Introdução: O molusco contagioso (MC) é um vírus da família Poxviridae que infecta os queratinócitos epidérmicos levando a hiperplasia e formação de inclusões eosinofílicas intracitoplasmáticas os corpos de molluscum. Poucos estudos analisam as alterações induzidas por este Mollucipox vírus nas estruturas que compõem o citoesqueleto e a adesão celular dos queratinócitos. Objetivos: Verificar o padrão de expressão de citoqueratinas, filagrina, involucrina, E-caderina e p63 pela técnica de imuno-histoquímica em lesões de MC e compará-las com a epiderme adjacente aparentemente normal (EAAN). Método: Através de técnica de imuno-histoquímica, estudou-se a expressão de K1, K10, K14, K16, filagrina, involucrina, E-caderina e p63 em lesões de MC de 41 pacientes imunocompetentes. Os padrões de expressão nas lesões de MC foram comparados com a EAAN. Resultados: A expressão de K1/K10 ocorreu como o habitual nas camadas suprabasais da epiderme. A marcação de K14 foi observada nas camadas epidérmicas basal e suprabasal nas lesões de MC e EAAN. A K16, que é expressa somente em processos hiperproliferativos, foi demonstrada na camada espinhosa tanto nos focos de MC como na EAAN. Filagrina e involucrina expressaram-se nas camadas granulosa, espinhosa e em alguns casos até mesmo na camada basal na epiderme infectada e EAAN. A E-caderina esteve presente até a porção inferior dos corpos de molusco enquanto na EAAN apresentou-se nas camadas basal e espinhosa. A expressão nuclear do p63 ocorreu nas camadas basal e espinhosa tanto no MC como EAAN. Conclusão: A infecção pelo Molluscipox vírus parece interferir no processo de diferenciação terminal dos queratinócitos. A expressão tardia de K14 e p63 na camada espinhosa, assim como a expressão precoce de filagrina e involucrina, associada ao estado hiperproliferativo demonstrado pela presença aberrante de K16, refletem um distúrbio no processo de maturação dos queratinócitos infectados. As alterações observadas na EAAN podem representar evento precoce no distúrbio de queratinização induzido pelo vírus na pele infectada. / Background: Molluscum contagiosum (MC) is a Molluscipox virus infection of the epidermal keratinocytes with hyperplasia and intracytoplasmic inclusions the molluscum bodies (MB). Few studies address cytokeratins (K) profile in MC, mainly focusing the terminal epidermal keratinization process. Methods: In order to verify K1, K10, K14, K16, involucrin, filaggrin, E-cadherin and p63 expression in MC, 41 lesions were subjected to immunohistochemical technique. The immunolabeling pattern of MC was compared to adjacent normal appearing epidermis (ANAE). Results: K1 and K10 were expressed in supra basal layers of MC and ANAE. K14 was expressed in basal and suprabasal layers in MC and also in ANAE. K16 was expressed in MC and ANAE, through all spinous layers. Involucrin and filaggrin were observed in granular, spinous and even in basal layer of ANAE and MC. E-cadherin was present up to the first layers of epidermis with MB while ANAE exhibited E-cadherin labeling at basal and spinous layers. Basal and spinous layers keratinocytes nuclei, in both MC and ANAE, express p63. Conclusion: Infection by Molluscipox virus may noticeably alter keratinocyte differentiation status and cell adhesion. The presence of K14 and p63 in spinous layer, as well as early expression of involucrin and filaggrin, associated to a hyperproliferative state disclosed by the presence of K16, may be a result of a disruption in keratinocytes maturation process. The changes observed at ANAE may represent early events in keratinization disturbance.

