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Skewed somatic X inactivation (XCI), X-linked gene overexpression and abnormal X content have been associated with breast and ovarian cancer. Partial or complete reactivation of the inactive X in females may be a step in breast and ovarian cancer progression, leading to overexpression of some tumour enhancing gene. Markers of an X reactivation event were examined: X gene dosage, expression, and methylation in 8 ovarian cancer cell lines. Another marker of an X reactivation event, skewed XCI, was assayed in peripheral blood DNA from 106 breast and/or ovarian cancer patients (52 BRCA1 mutation carriers, 24 BRCA2 mutation carriers, 30 non-mutation carriers), 147 age-matched population controls. Combined RNA/DNA FISH was used to quantify the number of inactive Xs compared to total number of Xs. Five cell lines had increased X content. Three cell lines localized XIST to the presumptive inactive X; however the numbers of inactive Xs were variable. Expression levels of 8 X-linked genes were assessed by real-time PCR. Expression was inconsistent between different genes and among cell lines, ranging from a 2 to 300-fold increase compared to a control. Overall, expression was greatly increased for genes subject to inactivation but not increased in genes that escape inactivation for most ovarian cancer cell lines. Methylation at AR and FMR1 was quantified by a real-time PCR based assay and SNuPE respectively. Methylation was lower than expected for 7 of 8 ovarian cancer cell lines at AR or FMR1, while three cell lines had low or no methylation for both genes. Skewed XCI was evaluated using a methylation-based PCR assay at AR. There was no significant increase in skewing above 90% for any cancer group assayed. In addition, two markers of X reactivation were assayed in two low passage cultures of normal ovarian surface epithelium from BRCA1 mutation positive breast cancer patients. One sample did not localize XIST to the inactive X and three of five genes subject to inactivation were overexpressed. In summary, there is evidence for loss of X silencing or gain of active X content in ovarian cancer cell lines and normal ovarian surface epithelium from BRCA1 mutation carriers.

Skewed somatic X inactivation (XCI), X-linked gene overexpression and abnormal X content have been associated with breast and ovarian cancer. Partial or complete reactivation of the inactive X in females may be a step in breast and ovarian cancer progression, leading to overexpression of some tumour enhancing gene. Markers of an X reactivation event were examined: X gene dosage, expression, and methylation in 8 ovarian cancer cell lines. Another marker of an X reactivation event, skewed XCI, was assayed in peripheral blood DNA from 106 breast and/or ovarian cancer patients (52 BRCA1 mutation carriers, 24 BRCA2 mutation carriers, 30 non-mutation carriers), 147 age-matched population controls. Combined RNA/DNA FISH was used to quantify the number of inactive Xs compared to total number of Xs. Five cell lines had increased X content. Three cell lines localized XIST to the presumptive inactive X; however the numbers of inactive Xs were variable. Expression levels of 8 X-linked genes were assessed by real-time PCR. Expression was inconsistent between different genes and among cell lines, ranging from a 2 to 300-fold increase compared to a control. Overall, expression was greatly increased for genes subject to inactivation but not increased in genes that escape inactivation for most ovarian cancer cell lines. Methylation at AR and FMR1 was quantified by a real-time PCR based assay and SNuPE respectively. Methylation was lower than expected for 7 of 8 ovarian cancer cell lines at AR or FMR1, while three cell lines had low or no methylation for both genes. Skewed XCI was evaluated using a methylation-based PCR assay at AR. There was no significant increase in skewing above 90% for any cancer group assayed. In addition, two markers of X reactivation were assayed in two low passage cultures of normal ovarian surface epithelium from BRCA1 mutation positive breast cancer patients. One sample did not localize XIST to the inactive X and three of five genes subject to inactivation were overexpressed. In summary, there is evidence for loss of X silencing or gain of active X content in ovarian cancer cell lines and normal ovarian surface epithelium from BRCA1 mutation carriers.

