A utilização de aditivos em dietas com altas proporções de concentrado para bovinos em confinamento tem sido uma prática bastante usual, visando o aumento da eficiência do sistema produtivo. Porém, em virtude de algumas restrições ao uso de substâncias antibióticas, devido a possibilidade do surgimento de microrganismos resistentes, o uso de produtos alternativos tem sido alvo de diversas pesquisas. Nesse contexto, este trabalho foi desenvolvido para avaliar os efeitos da inclusão de enzimas exógenas, em dietas de elevada proporção de concentrado para bovinos Nelores confinados. Foram realizados 3 experimentos, no primeiros foram utilizados 96 bovinos nelore alimentados com 3 níveis de inclusão de enzimas fibrolíticas exógenas (EFE) e duas granulometrias de milho (fino e grosso). Não foi observada interação entre os dois fatores testados, a granulometria do milho não influenciou o desempenho, características de carcaça, qualidade de carne, fermentação ruminal e morfologia ruminal. A inclusão de EFE não alterou o desempenho, qualidade de carne, morfologia e fermentação ruminal. Porém foi observado efeito quadrático, para GRPI em % e kg e efeito para a espessura de gordura subcutânea entre a 12ª e 13ª costela (EGS) em relação aos níveis de EFE. Para a realização dos 2º e 3º experimentos foram adotados os mesmos tratamentos, sendo composta de 90% de concentrado e 10% de volumoso (bagaço de cana), contendo 2 níveis de enzimas amilolíticas exógenas (EAE; com e sem), e dois níveis de amido (alto e baixo). No segundo experimento foram utilizados 48 bovinos nelores confinados distribuídos em um delineamento totalmente casualizados em esquema fatorial 2 x 2 (nível de amido X nível de enzima). Foi observado interação entre os fatores para espessura de gordura subcutânea na garupa (EGG), sendo que os animais alimentados com dietas alto amido e com enzima apresentaram resultados superiores quando comparados com os demais. Ao observar o efeito da utilização das enzimas, os animais alimentados com dietas sem enzima apresentaram maior espessura de gordura subcutânea 1,83 vs 1,50 mm e maior área de olho de lombo 61,85 vs 60,07 cm² em relação aos animais alimentados com dietas com enzimas. Já o efeito da suplementação com diferentes teores de amido, os animais alimentados com dietas de alto amido apresentaram maior ingestão de matéria seca (IMS), menor eficiência alimentar (EA) e rendimento de carcaça (RC). O terceiro experimento foi realizado utilizando 8 bovinos Nelore canulados no rúmen distribuídos em dois quadrados latinos contemporâneos em esquema fatorial 2 x 2 (nível de amido X nível de enzima). Foi observado efeito de interação entre os tratamentos (EAE e nível de amido) para IMS e nitrogênio amoniacal (N-NH3). Os animais alimentados com enzima apresentaram menores concentrações de propionato e maior relação acetato/propionato (A/P) em comparação com aos animais alimentados sem enzima. As dietas com alto amido diminuíram a relação A/P em relação ao que animais alimentado com baixo amido. A adição de enzimas exógenas não causou grande impacto no desempenho, qualidade de carne, porém afetaram a deposição de gordura de acabamento nas carcaças, juntamente com os padrões fermentativos ruminais. / The use of additives in diets with high proportions of concentrate for cattle in confinement has been a very usual practice, aiming at increasing the efficiency of the productive system. However, due to some restrictions on the use of antibiotic substances, due to the possibility of resistant microorganisms, the use of alternative products has been the subject of several studies. In this context, this study was developed to evaluate the effects of the inclusion of exogenous enzymes in high concentrate diets for feedlot Nellore cattle. Three experiments were carried out. In the first one, 96 Nelore cattle were fed with 3 levels of inclusion of exogenous fibrolytic enzymes (EFE) and two corn granulometry (fine and crush). There was no interaction between the two factors tested, corn grain size did not influence performance, carcass characteristics, meat quality, ruminal fermentation and ruminal morphology. The inclusion of EFE did not alter the performance, meat quality, ruminal morphology and fermentation. However, a quadratic effect was observed for pelvic kidney and inguinal fat (PIKF) in% and kg and effect on the thickness of the subcutaneous fat between the 12th and 13th rib (EGS) in relation to EFE levels. For the 2nd and 3rd experiments, the same treatments were used, being composed of 90% of concentrate and 10% of sugarcane bagasse, containing 2 levels of exogenous amylolytic enzymes (EAE, with and without), and two levels of starch (high and low). In the second experiment were used 48 confined Nellore cattle distributed in a completely randomized design in a 2 x 2 factorial scheme (starch level X enzyme level). Interaction between the factors for subcutaneous fat thickness in the croup (EGG) was observed, and the animals fed with high starch and enzyme diets presented superior results when compared with the others. When observing the effect of the use of the enzymes, the animals fed with diets without enzyme had a greater thickness of subcutaneous fat 1.83 vs 1.50 mm and greater area of loin eye 61.85 vs 60.07 cm² in relation to fed animals With enzyme diets. On the other hand, the effect of supplementation with different starch contents, the animals fed with high starch diets presented higher dry matter intake (IMS), lower feed efficiency (AE) and carcass yield (CR). The third experiment was carried out using 8 rumen cannulated Nellore cattle distributed in two contemporary Latin squares in a 2 x 2 factorial scheme (starch level X enzyme level). It was observed interaction effect between the treatments (EAE and starch level) for IMS and ammoniacal nitrogen (N-NH3). The animals fed with enzyme had lower concentrations of propionate and higher acetate / propionate ratio (A / P) compared to animals fed without enzyme. High starch diets decreased the A / P ratio in relation to animals fed low starch. The addition of exogenous enzymes did not have a great impact on the performance, meat quality, however they affected the deposition of finishing fat in the carcasses, along with ruminal fermentative standards.

