Subtypes Of Epithelial Ovarian Carcinoma Research Articles

Key immunological functions involved in the progression of epithelial ovarian serous carcinoma discovered by the gene ontology-based immunofunctionome analysis

Objective: Serous carcinoma (SC) is the most common and lethal subtype of epithelial ovarian carcinoma; immunotherapy is a potential treatment for SC. However, the global immunological functions of SC as well as their change during the progression of SC have not been investigated in detail until now.

Loss of 1p36.33 Frequent in Low-Grade Serous Ovarian Cancer

BACKGROUND: Low-grade serous ovarian cancer (LGSOC) is a rare subtype of epithelial ovarian carcinoma. Limited data regarding the molecular-genetic background exist beyond mutations in the RAS signaling pathway. There is a growing need to better characterize these tumors due to chemoresistance and limited therapeutic options in advanced or recurrent disease. METHODS: We performed genome-wide copy number aberration (CNA) profiles and mutation hotspot screening (KRAS, BRAF, NRAS, ERBB2, PIK3CA, TP53) in 38 LGSOC tumor samples. RESULTS: We detected mutations in the RAS-signaling pathway in 36.8% of cases, including seven KRAS, four BRAF, and three NRAS mutations. We identified two mutations in PIK3CA and one mutation in MAP3K1, EGFR, and TP53. CNAs were detected in 86.5% of cases. None of the focal aberrations was correlated with specific clinical characteristics. The most frequently detected CNA was loss of 1p36.33 in 54.1% of cases, with a trend towards lower progression-free survival and overall survival in patients with 1p36.33 loss. CONCLUSIONS: Activating RAS mutations were dominant in our series, with supplementary detection of two PIK3CA mutations which may lead to therapeutic options. Furthermore, we detected 1p36.33 deletions in half of the cases, indicating a role in tumorigenesis, and these deletions may serve as a prognostic marker.

Key Immunological Functions Involved in the Progression of Epithelial Ovarian Serous Carcinoma Discovered by the Gene Ontology-Based Immunofunctionome Analysis.

Serous carcinoma (SC) is the most common and lethal subtype of epithelial ovarian carcinoma; immunotherapy is a potential treatment for SC, however, the global immunological functions of SC as well as their change during the progression of SC have not been investigated in detail till now. We conducted a genome-wide integrative analysis to investigate the immunofunctionomes of SC at four tumor stages by quantifying the immunological functions defined by the Gene Ontology gene sets. DNA microarray gene expression profiles of 1100 SCs and 136 normal ovarian tissue controls were downloaded from the Gene Expression Omnibus database and converted to the functionome. Then the immunofunctionomes were reconstructed by extracting the offspring from the functionome for the four SC staging groups. The key immunological functions extracted from immunofunctionomes with a series of filters revealed that the immunopathy of SC consisted of a group of deregulated functions with the core members including B cell activation and differentiation, regulation of leukocyte chemotaxis/cellular extravasation, antigen receptor mediated signaling pathway, T helper mediated immunity and macrophage activation; and the auxiliary elements included leukocyte mediated immunity, regulation of inflammatory response, T cell differentiation, mononuclear cell migration, megakaryocyte differentiation, complement activation and cytokine production. These deregulated immunological functions reveal the candidates to target in the immunotherapy.

Abstract PR03: Arginine deprivation as a potential targeted therapy for clear cell ovarian carcinoma

