El mal pronòstic en una neoplàsia epitelial està associada a l'adquisició de característiques mòbils o invasives per part de les cèl·lules canceroses. Aquesta transformació morfològica es denomina transició epiteli-mesènquima (TEM). Snail és un factor de transcripció implicat en aquest procés, responsable de reprimir l'expressió de l'E-cadherina. Aquest treball demostra que Snail té la capacitat de reprimir l'expressió de MUC1 i VDR a través de la seva unió directa a caixes de reconeixement situades en els diferents promotors proximals. A més, la sobreexpressió d'Snail en diverses línies cel·lulars provoca un augment dels nivells d'ARNm de ZEB1 i un increment de l'activitat del seu promotor. L'activitat del promotor mínim d'Snail i els seus nivells d'ARNm depenen de la senyalització d'ERK. Finalment, hem demostrat que Snail i WT1, un regulador positiu de l'expressió de l'E-cadherina, competeixen per unir-se al promotor de l'E-cadherina i regular la seva transcripció. / The poor prognosis in epithelial neoplasia is associated with the acquisition of motile or invasive properties by the cancerous cells. This morphological transformation is often referred to as epithelial to mesenchymal transition (EMT). The Snail transcription factor is involved in this process by repressing the expression of E-cadherin. In this study we demonstrate the capacity of Snail to repress both MUC1 and VDR transcription by direct binding to specific sequences within their proximal promoter. Moreover, Snail overexpression in several cell lines induces ZEB1 mRNA and increases its promoter activity. The activity of the Snail minimal promoter is dependent on the ERK signaling pathway. Finally, we have demonstrated that Snail and WT1, a positive regulator of E-cadherin expression, compete for the binding to the E-cadherin promoter in order to regulate its transcription.

Colorectal carcinoma is the second most common type of cancer in both men and women in Sweden. Cancer of the colon and rectum are often considered together and their ten year survival rate is approximately 50 – 60 % depending on sex and location. Different histopathological characteristics of such cancers, including the complexity of growth, are of importance for prognosis. This thesis has compared different morphometric methods in order to achieve a quantitative and objective measurement of the invasive front of colon carcinoma. Since the growth pattern is dependent on the cell adhesiveness of different proteins we studied the distribution and localization of E-cadherin, Beta-catenin, Claudin 1,2,7 and Occludin as well as screened the genes for mutations. We found a perturbed protein expression of E-cadherin, Beta-catenin, Claudin 1,2,7 and Occludin in tumor sections compared to normal mucosa, but no relation to tumor volume or growth pattern could be seen. The tumor volume was found to be correlated to the growth pattern but not responsible to the perturbed protein expression. In the mutation screening we found a SNP in exon 13 the E-cadherin gene in the tumor, as well as in exon 2 of Claudin 1 and exon 4 of Claudin 7 in both tumor and normal mucosa. No correlation between mutations and growth pattern or tumor volume was found. In conclusion, this thesis shows that the computer image analysis with estimation of fractal dimension and number of free tumor cell clusters is superior to the semi quantitative visual grading of tumor invasive complexity. The aberrant expression of cell adhesion proteins in the tumor compared to normal mucosa as well as polymorphisms in the cell adhesion genes CLDN1 and CLDN7 in both tumor and normal mucosa can suggest that these aberrations are important in the tumorigenesis of colon carcinoma.

