bluuebunny/crossref_metadata_2025_split huggingface dataset:
Long-Term Expansion and Self Renewal Is Contained in the CD34+, but Not the CD34- Subfraction of Nucleophosmin Mutated Acute Myeloid Leukemia Cells.
Authors: Woolthuis Carolien , Han Lina , van Gosliga Djoke , Kluin Philip , Vellenga Edo , Schuringa Jan J. , Huls Geert 
Published: April 2020

Abstract
Mutations in the nucleophosmin (NPM) gene are found in about 30% of cases of acute myeloid leukemia (AML) and lead to a dislocation of the nucleophosmin protein from the nucleus to the cytoplasm (NPMc+ AML). NPMc+ AML shows distinctive biological and clinical features, including a unique gene expression profile, a distinct microRNA signature, low percentage of CD34+ cells, increased incidence of Flt3-ITD (about 40% of cases), good response to induction chemotherapy and (in the absence of Flt3-ITD) a favourable prognosis. Despite significant progress in the characterization of the NPMc+ AML subgroup, questions remain about the leukemia-initiating cell. Distinct features of NPMc+ AML, including multilineage involvement and overexpression of HOX-genes, may point to an early progenitor as the leukemia-initiating cell, but the characteristic low percentage of CD34+ cells may point to a more differentiated leukemic stem cell in NPMc+ AML. To gain more insight in the leukemia-initiating cell in AML with mutated NPM, NPMc+ AML cells were sorted based on the expression of CD34 (n=8, the percentage of CD34+ in the total AML fraction varied between 0.06 and 37%). Western blotting, using an antibody that specifically recognizes the nucleophosmin mutant protein revealed that the NPM mutant protein is expressed in both CD34+ and CD34− cells, proving that the CD34+ NPMc+ AML cells belong to the leukemic clone. This was verified by sequencing the NPM gene in CD34+ and CD34− AML cells. Importantly, culture of sorted CD34+ and CD34− NPMc+ AML cells on a stromal layer revealed that the CD34+ but not the CD34− cells of NPMc+ AML were capable of expanding and initiating long-term growth. In the first 5 weeks of culture an at least 16 fold (range 16–208) expansion of CD34+ AML cells was seen in 5 out of 6 NPMc+ AML cases. This expansion was associated with the formation of cobblestone areas (CAs) under the stromal layer within 3 weeks after plating. The NPMc+ AML cells which expanded in culture were able to expand further after replating in 4 out of 5 investigated cases (fold expansion range 1.6–2.5), indicative of the self renewal capacity of these CD34+ NPMc+ AML cells. Gene expression analysis of CD34+ and CD34− NPMc+ AML cells of 4 cases analyzed thus far revealed the presence of the characteristic HOX-overexpression profile in both CD34+ and CD34− NPMc+ AML cells. In summary, this study shows that the NPM mutation is not only present in CD34−, but also in CD34+ cells of NPMc+ AML and that the properties of long-term expansion and self renewal belong exclusively to the CD34+ subfraction of NPMc+ AML.
