bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bortezomib Resistant Constitutive NF-κB Activation in Mantle Cell Lymphoma.
Authors: Yang David T. , Young Ken H. , Kahl Brad S. , Miyamoto Shigeki 
Published: October 2019

Abstract
Bortezomib is a proteasome inhibitor whose antineoplastic effects include inhibition of NF-κB, a transcription factor whose deregulation may play a central role in mantle cell lymphoma (MCL) pathogenesis. Bortezomib has shown clinical efficacy in relapsed and refractory cases of MCL with response rates of 40%. NF-κB can be activated through several pathways, including a proteasome inhibitor resistant pathway. It remains unknown whether MCL harbors bortezomib resistant constitutive NF-κB activity, but characterization of this may have important implications in elucidating bortezomib resistance and also in establishing rational therapeutic combinations. We investigated the effect of bortezomib on constitutive NF-κB activity in 3 EBV-negative MCL cell lines (Jeko, Rec-1 and Z138) and 20 MCL patient samples. Electrophoretic mobility supershift assay demonstrated that each of the cell lines had distinct NF-κB complexes with the Jeko and Rec-1 containing mainly p50/p65 and p50/cRel heterodimers, and Z138 comprised almost entirely of p52/RelB heterodimers. At a physiologically achievable dose of bortezomib (20nM), a live cell-based proteasome inhibition assay demonstrated greater than 80% proteasome inhibition in all three cell lines. Treatment of Jeko cells with such a dose resulted in a 50% decrease of NF-κB DNA binding, in contrast to a 10 to 30% increase of DNA binding in Rec-1 and Z138 cells by electrophoretic mobililty shift assay. Of 10 MCL patient samples from which results could be obtained, only 2 demonstrated a greater than 50% decrease in NF-κB DNA binding after treatment with 20nM and 100nM of bortezomib, whereas the remainder showed either no inhibition or even increased binding. Thus, bortezomib resistant constitutive NF-κB activity appears to be present in Rec-1, Z138, and a majority of MCL cases. Cytotoxicity assessed by flow cytometry following staining with propidium iodide showed Rec-1 and Z138 cells had greater resistance to bortezomib induced apoptosis (82 ± 5% and 69 ± 5% viability) than Jeko cells (47 ± 6% viability) after 20nM bortezomib treatment for 24 hours. Combining bortezomib with perillyl alcohol, a known suppressor of proteasome inhibitor resistant NF-κB activation, resulted in a synergistic cytotoxic effect in all 3 cell lines as assessed by the combination index (CI) method with CIs of 0.31, 0.32, and 0.60 for Jeko, Rec-1, and Z138 cells respectively, where CI of 0.1–0.3 is strong synergism, 0.3–0.7 is synergism, 0.7–0.85 is moderate synergism and 0.85–0.9 is slight synergism. In conclusion, our findings suggest that bortezomib resistant NF-κB activity is present in a significant subset of MCL cases, and the combination of bortezomib with a suppressor of proteasome inhibitor resistant NF-κB activity may elicit a synergistic cytotoxic effect in MCL.
Dysregulation of Frizzled 6 Is a Critical Component of B Cell Leukemogenesis in a Mouse Model of Chronic Lymphocytic Leukemia.
Authors: Wu Qingli , Claudia Zierold , Ranheim Erik A. 
