@article{OroujiPeitschOroujietal.2020, author = {Orouji, Elias and Peitsch, Wiebke K. and Orouji, Azadeh and Houben, Roland and Utikal, Jochen}, title = {Unique role of histone methyltransferase PRDM8 in the tumorigenesis of virus-negative Merkel cell carcinoma}, series = {Cancers}, volume = {12}, journal = {Cancers}, number = {4}, issn = {2072-6694}, doi = {10.3390/cancers12041057}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-203815}, year = {2020}, abstract = {Merkel cell carcinoma (MCC) is a deadly skin cancer, and about 80\% of its cases have been shown to harbor integrated Merkel polyomavirus in the tumor cell genome. Viral oncoproteins expressed in the tumor cells are considered as the oncogenic factors of these virus-positive Merkel cell carcinoma (VP-MCC). In contrast, the molecular pathogenesis of virus-negative MCC (VN-MCC) is less well understood. Using gene expression analysis of MCC cell lines, we found histone methyltransferase PRDM8 to be elevated in VN-MCC. This finding was confirmed by immunohistochemical analysis of MCC tumors, revealing that increased PRDM8 expression in VN-MCC is also associated with increased H3K9 methylation. CRISPR-mediated silencing of PRDM8 in MCC cells further supported the histone methylating role of this protein in VN-MCC. We also identified miR-20a-5p as a negative regulator of PRDM8. Taken together, our findings provide insights into the role of PRDM8 as a histone methyltransferase in VN-MCC tumorigenesis.}, language = {en} } @article{KrebsSolimandoKalogirouetal.2020, author = {Krebs, Markus and Solimando, Antonio Giovanni and Kalogirou, Charis and Marquardt, Andr{\´e} and Frank, Torsten and Sokolakis, Ioannis and Hatzichristodoulou, Georgios and Kneitz, Susanne and Bargou, Ralf and K{\"u}bler, Hubert and Schilling, Bastian and Spahn, Martin and Kneitz, Burkhard}, title = {miR-221-3p Regulates VEGFR2 Expression in High-Risk Prostate Cancer and Represents an Escape Mechanism from Sunitinib In Vitro}, series = {Journal of Clinical Medicine}, volume = {9}, journal = {Journal of Clinical Medicine}, number = {3}, issn = {2077-0383}, doi = {10.3390/jcm9030670}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-203168}, year = {2020}, abstract = {Downregulation of miR-221-3p expression in prostate cancer (PCa) predicted overall and cancer-specific survival of high-risk PCa patients. Apart from PCa, miR-221-3p expression levels predicted a response to tyrosine kinase inhibitors (TKI) in clear cell renal cell carcinoma (ccRCC) patients. Since this role of miR-221-3p was explained with a specific targeting of VEGFR2, we examined whether miR-221-3p regulated VEGFR2 in PCa. First, we confirmed VEGFR2/KDR as a target gene of miR-221-3p in PCa cells by applying Luciferase reporter assays and Western blotting experiments. Although VEGFR2 was mainly downregulated in the PCa cohort of the TCGA (The Cancer Genome Atlas) database, VEGFR2 was upregulated in our high-risk PCa cohort (n = 142) and predicted clinical progression. In vitro miR-221-3p acted as an escape mechanism from TKI in PC3 cells, as displayed by proliferation and apoptosis assays. Moreover, we confirmed that Sunitinib induced an interferon-related gene signature in PC3 cells by analyzing external microarray data and by demonstrating a significant upregulation of miR-221-3p/miR-222-3p after Sunitinib exposure. Our findings bear a clinical perspective for high-risk PCa patients with low miR-221-3p levels since this could predict a favorable TKI response. Apart from this therapeutic niche, we identified a partially oncogenic function of miR-221-3p as an escape mechanism from VEGFR2 inhibition.}, language = {en} } @article{UeberschaarGoebelerKneitz2020, author = {Ueberschaar, Simon and Goebeler, Matthias and Kneitz, Hermann}, title = {CD10-Positive Cutaneous PEComa: An Extremely Rare Skin Tumour}, series = {Case Reports in Dermatology}, volume = {12}, journal = {Case Reports in Dermatology}, doi = {10.1159/000510718}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-236151}, pages = {192-198}, year = {2020}, abstract = {We here present the case of a 67-year-old woman with a history of a slowly progressive, polypous nodule on her left wrist. The lesion was excised, and the histological analysis revealed a clear cell tumour that was relatively sharply demarked from the surrounding tissue extending into the subcutaneous tissue. The tumour showed a characteristic trabecular pattern in which the tumour cells were arranged around numerous vessels. The neoplastic cells had a predominantly epithelioid shape, granular eosinophilic to clear cytoplasm and prominent centrally located nucleoli. The histological differential diagnosis included a metastatic clear-cell renal cell carcinoma and a primary cutaneous perivascular epithelioid cell tumour (PEComa). Immunohistochemically, the tumour cells revealed homogenous expression of HMB-45, MiTF and CD10, whereas MART-1 and S100 were negative. Antibodies against actin marked the trabecularly arranged vessels, and the neoplastic cells yielded a patchy positivity against actin and desmin. Additional immunohistochemical stains against pan-cytokeratin, CAIX, PAX-8 and EMA were negative. Based on the morphologic and immunophenotypic findings, the histological diagnosis of a CD10-positive cutaneous PEComa was made.