@phdthesis{Baumann2020, author = {Baumann, Christoph}, title = {Herzfrequenzregulation bei Patienten mit einer Anorexia nervosa}, doi = {10.25972/OPUS-21885}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-218858}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2020}, abstract = {In dieser Arbeit wurde die Herzratenvariabilit{\"a}t (HRV), das Interbeat-Intervall (IBI) sowie die Beziehung zwischen HRV und IBI bei gesunden Probanden, bradykarden Patienten mit einer Mutation im hyperpolarization-activated cyclic nucleotide-gated channel 4-(HCN4) Gen sowie Patienten mit einer Anorexie nervosa (AN) untersucht. Die Haupthypothese lautete, dass die bei Patienten mit AN oft zu beobachtenden Bradykardien durch neurale Mechanismen verursacht werden. Daher wurde angenommen, dass ein S{\"a}ttigungseffekt der HRV/IBI Beziehung infolge einer anhaltenden parasympathischen Kontrolle des Sinusknotenareals lediglich bei Patienten mit einer AN nachzuweisen ist. In dieser Arbeit konnte ein S{\"a}ttigungseffekt der HRV/IBI-Beziehung bei Patienten mit einer Anorexia nervosa sowie bei zwei von vier Patienten mit einer HCN4-Mutation nachgewiesen werden. Bei Kontrollen konnten hingegen kaum Zeichen eines S{\"a}ttigungseffekts der HRV/IBI Beziehung nachgewiesen werden. Es wurde daher geschlussfolgert, dass ein S{\"a}ttigungseffekt der HRV/IBI Beziehung keine parasympathisch-vermittelte Bradykardie beweist. Es zeigt sich vielmehr, dass die Regulation des HCN4-Gens f{\"u}r die Bradykardie und den festgestellten HRV-S{\"a}ttigungseffekt bei Patienten mit einer AN verantwortlich sein k{\"o}nnte.}, subject = {Anorexia nervosa}, language = {de} } @phdthesis{Haberzettl2020, author = {Haberzettl, Martin}, title = {Mittelfristige Ergebnisse nach stadienadaptierter, operativer Versorgung der Ruptur des Bandes zwischen Skaphoid und Lunatum mittels SL-Bandnaht zuz{\"u}glich dorsaler Kapsulodese oder 3-Ligament-Tenodese}, doi = {10.25972/OPUS-19994}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-199943}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2020}, abstract = {Einzeitige, retrospektive klinische Studie {\"u}ber die klinischen und radiologischen Ergebnisse nach stadienadaptierter Therapie der vollst{\"a}ndigen SL-Bandruptur {\O} 7,5 Jahre postoperativ. Es wurden 33 Patienten nach SL-Bandnaht zuz{\"u}glich dorsaler Kapsulodese (bei intraoperativ vorhandenen, n{\"a}hbaren SL-Bandresten) und 39 Patienten nach SL-Bandrekonstruktion mittels 3-Ligament-Tenodese (bei fehlenden SL-Bandresten) nachuntersucht. Ein Erhalt des physiologischen karpalen Gef{\"u}ges nach SL-Bandnaht zzgl. Kapsulodese war zum Zeitpunkt der Nachuntersuchung allenfalls in den statischen R{\"o}ntgenbildern, jedoch nicht in den Belastungsaufnahmen und nur in der Gruppe mit pr{\"a}operativ dynamischer SL-Instabilit{\"a}t ersichtlich. In allen Gruppen hatte sich bei >50\% der Patienten eine (posttraumatische) Handgelenksarthrose entwickelt. Die Handgelenksbeweglichkeit, die Griffkraft, die Schmerzsituation und die Funktionsscores waren leicht eingeschr{\"a}nkt, jedoch zufriedenstellend. Nach SL-Bandnaht zzgl. Kapsulodese resultierte lediglich eine revisionspflichtige Komplikation (3\%). Nach 3LT resultierten >30\% revisionspflichtige Komplikationen und >20\% Rettungsoperationen. Die 3LT ist ein komplexer, hochinvasiver operativer Eingriff mit hohen Komplikationsrisiken. Als Resultat unserer Studie stellen wir die Wertigkeit der 3LT zur kurativen Therapie der SL-Bandl{\"a}sion g{\"a}nzlich in Frage. Falls intraoperativ noch vitale und n{\"a}hbare SL-Bandreste vorliegen, sollte die Naht des SL-Bandes zuz{\"u}glich dorsaler Kapsulodese bevorzugt werden.}, subject = {Handgelenk}, language = {de} } @article{ReinersSchneiderPlatonovaetal.2020, author = {Reiners, Christoph and Schneider, Rita and Platonova, Tamara and Fridman, Mikhail and Malzahn, Uwe and M{\"a}der, Uwe and Vrachimis, Alexis and Bogdanova, Tatiana and Krajewska, Jolanta and Elisei, Rossella and Vaisman, Fernanda and Mihailovic, Jasna and Costa, Gracinda and Drozd, Valentina}, title = {Breast Cancer After Treatment of Differentiated Thyroid Cancer With Radioiodine in Young Females: What We Know and How to Investigate Open Questions. Review of the Literature and Results of a Multi-Registry Survey}, series = {Frontiers in Endocrinology}, volume = {11}, journal = {Frontiers in Endocrinology}, issn = {1664-2392}, doi = {10.3389/fendo.2020.00381}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-207766}, year = {2020}, abstract = {Published studies on the risk of radiation-induced second primary malignancy (SPM) after radioiodine treatment (RAI) of differentiated thyroid cancer (DTC) refer mainly to patients treated as middle-aged or older adults and are not easily generalizable to those treated at a younger age. Here we review available literature on the risk of breast cancer as an SPM after RAI of DTC with a focus on females undergoing such treatment in childhood, adolescence, or young adulthood. Additionally, we report the results of a preliminary international survey of patient registries from academic tertiary referral centers specializing in pediatric DTC. The survey sought to evaluate the availability of sufficient patient data for a potential international multicenter observational case-control study of females with DTC given RAI at an early age. Our literature review identified a bi-directional association of DTC and breast cancer. The general breast cancer risk in adult DTC survivors is low, ~2\%, slightly higher in females than in males, but presumably lower, not higher, in those diagnosed as children or adolescents than in those diagnosed at older ages. RAI presumably does not substantially influence breast cancer risk after DTC. However, data from patients given RAI at young ages are sparse and insufficient to make definitive conclusions regarding age dependence of the risk of breast cancer as a SPM after RAI of DTC. The preliminary analysis of data from 10 thyroid cancer registries worldwide, including altogether 6,449 patients given RAI for DTC and 1,116 controls, i.e., patients not given RAI, did not show a significant increase of breast cancer incidence after RAI. However, the numbers of cases and controls were insufficient to draw statistically reliable conclusions, and the proportion of those receiving RAI at the earliest ages was too low.In conclusion, a potential international multicenter study of female patients undergoing RAI of DTC as children, adolescents, or young adults, with a sufficient sample size, is feasible. However, breast cancer screening of a larger cohort of DTC patients is not unproblematic for ethical reasons, due to the likely, at most slightly, increased risk of breast cancer post-RAI and the expected ~10\% false-positivity rate which potentially produced substantial "misdiagnosis."}, language = {en} } @phdthesis{Liang2021, author = {Liang, Raimunde}, title = {Identification of new drug targets in adrenocortical carcinoma through targeted mRNA analysis}, doi = {10.25972/OPUS-23554}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-235545}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {Adrenocortical carcinomas (ACC) are aggressive tumors associated with a heterogeneous but generally poor prognosis and limited treatment options for advanced stages. Despite promising molecular insights and improved understanding of ACC biology, efficient targeted therapies have not been identified yet. Thus, this study aims to identify potential new drug targets for a future personalized therapeutic approach. RNA was isolated from 104 formalin-fixed paraffin-embedded tumor samples from ACC patients, 40 of those 104 cases proved to be suitable for further mRNA analyses according to the quality check of the extracted RNA. Gene expression of 84 known cancer drug targets was evaluated by quantitative real-time PCR using 5 normal adrenal glands as reference. Protein expression was investigated for selected candidate drug targets by immunohistochemistry in 104 ACC samples, 11 adenomas and 6 normal adrenal glands. Efficacy of an available inhibitor of the most promising candidate was tested by functional in vitro experiments in two ACC cell lines (NCI-H295R and MUC1) alone or in combination with other drugs. Most frequently overexpressed genes were TOP2A, IGF2, CDK1, CDK4, PLK4 and PLK1. Nuclear immunostaining of CDK1, CDK4 and PLK1 significantly correlated with the respective mRNA expression. CDK4 was chosen as the most promising candidate for functional validation as it is actionable by FDA-approved CDK4/6 inhibitors. ACC samples with copy number gains at CDK4 locus presented significantly higher CDK4 expression levels. The CDK4/6 inhibitor palbociclib showed a concentration- and time- dependent reduction of cell viability in vitro, which was more pronounced in NCI-H295R than in MUC1 cells. This was in line with higher CDK4 expression at western blot analysis in NCI-H295R cells. Furthermore, palbociclib