Objective: To evaluate the anti-tumor and histone deacetylase (HDAC) inhibitory activity of the dietary isothiocyanate, sulforaphane (SFN) in the paediatric cancer,neuroblastoma (NB). Materials and Methods: NB cell line (NUB-7), fibroblasts (FLF; negative control) and MCF-7 (positive control), were treated with SFN for up to 7 days and effects on growth, cytotoxicity, differentiation and tumorigenicity assessed. HDAC inhibition was determined by histone (H3/ H4) acetylation. Results: 10 μM SFN significantly decreased in vitro growth and survival of NUB-7 to 10.22 ± 0.71% (p < 0.001) with no significant effect on FLF. SFN induced G1, G2 and S phase cell cycle arrests and stimulated H3/H4 histone acetylation. SFN markedly decreased NUB-7 clonogenicity and tumorigenicity in vivo. Conclusion: Results suggest that low dose SFN reduces proliferation, survival and tumorigenicity of NB NUB-7. As a dietary factor of negligible intrinsic toxicity SFN is a promising therapeutic agent for the treatment of NB.

Objective: To evaluate the anti-tumor and histone deacetylase (HDAC) inhibitory activity of the dietary isothiocyanate, sulforaphane (SFN) in the paediatric cancer,neuroblastoma (NB). Materials and Methods: NB cell line (NUB-7), fibroblasts (FLF; negative control) and MCF-7 (positive control), were treated with SFN for up to 7 days and effects on growth, cytotoxicity, differentiation and tumorigenicity assessed. HDAC inhibition was determined by histone (H3/ H4) acetylation. Results: 10 μM SFN significantly decreased in vitro growth and survival of NUB-7 to 10.22 ± 0.71% (p < 0.001) with no significant effect on FLF. SFN induced G1, G2 and S phase cell cycle arrests and stimulated H3/H4 histone acetylation. SFN markedly decreased NUB-7 clonogenicity and tumorigenicity in vivo. Conclusion: Results suggest that low dose SFN reduces proliferation, survival and tumorigenicity of NB NUB-7. As a dietary factor of negligible intrinsic toxicity SFN is a promising therapeutic agent for the treatment of NB.

Uma premissa da Biologia Molecular atual estabelece a ativação de programas de transcrição voltados a processos biológicos específicos. Neste trabalho o objetivo é descrever genes regulados que, uma vez agrupados, são capazes de indicar os programas disparados na linhagem corticoadrenal murina Y1 quando tratada com o fator de crescimento de fibroblasto 2 (FGF2) ou pelo hormônio adrenocorticotrópico (ACTH). O papel de ACTH em células Y1 ainda não está bem estabelecido quanto ao seu potencial mitogênico, uma vez que este hormônio é capaz de agir por diferentes vias de sinalização, apresentando um comportamento dual. Ao traçar o perfil de genes regulados por este hormônio, comparando com o padrão observado por tratamentos de indutores clássicos, espera-se determinar o papel de ACTH frente ao ciclo celular. FGF2 é classicamente conhecido por sua atividade mitogênica, de forma que, em células Y1, é capaz de induzir a passagem G0?G1?S do ciclo celular. Recentemente foi descrita uma nova e surpreendente ação de FGF2, como um indutor de morte seletivo, agindo apenas em células potencialmente tumorigênicas (Costa e Armelin, dados não publicados). Foram feitos estudos de expressão gênica com ensaios de microarray, observando-se o padrão de transcrição da linhagem Y1, bem como de sub-linhagens de Y1 resistentes a morte desencadeada por FGF2, submetidas a tratamentos de FGF2, ACTH e soro. Os resultados indicam que a) o padrão de expressão gênica observado quando a linhagem Y1 é submetida a tratamentos de ACTH é diferente daqueles desencadeados por mitógenos clássicos; b) o tratamento de FGF2 regula genes envolvidos na via de MAPK, controle do ciclo celular e genes relacionados a processos de adesão, comunicação intercelular e sinalização a partir da matriz extracelular (ECM); c) o comportamento de morte induzida por FGF2 está relacionado a alterações na estrutura da célula, envolvendo mecanismos de adesão, remodelagem de citoesqueleto e transdução de sinais a partir da ECM. / Nowadays, a molecular biology premise establishes the activation of transcription programs related to specific biological processes. At this work the objective is to describe regulated genes that, once clustered, are able to indicate the running programs when murine adrenocortical lineage Y1 is treated with fibroblast growth factor (FGF2) or by adrenocorticotropin hormone (ACTH). The mitogenic potential of ACTH treatments in Y1 cells is not well established since this hormone acts by different signaling pathways, presenting a dual behavior. By tracing the profile of genes regulated by this hormone and comparing it to the transcription patterns observed in response to classic mitogens it is expected to determine the ACTH role in the cell cycle. FGF2 is known by its mitogenic activity, inducting