Patients with classical vitiligo lose partially their protecting inherited pigment. The cause of the disease is still unknown. Despite massive epidermal oxidative / nitrative stress and signs for DNA-damage in the skin and in the plasma, these patients have no higher prevalence for sun induced non-melanoma skin cancer and increased photo-damage. Protection and DNA-repair have been attributed to a functioning up-regulated wild type p53 / p21 cascade in association with up-regulated p76 MDM2. As some patients with cutaneous melanoma develop depigmentations away from their primary tumour site post surgical excision, it became of our interest, whether this melanoma associated leucoderma (MAL) is the same as classical vitiligo. The purpose of this thesis was two-fold. In part I, we wanted to further substantiate the reasons behind the constantly up-regulated wild-type functioning p53 / p21 cascade in classical vitiligo utilising a panel of proteins with direct and / or indirect action on p53 regulation, including p21, p76MDM2, MDM4/MDM4phospho, SPARC, VEGF-A and TGF-β1. In part II, we wanted to characterize MAL and compare this peculiar leucoderma with classical vitiligo using the same protein panel and methodologies. To achieve our goals, we used in vivo FT-Raman spectroscopy, in vitro cell cultures, in vitro and in situ immuno-fluorescence labelling, Western blot, dot blot and computer modelling techniques. Our data showed distinct differences between classical vitiligo and MAL. Our results in MAL exhibited a concentration dependent protein expression gradient between the basal / suprabasl layers and the upper layers of the epidermal compartment using catalase, ONOO-, p53, p21, MDM4, p76MDM2, TGF-β1 and VEGF-A expression gradient. Moreover, we document for the first time the presence of a nitrated non-fuctional SPARC protein in classical vitiligo which is absent in MAL. Although we show in vivo considerable ROS / RNS- mediated stress in MAL and classical vitiligo documented by FT-Raman spectroscopy, Western blot and in situ immuno-fluorescence, our results prove that MAL and classical vitiligo are two distinct entities.

Fundamentos: A literatura tem demonstrado que a detecção precoce e a remoção cirúrgica em fases iniciais reduz a mortalidade do melanoma e que, em conseqüência, a identificação do melanoma em fases curáveis deve ser encorajada. Objetivos: O interesse principal do estudo foi conhecer se os melanomas cutâneos, no meio, estão sendo diagnosticados em fases iniciais, através de método reprodutível e armazenável. Metodologia: Foi realizado um estudo transversal com os casos de melanomas cutâneos primários, analisados nos laboratórios de patologia de Porto Alegre, de 1° de janeiro de 1994 a 30 de junho de 1995, a fim de avaliar se os diagnósticos foram realizados em estágios precoces. Os casos foram revisados por três dermatopatologistas, que classificaram quanto ao tipo histológico e quanto ao nível de invasão de Clark. Foi realizado um consenso com pelo menos duas concordâncias. A espessura de Breslow foi considerada fator prognóstico determinante e foi medida através de um sistema de análise de imagem computadorizada, por dois membros da equipe. Resultados: Do total de 279 casos que preencheram os critérios de inclusão, 2,15% eram intraepiteliais. Dos melanomas invasivos, 52% tinham espessura ≤ 1,5 mm. Quando agrupado por sexo e procedência, as mulheres de Porto Alegre, capital do estado do Rio Grande do Sul, tiveram a mais alta taxa de diagnóstico precoce (75% ≤ 1,5 mm). O tronco foi o sítio predominante no homem e freqüente na mulher. O melanoma de espalhamento superficial foi o tipo histológico mais freqüente (80,9%), seguido pelo nodular (10,1%). Para definir os determinantes do diagnóstico precoce, foram realizados cruzamentos simples, dos melanomas intraepiteliais somados aos de espessura <0,76 mm, com o sexo, a idade, a procedência, a situação previdenciária, a região anatômica e o tipo histológico. A análise de variáveis múltiplas demonstrou que apenas o sexo (feminino), o sítio anatômico (outras regiões exceto membros inferiores) e a procedência (Porto Alegre) mostraram-se variáveis independentes para determinar um diagnóstico precoce. A idade ≥ 40 anos apresentou significância próxima ao limite. O tipo histológico foi excluído do modelo, uma vez que gerou instabilidade estatística. Conclusão: Embora o número de casos fosse pequeno, o diagnóstico