bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lineage-Specific Activation of p53 in Response to Ribosomal Haploinsufficiency in Human Bone Marrow Cells.
Authors: Dutt Shilpee , Narla Anupama , Kutok Jeffery Lorne , Ebert Benjamin L. 
Published: October 2019

Abstract
Abstract 948
Haploinsufficiency for the ribosomal protein genes RPS14 and RPS19 have been implicated in the erythroid defect in the 5q- syndrome and Diamond Blackfan Anemia, respectively. However, the mechanism by which defective ribosome biogenesis causes erythroid failure is unknown. In this study, we found that shRNA mediated knockdown of RPS14 or RPS19 in primary human CD34+ cells stabilize TP53 by day 4 after infection with concomitant arrest of these cells at G1 stage of cell cycle. The levels of TP53 attained are comparable to the levels observed following gamma irradiation (5Gy) of the CD34+ cells. Using quantitative PCR, we confirmed that stabilized TP53 activates expression of downstream target genes MDM2, p21, Bax and Wig-1. Furthermore, treatment of the CD34+ cells with Nutlin-3 phenocopies RPS14 or RPS19 knockdown, suggesting that the mechanism of TP53 activation is mediated by MDM2 pathway. Conversely, treatment with pifithrin-alpha, which inhibits the transactivation activity of TP53, rescues the effects of RPS14 or RPS19 knockdown. The in vitro activation of TP53 in CD34+ cells was restricted to erythroid cell lineage, consistent with the clinical phenotype of RPS14 or RPS19 haploinsufficiency. Moreover, immunohistochemical analysis of bone marrow biopsies from patient with the 5q- syndrome demonstrated intense staining of TP53 that was restricted to erythroid progenitor cells. Taken together our study indicates that inhibition of ribosomal biogenesis causes TP53 activation selectively in erythroid progenitor cells. Clinically, TP53 staining of patient samples could be used as a diagnostic marker for some types of MDS.

Disclosures:
No relevant conflicts of interest to declare.
Early 18fluorodeoxyglucose PET Scan as a Prognostic Tool in Diffuse Large B-Cell Lymphoma Patients Treated with An Anthracycline-Based Chemotherapy Plus Rituximab.
Authors: Safar Violaine , Dupuis Jehan , Jardin Fabrice , Fruchart Christophe , Bardet Stéphane , Vera Pierre , Tilly Herve , Meignan Michel , Itti Emmanuel , Haioun Corinne 
Published: October 2019

Abstract
Abstract 98

Background:
18Fluorodeoxyglucose PET has been quickly integrated to the diagnostic and therapeutic armamentarium in diffuse large-B cell lymphoma (DLBCL). Moreover, early PET appears a promising prognostic tool for tailoring treatment strategies. We evaluated the predictive value of early PET in a large prospective cohort of patients treated with immunochemotherapy.

Patients and methods:
112 previously untreated patients from three institutions were treated between January 2000 and October 2008 for DLBCL using an anthracycline-based regimen plus Rituximab. Chemotherapy was either an R-CHOP21 regimen (n=57) or a dose-dense regimen (R-ACVBP, n=31 or R-CHOP14, n= 24). PET was performed at diagnosis and after two cycles of treatment. Early PET results were interpreted visually as positive (PET2p) or negative (PET2n), as previously described1, but did not modify the scheduled therapy.

Results:
Median age at diagnosis was 59 years (range 20–79 years) and 67% of patients were males, 44% were over 60 years, 81% presented with an advanced Ann Arbor stage (III–IV), 29% had a poor performance status (ECOG 2-4), 36% had more than one extra-nodal site involved and LDH were elevated in 68%. The repartition on the basis of the International Prognosis Index was the following: low=5%, low-intermediate =35%, intermediate-high=37% and high risk=23%. After two cycles, 70 patients (63%) were PET2n and 42 (38%) were PET2p (38 patients in partial response and 4 with stable disease). Median follow-up was 38 months for living patients. Ten of 70 (14%) PET2n patients showed progression versus 22 of 42 (52%) PET2p patients. The estimated 5-year progression free survival (PFS) was 81% for PET2n and 47% for PET2p patients (log rank test, p<0.0001). Prognostic value of early PET was significant in terms of PFS whether patients were treated with R-CHOP21 (p=0.0006) or with dose-dense regimens (p=0.0056). Nine of 70 (13%) PET2n and 15 of 42 (36%) PET2p patients died. The estimated 5-year overall survival (OS) was 88% for PET2n and 62% for PET2p patients (log rank test, p<0.0034). Prognostic value of early PET was significant in terms of OS for patients treated with R-CHOP21 (p=0. 0225) but not for those treated with dose-dense regimens (p=0.133).