Introdução: O molusco contagioso (MC) é um vírus da família Poxviridae que infecta os queratinócitos epidérmicos levando a hiperplasia e formação de inclusões eosinofílicas intracitoplasmáticas os corpos de molluscum. Poucos estudos analisam as alterações induzidas por este Mollucipox vírus nas estruturas que compõem o citoesqueleto e a adesão celular dos queratinócitos. Objetivos: Verificar o padrão de expressão de citoqueratinas, filagrina, involucrina, E-caderina e p63 pela técnica de imuno-histoquímica em lesões de MC e compará-las com a epiderme adjacente aparentemente normal (EAAN). Método: Através de técnica de imuno-histoquímica, estudou-se a expressão de K1, K10, K14, K16, filagrina, involucrina, E-caderina e p63 em lesões de MC de 41 pacientes imunocompetentes. Os padrões de expressão nas lesões de MC foram comparados com a EAAN. Resultados: A expressão de K1/K10 ocorreu como o habitual nas camadas suprabasais da epiderme. A marcação de K14 foi observada nas camadas epidérmicas basal e suprabasal nas lesões de MC e EAAN. A K16, que é expressa somente em processos hiperproliferativos, foi demonstrada na camada espinhosa tanto nos focos de MC como na EAAN. Filagrina e involucrina expressaram-se nas camadas granulosa, espinhosa e em alguns casos até mesmo na camada basal na epiderme infectada e EAAN. A E-caderina esteve presente até a porção inferior dos corpos de molusco enquanto na EAAN apresentou-se nas camadas basal e espinhosa. A expressão nuclear do p63 ocorreu nas camadas basal e espinhosa tanto no MC como EAAN. Conclusão: A infecção pelo Molluscipox vírus parece interferir no processo de diferenciação terminal dos queratinócitos. A expressão tardia de K14 e p63 na camada espinhosa, assim como a expressão precoce de filagrina e involucrina, associada ao estado hiperproliferativo demonstrado pela presença aberrante de K16, refletem um distúrbio no processo de maturação dos queratinócitos infectados. As alterações observadas na EAAN podem representar evento precoce no distúrbio de queratinização induzido pelo vírus na pele infectada. / Background: Molluscum contagiosum (MC) is a Molluscipox virus infection of the epidermal keratinocytes with hyperplasia and intracytoplasmic inclusions the molluscum bodies (MB). Few studies address cytokeratins (K) profile in MC, mainly focusing the terminal epidermal keratinization process. Methods: In order to verify K1, K10, K14, K16, involucrin, filaggrin, E-cadherin and p63 expression in MC, 41 lesions were subjected to immunohistochemical technique. The immunolabeling pattern of MC was compared to adjacent normal appearing epidermis (ANAE). Results: K1 and K10 were expressed in supra basal layers of MC and ANAE. K14 was expressed in basal and suprabasal layers in MC and also in ANAE. K16 was expressed in MC and ANAE, through all spinous layers. Involucrin and filaggrin were observed in granular, spinous and even in basal layer of ANAE and MC. E-cadherin was present up to the first layers of epidermis with MB while ANAE exhibited E-cadherin labeling at basal and spinous layers. Basal and spinous layers keratinocytes nuclei, in both MC and ANAE, express p63. Conclusion: Infection by Molluscipox virus may noticeably alter keratinocyte differentiation status and cell adhesion. The presence of K14 and p63 in spinous layer, as well as early expression of involucrin and filaggrin, associated to a hyperproliferative state disclosed by the presence of K16, may be a result of a disruption in keratinocytes maturation process. The changes observed at ANAE may represent early events in keratinization disturbance.

Cadherin and catenin-family proteins regulate adhesion in malignant melanoma. Using AQUA (Automated Quantitative Analysis) to quantitate the levels of alpha-catenin, beta-catenin, p120-catenin, N-cadherin, E-cadherin, and P-cadherin in melanoma on tissue microarrays (TMAs), we classified 513 patients by protein expression using hierarchical clustering and regression analysis. The dendrogram supported positive correlations seen upon Spearman rho analysis of P-cadherin and beta-catenin (r=0.5238, p<0.0001) and negative, weak association of N-cadherin with other markers. Patients with high expression of N-cadherin had the highest 20-year survival rate (p=0.0003). Our adherens protein molecular classification of melanoma defines at least two distinctive sub-populations of melanoma patients, those with high expression of N-cadherin and those with low expression who have decreased survival. These findings extend previous cDNA array-based findings of an epithelioid class and neural crest class of melanomas.

