bluuebunny/crossref_metadata_2025_split huggingface dataset:
DCC-2036: A Novel Switch Pocket Inhibitor of ABL Tyrosine Kinase with Therapeutic Efficacy Against BCR-ABL T315I In Vitro and in a CML Mouse Model.
Authors: Van Etten Richard A. , Chan Wayne W. , Zaleskas Virginia M. , Evangelista Peter , Lazarides Katherine , Peng Cong , Li Shaoguang , Wise Scott C. , Petillo Peter , Flynn Daniel L. 
Published: October 2019

Abstract
Therapy with ATP-competitive ABL kinase inhibitors, including imatinib (Gleevec), dasatinib (Sprycel), and nilotinib (Tasigna), has revolutionized the treatment of chronic myeloid leukemia (CML), but a substantial proportion of patients develop resistance to these agents. A major mechanism of acquired resistance is mutations in the ABL kinase domain that render BCR-ABL insensitive to the drug; in particular, mutation of the ABL kinase “gatekeeper” Thr315 residue to Ile (T315I) confers pan-resistance to all ATP-competitive ABL inhibitors. To address this need, we developed and characterized a novel chemical class of compounds that bind to five structural pockets involved in the endogenous “switch” mechanism used by the ABL kinase to conformationally control its activity state. Using a structure-based drug design approach, diversity in these “switch pockets” between kinases can be exploited to develop inhibitors with high potency and specificity. The resulting ABL inhibitors have several attractive features, as they:
act through a non-ATP-competitive mechanism; avoid steric clash with Ile315; inhibit purified ABL that is either unphosphorylated (switch-off) or phosphorylated (switch-on) at Tyr393 with IC50 of 0.8–4.0 nM; co-crystallize with phospho-Y393-ABL WT and T315I; and have very prolonged residency time on the kinase (off-rate ∼400 min vs. 3 min for imatinib).
A lead compound, DCC-2036, is highly selective for ABL, FLT3, and SRC family kinases, and has favorable pharmacokinetic and toxicity profiles in animals. In vitro, DCC-2036 inhibited proliferation and induced apoptosis of Ba/F3 cells expressing BCR-ABL WT or several common imatinib-resistant mutants (Y253F, T315I, M351T) with IC50 from 5 to 25 nM, without appreciable inhibition of parental Ba/F3 cells in IL-3 (IC50 >1000 nM). In Balb/c mice injected with Ba/F3-BCR-ABL T315I cells, pharmacodynamic studies indicated >8 hour inhibition of phospho-Stat5 and phospho-ABL in the leukemic cells following a single oral 100 mg/kg dose of DCC-2036, whereas daily dosing of DCC-2036 significantly prolonged survival. In the mouse retroviral bone marrow transduction/transplantation model of CML, DCC-2036 at 100 mg/kg/d also reduced peripheral blood leukocyte counts and significantly prolonged survival vs. vehicle-treated control mice. These results demonstrate that ABL switch pocket inhibitors are a promising new pharmacologic weapon for the treatment of de novo and drug-resistant CML, including BCR-ABL T315I.
Valproate, a Histone Deacetylase Inhibitor, Enhances Purine Nucleoside Analogues Induced Apoptosis of B-Chronic Lymphocytic Leukemia Cells.
