L'interleukine 7 (IL-7) est une cytokine indispensable au développement et à l'homéostasie des lymphocytes T. Le récepteur à l'IL-7 (IL-7R) est composé de la chaîne alpha (ou CD127) partagée avec le récepteur au TSLP et de la chaîne commune gamma c (ou CD132) partagée avec plusieurs récepteurs de cytokines gamma. L'expression de son récepteur a été décrite dans les lymphocytes T, mais n'a pas été clairement démontrée dans les cellules présentatrices d'antigène (CPA). Cependant, l'expression de CD127 et des récepteurs aux cytokines gamma ont été décrits sur ces cellules suggérant l'expression d'un IL-7R fonctionnel par les CPA. De façon intéressante, la chaîne CD127 existe également sous différentes formes solubles (CD127s) résultant d'épissages alternatifs de l'ARN messager. Toutefois, l'expression et la régulation de l'expression des isoformes de CD127 ont été peu étudiées dans les CPA. Par ailleurs, des polymorphismes du gène CD127 ont été identifiés et associés à une forte concentration plasmatique de la forme soluble CD127s ∆6 chez l'Homme et à une plus forte susceptibilité de développer des maladies auto-immunes. Certains de ces polymorphismes ont également été associés à une évolution plus rapide vers le stade SIDA chez les patients HIV. Enfin, sa capacité à lier l'IL-7 suggère un rôle important de cette forme soluble dans la régulation de la réponse à l'IL-7 en agissant sur sa biodisponibilité. Cependant, l'expression de CD127s plasmatique est très controversée chez les patients HIV en phase chronique. De plus, son expression n'est pas connue dans les organes infectés et n'a jamais été décrite en phase aiguë de l'infection. Enfin, son origine et sa fonction ne sont pas encore élucidées. La quantification spécifique de CD127s ∆6 par RT-qPCR chez le macaque rhésus sain révèle une expression minoritaire de CD127s ∆6 dans les PBMC, faible dans les intestins, plus importante dans les ganglions et encore plus importante dans les poumons. De façon plus précise, cette étude met en évidence sur cellules isolées du sang et de la rate de singes sains, une faible expression de CD127 par les monocytes caractérisée néanmoins par une représentation majeure de la forme soluble contrairement aux lymphocytes T. Ces résultats ont été confirmés par la suite in vitro dans 2 populations immunitaires majoritaires des poumons : les macrophages alvéolaires primaires (MA) issus de lavages broncho-alvéolaires (LBA) de macaque rhésus sains et les cellules épithéliales pulmonaires (CEP) humaines de la lignée NCI-H226. Dans une deuxième partie, la quantification spécifique de CD127s ∆6 par RT-qPCR dans les organes (ganglions et poumons) et le dosage de la protéine CD127s plasmatique en phase aiguë de l'infection SIVmac251 révèlent une augmentation significative de son expression dans les poumons aux temps J7, J10 et J14 post infection et de sa concentration plasmatique à J10 chez les singes infectés. Enfin dans une dernière partie, la charge virale et l'IL-7 endogène ont également été mesurées chez les singes infectés afin de mieux comprendre les mécanismes de régulation de l'expression de CD127s ∆6 au cours de l'infection par le SIVmac251. De façon surprenante, aucune corrélation n'a été trouvée entre l'expression de CD127s ∆6 et la charge virale ou l'expression d'IL-7 endogène chez les singes infectés et les singes sains après injection d'une dose pharmacologique d'IL-7. Ces données suggèrent un effet indirect de l'IL-7 et du virus sur l'expression de CD127s ∆6 et un rôle des facteurs de l'inflammation dans la régulation de son expression. Dans l'objectif de mieux définir ces mécanismes de régulation, les transcrits codant pour la forme soluble ont été quantifiés dans les MA et les CEP in vitro après 6H de stimulation ou non sous IL-7 ou TSLP (ligands de CD127) seul ou couplé au TNFα (cytokine pro inflammatoire). (...) / Interleukin-7 (IL-7) is a crucial cytokine for T-cell development and peripheral T-cell homeostasis. The IL-7 receptor (IL-7R) is composed by the alpha chain (or CD127) shared with the TSLP receptor and the common gamma chain (or CD132) shared with several receptors of gamma cytokines. IL-7R expression was described in T lymphocytes but was not clearly demonstrated in antigen presenting cells (APC). However, CD127 chain and gamma cytokine receptors were described in these cells suggesting a functional