@phdthesis{Otto2003, author = {Otto, Christoph}, title = {Strategien zur antigenspezifischen Immunmodulation bei experimenteller Organtransplantation}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-10654}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2003}, abstract = {Die Transplantation ist die einzige effektive Therapie f{\"u}r irreversibel gesch{\"a}digte Organe. Um jedoch das Transplantat vor der Zerst{\"o}rung zu sch{\"u}tzen, wird die Abwehrfunktion des Immunsystems gezielt geschw{\"a}cht. Diese notwendige dauerhafte Schw{\"a}chung mit so genannten Immunsuppressiva haben jedoch in ihrer Langzeitanwendung erhebliche Nebenwirkungen f{\"u}r die Patienten. Sie sind einer gr{\"o}ßeren Gefahr als die Normalbev{\"o}lkerung ausgesetzt, an schwerwiegenden Infektionen und Tumore zu erkranken. Zwei antigenspezifische Strategien als Grundlage f{\"u}r zuk{\"u}nftige therapeutische Konzepte, die nicht die Immunabwehr behindern, werden unter dem Begriff "ideale Therapie" erl{\"a}utert.}, language = {de} } @article{GrimmLazariotouKircheretal.2010, author = {Grimm, Martin and Lazariotou, Maria and Kircher, Stefan and Stuermer, Luisa and Reiber, Christoph and Hoefelmayr, Andreas and Gattenloehner, Stefan and Otto, Christoph and Germer, Christoph T. and von Rahden, Burkhard H. A.}, title = {MMP-1 is a (pre-)invasive factor in Barrett-associated esophageal adenocarcinomas and is associated with positive lymph node status}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-68293}, year = {2010}, abstract = {Background: Esophageal adenocarcinomas (EACs) arise due to gastroesophageal reflux, with Barrett's esophagus (BE) regarded as precancerous lesion. Matrix metalloproteinases (MMPs) might play a role during the multistep carcinogenetic process. Methods: Expression of MMP-1 and -13 was analyzed in esophageal cancer (n = 41 EAC with BE, n = 19 EAC without BE, and n = 10 esophageal squamous-cell carcinomas, ESCC), furthermore in BE without intraepithelial neoplasia (IN) (n = 18), and the cell line OE-33. MMP-1 was co-labelled with Ki-67 (proliferation), Cdx-2 (marker for intestinal metaplasia, BE) and analyzed on mRNA level. MMP-1 staining results were correlated with clinicopatholocical parameters. Results: On protein level, MMP-1 expression was found in 39 of 41 (95\%) EAC with BE, in 19 of 19 (100\%) EAC without BE, in 6 of 10 (60\%) ESCC, and in 10 of 18 (56\%) BE without IN. No expression of MMP-13 was found in these specimens. Quantification showed 48\% MMP-1 positive cells in EAC with BE, compared to 35\% in adjacent BE (p < 0.05), 44\% in EAC without BE, 32\% in ESCC, and 4\% in BE without IN. Immunofluorescence double staining experiments revealed increased MMP-1 expressing in proliferating cells (MMP-1+/Ki-67+) (r = 0.943 for BE and r = 0.811 for EAC). On mRNA-level, expression of MMP-1 was significantly higher in EAC compared to BE (p = 0.01) and confirmed immunohistochemical staining results. High MMP-1 levels were associated with lymph node metastases but not with poorer survival (p = 0.307). Conclusions: Our findings suggest that MMP-1 plays a role as preinvasive factor in BE-associated EAC. Expression of MMP-1 in proliferating BE and EAC cells suggest malignant proliferation following the clonal expansion model.}, subject = {Medizin}, language = {en} } @article{vonRahdenKircherLazariotouetal.2011, author = {von Rahden, Burkhard H. A. and Kircher, Stefan and Lazariotou, Maria and Reiber, Christoph and Stuermer, Luisa and Otto, Christoph and Germer, Christoph T. and Grimm, Martin}, title = {LgR5 expression and cancer stem cell hypothesis: clue to define the true origin of esophageal adenocarcinomas with and without Barrett's Esophagus?