do melanoma ainda é tardio (52% com até 1,5 mm de espessura). Entretanto, existe um subgrupo de diagnóstico precoce que são mulheres, sobretudo de Porto Alegre, possivelmente por estarem mais atentas e informadas sobre os riscos do melanoma. As mudanças no estilo de vida, nas últimas décadas, provavelmente são responsáveis pela maior incidência no tronco e pela alta freqüência de melanoma de espalhamento superficial encontrada. A análise da espessura tumoral por projeção em tela de computador mostrou-se um recurso auxiliar vantajoso. / Background: Early detection and surgical removal of malignant melanoma has been shown to reduce mortality, therefore identification of primary cutaneous melanoma at early stages should be promptly encouraged. Objectives: The main subject of the study was analyze if cutaneos malignant melanoma have early diagnosis by a computer image analysis system. Methods: A cross-sectional study was performed with the cases of primary cutaneous melanoma, analysed by pathology laboratories in Porto Alegre, from 1st January, 1994 to 30th June, 1995, to determine whether the diagnosis was performed at early stages. Three dermatopathologists reviewed the histological type and Clark’s level of invasion by light microscopy and a consensus was achieved with at least two agreements. Breslow’s thickness was measured by computer analyses image system, by two members of the study. Results: Of a total 279 cases selected, 2,15% were in situ malignant melanoma, 52% of the invasive melanomas showed a thickness of ≤ 1,5 mm. When grouped by gender and citizenship, women from Porto Alegre had the earlier diagnosis (75% ≤1,5 mm). The predominant site in men was the trunk and also very frequent in woman. Superficial spreading melanomas comprised 80,9% of cases, followed by 10,1% nodular. Bivariate analysis was perfomed to define determinants of earlier diagnosis, using in situ and < 0,76 mm thickness cases: gender, age, citizenship, anatomic location, health insurance situation and histological type. Through multivariate analysis only gender (female), anatomic site (other than lower extremities) and citizenship (Porto Alegre) were significant independent determinants, while age ≤ 40 presented a marginal significance. The histological type was excluded from the model since it generated statistical instability. Conclusions: Although the number of cases was small, the diagnosis is still late (52% with ≤1,5 mm). This study identifies a group of patient with early diagnosis: women, mainly from Porto Alegre are probably more aware about risk of melanoma. Lifestyle changes in the last decades could be responsible for the highest incidence of melanomas on the trunk and of the high frequency of superficial spreading malignant melanoma. The computer image analysis system showed to be an advantajous tool for the measurement of tumor thickness.

Thesis on the topic "Search of New biomakers suitable for screening and early diagnostics of cancer" is dedicated to the issue of cancer, a cancer of the breast, prostate, ovarian and after the new findings out as melanom determination of tumor markers and their implications for clinical practice. Their aim is skouted up biomaker suitable for screening and early diagnostics of carcinoma( cancer ) of the breast, ovarian, prostate and malignant melanoma with utilization of various kinds of immunoassay. The theoretical part gives a brief and comprehensive overview of the epidemiology of selected tumors and tumor markers used and their qualities. In the methodological part are given principles applied iminoanalytics methods a list of the statistical methods and a detailed description of the groups of patients. Results section contains tables with results of biomarkers diveded by sort of avalueted tumors. In the discussion are then analyzed facts that follow from the results. It discussed the process and actualy status of searching convenients biomekers and their combinations that can distinguish a population of benign tumors of the population with malignant tumors and markers which are able to distinguish healthy population from the population with malignant tumors of the breast, ovary, prostate and melanoma. This work may serve as a source of knowledge and results to continue in search of such marker that could be used for screening and early diagnosis of cancer and so to improve the prevention of these illneses in the population.

