Dans les cellules il existe deux grandes sources d’énergie : l’ATP et la force proton-motrice, produites au niveau du cytoplasme et de la membrane interne respectivement. La mise en place de processus actifs dans la membrane externe ou à la surface des bactéries à Gram négatif requière la présence de machineries protéiques transmettant les forces de leur lieu de production à leur lieu d’utilisation. Durant ma thèse j’ai étudié une de ces machines : la machinerie de motilité (Agl-Glt) de Myxococcus xanthus. Plus précisément, j’ai cherché à comprendre comment les composants de cette machine s’organisent pour permettre le déplacement d’une bactérie. J’ai montré que l’assemblage de la machinerie de motilité au pôle avant des cellules nécessite la formation d’une plateforme cytosolique sur laquelle vient se fixer la machine Agl-Glt. Sous l’action du moteur, le complexe interne de la machine se déplace en direction du pôle arrière en suivant une trajectoire hélicoïdale de main droite. Au niveau de la surface les protéines de membrane externe sont recrutées au niveau d’adhésions focales et permettent l’ancrage de la machinerie au substrat. Enfin, la transmission des forces de la membrane interne à la surface par la machinerie de motilité génère le déplacement des cellules selon une trajectoire hélicoïdale de main gauche. Finalement, cette étude a révélé l’existence d’une machine protéique de l’enveloppe dont l’activité repose sur l’association d’un moteur linéaire et du cytosquelette bactérien. De par l’homologie qu’il existe entre les systèmes il est possible de proposer que ce type de machines peut-être retrouvé associées à d’autres fonctions que la motilité cellulaire. / Two energy sources are present in cells: the ATP and the Proton Motive Force, produced in the cytoplasm and inner membrane respectively. Active processes in the outer membrane or on the surface of Gram negative bacteria require the presence of a proteic machinery to transduce the forces from their production site, in the cytoplasm or inner membrane, to their usage site. During my thesis I have studied one of these machineries: the motility machinery (Agl-Glt) of Myxococcus xanthus. More precisely, I try to understand how the components of this transmembrane machinery interact with each other to promote cell motility. I have shown that the assembly of the motility machinery at the leading pole requires the formation of a cytoplasmic platform onto which the Agl-Glt machinery is going to nucleate. The inner-membrane motor complex moves intracellularly along a right-handed path in the cell and becomes stationary at focal adhesion sites on the surface through the connection of the motor to the outer membrane proteins of the complex. This powers the left-handed helical motion of the bacteria. Finally, this study reveals the existence of a dynamic transmembrane machinery which associates the bacterial cytoskeleton to a linear motor to promote cell movement. The homology between the systems tells us that this type of motor is likely to be found associate with other function than cell motility.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Cell migration is a prominent feature in cancer metastasis and the characterization of proteins related to migration is important in order to understand the behavior of tumor cells and their invasiveness during tumor progression. Among the proteins involved in cell migration, isoforms of non-muscle myosin type II play a pivotal role in several events related to cell migration, such as contractility, adhesion and cellular signaling. There are three isoforms of myosin type II that can be expressed in mammalian cells: myosin IIA (MIIA), myosin IIB (MIIB) and myosin IIC (MIIC). However, few studies have been conducted to characterize the expression and distribution patterns in cells of different types of tumors, including oral squamous cell carcinoma. The aim of the study was to analyze the expression and distribution of isoforms of myosin II (A, B and C) in surgical fragments of squamous cell carcinoma. Fragments of surgical specimen were collected from different regions of the tumor: a tumor-free zone, the center of the tumor and the invasion zone. These samples (n = 4) were fixed, crioprotected, cut on criostat, submitted to immunolocalization of MIIA, MIIB and MIIC and analyzed on confocal microscopy. The three isoforms of myosin II were expressed differently and showed distinct distribution in accordance with the region of the tumor sample. MIIA and MIIC were overexpressed at the center zone when compared with the free zone, whereas strong staining revealed MIIB at the zone