published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

Stat3 (signal transducer and activator of transcription-3) is activated by a number of receptor and non-receptor tyrosine kinases, while a constitutively active form of Stat3 alone is sufficient to induce neoplastic transformation. Results presented in this thesis reveal that Stat3 can also be activated through homophilic interactions by the epithelial (E)-cadherin and cadherin-11, two members of the classical type I and II cadherin family of surface receptors, responsible for the formation of cell to cell junctions. Indeed, by plating cells onto surfaces coated with fragments encompassing the two outermost domains of these cadherins, we definitively demonstrate that cadherin engagement can activate Stat3, even in the absence of direct cell to cell contact. At the same time, levels of the extracellular signal regulated kinase (Erk)1/2, which is often coordinately activated by growth factor receptors and oncogenes, remain unchanged upon cadherin ligation. Most importantly, we report, for the first time, an unexpected surge in total Rac1 and Cdc42 protein levels, triggered by cadherin engagement, and an increase in Rac1 and Cdc42 activity, which is responsible for the Stat3 stimulation observed. Inhibition of cadherin interactions reduced Rac/Cdc42 and Stat3 levels and induced apoptosis, pointing to a significant role of this pathway in cell survival signalling, a finding which could also have important therapeutic implications. To better understand the role of Rac/Cdc42 in the cadherin-mediated Stat3 activation, we compared Stat3 activity in mouse HC11 cells before and after expression of the mutationally activated, RacV12. We demonstrate a dramatic increase in protein levels and activity of both the endogenous Rac and RacV12 with cell density, which was due to inhibition of proteasomal degradation. Moreover, we clearly show that RacV12 expression can activate Stat3 through an increase in expression of members of the IL6 family of cytokines, known potent Stat3 activators. In fact, knockdown experiments indicate that gp130 receptor function, and Stat3 activation, are essential for the migration and proliferation of RacV12-expressing cells, thereby demonstrating that the gp130/Stat3 axis represents an essential target of activated Rac in the regulation of both of these fundamental cellular functions. / Thesis (Ph.D, Pathology & Molecular Medicine) -- Queen's University, 2010-02-18 10:38:29.549

Thesis (Ph.D.). / Written for the Dept. of Neurology and Neurosurgery. Title from title page of PDF (viewed 2008/05/09). Includes bibliographical references.

Thesis (M. Phil.)--University of Hong Kong, 2009. / Includes bibliographical references (leaves 101-124) Also available in print.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2010.

Epidermodisplasia verruciforme (EV) é uma genodermatose rara, com susceptibilidade para infecção pelo vírus do papiloma humano, considerada modelo de oncogênese viral. Comparou-se a expressão epidérmica das citoqueratinas (K) 1, 10, 14, 4, 16, involucrina, filagrina e e-caderina, em lesões de verrugas planas e nas verrugas planas da EV através de método imunohistoquímico. Na EV houve ausência ou retardo de expressão (queratinócitos mais superficias) de K1/10, com substituição pela K14. Houve expressão basal e suprabasal de K14 em ambos os grupos, bem como positividade para K4 e 16, e expressão de involucrina nas camadas mais inferiores da epiderme. A expressão de filagrina não foi alterada, e a de e-caderina apresentou-se diminuída nas células coilocitóticas superficiais na EV / Epidermodisplasia verruciforme (EV) is a rare genodermatosis with susceptibility to human papillomavirus infection, considered a model of viral oncogenesis. We compared epidermal expression of cytokeratins (K) 1, 10, 14, 4, 16, involucrin, filaggrin and e-cadherin in plane warts and plane wart-type lesions in EV by immunohistochemical technique. In EV there was absent or retarded expression (more superficial keratinocytes) of K1/10, being substituted by K14. There was basal and suprabasal expression of K14 in both groups, as well as positivity for K4 and K16, and involucrin expression in more inferior layers of epidermis. Filaggrin expression was not altered, and e-cadherin was diminished in superficial koilocytotic cells in EV