The aim of submited Thesis was to contribute to illustration on effect of TLR and fagocytate receptors in melanoma B16-F10 treatment with mouse model. Currently, a consequence of different ligands of fagocyte receptors and their combination with liposacharide (LPS) was tested. Ligands of fagocytate receptors was used in form enabled inside tumor cells anchoring. It deals with these compounds: f-MLFKK-BAM4000, laminarin-BAM4000, mannan-BAM4000. Gained results confirmed that previously observed huge synergy of LPS (activation of TLR4) and activation of phagocytic receptors by ligands anchored to tumor cells found the clarification in the form of extensive necrotization of tumor mass at the histological level.

20 000 Européens meurent chaque année du mélanome et le taux de mortalité ne cesse de s’accroître. Les cellules de mélanome se caractérisent principalement par la mutation des kinases RAS, B-RAF et RHO-B. Ces mutations leur confèrent une résistance aux agents chimiothérapeutiques. Un grand nombre de travaux a établi que les pigments d’algues présentent un intérêt majeur pour prévenir, diagnostiquer et traiter les cancers. L’objectif de ce travail de thèse est de réaliser un travail de recherche intégré pour identifier des pigments de microalgues pouvant présenter un intérêt pour le diagnostic ou le traitement des mélanomes et de caractériser leur activité pharmacologique. Notre choix s’est porté sur Porphyridium purpureum, une espèce qui contient des phycobiliprotéines, des caroténoïdes dont la zéaxanthine. Nous avons développé des procédés innovants pour l’extraction et l’identification des pigments de microalgues. Ce travail a permis de réaliser la première extraction de phycobiliprotéines assistée sous champ microondes ainsi que l’identification des pigments de microalgue par UPLC-MSE au sein d’un mélange complexe. De plus, nous avons montré l’activité pro-apoptotique de la zéaxanthine et la caractérisation de son mode d’action sur les cellules de mélanome humain A2058. L’IC50 obtenue pour ce pigment est inférieure à celle du cisplatine (agent chimiothérapeutique). Ces résultats montrent le fort potentiel de ce pigment pour le traitement du mélanome résistant à la chimiothérapie. / 20 000 Europeans die from melanoma each year and this number is constantly increasing. Melanoma cells are mainly characterized by the mutation of the RAS, B-RAF and RHO-B kinases. Because of these mutations, the cells are resistant to chemotherapeutic agents. A lot of studies have established that the algae pigments are of major interest to prevent diagnose and treat cancers. The objective of this thesis is to undertake an integrated research work to identify microalgae pigments that may be relevant for the diagnosis or treatment of melanomas and to characterize their pharmacological activity. We selected Porphyridium purpureum, a species which contains phycobiliproteins, carotenoids including zeaxanthin. We developed innovative processes for the extraction and identification of microalgae pigments. This work resulted in the first extraction of phycobiliproteins under microwave-assisted irradiations, and the identification of microalgae pigments by UPLC-MSE within a complex mixture. Moreover, we demonstrated the proapoptotic activity of zeaxanthin and the characterization of its mode of action on A2058 human melanoma cells. The CI50 obtained for this pigment is lower than that of cisplatin (chemotherapeutic drug). These results show the great potential of this pigment for the treatment of melanoma which are resistant to chemotherapy.