INTRODUÇÃO: O mapeamento do linfonodo sentinela (MLNS) é largamente utilizado em pacientes com melanoma cutâneo, câncer de mama e outras neoplasias malignas sólidas com a finalidade de estadiá-las e indicar esvaziamento linfático apenas na presença de metástase. Nos últimos anos aumentou o interesse pelo uso do MLNS em pacientes com carcinoma papilífero de tireoide (CPT) sem metástases linfáticas detectáveis clinicamente (estádio cN0), devido à alta frequência de metástases ocultas nesses pacientes. O MLNS pode evitar o esvaziamento linfático do compartimento central (ECC) em portadores de CPT sem metástase. Mesmo que não se planeje o ECC eletivo, o MLNS pode também ser usado para estadiar adequadamente o pescoço e indicar tratamento posterior com radioiodoterapia em casos com metástase. Esse estudo tem como objetivo verificar: 1) a efetividade da técnica do MLNS nos pacientes com CPT; 2) a acurácia do MLNS em diagnosticar as metástases linfáticas; 3) se o MLNS pode modificar o estadiamento dos pacientes com CPT cN0. MÉTODOS: Trata-se de estudo de acurácia, prospectivo longitudinal de 38 casos consecutivos de CPT clinicamente N0, atendidos em um único centro, no período de 2010 a 2015. Todos foram submetidos à tireoidectomia total, MLNS com radiofármaco e ECC eletivo. Os resultados relativos ao MLNS foram comparados com o exame anatomopatológico do conteúdo do ECC. RESULTADOS: O tempo médio de seguimento dos doentes foi de 36 ± 13 meses. Os LNS foram localizados com maior frequência nos níveis VI e III. O LNS foi detectado em 95% da casuística e os valores de avaliação de testes diagnósticos foram: 1 falso negativo, 95% de sensibilidade, 100% de especificidade, 94% de valor preditivo negativo e 97% de acurácia. O MLNS foi capaz de reestadiar 49% dos pacientes inicialmente N0 para pN positivo. Quanto ao grupo de estadiamento AJCC (que leva em conta a idade), 3% dos pacientes foram reestadiados para estádio III e 18% para estádio IV. CONCLUSÕES: 1) a técnica de MLNS utilizada nos pacientes com CPT foi efetiva em 95% dos procedimentos realizados; 2) a acurácia do MLNS em diagnosticar as metástases linfáticas cervicais foi de 97%; 3) o MLNS re-estadiou os portadores de CPT, classificados clinicamente como N0, para pN positivo em 49% da casuística, e para estádio III e IVa em 21% / INTRODUCTON: Sentinel lymph node mapping (SLNM) is widely perfomed in melanoma, breast cancer and other solid tumors, to adequately stage these diseases. More recently, the interest in SLNM for clinically N0 Papillary Thyroid Cancer (PTC) has increased due to the high rate of occult metastases in these patients, to avoid unnecessary central neck dissection (CND), and its complications. Even if routine elective CND is not planned, SLNM can be used to adequately stage the neck, and to indicate further treatment with radioiodine in cases with neck metastases, for instance. This study aims to evaluate 1) SLNM effectiveness in PTC patients, 2) SLNM accuracy to diagnosis lymph node metastases and 3) if SLNM can upstage cN0 PTC patients. METHODS: This is a prospective longitudinal, diagnostic test accuracy study with 38 consecutive cN0 PTC patients, treated in a single center between 2010 and 2015. Surgical treatment in all cases included total thyroidectomy and elective CND after SLNM. Results of SLNM were compared to CND pathological findings, in order to verify if sentinel lymph node (SLN) predicted the occurrence of PTC occult lymph node metastasis. RESULTS: The mean patients\' follow-up was 36 ± 13 months. 133 SLN were found in the neck, on levels VI and III. The SLN was identified in 95% of the patients with 1 false negative, 95% sensitivity, 94% negative predictive value and 97% accuracy. The SLNM upstaging from cN0 to pN+ was 49%, with 3% stage III and 18% stage IVa. CONCLUSION: 1) SLNM was effective in 95% of procedures, 2) SLNM accuracy was 97%, 3) SLNM upstaging from cN0 to pN+ was 49%, and to stage III and IVa was 21%

O carcinoma da glândula tireoide é o câncer endócrino mais prevalente, com crescente incidência anual. Dentre as neoplasias tireóideas, o carcinoma papilífero é o mais frequente, representando 80 a 90% destes tumores. A despeito do excelente prognóstico de seus portadores e da baixa taxa de mortalidade, cerca de 5% a 20% dos indivíduos submetidos à tireoidectomia total desenvolverão recidiva regional e todavia não há consenso sobre os fatores preditivos de recidiva tumoral. MicroRNAs são pequenos RNAs endógenos, que não codificam proteínas, e que medeiam a regulação póstranscricional da expressão gênica ligando-se seletivamente aos RNAs mensageiros por pareamento de bases. A expressão dos microRNAs de uma forma controlada exerce papel importante em múltiplos processos fisiológicos. Em contrapartida, em câncer, níveis de microRNAs podem estar diminuídos ou aumentados e existem evidências de que microRNAs estão envolvidos no processo de metástase e recidiva. No presente estudo, investigamos se os níveis de miR-9, miR-10b, miR-21 e miR-146b são preditores de recidiva em carcinoma papilífero de tireoide. Utilizando amostras de carcinoma papilífero de tireoide fixadas em formalina e emblocadas em parafina, avaliamos a expressão de miR-9, miR-10b, miR-21 e miR-146b em amostras de tumor primário de 66 pacientes através da PCR em tempo real. Os pacientes foram