@article{MoenchGrimmigKannenetal.2016, author = {Moench, Romana and Grimmig, Tanja and Kannen, Vinicius and Tripathi, Sudipta and Faber, Marc and Moll, Eva-Maria and Chandraker, Anil and Lissner, Reinhard and Germer, Christoph-Thomas and Waaga-Gasser, Ana Maria and Gasser, Martin}, title = {Exclusive inhibition of PI3K/Akt/mTOR signaling is not sufficient to prevent PDGF-mediated effects on glycolysis and proliferation in colorectal cancer}, series = {Oncotarget}, volume = {7}, journal = {Oncotarget}, number = {42}, doi = {10.18632/oncotarget.11899}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-176910}, pages = {68749-68767}, year = {2016}, abstract = {Platelet-derived growth factor (PDGF) and signaling via its receptors plays a crucial role in tumor cell proliferation and thus may represent an attractive target besides VEGF/EGFR-based antibody therapies. In this study we analyzed the influence of PDGF in colorectal cancer. PDGF was expressed intensively in early and even more intensively in late stage primary CRCs. Like VEGF, PDGF enhanced human colon cancer proliferation, and increased oxidative glycolytic activity, and activated HIF1α and c-Myc in vitro. PDGF activated the PI3K/Akt/mTOR pathway while leaving MAPK signaling untouched. Further dissection showed that inhibition of Akt strongly impeded cancer cell growth while inhibition of PI3K did not. MAPK analysis suggested an inhibitory crosstalk between both pathways, thus explaining the different effects of the Akt and PI3K inhibitors on cancer cell proliferation. PDGF stimulates colon cancer cell proliferation, and prevents inhibitor induced apoptosis, resulting in tumor growth. Therefore inhibition of PDGF signaling seems to be a promising target in colorectal cancer therapy. However, due to the multifaceted nature of the intracellular PDGF signaling, careful intervention strategies are needed when looking into specific signaling pathways like PI3K/Akt/mTOR and MAPK.}, language = {en} } @article{KimGrimmigGrimmetal.2013, author = {Kim, Mia and Grimmig, Tanja and Grimm, Martin and Lazariotou, Maria and Meier, Eva and Rosenwald, Andreas and Tsaur, Igor and Blaheta, Roman and Heemann, Uwe and Germer, Christoph-Thomas and Waaga-Gasser, Ana Maria and Gasser, Martin}, title = {Expression of Foxp3 in Colorectal Cancer but Not in Treg Cells Correlates with Disease Progression in Patients with Colorectal Cancer}, series = {PLoS ONE}, volume = {8}, journal = {PLoS ONE}, number = {1}, doi = {10.1371/journal.pone.0053630}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-130340}, pages = {e53630}, year = {2013}, abstract = {Background Measles virus (MV) causes T cell suppression by interference with phosphatidylinositol-3-kinase (PI3K) activation. We previously found that this interference affected the activity of splice regulatory proteins and a T cell inhibitory protein isoform was produced from an alternatively spliced pre-mRNA. Hypothesis Differentially regulated and alternatively splice variant transcripts accumulating in response to PI3K abrogation in T cells potentially encode proteins involved in T cell silencing. Methods To test this hypothesis at the cellular level, we performed a Human Exon 1.0 ST Array on RNAs isolated from T cells stimulated only or stimulated after PI3K inhibition. We developed a simple algorithm based on a splicing index to detect genes that undergo alternative splicing (AS) or are differentially regulated (RG) upon T cell suppression. Results Applying our algorithm to the data, 9\% of the genes were assigned as AS, while only 3\% were attributed to RG. Though there are overlaps, AS and RG genes differed with regard to functional regulation, and were found to be enriched in different functional groups. AS genes targeted extracellular matrix (ECM)-receptor interaction and focal adhesion pathways, while RG genes were mainly enriched in cytokine-receptor interaction and Jak-STAT. When combined, AS/RG dependent alterations targeted pathways essential for T cell receptor signaling, cytoskeletal dynamics and cell cycle entry. Conclusions PI3K abrogation interferes with key T cell activation processes through both differential expression and alternative splicing, which together actively contribute to T cell suppression.