TY - JOUR A1 - Rasche, Leo A1 - Duell, Johannes A1 - Morgner, Charlotte A1 - Chatterjee, Manik A1 - Hensel, Frank A1 - Rosenwald, Andreas A1 - Einsele, Hermann A1 - Topp, Max S. A1 - Brändlein, Stephanie T1 - The Natural Human IgM Antibody PAT-SM6 Induces Apoptosis in Primary Human Multiple Myeloma Cells by Targeting Heat Shock Protein GRP78 JF - PLoS ONE N2 - In contrast to other haematological malignancies, targeted immunotherapy has not entered standard treatment regimens for de novo or relapsed multiple myeloma (MM) yet. While a number of IgG-formatted monoclonal antibodies are currently being evaluated in clinical trials in MM, our study aimed to investigate whether the fully human IgM monoclonal antibody PAT-SM6 that targets a tumour-specific variant of the heat shock protein GRP78 might be an attractive candidate for future immunotherapeutic approaches. We here show that GRP78 is stably and consistently expressed on the surface on tumour cells from patients with de novo, but also relapsed MM and that binding of PAT-SM6 to MM cells can specifically exert cytotoxic effects on malignant plasma cells, whereas non-malignant cells are not targeted. We demonstrate that the induction of apoptosis and, to a lesser extent, complement dependent cytotoxicity is the main mode of action of PAT-SM6, whereas antibody dependent cellular cytotoxicity does not appear to contribute to the cytotoxic properties of this antibody. Given the favourable safety profile of PAT-SM6 in monkeys, but also in a recent phase I trial in patients with malignant melanoma, our results form the basis for a planned phase I study in patients with relapsed MM. KW - cytotoxicity KW - apoptosis KW - immunohistochemistry techniques KW - enzyme-linked immunoassays KW - multiple myeloma KW - cell staining KW - cell binding KW - complement system Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-130125 VL - 8 IS - 5 ER - TY - JOUR A1 - Pachel, Christina A1 - Mathes, Denise A1 - Bayer, Barbara A1 - Dienesch, Charlotte A1 - Wangorsch, Gaby A1 - Heitzmann, Wolfram A1 - Lang, Isabell A1 - Ardehali, Hossein A1 - Ertl, Georg A1 - Dandekar, Thomas A1 - Wajant, Harald A1 - Frantz, Stefan T1 - Exogenous Administration of a Recombinant Variant of TWEAK Impairs Healing after Myocardial Infarction by Aggravation of Inflammation JF - PLoS ONE N2 - Background: Tumor necrosis factor-like weak inducer of apoptosis (TWEAK) and its receptor fibroblast growth factorinducible 14 (Fn14) are upregulated after myocardial infarction (MI) in both humans and mice. They modulate inflammation and the extracellular matrix, and could therefore be important for healing and remodeling after MI. However, the function of TWEAK after MI remains poorly defined. Methods and results: Following ligation of the left coronary artery, mice were injected twice per week with a recombinant human serum albumin conjugated variant of TWEAK (HSA-Flag-TWEAK), mimicking the activity of soluble TWEAK. Treatment with HSA-Flag-TWEAK resulted in significantly increased mortality in comparison to the placebo group due to myocardial rupture. Infarct size, extracellular matrix remodeling, and apoptosis rates were not different after MI. However, HSA-Flag-TWEAK treatment increased infiltration of proinflammatory cells into the myocardium. Accordingly, depletion of neutrophils prevented cardiac ruptures without modulating all-cause mortality. Conclusion: Treatment of mice with HSA-Flag-TWEAK induces myocardial healing defects after experimental MI. This is mediated by an exaggerated neutrophil infiltration into the myocardium. KW - apoptosis KW - myocardial infarction KW - neutrophils KW - cytokines KW - inflammation KW - myocardium KW - heart KW - extracellular matrix Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-129889 VL - 8 IS - 11 ER - TY - JOUR A1 - Huang, Bei A1 - Belharazem, Djeda A1 - Li, Li A1 - Kneitz, Susanne A1 - Schnabel, Philipp A. A1 - Rieker, Ralf J. A1 - Körner, Daniel A1 - Nix, Wilfried A1 - Schalke, Berthold A1 - Müller-Hermelink, Hans Konrad A1 - Ott, German A1 - Rosenwald, Andreas A1 - Ströbel, Philipp A1 - Marx, Alexander T1 - Anti-apoptotic signature in thymic squamous cell carcinomas – functional relevance of anti-apoptotic BIRC3 expression in the thymic carcinoma cell line 1889c JF - Frontiers in Oncology N2 - The molecular pathogenesis of thymomas and thymic arcinomas (TCs) is poorly understood and results of adjuvant therapy are unsatisfactory in case of metastatic disease and tumor recurrence. For these clinical settings, novel therapeutic strategies are urgently needed. Recently, limited sequencing efforts revealed that a broad spectrum of genes that play key roles in various common cancers are rarely