Epithelial ovarian cancer (EOC) is the leading cause of death from gynecological malignancy due to the insufficient accurate screening programs for the early detection of EOC. To improve the accuracy of the early detection, there is a need to deeply understand the mechanism of EOC progression and the interaction between cancer cells with their unique microenvironment. Therefore, this work investigated the metabolic shift in the mouse model for progressive ovarian cancer, and evaluated the effects of hypoxic environment, spheroid formation as well as stromal vascular fractions (SVF) on the metabolic shift, proliferation rate, drug resistance and protein markers in functional categories. The results demonstrated an increasingly glycolytic nature of MOSE cells as they progress from a tumorigenic (MOSE-L) to a highly aggressive phenotype (MOSE-FFL), and also showed changes in metabolism during ovarian cancer spheroid formation with SVF under different oxygen levels. More specifically, the hypoxic environment enhanced glycolytic shift by upregulating the glucose uptake and lactate secretion, and the spheroid formation affected the cellular metabolism by increasing the lactate secretion to acidify local environments, modulating the expression of cell adhesion molecules to enhance cell motility and spheroids disaggregation, and up-regulating invasiveness markers and stemness makers to promote ovarian cancer aggressive potential. Hypoxia and spheroid formation decreased ovarian cancer cells growth but increased the chemoresistance, which leads to the promotion of aggressiveness and metastasis potential of ovarian cancer. SVF co-cultured spheroids further increased the glycolytic shift of the heterogeneous of ovarian cancer spheroids, induced the aggressive phenotype by elevating the corresponding protein markers. Decreasing the glycolytic shift and suppression of the proteins/pathways may be used to inhibit aggressiveness or metastatic potential of ovarian cancer heterogeneous of ovarian cancer spheroids, induced the aggressive phenotype by elevating the corresponding protein markers. Decreasing the glycolytic shift and suppression of the proteins/pathways may be used to inhibit aggressiveness or metastatic potential of ovarian cancer. / Master of Science / Epithelial ovarian cancer (EOC) is the leading cause of death from gynecological malignancy due to the usually late detection when the cancer has already spread throughout the peritoneal cavity. Physical, cellular and chemical factors can contribute to EOC progression and metastasis. Critical physical factors are the low oxygen content in the peritoneal cavity (hypoxia) that promotes tumor cells survival, and the formation of tumor spheres, which have been demonstrated to have a more aggressive phenotype. Moreover, obesity has been proposed to support ovarian cancer development and progression. Therefore, this work investigated the impact of oxygen deprivation, sphere formation, and white adipose tissue-derived stromal cells on ovarian cancer cells progression. The results showed that all these factors contribute to the aggressive potential of ovarian cancer cells by increasing the drug resistance, and modulation of cellular metabolism. The understanding of the interactions between ovarian cancer and other cells within their unique microenvironment may provide critical targets for chemotherapeutic interventions that are aimed to control the aggressiveness of ovarian metastases in their hypoxic tumor microenvironment, and enhance the life of women afflicted with ovarian cancer.

Yes / HOX genes are vital for all aspects of mammalian growth and differentiation, and their dysregulated expression is related to ovarian carcinogenesis. The aim of the current study was to establish the prognostic value of HOX dysregulation as well as its role in platinum resistance. The potential to target HOX proteins through the HOX/PBX interaction was also explored in the con-text of platinum resistance. HOX gene expression was determined in ovarian cancer cell lines and primary EOCs by QPCR, and compared to expression in normal ovarian epithelium and fallopian tube tissue samples. Statistical analysis included one-way ANOVA and t-tests, using statistical software R and GraphPad. The analysis identified 36 of the 39 HOX genes as being overex-pressed in high grade serous EOC compared to normal tissue. We detected a molecular HOX gene-signature that predicted poor outcome. Overexpression of HOXB4 and HOXB9 was identified in high grade serous cell lines after platinum resistance developed. Targeting the HOX/PBX dimer with the HXR9 peptide enhanced the cytotoxicity of cisplatin in platinum-resistant ovarian cancer. In conclusion, this study has shown the HOX genes are highly dysregulated in ovarian cancer with high expression of HOXA13, B6, C13, D1 and D13 being predictive of poor clinical outcome. Targeting the HOX/PBX dimer in platinum–resistant cancer represents a potentially new therapeutic option that should be further developed and tested in clinical trials. / This research was supported by GRACE, a gynaecological charity based in Surrey, UK.

