bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular Characterization Of Adult T-Cell Leukemia/Lymphoma
Authors: Nagata Yasunobu , Kitanaka Akira , Sanada Masashi , Sato Aiko , Okuno Yusuke , Shiraishi Yuichi , Chiba Kenichi , Tanaka Hiroko , Yoshizato Tetsuichi , Kon Ayana , Yoshida Kenichi , Ishiyama Ken , Miyawaki Shuichi , Miyano Satoru , Shimoda Kazuya , Ogawa Seishi 
Published: October 2019

Abstract
Adult T-cell leukemia/lymphoma (ATL) is an aggressive form of peripheral T-cell lymphoma (PTCL), which is etiologically associated with human T-lymphotropic virus type I (HTLV-1) infection during early infancy. Although HTLV-1 can effectively immortalize T-cells, there is a long latency period of ∼50 years prior to the onset of ATL, suggesting that HTLV-1 infection alone may not be sufficient for the development of ATL, but additional acquired genetic hits that occur in immortalized T-cells during the later life are essential for its pathogenesis. However, little has been known about those genetic hits that are involved in the pathogenesis of ATL.
The purpose of this study is to understand the genetic basis of ATL, 32 cases with different ATL subtypes, including acute (N=15), chronic (N=6), lymphoma (N=10), smoldering (N=1) types were analyzed by whole exome sequencing as well as copy number analysis. With a mean coverage of 119, 94% of the target sequences were analyzed at more than 20 depth on average. A total of 2,862 somatic changes were detected in 32 cases with a true positive rate of 99% (329 of the 334 tested were confirmed by PCR-based deep sequencing). These consisted of 2,512 missense mutations, 174 nonsense mutations, 65 splice-site mutations, and 111 indels. The mutation rate of 89 (44-227) per sample was significantly higher than that in acute myeloid leukemia (7.3–13), myelodysplastic syndromes (9.2) and chronic lymphocytic leukemia (11.5). Recurrent mutations were observed in 350 genes, of which 192 were considered to be significantly mutated (q < 0.05) compared to background mutation rates (1.79 mutations per megabase).
To investigate significantly mutated pathways, each pathway registered in the Kyoto Encyclopedia of Genes and Genomes, BioCarta, Reactome, Sigma-Aldrich and Signaling Transduction KE was tested on the basis of the background mutation rate observed in whole-exome sequencing data, which revealed a number of significantly mutated functional pathways, including pathways involeved in T cell receptor signaling, leukocyte trans-endothelial migration, VEGF and WNT signalings and other signaling pathways.
Genes for epigenetic regulations were also among the frequent targets of gene mutations. We performed targeted deep sequencing of TET2, IDH1/2 and DNMT3A in 182 ATL cases. In total, 19 TET2 mutations were identified in 16 cases (8.7%). Different subtypes of ATL were almost evenly affected with 9 out of 67 acute, 3 out of 42 chronic and 4 out of 56 lymphoma types having TET2 mutations. Less frequent mutations of IDH2 and DNMT3A (both 1%) were also identified. Our findings on genetic alterations provide a novel insight into the pathogenesis of ATL.

Disclosures:
No relevant conflicts of interest to declare.
Interrogation Of Signaling Networks In B Cell Malignancies To Improve Classification Of Patient Subsets For Targeted Therapy
Authors: Obidi Joyce , Burke Patricia , Goswami Trishna , Richman Laura , Mendel Dirk , Bao Haifeng 
Published: October 2019