Fundamentos: A literatura tem demonstrado que a detecção precoce e a remoção cirúrgica em fases iniciais reduz a mortalidade do melanoma e que, em conseqüência, a identificação do melanoma em fases curáveis deve ser encorajada. Objetivos: O interesse principal do estudo foi conhecer se os melanomas cutâneos, no meio, estão sendo diagnosticados em fases iniciais, através de método reprodutível e armazenável. Metodologia: Foi realizado um estudo transversal com os casos de melanomas cutâneos primários, analisados nos laboratórios de patologia de Porto Alegre, de 1° de janeiro de 1994 a 30 de junho de 1995, a fim de avaliar se os diagnósticos foram realizados em estágios precoces. Os casos foram revisados por três dermatopatologistas, que classificaram quanto ao tipo histológico e quanto ao nível de invasão de Clark. Foi realizado um consenso com pelo menos duas concordâncias. A espessura de Breslow foi considerada fator prognóstico determinante e foi medida através de um sistema de análise de imagem computadorizada, por dois membros da equipe. Resultados: Do total de 279 casos que preencheram os critérios de inclusão, 2,15% eram intraepiteliais. Dos melanomas invasivos, 52% tinham espessura ≤ 1,5 mm. Quando agrupado por sexo e procedência, as mulheres de Porto Alegre, capital do estado do Rio Grande do Sul, tiveram a mais alta taxa de diagnóstico precoce (75% ≤ 1,5 mm). O tronco foi o sítio predominante no homem e freqüente na mulher. O melanoma de espalhamento superficial foi o tipo histológico mais freqüente (80,9%), seguido pelo nodular (10,1%). Para definir os determinantes do diagnóstico precoce, foram realizados cruzamentos simples, dos melanomas intraepiteliais somados aos de espessura <0,76 mm, com o sexo, a idade, a procedência, a situação previdenciária, a região anatômica e o tipo histológico. A análise de variáveis múltiplas demonstrou que apenas o sexo (feminino), o sítio anatômico (outras regiões exceto membros inferiores) e a procedência (Porto Alegre) mostraram-se variáveis independentes para determinar um diagnóstico precoce. A idade ≥ 40 anos apresentou significância próxima ao limite. O tipo histológico foi excluído do modelo, uma vez que gerou instabilidade estatística. Conclusão: Embora o número de casos fosse pequeno, o diagnóstico do melanoma ainda é tardio (52% com até 1,5 mm de espessura). Entretanto, existe um subgrupo de diagnóstico precoce que são mulheres, sobretudo de Porto Alegre, possivelmente por estarem mais atentas e informadas sobre os riscos do melanoma. As mudanças no estilo de vida, nas últimas décadas, provavelmente são responsáveis pela maior incidência no tronco e pela alta freqüência de melanoma de espalhamento superficial encontrada. A análise da espessura tumoral por projeção em tela de computador mostrou-se um recurso auxiliar vantajoso. / Background: Early detection and surgical removal of malignant melanoma has been shown to reduce mortality, therefore identification of primary cutaneous melanoma at early stages should be promptly encouraged. Objectives: The main subject of the study was analyze if cutaneos malignant melanoma have early diagnosis by a computer image analysis system. Methods: A cross-sectional study was performed with the cases of primary cutaneous melanoma, analysed by pathology laboratories in Porto Alegre, from 1st January, 1994 to 30th June, 1995, to determine whether the diagnosis was performed at early stages. Three dermatopathologists reviewed the histological type and Clark’s level of invasion by light microscopy and a consensus was achieved with at least two agreements. Breslow’s thickness was measured by computer analyses image system, by two members of the study. Results: Of a total 279 cases selected, 2,15% were in situ malignant melanoma, 52% of the invasive melanomas showed a thickness of ≤ 1,5 mm. When grouped by gender and citizenship, women from Porto Alegre had the earlier diagnosis (75% ≤1,5 mm). The predominant site in men was the trunk and also very frequent in woman. Superficial spreading melanomas comprised 80,9% of cases, followed by 10,1% nodular. Bivariate analysis was perfomed to define determinants of earlier diagnosis, using in situ and < 0,76 mm thickness cases: gender, age, citizenship, anatomic location, health insurance situation and histological type. Through multivariate analysis only gender (female), anatomic site (other than lower extremities) and citizenship (Porto Alegre) were significant independent determinants, while age ≤ 40 presented a marginal significance. The histological type was excluded from the model since it generated statistical instability. Conclusions: Although the number of cases was small, the diagnosis is still late (52% with ≤1,5 mm). This study identifies a group of patient with early diagnosis: women, mainly from Porto Alegre are probably more aware about risk of melanoma. Lifestyle changes in the last decades could be responsible for the highest incidence of melanomas on the trunk and of the high frequency of superficial spreading malignant melanoma. The computer image analysis system showed to be an advantajous tool for the measurement of tumor thickness.

