@article{GlutschKneitzGesierichetal.2021,
  author    = {Glutsch, Valerie and Kneitz, Hermann and Gesierich, Anja and Goebeler, Matthias and Haferkamp, Sebastian and Becker, J{\"u}rgen C. and Ugurel, Selma and Schilling, Bastian},
  title     = {Activity of ipilimumab plus nivolumab in avelumab-refractory Merkel cell carcinoma},
  series = {Cancer Immunology, Immunotherapy},
  volume    = {70},
  journal   = {Cancer Immunology, Immunotherapy},
  number    = {7},
  issn      = {14320851},
  doi       = {10.1007/s00262-020-02832-0},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-265635},
  pages     = {2087-2093},
  year      = {2021},
  abstract  = {Background Merkel cell carcinoma (MCC) is a rare and aggressive neuroendocrine cutaneous malignancy with poor prognosis. In Europe, approved systemic therapies are limited to the PD-L1 inhibitor avelumab. For avelumab-refractory patients, efficient and safe treatment options are lacking. Methods At three different sites in Germany, clinical and molecular data of patients with metastatic MCC being refractory to the PD-L1 inhibitor avelumab and who were later on treated with combined IPI/NIVO were retrospectively collected and evaluated. Results Five patients treated at three different academic sites in Germany were enrolled. Three out of five patients investigated for this report responded to combined IPI/NIVO according to RECIST 1.1. Combined immunotherapy was well tolerated without any grade II or III immune-related adverse events. Two out of three responders to IPI/NIVO received platinum-based chemotherapy in between avelumab and combined immunotherapy. Conclusion In this small retrospective study, we observed a high response rate and durable responses to subsequent combined immunotherapy with IPI/NIVO in avelumab-refractory metastatic MCC patients. In conclusion, our data suggest a promising activity of second- or third-line PD-1- plus CTLA-4-blockade in patients with anti-PD-L1-refractory MCC.},
  language  = {en}
}
@article{SarmaWillmesAngereretal.2020,
  author    = {Sarma, Bhavishya and Willmes, Christoph and Angerer, Laura and Adam, Christian and Becker, J{\"u}rgen C. and Kervarrec, Thibault and Schrama, David and Houben, Roland},
  title     = {Artesunate affects T antigen expression and survival of virus-positive Merkel cell carcinoma},
  series = {Cancers},
  volume    = {12},
  journal   = {Cancers},
  number    = {4},
  issn      = {2072-6694},
  doi       = {10.3390/cancers12040919},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-203851},
  year      = {2020},
  abstract  = {Merkel cell carcinoma (MCC) is a rare and highly aggressive skin cancer with frequent viral etiology. Indeed, in about 80\% of cases, there is an association with Merkel cell polyomavirus (MCPyV); the expression of viral T antigens is crucial for growth of virus-positive tumor cells. Since artesunate — a drug used to treat malaria — has been reported to possess additional anti-tumor as well as anti-viral activity, we sought to evaluate pre-clinically the effect of artesunate on MCC. We found that artesunate repressed growth and survival of MCPyV-positive MCC cells in vitro. This effect was accompanied by reduced large T antigen (LT) expression. Notably, however, it was even more efficient than shRNA-mediated downregulation of LT expression. Interestingly, in one MCC cell line (WaGa), T antigen knockdown rendered cells less sensitive to artesunate, while for two other MCC cell lines, we could not substantiate such a relation. Mechanistically, artesunate predominantly induces ferroptosis in MCPyV-positive MCC cells since known ferroptosis-inhibitors like DFO, BAF-A1, Fer-1 and β-mercaptoethanol reduced artesunate-induced death. Finally, application of artesunate in xenotransplanted mice demonstrated that growth of established MCC tumors can be significantly suppressed in vivo. In conclusion, our results revealed a highly anti-proliferative effect of the approved and generally well-tolerated anti-malaria compound artesunate on MCPyV-positive MCC cells, suggesting its potential usage for MCC therapy.},
