Members of the Runx family of transcription factors play essential roles in the differentiation and development of several organ systems. Here we address the contribution of the osteoblast-related Runx gene, Runx2, to the osteogenic and chondrogenic differentiation of mesenchymal stem cells. Using a transgenic mouse model, we observe Runx2 transcription through one of its two known promoters (designated P1 in pre-cartilaginous mesenchymal condensations as early as E9.5. Runx2 gene activity is later repressed at the onset of cartilage formation, both in vivo and in vitro, necessitating examination of the regulation and function of Runx2 in mesenchymal stem cells. We demonstrate that Runx2 gene activity is repressed by the direct interaction of the homeodomain transcription factor Nkx3.2 with the proximal Runx2 P1 promoter. This repression was found to be required for the progression of BMP-induced chondrogenesis, thereby identifying Runx2 as a modulator of BMP activity in the chondrogenic as well as osteogenic differentiation program. To further understand the regulation of the Runx2 P1 promoter and to determine the contribution of P1-derived gene product, Runx2 Type II, to the formation of mineralized tissue, we have generated a Runx2 Type II-LacZ gene replacement mouse model in which the initial coding sequences and splice donor sites of the Type II isoform are replaced with the LacZ reporter gene. Activity of the endogenous P1 promoter can therefore be monitored by β-galactosidase production. Analysis of Runx2 Type II-LacZ mice demonstrates that the P1 promoter is transcriptionally most active in mature osteoblasts, but its product, Runx2 Type II is dispensable for embryonic skeletal formation. Lastly, we examine the link between growth control and osteogenic differentiation by tissue-specific deletion of the Mdm2 proto-oncogene in developing skeletal tissues of the mouse embryo. Loss of Mdm2 results in impaired bone formation, with skeletal elements exhibiting lower bone mineral content and higher porosity. Ex vivo cultures of calvarial osteoprogenitor cells exhibit severely decreased osteoblastogenesis and bone nodule formation accompanied by a failure to activate Runx2 gene activity. These findings suggest that Mdm2 is required for inhibition of p53 activity that ultimately allows for post-confluent proliferation and induction of Runx2 during maturation of the osteogenic phenotype. Taken together, our findings suggest that Runx2 modulates the commitment of progenitor cells to the osteogenic and chondrogenic lineages, and that Runx2 activity is inextricably linked to mechanisms that control cellular proliferation.

Nitric oxide is a ubiquitous signaling molecule with both physiological and pathological functions in biological systems. Formed by the enzymatic conversion of arginine to citrulline, NO, has known roles in circulatory, immune and nervous tissues. In the nervous system nitric oxide has been implicated in long-term potentiation, neurotransmitter release, channel function, neuronal protection and neuronal degeneration. Much of our work has focused on yet another role for nitric oxide in cells, namely, neuronal differentiation. During development, neuronal differentiation is closely coupled with cessation of proliferation. We use nerve growth factor (NGF)-induced differentiation of PC12 pheochromocytoma cells as a model and find a novel signal transduction pathway that blocks cell proliferation. Treatment of PC12 cells with NGF leads to induction of nitric oxide synthase (NOS). The resulting nitric oxide (NO) acts as a second messenger, activating the p21(WAF1) promoter and inducing expression of p21(WAF1) cyclin-dependent kinase inhibitor. NO activates the p21(WAF1) promoter by p53-dependent and p53-independent mechanisms. Blocking production of NO with an inhibitor of NOS reduces accumulation of p53, activation of the p21(WAF1) promoter, expression of neuronal markers, and neurite extension. To deternine whether p21(WAF1) is required for neurite extension, we prepared a PC12 line with an inducible p21(WAF1) expression vector. Blocking NOS with an inhibitor decreases neurite extension, but induction of p21(WAF1) with isopropyl-1-thio-beta-D-galactopyranoside restored this response. Levels of p21(WAF1) induced by isopropyl-1-thio-beta-D-galactopyranoside were similar to those induced by NGF. Therefore, we have identified a signal transduction pathway that is activated by NGF; proceeds through NOS, p53 and p21(WAF1) to block cell proliferation; and is required for neuronal differentiation by PC12 cells. In further studies of this pathway, we have examined the role of MAP kinase pathways in neuronal nitric oxide synthase (nNOS) induction during the differentiation of PC12 cells. In NGF-treated PC12 cells, we find that nNOS is induced at RNA and protein levels, resulting in increased NOS activity. We note that neither nNOS mRNA, nNOS protein nor NOS activity is induced by NGF treatment in cells that have been infected with a dominant negative Ras adenovirus. We have also used drugs that block MAP kinase pathways and assessed their ability to inhibit nNOS induction. Even though U0126 and PD98059 are both MEK inhibitors, we find that U0126, but not PD98059, blocks nNOS induction and NOS activity in NGF-treated PC12 cells. Also, the p38 kinase inhibitor, SB 203580, does not block nNOS induction in our clone of PC12 cells. Since the JNK pathway is not activated in NGF-treated PC12 cells, we determine that the Ras-ERK pathway and not the p38 or JNK pathway is required for nNOS induction in NGF-treated PC12 cells. We find that U0l26 is much more effective than PD98059 in blocking the Ras-ERK pathway, thereby explaining the discrepancy in nNOS inhibition. We conclude that the Ras-ERK pathway is required for nNOS induction. The activation of soluble guanylate cyclase and the production of cyclic GMP is one of