In the intestinal epithelium, Wnt signaling drives the expression of the genes encoding tyrosine kinase receptors EphB2 and EphB3 and represses the expression of their membrane-tethered ligands, ephrin-Bs. Eph-ephrin interactions result in cellular repulsion and are involved in boundary formation. The project of this thesis is to understand the mechanism by which EphB−ephrin-B signals restrict cell positioning of cell types (cell sorting) in the normal intestinal epithelium and suppress colorectal cancer (CRC) progression beyond the earliest stages. We have demonstrated that at the onset of CRC EphB receptors impair the expansion of tumor cells through a mechanism dependent on E-cadherin–mediated adhesion. We show that EphB-mediated compartmentalization restricts the spreading of EphB+ tumor cells into ephrin-B1+ territories in vitro and in vivo. Our results indicate that CRC cells must silence EphB expression to avoid repulsive interactions imposed by normal ephrin-B1+ intestinal cells at the onset of tumorigenesis. We have discovered that cell sorting is the outcome of two integrated mechanisms: cell contraction/repulsion and differential cell adhesion. The latter is the driving force to induce EphB/ephrin-B−mediated cell compartmentalization. We have developed in vitro models to analyze the mechanisms that induce E-cadherin remodeling upon EphB activation. We found RhoA, p120-catenin and the metalloproteinase ADAM10 as downstream effectors of EphB signaling involved in the control of cell sorting in CRC cells. / A l'epiteli intestinal, la ruta de senyalització Wnt indueix l'expressió dels gens que codifiquen per als receptors tirosina kinasa EphB2 i EphB3 i reprimeixen la dels seus lligands transmembrana, efrines de tipus B. Les interaccions Eph-efrina causen repulsió cel·lular i estan implicades en la formació de fronteres entre compartiments. La finalitat d'aquesta tesi és entendre el mecanisme pel qual la senyalització per EphB−efrina-B restringeix el posicionament dels diferents tipus cel·lulars a l'epiteli intestinal normal i suprimeix la progressió del càncer colorectal (CRC) en els primer estadis. Hem demostrat que, a l’inici del CRC, els receptors EphB restringeixen l'expansió de les cèl·lules tumorals a través d'un mecanisme depenent d'adhesió intercel·lular a través d’E-cadherina. En aquest treball es mostra in vitro i in vivo que la compartimentalització mitjançada per la senyalització dels receptors EphB restringeix l’invasió de les cèl·lules tumorals EphB+ als territoris efrina-B+. Aquests resultats indiquen que les cèl·lules de CRC han de silenciar l’expressió d'EphB per evitar les interaccions repulsives imposades per les cèl·lules intestinals normals efrina-B+ circumdants al començament del procés de tumorigènesi. Hem pogut discernir que el reordenament cel·lular per senyals EphB−efrina-B és el resultat de dos mecanismes integrats: la contracció/repulsió intercel·lular i l’adhesió diferencial entre diferents poblacions cel·lulars. Aquesta última és la força principal que condueix a la compartimentalització cel·lular mitjançada per EphB−efrina-B. Hem desenvolupat models in vitro per analitzar els mecanismes que provoquen el remodelament de la E-cadherina sota la senyalització per EphB. Presentem RhoA, p120-catenina i ADAM10 com a efectors de la senyalització de la ruta EphB implicats en el control de la compartimentalització cel·lular en el CRC.

La T-cadhérine est un récepteur de l'adiponectine, protéine impliquée dans la physiopathologie du diabète. Dans les études d'association pangénomiques, les polymorphismes du gène de la T-cadhérine (CDH13) sont associés aux variations de concentrations d'adiponectine. Le but de notre étude est d'approfondir les relations entre les polymorphismes de CDH13, l'adiponectine circulante, et le risque de diabète et de ses complications. Nous avons sélectionné deux polymorphismes du gène CDH13. Les génotypages ont été effectués dans plusieurs cohortes : D.E.S.I.R., issue de la population générale française, DIABHYCAR, cohorte de sujets atteints du diabète de type 2, et trois cohortes de patients diabétiques de type 1, GENESIS, GENEDIAB et SURGENE. Dans la population générale, les polymorphismes de CDH13 sont associés à l'indice de masse corporelle, à l'HbA1c, au Fatty Liver Index, indice de stéatose hépatique, et aux concentrations plasmatiques d'adiponectine. Dans une étude cas-contrôle entre D.E.S.I.R. et DIABHYCAR, les polymorphismes sont associés au risque de diabète de type 2. Ces associations pourraient être dues aux effets bénéfiques de l'adiponectine. Dans les cohortes de sujets diabétiques de type 1, GENESIS et GENEDIAB, nous avons observé des associations entre les polymorphismes de CDH13, la prévalence et l'incidence de la néphropathie. L'analyse dans l'étude prospective SURGENE confirme ces associations. Le sens des relations observées dans cette étude est en faveur d'un rôle délétère de l'adiponectine dans la néphropathie diabétique. En conclusion, les associations observées pourraient s'expliquer par des variations d'adiponectinémie et suggérer un lien de causalité. / T-cadherin is a receptor of adiponectin, a protein involved in the pathophysiology of diabetes. In genome-wide association studies, T-cadherin gene (CDH13) polymorphisms are associated with adiponectin concentrations. The aim of our study was to deepen the relationship between polymorphisms of CDH13, plasma adiponectin, and the risk of diabetes and its complications. We selected two polymorphisms in CDH13. Genotyping was performed in D.E.S.I.R., cohort drawn from the French general population, DIABHYCAR (subjects with type 2 diabetes) and three cohorts of patients with type 1 diabetes, GENESIS, GENEDIAB and SURGENE. In the general population, CDH13 polymorphisms were associated with body mass index, HbA1c, Fatty Liver Index, an index of hepatic steatosis, and plasma adiponectin. In a case-control study between D.E.S.I.R. and DIABHYCAR, polymorphisms were associated with the risk of type 2 diabetes. These associations with clinical phenotypes could be due to the beneficial effects of adiponectin. In subjects with type 1 diabetes from GENESIS and GENEDIAB, we observed associations between polymorphisms of CDH13 and the prevalence and the incidence of kidney disease. The analysis in the SURGENE prospective study confirmed these associations. The direction of the relationships observed in this study is in favor of a deleterious role of adiponectin in diabetic nephropathy. In conclusion, these associations may be explained by variations in adiponectin and suggest a causal relationship.

