bluuebunny/crossref_metadata_2025_split huggingface dataset:
C-KIT- Mutated t(8;21)AML Patients with >3log Reduction of MRD Conferred a Very High Relapse and Need HSCT to Improve Outcome
Authors: Zhu Hong-Hu , Qin Ya-Zhen , Xu Lan-Ping , Jiang Qian , Zhang Xiao-Hui , Jiang Hao , Huang Xiao-Jun 
Published: October 2019

Abstract
[Objective] Previous studies showed that c-KIT mutation and <3log reduction of minimal residual disease (MRD) were two poor prognostic markers for acute myeloid leukemia (AML) with t(8;21) . However, How to deal with c-KIT- mutated t(8;21)AML patients with >3log reduction of MRD remains undefined. To answer this question, we performed this study.
[Methods] The current retrospective study consisted of 70 newly diagnosed patients with c-KIT- mutated t(8;21)AML during July 2005 and March 2016 in Peking University People's Hospital. Induction treatment included standard 3+7' regimen or HAA regimen. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) was recommended to all patients with an available donor after 2-3 cycles of consolidation treatment with high-dose cytarabine(HDAC). Patients without a donor or refusing HSCT received HDAC-based intensive treatment. MRD was determined by RUNX1/RUNX1T1 transcript levels detected by Q-PCR. The last follow-up time was July 2016.
[Results] Sixty-nine out of 70 patients achieved complete remission(CR).Two patients relapsed after first cycle of consolidation treatment. There were 60 patients having the results of MRD after 2 cycles of consolidation treatment (Figure 1). Thirty-four patients achieved >3log reduction of RUNX1/RUNX1T1 transcript levels (defined as major molecular remission, MMR). There were 16 and 18 patients finally receiving chemotherapy and allo-HSCT. Twenty-six patients did not achieve MMR, and 12 and 14 patients finally receiving chemotherapy and allo-HSCH, respectively. For patients achieving MMR, the 4-year cumulative incidence of relapse (CIR) and disease-free survival (DFS) were 84.8% vs.6.7% (p<0.001) and 20.6% vs.87.5% (p<0.001) when receiving chemotherapy or allo-HSCT(Figure 2). For patients not achieving MMR, the 4-year CIR and DFS were 100% vs.30.8% (p<0.001) and 0% vs.60% (p<0.001) when receiving chemotherapy or allo-HSCT (Figure 2). Multivariate analysis revealed that MRD status (MMR or non-MMR and treatment choice (HSCT or chemotherapy) were independent prognostic factors for relapse, DFS.
[Conclusion] We concluded that c-KIT- mutated t(8;21)AML patients with >3log reduction of MRD conferred a very high relapse and need allo-HSCT to improve outcome.
Figure 1 The flowchart of the study. Figure 1. The flowchart of the study. Figure 2 Thecumulative incidence of relapse (CIR) and disease-free survival (DFS) of c-KIT mutated t(8;21)AML patients. .. Note : MMR: major molecular remission; CT: chemotherapy. HSCT: hematopoietic stem cell transplantation. Figure 2. Thecumulative incidence of relapse (CIR) and disease-free survival (DFS) of c-KIT mutated t(8;21)AML patients. .. / Note : MMR: major molecular remission; CT: chemotherapy. HSCT: hematopoietic stem cell transplantation. Figure 3 Figure 3.