CEBPA Mutations Predict Favorable Prognosis in Pediatric AML
Authors: Ho Phoenix , Alonzo Todd A. , Gerbing Robert B. , Pollard Jessica A. , Stirewalt Derek , Hurwitz Craig Alan , Heerema Nyla A. , Hirsch Betsy , Raimondi Susana C. , Lange Beverly , Franklin Janet , Radich Jerald , Meshinchi Soheil 
Published: April 2020

Abstract
C/EBPα is a transcription factor that regulates terminal granulocytic differentiation. Although functional mutations in the CEBPA gene have been associated with improved outcome, they have not been well-characterized in pediatric AML. We evaluated the prevalence and prognostic significance of CEBPA mutations in 847 children with de novo AML treated on three consecutive pediatric AML trials (CCG-2941, CCG-2961, and COG-AAML03P1). Clinical characteristics and outcomes for patients with CEBPA mutations were compared to that of patients with wild-type CEBPA. Two types of CEBPA mutations—N-terminal truncating mutations and in-frame bZip domain mutations—were detected in 38/847 (4.5%) patients tested, and 31/38 (82%) patients with mutations harbored both mutation types. Polymorphisms were also identified in 7.8% of patients screened; patients with polymorphisms were analyzed in the CEBPA wild-type subgroup. The presence of functional mutations was correlated with laboratory and clinical characteristics, and clinical outcome. CEBPA mutations were significantly more common in older patients, patients with FAB M1 and M2, and patients with normal cytogenetics. These mutations did not occur in patients with either favorable or unfavorable risk cytogenetics. CEBPA mutations were found almost exclusively in the normal karyotype cohort, and patients with CEBPA mutations accounted for 17% of all patients with normal cytogenetics. Actuarial event-free survival at 5 years from study entry was 69% vs. 38% (p=0.017) with a cumulative incidence of relapse after complete remission of 13% vs. 44% (p=0.007) for those with and without CEBPA mutations. For patients with known diagnostic cytogenetic information, clinical outcome of those with CEBPA mutations was compared to that of those with favorable risk Core Binding Factor (CBF) AML. Patients with CEBPA mutations had an overall survival similar to those with CBF AML (78% vs. 74%, p=0.999). The presence of CEBPA mutations was an independent prognostic factor for improved outcome (hazard ratio 0.24, p=0.047). CEBPA mutations are associated with a lower relapse rate and improved survival in pediatric AML. CEBPA mutation analysis needs to be incorporated into initial screening for risk identification and therapy allocation at diagnosis.
Humoral Immune Responses against the Immature Laminin Receptor Show Prognostic Significance in Patients with Multiple Myeloma.
Authors: Zeis Matthias , Siegel Sandra , Friedrichs Birte , Schmitz Norbert 
Published: April 2020

Abstract
Multiple myeloma (MM) is characterized by a highly variable clinical course. The role of an autologous tumor-specific immune control contributing to the variable length of survival in MM is poorly understood. In the current study, we investigated whether humoral immunity specific for the tumor-associated oncofetal antigen/immature laminin receptor (OFA/iLR) has a prognostic value in MM. In patients with monoclonal gammopathy of unknown significance (MGUS) we found significant levels of anti-OFA/iLR antibodies in 21 of 30 sera (70%) and in 7 of 27 (26%) patients with asymptomatic MM (AMM). In contrast, in sera from patients with progressive MM (n=67) and in normal healthy donors (HD, n=60) no humoral reactivity against OFA/iLR was present. To look on long-term persistence of humoral anti-OFA/iLR immune responses, significant and stable titers of anti-OFA/iLR-specific IgG antibodies in follow-up samples of MGUS patients were detected. IgG subclass analyses showed a predominant IgG1 and IgG3 response suggestive for a Th1-driven immune response in the vast majority of patients with MGUS and to smaller extent in patients with AMM. OFA/iLR-antibodies were capable of recognizing and selectively killing OFA/iLR-expressing myeloma cells in complement-mediated and antibody-dependent cellular cytotoxicity (ADCC) assays. To determine whether the presence of anti-OFA/iLR antibodies influenced progression-free survival (PFS), patients were analyzed according to the presence/absence of a humoral immune response against OFA/iLR protein. In a univariate analysis, the group of patients with reactive sera (n=28) showed a significantly lower probability of disease progression compared to patients with non-reactive sera (n=29). In the patient group with significant anti-OFA/iLR titers only 2 of 28 patients developed disease progression, but 18 of 29 patients with OFA/iLR non-reactive sera (p=0.001). Our data suggest that spontaneous tumor-specific humoral immune responses against OFA/iLR exist in a significant proportion of MM patients and that superior PFS in those patients could reflect autologous immune control.
T Cell Modulation Combined with Intratumoral CpG Cures Lymphoma without the Need for Chemotherapy.
