A Braquiterapia oftálmica utiliza radionuclídeos, como o Rutênio-106 no tratamento de melanomas uveais e outras neoplasias oculares. Para realização desse procedimento é necessária uma interação da equipe multidisciplinar principalmente entre a Oftalmologia, Oncologia, Radioterapia, Física Médica e Enfermagem, envolvendo estrutura física e profissionais qualificados para garantir os processos e resultados do procedimento. Este estudo tem o objetivo de avaliar os primeiros tratamentos de braquiterapia oftálmica com Rutênio-106 e também estabelecer protocolos e processos para implementação da técnica em um Hospital Geral. Os resultados obtidos para os primeiros 11 casos tratados entre 2015 e 2017, sendo 10 melanomas e 1 hemangioma, evidenciaram baixa toxicidade aguda. Foram analisados 5 pacientes com seguimento de 5 a 13 meses. Houve regressão da lesão em todos os pacientes, com média de 28% no ápice e 12% na base no período de até 12 meses, sendo observado uma regressão progressiva durante o período de avaliação. Os protocolos foram utilizados e validados durante todas as etapas do tratamento. O uso do Ru-106 mostra-se alternativa viável no tratamento de lesões oculares, sendo primordial a capacitação e integração da equipe e seguimento de protocolos para o êxito do tratamento. / Ophthalmic Brachytherapy uses radionuclides, such as Ruthenium-106 in the treatment of uveal melanomas and other ocular tumors. For this procedure is necessary a multidisciplinary interaction between Ophthalmology, Oncology, Radiotherapy, Medical Physics and Nursing, involving physical structure and qualified professionals to guarantee the processes and results of the procedure. This study aims to evaluate the first ophthalmic brachytherapy treatments with ruthenium- 106 and also to establish protocols and processes for the implementation of this service in a General Hospital. The results obtained for the first 11 cases treated between 2015 and 2017, being 10 melanomas and 1 hemangioma, showed low acute toxicity. Five patients were followed up for 5 to 13 months. There was regression of the lesion in all of these patients, with a mean of 28% at the apex and 12% at the base in the period close to 1 year, with a progressive regression during the evaluation period. The protocols were used and validated during all stages of treatment. The use of 106-Ru is a viable alternative in the treatment of ocular tumors, being the team qualification and the correct follow-up of the protocols crucial for the treatment success.

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Im Rahmen der Dissertation wurde ein Verfahren zur Quantifizierung monosomer Zellpopulationen innerhalb eines disomen Normalgewebes auf Basis der Pyrosequenzierung von Einzelbasenmutationen etabliert und hinsichtlich seiner Genauigkeit untersucht. Dabei liegt ein besonderer Schwerpunkt auf der Entwicklung eines Verfahrens zur Festlegung von Grenzwerten für die Detektion monosomer Population sowie für genetisch heterogene Subpopulationen. Zur Bestimmung der Genauigkeit wurden Mischreihen von DNA zweier Genotypen angefertigt und das Allelverhältnis durch Pyrosequenzierung gemessen. Diese Ergebnisse wurden genutzt, um Grenzwerte für die Detektion von LOH3-positiven Zellen im UMM estzulegen. In diesen Vorversuchen konnte die Anwendbarkeit der Analysemethode für Proben aus UMM sowohl aus Enukleations wie auch aus Feinnadelaspirationspräparaten demonstriert werden. Es wurde dann in einem weiteren Schritt analysiert, wie viele differente Loci für eine korrekte Diskriminierung zweier Genotypen analysiert werden müssen. Hier wurde gezeigt, dass zum einen die Anzahl der untersuchten SNP aber auch das gemessene Allelverhältnis maßgeblichen Einfluss auf die Genauigkeit der Analyse haben. Basierend auf diesen Daten wurde ein Verfahren entwickelt, das aus der gewünschten Genauigkeit eine Berechnung des Umfangs eines zu etablierenden SNP-Panels ermöglichte.

Numerous events during development require the tightly controlled and regulated interaction of cells - from gastrulation in the early embryo to axonal pathfinding and remodeling of synaptic networks. Each of these events is dependent upon signals generated by cell-cell interactions, which are in turn specified by a diverse number of cell adhesion molecules. Many families of cell adhesion molecules have been described, and these fall into the broad categories of cadherins, immunoglobulin superfamily (IgSF) members, selectins, and integrins. Activated Leukocyte Cell Adhesion Molecule (ALCAM) is a member of the IgSF, and controls numerous developmental processes, ranging from hematopoiesis to neuronal targeting. Furthermore, this protein has been implicated in the progression of numerous cancers of diverse origins. Despite the variety of developmental and pathological processes in which ALCAM has been implicated, little is known about how it signals in the cell - few extracellular binding partners have been isolated, and, as of this writing, no cytoplasmic interactors have been identified. The purpose of the work presented in this thesis was to elucidate the mechanisms by which ALCAM influences cell behavior, specifically in uveal melanoma cells, and to determine novel extra- and intracellular ligands. Here, I report the regulation of cadherin-based junctions by ALCAM in uveal melanoma cells, as well as provide evidence for a novel extracellular interaction with L1 cell adhesion molecule, and identify three novel intracellular binding partners.

