A laserterapia tem sido muito utilizada como tratamento alternativo em pacientes com dores crônicas relacionadas às disfunções temporomandibulares. Isso se deve aos efeitos: analgésico, antiinflamatório, miorrelaxante, de redução da fadiga durante as contrações tetânicas, aumento da força de mordida e diminuição da dor orofacial. Embora sejam observados resultados clínicos, ainda não é bem compreendido o seu efeito em nível celular. Assim, este estudo tem como objetivo analisar os efeitos das diferentes densidades (doses) de irradiação do laser de baixa intensidade (LLLI), em nível celular, sobre o músculo masseter de ratos Wistar. Os animais foram alocados aleatoriamente em 6 grupos (n=10), receberam 10 irradiações do laser (GaAlAs,780nm, 5mW e spot 0,04cm²) sobre o músculo masseter esquerdo variando a densidade de energia (I. 0; II. 0,5; III. 1,0; IV. 2,5; V. 5,0 e VI. 20 J/cm²). Após as 10 irradiações os músculos masseteres foram obtidos dos animais sob anestesia para análises: 1. Histoenzimológicas para atividade da nicotinamida adenina dinucleotídeo diaforase(NADH), succinato desidrogenase (SDH) e adenosina trifosfatase (ATPase), 2. Microscopia de luz (HE), 3. Microscopia eletrônica de transmissão e 4. Imunohistoquímica para fator de crescimento do endotélio vascular (VEGF) e o receptor 2 para VEGF (VEGFR-2). A atividade do NADH nos grupos IV, V e VI (30±1,26; 33,47±2,15; 31,67±1,77 - fibras intermediárias) apresentou um aumento significativo (p>0,05) no metabolismo oxidativo em relação aos demais grupos. Na atividade do SDH, o aumento foi discreto, com aumento significativo (p>0,05), apenas no grupo V (32,2±1,61 fibras intermediárias), com o padrão de aumento metabólico muito parecido nas reações de NADH e SDH. A atividade da ATPase não revelou diferenças entre os grupos tanto em meio ácido como no alcalino. A microscopia de luz revelou fibras musculares arredondadas e núcleos periféricos achatados, os quais tornaram mais arredondados com as densidades maiores de energia. Ultraestruturalmente as irradiações com as maiores densidades de energia revelaram mitocôndrias de tamanhos e formas variadas e cisternas do retículo sarcoplasmático dilatadas entre as miofibrilas. As análises qualitativas mostraram um padrão de aumento a expressão do VEGF e VEGFR-2 proporcionais à densidade de energia do laser usada. Conclui-se que o laser com densidades maiores foi capaz de aumentar o metabolismo oxidativo, sem alterar a capacidade contrátil, aumentar o volume do núcleo, modificar a ultraestrutura das fibras musculares e as expressões do VEGF e VEGFR-2. / The laser therapy has been widely used as an alternative treatment in patients with chronic pain related to temporomandibular disorders. This is due to the effects: analgesic, anti inflammatory, muscle relaxant, reducing fatigue during tetanic contractions, increased bite strength and decrease in orofacial pain. Although clinical results are observed, is not well understood its effect on the cellular level. This study aims to analyze the effects of different densities (doses) irradiation of low level laser therapy (LLLI) on cellular level, on the masseter muscle of rats. The animals were randomly assigned to 6 groups (n=10), received 10 laser irradiation (GaAlAs, 780nm, 5mW spot and 0.04 cm²) on the left masseter muscle by varying the energy density (I. 0; II. 0.5; III. 1.0; IV. 2.5; V. 5.0 and VI. 20 J/cm²). After 10 irradiations the masseter muscles were obtained from animals under anesthesia for analysis: 1. Histoenzimologic for nicotinamide adenine dinucleotide (NADH), succinate dehydrogenase (SDH) and adenosine triphosphatase (ATPase), 2. Light microscopy (HE), 3. Transmission electron microscopy and 4. Immunohistochemistry for vascular endothelial growth factor (VEGF) and receptor 2 for VEGF (VEGFR-2). The activity of NADH in groups IV, V and VI (30±1,26; 33,47±2,15; 31,67±1,77 - intermediate fiber) increased significantly (p> 0.05) in oxidative metabolism in relation to other groups. The activity of SDH showed a slight increase, only the group V (32,2±1,61 intermediate fiber) increased significantly (p> 0.05), but the pattern of metabolic increase was very similar in both reactions. The ATPase activity showed no differences between groups nor in acid or alkaline. The qualitative analysis showed a pattern of increased expression of VEGF and VEGFR-2 directly proportional to the energy density of laser. Light microscopy showed rounded muscle fibers and peripheral flattened nuclei, which become more rounded with the highest energy densities. Ultrastructurally the irradiation with higher energy densities showed mitochondria of different sizes and shapes and dilated cisterns of sarcoplasmic reticulum between the myofibrils. It is concluded that higher densities of laser was able to increase the oxidative metabolism without altering the contractile capacity, increasing nuclei volume, modify ultrastructure of muscle fibers and the expressions of VEGF and VEGFR-2.