Skewed somatic X inactivation (XCI), X-linked gene overexpression and abnormal X content have been associated with breast and ovarian cancer. Partial or complete reactivation of the inactive X in females may be a step in breast and ovarian cancer progression, leading to overexpression of some tumour enhancing gene. Markers of an X reactivation event were examined: X gene dosage, expression, and methylation in 8 ovarian cancer cell lines. Another marker of an X reactivation event, skewed XCI, was assayed in peripheral blood DNA from 106 breast and/or ovarian cancer patients (52 BRCA1 mutation carriers, 24 BRCA2 mutation carriers, 30 non-mutation carriers), 147 age-matched population controls. Combined RNA/DNA FISH was used to quantify the number of inactive Xs compared to total number of Xs. Five cell lines had increased X content. Three cell lines localized XIST to the presumptive inactive X; however the numbers of inactive Xs were variable. Expression levels of 8 X-linked genes were assessed by real-time PCR. Expression was inconsistent between different genes and among cell lines, ranging from a 2 to 300-fold increase compared to a control. Overall, expression was greatly increased for genes subject to inactivation but not increased in genes that escape inactivation for most ovarian cancer cell lines. Methylation at AR and FMR1 was quantified by a real-time PCR based assay and SNuPE respectively. Methylation was lower than expected for 7 of 8 ovarian cancer cell lines at AR or FMR1, while three cell lines had low or no methylation for both genes. Skewed XCI was evaluated using a methylation-based PCR assay at AR. There was no significant increase in skewing above 90% for any cancer group assayed. In addition, two markers of X reactivation were assayed in two low passage cultures of normal ovarian surface epithelium from BRCA1 mutation positive breast cancer patients. One sample did not localize XIST to the inactive X and three of five genes subject to inactivation were overexpressed. In summary, there is evidence for loss of X silencing or gain of active X content in ovarian cancer cell lines and normal ovarian surface epithelium from BRCA1 mutation carriers. / Medicine, Faculty of / Medical Genetics, Department of / Graduate

Wilms’ tumor gene 1 (WT1) is a zinc finger transcriptional regulator with crucial functions in embryonic development. Originally WT1 was described as a tumor suppressor gene, but later studies have shown oncogenic properties of WT1 in a variety of tumors. Because of its dual functions in tumorigenesis, WT1 has been described as a chameleon gene. In this thesis, the significance of WT1 as a biomarker was investigated in acute myeloid leukemia (AML), clear cell renal cell carcinoma (ccRCC), ovarian carcinoma (OC) and childhood B-cell precursor acute lymphoblastic leukemia (BCP-ALL). Previous studies have suggested that expression of WT1 is a potential marker for detection of minimal residual disease (MRD) in AML. We aimed to define expression of WT1 as an MRD marker in AML. In adult AML patients, we found that a reduction of WT1 expression in bone marrow (≥ 1-log) detected less than 1 month after diagnosis was associated with an improved overall survival (OS) and freedom from relapse (FFR). In peripheral blood, a reduction of WT1 expression (≥ 2-log) detected between 1 and 6 months after treatment initiation was associated with an improved OS and FFR. WT1 harbor pathogenic genetic variants in a considerable proportion of AML and T-lymphoblastic leukemia (T-ALL), but mutations have not been reported in BCP-ALL. We aimed to evaluate the clinical impact of WT1 mutations and single nucleotide polymorphisms (SNPs) in BCP-ALL. Pathogenic mutations in the WT1 gene were rarely seen in childhood BCP-ALL. However, five WT1 SNPs were identified. In survival analyses, WT1 SNP rs1799925 was found to be associated with worse OS, indicating that WT1 SNP rs1799925 may be a useful marker for clinical outcome in childhood BCP-ALL. We also explored whether WT1 mutations and SNPs in ccRCC could be used as biomarkers for risk and treatment stratification. We therefore examined whether SNPs or mutations in WT1 were associated with WT1 expression and clinical outcome. Sequencing analysis revealed that none of the previously reported WT1 mutations were found in ccRCC; however, we identified six different WT1 SNPs. Our data suggest that pathogenic WT1 mutations are not involved in ccRCC, and the prognostic significance of WT1 SNPs in ccRCC is considerably weak. However, a favorable OS and disease-specific survival were found in the few cases harboring the homozygous minor allele. OC has a poor prognosis, and early effective screening markers are lacking. Serous OCs are known to express the WT1 protein. Overexpressed oncogenic proteins can be considered potential candidate antigens for cancer vaccines and T-cell therapy. It was therefore of great interest to investigate whether anti-WT1 IgG antibody (Ab) measurements in plasma could serve as biomarkers of anti-OC response. We found limited prognostic impact, but the results indicated that anti-WT1 IgG Ab measurements in plasma and WT1 staining in tissue specimens could be potential biomarkers for patient outcome in the high-risk subtypes of OCs. In conclusion, the results of this thesis indicate that WT1 gene expression can provide information about MRD of patients with AML, and WT1 SNP rs1799925 may be used as a biomarker for predicting clinical outcome in childhood BCP-ALL. In ccRCC, the prognostic significance of WT1 SNPs is weak and limited to the subgroup of patients that are homozygous for the minor allele. In OCs anti-WT1 IgG Ab measurement in plasma and WT1 staining in tissue specimens could possibly be used as biomarkers for predicting patient outcome in the high-risk subtypes of OCs.

