bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanism of Acadesine-Induced Apoptosis in B-Cell Neoplasms.
Authors: Santidrián Antonio F. , Campàs Clara , Coll-Mulet Llorenç , Iglesias-Serret Daniel , Cosialls Ana M. , Defrias Mercé , Domindo Alicia , de Sevilla Alberto Fernandez , Pons Gabriel , Gil Joan 
Published: April 2020

Abstract
Mature B-cell neoplasms include B-cell chronic lymphocytic leukemia (B-CLL), follicular lymphoma (FL), mantle cell lymphoma (MCL) and splenic marginal zone B-cell lymphoma (SMZL), among others. We found that acadesine, 5-aminoimidazole-4-carboxamide (AICA) riboside, induced apoptosis in B-cell neoplasms and in normal B lymphocytes, but FL samples were resistant. T cells from these patients or from healthy donors were not affected (Campas et al. Blood101: 3674, 2003; Campas et al. Leukemia19: 292, 2005). We have studied the mechanism of acadesine-induced apoptosis. Acadesine uptake and phosphorylation to ZMP are necessary to induce apoptosis. The best known molecular target of ZMP described to date is adenosine monophosphate-activated protein kinase (AMPK). We have analyzed the expression of LKB1, an AMPKK, AMPK isoforms and related proteins in B-CLL cells. B-CLL cells express LKB1, the α1 catalytic isoform of AMPK and both the β1 and β2 isoforms of the β regulatory subunit, but do not express the α2 isoform. Moreover, the AMPK related protein Snark is expressed in B-CLL cells, while Melk and Ark5 are not. Incubation of B-CLL, MCL, SMZL cells with acadesine induces phosphorylation in Thr172 and activation of AMPK, which correlates with induction of apoptosis. Acadesine enters FL cells as it induces phosphorylation of AMPK, however FL cells are resistant to acadesine-induced apoptosis. Moreover, phenformin and metformin induce AMPK phosphorylation but not induce apoptosis in B-CLL cells. The phosphorylation of AMPK is not sufficient for induction of apoptosis by acadesine in B-cell neoplasms. In B-CLL cells, CD40L or TPA, but not IL-4 or SDF1 inhibit acadesine-induced apoptosis. Acadesine inhibit neither AKT phosphorylation induced by TPA, IL-4, SDF1 or CD40L nor basal AKT phosphorylation. Finally, acadesine induces a conformational change in Bax protein, and citochrome c release to cytosol which is not block by ZVAD.fmk. In conclusion, although further studies are necessary to elucidate the mechanism of acadesine-induced apoptosis, we propose that acadesine may provide an effective treatment for mature B-cell neoplasms such as B-CLL, MCL and SMZL.
Adoptive Immunotherapy of p53-Mutated B-CLL with a Trifunctional Antibody (Anti-CD3 x Anti-CD20) and Allogeneic Donor Lymphocyte Transfusion.
Authors: Buhmann Raymund , Stanglmaier Michael , Simoes Belinda , Yang Ting , Ruf Peter , Lindhofer Horst , Kolb Hans-Jochem 
Published: April 2020

Abstract
In most cases CLL patients with p53 aberrations are refractory to standard treatment approaches, even to allogeneic stem cell transplantation (ASCT). Here we report 3 patients with relapse after ASCT that were treated with the combination of the trifunctional antibody Bi20 and donor lymphocyte transfusions (DLT). The Bi20 antibody is trifunctional, it binds to CD20 and CD3 and activates phagocytosis of the leukemia cell by accessory cells via the Fc part. Bi20 was applied in escalating doses from 10 μg up to 640 μg and followed by DLT (1 x 107/kg body weight). Patient 2 and 3 received repeated courses of antibody and DLT. In all cases we observed a prompt, dose-dependent decrease of B-CLL cells in the peripheral blood, which already started hours after application of the antibody infusion. Furthermore, in all cases the reduction of the enlarged lymph nodes and spleen went along with a significant improvement of the clinical symptoms like night sweat. Clinically, side effects were restricted to fever, chills and bone pain that could be easily controlled. These effects peaked at a concentration of 80 μg and did not increase or even decreased at higher concentrations. The cytokine profile was characterized by a transient increase of IL-6, IL-12 and IL-10. With respect to the transaminases, only a transient and modest increase of γGT was observed. HAMAs (human anti mouse antibodies) were not detectable; the absence allowed repeated transfusions of the trifunctional antibodies. Moreover, graft-versus-host disease (GVHD) was not observed. Unfortunately relapse of the disease occurred in all cases. In two cases repeated application of Bi20 and T-cells induced a repeated response. The overall survival was 47, 151 and 196 days. Bi20 can induce a prompt anti tumor response in B-CLL patients with a p53 mutation. The toxicity of treatment is not severe. However the response is of short duration and further studies are necessary to improve the outcome of patients by e.g. optimizing the application schedule.