Abstract
Targeted therapies have demonstrated promising advances in treatment of B cell malignancies. The premise of this project is that patients with closely related signaling “fingerprints” will have similar biological and clinical features. The objectives were to identify signaling profiles that are associated with clinical features and classify patients based on a signaling signature. 19 DLBCL and CLL cell lines with different molecular features were assessed in this study to establish relevant signaling features. We examined chronic BCR signaling, which leads to the activation of several downstream signaling pathways such as MAPK, AKT and NFκB pathways, in DLBCL and CLL cell lines. Phosphoflow cytometry was used to profile cell lines; a panel of 2 stimulation conditions was combined with 3 phospho-protein readouts. Basal level signal activities in cells were compared to enhance activation with PMA/IONO and F(ab’)2 IgG/IgM. We observed that AKT signaling in cell lines contrasted significantly with signaling in Normal B cells (CD20+ PBMCs). Constitutive activation of the AKT signaling pathways at baseline was observed in DLBCL cell lines; very high basal phosphorylated Ribosomal Protein S6 was observed in ABC (activated B-cell) phenotype DLBCL cell lines. In addition, upon ex vivo stimulation 30% of the cell lines demonstrated high level of pathway activity when compared to normal B cells. In this study we have identified 2 distinct signaling profiles based on BCR signaling in DLBCL cell lines; 7 of 12 DLBCL cell lines demonstrated impaired BCR signaling and 4 of 12 cell lines were hyper responsive to BCR stimulation. In the case of NFκB signaling, ex vivo stimulation revealed an absence of functional NFκB activity in the several cell lines. However, the lack of NFκB pathway activity observed in these cell lines was restored with the use of a phosphatase inhibitor, indicating that impaired signaling is not through loss of kinase function but is due to an increase in negative regulation. We also explored inhibition of pathway activities in response to small molecule inhibitors targeting BCR signaling. The inconsistency in MAPK, AKT, and NFκB pathway activities observed could aid in defining a signaling profile applicable to patient stratification. Overall, our results suggest that profiling of signaling network activities represents a promising approach to molecularly classifying DLBCL and CLL subtypes.

Disclosures:
Obidi: MedImmune: Employment. Burke:MedImmune: Employment. Goswami:MediImmune: Employment. Richman:MedImmune: Employment. Mendel:Medimmune: Employment. Bao:MediImmune: Employment.
25-OH-Vitamin-D Deficiency Impairs Rituximab-Mediated Cellular Cytotoxicity and Is Associated With An Inferior Outcome Of Elderly DLBCL Patients Treated With Rituximab
Authors: Bittenbring Joerg Thomas , Altmann Bettina , Neumann Frank , Achenbach Marina , Reichrath Joerg , Ziepert Marita , Geisel Juergen , Regitz Evi , Held Gerhard , Pfreundschuh Michael 
Published: October 2019

Abstract

Background
To investigate the impact and underlying mechanisms of vitamin-D-deficiency (VDD) on outcome of elderly (61 to 80 year-old) DLBCL patients.

Methods
Pretreatment 25-OH-vitamin-D serum levels from 359 patients treated in the prospective multicenter RICOVER-60 trial with 6 or 8 cycles of CHOP-14 with and without 8 cycles rituximab and 63 patients in the RICOVER-noRT study treated with 6xCHOP-14 + 8xR were determined determined by LIASION®, a commercially available chemoluminescent immunoassay.

Results
RICOVER-60 patients with VDD (defined as serum levels ≤8 ng/m l) and treated with rituximab had a 3-year event-free survival of 59% compared to 79% in patients with >8 ng/ml; 3-year overall survival was 70% and 82%, respectively. These differences were significant in a multivariable analysis adjusting for IPI risk factors with a hazard ratio of 2.1 [p=0.008] for event-free survival and 1.9 [p=0.040] for overall survival. In patients treated without rituximab 3-year EFS was not significantly different in patients with vitamin-D levels ≤8 and >8 ng/ml (HR 1.2; p=0.388). These results were confirmed in an independent validation set of 63 patients treated within the RICOVER-noRT study. Rituximab-mediated cellular toxicity (RMCC) against the CD20+ cell line Daudi as determined by LDH release assay increased significantly (p<0.005) in 5/5 vitamin-D-deficient individuals after vitamin-D substitution and normalization of their vitamin-D levels.

Conclusions
VDD is a significant risk factor for elderly DLBCL patients treated with rituximab. Our results show that VDD impairs RMCC and that RMCC can be improved by vitamin-D substitution. This together with the differential effect of VDD in patients treated with and without rituximab suggests that vitamin-D substitution might result in a better outcome of these patients when treated with CHOP plus rituximab. Supported by a grant from Deutsche Krebshilfe.

Disclosures:
No relevant conflicts of interest to declare.
Consumption Of FVIII Concentrate During On-Demand and Prophylactic Treatment With Human-cl rhFVIII In Prospective Clinical Studies In Adult Patients With Severe Hemophilia A
Authors: Tiede Andreas , Knaub Sigurd , Oldenburg Johannes , Bichler Johann 
Published: October 2019

Abstract

Background
There is ample evidence to support prophylactic treatment with factor VIII (FVIII) in children with severe hemophilia A (HA). Adults with severe HA are often treated on-demand and the potential benefit of regular prophylaxis is linked to a higher consumption of FVIII concentrates. During the clinical development of Human-cl rhFVIII, the first recombinant FVIII concentrate from a human cell line, its efficacy and safety was evaluated in previously treated adult patients (PTPs) during on-demand treatment only (GENA-01) and prophylaxis (GENA-08).