Disclosures
No relevant conflicts of interest to declare.
Amelioration of Immune Thrombocytopenia in Human CD44 Transgenic Mice By Anti-Human CD44 Antibodies
Authors: Crow Andrew R. , Amash Alaa , Lazarus Alan H 
Published: October 2019

Abstract
Selected monoclonal antibodies to murine CD44 are able to successfully ameliorate murine immune thrombocytopenia (ITP) and other inflammatory diseases at a 3 log fold lower dose than IVIg. Since not all murine CD44 antibodies were successful and, like IVIg, the anti-inflammatory mechanism involved is speculative, progress toward human antibodies has been stymied. To potentially develop a therapeutic antibody for patients, we generated transgenic mice expressing the extracellular and transmembrane sequences of human CD44 linked to the murine intracellular CD44 sequence (huCD44) with knockout of murine CD44. Flow cytometric analysis revealed that these mice express huCD44 on leukocytes, but not on platelets or red blood cells.
HuCD44 mice injected with the anti-platelet antibody MWReg30 develop significant thrombocytopenia comparable to normal mice. Utilizing the huCD44 mouse model, we tested 5 monoclonal antibodies reactive with human CD44 of different isotypes; mouse IgG1, mouse IgG2a, mouse IgG2b, rat IgG2a, and rat IgG2b. We report here that pretreatment of mice with all of these antibodies, with the exception of the mouse IgG2b clone all ameliorated thrombocytopenia to the same extent as IVIg, but given at a 3 log-fold lower dosage than IVIg. Interestingly, the mouse IgG2b antibody that was not successful bound to white blood cells as well as the successful antibodies. When mice were re-injected with anti-platelet antibody 24 hr post anti-huCD44 antibody injection, they were still protected from thrombocytopenia at 48 hr, suggesting that these antibodies exhibit durable protection.
The clinical effectiveness of these antibodies does not appear to be related to their extent of huCD44 binding or IgG subtype. In addition, the effectiveness of these antibodies may not be restricted or related to specific activating IgG Fc receptors (FcγR) as the successful mouse IgG1 subtype is only known to interact with FcγRIII, while the IgG2b subtype can bind activating FcγRI, III and IV with only one-of-two of this subtype having therapeutic activity.
In conclusion we have developed, to our knowledge, the first huCD44 transgenic mouse and demonstrate herein that selected antibodies to huCD44 can ameliorate immune thrombocytopenia. These data suggest that some anti-CD44 antibodies may offer a new therapeutic modality for patients with ITP.

Disclosures
No relevant conflicts of interest to declare.
Essential Role for Phospholipase C Gamma 1 (PLC-γ1) in the Survival of t(8;21) Acute Myeloid Leukemia
Authors: Mahmud Hasan , Scherpen Frank JG , Meeuwsen-de Boer Tiny , Lourens Harm-Jan , de Bont Eveline S. 
Published: October 2019

Abstract
The t(8;21) (q22;q22) chromosomal translocation is one of the most frequent genetic alterations in acute myeloid leukemia (AML) and it remains a significant clinical problem especially for children which indicates the need for improved therapeutic strategies. Recently, we showed that peptide derived phospholipase C gamma 1 (PLC-γ1) was highly phosphorylated in pediatric t(8;21) AML. In this study, we determined PLC-γ1 phosphorylation and mRNA levels showing that PLC-γ1 expression was significantly higher in t(8;21) AML compared to other AML karyotypes and normal bone marrow (NBM) (peptide phosphorylation: p<0.01 compared to NBM, mRNA: p<0.001, compared to other AML karyotypes). This was confirmed by PLC-γ1 protein phosphorylation using primary AML samples and AML cell lines. PLC-γ1 is known to play a role in cancer progression, however, the impact of PLC-γ1 in AML is currently unknown. Therefore, we aimed to study the functional role of PLC-γ1 by investigating the cellular growth, survival and its underlying mechanism in a t(8;21) AML cell line (Kasumi-1) . ShRNA-mediated knockdown of PLC-γ1 in kasumi-1 cells significantly blocked leukemic cell growth at day 8 after transduction (p<0.05). The percentage of apoptosis in PLC-γ1 suppressed kasumi-1 cells at day 4 after transduction was two-fold higher compared to the scrambled control (p<0.01). The inhibition of cell proliferation and the induction of apoptosis upon PLC-γ1 suppression could be explained by cell cycle arrest and by increased activation of apoptotic related and cell cycle regulatory protein expressions (BAX, BCL2, p53 and Chk2). As the multidrug resistance is one of the major cause of relapse and poor prognosis in t(8;21) AML, therefore, we demonstrated, if PLC-γ1 suppression increased the sensitivity of kasumi-1 leukemia cells to cytotoxic chemotherapeutic agents (methotrexate, amsacrine and etoposide). PLC-γ1 knockdown cells at day 4 after transduction were shown to significantly reduced cell viability to the genotoxic agents, methotrexate (p<0.05, p<0.001), amsacrine (p<0.01, p<0.001) and etoposide (p<0.05, p<0.01 and p<0.001) in kasumi-1 in a dose-dependent manner. These results provide a strong rationale for the development of PLC-γ1-based therapeutic strategies for the enhancement of efficacy in t(8;21) AML treatment. Additionally, PLC-γ1 suppressed kasumi-1 cells showed significantly less proliferation upon hypoxic stress. Taken together, these results strongly support an important role for PLC-γ1 in the survival of t(8;21) AML mimicking kasumi-1 cell line and identify PLC-γ1 as a potential target for t(8;21) AML treatment.