A lagarta da espécie Lonomia obliqua é medicamente importante, cujo veneno, presente nas espículas, causa uma síndrome hemorrágica caracterizada por equimoses, alterações da coagulação, dentre outros sintomas. Isto sugere a presença de peptídeos bioativos com potencial farmacêutico, devido à capacidade de modular o comportamento das células endoteliais. O objetivo deste estudo é analisar os potenciais efeitos do veneno de Lonomia obliqua na angiogênese. Uma linhagem celular endotelial (HUVEC) foi exposta a diferentes concentrações do extrato de espículas da Lonomia obliqua (Lonomia obliqua Bristle extract - LOBE) 5 μg/mL, 10 μg/mL, 20 μg/mL e 50 μg/mL. Empregando citometria de fluxo, observou-se que nenhuma das doses afetou o ciclo celular, viabilidade ou apoptose das células endoteliais após 24h de exposição. Os esferóides das células HUVEC foram plaqueados numa matriz 3D de colágeno e observou-se que LOBE (10 μg/mL, 20 μg/mL e 50 μg/mL) induz um aumento na migração celular, consistente com o processo de angiogênese. A análise da dinâmica da VE-caderina indica que a exposição imediata a LOBE (10 μg/mL) induz um desprendimento da junção célula-célula, o que corrobora com a hemorragia observada nas vítimas de envenenamento. Através de espectrometria de massa, observou-se que LOBE possui vários potenciais peptídeos bioativos. Grupos destes peptídeos foram isolados por fracionamento com metanol a partir do veneno bruto. Os peptídeos presentes, em cada uma das 10 frações, foram caracterizados por espectrometria de massa e foram analisados os efeitos de cada fração sobre a angiogênese. Os resultados sugerem que alguns dos efeitos do envenenamento por Lonomia obliqua são devidos à presença de peptídeos bioativos que modulam o comportamento das células endoteliais. / The caterpillar of the species Lonomia obliqua is medically important, whose venom present in the bristles leads to an hemorrhagic syndrome characterized by ecchymosis, coagulation disorders and others symptoms. This suggests the presence of bioactive peptides with pharmaceutical potencial due to the ability to modulate the behavior of endothelial cells. The aim of this study is to analyze the potential effects of Lonomia obliqua venom on angiogenesis. An endothelial cell line (HUVEC) was exposed to different concentrations (5 μg/mL, 10 μg/mL, 20 μg/mL and 50 μg/mL) of Lonomia obliqua bristle extract (LOBE). Using flow cytometry, it was observed that none of the doses affected endothelial cell cycle, cell viability or apoptosis after 24h of exposition. Spheroids of HUVEC cells were plated in a 3D-collagen matrix and it was observed that LOBE (10 μg/mL, 20 μg/mL and 50 μg/mL) induced an increase on cell migration consistent with the angiogenesis process. Analysis of VE-cadherin dynamics indicates that the immediate exposition to LOBE (10 μg/mL) induced a loosening of cell-cell junction, which corroborates with the hemorrhage observed in the victims. By mass spectroscopy, it was observed that LOBE possesses several potentially bioactive peptides. Groups of these peptides were isolated by a methanol-based fractioning of the crude venom. The peptides present in each of the 10 fractions were characterized by mass spectroscopy and it was analyzed the effects of each fraction on angiogenesis. The results suggest that some of the effects of Lonomia obliqua envenomation are due to the presence of bioactive peptides that modulate the behavior of endothelial cells.