Abstract In this study, we explored the metabolic pathways of clear cell ovarian carcinoma (CCOC) and the therapeutic importance of aberrant arginine metabolism in this cancer. In 2017, an estimated 22,440 women will be diagnosed with epithelial ovarian carcinoma (EOC) in the United States. EOC is divided into subtypes based on histology and prognosis. Among them, CCOC is truly a unique entity. Histologically, CCOC is characterized by clear cytoplasm, which stains PAS positive, indicating aberrant cellular glycogen storage. Genomic studies in CCOC have identified recurrent mutations in the ARID1A and PIK3CA genes, both encoding proteins with crucial roles in cellular metabolism, which further supports CCOC being a metabolism-dependent malignancy. At late stage, CCOC is more aggressive and refractory to conventional platinum-based therapy, compared to other EOC subtypes. Despite the lack of efficacy, platinum-based chemotherapy is still the gold standard for treating all EOC subtypes. The lack of targeted therapy for CCOC paints a grim picture for the patients as they inevitably relapse. Using a mass spectrometry-based study, we characterized the whole proteome of 17 formalin-fixed, paraffin-embedded (FFPE) patient CCOC tumors. The CCOC cases separated into 2 distinct subgroups based on unsupervised hierarchical clustering. We identified the top 250 most differentially expressed proteins between these 2 groups using Protein Expression Control Analysis (PECA) and subsequent pathway analysis through KEGG. Of these 250 proteins, 56 were metabolism-related, including Argininosuccinate Synthase 1 (ASS1). ASS1 is a crucial enzyme in the cellular synthesis of arginine; a deficiency in the enzyme makes cancer cells dependent on extracellular arginine for survival. In ASS-1 deficient sarcomas, targeted small-molecule therapy depriving extracellular arginine results in cell death and sensitization to conventional chemotherapy. In transcriptomic analysis of 55 patient CCOC tumors and cell lines, 13 cases had low ASS1 RNA expression compared to others. Subsequently, we collected 97 CCOC cases from a local tissue bank and studied ASS1 protein expression using immunohistochemistry. In these cases, ASS1 expression ranges from strong to diffusely weak to null, confirming the differential expression discovered in the proteomic and transcriptomic study. To this end, ASS1 levels were assessed in CCOC, endometrioid, and high-grade serous cell lines. ASS1 was not expressed in a subset of CCOC cell lines and was low in others. We further demonstrate that a subset of CCOC cell lines are sensitive to arginine deprivation, indicating that there may be some CCOC tumors that would benefit from combined arginine deprivation in conjunction with the gold standard platinum-based therapy. This abstract is also being presented as Poster A13. Citation Format: Jennifer Xiao Ye Ji, Dawn R. Cochrane, Basile Tessier-Cloutier, Lien N. Hoang, Yikan Wang, Angela Cheung, Christine Chow, Shane Colborne, Christopher Hughes, Gregg B. Morin, David G. Huntsman. Arginine deprivation as a potential targeted therapy for clear cell ovarian carcinoma. [abstract]. In: Proceedings of the AACR Conference: Addressing Critical Questions in Ovarian Cancer Research and Treatment; Oct 1-4, 2017; Pittsburgh, PA. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(15_Suppl):Abstract nr PR03.

Clinical implication for endometriosis associated with ovarian cancer.

We reviewed current literature regarding the association of endometriosis and epithelial ovarian cancer based on epidemiology studies, molecular researches and clinical observations. Our methods include a review of literature research of MEDLINE, PubMed, Cochrane Library of Systematic Reviews and reference search in selected papers. The life time risk of epithelial ovarian cancer in women with endometriosis is low, yet there might be a cluster of individuals who have higher risk of developing epithelial ovarian cancer from endometriosis. Endometriosis associated ovarian cancer (EAOC) is predominant in particular histological subtypes of epithelial ovarian carcinoma and are related to some specific molecular aberrations. Clinical observations showed age as an important variable to the development of EAOC. Rapid growth of tumor and solid components in sonography are key features to detect malignant transformation of endometriosis. Evidence is not clear about prophylactic oophorectomy in preventing EAOC in patients with endometriosis. This review provided rationale data for identifying, monitoring, counseling and management of women with endometriosis who are potentially high risk for malignant transformation.