Uveal melanoma (UM) is a sight and life-threatening malignancy of the human eye. The potential for progress in translational UM research is, however, hampered by the short supply of clinical samples due to its rarity and also the lack of an informative animal model which would allow experimental intervention to dissect the molecular machinery governing tumor development. Towards this end, we aimed to generate a genetically relevant model of human UM in zebrafish that can be used to study the roles of key genetic determinants in tumor initiation and progression in vivo and also establish a valuable resource for future preclinical studies. Given the pervasive role of Gαq proteins in driving UM pathogenesis, we engineered transgenic zebrafish to express oncogenic GNAQQ209P in the melanocyte lineage. This resulted in hyperplasia of uveal (choroidal) melanocytes, but with no evidence of malignant progression nor perturbation of RPE or skin melanocytes. However, combining expression of oncogenic GNAQQ209P with tp53 inactivation resulted in an earlier onset and even more extensive hyperplasia of choroidal melanocytes that then progressed to UM. While NRASQ61L and BRAFV600E potently stimulate ERK1/2-MAPK signalling pathway, immunohistochemical analysis revealed only sporadic immunoreactivity to phosphorylated ERK1/2 in hyperplastic choroidal lesions and also uveal tumors driven by oncogenic GNAQQ209P, in contrast to an abundant immunoreactivity in oncogenic HRASG12V-driven cutaneous tumors. Rather, ubiquitous positive staining for nuclear YAP was observed in GNAQQ209P-driven uveal tumor specimens. In keeping with a lesser role of GNAQ in regulating ERK1/2-MAPK signalling in UM, we showed that downregulation of oncogenic GNAQQ209P/L or inhibition of PLC-β in the majority of human UM cells expressing oncogenic GNAQQ209P/L barely affected ERK phosphorylation. In summary, this study demonstrates the insufficiency of oncogenic GNAQQ209P alone in driving UM development which only became evident with a second genetic hit involving tp53 inactivation. Our findings also demonstrate a weak correlation between oncogenic GNAQ mutations and sustained ERK1/2-MAPK activation, implying that ERK1/2 signalling is unlikely to be instrumental in the maintenance of GNAQQ209P-driven uveal tumors.

Uveal melanoma (UM) is the most common primary cancer of the eye and its prognosis is strongly influenced by the occurrence of metastases, which are both rapidly developing and mostly fatal. The most frequent driver mutations occur in a small number of genes including GNAQ, GNA11, BAP1, CYSLTR2 and SF3B1. Due to a lack of suitable animal models, the mechanism through which mutations in these genes cause or cooperate in UM initiation and progression is still largely unknown. We aimed at generating transgenic strains expressing the human mutant proteins in zebrafish uveal melanocytes, using the kita promoter. We used the binary Gal4/UAS system to express the mutant genes mentioned above. Moreover, we performed xenotransplantation experiments with uveal melanoma human and zebrafish cell lines in optically-clear, immunocompromised, zebrafish larvae. Transplanted fish developed melanoma near the site of transplantation in two weeks and showed metastatic growth within one month of age. This approach could be used for short-term assays in larvae, and be further developed for long-term uveal melanoma studies. In parallel, we performed a chemical screen using a transgenic model previously generated in our laboratory, where oncogenic RAS is expressed under the kita promoter. As adults transgenic kita:RAS develop cutaneous melanoma with high frequency and uveal melanoma with a much lower percentage. Larvae showed an increased number of melanocytes already at 3 days post fertilization (dpf) as the earliest evidence of abnormal melanocyte growth. Using this model we performed a chemical screen based on automated detection of a reduction of melanocytes number caused by any of the 1280 FDA or EMA approved drugs of the Prestwick library. The analysis showed that 55 molecules were able to reduce by 60% or more the number of melanocytes per embryo. We identified clotrimazole, as the best candidate. The molecule is an azole derivative acting on the energetic metabolism of melanoma cells. We further tested two compounds for each of the 5 pharmacological classes, and a farnesyltransferase inhibitor (lonafarnib), that inhibits an essential post-translational modification of HRAS and suppresses the hyperpigmentation phenotype. Combinations of clotrimazole and lonafarnib showed the most promising results in zebrafish embryos, allowing a dose reduction of both drugs. We performed validation of these observations in the metastatic human melanoma cell line A375M, and in normal human epithelial melanocytes (NHEM) as control cells, in order to investigate the mechanism of action of clotrimazole in blocking the proliferation of transformed melanocytes. Viability assay and analysis of energy metabolism in clotrimazole treated cells show that this drug specifically affects melanoma cells in vitro and transformed melanocytes in vivo, having no effects on NHEM or wild type larvae. Similar effects were observed with another hit of the antifungal class, miconazole. Furthermore, we show that the effects of clotrimazole are mediated by the inhibition of hexokinase activity and suggest further testing of clotrimazole in combinatorial treatments. In conclusion, this thesis investigated different possibilities of modeling the rare cancer uveal melanoma in zebrafish, using both transgenic and transplantation approaches, and developed a pipeline for a high-throughput, semi-automated chemical screen in a zebrafish melanoma that identified clotrimazole and miconazole as targeting a metabolic vulnerability in melanoma cells.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 4 uppsatser.