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

Chlamydia trachomatis (C. trachomatis) is being investigated as a potential vector to directly deliver anti-cancer peptides to ovarian cancer cells as part of the “Bugs as Drugs” initiative, offering a possible future treatment option for women diagnosed with ovarian cancer. Successful delivery of peptides from chlamydia to host cells first requires elementary bodies (EBs), the metabolically inactive form of chlamydia, to gain entry to host cells. To test the viability of this proposition, this project aimed foremost to demonstrate whether C. trachomatis is even capable of infecting ovarian cancer cell strains in vitro. Serovar L2 C. trachomatis was chosen and incubated along with three separate ovarian cancer cell lines: SK-OV-3, PA-1, and SW 626. A HeLa control sample was also grown alongside and incubated with chlamydia. Further experiments were done with the addition to the media of chloramphenicol (CHL), a known antibiotic and inhibitor of bacterial translation. CHL was added to ascertain whether infection could also preclude the development of reticulate bodies (RBs) (the metabolically active form of chlamydia) which could potentially harm healthy cells in the ovaries. Qualitatively, successful invasion of all three cell lines by chlamydia was observed. Encouragingly, the addition of CHL produced the same results but also demonstrated that host cell infections did not result in the development of RBs. Furthermore, western blots done on collected cell lysates showed consistency with other previously published research on chlamydial host cell infections, adding greater validity to the results. These findings encourage the continuation of future experiments that will test whether genetic modifications, such as the addition of nucleotides encoding the CT20 anti-cancer peptide, or administration of chlamydia along with different reagents, produces more promising results for a potential new ovarian cancer treatment option.

Ovarian cancer is one of the most lethal gynecological conditions among women today. Having around a 50% survival rate, it has been the 5th leading cause for cancer-related deaths for women. Delayed manifestation of symptoms with late stage diagnosis has been a major factor for relatively high mortality. The 5-year survival rate for the early stage is over 90%; therefore, early detection of cancer is essential to improve the survival rate. Even though technology has improved today, early detection has not improved, and still it has been posing challenges. In addition to the clinical practices in diagnosis, scientists are looking for other novel promising methods to detect it at the early stage that would be inexpensive and user-friendly. Currently, cancer antigen 125 (CA125), a type of biomarker that can become elevated in a patient’s blood serum, is recommended mostly for clinical tests in the screening of ovarian cancer. However, because of the lack of sensitivity and specificity associated with CA125, the search for new potential biomarkers is a research priority to diagnose cancer at a localized stage.In this work, I report a nano/micro particle labeled immunoassay method for the detection of ovarian cancer biomarker CA125 in a Phosphate-Buffered Saline (PBS) medium. Here, a sandwich type immunoassay method is presented. For this goal, CA125 biomarkers are immobilized on a solid surface (magnetic beads) using a bioconjugation technique. In order to specifically target CA125, antibody and aptamer molecules are used. Here, the elemental nano/micro particles are used to label the antibody and aptamer. This labeled immunoassay is subjected to surface enhanced Raman spectroscopy (SERS) and laser induced breakdown spectroscopy (LIBS) for the detection of CA125. I establish a calibration curve by acquiring the spectroscopic signal for the known concentration of CA125. In addition to the detection part, other spectroscopic techniques such as attenuated total reflectance Fourier transform infrared spectroscopy (ATR FT-IR), UV-Vis spectroscopy, dynamic light scattering (DLS) and scanning electron microscopy (SEM) are employed to study the bioconjugation steps. In this regard, chapter 1 gives a general overview about ovarian cancer with necessary statistics. In chapter 2, I have given necessary background information on bioconjugation techniques for immunoassay methods, particularly in the perspective of my experiments. Chapter 3 covers the antibody-based immunoassay using Raman labeled gold nanoparticles. It describes how to build a nano/micro particle based sandwich type immunoassay for CA125 detection and the corresponding results. Chapter 4 describes a similar immunoassay method to chapter 3, using aptamers instead of antibodies for specifically targeting CA125. In both chapters, SERS is employed for detection. In chapter 5, I use LIBS for the detection of an aptamer based assay. Following a similar technique in the previous chapter, I use silica microparticles to label the aptamer instead gold nanoparticles. Chapter 6 focuses on the computational aspect of our experimental work, detailing the molecular docking process and presenting preliminary results regarding the interactions of the antibody and aptamer with the CA125 antigen. Chapter 7 offers a summary of my findings along with the relevant background information.