A laserterapia tem sido muito utilizada como tratamento alternativo em pacientes com dores crônicas relacionadas às disfunções temporomandibulares. Isso se deve aos efeitos: analgésico, antiinflamatório, miorrelaxante, de redução da fadiga durante as contrações tetânicas, aumento da força de mordida e diminuição da dor orofacial. Embora sejam observados resultados clínicos, ainda não é bem compreendido o seu efeito em nível celular. Assim, este estudo tem como objetivo analisar os efeitos das diferentes densidades (doses) de irradiação do laser de baixa intensidade (LLLI), em nível celular, sobre o músculo masseter de ratos Wistar. Os animais foram alocados aleatoriamente em 6 grupos (n=10), receberam 10 irradiações do laser (GaAlAs,780nm, 5mW e spot 0,04cm²) sobre o músculo masseter esquerdo variando a densidade de energia (I. 0; II. 0,5; III. 1,0; IV. 2,5; V. 5,0 e VI. 20 J/cm²). Após as 10 irradiações os músculos masseteres foram obtidos dos animais sob anestesia para análises: 1. Histoenzimológicas para atividade da nicotinamida adenina dinucleotídeo diaforase(NADH), succinato desidrogenase (SDH) e adenosina trifosfatase (ATPase), 2. Microscopia de luz (HE), 3. Microscopia eletrônica de transmissão e 4. Imunohistoquímica para fator de crescimento do endotélio vascular (VEGF) e o receptor 2 para VEGF (VEGFR-2). A atividade do NADH nos grupos IV, V e VI (30±1,26; 33,47±2,15; 31,67±1,77 - fibras intermediárias) apresentou um aumento significativo (p>0,05) no metabolismo oxidativo em relação aos demais grupos. Na atividade do SDH, o aumento foi discreto, com aumento significativo (p>0,05), apenas no grupo V (32,2±1,61 fibras intermediárias), com o padrão de aumento metabólico muito parecido nas reações de NADH e SDH. A atividade da ATPase não revelou diferenças entre os grupos tanto em meio ácido como no alcalino. A microscopia de luz revelou fibras musculares arredondadas e núcleos periféricos achatados, os quais tornaram mais arredondados com as densidades maiores de energia. Ultraestruturalmente as irradiações com as maiores densidades de energia revelaram mitocôndrias de tamanhos e formas variadas e cisternas do retículo sarcoplasmático dilatadas entre as miofibrilas. As análises qualitativas mostraram um padrão de aumento a expressão do VEGF e VEGFR-2 proporcionais à densidade de energia do laser usada. Conclui-se que o laser com densidades maiores foi capaz de aumentar o metabolismo oxidativo, sem alterar a capacidade contrátil, aumentar o volume do núcleo, modificar a ultraestrutura das fibras musculares e as expressões do VEGF e VEGFR-2. / The laser therapy has been widely used as an alternative treatment in patients with chronic pain related to temporomandibular disorders. This is due to the effects: analgesic, anti inflammatory, muscle relaxant, reducing fatigue during tetanic contractions, increased bite strength and decrease in orofacial pain. Although clinical results are observed, is not well understood its effect on the cellular level. This study aims to analyze the effects of different densities (doses) irradiation of low level laser therapy (LLLI) on cellular level, on the masseter muscle of rats. The animals were randomly assigned to 6 groups (n=10), received 10 laser irradiation (GaAlAs, 780nm, 5mW spot and 0.04 cm²) on the left masseter muscle by varying the energy density (I. 0; II. 0.5; III. 1.0; IV. 2.5; V. 5.0 and VI. 20 J/cm²). After 10 irradiations the masseter muscles were obtained from animals under anesthesia for analysis: 1. Histoenzimologic for nicotinamide adenine dinucleotide (NADH), succinate dehydrogenase (SDH) and adenosine triphosphatase (ATPase), 2. Light microscopy (HE), 3. Transmission electron microscopy and 4. Immunohistochemistry for vascular endothelial growth factor (VEGF) and receptor 2 for VEGF (VEGFR-2). The activity of NADH in groups IV, V and VI (30±1,26; 33,47±2,15; 31,67±1,77 - intermediate fiber) increased significantly (p> 0.05) in oxidative metabolism in relation to other groups. The activity of SDH showed a slight increase, only the group V (32,2±1,61 intermediate fiber) increased significantly (p> 0.05), but the pattern of metabolic increase was very similar in both reactions. The ATPase activity showed no differences between groups nor in acid or alkaline. The qualitative analysis showed a pattern of increased expression of VEGF and VEGFR-2 directly proportional to the energy density of laser. Light microscopy showed rounded muscle fibers and peripheral flattened nuclei, which become more rounded with the highest energy densities. Ultrastructurally the irradiation with higher energy densities showed mitochondria of different sizes and shapes and dilated cisterns of sarcoplasmic reticulum between the myofibrils. It is concluded that higher densities of laser was able to increase the oxidative metabolism without altering the contractile capacity, increasing nuclei volume, modify ultrastructure of muscle fibers and the expressions of VEGF and VEGFR-2.

