bluuebunny/crossref_metadata_2025_split huggingface dataset:
Targeting Drug-Resistant CML and Ph+-ALL with the Spectrum Selective Protein Kinase Inhibitor XL228.
Authors: Shah Neil P. , Kasap Corynn , Paquette Ronald , Cortes Jorge , Pinilla Javier , Talpaz Moshe , Bui Lynne A. , Clary Douglas O. 
Published: October 2019

Abstract
The fusion protein BCR-ABL is a hallmark of chronic myelogenous leukemia (CML) and Philadelphia-positive acute lymphocytic leukemia (Ph+-ALL), and has been demonstrated as the primary driver of these diseases. Control of CML for considerable periods of time has been achieved through use of selective ABL kinase inhibitors, particularly imatinib. Once patients fail imatinib therapy, they are commonly found to harbor a mutated and activated form of BCR-ABL which is unable to bind the inhibitor. A more recent ABL inhibitor, dasatinib, can block growth of cells harboring most of the imatinib-resistant mutations, but T315I and F317L mutations are often seen in patients relapsing after dasatinib therapy. Thus once a patient develops CML harboring these mutations, there are few therapeutic options available. XL228 is a potent multi-targeted protein kinase inhibitor with activity against IGF1R, src, and Abl. It displays low nanomolar biochemical activity against wild type Abl kinase (Ki = 5 nM), as well as the T315I form of Abl resistant to imatinib and dasatinib (Ki = 1.4 nM). XL228 also inhibits Aurora A with an IC50 of approximately 3 nM, demonstrating a more balanced inhibition profile compared to other dual Abl /Aurora inhibitors. CML and ALL cell lines were evaluated for sensitivity to XL228, and in each case the IC50 for inhibition of proliferation was less than 100 nM. XL228 inhibits phosphorylation of BCR-ABL and its substrate STAT5 in K562 cells in vitro with IC50s of 33 and 43 nM, respectively. Single-dose pharmacodynamics studies demonstrate a potent effect of XL228 on BCR-ABL signaling in K562 xenograft tumors. Phosphorylation of BCR-ABL was decreased by 50% at XL228 plasma concentrations of 3.5 μM; a similar decrease in phospho-STAT5 occurred at 0.8 μM plasma concentration. XL228 showed clear superiority to MK-0457, imatinib, and dasatinib in downregulating BCR-ABL phosphorylation in BaF3 cells expressing the T315I form of BCR-ABL in vitro (406 nM, 6912 nM, >10,000 nM, >10,000 nM, respectively), and in xenograft experiments in vivo. These results indicate that XL228 potently inhibits wild type and T315I forms of BCR-ABL, and provide a rationale for the clinical development of this agent for the treatment of patients with drug-resistant disease. A phase I dose escalation study of XL228 in subjects with CML or Ph+-ALL who have failed prior imatinib and dasatinib therapy has been initiated, focusing on safety/tolerability, pharmacodynamics, and pharmacokinetics. Pharmacodynamic assessments include a flow cytometry-based phospho-CrkL assay, quantitative PCR for BCR-ABL, and plasma markers of XL228 activity. An update on our clinical experience with XL228 in subjects resistant or intolerant to imatinib and dasatinib will be presented.
Translocation t(4;14) Is Not an Adverse Prognostic Factor in Patients with Multiple Myeloma Undergoing Allogeneic Stem Cell Transplantation.