Published: October 2019

Abstract
Wnt/Fzd signaling is known to play a key role in development, tissue specific stem cell maintenance, and tumorigenesis, particularly through the canonical pathway involving stabilization of β-catenin. We have previously shown that Fzd9−/− mice exhibit a decrease in pre-B cells at a stage when self-renewing division is occurring in preference to further differentiation, prior to light chain immunoglobulin recombination. To determine whether pathologic usurpation of this pathway plays a role in B cell leukemogenesis, we examined the expression of Wnt/Fzd pathway genes in the Eμ-TCL1 mouse model of chronic lymphocytic leukemia (CLL). We find that in the course of leukemogenesis, the expression of Wnt16, Wnt10b, Fzd1, and most dramatically, Fzd6, are progressively upregulated in the transformed CD5+ B cells of these mice, as are β-catenin protein levels. Fzd6 expression is increased an average of 35-fold in tumor B cells in comparison to CD5- normal B cells in the same mouse. In 3 animals we were able to compare oligoclonal, preleukemic CD5+ B cells with monoclonally transformed CD5+ B cells and noted between 4 and 340 fold incremental increases in Fzd6 expression. Elimination of Fzd6 gene expression by crossing Eμ-TCL1 into Fzd6−/− mice significantly delays or eliminates development of CLL in this model, while crossing into Fzd9−/− mice has no effect. Greater than 50% of Fzd6+/+ X Eμ-TCL1 mice have evidence of CLL in the peripheral blood at 5 months of age, while in Fzd6−/− X Eμ-TCL1 mice, this occurs at 8 months (p < 0.001). Even at 1 yr. of age, >30% of Fzd6−/− X Eμ-TCL1 mice remain disease free while >95% of Fzd6+/+ X Eμ-TCL1 mice have leukemia at 7 months of age. Tumors that do arise in Fzd6−/− mice are morphologically similar to the usual Eμ-TCL1 CLL cells, but do not show upregulation of β-catenin protein by flow cytometry, suggesting that Fzd6 is responsible for this aberrant expression. Further, rather than upregulating Wnt16, Wnt10b, and Fzd1, these genes are down-modulated in tumor cells lacking Fzd6, suggesting a balance between positive and negative signals in CLL B cells mediated by the Wnt/Fzd pathway with Fzd6 acting as an oncogene and other family members potentially as tumor suppressors. We and others have noted increases in LEF-1, Wnt10b, Wnt16, and Fzd3 in human CLL B cells as well, mirroring the findings in the mouse model. Our findings suggest that the self-renewal signals mediated by Wnt/Fzd that are enlisted during B cell development may be pathologically reactivated in the neoplastic transformation of mature B cells; and that agents targeting specific members of the beta-catenin signaling pathway may have therapeutic impact that could be tested in the Eμ-TCL1 model.
Vitamin K2 Induces Autophagy and Apoptosis Simultaneously in Leukemia Cells and Bcl-2 Expression Level Determines the Phenotype of Their Cell Death.
Authors: Miyazawa Keisuke , Yokoyama Tomohisa , Naito Munekazu , Toyotake Juri , Tauchi Testuzo , Itoh Masahiro , Yuo Akira , Kondo Yasuko , Kondo Seiji , Ohyashiki Kazuma 
Published: October 2019

Abstract
Vitamin K2 (menaquinone-2: VK2) is now known to be a potent inducer for apoptosis in leukemia cells in vitro. HL-60bcl-2 cells, which are derived from a stable transfectant clone of human bcl-2 gene into HL-60 leukemia cell line, show 5-fold greater expression of Bcl-2 protein compared with that in HL-60neo cells, a control clone transfected with vector alone. Although HL-60neo cells are induced apoptosis in response to VK2, HL-60bcl-2 cells are resistant against apoptosis induction but still show cell growth inhibition along with an increase of cytoplasmic vacuoles during exposure to VK2. Electron microscopy revealed autophagosomes and autolysosomes formation in HL-60bcl-2 cells after exposure to VK2. An increase of acid vesicular organelles (AVO) detected by acridine orange staining for lysosomes as well as conversion of LC3B-I into LC3B-II by immunonoblotting and an increased punctuated pattern of cytoplasmic LC3B by fluorescent immunostaining all supported enhanced autophagy induction in response to VK2 in HL-60bcl-2 cells. However, during shorter exposure to VK2, autophagosome formation was rather prominent in HL-60neo cells although nuclear chromatin condensations and nuclear fragments were also observed at the same time. These findings indicated the mixed morphologic features of apoptosis and autophagy. Inhibition of autophagy by either addition of 3-methyladenine, siRNA for Atg7, or Tet-off Atg5 system all resulted in attenuation of VK2-incuded cell death, indicating autophagy-mediated cell death in response to VK2. These data demonstrate that autophagy and apoptosis can be simultaneously induced by VK2. However, autophagy becomes prominent when the cells were protected from rapid apoptotic death by higher expression level of Bcl-2.