Este estudo teve como objetivo geral a análise do gene FMR1 (Fragile X Mental Retardation gene 1) quanto a sua relação com a insuficiência ovariana primária (Fragile X-related Primary Ovarian Insufficiency, FXPOI). No Capítulo I, apresentamos revisão da literatura sobre FXPOI. A pré-mutação do gene FMR1 constitui a mais frequente causa genética de predisposição para menopausa precoce e entre os casos familiais, cerca de 10% estão associados à pré-mutação do gene FMR1. Entretanto, pouco se conhece sobre a expressão do gene no ovário de mamíferos e os mecanismos pelos quais a pré-mutação causa POI permanecem desconhecidos. O Capítulo II apresenta os resultados do estudo da expressão do gene FMR1 nos ovários adultos, humano e murino. As enormes dificuldades inerentes à obtenção e ao estudo de células germinativas femininas nos levaram a estudar células da granulosa humana (HGC), que são de fácil obtenção, como subprodutos de procedimentos de fertilização in vitro. Também estudamos a expressão do Fmr1 em células da granulosa de camundongos da linhagem CD1 (MGC), coletadas nos ovidutos, após estimulação da ovulação. As células da granulosa interagem intensamente com os ovócitos durante a foliculogênese, transmitindo sinais através do ovário e apoiando o crescimento e a maturação dos ovócitos durante as últimas fases do crescimento folicular. É, portanto, possível que alterações celulares induzidas pela pré-mutação do gene FMR1 nas HGC afetem o crescimento folicular, a taxa de ovulação e a fecundidade. Padronizamos os protocolos de isolamento e de cultivo das HGC do fluido folicular e confirmamos a origem das células isoladas pela expressão de marcadores de HGC, por RT-PCR, e pela natureza lipídica dos grânulos citoplasmáticos, pela coloração com o corante lipofílico DiI. Demonstramos, por RT-PCR que as HGC isoladas do líquido folicular expressam o mRNA do FMR1. Em camundongos, também por RT-PCR, evidenciamos a expressão do mRNA do Fmr1 em ovócitos e nas MGC, coletados do oviduto após hiper-estimulação da ovulação. Por hibridação in situ de RNA em HCG cultivadas, detectamos o mRNA do FMR1 disperso no citoplasma e no núcleo, concentrado em regiões cujas características indicaram ser nucléolos. Essa mesma distribuição foi observada em fibroblastos cultivados. Essa provável localização nucleolar sugere que o transcrito do FMR1, nessas células, constitua ribonucleoproteínas mensageiras, para seu direcionamento do nucléolo para sítios citoplasmáticos específicos, onde ocorre sua tradução. Verificamos, por Western blotting, que as HGC expressam, em níveis elevados, isoformas da FMRP, com massa molecular entre 60 e 95 kDa. Determinamos a localização subcelular da FMRP nas HGC e da Fmrp nas MGC, por imunocoloração. Os sinais de hibridação foram visualizados dispersos, em grânulos finos, no citoplasma das HGC e das MGC, de maneira semelhante ao padrão de distribuição da proteína em neurônios. Nos filopódios das MGC, observamos marcação concentrada em alguns pontos, de forma semelhante ao padrão, previamente descrito, de distribuição da Fmrp em espinhas dendríticas de neurônios de hipocampo de rato, constituindo grânulos de RNA, que promovem o transporte de mRNA e controlam a tradução. O padrão de distribuição semelhante entre neurônios e MGC pode refletir similaridade da função da Fmrp nos dois tecidos. A indução de estresse oxidativo nas HGC por tratamento com arsenito sódico, levou a proteína a deixar de ter distribuição citoplasmática difusa e passar a fazer parte de grânulos de estresse perinucleares, colocalizando-se com TIA-1, marcador dessas estruturas. Resultados semelhantes foram anteriormente obtidos em células HeLa e no hipocampo de rato. Esses resultados apoiam a hipótese de que a FMRP participa do mecanismo transitório de parada da tradução após estresse. No Capítulo III, descrevemos nossas tentativas para obtenção de linhagem de células tronco embrionárias (ESC) de camundongo knockin (KI) quanto a pré-mutação do gene Fmr1. Para a obtenção de embriões KI, fêmeas selvagens (WT; linhagem C57) foram cruzadas com machos KI (linhagem C57/BL6) e fêmeas KI foram cruzadas com machos WT. Pretendíamos comparar a expressão do gene Fmr1 na linhagem de ESC KI e linhagem de ESC WT, inclusive durante a diferenciação Não tivemos sucesso, o que pode ser atribuído às dificuldades inerentes à obtenção de ESC. No acompanhamento dos primeiros quatro dias do desenvolvimento in vitro dos embriões, alterações de clivagem e parada de desenvolvimento foram mais