Authors: Hansen Timon , Schilling Georgia , Shimoni Avichai , Simon-Perez Jose-Antonio , Bethge Wolfgang , Liebisch Peter , Schwerdtfeger Rainer , Bornhaeuser Martin , Otterstetter Svenja , Ayuk Francis , Bokemeyer Carsten , Zander Axel R. , San-Miguel Jesus , Nagler Arnon , Kroeger Nicolaus 
Published: October 2019

Abstract
We analyzed the prognostic impact of the most frequent genetic abnormalities detected by fluorescence-in situ-hybridization combined with immunofluorescent cytoplasm immunoglobulin staining (cIg-FISH) in 101 patients with multiple myeloma, who underwent allogeneic stem cell transplantation after reduced melphalan/fludarabine-based conditioning from related (n=34) and unrelated (n=67) donors. The abnormalities were del(13q14) [62%], t(11;14)(q13;q32) [11%], t(4;14)(p16.3;q32) [16%], CMYC-gains (8q24) [17%], del(17p13.1) [16%], t(14;16)(q32;q23) [4%], whereas none of the patients had t(6;14)(p25;q32). Translocation t(4;14), CMYC-gains and del 17p were frequently associated with del(13q14): 64%, 80% and 92%, respectively. The complete remission (CR) rate was 45% for all patients. Patients with del(17p13) achieved fewer complete remission than others (7% vs. 56%; p=0.001), while no difference was seen for t(4;14) and other abnormalities. Univariate analysis revealed higher relapse rates for age > 50 years (p=0.002), del(13q14) (p=0.006) and del(17p13) (p=0.003). Patients with translocation t (4;14) had a similar four year event-free survival than others (50 vs 45%). In a multivariate analysis, only del(13q14) [HR: 2.34, p=0.03] and del(17p13) [HR: 2.24; p=0.04] influenced the risk of relapse, while for event-free survival, only age [HR 2.8; p=0.01] and del(17p13) [HR: 2.05; p=0.03] retained the prognostic value. These data seem to indicate that some adverse cytogenetic risk factors such as t(4;14) can be overcome by allogeneic stem cell transplantation, probably due to the graft versus myeloma effect. Del(17p13.1) is a significant factor for a lower chance of complete remissions and shorter event free survival following allogeneic stem cell transplantation. The presented data will have implications for risk-adapted strategies in the future.
Unlike Inactivating PTEN Mutations, Pharmacological Inhibition of PTEN Does Not Increase the Sensitivity of Multiple Myeloma Cells to Inhibition of the PI3K/Akt/mTOR Pathway.
Authors: Wang Xiaojing , Zhang Shuhong , Peng Xiaodong , Garlich Joe , Chen Li , Liang Jing , Farag Sherif Shafik 
Published: October 2019

Abstract
PTEN-deficient multiple myeloma (MM) and other tumor cell lines have been shown to be remarkably sensitive to inhibitors of the PI3K/Akt/mTOR pathway (Shi Y, et al. Cancer Res 2002; Simth Y, et al. Proc Am Assoc Cancer Res 2002; Neshat MS, et al. Proc. Natl. Acad. Sci. USA 2001.). Inactivating mutations of PTEN, however, are very rare in human MM cells. We investigated whether pharmacological inhibition of wild type PTEN might also sensitize MM cells to inhibitors of PI3K and mTOR, and therefore provide the rationale for novel therapeutically useful combinations. We tested the effect of the PTEN antagonist, SF1740 (Semafore Inc, Indianapolis, IN), in combination with the mTOR inhibitor, rapamycin, or the PI3K inhibitor, SF1101, (also known as LY294002, from Semafore Inc, Indianapolis, IN) in U266, MM1R, MM1S myeloma cells. Using the Malachite Green assay, the IC50 for PTEN inhibition by SF1740 was 0.4 μM, and maximal inhibition was achieved at a concentration of 1μM. We treated MM cells with rapamycin (1, 5, 10 nM) or SF1101 (10, 25, 50 μM) alone or in combination with SF1740 for 24, 48, 72 and 96 hours. Cellular toxicity was assessed using the MTT assay, apoptosis by annexin V/PI staining, and the effect on intracellular signaling was monitored by Western blotting. SF1740 (1 μM) alone increased cell growth, and failed to sensitize cells to the inhibitory effects of rapamycin (1–10 nM) at all time points. There were no significant differences in cell survival between the combination of the two drugs and rapamycin alone when treated from 48–96hr. Cytotoxicity was unaffected by the sequence of drug treatment; concurrent or 24-hour pre-treatment with SF1740. Similar results were obtained using the combination of SF1740 (1 μM) and SF1101 used at concentrations of 10, 25, and 50 μM, with no difference in MM cell inhibition and survival between the SF1101 and the combination with SF1740. We conclude that in MM cells, pharmacological inhibition of wild type PTEN does not appear to replicate the effect of inactivating mutations of PTEN in increasing cell sensitivity to inihibitors of the PI3K/Akt/mTOR pathway. The results do not support the clinical use of the PTEN inhibitor SF1740 in combination with either PI3K or mTOR inhibitors. Xiaojing Wang and Shuhong Zhang contributed equally to this work.
Halofuginone, an Old Anticoccidosis Drug, Induces Apoptosisin Multiple Myeloma Cells, Associated with Down Regulation of MCL1.
Authors: Leiba Merav , Tai Yu-Tzu , Hideshima Teru , Jakubikova Jana , Hiroshi Ikeda , Li Xian-Feng , Burger Peter , Richardson Paul , Munshi Nikhil C. , Nagler Arnon , Anderson Kenneth C. 