reunidos em dois grupos: pacientes que apresentaram recidiva tumoral (n=19) e pacientes que não apresentaram recidiva tumoral (n=47). Todos os pacientes foram submetidos à tireoidectomia total e seguidos por um tempo mínimo de 120 meses para serem considerados livres de recidiva. Comparamos os grupos de pacientes com e sem recidiva tumoral em relação às variáveis idade, sexo, tamanho do tumor, riscos ATA e MSKCC-NY, estadiamento TNM, variante histológica do tumor, presença de multicentricidade, invasão vascular e perineural, extensão extra-tireóidea e metástases linfonodais cervicais. Análises univariadas e multivariadas foram realizadas utilizando-se os modelos de riscos proporcionais de Cox. Conforme análise univariada, tamanho do tumor primário (p=0,001) e extensão extra-tireóidea (p=0,027) estão associados à recidiva tumoral. Da mesma forma, pacientes em estadios mais avançados (III e IV) segundo TNM (p=0,001) ou classificados em grupos de risco mais elevados segundo ATA (p=0,025) também apresentam maior risco de evoluírem com recidiva da doença. Observamos níveis de expressão de mir- 9 e miR-21 significativamente inferiores nos indivíduos que apresentaram recidiva quando comparados aos que não apresentaram recidiva neoplásica (p<0,001 e p=0,001, respectivamente). Os resultados deste estudo demonstraram que expressão diminuída de miR-9 ou de miR-21 é fator prognóstico significativo para recidiva em indivíduos portadores de carcinoma papilífero de tireoide quando avaliados em amostras do tumor primário (RR = 1,48; 95% IC: 1,24-1,77 e RR = 1,52; 95% IC: 1,18-1,94; respectivamente), enquanto miR-10b e miR-146 não se mostraram diferentemente expressos entre os dois grupos. A análises multivariada envolvendo os níveis de expressão de miR-9 e mR-21 e parâmetros clínicos indica que os níveis de expressão destes microRNAs são fatores prognósticos independentes para pacientes com carcinoma papilífero de tireoide. Concluindo, nossos resultados sugerem que o nível de expressão de miR-9 e miR-21 poderia ser utilizado na prática clínica como biomarcador para avaliar o potencial para recidiva em carcinoma papilífero de tireoide / Thyroid cancer is the most prevalent endocrine neoplasm, and its annual incidence continues to rise. Papillary thyroid cancer is the most common histological type, accounting for 80-90% of all thyroid cancers. Despite its excellent prognosis and low mortality rates, regional recurrence is observed in 5-20% of patients and there is still no consensus concerning tumor recurrence predictive factors. MicroRNAs are endogenous small noncoding RNAs that mediate, post-transcriptionally, gene expression regulation. MicroRNAs selectively bind to mRNAs, playing important roles in multiple physiological processes. On the other hand, microRNAs levels may be down regulated or over expressed in cancer, and have been implicated in recurrence and metastasis-related processes. In the present study, we investigated whether miR-9, miR-10b, miR-21 and miR-146b expression levels could be predictive factors of papillary thyroid cancer recurrence. Using macrodissection followed by quantitative real-time PCR, we measured miR-9, miR-10b, miR-21 and miR- 146b expression levels in formalin-fixed, paraffin-embedded primary tumor samples from 66 patients with papillary thyroid cancer. Patients were categorized into two groups: the recurrent group (n=19) and the non-recurrent group (n=47). All patients underwent total thyroidectomy and were followed for at least 120 months after surgery to be considered recurrence-free. Both groups were compared for clinical and pathological characteristics, including age, gender, tumor size, ATA and MSKCC-NY risk, TNM stage, multicentricity, vascular and perineural invasion, presence of cervical lymph node metastasis and histological type. Univariate and multivariate analysis were performed using the Cox proportional hazard analysis. Tumor size (p=0,001), extrathyroidal extension (p=0,027), higher risk ATA groups (p=0,025) and advanced TNM stages (p=0,001) were associated with recurrence. Expression levels of miR-9 and miR-21 were significantly lower in the recurrent group than in the nonrecurrent group (p<0,001 and p=0,001, respectively). MiR-9 and miR-21 expression levels were considered significant prognostic factors for recurrence in patients with papillary thyroid cancer (RR = 1,48; 95% CI: 1,24-1,77 and RR = 1,52; 95% CI: 1,18-1,94; respectively), but miR-10b and miR-146b were not. Multivariate analysis involving the expression levels of miR-9 and miR-21 and clinical parameters indicates that the expression levels are independent prognostic factor for papillary thyroid cancer patients. In conclusion, our results support the potential clinical value of miR-9 and miR-21 expression levels assessed in primary tumor samples as prognostic biomarkers for recurrence in papillary thyroid cancer

