Chemotherapy resistance in human epithelial ovarian cancer (EOC) is a significant reason for the high rate of death among patients. We hypothesized that chemotherapy- resistant EOC cells will be killed by novel drug treatments in non-adherent culture conditions. The objective of this study was to test the efficacy of novel drugs to affect platinum resistant EOC cell viability. To achieve this, the cell killing efficacy of several drugs were tested on drug-resistant EOCs growing in non-adherent cultures. Both EOC cell lines and primary EOC cells isolated from patient ascites were used for these studies. Two different classes of drugs were tested including multikinase inhibitors (dorsomorphin and LDN-193189), and an understudied class of novel chemotherapeutic agents called glycosylated antitumor ether lipids (GAELs). EOC cells were treated with the drugs at different doses alone or in combination with cisplatin. Because GAELs exhibited promising results in resistant EOC cells, the mechanism of GAEL-induced cell-death was evaluated. / October 2016

Resumo: O câncer epitelial do ovário representa um desafio à Oncologia Ginecológica devido ao seu caráter insidioso e alta letalidade. Evidências apontam para o conceito de que o sistema imunológico interage com o tumor em desenvolvimento e pode ser responsável pelo controle do crescimento e regressão tumoral. A resposta imune adaptativa no ambiente tumoral, inclui a imunidade humoral composta de anticorpos produzidos pelas células B e da imunidade celular composta de células T CD4+ e células T CD8+. Este estudo visa avaliar a resposta imune adaptativa sérica em mulheres com neoplasia ovariana. Foram analisadas amostras de sangue periférico obtidas de mulheres hígidas (n=10 - grupo controle), com tumor benigno de ovário (n=9) e com câncer de ovário (n=17). As amostras foram avaliadas pela técnica de citometria de fluxo, onde utilizou-se 5 parâmetros: tamanho celular , complexidade interna e três fluorescências: FITC, PE e TC. O painel de anticorpos monoclonais incluiu os marcadores: CD4, CD8, HLA-DR, CD54, CD62L, CD18, CCR2, CXCR4, CCR5, CCR3, CXCR3, CD25, CD5, CD69, CD19, CD23, e controle isotípico. As diferenças entre os grupos foram avaliadas pelo teste de Mann-Whitney ou Kruskal-Walis conforme indicados. As diferenças com valor de p<0,05 foram consideradas significativas. Houve uma diminuição estatisticamente significativa (p<0,05) da porcentagem de células T do grupo de mulheres com câncer de ovário quando comparado ao grupo controle. A análise dos resultados mostrou que o percentual de linfócitos T CD4+ apresentou diferenças significativas entre os grupos (p=0,0399). Entretanto a população de linfócitos T CD8+ não apresentou diferenças significativas (p=0,2939). A análise de percentual de linfócitos B (CD19+) identificou diferença significativa na comparação entre os três grupos avaliados (p=0,0463). Foi observado uma diminuição do percentual... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Introduction: The epithelial ovarian cancer represents a challenge to Gynecologic Oncology due to its insidious nature and high fatality. Evidences show that the immune system interacts with the tumor development and may be responsible for growth control and tumor regression. The adaptive immune response in the tumor environment, includes antibodies produced by B cells and cellular immunity consisting of CD4 + and CD8 + T cells. This study aims to evaluate the adaptive immune response in peripheral blood of women with ovarian cancer. Methods:. We analyzed peripheral blood samples obtained from healthy women (n = 10 - control group) with benign ovarian tumor (n = 9) and ovarian cancer (n = 17). The samples were evaluated by the technique of flow cytometry, where we used 5 parameters: cell size, internal complexity and three fluorescence: FITC, PE and TC. The panel of monoclonal antibodies included markers: CD4, CD8, HLA-DR, CD54, CD62L, CD18, CCR2, CXCR4, CCR5, CCR3, CXCR3, CD25, CD5, CD69, CD19, CD23, and isotype control. Differences between groups were evaluated by the Mann-Whitney or Kruskal- Wallis tests. Differences with p <0.05 were considered significant.Results: There was a significant decrease (p <0.05) of the percentage of T cells in the group of women with ovarian cancer when compared to the control group. The results