frequentemente observadas nos embriões obtidos de fêmeas KI. Entretanto as taxas médias de sobrevivência de ovócitos para blastocistos e de embriões com 8 a 16 células para blastocistos não diferiram estatisticamente entre as fêmeas KI e selvagens; a grande variabilidade entre o número de blastocistos obtidos por fêmea e o pequeno número delas nos grupos KI (seis) e selvagem (sete) indicam que esses resultados devem ser interpretados com cautela. A análise da proteína Fmrp nos blastocistos, por imunocoloração, mostrou distribuição provavelmente citoplasmática, com padrão granular de marcação, sendo as granulações mais frequentes nos blastocistos de fêmeas WT, porém mais grosseiras nos blastocistos de fêmeas KI. Esse conjunto de dados é sugestivo de efeito da pré-mutação do gene Fmr1 em fêmea murina sobre o início do desenvolvimento de seus embriões. Esse aspecto necessita investigação mais aprofundada / This study aimed at investigating the FMR1 gene (Fragile X Mental Retardation gene 1), regarding its relationship with primary ovarian insufficiency (Fragile X-related Primary Ovarian Insufficiency, FXPOI). In Chapter I, we present a literature review on FXPOI. The FMR1 premutation is the most frequent genetic cause of predisposition to premature ovary insufficiency (POI) and, among the POI familial cases, about 10% are associated with the FMR1 gene premutation. However, little is known about the gene expression in the mammal ovary, and the mechanisms by which the premutation causes POI remain unknown. Chapter II presents the study of the FMR1 gene expression in the human and murine adult ovaries. The enormous difficulties inherent in obtaining and studying female germ cells led us to study human granulosa cells (HGC), which are easily obtained as byproducts of in vitro fertilization procedures. We also studied the FMR1 expression in granulosa cells of mice of the CD1 strain (MGC), collected from the oviducts after ovulation induction. Granulosa cells interact functionally with oocytes during folliculogenesis, transmitting signals through the ovary and supporting growth and maturation of oocytes during the later stages of follicular growth. It is, therefore, possible that cellular changes induced by the FMR1 premutation in HGCs affect follicular growth, ovulation rate and fecundity. We standardized protocols for isolation and culture of HGCs obtained from follicular fluid and confirmed the origin of the isolated cells by the expression of HGC markers, using RT-PCR, and by the lipid nature of the cytoplasmic granules, as demonstrated by the staining with the lipophilic dye DiI. We demonstrated, by RT-PCR, that HGCs isolated from follicular fluid express the FMR1 mRNA. In mice, also by RT-PCR, we detected the Fmr1 mRNA in oocytes and in the MGCs, collected from the oviduct after ovulation hyperstimulation. Using RNA in situ hybridization on cultured HCGs, we detected the FMR1 mRNA dispersed in the cytoplasm and, in the nucleus, concentrated in regions whose features indicated to be nucleoli. This same distribution was observed in cultured fibroblasts. This probable nucleolar localization of the FMR1 transcript in these cells suggests that it constitutes messenger ribonucleoproteins for further targeting to specific cytoplasmic sites where translation occurs. We verified, by Western blotting, that HGCs express high levels of the main FMRP isoforms, with molecular mass between 60 and 95 kDa. We determined the FMRP subcellular localization in HGCs and that of Fmrp in MGCs, by immunostaining. The hybridization signals were seen scattered in fine granules in the cytoplasm of both HGCs and MGCs, in a pattern of distribution similar to that observed in neurons. In the MGC filopodia, the protein labeling was concentrated at some sites, similar to the previously described pattern of Fmrp distribution in neuronal dendritic spines of rat hippocampus, where it is part of RNA granules, promoting mRNA transport and translation control. The similar distribution pattern between neurons and MGC may reflect the similarity of FMRP function in both tissues. The induction of oxidative stress in the HGC by treatment with sodium arsenite led the protein to leave its diffuse cytoplasmic distribution to become part of perinuclear stress granules, co-localized with TIA-1, a marker of these structures. Similar results were previously obtained in HeLa cells and in rat hippocampus. These results support the hypothesis that FMRP participates in the mechanism of the transient