IL-7R expression in APC. Interestingly, the CD127 chain also exists under various soluble forms (CD127s) resulting in alternative splicing of CD127 mRNA. However, the expression and the regulation of CD127 isoforms expression have been barely studied in APC. Moreover, polymorphisms in CD127 gene were identified and associated with a strong plasmatic concentration of the soluble form CD127s ∆6 in Humans and a stronger susceptibility to develop autoimmune diseases. Some of these polymorphisms are also associated with a faster evolution to the AIDS stage for HIV patients. Finally, the capacity of this soluble form to bound IL-7 suggests an important role of CD127s ∆6 to regulate IL-7 response by acting on his availability. However, the plasmatic CD127s expression is very controversial in HIV patients in chronic phase of infection. Moreover it expression was not known in infected organs and has never been described in acute phase of infection. Finally, nobody defines its origin and its function yet. The specific quantification of CD127s ∆6 by RT-qPCR revealed a minority expression of CD127s ∆6 in PBMC, weak in gut, more important in ganglions and even more in lung. More precisely, this study highlight on isolated cells from healthy monkey’s blood and spleen, a weak expression of CD127 by monocytes characterized by a majority expression of the soluble form contrary to T lymphocytes. Afterwards, we confirmed these results in vitro in two major immune populations in lung: in primary alveolar macrophages (AM) isolated from broncho-alveolar lavages (BAL) from healthy rhesus monkey and in the NCI-H226 lineage of human lung epithelial cells (LEC). In a second part, the specific quantification of CD127s Δ6 by RT-qPCR in organs (ganglions and lung) and the determination of the CD127s plasmatic protein at the acute phase of SIVmac251 infection revealed a significant up-regulation of this expression in lung in times D7, D10 and D14 post infection and its plasmatic concentration at D10 in infected monkeys. Finally, in the last part, we also quantified the viral load and IL-7 expression from infected monkeys to understand mechanisms implicated in regulation of CD127 expression during SIVmac251 infection. Surprisingly, we found none correlation between CD127s ∆6 expression and viral load or IL-7 expression from infected monkeys and healthy monkeys after injection of a pharmacological dose of IL-7. These data suggest an indirect effect of IL-7 and virus on CD127s ∆6 expression and a role of inflammation factors in regulation of his expression. In order to better define these mechanisms of regulation, the transcripts coding for the soluble form were quantified on AM and LEC in vitro after 6H of stimulation with or without IL-7 or TSLP (ligands of CD127) alone or combined with TNFα (pro inflammatory cytokine). Surprisingly, contrary to T lymphocytes, IL-7 do not induces down regulation of CD127 expression on AM and LEC. Nevertheless, CD127s ∆6 expression is upregulated upon TNFα by AM in a dose dependent manner. Moreover, the costimulation (IL-7 + TNFα) induces CD127s ∆6 expression by LEC revealing a synergic effect of IL-7 and TNFα. Finally the polarization of macrophages derived from human monocytes (hMDM) show that activated state of macrophages impact not only expression but also regulation of CD127 expression by these cytokines. (...)

O desenvolvimento da metástase depende, entre outros fatores de um microambiente propício e é possível que as células do câncer de mama influenciem o perfil da expressão gênica das células estromais, tanto no tumor primário como no linfonodo regional. Para estudar este último evento obtivemos fibroblastos de linfonodos comprometidos (n=3) ou não (n=3) de pacientes com câncer de mama, os quais foram co-cultivados com células de câncer de mama MDA-MB-231, separados fisicamente por membranas porosas por 72 horas. O perfil da expressão gênica foi determinado utilizando-se uma plataforma de cDNA microarray. A presença de células MDA-MB231 modulou a expressão de 415 genes em fibroblastos de linfonodos não comprometidos e 779 genes em fibroblastos de linfonodos comprometidos, em relação a células mantidas em mono-cultura, sendo que 120 genes tiveram sua expressão reguladas em ambas comparações. A expressão destes genes determinou a separação dos fibroblastos mantidos em co-cultura