@article{SbieraTryfonidouWeigandetal.2016,
  author    = {Sbiera, Silviu and Tryfonidou, Marianna A. and Weigand, Isabel and Grinwis, Guy C. M. and Broeckx, Bart and Herterich, Sabine and Allolio, Bruno and Deutschbein, Timo and Fassnacht, Martin and Meij, Bj{\"o}rn P.},
  title     = {Lack of Ubiquitin Specific Protease 8 (USP8) Mutations in Canine Corticotroph Pituitary Adenomas},
  series = {Plos One},
  volume    = {11},
  journal   = {Plos One},
  number    = {12},
  doi       = {10.1371/journal.pone.0169009},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-148020},
  pages     = {e0169009},
  year      = {2016},
  abstract  = {Purpose Cushing's disease (CD), also known as pituitary-dependent hyperadrenocorticism, is caused by adrenocorticotropic hormone (ACTH)-secreting pituitary tumours. Affected humans and dogs have similar clinical manifestations, however, the incidence of the canine disease is thousand-fold higher. This makes the dog an obvious model for studying the pathogenesis of pituitary-dependent hyperadrenocorticism. Despite certain similarities identified at the molecular level, the question still remains whether the two species have a shared oncogenetic background. Recently, hotspot recurrent mutations in the gene encoding for ubiquitin specific protease 8 (USP8) have been identified as the main driver behind the formation of ACTH-secreting pituitary adenomas in humans. In this study, we aimed to verify whether USP8 mutations also play a role in the development of such tumours in dogs. Methods Presence of USP8 mutations was analysed by Sanger and PCR-cloning sequencing in 38 canine ACTH-secreting adenomas. Furthermore, the role of USP8 and EGFR protein expression was assessed by immunohistochemistry in a subset of 25 adenomas. Results None of the analysed canine ACTH-secreting adenomas presented mutations in the USP8 gene. In a subset of these adenomas, however, we observed an increased nuclear expression of USP8, a phenotype characteristic for the USP8 mutated human tumours, that correlated with smaller tumour size but elevated ACTH production in those tumours. Conclusions Canine ACTH-secreting pituitary adenomas lack mutations in the USP8 gene suggesting a different genetic background of pituitary tumourigenesis in dogs. However, elevated nuclear USP8 protein expression in a subset of tumours was associated with a similar phenotype as in their human counterparts, indicating a possible end-point convergence of the different genetic backgrounds in the two species. In order to establish the dog as a useful animal model for the study of CD, further comprehensive studies are needed.},
  language  = {en}
}
@article{RonchiSbieraVolanteetal.2014,
  author    = {Ronchi, Cristina L. and Sbiera, Silviu and Volante, Marco and Steinhauer, Sonja and Scott-Wild, Vanessa and Altieri, Barbara and Kroiss, Matthias and Bala, Margarita and Papotti, Mauro and Deutschbein, Timo and Terzolo, Massimo and Fassnacht, Martin and Allolio, Bruno},
  title     = {CYP2W1 Is Highly Expressed in Adrenal Glands and Is Positively Associated with the Response to Mitotane in Adrenocortical Carcinoma},
  doi       = {10.1371/journal.pone.0105855},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-113096},
  year      = {2014},
  abstract  = {Background Adrenocortical tumors comprise frequent adenomas (ACA) and rare carcinomas (ACC). Human cytochrome P450 2W1 (CYP2W1) is highly expressed in some cancers holding the potential to activate certain drugs into tumor cytotoxins. Objective To investigate the CYP2W1 expression in adrenal samples and its relationship with clinical outcome in ACC. Material and Methods CYP2W1 expression was investigated by qRT-PCR in 13 normal adrenal glands, 32 ACA, 25 ACC, and 9 different non-adrenal normal tissue samples and by immunohistochemistry in 352 specimens (23 normal adrenal glands, 33 ACA, 239 ACC, 67 non-adrenal normal or neoplastic samples). Results CYP2W1 mRNA expression was absent/low in normal non-adrenal tissues, but high in normal and neoplastic adrenal glands (all P<0.01 vs non-adrenal normal tissues). Accordingly, CYP2W1 immunoreactivity was absent/low (H-score 0-1) in 72\% of non-adrenal normal tissues, but high (H-score 2-3) in 44\% of non-adrenal cancers, in 65\% of normal adrenal glands, in 62\% of ACAs and in 50\% of ACCs (all P<0.001 vs non-adrenal normal tissues), being significantly increased in steroid-secreting compared to non-secreting tumors. In ACC patients treated with mitotane only, high CYP2W1 immunoreactivity adjusted for ENSAT stage was associated with longer overall survival and time to progression (P<0.05 and P<0.01, respectively), and with a better response to therapy both as palliative (response/stable disease in 42\% vs 6\%, P<0.01) or adjuvant option (absence of disease recurrence in 69\% vs 45\%, P<0.01). Conclusion CYP2W1 is highly expressed in both normal and neoplastic adrenal glands making it a promising tool for targeted therapy in ACC. Furthermore, CYP2W1 may represent a new predictive marker for the response to mitotane treatment.},