the G0? G1?S cell cycle transitions in Y1 cells. Recently it has been described a new and surprising feat of FGF2, acting as a selective death inductor, only in potentially tumorigenic cells (Costa and Armelin, unpublished data). Microarray assays were used to determine the transcription patterns observed in Y1 lineage, as well as in FGF2 death-resistant Y1 sub-lineages, submitted to FGF2, ACTH and serum treatments. The results indicate that a) the gene expression profile displayed when Y1 cells are under ACTH treatments is different from the patterns observed when this lineage is submitted to classic mitogens; b) FGF2 treatment regulates genes involved in the MAPK pathway, cell cycle control and genes related to adhesion processes, intercellular communication and signaling from the extra cellularmatrix (ECM); c) the death behavior initiated by FGF2 is related to structural alterations in the cell, involving adhesion mechanisms, citoskeleton remodeling and signal transduction from the ECM.

Uma premissa da Biologia Molecular atual estabelece a ativação de programas de transcrição voltados a processos biológicos específicos. Neste trabalho o objetivo é descrever genes regulados que, uma vez agrupados, são capazes de indicar os programas disparados na linhagem corticoadrenal murina Y1 quando tratada com o fator de crescimento de fibroblasto 2 (FGF2) ou pelo hormônio adrenocorticotrópico (ACTH). O papel de ACTH em células Y1 ainda não está bem estabelecido quanto ao seu potencial mitogênico, uma vez que este hormônio é capaz de agir por diferentes vias de sinalização, apresentando um comportamento dual. Ao traçar o perfil de genes regulados por este hormônio, comparando com o padrão observado por tratamentos de indutores clássicos, espera-se determinar o papel de ACTH frente ao ciclo celular. FGF2 é classicamente conhecido por sua atividade mitogênica, de forma que, em células Y1, é capaz de induzir a passagem G0?G1?S do ciclo celular. Recentemente foi descrita uma nova e surpreendente ação de FGF2, como um indutor de morte seletivo, agindo apenas em células potencialmente tumorigênicas (Costa e Armelin, dados não publicados). Foram feitos estudos de expressão gênica com ensaios de microarray, observando-se o padrão de transcrição da linhagem Y1, bem como de sub-linhagens de Y1 resistentes a morte desencadeada por FGF2, submetidas a tratamentos de FGF2, ACTH e soro. Os resultados indicam que a) o padrão de expressão gênica observado quando a linhagem Y1 é submetida a tratamentos de ACTH é diferente daqueles desencadeados por mitógenos clássicos; b) o tratamento de FGF2 regula genes envolvidos na via de MAPK, controle do ciclo celular e genes relacionados a processos de adesão, comunicação intercelular e sinalização a partir da matriz extracelular (ECM); c) o comportamento de morte induzida por FGF2 está relacionado a alterações na estrutura da célula, envolvendo mecanismos de adesão, remodelagem de citoesqueleto e transdução de sinais a partir da ECM. / Nowadays, a molecular biology premise establishes the activation of transcription programs related to specific biological processes. At this work the objective is to describe regulated genes that, once clustered, are able to indicate the running programs when murine adrenocortical lineage Y1 is treated with fibroblast growth factor (FGF2) or by adrenocorticotropin hormone (ACTH). The mitogenic potential of ACTH treatments in Y1 cells is not well established since this hormone acts by different signaling pathways, presenting a dual behavior. By tracing the profile of genes regulated by this hormone and comparing it to the transcription patterns observed in response to classic mitogens it is expected to determine the ACTH role in the cell cycle. FGF2 is known by its mitogenic activity, inducting the G0? G1?S cell cycle transitions in Y1 cells. Recently it has been described a new and surprising feat of FGF2, acting as a selective death inductor, only in potentially tumorigenic cells (Costa and Armelin, unpublished data). Microarray assays were used to determine the transcription patterns observed in Y1 lineage, as well as in FGF2 death-resistant Y1 sub-lineages, submitted to FGF2, ACTH and serum treatments. The results indicate that a) the gene expression profile displayed when Y1 cells are under ACTH treatments is different from the patterns observed when this lineage is submitted to classic mitogens; b) FGF2 treatment regulates genes involved in the MAPK pathway, cell cycle control and genes related to adhesion processes, intercellular communication and signaling from the extra cellularmatrix (ECM); c) the death behavior initiated by FGF2 is related to structural alterations in the cell, involving adhesion mechanisms, citoskeleton remodeling and signal transduction from the ECM.