Authors: Houot Roch , Levy R. 
Published: April 2020

Abstract
Introduction: We have previously shown that intratumoral injection of CpG oligodeoxynucleotide plus systemic chemotherapy can induce T cell immunity against lymphoma and serve as a therapeutic vaccine to cure tumors in a murine lymphoma model (Li et al., J Immunol. 2007). CpG is a Toll-like receptor 9 agonist capable of activating tumor-infiltrating dendritic cells and/or tumor B cells to force tumor antigen presentation in situ when injected intratumorally. Here, we demonstrate that antibody-mediated modulation of T cells enhances the efficacy of CpG vaccination, thereby eliminating the need for chemotherapy.
Materials and Methods: Mice were inoculated s.c. with A20 lymphoma tumor cells at two sites (right and left abdomen). Only one site was injected with CpG allowing us to evaluate the systemic anti-tumor response at the distant site. Treatment started when tumors became palpable. CpG was administered intratumorally. T cell modulation was accomplished using systemic (i.p.) administration of monoclonal antibodies against T cell targets:
- Regulatory T cells were depleted using anti-Folate Receptor 4 (FR4) antibody or functionally blocked using anti-GITR antibody, - Effector T cells were stimulated using anti-OX40 antibody (to trigger their costimulatory molecule) or anti-CTLA4 antibody (to block inhibitory signals).
Results: Treatment with intratumoral injection of CpG alone did not cure any mice. Treatment with CpG and a single antibody (anti-OX40, anti-CTLA4, anti-FR4, or anti-GITR) cured 20–30% of mice. Interestingly, some combinations of antibodies (anti-OX40+anti-CTLA4, anti-OX40+anti-FR4, anti-CTLA4+anti-GITR) potentiated T cell modulation and further enhanced the efficacy of CpG vaccination. In particular, the combination of anti-OX40 and anti-CTLA4 appeared to be especially potent when combined with intratumoral CpG. Indeed, this combination (CpG+anti-OX40+anti-CTLA4) induced anti-tumor T cells capable of secreting IFN-γ in response to overnight culture with A20 tumor cells; it cured more than 80% of mice bearing large and systemic lymphoma tumors without the need for chemotherapy (effective therapy required both CD4 and CD8 T cells); finally, this therapy produced high numbers of anti-tumor memory T cells and provided long-lasting immunity against tumor re-challenge.
Conclusions: Our results show that antibody-mediated T cell modulation greatly enhances the therapeutic efficacy of intratumoral vaccination with CpG. Importantly, we show that T cell modulation can be potentiated by appropriate combinations of antibodies against T cell targets. As these reagents (CpG, anti-OX40 and anti-CTLA4 notably) are becoming available for human clinical trials, the combination of intratumoral CpG and immunomodulatory T cell antibodies holds promise for therapeutic vaccination against lymphoma.
Preclinical Analysis of the Combined Activity of SGN-40, Anti-CD40 Monoclonal Antibody, with Rituximab in Non-Hodgkin Lymphoma.