  language  = {en}
}
@article{FanZebischHornyetal.2020,
  author    = {Fan, Kaiji and Zebisch, Armin and Horny, Kai and Schrama, David and Becker, J{\"u}rgen C.},
  title     = {Highly expressed miR-375 is not an intracellular oncogene in Merkel cell polyomavirus-associated Merkel cell carcinoma},
  series = {Cancers},
  volume    = {12},
  journal   = {Cancers},
  number    = {3},
  issn      = {2072-6694},
  doi       = {10.3390/cancers12030529},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-200678},
  year      = {2020},
  abstract  = {miR-375 is a highly abundant miRNA in Merkel cell carcinoma (MCC). In other cancers, it acts as either a tumor suppressor or oncogene. While free-circulating miR-375 serves as a surrogate marker for tumor burden in patients with advanced MCC, its function within MCC cells has not been established. Nearly complete miR-375 knockdown in MCC cell lines was achieved using antagomiRs via nucleofection. The cell viability, growth characteristics, and morphology were not altered by this knockdown. miR-375 target genes and related signaling pathways were determined using Encyclopedia of RNA Interactomes (ENCORI) revealing Hippo signaling and epithelial to mesenchymal transition (EMT)-related genes likely to be regulated. Therefore, their expression was analyzed by multiplexed qRT-PCR after miR-375 knockdown, demonstrating only a limited change in expression. In summary, highly effective miR-375 knockdown in classical MCC cell lines did not significantly change the cell viability, morphology, or oncogenic signaling pathways. These observations render miR-375 an unlikely intracellular oncogene in MCC cells, thus suggesting that likely functions of miR-375 for the intercellular communication of MCC should be addressed.},
  language  = {en}
}
@article{RitterFanPaulsonetal.2016,
  author    = {Ritter, Cathrin and Fan, Kaiji and Paulson, Kelly G. and Nghiem, Paul and Schrama, David and Becker, J{\"u}rgen C.},
  title     = {Reversal of epigenetic silencing of MHC class I chain-related protein A and B improves immune recognition of Merkel cell carcinoma},
  series = {Scientific Reports},
  journal   = {Scientific Reports},
  number    = {21678},
  edition   = {6},
  doi       = {10.1038/srep21678},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-167992},
  year      = {2016},
  abstract  = {Merkel cell carcinoma (MCC) is a virally associated cancer characterized by its aggressive behavior and strong immunogenicity. Both viral infection and malignant transformation induce expression of MHC class I chain-related protein (MIC) A and B, which signal stress to cells of the immune system via Natural Killer group 2D (NKG2D) resulting in elimination of target cells. However, despite transformation and the continued presence of virally-encoded proteins, MICs are only expressed in a minority of MCC tumors in situ and are completely absent on MCC cell lines in vitro. This lack of MIC expression was due to epigenetic silencing via MIC promoter hypo-acetylation; indeed, MIC expression was re-induced by pharmacological inhibition of histone deacetylases (HDACs) both in vitro and in vivo. This re-induction of MICs rendered MCC cells more sensitive to immune-mediated lysis. Thus, epigenetic silencing of MICs is an important immune escape mechanism of MCCs.},
  language  = {en}
}
@article{KollgaardUgurelBeckerIdornetal.2015,
  author    = {K{\o}llgaard, Tania and Ugurel-Becker, Selma and Idorn, Manja and Andersen, Mads Hald and Becker, J{\"u}rgen C. and Straten, Per thor},
  title     = {Pre-Vaccination Frequencies of Th17 Cells Correlate with Vaccine-Induced T-Cell Responses to Survivin-Derived Peptide Epitopes},
  series = {PLoS One},
  volume    = {10},
  journal   = {PLoS One},
  number    = {7},
  doi       = {10.1371/journal.pone.0131934},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-151509},
  pages     = {e0131934},
  year      = {2015},