Different Cooperating Mutation Patterns of Receptor Tyrosine Kinases/Ras/JAK2 between De Novo AML1-ETO and CBFβ-MYH11 Acute Myeloid Leukemia.
Authors: Liang Der-Cherng , Shih Lee-Yung , Huang Chein-Fuang , Lai Chang-Liang , Chang Ya-Tzu , Lin Tung-Huei , Wu Jin-Hou , Kou Ming-Chung , Lin Tung-Liang , Yang Chao-Ping , Liu Hsu-Che 
Published: October 2019

Abstract
Background. Two-hit model of leukemogenesis has been proposed for AML; class I mutations that drive proliferation and survival, and class II mutations that block differentiation. Core-binding factor (CBF) AML consists of AML with AML1-ETO and AML with CBFβ-MYH11, that are class II mutations.
Aim. We sought
to determine the frequencies of cooperating mutations of class I including receptor tyrosine kinases (RTK)/Ras/JAK2 signaling pathways in CBF-AML, and to compare the patterns of cooperating mutations between AML with AML1-ETO and AML with CBFβ-MYH11.
Patients and methods. By RT-PCR analysis, 130 adult and 45 children were identified to have CBF-AML, 129 with AML1-ETO and 46 with CBFβ-MYH11. Bone marrow samples at diagnosis were analyzed for FLT3-LM, FLT3-TKD, c-KIT, c-FMS, N-ras, K-ras and JAK2 mutations.
Results. Sixty-six of 129 patients (51.2%) with AML1-ETO had RTK/Ras/JAK2 mutations compared with 30 of 46 patients (65.2%) with CBFβ-MYH11 (p=0.121). The frequencies of RTK/Ras/JAK2 mutations in 129 AML1-ETO AML were 3.9% (n=5) for FLT3-LM, 6.2% (n=8) for FLT3-TKD, 2.3% (n=3) for N-ras, 3.9% (n=5) for K-ras, 35.7% (n=46) for c-KIT, and1.6% (n=2) for JAK2 mutation. The frequencies of RTK/Ras/JAK2 mutations in 46 CBFβ-MYH11 AML were 2.2% (n=1) for FLT3-LM, 19.6% (n=9) for FLT3-TKD, 21.7% (n=10) for N-ras, 23.9% (n=11) for c-KIT, and none for K-ras or JAK2 mutations. No c-FMS mutations were detected in both subtypes of CBF-AML. All RTK/Ras/JAK2 mutations were mutually exclusive except three, one each with N-ras and K-ras mutations, FLT3-TKD and c-KIT mutations, c-KIT and JAK2 mutations, respectively. Patients with CBFβ-MYH11 had a significantly higher frequency of FLT3-TKD and N-ras mutations than patients with AML1-ETO (p=0.017 for FLT3-TKD, and p<0.001 for N-ras). Taken together, c-KIT mutations accounted for 32.6% in CBF-AML, the frequency of c-KIT mutations in patients with AML1-ETO was significantly higher than that of CBFβ-MYH11 subtype. Of the 46 patients with AML1-ETO and c-KIT mutations, 34 had mutations located at kinase domain (exon 17), 7 in exon 8, 1 in exon 9, and 4 in exon 11. Of the 11 patients with CBFβ-MYH11 and c-KIT mutations, 5 had mutations in exon 8, 2 in exon 11 and 4 in exon 17. Patients with AML1-ETO were more frequently associated with c-KIT mutations at kinase domain compared with patients with CBFβ-MYH11 (p=0.031), whereas those with CBFβ-MYH11 had a higher frequency of c-KIT mutations in exon 8 than patients with AML1-ETO (p=0.042).