Breast cancer is a world health problem and is a leading cause of cancer-related death among women in the United States. However, breast cancer risks were reported to be reduced through exposure to Vitamin D through its Receptors identified as the p53 target gene. The purpose of this study was to assess the associations between VDR gene polymorphisms knowledge/awareness and decisions to reduce breast cancer risks and likelihood of mammogram screening among women in Texas. Data from survey were used. Roy adaptation model was the theoretical framework that guided this quasi- experimental, quantitative research. The dependent variables were decisions to reduce breast cancer risks and likelihood of mammogram screening. The independent variables were knowledge about VDR gene polymorphisms and exposure to vitamin D. The covariates were level of education, awareness, lifestyle, breast self-exams, mammograms, age, early menarche, late menopause, and family history of breast cancer. The chi-square test and regression analysis were used to test the stated research hypotheses and to answer the research questions. Knowledge of VDR gene polymorphisms and exposure to vitamin D were not significantly associated with breast cancer risk, ï?£2 (3, N= 250) =3.84, p > 0.05. Also, awareness of the risk factors for breast cancer was not significantly associated with decisions to go for mammogram screenings or to enroll in breast cancer risk-reduction programs, ï?£2 (3, N= 250) =1.58, p > 0.05. To advocate for the promotion of awareness of the importance of pharmacogenetic testing for VDR gene polymorphisms for early detection of breast cancer, which would help to undertake appropriate therapeutic measures in a timely manner to prevent cancer metastasis, further research is warranted.

Insulin-like growth factor binding proteins (IGFBPs) modulate the bioavailability of IGFs in circulation. IGFBPs 1-6 bind IGFs with high affinity and can either potentiate or inhibit IGF signaling in a context dependent manner. IGFBP2 is a 36 kDa protein and the second most abundant IGFBP in serum. Numerous studies in the recent past have implied a pro-tumorigenic role of IGFBP2. Elevated expression of IGFBP2 has been observed in multiple malignancies, including glioblastoma multiforme (GBM), ovarian, pancreatic, gastric, prostate, colon, breast, thyroid cancer and leukemia. In addition, increased expression of IGFBP2 in both tissues and serum of patients has been correlated with poor prognosis in prostate, glioblastoma and colon cancers. Pro-tumorigenic actions of IGFBP2 have been supported by in vitro studies, where IGFBP2 increases the tumorigenic potential of adrenocortical tumor cells, epidermoid carcinoma cells, glioma cells and ovarian cancer cells. Further, using xenograft animal models, the role of IGFBP2 in the progression of glioma has been established. In breast cancer, IGFBP2 was found to be over expressed in ductal carcinoma in situ and invasive breast cancer samples. IGFBP2 over expression has been shown to confer drug resistance and an increased expression has been reported to correlate with lymph node metastasis in T1 breast carcinomas. These reports implicate IGFBP2 in breast cancer biology. However, its role in breast cancer progression is not well defined. With this background, the following objectives were set for the current study: Functional characterization of IGFBP2 with respect to its possible role in breast cancer progression. Elucidation of the molecular mechanisms of IGFBP2 actions. Towards this, immunohistochemistry was performed on 132 invasive ductal carcinoma (IDC) grade III tumors using IGFBP2 specific antibody. It was observed that IGFBP2 expression was significantly higher in tumors in comparison to normal tissues that showed no detectable staining for IGFBP2. It was also observed that expression of IGFBP2 significantly correlated with the expression of ER. To understand the functional significance of IGFBP2 over expression in breast cancer, IGFBP2 was characterized with respect to proliferation, survival and tumor forming ability (in vitro and in vivo) in