showed that the percentage of CD4 + T cells showed significant differences between the groups (p = 0.0399). However the population of CD8+ T cells did not show significant differences (p = 0.2939). The analysis of the percentage of B lymphocytes (CD19+) identified a significant difference between the three study groups (p = 0.0463). We observed a decrease in the percentage of B cells of groups of women with benign tumor and ovarian cancer in the control group. Among the adhesion molecules tested... (Complete abstract click electronic access below) / Orientador: Agnaldo Lopes da Silva Filho / Coorientador: Andréa Teixeira de Carvalho / Banca: Paulo Traiman / Banca: Luciana Maria Silva / Mestre

Made available in DSpace on 2014-06-11T19:29:51Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-02-26Bitstream added on 2014-06-13T20:39:42Z : No. of bitstreams: 1 freitas_gf_me_botfm.pdf: 572966 bytes, checksum: 78f32ce23035c30197d379a64992ac2f (MD5) / O câncer epitelial do ovário representa um desafio à Oncologia Ginecológica devido ao seu caráter insidioso e alta letalidade. Evidências apontam para o conceito de que o sistema imunológico interage com o tumor em desenvolvimento e pode ser responsável pelo controle do crescimento e regressão tumoral. A resposta imune adaptativa no ambiente tumoral, inclui a imunidade humoral composta de anticorpos produzidos pelas células B e da imunidade celular composta de células T CD4+ e células T CD8+. Este estudo visa avaliar a resposta imune adaptativa sérica em mulheres com neoplasia ovariana. Foram analisadas amostras de sangue periférico obtidas de mulheres hígidas (n=10 – grupo controle), com tumor benigno de ovário (n=9) e com câncer de ovário (n=17). As amostras foram avaliadas pela técnica de citometria de fluxo, onde utilizou-se 5 parâmetros: tamanho celular , complexidade interna e três fluorescências: FITC, PE e TC. O painel de anticorpos monoclonais incluiu os marcadores: CD4, CD8, HLA-DR, CD54, CD62L, CD18, CCR2, CXCR4, CCR5, CCR3, CXCR3, CD25, CD5, CD69, CD19, CD23, e controle isotípico. As diferenças entre os grupos foram avaliadas pelo teste de Mann-Whitney ou Kruskal-Walis conforme indicados. As diferenças com valor de p<0,05 foram consideradas significativas. Houve uma diminuição estatisticamente significativa (p<0,05) da porcentagem de células T do grupo de mulheres com câncer de ovário quando comparado ao grupo controle. A análise dos resultados mostrou que o percentual de linfócitos T CD4+ apresentou diferenças significativas entre os grupos (p=0,0399). Entretanto a população de linfócitos T CD8+ não apresentou diferenças significativas (p=0,2939). A análise de percentual de linfócitos B (CD19+) identificou diferença significativa na comparação entre os três grupos avaliados (p=0,0463). Foi observado uma diminuição do percentual... / Introduction: The epithelial ovarian cancer represents a challenge to Gynecologic Oncology due to its insidious nature and high fatality. Evidences show that the immune system interacts with the tumor development and may be responsible for growth control and tumor regression. The adaptive immune response in the tumor environment, includes antibodies produced by B cells and cellular immunity consisting of CD4 + and CD8 + T cells. This study aims to evaluate the adaptive immune response in peripheral blood of women with ovarian cancer. Methods:. We analyzed peripheral blood samples obtained from healthy women (n = 10 - control group) with benign ovarian tumor (n = 9) and ovarian cancer (n = 17). The samples were evaluated by the technique of flow cytometry, where we used 5 parameters: cell size, internal complexity and three fluorescence: FITC, PE and TC. The panel of monoclonal antibodies included markers: CD4, CD8, HLA-DR, CD54, CD62L, CD18, CCR2, CXCR4, CCR5, CCR3, CXCR3, CD25, CD5, CD69, CD19, CD23, and isotype control. Differences between groups were evaluated by the Mann-Whitney or Kruskal- Wallis tests. Differences with p <0.05 were considered significant.Results: There was a significant decrease (p <0.05) of the percentage of T cells in the group of women with ovarian cancer when compared to the control group. The results showed that the percentage of CD4 + T cells showed significant differences between the groups (p = 0.0399). However the population of CD8+ T cells did not show significant differences (p = 0.2939). The analysis of the percentage of B lymphocytes (CD19+) identified a significant difference between the three study groups (p = 0.0463). We observed a decrease in the percentage of B cells of groups of women with benign tumor and ovarian cancer in the control group. Among the adhesion molecules tested... (Complete abstract click electronic access below)