Les tissus épithéliaux sont des couches de cellules adhérentes qui servent de barrières entre différents compartiments morphologiques et procurent un transport directionnel de molécules. L’action coopérative de plusieurs déterminants de la polarité gouverne l’identité et la morphogenèse spécifiques de ces domaines : 1) le cytosquelette d’actomyosine, 2) les jonctions adhérentes (AJs) basées sur la E-cadhérine et 3) les complexes de polarité conservés au cours de l’évolution. Une perte de l’adhérence via la DE-cadhérine (DE-Cad) conduit à des défauts de polarité apico-basale, tandis que la localisation apicale de DE-Cad nécessite les protéines de polarité Crumbs (Crb) et Bazooka (Baz) (L’homologue de Par3 chez la mouche). Notablement, DE-Cad forme des amas qui co-localisent partiellement avec les amas de Baz, génèrent l’adhésion intercellulaire et transmettent la tension. Les mécanismes impliqués dans le contrôle de la taille, le nombre, la répartition et la dynamique des amas de DE-Cad restent peu connus.J’ai étudié le rôle de Crumbs et Baz dans la régulation de la distribution fine de DE-Cad. J’ai montré que Crb contrôle la distribution macroscopique de DE-Cad, au moins, partiellement via Baz. En générant des mutations de Baz sur des sites régulateurs variés grâce à de la transgenèse spécifique de site et en utilisant de la microscopie en temps réel quantitative, j’ai montré que Crb agit via le domaine d’oligomérisation CR1 et le site Ser980 de Baz afin d’ajuster les niveaux de DE-Cad. Remarquablement, j’ai aussi révélé que le domaine d’oligomérisation de Baz est inutile à la formation d’amas Baz-DE-Cad et j’ai caractérisé la réciprocité de l’interaction DE-Cad-Baz. / Epithelia are sheets of adherent cells that serve as barriers between distinct morphological compartments and provide directed transport of molecules.. The cooperative action of several polarity determinants governs the proper identity and morphogenesis of these domains: 1) actomyosin cytoskeleton; 2) E-Cadherin-based adherens junctions (AJs) and 3) evolutionarily conserved polarity complexes.A loss of DE-cadherin (DE-Cad) adhesion leads to apico-basal polarity defects, while the apical localization of DE-Cad requires the polarity proteins Crumbs (Crb) and Bazooka (Baz) (Par3 homolog in fly). Notably, DE-Cad builds clusters that display a certain degree of colocalization with the clusters of Baz, provide intercellular adhesion and transmit tension.I have addressed the role of Crumbs and Baz in the regulation of DE-Cad fine distribution. I demonstrated that Crb controls DE-cad macroscopic distribution, at least, partially via Baz. By generating Baz mutants on various regulatory sites using site-specific transgenesis and quantitative live-imaging microscopy, I showed that Crb acts via CR1 oligomerization domain and Ser980 site of Baz to adjust DE-Cad levels. I also revealed that Baz oligomerization domain is dispensable for Baz-DE-Cad clusters formation and characterized the reciprocity of DE-Cad-Baz crosstalk.

