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ABSTRACT: Störungen in der Regulation des Zelltodes sind wichtige Ursachen für die Entstehung von Krebs. Das HMGB1-Protein löst eine
bislang nicht beschriebene Art des Zelltodes aus, die zukünftig auch zur Therapie maligner Tumoren genützt werden könnte.
Defects in the regulation of cell death contribute to the development of cancer. The HMGB1 protein induces a novel type of
cell death which could be employed in the therapy of malignant tumors in the future.
BioSpektrum 04/2012; 17(4):415-417.
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Tim Kees,
Jennifer Lohr,
Johannes Noack,
Rodrigo Mora, Georg Gdynia,
Grischa Tödt,
Aurélie Ernst,
Bernhard Radlwimmer,
Christine S Falk,
Christel Herold-Mende,
Anne Régnier-Vigouroux
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ABSTRACT: The role of microglia, the brain-resident macrophages, in glioma biology is still a matter of debate. Clinical observations and in vitro studies in the mouse model indicate that microglia and macrophages that infiltrate the brain tumor tissue in high numbers play a tumor-supportive role. Here, we provide evidence that human microglia isolated from brain tumors indeed support tumor cell growth, migration, and invasion. However, after stimulation with the Toll-like receptor 3 agonist poly (I:C), microglia secrete factors that exerted toxic and suppressive effects on different glioblastoma cell lines, as assessed in cytotoxicity, migration, and tumor cell spheroid invasion assays. Remarkably, these effects were tumor-specific because the microglial factors impaired neither growth nor viability of astrocytes and neurons. Culture supernatants of tumor cells inhibited the poly (I:C) induction of this microglial M1-like, oncotoxic profile. Microglia stimulation before coculture with tumor cells circumvented the tumor-mediated suppression, as demonstrated by the ability to kill and phagocytose glioma cells. Our results show, for the first time to our knowledge, that human microglia exert tumor-supporting functions that are overridden by tumor-suppressing activities gained after poly (I:C) stimulation.
Neuro-Oncology 01/2012; 14(1):64-78. · 5.72 Impact Factor
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ABSTRACT: The main cause of death from novel (swine origin) influenza A/H1N1 infection is acute respiratory distress syndrome. Most fatal cases are immunocompromised patients or patients with a severe underlying disease. Here, we report a fatal case of acute interstitial myocarditis associated with novel influenza A/H1N1 infection in an immunocompetent young woman. A previously healthy 18-year-old woman experienced malaise, diarrhea, and fever for several days prior to a sudden collapse at home. Autopsy revealed a predominantly lymphocytic myocarditis in the absence of a significant respiratory tract infection. Infection with novel (swine origin) influenza A/H1N1 was confirmed by PCR analysis of blood as well as myocardial tissue. Influenza-caused diarrhea with consecutive hypokalemia potentially contributed to the fatal outcome of the myocarditis, characterized by ventricular fibrillation. In conclusion, sudden death by myocarditis may be a rare complication of novel influenza A/H1N1 infection in otherwise healthy individuals, even in the absence of significant respiratory tract infection.
Archiv für Pathologische Anatomie und Physiologie und für Klinische Medicin 01/2011; 458(3):371-6. · 2.49 Impact Factor
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Georg Gdynia,
Martina Keith,
Jürgen Kopitz,
Marion Bergmann,
Anne Fassl,
Alexander N R Weber,
Julie George,
Tim Kees,
Hans-Walter Zentgraf,
Otmar D Wiestler,
Peter Schirmacher,
Wilfried Roth
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ABSTRACT: Cells dying by necrosis release the high-mobility group box 1 (HMGB1) protein, which has immunostimulatory effects. However, little is known about the direct actions of extracellular HMGB1 protein on cancer cells. Here, we show that recombinant human HMGB1 (rhHMGB1) exerts strong cytotoxic effects on malignant tumor cells. The rhHMGB1-induced cytotoxicity depends on the presence of mitochondria and leads to fast depletion of mitochondrial DNA, severe damage of the mitochondrial proteome by toxic malondialdehyde adducts, and formation of giant mitochondria. The formation of giant mitochondria is independent of direct nuclear signaling events, because giant mitochondria are also observed in cytoplasts lacking nuclei. Further, the reactive oxygen species scavenger N-acetylcysteine as well as c-Jun NH(2)-terminal kinase blockade inhibited the cytotoxic effect of rhHMGB1. Importantly, glioblastoma cells, but not normal astrocytes, were highly susceptible to rhHMGB1-induced cell death. Systemic treatment with rhHMGB1 results in significant growth inhibition of xenografted tumors in vivo. In summary, rhHMGB1 induces a distinct form of cell death in cancer cells, which differs from the known forms of apoptosis, autophagy, and senescence, possibly representing an important novel mechanism of specialized necrosis. Further, our findings suggest that rhHMGB1 may offer therapeutic applications in treatment of patients with malignant brain tumors.