Disclosures
No relevant conflicts of interest to declare.
AMPK Protects Against Energy Stress and Maintains Histone Acetylation in Leukemia-Initiating-Cell
Authors: Jiang Yajian , Nakada Daisuke , Kitano Ayumi , Chapple Richard , Hu Tianyuan , Lin Angelique 
Published: October 2019

Abstract
Maintaining metabolic homeostasis is a fundamental requirement for cells to survive. One critical requirement is to accomplish a balance between anabolism and catabolism. AMPK regulates this balance by directly sensing AMP-to-ATP ratio and its activation during cell energy deficit promotes ATP production and inhibits ATP usage.
Several pieces of evidence point AMPK as a tumor suppressor: the upstream protein, LKB1, is a well-established tumor suppressor; AMPK negatively interacts with the tumor promoting mTOR pathway; anti-diabetic drugs such as metformin with tumor preventive potential are shown to activate AMPK. However, emerging evidence accumulates to support an opposite role of AMPK in promoting tumor growth. AMPK is found to protect tumor cells from metabolic crisis through different mechanisms: autophagy induction; maintaining proper ATP levels and redox environment; histone H2B tail phosphorylation. These two contrasting findings suggested multiple facets of AMPK, thus pointing to the urge to understand mechanisms of AMPK in specific contexts.
We examined the role of AMPK by deleting both α1 and α2 subunit in a mouse model of acute myeloid leukemia with t(9;11) translocation. AMPK deficiency depletes the leukemia-initiating-cell population and decreases the leukemogenic potential of these cells. In order to study the metabolic regulatory effects of AMPK, we profiled the metabolites and found AMPK deficiency associates with a decreased level of glycolytic activity and reduction of acetyl-CoA, which is the major donor for histone acetylation.
Therefore, we hypothesized that AMPK can affect histone acetylation through regulating the level of acetyl-CoA, and functionally alter leukemogenic potential. We first profiled histone acetylation using western blot with antibodies targeting global histone acetylation and specific histone residues. Intriguingly, we found in AMPK-deficient cells, global histone H3 and H4 acetylation levels are decreased, as well as acetylation at specific histone residues such as H3K9, H3K27 and H4K8. To build a causal link between decreased acetyl-CoA and histone acetylation, we supplemented leukemia-initiating-cells in culture with acetyl-CoA precursors such as acetate and pyruvate. The supplementation successfully increased intracellular acetyl-CoA levels as well as histone acetylation levels. Functionally restoring the intracellular acetyl-CoA and histone acetylation increased the proliferative potential of AMPK-deficient leukemia-initiating-cells and maintained cell at a more undifferentiated state. These results suggest that AMPK regulates a set of leukemogenic genes by maintaining histone acetylation levels. We hypothesize that AMPK links metabolic status to epigenetic gene regulation to promote leukemogenesis.