Authors: Lewis Timothy S. , McCormick Renee S. , McEarchern Julie A. , Kissler Kim , Stone Ivan J. , Gerber Hans-Peter , Drachman Jonathan G. , Grewal Iqbal , Law Che-Leung 
Published: April 2020

Abstract
SGN-40 is a humanized monoclonal antibody against CD40, a TNF receptor family member expressed in non-Hodgkin lymphoma (NHL), multiple myeloma, and several carcinomas. SGN-40 is cytotoxic to NHL cell lines via activation of proapoptotic signal transduction pathways and mediates antibody dependent cellular cytotoxicity (ADCC) effector function activity. In this study we examined the anti-tumor activity of SGN-40 in combination with the anti-CD20 antibody, rituximab, in lymphoma cell line models. Cell proliferation data (3H-thymidine incorporation assay) was generated for SGN-40 and rituximab alone and in combination for three NHL cell lines (Ramos, RL, and SU-DHL-4) and combination index (CI) analyses performed. SGN-40 was reproducibly synergistic with rituximab in Ramos cells and additive in the RL and SU-DHL-4 cell lines in this assay. This suggested that different anti-proliferative signaling events are activated by these antibodies, which produce a greater anti-tumor effect when combined. To better understand the combined activity of SGN-40 and rituximab, the signal transduction pathways activated by each antibody were examined. In Ramos cells SGN-40 signaling caused the degradation of pro-survival BCL-6 oncoprotein and upregulation of TAp63α, a proapoptic p53 family member, while only BCL-6 degradation was triggered in the RL and SU-DHL-4 cell lines. In contrast, rituximab signaling degraded BCL-6 protein in only one cell line (SU-DHL-4), and did not upregulate TAp63α expression in any of the cell lines examined. To further define the combined activity of SGN-40 with rituximab the effector function activity of both antibodies were examined in vitro. ADCC assays in the WIL2-S and Raji cell lines both showed a greater percent cell lysis in the presence of both SGN-40 and rituximab compared to either drug alone. Next, the SGN-40 and rituximab were tested in subcutaneous mouse models of NHL to evaluate this combination in vivo. In a Ramos model, SGN-40 and rituximab (dosed at 4.0mg/kg, q4dx4, ip) had significantly greater anti-tumor response when combined compared to the equivalent dose of either antibody alone. The anti-tumor response achieved with dual dosing of SGN-40 and rituximab was greater than the response expected if the combination was additive. Our data suggests that the improved efficacy of SGN-40, rituximab combination therapy in vivo is due to distinct apoptotic signaling pathways activated by these two antibodies in addition to augmented effector function activity. The combination of SGN-40 and rituximab is currently being studied in clinical trials of NHL.
A Promising Therapeutic Implication of a Novel Bcl-2 Family Inhibitor ABT-737 for Adult T-Cell Leukemia/Lymphoma.
Authors: Ishitsuka Kenji , Yotsumoto Fusanori , Katsuya Hiroo , Ushijima Emiko , Miyamoto Shingo , Tamura Kazuo 
Published: April 2020

Abstract
Adult T-cell leukemia/lymphoma (ATLL) is a peripheral T-cell malignancy caused by human T-cell lymphotrophic virus type I. Conventional chemotherapeutic regimens used against other malignant lymphoma have been administered to ATLL patients, but the treatment outcome of acute and lymphoma type ATLL remains very poor. Therefore, new therapeutic strategies are needed to improve patient outcome. Anti-apoptotic proteins, Bcl-2 and Bcl-XL have been reported to be highly expressed in ATLL cells, and confer resistance to chemotherapy. The aim of this study is to elucidate the therapeutic implication of ABT-737 (Abbott Laboratories, Abbott Park, IL, USA), a potent small-molecule inhibitor of Bcl-2, Bcl-XL and Bcl-w for ATLL. We first examined the direct toxicity of ABT-737 against tumor cell lines in vitro. ABT-737 significantly inhibited growth of ATLL cell lines (MT-1, MT-2 and HuT102) and an acute T-cell leukemia cell line, Jurkat with IC50 values at 72h of 2.5μM, 0.4μM, 0.01μM and 0.75μM, respectively. In contrast, Burkitt lymphoma cell lines, Raji and Ramos were resistant to ABT-737 with IC50 values at 72h of 24μM and 7.0μM, respectively. Importantly, Bcl-2 protein was highly expressed in MT-1, MT-2, HuT102 and Jurkat cells, but not in Raji and Ramos cells. We next examined the mechanism of ABT-737 induced growth inhibition using MT-1 and MT-2 cells. ABT-737 induced apoptosis with cleavage of caspase 9 and caspase 3 without modulating cell cycle distribution. Furthermore, ABT-737 significantly induced apoptosis in fresh tumor cells obtained from ATLL patients. We finally elucidated the potential of ABT-737 to enhance the apoptosis induced by anti-Fas monoclonal antibody (mAb), and cytotoxicity induced by conventional chemotherapeutics. ABT-737 enhanced apoptosis induced by anti-Fas mAb in MT-1 and MT-2 cells. Most importantly, ABT-737 synergistically enhanced the cytotoxicity induced by either of doxorubicin, vincristine or etoposide. These results suggest that ABT-737, used either alone or in combination with other conventional cytotoxic drugs, represents a promising novel targeted approach to overcome drug resistance and improve patient outcome in ATLL.