Characterization of ovarian clear cell carcinoma using target drug-based molecular biomarkers: implications for personalized cancer therapy

BackgroundIt has long been appreciated that different subtypes (serous, clear cell, endometrioid and mucinous) of epithelial ovarian carcinoma (EOC) have distinct pathogenetic pathways. However, clinical management, especially chemotherapeutic regimens, for EOC patients is not subtype specific. Ovarian clear cell carcinoma (CCC) is a rare histological subtype of EOC, which exhibits high rates of recurrence and low chemosensitivity. We assessed potential therapeutic targets for ovarian CCC patients through analyzing the variation of drug-based molecular biomarkers expression between ovarian CCC and high-grade serous carcinoma (HGSC).MethodsSeven candidate drug-based molecular biomarkers, human epidermal growth factor receptor (EGFR), human epidermal growth factor receptor-2 (HER2), phosphatase and tensin homolog deleted on chromosome ten (PTEN), aurora kinase A (AURKA), breast cancer susceptibility gene 1 (BRCA1), breast cancer susceptibility gene 2 (BRCA2) and programmed death-ligand 1 (PD-L1) were measured in 96 ovarian CCC and 113 HGSC by immunohistochemistry in paraffin embedded tissues. The relationship between these biomarkers and clinicopathological factors were explored.ResultsThe expression level of four of the seven drug-based molecular biomarkers was markedly different between HGSC and CCC. High expression levels of HER2 and PD-L1 were more commonly observed in CCC patients (12.6% vs 2.7%, 21.1% vs 11.6%, P = 0.006, 0.064, respectively), while loss of BRCA1 and BRCA2 expression were more frequently occurred in HGSC patients (72.6% vs 54.3%, 89.4% vs 79.8%, P = 0.007, 0.054, respectively). Survival analysis showed that five of seven biomarkers had prognostic values but varied between subtypes. Furthermore, EGFR expressed frequently in CCC patients with endometriosis than in HGSC patients (44.4% vs 8.3%, P = 0.049). AURKA and PD-L1 correlated with the resistance to platinum-based chemotherapy in CCC patients (P = 0.043, 0.028, respectively) while no similar results were observed in HGSC patients.ConclusionOvarian CCC showed a markedly different expression map of drug-based molecular biomarkers from HGSC, which suggested a new personalized target therapy in this rare subtype.

Efficacy of glypican-3-derived peptide vaccine therapy on the survival of patients with refractory ovarian clear cell carcinoma

ABSTRACTCompared with other epithelial ovarian carcinoma subtypes, ovarian clear cell carcinoma (OCCC) has been recognized to show chemoresistance. Therefore, new treatment modalities are required for patients with OCCC that is refractory to chemotherapy. The carcinoembryonic antigen glypican-3 (GPC3) is expressed by approximately half of OCCC and is a promising immunotherapeutic target. The purpose of this study was to evaluate the effect of GPC3 peptide vaccine against refractory OCCC patients. We conducted a phase II trial with a GPC3-derived peptide vaccine in OCCC patients. Immunological responses were analyzed by ex vivo IFNγ ELISPOT assay. We also evaluated control subjects, who received best supportive care without vaccinations during the same period.Thirty-two patients with refractory OCCC were enrolled between July 2010 and September 2015, and underwent GPC3 peptide vaccination. Fifteen patients were vaccinated less than six times because their general condition progressively deteriorated, and 17 patients were vaccinated at least six times. Three patients showed a partial response as the best overall response. The GPC3 peptide vaccine induced a GPC3-specific CTL response in 15 out of 24 patients who had PBMCs collected three times or more. The prognosis of palliative care patients without GPC3 peptide vaccinations was significantly poorer than that of those with GPC3 peptide vaccinations (post cancer-treatment survival: p = 0.002).Although the disease control rate was not high, our results suggest that GPC3 peptide vaccinations may hold a significant impact to prolong survival of patients with refractory OCCC, allowing them to maintain quality of life with no serious toxicities.