Made available in DSpace on 2014-06-11T19:23:46Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-02-11Bitstream added on 2014-06-13T19:50:57Z : No. of bitstreams: 1 joao_cf_me_jabo.pdf: 526121 bytes, checksum: c3baa3dbdea179c60aaaa5d5df24f283 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O carcinoma de células escamosas é uma neoplasia maligna que emerge dos queratinócitos e corresponde a aproximadamente 5% dos tumores cutâneos dos cães. Os tumores de células basais são compostos quase exclusivamente por células basais e apresentam uma incidência de 4 a 12% entre as neoplasias cutâneas caninas. O carcinoma de células escamosas e o tumor de células basais são neoplasias comumente registradas na clínica de pequenos animais. As caderinas compreendem uma classe de moléculas de adesão celular expressas na superfície de todas as camadas epidérmicas. A E-caderina é a principal caderina envolvida na adesão celular epitelial. A redução de sua expressão está envolvida com a progressão de alguns tipos de câncer, principalmente os carcinomas, seu poder metastático, e ainda na definição do prognóstico. Não há muitos estudos na veterinária com relação à expressão dessas moléculas em tumores. O fator de crescimento do endotélio vascular (VEGF) é um potente mitógeno para células endoteliais e sua expressão tem sido relacionada com o aumento da angiogênese tumoral. O VEGF além de estimular a angiogênese, produz colagenase e outras enzimas degradativas que facilitam a saída das células neoplásicas para a circulação, além de estimularem o crescimento das células tumorais. O objetivo desse estudo foi avaliar a expressão da E-caderina e do fator de crescimento do endotélio vascular (VEGF) em tecidos caninos histologicamente classificados como carcinoma de células escamosas e tumor de células basais, buscando-se uma correlação com o grau histológico desses tumores. A expressão normal e reduzida da Ecaderina apresentou diferenças significativas comparando-se o tumor de células basais com o carcinoma de células escamosas quando avaliada pelo teste de Fisher... / The squamous cell carcinoma (SCC) is a malignant epithelial neoplasm of keratinocytes and accounts for about 5% of the canine skin neoplasms The basal cells tumors (BCT) are made up almost entirely of basal cells and accounts for 4 to 12% of the canine skin neoplasms. Squamous cell carcinoma and basal cell tumor are neoplasms commonly seen in the Small Animal Practice. The cadherins are a group of cellular adhesion molecules that are expressed on the surface of all epidermic layer. The Ecadherin is the main cadherin involved in epithelial cellular adhesion; the decrease in its expression is related to the progression of some types of cancer, specially carcinomas, to its metastatic characteristics, and to the prognosis. There are few studies in Veterinary Medicine researching the expression of this molecule in canine tumors. The vascular endothelial growth factor (VEGF) is a potent mitogen to endothelial cells and its expression has been correlated with increased tumoral angiogenesis. Besides stimulating angiogenesis, VEGF produces colagenase and other enzymes thus helping neoplastic cells scape into the vascular system and stimulating tumoral cell growth. The goal of this study was to evaluate E-cadherin’s and vascular endothelial growth factor expression in canine tissues that were classified as squamous cell carcinoma or basal cell tumor, and to find a correlation with the histological grade of the tumors. Both normal and decreased expression of E-cadherin had significant differences when comparing squamous cell carcinoma to basal cell tumor using the Fisher test (P=0,0039). Also, in some samples the more differentiated neoplastic cells had a higher intensity of color than the less differentiated...(Complete abstract, click electronic access below)

Orientadora: Mirela Tinucci Costa / Banca: Rosemeri de Oliveira Vasconcelos / Banca: Renée laufer Amorim / Resumo: O carcinoma de células escamosas é uma neoplasia maligna que emerge dos queratinócitos e corresponde a aproximadamente 5% dos tumores cutâneos dos cães. Os tumores de células basais são compostos quase exclusivamente por células basais e apresentam uma incidência de 4 a 12% entre as neoplasias cutâneas caninas. O carcinoma de células escamosas e o tumor de células basais são neoplasias comumente registradas na clínica de pequenos animais. As caderinas compreendem uma classe de moléculas de adesão celular expressas na superfície de todas as camadas epidérmicas. A E-caderina é a principal caderina envolvida na adesão celular epitelial. A redução de sua expressão está envolvida com a progressão de alguns tipos de câncer, principalmente os carcinomas, seu poder metastático, e ainda na definição do prognóstico. Não há muitos estudos na veterinária com relação à expressão dessas moléculas em tumores. O fator de crescimento do endotélio vascular (VEGF) é um potente mitógeno para células endoteliais e sua expressão tem sido relacionada com o aumento da angiogênese tumoral. O VEGF além de estimular a angiogênese, produz colagenase e outras enzimas degradativas que facilitam a saída das células neoplásicas para a circulação, além de estimularem o crescimento das células tumorais. O objetivo desse estudo foi avaliar a expressão da E-caderina e do fator de crescimento do endotélio vascular (VEGF) em tecidos caninos histologicamente classificados como carcinoma de células escamosas e tumor de células basais, buscando-se uma correlação com o grau histológico desses tumores. A expressão normal e reduzida da Ecaderina apresentou diferenças significativas comparando-se o tumor de células basais com o carcinoma de células escamosas quando avaliada pelo teste de Fisher...