Blockade of mTOR Signaling Potentiates the Ability of Histone Deacetylase Inhibitor to Induce Growth Arrest and Differentiation of Acute Myelogenous Leukemia Cells.
Authors: Nishioka Chie , Ikezoe Takayuki , Jing Yang , Koeffler H. Phillip , Yokoyama Akihito 
Published: April 2020

Abstract
This study found that MS-275, a novel synthetic benzamide histone deacetylase inhibitor (HDACI), blocked Akt/mTOR signaling in acute myelogenous leukemia (AML) HL60 and acute promyelocytic leukemia (APL) NB4 cells, as assessed by decreased levels of the phosphorylated (p)-Akt, p-p70 ribosomal S6 kinase (p70S6K), and p-S6K by Western blot analysis. Interestingly, further inactivation of mTOR by rapamycin analogue RAD001 (everolimus) significantly enhanced MS-275-mediated growth inhibition and apoptosis of these cells in parallel with enhanced upregulation of p27 kip1 and downregulation of c-Myc. In addition, RAD001 potentiated the ability of MS-275 to induce differentiation of HL60 and NB4 cells, as measured by expression of CD11b cell surface antigens, as well as reduction of nitroblue tetrazolium. Importantly, RAD001 potentiated the ability of MS-275 to induce expression of the myeloid differentiation-related transcription factor CCAAT enhancer binding protein e in these cells in association with enhanced acetylation of histone H3 on its promoter. Furthermore, RAD001 (5 mg/kg) significantly enhanced the effects of MS-275 (10 mg/kg) to inhibit proliferation of HL60 tumor xenografts in nude mice without adverse effects. Taken together, concomitant administration of a HDACI and a mTOR inhibitor may be a promising treatment strategy for the individuals with a subset of human leukemia.
A Functional Promoter Polymorphism (−8C&gt;G) of the Proteasome Subunit α6 Gene Is Associated with Multiple Myeloma and Poor Outcome Independent of Circulating Proteasome Serum Levels.
Authors: Bachmann Hagen S , Novotny Juergen , Sixt Stephan , Liebisch Peter , Frey Ulrich , Peters Juergen , Duehrsen Ulrich , Siffert Winfried , Nückel Holger 
Published: April 2020

Abstract
Introduction: The proteasome system plays a crucial role in several malignant diseases, especially in multiple myeloma (MM). Recently, the serum 20S circulating proteasome level (CPL) was shown to be an independent prognostic factor in MM.
A single nucleotide polymorphism (SNP) −8C&gt;G in PSMA6, one of seven α-subunit genes of the 20S proteasome, was currently demonstrated to be associated with myocardial infarction. Additionally, it has been shown that PSMA6 expression is genotype-dependently altered e.g. in human B cells, whereas the G allele is associated with a 1.8 fold higher expression. Demonstrating the extensive role of the proteasome system in MM we investigated the role of the novel SNP in our cohort of 116 patients with MM.
Methods: DNA-samples of 116 patients with MM, all treated at the University Hospital Essen, and 125 healthy controls were genotyped for PSMA6 −8C&gt;G. CPL of 70 patients were studied by an anti-20S proteasome enzyme-linked immunoabsorbant assay (ELISA). PSMA6 −8C&gt;G genotypes were correlated with patients’ survival and CPL.