daqueles mantidos isoladamente em cultura por análise de agrupamento hierárquico, indicando que a presença das células de câncer de mama influencia o perfil da expressão gênica das células. Entre as funções reguladas pela presença de células MDA-MB231 encontramse tradução e receptor de superfície ligado à transmissão de sinal, em fibroblastos de linfonodos não comprometidos e autofosforilação de proteína e ciclo celular, em fibroblastos de linfonodos comprometidos. Para determinar se a expressão gênica diferencial é um fenômeno que pode ser generalizado para o câncer de mama, realizamos ensaios utilizando outras amostras de fibroblastos obtidos de linfonodos comprometidos de 5 pacientes e de linfonodos não comprometidos de outras 5 pacientes (incluindo as 6 amostras de fibroblastos previamente analisadas), as quais foram co-cultivadas com três linhagens celulares de câncer de mama (MDA-MB231, MDA-MB435 e MCF-7). A expressão relativa de MAP2K3, AKAP8L e CREG1, inicialmente identificados como diferencialmente expressos em análise de cDNA microarray, foi então determinada por RT-PCR em tempo real. Observamos que nenhuma das três linhagens celulares influenciou a expressão de AKAP8L e CREG1 tanto em fibroblastos de linfonodos comprometidos quanto não comprometidos. MAP2K3 foi hiperexpresso tanto em fibroblastos de linfonodos comprometidos quanto em não comprometidos co-cultivados com células MDA-MB231, mas não com células MDA-MB435 ou MCF-7. Nossos resultados indicam que a presença de células MDA-MB231 influencia o perfil de expressão gênica de fibroblastos originário tanto de linfonodos comprometidos quanto de não comprometidos. Alguns genes comumente regulados em fibroblastos de linfonodo comprometido ou não comprometidos, incluindo MAP2K3, podem estar envolvidos no estabelecimento de metástase regional. / Metastasis development may depend on a favorable microenvironment and breast cancer cells may influence stromal cells gene expression profile not only in the primary site but also in the lymph nodes. To study the latter event, fibroblasts were obtained from involved or uninvolved lymph nodes from six breast cancer patients and co-cultivated with breast cancer MDA-MB-231 cells, physically separated by porous membranes, for 72 hours. The gene expression profile was determined utilizing a cDNA microarray platform. The presence of MDA-MB231 cells modulated the expression of 415 genes in fibroblasts from uninvolved nodes and 779 genes in fibroblasts from involved nodes, as compared to fibroblasts cultured isolated, including 120 genes, which were regulated in fibroblasts from both origins. Unsupervised hierarchical clustering allowed a correct segregation of fibroblasts co-cultured with MDA-MB231 cells from fibroblasts cultured alone, indicating that the gene expression profile gene is influenced by the presence of breast cancer cells. Functions, which were regulated by presence of MDA-MB231 cells included translation and cell surface receptor linked signal transduction in fibroblasts from uninvolved nodes and protein autophosphorylation and cell cycle in fibroblasts from involved nodes. To determine whether this differential gene expression was a general process influenced by breast cancer cells, further assays were performed utilizing samples of fibroblasts from involved (n=5) and uninvolved nodes (n=5) from breast cancer patients (including the 6 samples of fibroblasts previously analyzed), which were co-cultured with three breast cancer cell lines (MDAMB231, MDA-MB435 and MCF-7). Relative expression of MAP2K3, AKAP8L and CREG1, initially identified as differentially expressed in co-cultured fibroblasts upon cDNA microarray analysis, was determined by RT-PCR real time. AKAP8L and CREG1 expression in fibroblasts from involved or uninvolved nodes was not influenced by the presence of any of the three cell lines. MAP2K3 was over-expressed in fibroblasts from both involved and uninvolved nodes when co-cultured with MDA-MB231 cells, but not with MDA-MB435 or MCF-7 cells. Our results indicate that the gene expression profile of fibroblasts from involved and uninvolved lymph nodes are influenced by the presence of MDA-MB231. Some genes commonly regulated in fibroblasts from both involved and uninvolved nodes, as MAP2K3, may be involved in regional metastasis establishment.

No description available.