the best characterized modes of NO action. Having shown that inhibition of NOS blocks PC12 cell differentiation we tested whether nitric oxide acts through soluble guanylate cyclase to lead to cell cycle arrest and neuronal differentiation. Unlike NOS inhibition, the inhibition of soluble guanylate cylcase does not block the induction of neuronal markers. Moreover, treatment of NGF-treated, NOS-inhibited PC12 cells with a soluble analog of cyclic GMP was unable to restore differentiation of those cells. Hence, cGMP is not a component of this pathway and we had to consider other mechanisms of NO action. It has become increasingly evident that another manner by which NO may exert its effects is by S-nitrosylation of cysteine residues. We tested, in vitro whether nitric oxide may control p53 by S-nitrosylation and inactivation of the p53 negative regulator, Hdm2. Treatment of Hdm2 with a nitric oxide donor inhibits Hdm2-p53 binding, the first step in Hdm2 regulation of p53. The presence of cysteine or DTT blocks this inhibition of binding. Moreover, nitric oxide inhibition of Hdm2-p53 binding was found to be reversible. Sulfhydryl-sensitivity and reversibility are consistent with nitrosylation. Finally, we have identified a critical cysteine residue that nitric oxide modifies in order to disrupt Hdm2-p53 binding. Mutation of this residue from a cysteine to an alanine does not interfere with binding but rather eliminates the sensitivity of Hdm2 to nitric oxide inactivation.

Synaptic plasticity, the ability of synapses to change in strength, underlies complex brain functions such as learning and memory, yet little is known about the precise molecular mechanisms and downstream signaling pathways involved. The major goal of my doctoral thesis was to understand these molecular mechanisms and cellular processes underlying synaptic plasticity using the Drosophilalarval neuromuscular junction (NMJ) as a model system. My work centered on a signaling pathway, the Wg/Wnt signaling pathway, which was found to be crucial for activity-driven synapse formation. The Wg/Wnt family of secreted proteins, besides its well-characterized roles in embryonic patterning, cell growth and cancer, is beginning to be recognized as a pivotal player during synaptic differentiation and plasticity in the brain. At the DrosophilaNMJ, the Wnt-1 homolog Wingless (Wg) is secreted from presynaptic terminals and binds to Frizzled-2 (DFz2) receptors in the postsynaptic muscle. Perturbations in Wg signaling lead to poorly differentiated NMJs, containing synaptic sites that lack both neurotransmitter release sites and postsynaptic structures. In collaboration with other members of the Budnik lab, I set out to unravel the mechanisms by which Wg regulates synapse differentiation. We identified a novel transduction pathway that provides communication between the postsynaptic membrane and the nucleus, and which is responsible for proper synapse development. In this novel Frizzled Nuclear Import (FNI) pathway, the DFz2 receptor is internalized and transported towards the nucleus. The C-terminus of DFz2 is subsequently cleaved and imported into the postsynaptic nucleus for potential transcriptional regulation of synapse development (Mathews, Ataman, et al. Science (2005) 310:1344). My studies also centered on the genetic analysis of Glutamate Receptor (GluR) Interacting Protein (dGRIP), which in mammals has been suggested to regulate the localization of GluRs and more recently, synapse development. I generated mutations in the gene, transgenic strains carrying a dGRIP-RNAi and fluorescently tagged dGRIP, and antibodies against the protein. Remarkably, I found dgrip mutants had synaptic phenotypes that closely resembled those in mutations altering the FNI pathway. Through the genetic analysis of dgrip and components of the FNI pathway, immunoprecipitation studies, electron microscopy, in vivotrafficking assays, time-lapse imaging, and yeast two-hybrid assays, I demonstrated that dGRIP had a hitherto unknown role as an essential component of the FNI pathway. dGRIP was found in trafficking vesicles that contain internalized DFz2. Further, DFz2 and dGRIP likely interact directly. Through the use of pulse chase experiments I found that dGRIP is required for the transport of DFz2 from the synapse to the nucleus. These studies thus provided a molecular mechanism by which the Wnt receptor, DFz2, is trafficked from the postsynaptic membrane to the nucleus during synapse development and implicated dGRIP as an essential component of the FNI pathway (Ataman et al. PNAS (2006) 103:7841). In the final part of my dissertation, I concentrated on understanding the mechanisms by which neuronal activity regulates synapse formation, and the role of the Wnt pathway in this process. I found that acute changes in patterned activity lead to rapid modifications in synaptic structure and function, resulting in the formation of undifferentiated synaptic sites and to the potentiation of spontaneous neurotransmitter release. I also found that these rapid modifications required a bidirectional Wg transduction pathway. Evoked activity induced Wg release from synaptic sites, which stimulated both the postsynaptic FNI pathway, as well as an alternative presynaptic Wg pathway involving GSK-3ß/Shaggy. I suggest that the concurrent activation of these alternative pathways by the same ligand is employed as a mechanism for the simultaneous and coordinated assembly of the pre- and postsynaptic apparatus during activity-dependent synapse remodeling (Ataman et al. Neuron (2008) in press). In summary, my thesis work identified and characterized a previously unrecognized synaptic Wg/Wnt transduction pathway. Further, it established a mechanistic link between activity-dependent synaptic plasticity and bidirectional Wg/Wnt signaling. These findings provide novel mechanistic insight into synaptic plasticity.