was applied in combination with dual IGFR/IR inhibitor linsitinib showing a synergistic effect on reducing cell viability. In conclusion, this proof-of-principle study confirmed RNA profiling to be useful to discover potential drug targets. Detected drug targets are suitable to be investigated by immunohistochemistry in the clinical setting. Moreover, CDK4/6 inhibitors are promising candidates for treatment of a subset of patients with tumors presenting CDK4 copy number gains and/or overexpression, while linsitinib might be an interesting combination partner in patients with both IGF2 and IGF1R overexpression. These results are intended as a basis for a validation study in a prospective cohort, further evaluation in vivo in suitable mouse models or testing in patients with ACC in clinical trials are needed and might improve the future management of patients with ACC in terms of precision medicine.}, subject = {Adrenokortikales Karzinom}, language = {en} } @phdthesis{Stark2024, author = {Stark, Irmgard Katharina}, title = {Einfluss von Interferon auf das Infektionsverhalten von Herpes simplex Virus 1 und seiner DUB - Mutante C65A in der Zellkultur}, doi = {10.25972/OPUS-35195}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-351950}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Die Erforschung viraler Proteine ist wichtig, um virale Infektionen besser verstehen und damit therapieren zu k{\"o}nnen. Die Aufkl{\"a}rung der DUB-Funktion auf dem viralen Herpesprotein pUL36 erm{\"o}glicht ein besseres Verst{\"a}ndnis des Infektionshergangs und k{\"o}nnte zur Entwicklung eines Enzyminhibitors f{\"u}hren, der nur an diesem Enzym ansetzt, nachdem es sich von den zellul{\"a}ren DUBs unterscheidet (Kattenhorn et al., 2005). In dieser Arbeit konnten die vorherigen Daten, die eine st{\"a}rkere Hemmung der DUB- Mutante unter Interferoneinfluss zeigten, in unterschiedlichen Assay-Designs best{\"a}tigt werden. Auch Versuche mit einem anderen Herpes simplex Virus Strang, best{\"a}tigten die vorherigen Daten. Die Ergebnisse zeigen, dass die DUB-Funktion f{\"u}r HSV-1 wichtig ist f{\"u}r die virale Evasion der zellul{\"a}ren Immunantwort. Die genaue Funktion der DUB in der Infektion ist jedoch unklar. Aufgrund der vorbestehenden Datenlage erschien am wahrscheinlichsten, dass die DUB-Funktion vor Eindringen des Herpes Simplex Virus in den Zellkern zum Tragen kommt, womit es nach Abnahme des Interferons nicht zu einer viralen Reaktivierung k{\"a}me. Deshalb wurden Untersuchungen unternommen, um eine m{\"o}gliche Reaktivierung nach Abnahme des Interferons n{\"a}her zu untersuchen. Hierf{\"u}r wurden zwei verschiedene Experimente entwickelt. Einmal wurde das Interferon direkt nach Infektion und einmal 3 Tage nach Infektion (3dpi) abgenommen. Die Ergebnisse zeigten beide eine st{\"a}rkere Hemmung der DUB-HSV-1-Mutante unter Interferoneinfluss. Bei Abnahme des Interferons direkt nach Infektion lag bei Wildtyp und Mutante ein leichter Anstieg der Plaquezahlen vor, wobei dieser Effekt von der Dosis des Interferons abh{\"a}ngig war. Eine hohe Interferondosis beg{\"u}nstigte bei beiden eine st{\"a}rkere Hemmung, allerdings bei beiden auch eine leichte Erh{\"o}hung der Plaquezahl nach Abnahme. Bei einer niedrigen Dosis konnte nur eine st{\"a}rkere Hemmung der DUB-Mutante, jedoch keine Reaktivierung bei Wildtyp und Mutante nach Abnahme des Interferons gezeigt werden. Bei Abnahme drei Tage nach Infektion zeigte sich sowohl bei dem Wildtyp-Virus als auch der DUB- Mutante kein Anstieg in den Plaquezahlen. Es sind, nachdem Deubiquitinierung nicht nur eine Rolle in der Verhinderung des proteosomalen Abbaus von in die Zelle eingedrungenem Virus spielt, sondern auch der Zellregulation, mehrere Szenarien denkbar, die diesen Ph{\"a}notyp erkl{\"a}ren k{\"o}nnten. Die DUB-Funktion k{\"o}nnte zwar den proteosomalen Abbau durch Deubiqutinierung und damit Verhinderung der Markierung des Virus zum zellul{\"a}ren Abbau verhindern. Allerdings k{\"o}nnten sich durch einen langsameren Transport aus der Zelle oder in den Nucleus auch weniger Plaques bei der Mutante als wie beim Wildtyp unter Interferoneinfluss bilden, nachdem das Virus dann leichter Ziel antiviraler Proteine werden k{\"o}nnte. Oder die DUB-Funktion spielt eine Rolle beim Eintritt in den Kern durch Modifikationen anderer Proteine. Virengenome k{\"o}nnten auch durch eine fehlende DUB-Funktion reprimiert werden oder die Zelle durch Apoptose absterben. Interessanterweise konnte keine Hemmung der DUB-Mutante in Interferon behandelten U-2 OS Zellen gezeigt werden, von denen ein Defekt im STING- vermittelten Signalweg bekannt ist. Vielleicht zeigt dies, dass das STING-Protein an dem gezeigten DUB-Ph{\"a}notyp beteiligt ist. Nachgewiesen ist außerdem bereits eine Funktion des Enzyms bei der zweiten Umh{\"u}llung der Kapside bei Pseudorabiesvirus (M{\"o}hl, 2011). Weitere Untersuchungen unter Einsatz bspw. von Immunfluoreszenz, Proteasominhibitoren oder weiteren Zelllinien wie Saos-2, sind n{\"o}tig, um die genaue Funktion zu kl{\"a}ren.