Einleitung: Nasenhöhlentumoren stellen mit bis zu 47 % die Hauptursache für Nasenausfluss beim Hund dar. Sie sind überwiegend maligne, zu 60 % Karzinome und zu 34 % Sarkome. Die mediane Überlebenszeit (MÜZ) liegt ohne Therapie bei etwa drei Monaten. Nach einer Bestrahlungstherapie beträgt sie etwa 8-20 Monate. Eine Therapie mit klassischen Chemotherapeutika oder eine Tumorablation über eine offen-chirurgische Rhinotomie führen nicht zu einer Verlängerung der Überlebenszeit. Durch ein neues Therapieverfahren, die endoskopisch interventionelle Zytoreduktion (EIZ), werden bei deutlich weniger Nebenwirkungen und Sitzungen in Allgemeinanästhesie ähnliche Überlebenszeiten erreicht wie durch eine Radiotherapie. Da es sich bei der EIZ um eine Zytoreduktion handelt, bei der die Nasenhöhlentumoren nicht mit Sicherheitsabstand im gesunden Gewebe entfernt werden können, stellt sich die Frage, ob die Überlebenszeit zusätzlich durch adjuvante Therapeutika verlängert werden kann. Als solche kommen beispielsweise Tyrosinkinase-Inhibitoren (TKI) und Cyclooxygenase-2 (COX-2)-Inhibitoren infrage, deren Zielstruktur-Expression besonders in kaninen nasalen Sarkomen noch unbekannt ist. Ziele der Untersuchungen: Ziel dieser Arbeit ist, anhand von Bioptaten von kaninen nasalen Karzinomen und Sarkomen eine immunhistochemische Charakterisierung durchzuführen. Hierzu wurden 10 Marker ausgewählt. Besonders im Fokus standen die Wachstumsfaktorrezeptoren vascular endothelial growth factor receptor-2 (VEGFR-2) und epidermal growth factor receptor (EGFR) sowie COX-2, die ersten beiden als Zielstrukturen von TKI und der letztere als Zielstruktur von COX-2-Inhibitoren. So soll eine Wirksamkeit dieser Medikamente bei kaninen nasalen Karzinomen und Sarkomen evaluiert werden. Weiterhin soll eine Korrelation zwischen der Expression von bestimmten Markern (p53, Ki-67, aktivierte Caspase-3, Survivin, E-Cadherin) mit den klinischen Daten zur Tumorkategorie und Überlebenszeit der Patienten untersucht werden. Außerdem soll als Grundlage für den Einsatz neuartiger Medikamente analysiert werden, ob EGFR, VEGFR-2 oder COX-2 in Karzinomen und Sarkomen unterschiedlich stark exprimiert werden. Tiere, Material und Methoden: Es wurden 19 Karzinome, sieben Sarkome und drei andere Tumorarten (ein malignes Melanom, zwei undifferenzierte maligne Tumoren unklarer Histogenese) retrospektiv immunhistochemisch auf die Expression von EGFR, VEGFR-2, COX-2, p53, Ki-67, aktivierter Caspase-3, Survivin, E-Cadherin, Zytokeratinen und Vimentin untersucht. Von drei Patienten wurden insgesamt vier Rezidivbioptate entnommen und ebenfalls immunhistochemisch untersucht. Beidseitige Nasenschleim-hautbioptate von neun gesunden Beagles dienten als Kontrollgruppe (genehmigungspflichtiger Tierversuch: TVV 02/18, Landesdirektion Sachsen). Alle Bioptate wurden während einer standardisierten Diagnostik mit computer-/ magnetresonanztomographischer Untersuchung - bei der auch ein Staging in vier Tumor-Kategorien (T1-T4) durchgeführt wurde - und Rhinoskopie zwischen Jan. 2015 und Dez. 2018 entnommen. Die immunhistochemische Untersuchung der in Formalin fixierten und in Paraffin eingebetteten Gewebeschnitte wurde mit der Avidin-Biotin-Komplex-Methode durchgeführt, nachdem die histopathologischen Diagnosen an Hämatoxylin-Eosin-gefärbten Schnitten gestellt wurden. Die immun-histochemischen Färbungen wurden entweder quantitativ oder semiquantitativ ausgewertet. Die Ergebnisse wurden auf Normalverteilung getestet und u.a. mit One-way Anova oder Kruskal-Wallis Test analysiert. Die MÜZ wurde mit der Kaplan Meier Methode berechnet und mit Log-Rank Test und Gehan-Breslow-Wilcoxon Test verglichen (Signifikanzniveau alpha = 5 %). Ergebnisse: 29 Hunde haben die Einschlusskriterien erfüllt. 14 Hunde wurden unmittelbar nach der Diagnostik euthanasiert; 15 Hunde wurden mit einer EIZ behandelt. Die MÜZ der Patienten in T1 (n = 3) nach EIZ betrug 1362 Tage und war signifikant länger als die MÜZ der Patienten in T2 (n = 1) mit 379 Tagen, in T3 (n = 8) mit 250 Tagen und in T4 (n = 1) mit 75 Tagen (p = 0,0062). Von den nasalen Karzinomen zeigten 68 % für EGFR, 100 % für VEGFR-2, 63 % für COX-2, 100 % für Survivin und 100 % für E-Cadherin eine immunhistochemisch positive Reaktion. Von den nasalen Sarkomen reagierten 100 % für VEGFR-2, 57 % für COX-2 und 86 % für Survivin positiv. Die Proteine EGFR und E-Cadherin werden ausschließlich von epithelialen Zellen exprimiert. Die Expression lag somit bei den vorliegenden Sarkomen bei 0 %. Unter den anderen Tumoren waren 33 % für EGFR, 100 % für VEGFR-2, 67 % für COX-2, 67 % für Survivin und 67 % für E-Cadherin positiv. Die mediane Expression von p53 lag bei 0,9 %, von Ki-67 bei 25 % und von aktivierter Caspase-3 bei 0,7 %. Die Unterschiede in der Expression von EGFR, VEGFR-2, COX-2, p53, Ki-67, aktivierter Caspase-3, Survivin und E-Cadherin zwischen den einzelnen histogenetischen Gruppen sowie zwischen den vier Tumor-Kategorien und in der MÜZ waren nicht signifikant. Eine Korrelation der VEGFR-2-Expression mit der MÜZ oder den T-Kategorien konnte nicht untersucht werden, da alle Tumoren der drei histogenetischen Gruppen VEGFR-2-positiv waren. 