BT474 breast cancer cells. The knockdown of IGFBP2 expression resulted in suppression of colony formation (nearly 70%) in these breast cancer cells, which could be partially reversed upon exogenous addition of IGFBP2 protein. Proliferation assays using stable clones with knockdown of IGFBP2 in BT474 cells showed a significant decrease in proliferation as compared to vector transfected cells in the presence of serum. Culturing of IGFBP2 knockdown breast cancer cells in serum free medium resulted in their growth arrest in G0/G1 phase of cell cycle as compared to control cells, which progressed through the cell cycle. Prolonged culturing of IGFBP2 knockdown cells in serum free condition (up to 72 h) resulted in the increase of cells in sub G1 phase of the cell cycle. Prolonged depletion of growth factors (serum free conditions) could result in apoptosis of these G1 arrested IGFBP2 knockdown cells. When serum starved IGFBP2 knockdown cells were treated with IGFBP2 protein, the cells arrested in G0/G1 phase were able to progress through the cell cycle and concomitant decrease in sub G1 fraction was observed. Knockdown of IGFBP2 resulted in significantly decreased number and visibly smaller colonies in anchorage independent conditions in vitro. Consistent with this observation, in vivo tumor xenograft formation with IGFBP2 knockdown cells also showed significant reduction in tumor weight as compared to vector generated tumors. These results imply that IGFBP2 has potent growth promoting effects on breast cancer and acts as a mitogen/survival factor for breast cancer cells. To elucidate the molecular mechanisms underlying the pro-tumorigenic effects of IGFBP2, the transcriptome profile following IGFBP2 perturbation in breast cancer cells was determined. IGFBP2 knockdown resulted in significant changes in the expression of genes associated with cellular proliferation and tumorigenicity. The down regulated genes were found to be associated with several events, notably cell cycle, p53 and Wnt signaling, as revealed by Gene Set Enrichment Analysis (GSEA). To further validate these results in breast cancer tissues, whole genome expression analysis was performed in 19 breast tumor samples which were categorized as IGFBP2 positive or negative based on immunohistochemical staining pattern. In comparison to IGFBP2 negative tumors, IGFBP2 positive tumors showed increased expression of genes belonging to MAPK, focal adhesion and Wnt signaling pathway. In order to identify the genes commonly regulated by IGFBP2 in cell lines and tumors, the gene expression profiles of IGFBP2 positive versus IGFBP2 negative tumors and IGFBP2 knockdown breast cancer cells were compared. 347 genes were found to be common among IGFBP2 regulated genes in tumors and cell line. The most significant networks representing the web of interactions among these genes were found to be associated with cellular growth and proliferation, cellular movement and nucleic acid metabolism, indicating an association of IGFBP2 expression phenotype to the distinct changes in expression of genes associated with the regulation of cellular growth and migration. Silencing of IGFBP2 in BT474 cells resulted in a reduced IGF signaling as evidenced by the reduced phosphorylation of IGF1R and concomitantly that of ERK. This effect could be reversed upon addition of the IGFBP2 protein, implying that IGFBP2 potentiates IGF signaling in breast cancer cells. Besides IGF ligand and their receptors, regulation of proliferation associated genes like CENPF, TOP2A, CCND1 and FOXM1 by IGFBP2 was observed, thus providing a molecular basis for the pro-proliferative effects of IGFBP2 on breast cancer cells. Addition of IGFBP2 to immortal breast cells resulted in reduced IGF1R signaling and reduced pERK and pAKT signaling. Additionally, the genes involved in cellular proliferation were down regulated upon IGFBP2 treatment in immortal cells. IGFBP2 knockdown clones had reduced expression of FOXM1, a key regulator of cell cycle for G1/S and G2/M transition, and M phase progression. The regulation of CENPF and CCND1 genes was established