invasion. Based on these observations, the isoforms of myosin IIC and IIA appeared to be more associated with tumor proliferation while MIIB appeared to be more involved in the invasive behavior of tumor, indicating that the isoforms can participate in different ways regulating the behavior and development of tumor type analyzed. / A migração celular é uma característica proeminente na metástase do câncer e a caracterização de proteínas relacionadas com a migração é importante para que se compreenda o comportamento de células tumorais e sua capacidade de invasão durante a progressão tumoral. Entre as proteínas envolvidas na migração celular, as isoformas de miosina não-muscular do tipo II desempenham um papel central em vários eventos relacionados com a migração de células, como a contratilidade, a adesão e a sinalização celular. Existem três isoformas de miosina do tipo II que podem ser expressas em células de mamíferos: miosina IIA (MIIA), miosina IIB (MIIB) e miosina IIC (MIIC). Entretanto, poucos estudos têm sido realizados para caracterizar a sua expressão e padrões de distribuição em células de diferentes tipos de tumores, incluindo carcinoma epidermóide. O objetivo do estudo foi analisar a expressão e distribuição de isoformas de miosina II (A, B e C) em fragmentos de peça cirúrgica de carcinoma epidermóide. Os fragmentos de peça cirúrgica foram coletados a partir de distintas regiões do tumor: a zona livre de tumor, o centro do tumor e a zona de invasão. Estas amostras (n = 4) foram fixadas, crioprotegidas, cortadas em criostato, submetidas à imunolocalização de MIIA, MIIB e MIIC e analisadas em microscopia confocal. As três isoformas de miosina II foram expressas diferentemente e apresentaram distribuição distinta de acordo com a região da amostra de tumor. MIIA e MIIC foram superexpressas na zona central quando comparadas com a zona livre, ao passo que MIIB revelou forte marcação para região de zona de invasão. Com base nas presentes observações, as isoformas de miosina IIA e IIC pareceram estar mais associadas ao evento de proliferação tumoral ao passo que MIIB pareceu mostrar-se mais envolvida com o comportamento invasivo do tumor, indicando que as isoformas podem participar de formas distintas na regulação do comportamento e do desenvolvimento do tipo de tumor analisado.

Abstract Type 1 neurofibromatosis (NF1) syndrome is caused by a mutation of the NF1 gene. NF1 protein (neurofibromin) contains a domain which is related to the GTPase activating protein (GAP) and accelerates the switch of active Ras-GTP to inactive Ras-GDP. The clinical symptoms of NF1 patients include e.g. the formation of benign neurofibroma tumors and hyperpigmented lesions of the skin. The NF1 protein has been referred to as a tumor suppressor since cells of malignant schwannomas of NF1 patients may display loss of heterozygosity of the NF1 gene. In the present study, the expression of the NF1 gene was investigated during tissue repair in human skin. Elevated NF1 protein levels were seen in a fibroblastic cell population of healing wounds. In vitro studies were designed to investigate NF1 expression in dermal fibroblasts under the influence of growth factors that are operative during wound healing. Platelet-derived growth factor (PDGF) isoforms AB and BB and transforming growth factor β1 (TGFβ1) elevated NF1 mRNA levels in cultured dermal fibroblasts. In further studies, histological examination on apparently healthy skin of NF1 patients revealed frequently small masses of neurofibromatous tissue at the vicinity of hair follicles. Thus, action of the NF1 gene appears to be an integral part of normal tissue repair. Enhanced NF1 tumor suppressor expression may serve to limit excessive fibrosis in wound healing. As Ras proteins play a role in the regulation of cell differentiation and formation of cell junctions, the functional expression of NF1 protein was elucidated using differentiating keratinocytes as an in vitro model system. The results demonstrate that an intense NF1 tumor suppressor signal on intermediate filaments was temporally limited to the period in which the formation of desmosomes takes place. In analogy to NF1 protein, a rapid elevation of NF1 mRNA level was detected following initiation of differentiation. Interestingly, NF1 mRNA hybridization signal polarized towards cell-cell contact zones. This finding recognizes a potential way for post-transcriptional modification of NF1 expression and targeting of translation to subplasmalemmal location. The results demonstrate that the function of NF1 protein is associated with the formation of cell junctions, and thus to cellular communication.