}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-68810}, year = {2011}, abstract = {Background: Investigation of the expression of an intestinal stem cell marker in esophageal adenocarcinomas (EAC) with and without Barrett's Esophagus (BE), with respect to a cancer stem cell (CSC) hypothesis. Materials and methods: Expression of a putative intestinal stem cell marker LgR5 was analyzed in esophageal cancer specimen (n = 70: 41 EAC with BE, 19 EAC without BE, and n = 10 esophageal squamous-cell carcinomas, ESCC) and in the adenocarcinoma cell line OE-33. Ki-67 and Cdx-2 were co-labelled with LgR5 in double staining experiments. Immunhistochemical expression results were confirmed by RT-PCR and correlated with tumor stage and five-year survival rates. Results: LgR5was found expressed in 35 of 41 (85\%) EAC with BE and in 16 of 19 (81\%) EAC without BE. By contrast, LgR5 was not found to be expressed in ESCC. Quantification of immunolabeling showed 15\% LgR5+ cells in EAC with BE, 32\% LgR5+ cells in adjacent BE and 13\% in EAC without BE. Immunofluorescence double staining experiments with LgR5 and Ki-67 revealed a subpopulation (~5\%) of proliferating LgR+/Ki-67+ cells. On mRNAlevel, expression of LgR5 was higher in BE in comparison to EAC (p = 0.0159). High levels of LgR5 expression in BE associated EAC were associated with poorer survival in univariate analysis. Conclusion: The stem cell marker LgR5 is expressed in EAC, irrespective of association with BE, and appears to have negative impact on survival. The subset of proliferating LgR5+ cells (<5\%) might resemble rapidly cycling CSCs, which needs to be substantiated in further investigations.}, subject = {Medizin}, language = {en} } @article{vonRahdenKircherLazariotouetal.2011, author = {von Rahden, Burkhard H.A. and Kircher, Stefan and Lazariotou, Maria and Reiber, Christoph and Stuermer, Luisa and Otto, Christoph and Germer, Christoph T. and Grimm, Martin}, title = {LgR5 expression and cancer stem cell hypothesis: clue to define the true origin of esophageal adenocarcinomas with and without Barrett's Esophagus?}, series = {Journal of Experimental \& Clinical Cancer Research}, volume = {30}, journal = {Journal of Experimental \& Clinical Cancer Research}, number = {23}, doi = {10.1186/1756-9966-30-23}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-137783}, year = {2011}, abstract = {Background Investigation of the expression of an intestinal stem cell marker in esophageal adenocarcinomas (EAC) with and without Barrett's Esophagus (BE), with respect to a cancer stem cell (CSC) hypothesis. Materials and methods Expression of a putative intestinal stem cell marker LgR5 was analyzed in esophageal cancer specimen (n = 70: 41 EAC with BE, 19 EAC without BE, and n = 10 esophageal squamous-cell carcinomas, ESCC) and in the adenocarcinoma cell line OE-33. Ki-67 and Cdx-2 were co-labelled with LgR5 in double staining experiments. Immunhistochemical expression results were confirmed by RT-PCR and correlated with tumor stage and five-year survival rates. Results LgR5was found expressed in 35 of 41 (85\%) EAC with BE and in 16 of 19 (81\%) EAC without BE. By contrast, LgR5 was not found to be expressed in ESCC. Quantification of immunolabeling showed 15\% LgR5+ cells in EAC with BE, 32\% LgR5+ cells in adjacent BE and 13\% in EAC without BE. Immunofluorescence double staining experiments with LgR5 and Ki-67 revealed a subpopulation (~5\%) of proliferating LgR+/Ki-67+ cells. On mRNA-level, expression of LgR5 was higher in BE in comparison to EAC (p = 0.0159). High levels of LgR5 expression in BE associated EAC were associated with poorer survival in univariate analysis. Conclusion The stem cell marker LgR5 is expressed in EAC, irrespective of association with BE, and appears to have negative impact on survival. The subset of proliferating LgR5+ cells (<5\%) might resemble rapidly cycling CSCs, which needs to be substantiated in further investigations.}, language = {en} } @article{KlingelhoefferKaemmererKoospaletal.2012, author = {Klingelhoeffer, Chr{\´i}stoph and K{\"a}mmerer, Ulrike and Koospal, Monika and M{\"u}hling, Bettina and Schneider, Manuela and Kapp, Michaela and K{\"u}bler, Alexander, and Germer, Christoph-Thomas and Otto, Christoph}, title = {Natural resistance to ascorbic acid induced oxidative stress is mainly mediated by catalase activity in human cancer cells and catalase-silencing sensitizes to oxidative stress}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-75142}, year = {2012}, abstract = {Background: Ascorbic acid demonstrates a cytotoxic effect by generating hydrogen peroxide, a reactive oxygen species (ROS) involved in oxidative cell stress. A panel of eleven human cancer cell lines, glioblastoma and carcinoma, were exposed to serial dilutions of ascorbic acid (5-100 mmol/L). The purpose of this study was to analyse the impact of catalase, an important hydrogen peroxide-detoxifying enzyme, on the resistance of cancer cells to ascorbic acid mediated oxidative stress. Methods: Effective concentration (EC50) values, which indicate the concentration of ascorbic acid that reduced the number of viable cells by 50\%, were detected with the crystal violet assay. The level of intracellular catalase protein and enzyme activity was determined. Expression of catalase was silenced by catalase-specific short hairpin RNA (sh-RNA) in BT-20 breast carcinoma cells. Oxidative cell stress induced apoptosis was measured by a caspase luminescent assay. Results: The tested human cancer cell lines demonstrated obvious differences in their resistance to ascorbic acid mediated oxidative cell stress. Forty-five percent of the cell lines had an EC50>20 mmol/L and fifty-five percent had an EC50<20 mmol/L. With an EC50 of 2.6-5.5 mmol/L, glioblastoma cells were the most susceptible cancer cell lines analysed in this study. A correlation between catalase activity and the susceptibility to ascorbic acid was observed. To study the possible protective role of catalase on the resistance of cancer cells to oxidative cell stress, the expression of catalase in the breast carcinoma cell line BT-20, which cells were highly resistant to the exposure to ascorbic acid (EC50: 94,9 mmol/L), was silenced with specific sh-RNA. The effect was that catalase-silenced BT-20 cells (BT-20 KD-CAT) became more susceptible to high concentrations of ascorbic acid (50 and 100 mmol/L). Conclusions: Fifty-five percent of the human cancer cell lines tested were unable to protect themselves against oxidative stress mediated by ascorbic acid induced hydrogen peroxide production. The antioxidative enzyme catalase is important to protect cancer cells against cytotoxic hydrogen peroxide. Silenced catalase expression increased the susceptibility of the formerly resistant cancer cell line BT-20 to oxidative stress.}, subject = {Medizin}, language = {en} } @article{WiegeringPfannUtheetal.2013, author = {Wiegering, Armin and Pfann, Christina and Uthe, Friedrich Wilhelm and Otto, Christoph and Rycak, Lukas and M{\"a}der, Uwe and Gasser, Martin and Waaga-Gasser, Anna-Maria and Eilers, Martin and Germer, Christoph-Thomas}, title = {CIP2A Influences Survival in Colon Cancer and Is Critical for Maintaining Myc Expression}, series = {PLoS ONE}, journal = {PLoS ONE}, doi = {10.1371/journal.pone.0075292}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-97252}, year = {2013}, abstract = {The cancerous inhibitor of protein phosphatase 2A (CIP2A) is an oncogenic factor that stabilises the c-Myc protein. CIP2A is overexpressed in several tumours, and expression levels are an independent marker for long-term outcome. To determine whether CIP2A expression is elevated in colon cancer and whether it might serve as a prognostic marker for survival, we analysed CIP2A mRNA expression by real-time PCR in 104 colon cancer samples. CIP2A mRNA was overexpressed in colon cancer samples and CIP2A expression levels correlated significantly with tumour stage. We found that CIP2A serves as an independent prognostic marker for disease-free and overall survival. Further, we investigated CIP2A-dependent effects on levels of c-Myc, Akt and on cell proliferation in three colon cancer cell lines by silencing CIP2A using small interfering (si) and short hairpin (sh) RNAs. Depletion of CIP2A substantially inhibited growth of colon cell lines and reduced c-Myc levels without affecting expression or function of the upstream regulatory kinase, Akt. Expression of CIP2A was found to be dependent on MAPK activity, linking elevated c-Myc expression to deregulated signal transduction in colon cancer.