Orientador: José Maurício Sforcin / Banca: Alexandrina Sartori / Banca: Sueli Calvo / Banca: Daniel Araki Ribeiro / Banca: Maria Lúcia Zaidan Gagli / Resumo: Não disponível. / Abstract: Several studies have shown that stress affects the immune system, promoting the progression of cancer. Since propolis is a honeybee product showing immunomodulatory and antitumoral activities, the goal of this work was to evaluate propolis effect on Th1 (IL-2 and IFN-) and Th2 (IL-4 and IL-10) cytokines' expression and production by melanoma-bearing mice submitted to immobilization stress. In groups without melanoma, stress did not affect IL-2, IL-4 and IL-10 gene expression. Propolis treatment of stressed animals did not influence these cytokines expression as well. On the other hand, IL-2 and IL-10 expression was inhibited in melanoma-bearing mice, stressed or not. Th1 cytokines production was also inhibited in melanoma-bearing mice. Propolis administration to melanoma-bearing mice submitted to stress stimulated IL-2 expression, as well as Th1 (IL-2 and IFN-) production, indicating the activation of antitumor cell-mediated immunity. Propolis also stimulated IL-10 expression and production, what may be related to immunoregulatory effects. Our data indicate that propolis showed an immunomodulatory activity in this assay, what may be related to its antitumoral action in vivo. Further investigation will help to understand propolis usefulness during stress. / Doutor

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-02-17T19:43:31Z No. of bitstreams: 1 LucianaMariaAraujoRabelo_TESE.pdf: 3802625 bytes, checksum: 997bf48b7638b7c1490b5a664ca3194e (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-02-20T18:59:27Z (GMT) No. of bitstreams: 1 LucianaMariaAraujoRabelo_TESE.pdf: 3802625 bytes, checksum: 997bf48b7638b7c1490b5a664ca3194e (MD5) / Made available in DSpace on 2017-02-20T18:59:27Z (GMT). No. of bitstreams: 1 LucianaMariaAraujoRabelo_TESE.pdf: 3802625 bytes, checksum: 997bf48b7638b7c1490b5a664ca3194e (MD5) Previous issue date: 2016-10-25 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / O c?ncer ? um termo utilizado para representar um conjunto de mais de 200 patologias, incluindo tumores malignos de diferentes localiza??es. V?rios s?o os mecanismos que contribuem para a carcinog?nese: sinal proliferativo sustentado, desregula??o da energia celular, evas?o a apoptose, indu??o a angiog?nese, replica??o ilimitada, entre outros. Dentre os principais tipos de c?ncer existentes, o c?ncer de pele se destaca: surge nos melan?citos e ? o mais frequente no Brasil, correspondendo a 30% de todos os tumores malignos registrados no Pa?s. Melanomas em est?gio inicial podem, na maioria das vezes, ser tratados apenas com cirurgia, por?m os c?nceres mais avan?ados requerem outros tratamentos. Neste trabalho, um inibidor de tripsina do tipo Kunitz foi purificado de sementes da leguminosa Mimosa regnellii Benth (ITJ), parcialmente caracterizado e avaliado quanto sua toxicidade frente a linhagens de c?lulas tumorais, atuando especificamente com um IC50 de 0,65 ?M em linhagem celular B16-F10, n?o apresentando toxicidade frente a linhagens de c?lulas n?o transformadas. Sua capacidade de induzir morte celular pela via de apoptose em c?lulas de melanoma de camundongo B16-F10 tamb?m foi avaliada, atrav?s de citometria de fluxo com os marcadores Anexina V-FITC/PI, induzindo cerca de 45% das c?lulas a apoptose. Al?m disso, o inibidor tamb?m foi avaliado quanto a sua capacidade de: alterar o potencial de membrana mitocondrial, visualizado por experimentos em citometria de fluxo utilizando a sonda Rodamina123 e microscopia confocal com o marcador Mitotracker Red, onde foi capaz de alterar de forma significativa o ??m; Liberar esp?cies reativas de oxig?nio e nitrog?nio, atrav?s de sondas espec?ficas visualizadas por t?cnicas de microscopia, causando libera??o de ROS na concentra??o de IC50, por?m n?o influenciando libera??o de ERNs; Liberar c?lcio citos?lico, evento que influencia na ativa??o de apoptose, com efeito significativo em c?lulas B16-f10; Inibir atividade angiog?nica de c?lulas endoteliais de coelho, atrav?s de experimentos de inibi??o de forma??o de novos vasos em matrigel, an?lise da express?o de VEGF por t?cnicas