following over expression of FOXM1 in IGFBP2 knockdown cells. One of the important and novel finding of this study is the regulation of Wnt signaling pathway genes such as CCND1, MMP7, FGF18, MYCBP, FN1 and survivin by IGFBP2. In support of this, β-catenin protein was found to be regulated by IGFBP2 in breast cancer and GBM cells, as evidenced by knockdown and over expression studies. Furthermore, regulation of β-catenin by IGFBP2 was found to involve integrin-FAK and IGF1R signaling. Another important finding of this study is the correlation of IGFBP2 over expression with elevated β-catenin levels in breast tumors. When expression of both IGFBP2 and β-catenin was correlated with the lymph node status of breast cancers, a significant association of IGFBP2 and β-catenin staining with increased lymph node metastasis was observed in comparison with tumors that did not show staining for either protein. Altogether, in this study employing genomic, cellular and molecular approaches, a pro- tumorigenic role for IGFBP2 in breast cancer has been established. Furthermore, this study provides novel insights into the molecular mechanisms employed by IGFBP2 involving IGF1R, FAK and Wnt signaling pathways during breast cancer progression.

La reconnaissance de l’implication du système immunitaire dans le cancer a guidé l’industrie vers de développement d’immunothérapies nombreuses et prometteuses. Or, à l’ère de l’immuno-oncologie, on constate un manque criant de modèles précliniques capables de simuler les interactions immunitaires entre un patient et sa tumeur. Pour remédier à cette situation, nous avons développé des modèles de souris humanisées combinant la reconstitution immunitaire de souris immunodéficiente et l’injection de lignées tumorales issues d’un même donneur. L’utilisation de cellules souches pluripotentes induites (iPSC) a permis notamment le développement de multiples lignées tumorales à partir d’un seul donneur sain, facilitant ainsi l’accès aux cellules immunitaires nécessaires à l’humanisation des souris. La transformation des cellules primaires ou dérivées d’iPSC a été faite par la transduction lentivirale des proto-oncogènes de la télomérase (hTERT), de Ras oncogénique (HRASV12) et de la région précoce du viruse simen 40 (SV40ER) encodant les gros et petits antigènes T (LgT et SmT). Cette approche permis de générer des tumeurs de haut grade, agressives et peu différenciées à l’aide de fibroblastes primaires et de cellules hépatiques, de cellules souches neurales et d’astrocytes dérivés d’iPSC. Dans tous les cas, les tumeurs ainsi générées ont été efficacement reconnues, infiltrées et souvent rejetées par le système immunitaire autologue implanté. Le rejet partiel de la plupart de ces tumeurs ouvre toutefois la porte à l’évaluation préclinique d’immunothérapies diverses reposant sur les réactions immunitaires anti-tumorales de l’hôte. Par exemple, nous avons pu étudier l’impact d’un traitement d’inhibition du point de contrôle immunitaire PD-1 sur la croissance de tumeurs d’origine fibroblastique où une augmentation marquée du taux d’infiltration immunitaire humaine a été observé sans toutefois mener à une réduction significative du fardeau tumoral. Nous avons aussi pu produire, de façon autologue, des lymphocytes T exprimant un récepteur d’antigène chimérique (CAR) contre le ganglioside GD2, un antigène tumoral préalablement identifié et détecté sur les tumeurs de cellules souches neurales générées par notre approche. L’efficacité cytotoxique de ces CAR a ainsi pu être validée in vitro dans un système autologue. Finalement, nous avons utilisé le modèle de tumeurs fibroblastiques dans des contextes immunitaires autologues et allogéniques pour déterminer si le potentiel immunomodulateur des cellules stromales mésenchymateuses (MSC) pouvait affecter la croissance tumorale. Selon nos résultats, les MSC n’auraient aucun effet ni sur le taux d’émergence et de croissance tumoral, ni sur l’infiltrat immunitaire, suggérant que leur utilisation thérapeutique serait sécuritaire en ce qui concerne ce type de tumeurs ayant préalablement un microenvironnement