Disclosures
No relevant conflicts of interest to declare.
Mutant nucleophosmin1 (NPM1) Links Protein Translation with Oncogenic Metabolism in Leukemia
Authors: Juntilla Marisa , Garbuzov Alina , Ortiz Natalie , Eberhard Julia , Roake Caitlin , Yin Yi , Gruber Josh , Artandi Steven 
Published: October 2019

Abstract
Nucleophosmin 1 (NPM1) is the most common gene mutated in acute myeloid leukemia (AML). Several putative mechanisms for the role of NPM1 in the generation of AML have been proposed, including acting as a tumor suppressor by promoting the degradation of p53 and sequestration of wild-type NPM1. However, the specificity of the mutation- most commonly a 4 base pair duplication in the C-terminus- suggests that it may be a gain- of- function mutation conferring an unidentified pro-leukemic effect. Using a novel set of leukemia cell lines generated with CRISPR/Cas9 technology in combination with studies in primary hematopoietic cells, we show that mutant NPM1 may promote leukemia by deregulating protein translation with downstream effects on cellular metabolism. Thus, mutant NPM1 may serve as a critical lynchpin to match metabolic precursors and cellular energetics to ribosomal output. The implications of our results suggest that combined metabolic and protein translation inhibition may be a previously unidentified vulnerability in AML with mutated NPM1.
CRISPR/Cas9 technology was used to generate a set of isogenic cell lines derived from the heterozygous OCI-AML3 line. Transcriptomic analysis of clones with either parental allele configuration (wild-type and mutant, WTAM) vs. inactivation of the mutant allele (wild-type only, WTO) confirmed that mutant NPM1 regulates HOX genes, as shown in both mouse models and patient samples. Next, the effects of mutant NPM1 on ribosome biogenesis and protein translation were assayed with pulse- chase and static experiments and showed both ribosomal RNA and protein translation were increased in WTAM clones vs. WTO clones. During these investigations, cell size was noted to be increased in WTAM cells. Cell size can be a consequence of the metabolic activity of a cell. Analysis of the rate of glucose consumption and lactate production showed that WTAM cells have increased aerobic glycolysis compared with WTO cells. To test if mutant NPM1 is sufficient to drive both protein translation and aerobic glycolysis in a normal cell, these studies were replicated in normal human hematopoietic stem cells stably expressing either wild-type NPM1 or mutant NPM1.
In summary, our results suggest that mutant NPM1 acts through dysregulation of protein translation and participates in metabolic reprogramming required to drive oncogenic transformation.

Disclosures
No relevant conflicts of interest to declare.
VAV1 Activating Mutations and Translocations in Peripheral T-Cell Lymphomas
Authors: Palomero Teresa , Abate Francesco , da Silva Almeida Ana Carolina , Zairis Sakellarios , Robles-Valero Javier , Couronne Lucile , Khiabanian Hossein , Quinn S Aidan , Kim Mi-Yeon , Laginestra Maria Antonella , Kim Christine S , Fiore Danilo , Bhagat Govind , Piris Miguel Angel A. , Campo Elias , Lossos Izidore S , Bernard Olivier A. , Inghirami Giorgio , Pileri Stefano A , Bustelo Xose R , Rabadan Raul , Ferrando Adolfo A. 
Published: October 2019