Orientador: Antonio Gonçalves de Oliveira Filho / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-13T04:54:32Z (GMT). No. of bitstreams: 1 Patricio_FlaviaRezendePereira_M.pdf: 2174141 bytes, checksum: 0011ea137b3f271896d984e54bb4f4d6 (MD5) Previous issue date: 2009 / Resumo: Tumores do córtex da supra-renal (TCSR) em crianças são raros e correspondem a 0,2% dos tumores da infância. Estes tumores são endocrinologicamente ativos, causando na maioria das vezes, virilização do paciente associada, ou não, a um aumento de cortisol. O tratamento dos TCSR é principalmente cirúrgico, sendo a cirurgia com o procedimento de ressecção completa do tumor e sem ruptura a principal modalidade terapêutica. No entanto, a distinção entre tumores benignos e malignos, baseada exclusivamente na histologia, pode ser difícil de ser realizada. Os fatores prognósticos são baseados quase exclusivamente no estadiamento da doença, o qual leva em conta o peso e volume tumoral e a disseminação metastática do tumor. Estudos clínicos e experimentais sugerem que a propagação metastática em alguns tumores está relacionada aos níveis de E-caderina e ?-catenina, que são moléculas presentes no tecido epitelial normal, estando envolvidas diretamente na adesão intercelular. A análise da expressão destas moléculas pode fornecer dados que permite identificar grupos de pacientes mais propensos à evolução tumoral desfavorável, proporcionando, assim, um tratamento mais adequado e individualizado a estes pacientes. Com o objetivo de analisar a expressão da E-caderina e ?-catenina em crianças com TCSR e sua correlação com a evolução da doença, foi realizada uma revisão retrospectiva dos prontuários de 33 crianças com diagnóstico de TCSR tratadas no Centro Infantil Boldrini (Janeiro de 1998 a Janeiro de 2005). Foram coletados e analisados dados referentes ao sexo, idade, manifestações clínicas, estadiamento, tratamento e evolução dos pacientes. Para a análise imunoistoquímica, foi empregada a técnica de multitissue array com anticorpos específicos para E-caderina e ?-catenina em 30 tumores de crianças com TCSR e uma adrenal normal. Houve predominância do sexo feminino na amostra e a apresentação clínica mais freqüente foi a virilização. Nesta série, observou-se que crianças com idade inferior a dois anos apresentaram melhor prognóstico e, também que a ruptura e recidiva tumoral apresentaram influência negativa na sobrevida dos pacientes. A análise imunoistoquímica mostrou expressão da E-caderina em 73,3% e ?-catenina em 83,3% das crianças que apresentavam TCSR. Além disso, não foi verificada sua expressão na glândula adrenal normal. Quando avaliada a relação da expressão da E-caderina e ?-catenina com os estádios evolutivos da doença, não foi verificada associação significativa entre as variáveis. A positividade da E-caderina e ?-catenina na membrana celular, citoplasma ou núcleo, verificou-se que a expressão na membrana celular mostrou associação significativa com mau prognóstico / Abstract: Adrenal cortical tumor (ACT) in children are rare and they correspond to 0,2% of the tumors of the childhood. They are usually active, causing mainly virilization of patient associate or not with increased levels of corticoids. The treatment of the TCSR is mainly surgical, being the surgery with complete resection of the tumor without spillage the therapeutic mainstay. The distinction between benign and malignant tumors based exclusively on the histology can be difficult and very often uncertain. The prognostic factors are based almost exclusively on the staging of the disease, who takes into account the weight and volume tumoral and the metastatic dissemination. Clinical and experimental studies suggest that metastatic dissemination in some tumors is related with the levels of E-cadherin and ?-catenin. These molecules are found in the normal epithelial tissues and are strongly related with intercellular adhesion. The analysis of the expression of these molecules maybe can allow identifying groups of patients with higher risk of presenting unfavorable outcomes and ensuing appropriate and individualized treatment. With the objective of analyzing the expression of E-cadherin and ?-catenin in children with ACT and its correlation with the evolution of the disease, a retrospective chart review of 33 children with diagnosis of ACT treated at Centro Infantil Boldrini (January of 1998 through January of 2005). Data regarding sex, age, clinical presentation, staging, treatment and outcome were collected and analyzed. Multitissue array technique using specific antibodies for E-cadherin and ?-catenin was done in 30 tumors from children with ACT and 1 normal adrenal tissue. There was predominance of the feminine sex and the most frequent clinical presentation was virilization. In these series children with age bellow two years had a better outcome and tumoral spillage and relapse have had negative influence in the survival of the patients. Immunohistochemical analysis showed expression of E-cadherin in 73,3 % and ?-catenin in 83,3 % of the children who had ACT but showed no expression in the normal adrenal tissue. When the relationship between the expression of E-cadherin and ?-catenin with the stages of the disease was analyzed, no significant association was found. When analyzed the expression of E-cadherin and ?-catenin in the cellular membrane, cytoplasm or nucleus, its presence in the membrane of the cell was found as associated with poor outcome. As far we know, this is the first study to evaluate the expression of E-cadherin and ?-catenin in children with ACT and, although with small number of patients due to the rarity of the disease, it apparently shows some relationship with prognosis. When the relationship between the expression of E-cadherin and ?-catenin with the stages of the disease was analyzed, no significant association was found. When analyzed the expression of E-cadherin and ?-catenin in the cellular membrane, cytoplasm or nucleus, its presence in the membrane of the cell was found as associated with poor outcome. As far we know, this is the first study to evaluate the expression of E-cadherin and ?-catenin in children with ACT and, although with small number of patients due to the rarity of the disease, it apparently shows some relationship with prognosis / Mestrado / Cirurgia / Mestre em Cirurgia