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No. of bitstreams: 2 Dissertalçao - Vanessa de Sousa Cruz Pimenta - 2012.pdf: 3213134 bytes, checksum: b135b98e005a73bd0b991b974142808b (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2012-04-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The objective of this study was to verify the pattern of staining by Bismarck Brown and evaluate the expression of p53 and c-KIT in neoplastic mast cells, quantifying the marking obtained by these antibodies using the Image J software and correlating the values found with histologic subtypes. Mast cell tumors are the most common skin neoplasms of dogs, is an excessive proliferation of neoplastic mast cells, of variable and unpredictable biological behavior, with great capacity of recurrences and metastasis. The lesions may be dermis or subcutaneous location and three grades are described. At the first, the tumor is well differentiated, moderately differentiated is the second and the third is little differentiated. Their cause is still unknown. One of the mechanisms proposed for the proliferation of mast cells is to change the nucleotide sequence of the c-KIT gene. The tumor suppressor gene TP53 is directly related to blockage of cell cycle and the protection is changed by mutations in the p53. Were reviewed 1242 protocols of histopathology exams obtained the archives of Laboratory of Animal Pathology/UFG, from January 2007 to April 2011, found 37 diagnosis of canine cutaneous mast cell tumor. Regarding the epidemiologic aspects the prevalence of 55.26% was noted in dogs in the age group 6-10 years, 63.16% female and 39.48% of the Boxer breed. The most common anatomic site was the hind-limb with 31.58% of records. Histologic evaluation and histochemistry using Hematoxylin - Eosin and Toluidine Blue allowed to classify the majority of mast cell tumors studied, although only 24.32% of the samples were identified using the color Bismarck Brown. The prevalence of Grade II was 43.24% of all cases The lowest value expressed for p53 and c-KIT, was in Grade II, the highest value in the Grade III and the highest average in grade I. Was concluded that the coloration of Bismarck Brown proved efficient to aid in the diagnostic accuracy of laboratory routine and utilization of antibodies anti p53 and anti c-kit promoted good immunostaining with important role to determine the prognosis of canine mast cell tumors. / O objetivo deste estudo foi verificar o padrão de coloração pelo Pardo de Bismarck e avaliar a expressão de p53 e c-KIT nos mastócitos neoplásicos, quantificando a marcação obtida por estes anticorpos através do software Image J e correlacionando os valores encontrados com os subtipos histológicos. O mastocitoma é a neoplasia cutânea mais frequente do cão, sendo uma proliferação excessiva de mastócitos neoplásicos, de comportamento biológico variável e imprevisível, com grande capacidade de recidivas e metástases. As lesões podem ser de localização dérmica a subcutânea e três graus são descritos. No primeiro, o tumor é bem diferenciado, no segundo é moderadamente diferenciado e no terceiro é pouco diferenciado. Sua causa ainda é desconhecida. Um dos mecanismos propostos para a proliferação de mastócitos é a alteração da sequência de nucleotídeos do gene c-KIT. O gene supressor de tumor TP53 está diretamente relacionado ao bloqueio do ciclo celular e a proteção é alterada por mutações da p53. Foram revisados 1242 protocolos de exames histopatológicos obtidos dos arquivos do Laboratório de Patologia Animal/UFG, do período de janeiro de 2007 a abril de 2011, encontrando 37 diagnósticos de mastocitoma cutâneo canino. Quanto aos aspectos epidemiológicos a prevalência notada foi de 55,26% de cães na faixa etária de 6-10 anos, 63,16% do gênero feminino e 39,48% da raça Boxer. A localização anatômica mais frequente foi o membro pélvico com 31,58% de registros. A avaliação histológica e histoquímica utilizando a Hematoxilina - Eosina e o Azul de Toluidina permitiu classificar a maioria dos mastocitomas estudados, porém 24,32% das amostras só foram identificadas com a utilização da coloração Pardo de Bismarck. A prevalência do Grau II foi de 43,24% do total dos casos. O menor valor expresso, por p53 e c-KIT, foi no Grau II, o maior valor no Grau III e a maior média no grau I. Foi possível concluir que a coloração Pardo de Bismarck mostrou-se eficiente para auxiliar na precisão dos diagnósticos da rotina laboratorial e a utilização dos anticorpos anti p53 e anti c-KIT promoveu boa imunomarcação, com papel importante na determinação do prognóstico do mastocitoma canino.