Conclusion:
Early PET after 2 cycles of treatment is a powerful tool to predict outcome in DLBCL patients treated with Rituximab combined with an anthracycline-based chemotherapy. It brings promising opportunities in the designing of new treatment strategies for DLBCL.
Reference : 1 Haioun et al. Blood 2005; 106(4):1376–81.

Disclosures:
No relevant conflicts of interest to declare.
Loss of Non-Inherited Maternal MHC and Materno-Fetal Transmission of p190 Type BCR-ABL Leukemia.
Authors: Isoda Takeshi , Ford Anthony , Tomizawa Daisuke , Delft Frederik W van , Castro David Gonzalez de , Mitsuiki Noriko , Score Joannah , Taki Tomohiko , Morio Tomohiro , Takagi Masatoshi , Saji Hiroh , Mizutani Shuki , Greaves Mel 
Published: October 2019

Abstract
Abstract 980
Poster Board I-2

Introduction:
Materno-fetal transmission of malignant clone is one of the rare causes of leukemia in infants. It has been recorded some 20 times over the past 100 years but definitive, genetic evidence for a maternal origin has been lacking. Here we present a detailed genetic analysis of materno-fetal transmission in a case with p190 type BCR-ABL leukemia.

Patients course:
A mother was found to have p190 type BCR-ABL positive acute lymphoblastic leukemia (ALL) one month after delivery of a baby, and died during induction therapy by uncontrolled bacillus cereus encephalitis. Her baby developed p190 type BCR-ABL positive B-precursor lymphoblastic lymphoma (B-LBL stage3 jaw tumor and pleural effusion) at 11-month old. Non-Hodgkin's lymphoma type chemotherapy according to Japanese Pediatric Leukemia/Lymphoma Study Group (JPLSG) ALB-NHL03, followed by Hyper-CVAD imatinib therapy without stem cell transplantation were given to her, leading to complete remission for more than 31 months.

Material and methods:
We first cloned the BCR-ABL genomic breakpoint region from the infant's pleural effusion (PE). The breakpoint was designated as a fusion between BCR intron 1 and ABL intron1. Then, We conducted Q-PCR by using BCR-ABL genomic breakpoint specific primer and sequencing. Fifteen polymorphic STR markers were amplified in the paternal blood DNA and Patient's PE and PB DNA samples using the Powerplex-16 system. HLA serotyping was by microdroplet lymphocyte cytotoxity. Genotyping was carried out using a reversed SSO HLA DNA typing method. The infant jaw tumor was further analyzed by Affymetrix high resolusion (250K) SNP arrays.

Results:
Short tandem repeat profiles indicated that the infant jaw tumor was, unambiguously, of maternal origin. Amplification of BCR-ABL genomic breakpoints on maternal leukemic cells and infant lymphoma cells revealed that these leukemia clones shared the same unique BCR-ABL genomic sequence, indicating a shared, single cell origin. Positivity of BCR-ABL specific PCR on Guthrie card blood spot also indicated that the leukemic clone was present in the blood at birth. Additionally the infant, maternal-derived leukemic cells had uniparental disomy of chromosome 6p with a deletion of non-inherited maternal MHC allele (NIMA), suggesting a mechanism for immune evasion in the baby.

Conclusions:
This is the first case with definite evidence of in utero materno-fetal transmission of mother's leukemic cells. This case also suggests that materno-feto transfer of leukemic cells is more common than as reflected in the frequency of clinically diagnosed cases, where the immuno-surveillance, predominantly directed against major HLA locus antigens, may be the principal constraint.