O comportamento do câncer de mama pode ser influenciado pela interação entre células tumorais e estromais que infiltram e circundam o tumor. Acredita-se também que as células que compõem o microambiente linfonodal possam influenciar o perfil da expressão gênica de células mamárias malignas MDA-MB231, induzindo ou inibindo o desenvolvimento de metástase regional. Para avaliar essa possibilidade, células MDA-MB231 foram co-cultivadas com fibroblastos obtidos de linfonodos comprometidos ou não comprometidos de pacientes com câncer de mama, separadas por membranas porosas por 72 horas. O perfil da expressão gênica foi avaliado através de uma plataforma de cDNA microarray de 4608 genes. Observamos que 155 e 188 genes foram modulados em células MDA-MB231 na presença de fibroblastos de linfonodos não comprometidos e comprometidos, respectivamente, quando comparados com células MDA-MB231 cultivadas isoladamente. Análise do agrupamento hierárquico não supervisionado utilizando os genes diferencialmente expressos revelou a presença de dois grupos, um constituído por células MDA-MB 231 em monocultura e outro por células mantidas em co-cultura com fibroblastos. Splicing de RNAm, via spliceossoma, ciclo celular e regulação da transcrição por promotores da RNA polimerase II, foram algumas funções moduladas em células MDA-MB231. A seguir novos ensaios de co-cultura foram realizados e a expressão de alguns genes foram analisados por RT-PCR. FN3K e COMT foram menos expressos em células MDA-MB231 na presença de fibroblastos de linfonodos, mas não em co-cultura com células MCF-7, nas quais apenas HTRA1 mostrou-se hipoexpresso em casos de co-cultura com fibroblastos. Esses resultados sugerem que a inter-relação entre células estromais e células tumorais são dependentes do subtipo do tumor, de fenótipo luminal ou basal / Breast cancer behavior may be influenced by interactions between cancer and stromal cells, which infiltrate and surround the tumor. It is also believed that cells within the lymph node microenvironment may influence the gene expression profile of breast cancer cells, stimulating or inhibiting regional metastasis development. To evaluate this possibility, breast cancer MDAMB231 cells were co-cultured with fibroblasts obtained from involved or uninvolved lymph nodes from breast cancer patients, using a porous membrane, for 72 hours. Gene expression profile was evaluated through a cDNA microarray platform containing 4608 genes. MDA-MB231 cells had 155 and 188 genes modulated by the presence of fibroblasts from uninvolved or involved nodes, respectively, as compared to MDA-MB231 cells cultured alone. Unsupervised hierarchical clustering using the differentially expressed genes revealed the presence of two groups, one comprising MDA-MB231 cells cultured aloned and another one, MDA-MB231 cells co-cultured with fibroblasts. Nuclear mRNA splicing, via spliceosome, cell cycle, and regulation of transcription from RNA polymerase II promoter, were functions regulated in cocultured MDA-MB231 cells. New co-culture assays were performed and expression of a few genes was further evaluated by RT-PCR. FN3K and COMT were both down-regulated in MDA-MB231 cells in the presence of nodes\' fibroblasts, but not in co-cultured MCF7 cells, while HTRA1 was just down regulated in MCF7 co-cultured cells. These results suggest that the interrelationship between stromal and cancer cells are dependent on the subtype of tumor, whether from luminal or basal-like phenotype

A remodelação do epitélio e do mesênquima subjacente tem um papel crucial na patogênese da fibrose pulmonar experimental. A iniciação, gravidade e distribuição de fibrose varia entre os diferentes agentes químicos. Estudos recentes indicaram que o envolvimento epitelial, a expressão de proteínas reguladoras do epitélio, ativação endotelial, estresse do retículo endoplasmático, a ativação de fibroblastos e acumulação de diferentes tipos de colágeno, pode ser específica em lesão causadas por diferentes agentes químicos. Neste estudo, comparou-se a fibrose pulmonar induzida por bleomicina (BLM) e hidroxitolueno butilado (BHT). Envolvimento epitelial, proteínas reguladoras, ativação endotelial e de fibroblastos foram quantitativamente avaliados pela densidade de células alveolares, expressão de telomerase, endotelina-1 (ET-1), fator de crescimento vascular (VEGF), fator de transformação do crescimento beta (TGF-beta) e do fator de crescimento de fibroblastos básico (bFGF). Estresse celular em células epiteliais alveolares do tipo 2 (AEC II) e fibroblastos, eventualmente, responsáveis pela gênese da fibrose pulmonar, foram investigados por microscopia eletrônica. Os colágenos do tipo I (Col I), III (Col III) e V (Col V) foram caracterizados e quantificados por imunofluorescência. A quantidade de colágeno pulmonar e alterações histológicas fibróticas foram significativamente aumentadas nos grupos BLM e BHT em relação aos controles, com diferença significativa entre a resposta fibrótica precoce e tardia. A densidade AEC II, a expressão da telomerase, ET-1, VEGF, TGF-beta e bFGF foram significativamente maiores nos grupos BLM e BHT do que em pulmões dos grupos controles, com diferença significativa entre a fase precoce e tardia