affected in thymomas and TCs, suggesting that other oncogenic principles might be important.This made us re-analyze historic expression data obtained in a spectrumof thymomas and thymic squamous cell carcinomas (TSCCs) with a custom-made cDNA microarray. By cluster analysis, different anti-apoptotic signatures were detected in type B3 thymoma and TSCC, including overexpression of BIRC3 in TSCCs. This was confirmed by qRT-PCR in the original and an independent validation set of tumors. In contrast to several other cancer cell lines, the BIRC3-positive TSCC cell line, 1889c showed spontaneous apoptosis after BIRC3 knock-down. Targeting apoptosis genes is worth testing as therapeutic principle in TSCC. KW - gene expression KW - MTCH2 KW - targeted KW - myasthenia gravis KW - apoptosis KW - thymus KW - thymoma KW - thymic carcinoma Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-132214 VL - 3 IS - 316 ER - TY - JOUR A1 - Rukoyatkina, N. A1 - Mindukshev, I. A1 - Walter, U. A1 - Gambaryan, S. T1 - Dual role of the p38 \(MAPK/cPLA_2\) pathway in the regulation of platelet apoptosis induced by ABT-737 and strong platelet agonists JF - Cell Death & Disease N2 - p38 Mitogen-activated protein (MAP) kinase is involved in the apoptosis of nucleated cells. Although platelets are anucleated cells, apoptotic proteins have been shown to regulate platelet lifespan. However, the involvement of p38 MAP kinase in platelet apoptosis is not yet clearly defined. Therefore, we investigated the role of p38 MAP kinase in apoptosis induced by a mimetic of BH3-only proteins, ABT-737, and in apoptosis-like events induced by such strong platelet agonists as thrombin in combination with convulxin (Thr/Cvx), both of which result in p38 MAP kinase phosphorylation and activation. A p38 inhibitor (SB202190) inhibited the apoptotic events induced by ABT-737 but did not influence those induced by Thr/Cvx. The inhibitor also reduced the phosphorylation of cytosolic phospholipase \(A_2\) (cPLA2), an established p38 substrate, induced by ABT-737 or Thr/Cvx. ABT-737, but not Thr/Cvx, induced the caspase 3-dependent cleavage and inactivation of cPLA2. Thus, p38 MAPK promotes ABT-737-induced apoptosis by inhibiting the cPLA2/arachidonate pathway. We also show that arachidonic acid (AA) itself and in combination with Thr/Cvx or ABT-737 at low concentrations prevented apoptotic events, whereas at high concentrations it enhanced such events. Our data support the hypothesis that the p38 MAPK-triggered arachidonate pathway serves as a defense mechanism against apoptosis under physiological conditions. KW - cPLA2 KW - platelet KW - apoptosis KW - p38 MAP kinase Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-128783 VL - 4 IS - e931 ER - TY - JOUR A1 - El-Mesery, M. A1 - Trebing, J. A1 - Schafer, V. A1 - Weisenberger, D. A1 - Siegmund, D. A1 - Wajant, H. T1 - CD40-directed scFv-TRAIL fusion proteins induce CD40-restricted tumor cell death and activate dendritic cells JF - Cell Death & Disease N2 - Targeted cancer therapy concepts often aim at the induction of adjuvant antitumor immunity or stimulation of tumor cell apoptosis. There is further evidence that combined application of immune stimulating and tumor apoptosis-inducing compounds elicits a synergistic antitumor effect. Here, we describe the development and characterization of bifunctional fusion proteins consisting of a single-chain variable fragment (scFv) domain derived from the CD40-specific monoclonal antibody G28-5 that is fused to the N-terminus of stabilized trimeric soluble variants of the death ligand TNF-related apoptosis-inducing ligand (TRAIL). As shown before by us and others for other cell surface antigen-targeted scFv-TRAIL fusion proteins, scFv:G28-TRAIL displayed an enhanced capacity to induce apoptosis upon CD40 binding. Studies with scFv:G28 fusion proteins of TRAIL mutants that discriminate between the two TRAIL death receptors, TRAILR1 and TRAILR2, further revealed that the CD40 binding-dependent mode of apoptosis induction of scFv:G28-TRAIL is operable with each of the two TRAIL death receptors. Binding of scFv:G28-TRAIL fusion proteins to CD40 not only result in enhanced TRAIL death receptor signaling but also in activation of the targeted CD40 molecule. In accordance with the latter, the scFv:G28-TRAIL fusion proteins triggered strong CD40-mediated maturation of dendritic cells. The CD40-targeted TRAIL fusion proteins described in this study therefore represent a novel type of bifunctional fusion proteins that couple stimulation of antigen presenting cells and apoptosis induction. KW - dendritic cells KW - apoptosis KW - CD40 KW - TRAIL Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-128777 