@phdthesis{Schreiner2023,
  author    = {Schreiner, Jochen Josef},
  title     = {Etablierung und Charakterisierung einer humanen adrenokortikalen Zelllinie},
  doi       = {10.25972/OPUS-31211},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-312119},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {Background: The response of advanced adrenocortical carcinoma (ACC) to current chemotherapies is unsatisfactory and a limited rate of response to immunotherapy was observed in clinical trials. High tumour mutational burden (TMB) and the presence of a specific DNA signature are characteristic features of tumours with mutations in the gene MUTYH encoding the mutY DNA glycosylase. Both have been shown to potentially predict the response to immunotherapy. High TMB in an ACC cell line model has not been reported yet. Design and methods: The JIL-2266 cell line was established from a primary ACC tumour, comprehensively characterised and oxidative damage, caused by a dysfunctional mutY DNA glycosylase, confirmed. Results: Here, we characterise the novel patient-derived ACC cell line JIL-2266, which is deficient in mutY-dependent DNA repair. JIL-2266 cells have a consistent STR marker profile that confirmed congruousness with primary ACC tumour. Cells proliferate with a doubling time of 41 ± 13 h. Immunohistochemistry revealed positivity for steroidogenic factor-1. Mass spectrometry did not demonstrate significant steroid hormone synthesis. JIL-2266 have hemizygous mutations in the tumour suppressor gene TP53 (c.859G>T:p.E287X) and MUTYH (c.316C>T:p.R106W). Exome sequencing showed 683 single nucleotide variants and 4 insertions/deletions. We found increased oxidative DNA damage in the cell line and the corresponding primary tumour caused by impaired mutY DNA glycosylase function and accumulation of 8-oxoguanine. Conclusion: This model will be valuable as a pre-clinical ACC cell model with high TMB and a tool to study oxidative DNA damage in the adrenal gland.},
  subject      = {Nebennierenrindenkarzinom},
  language  = {de}
}
@phdthesis{Maukner2023,
  author    = {Maukner, Alfred},
  title     = {Individualisierte Chemotherapie mit Streptozotocin beim Nebennierenrindenkarzinom},
  doi       = {10.25972/OPUS-32567},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-325675},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {Die Chemotherapie eines Nebennierenrindenkarzinomes gestaltet sich als insgesamt schwierig, da nur wenige prognostische Faktoren existieren. Ein m{\"o}gliches Chemotherapie-Regime beinhaltet Streptozotocin, ein alkylierendes Chemotherapeutikum, welches Guanin in Methylguanin alkyliert. Das andere verwendete Therapieregime umfasst EDP. Die FIRM-ACT Studie war die erste randomisierte Studie, welche die beiden Chemotherapie Regime EDP und STZ in Kombination mit Mitotan in der Behandlung des fortgeschrittenen ACC analysierte. Hier konnte ein signifikant l{\"a}ngeres progressionsfreies {\"U}berleben bei der Behandlung mit EDP + M (5 Monate) vs. STZ + M (2,1 Monate) festgestellt werden. Ein objektives Ansprechen des Tumors zeigte sich bei EDP + M bei (35 von 151 Patienten) und bei STZ + M bei (14 von 153) Patienten. Es folgte daher die Empfehlung im Versorgungsalltag EDP + M als Erstlinientherapie einzusetzen. Zur Evaluierung eines m{\"o}glichen Ansprechens von STZ wurde der Methylierungsstatus von MGMT analysiert. MGMT ist ein Protein, welches Alkylierungen durch Bindung entfernt und repariert Methylguanin in Guanin. Eine Hypermethylierung f{\"u}hrt zu einer reduzierten Expression von MGMT und folglich zu einer verminderten Reparaturkapazit{\"a}t. Dies f{\"u}hrt insgesamt zu einem besseren Ansprechen der alkylierenden Chemotherapie mit l{\"a}ngerem progressionsfreiem {\"U}berleben und Gesamt{\"u}berleben. In der Kohorte konnten dabei zwei Amplicons des MGMT-Gens mit einem statistisch signifikanten Unterschied zwischen Responder und Non-Responder festgestellt werden. Zudem untersuchten wir die Expression von GLUT-2, welcher STZ {\"u}ber die Zellmembran transportiert. Vier der untersuchten Proben zeigten jedoch keine membran{\"a}re Expression, diese waren Non-Responder, sodass die membran{\"a}re Expression von GLUT-2 eine erste Voraussetzung f{\"u}r die Aufnahme von STZ in Tumorzellen zu sein scheint. Entsprechend der Ergebnisse kann davon ausgegangen werden, dass der Methylierungsstatus der Promotorregion des MGMT-Gens als prognostischer Faktor zur Therapieentscheidung mit STZ hinzugezogen werden sollte, wenn die Tumorzellen GLUT-2 membran{\"a}r exprimieren. Insgesamt k{\"o}nnte dies der erste Schritt einer individualisierten/stratifizierten Chemotherapie beim fortgeschrittenen ACC mit STZ sein.},