Published: October 2019

Abstract
Halofuginone, a synthetic derivative of quinazolinone alkaloid, has recently been shown to have an anti-cancer effect in various solid and hematological malignancies. It is an orally available drug with a safe toxicity profile in clinical trials of inflammatory disease and has anti-angiogenic, anti-metastatic and anti-proliferative effects in preclinical studies. It blocks TGFb signaling by targeting Smad 2/3, inhibits NFkB activity, as well as downregulates extra cellular matrix (ECM) formation via the inhibition of collagen type I formation and matrix metalloproteinase 2(MMP2). Since ECM has an important role in the bone marrow microenvironment in multiple myeloma (MM) pathogenesis, we here examined whether halofuginone induces cytotoxicity against various MM cell lines, including those sensitive and resistant to conventional and novel chemotherapies. Halofuginone (12.5–400 nM) induced cytotoxicity in a dose-dependent fashion in a variety of MM cell lines (n=20), regardless of the sensitivity to conventional chemotherapy (i.e., dexamethasone, melphalan, doxorubicin) and novel therapies (i.e., lenalidomide, bortezomib) with IC50 of 50–200 nM. In contrast, halofuginone did not induce cytotoxicity against CD40-activated peripheral blood mononuclear cells from normal donors, even at high doses (500–1000nM). Importantly, neither IL6 nor IGF1, two key growth and survival factors in MM, overcame the growth inhibitory effect of halofuginone. We further examined molecular mechanisms whereby halofuginone triggers growth inhibition in MM cells. It induced both apoptosis and necrosis in a time- (2–48h) and dose (50–200 nM) dependent manner in MM1R and OPM1 MM cells, assessed by annexin V/ PI staining. Significant dose- dependent activation of caspase 3 and 8 was demonstrated after 25–200 nM of halofuginone treatment of MM1R, MM1S, and OPM1 cells. Mitochondrial membrane potential was also reduced after 24 hours of halofuginone treatment (50, 200 nM) of MM1R and OPMI cells, as evident by the accumulation of JC1 monomers. In addition, western blot analysis showed that halofuginone induces cleavage of apoptotic proteins caspase 3/8 and PARP, and downregulates anti-apoptotic protein MCL1. Taken together, these data suggest that halofuginone has significant anti-MM activities and is a potential novel therapy in MM.
Enhanced Interaction Between Hsp90 and Raptor Regulates mTOR Signaling upon T Cell Activation
Authors: Delgoffe Greg M , Kole Thomas P. , Cotter Robert J , Powell Jonathan 
Published: October 2019

Abstract
Full T cell activation requires antigen recognition (Signal 1) in the context of costimulation (Signal 2). Our group and others have determined that the mammalian Target of Rapamycin (mTOR) plays an important role in integrating costimulatory signals. Specifically, Th1 T cell activation in the absence of mTOR activation leads to tolerance in the form of T cell anergy. mTOR is an evolutionarily-conserved serine/threonine kinase which has been shown to interpret environmental cues in mammalian cells. mTOR is activated by an array of diverse inputs including insulin, amino acids, growth factors and CD28. mTOR signals through two signaling complexes: TORC1 and TORC2. A critical component of TORC1 signaling is the Regulatory Associated Protein of TOR (raptor). One of the central questions in understanding mTOR function is determining how diverse upstream signals can lead to diverse downstream functional consequences. To address this issue in T cells we undertook a proteomic approach to identify novel binding proteins for raptor. Jurkat T cells were either incubated in serum-free media or hyper-activated. Raptor was immunoprecipitated (IP) from the two lysates, separated by SDS-PAGE and silver stained. Next, protein bands that were differentially bound to raptor in the lysates from stimulated versus unstimulated cells were identified. One band located near 90 kDa was excised and using mass spectrometry subsequently determined to be Hsp90, a chaperone protein necessary for the correct folding of many protein “clients”. These findings were next confirmed in primary T cells. Upon activation with anti-CD3 and anti-CD28, IP of raptor led to co-IP of Hsp90 and IP of Hsp90 led to the concomitant precipitation of raptor. To further determine the role of the Hsp90-raptor interaction in T cells we used 17-AAG, an Hsp90 inhibitor. Primary T cells were stimulated in the presence of rapamycin or 17-AAG. Incubation with 17-AAG but not rapamycin led to a decrease in raptor protein levels consistent with the concept that raptor is an Hsp90 client. Functionally, this led to a decrease in TORC1 activation as measured by phosphorylation of S6K-1. More importantly, although17-AAG did not inhibit IL-2 production upon initial stimulation, primary T cells stimulated with anti-CD3 and anti-CD28 in the presence of 17-AAG failed to produce IL-2 upon rechallenge 5 days later; they were anergic. Overall, our findings demonstrate a novel activation-induced interaction between Hsp90 and raptor in T cells. This interaction can regulate the decision between TCR-induced activation and tolerance. Hsp90 inhibitors are currently being evaluated as anti-neoplastic agents, and while such agents do not acutely inhibit T cell function, they may induce anergy in activated Th1 cells. Thus, Hsp90 inhibitors might be incorporated into novel immunosuppressive regimens to treat and prevent GVHD and transplant rejection through the promotion of T cell tolerance.