La maladie du sommeil ou trypanosomiase africaine humaine fait partie des maladies tropicales négligées sévissant en Afrique sub-saharienne. Elle est causée par le parasite mono-flagellé, Trypanosoma brucei, véhiculé par la mouche tsé-tsé (Glossina spp.). Le flagelle de ce parasite prend naissance au niveau du corps basal et émerge de la cellule en traversant une structure appelée poche flagellaire (FP). Cette poche est formée par l’invagination de la membrane plasmique autour de la base proximale du flagelle. Elle est essentielle à la survie du parasite, car elle constitue l’unique site d’endo- et d’exocytose de la cellule. Cette structure est maintenue autour du flagelle via un constituant du cytosquelette appelé, collier de la poche flagellaire (FPC). Ce collier décrit une structure en anneau ou en fer-à-cheval à la zone de sortie du flagelle. Le premier composant identifié au niveau du FPC est une protéine appelée BILBO1. BILBO1 est essentielle et nécessaire à la biogenèse du FPC et de la FP. Une analyse protéomique et un crible en double-hybride réalisé contre une banque génomique de T. brucei ont permis d’identifier plusieurs partenaires potentiels de BILBO1. Nous avons pu identifier et caractériser de nouvelles protéines du FPC, localisées comme BILBO1 dans une structure en anneau. Nous avons étudié leur fonction chez le parasite, en caractérisant les effets de la surexpression de ces protéines ou de leur ARN interférence sur la croissance et la morphologie cellulaire. / The Human African Trypanosomiasis is a Sub-Saharan Neglected Tropical Disease, caused by Trypanosoma brucei, a mono-flagellate protozoan transmitted by the tsetse fly (Glossina spp.). The T. brucei flagellum originates from a cytoplasmic basal body then grows, to emerge from the cell, by traversing an unusual and essential structure called the Flagellar Pocket (FP). This pocket is an invagination of the pellicular membrane at the base of the flagellum. The FP is essential for the survival of the parasite, because it is the unique site for endo- and exocytosis. The Flagellar Pocket Collar (FPC) is a cytoskeletal component of the FP, and is located at the neck of the FP where it maintains a ring/horseshoe structure at the exit site of the flagellum. The FPC contains numerous uncharacterised proteins, including the first protein identified as FPC component - BILBO1. BILBO1 is essential and required for FPC and FP biogenesis. A proteomic analysis and a private two-hybrid genomic screen experiment on T. brucei have revealed a number of potential BILBO1 partners. We found several proteins localize to the FPC like BILBO1 in a ring-like structure. We characterise these new FPC proteins and their function in the parasite. We have characterised the effects of the GFP fusion protein over-expression and RNAi on cell growth and morphology in T. brucei.

La sonoporation, associant les ultrasons (US) et les microbulles (MB) permet une délivrance localisée des molécules thérapeutiques (e.g., acides nucléiques, molécules chimio-thérapeutiques), avec une efficacité thérapeutique élevée et un faible taux de toxicité. Cependant, les mécanismes impliqués dans le transfert de ces molécules restent jusqu’alors mal connus. Les travaux présentés dans ce manuscrit de thèse ont pour objectif de mettre en évidence l’importance du contact microbulle/cellule et les forces de radiation au cours de la sonoporation et s’intéressent par ailleurs, à l’étude des mécanismes sous-jacents durant le processus de sonoporation ainsi que les conséquences cellulaires (membranaire et intracellulaire) engendrées. Ces études sont réalisées par microscopie électronique, et comparent deux lignées cellulaires U-87 MG et MDA-MB-231. Nous nous intéresserons également aux effets du sérum sur l’efficacité de la sonoporation dans la délivrance de molécules (gènes), mais aussi aux changements du cytosquelette et son implication au cours du processus de sonoporation. / Sonoporation combines ultrasound and microbubbles, and promises a local delivery of therapeutic molecules (i.e., nucleic acids, chemotherapeutic molecules) with a high therapeutic efficacy and a low toxicity level. However, the mechanisms involved in the molecules uptake remain hitherto unclear. The work presented in this thesis manuscript aims to highlighting the processes of action of sonoporation by exploring the importance of microbubble/cell contact and the radiation forces and the study of underlying mechanisms during sonoporation and the generated cellular consequences (membrane and intracellular), by electron microscopy, and by comparing two cell lines U-87 MG and MDA-MB-231. We also explore the serum effects on the efficiency of sonoporation in the delivery of molecules (genes) but also the changes in the cytoskeleton and its involvement during sonoporation.