Conclusion. Our results showed that occurrence of cooperating mutations of RTK/Ras/JAK2 pathways are common in patients with CBF-AML, but the patterns of mutations were different between AML1-ETO and CBFβ-MYH11 subtypes.
The In Vivo Impact of Human Regulatory T Cells on the Graft Versus Tumor Effect.
Authors: Mutis Tuna , Rozemuller Henk , Emmelot Maarten E. , Aarts-Riemens Tineke , Verweij Vivienne , Ebeling Saskia , Verdonck Leo F. , Lockhorst Henk , Martens Anton 
Published: October 2019

Abstract
The curative Graft-vs-Tumor effect (GvT) of allogeneic Stem cell transplantation (SCT) is frequently complicated with life threatening Graft-vs-Host Disease (GvHD). In mice, prevention of GvHD, without abrogation of GvT is possible by co-transplantation of naturally occurring regulatory T cells (Tregs) with SC grafts. Consistent with these murine studies, we recently demonstrated that also human Tregs possess potent GvHD-downregulatory capacities in a xenogeneic(x) model, where x-GvHD is induced by infusion of autologous human T cells in RAG2−/−γc−/− mice (Mutis et al. Clin. Cancer Res.2006, 12: 5520–5525). Towards clinical application of Tregs, we now explored the impact of human Treg-administration on GvT in a bioluminescence imaging (BLI) based human-GvT model in the RAG2−/−γc−/− mice. In this model, mice inoculated with luciferase (LUC)-transduced human myeloma (MM) cell lines developed BLI-detectable, progressive, MM-like multifocal tumors exclusively in the bone marrow (BM). Full blown tumors were effectively eliminated by infusion of allogeneic human PBMC. This treatment also caused lethal x-GvHD as expected. In this setting, co-infusion of human PBMC with autologous, in vitro cultured Tregs at a 1:1 Treg: T effector cell ratio had no adverse effects on the development of GvT while significantly reducing the lethality of x-GvHD. In vitro analyses of sacrificed mice at day 21 revealed that administered Tregs homed to BM and spleen, significantly downregulated the total numbers of IFN-γ-producing CD4+ and CD8+ T cells responding to CD3 mediated signals, but had no downregulatory effect on the frequencies of IFN-γ-producing T cells responding to tumor cells. There was also no downregulation of cytotoxic activity against tumor cells in Treg-treated mice. Conclusively, these results showed that Tregs, at doses which are inhibitory for x-GvHD-inducing T cells, could maintain the GvT effect by allowing T cell reactivity against tumor cells. Human Tregs thus still hold promise as attractive cellular tools for separating GvT from GvHD.
NF-kB as a Regulator of FA/BRCA Gene Expression in Multiple Myeloma.
Authors: Oliveira Vasco A. , Mathews Linda , Yarde Danielle , Wang Xingyu , Boulware David , Hazlehurst Lori A. , Chen Dung-Tsa , Beg Amer , Dalton William S. 