de western Blotting e redu??o da express?o de IL-6 analisado por microscopia confocal; Inibir o processo de migra??o celular em ensaio de indu??o de ferimento e an?lise em microscopia e, por fim, a alterar a morfologia celular de B16-F10, analisada por incuba??o com anticorpos espec?ficos para componentes da matriz extracelular e filamentos intermedi?rios das c?lulas de melanoma, realizados em microscopia de fluoresc?ncia. Todos esses resultados reunidos favorecem a proposi??o de um poss?vel mecanismo de a??o de ITJ na indu??o de morte celular por apoptose em c?lulas B16-F10, onde o inibidor atuaria inicialmente aumentando os n?veis de c?lcio citos?lico e ROS, alterando posteriormente a express?o de p53 em 36h de incuba??o, que agiriam alterando o metabolismo mitocondrial, ativando vias de apoptose dependentes da participa??o de caspases; ITJ tamb?m atuaria inibindo processos migrat?rios at? 18 horas de exposi??o, al?m de influenciar de forma tardia na inibi??o do processo angiog?nico in vitro. Estes resultados sugerem que ITJ apresenta potencial para ser utilizado como f?rmaco em tratamento adjuvante contra melanomas, devido a sua especificidade e baixa dosagem quando comparado a outras mol?culas bioativas. / Cancer is a term used to represent a set of more than 200 diseases, including malignant tumors of different localizations. There are several mechanisms that contribute to carcinogenesis: sustained proliferative signals, deregulation of cellular energy, evasion of apoptosis, angiogenesis induction and unlimited replication, among others. Among the main types of cancer, skin cancer stands out: arises in melanocytes and is the most common in Brazil, accounting for 30% of all malignant tumors registered in the country melanomas at an early stage can, in most cases,. It is treated with surgery, but the most advanced cancers require other treatments. In this work a Kunitz-type trypsin inhibitor was purified from Mimosa regnellii Benth (ITJ) legume seeds, partially characterized and evaluated for their toxicity front tumor cell lines, specifically acting with an IC50 of 0.65 ?M in B16-F10 cell line, showing no toxicity compared to non-transformed cell lines. Its ability to induce cell death by apoptosis pathway in mouse B16-F10 melanoma cells was evaluated by flow cytometry with Annexin V-FITC / PI markers, inducing about 45% apoptosis of cells. In addition, the inhibitor was also evaluated for their ability to: change the mitochondrial membrane potential, visualized by flow cytometry experiments using Rhodamine123 probe and confocal microscopy with Mitotracker Red marker, which was able to significantly change the ??m; Release of ROS and RNs through specific probes visualized by microscopy techniques, causing release of ROS in the concentration of IC50, but not influencing release RNS; Liberation of cytosolic calcium, an event that influences the apoptosis activation, with significant effect on B16-F10 cells; Inhibition of angiogenic activity on rabbit endothelial cells through experiments of inhibition of new vessel formation in Matrigel, analysis of VEGF expression by western blotting techniques and reduction of IL-6 expression analyzed by confocal microscopy; Inhibition of cell migration process in wound induction assay and microscopy analysis and, finally, to alter the cellular morphology of B16-F10 analyzed by incubation with specific antibodies to extracellular matrix components and intermediate filaments of melanoma cells, conducted in fluorescence microscopy. All these combined results favor the proposal of a possible ITJ action mechanism in the induction of cell death by apoptosis in B16-F10 cells, where the inhibitor initially act by altering the p53 expression in 36h of incubation, increasing calcium cytosolic levels and ROS, which would act changing the mitochondrial metabolism, activating dependent apoptosis pathways of caspase participation; ITJ also act by inhibiting migration processes up to 18 hours of exposure, as well as influence belatedly in inhibiting the angiogenic process in vitro. These results suggest that ITJ has the potential to be used as a drug adjuvant treatment for melanomas, due to their specificity and low-dose when compared to other bioactive molecules.