100 % der Karzinome zeigten eine Zytokeratin-Expression, 0 % eine Vimentin-Expression. Sarkome verhielten sich dazu konträr. In den anderen Tumoren konnten weder Zytokeratine noch Vimentin immunhistochemisch nachgewiesen werden. In den Rezidivbioptaten war ein Anstieg der COX-2 und aktivierte-Caspase-3-Expression zu beobachten, der aufgrund der geringen Fallzahl nicht statistisch untersucht werden konnte. Schlussfolgerungen: In der vorliegenden Studie wurden erstmalig kanine nasale Karzinome und Sarkome vergleichend immunhistochemisch untersucht. Weiterhin konnte erstmalig gezeigt werden, dass auch mesenchymale und andere Tumoren in vergleichbarer Häufigkeit wie Karzinome der Nase COX-2 exprimieren, wodurch ein Einsatz von COX-2-Inhibitoren nach einer Zytoreduktion bei Nasenhöhlentumoren allgemein von Nutzen sein könnte. Da alle Tumoren VEGFR-2 und die Mehrzahl der Karzinome (68 %) EGFR exprimierten, könnte eine adjuvante Therapie nach EIZ durch einen TKI mit VEGFR-2 oder EGFR als Zielstruktur einen positiven Einfluss auf die Überlebenszeit der erkrankten Hunde haben. Durch die Expression von E-Cadherin und Zytokeratinen in 100 % der Karzinome und 0 % der Sarkome sowie der Expression von Vimentin in 0 % der Karzinome und 100 % der Sarkome konnte die histopathologische Diagnose im Hinblick auf die Histogenese der Tumoren bestätigt werden. Auf der Grundlage der Ergebnisse der vorliegenden Studie sollte eine klinische Studie zur Anwendung von TKI und COX-2-Inhibitoren zur Untersuchung der klinischen Wirksamkeit und Sicherheit bei nasalen Tumoren von Hunden durchgeführt werden.:1 EINLEITUNG 1 2 LITERATURÜBERSICHT 2 2.1 Physiologie der Nasenhöhle 2 2.1.1 Anatomischer und histologischer Aufbau 2 2.1.2 Funktionen der Nasenhöhle und Nasenschleimhaut 3 2.2 Tumoren der Nase und der Nasennebenhöhlen 3 2.2.1 Prävalenz und Signalement von Hunden mit Nasentumoren 3 2.2.2 Biologisches Verhalten der Tumoren 3 2.3 Klinische Symptome 4 2.4 Diagnostik 5 2.4.1 Laboruntersuchungen 5 2.4.2 Bildgebende Verfahren 6 2.4.3 Rhinoskopie 9 2.4.4 Histopathologische Untersuchung 10 2.5 Therapieoptionen 10 2.5.1 Radiotherapie 10 2.5.2 Rhinotomie 11 2.5.3 Chemotherapie 11 2.5.4 Endoskopisch interventionelle Zytoreduktion (EIZ) 12 2.5.5 Tyrosinkinase-Inhibitoren 13 2.5.6 Antikörper gegen Rezeptortyrosinkinasen 15 2.5.7 Cyclooxigenase-Inhibitoren 16 2.6 Prognose 16 2.7 Zielantigene für die Immunhistochemie 17 2.7.1 Epidermal growth factor receptor (EGFR) 17 2.7.2 Vascular endothelial growth factor receptor-2 (VEGFR-2) 18 2.7.3 Cyclooxygenase-2 (COX-2) 18 2.7.4 p53 19 2.7.5 Ki-67 19 2.7.6 Aktivierte Caspase-3 20 2.7.7 Survivin 20 2.7.8 E-Cadherin 21 2.7.9 Zytokeratine 21 2.7.10 Vimentin 21 3 HUNDE, MATERIAL UND METHODEN 22 3.1 Patienten 22 3.2 Bioptate und Einschlusskriterien 23 3.3 Kontrolltiere 24 3.4 Immunhistochemische Untersuchungen 25 3.5 Auswertung der immunhistochemischen Reaktionen 28 3.6 Statistische Auswertung 29 4 ERGEBNISSE 31 4.1 Patienten 31 4.1.1 Signalement und Anamnese 31 4.1.2 Einteilung der Patienten in T-Kategorien 33 4.1.3 Histopathologische Befunde 34 4.1.4 Mediane Überlebenszeit nach endoskopisch interventioneller Zytoreduktion 34 4.1.5 Gesunde Kontrollgruppe 35 4.2 Ergebnisse der immunhistochemischen Untersuchungen 37 4.2.1 Kontrollen und Absorptionsreaktionen 37 4.2.2 Epidermal growth factor receptor (EGFR) 37 4.2.3 Vascular endothelial growth factor receptor-2 (VEGFR-2) 40 4.2.4 Cyclooxygenase-2 (COX-2) 42 4.2.5 p53 46 4.2.6 Ki-67 48 4.2.7 Aktivierte Caspase-3 50 4.2.8 Survivin 52 4.2.9 E-Cadherin 55 4.2.10 Zytokeratine 58 4.2.11 Vimentin 58 4.2.12 Bioptate von Tumorrezidiven 60 5 DISKUSSION 62 6 ZUSAMMENFASSUNG 84 7 SUMMARY 86 8 LITERATURVERZEICHNIS 88 9 ANHANG 105 9.1 Übersicht über die Hunde und Bioptate 105 9.2 Ergebnistabellen 107 9.3 Immunhistochemisches Reaktionsprotokoll 120 9.4 Ansatz der Lösungen und Puffer für die Immunhistochemie 122 9.5 Bezugsquellen für Geräte, Einmalartikel, Reagenzien und Chemikalien 123 9.6 Abbildungs- und Tabellenverzeichnis 125 / Introduction: Tumours of the nasal cavity are the main cause of nasal discharge in dogs (up to 47 %). They are almost always malignant, 60 % are carcinomas and 34 % are sarcomas. Without performing any treatment, the median survival time (MST) is about three months. After radiation therapy, the MST is about 8-20 months. A therapy with conventional chemotherapeutics or tumour ablation via open surgical rhinotomy does not prolong the survival time. A new treatment method, the endoscopic interventional cytoreduction (EIC), achieves survival times similar to radiotherapy with considerably fewer sessions under general anaesthesia and fewer potential adverse events. As EIC is a cytoreduction procedure in which the intranasal tumours cannot be removed with safety margins in surrounding healthy tissue, the question arises whether survival could be prolonged by an additional application of adjuvant therapeutics. As such, for example, tyrosine kinase inhibitors (TKIs) and cyclooxygenase-2 (COX-2) inhibitors may be considered, whose target expression is still unknown, especially in canine nasal sarcomas. Aims of the study: One aim of this study is to perform an immunohistochemical characterisation on the basis of biopsy specimens from canine nasal carcinomas and sarcomas. For this purpose, 10 markers were selected. We particularly focused on the growth factor receptors vascular endothelial growth factor receptor-2 (VEGFR-2) and epidermal growth factor receptor (EGFR) as well as COX-2, the first two being targets of TKIs and the latter one being the target of COX-2-inhibitors. Thus, a possible efficacy of these drugs in canine nasal carcinomas and sarcomas should be evaluated. Furthermore, a correlation between the expression of specific markers (p53, Ki-67, cleaved caspase-3, survivin, E-cadherin) with clinical data of the tumour stage and patient survival time should be investigated. Moreover, it will be analysed as a basis for the use of novel drugs whether EGFR, VEGFR-2 or COX-2 are differentially expressed in carcinomas and sarcomas. Animals, Material