  abstract  = {Various subsets of immune regulatory cells are suggested to influence the outcome of therapeutic antigen-specific anti-tumor vaccinations. We performed an exploratory analysis of a possible correlation of pre-vaccination Th17 cells, MDSCs, and Tregs with both vaccination-induced T-cell responses as well as clinical outcome in metastatic melanoma patients vaccinated with survivin-derived peptides. Notably, we observed dysfunctional Th1 and cytotoxic T cells, i.e. down-regulation of the CD3\(\zeta\)chain (p=0.001) and an impaired IFN\(\gamma\)-production (p=0.001) in patients compared to healthy donors, suggesting an altered activity of immune regulatory cells. Moreover, the frequencies of Th17 cells (p=0.03) and Tregs (p=0.02) were elevated as compared to healthy donors. IL-17-secreting CD4\(^{+}\) T cells displayed an impact on the immunological and clinical effects of vaccination: Patients characterized by high frequencies of Th17 cells at pre-vaccination were more likely to develop survivin-specific T-cell reactivity post-vaccination (p=0.03). Furthermore, the frequency of Th17 (p=0.09) and Th17/IFN\(\gamma\)\(^{+}\) (p=0.19) cells associated with patient survival after vaccination. In summary, our explorative, hypothesis-generating study demonstrated that immune regulatory cells, in particular Th17 cells, play a relevant role for generation of the vaccine-induced anti-tumor immunity in cancer patients, hence warranting further investigation to test for validity as predictive biomarkers.},
  language  = {en}
}
@article{HafnerHoubenBaeurleetal.2012,
  author    = {Hafner, Christian and Houben, Roland and Baeurle, Anne and Ritter, Cathrin and Schrama, David and Landthaler, Michael and Becker, J{\"u}rgen C.},
  title     = {Activation of the PI3K/AKT Pathway in Merkel Cell Carcinoma},
  series = {PLoS One},
  volume    = {7},
  journal   = {PLoS One},
  number    = {2},
  doi       = {10.1371/journal.pone.0031255},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-131398},
  pages     = {e31255},
  year      = {2012},
  abstract  = {Merkel cell carcinoma (MCC) is a highly aggressive skin cancer with an increasing incidence. The understanding of the molecular carcinogenesis of MCC is limited. Here, we scrutinized the PI3K/AKT pathway, one of the major pathways activated in human cancer, in MCC. Immunohistochemical analysis of 41 tumor tissues and 9 MCC cell lines revealed high levels of AKT phosphorylation at threonine 308 in 88\% of samples. Notably, the AKT phosphorylation was not correlated with the presence or absence of the Merkel cell polyoma virus (MCV). Accordingly, knock-down of the large and small T antigen by shRNA in MCV positive MCC cells did not affect phosphorylation of AKT. We also analyzed 46 MCC samples for activating PIK3CA and AKT1 mutations. Oncogenic PIK3CA mutations were found in 2/46 (4\%) MCCs whereas mutations in exon 4 of AKT1 were absent. MCC cell lines demonstrated a high sensitivity towards the PI3K inhibitor LY-294002. This finding together with our observation that the PI3K/AKT pathway is activated in the majority of human MCCs identifies PI3K/AKT as a potential new therapeutic target for MCC patients.},
  language  = {en}
}
@article{BeckerAndersenHofmeisterMuelleretal.2012,
  author    = {Becker, J{\"u}rgen C. and Andersen, Mads H. and Hofmeister-M{\"u}ller, Valeska and Wobser, Marion and Frey, Lidia and Sandig, Christiane and Walter, Steffen and Singh-Jasuja, Harpreet and K{\"a}mpgen, Eckhart and Opitz, Andreas and Zapatka, Marc and Br{\"o}cker, Eva-B. and thor Straten, Per and Schrama, David and Ugurel, Selma},
  title     = {Survivin-specific T-cell reactivity correlates with tumor response and patient survival: a phase-II peptide vaccination trial in metastatic melanoma},
  series = {Cancer Immunology, Immunotherapy},
  volume    = {61},
  journal   = {Cancer Immunology, Immunotherapy},
  number    = {11},
  doi       = {10.1007/s00262-012-1266-9},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-126215},
  pages     = {2091-2103},
  year      = {2012},