Aims
To compare post-hoc the annualized bleeding rate (ABR) and the consumption of FVIII concentrate in patients treated exclusively on-demand with those treated prophylactically.

Methods
Both prospective multi-centre studies were approved by the Ethics Committees of each participating institution and informed consent was obtained from the patient prior to any trial activity. In GENA-01, patients were to be treated on-demand for ≥6 months and ≥50 exposure days with protocol recommended doses ranging from 20 to 60 IU/kg, depending on the severity of the bleed. In GENA-08, patients were to be treated prophylactically with Human-cl rhFVIII every other day with 30-40 IU/kg for ≥6 months. Human-cl rhFVIII was also to be used in case of breakthrough bleeds.

Results
22 PTPs with severe HA were enrolled in GENA-01, and 32 in GENA-08. The study populations were reasonably well comparable to each other (GENA-01 vs. GENA-08, mean±SD), regarding age (39.6±14.1 vs. 37.3±13.6 years), body mass index (23.9±4.8 vs. 25.8±4.9 kg/m2), hemophilia joint health score (38.4±30.3 vs. 34.6±32.2), race (>80% White in both studies) and historical bleeding sites. In GENA-08, the majority of patients (65.6%) had been treated prophylactically prior to study entry. Their historical mean±SD ABR was 6.6 ±11.3 (median: 2.0, range: 0-48.7) and their mean prophylactic dose/month was 293 IU/kg. The other 11 patients who had been treated on-demand had a mean±SD ABR of 47.4±34.6 (median: 36.5, range: 12.2-121.7). In GENA-01, all but 2 patients were treated on-demand prior to study entry. The historical mean±SD ABR of all GENA-01 patients was 49.5±35.9 (median: 44.6, range: 2.0-158.7). The ABR and FVIII consumption during the studies are shown in Table 1.

Conclusion
The data suggest that regular prophylactic treatment with Human-cl rhFVIII in adult PTPs with severe HA resulted in an approximately 25-fold reduction of bleeding rate, and a 3-fold increase of FVIII concentrate consumption.

Disclosures:
Tiede: Octapharma AG: Consultancy, Investigator Other. Knaub:Octapharma AG: Employment. Oldenburg:Octapharma AG: Consultancy, Investigator Other. Bichler:Octapharma AG: Employment.
Latest Results From The PUP-GCP Clinical Trial: A Low Inhibitor Rate In Previously Untreated Patients With Severe Hemophilia A Treated With Octanate
Authors: Klukowska Anna , Jansen Martina , Komrska Vladimir , Laguna Pawel , Vdovin Vladimir , Knaub Sigurd 
Published: October 2019

Abstract

Background
Octanate is a highly purified, double virus inactivated, human plasma-derived factor VIII (FVIII) concentrate with all coagulation FVIII bound to its natural stabilizer VWF in a VWF:RCo/FVIII:C ratio of approximately 0.4. Five prospective GCP studies with octanate were conducted in 77 previously treated patients (PTPs) with severe hemophilia A. None of these 77 PTPs developed an inhibitor while treated exclusively with octanate.

Aim
To assess the immunogenicity in previously untreated patients (PUPs), a prospective clinical trial has been initiated in 2000. This included 50 PUPs with severe hemophilia A for an observational period of 100 exposure days with octanate, for at least 6 months.

Methods
Patients with severe hemophilia A without previous exposure to FVIII or FVIII-containing products were enrolled. Efficacy and tolerability were assessed by a 4-point verbal rating scale. Inhibitors were assessed according to modified Bethesda method prior to treatment every 3-4 exposure days (ED 1-20), and after treatment every 10 EDs (ED 21-100), but at minimum every three months.

Results
Two of 50 (4%) subjects developed clinically relevant inhibitor titers over the course of the study. Another two displayed inhibitors that disappeared spontaneously without change of dose or dosing interval. All inhibitors developed under on-demand treatment and before ED 50. From the 50 subjects, 42 had exceeded 50 EDs at the time of this analysis. Octanate was well-tolerated and the adverse event profile was consistent with the population studied. The hemostatic efficacy in prophylaxis and treatment of bleeding episodes was generally rated as “excellent” and no complication was reported for any surgical treatment.

Conclusion
Despite frequent inhibitor testing and predominant on-demand treatment, the data indicate a low overall inhibitor rate for octanate in patients who exceeded 50 exposure days (4/42) of which only 2 (4.8%) were clinically relevant.