translation arrest after stress. In Chapter III, we describe our attempts to obtain an embryonic stem cell line (ESC) from knock-in mice (KI) for the FMR1 premutation. To obtain KI embryos, wild females (WT, strain C57) were crossed with males KI (strain C57/BL6), and KI females were crossed with WT males. We planned to compare the expression of the fmr1 gene in the ESCs from the KI and WT strains, including during differentiation. We did not succeed in obtaining an ESC KI line, which can be attributed to difficulties inherent to the procedure. At follow-up of the first four days of in vitro development of embryos, changes in cleavage and developmental arrest were more frequently observed in embryos obtained from KI females. Meanwhile, the average survival rates of oocytes to blastocysts, and 8-16 cell embryos to blastocysts were not statistically different between the KI and WT females. The great variability among the numbers of blastocysts obtained per female and the small size of the KI (six females) and WT (seven females) groups indicate that these results should be interpreted with caution. Immunostaining analysis of the Fmrp in blastocysts showed a probably cytoplasmic distribution, with a granular pattern of labeling, the grains being more common in blastocysts from WT females, but coarser in blastocysts from KI females. These data are suggestive that the Fmr1 premutation in murine females affects the early development of their embryos. This aspect needs further investigation

Introdução: Anormalidades nos supressores tumorais p14, p16 e p53 são relatadas em diversos tipos de câncer em humanos. Na carcinogênese ovariana, p16 e p53 foram extensivamente estudados, mas p14 foi analisado somente em carcinomas. Objetivo: O estudo visa determinar a expressão imuno-histoquímica de p14, p16 e p53 em tumores ovarianos epiteliais benignos, borderline e malignos. Método: Estudo transversal utilizando imuno-histoquímica em amostras de tumores epiteliais ovarianos emblocados em parafina do Hospital de Clínicas de Porto Alegre. Resultados: p14 foi positivo em 93% dos tumores benignos, 94% dos borderline e 60% dos malignos. A perda de expressão foi estatisticamente associada com carcinomas. p16 foi positivo em 94,6% dos carcinomas, 75% dos tumores borderline e 45,7% dos benignos. p53 foi positivo em 29,7%, 16,7% e 2,9% dos tumores malignos, borderline e benignos, respectivamente. Os subtipos de carcinoma não mostraram diferenças de expressão. Conclusão: Nosso estudo foi o primeiro a descrever a expressão de p14 em tumores benignos e borderline. Ela permanece estável nos benignos e borderline, enquanto os carcinomas exibem uma perda de expressão significativa. Isso pode indicar que anormalidades de p14 acontecem tardiamente na carcinogênese. As taxas de expressão de p16 e p53 foram semelhantes a estudos anteriores. Estudos futuros devem investigar anormalidades genéticas nas sequencias codificadoras de p14 e incluir todos os tipos de tumor epitelial ovariano. / Background: Abnormalities in tumor suppressors p14, p16 and p53 are reported in several human cancers. In ovarian carcinogenesis, p16 and p53 have been extensively studied, but p14 was only analyzed in carcinomas. Aim: This study seeks to determine p14, p16 and p53 immunohistochemical expression in benign, borderline and malignant ovarian epithelial tumors and correlate them with survival and clinical variables. Methods: Cross-sectional study utilizing immunohistochemical staining of p14, p16 and p53 in paraffin-embedded tissue samples from ovarian epithelial tumors obtained from Hospital de Clinicas de Porto Alegre. Results: p14 was positive in 93% of benign, 94% of borderline and 60% of malignant tumors. Loss of expression was statistically associated with carcinomas. p16 was positive in 94.6% of carcinomas, 75% of borderline and 45.7% of benign tumors. p53 was positive in 29.7%, 16.7% and 2.9% of malignant, borderline and benign tumors, respectively. Carcinoma subtypes showed no difference in expression. Conclusions: To our knowledge, this is the first description of p14 expression in benign and borderline tumors. It remains stable in benign and borderline tumors, while carcinomas show a significant absence of staining. This may indicate p14 abnormalities occur later in carcinogenesis. p16 and p53 expression rates show similar results to previous reports. Future studies should investigate genetic abnormalities in p14 coding sequences and include all types of ovarian epithelial tumors.