As células intersticiais de Cajal (CIC) têm sido estudadas como participante do peristaltismo em vários sistemas. Sua presença no trato geniturinário pode sustentar a importância dessas células na fisiopatologia da estenose da junção ureteropielica (JUP). O Objetivo desse estudo foi avaliar a densidade das CIC em pacientes adultos e no final da adolescência, portadores de estenose da JUP, submetidos à pieloplastia e verificar se há associação entre a densidade das CIC com os achados clínicos e de imagem pré e pós-operatórios, notadamente ultrassonografia e cintilografia renal. Foram estudados 23 pacientes com estenose da JUP, submetidos à pieloplastia desmembrada pela técnica videolaparoscópica na Divisão de Clínica Urológica do Departamento de Cirurgia do HCFMUSP, de forma consecutiva, pelo mesmo grupo de cirurgiões, no período entre fevereiro de 2011 a janeiro de 2012. Foi realizada análise imunohistoquímica para expressão do receptor de tirosina quinase (c-KIT) em todas as amostras das JUP e quantificada a densidade das CIC. Os pacientes foram acompanhados periodicamente para avaliação da resposta clínica e dos exames de imagem. Foi encontrado que a média de idade da amostra foi de 34,83 anos. Houve predomínio do gênero masculino (56,5%). O rim direito foi o mais acometido (56,5%). A hidronefrose grave foi identificada na maioria dos pacientes (52,2%). A média da função renal do rim acometido estimada pela cintilografia, pré e pós-operatória foi de respectivamente, 33,7 e 33,4%. Dos 23 pacientes, 20 apresentaram melhora do padrão cintilográfico de drenagem ureteral. Houve predomínio de pacientes que apresentavam alta densidade das CIC (52,2%). Houve significância estatística quando associado a densidade das CIC e a melhora do padrão ultrassonográfico (p= 0,032). Contudo, não houve associação entre a densidade das CIC e as outras variáveis clínicas ou de imagem. Pode-se concluir que a densidade das CIC pode ser um bom preditor da resposta ultrassonográfica pósoperatória em pacientes adultos com estenose da JUP submetidos à pieloplastia / The interstitial cells of Cajal (ICC) have been studied as peristalsis participating in various systems. Its presence in the genitourinary tract can sustain the importance of these cells in the pathophysiology of ureteropelvic junction obstruction (UPJO). The aim of this study was to evaluate the density of ICC in adults and in the late adolescence patients with UPJO, undergoing pyeloplasty and to check if there is association of changes in the ICC density with clinical findings, as well as pre and postoperative images, especially ultrasound and diuretic radioisotope renography. We selected 23 patients with UPJO, undergoing laparocopic dismembered pyeloplasty in the Urology Division of the HC-FMUSP Department of Surgery, consecutively, by the same group of surgeons in the period between February 2011 and January 2012. It was performed immunohistochemical analysis for tyrosine kinase receptor expression (c-KIT) in all samples of UPJO quantified the ICC density. The patients were followed up periodically to evaluate the clinical response and imaging. The average age of the sample was 34.83 years. There was a predominance of males (56.5%). The right kidney was the most affected (56.5%). Severe hydronephrosis was identified in most patients (52.2%). The average renal function affected estimated by diuretic radioisotope renography, pre and post-operative was respectively 33.7 and 33.4%. Of the 23 patients, 20 had an improvement on diuretic radioisotope renography pattern of ureteral drainage. There was a predominance of patients with high ICC density (52.2%). There was statistical significance when associated with ICC density and the improvement of ultrasonographic pattern (p = 0.032). However, there was no association between the ICC density and other clinical or imaging variables. It can be concluded that the density of the ICC maybe a good predictor of post-operative ultrasound response in adult patients with UPJO undergoing pyeloplasty

A incidência de melanomas tem crescido mundialmente. Apesar de representar um potencial problema de saúde pública pela sua incidência crescente, melanomas ainda se apresentam como tumores de difícil tratamento, especialmente quando diagnosticados em estadios avançados. A taxa de resposta a quimioterapia não ultrapassa 30% de resposta clínica objetiva nestes casos. As bases moleculares da quimiorresistência não são ainda completamente esclarecidas e seu conhecimento será útil para o delineamento de estratégias de quimiossensibilização. Em estudos anteriores, observamos que o tratamento de linhagem de células de melanoma metastático humano com o quimioterápico cisplatina induz o acúmulo de proibitina nas células sobreviventes. Proibitina é uma molécula expressa ubiquamente na maioria das células. Há evidências de que a forma nuclear esteja envolvida com o processo de morte celular e inibição de E2F1 enquanto a forma citoplasmática parece atuar como chaperona mitocondrial, garantindo sua homeostasia. O objetivo deste projeto foi avaliar a compartimentalização subcelular e a expressão de proibitina, após tratamento com 25 M de cisplatina por 24 horas em diferentes linhagens de melanoma metastático humano; e, o efeito de sua subexpressão, usando-se small interference (si) RNA. Nós mostramos que nas linhagens de melanoma humano LB373Mel, SKMel 37 e Mel 85, a proibitina foi encontrada predominantemente no citoplasma, associada, pelo menos em parte, com a mitocôndria. Após tratamento com cisplatina, uma porção da proibitina também foi encontrada no núcleo, como pode ser detectado utilizando-se anticorpo monoclonal (clone II-14-1). Experimentos de knockdown de proibitina por siRNA obtiveram sucesso em duas de três linhagens. Nessas duas linhagens (LB373Mel e Mel 85), o bloqueio do acúmulo de proibitina após tratamento com cisplatina levou à quimiossensibilização. A quimiossensibilização à cisplatina não foi observada na linhagem SKMel 37, que foi capaz de acumular proibitina mesmo quando tratada com siRNA específico para proibitina. A conclusão deste projeto é que a expressão de proibitina é parte da resposta celular que leva a sobrevivência de células de melanoma expostas à cisplatina / The incidence of melanomas has grown world-wide. Besides representing a potential problem of public health for its increasing incidence, melanomas are tumors of difficult treatment, especially when diagnosed in advanced phases. The clinical objective response rate does not exceed 30% in these cases. The molecular bases of chemoresistance are not completely clarified and their understanding will be useful for the delineation of chemosensitization strategies. In previous studies, we observed that the treatment of a human metastatic melanoma cell line with the chemotherapeutic agent cisplatin induced the accumulation of prohibitin in the surviving cells. Prohibitin is ubiquitously expressed molecule in most cells. There is evidence that the nuclear form is involved with the process of cell death and inhibition of E2F1, while the cytoplasmic form seems to act as mitochondrial chaperone, guaranteeing its homeostasis. The aim of this project was to evaluate the subcellular compartmentalization and protein expression profile of prohibitin, after treatment with 25M of cisplatin for 24 hours in different human metastatic melanoma cell line, and the effect of its underexpression, using siRNA. We showed that, in human melanoma cell lines, LB373Mel, SKMel 37 and Mel 85, prohibitin was found predominantly in the cytoplasm, associated at least in part with the mitochondria. Upon cisplatin treatment, a fraction of prohibitin was also found in the nucleus, as detected by using a monoclonal antibody (clone II-14-10). Knockdown experiments were successful in two out of three cell lines. In these two cell lines (LB373Mel and Mel 85) blockage of the accumulation of prohibitin upon cisplatin treatment led to chemosensitization. Chemosensitization to cisplatin was not observed for SKMel 37 cells, which accumulated prohibitin even when treated with prohibitin specific siRNA oligonucleotides. Altogether, we concluded that expression of prohibitin is part of the cellular response that leads to cell survival in melanoma cells exposed to cisplatin

O objetivo deste trabalho foi estudar a expressão protéica de mdm2 e avaliar a sua relação com alguns aspectos anatomopatológicos, visando também identificar fatores prognósticos no que diz respeito à sobrevida livre de recidiva local (SLRL), sobrevida livre de metástase (SLM) e sobrevida global (SG), em pacientes portadores de lipossarcoma primário de extremidades. Vinte e cinco entre 50 pacientes admitidos no Instituto de Ortopedia e Traumatologia do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo – IOT/HC/FMUSP, entre 1968 e 2004, foram eleitos para o estudo. As probabilidades de sobrevida acumuladas foram feitas pela técnica de Kaplan-Meier e as curvas de sobrevida comparadas pelo teste de Log Rank. A validade estatística foi estabelecida para valores de p<0,05. As associações entre os índices positivo ou negativo para o mdm2 com outras variáveis foram feitas utilizando-se o teste exato de Fischer. A expressão imunoistoquímica da proteína mdm2 não foi considerada de valor prognóstico em nenhuma das sobrevidas estudadas (SLRL, SLM ou SG). Os fatores adversos que influenciaram o risco de recidiva local na análise univariada foram: o gênero masculino (p = 0,023), subtipo histológico pleomórfico (p = 0,027) e alto grau histológico (p=0,007). Em relação a SLM a idade inferior a 50 anos (p = 0,040), o gênero masculino (p = 0,040), o subtipo pleomórfico (p < 0,001), o alto grau histológico (p = 0,003) tiveram um pior prognóstico. Os fatores adversos para SG foram: idade inferior a 50 anos (p = 0,040); o gênero masculino (p = 0,040); o subtipo pleomórfico (p < 0,001) e o alto grau histológico (p = 0,003). / The purpose of this was to study the expression by imunohistochemistry of mdm2 and your correlation with anatomopathological selected variables, aiming at identifying prognostic factors concerning to local recurrence free survival (LRFS), metastases free survival (MFS) and overall survival (OS) in patients with liposarcomas primary extremities. This study included 25 patients registred in the Instituto de Ortopedia e Traumatologia do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo - Brazil, from 1968 to 2004. The accumulated survival probabilities were calculated by Kaplan-Meier method and survival curves were compared using the logrank test. Statistical significance was defined as a p value less than 0,05. Associations between expression of mdm2 and other variables were analyzed using Fischer’s exact test. The expression by imunohistochemistry of mdm2 was not significant factor for LRFS, MFS or OS. The adverse factors for LRFS in univariate analysis were male gender (p = 0,023), pleomorfic histologic subtypes (p = 0,027) and high grade tumor (p = 0,007). For MFS age < 50 years (p = 0,040), male gender (p = 0,040), pleomorfic histologic subtypes (p < 0,001) and high grade tumor (p = 0,003) had worse prognostic. Negative prognostic factors for OS were age < 50 years (p = 0,040), male gender (p = 0,040), pleomorfic histologic subtypes (p < 0,001) and high grade tumor (p = 0,003).