In Vitro Activity of the Humanized Anti-HLA-DR Antibodies KRN848 and Apolizumab in Non-Hodgkins Lymphoma Cell Lines.
Authors: Hill Matthew L. , Weiner George J. , Link Brian K. 
Published: April 2020

Abstract
Apolizumab (Hu1D10) and KRN848 are humanized IgG1 anti-HLA-DR monoclonal antibodies (mAb). Apolizumab binds a polymorphic determinant on the HLA-DR-β chain, whereas KRN848 is a pan-HLA-DR mAb. We undertook preclinical studies to assess the properties of these two mAbs with regard to antibody-dependent cellular cytotoxicity (ADCC), complement-mediated cytotoxicity (CMC) and their direct effects on target cells. HLA-DR (+) Raji and Daudi lymphoblastic cell lines served as target cells. KRN848 is reactive with HLA-DR expressed on both cell lines, while apolizumab is reactive only with Raji.
ADCC assays were performed using 51Cr-labeled target cells and normal donor peripheral blood mononuclear cells (PBMCs) as effector cells. At an E:T ratio of 40:1 and a mAb concentration of 2 μg/ml, all mAbs mediated ADCC. Apolizumab mediated greater specific lysis of Raji cells (37%) than did KRN848 (15%) or rituximab (14%). When Daudi cells were used as targets, apolizumab induced &lt;3% lysis, while KRN848 and rituximab both induced 20% lysis. Similar findings were seen when EBV-transformed lymphoblastoid cells served as targets, and autologous healthy PBMCs as effector cells, with the degree of lysis induced by apolizumab varying depending on the degree of reactivity of apolizumab with the lymphoblastoid cells. In CMC assays, apolizumab, KRN848 and rituximab mediated comparable lysis of Raji cells (77%, 80% and 83%) at 2 μg/ml. In Daudi cells, there was &lt;4% specific lysis with apolizumab, 45% lysis with KRN848 and 90% with rituximab.
Evidence for direct killing mediated by mAbs varied based on the assay used. When 51Cr-labeled Raji cells were incubated with KRN848 or apolizumab for 4–17 hours, and 51Cr in the supernatant used as a measure of cell death, there was minimal evidence (&lt;10% specific lysis) of direct antibody-induced lysis over a range of concentrations (0.0016–2 μg/ml). In contrast, anti-HLA-DR mAbs had a significant effect on annexin-V/PI staining of target cells. Annexin-V/PI staining of Raji cells was positive after treatment with apolizumab (78%) and KRN848 (67%) at 2 μg/ml at four hours. KRN848 induced annexin-V/PI uptake by Daudi cells (39%) while apolizumab did not, demonstrating this effect was dependent on expression of the target antigen.
We conclude the anti-HLA-DR mAbs apolizumab and KRN848 can induce ADCC and CMC based on expression of target antigen. Anti-HLA-DR mAbs can directly alter the annexin-V/PI positivity of target lymphoma cells but do not induce 51Cr release, suggesting anti-HLA-DR mAbs alter cell membrane polarization and permeability but may not induce apoptosis directly.
Motexafin Gadolinium Causes Apoptosis in Lymphoma Cells by Increasing Intracellular Free Zinc and Disrupting Redox Balance.