Fundamentos: A literatura tem demonstrado que a detecção precoce e a remoção cirúrgica em fases iniciais reduz a mortalidade do melanoma e que, em conseqüência, a identificação do melanoma em fases curáveis deve ser encorajada. Objetivos: O interesse principal do estudo foi conhecer se os melanomas cutâneos, no meio, estão sendo diagnosticados em fases iniciais, através de método reprodutível e armazenável. Metodologia: Foi realizado um estudo transversal com os casos de melanomas cutâneos primários, analisados nos laboratórios de patologia de Porto Alegre, de 1° de janeiro de 1994 a 30 de junho de 1995, a fim de avaliar se os diagnósticos foram realizados em estágios precoces. Os casos foram revisados por três dermatopatologistas, que classificaram quanto ao tipo histológico e quanto ao nível de invasão de Clark. Foi realizado um consenso com pelo menos duas concordâncias. A espessura de Breslow foi considerada fator prognóstico determinante e foi medida através de um sistema de análise de imagem computadorizada, por dois membros da equipe. Resultados: Do total de 279 casos que preencheram os critérios de inclusão, 2,15% eram intraepiteliais. Dos melanomas invasivos, 52% tinham espessura ≤ 1,5 mm. Quando agrupado por sexo e procedência, as mulheres de Porto Alegre, capital do estado do Rio Grande do Sul, tiveram a mais alta taxa de diagnóstico precoce (75% ≤ 1,5 mm). O tronco foi o sítio predominante no homem e freqüente na mulher. O melanoma de espalhamento superficial foi o tipo histológico mais freqüente (80,9%), seguido pelo nodular (10,1%). Para definir os determinantes do diagnóstico precoce, foram realizados cruzamentos simples, dos melanomas intraepiteliais somados aos de espessura <0,76 mm, com o sexo, a idade, a procedência, a situação previdenciária, a região anatômica e o tipo histológico. A análise de variáveis múltiplas demonstrou que apenas o sexo (feminino), o sítio anatômico (outras regiões exceto membros inferiores) e a procedência (Porto Alegre) mostraram-se variáveis independentes para determinar um diagnóstico precoce. A idade ≥ 40 anos apresentou significância próxima ao limite. O tipo histológico foi excluído do modelo, uma vez que gerou instabilidade estatística. Conclusão: Embora o número de casos fosse pequeno, o diagnóstico do melanoma ainda é tardio (52% com até 1,5 mm de espessura). Entretanto, existe um subgrupo de diagnóstico precoce que são mulheres, sobretudo de Porto Alegre, possivelmente por estarem mais atentas e informadas sobre os riscos do melanoma. As mudanças no estilo de vida, nas últimas décadas, provavelmente são responsáveis pela maior incidência no tronco e pela alta freqüência de melanoma de espalhamento superficial encontrada. A análise da espessura tumoral por projeção em tela de computador mostrou-se um recurso auxiliar vantajoso. / Background: Early detection and surgical removal of malignant melanoma has been shown to reduce mortality, therefore identification of primary cutaneous melanoma at early stages should be promptly encouraged. Objectives: The main subject of the study was analyze if cutaneos malignant melanoma have early diagnosis by a computer image analysis system. Methods: A cross-sectional study was performed with the cases of primary cutaneous melanoma, analysed by pathology laboratories in Porto Alegre, from 1st January, 1994 to 30th June, 1995, to determine whether the diagnosis was performed at early stages. Three dermatopathologists reviewed the histological type and Clark’s level of invasion by light microscopy and a consensus was achieved with at least two agreements. Breslow’s thickness was measured by computer analyses image system, by two members of the study. Results: Of a total 279 cases selected, 2,15% were in situ malignant melanoma, 52% of the invasive melanomas showed a thickness of ≤ 1,5 mm. When grouped by gender and citizenship, women from Porto Alegre had the earlier diagnosis (75% ≤1,5 mm). The predominant site in men was the trunk and also very frequent in woman. Superficial spreading melanomas comprised 80,9% of cases, followed by 10,1% nodular. Bivariate analysis was perfomed to define determinants of earlier diagnosis, using in situ and < 0,76 mm thickness cases: gender, age, citizenship, anatomic location, health insurance situation and histological type. Through multivariate analysis only gender (female), anatomic site (other than lower extremities) and citizenship (Porto Alegre) were significant independent determinants, while age ≤ 40 presented a marginal significance. The histological type was excluded from the model since it generated statistical instability. Conclusions: Although the number of cases was small, the diagnosis is still late (52% with ≤1,5 mm). This study identifies a group of patient with early diagnosis: women, mainly from Porto Alegre are probably more aware about risk of melanoma. Lifestyle changes in the last decades could be responsible for the highest incidence of melanomas on the trunk and of the high frequency of superficial spreading malignant melanoma. The computer image analysis system showed to be an advantajous tool for the measurement of tumor thickness.