Platelets Regulate Tumor-Induced Angiogenesis
Authors: Chang Yali , Zhang Jing , Lin Huifeng , Italiano Joseph , Handin Robert I. 
Published: October 2019

Abstract
The hypothesis that tumors require a vascular network to grow beyond a critical size is now widely accepted. There is also circumstantial evidence implicating the blood platelet in the process of angiogenesis. We have previously shown that the platelet sequesters pro- and anti-angiogenic proteins in discrete subsets of alpha granules and differentially releases them in vitro in response to PAR1 and PAR4 activating peptides. We have extended these studies by injecting two murine -- Lewis Lung Carcinoma (LLC), B16 F10 melanoma and a human renal cell carcinoma (RCC 786-O) into the perivitelline space of wild type and Fli1-GFP transgenic zebrafish embryos 48 hours post fertilization (hpf). One day after injecting 2000 tumor cells suspended in Matrigel, a network of new blood vessels had grown up toward the site of tumor injection. By 3 to 4 days post-injection (dpi) the vascular network had entered and enveloped the tumor mass. We then blocked the production of zebrafish thrombocytes, the fish equivalent of mammalian platelets, by injecting an anti-sense morpholino directed against c-mpl, the thrombopoietin receptor, into single cell embryos followed, at 48 hpf, by the injection of tumor cells. We have previously shown that this c-mpl morpholino inhibits thrombocyte production for 5–7 days. The initial wave of angiogenesis was normal in all of the c-mpl morphants but there was almost complete inhibition of subsequent angiogenesis and blood vessel extension into the LLC, B16 melanoma and RCC 1080 tumors. In contrast, control fish that had received a scrambled morpholino and had a normal number of circulating thrombocytes, had normal angiogenesis within the tumor mass. We then transplanted LLC and B16 F10 cells into CD41-GFP embryos that have fluorescent thrombocytes in their circulation. Three dpi we observed the arrest and adhesion of GFP+ thrombocytes to vessels within the tumor mass. We also noted that thrombocytes were present in tumor vessels before blood flow had been established. We conclude that platelets/thrombocytes play an important role in TIA and may serve as a vehicle for the delivery of angiogenic factors to human and murine tumors. Thrombocytes appear to be particularly important for the penetration of new vessels into the tumor mass. These studies raise the interesting possibility that inhibiting platelet production or granule secretion might help to inhibit TIA.
Targeting STAT3 Signaling to Augment the Immunogenicity of B-Cell Lymphomas
Authors: Wang Hongwei , Cheng F. , Wright K. , Tao J. , Smith M. , Pinilla J. , Dessureault S. , Sebti S. , Sotomayor E.M. 