}, 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{JessenKressBaluapurietal.2020, author = {Jessen, Christina and Kreß, Julia K. C. and Baluapuri, Apoorva and Hufnagel, Anita and Schmitz, Werner and Kneitz, Susanne and Roth, Sabine and Marquardt, Andr{\´e} and Appenzeller, Silke and Ade, Casten P. and Glutsch, Valerie and Wobser, Marion and Friedmann-Angeli, Jos{\´e} Pedro and Mosteo, Laura and Goding, Colin R. and Schilling, Bastian and Geissinger, Eva and Wolf, Elmar and Meierjohann, Svenja}, title = {The transcription factor NRF2 enhances melanoma malignancy by blocking differentiation and inducing COX2 expression}, series = {Oncogene}, volume = {39}, journal = {Oncogene}, issn = {0950-9232}, doi = {10.1038/s41388-020-01477-8}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-235064}, pages = {6841-6855}, year = {2020}, abstract = {The transcription factor NRF2 is the major mediator of oxidative stress responses and is closely connected to therapy resistance in tumors harboring activating mutations in the NRF2 pathway. In melanoma, such mutations are rare, and it is unclear to what extent melanomas rely on NRF2. Here we show that NRF2 suppresses the activity of the melanocyte lineage marker MITF in melanoma, thereby reducing the expression of pigmentation markers. Intriguingly, we furthermore identified NRF2 as key regulator of immune-modulating genes, linking oxidative stress with the induction of cyclooxygenase 2 (COX2) in an ATF4-dependent manner. COX2 is critical for the secretion of prostaglandin E2 and was strongly induced by H\(_2\)O\(_2\) or TNFα only in presence of NRF2. Induction of MITF and depletion of COX2 and PGE2 were also observed in NRF2-deleted melanoma cells in vivo. Furthermore, genes corresponding to the innate immune response such as RSAD2 and IFIH1 were strongly elevated in absence of NRF2 and coincided with immune evasion parameters in human melanoma datasets. Even in vitro, NRF2 activation or prostaglandin E2 supplementation blunted the induction of the innate immune response in melanoma cells. Transcriptome analyses from lung adenocarcinomas indicate that the observed link between NRF2 and the innate immune response is not restricted to melanoma.}, language = {en} } @article{KosnopfelSinnbergSaueretal.2020, author = {Kosnopfel, Corinna and Sinnberg, Tobias and Sauer, Birgit and Niessner, Heike and Muenchow, Alina and Fehrenbacher, Birgit and Schaller, Martin and Mertens, Peter R. and Garbe, Claus and Thakur, Basant Kumar and Schittek, Birgit}, title = {Tumour progression stage-dependent secretion of YB-1 stimulates melanoma cell migration and invasion}, series = {Cancers}, volume = {12}, journal = {Cancers}, number = {8}, issn = {2072-6694}, doi = {10.3390/cancers12082328}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-211206}, year = {2020}, abstract = {Secreted factors play an important role in intercellular communication. Therefore, they are not only indispensable for the regulation of various physiological processes but can also decisively advance the development and progression of tumours. In the context of inflammatory disease, Y-box binding protein 1 (YB-1) is actively secreted and the extracellular protein promotes cell proliferation and migration. In malignant melanoma, intracellular YB-1 expression increases during melanoma progression and represents an unfavourable prognostic marker. Here, we show active secretion of YB-1 from melanoma cells as opposed to benign cells of the skin. Intriguingly, YB-1 secretion correlates with the stage of melanoma progression and depends on a calcium- and ATP-dependent non-classical secretory pathway leading to the occurrence of YB-1 in the extracellular space as a free protein. Along with an elevated YB-1 secretion of melanoma cells in the metastatic growth phase, extracellular YB-1 exerts a stimulating effect on melanoma cell migration, invasion, and tumourigenicity. Collectively, these data suggest that secreted YB-1 plays a functional role in melanoma cell biology, stimulating metastasis, and may serve as a novel biomarker in malignant melanoma that reflects tumour aggressiveness.