Yes / Background: Epithelial ovarian cancer is a common malignancy, with no clinically approved diagnostic biomarker. Engrailed-2 (EN2) is a homeodomain-containing transcription factor, essential during embryological neural development, which is dysregulated in several cancer types. We evaluated the expression of EN2 in Epithelial ovarian cancer, and reviewed its role as a biomarker. Methods: We evaluated 8 Epithelial ovarian cancer cell lines, along with > 100 surgical specimens from the Royal Surrey County Hospital (2009–2014). In total, 108 tumours and 5 normal tissue specimens were collected. En2 mRNA was evaluated by semi-quantitative RT-PCR. Histological sub-type, and platinum-sensitive/−resistant status were compared. Protein expression was assessed in cell lines (immunofluorescence), and in > 150 tumours (immunohistochemistry). Results: En2 mRNA expression was elevated in serous ovarian tumours compared with normal ovary (p < 0.001), particularly in high-grade serous ovarian cancer (p < 0.0001) and in platinum-resistant tumours (p = 0.0232). Median Overall Survival and Progression-free Survival were reduced with high En2 expression (OS = 28 vs 42 months, p = 0.0329; PFS = 8 vs 27 months; p = 0.0004). Positive cytoplasmic EN2 staining was demonstrated in 78% of Epithelial ovarian cancers, with absence in normal ovary. EN2 positive high-grade serous ovarian cancer patients had a shorter PFS (10 vs 17.5 months; p = 0.0103). Conclusion: The EN2 transcription factor is a novel ovarian cancer biomarker. It demonstrates prognostic value, correlating with worse Overall Survival and Progression-free Survival. It is hoped that further work will validate its use as a biomarker, and provide insight into the role of EN2 in the development, progression and spread of ovarian cancer. / Oncology Research and Development Departments at the Royal Surrey County Hospital and the University of Surrey

The human ovarian surface epithelium (hOSE) is a cell monolayer that covers the surface of the ovary. Natural events like incessant ovulation, associated reproductive hormone action prior to and post-ovulation, along with the ovulationassociated inflammation, that result in injury and repair of hOSE, are considered to have a role in the development of epithelial ovarian cancer (EOC). Progesterone is apoptotic and anti-inflammatory, whereas androgens appear cytoproliferative for hOSE. Local generation of these steroid hormones is subject to 3β-hydroxysteroid dehydrogenase (3β-HSD) activity. Moreover, action of these hormones is achieved through coupling to their cognate receptors, progesterone (PR) and androgen receptors (AR). The overall aim of this thesis is to elucidate in vitro the regulation of progesterone and androgen biosynthesis and downstream signalling during the injury and repair of primary hOSE cells that were collected from pre-menopausal women who underwent surgery for benign gynaecological disorders. Injury was mimicked by treatment of cells with several pro-inflammatory cytokines, whereas repair was mimicked with T-lymphocyte, ‘anti-inflammatory’ cytokines. Immunohistochemical studies showed immunodetectable 3β-HSD in the human ovarian cell surface of whole ovary and three-week cultured hOSE cells, establishing 3β-HSD expression in vivo and in vitro. Cross-reaction of the 3β-HSD antibody with both enzyme isoforms did not allow investigation of isoform expression pattern. However, mRNA transcriptional studies with isoform specific primers and probe sets for semi-quantitative (sq) and quantitative (q) PCR revealed expression of both isoforms in hOSE cells; 3β-HSD1 mRNA was expressed at higher levels relative to 3β-HSD2 mRNA in accordance with the preference of this isoform in peripheral non-steroidogenic tissues. Of the cytokines tested, only IL-1α and IL-4 affected 3β-HSD expression. IL- 1α suppressed 3β-HSD1 mRNA, whereas it up-regulated 3β-HSD2 mRNA as assessed with qPCR, without