}, language = {en} } @article{WiegeringKorbThalheimeretal.2014, author = {Wiegering, Armin and Korb, Doreen and Thalheimer, Andreas and K{\"a}mmerer, Ulrike and Allmanritter, Jan and Matthes, Niels and Linnebacher, Michael and Schlegel, Nicolas and Klein, Ingo and Erg{\"u}n, S{\"u}leyman and Germer, Christoph-Thomas and Otto, Christoph}, title = {E7080 (Lenvatinib), a Multi-Targeted Tyrosine Kinase Inhibitor, Demonstrates Antitumor Activities Against Colorectal Cancer Xenografts}, doi = {10.1016/j.neo.2014.09.008}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-111165}, year = {2014}, abstract = {Clinical prognosis of metastasized colorectal carcinoma (CRC) is still not at desired levels and novel drugs are needed. Here, we focused on the multi-tyrosine kinase inhibitor E7080 (Lenvatinib) and assessed its therapeutic efficacy against human CRC cell lines in vitro and human CRC xenografts in vivo. The effect of E7080 on cell viability was examined on 10 humanCRCcell lines and humanendothelial cells (HUVEC). The inhibitory effect of E7080 on VEGF-induced angiogenesis was studied in an ex vivo mouse aortic ring angiogenesis assay. In addition, the efficacy of E7080 against xenografts derived fromCRC cell lines and CRC patient resection specimenswithmutated KRASwas investigated in vivo. Arelatively low cytotoxic effect of E7080 on CRC cell viabilitywas observed in vitro. Endothelial cells (HUVEC)weremore susceptible to the incubation with E7080. This is in line with the observation that E7080 demonstrated an anti-angiogenic effect in a three-dimensional ex vivo mouse aortic ring angiogenesis assay. E7080 effectively disrupted CRC cell-mediated VEGF-stimulated growth of HUVEC in vitro. Daily in vivo treatment with E7080 (5 mg/kg) significantly delayed the growth of KRAS mutated CRC xenografts with decreased density of tumor-associated vessel formations and without tumor regression. This observation is in line with results that E7080 did not significantly reduce the number of Ki67-positive cells in CRC xenografts. The results suggest antiangiogenic activity of E7080 at a dosage thatwas well tolerated by nudemice. E7080 may provide therapeutic benefits in the treatment of CRC with mutated KRAS.}, language = {en} } @article{PeterBultinckMyantetal.2014, author = {Peter, Stefanie and Bultinck, Jennyfer and Myant, Kevin and Jaenicke, Laura A. and Walz, Susanne and M{\"u}ller, Judith and Gmachl, Michael and Treu, Matthias and Boehmelt, Guido and Ade, Casten P. and Schmitz, Werner and Wiegering, Armin and Otto, Christoph and Popov, Nikita and Sansom, Owen and Kraut, Norbert and Eilers, Martin}, title = {H Tumor cell-specific inhibition of MYC function using small molecule inhibitors of the HUWE1 ubiquitin ligase}, series = {EMBO Molecular Medicine}, volume = {6}, journal = {EMBO Molecular Medicine}, number = {12}, issn = {1757-4684}, doi = {10.15252/emmm.201403927}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-118132}, pages = {1525-41}, year = {2014}, abstract = {Deregulated expression of MYC is a driver of colorectal carcinogenesis, necessitating novel strategies to inhibit MYC function. The ubiquitin ligase HUWE1 (HECTH9, ARF-BP1, MULE) associates with both MYC and the MYC-associated protein MIZ1. We show here that HUWE1 is required for growth of colorectal cancer cells in culture and in orthotopic xenograft models. Using high-throughput screening, we identify small molecule inhibitors of HUWE1, which inhibit MYC-dependent transactivation in colorectal cancer cells, but not in stem and normal colon epithelial cells. Inhibition of HUWE1 stabilizes MIZ1. MIZ1 globally accumulates on MYC target genes and contributes to repression of MYC-activated target genes upon HUWE1 inhibition. Our data show that transcriptional activation by MYC in colon cancer cells requires the continuous degradation of MIZ1 and identify a novel principle that allows for inhibition of MYC function in tumor cells.