VL - 4 IS - e916 ER - TY - JOUR A1 - Schlereth, Katharina A1 - Heyl, Charlotte A1 - Krampitz, Anna-Maria A1 - Mernberger, Marco A1 - Finkernagel, Florian A1 - Scharfe, Maren A1 - Jarek, Michael A1 - Leich, Ellen A1 - Rosenwald, Andreas A1 - Stiewe, Thorsten T1 - Characterization of the p53 Cistrome - DNA Binding Cooperativity Dissects p53's Tumor Suppressor Functions JF - PLOS Genetics N2 - p53 protects us from cancer by transcriptionally regulating tumor suppressive programs designed to either prevent the development or clonal expansion of malignant cells. How p53 selects target genes in the genome in a context-and tissue-specific manner remains largely obscure. There is growing evidence that the ability of p53 to bind DNA in a cooperative manner prominently influences target gene selection with activation of the apoptosis program being completely dependent on DNA binding cooperativity. Here, we used ChIP-seq to comprehensively profile the cistrome of p53 mutants with reduced or increased cooperativity. The analysis highlighted a particular relevance of cooperativity for extending the p53 cistrome to non-canonical binding sequences characterized by deletions, spacer insertions and base mismatches. Furthermore, it revealed a striking functional separation of the cistrome on the basis of cooperativity; with low cooperativity genes being significantly enriched for cell cycle and high cooperativity genes for apoptotic functions. Importantly, expression of high but not low cooperativity genes was correlated with superior survival in breast cancer patients. Interestingly, in contrast to most p53-activated genes, p53-repressed genes did not commonly contain p53 binding elements. Nevertheless, both the degree of gene activation and repression were cooperativity-dependent, suggesting that p53-mediated gene repression is largely indirect and mediated by cooperativity-dependently transactivated gene products such as CDKN1A, E2F7 and non-coding RNAs. Since both activation of apoptosis genes with non-canonical response elements and repression of pro-survival genes are crucial for p53's apoptotic activity, the cistrome analysis comprehensively explains why p53-induced apoptosis, but not cell cycle arrest, strongly depends on the intermolecular cooperation of p53 molecules as a possible safeguard mechanism protecting from accidental cell killing. KW - cell-cycle arrest KW - gene expression KW - breast cancer KW - human genome KW - transcriptional repression KW - consensus DNA KW - in-vivo KW - apoptosis KW - network KW - damage Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-127579 SN - 1553-7404 VL - 9 IS - 8 ER - TY - JOUR A1 - Hohenauer, Tobias A1 - Berking, Carola A1 - Schmidt, Andreas A1 - Haferkamp, Sebastian A1 - Senft, Daniela A1 - Kammerbauer, Claudia A1 - Fraschka, Sabine A1 - Graf, Saskia Anna A1 - Irmler, Martin A1 - Beckers, Johannes A1 - Flaig, Michael A1 - Aigner, Achim A1 - Höbel, Sabrina A1 - Hoffmann, Franziska A1 - Hermeking, Heiko A1 - Rothenfusser, Simon A1 - Endres, Stefan A1 - Ruzicka, Thomas A1 - Besch, Robert T1 - The neural crest transcription factor Brn3a is expressed in melanoma and required for cell cycle progression and survival JF - EMBO Molecular Medicine N2 - Pigment cells and neuronal cells both are derived from the neural crest. Here, we describe the Pit-Oct-Unc (POU) domain transcription factor Brn3a, normally involved in neuronal development, to be frequently expressed in melanoma, but not in melanocytes and nevi. RNAi-mediated silencing of Brn3a strongly reduced the viability of melanoma cell lines and decreased tumour growth in vivo. In melanoma cell lines, inhibition of Brn3a caused DNA double-strand breaks as evidenced by Mre11/Rad50-containing nuclear foci. Activated DNA damage signalling caused stabilization of the tumour suppressor p53, which resulted in cell cycle arrest and apoptosis. When Brn3a was ectopically expressed in primary melanocytes and fibroblasts, anchorage-independent growth was increased. In tumourigenic melanocytes and fibroblasts, Brn3a accelerated tumour growth in vivo. Furthermore, Brn3a cooperated with proliferation pathways such as oncogenic BRAF, by reducing oncogene-induced senescence in non-malignant melanocytes. Together, these results identify Brn3a as a new factor in melanoma that is essential for melanoma cell survival and that promotes melanocytic transformation and tumourigenesis. KW - oncogene-induced senescence KW - BRN-3A KW - DNA KW - DNA damage KW - tumourigenesis KW - P53 KW - in-vitro KW - neural crest factors KW - family KW - apoptosis KW - melanoma KW - BRAF mutations KW - domain Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-122193 SN - 1757-4676 VL - 5 ER -