and Methods: A total of 19 carcinomas, seven sarcomas and three other tumour types (one malignant melanoma, two undifferentiated malignant tumorus of unclear histogenesis) were retrospectively examined by immunohistochemistry for the expression of EGFR, VEGFR-2, COX-2, p53, Ki-67, cleaved caspase-3, survivin, E-cadherin, cytokeratins and vimentin. A total of four biopsies from recurrent tumours were obtained from three patients and also examined by immunohistochemistry. Bilateral nasal mucosal samples from nine healthy beagles served as a control group (animal experiment requiring approval: TVV 02/18, Directorate of the Federal State of Saxony, Germany). All biopsy specimens were collected during a standardised diagnostic procedure with computer /magnetic resonance tomography, which also included a staging into four tumour stages (T1-T4) and rhinoscopy between Jan 2015 and Dec 2018. The immunohistochemical examination of tissue sections fixed in formalin and embedded in paraffin was performed using the avidin-biotin complex method after histopathological diagnoses had been made on haematoxylin-eosin stained sections. The immunohistochemically stained sections were evaluated either quantitatively or semiquantitatively. Results were tested for normal distribution and analysed by the one-way anova or Kruskal-Wallis test, among others. MST was calculated using the Kaplan Meier method and compared with the log-rank test and Gehan-Breslow-Wilcoxon test (significance level alpha = 5 %). Results: A total of 29 dogs met the inclusion criteria. A total of 14 dogs were euthanised immediately after diagnosis; 15 dogs were treated with an EIC. The MST of patients in T1 (n = 3) after EIC was 1362 days and was significantly longer than the MST of those patients in T2 (n = 1) at 379 days, T3 (n = 8) at 250 days and T4 (n = 1) at 75 days (p = 0.0062). Of the nasal carcinomas, 68 % were immunohistochemically positive for EGFR, 100 % for VEGFR-2, 63 % for COX-2, 100 % for survivin and 100 % for E-cadherin. Of the nasal sarcomas, 100 % reacted positively for VEGFR-2, 57 % for COX-2 and 86 % for survivin. The proteins EGFR and E-cadherin were expressed exclusively by epithelial cells and, therefore, the expression was 0 % in the present sarcomas. Amongst the other tumours, 33 % were positive for EGFR, 100 % for VEGFR-2, 67 % for COX-2, 67 % for survivin and 67 % for E-cadherin. The median expression of p53 was 0.9 %, that of Ki-67 25 % and that of cleaved caspase-3 0.7 %. Differences in expression of EGFR, VEGFR-2, COX-2, p53, Ki-67, cleaved caspase-3, survivin and E-cadherin among the histogenetic groups, the four tumour stages and in MST were not significant. However, a correlation of VEGFR-2 expression with MST or the tumour stages could not be investigated because all tumours in the three histogenetic groups were VEGFR-2 positive. A total of 100 % of carcinomas showed cytokeratin expression, and 0 % showed vimentin expression. Sarcomas behaved in a contrary manner. In the other tumours, neither cytokeratins nor vimentin could be detected by immunohistochemistry. An increase in COX-2 and cleaved caspase-3 expression was observed in the recurrent tumour biopsies, which could not be statistically investigated due to the small number of cases. Conclusions: In the present study, canine nasal carcinomas and sarcomas were investigated comparatively by immunohistochemistry for the first time. Again, it was shown for the first time that mesenchymal and other tumours also express COX-2 at comparable frequencies to carcinomas of the nose, suggesting that the use of COX-2 inhibitors after cytoreduction may be of general benefit in nasal cavity tumours. As all tumours expressed VEGFR-2 and the majority of carcinomas (68 %) expressed EGFR, the adjuvant therapy after EIC by a TKI targeting VEGFR-2 or EGFR could have a beneficial effect on the survival of diseased dogs. The expression of E-cadherin and cytokeratins in 100 % of the carcinomas and 0 % of the sarcomas as well as the expression of vimentin in 0 % of the carcinomas and 100 % of the sarcomas confirmed the histopathological diagnosis with regard to the histogenesis of the tumours. Based on these results of the present study, a clinical trial should be performed on the use of TKIs and COX-2 inhibitors to investigate the clinical efficacy and safety of canine nasal tumours.:1 EINLEITUNG 1 2 LITERATURÜBERSICHT 2 2.1 Physiologie der Nasenhöhle 2 2.1.1 Anatomischer und histologischer Aufbau 2 2.1.2 Funktionen der Nasenhöhle und Nasenschleimhaut 3 2.2 Tumoren der Nase und der Nasennebenhöhlen 3 2.2.1 Prävalenz und Signalement von Hunden mit Nasentumoren 3 2.2.2 Biologisches Verhalten der Tumoren 3 2.3 Klinische Symptome 4 2.4 Diagnostik 5 2.4.1 Laboruntersuchungen 5 2.4.2 Bildgebende Verfahren 6 2.4.3 Rhinoskopie 9 2.4.4 Histopathologische Untersuchung 10 2.5 Therapieoptionen 10 2.5.1 Radiotherapie 10 2.5.2 Rhinotomie 11 2.5.3 Chemotherapie 11 2.5.4 Endoskopisch interventionelle Zytoreduktion (EIZ) 12 2.5.5 Tyrosinkinase-Inhibitoren 13 2.5.6 Antikörper gegen Rezeptortyrosinkinasen 15 2.5.7 Cyclooxigenase-Inhibitoren 16 2.6 Prognose 16 2.7 Zielantigene für die Immunhistochemie 17 2.7.1 Epidermal growth factor receptor (EGFR) 17 2.7.2 Vascular endothelial growth factor receptor-2 (VEGFR-2) 18 2.7.3 Cyclooxygenase-2 (COX-2) 18 2.7.4 p53 19 2.7.5 Ki-67 19 2.7.6 Aktivierte Caspase-3 20 2.7.7 Survivin 20 2.7.8 E-Cadherin 21 2.7.9 Zytokeratine 21 2.7.10 Vimentin 21 3 HUNDE, MATERIAL UND METHODEN 22 3.1 Patienten 22 3.2 Bioptate und Einschlusskriterien 23 3.3 Kontrolltiere 24 3.4 Immunhistochemische Untersuchungen 