Disclosures:
No relevant conflicts of interest to declare.
Testing the BCL-2 Family to Direct Therapy and Predict Response.
Authors: Letai Anthony 
Published: October 2019

Abstract
Abstract SCI-14
Many, if not most, chemotherapeutic agents kill cancer cells via the mitochondrial apoptotic pathway. A simple model of this pathway breaks the killing into three steps. In Step 1, drug contacts target. In Step 2, prodeath signaling is generated. In Step 3, this pro-death signaling is interpreted by the BCL-2 family proteins at the mitochondrion, and when sufficient, the cancer cell is committed to the fate of death. Despite prominent exceptions, it is generally poorly understood why some cells are killed by chemotherapy and others are not. This is particularly perplexing in the case of most conventional chemotherapeutics which target ubiquitous elements such as DNA or microtubules. Most studies of determinants of chemotherapy induced cell death are focused on Steps 1 and 2. Relatively little is known about how mitochondrial preconditions affect chemosensitivity in cancer cells. We have developed a tool called BH3 profiling which exposes mitochondria to measured doses of BH3 domains, pro-death molecules of the BCL-2 family that ultimately carry pro-death signaling from Step 2 to the mitochondrion. By comparing mitochondrial dysfunction between different cells exposed to identical doses of BH3 domains, we can compare readiness of different cell types to undergo apoptosis. We have shown that this mitochondrial preset predicts response to conventional therapies of disparate mechanism, including etoposide, vincristine, and doxorubicin. Furthermore, BH3 profiling can predict response to agents such as ABT-737 which selectively kill cells dependent on anti-apoptotic proteins BCL-2, BCL-XL, and BCL-w. We have found BH3 profiling to be useful in many hematologic malignancies, including CLL, AML, ALL, lymphoma and myeloma. We have recently improved the BH3 profiling tool so that now it can be performed in a fluorescence activated cell sorting (FACS) format. The FACS format allows us to deconvolute complex, heterogeneous samples such are typically provided by clinical material. Our results suggest that heterogeneity of response to therapies, either within heterogeneous samples or between different tumors, relies to a very great extent on the mitochondrial preset measured by BH3 profiling.

Disclosures
Letai: Abbott Laboratories: Served as advisor for clinical development meeting.; Eutropics Pharmaceuticals: Equity Ownership.
Mitochondria in Neuroplasticity, Neurologic Disease and Aging.
Authors: Mattson Mark P. 
Published: October 2019

Abstract
Abstract SCI-2
Brain cells are influenced in health and disease by several types of bone marrow-derived cells (BMDC) that either reside in, or are recruited to, the brain. Microglia are macrophage-like cells that continuously surveil the brain, and respond to injury, infection or disease by endocytosing damaged/dead cells and microorganisms, and by producing pro-inflammatory cytokines. Lymphocytes of various phenotypes enter the brain in large numbers in response to acute injury (stroke, severe epileptic seizures, trauma) or chronic disease (multiple sclerosis, Alzheimer's disease). While microglia and lymphocytes are best known for their adverse effects on neuronal function and survival in injury or disease (Arumugam et al., Nat Med. 2006; 12:621-3), recent findings suggest that these cells may also serve important beneficial roles in processes such as learning and memory (Ziv et al. Nat Neurosci. 2006; 9:268-75). Here I describe how BMDC can affect neuronal excitability and mitochondrial function in normal physiological settings and in disease states. We have found that low concentrations of tumor necrosis factor (TNF), which is produced by microglia/macrophages and lymphocytes, can promote neuronal survival and synaptic plasticity by activating the transcription factor NF-kB to induce the expression of glutamate receptor subunits, mitochondrial SOD2 and Bcl2 (Mattson and Meffert, Cell Death Differ. 2006; 13:852-60). When bone marrow from TNF receptor-deficient mice was transplanted into irradiated wild type mice, neurons in the brain were more vulnerable to epileptic seizures, suggesting that TNF suppresses neuronal excitability (Guo et al., Neuromolecular Med. 2004; 5:219-34). In other studies we found that a mutation in presenilin-1 (PS1) that causes early-onset inherited Alzheimer's disease (AD) perturbs lymphocyte signaling (Morgan et al., Neuromolecular Med. 2007; 9:35-45). Splenic T cells isolated from PS1 mutant knockin mice respond poorly to proliferative signals and have downregulated cluster designation 3 and interleukin (IL)- 2-receptor expression necessary for a normal T-cell immune response. The adverse effect of mutant PS1 involves perturbed calcium regulation and cytokine signaling in lymphocytes, and associated sensitivity of lymphocytes to mitochondria-mediated apoptosis. These findings suggest that abnormalities in immune function might play roles in the pathogenesis of AD. Finally, I describe very recent findings that suggest roles for toll-like receptor signaling in learning and memory processes, and in neuronal responses to energy deprivation (Tang et al., Proc Natl Acad Sci U S A. 2007; 104:13798-803). Emerging findings therefore suggest that both innate and humoral signaling from BMDC to neurons play interesting roles in regulating neuronal plasticity and energy metabolism in health and disease.