Les cellules des muscles striés squelettiques sont constituées d'éléments contractiles enveloppés par un réseau membranaire. La formation et l'entretien du muscle strié squelettique impliquent la migration des précurseurs myogéniques, la fusion des myoblastes en myotubes et la mise en place des triades. Ces évènements reposent sur le remodelage des membranes et du cytosquelette d'actine des cellules musculaires. Au cours de ma thèse, j’ai étudié le rôle de la protéine adaptatrice CKIP-1 (casein kinase 2 interacting protein-1) dans certaines étapes du développement du muscle strié squelettique. Après avoir identifié le complexe de nucléation de l’actine Arp (actin-related protein) 2/3 comme un nouvel interacteur de CKIP-1, nous avons montré que l’inhibition de l’expression de ckip-1 chez l’embryon de poisson zèbre altère la morphologie des myoblastes et empêche leur fusion du fait d’une désorganisation du cytosquelette d’actine. J’ai également montré que CKIP-1 n’est présente qu’au cours des étapes précoces de la myogenèse in vitro et in vivo chez la souris, puis elle est progressivement clivée. En outre, la modulation de l’expression de CKIP-1 provoque des défauts membranaires aussi bien in vitro qu’in vivo dans le muscle adulte de souris, suggérant que CKIP-1 est impliquée dans le remodelage des membranes. CKIP-1, par ses capacités à remodeler le cytosquelette d’actine et les membranes, pourrait intervenir dans plusieurs étapes de la vie du muscle : la migration, la fusion des myoblastes et la mise en place ou le maintien du réseau membranaire interne des cellules du muscle strié squelettique. / Skeletal muscle cells are composed of contractile elements wrapped in a membrane network. Formation and maintenance of skeletal muscle involve muscle precursor migration, fusion and triad formation. These events rely on actin cytoskeleton and membrane remodelling in muscle cells. The aim of my thesis work was to study the role of the scaffold protein CKIP-1 (casein kinase 2 interacting protein-1) at different steps of skeletal muscle development. We identified the actin nucleation complex Arp (actin-related protein) 2/3 as a CKIP-1 new interactor and showed that Ckip-1 depletion in zebrafish embryos alters fast twitch myoblast morphology and prevents their fusion due to actin cytoskeleton disorganization. I further showed that CKIP-1 is only present during early myogenesis in vitro and in vivo in mouse, and is then cleaved. Modulation of CKIP-1 expression induces membrane defects in vitro but also in vivo in adult mouse muscle, suggesting that CKIP-1 is involved in membrane remodelling. Through its abilities to remodel actin cytoskeleton and thus membranes, CKIP-1 could be implicated in various steps of muscle life: myoblast migration, fusion, and formation or maintenance of the intracellular membrane compartments of skeletal muscle cells.

Objectifs: La cytokine TRAIL (TNF Related Apoptosis Inducing Ligand) suscite un intérêt majeur en thérapie anti-cancéreuse grâce à sa capacité à induire l’apoptose des cellules cancéreuses tout en épargnant les cellules saines. L’association du récepteur Fas et de l’actine via l’ezrine, une protéine de la famille ERM (Ezrin, Moesin, Radixin), régule les premières étapes de l’induction de l’apoptose par FasL. Au cours de mon projet de thèse, nous avons voulu déterminer le rôle que pouvait jouer l’ezrine au cours de l’apoptose induite par TRAIL, dans des lymphomes B ou des cellules cancéreuses adhérentes (HeLa, HCT116 et SW480). Matériel et Méthodes: Des approches biochimiques et moléculaires nous ont permis d’étudier et de déterminer l’implication de l’ezrine et sa phosphorylation dans la régulation de la mort induite par TRAIL. Résultats: Ce travail démontre que l’ezrine peut réguler de manière négative l’apoptose induite par TRAIL et FasL. Cette activité inhibitrice est régulée par la phosphorylation/déphosphorylation sur la serine 66 ainsi que sur la thréonine 353. Néanmoins cette régulation n’affecte ni la formation, ni l’activation du DISC (Death Inducing Signalling Complex). Des mutations de ces résidus par une alanine (S66A) ou un acide aspartique (Y353D) augmente sélectivement la capacité de TRAIL à induire l’apoptose. Au contraire, des mutations ponctuelles de ces résidus permettant de mimer la phosphorylation de l’ezrine sur la serine 66 (S66D) ou l’expression d’un variant non phosphorylable sur la thréonine 353 (Y353F) protègent les cellules cancéreuses de l’apoptose induite par TRAIL. De manière concordante, l’utilisation du H89, un inhibiteur de PKA, kinase responsable de la phosphorylation de la serine 66 augmente