Un naevus congénital mélanocytique (CMN) est une prolifération bénigne de mélanocytes cutanés, cliniquement apparente à la naissance. On en retrouve chez approximativement 1% des nouveau-nés. Les CMN de taille large (LCMN), définis par un diamètre le plus large de plus de 20 cm, affectent environ 1 nouveau-né sur 20.000.<p>Puisque les LCMN ont une propension à dégénérer en tumeur mélanomateuse (dans 2 à 5% des cas) et que leur grande taille apporte un contingent cellulaire abondant, ils représentent un bon modèle d’étude des étapes initiales de la mélanotumorigénèse. Nous disposions précisément de cultures primaires de mélanocytes établies à partir de vingt-sept cas de naevi congénitaux (24 de taille large et 3 de taille moyenne (MCMN)) curetés pour la plupart chez des enfants en période néonatale.<p>La première phase de ce projet a permis d’identifier un mécanisme alternatif d’activation de l’oncogène BRAF dans deux cas de LCMN. Nous avons en effet mis en évidence dans ces deux cas de LCMN une translocation chromosomique entrainant une activation constitutive de BRAF par le biais d’une perte de son domaine auto-inhibiteur. Si des mutations activatrices de BRAF sont fréquemment rencontrées dans les tumeurs mélanocytiques, elles restent rares dans les naevi congénitaux et les mélanomes survenant dans des zones non exposées au soleil. Les translocations chromosomiques décrites ici pourraient représenter un mécanisme moléculaire récurrent d’activation de l’oncogène BRAF dans ces groupes de tumeurs mélanocytiques.<p>La seconde phase du projet consistait à réaliser sur notre série de 27 L/MCMN des analyses caryotypiques, des analyses « mutationnelles » (pour rechercher la présence de mutations activatrices des oncogènes BRAF et NRAS) et des études d’expression différentielle.<p>A l’inverse de ce que l’on observe dans le mélanome malin, les anomalies chromosomiques sont rares et isolées, reflétant très probablement le caractère bénin de ces lésions.<p>La mutation BRAFV600E a été mise en évidence pour 4/27 CMN (15%), des mutations du gène NRAS pour 19/27 (70%), soit une situation en miroir de ce que l’on observe dans les CMN de petite taille (SCMN) et dans les naevi acquis bénins, confirmant les résultats obtenus par d’autres. <p>L’étude du profil d’expression transcriptionnelle révèle des dysrégulations communes à l’ensemble des échantillons naeviques, comme une franche augmentation d’expression du transcrit de l’Ostéopontine.<p>Le profil d’expression des échantillons de CMN BRAFV600E semble refléter une réduction de la synthèse et de la distribution de pigment et une activation de gènes impliqués dans la réponse cellulaire aux dommages à l’ADN. Comme des altérations des mécanismes de la pigmentation peuvent générer des dommages oxydatifs au niveau de l’ADN, l’activation de la réponse cellulaire aux dommages à l’ADN pourrait refléter la capacité des cellules naeviques à se protéger contre le stress cellulaire. Enfin, on observait aussi une expression élevée de gènes médiant la chimiorésistance dans différents cancers, ce qui pourrait éventuellement jouer un rôle dans l’inefficacité caractéristique et bien connue de la chimiothérapie dans le mélanome malin.<p> / Doctorat en Sciences médicales / info:eu-repo/semantics/nonPublished