Authors: Bouzar Amel B. , Boxus Mathieu , Defoiche Julien , Techn Hervé Balon , Berchem Guy , Macallan Derek , Pettengel Ruth , Willis Fenella , Burny Arsene , Lagneaux Laurence , Bron Dominique , Chatelain Bernard , Chatelain Christian , Willems Luc 
Published: October 2019

Abstract
Resistance to chemotherapy and drug toxicity are two major concerns of Chronic Lymphocytic Leukemia (B-CLL) treatment by Purine Nucleoside Analogs (PNA, i.e. fludarabine and cladribine). We hypothesized that targeting epigenetic changes might address these issues and evaluated the effect of the histone deacetylase (HDAC) inhibitor valproate (VPA) at a clinically relevant concentration. We show that VPA acts in a highly synergistic/additive manner with 9-ß-D-arabinosyl-2-fluoroadenine-5′-monophosphate (F-ara-AMP, fludarabine, 1μM) and 2-chloro-2′-deoxyadenosine (CdA, cladribine, 1μM) to induce apoptosis of CLL cells. VPA, but neither fludarabine nor cladribine, enhances the production of Reactive Oxygen Species (ROS) and inhibition of ROS with N-acetylcysteine decreases apoptosis of CLL cells. VPA-induced apoptosis is caspase-dependent and involves the extrinsic initiation pathway. VPA stimulates hyperphosphorylation of p42/p44 Erk as well as overexpression of Bax, cytochrome c and Fas. These observations support a potential use of VPA alone or in combination with nucleosidic analogs in CLL therapeutic protocols allowing a reduction of their effective doses or improving their efficacy in PNA-resistant patients.
Anti-Angiogenic Effects of Sorafenib in Relapsed Chronic Lymphocytic Leukemia: Correlative Studies of a Phase 2 Clinical Trial.
Authors: Reganti Sowjanya , Kabba Edith , Stock Wendy , Wright John J. , Godwin John E. , Kini Ameet R. 
Published: October 2019

Abstract
Chronic lymphocytic leukemia (CLL) is a malignant B-cell disorder that remains a largely incurable disease. We and others have previously shown that angiogenesis is important in the pathogenesis of CLL. Sorafenib is a small molecule signal transduction inhibitor that exhibits anti-tumor activity through a number of mechanisms including blocking of the Raf/MEK/ERK pathway and inhibition of receptor tyrosine kinases involved in angiogenic signaling such as the VEGF receptors. The data presented here are correlative studies performed on a Phase 2 clinical trial designed to measure the overall response rate to oral doses of sorafenib in CLL patients who have failed previous nucleoside analog therapy (alone or in combination with alkylating agents) or monoclonal antibody therapy. Each cycle consisted of 400 mg of sorafenib administered orally twice a day for 28 days. Treatment continued until any of the withdrawal criteria (unacceptable toxicity, disease progression, patient’s decision to withdraw) were reached. Peripheral blood samples for correlative studies were obtained before initiation of therapy, after 12 weeks (beginning of cycle 4) and after 24 weeks (beginning of cycle 7), or when the patient went off-study for any indication. In these studies, we specifically focused on examining VEGF and the VEGF receptors VEGFR-1 (flt-1), VEGFR-2 (KDR), VEGFR-3 (flt-4), neuropilin-1 and neuropilin-2. These molecules were analyzed at the transcript level by RT-PCR and at the protein level by western blotting or ELISA. In addition we examined plasma levels of IL-8 by ELISA, since IL-8 has been recently shown to be an important mediator of cell survival and angiogenesis in CLL. Specimens were analyzed from a total of five patients. Plasma IL-8 levels were markedly decreased in all three patients who underwent therapy beyond 12 weeks. The two patients went off study at or before 12 weeks did not show any decrease in IL-8 levels. No decrease was noted between the pre-treatment and post-treatment plasma concentrations of VEGF for any of the patients. No consistent change in cellular expression was observed between the pre-treatment and post-treatment samples for VEGF, VEGFR-1, VEGFR-2 or VEGFR-3. Neuropilin-1 expression was decreased or absent in the post therapy samples in patients who received therapy beyond 12 weeks, while no change in expression was seen in the two patients who went off study at or before 12 weeks. Neuropilin-2 expression was not detected in any of the samples. These results suggest that sorafenib suppresses angiogenic pathways by inhibiting secretion of IL-8 and expression of neuropilin-1. Additional studies and samples are needed to confirm these interesting findings, and to further delineate the anti-angiogenic effects of sorafenib in CLL.
What Is the Role for Donor NK Cells after Nonmyeloablative Conditioning?
Authors: Baron Frederic , Petersdorf Effie W. , Sandmaier Brenda M. , Gooley Ted , Malkki Mari , Maloney David G. , Storb Rainer F. 