Published: October 2019

Abstract
Results to date argue compellingly that disruption of FA/BRCA gene expression plays a pivotal role in human somatic carcinogenesis. Melphalan, a DNA cross-linker, is one of the most widely used and effective drugs in the treatment of multiple myeloma (MM). Although most patients respond to standard and high dose melphalan, eventually patients acquire resistance and develop progressive disease. In 1991, our laboratory reported that acquired resistance in a human myeloma cell line was associated with reduced DNA crosslinks, elevated glutathione levels, and increased radiation survival (Cancer Res. 5:993; 1991). Most recently, we reported that the melphalan-resistant myeloma cell lines, 8226/LR5 and U266/LR6, showed a significant increase in several FA/BRCA genes compared to drug-sensitive cells, and that enhanced interstrand crosslink (ICL) repair via this signaling pathway contributes to acquired drug resistance in melphalan resistant cell lines (Blood 10:698; 2005). Here, we report that IKKa is constitutively phosphorylated in unstimulated 8226/LR5 cells, but not in melphalan-sensitive control cells. The specific phosphorylation of IKKa leads to an increase in basal NF-kB DNA binding activity, and 8226/LR5 cells are found to be markedly sensitive to BMS-345541 (a highly selective inhibitor of IkB) relative to control cells. Importantly, a cytotoxic dose of BMS-345541 induces a dramatic decrease in FA/BRCA gene expression, and a concomitant inhibition of NF-kB DNA binding activity in both 8226/S and 8226/LR5 cells. Furthermore, we show that 8226/LR5 cells experience the highest degree of direct binding between FANCD2 promoter and NF-kB/Rel family members, which, in turn, leads to an increase in basal FANCD2-specific NF-kB activity. Small-interfering RNA (siRNA)-mediated depletion of RelB and p50, but not other NF-kB subunits, in 8226 cells results in impaired NF-kB binding activity, and visible decrease in FANCD2 protein expression. Studies designed to dissect the role of NF-kB in acquired melphalan resistance are in progress, and the results will be presented. Our findings suggest that NF-kB functions as a regulator of FA/BRCA expression, and that this pathway represents a new target for preventing acquired drug resistance in myeloma patients.
Serum Concentrations of DKK-1 Correlate with the Extent of Bone Disease in Multiple Myeloma.
Authors: Kaiser Martin , Mieth Maren , Liebisch Peter , Rötzer Susanne , Jakob Christian , Fleissner Claudia , Braendle Edgar , Stover David , Peters Malte , Sezer Orhan , Heider Ulrike 
Published: October 2019

Abstract
Objectives: Lytic bone disease is a hallmark of multiple myeloma (MM) and is caused by osteoclast activation and osteoblast inhibition. Secretion of Dickkopf (DKK)-1 by myeloma cells was reported to cause inhibition of osteoblast precursors. DKK-1 is an inhibitor of the Wnt/β-catenin signaling, which is a critical signaling pathway for the differentiation of mesenchymal stem cells into osteoblasts. So far there is no study showing a significant difference in serum DKK-1 levels in MM patients with or without lytic bone lesions.
Methods: DKK-1 serum levels were quantified in 184 previously untreated MM patients and 33 MGUS patients by ELISA, using a monoclonal anti-DKK-1 antibody. For the evaluation of bone disease, skeletal X-rays were performed.
Results: Serum DKK-1 was elevated in MM as compared to MGUS (mean 11,963 pg/mL versus 1993 pg/mL, P < 0.05). Serum DKK-1 levels significantly correlated with myeloma stage according to Durie and Salmon (mean 2223 pg/mL versus 15,209 pg/mL in stage I and II/III, respectively; P = 0.005). Importantly, myeloma patients without lytic lesions in conventional radiography had significantly lower DKK-1 levels than patients with lytic bone disease (mean 3114 pg/mL versus 17,915 pg/mL; P = 0.003). Of interest, serum DKK-1 correlated with the number of bone lesions (0 vs. 1–3 vs. >3 lesions: mean 3114 pg/mL vs. 3559 pg/mL vs. 24,068 pg/mL; P = 0.002).
Conclusion: This is the largest study of DKK-1 serum levels in multiple myeloma patients and data show for the first time a correlation between DKK-1 serum concentration and the amount of lytic bone disease, suggesting that DKK1 is an important factor for the extent of bone disease and supporting the hypothesis of DKK-1 as a therapeutic target in myeloma bone disease.
Biological Sequelae of TRAF2 Downregulation in Waldenstrom Macroglobulinemia Cells.