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The squamous cell carcinoma (SCC) is a malignant epithelial neoplasm of keratinocytes and accounts for about 5% of the canine skin neoplasms The basal cells tumors (BCT) are made up almost entirely of basal cells and accounts for 4 to 12% of the canine skin neoplasms. Squamous cell carcinoma and basal cell tumor are neoplasms commonly seen in the Small Animal Practice. The cadherins are a group of cellular adhesion molecules that are expressed on the surface of all epidermic layer. The Ecadherin is the main cadherin involved in epithelial cellular adhesion; the decrease in its expression is related to the progression of some types of cancer, specially carcinomas, to its metastatic characteristics, and to the prognosis. There are few studies in Veterinary Medicine researching the expression of this molecule in canine tumors. The vascular endothelial growth factor (VEGF) is a potent mitogen to endothelial cells and its expression has been correlated with increased tumoral angiogenesis. Besides stimulating angiogenesis, VEGF produces colagenase and other enzymes thus helping neoplastic cells scape into the vascular system and stimulating tumoral cell growth. The goal of this study was to evaluate E-cadherin's and vascular endothelial growth factor expression in canine tissues that were classified as squamous cell carcinoma or basal cell tumor, and to find a correlation with the histological grade of the tumors. Both normal and decreased expression of E-cadherin had significant differences when comparing squamous cell carcinoma to basal cell tumor using the Fisher test (P=0,0039). Also, in some samples the more differentiated neoplastic cells had a higher intensity of color than the less differentiated...(Complete abstract, click electronic access below) / Mestre

Made available in DSpace on 2014-12-17T15:32:33Z (GMT). No. of bitstreams: 1 MariaCFNC.pdf: 1259034 bytes, checksum: abf51afcd72b5241d217ca5d19610bd4 (MD5) Previous issue date: 2006-09-29 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The objective of this study was perform, by the streptoavidin-biotin technique, an immunohistochemical analysis of the E-cadherin and CD44v6 in 15 lower lip squamous cell carcinomas and 15 of tongue, with varied histologic gradation of malignidade, in order to establish a possible relation between the expression these proteins and the anatomical localization of the lesions, metastasis, as well as with the Bryne`s histolologic grading of malignancy system. It was not observed significant statistical association between the localization of the lesions and the malignancy score, however, had a significant correlation between the histologic parameters of malignancy gradation and the total score of malignancy, being that the parameter degree of keratinization presented the highest correlation (r = 0,844). Taking in consideration the anatomical localization of the lesions, it was not significant difference between the profile of expression and the amount of immunopositive cells for Ecaderina and CD44v6. To the metastasis variable, also it was not observed significant difference between the profile of expression and the amount of immunopositive cells for evaluated proteins. However, it was observed a statistical significant difference in relation to the scores of malignancy, being that the low score presented the highest values for the profile of expression and the amount of immunopositive cells for the E-caderina and the CD44v6. It was observed a statistically significant and negative correlation between the expression profile, the amount of E-cadherin and CD44v6 immunopositive cells and the total score of malignancy. Therefore, based in the results of this study, it was concluded that the expression of the immunohistochemical markers E-caderina and CD44v6 did not constitute histological indicator of aggressiveness for the patients with lower lip and tongue squamous cell carcinomas / Este trabalho teve como objetivo verificar, atrav?s da t?cnica da estreptoavidina-biotina, a express?o imuno-histoqu?mica das prote?nas E-caderina e CD44v6 em 15 esp?cimes de carcinoma epiderm?ide de l?bio inferior e 15 de l?ngua, com variada grada??o histol?gica de malignidade, a fim de estabelecer uma poss?vel rela??o entre a express?o das referidas prote?nas e a localiza??o