Carcinomas papilíferos (CP) estão relacionados à ativação da via de sinalização MAPK por diversos oncogenes. Estudos têm relacionado a incidência de CP com a disponibilidade de iodo, um dos mais importante reguladores da função tiroidiana. Recentemente, nosso grupo descreveu que a inibição da via de sinalização TGF<font face=\"symbol\">b pode estar vinculada ao desenvolvimento de CP. Nosso objetivo foi avaliar os efeitos do excesso de iodo na transformação de células tiroidianas. Utilizamos células PCCL3 com indução do oncogene RET/PTC3, tratadas com excesso de iodo. Observamos que o iodo reduziu a proliferação, sem alterar a morte das células e recuperou a expressão de genes específicos tiroidianos, evento geralmente vinculado à transformação maligna tiroidiana. O tratamento com excesso de iodo, ainda, reduziu a expressão de proteínas envolvidas na via MAPK e promoveu o restabelecimento da expressão da via TGF<font face=\"symbol\">b, uma importante via inibitória da proliferação de células tiroidianas. Concluímos que o excesso iodo tenha uma ação antioncogênica durante a transformação maligna tiroidiana. / Papillary Carcinomas (PC) are frequently related to MAPK signaling pathway, activation by several oncogenes. Recent studies had related PC incidence and iodine availability, one of the most important thyroid function regulators. Our group has recently showed that TGF<font face=\"symbol\">b pathway inhibition is directly related to PC development. Our aim was to evaluate iodine excess effects during thyroid cells transformation. We used the PCCL3 cells with RET/PTC3 oncogene induction, treated with iodine excess. We observed that iodine reduced the cell proliferation, not altering cell death and recovered thyroid specific genes expression, event frequently liked to thyroid cells malignant transformation. Iodine excess treatment also reduced MAPK proteins expression and reestablished TGF<font face=\"symbol\">b pathway components expression, an important inhibitory pathway of epithelial cells. We can conclude that iodine excess treatment plays an antioncogenic role during thyroid malignant transformation.

A utilização de aditivos em dietas com altas proporções de concentrado para bovinos em confinamento tem sido uma prática bastante usual, visando o aumento da eficiência do sistema produtivo. Porém, em virtude de algumas restrições ao uso de substâncias antibióticas, devido a possibilidade do surgimento de microrganismos resistentes, o uso de produtos alternativos tem sido alvo de diversas pesquisas. Nesse contexto, este trabalho foi desenvolvido para avaliar os efeitos da inclusão de enzimas exógenas, em dietas de elevada proporção de concentrado para bovinos Nelores confinados. Foram realizados 3 experimentos, no primeiros foram utilizados 96 bovinos nelore alimentados com 3 níveis de inclusão de enzimas fibrolíticas exógenas (EFE) e duas granulometrias de milho (fino e grosso). Não foi observada interação entre os dois fatores testados, a granulometria do milho não influenciou o desempenho, características de carcaça, qualidade de carne, fermentação ruminal e morfologia ruminal. A inclusão de EFE não alterou o desempenho, qualidade de carne, morfologia e fermentação ruminal. Porém foi observado efeito quadrático, para GRPI em % e kg e efeito para a espessura de gordura subcutânea entre a 12ª e 13ª costela (EGS) em relação aos níveis de EFE. Para a realização dos 2º e 3º experimentos foram adotados os mesmos tratamentos, sendo composta de 90% de concentrado e 10% de volumoso (bagaço de cana), contendo 2 níveis de enzimas amilolíticas exógenas (EAE; com e sem), e dois níveis de amido (alto e baixo). No segundo experimento foram utilizados 48 bovinos nelores confinados distribuídos em um delineamento totalmente casualizados em esquema fatorial 2 x 2 (nível de amido X nível de enzima). Foi observado interação entre os fatores para espessura de gordura subcutânea na garupa (EGG), sendo que os animais alimentados com dietas alto amido e com enzima apresentaram resultados superiores quando comparados com os demais. Ao observar o efeito da utilização das enzimas, os animais alimentados com dietas sem enzima apresentaram maior espessura de gordura subcutânea 1,83 vs 1,50 mm e maior área de olho de lombo 61,85 vs 60,07 cm&sup2; em relação aos animais alimentados com dietas com enzimas. Já o efeito da suplementação com diferentes teores de amido, os animais alimentados com dietas de alto amido apresentaram maior ingestão de matéria seca (IMS), menor eficiência alimentar (EA) e rendimento de carcaça (RC). O terceiro experimento foi realizado utilizando 8 bovinos Nelore canulados no rúmen distribuídos em dois quadrados latinos contemporâneos em esquema fatorial 2 x 2 (nível de amido X nível de enzima). Foi observado efeito de interação entre os tratamentos (EAE e nível de amido) para IMS e nitrogênio amoniacal (N-NH3). Os animais alimentados com enzima apresentaram menores concentrações de propionato e maior relação acetato/propionato (A/P) em comparação com aos animais alimentados sem enzima. As dietas com alto amido diminuíram a relação A/P em relação ao que animais alimentado com baixo amido. A adição de enzimas exógenas não causou grande impacto no desempenho, qualidade de carne, porém afetaram a deposição de gordura de acabamento nas carcaças, juntamente com os padrões fermentativos ruminais. / The use of additives in diets with high proportions of concentrate for cattle in confinement has been a very usual practice, aiming at increasing the efficiency of the productive system. However, due to some restrictions on the use of antibiotic substances, due to the possibility of resistant microorganisms, the use of alternative products has been the subject of several studies. In this context, this