Published: October 2019

Abstract
Background: The potential role of donor NK cells after nonmyeloablative conditioning for allogeneic hematopoietic cell transplantation (HCT) is not defined. We investigated the impact of the kinetics of donor NK cell engraftment as well as the impact of missing recipient KIR ligands and the number of donor inhibitory and activating KIR genes on HCT outcomes in 282 patients (153 with HLA-matched related donors and 129 with unrelated donors) conditioned with 2 Gy TBI +/− fludarabine. Postgrafting immunosuppression consisted of cyclosporine and mycophenolate mofetil. Diagnoses were hematological malignancies (n=274) or solid tumors (8).
Methods: NK cells were isolated from peripheral blood by flow cytometry on days 14, 28 and 42 after HCT. The proportions of cells of donor and host origin were assessed by FISH or by VNTR-PCR. High-resolution HLA-typing was performed using oligonucleotide probe and/or direct sequencing methods. Donor KIR genotyping was performed using a commercial PCR-SSP kit (Invitrogen) following manufacturers protocol.
Results: High numbers of T (P=0.01) and CD34+ (P=0.009) cells in the graft, as well as lower numbers of donor inhibitory KIR genes (P=0.01) were each associated with higher levels of donor NK cell chimerism. There was a suggestion of an association between lower numbers of activating KIR genes and higher CD56 chimerism, however this was not statistically significant. NK cell chimerism levels were comparable in patients who had all KIR ligands present vs. in those who were missing any ligand, and there was no association between the specific missing ligand and NK chimerism. A day-14 NK cell chimerism level of < 50% was associated with increased risks of graft rejection (P=.009). Modeling chimerism levels as a continuous linear variable, there was no association between NK cell chimerism levels on day 14 and occurrence of grade II-IV acute GVHD. In contrast, high levels of donor NK cell chimerism on days 14–42 were associated with a lower risk of relapse (P=0.006) and better progression-free survival (P=0.003) in time-dependent analyses. The qualitative associations between donor NK cell chimerism and graft rejection, GVHD, relapse or progression-free survival did not change after adjustment for the presence of recipient KIR ligands nor after adjustment for the number of donor inhibitory or activating KIR genes. Finally, the 3-year cumulative incidence of relapse was 42% in patients who have all ligand for donor NK cell KIR, versus 38% in patients who miss one or more ligand for donor NK cell KIR (adjusted hazard ratio = 1.05; 95% confidence interval 0.65–1.68; p=0.85).
Conclusions: Robust engraftment of donor NK cells correlated with low risk of graft rejection, low risk of relapse and high progression-free survival but not with acute GVHD. The clinical importance of donor KIR inhibitory and activating genes on post-transplant donor NK chimerism merits further study.
Phenotypic and Functional Effects of Perifosine on Dendritic Cells.
Authors: Song Weihua , Hideshima Teru , Tai Yu-Tzu , Anderson Kenneth C. , Munshi Nikhil C. 
