@article{OttoHahlbrockEichetal.2016, author = {Otto, Christoph and Hahlbrock, Theresa and Eich, Kilian and Karaaslan, Ferdi and J{\"u}rgens, Constantin and Germer, Christoph-Thomas and Wiegering, Armin and K{\"a}mmerer, Ulrike}, title = {Antiproliferative and antimetabolic effects behind the anticancer property of fermented wheat germ extract}, series = {BMC Complementary and Alternative Medicine}, volume = {16}, journal = {BMC Complementary and Alternative Medicine}, number = {160}, doi = {10.1186/s12906-016-1138-5}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-146013}, year = {2016}, abstract = {Background Fermented wheat germ extract (FWGE) sold under the trade name Avemar exhibits anticancer activity in vitro and in vivo. Its mechanisms of action are divided into antiproliferative and antimetabolic effects. Its influcence on cancer cell metabolism needs further investigation. One objective of this study, therefore, was to further elucidate the antimetabolic action of FWGE. The anticancer compound 2,6-dimethoxy-1,4-benzoquinone (DMBQ) is the major bioactive compound in FWGE and is probably responsible for its anticancer activity. The second objective of this study was to compare the antiproliferative properties in vitro of FWGE and the DMBQ compound. Methods The IC\(_{50}\) values of FWGE were determined for nine human cancer cell lines after 24 h of culture. The DMBQ compound was used at a concentration of 24 μmol/l, which is equal to the molar concentration of DMBQ in FWGE. Cell viability, cell cycle, cellular redox state, glucose consumption, lactic acid production, cellular ATP levels, and the NADH/NAD\(^+\) ratio were measured. Results The mean IC\(_{50}\) value of FWGE for the nine human cancer cell lines tested was 10 mg/ml. Both FWGE (10 mg/ml) and the DMBQ compound (24 μmol/l) induced massive cell damage within 24 h after starting treatment, with changes in the cellular redox state secondary to formation of intracellular reactive oxygen species. Unlike the DMBQ compound, which was only cytotoxic, FWGE exhibited cytostatic and growth delay effects in addition to cytotoxicity. Both cytostatic and growth delay effects were linked to impaired glucose utilization which influenced the cell cycle, cellular ATP levels, and the NADH/NAD\(^+\) ratio. The growth delay effect in response to FWGE treatment led to induction of autophagy. Conclusions FWGE and the DMBQ compound both induced oxidative stress-promoted cytotoxicity. In addition, FWGE exhibited cytostatic and growth delay effects associated with impaired glucose utilization which led to autophagy, a possible previously unknown mechanism behind the influence of FWGE on cancer cell metabolism.}, 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{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{OttoKastnerSchmidtetal.2022, author = {Otto, Christoph and Kastner, Carolin and Schmidt, Stefanie and Uttinger, Konstantin and Baluapuri, Apoorva and Denk, Sarah and Rosenfeldt, Mathias T. and Rosenwald, Andreas and Roehrig, Florian and Ade, Carsten P. and Schuelein-Voelk, Christina and Diefenbacher, Markus E. and Germer, Christoph-Thomas and Wolf, Elmar and Eilers, Martin and Wiegering, Armin}, title = {RNA polymerase I inhibition induces terminal differentiation, growth arrest, and vulnerability to senolytics in colorectal cancer cells}, series = {Molecular Oncology}, volume = {16}, journal = {Molecular Oncology}, number = {15}, doi = {10.1002/1878-0261.13265}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-312806}, pages = {2788-2809}, year = {2022}, abstract = {Ribosomal biogenesis and protein synthesis are deregulated in most cancers, suggesting that interfering with translation machinery may hold significant therapeutic potential. Here, we show that loss of the tumor suppressor adenomatous polyposis coli (APC), which constitutes the initiating event in the adenoma carcinoma sequence for colorectal cancer (CRC), induces the expression of RNA polymerase I (RNAPOL1) transcription machinery, and subsequently upregulates ribosomal DNA (rDNA) transcription. Targeting RNAPOL1 with a specific inhibitor, CX5461, disrupts nucleolar integrity, and induces a disbalance of ribosomal proteins. Surprisingly, CX5461-induced growth arrest is irreversible and exhibits features of senescence and terminal differentiation. Mechanistically, CX5461 promotes differentiation in an MYC-interacting zinc-finger protein 1 (MIZ1)- and retinoblastoma protein (Rb)-dependent manner. In addition, the inhibition of RNAPOL1 renders CRC cells vulnerable towards senolytic agents. We validated this therapeutic effect of CX5461 in murine- and patient-derived organoids, and in a xenograft mouse model. These results show that targeting ribosomal biogenesis together with targeting the consecutive, senescent phenotype using approved drugs is a new therapeutic approach, which can rapidly be transferred from bench to bedside.