  language  = {en}
}
@article{SbieraRonchiLeichetal.2013,
  author    = {Sbiera, Silviu and Ronchi, Cristina L. and Leich, Ellen and Henzel, Katharina and Rosenwald, Andreas and Allolio, Bruno and Fassnacht, Martin},
  title     = {Single Nucleotide Polymorphism Array Profiling of Adrenocortical Tumors - Evidence for an Adenoma Carcinoma Sequence?},
  series = {PLoS ONE},
  journal   = {PLoS ONE},
  doi       = {10.1371/journal.pone.0073959},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-97218},
  year      = {2013},
  abstract  = {Adrenocortical tumors consist of benign adenomas and highly malignant carcinomas with a still incompletely understood pathogenesis. A total of 46 adrenocortical tumors (24 adenomas and 22 carcinomas) were investigated aiming to identify novel genes involved in adrenocortical tumorigenesis. High-resolution single nucleotide polymorphism arrays (Affymetrix) were used to detect copy number alterations (CNAs) and copy neutral losses of heterozygosity (cnLOH). Genomic clustering showed good separation between adenomas and carcinomas, with best partition including only chromosome 5, which was highly amplified in 17/22 malignant tumors. The malignant tumors had more relevant genomic aberrations than benign tumors, such as a higher median number of recurrent CNA (2631 vs 94), CNAs >100 Kb (62.5 vs 7) and CN losses (72.5 vs 5.5), and a higher percentage of samples with cnLOH (91\% vs 29\%). Within the carcinoma cohort, a precise genetic pattern (i.e. large gains at chr 5, 7, 12, and 19, and losses at chr 1, 2, 13, 17, and 22) was associated with a better prognosis (overall survival: 72.2 vs 35.4 months, P=0.063). Interestingly, >70\% of gains frequent in beningn were also present in malignant tumors. Notch signaling was the most frequently involved pathway in both tumor entities. Finally, a CN gain at imprinted "IGF2" locus chr 11p15.5 appeared to be an early alteration in a multi-step tumor progression, followed by the loss of one or two alleles, associated with increased IGF2 expression, only in carcinomas. Our study serves as database for the identification of genes and pathways, such as Notch signaling, which could be involved in the pathogenesis of adrenocortical tumors. Using these data, we postulate an adenoma-carcinoma sequence for these tumors.},
  language  = {en}
}
@article{FassnachtSbieraDexneitetal.2011,
  author    = {Fassnacht, Martin and Sbiera, Silviu and Dexneit, Thomas and Reichardt, Sybille D. and Michel, Kai D. and van den Brandt, Jens and Schmull, Sebastian and Kraus, Luitgard and Beyer, Melanie and Mlynski, Robert and Wortmann, Sebastian and Allolio, Bruno and Reichardt, Holger M.},
  title     = {Influence of Short-Term Glucocorticoid Therapy on Regulatory T Cells In Vivo},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-74749},
  year      = {2011},
  abstract  = {Background: Pre- and early clinical studies on patients with autoimmune diseases suggested that induction of regulatory T(Treg) cells may contribute to the immunosuppressive effects of glucocorticoids(GCs). Objective: We readdressed the influence of GC therapy on Treg cells in immunocompetent human subjects and na{\i}¨ve mice. Methods: Mice were treated with increasing doses of intravenous dexamethasone followed by oral taper, and Treg cells in spleen and blood were analyzed by FACS. Sixteen patients with sudden hearing loss but without an inflammatory disease received high-dose intravenous prednisolone followed by stepwise dose reduction to low oral prednisolone. Peripheral blood Treg cells were analyzed prior and after a 14 day GC therapy based on different markers. Results: Repeated GC administration to mice for three days dose-dependently decreased the absolute numbers of Treg cells in blood (100 mg dexamethasone/kg body weight: 2.861.86104 cells/ml vs. 336116104 in control mice) and spleen (dexamethasone: 2.861.96105/spleen vs. 956226105/spleen in control mice), which slowly recovered after 14 days taper in spleen but not in blood. The relative frequency of FOXP3+ Treg cells amongst the CD4+ T cells also decreased in a dose dependent manner with the effect being more pronounced in blood than in spleen. The suppressive capacity of Treg cells was unaltered by GC treatment in vitro. In immunocompetent humans, GCs induced mild T cell lymphocytosis. However, it did not change the relative frequency of circulating Treg cells in a relevant manner, although there was some variation depending on the definition of the Treg cells (FOXP3+: 4.061.5\% vs 3.461.5\%*; AITR+: 0.660.4 vs 0.560.3\%, CD127low: 4.061.3 vs 5.063.0\%* and CTLA4+: 13.8611.5 vs 15.6612.5\%; * p,0.05). Conclusion: Short-term GC therapy does not induce the hitherto supposed increase in circulating Treg cell frequency, neither in immunocompetent humans nor in mice. Thus, it is questionable that the clinical efficacy of GCs is achieved by modulating Treg cell numbers.},
  subject      = {Medizin},
  language  = {en}
}