tumoral immunosuppresseur. En somme, les modèles innovateurs décrits dans cette thèse visent à améliorer la qualité prédictive des modèles murins précliniques en immuno-oncologie en récapitulant certaines interactions immunitaires entre un patient et sa tumeur. La grande flexibilité de cette approche permettra d’adapter aisément le modèle aux problématiques d’intérêt, tant fondamentales que précliniques. / Identification of the human’s immune system implication in cancer has guided the biotech industry towards the development of numerous and promising cancer immunotherapies. However, in the era of immuno-oncology, a distinct lack preclinical models can simulate the interactions between a patient’s tumor and immune cells. To tackle this issue, we developed humanized mouse models combining immune reconstitution of immunodeficient mice and injection of tumor cells lines from the same human donor. The use of induced pluripotent stem cells (iPSC) allowed the generation of multiple tumorigenic cell lines from a single donor, facilitating access to autologous immune cells necessary for mouse immune humanization. The transformation of primary or iPSC-derived cell lines was done using lentiviral transduction of proto-oncogenes telomerase (hTERT), oncogenic Ras (HRASV12) and simian virus 40 early region (SV40ER) encoding large and small T antigens (LgT and SmT). This approach allowed to generate high grade, aggressive and undifferentiated tumors from primary fibroblasts and iPSC-derived hepatic cells, neural stem cells and astrocytes. In all cases, such tumors were efficiently recognized, infiltrated and often rejected by the implanted autologous immune system. However, partial rejection of most tumors allows for preclinical evaluation of targeted immunotherapies relying on the hosts’ pre-existing immune response. For instance, we could study the impact of PD-1 checkpoint blockade inhibition on tumor growth in fibroblastic tumors where a significant increase in tumor infiltration was observed, but without an associated decrease in tumor burden. We could also produce autologous chimeric antigen receptor (CAR)-expressing T lymphocytes against GD2 ganglioside, a previously described tumor antigen detected on our neural stem cell-derived tumor cells. Cytotoxic efficiency of these autologous CAR T cells could thus be validated in vitro. Finally, we used our fibroblast-derived tumor models in autologous and allogeneic settings to determine if mesenchymal stem cells’ (MSC) immunomodulatory potential could impact tumor growth. Our results showed that MSC had no effect neither on tumor emergence and growth nor on immune infiltration, suggesting therapeutic use of these cells should be safe regarding such tumors already harboring a strongly immunodeficient microenvironment. Overall, the novel models described in this thesis aim at improving the predictive capacity of mouse pre-clinical models in immuno-oncology by recapitulating some immune interactions between a patient and its tumor. The great flexibility of this approach will allow for easy adaptation to many research problematics both preclinical and fundamental.

Le cancer épithélial de l’ovaire (CÉO) est le cancer gynécologique le plus létal. Le CÉO de type séreux, la forme la plus commune avec plus de 50% des cas, est souvent diagnostiqué tardivement et associé à un mauvais pronostic. Le CÉO avancé, surtout traité par chimiothérapie, va devenir chimiorésistant chez la majorité des patientes traitées. Bien que des lignées cellulaires du CÉO aient été dérivées à partir de tumeurs solides et d’ascites de patientes ayant ou non subi une chimiothérapie, aucune des lignées cellulaires du CÉO provenant d’une même patiente avant et après ses traitements de chimiothérapie n’ont été établies précédemment. Notre laboratoire est le premier à développer de telles lignées cellulaires. Nos nouvelles lignées cellulaires sont dérivées de trois patientes différentes (1369, 2295 et 3133) et classées selon leur provenance, soit la tumeur solide (TOV) ou l’ascite (OV). Nous avons donc caractérisé ces nouvelles lignées de