}, subject = {Interferon}, language = {de} } @phdthesis{CruzdeCasas2024, author = {Cruz de Casas, Paulina}, title = {Sphingolipids as modulators of T cell function}, doi = {10.25972/OPUS-35969}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-359698}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {The immune system is responsible for the preservation of homeostasis whenever a given organism is exposed to distinct kinds of perturbations. Given the complexity of certain organisms like mammals, and the diverse types of challenges that they encounter (e.g. infection or disease), the immune system evolved to harbor a great variety of distinct immune cell populations with specialized functions. For instance, the family of T cells is sub-divided into conventional (Tconv) and unconventional T cells (UTCs). Tconv form part of the adaptive arm of the immune system and are comprised of αβ CD4+ or CD8+ cells that differentiate from na{\"i}ve to effector and memory populations upon activation and are essential during infection and cancer. Furthermore, UTCs, which include γδ T cells, NKT and MAIT, are involved in innate and adaptive immune responses, due to their dual mode of activation, through cytokines (innate-like) or TCR (adaptive), and function. Despite our understanding of the basic functions of T cells in several contexts, a great number of open questions related to their basic biology remain. For instance, the mechanism behind the differentiation of na{\"i}ve CD4+ and CD8+ T cells into effector and memory populations is not fully understood. Moreover, the exact function and relevance of distinct UTC subpopulations in a physiological context have not been fully clarified. Here, we investigated the factors mediating na{\"i}ve CD8+ T cell differentiation into effector and memory cells. By using flow cytometry, mass spectrometry, enzymatic assays, and transgenic mouse models, we found that the membrane bound enzyme sphingomyelin-phosphodiesterase acid-like 3b (Smpdl3b) is crucial for the maintenance of memory CD8+ T cells. Our data show that the absence of Smpdl3b leads to diminished CD8+ T cell memory, and a loss of stem-like memory populations due to an aggravated contraction. Our scRNA-seq data suggest that Smpdl3b could be involved in clathrinmediated endocytosis through modulation of Huntingtin interacting protein 1 (Hip1) levels, likely regulating TCR-independent signaling events. Furthermore, in this study we explored the role of UTCs in lymph node-specific immune responses. By using transgenic mouse models for photolabeling, lymph node transplantation models, infection models and flow cytometry, we demonstrate that S1P regulates the migration of tissue-derived UTC from tissues to draining lymph nodes, resulting in heterogeneous immune responses mounted by lymph nodes draining different tissues. Moreover, our unbiased scRNAseq and single lineage-deficient mouse models analysis revealed that all UTC lineages (γδ T cells, NKT and MAIT) are organized in functional units, based on transcriptional homogeneity, shared microanatomical location and migratory behavior, and numerical and functional redundancy. Taken together, our studies describe additional cell intrinsic (Smpdl3b) and extrinsic (S1Pmediated migration) functions of sphingolipid metabolism modulating T cell biology. We propose the S1P/S1PR1/5 signaling axis as the potential survival pathway for Smpdl3b+ memory CD8+ T cells and UTCs, mainly in lymph nodes. Possibly, Smpdl3b regulates S1P/S1PR signaling by balancing ligandreceptor endocytosis, while UTCs migrate to lymph nodes during homeostasis to be exposed to specific levels of S1P that assure their maintenance. Our results are clinically relevant, since several drugs modulating the S1P/S1PR signaling axis or the levels of Smpdl3b are currently used to treat human diseases, such as multiple sclerosis and B cell-mediated diseases. We hope that our discoveries will inspire future studies focusing on sphingolipid metabolism in immune cell biology.