study was developed to evaluate the effects of the inclusion of exogenous enzymes in high concentrate diets for feedlot Nellore cattle. Three experiments were carried out. In the first one, 96 Nelore cattle were fed with 3 levels of inclusion of exogenous fibrolytic enzymes (EFE) and two corn granulometry (fine and crush). There was no interaction between the two factors tested, corn grain size did not influence performance, carcass characteristics, meat quality, ruminal fermentation and ruminal morphology. The inclusion of EFE did not alter the performance, meat quality, ruminal morphology and fermentation. However, a quadratic effect was observed for pelvic kidney and inguinal fat (PIKF) in% and kg and effect on the thickness of the subcutaneous fat between the 12th and 13th rib (EGS) in relation to EFE levels. For the 2nd and 3rd experiments, the same treatments were used, being composed of 90% of concentrate and 10% of sugarcane bagasse, containing 2 levels of exogenous amylolytic enzymes (EAE, with and without), and two levels of starch (high and low). In the second experiment were used 48 confined Nellore cattle distributed in a completely randomized design in a 2 x 2 factorial scheme (starch level X enzyme level). Interaction between the factors for subcutaneous fat thickness in the croup (EGG) was observed, and the animals fed with high starch and enzyme diets presented superior results when compared with the others. When observing the effect of the use of the enzymes, the animals fed with diets without enzyme had a greater thickness of subcutaneous fat 1.83 vs 1.50 mm and greater area of loin eye 61.85 vs 60.07 cm&sup2; in relation to fed animals With enzyme diets. On the other hand, the effect of supplementation with different starch contents, the animals fed with high starch diets presented higher dry matter intake (IMS), lower feed efficiency (AE) and carcass yield (CR). The third experiment was carried out using 8 rumen cannulated Nellore cattle distributed in two contemporary Latin squares in a 2 x 2 factorial scheme (starch level X enzyme level). It was observed interaction effect between the treatments (EAE and starch level) for IMS and ammoniacal nitrogen (N-NH3). The animals fed with enzyme had lower concentrations of propionate and higher acetate / propionate ratio (A / P) compared to animals fed without enzyme. High starch diets decreased the A / P ratio in relation to animals fed low starch. The addition of exogenous enzymes did not have a great impact on the performance, meat quality, however they affected the deposition of finishing fat in the carcasses, along with ruminal fermentative standards.

Une des propriétés majeures de la thyroïde est de capter l’iode de la circulation sanguine grâce à la présence d’un transporteur d’iodure (NIS pour Natrium Iodide Symporter). Cette capacité d’accumulation d’iode par les thyrocytes joue un rôle clé dans la synthèse des hormones thyroïdiennes ainsi dans le diagnostic et le traitement des cancers de la thyroïde. Cependant, en raison d’une diminution ou de l’absence de l’expression du NIS dans certaines tumeurs et métastases, des patients deviennent réfractaires à la radiothérapie métabolique et présentent une radiorésistance, causant ainsi un problème de santé publique.L’oncogène BRAFV600E, un puissant activateur de La voie MAP kinase, est détecté dans 40 - 60% des cancers thyroïdiens de type papillaires (CPT) qui représentent 80% de la totalité des cancers thyroïdiens. La mutation BRAFV600E est associée aux tumeurs thyroïdiennes les plus agressives. Cependant l’inhibition pharmacologique de la voie MAP kinase induite constitutivement par l’oncogène BRAFV600E ne permet pas, à elle seule, de rétablir l’expression du NIS chez des patients atteints d’un cancer de la thyroïde muté BRAFV600E. Ceci suggère que d’autres mécanismes compensatoires peuvent contribuer à la radiorésistance. Une étude récente menée sur un modèle murin a montré que la régulation négative du NIS par l’oncogène BRAFV600E est médiée par la voie du TGF beta. Une autre a montré que l’expression du NIS serait dépendante de l’état redox de la cellule, suggérant un rôle des espèces réactives de l’oxygène (ROS). Dans les cellules les ROS peuvent être produites par les NADPH oxydases (NOX/DUOX). La thyroïde en exprime trois : DUOX2 nécessaire à la synthèse des hormones thyroïdiennes ainsi que DUOX1 et NOX4 dont le rôle physiologique reste inconnu. NOX4, surexprimé dans les CPTs, a été montré être un nouvel effecteur clé de la voie du TGF beta dans d’autres cancers.Dans mon projet de thèse, je me suis intéressée à l’étude du rôle de NOX4 dans la régulation négative du NIS dans les CPT mutés BRAFV600E. L’étude du mécanisme, réalisée à partir de deux lignées humaines issues de cancers papillaires mutés pour BRAF (BCPAP et 8505C), a permis d’établir que l’oncogène BRAFV600E contrôle l’expression de NOX4 au niveau transcriptionnel via la voie TGF-beta/Smad3. Ces résultats ont été validés sur une lignée de rat exprimant de manière conditionnelle BRAFV600E ainsi que sur des thyrocytes humains en culture primaire. De manière importante, l’utilisation d’antioxydants tels que le N-acetyl cystéine (NAC) ou l’inhibition spécifique de l’expression de NOX4 par ARN interférence permet de réinduire l’expression du NIS. Ces résultats qui