cellules pré-chimiothérapie (TOV1369TR, OV2295, TOV3133D et TOV3133G) et post-chimiothérapie (OV1369(2), OV2295(2), TOV2295, OV3133 et OV3133(2)) par diverses approches. Par immunohistochimie et immunobuvardage de type Western, nous avons caractérisé les niveaux d’expression de marqueurs épithéliaux typiques de kératines (KRT7, KRT8, KRT18, KRT19, KRT20) pour confirmer l’origine épithéliale et ovarienne des cellules. Nous avons également analysé le niveau d’expression de HER2 et p53, deux marqueurs importants dans le CÉO. Cependant, il ne semble pas y avoir d’expression différentielle évidente de ces marqueurs entre les lignées pré-chimiothérapie et post-chimiothérapie. Plus encore, nous avons étudié plusieurs caractéristiques tumorigéniques des lignées cellulaires, dont la prolifération cellulaire (par compte cellulaire), la migration cellulaire (par recouvrement de plaie), la capacité à former des sphéroïdes en 3D (par la méthode des gouttelettes inversées), et la formation de tumeurs in vivo dans des souris SCID (xénogreffes sous-cutanées). En général, il ne semble pas y avoir de différences claires entre les cellules pré-chimiothérapie et post-chimiothérapie au niveau du comportement cellulaire, à l’exception du fait qu’aucune des lignées post-chimiothérapie semblent être en mesure de former des structures tridimensionnelles compactes, contrairement à certaines lignées post-chimiothérapie. Nos résultats pourront servir à mieux comprendre les différents mécanismes régissant les tumeurs malignes du CÉO de type séreux et à mieux comprendre la progression de la maladie à travers les différents traitements, ce qui nous permettra d’acquérir des informations essentielles pour mieux évaluer et traiter différentes patientes. / Epithelial ovarian cancer (EOC) is the deadliest of all gynecologic cancers. The serous type of EOC is the most common form of the disease, and it accounts for more than 50% of the cases. It is often diagnosed at advanced stages where its prognosis is poor. Advanced EOC is treated mainly with chemotherapy. However, chemoresistance development eventually impedes the success of the treatments for most patients. Researchers have derived cell lines from EOC from solid tumors or from ascites. So far, there has not been EOC cell lines established from samples taken before and after chemotherapy treatments within the same patient. Our laboratory is thus the first to develop a new and powerful model of pre-chemotherapy and post-chemotherapy cell lines. All cell lines were derived sequentially from 3 different patients (1369, 2295 and 3133), from either solid tumors (TOV) or ascites (OV). We therefore characterized these new pre-chemotherapy cell lines (TOV1369TR, OV2295, TOV3133D and TOV3133G) and post-chemotherapy cell lines (OV1369(2), OV2295(2), TOV2295, OV3133 and OV3133(2)) through several approaches. Using immunohistochemistry and Western blot, we have characterized the level of expression of typical epithelial keratin markers (KRT7, KRT8, KRT18, KRT19, KRT20) to confirm the epithelial and ovarian nature of the cells. We have also analysed the expression level of important EOC markers, such as that of HER2 and p53, and found no clear difference between the pre-chemotherapy and post-chemotherapy EOC cells. Moreover, we have studied various tumorigenic features of the cell lines, such as cell proliferation (by cell count), cell migration (by the wound healing assay), 3D spheroid formation (by the hanging drop method), in vivo tumor formation in SCID mice (subcutaneous xenografts). In general, there were no notable differences between the two categories of cell lines at the cellular level, except that post-chemotherapy cell lines seemed to be unable to form compact 3D structures, contrary to some pre-chemotherapy cell lines. The obtained results would aid in better understanding the different mechanisms that malignant serous EOC tumors undergo and the progression of the disease with respect to the different treatments. Such study would allow us to gain valuable insight into the optimal treatment decisions to take for different EOC patients.