Ovarian cancer is thought to be derived from the ovarian surface epithelium (OSE), but it is often diagnosed during the late stages and therefore the events that contribute to the initiation and progression of ovarian cancer are poorly defined. Epidemiological studies have indicated an association between the female reproductive hormones and ovarian cancer etiology, but the direct effects of 17β-estradiol (E2), progesterone (P4), luteinizing hormone (LH) and follicle stimulating hormone (FSH) on disease pathophysiology are not well understood. A novel transgenic mouse model of ovarian cancer was generated that utilized the Cre/loxP system to inducibly express the oncogene SV40 large and small T-Antigen in the OSE. The tgCAG-LS-TAg mice developed poorly differentiated ovarian tumours with metastasis and ascites throughout the peritoneal space. Although P4 had no effect; E2 significantly accelerated disease progression in tgCAG-LS-TAg mice. The early onset of ovarian cancer was likely mediated by E2’s ability to increase the areas of putative preneoplastic lesions in the OSE. E2 also significantly decreased survival time in ovarian cancer cell xenografts. Microarray analysis of the tumours revealed that E2 mainly affects genes involved in angiogenesis and cellular differentiation, proliferation, and migration. These results suggest that E2 acts on the tumour microenvironment in addition to its direct effects on OSE and ovarian cancer cells. In order to examine the role of the gonadotropins in ovarian cancer progression, the tgCAG-LS-TAg mice were treated with 4-vinylcyclohexene-diepoxide (VCD) to induce menopause. Menopause slowed the progression of ovarian cancer due to a change in the histological subtype from poorly differentiated tumours to Sertoli tumours. Using a transgenic mouse model, it was shown that E2 accelerated ovarian cancer progression, while P4 had little effect on the disease. Menopause (elevated levels of LH and FSH) altered the histological subtype of the ovarian tumours in the tgCAG-LS-TAg mouse model. These results emphasize the importance of generating animal models to accurately recapitulate human disease and utilizing these models to develop novel prevention and treatment strategies for women with ovarian cancer.

Dissertation (Ph.D.)--University of South Florida, 2008. / Includes vita. Also available online. Includes bibliographical references (leaves 93-111).

Ovarian cancer is thought to be derived from the ovarian surface epithelium (OSE), but it is often diagnosed during the late stages and therefore the events that contribute to the initiation and progression of ovarian cancer are poorly defined. Epidemiological studies have indicated an association between the female reproductive hormones and ovarian cancer etiology, but the direct effects of 17β-estradiol (E2), progesterone (P4), luteinizing hormone (LH) and follicle stimulating hormone (FSH) on disease pathophysiology are not well understood. A novel transgenic mouse model of ovarian cancer was generated that utilized the Cre/loxP system to inducibly express the oncogene SV40 large and small T-Antigen in the OSE. The tgCAG-LS-TAg mice developed poorly differentiated ovarian tumours with metastasis and ascites throughout the peritoneal space. Although P4 had no effect; E2 significantly accelerated disease progression in tgCAG-LS-TAg mice. The early onset of ovarian cancer was likely mediated by E2’s ability to increase the areas of putative preneoplastic lesions in the OSE. E2 also significantly decreased survival time in ovarian cancer cell xenografts. Microarray analysis of the tumours revealed that E2 mainly affects genes involved in angiogenesis and cellular differentiation, proliferation, and migration. These results suggest that E2 acts on the tumour microenvironment in addition to its direct effects on OSE and ovarian cancer cells. In order to examine the role of the gonadotropins in ovarian cancer progression, the tgCAG-LS-TAg mice were treated with 4-vinylcyclohexene-diepoxide (VCD) to induce menopause. Menopause slowed the progression of ovarian cancer due to a change in the histological subtype from poorly differentiated tumours to Sertoli tumours. Using a transgenic mouse model, it was shown that E2 accelerated ovarian cancer progression, while P4 had little effect on the disease. Menopause (elevated levels of LH and FSH) altered the histological subtype of the ovarian tumours in the tgCAG-LS-TAg mouse model. These results emphasize the importance of generating animal models to accurately recapitulate human disease and utilizing these models to develop novel prevention and treatment strategies for women with ovarian cancer.