  abstract  = {Background Therapeutic vaccination directed to induce an anti-tumoral T-cell response is a field of extensive investigation in the treatment of melanoma. However, many vaccination trials in melanoma failed to demonstrate a correlation between the vaccine-specific immune response and therapy outcome. This has been mainly attributed to immune escape by antigen loss, rendering us in the need of new vaccination targets. Patients and methods This phase-II trial investigated a peptide vaccination against survivin, an oncogenic inhibitor-of-apoptosis protein crucial for the survival of tumor cells, in HLA-A1/-A2/-B35-positive patients with treatment-refractory stage-IV metastatic melanoma. The study endpoints were survivin-specific T-cell reactivity (SSTR), safety, response, and survival (OS). Results Sixty-one patients (ITT) received vaccination therapy using three different regimens. 55 patients (PP) were evaluable for response and survival, and 41/55 for SSTR. Patients achieving progression arrest (CR + PR + SD) more often showed SSTRs than patients with disease progression (p = 0.0008). Patients presenting SSTRs revealed a prolonged OS (median 19.6 vs. 8.6 months; p = 0.0077); multivariate analysis demonstrated SSTR as an independent predictor of survival (p = 0.013). The induction of SSTRs was associated with gender (female vs. male; p = 0.014) and disease stage (M1a/b vs. M1c; p = 0.010), but not with patient age, HLA type, performance status, or vaccination regimen. Conclusion Survivin-specific T-cell reactivities strongly correlate with tumor response and patient survival, indicating that vaccination with survivin-derived peptides is a promising treatment strategy in melanoma.},
  language  = {en}
}
@article{AlbSieAdametal.2012,
  author    = {Alb, Miriam and Sie, Christopher and Adam, Christian and Chen, Suzie and Becker, J{\"u}rgen C. and Schrama, David},
  title     = {Cellular and cytokine-dependent immunosuppressive mechanisms of grm1-transgenic murine melanoma},
  series = {Cancer Immunology, Immunotherapy},
  volume    = {61},
  journal   = {Cancer Immunology, Immunotherapy},
  number    = {12},
  doi       = {10.1007/s00262-012-1290-9},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-125096},
  pages     = {2239-2249},
  year      = {2012},
  abstract  = {Grm1-transgenic mice spontaneously develop cutaneous melanoma. This model allowed us to scrutinize the generic immune responses over the course of melanoma development. To this end, lymphocytes obtained from spleens, unrelated lymph nodes and tumor-draining lymph nodes of mice with no evidence of disease, and low or high tumor burden were analyzed ex vivo and in vitro. Thereby, we could demonstrate an increase in the number of activated CD4\(^+\) and CD8+ lymphocytes in the respective organs with increasing tumor burden. However, mainly CD4\(^+\) T cells, which could constitute both T helper as well as immunosuppressive regulatory T cells, but not CD8\(^+\) T cells, expressed activation markers upon in vitro stimulation when obtained from tumor-bearing mice. Interestingly, these cells from tumor-burdened animals were also functionally hampered in their proliferative response even when subjected to strong in vitro stimulation. Further analyses revealed that the increased frequency of regulatory T cells in tumor-bearing mice is an early event present in all lymphoid organs. Additionally, expression of the immunosuppressive cytokines TGF-β1 and IL-10 became more evident with increased tumor burden. Notably, TGF-β1 is strongly expressed in both the tumor and the tumor-draining lymph node, whereas IL-10 expression is more pronounced in the lymph node, suggesting a more complex regulation of IL-10. Thus, similar to the situation in melanoma patients, both cytokines as well as cellular immune escape mechanisms seem to contribute to the observed immunosuppressed state of tumor-bearing grm1-transgenic mice, suggesting that this model is suitable for preclinical testing of immunomodulatory therapeutics.},
  language  = {en}
}