Epithelialization of mouse ovarian tumor cells originating in the fallopian tube stroma.

Epithelial ovarian carcinoma accounts for 90% of all ovarian cancer and is the most deadly gynecologic malignancy. Recent studies have suggested that fallopian tube fimbriae can be the origin of cells for high-grade serous subtype of epithelial ovarian carcinoma (HGSOC). A mouse HGSOC model with conditional Dicer-Pten double knockout (Dicer-Pten DKO) developed primary tumors, intriguingly, from the fallopian tube stroma. We examined the growth and epithelial phenotypes of the Dicer-Pten DKO mouse tumor cells contributable by each gene knockout. Unlike human ovarian epithelial cancer cells that expressed full-length E-cadherin, the Dicer-Pten DKO stromal tumor cells expressed cleaved E-cadherin fragments and metalloproteinase 2, a mixture of epithelial and mesenchymal markers. Although the Dicer-Pten DKO tumor cells lost the expression of mature microRNAs as expected, they showed high levels of tRNA fragment expression and enhanced AKT activation due to the loss of PTEN function. Introduction of a Dicer1-expressing construct into the DKO mouse tumor cells significantly reduced DNA synthesis and the cell growth rate, with concurrent diminished adhesion and ZO1 epithelial staining. Hence, it is likely that the loss of Dicer promoted mesenchymal-epithelial transition in fallopian tube stromal cells, and in conjunction with Pten loss, further promoted cell proliferation and epithelial-like tumorigenesis.

Gene Set-Based Integrative Analysis Revealing Two Distinct Functional Regulation Patterns in Four Common Subtypes of Epithelial Ovarian Cancer.

Clear cell (CCC), endometrioid (EC), mucinous (MC) and high-grade serous carcinoma (SC) are the four most common subtypes of epithelial ovarian carcinoma (EOC). The widely accepted dualistic model of ovarian carcinogenesis divided EOCs into type I and II categories based on the molecular features. However, this hypothesis has not been experimentally demonstrated. We carried out a gene set-based analysis by integrating the microarray gene expression profiles downloaded from the publicly available databases. These quantified biological functions of EOCs were defined by 1454 Gene Ontology (GO) term and 674 Reactome pathway gene sets. The pathogenesis of the four EOC subtypes was investigated by hierarchical clustering and exploratory factor analysis. The patterns of functional regulation among the four subtypes containing 1316 cases could be accurately classified by machine learning. The results revealed that the ERBB and PI3K-related pathways played important roles in the carcinogenesis of CCC, EC and MC; while deregulation of cell cycle was more predominant in SC. The study revealed that two different functional regulation patterns exist among the four EOC subtypes, which were compatible with the type I and II classifications proposed by the dualistic model of ovarian carcinogenesis.

Gene Set-Based Functionome Analysis of Pathogenesis in Epithelial Ovarian Serous Carcinoma and the Molecular Features in Different FIGO Stages.

Serous carcinoma (SC) is the most common subtype of epithelial ovarian carcinoma and is divided into four stages by the Federation of Gynecologists and Obstetrics (FIGO) staging system. Currently, the molecular functions and biological processes of SC at different FIGO stages have not been quantified. Here, we conducted a whole-genome integrative analysis to investigate the functions of SC at different stages. The function, as defined by the GO term or canonical pathway gene set, was quantified by measuring the changes in the gene expressional order between cancerous and normal control states. The quantified function, i.e., the gene set regularity (GSR) index, was utilized to investigate the pathogenesis and functional regulation of SC at different FIGO stages. We showed that the informativeness of the GSR indices was sufficient for accurate pattern recognition and classification for machine learning. The function regularity presented by the GSR indices showed stepwise deterioration during SC progression from FIGO stage I to stage IV. The pathogenesis of SC was centered on cell cycle deregulation and accompanied with multiple functional aberrations as well as their interactions.