}, 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{NietzerBaurSieberetal.2016, author = {Nietzer, Sarah and Baur, Florentin and Sieber, Stefan and Hansmann, Jan and Schwarz, Thomas and Stoffer, Carolin and H{\"a}fner, Heide and Gasser, Martin and Waaga-Gasser, Ana Maria and Walles, Heike and Dandekar, Gudrun}, title = {Mimicking metastases including tumor stroma: a new technique to generate a three-dimensional colorectal cancer model based on a biological decellularized intestinal scaffold}, series = {Tissue Engineering Part C-Methods}, volume = {22}, journal = {Tissue Engineering Part C-Methods}, number = {7}, doi = {10.1089/ten.tec.2015.0557}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-188202}, pages = {621-635}, year = {2016}, abstract = {Tumor models based on cancer cell lines cultured two-dimensionally (2D) on plastic lack histological complexity and functionality compared to the native microenvironment. Xenogenic mouse tumor models display higher complexity but often do not predict human drug responses accurately due to species-specific differences. We present here a three-dimensional (3D) in vitro colon cancer model based on a biological scaffold derived from decellularized porcine jejunum (small intestine submucosa+mucosa, SISmuc). Two different cell lines were used in monoculture or in coculture with primary fibroblasts. After 14 days of culture, we demonstrated a close contact of human Caco2 colon cancer cells with the preserved basement membrane on an ultrastructural level as well as morphological characteristics of a well-differentiated epithelium. To generate a tissue-engineered tumor model, we chose human SW480 colon cancer cells, a reportedly malignant cell line. Malignant characteristics were confirmed in 2D cell culture: SW480 cells showed higher vimentin and lower E-cadherin expression than Caco2 cells. In contrast to Caco2, SW480 cells displayed cancerous characteristics such as delocalized E-cadherin and nuclear location of beta-catenin in a subset of cells. One central drawback of 2D cultures-especially in consideration of drug testing-is their artificially high proliferation. In our 3D tissue-engineered tumor model, both cell lines showed decreased numbers of proliferating cells, thus correlating more precisely with observations of primary colon cancer in all stages (UICC I-IV). Moreover, vimentin decreased in SW480 colon cancer cells, indicating a mesenchymal to epithelial transition process, attributed to metastasis formation. Only SW480 cells cocultured with fibroblasts induced the formation of tumor-like aggregates surrounded by fibroblasts, whereas in Caco2 cocultures, a separate Caco2 cell layer was formed separated from the fibroblast compartment beneath. To foster tissue generation, a bioreactor was constructed for dynamic culture approaches. This induced a close tissue-like association of cultured tumor cells with fibroblasts reflecting tumor biopsies. Therapy with 5-fluorouracil (5-FU) was effective only in 3D coculture. In conclusion, our 3D tumor model reflects human tissue-related tumor characteristics, including lower tumor cell proliferation. It is now available for drug testing in metastatic context-especially for substances targeting tumor-stroma interactions.}, language = {en} } @article{MencacciIsaiasReichetal.2014, author = {Mencacci, Niccol{\´o} E. and Isaias, Ioannis U. and Reich, Martin M. and Ganos, Christos and Plagnol, Vincent and Polke, James M. and Bras, Jose and Hersheson, Joshua and Stamelou, Maria and Pittman, Alan M. and Noyce, Alastair J. and Mok, Kin Y. and Opladen, Thomas and Kunstmann, Erdmute and Hodecker, Sybille and M{\"u}nchau, Alexander and Volkmann, Jens and Samnick, Samuel and Sidle, Katie and Nanji, Tina and Sweeney, Mary G. and Houlden, Henry and Batla, Amit and Zecchinelli, Anna L. and Pezzoli, Gianni and Marotta, Giorgio and Lees, Andrew and Alegria, Paulo and Krack, Paul and Cormier-Dequaire, Florence and Lesage, Suzanne and Brice, Alexis and Heutink, Peter and Gasser, Thomas and Lubbe, Steven J. and Morris, Huw R. and Taba, Pille and Koks, Sulev and Majounie, Elisa and Gibbs, J. Raphael and Singleton, Andrew and Hardy, John and Klebe, Stephan and Bhatia, Kailash P. and Wood, Nicholas W.}, title = {Parkinson's disease in GTP cyclohydrolase 1 mutation carriers}, series = {Brain}, volume = {137}, journal = {Brain}, number = {9}, doi = {10.1093/brain/awu179}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-121268}, pages = {2480-92}, year = {2014}, abstract = {GTP cyclohydrolase 1, encoded by the GCH1 gene, is an essential enzyme for dopamine production in nigrostriatal cells. Loss-of-function mutations in GCH1 result in severe reduction of dopamine synthesis in nigrostriatal cells and are the most common cause of DOPA-responsive dystonia, a rare disease that classically presents in childhood with generalized dystonia and a dramatic long-lasting response to levodopa. We describe clinical, genetic and nigrostriatal dopaminergic imaging ([(123)I]N-ω-fluoropropyl-2β-carbomethoxy-3β-(4-iodophenyl) tropane single photon computed tomography) findings of four unrelated pedigrees with DOPA-responsive dystonia in which pathogenic GCH1 variants were identified in family members with adult-onset parkinsonism. Dopamine transporter imaging was abnormal in all parkinsonian patients, indicating Parkinson's disease-like nigrostriatal dopaminergic denervation. We subsequently explored the possibility that pathogenic GCH1 variants could contribute to the risk of developing