Published: October 2019

AbstractSTAT3 signaling has emerged as a negative regulator of inflammatory responses in immune cells. In bone-marrow derived antigen-presenting cells (APCs), genetic or pharmacologic disruption of STAT3 led to inflammatory cells that effectively prime antigen-specific T-cell responses and restore the responsiveness of tolerized T-cells. In contrast, enhanced Stat3 activity in APCs resulted in increased production of the immunosuppressive cytokine IL-10 and induction of T-cell tolerance1. B-cell lymphomas being tumors derived from B-lymphocytes display intrinsic antigen-presenting capabilities. Augmentation of this APC function has been shown to result in effective anti-lymphoma immunity2. In this study we determined whether targeting Stat3 signaling might influence the intrinsic APC function of malignant B-cells and the responsiveness –or not- of antigen-specific CD4+ T-cells. First, we specifically block STAT3 signaling in A20 lymphoma B-cells by using a dominant negative variant of STAT3, Stat3b. Inhibition of STAT3 resulted in tumor cells capable not only of fully priming naïve antigen-specific CD4+T-cells but also able of restoring the responsiveness of tolerant T-cells from lymphoma bearing mice. Conversely, transfection of A20 B-cells with Stat3c, a constitutively activated mutant form of STAT3, led to T-cell unresponsiveness. Of note, manipulation of STAT3 in B cell tumors was associated with changes in the mRNA expression and protein levels of IL-10. Second, we evaluated the effects of two novel Stat3 inhibitors, CPA-7 (a platinum-containing compound that disrupts STAT3 DNA binding activity) and S3I-201 (inhibitor of Stat3:Stat3 complex formation and Stat3 DNA binding and transcriptional activities) in a murine model of Mantle Cell Lymphoma (MCL). In vitro treatment of FC-muMCL1 cells - derived from a tumor elicited in Em-Cyclin D1 transgenic mice- with increasing concentrations of either CPA-7 or S3I-201 resulted in an enhanced presentation of OVA-peptide to naïve CD4+ T-cells specific for a MHC class II restricted epitope of ovalbumin (OT-II cells). Indeed, these T-cells produce higher levels of IL-2 and IFN-gamma compared to anti-OVA T cells that encountered cognate antigen in untreated FC-muMCL1 cells. More importantly, MCL cells treated with CPA-7 restored the responsiveness of tolerized anti-OVA CD4+ T-cells. Finally, in vivo treatment of MCL-bearing mice with CPA-7 (5 mg/kg/iv given on days +21, +24 and +27 after tumor challenge) resulted in significant inhibition of p-Stat3 in malignant B-cells and augmentation of their APC function. Taken together, STAT3 signaling is involved in the regulation of the antigen-presenting capabilities of B-cell lymphomas and as such represents a novel molecular target to augment the immunogenicity of these tumors.
NKX3.1 Is a Direct TAL1 Target Gene That Mediates the TAL1 Dependent Proliferation of Human T-Cell Acute Lymphoblastic Leukemia (T-ALL)
Authors: Kusy Sophie , Goardon Nicolas , Armstrong Florence , Pflumio Francoise , Romeo paul-Henri 
Published: October 2019

Abstract
The TAL1/SCL gene encodes a bHLH (basic Helix-Loop-helix) protein that acts as a master gene in hematopoiesis. The TAL1/SCL gene is also the most frequently activated gene in human T-ALL but the oncogenic transcriptional programs, downstream of TAL1 in human T-ALL, are not well characterized. Using RNA interference to knockdown TAL1 expression, we show that TAL1 regulates both cell proliferation and death of human T-ALL cells. To determine the TAL1 target genes in human T-ALL, we combine TAL1 knockdown and gene expression profiling and show that TAL1 activates and repress a common subset of genes in cell lines. This subset includes known TAL1 target genes but also the NKX3.1 gene that is a homeobox gene, specifically expressed in the prostate epithelium during prostate development and in adulthood. NKX3.1 gene inactivation is one of the earliest events that occur in prostate cancer initiation, defining NKX3.1 as a major tumor suppressor gene of this cancer. TAL1 expression is associated with NKX3.1 activation in human T-ALL cell lines and NKX3.1 is expressed in TAL1 expressing human T-ALL blasts. TAL1 and GATA-3 are specifically bound in vivo to the [−870/−570] region of the human NKX3.1 gene promoter, and ex vivo, TAL1 can either directly binds an E-box [position −738] or be recruited by GATA-3 on a GATA binding site [position −697]. Finally, functional analyses of the NKX3.1 promoter indicate that these binding sites mediate the transcriptional activity of this promoter in T-cell lines. Sequences analysis of the human and mouse NKX3.1 promoters show that the regulatory sequences involved in the TAL1 activation of the human NKX3.1 gene are not conserved in the mouse gene, indicating why the NKX3.1 gene is not expressed in mouse models of TAL1 mediated leukemogenesis. NKX3.1 knockdown shows that NKX3.1 is necessary for the proliferation of TAL1 expressing T-ALL cell lines and NKX3.1 overexpression can complement the proliferation defects associated with TAL1 knockdown in T-ALL cell lines. Microarray analyses show that TAL1 and NKX3.1 regulate a common subset of genes in T-ALL that includes numerous genes encoding proteins known to be involved in T-cell proliferation and/or signaling. Finally, using a new culture system that enables proliferation of primary human leukemic cells, we show that the NKX3.1 gene is specifically activated in human TAL1 expressing T-ALL together with the defined potential TAL1 and/or NKX3.1 target genes. These results characterize NKX3.1 as the first gene directly activated by TAL1 and involved in the TAL1 dependent proliferation of human T-cell Acute Lymphoblastic Leukemia.