Endometriosis-associated ovarian cancer

This article reviews recent advance in our understanding of ovarian endometriomas, with special reference of atypical epithelial features (atypical endometriosis) and its relationship to neoplasm. Mainly, two epithelial ovarian carcinoma subtypes, the ovarian clear cell carcinomas and the endometrioid ovarian carcinomas, have been molecularly and epidemiologically linked to endometriosis. The clear cell and endometrioid adenocarcinomas have common immunohistochemical markers, genetic changes are the same as atypical endometriosis. The occurrence of ARID1A mutations and alterations in the PI3K/AKT pathway in endometriosis and endometriosis-associated ovarian carcinomas, as well as the possible functional and clinical implications are discussed in this review. Therefore, development of a screening method that can detect mutations of ARID1A and activation of the PI3K/AKT pathway might enable early diagnosis of endometriosis associated ovarian cancers and endometrial cancers.

Abstract CT219: Clinical and immunological analysis in a phase II trial of the glypican-3 peptide vaccine for patients with ovarian clear cell carcinoma

Abstract Compared with other epithelial ovarian carcinoma subtypes, ovarian clear cell carcinoma (OCCC) is associated with a poorer prognosis and increased chemoresistance. Therefore, new treatment modalities are urgently required for patients with OCCC refractory to chemotherapy. Glypican-3 (GPC3) is useful not only as a novel tumor marker, but also as an oncofetal antigen for immunotherapy. It is specifically overexpressed in hepatocellular carcinoma (HCC). Previous studies demonstrated that GPC3 was also overexpressed in several malignant tumors, including OCCC. We previously reported the safety of and immunological and clinical responses to a GPC3-derived peptide vaccine in a phase I clinical trial of patients with advanced HCC. Although the efficacy of the GPC3-derived peptide vaccine against HCC patients was evaluated, other GPC3-positive cancer patients have not yet been investigated. Therefore, we conducted a phase II trial to evaluate the clinical outcome of OCCC patients treated with a GPC3-derived peptide vaccine (UMIN-CTR: 000003696). In this study, we describe the effect of vaccination with the HLA-A24 or A2-restricted GPC3 peptide on patients with OCCC. The patients were divided into three groups such as adjuvant therapy group, combined therapy group (combined to second-line chemotherapy) and recurrence or advanced group (single of vaccine treatment). The dose of GPC3 peptide injected was 3 mg per body. Patients received the intradermal injection of GPC3 peptide emulsified with incomplete Freund's adjuvant. Vaccinations were carried out biweekly from the first until the 6th and repeated at 6-week intervals after the 7th. Immunological responses were analyzed by ex vivo IFN-γ enzyme-linked immunospot assay (ELISPOT). Seventy OCCC patients were entered into clinical trial until the end of October 2014. In adjuvant group, twenty-nine of thirty-five patients have no recurrence. Recurrence pattern of all 6 patients was peritoneal metastasis. Three of twenty-nine patients with refractory OCCC achieved a significant clinical response. Ex vivo IFN-γ ELISPOT analysis in most OCCC patients revealed vaccine-induced immune reactivity against the GPC3 peptide. Our current data provide preliminary evidence of clinically meaningful benefit for GPC3 peptide vaccines in OCCC and support further evaluation of this approach in these patient populations. Citation Format: Shiro Suzuki, Kiyosumi Shibata, Fumitaka Kikkawa, Tetsuya Nakatsura. Clinical and immunological analysis in a phase II trial of the glypican-3 peptide vaccine for patients with ovarian clear cell carcinoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr CT219. doi:10.1158/1538-7445.AM2015-CT219