Published: October 2019

Abstract
Perifosine is a synthetic novel alkylphospholipid, a new class of antitumor agent which targets cell membranes and inhibits Akt activation. Perifosine inhibits multiple myeloma (MM) cell growth in vitro and in vivo mouse model. Currently perifosine is under the evaluation of phase II clinical trail in MM. Although perifosine has shown significant direct antitumor effects, its effect on immune system has not yet been clarified. The objective of this study is to evaluate the effects of perifosine on the activity of antigen presenting cells (APCs). Monocyte-derived dendritic cells (DCs) from normal human donors were used as the APCs, and mature DCs were obtained by the treatment of TNF-α and IL-1β. Perifosine was used at the concentrations of 2.5 uM, 5 uM and 10 uM for the treatment with DCs. We first evaluated the effect of perifosine on the survival of DCs. We observed that the perifosine treatment up to 48 hours had no effect on viability (>90%) of DCs, assessed by annexin V and PI staining. Alteration of phenotype by perifosine on DCs was further examined by flow cytometry. Our results demonstrated that with dose-dependent manner, perifosine led to a significant down-regulation of surface antigens on immature DCs at 24 and 48 hours, which associated to costimulation (CD40, CD80 and CD86), antigen presentation (HLA-ABC, HLA-DPQR) and maturation (CD83). However, we did not observed significant effect of perifosine on above surface markers on mature DCs. Since DCs play a crucial role on the regulation of Th1/Th2 immune responses by the production of IL-12, we next evaluated IL-12 secretion by DCs with and without perifosine treatment. Importantly, treatment with perifosine significantly decreased LPS-induced-IL-12 production, compared to untreated DCs (untrt vs. trt = 192.29 vs. 166.23 pg/ml (2.5uM), 111.19 pg/ml (5uM) and 44.886 pg/ml (10uM)) at 24 hours. To assess the effect of perifosine on DCs function on the regulation of T cell responses, we stimulated allogenic T cells with mature DCs with or without the pre-treatment of perifosine. The proliferation assay by 3H-TdR incorporation and IFN-γ production by ELISA indicated perifosine-treated DCs had no significant effect on the regulation of T cells function. Taken together, these results showed that DCs function are influenced by the treatment of perifosine. Our pre-clinical data therefore indicates the need to monitor immune functions in patients under the Akt inhibitor treatment.
Tetra-Arsenic Tetra-Sulfide Containing Triple-Agent Regimen as the First Line Therapy for Acute Promyelocytic Leukemia: Expeditiously Consecutive Complete Remission and Improved Disease-Free Survival.
Authors: Wu Tong , Zhao Jie , Jiang Bin , Wu Shu-Lan , Yang Ping-Di , Shan Fu-Xiang , Tong Chun-Rong , Lu Dao-Pei 
Published: October 2019

Abstract
Our previous study has demonstrated that tetra-arsenic tetra-sulfide (As4S4) treatment alone is highly effective and safe in both induction and maintenance therapy in acute promyelocytic leukemia (APL) patients (Lu DP et al, Blood2002; 99: 3136). In current clinical study, we explored whether As4S4 combined sequentially or simultaneously with all-trans retinoid acid (ATRA) and cytotoxic agents according to specific clinical condition as the first line therapy could expedite complete remission (CR) but in a safer way and further improve disease-free survival (DFS). The treatment-related toxicities were also studied. From April 2001 to May 2007, 114 patients with APL in a median age of 32.5 years (10–73 years) were enrolled including consecutive 68 newly diagnosed cases and 46 patients in hematological remission. For induction therapy, both As4S4 (60 mg/kg) and, if leukocytosis or retinoid acid syndrome was not a risk, ATRA (25mg/m2) were taken orally per day till CR. Cytotoxic agents such as mitoxantrone and/or hydroxyurea were added when WBC counts were more than 4 × 109/L. After hematological remission, 4 to 6 cycles of combined chemotherapy were given, and followed by alternatively oral use of As4S4 (3 cycles) and ATRA (1 cycle) in outpatient base for maintenance therapy until 4 years after diagnosis. PML/RARa transcript was monitored quantitatively by real-time PCR. Arsenic levels in blood and urine were also monitored with an atomic absorption spectrophotometer. Consecutive 68 newly diagnosed patients all achieved complete hematological remission in a median time of 29.5 days (14 – 62 days) without early death. The median time to achieve molecular remission was 61.5 days (34 – 120 days). Four out of 114 patients relapsed. One of them had obtained CR again. One patient died from leukemia relapse. Treatment with As4S4containing regimen was well tolerated. Mild gastrointestinal discomfort, transient elevation in liver enzyme, rash, and edema were noted in a few cases. Estimated DFS rate for 4 years was 94%, with a median follow-up time of 36.5 months (3–76 months). Our encouraging results show that faster consecutive CR, higher DFS rate and better quality of life have been achieved with the above regimen as the first line therapy for APL patients.
Phase II Multicenter Trial To Evaluate the Safety and Efficacy of Low-Toxicity Treosulfan/Fludarabine Conditioning Prior to Allogeneic Haematopoietic Stem Cell Transplantation in Patients with Acute Myeloid Leukemia.