though affecting total 3β-HSD protein and activity levels as assessed with western immunoblotting and radiometric activity assays, respectively. IL-1α did not affect AR or PR mRNA levels, suggesting a balance in androgen and progesterone biosynthesis during post-ovulatory wounding. IL-4 massively induced 3β-HSD1 and 3β-HSD2 mRNA and total 3β-HSD protein and activity. It also attenuated AR mRNA and protein, without affecting PR mRNA. Collectively, these data demonstrate that IL-4 sustains progesterone rather than androgen signalling and this may be part of the anti-inflammatory steroid action that protects hOSE from genetic damage. IL-1α effects appear to be mediated by NF-κB signalling pathway. PI-3K and p38 MAPK appeared involved in IL-1α-induced 3β- HSD2. IL-4-induced 3β-HSDs required STAT-6 and PI-3K pathways and also p38 MAPK at the case of 3β-HSD2. IL-4-attenuated AR was reversed by a p38 MAPK inhibitor. These data suggest that steroid signalling by IL-1α and IL-4 involve multiple signalling pathways. In primary EOC, 3β-HSD1 and 3β-HSD2 transcripts were attenuated relative to hOSE cells, suggestive of an acquired feature of neoplastic transformation. However, both transcripts could be restored after IL-4 treatment, attesting a therapeutic advantage of this cytokine. In conclusion, we have shown that 3β-HSD is under inflammatory control during ovarian post-ovulatory wound healing of hOSE. IL-1α- and IL-4-mediated 3β-HSD1 and 3β-HSD2 are regulated by multiple signalling pathways. Also, IL-4 was identified as an anti-inflammatory agent in hOSE with putative therapeutic benefit in malignancy.

Epithelial ovarian cancer frequently metastasizes to the omentum, a process that requires pro-angiogenic activation of local microvascular endothelial cells (ECs) by tumour-secreted factors. We have previously shown that ovarian cancer cells secrete factors, other than vascular endothelial growth factor (VEGF), with possible roles in metastatic angiogenesis including the lysosomal proteases cathepsin L (CathL) and cathepsin D (CathD), and insulin-like growth factor binding protein 7 (IGFBP7). However, the mechanisms by which these factors may contribute to omental endothelial angiogenic changes are unknown. Therefore the aims of this thesis were a) to examine disease relevant human omental microvascular endothelial cell (HOMEC) proliferation, migration and angiogenesis tube-formation induced by CathL, CathD and IGFBP7; b) to investigate whether CathL and CathD act via a proteolytic or non-proteolytic mechanism; c) to identify activated downstream intracellular signalling cascades in HOMECs and their activation in proliferation and migration; and finally d) to identify activated cell surface receptors by these factors. CathL, CathD and IGFBP7 significantly induced proliferation and migration in HOMECs, with CathL and CathD acting in a non-proteolytic manner. Proteome-profiler and ELISA data identified increased phosphorylation of the ERK1/2 and AKT (protein kinase B) pathways in HOMECs in response to these factors. CathL induced HOMEC proliferation and migration via the ERK1/2 pathway, whereas, although CathD-induced proliferation was mediated by activation of ERK1/2, its migratory effect was dependent on both ERK1/2 and AKT pathways. Interestingly, CathL induced secretion of galectin-1 (Gal1) from HOMECs which in turn significantly induced HOMEC proliferation via ERK1/2. However, none of the ERK1/2 or AKT pathways was observed to be active in Gal1-induced HOMEC migration. Interestingly, Gal1-induced proliferation and migration were significantly inhibited by L-glucose, suggesting a role for a receptor with extracellular sugar moieties. IGFBP7-induced migration was shown to be mediated via activation of the ERK1/2 pathway only. CathL, Gal1 and IGFBP7 significantly induced angiogenesis tube-formation in HOMECs which was not observed in CathD-treated cells. Receptor tyrosine kinase array revealed activation of Tie-1 and VEGF receptor type 2 (VEGFR2) in CathL and IGFBP7-treated HOMECs respectively. In conclusion, all CathL, CathD, Gal1 and IGFBP7 have the potential to act as proangiogenic factors in the metastasis of ovarian cancer to the omentum. These in vitro data suggest all four factors activate intracellular pathways which are involved in well-known angiogenesis models.

