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Breitenmoser A, Bader B, Berg N. Why does repatriate career success vary? An empirical investigation from both traditional and protean career perspectives. HUMAN RESOURCE MANAGEMENT 2017. [DOI: 10.1002/hrm.21888] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Ellermann M, Eheim A, Rahm F, Viklund J, Guenther J, Andersson M, Ericsson U, Forsblom R, Ginman T, Lindström J, Silvander C, Trésaugues L, Giese A, Bunse S, Neuhaus R, Weiske J, Quanz M, Glasauer A, Nowak-Reppel K, Bader B, Irlbacher H, Meyer H, Queisser N, Bauser M, Haegebarth A, Gorjánácz M. Novel Class of Potent and Cellularly Active Inhibitors Devalidates MTH1 as Broad-Spectrum Cancer Target. ACS Chem Biol 2017; 12:1986-1992. [PMID: 28679043 DOI: 10.1021/acschembio.7b00370] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
MTH1 is a hydrolase responsible for sanitization of oxidized purine nucleoside triphosphates to prevent their incorporation into replicating DNA. Early tool compounds published in the literature inhibited the enzymatic activity of MTH1 and subsequently induced cancer cell death; however recent studies have questioned the reported link between these two events. Therefore, it is important to validate MTH1 as a cancer dependency with high quality chemical probes. Here, we present BAY-707, a substrate-competitive, highly potent and selective inhibitor of MTH1, chemically distinct compared to those previously published. Despite superior cellular target engagement and pharmacokinetic properties, inhibition of MTH1 with BAY-707 resulted in a clear lack of in vitro or in vivo anticancer efficacy either in mono- or in combination therapies. Therefore, we conclude that MTH1 is dispensable for cancer cell survival.
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Puck J, Hödl MK, Filatotchev I, Wolff HG, Bader B. Ownership mode, cultural distance, and the extent of parent firms’ strategic control over subsidiaries in the PRC. ASIA PACIFIC JOURNAL OF MANAGEMENT 2016. [DOI: 10.1007/s10490-016-9471-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Held K, Bader B. The influence of images on organizational attractiveness: comparing Chinese, Russian and US companies in Germany. INTERNATIONAL JOURNAL OF HUMAN RESOURCE MANAGEMENT 2016. [DOI: 10.1080/09585192.2016.1173085] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Wengner AM, Siemeister G, Koppitz M, Schulze V, Kosemund D, Klar U, Stoeckigt D, Neuhaus R, Lienau P, Bader B, Prechtl S, Raschke M, Frisk AL, von Ahsen O, Michels M, Kreft B, von Nussbaum F, Brands M, Mumberg D, Ziegelbauer K. Novel Mps1 Kinase Inhibitors with Potent Antitumor Activity. Mol Cancer Ther 2016; 15:583-92. [PMID: 26832791 DOI: 10.1158/1535-7163.mct-15-0500] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 01/04/2016] [Indexed: 11/16/2022]
Abstract
Monopolar spindle 1 (Mps1) has been shown to function as the key kinase that activates the spindle assembly checkpoint (SAC) to secure proper distribution of chromosomes to daughter cells. Here, we report the structure and functional characterization of two novel selective Mps1 inhibitors, BAY 1161909 and BAY 1217389, derived from structurally distinct chemical classes. BAY 1161909 and BAY 1217389 inhibited Mps1 kinase activity with IC50 values below 10 nmol/L while showing an excellent selectivity profile. In cellular mechanistic assays, both Mps1 inhibitors abrogated nocodazole-induced SAC activity and induced premature exit from mitosis ("mitotic breakthrough"), resulting in multinuclearity and tumor cell death. Both compounds efficiently inhibited tumor cell proliferation in vitro (IC50 nmol/L range). In vivo, BAY 1161909 and BAY 1217389 achieved moderate efficacy in monotherapy in tumor xenograft studies. However, in line with its unique mode of action, when combined with paclitaxel, low doses of Mps1 inhibitor reduced paclitaxel-induced mitotic arrest by the weakening of SAC activity. As a result, combination therapy strongly improved efficacy over paclitaxel or Mps1 inhibitor monotreatment at the respective MTDs in a broad range of xenograft models, including those showing acquired or intrinsic paclitaxel resistance. Both Mps1 inhibitors showed good tolerability without adding toxicity to paclitaxel monotherapy. These preclinical findings validate the innovative concept of SAC abrogation for cancer therapy and justify clinical proof-of-concept studies evaluating the Mps1 inhibitors BAY 1161909 and BAY 1217389 in combination with antimitotic cancer drugs to enhance their efficacy and potentially overcome resistance. Mol Cancer Ther; 15(4); 583-92. ©2016 AACR.