da resposta fibrótica. Mitocôndrias anormais e estresse do retículo endoplasmático em AEC II e fibroblastos foram encontrados em ambos os grupos fibróticos. Aumento no acumulo de fibras de Col I, III e V, foram encontradas no interstício pulmonar após instilação de BLM e BHT. A expressão gênica de TGF-beta1 e alfa actina de músculo liso (alfa-SMA) foi significativamente maior em ambos modelos de fibrose pulmonar. Ativação de Smad3 (Mothers against decapentaplegic homolog 3) associada à expressão de IL-beta1 (Interleucina-1 beta), Lox (lisil-oxidase) e o fator de transcrição Sp1 (Specificity protein 1) foi associada com a ativação do gene alfa-SMA. Em conclusão, os nossos resultados tornam-se relevantes pois demonstram que, independentemente do insulto inicial, há uma convergência no perfil de sinalização, onde fica evidente que a lesão epitélio/endotelial está envolvida num amplo e contínuo processo de reparação com consequente final fibrótico. Um elemento chave no reparo e remodelamento tecidual ou fibrose é a resposta mesenquimal que fornece componentes essenciais de MEC necessários para a infraestrutura da cura e por outro lado para a fibrose progressiva crônica / Epithelial and underlying mesenchyme remodeling have a critical role in the pathogenesis of experimental pulmonary fibrosis. The initiation, distribution and severity of fibrosis varies among different chemical agents. Recent studies have indicated that epithelial involvement, expression of epithelial regulatory proteins, endothelium activation, endoplasmic reticulum stress, fibroblast activation and accumulation of different types of collagen may be specific in various chemical agents of injury. In this study, bleomycin (BLM) and Butylated hydroxytoluene (BHT)-induced pulmonary fibrosis in mice were compared. Epithelial involvement, regulatory proteins, endothelium and fibroblast activation were quantitatively evaluated by alveolar cells density, telomerase, endothelin-1 (ET-1), Vascular endothelial growth factor (VEGF), Transforming growth factor beta (TGF-beta) and basic fibroblast growth factor (bFGF) expression. Cellular stress in type 2 alveolar epithelial cells (AEC II) and fibroblasts, eventually responsible by generating lung fibrosis, were investigated by electron microscopy. We characterized and quantified collagen type I (Col I), III (Col III) and V (Col V) by immunofluorescence. Lung collagen content and fibrotic histological changes were significantly increased in BLM and BHT models compared to control with significant difference between early and late fibrotic response. AEC II density, telomerase expression, ET-1, VEGF, TGF-beta and bFGF were significantly higher than control lungs with significant difference between early and late BLM and BHT fibrotic response. Abnormal mitochondria and endoplasmic reticulum in AEC II and fibroblasts was found in both groups of chemical agents. Increased of Col I, Col III and V fibers accumulation was found in the lung interstitium after BLM and BHT instillation. The expression of TGF-beta1 and alfa smooth muscle actin (alfa-SMA) gene was significantly increased in both model of pulmonary fibrosis. Activated Smad3 (Mothers against decapentaplegic homolog 3) associated to the IL-beta1 (Interleukin-1 beta), Lox (Lysyl oxidase) and the transcription factor Sp1 (Specificity protein 1) was associated to the activation of alfa-SMA gene. In conclusion, our results become relevant because they demonstrate that, regardless of the initial insult, there is a convergence in the signaling profile, where it is clear that the epithelial/endothelial injury is involved in a broad and continuous repair process with consequent fibrotic end. A key component in tissue repair and remodeling, or fibrosis is the mesenchymal response which provides essential components of extracellular matrix infrastructure needed to cure and secondly for chronic progressive fibrosis

No description available.

O comportamento do câncer de mama pode ser influenciado pela interação entre células tumorais e estromais que infiltram e circundam o tumor. Acredita-se também que as células que compõem o microambiente linfonodal possam influenciar o perfil da expressão gênica de células mamárias malignas MDA-MB231, induzindo ou inibindo o desenvolvimento de metástase regional. Para avaliar essa possibilidade, células MDA-MB231 foram co-cultivadas com fibroblastos obtidos de linfonodos comprometidos ou não comprometidos de pacientes com câncer de mama, separadas por membranas porosas por 72 horas. O perfil da expressão gênica foi avaliado através de uma plataforma de cDNA microarray de 4608 genes. Observamos que 155 e 188 genes foram modulados em células MDA-MB231 na presença de fibroblastos de linfonodos não comprometidos e comprometidos, respectivamente, quando comparados com células MDA-MB231 cultivadas isoladamente. Análise do agrupamento hierárquico não supervisionado utilizando os genes diferencialmente expressos revelou a presença de dois grupos, um constituído por células MDA-MB 231 em monocultura e outro por células mantidas em co-cultura com fibroblastos. Splicing de RNAm, via spliceossoma, ciclo celular e regulação da transcrição por promotores da RNA polimerase II, foram algumas