  subject      = {Streptozocin},
  language  = {de}
}
@phdthesis{Landwehr2023,
  author    = {Landwehr, Laura-Sophie},
  title     = {Steroid Hormones and Cancer Immunity - learning from Adrenocortical Carcinoma},
  doi       = {10.25972/OPUS-25189},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-251895},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {Adrenocortical carcinoma (ACC) is a rare, but highly aggressive endocrine malignancy. Tumor-related hypercortisolism is present in 60 \% of patients and associated with worse outcome. While cancer immunotherapies have revolutionized the treatment of many cancer entities, the results of initial studies of different immune checkpoint inhibitors in ACC were heterogeneous. Up to now, five small clinical trials with a total of 121 patients have been published and demonstrated an objective response in only 17 patients. However, one of the studies, by Raj et al., reported a clinically meaningful disease control rate of 52 \% and a median overall survival of almost 25 months suggesting that a subgroup of ACC patients may benefit from immunotherapeutic approaches. Following the hypothesis that some ACCs are characterized by a glucocorticoid-induced T lymphocytes depletion, several studies were performed as part of the presented thesis. First, the immune cell infiltration in a large cohort of 146 ACC specimens was investigated. It was demonstrated for the first time, and against the common assumption, that ACCs were infiltrated not only by FoxP3+ regulatory T cells (49.3 \%), but also that a vast majority of tumor samples was infiltrated by CD4+ TH cells (74 \%) and CD8+ cytotoxic T cells (84.3 \%), albeit the immune cell number varied heterogeneously and was rather low (median: 7.7 CD3+ T cells / high power field, range: 0.1-376). Moreover, the presence of CD3+-, CD4+- and CD8+ ACC-infiltrating lymphocytes was associated with an improved recurrence-free (HR: 0.31 95 \% CI 0.11-0.82) and overall survival (HR: 0.47 96 \% CI 0.25-0.87). Particularly, patients with tumor-infiltrating CD4+ TH cells without glucocorticoid excess had a significantly longer overall survival compared to patients with T cell-depleted ACC and hypercortisolism (121 vs. 27 months, p = 0.004). Hence, the impact of glucocorticoids might to some extent be responsible for the modest immunogenicity in ACC as hypercortisolism was reversely correlated with the number of CD4+ TH cells. Accordingly, CD3+ T cells co-cultured with steroidogenic NCI-H295R ACC cells demonstrated in vitro an enhanced anti-tumoral cytotoxicity by secreting 747.96 ±225.53 pg/ml IFN-γ in a therapeutically hormone-depleted microenvironment (by incubation with metyrapone), versus only 276.02 ±117.46 pg/ml IFN-γ in a standard environment with glucocorticoid excess. Other potential biomarkers to predict response to immunotherapies are the immunomodulatory checkpoint molecules, programmed cell death 1 (PD-1) and its ligand PD-L1, since both are targets of antibodies used therapeutically in different cancer entities. In a subcohort of 129 ACCs, expressions of both molecules were heterogeneous (PD-1 17.4 \%, range 1-15; PD-L1 24.4 \%, range 1 - 90) and rather low. Interestingly, PD-1 expression significantly influenced ACC patients´ overall (HR: 0.21 95 \% CI 0.53-0.84) and progression- free survival (HR: 0.30 95 \% CI 0.13-0.72) independently of established factors, like ENSAT tumor stage, resection status, Ki67 proliferation index and glucocorticoid excess, while PD-L1 had no impact. In conclusion, this study provides several potential explanations for the heterogeneous results of the immune checkpoint therapy in advanced ACC. In addition, the establishment of PD-1 as prognostic marker can be easily applied in routine clinical care, because it is nowadays anyway part of a detailed histo-pathological work-up. Furthermore, these results provide the rationale and will pave the way towards a combination therapy using immune checkpoint inhibitors as well as glucocorticoid blockers. This will increase the likelihood of re-activating the immunological anti-tumor potential in ACC. However, this will have to be demonstrated by additional preclinical in vivo experiments and finally in clinical trials with patients.},
  subject      = {Steroidhormon},
  language  = {en}
}