Parkinson's disease, even in the absence of a family history for DOPA-responsive dystonia. The frequency of GCH1 variants was evaluated in whole-exome sequencing data of 1318 cases with Parkinson's disease and 5935 control subjects. Combining cases and controls, we identified a total of 11 different heterozygous GCH1 variants, all at low frequency. This list includes four pathogenic variants previously associated with DOPA-responsive dystonia (Q110X, V204I, K224R and M230I) and seven of undetermined clinical relevance (Q110E, T112A, A120S, D134G, I154V, R198Q and G217V). The frequency of GCH1 variants was significantly higher (Fisher's exact test P-value 0.0001) in cases (10/1318 = 0.75\%) than in controls (6/5935 = 0.1\%; odds ratio 7.5; 95\% confidence interval 2.4-25.3). Our results show that rare GCH1 variants are associated with an increased risk for Parkinson's disease. These findings expand the clinical and biological relevance of GTP cycloydrolase 1 deficiency, suggesting that it not only leads to biochemical striatal dopamine depletion and DOPA-responsive dystonia, but also predisposes to nigrostriatal cell loss. Further insight into GCH1-associated pathogenetic mechanisms will shed light on the role of dopamine metabolism in nigral degeneration and Parkinson's disease.}, language = {en} } @article{SeyfriedvonRahdenMirasetal.2015, author = {Seyfried, Florian and von Rahden, Burkhard H. and Miras, Alexander D. and Gasser, Martin and Maeder, Uwe and Kunzmann, Volker and Germer, Christoph-Thomas and Pelz, J{\"o}rg O. W. and Kerscher, Alexander G.}, title = {Incidence, time course and independent risk factors for metachronous peritoneal carcinomatosis of gastric origin - a longitudinal experience from a prospectively collected database of 1108 patients}, series = {BMC Cancer}, volume = {15}, journal = {BMC Cancer}, number = {73}, doi = {10.1186/s12885-015-1081-8}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-125014}, year = {2015}, abstract = {Background Comprehensive evidence on the incidence, time course and independent risk factors of metachronous peritoneal carcinomatosis (metaPC) in gastric cancer patients treated with curative intent in the context of available systemic combination chemotherapies is lacking. Methods Data from a prospectively collected single-institutional Center Cancer Registry with 1108 consecutive patients with gastric adenocarcinoma (GC), clinical, histological and survival data were analyzed for independent risk factors and prognosis with focus on the development of metaPC. Findings were then stratified to the time periods of treatment with surgery alone, 5-Fluorouracil-only and contemporary combined systemic perioperative chemotherapy strategies, respectively. Results Despite R0 D2 gastrectomy (n = 560), 49.6\% (±5.4\%) of the patients were diagnosed with tumour recurrence and 15.5\% (±1.8\%) developed metaPC after a median time of 17.7 (15.1-20.3) months after surgery resulting in a tumour related mortality of 100\% with a median survival of 3.0 months (2.1 - 4.0). Independent risk factors for the development of metaPC were serosa positive T-category, nodal positive-status, signet cell and undifferentiated gradings (G3/G4). Contemporary systemic combination chemotherapy did not improve the incidence and prognosis of metaPC (p = 0.54). Conclusions Despite significant improvements in the overall survival for the complete cohort with gastric cancer over time, those patients with metaPC did not experience the same benefits. The lack of change in the incidence, and persistent poor prognosis of metaPC after curative surgery expose the need for further prevention and/or improved treatment options for this devastating condition.}, language = {en} } @article{SchattonYangKleffeletal.2015, author = {Schatton, Tobias and Yang, Jun and Kleffel, Sonja and Uehara, Mayuko and Barthel, Steven R. and Schlapbach, Christoph and Zhan, Qian and Dudeney, Stephen and Mueller, Hansgeorg and Lee, Nayoung and de Vries, Juliane C. and Meier, Barbara and Beken, Seppe Vander and Kluth, Mark A. and Ganss, Christoph and Sharpe, Arlene H. and Waaga-Gasser, Ana Maria and Sayegh, Mohamed H. and Abdi, Reza and Scharffetter-Kochanek, Karin and Murphy, George F. and Kupper, Thomas S. and Frank, Natasha Y. and Frank, Markus H.