la sensibilité des cellules cancéreuses à TRAIL, alors qu’au contraire, un activateur de PKA (8bromocyclic AMP) rend ces mêmes cellules plus résistantes à TRAIL. Enfin, l’association de TRAIL et du cisplatine permet de dépasser l’inhibition de l’apoptose par l’ezrine. / Background and Aim: TRAIL has sparked a growing interest in oncology due to its ability to selectively trigger cancer cell death while sparing normal cells. The Fas/actin association through ezrin, a member of the ERM protein family, has been reported to regulate early steps of Fas-mediated apoptosis. In this project, we addressed the role of ezrin regarding TRAIL-induced cell death in B lymphoma cell lines, or adherent cancer cell lines (HeLa WT, HCT116, SW480). Methods: Molecular and biochemical approaches were employed to study the relevance of ezrin and its phosphorylation status in TRAIL signaling. Results: We found that ezrin displays a negative function towards TRAIL- and Fas-mediated apoptosis and that the ezrin-mediated TRAIL-induced cell death inhibition led to ezrin activation through phosphorylation/dephosphorylation events at serine 66 and tyrosine 353, but is mainly independent of TRAIL DISC (Death Inducing Signalling Complex) formation or activation. Mutations of these residues to alanine (S66A) or aspartic acid (Y353D) selectively enhanced TRAIL-induced cell death, whereas point mutations mimicking ezrin phosphorylation on S66 (S66D) or a nonphosphorylable variant on Y353 (Y353F) strongly protected cancer cells from apoptosis induced by TRAIL. Moreover, inhibition of the ezrin serine 66 PKA target site, using H89, increased cancer cell sensitivity to TRAIL, while treatment with 8bromocyclic AMP, a PKA activator, decreased TRAIL-induced cell death. In addition, combined TRAIL/cisplatin treatments abrogated ezrin-mediated inhibition of TRAIL-induced apoptosis.

The outer surface of the human placenta, the syncytiotrophoblast, results from the fusion of many cytotrophoblast cells such that many nuclei are contained in this layer. It is possible for these nuclei to cluster forming syncytial nuclear aggregates (SNAs). SNAs have been linked to pathology with increased numbers and earlier formation of SNAs in preeclampsia and fetal growth restriction (FGR). SNAs can be grouped into subtypes including bridges, knots and sprouts, dependent on morphology and attachment to surrounding placental villi. Little is known about SNA formation, but the pyknotic appearance of nuclei within SNAs has led to development of a hypothesis that SNAs are the terminal point of nuclear turnover in the syncytiotrophoblast. Some cytoskeletal proteins have been associated with SNAs indicating their potential involvement in SNA formation. This project aimed to uncover differences between SNA subtypes, whether the degenerate nuclear morphology represents apoptosis and to understand which mechanisms drive nuclear collection into SNAs. Experimental approaches included a review of an electron micrograph archive and application of immunohistochemical techniques to ex vivo placental tissue. A long-term explant model was developed to examine SNA development in vitro; these experiments were further explored using an isolated primary cytotrophoblast model. Nuclei within SNAs were more frequently pyknotic and less frequently eukaryotic than nuclei dispersed in the syncytiotrophoblast. However, few SNAs were positive for the cytokeratin-M30 neoepitope, a caspase dependent breakdown product of cytokeratin-18 and no subtype of SNA showed greater M30 staining than general areas of syncytiotrophoblast. There were increased syncytial knots and decreased syncytial bridges in placentas from women with preeclampsia compared to controls and FGR. While cytoskeletal proteins are seen surrounding SNAs, inhibition of actin and tubulin had no effect on SNA turnover or stability. Very limited nuclear movement was recorded from in vitro culture indicating that syncytiotrophoblast nuclei move far less than had been expected. These data suggest that cell death was not prominent within SNAs but different prevalence of subtypes were present in preeclampsia indicating that SNAs might represent larger changes in placenta structure. As nuclei moved less and SNAs were more static than expected it is suggests that SNAs are more stable than previously thought. Overall, the hypothesis that SNAs are highly active in preeclampsia is questioned and new hypotheses of the role of SNAs are considered in the light of these experimental findings, including whether they form by chance and represent changes in cell turnover of the syncytiotrophoblast.