Background: The aim of this thesis was to study the relationship of pre-diagnostic circulating concentrations of sex steroid hormones (androgens, estradiol, 17-hydroxyprogesterone, and progesterone), growth factors (insulin-like growth factor-I (IGF-I), placental growth hormone (GH)), sex hormone binding globulin (SHBG), and anti-Müllerian hormone (AMH) with risk of epithelial ovarian cancer (EOC) overall, and by tumor invasiveness and histology. A longitudinal study was used to assess patterns of hormonal changes during a single pregnancy, and in two consecutive pregnancies. Materials &amp; Methods: A case-control study was nested within the Finnish Maternity Cohort and the Northern Sweden Maternity Cohort. A total of 1 052 EOC cases were identified through linkages with the cancer registries in both countries. For each case, 2-3 controls were selected. Cases and controls were matched on cohort, age and date at blood draw, as well as for parity at blood draw and at diagnosis (n=2 695). Odds ratios (OR) and corresponding 95% confidence intervals [CI] were estimated using conditional logistic regression. The longitudinal study was based on 71 pregnant Finnish women, who donated blood samples in each trimester of pregnancy. Results: Higher androgen concentrations were associated with an increased risk of overall EOC (e.g., testosterone ORT3 vs. T1: 1.56 [1.30-1.87], ptrend&lt;0.0001), while the risk of endometrioid tumors increased with higher estradiol concentrations (ORT3 vs. T1: 2.76 [1.04-7.33], ptrend=0.03). Higher IGF-I was associated with a non-significant decrease in risk for invasive (ORT3 vs. T1: 0.79 [0.62-1.02], ptrend=0.07) and endometrioid tumors (ORT3 vs. T1: 0.55 [0.28-1.07], ptrend=0.07). The inverse association between IGF-I levels and risk of invasive EOC was stronger in analyses limited to women aged &lt;55 years at diagnosis (ORT3 vs. T1: 0.74 [0.57-0.96], ptrend=0.03). No associations were observed between pre-diagnostic progesterone, SHBG, placental GH, and AMH with EOC risk overall, or by tumor invasiveness and histology. The longitudinal study showed that hormone concentrations were more strongly correlated between consecutive trimesters of a pregnancy than between the 1st and 3rd trimesters. Further, 3rd trimester hormone concentrations can be estimated from 1st or 2nd trimester measurements. Conclusion: Higher pre-diagnostic androgens, estradiol, and IGF-I are associated with EOC risk, and associations differ by tumor invasiveness and histology.