}, title = {ABCB5 Identifies Immunoregulatory Dermal Cells}, series = {Cell Reports}, volume = {12}, journal = {Cell Reports}, doi = {10.1016/j.celrep.2015.08.010}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-149989}, pages = {1564 -- 1574}, year = {2015}, abstract = {Cell-based strategies represent a new frontier in the treatment of immune-mediated disorders. However, the paucity of markers for isolation of molecularly defined immunomodulatory cell populations poses a barrier to this field. Here, we show that ATP-binding cassette member B5 (ABCB5) identifies dermal immunoregulatory cells (DIRCs) capable of exerting therapeutic immunoregulatory functions through engagement of programmed cell death 1 (PD-1). Purified Abcb5\(^+\) DIRCs suppressed T cell proliferation, evaded immune rejection, homed to recipient immune tissues, and induced Tregs in vivo. In fully major-histocompatibility-complex-mismatched cardiac allotransplantation models, allogeneic DIRCs significantly prolonged allograft survival. Blockade of DIRC-expressed PD-1 reversed the inhibitory effects of DIRCs on T cell activation, inhibited DIRC-dependent Treg induction, and attenuated DIRC-induced prolongation of cardiac allograft survival, indicating that DIRC immunoregulatory function is mediated, at least in part, through PD-1. Our results identify ABCB5\(^+\) DIRCs as a distinct immunoregulatory cell population and suggest promising roles of this expandable cell subset in cellular immunotherapy.}, language = {en} } @article{BaurMatheGesierichetal.2017, author = {Baur, Johannes and Mathe, Katrin and Gesierich, Anja and Weyandt, Gerhard and Wiegering, Armin and Germer, Christoph-Thomas and Gasser, Martin and Pelz, J{\"o}rg O. W.}, title = {Morbidity and oncologic outcome after saphenous vein-sparing inguinal lymphadenectomy in melanoma patients}, series = {World Journal of Surgical Oncology}, volume = {15}, journal = {World Journal of Surgical Oncology}, number = {99}, doi = {10.1186/s12957-017-1164-x}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-157687}, year = {2017}, abstract = {Background: Inguinal lymph node dissection (LND) is a surgical procedure with a high morbidity rate. Variations in surgical procedure, such as sparing of the saphenous vein, have been proposed to reduce surgical morbidity. While sparing of the saphenous vein has shown promising results in earlier studies, data for this procedure in melanoma patients are rare. In this retrospective study, we report 10-year findings on the effects of saphenous vein-sparing LND on surgical morbidity and oncologic outcomes in melanoma patients. Methods: A retrospective analysis of melanoma patients receiving inguinal LND in our facility between 2003 and 2013 was performed. Patients were divided into two groups: the saphenous vein resection group and the vein sparing group. Surgical morbidity, including wound infection, lymphatic fistula, severe bleeding, neurological complications, and chronic lymphedema, as well as regional recurrence-free survival were investigated. Results: A total of 106 patients were included in this study; of these, the saphenous vein was spared in 41 patients (38.7\%). The rate of lymphatic fistula was 51.6 vs. 48.8\%, wound infection occurred in 31.3 vs. 24.4\%, and patients suffered from chronic lymphedema in 30.0 vs. 26.5\% in V. saphena magna resection vs. sparing group. Differences observed, however, were not significant. No difference in regional recurrence-free survival between the two study groups was detected. Conclusions: The results of our retrospective analysis could not confirm the promising results reported in earlier studies. Thus, sparing of the saphenous vein appears to be optional.}, language = {en} } @article{HoernesFaserlJuenetal.2018, author = {Hoernes, Thomas Philipp and Faserl, Klaus and Juen, Michael Andreas and Kremser, Johannes and Gasser, Catherina and Fuchs, Elisabeth and Shi, Xinying and Siewert, Aaron and Lindner, Herbert and Kreutz, Christoph and Micura, Ronald and Joseph, Simpson and H{\"o}bartner, Claudia and Westhof, Eric and H{\"u}ttenhofer, Alexander and Erlacher, Matthias David}, title = {Translation of non-standard codon nucleotides reveals minimal requirements for codon-anticodon interactions}, series = {Nature Communications}, volume = {9}, journal = {Nature Communications}, doi = {10.1038/s41467-018-07321-8}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-321067}, year = {2018}, abstract = {The precise interplay between the mRNA codon and the tRNA anticodon is crucial for ensuring efficient and accurate translation by the ribosome. The insertion of RNA nucleobase derivatives in the mRNA allowed us to modulate the stability of the codon-anticodon interaction in the decoding site of bacterial and eukaryotic ribosomes, allowing an in-depth analysis of codon recognition. We found the hydrogen bond between the N1 of purines and the N3 of pyrimidines to be sufficient for decoding of the first two codon nucleotides, whereas adequate stacking between the RNA bases is critical at the wobble position. Inosine, found in eukaryotic mRNAs, is an important example of destabilization of the codon-anticodon interaction. Whereas single inosines are efficiently translated, multiple inosines, e.g., in the serotonin receptor 5-HT2C mRNA, inhibit translation. Thus, our results indicate that despite the robustness of the decoding process, its tolerance toward the weakening of codon-anticodon interactions is limited.}, language = {en} }