Authors: Magda Darren , Lecane Philip , Karaman Mazen W. , Sirisawad Mint , Naumovski Louie , Miller Richard A. , Hacia Joseph G. 
Published: April 2020

Abstract
Motexafin gadolinium (MGd, Xcytrin®) is an anti-cancer agent that is being studied in clinical trials in various types of cancer including hematologic malignancies. MGd has been shown to generate reactive oxygen species and induce apoptosis in myeloma and lymphoma cells, and to cause an increase in intracellular levels of free zinc. We now report the effect of MGd and exogenous zinc on intracellular levels of free zinc, oxidative stress, proliferation, and cell death in human B-cell lymphoma and other hematologic cell lines. To better understand the molecular basis of these cellular responses, gene expression profiling analyses were conducted on Ramos cell cultures treated with MGd and/or zinc acetate. In cultures treated with MGd and zinc, 21% of Ramos cells were apoptotic within 8 hours of treatment as demonstrated by Annexin V staining. The apoptotic fraction increased to 30% within 12 hours and 68% by 24 hours. Analogous results were obtained using JC-1, with 38% of Ramos cells exhibiting non-aggregated (green) JC-1 fluorescence characteristic of mitochondrial dysfunction within 8 hours of combined treatment with MGd and zinc. This fraction increased to 52% by 12 hours and 74% by 24 hours. MGd and zinc similarly increased cell death in other B-cell lines (Raji, DB, DHL-4 and HF-1) tested. We also found that increased levels of oxidative stress and intracellular free zinc preceded and correlated with cell cycle arrest and apoptosis. Cultures treated with MGd or zinc acetate alone elicited transcriptional responses characterized by induction of metal response element-binding transcription factor-1 (MTF-1) and hypoxia inducible transcription factor 1 (HIF-1) regulated genes. Cultures co-treated with MGd and zinc acetate displayed further increases in the levels of MTF-1 and HIF-1 regulated transcripts and also additional transcripts regulated by NF-E2-related transcription factor 2 (NRF-2). HIF-1 activation can have negative consequences for cell growth and survival by induction of targets linked to apoptosis, whereas NRF-2 activation is characteristic of cells responding to disruption of redox balance. These data demonstrate that MGd increases intracellular free zinc and oxidative stress levels in lymphoma cells that activate adaptive survival responses but eventually lead to cell death.
Motexafin Gadolinium Enhances Rituximab-Induced Cytotoxicity Against B-Cell Lymphoma Cell Lines: Role of Elevated Intracellular Calcium.
Authors: Chen Jun , Ramos Jason , Sirisawad Mint , Miller Richard A. , Naumovski Louie 
Published: April 2020

Abstract
Motexafin gadolinium (MGd, Xcytrin®) is a tumor selective redox active drug that is directly cytotoxic to some hematolymphoid cell lines and chronic lymphocytic leukemia (CLL) patient samples. MGd has shown single agent activity in early phase II studies of lymphoma and CLL patients. Rituximab, an anti-CD20 antibody, is used widely in the treatment of B-cell malignancies. We evaluated the effects of MGd, rituximab and the combination in HF-1, a follicular lymphoma-derived cell line. Data analysis with CalcuSyn software revealed that the combination of MGd and rituximab showed synergistic growth inhibition and cytotoxicity compared to either agent used alone. MGd/rituximab activated a caspase-dependent apoptotic pathway as demonstrated by loss of mitochondrial membrane potential and PARP cleavage. Similar results were obtained with the combination of MGd and rituximab in DHL-4 and Ramos lymphoma cell lines. Since intracellular calcium ([Ca2+]i) levels have been implicated in rituximab cytotoxicity, we explored [Ca2+]i in rituximab and MGd/rituximab treated cells. Rituximab and MGd/rituximab treated cells have increased levels of [Ca2+]i. Elevation of [Ca2+]i with thapsigargin, an agent that releases calcium from internal stores or the ionophore A23187 that transports calcium into cells, results in synergistic cytotoxicity with rituximab or the MGd/rituximab combination. These in vitro findings suggest a role for [Ca2+]i in MGd/rituximab-induced cell death and support the combined use of MGd and rituximab in the treatment of B-cell lymphoma.