montrent que les ROS produites par NOX4 inhibent l’expression du transporteur de l’iode (NIS) établissent un lien entre l’oncogène BRAFV600E et NOX4. Une analyse comparative de l'expression de NOX4 effectuée à partir de 500 cancers papillaires de la thyroïdes mutés ou non pour BRAF (données TCGA) confirme que NOX4 est significativement augmenté dans les cancers porteurs de la mutation BRAF et que ceci est corrélé à une diminution de l’ARNm du NIS. Par ailleurs, le niveau de NOX4 est inversement corrélé au score de différenciation thyroïdien, suggérant que NOX4 pourrait être impliqué dans le processus de dédifférenciation. Cette étude ouvre une nouvelle opportunité pour l’optimisation de l’utilisation de la radiothérapie métabolique dans le traitement des cancers thyroïdiens réfractaires à l’iode I131 et présente NOX4 comme une cible thérapeutique potentielle. / One of the major properties of the thyroid is iodine uptake from the bloodstream through an iodide transporter (NIS for Natrium Iodide Symporter). This capacity plays a key role in the thyroid hormones synthesis, but also in both diagnosis and treatment of thyroid cancer. However, due to a decrease or absence of the NIS expression in some tumors and metastases, patients become refractory to the metabolic radiotherapy and present a radioresistance, which cause a public health problem.The BRAFV600E oncogene, a potent activator of the MAP kinase pathway, is detected in 40-60% of papillary thyroid cancer (PTC), which represent 80% of total thyroid cancers. The BRAFV600E mutation is associated with the more aggressive thyroid tumors. However, the pharmacological inhibition of the MAP kinase pathway, constitutively induced by the BRAFV600E oncogene, is not able to restore alone the expression of NIS in patients with BRAFV600E mutated thyroid cancer. This suggests that other compensatory mechanisms may contribute to the radioresistance. A recent study in a mouse model demonstrated that downregulation of NIS by BRAFV600E oncogene is mediated through the TGF beta activation. An other showed that the expression of NIS is dependent on the redox status of the cell, suggesting a role for the reactive oxygen species (ROS). In cells, ROS can be produced by the NADPH oxidases (NOX/DUOX). The Thyroid gland expresses three of them: DUOX2, which is necessary for the thyroid hormones synthesis, but also DUOX1 and NOX4 whose the physiological role remains unknown. NOX4, which is overexpressed in the PTCs, has been shown to be a new key effector of the TGF beta pathway.In my thesis project, I was interested in studying the role of NOX4 in the negative regulation of NIS in BRAFV600E mutated CPT. The study of the mechanism, made from two human cell lines derived from BRAF-mutated papillary thyroid cancers (BCPAP and 8505C), has revealed that the oncogene BRAFV600E controls the expression of NOX4 at the transcriptional level via the TGF-beta/Smad3 pathway. These results were validated on both a rat thyroid cell line conditionnaly expressing BRAFV600E and on human thyrocytes in primary culture. Importantly, the use of antioxidants such as N-acetyl cysteine (NAC) or specific inhibition of NOX4 expression by RNA interference allow reinduction of NIS expression. These results, which show that ROS produced by NOX4 inhibit the expression of iodine transporter (NIS), establish a link between the oncogene BRAFV600E and NOX4. A comparative analysis of the NOX4 expression, made from 500 papillary thyroid cancers mutated or not for BRAF (TCGA data), confirms that NOX4 is significantly increased in BRAF-mutated cancers and that this is correlated with a decrease of NIS mRNA. Furthermore, the level of NOX4 is inversely related to thyroid differentiation score, suggesting that NOX4 might be involved in the dedifferentiation process. This study opens a new opportunity for optimizing the use of metabolic radiotherapy in the treatment of thyroid cancers refractory to radioiodine I131and makes NOX4 as a potential therapeutic target.

The aim of this study was molecular characterization of four types of renal tumours (papillary renal cell carcinoma [PRCC], tubulocystic renal carcinoma [TCRC], pseudorossette forming renal carcinoma [PRRC] and unclassified renal carcinomas [URC]) and two types of rare tumours of the testes (Adult type of granulosa cell tumours [ATGCTs] and Incompletely differentiated sex cord stromal tumours [ISCSTs]). In case of TCRC the activity of signalling pathways involved in angiogenesis was studied. The aim was to determine the suitability of antiangiogenic agents for treatment of TCRC. Next, the methylation profile of 24 tumor suppressor genes was studied in TCRC and PRCC in order to analyze their similarity. Eventual differences could be helpful tool in differential diagnostics. Also, spectrum of chromosomal aberrations was analyzed by array-CGH in one case of PRRC and two cases of URC. Any unique aberration found would be useful in differential diagnostics of these tumors. Last, but not least, the specificity of mutation c.402C>G of FOXL2 gene for ovarian ATGCTs was verified by studying its occurrence in testicular ATGCTs and ISCSTs. Analysis of mRNA levels did not reveal any enhanced activity of the studied signalling pathways. Cluster analysis of methylation profiles showed close relationship between PRCC a...

