validated molecular markers for MDS prognosis. Multivariate analysis is currently being performed.
Figure 1 Figure 1.
Figure 2 Figure 2.

Disclosure:
No relevant conflicts of interest to declare.
Towards Effective Immunotherapy of Multiple Myeloma: Enhanced Elimination of Myeloma Cells by Combination of Lenalidomide with the Human CD38 Monoclonal Antibody Daratumumab
Authors: van der Veer Michael S. , de Weers Michel , van Kessel Berris , Wittebol Shulamiet , Bakker Joost M , Parren Paul W.H.I. , Lokhorst Henk M , Mutis Tuna 
Published: October 2019

Abstract
Abstract 3059
Since its approval by the FDA, lenalidomide (LEN) demonstrates impressive results in patients with newly-diagnosed and relapsed multiple myeloma (MM). Despite these improvements, MM remains incurable, and new innovative treatments need to be developed in efforts to improve long term outcomes. Recently we have developed a new human CD38 antibody, daratumumab (DARA) which mediates MM cell killing via complement dependent cytotoxicity (CDC), antibody dependent cellular cytotoxicity (ADCC) and apoptosis. In the current study we evaluated the potential benefits of combining lenalidomide (LEN) with daratumumab (DARA). We demonstrate that DARA-dependent ADCC of purified primary MM cells, as well as of CD38+ UM 9 MM cells was significantly augmented by pre-treatment of PBMC effector cells with LEN. Importantly, a synergism between LEN and DARA was observed in ex-vivo assays, which allowed us to investigate ADCC directly in whole BM-MNC, thus without isolating MM cells from their natural environment. Interestingly, DARA-induced ADCC was significantly upregulated in PBMC derived from three MM patients who were undergoing LEN treatment. In conclusion, these results support the hypothesis that powerful and complementary effects may be achieved by combining LEN and DARA in clinical MM management.

Disclosures:
Veer: GenMab, Utrecht: Research Funding. Weers:Genmab: Employment. Bakker:GenMab, Utrecht, Netherlands: Employment. Parren:Genmab: Employment. Lokhorst:GenMab: Research Funding. Mutis:GenMab: Research Funding.
Comparison of Conventional Cytology Vs. High Sensitivity Flow Cytometry for the Diagnosis of Leptomeningeal Involvement by Hematological Lymphoid Malignancies
Authors: Lam Selay , Chin-Yee Ian H. , Keeney Michael , Popma Janice , Rizkalla Kamilia , Mangel Joy 
Published: October 2019

Abstract
Abstract 3112

Objective:
To compare the utility of high sensitivity (5-colour) flow cytometry (FCM) vs. conventional cytology (CC) for detecting cerebrospinal fluid (CSF) involvement in patients with hematological lymphoid malignancies.

Methods:
The results of diagnostic evaluations on all CSF samples analyzed for involvement by neoplastic lymphoid cells between January 2005 and February 2010 were reviewed retrospectively. Cases were identified by reviewing logs of all FCM procedures performed during that time period. FCM was performed on the CSF using a 5-antibody panel (“high sensitivity”).

Result:
108 patients (62M/46F) diagnosed with non-Hodgkin lymphoma or acute lymphoblastic leukemia underwent a total of 609 lumbar punctures (LP). The 359 samples that were sent for both CC and FCM form the basis of this analysis. The majority of the LP's (312/359, 87%) were negative for malignant cells by both FCM and CC (FCM-/CC-). 47 samples showed infiltration by tumor cells; of these, 25 (7%) were FCM+/CC+, and 22 (6%) were FCM+/CC-. No cases (0%) were FCM-/CC+. Using FCM as the gold standard, CC had a specificity of 100%, but a sensitivity of only 53%.

Conclusion:
High-sensitivity FCM has superior sensitivity to CC for diagnosing leptomeningeal involvement by lymphoid malignancies. CC failed to identify any additional cases that were not seen on FCM. This raises the question of whether performing CC on CSF samples to search for neoplastic lymphoid cells is of any additional diagnostic value.

Disclosures:
No relevant conflicts of interest to declare.
Myc Represses miR15a/Mir-16-1 Expression through Recruitment of HDAC3 In Mantle Cell Lymphoma
Authors: Zhang Xinwei , Chen Xia , Lin Jianhong , Lwin Tint , Ely Scott A , Chen-Kiang Selina , Dalton William S. , Seto Edward , Wright Kenneth , Sotomayor Eduardo M. , Tao Jianguo 
Published: October 2019

Abstract
Abstract 3121
MicroRNAs (miR)-15a and miR-16-1 are known to act as tumor suppressors. Expression of these miRNAs inhibits cell proliferation, promotes apoptosis of cancer cells, and suppresses tumorigenicity by targeting multiple oncogenes. Loss or down-regulation of these miRNAs has been reported in a variety of hematopoietic and solid tumors. Our recent study demonstrated that miR-15a/16-1 are down-regulated in the majority of patients with mantle cell lymphoma (MCL, Zhao et al., Blood. 2010 1;115(13):2630-9). However, the mechanism responsible for miR-15a/16 suppression was unknown. Here, we have investigated mechanism of miR-15a/16-1 repression and its transcriptional and epigenetic regulation by Myc and histone deacetylase (HDAC) in MCL. Over-expression of Myc protein was detected in all MCL cell lines, and miR-15a/16 and DLEU-2 mRNA were significantly up-regulated in Mino and Jeko-1 cells when Myc was depleted by c-Myc siRNA. Treatment with pan HDAC inhibitor, SAHA and specific HDAC-3 shRNA resulted in increase of miR15a/16 expression. Co-immunoprecipitation study showed that c-Myc interacted with HDAC3. Moreover, chromatin immunoprecipitation (ChIP)demonstrated that both Myc and HDAC3 co-localized to the two promoters of miR-15a/16 cluster gene, DLEU-2. Luciferase reporter assay confirmed that both c-Myc and HDAC3 inhibited transcriptional activity of two E-box (Myc-binding)-specific DLEU-2 promoters. Computational analysis and mutagenesis study further supported direct association of Myc with miR-15a/16 promoter resulting in HDAC3-mediated transcriptional repression. These findings highlight an important role for HDAC-3 in Myc-driven lymphoma cell proliferation and reveal novel transcriptional and posttranscriptional mechanisms in Myc-mediated malignant transformation in MCL.