}, language = {en} } @phdthesis{Kervarrec2020, author = {Kervarrec, Thibault}, title = {Histogenesis of Merkel cell carcinoma}, doi = {10.25972/OPUS-19975}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-199750}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2020}, abstract = {Merkel cell carcinoma (MCC) is a rare and aggressive skin cancer. In approximately 80\% of cases, genomic integration of the Merkel cell polyomavirus (MCPyV) is observed and overexpression of the two MCPyV T antigens (TAgs) is regarded as the main oncogenic determinant of MCPyV-positive MCC cases. However, the nature of the cells from which MCC arises is unknown. Therefore, the goal of the present work was to determine the cell of origin of MCC. First, we characterized MCC patients' tumors and demonstrated a high similarity of MCPyV- negative MCC with extracutaneous neuroendocrine carcinoma while MCPyV-positive MCC differs from these two groups with respect to morphology, immunohistochemical profile, genetics, origin and behavior. Based on the analysis of a trichoblastoma/MCC combined tumor, we demonstrated that a MCPyV-positive MCC can arise following MCPyV integration in an epithelial cell. In addition, the high similarity between trichoblastoma cells and Merkel cell (MC) progenitors of the hair follicle suggests that these hair follicle cells may represent a general start point for the development of MCPyV-positive MCC. A contribution of the viral TAgs to the development of the characteristic Merkel cell-like MCC phenotype is suggested by experiments demonstrating induction of Merkel cell markers upon TAg expression in human primary keratinocytes or hair follicle cells. As potential mechanisms mediating these phenotypic changes, we identified the capability of MCPyV LT to repress degradation of master regulator of MC development, i.e. the transcription factor ATOH1. To conclude, our work suggests that MCPyV integration in epithelial cells of the hair follicle may represent an important path for MCC development.}, subject = {Merkel-Zellkarzinom}, language = {en} } @article{OroujiPeitschOroujietal.2020, author = {Orouji, Elias and Peitsch, Wiebke K. and Orouji, Azadeh and Houben, Roland and Utikal, Jochen}, title = {Oncogenic role of an epigenetic reader of m\(^6\)A RNA modification: YTHDF1 in Merkel cell carcinoma}, series = {Cancers}, volume = {12}, journal = {Cancers}, number = {1}, issn = {2072-6694}, doi = {10.3390/cancers12010202}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-200815}, year = {2020}, abstract = {Merkel cell carcinoma is a deadly skin cancer, which in the majority of cases is caused by the Merkel cell polyomavirus (MCPyV). The viral small T antigen is regarded as the dominant oncoprotein expressed in the tumor cells. We used genomic screening of copy number aberrations along with transcriptomic analysis to investigate regions with amplification that harbor differentially expressed genes. We identified YTHDF1, a protein that is a reader of N\(^6\)-methyladenosine (m\(^6\)A) RNA modifications, to have high copy gains and to be highly expressed in Merkel cell carcinoma. Importantly, we identified the presence of m\(^6\)A on small T antigen mRNA suggesting a relation between YTHDF1 amplification and MCPyV gene expression. Interestingly, knockdown of YTHDF1 in Merkel cell carcinoma (MCC) cell lines negatively affected the translation initiation factor eIF3 and reduced proliferation and clonogenic capacity in vitro. Furthermore, analysis of survival data revealed worse overall survival in YTHDF1\(^{high}\) MCC patients compared to YTHDF1\(^{low}\) patients. Our findings indicate a novel oncogenic role of YTHDF1 through m\(^6\)A machinery in the tumorigenesis of MCC.}, 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{WallstabeBussemerGroeberBeckeretal.2020, author = {Wallstabe, Julia and Bussemer, Lydia and Groeber-Becker, Florian and Freund, Lukas and Alb, Mirian and Dragan, Mariola and Waaga-Gasser, Ana Maria and Jakubietz, Rafael and Kneitz, Hermann and Rosenwald, Andreas and Rebhan, Silke and Walles, Heike and Mielke, Stephan}, title = {Inflammation-Induced Tissue Damage Mimicking GvHD in Human Skin Models as Test Platform for Immunotherapeutics}, series = {ALTEX}, volume = {37}, journal = {ALTEX}, number = {3}, doi = {10.14573/altex.1907181}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-229974}, pages = {429-440}, year = {2020}, abstract = {Due to the rapidly increasing development and use of cellular products, there is a rising demand for non-animal-based test platforms to predict, study and treat undesired immunity. Here, we generated human organotypic skin models from human biopsies by isolating and expanding keratinocytes, fibroblasts and microvascular endothelial cells and seeding these components on a collagen matrix or a biological vascularized scaffold matrix in a bioreactor. We then were able to induce inflammation-mediated tissue damage by adding pre-stimulated, mismatched allogeneic lymphocytes and/or inflammatory cytokine-containing supernatants histomorphologically mimicking severe graft versus host disease (GvHD) of the skin. This could be prevented by the addition of immunosuppressants to the models. Consequently, these models harbor a promising potential to serve as a test platform for the prediction, prevention and treatment of GvHD. They also allow functional studies of immune effectors and suppressors including but not limited to allodepleted lymphocytes, gamma-delta T cells, regulatory T cells and mesenchymal stromal cells, which would otherwise be limited to animal models. Thus, the current test platform, developed with the limitation that no professional antigen presenting cells are in place, could greatly reduce animal testing for investigation of novel immune therapies.}, language = {en} }