Authors: Holowiecki Jerzy , Giebel S. , Beelen D. , Trenschel R. , Wandt H. , Schaefer-Eckart K. , Ruutu T. , Volin L. , Einsele H. , Stuhler G. , Uharek L. , Blau I. , Bornhaeuser M. , Zander A. , Kroeger N. , Aschan J. , Wojnar J. , Markiewicz M. , Freund M. , Casper J. 
Published: October 2019

Abstract
BACKGROUND: The toxicity of commonly used myeloablative regimens is the main factor limiting applicability and restricting upper age limit for allogeneic hematopoietic stem cell transplantation (alloHSCT). However, reduced intensity conditioning (RIC) protocols are associated with high risk of relapse. Previous dose-escalation trials revealed high-dose treosulfan-based conditioning an alternative treatment with myeloablative as well as antileukemic potential, accompanied by low non-hematological toxicity. The goal of this multicenter phase II trial was to evaluate safety and efficacy of treosulfan/fludarabine conditioning in AML patients.
PATIENTS AND METHODS: Seventy-five patients (median age 45 years, range 19–59) with AML in 1st (80%), 2nd (17%), or 3rd (3%) complete remission were treated with alloHSCT from either matched related (MRD, 40%) or unrelated donors (MUD, 60%). Preparative regimen consisted of treosulfan 14 g/m2/day on days −6 to −4, fludarabine 30 mg/m2/day on days −6 to −2, and in case of MUD-HSCT additionally ATG (Fresenius) 10 mg/kg/day on days −4 to −2. Graft-vs.-host disease (GvHD) prophylaxis consisted of cyclosporine and short-course methotrexate. 25% of the patients had an increased risk of toxicity for standard myeloablative conditioning regimens because of higher age or co-morbidities.
RESULTS: All patients engrafted after a period of absolute neutropenia with the median time to ANC >0.5 G/L and PLT >50 G/L of 21 (13–39) days and 19 (11–48) days, respectively. The cumulative incidence of complete donor chimerism was 72% on day +28 and 92% on day +100. Most frequent CTC grade 3 or 4 complications until day 28 after transplantation were febrile neutropenia (28%), infection in neutropenia (16%), and mucositis (5%). None of the patients experienced severe hepatic toxicity, including VOD. After a median follow up of 457 days (98–988), the probabilities of overall (OS) and disease-free survival (DFS) at 2 years equaled 67% resp. 58% (MRD-HSCT) and 58% resp. 45% (MUD-HSCT, p=NS). The 2-year cumulative incidence of relapse was 34% for MRD-HSCT and 37% for MUD-HSCT, whereas non-relapse mortality was 8% and 17%, respectively. Outcome was not significantly influenced by disease status (CR1 vs. ≥CR2) or age.
CONCLUSIONS: Conditioning therapy based on treosulfan at a dose of 3x14 g/m2 in combination with fludarabine is very well tolerated, resulting in a low NRM. The regimen demonstrated reliable efficacy in AML patients with confirmed first or subsequent remission. Further randomized studies are warranted to verify advantageous survival results.
ITK-SYK Induces T-Cell Lymphoma with Accompanying Inflammatory Disease in Mice.
Authors: Dierks Christine , Ma Hong , Veelken Hendrik , Warmuth Markus , Adrian Francisco 
Published: October 2019

Abstract
The ITK-SYK fusion protein was previously described to be present in 17% of unspecified peripheral T-cell lymphomas. Here we demonstrate that expression of ITK-SYK in the bone marrow of Balb\c mice causes T-cell lymphomas in mice with a latency of only 3–4 weeks. The disease is characterized by infiltration of the spleen, lymph nodes, bone marrow and the skin with malignant T-cells and progredient destruction of these organs. The mice die about 2 months after the transplantation due to dramatic weight loss caused by infiltration of T-cells into the colon and because of progredient anemia end neutropenia due to progredient infiltration of the bone marrow. The malignant T-cells were characterized as a mixed population of CD3+, CD4+, CD8- T cells and CD3+, CD4-, CD8- T-cells. The malignant disease was accompanied by a generalized inflammatory reaction including upregulation of the inflammatory cytokines IL-5 and INF-γ. Modulation of the membrane binding of ITK-SYK or its binding to Cbl by point mutations in the pleckstrin homology domain of ITK could alter the transforming activity of ITK-SYK. The intact kinase domain was essential for the transformation process and the disease could be reversed by treatment of diseased mice with the Syk-inhibitor Curcumine. Our results demonstrate that the fusion protein ITK-SYK causes T-cell lymphomas in mice and mimics the human disease. Therefore pharmacological inhibition of Syk in patients with U-PTCL carrying the ITK-SYK fusion protein might be a new and effective treatment strategy.