Disclosures:
Klukowska: Octapharma AG: Investigator Other. Jansen:Octapharma AG: Employment. Komrska:Octapharma AG: Investigator Other. Laguna:Octapharma AG: Investigator Other. Vdovin:Octapharma AG: Investigator Other. Knaub:Octapharma AG: Employment.
The Leukemia-Associated Rho Guanine Nucleotide Exchange Factor (LARG) /ARHGEF12 Is Important For Erythroid Differentiation
Authors: Gao Li , Zhou Yong , Tang JingYan , Shen Shuhong 
Published: October 2019

Abstract
ARHGEF12,which was initially identified as a fusion partner of MLL in acute myeloid leukemia, is a regulatory protein involved in the GDP/GTP exchange reaction of the Rho A and activates a Rho-GTPase-dependent signaling pathway. However, the role of ARHGEF12 in hematopoiesis remains unknown. Here, we first report that ARHGEF12 takes part in erythroid differentiation not only in erythroleukemia cell line K562 but also in zebra fish based on knockdown technology. Although primitive hematopoiesis including erythroid differentiation progressed normally, double silencing of both orthologues arhgef12a and arhgef12b in Danio rerio with morpholino caused erythropenia during definitive hematopoiesis. Meanwhile, cytology assay reveal less mature red blood cells with large and loose nuclear in morpholino injected embryos. The phenotype of blocked erythroid differentiation can be rescured by mRNA overexpression of RhoA active mutant. On the other hand, injection of mRNA transcripted from the dominant negative mutant of RhoA could replicate the phenotype of arhgef12 silencing. Antibody array screen of kinase phosphorylation suggested STAT1 and MAPK pathways downstream of Rho A may be important for erythroid differentiation in our modles.

Disclosures:
No relevant conflicts of interest to declare.
Human NUP98/Iqcg Fusion Gene Induced An Acute Myelomonocytic Leukemia In Mice
Authors: Zhang Qi-Yao , Liu Ping , Pan Mengmeng , Chen Sai-Juan 
Published: October 2019

Abstract
NUP98 gene encoding a nucleoporin located at 11p15 has been reported to be fused with about 30 different partner genes by chromosomal translocations in hematological malignances. NUP98/IQCG was cloned in a patient of Myeloid/ T-lymphoid bi-phenotypic leukemia with 47, XX, t(3;11)(q29q13;p15)der(3)(q29), +21 karyotype. However, NUP98/IQCG’s ability for leukemogenesis has not been identified yet.In this study, we established a retrovirus-mediated murine bone marrow transduction and transplantation (BMT) model of NUP98/IQCG to investigate its oncogenicity. In our model, half of the NUP98/IQCG mice developed a penetrable and transplantable acute myelomonocytic leukemia ,which was similar to the phenotype of patient with t(3;11). It suggested that NUP98/IQCG could induce the disease development.
To investigate how the fusion gene promoted leukemogenesis, we transduced NUP98/IQCG into primary bone marrow cells, and found that NUP98/IQCG-expressing cells retained the ability to generate colonies in serial replating, while seldom control cells did, which indicated the increasing self-renewal ability caused by NUP98/IQCG. Meanwhile, when induced by Macrophage-Colony Stimulating Factor, NUP98/IQCG -expression bone marrow cells showed enhanced proliferation in vitro. Further molecular mechanism studies revealed that NUP98/IQCG could be involved in both NFκB and CREB pathways during leukemia development.
In summary, we showed that NUP98/IQCG promoted leukemogenesis in BMT mouse model through increasing the bone marrow cells’ proliferation and self-renewal capacity, which explained the fusion gene’s oncogenicity in patient with t(3;11). Our mouse model will be a powerful tool both to investigate the leukemogenic mechanism of NUP98-related fusion gene, and to find the drugs for treating the disease.