Introdução: O melanoma mucoso de cabeça e pescoço (MMCP) é mais agressivo do que o melanoma cutâneo, marcadores prognósticos desta patologia não foram completamente esclarecidos devido a sua raridade. Em recentes estudos, algumas vias moleculares foram descritas na fisiopatologia destes tumores. Entre estas vias, existe a via da MAPK (Mitogen Activated Protein Quinase). Esta via de sinalização está envolvida no controle do crescimento celular, proliferação e migração, com um papel no desenvolvimento e progressão do melanoma. Além disso, a mutação do gene KIT foi identificada em melanomas, indicando a possibilidade de benefícios terapêuticos com o uso dos inibidores de tirosino-quinase. Objetivos: descrever a prevalência e características de mutações ativadoras do gene KIT em 28 pacientes com MMCP tratados no Instituto Nacional do Câncer-INCa; avaliar a relação entre a presença de mutação ativadora do gene KIT e evolução clínica dos pacientes tratados em relação ao estadiamento, sobrevida livre de doença e sobrevida global. Métodos: Estudo retrospectivo de coorte, foram incluídos 28 pacientes com MMCP tratados no INCA, entre 1998 e 2009. Foram analisados: estadiamento, tratamento primário, sobrevida livre de doença (SLD) e sobrevida global (SG). As curvas de sobrevida foram analisados utilizando o método de Kaplan-Meier, com software SPS 11.0. Análise KIT: O DNA foi extraído a partir de tecido incluído e fixado em parafina. O procedimento consiste de múltiplas etapas de desparafinização com xilol. Os restos celulares são precipitados por centrifugação e o DNA, no sobrenadante é utilizado nas reações de PCR (direto ou diluído). A análise mutacional do gene foi realizada utilizando-se a amplificação por PCR seguida pelo sequenciamento genômico. As análises são iniciadas pelo éxon 11, seguidas do éxon 9, 17 e 13. Resultados: Os pacientes eram predominantemente do sexo feminino (57%). A idade de apresentação variou de 27 a 85 anos. A região nasossinusal foi o sítio primário mais frequente (75%). Todos os pacientes foram submetidos a ressecção cirúrgica. Dezessete pacientes receberam radioterapia adjuvante (37%). As recorrências ocorreram em 82% dos pacientes. Presença de mutação de KIT foi encontrada em 7 casos (25%), três no éxon 9, 3 no éxon 11 e 1 no éxon 13. Fatores preditivos de recorrência foram índice mitótico (p = 0,05), invasão vascular (p = 0,043), e a disseminação perineural (p = 0,034). Não houve diferenças significativas na SLD e SG de acordo com a mutação KIT. Conclusão: A presente série incluiu 28 casos tratados. Sete casos (25%) tinham mutações ativadoras KIT. Esta descoberta sugere que existe um grupo de pacientes que poderiam se beneficiar com a terapia-alvo adequado com inibidores de tirosino-quinase / Unlike their cutaneous counterparts, head and neck mucosal malignant melanomas (HNMM) behave much more aggressively and their prognostic markers have not been fully elucidated. In recent studies, some molecular pathways have been found to be involved in the pathogenesis of melanomas. Among these, there is a proliferative MAPK pathway (\"Mitogen Activated Protein Kinase\"). This signaling pathway is involved in controlling cell growth, proliferation and migration, with a role in the development and progression of melanoma. In addition, KIT gene mutation has been identified in melanomas, indicating that there may be potential therapeutic benefits of tyrosine kinase inhibitors. Objectives: Evaluation of KIT mutation prevalence in a subset of 28 patients with HNMM treated at a single institution, establishing the relationship between different mutations and outcome (DFS and OS). The primary end-point of the study was to define the incidence of KIT mutations in HNMM, including the relationship between KIT mutations with disease-free survival (DFS) and overall survival (OS) in HNMM. Secondary end-points were correlation among therapeutic options, histopathological findings, demographic data and clinical response. Methods: This retrospective study comprised data of 28 patients with HNMM treated at Brazilian National Cancer Institute (INCA) between 2000 and 2011. Clinical analysis included patients characteristics, staging, primary and palliative treatments, disease free survival and overall survival. Progression-free survival and overall survival were analyzed using the Kaplan-Meier method, with SPS 11.0 software. KIT analysis: paraffin blocks were selected following analyses of histologic preparations, enabling DNA extraction. Different DNA concentrations were employed in PCR amplifications, based on DNA integrity. PCR amplification of exon, 9, 11, 13 and 17 was performed. . Results: Patients were predominantly females (57%). The age of presentation ranged from 27 to 85 years. The sinonasal region was the most frequent primary site (75%). All patients underwent surgical resection. Seventeen patients received adjuvant radiotherapy (37%). Recurrences occurred in 82% patients. Oncologic mutations in KIT were found in 7 (25%) of seven tumors, 3 in exon 9, 3 in exon 11 and 1 in exon 13. Predictive factors for recurrence were mitotic rate (p=0.05), vascular invasion (p=0.043), and perineural spread (p=0.034). There were no significant differences in DFS and OS according to KIT mutation. Conclusion: HNMM remains a rare disease. The present single-institution series includes 28 cases treated in single institution. Seven cases (25%) had activating KIT mutations, which is an increased prevalence of activating KIT mutations in this specific subset of mucosal melanomas. This finding suggests that there is a group of patients who might benefit with appropriate targeted therapy with kinase inhibitors