Abstract
Peripheral T-cell lymphomas (PTCL) are malignant and highly aggressive hematologic tumors arising from mature post thymic T-cells. The diagnosis of PTCL includes diverse lymphoma subgroups, altogether accounting for about 15% of all non-Hodgkin lymphomas. Despite much effort in developing reliable diagnostic markers, the diagnosis of PTCLs is challenging and 20-30% of cases are diagnosed as PTCL-NOS (not otherwise specified). This heterogeneous and poorly defined group of lymphomas is frequently characterized by chemotherapy resistance and a very poor prognosis. Here we report the presence of recurrent driver activating genetic alterations in the VAV1 gene in PTCL, NOS. RNA-seq analysis of a comprehensive series of 154 PTCLs and targeted sequencing identified VAV1 gene fusions with different partners including VAV1-THAP4, VAV1-MYO1F and VAV1-S100A7. In all cases the resulting oncoproteins lack the C-terminal SH3 domain of VAV1, a motif implicated in the negative regulation of VAV1 signaling, leading to increased activation of VAV1 catalytic-dependent (MAPK, JNK) and non-catalytic-dependent (NFAT) VAV1 effector pathways. In addition, and most notably, we also identified focal microdeletions at the VAV1 intron 25-exon 26 boundary, which result in the activation of an alternative intraexonic splice acceptor site and the consequent expression of mis-splicing-driven mutant transcripts harboring a recurrent VAV1 Δ778-786 in-frame deletion. Mechanistically, the VAV1 Δ778-786 mutation removes 9 amino acids proximal to the C-terminal VAV1 SH3 domain and induces in increased VAV1 activation and signaling in biochemical assays. In all, these results support a driver role for oncogenic VAV1 signaling in T-cell transformation of major importance for the design of targeted therapies for the treatment of PTCL, NOS.

Disclosures
No relevant conflicts of interest to declare.
The Dose-Dependent Effects of Microrna-155 in Acute Myeloid Leukemia
Authors: Narayan Nisha , Morenos Leah , Phipson Belinda , Brumatti Gabriella , Eggers Stefanie , Saffery Richard , Willis Simon , Oshlack Alicia , Goodall Gregory J , Ekert Paul G 
Published: October 2019

Abstract
MicroRNAs are a class of non-coding, regulatory RNAs that control several critical cellular processes. Subsets of microRNAs are dysregulated in cancer, and can act as oncogenes or tumour suppressors.
MicroRNA-155 (miR-155) has a well-established role as an oncogene in B cell lymphoma but has a more enigmatic role in acute myeloid leukemia (AML), in which there is evidence that miR-155 may promote or repress the development and progression of AML. We have used enforced expression of miR-155 in murine AML cell lines and AML models to explore the biology of miR-155 in AML.
We show that the capacity of miR-155 to promote or repress the ability of AML cells to form colonies and to proliferate is dependent on miR-155 expression levels. Enforced high expression of miR-155 in AML cell lines results in reduced proliferation and colony formation. However, critical long-term assays of cells transduced with miR-155 resulted in selection in favour of an intermediate miR-155 expression level accompanied by a restoration in clonogenic potential. In vivo, enforced expression of miR-155 in murine AML models showed no differences in disease latency compared to controls, but resulted in an increased tumour burden. Most interestingly, RNA-Sequencing analysis demonstrated that the contrasting levels of miR-155 regulate a substantially different set of gene targets, with downstream consequences on transcription that are consistent with the contrasting effects of high and intermediate miR-155 levels. The intermediate levels of miR-155 we observe are the same as that seen in human AML, whereas the high levels of miR-155 have a completely different inflammatory counterpart. Our data shows that that the levels of miR-155 powerfully influences that gene targets it controls and the resultant phenotypes observed. MiR-155 expressed within a specific range promotes AML disease progression.

Disclosures
No relevant conflicts of interest to declare.
JAM-A as a Prognostic Factor and New Therapeutic Target in Multiple Myeloma
Authors: Solimando Antonio , Brandl Andreas , Katharina Mattenheimer , Graf Carolin , Ritz Miriram , Ruckdeschel Anna , Stühmer Thorsten , Rudelius Martina , Frassanito Maria Antonia , Andreas Rosenwald , Jakob Franz , Vacca Angelo , Einsele Hermann , Beilhack Andreas 
Published: October 2019