funções moduladas em células MDA-MB231. A seguir novos ensaios de co-cultura foram realizados e a expressão de alguns genes foram analisados por RT-PCR. FN3K e COMT foram menos expressos em células MDA-MB231 na presença de fibroblastos de linfonodos, mas não em co-cultura com células MCF-7, nas quais apenas HTRA1 mostrou-se hipoexpresso em casos de co-cultura com fibroblastos. Esses resultados sugerem que a inter-relação entre células estromais e células tumorais são dependentes do subtipo do tumor, de fenótipo luminal ou basal / Breast cancer behavior may be influenced by interactions between cancer and stromal cells, which infiltrate and surround the tumor. It is also believed that cells within the lymph node microenvironment may influence the gene expression profile of breast cancer cells, stimulating or inhibiting regional metastasis development. To evaluate this possibility, breast cancer MDAMB231 cells were co-cultured with fibroblasts obtained from involved or uninvolved lymph nodes from breast cancer patients, using a porous membrane, for 72 hours. Gene expression profile was evaluated through a cDNA microarray platform containing 4608 genes. MDA-MB231 cells had 155 and 188 genes modulated by the presence of fibroblasts from uninvolved or involved nodes, respectively, as compared to MDA-MB231 cells cultured alone. Unsupervised hierarchical clustering using the differentially expressed genes revealed the presence of two groups, one comprising MDA-MB231 cells cultured aloned and another one, MDA-MB231 cells co-cultured with fibroblasts. Nuclear mRNA splicing, via spliceosome, cell cycle, and regulation of transcription from RNA polymerase II promoter, were functions regulated in cocultured MDA-MB231 cells. New co-culture assays were performed and expression of a few genes was further evaluated by RT-PCR. FN3K and COMT were both down-regulated in MDA-MB231 cells in the presence of nodes\' fibroblasts, but not in co-cultured MCF7 cells, while HTRA1 was just down regulated in MCF7 co-cultured cells. These results suggest that the interrelationship between stromal and cancer cells are dependent on the subtype of tumor, whether from luminal or basal-like phenotype

O desenvolvimento da metástase depende, entre outros fatores de um microambiente propício e é possível que as células do câncer de mama influenciem o perfil da expressão gênica das células estromais, tanto no tumor primário como no linfonodo regional. Para estudar este último evento obtivemos fibroblastos de linfonodos comprometidos (n=3) ou não (n=3) de pacientes com câncer de mama, os quais foram co-cultivados com células de câncer de mama MDA-MB-231, separados fisicamente por membranas porosas por 72 horas. O perfil da expressão gênica foi determinado utilizando-se uma plataforma de cDNA microarray. A presença de células MDA-MB231 modulou a expressão de 415 genes em fibroblastos de linfonodos não comprometidos e 779 genes em fibroblastos de linfonodos comprometidos, em relação a células mantidas em mono-cultura, sendo que 120 genes tiveram sua expressão reguladas em ambas comparações. A expressão destes genes determinou a separação dos fibroblastos mantidos em co-cultura daqueles mantidos isoladamente em cultura por análise de agrupamento hierárquico, indicando que a presença das células de câncer de mama influencia o perfil da expressão gênica das células. Entre as funções reguladas pela presença de células MDA-MB231 encontramse tradução e receptor de superfície ligado à transmissão de sinal, em fibroblastos de linfonodos não comprometidos e autofosforilação de proteína e ciclo celular, em fibroblastos de linfonodos comprometidos. Para determinar se a expressão gênica diferencial é um fenômeno que pode ser generalizado para o câncer de mama, realizamos ensaios utilizando outras amostras de fibroblastos obtidos de linfonodos comprometidos de 5 pacientes e de linfonodos não comprometidos de outras 5 pacientes (incluindo as 6 amostras de fibroblastos previamente analisadas), as quais foram co-cultivadas com três linhagens celulares de câncer de mama (MDA-MB231, MDA-MB435 e MCF-7). A expressão relativa de MAP2K3, AKAP8L e CREG1, inicialmente identificados como diferencialmente expressos em análise de cDNA microarray, foi então determinada por RT-PCR em tempo real. Observamos que nenhuma das três linhagens celulares influenciou a expressão de AKAP8L e CREG1 tanto em fibroblastos de linfonodos comprometidos quanto não comprometidos. MAP2K3 foi hiperexpresso tanto em fibroblastos de linfonodos comprometidos quanto em não comprometidos co-cultivados com células MDA-MB231, mas não com células MDA-MB435 ou MCF-7. Nossos resultados indicam que a presença de células MDA-MB231 influencia o perfil de expressão gênica de fibroblastos originário tanto de linfonodos comprometidos quanto de não comprometidos. Alguns genes comumente regulados em fibroblastos de linfonodo comprometido ou não comprometidos, incluindo MAP2K3, podem estar envolvidos no estabelecimento de metástase regional. / Metastasis development may depend on a favorable microenvironment and breast cancer cells may influence stromal cells gene expression profile not only in the primary site but also in the lymph nodes. To study the latter