Cancer Research 10/2010; 70(21):8558-68. · 7.86 Impact Factor
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Benjamin Goeppert,
Peter Schmezer,
Céline Dutruel,
Christopher Oakes,
Marcus Renner,
Marco Breinig,
Arne Warth,
Monika Nadja Vogel,
Michel Mittelbronn,
Arianeb Mehrabi, Georg Gdynia,
Roland Penzel,
Thomas Longerich,
Kai Breuhahn,
Odilia Popanda,
Christoph Plass,
Peter Schirmacher,
Michael André Kern
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ABSTRACT: The A kinase anchor protein 12 (AKAP12) is a central mediator of protein kinase A and protein kinase C signaling. Although AKAP12 has been described to act as a tumor suppressor and its expression is frequently down-regulated in several human malignancies, the underlying molecular mechanisms responsible for the AKAP12 reduction are poorly understood. We therefore analyzed the expression of AKAP12 and its genetic and epigenetic regulatory mechanisms in human hepatocarcinogenesis. Based on tissue microarray analyses (n = 388) and western immunoblotting, we observed a significant reduction of AKAP12 in cirrhotic liver (CL), premalignant lesions (DN), and hepatocellular carcinomas (HCCs) compared to histologically normal liver specimens (NL). Analyses of array comparative genomic hybridization data (aCGH) from human HCCs revealed chromosomal losses of AKAP12 in 36% of cases but suggested additional mechanisms underlying the observed reduction of AKAP12 expression in hepatocarcinogenesis. Quantitative methylation analysis by MassARRAY of NL, CL, DN, and HCC tissues, as well as of various tumorigenic and nontumorigenic liver cell lines revealed specific hypermethylation of the AKAP12α promoter but not of the AKAP12β promoter in HCC specimens and in HCC cell lines. Consequently, restoration experiments performed with 5-aza-2'deoxycytidine drastically increased AKAP12α mRNA levels in a HCC cell line (AKN1) paralleled by AKAP12α promoter demethylation. As hypermethylation is not observed in CL and DN, we investigated microRNA-mediated posttranscriptional regulation as an additional mechanism to explain reduced AKAP12 expression. We found that miR-183 and miR-186 are up-regulated in CL and DN and are able to target AKAP12. Conclusion: In addition to genetic alterations, epigenetic mechanisms are responsible for the reduction of the tumor suppressor gene AKAP12 in human hepatocarcinogenesis.
Hepatology 08/2010; 52(6):2023-33. · 11.66 Impact Factor
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Benito Campos,
Feng Wan,
Mohammad Farhadi,
Aurélie Ernst,
Felix Zeppernick,
Katrin E Tagscherer,
Rezvan Ahmadi,
Jennifer Lohr,
Christine Dictus, Georg Gdynia,
Stephanie E Combs,
Violaine Goidts,
Burkhard M Helmke,
Volker Eckstein,
Wilfried Roth,
Philipp Beckhove,
Peter Lichter,
Andreas Unterberg,
Bernhard Radlwimmer,
Christel Herold-Mende
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ABSTRACT: Stem-like tumor cells comprise a highly tumorigenic and therapy-resistant tumor subpopulation, which is believed to substantially influence tumor initiation and therapy resistance in glioma. Currently, therapeutic, drug-induced differentiation is considered as a promising approach to eradicate this tumor-driving cell population; retinoic acid is well known as a potent modulator of differentiation and proliferation in normal stem cells. In glioma, knowledge about the efficacy of retinoic acid-induced differentiation to target the stem-like tumor cell pool could have therapeutic implications.
Stem-like glioma cells (SLGC) were differentiated with all-trans retinoic acid-containing medium to study the effect of differentiation on angiogenesis, invasive growth, as well as radioresistance and chemoresistance of SLGCs. In vivo effects were studied using live microscopy in a cranial window model.