Results: Patients’ genotype distribution (69 CC, 44 CG, 3 GG) and genotype distribution of healthy controls (90 CC, 31 CG, 4 GG) were consistent with Hardy-Weinberg equilibrium. Genotypes were significantly associated with MM in a dominant genetic model (CC vs. CG+GG), with an odds ratio of 1.75 (95% confidence interval (CI): 1.02–3.00, p=0.043). Kaplan-Meier curves revealed a significant association of PSMA6 −8C&gt;G with 5-year survival (p=0.014). Median survival time was 43 months for the GG genotype and 50 months for the CG genotype. It was not reached within follow-up by the CC genotype (CC 5-year survival rate 61.2%). Following hazard ratios (HR) were calculated: CC vs. CG: 2.007, 95%CI 1.11–3.63, p=0.022; CC vs. GG: 2.515, 95%CI 0.58–10.86, p=0.217 and in the dominant genetic model CC vs. CG+GG: 2.038, 95%CI 1.14–3.65, p=0.017. In multivariate analysis the GG/GC genotypes were independent prognostic factors (HR 2.1, p=0.014).
To proove if the detected effect of individual PSMA6 genotypes was dependent or independent from CPL, ELISA experiments were performed. There was no detectable difference in CPL between the genotypes. Mean CPL was 255 ng/mL for CC homozygous and 205 ng/mL for G allele carriers (p=0.718).
Conclusions: These results suggest the PSMA6 −8C&gt;A polymorphism as a survival prognosticator as well as indicator of a high risk group within patients with MM. PSMA6 genotypes were not associated with CPL. Therefore, the SNP is independent of this known prognostic factor and could lead to additional prognostic information for MM patients.
The Novel NFkB Inhibitor V1810 Induces Apoptosis and Cell Cycle Arrest in Multiple Myeloma Cells and Overcomes NFkB Mediated Drug Resistance.
Authors: Meinel Felix , Mandl-Weber Sonja , Baumann Philipp , Leban Johann , Schmidmaier Ralf 
Published: April 2020

Abstract
Multiple Myeloma (MM) is a fatal malignancy characterised by the accumulation and expansion of antibody producing plasma cells in the bone marrow. Evidence is increasing that nuclear factor kappa B (NFκB) is a promising target for new anti-myeloma therapies. In this study, we assessed the in vitro activity of V1810, a novel NFκB inhibitor. V1810 potently induces cell death in all tested MM cell lines (OPM-2, U266, NCI-H929, RPMI-8226) with an IC50 ranging between 5μM to 10μM as well as in primary MM cells from patients. Cell death induced by V1810 clearly shows biological features of apoptosis such as DNA fragmentation and caspase 3 cleavage. In OPM2, U266 and RPMI-8226 cells induction of apoptosis is accompanied by cell cycle arrest. Western blots revealed downregulation of cyclin D1 (U266) or cyclin D2 (OPM2, NCI-H929, RPMI-8226) respectively, but not cyclin D3. Consistent with the downregulation of cyclin D1/2, retinoblastoma protein was found to be hypophosphorylated. Considering that cyclin D1 and D2 are known to be NFκB target genes, this is in line with our finding that V1810 inhibits baseline NFκB activity in MM cells (36% relative reduction). Importantly, V1810 also abrogates NFκB activation induced by genotoxic drugs like melphalan and doxorubicin. Accordingly, V1810 and melphalan synergistically decrease MM cell viability. Taken together, V1810 induces apoptosis and cell cycle arrest in MM cells by inhibition of NFκB and overcomes NFκB mediated drug resistance to melphalan. The maximum tolerable dose (MTD) of V1810 in BalbC mice was 10mg/kg i.v. and plasma concentrations of 9.5μM are achievable in NRMI mice after 5mg/kg V1810 i.v., which corresponds well to the used in vitro concentrations. This study strongly supports the further development of NFkB inhibitors in MM, especially in combination with genotoxic drugs.