Uveal Melanoma (UM) is the most common malignant intra-ocular tumor in adults. Despite the high accuracy of clinical diagnosis and advances in local treatment, more than 50% of UM patients develop metastasis within ten years of initial diagnosis. NM23 is a human metastasis suppressor gene. Reduced Nm23-H1 expression is correlated with high metastatic potential in a variety of different cancers including melanoma. C-Met is a receptor tyrosine kinase (RTK) that has been known to stimulate the invasive growth and increase the metastatic potential of cancer cells. Expression of c-Met is correlated with high mortality rate in UM patients. Treatment with CQX-2 inhibitors showed promise as an adjuvant therapy in adenocarcinoma of the colon. A previous report from our laboratory showed that topical treatment with Nepafenac (a CQX-2 inhibitor) delayed the progression of the primary tumor and the formation of metastasis in the experimental rabbit model of UM. / The purpose of this thesis is to investigate the expression levels ofNm23-H1 in UM cell lines with different metastatic potentials, in paraffin embedded tissues from primary tumors of UM patients, and in an experimental rabbit model. In addition, the aim of this thesis is to determine whether treating human uveal melanoma cell lines with Nepafenac would increase the expression levels of Nm23-H1 and decrease the expression levels of c-Met in vitro (UM cell lines) and in vivo (experimental rabbit model). / To achieve our goal, we used several types of assays in our UM cell lines and paraffin embedded tissues from patient samples and experimental rabbit model, including quantitative immunostaining, quantitative Real-time PCR, and small interference RNA (siRNA). / The Real-time PCR results of five human uveal melanoma cell lines showed that expression of Nm23-HI is higher in cell lines with low metastatic potential compared to those with high metastatic potential. The invasive ability of the uveal melanoma cell lines increased after silencing Nm23-H1 expression with siRNA. The increased immunostaining intensity of Nm23-H1 in patient samples is associated with better survival rate. Moreover, treatment with Nepafenac resulted in increase of Nm23-H1 levels and decrease of c-Met levels in both the UM cell lines and the experimental rabbit model. / In conclusion, Nm23-H1 is a potent prognostic marker to predict the survival rate of UM patients and it has the potential to identify high-risk patients. To the best of our knowledge, this is the first study to show that treatment with COX-2 inhibitor causes an upregulation of Nm23-H1 and downregulation of c-Met in UM. Therefore, treatment with COX-2 inhibitors may be a useful strategy as an adjuvant therapy for UM patients.

Uveal Melanoma (UM) is the most common malignant intra-ocular tumor in adults. Forty-five percent of UM patients develop metastasis within fifteen years of the initial diagnosis. Cutaneous Melanoma (CM) is a highly metastatic cancer that accounts for the majority of skin cancer deaths. Current treatments are not especially effective for the metastatic phase of the disease. Therefore, the identification of new molecular targets that can be exploited in the clinic are needed. / KISS1 is a putative human metastasis suppressor gene. The purpose of this study was to investigate the expression of KISS1 in melanoma and its potential value as a prognostic marker. / From results in vitro and in vivo we were able to characterize KISS1 in UM for the first time as well as its expression at the protein level, in CM. The correlation between KISS1 expression and UM survival rate suggests an important role for KISS1 as a prognostic marker in this tumor.

Uveal melanoma is the most common primary intraocular malignant tumour in adults. Despite improvements in the diagnosis and treatment of the primary tumour, patients continue to have the same mortality rate as several decades ago, reflecting our poor understanding of the mechanisms behind the formation of metastases in this disease. The purpose of this study was therefore to characterize an animal model of uveal melanoma and use this model to study the transcriptional changes that cells undergo from culture to intraocular tumour, to circulation and finally to the formation of a metastatic nodule. / Using microarrays we identified 314 changes in transcript abundance between the intraocular tumour and metastatic lesions. Principal Components Analysis was used to cluster these transcripts into four distinct groups. A further 61 gene transcripts showed statistically significant changes between re-cultured cells isolated from the model, with the circulating malignant cells representing an intermediate step between cells isolated from intraocular tumours and metastatic lesions. We have produced a detailed analysis of the molecular changes that take place as human uveal melanoma cells evolve from a primary tumour to metastasis in an animal model, including the decrease in expression of specific melanoma markers. These changes were verified using quantitative real time polymerase chain reaction and three different functional assays. / In addition we sought to describe the genetic changes that are present in these cells. Using comparative genomic hybridization arrays we were able to successfully describe the deletions and amplifications that are present in genomic DNA extracted from paraffin embedded sections of the primary tumour. This represents the first time that archival tissue has successfully been used for this sort of analysis in uveal melanoma. We identified several genomic amplifications and deletions including an area of amplification of Wnt2, which is involved in beta-catenin regulation and C-Met, which plays a role in tumour cell homing to the liver in patients. / To the best of our knowledge, this is the first time that a detailed genetic analysis has been carried out on the progression of uveal melanoma from intraocular tumour, to circulation, to the formation of metastases.