Our data suggest that in vitro differentiation of SLGCs induces therapy-sensitizing effects, impairs the secretion of angiogenic cytokines, and disrupts SLGCs motility. Further, ex vivo differentiation reduces tumorigenicity of SLGCs. Finally, we show that all-trans retinoic acid treatment alone can induce antitumor effects in vivo.
Altogether, these results highlight the potential of differentiation treatment to target the stem-like cell population in glioblastoma.
Clinical Cancer Research 05/2010; 16(10):2715-28. · 7.74 Impact Factor
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ABSTRACT: Approximately 15% of small intestinal adenocarcinomas show inactivation of DNA-mismatch repair (MMR) and display high-level microsatellite instability (MSI-H). MSI-H tumors progress as a result of mutations affecting coding microsatellites (coding microsatellite instability, cMSI) that may result in a functional inactivation of the encoded proteins and provide a selective growth advantage for the affected cell. To investigate the cMSI selection in small intestinal carcinogenesis 56 adenocarcinomas were tested for MSI. Eleven MSI-H carcinomas (19.6%) were identified and subjected to cMSI analysis in 24 potentially tumor relevant genes. Mutation frequencies were similar to those observed in colorectal cancer (CRC). Beside high frequencies of cMSI in TGFbetaR2, ACVR2, and AIM2 we detected MARCKS mutations in 10 out of 11 (91%) tumors with a 30% share of biallelic mutations. Since little is known about MARCKS expression in the intestine, we analyzed MARCKS protein expression in 31 carcinomas. In non-neoplastic mucosa, MARCKS was found to be expressed with a concentration gradient along the crypt-villus axis. In line with cMSI induced functional inactivation of MARCKS, 8 out of 11 MSI-H adenocarcinomas showed regional or complete loss of the protein. In microsatellite stable (MSS) small bowel adenocarcinoma, loss of MARCKS expression was seen in 2 out of 20 tumors (10%). In conclusion, we herein present a cMSI profile of MSI-H small intestinal adenocarcinomas identifying MARCKS as a frequent target of mutation. Loss of MARCKS protein expression suggests a significant role of MARCKS inactivation in the pathogenesis of small intestinal adenocarcinomas.
Molecular Carcinogenesis 10/2009; 49(2):175-82. · 3.16 Impact Factor
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ABSTRACT: Chemotherapy of non-Hodgkin's lymphoma is frequently hampered by drug resistance. The monoclonal antibody rituximab specifically targets the CD20 antigen and sensitizes B-cell lymphoma cells to standard anticancer drugs. In the present investigation, we analyzed, whether a combination of rituximab and artesunate may act in a complementary manner and eventually synergize in tumor cell killing. Artesunate is an anti-malarial drug, which also exerts profound activity towards cancer cells. While rituximab alone was minimally cytotoxic, rituximab increased cytotoxicity to artesunate in Ramos cells. Artesunate induced apoptosis, induced Fas/CD95 expression and the formation of reactive oxygen species (ROS) and resulted in a breakdown of mitochondrial membrane potential. This argues for the involvement of both receptor-driven extrinsic and mitochondrial intrinsic routes of apoptosis. Rituximab increased Fas/CD95 expression and ROS formation and decreased mitochondrial membrane potential ultimately leading to increased apoptosis induced by artesunate. The transcription factors YY1 and Sp1 are upstream regulators of apoptosis by controlling the expression of apoptosis-regulating genes. YY1 and Sp1 were down-regulated and Fas/CD95 was up-regulated by rituximab and artesunate indicating that artesunate activated the Fas/CD95 pathway and that rituximab increased the susceptibility of tumor cells to artesunate-induced apoptosis. Furthermore, rituximab affected the expression of antioxidant genes. The antibody decreased artesunate-induced up-regulation of catalase expression and increased artesunate-induced down-regulation of glutathione S-transferase-phi expression. Manganese-dependent superoxide dismutase expression was not changed by artesunate. Antioxidant proteins may help to detoxify artesunate-induced ROS. Rituximab reversed the artesunate-induced expression changes of antioxidant genes and, hence, reduced the detoxification capacity of Ramos cells. The effects of rituximab on antioxidant genes represent a novel mechanism of rituximab for chemosensitization.
