@article{LivingstoneZarembaHornetal.2020, author = {Livingstone, E. and Zaremba, A. and Horn, S. and Ugurel, S. and Casalini, B. and Schlaak, M. and Hassel, J.C. and Herbst, R. and Utikal, J.S. and Weide, B. and Gutzmer, R. and Meier, F. and Koelsche, C. and Hadaschik, E. and Sucker, A. and Reis, H. and Merkelbach-Bruse, S. and Siewert, M. and Sahm, F. and von Deimling, A. and Cosgarea, I. and Zimmer, L. and Schadendorf, D. and Schilling, B. and Griewank, K.G.}, title = {GNAQ and GNA11 mutant nonuveal melanoma: a subtype distinct from both cutaneous and uveal melanoma}, series = {British Journal of Dermatology}, volume = {183}, journal = {British Journal of Dermatology}, number = {5}, doi = {10.1111/bjd.18947}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-215434}, pages = {928 -- 939}, year = {2020}, abstract = {Background GNAQ and GNA11 mutant nonuveal melanoma represent a poorly characterized rare subgroup of melanoma with a gene mutation profile similar to uveal melanoma. Objectives To characterize these tumours in terms of clinical behaviour and genetic characteristics. Methods Patients with nonuveal GNAQ/11 mutated melanoma were identified from the prospective multicentre tumour tissue registry ADOREG, Tissue Registry in Melanoma (TRIM) and additional cooperating skin cancer centres. Extensive data on patient, tumour and treatment characteristics were collected retrospectively. Targeted sequencing was used to determine tumour mutational burden. Immunohistochemistry staining was performed for programmed death-ligand 1 and BRCA1-associated protein (BAP)1. Existing whole-exome cutaneous and uveal melanoma data were analysed for mutation type and burden. Results We identified 18 patients with metastatic GNAQ/11 mutant nonuveal melanoma. Tumours had a lower tumour mutational burden and fewer ultraviolet signature mutations than cutaneous melanomas. In addition to GNAQ and GNA11 mutations (nine each), six splicing factor 3b subunit 1 (SF3B1), three eukaryotic translation initiation factor 1A X-linked (EIF1AX) and four BAP1 mutations were detected. In contrast to uveal melanoma, GNAQ/11 mutant nonuveal melanomas frequently metastasized lymphatically and concurrent EIF1AX, SF3B1 and BAP1 mutations showed no apparent association with patient prognosis. Objective response to immunotherapy was poor with only one partial response observed in 10 treated patients (10\%). Conclusions Our findings suggest that GNAQ/11 mutant nonuveal melanomas are a subtype of melanoma that is both clinically and genetically distinct from cutaneous and uveal melanoma. As they respond poorly to available treatment regimens, novel effective therapeutic approaches for affected patients are urgently needed. What is already known about this topic? The rare occurrence of GNAQ/11 mutations in nonuveal melanoma has been documented. GNAQ/11 mutant nonuveal melanomas also harbour genetic alterations in EIF1AX, SF3B1 and BAP1 that are of prognostic relevance in uveal melanoma. What does this study add? GNAQ/11 mutant nonuveal melanomas show metastatic spread reminiscent of cutaneous melanoma, but not uveal melanoma. GNAQ/11 mutant nonuveal melanomas have a low tumour mutational burden that is higher than uveal melanoma, but lower than cutaneous melanoma. What is the translational message? Primary GNAQ/11 mutant nonuveal melanomas are a subtype of melanoma that is clinically and genetically distinct from both cutaneous and uveal melanoma. As metastatic GNAQ/11 mutant nonuveal melanomas respond poorly to available systemic therapies, including immune checkpoint inhibition, novel therapeutic approaches for these tumours are urgently needed.}, language = {en} } @article{ZeinerZinkeKowalewskietal.2018, author = {Zeiner, P. S. and Zinke, J. and Kowalewski, D. J. and Bernatz, S. and Tichy, J. and Ronellenfitsch, M. W. and Thorsen, F. and Berger, A. and Forster, M. T. and Muller, A. and Steinbach, J. P. and Beschorner, R. and Wischhusen, J. and Kvasnicka, H. M. and Plate, K. H. and Stefanović, S. and Weide, B. and Mittelbronn, M. and Harter, P. N.}, title = {CD74 regulates complexity of tumor cell HLA class II peptidome in brain metastasis and is a positive prognostic marker for patient survival}, series = {Acta Neuropathologica Communications}, volume = {6}, journal = {Acta Neuropathologica Communications}, doi = {10.1186/s40478-018-0521-5}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-233882}, year = {2018}, abstract = {Abstract Despite multidisciplinary local and systemic therapeutic approaches, the prognosis for most patients with brain metastases is still dismal. The role of adaptive and innate anti-tumor response including the Human Leukocyte Antigen (HLA) machinery of antigen presentation is still unclear. We present data on the HLA class II-chaperone molecule CD74 in brain metastases and its impact on the HLA peptidome complexity. We analyzed CD74 and HLA class II expression on tumor cells in a subset of 236 human brain metastases, primary tumors and peripheral metastases of different entities in association with clinical data including overall survival. Additionally, we assessed whole DNA methylome profiles including CD74 promoter methylation and differential methylation in 21 brain metastases. We analyzed the effects of a siRNA mediated CD74 knockdown on HLA-expression and HLA peptidome composition in a brain metastatic melanoma cell line. We observed that CD74 expression on tumor cells is a strong positive prognostic marker in brain metastasis patients and positively associated with tumor-infiltrating T-lymphocytes (TILs). Whole DNA methylome analysis suggested that CD74 tumor cell expression might be regulated epigenetically via CD74 promoter methylation. CD74\(^{high}\) and TIL\(^{high}\) tumors displayed a differential DNA methylation pattern with highest enrichment scores for antigen processing and presentation. Furthermore, CD74 knockdown in vitro lead to a reduction of HLA class II peptidome complexity, while HLA class I peptidome remained unaffected. In summary, our results demonstrate that a functional HLA class II processing machinery in brain metastatic tumor cells, reflected by a high expression of CD74 and a complex tumor cell HLA peptidome, seems to be crucial for better patient prognosis.}, language = {en} }