Ovarian carcinoma is a serious illness with the highest mortality rate among all female cancers. No suitable methods for early diagnosis, precise determination of prognosis or prediction of therapy efficacy are currently available, which leads to diagnosis in advanced stages of disease and therapy efficacy limitation. Consequently, the development of chemoresistance to conventional drugs and frequent relapse of the disease pose a fundamental complication too. The main goal of the current study was identification of new putative prognostic and therapeutic biomarkers, whose introduction into clinical practice could help to improve the dismal outcome of ovarian carcinoma patients. The present master thesis provides results of expression analysis of genes whose products take part in the transport, metabolism and mechanism of action of platinum based drugs and taxanes, and also the regulation of cell cycle and signaling. Transcript levels of these genes have been assessed in series of tumor and control ovarian tissue samples and the difference between both tissue types was evaluated. Gene expression level in tumors was then compared with patient's clinical data and candidate genes, ABCA2 and PRC1, were selected from the obtained results for more detailed analysis. The protein level of candidate genes...

In humans, multi enzymatic processes are involved in maintaining DNA stability and cellular homeostasis. Cells undergo several episodes to survive and protect itself in daily basis. Accumulation of DNA errors and breaks are repaired by dynamic machinery, such as mismatch repair (MMR), replication-related process. In presented diploma thesis, we report the studied MMR pathway and its involvement in malignancy of epithelial ovarian cancer (EOC). Our working hypothesis postulated that core genes of MMR, such as MLH1 and MSH2 are down-regulated in malignant cells. Cells therefore become incapable to repair accumulating DNA damage, undergo apoptosis or most likely uncontrolled proliferation. Above mentioned genes may also be silenced in cancer patients at transcription, translation or epigenetic levels. Our aims were to clarify and to investigate the importance of MMR based on mRNA transcription, protein stability and promoter hypermethylation on a set of major MMR genes, particularly MLH1, MSH2, PMS1, MLH3, MSH6, MSH3, and PMS2. In our study, we analysed samples from 63 epithelial ovarian cancer patients and 12 non-malignant reference tissues using RT-qPCR, MS-HRM, and Western Blotting methods. Consequently, our results show down-regulation of all MMR genes except for MSH2 (up-regulated) in tumor...

This diploma thesis deals with the topic of hidden malnutrition in patients with advanced stage of ovarian carcinoma. Tumor diseases are often accompanied by malnutrition. In the case of ovarian cancer, malnutrition may be hidden, primarily due to ascites, which can distort body weight. Out of the patients included in this study 32 % had ascites. The basic nutritional status test in hospitals is the nutritional screening performed on each hospitalized patient to detect the risk of malnutrition. Other methods such as anthropometric measurements, laboratory values, bioimpedance analysis, or less commonly, imaging processes can also be used to detect malnutrition. The aim of this thesis was to evaluate whether nutritional screening and regular weight control in patients with advanced ovarian cancer is sufficient to diagnose malnutrition. The results have shown that the inclusion of anthropometric measurements between routine screening can be beneficial in detecting a greater number of malnourished patients. Also shifting the BMI threshold in nutritional screening for patients over 65 would greatly increase the capture of patients at risk of malnutrition. The secondary focus was to find whether the presence of ascites can be a determining factor in malnutrition being left undiagnosed, and which simple...

Dihydrodiol dehydrogenases are a family of aldo-keto reductases (AKR1Cs) involved in the metabolism of steroid hormones and xenobiotics. Whilst, several phase II drugs as well as endogenous & exogenous steroids/steroid metabolites have been identified as inducers of gene transcription, the cellular transcription factors controlling the expression of AKR1C1 are incompletely elucidated. Herein, we have cloned and characterized the proximal promoter region of the human AKR1C1 gene that controls its transcription. The 5’ flanking proximal promoter region of the AKR1C1 gene consists of a TATA box and an inverted CCAAT binding site. Deletion analysis of the 5’-flanking, ~3.0 kb region of the human AKR1C1 gene identified the region between -128 to -88 as the minimal proximal promoter essential for basal transcription of AKR1C1 in human ovarian (2008 & 2008/C13*), lung (H23 & A549) and liver carcinoma (HepG2) cells. Antioxidant response elements (ARE) have been shown to modulate the transcription ofv genes coding for phase II drug metabolizing enzymes. Cloning of the ARE upstream of the AKR1C1 proximal promoter resulted in increased transcription in human lung adenocarcinoma and liver hepatoblastoma cells but not in human ovarian carcinoma cells. Further, ARE increased the induction of the AKR1C1 gene in response to treatment with phase II drug inducers. However, ARE did not induce the transcription of AKR1C1 gene promoter in the presence of cisplatin in any of the cell lines. A computational analysis utilizing the Alibaba 2.0 on the proximal AKR1C1 gene promoter region was performed to identify potential transcription factor binding sites. Based on this analysis, a set of potential, putative transcription factor binding sites for Oct1, Sp1, Cp-1/NF-Y, CEBP, p40X, USF, NF1 and AP-2 were identified in the region -180 to -88 of the AKR1C1 gene promoter. Site-directed mutagenesis studies indicated that the transcription factor binding sites for NF-Y/CEBP were involved in controlling the basal transcription of AKR1C1 in all the cancer cells studied. Electrophoretic mobility shift (EMSAs) and gel supershift assays demonstrated that the transcription factor NF-Y preferentially binds to the inverted CCAAT box at -109ATTGG-105 of the AKR1C1 gene. Chromatin immunoprecipitation (ChIP) analysis confirmed the in vivo association between NF-Y and human AKR1C1 gene promoter in human ovarian, lung and liver carcinoma cells. Further, ectopic expression of NF-Y’s increased the AKR1C1 gene transcription, whereas expression of a dominant-negative NF-YA or knockdown of NF-YA by siRNA transfection, decreased the AKR1C1 gene transcription. A 2-fold increase in AKR1C1 transcription was observed specifically in cisplatin-treated 2008 cells that was CCAAT box-dependent. These results indicate that NF-Y regulates basal transcription of AKR1C1 in human ovarian, lung and liver carcinoma cells and cisplatin-induced transcription in human ovarian carcinoma cells. / Pathology