Orientadores: Laura Sterian Ward, Antônio Hugo José Fróes Marques Campos / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-26T01:02:11Z (GMT). No. of bitstreams: 1 Rocha_AngelicaGomes_M.pdf: 1644333 bytes, checksum: e3503fb6e2c8209f7a6696df111d6a78 (MD5) Previous issue date: 2014 / Resumo: Marcadores de malignidade, especialmente capazes de distinguir lesões de padrão folicular, que sejam de fácil implantação na rotina do diagnóstico de nódulos tireoidianos, continuam sendo extremamente necessários, dado o crescente aumento de nódulos tireoidianos diagnosticados nos últimos anos. A via HGF/c-Met/STAT3 está relacionada com desenvolvimento e progressão tumoral, sendo que a expressão de c-Met, HGF e de STAT3 foram descritas em grande parte dos carcinomas papilíferos de tireoide (CPT), mas não em tecido tireoidiano normal, sugerindo sua relação com o desenvolvimento e progressão do CPT. Para avaliar a utilidade da expressão proteica de c-Met, HGF, STAT3, e de sua proteína fosforilada (pSTAT3) no diagnóstico e no prognóstico de pacientes com nódulos tireoidianos, analisamos 356 tecidos tireoidianos, sendo 153 carcinomas papilíferos (CPT), dos quais 95 eram clássicos (CPC), 47 carcinomas papilíferos variante folicular (CPVF), e 11 carcinomas papilíferos de células altas (CPCA); 34 carcinomas foliculares (CFT), 34 adenomas foliculares (AF), 124 bócios e 11 tecidos normais. Todos os pacientes foram tratados e acompanhados de acordo com um mesmo protocolo padrão por 1-10 anos (Mo=5 anos). Áreas representativas do tecido foram selecionadas para a construção de uma lâmina de tissue microarray (TMA) que foi submetida à técnica de imunoistoquímica e analisada pelo score de Allred. A expressão citoplasmática de c-Met foi capaz de diferenciar nódulos malignos de benignos (p<0,0001, sensibilidade 86%, especificidade 76%, VPP 77%, VPN 86%); CPT de CF (p=0,0003, sensibilidade 96%, especificidade 31%, VPP 87%, VPN 63%); variante folicular de CPT de CF (p=0,0232 sensibilidade 93%, especificidade 31%, VPP 66%, VPN 77%); assim como variante folicular de CPT de AF (p=0,0003, sensibilidade 93%, especificidade 50%, VPP 68%, VPN 87%). Além disso, a expressão de c-Met se correlacionou com tireoidite (p<0,0001) e multifocalidade (p=0,0028), mas não com presença de cápsula, invasão, tamanho do tumor, estadiamento TNM, e presença de metástase no diagnóstico e na evolução. A expressão nuclear de STAT3 diferenciou os nódulos benignos dos malignos (p<0,0001, sensibilidade 83%, especificidade 74%, VPP 75%, VPN 83%); CF de AF (p=0,0457, sensibilidade 80%, especificidade 52%, VPP 65%, VPN 71%); bócios de CPT variante folicular (p<0,001, sensibilidade 89%, especificidade 65%, VPP 91%, VPN 60%); bócio de CF (p<0,0001, sensibilidade 89%, especificidade 80%, VPP 95%, VPN 60%); bócio de AF (p=0,0005, sensibilidade 89%, especificidade 80%, VPP 95%, VPN 60%). Além disso, a expressão de STAT3 se correlacionou com tireoidite (p=0,0095) e multifocalidade (p<0,0001), mas não com presença de cápsula, invasão, tamanho do tumor, estadiamento TNM, e presença de metástase no diagnóstico e na evolução. A expressão de pSTAT3 e HGF não auxiliou no diagnóstico dos nódulos, e tampouco se correlacionou com características de agressividade dos tumores. Conclui-se que as proteínas c-Met e STAT3 podem ser consideradas marcadores clínicos úteis na rotina de laboratórios, uma vez que foram capazes de diferenciar os nódulos malignos dos benignos, alguns tipos histológicos dos nódulos, além de se correlacionarem com fatores de agressividade dos tumores / Abstract: Malignancy markers, especially the ones that are capable of distinguishing follicular lesions and with easy deployment in the routine diagnosis of thyroid nodules are much needed, given the increasing number of thyroid nodules in recent years. The HGF/c-Met/STAT3 pathway is related to the development and progression of many types of cancers, and c-Met, HGF and STAT3 expression were described in most papillary thyroid carcinomas (PTC), but not in normal thyroid tissue, suggesting it is related with the development and progression of PTC. To evaluate the usefulness of c-Met, HGF, STAT3, and its phosphorylated form (pSTAT3) protein expression in the diagnosis and prognosis of patients with thyroid nodules, we analyzed 356 thyroid tissues, including 153 papillary carcinomas (PTC), 95 classical type, 47 follicular variants of papillary carcinoma, and 11 tall cells carcinomas; 34 follicular carcinomas (FC), 34 follicular adenomas (FA), 124 goiters and 11 normal tissues. All patients were treated and monitored according to the same standard protocol for 1-10 years (Mo = 5 years). Representative tissue areas