Disclosures
No relevant conflicts of interest to declare.
Defining the Mechanism of Transcription Factor-Induced Epigenetic Reprogramming.
Authors: Plath Kathrin , Sridharan Rupa , Tchieu Jason , Mason Mike J. , Chin Mark , Yachechko Robin , Kuoy Edward , Zhou Qing , Lowry Bill 
Published: October 2019

Abstract
Abstract SCI-41
The great excitement surrounding induced pluripotent stem (iPS) cells is tempered by the fact that little is known about how they are generated and why this process is so inefficient. We have set out to ask how the four transcription factors Oct4, Sox2, cMyc and Klf4 can induce pluripotency. By analyzing the role of the reprogramming factors Oct4, Sox2, Klf4 and cMyc during the initial step of reprogramming and comparing their binding and global expression in fully and partially reprogrammed cells, we previously uncovered that cMyc has a central role in the repression of the somatic cell expression program. With respect to the upregulation of the embryonic cell transcription, the four factors cooperate to activate the metabolic program, followed by binding of Oct4, Klf4 and Sox2 to genes encoding pluripotency regulators leading to the self-sustained, pluripotent state. Thus, we suggested that the factors have separable and temporal contributions to the reprogramming process. We are particularly interested in further deciphering the mechanism of reprogramming, understanding barriers of the reprogramming process, and comparing the embryonic stem cell state with the iPS cell state.

Disclosures
No relevant conflicts of interest to declare.
Genetic Risk Factors of Thrombosis.
Authors: Reitsma Pieter H. 
Published: October 2019

Abstract
Abstract SCI-43
Venous thrombosis is a common episodic disease with a steep age gradient. Interactions between various risk factors determine the development of the disease, and the proportion of variance attributable to genetic factors may be as high as 50-60%. There are six (moderately) strong genetic risk factors. First there are heterozygous deficiencies of the natural anticoagulants protein C, protein S, and antithrombin. These deficiency states are quite rare in the general population (in all races) and their genetic architecture is complex with hundreds of documented mutations. The risk for the development of venous thrombosis may be increased 10-20-fold in these deficiency states. There is no consistent evidence that deficiencies of other members of the anticoagulant systems - such as thrombomodulin, EPCR, and heparin co-factor II - are also strong risk factors for venous thrombosis, possibly because these natural anticoagulants are associated with other episodic or chronic diseases. Secondly there are three genetic factors associated with an increase, directly or indirectly, in the procoagulant potential of the coagulation system: blood group non-O, factor V Leiden and prothrombin G20201A. The genetic architecture of these risk factors is extremely simple. The prevalence in the general Caucasian population is modest for prothrombin G20210A and factor V Leiden; in other races these two risk factors are extremely rare. The increase in thrombotic risk is about 3-fold or 7-fold for prothrombin G20210 and Factor V Leiden respectively. Blood group non-O is the most common of the prothrombotic genetic risk factors and approximately doubles the risk of venous thrombosis, and may do so in all races. In addition to these six ‘classical’ risk factors, a growing list of weak genetic risk factors has been discovered. Almost without exception, these weak risk factors are common single nucleotide polymorphisms in coagulation factor genes - e.g. those encoding for fibrinogen, factor XIII, factor IX, et cetera - that have a small effect on gene function, and consequently a small effect on thrombotic risk. This list of weak but common risk factors is expected to grow considerably in the near future as the large-scale genome wide association studies that are currently under way deliver their results. Moreover, deep resequencing studies are expected to start soon, whether based on a candidate gene approach or genome-wide, which will yield unprecedented insight in the extend to which rare genetic variation determines individual thrombotic risk.