Le cancer de l'ovaire est la première cause de décès par cancer gynécologique. Cette thèse avait pour objectif la prospection de nouvelles solutions thérapeutiques fondées sur la délivrance prolongée d'agents anti tumoraux à l'aide de systèmes macromoléculaires de synthèse. L'un des obstacles majeurs était la disposition d'un modèle de tumeur pertinent chez l'animal. Après un examen bibliographique des connaissances acquises, le deuxième chapitre examine le potentiel d'un panel de xénogreffes dérivées de tumeurs ovariennes humaines directement greffées chez la souris immunodéprimée. Il est montré que les principales caractéristiques phénotypiques et moléculaires des tumeurs originales sont maintenues au niveau des greffes. Les résultats traduisent la présence d'une hétérogénéité intra-tumorale et d'une oligoclonalité au niveau des tumeurs primaires. L'ensemble confirme l'importance du choix du modèle tumoral pour l'évaluation de nouveaux traitements et l'étude des mécanismes aboutissant aux rechutes de la maladie et au développement d'une chimiorésistance. Un troisième chapitre traite l'exemple d'un système de délivrance prolongée fondé sur le couplage d'un agent antitumoral modèle, la doxorubicine, associé de diverses manières à un vecteur macromoléculaire biorésorbable, le poly(L-lysine citramide). Le premier conjugué obtenu par couplage direct sur le vecteur étant trop stable, divers systèmes ont été conçus pour obtenir la libération souhaitée. L'utilisation d'un bras espaceur clivable de type ester-hydrazone a fourni le meilleur résultat. Pour pallier la complexité de ces conjugués, une stratégie innovante fondée sur le piégeage de la doxorubicine dans une gélatine artificielle à base de poly(N-acryloyl glycinamide) est prospectée qui devrait permettre l'utilisation simultanée de plusieurs principes actifs piégés temporairement par voie physique dans un gel adhésif et fournir des solutions mieux adaptées aux contraintes cliniques des traitements intrapéritonéaux. / Ovarian carcinoma is the most lethal gynecologic malignancy. The aim of this PhD thesis was to develop new therapeutic approaches based on novel synthetic macromolecular drug delivery systems for intraperitoneal chemotherapy. These objectives were limited by the requirement of reliable tumor models for experimental studies. After a concise review of knowledge published in the literature, the potential interest of the establishment of a collection of tumor grafts derived from samples of human tumors is examined in a second chapter. Data show that the major phenotypic and genotypic features of the original tumors are maintained in the xenografts. They also confirm the importance of this tumor model to test new drugs and to analyze intratumoral heterogeneity and oligoclonality in primary ovarian carcinoma. The collection will be also helpful to study the mechanisms leading to disease recurrences and resistance to chemotherapies. An example of drug delivery system based on the different associations of a model chemotherapeutic drug (doxorubicin) with a bioresorbable macromolecular vector, namely poly(L-lysine citramide), is addressed in a third chapter. Direct amid linkage in the first conjugate was too stable with respect to antitumoral cytotoxicity desired after in vivo administration and different systems were generated subsequently to increase drug release in tumor deposits. The best results were obtained with a hydrazone cleavable spacer containing an ester group. To overcome the complexity of these conjugates, a novel strategy based on doxorubicin entrapment in a synthetic gelatin made of (poly(N-acryloyl glycinamide) is developed. This strategy should allow physical temporary entrapment of different drug molecules in a adhesive gel and could provide new solutions to the therapeutic challenges of intraperitoneal administration.