Identification of Genes That Potentially Allow Prediction of Interferon Response in Chronic Phase CML Diagnostic Samples through Gene Expression Analysis.
Authors: Barbany Gisela , Hagberg Anette , Strömberg-Olsson Ulla , Isaksson Anders , Bengtzon Mats , Höglund Martin , Simonsson Bengt 
Published: April 2020

Abstract
Interferon (INF) was the first drug to significantly prolong survival in chronic myeloid (CML) and has been extensively used to treat CML patients over the past years. Today, in the Imatinib era INF still has a role as additional agent in patients with a suboptimal response to Imatinib. However, not all patients will respond to INF and the reasons for this heterogeneity are largely unknown. The aim of the study was to identify biomarkers that allow prediction of future response to INF in CML diagnostic samples. Microarray-based gene expression analysis enables the study of thousands of genes in one single experiment and has been shown to be a useful tool to identify biomarkers that can assign samples to specific categories. Gene expression profiles in diagnostic samples from 15 CML chronic phase patients were analyzed using cDNA microarrays with 7458 genes. Blood samples were collected at diagnosis and all patients were treated with alpha-interferon. Seven patients were responders, defined as patients achieving a complete or major cytogenetic response at 12 months or earlier after initiation of interferon. Eight patients that had no cytogenetic response at 6–18 months were regarded as non responders. A list of 61 genes differentially expressed in both sample groups was generated by sorting those genes that showed the largest difference in median expression between the groups. The top 20 genes were subsequently used in an “all pair” selection procedure to identify those genes that are highly predictive of response to INF. The genes selected by this procedure were LTF, PRG2, JARID1A, NRGN, RNASE2 and DEFA4. The accuracy of these genes in predicting response to INF was determined in a “leave one out cross validation” procedure and the estimated error rate was found to be 0,13. The expression level of these six genes was verified with real-time PCR. The data generated by real-time PCR were used in a principal component analysis that separated the samples in two clusters.We conclude that it might be possible to use microarray-based gene expression analysis to predict future treatment outcome in CML diagnostic samples.
In Vitro and In Vivo Antileukemic Effects of the mTOR-Targeting Drug Rapamycin in Patients with Imatinib-Resistant CML.
Authors: Mayerhofer Matthias , Boehm Alexandra , Aichberger Karl J. , Esterbauer Harald , Derdak Sophia , Pickl Winfried F. , Sillaber Christian , Valent Peter 
Published: April 2020

Abstract
The mammalian target of rapamycin (mTOR) has been described to be activated in BCR/ABL-transformed cells and to mediate rapamycin-induced inhibition of cell growth. We have recently shown that rapamycin downregulates expression of vascular endothelial growth factor (VEGF), a mediator of leukemia-associated angiogenesis, in primary CML cells. In the current study, we analyzed growth-inhibitory in vitro- and in vivo effects of rapamycin in leukemic cells in patients with imatinib-resistant CML, and asked, whether the rapamycin-induced suppression of VEGF in these cells is related to growth-inhibition. Rapamycin dose-dependently inhibited the in vitro growth of primary CML cells in all pts with imatinib-resistant CML tested (rapamycin, 10 nM: 50±17% of control; p&lt;0.05). Moreover, rapamycin was found to downregulate growth of Ba/F3 cells exhibiting wild type (wt) BCR/ABL or various imatinib-resistant mutants of BCR/ABL including the T315I-mutation, which renders BCR/ABL resistant against tyrosine kinase inhibitors. We also found that rapamycin and imatinib exert synergistic inhibitory effects on growth of Ba/F3p210WT cells as well as on Ba/F3 cells containing imatinib-resistant mutants of BCR/ABL. In all cells tested including imatinib-resistant primary cells, rapamycin was found to downregulate expression of VEGF mRNA and secretion of the VEGF protein. However, exogenously added VEGF did not counteract the rapamycin-induced decrease in proliferation suggesting that these two effects of rapamycin are separable. In a consecutive phase of the project, we treated 7 pts with imatinib-resistant CML with rapamycin at 2 mg per os daily for 14 consecutive days, with dose-adjustment allowed to reach a target serum rapamycin concentration of 10–20 ng/ml. A major leukocyte response with decrease from &gt;20,000 to normal values (&lt;10,000/μL) was obtained in 3 pts, and a minor transient response in 2 other pts, whereas 2 pts did not respond. No molecular or cytogenetic responses were seen. No severe side effects of rapamycin were recorded. In aggregate, rapamycin may be an interesting targeted drug in imatinib-resistant CML. However, combinations with other targeted (or conventional) drugs may be required to obtain sufficient antileukemic activity in vivo.