25 3.5 Auswertung der immunhistochemischen Reaktionen 28 3.6 Statistische Auswertung 29 4 ERGEBNISSE 31 4.1 Patienten 31 4.1.1 Signalement und Anamnese 31 4.1.2 Einteilung der Patienten in T-Kategorien 33 4.1.3 Histopathologische Befunde 34 4.1.4 Mediane Überlebenszeit nach endoskopisch interventioneller Zytoreduktion 34 4.1.5 Gesunde Kontrollgruppe 35 4.2 Ergebnisse der immunhistochemischen Untersuchungen 37 4.2.1 Kontrollen und Absorptionsreaktionen 37 4.2.2 Epidermal growth factor receptor (EGFR) 37 4.2.3 Vascular endothelial growth factor receptor-2 (VEGFR-2) 40 4.2.4 Cyclooxygenase-2 (COX-2) 42 4.2.5 p53 46 4.2.6 Ki-67 48 4.2.7 Aktivierte Caspase-3 50 4.2.8 Survivin 52 4.2.9 E-Cadherin 55 4.2.10 Zytokeratine 58 4.2.11 Vimentin 58 4.2.12 Bioptate von Tumorrezidiven 60 5 DISKUSSION 62 6 ZUSAMMENFASSUNG 84 7 SUMMARY 86 8 LITERATURVERZEICHNIS 88 9 ANHANG 105 9.1 Übersicht über die Hunde und Bioptate 105 9.2 Ergebnistabellen 107 9.3 Immunhistochemisches Reaktionsprotokoll 120 9.4 Ansatz der Lösungen und Puffer für die Immunhistochemie 122 9.5 Bezugsquellen für Geräte, Einmalartikel, Reagenzien und Chemikalien 123 9.6 Abbildungs- und Tabellenverzeichnis 125

Résumé L’angiogenèse est l’un des processus les plus importants pour le maintien de l’homéostasie de l’oxygène dans les tissus. Le facteur de croissance de l’endothélium vasculaire, VEGF, joue un rôle primordial dans la réponse angiogénique. Ce facteur de croissance mène à l’activation du récepteur de type 2 du facteur de croissance de l’endothélium vasculaire, VEGFR-2. Suite à une activation du VEGFR-2, plusieurs cascades de signalisation sont activées dans les cellules endothéliales. Afin d’atténuer cette signalisation, le VEGFR-2 est multi-ubiquitiné sur des résidus lysine et de cette manière, il est amené aux voies de dégradation, principalement dans les lysosomes. Cette ubiquitination est induite par l’association de l’ubiquitine ligase (E3) c-Cbl à un résidu tyrosine phosphorylé du domaine C-terminal du récepteur. Dans cette étude, nous avons identifié la tyrosine 1319 comme étant nécessaire pour l’association de c-Cbl au VEGFR-2 et son ubiquitination. Nos résultats démontrent aussi que dans des cellules endothéliales aortiques bovines, BAEC, la surexpression du récepteur mutant Y1319F ralentit la dégradation du VEGFR-2 et induit une activation plus forte et prolongée de la synthétase endothéliale du monoxyde d’azote (eNOS). Ces résultats nous permettent de mieux comprendre le déroulement de la régulation de la signalisation du VEGFR-2 au niveau intracellulaire. Mots-clés: [Angiogenèse, VEGFR-2, VEGF, c-Cbl, Ubiquitination, Tyrosine 1319, Dégradation] / Abstract Angiogenesis is one of the most important processes to maintain oxygen homeostasis throughout the different tissues. The different signaling pathways of the vascular endothelial growth factor receptor 2, VEGFR-2, play a primordial role in the angiogenic response induced by different angiogenic factors, one of which is the vascular endothelial growth factor, VEGF. Following VEGFR-2 activation, many signaling cascades are triggered in endothelial cells; in order to attenuate this response, VEGFR-2 undergoes multi ubiquitination on lysine residues and in this fashion it is brought into the degradation pathways, mainly through the lysosomes. This ubiquitination is induced by the association of the ubiquitin ligase (E3) c-Cbl to a phosphorylated tyrosine residue in the c-terminal domain of VEGFR-2. In this study, we identified tyrosine residue 1319 as being necessary for the association of c-Cbl to VEGFR-2 and for its ubiquitination. Our results show as well that overexpression of the mutant Y1319F version of VEGFR-2 in bovine aortic endothelial cells, BAEC, slows down the degradation process of VEGFR-2 and at the same time increases and prolongs the activation of endothelial nitric oxide synthase, eNOS. These results allow us to better understand the process of VEGFR-2 signaling regulation at the intracellular level. Keywords: [Angiogenesis, VEGFR-2, VEGF, c-Cbl, Ubiquitination, Tyrosine 1319, Degradation]

Atherosklerotische Arterien unterliegen strukturellem Umbau und chronischer Inflammation, die von einer dynamischen Entwicklung von Vasa vasorum (VV) begleitet wird. Die Beteiligung von Leukozyten und von vaskulären Vorläuferzellen an der Neovaskularisierung sowie die intimale Hyperplasie stehen im Zentrum der Atheroskleroseforschung. Damit verbundene Erkenntnisse könnten neue therapeutische Ansätze ermöglichen. Die vorliegende Arbeit befaßt sich mit der morphologischen Verteilung von Leukozyten (CD45, CD68, Mastzellen) und von Zellen mit Vorläufermarkern (CD34, CD117, VEGFR-2) in menschlichen Coronararterien mit verschiedenen atherosklerotischen Schweregraden. Mittels immunhistologischer Technik wurden Intima und Adventitia untersucht und die Ergebnisse zu den atherosklerotischen Schweregraden und der Neovaskularisierung korreliert. In Intima, Adventitia und dem perivaskulären Fettgewebe hat die Dichte der CD45+ Lymphozyten ihr Maximum im atherosklerotischen Grad 3. Dabei konnte sowohl in der Intima als auch in der Adventitia gezeigt werden, daß eine lineare Korrelation der CD45+ Lymphozyteninfiltration und VV-Dichte vorliegt. Es wurden zwei unterschiedliche Entzündungsmuster festgestellt. Beide zeigen in Grad 3 eine Zunahme der Zelldichten. In Grad 4-5 fällt die Dichte des einen Musters (CD45+, VEGFR-2+, VV) jedoch ab, während die Dichte des anderen Musters (CD34+, CD68+, Tryptase+, CD117+) in Grad 4-5 keine Veränderung aufweist. Die Ergebnisse deuten darauf hin, daß Leukozyten und vaskuläre Vorläuferzellen im Verlauf der Atherogenese wechselnde Funktionen wahrnehmen können. Sie nehmen offensichtlich VV als Eintrittspforte in die Gefäßwand.