Ovarian cancer is the fifth leading cause of cancer death in women between the ages of 35 and 74. With 22 thousand new cases and 15 thousand deaths annually ovarian cancer is among the most deadly cancers with a death to incidence ratio of 68%. With 70% of cases High Grade Serous Ovarian Carcinoma (HGSOC) is the most common type of ovarian cancer and causes 90% of ovarian cancer deaths. 80% of patients have reoccurrence within five years and only 15-30% of patients with recurrent metastatic ovarian cancer respond to current therapies, chemotherapy and surgery. One reason for the high reoccurrence rate is thought to be linked to the heterogeneity of tumors: there is evidence that, among tumor cells, a subpopulation is cancer stem cells (CSCs). Since CSCs are frequently drug resistant, when the patient undergoes chemotherapy many of the cells may die but the CSCs are left behind and the tumors can therefore regrow. CSCs are also more likely to undergo epithelial-mesenchymal transition which gives these cells the ability to more readily migrate and invade through the extracellular matrix, leaving the primary tumor to form metastases. One key inducer of EMT and therefore possibly of metastasis of particular interest in this project is SNAI1 (Snail). It is therefore the goal of this project to understand the growth, makeup and metastatic ability of HGSOC cell lines to test possible strategies to decrease growth of cancer and prevent metastasis. In this thesis project the phenotype, CSC population make up, and functionality of various HGSOC cell lines was examined. The cell lines assessed were A2780, Kuramochi, OVSAHO, COV318, SKOV3 and OVCAR8. A Snail knockdown OVCAR8 cell line was also assessed as described above and in a xenograft model. It was determined that the cell lines show varying phenotype from epithelial like to mesenchymal like morphology and the cell lines have varying concentrations of cancer stem cells. It was also determined that the CSC population of the HGSOC cell lines were positive for both epithelial and mesenchymal markers in the same cells. OVCAR8 stood out as a hybrid line with both epithelial and mesenchymal characteristics and was therefore chosen for the Snail knockdown model. In the Snail knockdown we observed that CSC markers were reduced, however no change between control and knockdown was seen in the in vitro functional experiments. There was a difference seen between Snail knockdown and control in the in vivo mouse xenograft model. Snail knockdown showed a trend for decreasing tumor burden in both primary and metastatic tumors and showed a significant decrease in growth of metastatic tumor at day 43. Based on these results Snail may be an important target for cancer therapy.

Le cancer épithélial de l’ovaire (CEO) est une cause majeure de mortalité parcancer gynécologique. Il est associé à un mauvais pronostic car il est souventdécouvert à un stade tardif. Mieux comprendre les causes et les mécanismesmoléculaires et cellulaires associés à la progression de ce cancer représente unenjeu majeur.Les deux chimiokines CXCL12/SDF-1 et fractalkine (FKN)/CX3CL1 ont étéimpliquées dans diverses tumeurs. La chimiokine SDF-1, a un effetimmunosuppresseur dans le CEO. Elle est aussi impliquée dans l’angiogenèsetumorale. L’effet de SDF-1 médié par CXCR4 est également impliqué dans larégulation de la prolifération, la survie, la migration et l'invasion des cellulescancéreuses. La FKN, a largement été mise en évidence dans les tissusépithéliaux et dans divers cancers où elle peut avoir soit un rôle anti-tumoral soitun rôle pro-tumoral. Jusqu’à présent la FKN n’a pas été étudié dans le CEO.Dans notre étude, nous avons démontré l’expression de SDF-1 et de la FKNdans l’épithélium de surface de l’ovaire sain et dans les tumeurs bénignes etmalignes. Ces résultats montrent que l’expression de SDF-1 et de la FKNpréexiste à la tumorigenèse. Nous avons démontré une expression hétérogènedes deux chimiokines dans les cellules du CEO. Les niveaux d’expression deSDF-1 dans les cellules tumorales sur une cohorte de 183 patientes n’ont aucunevaleur pronostique sur la survie globale et sur la survie sans progressiontumorale des patientes atteintes par le CEO. L’étude de la corrélation del’expression de la FKN avec les deux marqueurs de prolifération, Ki-67 etGILZ, sur une autre cohorte de 54 patientes, complétée par des expériences invitro, a montré que GILZ augmente l’expression de la FKN et d’autre part que laFKN elle-même augmente la prolifération. Cette étude contribue à élucider lerôle de SDF-1 et de la FKN dans le CEO. / Little is known about the molecules that contribute to tumor growth ofepithelial ovarian carcinomas (EOC) that remains the most lethal gynecologicalneoplasm in women.The two chemokines CXCL12/SDF-1 and fractalkine (FKN)/CX3CL1 havebeen widely studied in tumorigenesis. In epithelial ovarian cancer (EOC), SDF-1enhances tumor angiogenesis and contributes to the immunosuppressivenetwork. SDF-1 also acts on tumor cell proliferation and survival and, throughits main receptor CXCR4, governs the migration of malignant cells and theirinvasion of the peritoneum. The chemokine FKN has been documented inepithelial tissues and in various cancers. FKN have paradoxical effects intumors: anti-tumoral effect in some tumor entities and pro-tumoral effect inother tumor entities.In our study, we demonstrated the expression of SDF-1 and FKN on thesurface epithelium of normal ovaries and benign and malignant tumors,suggesting that the expression of these chemokines preexists to tumorigenesis.We also demonstrated an heterogeneous expression of both chemokines in EOC.In our large and homogeneous cohort (183 specimens of EOC), SDF-1expression levels had no effect on overall survival or progression-free survival.Thus, SDF-1 expression by tumor epithelial cells is not in itself a valuableprognostic factor in patients with advanced EOC. FKN immunostaining scores(in 54 specimens of EOC) correlated positively with the two proliferationmarkers : Ki-67 and GILZ. In vitro, we demonstrated that GILZ increases theexpression of FKN and that FKN itself increased proliferation. This studycontributes in elucidating the role of the two chemokines SDF-1 and FKN inEOC.