Monitoring of Chronic Myeloid Leukemia (CML) Imatinib Response by Fluorescence-In-Situ-Hybridization (FISH).
Authors: Yip Sze Fai , Wan Thomas Shek Kong , Lie Albert Kwok Wai , Liu Herman Sung Yu , Chan Li Chong 
Published: April 2020

Abstract
Glivec, a tyosine kinase inhibitor is the drug of choice for newly diagnosed chronic phase CML. Whilst Q-PCR is the most sensitive method to monitor response; cytogenetic analysis as well as FISH is routinely used in many laboratories. FISH has the advantage over marrow cytogenetic by allowing analysis of more cells, and cells in interphase, obviating necessity for an invasive marrow procedure. We performed 126 FISH studies using BCR-ABL dual color dual fusion translocation probe for 69 CML patients on imatinib. For each samples, 300 nucleated cells were counted. Clinical information was available from 57 patients (34 chronic-phase (CP), 7 accelerated phase (AP), 8 blastic phase (BT) and 8 post-BMT relapses). Most CP patients (94%) could achieve sustained complete hematological responses (CHR), including 14 of the 15 patients pre-treated with IFN. IFN pre-treated patients received imatinib generally late in the course of CP compared to those without (median 19M vs 0.8M, p&lt;0.001). At 12–15 months, 61% CP patients were FISH-ve. Fewer IFN-pretreated patients achieved FISH-ve responses (41.7% vs 90%, p=0.03). With a mean follow-up of 25 months (4–55M), none of the FISH-ve patients had disease transformation while AP/BT developed in 2 FISH+ patients (0% vs 22%, p=0.14). In CML-AP, early institution of imatinib (1–10M) achieved more FISH-ve responses than late treatment (30–36M) and degree of FISH response after 6–12 months of imatinib in CML-AP appeared to predict prognosis. For patients treated in BT, 4 received imatinib upfront and 4 after remissions or reversion to CP after chemotherapy. FISH negativity in the first few months of imatinib treatment, however, did not predict better prognosis. Two patients remained FISH-ve and disease-free 52 months without transplant, suggesting imatinib may be useful as maintenance after chemotherapy induction for BT patients not eligible for transplant. The observation that imatinib after chemotherapy induction has better prognosis than imatinib upfront requires confirmation by larger studies. In post-BMT relapses (8 patients: 1 cytogenetic relapse, 4 CP relapses, 1 blastic relapse, 2 AP relapses), hematological response could be achieved in all. Half became FISH-ve at 6–9 months and remained so at latest follow-up (44–56M). Three patients (1 CP, all 2 AP) were FISH+ at 6–9 months (42–90% Ph+ cells) and remained FISH+ thereafter, with one progressed to blastic disease at 24 months. FISH response at 6–9 months, thus, appears to carry prognostic significance in post-transplant CML relapses. In summary, our initial experience suggests monitoring of imatinib response by FISH provides useful prognostic information in different stages of CML.
RANBP2/ALK Rearrangement Is a New Rare but Recurrent Fusion Gene in Childhood Myeloid Disorders.