were selected for the construction of a tissue microarray (TMA) which was subjected to immunohistochemistry and analyzed by the Allred score. The cytoplasmic expression of c-Met was able to differentiate malignant from benign nodules (p <0.0001, sensitivity 86%, specificity 76%, PPV 77%, 86% NPV); PTC from FCT (p = 0.0003, sensitivity 96%, specificity 31%, PPV 87%, 63% NPV); follicular variant of PTC from FCT (p = 0.0232 sensitivity 93%, specificity 31%, PPV 66%, NPV 77%); as well as follicular variant of CPT from FA (p = 0.0003, sensitivity 93%, specificity 50%, PPV 68%, 87% NPV). Furthermore, c-Met expression was correlated to the presence of thyroiditis (p<0.0001) and multifocality (p=0.0028), but not with the presence of capsule, invasion, tumour size, TNM staging, and metastasis at diagnosis or evolution of the disease. The nuclear expression of STAT3 differentiated benign from malignant nodules (p <0.0001, sensitivity 83%, specificity 74%, PPV 75%, NPV 83%); FCT from FA (p = 0.0457, sensitivity 80%, specificity 52%, PPV 65%, NPV 71%); goiter follicular variant of PTC (p <0.001, sensitivity 89%, specificity 65%, PPV 91%, 60% NPV); goiter from FCT (p <0.0001, sensitivity 89%, specificity 80%, PPV 95%, NPV 60%); goiter from FA (p = 0.0005, sensitivity 89%, specificity 80%, PPV 95%, NPV 60%). In addition, STAT3 expression was associated with thyroiditis (p=0.0095) and multifocality (p<0.0001), but not with the presence of capsule, invasion, tumour size, TNM staging, and metastasis at diagnosis or evolution of the disease. The expression of pSTAT3 and HGF did not help the diagnostic of nodules and was not correlated with any tumour characteristic of aggressiveness. We concluded that c-Met and STAT3 could be useful as molecular markers in laboratory routine, helping to differentiate malignant from benign nodules, and some histological types of nodules, and was also associated with some tumour characteristics of aggressiveness / Mestrado / Ensino em Saúde / Mestra em Clínica Médica

Orientador: Morgana Rodrigues Guimarães Stabili / Resumo: Células dendríticas têm papel crucial na patogênese das doenças periodontais por orquestrarem a resposta imune adaptativa e por seu papel como precursoras de osteoclastos. A sinalização via Akt tem importante papel em processos como metabolismo, proliferação, apoptose e também na resposta imune. Evidências indicam que Akt1 tem papel de regulador endógeno negativo da resposta inflamatória; porém pode tanto estimular quanto inibir a osteoclastogênese. Considerando que as células dendríticas participam tanto da inflamação/resposta imune quanto do turnover do tecido ósseo como células precursoras de osteoclastos, propusemos avaliar através de um estudo in vivo o papel da atividade de Akt1 na inflamação associada a interações microbiota-hospedeiro, bem como investigar in vitro os efeitos desta via de sinalização sobre os diferentes eventos biológicos das células dendríticas. Para o estudo in vivo foi utilizado um modelo de doença periodontal experimental induzida por P. gingivalis e Fusobacterium nucleatum, em um modelo de animais transgênicos com deleção gênica condicional. Os desfechos avaliados foram: inflamação (morfometria), reabsorção óssea (μCT), osteoclastogênese (IHC), anticorpos específicos para P.gingivalis e Fusobacterium nucleatum (ELISA). No estudo in vitro foi avaliado o papel da via de sinalização Akt1 sobre as seguintes atividades das células dendríticas: proliferação, apoptose, atividade fagocitária, migração, apresentação de antígeno e osteoclastogênese. Resulta... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Dendritic cells play a crucial role in the pathogenesis of periodontal diseases by orchestrating the adaptive immune response and their role as osteoclasts precursors. Akt signaling plays an important role in processes such as metabolism, proliferation, apoptosis and also in the immune response. Evidence indicates that Akt1 plays a role of negative endogenous regulator of the inflammatory response; but can both stimulate and inhibit osteoclastogenesis. Considering that dendritic cells participate in both inflammation/immune response and turnover of bone tissue as osteoclast precursor cells, we have proposed to evaluate in a vivo study the role of Akt1 activity in inflammation associated with microbiota-host interactions, as well as to evaluate in vitro the role of the Akt1 signaling pathway in dendritic cell biology. In vivo study was employed a model of experimental periodontal disease induced by P. gingivalis and Fusobacterium nucleatum in transgenic animals model with conditional gene deletion. The outcomes evaluated were: inflammation (morphometry), bone resorption (μCT), osteoclastogenesis (IHC), antibodies specific for P.gingivalis and Fusobacterium nucleatum (ELISA). In vitro study was evaluated the role of Akt1 signaling pathway on the following outcomes related to dendritic cell biology: proliferation, apoptosis, phagocytic activity, migration, antigen presentation and osteoclastogenesis The results showed that signaling via Akt1 in dendritic cells seems to play an i... (Complete abstract click electronic access below) / Doutor