International Journal of Oncology 08/2009; 35(1):149-58. · 2.40 Impact Factor
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Stephan Singer,
Mona Malz,
Esther Herpel,
Arne Warth,
Michaela Bissinger,
Martina Keith,
Thomas Muley,
Michael Meister,
Hans Hoffmann,
Roland Penzel, Georg Gdynia,
Volker Ehemann,
Philipp Albert Schnabel,
Ruprecht Kuner,
Peter Huber,
Peter Schirmacher,
Kai Breuhahn
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ABSTRACT: Dynamic instability of the microtubule network modulates processes such as cell division and motility, as well as cellular morphology. Overexpression of the microtubule-destabilizing phosphoprotein stathmin is frequent in human malignancies and represents a promising therapeutic target. Although stathmin inhibition gives rise to antineoplastic effects, additional and functionally redundant microtubule-interacting proteins may attenuate the efficiency of this therapeutic approach. We have systematically analyzed the expression and potential protumorigenic effects of stathmin family members in human non-small cell lung cancer (NSCLC). Both stathmin and stathmin-like 3 (SCLIP) were overexpressed in adenocarcinoma as well as squamous cell carcinoma (SCC) tissues and induced tumor cell proliferation, migration, and matrix invasion in respective cell lines. Accordingly, reduced stathmin and SCLIP levels affected cell morphology and were associated with a less malignant phenotype. Combined inhibition of both factors caused additive effects on tumor cell motility, indicating partial functional redundancy. Because stathmin and SCLIP expression significantly correlated in NSCLC tissues, we searched for common upstream regulators and identified the far upstream sequence element-binding protein-1 (FBP-1) as a pivotal inducer of several stathmin family members. Our results indicate that the coordinated overexpression of microtubule-destabilizing factors by FBP-1 is a critical step to facilitate microtubule dynamics and subsequently increases proliferation and motility of tumor cells.
Cancer Research 04/2009; 69(6):2234-43. · 7.86 Impact Factor
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Kerstin Grund,
Rezvan Ahmadi,
Fortunata Jung,
Verena Funke, Georg Gdynia,
Axel Benner,
Jaromir Sykora,
Henning Walczak,
Stefan Joos,
Jörg Felsberg,
Guido Reifenberger,
Otmar D Wiestler,
Christel Herold-Mende,
Wilfried Roth
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ABSTRACT: Resistance to apoptosis is one reason for the poor response of malignant brain tumors to therapy. The PPARgamma-modulating drug Troglitazone downregulates the anti-apoptotic FLIP protein and sensitizes glioblastoma cells to apoptosis induced by the death ligand TRAIL. To investigate the molecular basis of an experimental combination therapy for malignant gliomas with TRAIL and Troglitazone, we investigated the Troglitazone-induced signaling cascades and the expression of TRAIL receptors and FLIP in malignant gliomas. Troglitazone downregulated the FLIP protein through accelerated ubiquitin/proteasome-dependent degradation, which might be mediated by a Troglitazone-induced increase in reactive oxygen species. Moreover, Troglitazone induced the phosphorylation of the MAP kinase ERK1/2 as well as of the BAD protein. Inhibition of either PPARgamma or MEK1/2 blocked the Troglitazone-mediated phosphorylation of BAD and further increased the synergistic induction of glioma cell death by TRAIL and Troglitazone. Immunohistochemical analysis demonstrated that FLIP and TRAIL-R2 were significantly higher expressed in anaplastic (WHO grade III) than in diffuse (WHO grade II) gliomas. High FLIP and low TRAIL-R2 expression levels were associated with a poor prognosis of patients. Our findings warrant a further pre-clinical evaluation of an experimental anti-glioma therapy with TRAIL and Troglitazone, potentially in conjunction with a MAP kinase inhibitor.
Cancer biology & therapy 01/2009; 7(12):1982-90. · 2.64 Impact Factor
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B Funke,
F Autschbach,
S Kim,
F Lasitschka,
U Strauch,
G Rogler, G Gdynia,
L Li,
N Gretz,
S Macher-Goeppinger,
B Sido,
P Schirmacher,
S C Meuer,
W Roth
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ABSTRACT: Both epithelial barrier dysfunction and apoptosis resistance of immune cells contribute to the pathogenesis of Crohn's disease. The soluble decoy receptor 3 (DcR3) acts in an anti-apoptotic manner by neutralising the death ligand CD95L. Here, we investigated the possible involvement of DcR3 in Crohn's disease.