}, subject = {T-Lymphozyt}, language = {en} } @phdthesis{Yu2024, author = {Yu, Yanying}, title = {Applied machine learning for the analysis of CRISPR-Cas systems}, doi = {10.25972/OPUS-32021}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-320219}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Among the defense strategies developed in microbes over millions of years, the innate adaptive CRISPR-Cas immune systems have spread across most of bacteria and archaea. The flexibility, simplicity, and specificity of CRISPR-Cas systems have laid the foundation for CRISPR-based genetic tools. Yet, the efficient administration of CRISPR-based tools demands rational designs to maximize the on-target efficiency and off-target specificity. Specifically, the selection of guide RNAs (gRNAs), which play a crucial role in the target recognition of CRISPR-Cas systems, is non-trivial. Despite the fact that the emerging machine learning techniques provide a solution to aid in gRNA design with prediction algorithms, design rules for many CRISPR-Cas systems are ill-defined, hindering their broader applications. CRISPR interference (CRISPRi), an alternative gene silencing technique using a catalytically dead Cas protein to interfere with transcription, is a leading technique in bacteria for functional interrogation, pathway manipulation, and genome-wide screens. Although the application is promising, it also is hindered by under-investigated design rules. Therefore, in this work, I develop a state-of-art predictive machine learning model for guide silencing efficiency in bacteria leveraging the advantages of feature engineering, data integration, interpretable AI, and automated machine learning. I first systematically investigate the influential factors that attribute to the extent of depletion in multiple CRISPRi genome-wide essentiality screens in Escherichia coli and demonstrate the surprising dominant contribution of gene-specific effects, such as gene expression level. These observations allowed me to segregate the confounding gene-specific effects using a mixed-effect random forest (MERF) model to provide a better estimate of guide efficiency, together with the improvement led by integrating multiple screens. The MERF model outperformed existing tools in an independent high-throughput saturating screen. I next interpret the predictive model to extract the design rules for robust gene silencing, such as the preference for cytosine and disfavoring for guanine and thymine within and around the protospacer adjacent motif (PAM) sequence. I further incorporated the MERF model in a web-based tool that is freely accessible at www.ciao.helmholtz-hiri.de. When comparing the MERF model with existing tools, the performance of the alternative gRNA design tool optimized for CRISPRi in eukaryotes when applied to bacteria was far from satisfying, questioning the robustness of prediction algorithms across organisms. In addition, the CRISPR-Cas systems exhibit diverse mechanisms albeit with some similarities. The captured predictive patterns from one dataset thereby are at risk of poor generalization when applied across organisms and CRISPR-Cas techniques. To fill the gap, the machine learning approach I present here for CRISPRi could serve as a blueprint for the effective development of prediction algorithms for specific organisms or CRISPR-Cas systems of interest. The explicit workflow includes three principle steps: 1) accommodating the feature set for the CRISPR-Cas system or technique; 2) optimizing a machine learning model using automated machine learning; 3) explaining the model using interpretable AI. To illustrate the applicability of the workflow and diversity of results when applied across different bacteria and CRISPR-Cas systems, I have applied this workflow to analyze three distinct CRISPR-Cas genome-wide screens. From the CRISPR base editor essentiality screen in E. coli, I have determined the PAM preference and sequence context in the editing window for efficient editing, such as A at the 2nd position of PAM, A/TT/TG downstream of PAM, and TC at the 4th to 5th position of gRNAs. From the CRISPR-Cas13a screen in E. coli, in addition to the strong correlation with the guide depletion, the target expression level is the strongest predictor in the model, supporting it as a main determinant of the activation of Cas13-induced immunity