Disclosures
No relevant conflicts of interest to declare.
Immunologic Responder Groups.
Authors: Sloan Steven R. 
Published: October 2019

Abstract
Abstract SCI-47
Transfusion medicine has long recognized that there is significant variation in the human immune response to red blood cell (RBC) transfusions.1 All allogeneic RBC transfusions expose the recipient to multiple foreign antigens, but very few RBC transfusions induce a detectable humoral immune response. Using statistical analyses of antibody responses among transfused patient populations, we found that the response closely approximates a geometric distribution that would be predicted by a random memory-less (stochastic) process. These statistical analyses demonstrate that most patients fail to mount immune responses to RBC transfusions but a distinct group of patients, termed potential responders, is capable of mounting an immune response to blood transfusions. Potential responders comprise approximately 13% of the transfused population and this proportion does not depend on pathologic diagnoses, age, gender or racial group. The only group that has a higher rate of potential responders are pregnant women, but those patients have a second route of antibody exposure. Although the ability to immunologically respond to blood transfusions appears to be limited to the relatively small population of potential responders, even potential responders do not mount an immune response to most RBC transfusions. Additionally, the specific antibodies that patients make are not completely independent of each other. Indeed, patients who have made some specific antibodies are more likely to subsequently make one set of anti-erythrocyte antibodies and less likely to make another set of anti-erythrocyte antibodies. This suggests that the potential immune repertoire differs between patients and the difference in potential repertoire is not solely explained by the antigens expressed on the patients' erythrocytes. Moreover, the potential repertoire is influenced by the age of the patient. Younger patients have a more diverse immune response producing antibodies against a broad spectrum of RBC antigens. As patients get older, the immune response becomes more limited and usually only responds against the most immunogenic RBC antigens. In summary, these results suggest that potential responders to intravenous administration of RBCs comprise a genetically distinct group and that additional factors determine which transfusion will induce an immune response in potential responders. The factors that cause a person to be a potential responder and the factors that cause a potential responder actually respond to a specific transfusion are subjects of ongoing research. In the meantime, transfusion services may consider minimizing immunologic stimuli to patients who are clearly responders. 1. Higgins JM, Sloan SR. Stochastic modeling of human RBC alloimmunization: evidence for a distinct population of immunologic responders. Blood. 2008;112:2546-2553.

Disclosures
No relevant conflicts of interest to declare.
Codanin-1, the Product of the Gene Mutated In Congenital Dyserythropoietic Anemia Type I (CDA I), Binds to Histone Chaperone Asf1a and Inhibits Its Nucleosome Assembly Activity
Authors: Tamary Hannah , Marcoux Nathaly , Noy-Lotan Sharon , Yaniv Isaac , Dgany Orly 
Published: October 2019

Abstract
Abstract 1004
Congenital dyserythropoietic anemia type I (CDA1) is an inherited recessive macrocytic anemia associated with ineffective erythropoiesis. The disorder is characterized by the accumulation of erythroid precursors containing spongy heterochromatin and internuclear chromatin bridges. The mutated gene (CDAN1) encodes an ubiquitously expressed protein (codanin-1) of unknown function. We have previously shown that codanin-1 is a direct transcriptional target of the E2F1 transcription factor and that the levels of codanin-1 increase during S-phase and decrease during mitosis. In an attempt to further define the role of codanin-1, we conducted a yeast two-hybrid screen using a human bone marrow library and found that codanin-1 binds to Asf1a. Asf1 (anti silencing function) is a H3/H4 histone chaperone involved in the chromatin structure dynamics by its role in nucleosome assembly and disassembly. Using coimmunoprecipitation experiments we confirmed that histone chaperone Asf1a is a direct binding partner of codanin-1. Minimal 100 amino acids domain of codanin-1, involved in binding Asf1, was identified and defined as the Asf1-binding domain. We found that codanin-1 binds to the conserved N-terminal core of Asf1a, where histones and other histone chaperones also bind. FLAG-tagged codanin-1 or its Asf1-binding domain immunoprecipitated from transfected Hela cells and subsequently coimmunoprecipitated histone H3 and Asf1a simultaneously. A pull-down assay of purified Asf1-binding domain in the presence of core histones showed, however, no direct binding of this domain of codanin-1 to H3/H4 histones. By using the replication-independent nucleosome formation assay we noticed that the nucleosome assembly activity of GST-Asf1a was severely decreased by the addition of the purified Asf1-binding domain of codanin-1, a phenotype similar to the one observed in Asf1 depletion. One possible explanation is that binding of codanin-1 inhibits dissociation of histones from Asf1a, which therefore cannot be deposited onto DNA. It will be of interest to determine if codanin-1 is involved in modulating Asf1a activity in vivo and also in response to DNA replication or damage and to determine its role in erythroid heterochromatin formation.

Disclosures:
No relevant conflicts of interest to declare.