event, fibroblasts were obtained from involved or uninvolved lymph nodes from six breast cancer patients and co-cultivated with breast cancer MDA-MB-231 cells, physically separated by porous membranes, for 72 hours. The gene expression profile was determined utilizing a cDNA microarray platform. The presence of MDA-MB231 cells modulated the expression of 415 genes in fibroblasts from uninvolved nodes and 779 genes in fibroblasts from involved nodes, as compared to fibroblasts cultured isolated, including 120 genes, which were regulated in fibroblasts from both origins. Unsupervised hierarchical clustering allowed a correct segregation of fibroblasts co-cultured with MDA-MB231 cells from fibroblasts cultured alone, indicating that the gene expression profile gene is influenced by the presence of breast cancer cells. Functions, which were regulated by presence of MDA-MB231 cells included translation and cell surface receptor linked signal transduction in fibroblasts from uninvolved nodes and protein autophosphorylation and cell cycle in fibroblasts from involved nodes. To determine whether this differential gene expression was a general process influenced by breast cancer cells, further assays were performed utilizing samples of fibroblasts from involved (n=5) and uninvolved nodes (n=5) from breast cancer patients (including the 6 samples of fibroblasts previously analyzed), which were co-cultured with three breast cancer cell lines (MDAMB231, MDA-MB435 and MCF-7). Relative expression of MAP2K3, AKAP8L and CREG1, initially identified as differentially expressed in co-cultured fibroblasts upon cDNA microarray analysis, was determined by RT-PCR real time. AKAP8L and CREG1 expression in fibroblasts from involved or uninvolved nodes was not influenced by the presence of any of the three cell lines. MAP2K3 was over-expressed in fibroblasts from both involved and uninvolved nodes when co-cultured with MDA-MB231 cells, but not with MDA-MB435 or MCF-7 cells. Our results indicate that the gene expression profile of fibroblasts from involved and uninvolved lymph nodes are influenced by the presence of MDA-MB231. Some genes commonly regulated in fibroblasts from both involved and uninvolved nodes, as MAP2K3, may be involved in regional metastasis establishment.

As interações epitélio-mesênquima podem influenciar o desenvolvimento do tumor no sítio primário e no linfonodo comprometido de pacientes com câncer de mama. Nosso objetivo foi avaliar a taxa de proliferação e perfil gênico de fibroblastos de linfonodos comprometidos e não comprometidos obtidos de pacientes com câncer de mama e determinar a influência de células epiteliais mamárias normais (MCF10A) ou malignas (MDA-MB-231) na expressão gênica destes fibroblastos. Foram estabelecidas culturas primárias de fibroblastos de linfonodos (3 comprometidos e 3 não comprometidos) de 6 diferentes pacientes com câncer de mama e não houve diferença na taxa de proliferação destes fibroblastos. Co-culturas de células MCF10A ou MDA-MB-231 com fibroblastos, separadas fisicamente por membranas porosas, foram realizadas por 72 horas. O RNA total dos fibroblastos foi extraído, amplificado e o perfil gênico foi analisado usando-se uma lâmina de cDNA microarray. Fibroblastos de linfonodos comprometidos e não comprometidos apresentaram perfil gênico similar, pois apenas 13 genes foram modulados, sendo que maior expressão de PGBD3 e PTBP2 em fibroblastos de linfonodos comprometidos foi confirmada em ensaios de RT-PCR em tempo real. Em fibroblastos, a cocultura com células MCF10A alterou a expressão de maior número de genes que a co-cultura com células MDA-MB-231. Em fibroblastos originários de linfonodos não comprometidos mantidos em co-cultura com células MDA-MB-231 foram modulados 151 genes, em relação aos mesmos fibroblastos cultivados na ausência de células epiteliais, sendo que oito deles apresentaram variação de expressão superior a três vezes (BET1, ENTPD1, USP7, DAPK1, ERBB2 e NCF2). As células MDA-MB-231 modularam algumas vias de sinalização em fibroblastos não comprometidos, como vias do cálcio, insulina, hormônio liberador de gonadotrofina (GnRH) e da regulação do citoesqueleto de actina, mas o mesmo não ocorreu em fibroblastos de linfonodos comprometidos. Duzentos e quarenta e nove genes foram diferencialmente expressos em fibroblastos originários de linfonodos comprometidos mantidos em co-cultura com células MDA-MB-231 e quatro genes apresentaram variação superior a três vezes (ACLY, AXUD1, CLCN5 e PDE6D). Nestes fibroblastos, algumas funções biológicas foram reguladas apenas por influência da célula MDA-MB-231, entre as quais metabolismo de aminoácidos, excreção, transporte intra Golgi e regulação da forma celular. As vias de sinalização e funções biológicas reguladas em fibroblastos pela interação com células epiteliais malignas podem estar implicadas no desenvolvimento de metástases regionais no câncer de mama. / Tumor development may be influenced by epithelial-mesenchimal interactions in the primary site as well as in the involved lymph node from breast cancer patients. Our aim was to evaluate the proliferation rate and gene profile of fibroblasts obtained from involved and uninvolved lymph nodes from breast câncer