<p>During development of the mammalian embryo, spatial and temporal expression of fibroblast growth factors (FGFs) and their cognate receptors are vital in the regulation of a number of patterning processes. Inappropriate or decreased expression leads to severe malformations and even embryonic death. The objectives of this thesis have been to evaluate the usefulness of differentiating embryonic stem (ES) cells as a model to study FGF and FGF receptors in endothelial and hematopoietic cell function in vitro and in vivo, and the effect of an activating mutation in the platelet-derived growth factor receptor-β (PDGFR-β) on endothelial cells and vessel formation.</p><p>Aggregates of differentiating ES cells, denoted embryoid bodies, faithfully recapitulate many developmental processes. Embryoid bodies cultured in fetal calf serum spontaneously develop cardiomyocytes and endothelial cells. The endothelial cells organize into lumen-containing vessels carrying erythroblasts. Administration of FGF or vascular endothelial growth factor (VEGF)-A promotes development of specific vascular phenotypes. About 20% of endothelial cells in embryoid bodies and teratomas express FGFR-1, and these FGFR-1-expressing endothelial cells are mitogenically active in the absence of exogenous stimuli and respond to VEGF-A to the same extent as endothelial cells lacking FGFR-1 expression. FGFR-1 deficiency leads to arrest in hematopoietic differentiation, whereas endothelial cell development is enhanced. As a consequence, teratomas derived from ES cells lacking FGFR-1 expression display vessels composed of a double layer of endothelial cells. The hyperactivity of endothelial cells derived from FGFR-1-deficient ES cells is suggested to be due to hyperactivity of VEGF receptor-2, as well as to loss of negative regulators of angiogenesis, such as interleukin-4.</p><p>Mutation of platelet-derived factor receptor-β (PDGFR-β) to replace D849 in the activating loop in the kinase domain with V leads to ligand-independent kinase activity, increased basal signal transduction, and enhanced expression of VEGF-A as well as VEGFR-2. As a result, endothelial cell sprouts covered with pericyte-like cells are formed in a VEGF-A/VEGFR-2 dependent manner in ES cells expressing the mutated PDGFR-β.</p><p>In conclusion, embryoid bodies represent a high-quality model for the study of growth factor-regulated vascular development and sprouting angiogenesis.</p>

<p>Blood vessels transport blood with essential nutrients and oxygen to the cells in our body. In a healthy adult, formation of new vessels (angiogenesis) occurs only in case of tissue repair and growth. Physiological angiogenesis requires precise regulation of multiple signaling components, a process which is deregulated in a number of pathological conditions, such as cancer. This thesis is focused on the role of laminins, heparan sulfate proteoglycans (HSPGs) and vascular endothelial growth factor (VEGF)-A in regulation of vascular development and angiogenesis. As a model, we have used embryonic stem cells that differentiate to form blood vessels in a manner faithfully recapitulating the <i>in vivo</i> processes. </p><p>We show that the basement membrane (BM) protein laminin-111 promotes maturation of endothelial cells in the presence of fibroblast growth factor-2, a known endothelial cell mitogen. However, embryonic stem cells are able to differentiate into endothelial cells also in the absence of laminin deposition in the vascular BM. Sprouting angiogenesis, induced by VEGF-A, is also not strictly dependent on laminin deposition. On the other hand, in the absence of laminins, vessels are enlarged. These data suggest an important role for laminins in regulation of the vessel diameter.</p><p>We also show that HSPGs serve as coreceptors for VEGF-A to regulate vascular development. The mode of presentation of HSPGs, <i>in</i> <i>cis</i> (on the endothelial cell) or <i>in</i> <i>trans</i> (on an adjacent cell such as pericytes), is critical in regulation of VEGF receptor-2 activation and stimulation of vascular development. Binding of VEGF-A to HSPGs <i>in</i> <i>trans</i> leads to accumulation of activated VEGFR-2 in endothelial cells and to prolonged signaling. This demonstrates a potential role for HSPGs in regulation of receptor trafficking and signaling kinetics, with possible implications also for other HS-binding ligand/receptor systems.</p>

During development of the mammalian embryo, spatial and temporal expression of fibroblast growth factors (FGFs) and their cognate receptors are vital in the regulation of a number of patterning processes. Inappropriate or decreased expression leads to severe malformations and even embryonic death. The objectives of this thesis have been to evaluate the usefulness of differentiating embryonic stem (ES) cells as a model to study FGF and FGF receptors in endothelial and hematopoietic cell function in vitro and in vivo, and the effect of an activating mutation in the platelet-derived growth factor receptor-β (PDGFR-β) on endothelial cells and vessel formation. Aggregates of differentiating ES cells, denoted embryoid bodies, faithfully recapitulate many developmental processes. Embryoid bodies cultured in fetal calf serum spontaneously develop cardiomyocytes and endothelial cells. The endothelial cells organize into lumen-containing vessels carrying erythroblasts. Administration of FGF or vascular endothelial growth factor (VEGF)-A promotes development of specific vascular