Disclosures:
No relevant conflicts of interest to declare.
BCL6 Interacts with Cullin-3 Ubiquitin Ligase Complex In B Cells
Authors: Phan Ryan T , Nguyen DanVy , Nham Phillipp , Dalla-Favera Riccardo 
Published: October 2019

Abstract
Abstract 3129
The proto-oncogene BCL6 encodes for a BTB/POZ-zinc finger transcriptional repressor which plays an essential role in germinal center (GC) formation and is implicated in the pathogenesis of B-cell lymphoma. BCL6 is shown to be a critical regulator modulating many important functions in B cells, including activation, differentiation, cell cycle arrest and apoptosis. Tight regulation of BCL6 is, therefore, critical for the control of GC reaction as well as for the phenotype of GC-derived lymphomas. In response to B cell receptor activation or DNA damage induction, BCL6 protein is phosphorylated and subsequently degraded through distinct mechanisms that involve ubiquitination process. Here we report that BCL6 interacts with Cullin-3 (Cul3), major component of a multimeric E3 ubiquitin ligase complex. Consistent with previous reports indicating that BTB/POZ domain proteins interact with Cul3, the BCL6-POZ domain is sufficient for BCL6 interaction with Cul3. Importantly, BCL6 and Cul3 interaction is also readily detected in native B cells. Interestingly, this interaction does not affect BCL6 transcriptional repression activity nor does it affect basal level of BCL6 stability. The pathophysiological consequence of this interaction is investigated, including a possibility that BCL6 functions as a specific substrate adaptor for the Cullin-3 ubiquitin complex.

Disclosures:
No relevant conflicts of interest to declare.
Aberrant Ras Activation Associated with Functional Loss of Tnk1/Kos1 In Human B-Cell Lymphoma
Authors: Hoare Kishalay , Hoare Sarasija , Zamora Bernadette , Flagg Tammy , Fu Ann Dongtao , McClellan Steve , Shipp Margaret A. , Reinhard Mary , May W. Stratford 
Published: October 2019

Abstract
Abstract 3159
Tnk1/Kos1 (Thirty-eight negative kinase/Kinase of embryonic stem cells) is the first demonstrated nonreceptor protein tyrosine kinase (PTK) to be identified as a tumor suppressor (Hoare et al.2008). The Tnk1/Kos1 knockout mice (∼80%) spontaneously develop B-cell lymphomas, specifically DLBCL, which express aberrantly high levels of Ras activity due to the loss of Tnk1/Kos1. Mechanistically the high Ras activity in the tumor tissue results from the stabilization of the RasGEF (Grb2-Sos1) complex since Ras is not found to be mutated in B-cell lymphomas. Importantly, in humans, the allelic loss of Tnk1 and/or reduced expression of Tnk1 transcripts occur in patients with DLBCL (Oncomine.org). In support of a tumorigenic mechanism, Immunohistochemical (IHC) analysis using a phospho-specific Tnk1 antibody that we developed confirms the functional loss of Tnk1 activity in DLBCL tissue. These data underscore the potential clinical relevance of Tnk1 in human hematological malignancies. Interestingly, the L540 cell line, derived from a patient with Hodgkin Lymphoma was recently reported to express a 60 Kda truncated fusion Tnk1-C17orf61 gene product (Gu et al. 2010). Although the Tnk fusion gene product is heavily tyrosine phosphorylated, we find that it possesses poor to no enzymatic activity toward the Tnk1/Kos1 substrate Grb2. This indicates that its PTK activity is possibly inhibited by steric hindrance as a result of hyper Y-phosphorylation. This is reminiscent of kinase-dead Tnk1/Kos1 and hence the truncated L540 Tnk fusion protein may function as an oncogene (Hoare et al. 2003). Interestingly, when L540 cells were exposed to 5 Aza cytidine (40μM) or Trichostatin A (100ng/ml), we find a reduction in the expression of the truncated L540 Tnk fusion protein with a concomitant increase in Ras activity (hyper Ras activation) and accumulation of cells in sub G1 phase, indicating Ras mediated induction of cell senescence and death, an event commonly observed in the over expression of several oncogenes (Serrano et al 1997; Ruggero et al, 2004). Our findings may therefore, point the way to designing a novel and effective therapy that may prevent the progression of B-cell lymphomas associated with abnormal expression of mutated Tnk1. Importantly, since Ras is infrequently mutated to oncogenic Ras in human lymphoid tumors (unlike myeloid leukemias), aberrant Ras activation in such lymphoid tumors may result from the loss of Tnk1 kinase activity due to the constitutive activation of Ras-GEF activity. These findings indicate the mechanism by which wt-Ras can be aberrantly activated to an “oncogenic” equivalent form with the loss of Tnk1 to induce and/or contribute to spontaneous tumorigenesis in hematological malignancies.

Disclosures:
No relevant conflicts of interest to declare.