Authors: Leleu Xavier , Xu Lian , Hunter Zachary R. , Adamia Sophia , Hatjiharissi Evdoxia , Moreau Anne-Sophie , Roccaro Aldo , Sacco Antonio , Ciccarelli Brian , Manning Robert J. , Patterson Christopher J. , Ghobrial Irene M. , Treon Steven P. 
Published: October 2019

Abstract
Background. Several TNF family members (CD40L and BAFF/BLYS) have been implicated in Waldenstrom’s Macroglobulinemia (WM) cell growth and survival. More recently, abnormalities in the APRIL-TACI pathway have been demonstrated by us in WM cells (Hunter, ASH2006, #228). TRAFs (TNFR-associated factor) are a family of adaptor proteins that mediate signal transduction from multiple members of the TNF receptor superfamily. In particular, TRAFs facilitate pro-apoptotic signaling from the TACI receptor, and TRAF2 is of importance among the TRAF adapter proteins since this protein is required for TNF-alpha-mediated activation of SAPK/JNK MAPK known to be involved in drug-induced death of tumor B cells. We therefore examined the role of TRAF2 in WM growth and survival.
Method. We investigated TRAF2, 3 and 5 gene expression in WM patient bone marrow (BM) CD19+ cells and cell lines (BCWM.1, WSU-WM) and compared their expression to BM CD19+ cells from healthy donors. Expression of human TRAF transcripts were determined using real time quantitative RT-PCR (qPCR) based on TaqMan fluorescence methodology. To evaluate the role of TRAF2, a knockdown model was prepared in BL2126 B-cells and BCWM.1 WM cells using electroporation, with resulted ≥50% knockdown efficiency using RT-PCR and immunoblotting.
Results. We found that TRAF3 and 5 gene expression was higher in WM versus healthy donors, while TRAF2 expression was lower in 8/13 (60%) patients, using qPCR. TRAFs gene expression did not correlate with tumor burden or WM prognostic markers. We next sought to understand the biological sequelae of TRAF2 deficiency in BL2126 and BCWM.1 cells and found that TRAF2 knockdown induced increased survival at 72 hours in both cell lines. We next studied sequence analysis of 20 WM patients CD19+ BM cells to determine whether there was a TRAF2 genomic alteration, and found heterozygous early termination mutation in exon 5 in 1 (5%) patient.
Conclusion. Our data demonstrate that TRAF2 is a commonly dysregulated TNF family adapter protein in patients with WM, with important consequences in WM cell growth and survival.
Amyloidogenic lambda Light Chain Renal Toxicity: Oxidative Stress Implicated.
Authors: Zeldenrust Steven R. , Blanco Ellen W. , Nath Karl A. 
Published: October 2019

Abstract
The kidney is the most common organ involved in systemic light-chain amyloidosis (AL), seen in up to 40% of patients. Renal involvement can result in proteinuria and/or renal insufficiency. The mechanism of renal injury in amyloidosis remains unclear. We present data supporting a central role for oxidative stress in amyloid-induced renal damage. Soluble free light chains(LCs) were isolated from plasma of AL and myeloma patients obtained at the time of stem cell collection. LCs were purified by liquid-phase iso-electric fractionation of pooled plasma samples from each patient. Purified LC were incubated with cultured rat renal epithelial cells, both wild-type and heme oxygenase-1 (HO-1) over-expressing, for 16 hours. Macrophage chemoattractant protein-1 (MCP-1) induction was measured in the media by ELISA. LC from myeloma patients were used as negative controls. Significant induction of MCP-1, a sensitive indicator of oxidative stress, was seen in 4/5 patients with lambda light-chain amyloidosis and 0/4 kappa light-chain amyloidosis patients. Induction of MCP-1 was seen in only 1/8 myeloma patients tested (4 lambda and 4 kappa). Induction of MCP-1 was reduced in the presence of HO-1 overexpression, implicating oxidative stress as a critical pathway of toxicity of amyloidogenic lambda light chains in this system. These results suggest that lambda and kappa light chains may cause renal injury through distinct pathways in the kidney.