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Die vorliegende Untersuchung sollte die kontraktile Funktion von humanen Vorhoftrabekeln und linksventrikulären Papillarmuskeln der Ratte während Hypoxie / Reoxygenierung als Hauptkomponenten von Ischämie / Reperfusion charakterisieren. Weitere Merkmale der Ischämie wurden durch erhöhte extrazelluläre K+-Konzentration und Azidose simuliert. Einblicke in die zelluläre Ca2+-Regulation ergaben sich aus Aktionspotential-(AP)-messungen, der SR- Ca2+-ATPase-Aktivität und Kraft-Intervall- Beziehungen. Die Rolle des Energiestoffwechsels und der endogenen antioxidativen Kapazität für die kontraktile Funktion von infarktbedingt hypertrophiertem Rattenmyokard während Hypoxie / Reoxygenierung ist durch Messung der Kreatinkinase-(CK)-Aktivität, ihrer Isoenzymverteilung und der Aktivitäten von Superoxiddismutase (SOD) und Glutathionperoxidase (GSH-Px) charakterisiert worden. Der Einsatz der Radikalfänger Histidin und Butylhydroxytoluen während Hypoxie und schneller Reoxygenierung an Rattenpapillarmuskeln sollte zur Protektion gegen den toxischen Effekt unterschiedlicher reaktiver Sauerstoffspezies dienen. In den durchgeführten Experimenten zeigte sich eine geringere Empfindlichkeit des humanen Vorhofmyokards gegenüber reduzierter O2-Versorgung und Reoxygenierung als im Rattenmyokard. Die während simulierter Ischämie im humanen Myokard auftretende Azidose hat einen günstigen Effekt auf die Wiederherstellung der isometrischen Kontraktionskraft nach Reoxygenierung, was jedoch mit einer gestörten Regulation der kontraktilen Funktion verbunden ist. Hypertrophiertes Myokard in der chronischen Phase nach Infarkt zeigt eine verminderte Empfindlichkeit gegenüber Hypoxie / Reoxygenierung, was auf adaptive Veränderungen im Energiestoffwechsel (erhöhte CK-MB und CK-BB Isoenzyme mit kleinerem Km-Wert für Kreatinphosphat), in der endogenen antioxidativen Kapazität (Erhöhung der Aktivitäten von SOD und GSH-Px um 40% bzw. 50%) und in der Regulation der kontraktilen Funktion (verminderte SR Ca2+-ATPase-Aktivität und Isomyosinverschiebung von V1 nach V3) zurückgeführt werden kann. Eine bessere Erholung der kontraktilen Funktion nach Reoxygenierung kann durch schnellen pO2- Wiederanstieg erreicht werden. Der Einsatz von Pharmaka mit verschiedenen Angriffspunkten im Radikalstoffwechsel und besonders deren Kombination während Hypoxie / Reoxygenierung ermöglicht zusätzlich eine verbesserte Kardioprotektion. / This study characterizes the contractile function of human atrial trabeculae and rat left ventricular papillary muscles during hypoxia / reoxygenation as the major components of ischemia / reperfusion. Further characteristics of ischemia were simulated by increased extracellular K+ concentration and acidosis during hypoxia. Insights into the cellular Ca2+ regulation were obtained from action potential recordings, from measurements of sarcoplasmic reticulum (SR) Ca2+ transport, and from force-interval relations. We examined changes in SR calcium transport, creatine kinase (CK) system, the antioxidant enzymes glutathionperoxidase (GSH-Px) and superoxiddismutase (SOD) 6 wks. after infarction (MI) due to coronary ligation in rats. Phenotypic modifications vs. sham operation (SHAM) were related to the contractile response of hypertrophied papillary muscle to hypoxia / reoxygenation. The oxygen radical scavengers histidine and butylhydroxytoluene were applied during hypoxia and rapid reoxygenation to protect the myocardium against oxygen radical damage. Generally, human atrial trabeculae were less sensitive to reduced oxygen supply and reoxygenation when compared to rat papillary muscles. In human atrial trabeculae, isometric peak force development recovered better after simulated ischemia than after hypoxia but the regulation of contractile function was clearly disturbed. In rat papillary muscles, rapid reoxygenation caused a better recovery of contractile function after hypoxia. Application of the oxygen radical scavengers histidine, butylhydroxytoluene, and especially their combination during hypoxia / reoxygenation had additional cardioprotective effects. In MI vs. SHAM we observed under aerobic control conditions: decreses in isometric contraction and relaxation rate, a reduced Vmax-equivalent of sarcomeric shortening, a faster twitch-to- twitch decay of post-rest potentiation (PRC) which correlated closely to the decrease in SR Ca2+ uptake (-25%), a decrease in CK activity (-20%), reduced CK-MI and CK-MM, increased CK-MB and CK-BB, and enhanced activities of SOD (+40%) and GSH-Px (+50%). During hypoxia, an initial increase in peak force (PF) was followed by a slower PF decline in MI vs. SHAM. During reoxygenation, rates of contraction and relaxation recovered better in MI. In SHAM but not MI, twitch-to-twitch decay of PRC was accelerated after reoxygenation vs. aerobic control. The results suggest that adaptive changes in SR Ca2+ handling, CK isoenzymes, and antioxidant enzymes may contribute to higher resistance against reduced O2 supply and reoxygenation in hypertrophy due to MI.