patients and to determine the influence of normal (MCF10A) or malignant (MDA-MB-231) mammary epithelial cells on the gene expression of these fibroblasts. Primary culture from fibroblasts obtained from 3 involved and 3 uninvolved lymph nodes (ILF and NILF) from 6 different breast cancer patients was established and no difference in their proliferation rate was detected. These fibroblasts were co-cultured with MCF10A or MDA-MB-231 cells, physically separated by a porous membrane for 72 hours. Total RNA was extracted from the cells, amplified and the gene profile from fibroblasts cultured alone or with epithelial cells was analyzed by cDNA microarray slides. Fibroblasts from involved and uninvolved lymph nodes present a similar gene profile as only 13 genes were differentially expressed between them, including PGBD3 and PTBP2, which higher expression in fibroblasts from involved lymph nodes was confirmed by real time RT-PCR. In fibroblasts, more genes seem to be regulated upon co-cultured with MCF10A than with MDA-MB-231 cells. In fibroblasts from uninvolved lymph nodes co-cultured with MDA-MB-231 cells, 151 genes were modulated as compared with fibroblasts cultured alone, and eight of them, presented an expression variation superior to three times (BET1, ENTPD1, USP7, DAPK1, ERBB2 e NCF2). In these fibroblasts, MDA-MB-231 could modulate some signaling pathways as calcium, insulin, gonadotrophin releasing hormone (GnRH) and actin cytoskeleton regulation signaling pathways. Two hundred forty nine genes were differentially expressed by fibroblasts from involved lymph nodes co-cultured with MDA-MB-231 cells, four of which with an expression variation superior to three times (ACLY, AXUD1, CLCN5 e PDE6D). In the last condition, fibroblasts had some biological functions regulated upon MDA-MB-231 cells influence, among which amino acid metabolism, excretion, intra-Golgi transport and regulation of cell shape. Signaling pathways and biological functions regulated in fibroblasts after interaction with malignant epithelial cells might be implicated in the development of regional metastasis in breast cancer.

From a physical perspective biological cells consist of active soft matter that exist in a thermodynamic state far from equilibrium. Not only in muscles but also during cell proliferation, wound healing, embryonic development, and many other physiological tasks, generation of forces on the scale of whole cells is required. To date, cellular contractions have been ascribed to adhesion dependent processes such as myosin driven stress fiber formation and the development of focal adhesion complexes. In this thesis it is shown for the first time that contractions can occur independently of focal adhesions in single suspended cells. To measure mechanical properties of suspended cells the Optical Stretcher – a dualbeam laser trap – was used with phase contrast video microscopy which allowed to extract the deformation of the cell for every single frame. For fluorescence imaging confocal laser scanning microscopy was employed. The ratio of the fluorescence of a temperature sensitive and a temperature insensitive rhodamine dye was utilized to determine the temperatures inside the optical trap during and after Optical Stretching. The rise in temperature at a measuring power of 0.7W turned out to be enough to open a temperature sensitive ion channel transfected into an epithelial cell line. In this way a massive Ca2+ influx was triggered during the Optical Stretcher experiment. A new setup combining Optical Stretching and confocal laser scanning microscopy allowed fluorescence imaging of these Ca2+ signals while the cells were deformed by optically induced surface forces, showing that the Ca2+ influx could be manipulated with adequate drugs. This model system was then employed to investigate the influence of Ca2+ on the observed contractions, revealing that they are partially triggered by Ca2+. A phenomenological mathematical model based on the fundamental constitutive equation for linear viscoelastic materials extended by a term accounting for active contractions allowed to quantify the activity of the measured cells. The skewness and the median of the strain distributions were shown to depend on the activity of the cells. The introduced model reveals that even in measurements, that seemingly are describable by passive viscoelasticity, active contractililty might be superimposed. Ignoring this effect will lead to erroneous material properties and misinterpretation of the data. Taken together, the findings presented in this thesis demonstrate that active processes are an essential part of cellular mechanics and cells can contract even independently of adhesions. The results provide a method that allows to quantify active contractions of suspended cells. As the proposed model is not based on specific assumptions on force generating processes, it paves the way for a thorough investigation of different influences, such as cytoskeletal structures and intra-cellular signaling processes, to cellular contractions. The results present an important contribution for better mechanical classification of cells in future research with possible implications for medical diagnosis and therapy.