Authors: Harbott Jochen , Bruch Jochen , Busch Kerstin , Gammerdinger Ulrike A. , Rottgers Silja , Teigler-Schlegel Andrea , Viehmann Susanne 
Published: April 2020

Abstract
The ALK gene which is typically rearranged in anaplastic large cell lymphoma (ALCL) and inflammatory myofibroblastic tumor (IMT) is located in the band 2p23. An involvement of this band was detected in 6 patients (0.35%) when we checked the cytogenetic database of our laboratory with approximately 1500 successfully analyzed karyotypes of childhood AML and MDS. Patient 1 had a t(2;4)(p23;q27) and patient 2 showed a del(2)(p23). In both cases, the 2p23 abnormality was part of a complex karyotype that included several non-specific alterations. Among the remaining four children, three (pts. 3–5) showed an inv(2)(p23q13) and patient 6 a t(2;2)(p23;q13). We performed a hybridization using the LSI ALK Dual Color Break Apart Rearrangement Probe (Vysis, Downers Grove, IL) onto all six patients. Whereas in the nuclei of pts 1, 2, 3 two normal fusion signals were found, a split hybridization signal showed the ALK involvement in the inv(2) and the t(2;2) of patients 4, 5 and 6. The latter case was further analyzed using chromosome arm-specific painting probes and this approach also confirmed the translocation. For the identification of the partner gene we used the primers for RANBP2/ALK which were described for IMT. In all patients with ALK involvement a PCR product was found and the sequencing identified identical breakpoints within the ALK and RANBP2 gene. In addition, a FISH and RT-PCR screening was performed in 20 children with AML or MDS, but no ALK involvement could be detected. All 3 ALK rearranged patients were originally diagnosed as myeloid disease (AML/MDS), but showed different unspecific morphological features. To the best of our knowledge this is the first description of an inv(2)(p23q13) and a t(2;2)(p23;q13) and the first report of an RANBP2/ALK rearrangement in childhood AML/MDS. Further studies will help to elucidate the role of this rearrangement in pediatric leukemia.
Bone Marrow-Derived, BCR/ABL+ and Flk1+CD31−CD34− Stem Cells from CML Patients That Are Insensitive to STI571 In Vitro.
Authors: Song Yongping , Fang Baijun , Zhang Yanli , Wei Xudong , Lu Lulu , Zhu Xinhu , Wang Ping , Li Yufu , Gao Quanli , Wang Guiye , Qiu Lugui , Zhao Chunhua 
Published: April 2020

Abstract
To evaluate the effect of imatinib mesylate (STI571, Gleevec) on primitive/committed malignant progenitor cells in chronic myelogenous leukemia (CML) and to further elucidate the mechanisms involved in CML relapse, bone marrow-derived, malignant, BCR/ABL+Flk1+CD31CD34− cells with hemangioblastic characteristics from CML patients were labeled with carboxy-fluorescein diacetate succinimidyl diester dye to enable high-resolution tracking of cell division. Then they were cultured in Methocult GF+ media with or without STI571. After culture, the cells were separated by fluorescence-activated cell sorting into populations of viable quiescent versus cycling cells. Then the mechanisms involved in CML stem cells that became resistant to STI571 were studied. We found that in the most sensitive cases, STI571 killed almost all dividing cells; however, a significant population of viable BCR/ABL-positive cells were recovered in the undivided peak and confirmed to be the leukemic stem cells. STI571 also appeared to exhibit antiproliferative activity on the quiescent population. We further demonstrate that apoptosis was restricted to dividing cells, whereas nonproliferating BCR/ABL+Flk1+CD31CD34− cells were resistant to apoptosis induced by imatinib, Ara-C, VP-16, ceramide, or arsenic, either alone or in combination. These studies suggested that CML primitive stem cells remain viable in the presence of STI571 and that inhibition of BCR/ABL tyrosine kinase by STI571 restores normal hematopoiesis by removing the proliferative advantage of CML committed progenitors but that elimination of all CML progenitors may not occur. So despite dramatic short-term responses in vivo, such in vitro insensitive to STI571, might translate into disease relapse after prolonged therapy.