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Wengner AM, Siemeister G, Koppitz M, Schulze V, Kosemund D, Klar U, Stoeckigt D, Neuhaus R, Lienau P, Bader B, Prechtl S, Doehr O, Raschke M, von Ahsen O, Elbi C, Bruns I, Michels M, Kreft B, von Nussbaum F, Brands M, Mumberg D, Ziegelbauer K. Abstract 3090: Novel Mps1 kinase inhibitors with potent anti-tumor activity. Mol Cell Biol 2015. [DOI: 10.1158/1538-7445.am2015-3090] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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32
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Schuster T, Bader B. Corporate masterminds – executive management teams in focus. TEAM PERFORMANCE MANAGEMENT 2015. [DOI: 10.1108/tpm-03-2015-0016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Bader B, Schuster T, Dickmann M. Special issue of International Journal of Human Resource Management: Danger and risk as challenges for HRM: how to manage people in hostile environments. INTERNATIONAL JOURNAL OF HUMAN RESOURCE MANAGEMENT 2015. [DOI: 10.1080/09585192.2015.1038116] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Bader B, Schuster T, Dickmann M. Special issue ofInternational Journal of Human Resource Management: Danger and risk as challenges for HRM: how to manage people in hostile environments. INTERNATIONAL JOURNAL OF HUMAN RESOURCE MANAGEMENT 2015. [DOI: 10.1080/09585192.2015.1019256] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Bader B, Schuster T. Expatriate Social Networks in Terrorism-Endangered Countries: An Empirical Analysis in Afghanistan, India, Pakistan, and Saudi Arabia. JOURNAL OF INTERNATIONAL MANAGEMENT 2015. [DOI: 10.1016/j.intman.2014.09.004] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Bader B. The power of support in high-risk countries: compensation and social support as antecedents of expatriate work attitudes. INTERNATIONAL JOURNAL OF HUMAN RESOURCE MANAGEMENT 2014. [DOI: 10.1080/09585192.2014.962071] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Schulze J, Moosmayer D, Weiske J, Fernández-Montalván A, Herbst C, Jung M, Haendler B, Bader B. Cell-Based Protein Stabilization Assays for the Detection of Interactions between Small-Molecule Inhibitors and BRD4. ACTA ACUST UNITED AC 2014; 20:180-9. [DOI: 10.1177/1087057114552398] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Bromodomain protein 4 (BRD4), a member of the bromodomain and extra-terminal (BET) protein family, acts as a central element in transcriptional elongation and plays essential roles in cell proliferation. Inhibition of BRD4 binding to acetylated histone tails via its two bromodomains, BD1 and BD2, with small-molecule inhibitors has been shown to be a valid strategy to prevent cancer growth. We have evaluated and established two novel assays that quantify the interaction of transfected BRD4 BD1 with chemical inhibitors inside cultured cells. Both methods are based on the principle of ligand-induced protein stabilization by which the binding of a small-molecule inhibitor stabilizes intracellular BRD4 BD1 and protects it from proteolytic degradation. We demonstrate the universal character of this principle by using two orthogonal, highly sensitive detection technologies for the quantification of BRD4 BD1 levels in cellular lysates: enzyme fragment complementation and time-resolved fluorescence resonance energy transfer (TR-FRET). Upon optimization of both assays to a miniaturized high-throughput format, the methods were validated by testing a set of small-molecule BET inhibitors and comparing the results with those from a cell-free binding assay and a biophysical thermal shift assay. In addition, point mutations were introduced into BRD4 BD1, and the corresponding mutants were characterized in the TR-FRET stabilization assay.