The epithelial fraction of human small intestinal mucosa samples was obtained by laser microdissection. Expression of DcR3 was examined by global gene expression profiling, quantitative reverse transcription polymerase chain reaction, immunoblot analysis, and immunohistochemistry. DcR3 concentrations in the serum of patients with Crohn's disease were measured by enzyme-linked immunosorbent assay. Apoptosis assays were performed to study the effects of DcR3 in intestinal epithelial cells and lamina propria T cells.
DcR3 is over-expressed in the epithelial layer of ileum specimens in patients with Crohn's disease, both at actively inflamed and non-active sites. DcR3 serum levels are significantly elevated in patients with active and non-active Crohn's disease as compared to healthy controls. The expression of DcR3 in intestinal epithelial cells is induced by tumour necrosis factor alpha. Increased DcR3 expression is associated with activation of nuclear factor kappa B (NF-kappaB) and results in protection of intestinal epithelial cells and lamina propria T cells from CD95L-induced apoptosis.
DcR3 may promote inflammation in Crohn's disease by inhibiting CD95L-induced apoptosis of epithelial and immune cells as well as by inducing NF-kappaB activation.
Gut 12/2008; 58(4):483-91. · 10.11 Impact Factor
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ABSTRACT: The HIPPI (HIP-1 protein interactor) protein is a multifunctional protein that is involved in the regulation of apoptosis. The interaction partners of HIPPI include HIP-1 (Huntingtin-interacting protein-1), Apoptin, Homer1c, Rybp/DEDAF, and BAR (bifunctional apoptosis regulator). In search for other binding partners of HIPPI, we performed a yeast two hybrid screen and identified BLOC1S2 (Biogenesis of lysosome-related organelles complex-1 subunit 2) as a novel HIPPI-interacting protein. In co-immunoprecipitation assays, BLOC1S2 specifically associates with HIPPI, but not with HIP-1. To study the expression of BLOC1S2 on the protein level, we generated a mouse monoclonal antibody specific for BLOC1S2 and a multiple tissue array comprising 70 normal and cancer tissue samples of diverse origin. BLOC1S2 protein is widely expressed in normal tissue as well as in malignant tumors with a tendency towards lower expression levels in certain subtypes of tumors. On the subcellular level, BLOC1S2 is expressed in an organellar-like pattern and co-localizes with mitochondria. Over-expression of BLOC1S2 in the presence or absence of HIPPI does not induce apoptosis. However, BLOC1S2 and HIPPI sensitize NCH89 glioblastoma cells to the pro-apoptotic actions of staurosporine and the death ligand TRAIL by enhancing caspase activation, cytochrome c release, and disruption of the mitochondrial membrane potential. Given its interaction with HIPPI and its pro-apoptotic activity, BLOC1S2 might play an important functional role in cancer and neurodegenerative diseases.
Apoptosis 04/2008; 13(3):437-47. · 4.07 Impact Factor
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Georg Gdynia,
Kerstin Grund,
Anika Eckert,
Barbara C Böck,
Benjamin Funke,
Stephan Macher-Goeppinger,
Sebastian Sieber,
Christel Herold-Mende,
Benedict Wiestler,
Otmar D Wiestler,
Wilfried Roth
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ABSTRACT: Glioblastomas, the most malignant of all brain tumors, are characterized by cellular resistance to apoptosis and a highly invasive growth pattern. These factors contribute to the poor response of glioblastomas to radiochemotherapy and prevent their complete neurosurgical resection. However, the driving force behind the distinct motility of glioma cells is only partly understood. Here, we report that in the absence of cellular stress and proapoptotic stimuli, human glioblastoma cells exhibit a constitutive activation of caspases in vivo and in vitro. The inhibition of caspases by various peptide inhibitors decreases the migration of cells in scrape motility assays and the invasiveness of cells in spheroid assays. Similarly, specific small interfering RNA- or antisense-mediated down-regulation of caspase-3 and caspase-8 results in an inhibition of the migratory potential of glioma cells. The constitutive caspase-dependent motility of glioblastoma cells is independent of CD95 activation and it is not mediated by mitogen-activated protein/extracellular signal-regulated kinase kinase signaling. The basal caspase activity is accompanied by a constant cleavage of the motility-associated gelsolin protein, which may contribute to the caspase-mediated promotion of migration and invasiveness in glioblastoma cells. Our results suggest that the administration of low doses of caspase inhibitors that block glioma cell motility without affecting the execution of apoptotic cell death may be exploited as a novel strategy for the treatment of glioblastomas.
Molecular Cancer Research 01/2008; 5(12):1232-40. · 4.29 Impact Factor