}, language = {en} } @article{WiegeringMatthesMuehlingetal.2017, author = {Wiegering, Armin and Matthes, Niels and M{\"u}hling, Bettina and Koospal, Monika and Quenzer, Anne and Peter, Stephanie and Germer, Christoph-Thomas and Linnebacher, Michael and Otto, Christoph}, title = {Reactivating p53 and Inducing Tumor Apoptosis (RITA) Enhances the Response of RITA-Sensitive Colorectal Cancer Cells to Chemotherapeutic Agents 5-Fluorouracil and Oxaliplatin}, series = {Neoplasia}, volume = {19}, journal = {Neoplasia}, number = {4}, doi = {10.1016/j.neo.2017.01.007}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-171067}, pages = {301-309}, year = {2017}, abstract = {Colorectal carcinoma (CRC) is the most common cancer of the gastrointestinal tract with frequently dysregulated intracellular signaling pathways, including p53 signaling. The mainstay of chemotherapy treatment of CRC is 5-fluorouracil (5FU) and oxaliplatin. The two anticancer drugs mediate their therapeutic effect via DNA damage-triggered signaling. The small molecule reactivating p53 and inducing tumor apoptosis (RITA) is described as an activator of wild-type and reactivator of mutant p53 function, resulting in elevated levels of p53 protein, cell growth arrest, and cell death. Additionally, it has been shown that RITA can induce DNA damage signaling. It is expected that the therapeutic benefits of 5FU and oxaliplatin can be increased by enhancing DNA damage signaling pathways. Therefore, we highlighted the antiproliferative response of RITA alone and in combination with 5FU or oxaliplatin in human CRC cells. A panel of long-term established CRC cell lines (n = 9) including p53 wild-type, p53 mutant, and p53 null and primary patient-derived, low-passage cell lines (n = 5) with different p53 protein status were used for this study. A substantial number of CRC cells with pronounced sensitivity to RITA (IC\(_{50}\)< 3.0 μmol/l) were identified within established (4/9) and primary patient-derived (2/5) CRC cell lines harboring wild-type or mutant p53 protein. Sensitivity to RITA appeared independent of p53 status and was associated with an increase in antiproliferative response to 5FU and oxaliplatin, a transcriptional increase of p53 targets p21 and NOXA, and a decrease in MYC mRNA. The effect of RITA as an inducer of DNA damage was shown by a strong elevation of phosphorylated histone variant H2A.X, which was restricted to RITA-sensitive cells. Our data underline the primary effect of RITA, inducing DNA damage, and demonstrate the differential antiproliferative effect of RITA to CRC cells independent of p53 protein status. We found a substantial number of RITA-sensitive CRC cells within both panels of established CRC cell lines and primary patient-derived CRC cell lines (6/14) that provide a rationale for combining RITA with 5FU or oxaliplatin to enhance the antiproliferative response to both chemotherapeutic agents.}, language = {en} } @article{KaemmererGiresPfetzeretal.2015, author = {K{\"a}mmerer, Ulrike and Gires, Olivier and Pfetzer, Nadja and Wiegering, Armin and Klement, Rainer Johannes and Otto, Christoph}, title = {TKTL1 expression in human malign and benign cell lines}, series = {BMC Cancer}, volume = {15}, journal = {BMC Cancer}, number = {2}, doi = {10.1186/1471-2407-15-2}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-126397}, year = {2015}, abstract = {Background Overexpression of transketolase-like 1 protein TKTL1 in cancer cells has been reported to correlate with enhanced glycolysis and lactic acid production. Furthermore, enhanced TKTL1 expression was put into context with resistance to chemotherapy and ionizing radiation. Here, a panel of human malign and benign cells, which cover a broad range of chemotherapy and radiation resistance as well as reliance on glucose metabolism, was analyzed in vitro for TKTL1 expression. Methods 17 malign and three benign cell lines were characterized according to their expression of TKTL1 on the protein level with three commercially available anti-TKTL1 antibodies utilizing immunohistochemistry and Western blot, as well as on mRNA level with three published primer