INTRODUÇÃO: Os carcinomas papilífero e folicular são neoplasias malignas primárias da glândula tireóide. Em conjunto, recebem o nome de carcinoma bem diferenciado. Determinar o risco individual da ocorrência de metástase nesses casos auxilia na seleção da terapêutica que é atualmente baseada na classificação de acordo com fatores prognósticos, aos quais pode ser associada a pesquisa de marcadores biológicos. Dentre eles, destaca-se a galectina-3, cujas funções exercidas nos compartimentos celulares foram descritas em uma variedade de neoplasias. Entretanto, seu papel no carcinoma tireóideo permanece controverso. Com o intuito de investigar se a galectina-3 pode auxiliar na predição do risco individual da ocorrência de metástase e se está associada aos critérios de malignidade do carcinoma bem diferenciado, a presente pesquisa objetivou verificar as seguintes hipóteses: 1) se há diferença da imunoexpressão da galectina-3 nos compartimentos do tireócito maligno entre os doentes com e sem metástase e se é possível predizer o risco de metástase em função da quantificação digital desse marcador; 2) se há diferença da imunoexpressão da galectina-3 entre o tecido tireóideo maligno e o não neoplásico; conforme a presença de invasão tecidual; e conforme a sobrevivência; 3) se há indício do envolvimento da galectina-3 com apoptose, indução da proliferação celular e angiogênese. MÉTODO: Trata-se de estudo retrospectivo de caso-controle que envolveu 109 doentes operados por carcinoma bem diferenciado da tireóide e seguidos por mais de cinco anos, distribuídos em dois grupos equivalentes: com e sem metástase. Foram feitos coleta de dados clínicos, avaliação anátomo-patológica e análise imunohistoquímica digital dos biomarcadores galectina-3, Ki-67, caspase-3 e CD-34. RESULTADOS: 1) A média do índice de positividade nucleolar da galectina-3 foi maior no grupo de doentes com metástase linfática cervical (1,78 ± 0,41 nucléolos/CGA contra 0,35 ± 0,13, p=0,004). A expressão nucleolar da galectina-3 apresentou especificidade de 75% para identificação da ocorrência de metástase e foi fator independente associado à ocorrência metástase linfática (p=0,01). A equação logística obtida permitiu calcular o risco individual de desenvolvimento de metástase linfática cervical que é próximo a 100% quando a galectina-3 está imunoexpressa em quatro ou mais nucléolos por campo microscópico de grande aumento. 2) não houve expressão da galectina-3 no tireócito não neoplásico; o índice de expressão citoplasmático foi fator independente associado à presença de invasão linfática (p=0,013) e a média desse índice foi maior nos casos com extensão extratireóidea (52,7 ± 3,9 uo/µm2 contra 41,0 ± 4,0, p=0,037); não houve associação dos índices de imunoexpressão da galectina-3 e sobrevivência; 3) no grupo de doentes com metástase, a expressão nucleoplasmática da galectina-3 correlacionou-se de forma positiva com o índice de positividade do Ki-67 e, nos dois grupos, a expressão citoplasmática com o índice de expressão da caspase-3. CONCLUSÕES: Foi possível predizer o risco individual da ocorrência de metástase linfática cervical em função da quantificação digital da imunoexpressão nucleolar da galectina-3. O presente estudo sugere que alta expressão citoplasmática está associada com algumas características de invasão local. Houve indícios do envolvimento da galectina-3 com indução da proliferação celular e apoptose no grupo de doentes com metástase. / INTRODUCTON: Papillary and follicular carcinomas are primary malignant neoplasias of the thyroid gland and are classified as well-differentiated carcinoma. In these cases, determination of individual risk of metastasis allows offering an adequate treatment. Nowadays therapy is chosen based on classification according to prognostic factors and biomarkers can be associated with them. Galectin-3 is one of these markers and has been thoroughly studied. A wide range of functions that it carries out in the subcellular compartments have been described in several neoplasms. However, its role in thyroid carcinomas remains controversial. In order to investigate if galectin-3 can be used to predict the individual risk of metastasis and if this marker is associated with malignant criteria of well-differentiated carcinoma, this study was proposed to verify the following hypotheses: 1) if galectin-3 immunostaining in subcellular compartments of the malignant thyrocyte is different when comparing patients with and without metastasis and if it is possible to predict the individual risk of metastasis based on digital quantification of the galectin-3 immunostaining; 2) if galectin-3 immunoexpression is different from malignant and benign thyroid tissue; according to tissue invasion and survival; 3) if there are indications that galectin-3 plays a role in apoptosis and cell proliferation or angiogenesis induction. METHODS: It was performed a retrospective case-control study involving 109 patients treated for well-differentiated thyroid carcinoma and followed up for more than five years. They were divided into two equivalent groups: with and without metastasis. The search of clinical data, morphological evaluation and digital immunohistochemical analysis with galectin-3, Ki-67, caspase-3 and CD-34 antibodies were done. RESULTS: 1) the average of the nucleolar galectin-3 positive index was higher in lymph node metastasis group (1.78 ± 0.41 nucleoli/HPF versus 0.35 ± 0.13, P=.004). Nucleolar staining was an independent factor associated with lymph node metastasis (P=.01) and its specificity to identify metastasis was 75%. The logistic model allowed predicting the individual risk of cervical lymph node metastasis. It was almost 100% for carcinomas displaying more than four galectin-3 immunostained nucleoli by microscopic high power field. 2) There was no galectin-3 immunostaining in non-neoplasic thyrocyte; the cytoplasmic galectin-3 expression index was an independent factor associated with lymphatic invasion (P=.013) and these index average was higher in cases with extrathyroidal extension (52.7 ± 3.9 uo/µm2 versus 41.0 ± 4.0, P=.037); there was no association of galectin-3 immunostaining indexes with survival; 3) in the metastasis group, there was positive correlation between nucleoplasmic staining of galectin-3 and Ki-67 positive index; there was positive correlation between cytoplasmic staining of galectin-3 and caspase-3 positive index in both groups. CONCLUSION: It was possible to predict the individual risk of cervical lymph node metastasis based on digital quantification of the nucleolar galectin-3 immunostaining. This study suggests that there is association of high cytoplasmic expression with local tissue invasion. In the metastasis group there were indications that galectin-3 plays a role in cell proliferation and apoptosis induction.