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Jung M, Philpott M, Müller S, Schulze J, Badock V, Eberspächer U, Moosmayer D, Bader B, Schmees N, Fernández-Montalván A, Haendler B. Affinity map of bromodomain protein 4 (BRD4) interactions with the histone H4 tail and the small molecule inhibitor JQ1. J Biol Chem 2014; 289:9304-19. [PMID: 24497639 PMCID: PMC3979416 DOI: 10.1074/jbc.m113.523019] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Bromodomain protein 4 (BRD4) is a member of the bromodomain and extra-terminal domain (BET) protein family. It binds to acetylated histone tails via its tandem bromodomains BD1 and BD2 and forms a complex with the positive transcription elongation factor b, which controls phosphorylation of RNA polymerase II, ultimately leading to stimulation of transcription elongation. An essential role of BRD4 in cell proliferation and cancer growth has been reported in several recent studies. We analyzed the binding of BRD4 BD1 and BD2 to different partners and showed that the strongest interactions took place with di- and tetra-acetylated peptides derived from the histone 4 N-terminal tail. We also found that several histone 4 residues neighboring the acetylated lysines significantly influenced binding. We generated 10 different BRD4 BD1 mutants and analyzed their affinities to acetylated histone tails and to the BET inhibitor JQ1 using several complementary biochemical and biophysical methods. The impact of these mutations was confirmed in a cellular environment. Altogether, the results show that Trp-81, Tyr-97, Asn-140, and Met-149 play similarly important roles in the recognition of acetylated histones and JQ1. Pro-82, Leu-94, Asp-145, and Ile-146 have a more differentiated role, suggesting that different kinds of interactions take place and that resistance mutations compatible with BRD4 function are possible. Our study extends the knowledge on the contribution of individual BRD4 amino acids to histone and JQ1 binding and may help in the design of new BET antagonists with improved pharmacological properties.
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Bader B, Berg N. The influence of terrorism on expatriate performance: a conceptual approach. INTERNATIONAL JOURNAL OF HUMAN RESOURCE MANAGEMENT 2013. [DOI: 10.1080/09585192.2013.814702] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Bader B, Berg N. An Empirical Investigation of Terrorism-induced Stress on Expatriate Attitudes and Performance. JOURNAL OF INTERNATIONAL MANAGEMENT 2013. [DOI: 10.1016/j.intman.2013.01.003] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Wehrman T, Nguyen M, Feng W, Bader B. EphB4 cellular kinase activity assayed using an enzymatic protein interaction system. Assay Drug Dev Technol 2013; 11:237-43. [PMID: 23557019 DOI: 10.1089/adt.2012.490] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Receptor tyrosine kinases (RTKs) are important players in various cellular processes, including proliferation, migration, metabolism, and neuronal development. EphB4 RTK is essential for the development of a functional arterial-venous network in embryonic and adult neoangiogenesis. To develop novel inhibitors of EphB4 that might have applications in severe diseases like cancer and retinopathies, assays need to be in place that resemble, in a most physiological fashion, the activation and downstream function of the kinase. In addition, such assays need to be amenable to high-throughput screening to serve efficiently the modern drug discovery processes in the pharmaceutical industry. The authors have developed an enzyme fragment complementation assay that measures the interaction of a downstream docking protein to the activated and phosphorylated full-length EphB4 kinase in cells. The assay is specific, robust, and amenable to miniaturization and high-throughput screening. It covers most steps in the activation process of EphB4, including ligand binding, autophosphorylation, and docking of a downstream interactor. This assay format can be transferred to other RTKs and adds an important cell-based kinase assay option to researchers in the field.