pairs for RT-qPCR. Furthermore, sensitivities to paclitaxel, cisplatin and ionizing radiation were assessed in cell survival assays. Glucose consumption and lactate production were quantified as surrogates for the "Warburg effect". Results Considerable amounts of tktl1 mRNA and TKTL1 protein were detected only upon stable transfection of the human embryonic kidney cell line HEK293 with an expression plasmid for human TKTL1. Beyond that, weak expression of endogenous tktl1 mRNA was measured in the cell lines JAR and U251. Western blot analysis of JAR and U251 cells did not detect TKTL1 at the expected size of 65 kDa with all three antibodies specific for TKTL1 protein and immunohistochemical staining was observed with antibody JFC12T10 only. All other cell lines tested here revealed expression of tktl1 mRNA below detection limits and were negative for TKTL1 protein. However, in all cell lines including TKTL1-negative HEK293-control cells, antibody JFC12T10 detected multiple proteins with different molecular weights. Importantly, JAR and U251 did neither demonstrate an outstanding production of lactic acid nor increased resistance against chemotherapeutics or to ionizing radiation, respectively. Conclusion Using RT-qPCR and three different antibodies we observed only exceptional occurrence of TKTL1 in a panel of malignant human cell lines in vitro. The presence of TKTL1 was unrelated to either the rate of glucose consumption/lactic acid production or resistance against chemo- and radiotherapy.}, 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{ZaitsevaHoffmannLoestetal.2023, author = {Zaitseva, Olena and Hoffmann, Annett and L{\"o}st, Margaretha and Anany, Mohamed A. and Zhang, Tengyu and Kucka, Kirstin and Wiegering, Armin and Otto, Christoph and Wajant, Harald}, title = {Antibody-based soluble and membrane-bound TWEAK mimicking agonists with FcγR-independent activity}, series = {Frontiers in Immunology}, volume = {14}, journal = {Frontiers in Immunology}, doi = {10.3389/fimmu.2023.1194610}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-323116}, year = {2023}, abstract = {Fibroblast growth factor (FGF)-inducible 14 (Fn14) activates the classical and alternative NFκB (nuclear factor 'kappa-light-chain-enhancer' of activated B-cells) signaling pathway but also enhances tumor necrosis factor (TNF)-induced cell death. Fn14 expression is upregulated in non-hematopoietic cells during tissue injury and is also often highly expressed in solid cancers. In view of the latter, there were and are considerable preclinical efforts to target Fn14 for tumor therapy, either by exploiting Fn14 as a target for antibodies with cytotoxic activity (e.g. antibody-dependent cellular cytotoxicity (ADCC)-inducing IgG variants, antibody drug conjugates) or by blocking antibodies with the aim to interfere with protumoral Fn14 activities. Noteworthy, there are yet no attempts to target Fn14 with agonistic Fc effector function silenced antibodies to unleash the proinflammatory and cell death-enhancing activities of this receptor for tumor therapy. This is certainly not at least due to the fact that anti-Fn14 antibodies only act as effective agonists when they are presented bound to Fcγ receptors (FcγR). Thus, there are so far no antibodies that robustly and selectively engage Fn14 signaling without triggering unwanted FcγR-mediated activities. In this study, we investigated a panel of variants of the anti-Fn14 antibody 18D1 of different valencies and domain architectures with respect to their inherent FcγR-independent ability to trigger Fn14-associated signaling pathways. In contrast to conventional 18D1, the majority of 18D1 antibody variants with four or more Fn14 binding sites displayed a strong ability to trigger the alternative NFκB pathway and to enhance TNF-induced cell death and therefore resemble in their activity soluble (TNF)-like weak inducer of apoptosis (TWEAK), one form of the natural occurring ligand of Fn14. Noteworthy, activation of the classical NFκB pathway, which naturally is predominately triggered by membrane-bound TWEAK but not soluble TWEAK, was preferentially observed with a subset of constructs containing Fn14 binding sites at opposing sites of the IgG scaffold, e.g. IgG1-scFv fusion proteins. A superior ability of IgG1-scFv fusion proteins to trigger classical NFκB signaling was also observed with the anti-Fn14 antibody PDL192 suggesting that we identified generic structures for Fn14 antibody variants mimicking soluble and membrane-bound TWEAK.}, language = {en} }