Le cancer épithélial de l’ovaire est le cancer gynécologique le plus létal. La survie à 5 ans est de 30-40% chez les patientes atteintes d’une tumeur invasive (TOV), comparativement à 95% chez les patientes diagnostiquées pour une tumeur à faible potentiel de malignité ou borderline (LMP). Au laboratoire, l’analyse de l’expression des gènes de la micropuce à ADN U133 d’Affymetrix a révélé que la SERPINA1 est un gène dont l’expression varie entre les tumeurs LMP et TOV. La validation par Q-PCR nous a confirmé que cette antiprotéase est majoritairement surexprimée dans les tumeurs LMP, par rapport aux tumeurs bénignes (BOV) et aux tumeurs TOV. Nous avons donc surexprimé la SERPINA1 dans les lignées cellulaires invasives TOV 112D et TOV 1946 du cancer de l’ovaire et dérivé des clones stables. Les résultats obtenus nous indiquent que la surexpression de la SERPINA1 a un effet sur la capacité d’invasion et de migration cellulaire et non au niveau de la croissance cellulaire et la formation de structures tridimensionnelles. Les résultats issus de l’étude in vivo dans les souris SCID nous permettront de déterminer si la surexpression de la SERPINA1 a un effet sur la tumorigénèse ovarienne. Ainsi, la SERPINA1 demeure à notre avis un candidat d’intérêt pour tenter de mieux comprendre les différences biologiques entre les tumeurs LMP et TOV, ainsi que le rôle des protéases et de leurs inhibiteurs dans la progression tumorale du cancer de l’ovaire. / Epithelial ovarian cancer is the most lethal gynecologic cancer with a five-year survival rate of 30-40% in patients diagnosed with high-grade invasive disease (TOV). This is in stark contrast to the 95% five-year survival in patients diagnosed with low malignant potential (LMP) disease. It is therefore important to understand the biological differences between LMP and TOV. We have previously identified differential expression of SERPINA1 between serous LMP and TOV tumors through gene expression analysis using Affymetrix U133 DNA microarrays. Expression of this protease inhibitor in the majority of LMP tumors was confirmed and validated by Q-PCR. To study the effects of its overexpression on the invasive potential of ovarian cancer cell lines, SERPINA1 was cloned in the pcDNA3.1+ plasmid and stable clones were derived from two invasive ovarian cancer cell lines, TOV 112D and TOV 1946. Comparisons between clones and controls have shown no SERPINA1-dependent difference in cellular growth or spheroid formation. However, effects on cellular migration and invasion are observed in cells overexpressing SERPINA1. Results from an in vivo xenograft study in SCID mice will allow us to determine if SERPINA1 overexpression affects ovarian tumorigenesis. SERPINA1 remains an interesting candidate gene whose further characterization may lead to insights into its role, and the role of proteases and their inhibitors, in ovarian cancer disease progression.