Muitas evidências indicam que a tumorigênese em humanos é um processo com várias etapas. A progressão de um tumor em direção a malignidade ocorre de maneiras muito distintas entre os diferentes tipos de câncer. Entender os processos celulares que levam a tumorigênese é importante para se delinear tratamentos mais adequados contra os diversos tipos de câncer. Drogas antimitóticas (ou venenos de fuso) são utilizadas no tratamento de alguns cânceres, e entre eles está o câncer de mama. A ação dessas drogas reside sobre a mitose, e têm como alvo os fusos mitóticos, estruturas essenciais que dirigem o ciclo celular na divisão das células. Recentemente, pesquisadores têm delineado possíveis respostas da célula aos venenos de fuso, e essas respostas são dependentes da concentração da droga. Baixas concentrações de venenos de fuso provocam o aparecimento de populações celulares aneuplóides, que ocorrem quando a célula sai do bloqueio mitótico. O presente trabalho utilizou as drogas vincristina e paclitaxel sobre linhagens celulares de mama humana (células normais e tumorais) para pesquisar se as drogas são capazes de induzir células aneuplóides. Os resultados obtidos no presente trabalho indicam que baixa concentração de vincristina e paclitaxel pode induzir o aparecimento de população aneuplóide através de mitoses aberrantes. Os venenos de fuso induzem a formação de mitoses contendo múltiplos fusos mitóticos, e essas mitoses não ficam bloqueadas, dando origem a células aneuplóides. O papel da aneuploidia na tumorigênese não foi ainda estabelecido, mas indiferente da sua importância no desenvolvimento do tumor, encontrar maneiras de inibir sua formação ou de super induzir seu aparecimento podem ter implicações significativas para as terapias contra o câncer. / Several lines of evidence indicate that tumorigenesis in humans is a multistep process and that these steps reflect genetic alterations that drive the progressive transformation of normal cells into highly malignant derivatives. Understanding the cellular processes that lead to tumorigenesis is important to devise more appropriate treatments against various types of cancer. Antimitotic drugs are used in the treatment of some cancers, and among them is breast cancer. The action of these drugs lies on the mitotic spindles, essential structures that drive the cell cycle in the division of cells. Recently, researchers have outlined possible responses to the antimitotic drugs on cells, and these responses are dependent on the concentration of the drug. Low concentrations of drugs can cause the appearance of aneuploid population, which occur when a cell leaves the mitotic block. This study used the drug vincristine and paclitaxel on human breast cancer cell lines (normal and tumoral cells) to find if the drugs are capable of inducing cell aneuploidy. The results of this study indicate that low concentration of vincristine and paclitaxel can induce the emergence of aneuploidy population through aberrant mitosis. The drugs induce the formation of mitosis containing multiple mitotic spindles, resulting in aneuploidy population of cells. The role of aneuploidy in tumorigenesis has not yet been established, but indifferent to this is important find ways to inhibit its formation or the super-induce their appearance. These questions may have significant implications for therapies against cancer.

No processo de metástase os movimentos de migração e invasão tem um papel essencial e em ambos a função dos microfilamentos é de grande importância. Neste contexto, o presente trabalho buscoui analisar os efeitos da droga jaspamídeo e após a determinação das concentrações de IC50 para as linhagens HT144 e NGM foram estudados os efeitos da droga. Os tratamentos mostraram que o fármaco atua desorganizando o citoesqueleto de modo dependente de sua concentração. Os ensaios de ferida mostraram diminuição da taxa de fechamento da área livre após os tratamentos e os ensaios de migração com placas de transwell mostraram que os grupos tratados sofrem aumento desse parâmetro. Nos ensaios de invasão com câmara de Boyden o tratamento mostrou-se efetivo apenas para a célula NGM quando tratadas com 75 nM de jaspamídeo e 30 <font face=\"Symbol\">mM de Y-27632. Quanto à migração, a linhagem NGM não completava este processo quando tratada com as concentrações do IC50 e do IC50/2 acrescido de Y-27632 e a linhagem HT144 apresenta aumento deste parâmetro quando tratado com jaspamídeo e 200 <font face=\"Symbol\">mM de NSC23766. / Many signaling ways are involved in metastasis and the cellular migration and invasion are important in this context. The role of microfilaments is essential in mesenchymal and amoeboid migration. In this context, the present work aimed to analyze the effects of the drug jaspamide and. after the determination of the IC50 concentrations for the HT144 and NGM cell lines, the effects of the treatment with jaspamide were studied. The wound assays indicated a decrease in the free area after the treatments, and the migration assays with transwell showed that, after the inoculation with the drug, the cells increased the process of migration. In the invasion assays with Boydens chamber, the treatment with jaspamide was effective only in NGM cells, when they are treated with 75 nM of the drug plus 30 <font face=\"Symbol\">mM of Y-27632. Regarding the migration process, the NGM cell line did not show movement when treated with the IC50 concentration and the IC50/2 concentration plus Y-27632, and the HT144 cell line increases this parameter when treated with jaspamide and 200 <font face=\"Symbol\">mM of NSC23766.