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Williamson J, Fiddes B, Chan J, Mohiddin S, Danek A, Bader B, Earley M, Page S, Radunovic A. A PATIENT WITH CHOREA-ACANTHOCYTOSIS AND DILATED CARDIOMYOPATHY. Journal of Neurology, Neurosurgery and Psychiatry 2012. [DOI: 10.1136/jnnp-2012-304200a.55] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Paradas Lopez C, Cabrera Serrano M, Rivas Infante E, Morales JM, Marquez C, Bader B, Mir P. Neuromuscular Involvement in Choreoacanthocytosis (P07.204). Neurology 2012. [DOI: 10.1212/wnl.78.1_meetingabstracts.p07.204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Bader B, Liu J, Kretzschmar H, Danek A. DNA-Datenbank seltener Bewegungsstörungen. KLIN NEUROPHYSIOL 2011. [DOI: 10.1055/s-0031-1272685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Langer G, Bader B, Meoli L, Isensee J, Delbeck M, Noppinger PR, Otto C. A critical review of fundamental controversies in the field of GPR30 research. Steroids 2010; 75:603-10. [PMID: 20034504 DOI: 10.1016/j.steroids.2009.12.006] [Citation(s) in RCA: 125] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2009] [Revised: 11/25/2009] [Accepted: 12/12/2009] [Indexed: 01/01/2023]
Abstract
The female sex hormone estradiol plays an important role in reproduction, mammary gland development, bone turnover, metabolism, and cardiovascular function. The effects of estradiol are mediated by two classical nuclear receptors, estrogen receptor alpha (ERalpha) and estrogen receptor beta (ERbeta). In 2005, G-protein-coupled receptor 30 (GPR30) was claimed to act as a non-classical estrogen receptor that was also activated by the ERalpha and ERbeta antagonists tamoxifen and fulvestrant (ICI 182780). Despite many conflicting results regarding the potential role of GPR30 as an estrogen receptor, the official nomenclature was changed to GPER (G-protein-coupled estrogen receptor). This review revisits the inconsistencies that still exist in the literature and focuses on selected publications that basically address the following two questions: what is the evidence for and against the hypothesis that GPR30 acts as an estrogen receptor? What is the potential in vivo role of GPR30? Thus, in the first part we focus on conflicting results from in vitro studies analysing the subcellular localization of GPR30, its ability to bind (or not to bind) estradiol and to signal (or not to signal) in response to estradiol. In the second part, we discuss the strengths and limitations of four available GPR30 mouse models. We elucidate the potential impact of different targeting strategies on phenotypic diversity.
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Janati AB, Jalili B, Scheid R, Bader B. DEVELOPMENT OF MESIAL TEMPORAL LOBE EPILEPSY IN CHOREA-ACANTHOCYTOSIS. Neurology 2010; 74:1747; author reply 1747. [DOI: 10.1212/wnl.0b013e3181e02e49] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Bader B, Schäfer P. Skeletal morphogenesis and growth check lines in the Antarctic bryozoanMelicerita obliqua. J NAT HIST 2010. [DOI: 10.1080/00222930310001657685] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Hilal T, Puetter V, Otto C, Parczyk K, Bader B. A dual estrogen receptor TR-FRET assay for simultaneous measurement of steroid site binding and coactivator recruitment. ACTA ACUST UNITED AC 2010; 15:268-78. [PMID: 20150592 DOI: 10.1177/1087057109359196] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The human estrogen receptors (hER) are members of the nuclear hormone receptor (NHR) superfamily and represent important drug targets for the pharmaceutical industry. Initially, ligand binding assays were used to identify novel ligands using receptors purified from native tissues. With the advent of molecular cloning techniques, cell-based transactivation assays have been the gold standard for many years of drug discovery. With the elucidation of the structural mechanisms underlying the activation of NHRs, cell-free assays with purified receptors have become important tools to directly assess different binding sites (e.g., the hormone binding site or the cofactor binding site). The available cell-free assays have so far facilitated the study of one binding site at a time. With the introduction of Terbium (Tb(3+))-based time-resolved fluorescence energy transfer (TR-FRET), it has become possible to measure 2 different interactions within 1 test tube in parallel. The authors have applied this technology to develop a dual readout system for the simultaneous monitoring of steroid hormone site binding and cofactor peptide recruitment. They took advantage of a commercially available fluorescent tracer as an indicator for classical steroid site binding and designed a novel peptide derived from the peroxisome proliferator-activated receptor gamma coactivator-1a (PGC1a) as an indicator for functional agonistic behavior of a test compound. The established assay is able to differentiate between agonists, antagonists, partial agonists, and compounds binding to the cofactor recruitment site. The IC(50) values obtained for a number of reference compounds in the multiplexed assay are in concordance with published data. The simple 1-step mix-and-measure protocol gives excellent quality and robustness and can be miniaturized to 5-microL volume.
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Scheid R, Bader B, Ott DV, Merkenschlager A, Danek A. Development of mesial temporal lobe epilepsy in chorea-acanthocytosis. Neurology 2009; 73:1419-22. [PMID: 19858465 DOI: 10.1212/wnl.0b013e3181bd80d4] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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50
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Kassem G, Al Tabash N, Bader B, Mohe-eldin D. P416 Secondary ectopic omental conjoined twin pregnancy: case report and review of literature. Int J Gynaecol Obstet 2009. [DOI: 10.1016/s0020-7292(09)61908-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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