and better characterizing the CRISPR-Cas13 system. From the CRISPR-Cas12a screen in Klebsiella pneumoniae, I have extracted the design rules for robust antimicrobial activity across K. pneumoniae strains and provided a predictive algorithm for gRNA design, facilitating CRISPR-Cas12a as an alternative technique to tackle antibiotic resistance. Overall, this thesis presents an accurate prediction algorithm for CRISPRi guide efficiency in bacteria, providing insights into the determinants of efficient silencing and guide designs. The systematic exploration has led to a robust machine learning approach for effective model development in other bacteria and CRISPR-Cas systems. Applying the approach in the analysis of independent CRISPR-Cas screens not only sheds light on the design rules but also the mechanisms of the CRISPR-Cas systems. Together, I demonstrate that applied machine learning paves the way to a deeper understanding and a broader application of CRISPR-Cas systems.}, subject = {Maschinelles Lernen}, language = {en} } @article{AltieriDiDatoMartinietal.2019, author = {Altieri, Barbara and Di Dato, Carla and Martini, Chiara and Sciammarella, Concetta and Di Sarno, Antonella and Colao, Annamaria and Faggiano, Antongiulio}, title = {Bone Metastases in Neuroendocrine Neoplasms: From Pathogenesis to Clinical Management}, series = {Cancers}, volume = {11}, journal = {Cancers}, doi = {10.3390/cancers11091332}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-221079}, pages = {1-20}, year = {2019}, abstract = {Bone represents a common site of metastases for several solid tumors. However, the ability of neuroendocrine neoplasms (NENs) to localize to bone has always been considered a rare and late event. Thanks to the improvement of therapeutic options, which results in longer survival, and of imaging techniques, particularly after the introduction of positron emission tomography (PET) with gallium peptides, the diagnosis of bone metastases (BMs) in NENs is increasing. The onset of BMs can be associated with severe skeletal complications that impair the patient's quality of life. Moreover, BMs negatively affect the prognosis of NEN patients, bringing out the lack of curative treatment options for advanced NENs. The current knowledge on BMs in gastro-entero-pancreatic (GEP) and bronchopulmonary (BP) NENs is still scant and is derived from a few retrospective studies and case reports. This review aims to perform a critical analysis of the evidence regarding the role of BMs in GEP- and BP-NENs, focusing on the molecular mechanisms underlining the development of BMs, as well as clinical presentation, diagnosis, and treatment of BMs, in an attempt to provide suggestions that can be used in clinical practice.}, language = {en} } @phdthesis{Gronemeyer2024, author = {Gronemeyer, Karen}, title = {Kardiovaskul{\"a}re und renale Komorbidit{\"a}ten in Zusammenhang mit chronischem Hypoparathyreoidismus}, doi = {10.25972/OPUS-36069}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-360693}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Der cHPT ist eine seltene Erkrankung, die durch zu niedriges Kalzium im Serum aufgrund einer zu geringen PTH-Sekretion {\"u}ber 6 Monate charakterisiert ist. Auch bei Patienten mit einem gut kontrollierten cHPT treten Komorbidit{\"a}ten und Langzeitkomplikationen auf, die jedoch bisher kaum in prospektiven Studien untersucht wurden. Ziel dieser Arbeit war es daher, im Rahmen einer systematischen und prospektiv erfassten Studie das Auftreten kardiovaskul{\"a}rer und renaler Komorbidit{\"a}ten bei Patienten mit cHPT zu untersuchen und m{\"o}gliche Pr{\"a}diktoren f{\"u}r diese zu ermitteln. Außerdem erfolgte ein Vergleich mit gematchten Kontrollgruppen der deutschen Normalbev{\"o}lkerung mithilfe der SHIP-TREND Studie. Patienten mit cHPT zeigten eine signifikant h{\"o}here QTc-Zeit, eine h{\"o}here Pr{\"a}valenz f{\"u}r QTc-Zeit-Verl{\"a}ngerung und signifikant h{\"o}here systolische und diastolische Blutdruckwerte trotz tendenziell, jedoch nicht signifikant, h{\"a}ufigerer Einnahme antihypertensiver Medikamente. In der Echokardiographie lagen eine geringere linksventrikul{\"a}re Masse, eine geringere Pr{\"a}valenz f{\"u}r linksventrikul{\"a}re Hypertrophie und signifikant h{\"a}ufiger Klappenstenosen vor. Eine renale Insuffizienz lag mit 21\% der Patienten mit cHPT signifikant h{\"a}ufiger als bei gesunden Kontrollpersonen vor. Die Pr{\"a}valenz renaler Kalzifikationen betrug 9,6\%. M{\"o}gliche