Disclosures:
No relevant conflicts of interest to declare.
Ezh2 Is An Essential Regulator Of T-Cell Development and Oncogenic Transformation
Authors: Simon Camille , Chagraoui Jalila , Krosl Jana , Hebert Josee , Sauvageau Guy 
Published: October 2019

Abstract
Enhancer of zeste homolog 2 (EZH2) catalyzes di- and trimethylation of lysine 27 on histone H3 (H3K27me2/3) and establishes chromatin marks associated with gene silencing. We and others have recently shown that Ezh2 and its partners act as tumour suppressor genes in mouse and likely human lymphoblastic leukemia. Moreover some studies also suggest that Ezh2 is strongly required during B and T cell differentiation. However, the function of EZH2 during these processes remains unclear. For functional study we exploited an Ezh2 conditional knockout mouse model. The Cre-mediated deletion generates a mutated Ezh2Δ allele and abrogates production of EZH2 protein. Upon gene inactivation we monitored T-cell maturation and cancer development. We found that Ezh2 inactivation induces a block at the DN3-DN4 transition of TCRab+T-cells while TCRγδ T-cells were increased by 5 fold compared to wild type animals. Cell cycle analysis revealed increase in the proportions of TCRγδ+T-cells in the G2 phase compared to TCRβ+T-cells and wild type controls. This observation suggested a possibility of G2/M checkpoint activation resulting from either improper DNA replication, or a non-repaired DNA damage. Moreover we found that the Ezh2 deficient TCRγδ+ leukemia were prone to genomic instability. A majority of leukemias analyzed were aneuploid, and ∼50% were near-tetraploid. These observations were confirmed by Spectral Karyotyping (SKY), which also enabled detection of several chromosomal rearrangements. Consistent with these observations, analysis of global gene expression data from various RNA-Seq-derived datasets revealed that the genes having the highest correlation factor with Ezh2 are involved in cell division, DNA replication and DNA damage repair. Together, these studies show that Ezh2 is an essential regulator of the TCRγδ T-cell state, and prevents T-cell transformation, likely through regulation of DNA replication, cell division or DNA damage repair.

Disclosures:
No relevant conflicts of interest to declare.
ABR, a Novel Inducer Of Transcription Factor C/EBPα, Is Necessary For Myeloid Differentiation and a Prognostic Factor In Acute Myeloid Leukemia
Authors: Namasu Carolina Yaeko , Gerloff Dennis , Wurm Alexander Arthur , Braeuer-Hartmann Daniela , Hartmann Jens-Uwe , Katzerke Christiane , Schwind Sebastian , Hilger Nadja , Fricke Stephan , Niederwieser Dietger , Behre Gerhard 
Published: October 2019

Abstract
ABR (Active BCR-related) is the only protein in humans and mice closely homologous to BCR. BCR acts as a tumor suppressor in different cancers, such as chronic myeloid leukemia and meningiomas. A putative anti-oncogenic role of ABR has been shown in tumors of the central nervous system, such as medulloblastoma and astrocytomas, in which deletion of ABR was found. However, the role of ABR in hematopoiesis or leukemia remains unclear. We hypothesized that ABR might be important for myelopoiesis via increasing the expression of C/EBPα, a transcription factor known to be pivotal for myeloid differentiation and functionally impaired in acute myeloid leukemia (AML). In fact, we found that ABR expression is dramatically down-regulated (Figure 1, p=0.01) in bone marrow from AML patients (pts; n=63) compared to bone marrow (BM) mononuclear cells from healthy donors (n=3). In agreement with this finding, Abr is significantly increased during M-CSF and G-CSF-stimulated differentiation of primary wild type mouse BM cells (p<0.05). Additionally, we observe that ABR is necessary for monopoiesis induced by PMA (phorbol 12-myristate 13-acetate), since ABR knockdown in leukemic U937 cells results in a significant reduction of about 50% in the number of CD11b+ cells 48h after PMA treatment (p<0.05). Enforced ABR expression induces C/EBPα and its targets M-CSFR, G-CSFR and microRNA (miR)-223 in U937 cells (p<0.01). Moreover, we prove that ABR knockdown prevents induction of CEBPA, M-CSFR and G-CSFR during PMA-mediated differentiation (p<0.05). ABR overexpression blocks cell-cycle progression and down-regulates the known C/EBPα inhibitor E2F1 (p<0.01) in U937 cells, indicating the functional role of ABR as tumor suppressor. Those data suggest that ABR might induce CEBPA expression via inhibition of cell cycle activator E2F1. Finally, we are the first to identify ABR as a good prognostic factor in AML: patients with high ABR expression (median cut) survive significantly longer after allogeneic hematopoietic stem cell transplantation (Figure 2, p=0.04, log-rank test). Furthermore, high ABR expression associates with a low percentage of blasts in the peripheral blood (p=0.006) and high levels of antileukemic miR-181a (p<0.001). In conclusion, these data indicate that ABR, a novel inducer of C/EBPα, is necessary for myelopoiesis and a prognostic factor in AML. Raising ABR levels might be a goal for future therapeutics in AML.

Disclosures:
No relevant conflicts of interest to declare.