}, language = {en} } @article{WiedmannHeuschmannHillmannetal.2014, author = {Wiedmann, Silke and Heuschmann, Peter U. and Hillmann, Steffi and Busse, Otto and Wiethoelter, Horst and Walter, Georg M. and Seidel, Guenter and Misselwitz, Bjoern and Janssen, Alfred and Berger, Klaus and Burmeister, Christoph and Matthias, Christine and Kolominsky-Rabas, Peter and Hermanek, Peter}, title = {The Quality of Acute Stroke Care-an Analysis of Evidence-Based Indicators in 260 000 Patients}, series = {Deutsches {\"A}rzteblatt International}, volume = {111}, journal = {Deutsches {\"A}rzteblatt International}, number = {45}, issn = {1866-0452}, doi = {10.3238/arztebl.2014.0759}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-114747}, pages = {759-765}, year = {2014}, abstract = {Background: Stroke patients should be cared for in accordance with evidence-based guidelines. The extent of implementation of guidelines for the acute care of stroke patients in Germany has been unclear to date. Methods: The regional quality assurance projects that cooperate in the framework of the German Stroke Registers Study Group (Arbeitsgemeinschaft Deutscher Schlaganfall-Register, ADSR) collected data on the care of stroke patients in 627 hospitals in 2012. The quality of the acute hospital care of patients with stroke or transient ischemic attack (TIA) was assessed on the basis of 15 standardized, evidence-based quality indicators and compared across the nine participating regional quality assurance projects. Results: Data were obtained on more than 260 000 patients nationwide. Intravenous thrombolysis was performed in 59.7\% of eligible ischemic stroke patients patients (range among participating projects, 49.7-63.6\%). Dysphagia screening was documented in 86.2\% (range, 74.8-93.1\%). For the following indicators, the defined targets were not reached for all of Germany: antiaggregation within 48 hours, 93.4\% (range, 86.6-96.4\%); anticoagulation for atrial fibrillation, 77.6\% (range, 72.4-80.1\%); standardized dysphagia screening, 86.2\% (range, 74.8-93.1\%); oral and written information of the patients or their relatives, 86.1\% (range, 75.4-91.5\%). The rate of patients examined or treated by a speech therapist was in the target range. Conclusion: The defined targets were reached for most of the quality indicators. Some indicators, however, varied widely across regional quality assurance projects. This implies that the standardization of care for stroke patients in Germany has not yet been fully achieved.}, language = {en} } @article{JurowichOttoRikkalaetal.2015, author = {Jurowich, Christian Ferdinand and Otto, Christoph and Rikkala, Prashanth Reddy and Wagner, Nicole and Vrhovac, Ivana and Sabolić, Ivan and Germer, Christoph-Thomas and Koepsell, Hermann}, title = {Ileal interposition in rats with experimental type 2 like diabetes improves glycemic control independently of glucose absorption}, series = {Journal of Diabetes Research}, volume = {2015}, journal = {Journal of Diabetes Research}, number = {490365}, doi = {10.1155/2015/490365}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-149166}, year = {2015}, abstract = {Bariatric operations in obese patients with type 2 diabetes often improve diabetes before weight loss is observed. In patients mainly Roux-en-Y-gastric bypass with partial stomach resection is performed. Duodenojejunal bypass (DJB) and ileal interposition (IIP) are employed in animal experiments. Due to increased glucose exposition of L-cells located in distal ileum, all bariatric surgery procedures lead to higher secretion of antidiabetic glucagon like peptide-1 (GLP-1) after glucose gavage. After DJB also downregulation of Na\(^{+}\)-D-glucose cotransporter SGLT1 was observed. This suggested a direct contribution of decreased glucose absorption to the antidiabetic effect of bariatric surgery. To investigate whether glucose absorption is also decreased after IIP, we induced diabetes with decreased glucose tolerance and insulin sensitivity in male rats and investigated effects of IIP on diabetes and SGLT1. After IIP, we observed weight-independent improvement of glucose tolerance, increased insulin sensitivity, and increased plasma GLP-1 after glucose gavage. The interposed ileum was increased in diameter and showed increased length of villi, hyperplasia of the epithelial layer, and increased number of L-cells. The amount of SGLT1-mediated glucose uptake in interposed ileum was increased 2-fold reaching the same level as in jejunum. Thus, improvement of glycemic control by bariatric surgery does not require decreased glucose absorption.}, language = {en} }