phenotypes. About 20% of endothelial cells in embryoid bodies and teratomas express FGFR-1, and these FGFR-1-expressing endothelial cells are mitogenically active in the absence of exogenous stimuli and respond to VEGF-A to the same extent as endothelial cells lacking FGFR-1 expression. FGFR-1 deficiency leads to arrest in hematopoietic differentiation, whereas endothelial cell development is enhanced. As a consequence, teratomas derived from ES cells lacking FGFR-1 expression display vessels composed of a double layer of endothelial cells. The hyperactivity of endothelial cells derived from FGFR-1-deficient ES cells is suggested to be due to hyperactivity of VEGF receptor-2, as well as to loss of negative regulators of angiogenesis, such as interleukin-4. Mutation of platelet-derived factor receptor-β (PDGFR-β) to replace D849 in the activating loop in the kinase domain with V leads to ligand-independent kinase activity, increased basal signal transduction, and enhanced expression of VEGF-A as well as VEGFR-2. As a result, endothelial cell sprouts covered with pericyte-like cells are formed in a VEGF-A/VEGFR-2 dependent manner in ES cells expressing the mutated PDGFR-β. In conclusion, embryoid bodies represent a high-quality model for the study of growth factor-regulated vascular development and sprouting angiogenesis.

Blood vessels transport blood with essential nutrients and oxygen to the cells in our body. In a healthy adult, formation of new vessels (angiogenesis) occurs only in case of tissue repair and growth. Physiological angiogenesis requires precise regulation of multiple signaling components, a process which is deregulated in a number of pathological conditions, such as cancer. This thesis is focused on the role of laminins, heparan sulfate proteoglycans (HSPGs) and vascular endothelial growth factor (VEGF)-A in regulation of vascular development and angiogenesis. As a model, we have used embryonic stem cells that differentiate to form blood vessels in a manner faithfully recapitulating the in vivo processes. We show that the basement membrane (BM) protein laminin-111 promotes maturation of endothelial cells in the presence of fibroblast growth factor-2, a known endothelial cell mitogen. However, embryonic stem cells are able to differentiate into endothelial cells also in the absence of laminin deposition in the vascular BM. Sprouting angiogenesis, induced by VEGF-A, is also not strictly dependent on laminin deposition. On the other hand, in the absence of laminins, vessels are enlarged. These data suggest an important role for laminins in regulation of the vessel diameter. We also show that HSPGs serve as coreceptors for VEGF-A to regulate vascular development. The mode of presentation of HSPGs, in cis (on the endothelial cell) or in trans (on an adjacent cell such as pericytes), is critical in regulation of VEGF receptor-2 activation and stimulation of vascular development. Binding of VEGF-A to HSPGs in trans leads to accumulation of activated VEGFR-2 in endothelial cells and to prolonged signaling. This demonstrates a potential role for HSPGs in regulation of receptor trafficking and signaling kinetics, with possible implications also for other HS-binding ligand/receptor systems.

Angiogenesis, de novo formation of blood vessels from the pre-existing vasculature, is crucial in embryo development, and in processes in the adult such as wound healing and ovulation. Angiogenesis is also involved in pathological conditions such as cancer and chronic inflammatory diseases, which are propagated by dysregulated, excess angiogenesis. On the other hand, lack of functional vessels and poor blood flow is a major problem in myocardial and peripheral ischemia. A detailed understanding of the molecular mechanisms underlying angiogenesis is of vital importance for the development of drugs to regulate angiogenesis. The aim of this thesis has been to identify genes involved in regulation of angiogenesis. We have investigated gene expression over time in endothelial cells (ECs), using different in vitro models. We show that the proteoglycan endocan is upregulated in ECs invading a fibrin matrix in response to vascular endothelial growth factor (VEGF)-A. There was increased expression of endocan in renal tumour cells and tumour vessels compared to normal renal tissues, indicating that endocan might have a role in tumour growth and tumour angiogenesis. We also show that vascular endothelial protein tyrosine phosphatase (VE-PTP) is induced in ECs during differentiation into vessel structures in a three dimensional collagen matrix. Silencing of VE-PTP disrupts vessel formation and increases the activity of VEGF receptor-2 (VEGFR-2) and downstream signalling, leading to increased EC proliferation. This presents a possible mechanism for the failure of vessel formation, as EC morphogenesis requires growth arrest of the cells. We also show that VE-PTP and VEGFR-2 are closely associated in resting ECs. VEGF-A stimulation leads to rapid loss of association, coinciding with increased phosphorylation of VEGFR-2. The function of VE-PTP in vivo was investigated using the zebrafish model. We demonstrate specific expression of a zebrafish VE-PTP orthologue (zVE-PTP) in the developing vasculature. Silencing of zVE-PTP leads to defective vessel sprouting and branching, indicating a critical role for zVE-PTP in development of the zebrafish vasculature. In conclusion, this thesis presents gene regulation during endothelial cell morphogenesis and details the expression pattern of endocan and the function of VE-PTP in regulation of VEGFR-2-driven angiogenesis.