Risikofaktoren f{\"u}r das Auftreten kardiovaskul{\"a}rer und renaler Komorbidit{\"a}ten bei cHPT sind weiterhin unklar. In dieser Studie zeigte sich eine m{\"o}gliche Assoziation zwischen den Elektrolytst{\"o}rungen wie Hyperphosphat{\"a}mie und Hypomagnesi{\"a}mie, der Hyperkalziurie und dem PTH-Mangel mit valvul{\"a}ren, vaskul{\"a}ren und renalen Kalzifikationen sowie den Blutdruckwerten und der Nierenfunktion. Demnach erscheint eine {\"U}berwachung der Serumelektrolyte sowie der Kalziumausscheidung im Urin notwendig und essenziell. Auch die Bedeutung der PTH-Ersatztherapie ist weiterhin im Hinblick auf die Pr{\"a}vention kardiovaskul{\"a}rer und renaler Erkrankungen unklar.}, subject = {Hypoparathyreoidismus}, language = {de} } @phdthesis{Papay2024, author = {Papay, Marion}, title = {Notwendigkeit der pr{\"a}operativen Reposition von distalen, nach dorsal dislozierten Radiusfrakturen bei bestehender Operationsindikation im Hinblick auf das Schmerzniveau sowie postoperative Ergebnisse}, doi = {10.25972/OPUS-36388}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-363882}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Die distale Radiusfraktur geh{\"o}rt zu den h{\"a}ufigsten Frakturen in Deutschland mit einem Inzidenzanstieg im Alter unter Betonung des weiblichen Geschlechts. Dabei zeigt sich ein zunehmender Trend in Richtung operative Versorgung, allen voran die Versorgung mittels winkelstabiler Plattensysteme. Instabile, distale Radiusfrakturen werden dabei vor geplanter operativer Versorgung im Rahmen der Initialbehandlung {\"u}blicherweise geschlossen reponiert und im Gipsverband retiniert. Ziel der vorliegenden monozentrischen, prospektiv randomisierten Studie mit zwei Studiengruppen war es herauszufinden, ob sich das Unterlassen der Reposition vor geplanter Operation nachteilig auf das Schmerzniveau in der pr{\"a}operativen Phase auswirkt und ob sich durch die Dislokation Nachteile in Bezug auf den Nervus medianus im Sinne eines Traktionsschadens sowie bez{\"u}glich des klinisch-radiologischen Ausheilungsergebnisses zeigen. Die Studie zeigte, dass das Schmerzempfinden w{\"a}hrend der pr{\"a}operativen Gipsbehandlung unabh{\"a}ngig von einer vorherigen Reposition war. F{\"u}r den prim{\"a}ren Endpunkt an Tag 1 nach der Akutbehandlung konnte statistisch signifikante Nichtunterlegenheit der Gruppe ohne Reposition gegen{\"u}ber der Gruppe mit Reposition nachgewiesen werden. Gleiches galt f{\"u}r Tag 2, sowohl f{\"u}r die absoluten Schmerzniveaus als auch f{\"u}r die Schmerzlinderung. Das Unterlassen der Reposition hatte zudem keine nachteiligen Effekte auf den Nervus medianus. Gleiches zeigte sich f{\"u}r das klinische und radiologische Ausheilungsergebnis. F{\"u}r die funktionellen DASH- und Krimmer-Scores konnte ein Jahr postoperativ ebenfalls statistisch signifikante Nichtunterlegenheit der Gruppe ohne Reposition nachgewiesen werden. Diese Erkenntnisse best{\"a}tigen die in der Literatur vorhandenen Ergebnisse verschiedener Studien dahingehend, dass das Unterlassen der Reposition keine nachteiligen Effekte auf das postoperative Outcome hat. Einige Studien verdeutlichen zudem, dass es nach Reposition, insbesondere bei Vorliegen gewisser Risiko- und Instabilit{\"a}tsfaktoren, ohnehin zur sekund{\"a}ren Dislokation kommt, sodass die generelle Notwendigkeit der Reposition vor Gipsanlage sowohl vor einer operativen als auch vor einer konservativen Weiterbehandlung angezweifelt werden muss.}, subject = {distale Radiusfraktur}, language = {de} } @phdthesis{Reissland2024, author = {Reissland, Michaela}, title = {USP10 is a \(de\) \(novo\) tumour-specific regulator of β-Catenin and contributes to cancer stem cell maintenance and tumour progression}, doi = {10.25972/OPUS-31957}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-319579}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Colorectal Cancer (CRC) is the third most common cancer in the US. The majority of CRC cases are due to deregulated WNT-signalling pathway. These alterations are mainly caused by mutations in the tumour suppressor gene APC or in CTNNB1, encoding the key effector protein of this pathway, β-Catenin. In canonical WNT-signalling, β-Catenin activates the transcription of several target genes, encoding for proteins involved in proliferation, such as MYC, JUN and NOTCH. Being such a critical regulator of these proto-oncogenes, the stability of β-Catenin is tightly regulated by the Ubiquitin-Proteasome System. Several E3 ligases