@article{BeckerAndersenHofmeisterMuelleretal.2012,
  author    = {Becker, J{\"u}rgen C. and Andersen, Mads H. and Hofmeister-M{\"u}ller, Valeska and Wobser, Marion and Frey, Lidia and Sandig, Christiane and Walter, Steffen and Singh-Jasuja, Harpreet and K{\"a}mpgen, Eckhart and Opitz, Andreas and Zapatka, Marc and Br{\"o}cker, Eva-B. and thor Straten, Per and Schrama, David and Ugurel, Selma},
  title     = {Survivin-specific T-cell reactivity correlates with tumor response and patient survival: a phase-II peptide vaccination trial in metastatic melanoma},
  series = {Cancer Immunology, Immunotherapy},
  volume    = {61},
  journal   = {Cancer Immunology, Immunotherapy},
  number    = {11},
  doi       = {10.1007/s00262-012-1266-9},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-124830},
  pages     = {2091-2103},
  year      = {2012},
  abstract  = {Background Therapeutic vaccination directed to induce an anti-tumoral T-cell response is a field of extensive investigation in the treatment of melanoma. However, many vaccination trials in melanoma failed to demonstrate a correlation between the vaccine-specific immune response and therapy outcome. This has been mainly attributed to immune escape by antigen loss, rendering us in the need of new vaccination targets. Patients and methods This phase-II trial investigated a peptide vaccination against survivin, an oncogenic inhibitor-of-apoptosis protein crucial for the survival of tumor cells, in HLA-A1/-A2/-B35-positive patients with treatment-refractory stage-IV metastatic melanoma. The study endpoints were survivin-specific T-cell reactivity (SSTR), safety, response, and survival (OS). Results Sixty-one patients (ITT) received vaccination therapy using three different regimens. 55 patients (PP) were evaluable for response and survival, and 41/55 for SSTR. Patients achieving progression arrest (CR + PR + SD) more often showed SSTRs than patients with disease progression (p = 0.0008). Patients presenting SSTRs revealed a prolonged OS (median 19.6 vs. 8.6 months; p = 0.0077); multivariate analysis demonstrated SSTR as an independent predictor of survival (p = 0.013). The induction of SSTRs was associated with gender (female vs. male; p = 0.014) and disease stage (M1a/b vs. M1c; p = 0.010), but not with patient age, HLA type, performance status, or vaccination regimen. Conclusion Survivin-specific T-cell reactivities strongly correlate with tumor response and patient survival, indicating that vaccination with survivin-derived peptides is a promising treatment strategy in melanoma.},
  language  = {en}
}
@article{BuderMuellerBeekmannetal.2014,
  author    = {Buder, Kristina and M{\"u}ller, Philip A. and Beekmann, Gabriele and Ugurel, Selma and Br{\"o}cker, Eva-Bettina and Becker, J{\"u}rgen C.},
  title     = {Denileukin Diftitox plus Total Skin Electron Beam Radiation in Patients with Treatment-refractory Cutaneous T-cell Lymphoma (Mycosis Fungoides): Report of Four Cases},
  series = {Acta Dermato-Venereologica},
  volume    = {94},
  journal   = {Acta Dermato-Venereologica},
  doi       = {10.2340/00015555-1627},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-120091},
  pages     = {94-96},
  year      = {2014},
  abstract  = {Mycosis fungoides (MF) is the most common cutaneous T-cell lymphoma (CTCL) (1). Most patients initially respond well to standard therapy, but advanced MF is often treatment refractory. Thus, a combination of the available treatment options is an important strategy. Total skin electron beam radiation (TSEB) is effective in MF, with a complete remission rate of up to 90\% in the early stages. However, in patients with more advanced stages, remission rates are considerably lower (2, 3). Denileukin diftitox (DD) (Ontak®) is a recombinant fusion protein of the receptor-binding domain of interleukin (IL)-2 and the enzymatic and translocation domains of diphtheria toxin (4). It targets the alpha-subunit of the IL-2-receptor (CD25). There are no reports on this combination therapy in MF.},
  language  = {en}
}