anat?mica da les?o, met?stase, assim como com a grada??o histol?gica de malignidade proposta por Bryne (1998). A an?lise estat?stica demonstrou que n?o houve associa??o significativa entre a localiza??o da les?o e os escores de malignidade, entretanto, houve uma correla??o significativa entre os par?metros de grada??o histol?gica de malignidade e o escore total de malignidade, sendo que o par?metro grau de ceratiniza??o apresentou a maior correla??o (r = 0,844). Levando-se em considera??o a localiza??o anat?mica das les?es, n?o houve diferen?a significativa entre o padr?o de express?o e a quantidade de c?lulas imunopositivas para E-caderina e CD44v6. Em se tratando da vari?vel met?stase, tamb?m n?o houve diferen?a significativa entre o padr?o de express?o e a quantidade de c?lulas imunopositivas para as prote?nas avaliadas. Entretanto, ressalta-se que foi observada uma diferen?a estatisticamente significativa em rela??o aos escores de malignidade, sendo que o escore baixo apresentou os maiores valores para o padr?o de express?o e a quantidade de c?lulas imunopositivas para a E-caderina e o CD44v6. Uma correla??o estatisticamente significativa e negativa entre o padr?o de express?o e a quantidade de c?lulas imunopositivas para a E-caderina e o CD44v6 e o escore total de malignidade foi observada. Portanto, com base nestes resultados, conclui-se que a express?o dos marcadores imuno-histoqu?micos E-caderina e CD44v6 n?o constituiu fator indicativo de maior agressividade morfol?gica para os pacientes portadores de carcinomas epiderm?ides de l?bio inferior e de l?ngua

A lagarta da espécie Lonomia obliqua é medicamente importante, cujo veneno, presente nas espículas, causa uma síndrome hemorrágica caracterizada por equimoses, alterações da coagulação, dentre outros sintomas. Isto sugere a presença de peptídeos bioativos com potencial farmacêutico, devido à capacidade de modular o comportamento das células endoteliais. O objetivo deste estudo é analisar os potenciais efeitos do veneno de Lonomia obliqua na angiogênese. Uma linhagem celular endotelial (HUVEC) foi exposta a diferentes concentrações do extrato de espículas da Lonomia obliqua (Lonomia obliqua Bristle extract - LOBE) 5 μg/mL, 10 μg/mL, 20 μg/mL e 50 μg/mL. Empregando citometria de fluxo, observou-se que nenhuma das doses afetou o ciclo celular, viabilidade ou apoptose das células endoteliais após 24h de exposição. Os esferóides das células HUVEC foram plaqueados numa matriz 3D de colágeno e observou-se que LOBE (10 μg/mL, 20 μg/mL e 50 μg/mL) induz um aumento na migração celular, consistente com o processo de angiogênese. A análise da dinâmica da VE-caderina indica que a exposição imediata a LOBE (10 μg/mL) induz um desprendimento da junção célula-célula, o que corrobora com a hemorragia observada nas vítimas de envenenamento. Através de espectrometria de massa, observou-se que LOBE possui vários potenciais peptídeos bioativos. Grupos destes peptídeos foram isolados por fracionamento com metanol a partir do veneno bruto. Os peptídeos presentes, em cada uma das 10 frações, foram caracterizados por espectrometria de massa e foram analisados os efeitos de cada fração sobre a angiogênese. Os resultados sugerem que alguns dos efeitos do envenenamento por Lonomia obliqua são devidos à presença de peptídeos bioativos que modulam o comportamento das células endoteliais. / The caterpillar of the species Lonomia obliqua is medically important, whose venom present in the bristles leads to an hemorrhagic syndrome characterized by ecchymosis, coagulation disorders and others symptoms. This suggests the presence of bioactive peptides with pharmaceutical potencial due to the ability to modulate the behavior of endothelial cells. The aim of this study is to analyze the potential effects of Lonomia obliqua venom on angiogenesis. An endothelial cell line (HUVEC) was exposed to different concentrations (5 μg/mL, 10 μg/mL, 20 μg/mL and 50 μg/mL) of Lonomia obliqua bristle extract (LOBE). Using flow cytometry, it was observed that none of the doses affected endothelial cell cycle, cell viability or apoptosis after 24h of exposition. Spheroids of HUVEC cells were plated in a 3D-collagen matrix and it was observed that LOBE (10 μg/mL, 20 μg/mL and 50 μg/mL) induced an increase on cell migration consistent with the angiogenesis process. Analysis of VE-cadherin dynamics indicates that the immediate exposition to LOBE (10 μg/mL) induced a loosening of cell-cell junction, which corroborates with the hemorrhage observed in the victims. By mass spectroscopy, it was observed that LOBE possesses several potentially bioactive peptides. Groups of these peptides were isolated by a methanol-based fractioning of the crude venom. The peptides present in each of the 10 fractions were characterized by mass spectroscopy and it was analyzed the effects of each fraction on angiogenesis. The results suggest that some of the effects of Lonomia obliqua envenomation are due to the presence of bioactive peptides that modulate the behavior of endothelial cells.