that ubiquitylate and degrade β-Catenin have been described in the past, but the antagonists, the deubiquitylases, are still unknown. By performing an unbiased siRNA screen, the deubiquitylase USP10 was identified as a de novo positive regulator of β-Catenin stability in CRC derived cells. USP10 has previously been shown in the literature to regulate both mutant and wild type TP53 stability, to deubiquitylate NOTCH1 in endothelial cells and to be involved in the regulation of AMPKα signalling. Overall, however, its role in colorectal tumorigenesis remains controversial. By analysing publicly available protein and gene expression data from colorectal cancer patients, we have shown that USP10 is strongly upregulated or amplified upon transformation and that its expression correlates positively with CTNNB1 expression. In contrast, basal USP10 levels were found in non-transformed tissues, but surprisingly USP10 is upregulated in intestinal stem cells. Endogenous interaction studies in CRC-derived cell lines, with different extend of APCtruncation, revealed an APC-dependent mode of action for both proteins. Furthermore, by utilising CRISPR/Cas9, shRNA-mediated knock-down and overexpression of USP10, we could demonstrate a regulation of β-Catenin stability by USP10 in CRC cell lines. It is widely excepted that 2D cell culture systems do not reflect complexity, architecture and heterogeneity and are therefore not suitable to answer complex biological questions. To overcome this, we established the isolation, cultivation and genetically modification of murine intestinal organoids and utilised this system to study Usp10s role ex vivo. By performing RNA sequencing, dependent on different Usp10 levels, we were able to recapitulate the previous findings and demonstrated Usp10 as important regulator of β-dependent regulation of stem cell homeostasis. Since genetic depletion of USP10 resulted in down-regulation of β-Catenin-dependent transcription, therapeutic intervention of USP10 in colorectal cancer was also investigated. Commercial and newly developed inhibitors were tested for their efficacy against USP10, but failed to significantly inhibit USP10 activity in colorectal cancer cells. To validate the findings from this work also in vivo, development of a novel mouse model for colorectal cancer has begun. By combining CRISPR/Cas9 and classical genetic engineering with viral injection strategies, WT and genetically modified mice could be transformed and, at least in some animals, intestinal lesions were detectable at the microscopic level. The inhibition of USP10, which we could describe as a de novo tumour-specific regulator of β-Catenin, could become a new therapeutic strategy for colorectal cancer patients.}, subject = {Biomedizin}, language = {en} } @phdthesis{Hahn2024, author = {Hahn, Sarah}, title = {Investigating non-canonical, 5' UTR-dependent translation of MYC and its impact on colorectal cancer development}, doi = {10.25972/OPUS-36420}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-364202}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Colorectal cancer (CRC) is the second most common tumour disease in Germany, with the sequential accumulation of certain mutations playing a decisive role in the transition from adenoma to carcinoma. In particular, deregulation of the Wnt signalling pathway and the associated deregulated expression of the MYC oncoprotein play a crucial role. Targeting MYC thus represents an important therapeutic approach in the treatment of tumours. Since direct inhibition of MYC is challenging, various approaches have been pursued to date to target MYC indirectly. The MYC 5' UTR contains an internal ribosomal entry site (IRES), which has a particular role in the initiation of MYC translation, especially in multiple myeloma. As basis for this work, it was hypothesised on the basis of previous data that translation of MYC potentially occurs via its IRES in CRC as well. Based on this, two IRES inhibitors were tested for their potential to regulate MYC expression in CRC cells. In addition, alternative, 5' UTR-dependent translation of MYC and interacting factors were investigated. EIF3D was identified as a MYC 5' UTR binding protein which has the potential to regulate MYC expression in CRC. The results of this work suggest that there is a link between eIF3D and MYC expression/translation, rendering eIF3D a potential therapeutic target for MYC-driven CRCs.}, subject = {Myc}, language = {en} }