ABT-737 Is a Useful Component of Combinatory Chemotherapies for Chronic Myelogenous Leukemias with Diverse Drug Resistance Mechanisms.
Authors: Kuroda Junya , Kimura Shinya , Andreeff Michael , Ashihara Eishi , Kamitsuji Yuri , Strasser Andreas , Taniwaki Masafumi , Maekawa Taira 
Published: October 2019

Abstract
Chronic myelogenous leukemia (CML) is characterized by its refractoriness to various apoptotic insults by Bcr-Abl tyrosine kinase (TK)-mediated signalling. Although imatinib mesylate (IM), a Bcr-Abl TK inhibitor, has markedly improved the therapeutic outcomes of CML, additional or alternative molecular targeting strategies are still needed. Since the interplay of anti-apoptotic Bcl-2 proteins and BH3-only proteins, such as Bim and Bad, is crucial for regulating the cellular fate of Bcr-Abl+ leukemic cells (Kuroda J et al, PNAS , 2006; Cell Death Differ, 2007), the direct targeting of anti-apoptotic Bcl-2 proteins by the use of a BH3-only protein mimetic is an attractive approach for treating CML. We here investigated the activity of ABT-737, a mimic of BH3-only proteins that inhibit anti-apoptotic Bcl-2, Bcl-XL and Bcl-w, but not Mcl-1 or A1, against CML. The Annexin-V-staining study, the assay for mitochondrial outer membrane potential and the internucleosomal fragmentation assay revealed that ABT-737 potently induced apoptosis in CML cell lines (BV173, K562, KCL22, KT-1, MEG-01 and MYL) with the IC50 for induction of cell death by 48 h of treatment ranging from 0.04 to 4.06 μM. ABT-737 was also effective in killing primary CML samples in vitro. ABT-737 prolonged the survival of mice xenografted with a CML cell line, BV173, demonstrating its in vivo bioactivity. Higher expression of Bcl-2, Bcl-XL, or Mcl-1 reduced cell killing by ABT-737 in each cell line, but we found no correlation between the sensitivities to ABT-737 and the specific expression patterns of Bcl-2 family proteins among different cell lines. The levels of Bcr-Abl and Lyn, a member of Src kinase family associated with apoptosis resistance in CML, also varied among the cell lines, and we found no consistent relationship between the sensitivity to ABT-737 and the expression levels of these proteins Thus, the cell killing effect of ABT-737 in CML must be determined in part by other drug resistance mechanisms, such as high expression of Bcr-Abl, overexpression of P-glycoprotein (P-gp), a drug-efflux pump, and/or their combination. Importantly, ABT-737 augmented the cell killing effect of IM in CML cell lines with high levels of anti-apoptotic Bcl-2 family proteins (Bcl-2, Bcl-XL, or even Mcl-1), Bcr-Abl, P-gp, or Lyn, unless leukemic cells harboured IM-insensitive Abl kinase domain (KD) mutations. Moreover, the combination of ABT-737 with homoharringtonine, an herbal-derived anti-CML therapeutic that potently reduces Mcl-1 within 6 hours in vitro, dramatically enhanced the killing by ABT-737 in CML cells with diverse drug resistance mechanisms, including IM-insensitive Abl KD mutations, such as T315I mutation. These results suggest that ABT-737 could be a useful component of combinatory chemotherapies for CML.