Abstract
Cell adhesion in the multiple myeloma (MM) microenvironment is a mechanism by which MM plasma cells escape the effects of therapy and survive. To improve clinical strategies and overcome drug resistance, approaches directed to both MMPCs and bone marrow microenvironment are under investigation. Here, we examined the cell membrane protein Junctional adhesion molecule-A (JAM-A) as a clinical biomarker and novel therapeutic target for MM.
We evaluated JAM-A expression by real time PCR (RT-PCR), flow cytometry and immunofluorescence microscopy in 132 MM patients at different stages and various MM cell lines. Next, we measured the concentrations of soluble JAM-A from MM and healthy subjects sera by enzyme linked immune assay (ELISA). We investigated JAM-A functionally in vitro and in vivo by transient gene silencing (siRNA) and with blocking antibodies.
Patient-derived plasma cells (MMPCs) expressed increased JAM-A expression levels when compared to control PC from healthy individuals. Elevated JAM-A expression correlated with poor prognosis (Figure 1A,B). Furthermore, soluble JAM-A was significantly increased in MM patient sera when compared to healthy subjects. Additionally, MM cell lines showed high expression of both membrane and cytoplasmic JAM-A. Consequently, inhibition of JAM-A using specific siRNA treatment resulted in diminished tumorigenic potential, including decreased colony formation, chemotaxis and migration. Importantly, treatment of luciferase+RPMI-8226 MM bearing NSG with a JAM-A blocking monoclonal antibody reduced significantly MM progression and dissemination in vivo when compared to MM bearing mice that received an non-specific isotype control antibody (Figure 1C).
Conclusively, our data suggest that JAM-A can serve as a biomarker of malignancy in MM patients. Soluble plasma JAM-A could contribute to serum-based clinical stratification. Furthermore, therapeutic targeting of JAM-A appears attractive for clinical translation.
Figure 1 Figure 1.

Disclosures
Einsele: Celgene: Consultancy, Honoraria, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau; Amgen: Consultancy, Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria.
PFKFB3 Is a Crucial Target in the Treatment of Tyrosine Kinase Inhibitor Resistant Chronic Myelogenous Leukemia
Authors: Zhu Yu , Li Jianyong , Qiao Chun , Shan Yi , Qian Sixuan , Chen Yaoyu , Hong Ming , Zhao Huihui , LI Huapeng , Zhu Xuejun , Zhongfa Yang 
Published: October 2019

Abstract
Resistance to the BCR-ABL tyrosine kinase inhibitor (TKI) imatinib mesylate (IM) remains challenge for the treatment of chronic myeloid leukemia (CML). IM resistance often results from unknown mechanisms with wild type BCR-ABL that have no effects on TKIs binding to ABL kinase domain. The basis of such BCR-ABL-independent IM resistance remains to be elucidated. To gain insight into BCR-ABL-independent IM resistance mechanisms, we performed an initial bioinformatics screen on over represented CML genes, followed by a quantitative PCR screen of genes that were elevated in TKIs resistant CML samples. We identified a total of 33 candidate genes that were highly expressed in TKIs resistant patients. Among these genes, 6-Phosphofructo-2-Kinase/Fructose-2,6-Biphosphatase 3 (PFKFB3) controlling the limiting step of glycolysis, was found to strongly associated with TKIs resistance. RNA interference of the expression of PFKFB3 and pharmacological inhibition of its kinase activity markedly increased the sensitivity of TKIs resistant CML cells to TKIs. Furthermore, pharmacological inhibition of PFKFB3 prevented CML cells growth and significantly improved the survival of both allograft and xenograft CML mice. ChIP-seq data analysis combined with subsequent knockdown experiment demonstrated that the Ets transcription factor PU.1 regulates the elevated expression of PFKFB3 in TKIs resistant CML cells. Collectively, our results identify a therapeutically targetable mechanism of BCR-ABL-independent TKIs resistant CML.

Disclosures
No relevant conflicts of interest to declare.