Le cancer épithélial de l’ovaire (CÉO) est le cancer gynécologique le plus létal. Le CÉO de type séreux, la forme la plus commune avec plus de 50% des cas, est souvent diagnostiqué tardivement et associé à un mauvais pronostic. Le CÉO avancé, surtout traité par chimiothérapie, va devenir chimiorésistant chez la majorité des patientes traitées. Bien que des lignées cellulaires du CÉO aient été dérivées à partir de tumeurs solides et d’ascites de patientes ayant ou non subi une chimiothérapie, aucune des lignées cellulaires du CÉO provenant d’une même patiente avant et après ses traitements de chimiothérapie n’ont été établies précédemment. Notre laboratoire est le premier à développer de telles lignées cellulaires. Nos nouvelles lignées cellulaires sont dérivées de trois patientes différentes (1369, 2295 et 3133) et classées selon leur provenance, soit la tumeur solide (TOV) ou l’ascite (OV). Nous avons donc caractérisé ces nouvelles lignées de cellules pré-chimiothérapie (TOV1369TR, OV2295, TOV3133D et TOV3133G) et post-chimiothérapie (OV1369(2), OV2295(2), TOV2295, OV3133 et OV3133(2)) par diverses approches. Par immunohistochimie et immunobuvardage de type Western, nous avons caractérisé les niveaux d’expression de marqueurs épithéliaux typiques de kératines (KRT7, KRT8, KRT18, KRT19, KRT20) pour confirmer l’origine épithéliale et ovarienne des cellules. Nous avons également analysé le niveau d’expression de HER2 et p53, deux marqueurs importants dans le CÉO. Cependant, il ne semble pas y avoir d’expression différentielle évidente de ces marqueurs entre les lignées pré-chimiothérapie et post-chimiothérapie. Plus encore, nous avons étudié plusieurs caractéristiques tumorigéniques des lignées cellulaires, dont la prolifération cellulaire (par compte cellulaire), la migration cellulaire (par recouvrement de plaie), la capacité à former des sphéroïdes en 3D (par la méthode des gouttelettes inversées), et la formation de tumeurs in vivo dans des souris SCID (xénogreffes sous-cutanées). En général, il ne semble pas y avoir de différences claires entre les cellules pré-chimiothérapie et post-chimiothérapie au niveau du comportement cellulaire, à l’exception du fait qu’aucune des lignées post-chimiothérapie semblent être en mesure de former des structures tridimensionnelles compactes, contrairement à certaines lignées post-chimiothérapie. Nos résultats pourront servir à mieux comprendre les différents mécanismes régissant les tumeurs malignes du CÉO de type séreux et à mieux comprendre la progression de la maladie à travers les différents traitements, ce qui nous permettra d’acquérir des informations essentielles pour mieux évaluer et traiter différentes patientes. / Epithelial ovarian cancer (EOC) is the deadliest of all gynecologic cancers. The serous type of EOC is the most common form of the disease, and it accounts for more than 50% of the cases. It is often diagnosed at advanced stages where its prognosis is poor. Advanced EOC is treated mainly with chemotherapy. However, chemoresistance development eventually impedes the success of the treatments for most patients. Researchers have derived cell lines from EOC from solid tumors or from ascites. So far, there has not been EOC cell lines established from samples taken before and after chemotherapy treatments within the same patient. Our laboratory is thus the first to develop a new and powerful model of pre-chemotherapy and post-chemotherapy cell lines. All cell lines were derived sequentially from 3 different patients (1369, 2295 and 3133), from either solid tumors (TOV) or ascites (OV). We therefore characterized these new pre-chemotherapy cell lines (TOV1369TR, OV2295, TOV3133D and TOV3133G) and post-chemotherapy cell lines (OV1369(2), OV2295(2), TOV2295, OV3133 and OV3133(2)) through several approaches. Using immunohistochemistry and Western blot, we have characterized the level of expression of typical epithelial keratin markers (KRT7, KRT8, KRT18, KRT19, KRT20) to confirm the epithelial and ovarian nature of the cells. We have also analysed the expression level of important EOC markers, such as that of HER2 and p53, and found no clear difference between the pre-chemotherapy and post-chemotherapy EOC cells. Moreover, we have studied various tumorigenic features of the cell lines, such as cell proliferation (by cell count), cell migration (by the wound healing assay), 3D spheroid formation (by the hanging drop method), in vivo tumor formation in SCID mice (subcutaneous xenografts). In general, there were no notable differences between the two categories of cell lines at the cellular level, except that post-chemotherapy cell lines seemed to be unable to form compact 3D structures, contrary to some pre-chemotherapy cell lines. The obtained results would aid in better understanding the different mechanisms that malignant serous EOC tumors undergo and the progression of the disease with respect to the different treatments. Such study would allow us to gain valuable insight into the optimal treatment decisions to take for different EOC patients.