Abstract 3283: GWAS identifies risk variants for mucinous ovarian carcinoma

Abstract Background Genome-wide association studies (GWAS) previously identified 8 new risk loci for all subtypes of epithelial ovarian carcinoma (EOC) and one specific to invasive serous EOC. One locus, at 2q31, was also associated with invasive mucinous EOC (mEOC) at P=7.3 x 10-7 (Nat Genet 2010:874). Here, we report new risk loci for mEOC, which is thought to develop from a borderline mucinous tumor. These loci may provide clues to the molecular basis of the disease. Methods We used genotype data from 4 GWAS of EOC and from multiple case-control studies in the Ovarian Cancer Association Consortium that had been genotyped using the iCOGS custom SNP panel (210k SNPs) developed for the Collaborative Oncological Gene-environment Study. We imputed genotypes of common variation across the genome using the 1000 Genomes Project reference panel and tested for association using log-additive unconditional regression models. Results Genotypes were available for 1,643 combined invasive and borderline mEOC and for 1,002 invasive-only mEOC of European ancestry. Three loci in new regions, and one locus in a previously published region, with minor allele frequency (MAF) > 1% and P ≤ 10-7 were found. The imputed SNP rs72831838 (imputation r2=0.67, MAF=0.15) is located at 2q13 in an intron of the PAX8 (paired box 8) gene (all mEOC OR=1.35, P=4.2 x 10-8 and invasive-only OR=1.43, P=9.6 x 10-8). PAX8 is a transcription factor and may be a Müllerian lineage marker that distinguishes carcinomas of gynecologic origin from other sites. The imputed variant at chr19:39745695 (imputation r2=0.61, MAF=0.32) is an insertion/deletion polymorphism located at 19q13.2 and falls within the MSRB1P1 (methionine sulfoxide reductase B1 pseudogene 1). This locus was associated with decreased risk (all mEOC OR=0.74, P = 2.1 x 10-9 and invasive-only OR=0.79, P = 8.1 x 10-5) and is enriched with the H3K27Ac histone mark that identifies active enhancers of gene expression. The imputed SNP rs6425050 (imputation r2=0.45, MAF=0.19) is located at 1q25 (all mEOC OR=1.38, P=4.7 x 10-8 and invasive-only OR=1.41, P=1.6x10-6). This SNP is intronic to PLA2G4A (phospholipase A2, group IVA), which encodes an enzyme that hydrolyzes membrane phospholipids for eicosanoid metabolism and signaling. None of these loci were associated with other EOC histological subtypes at P ≤ 10-7. The genotyped SNP, rs711830 (MAF=0.32), is located at 2q31.1 in the 3′ region of the HOXD3 homeobox gene (all mEOC OR=1.30, P=7.5 x 10-12 and invasive-only OR=1.26, P=7.8 x 10-7). This SNP is highly correlated (r2=0.99) with rs2072590, which is located 5.3kb upstream and previously reported by us to be associated with mEOC and invasive serous EOC (Nat Genet 2010:874). The HOXD3 locus is highly conserved and may also be a marker of Müllerian cell type origin. Conclusions The 3 new loci for mEOC require confirmation by genotyping. Fine mapping and functional analysis of all loci is needed in order to determine their likely target genes. Citation Format: Linda E. Kelemen, Jonathan Tyrer, Catherine M. Phelan, Susan J. Ramus, Andrew Berchuck, Simon A. Gayther, Ellen L. Goode, Celeste L. Pearce, Joellen M. Schildkraut, Georiga Chenevix-Trench, Alvaro N. Monteiro, Marc T. Goodman, Thomas A. Sellers, Paul PD Pharoah. GWAS identifies risk variants for mucinous ovarian carcinoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3283. doi:10.1158/1538-7445.AM2014-3283

Expression of mitochondrial regulators PGC1α and TFAM as putative markers of subtype and chemoresistance in epithelial ovarian carcinoma.

Epithelial ovarian carcinoma (EOC), the major cause of gynaecological cancer death, is a heterogeneous disease classified into five subtypes. Each subtype has distinct clinical characteristics and is associated with different genetic risk factors and molecular events, but all are treated with surgery and platinum/taxane regimes. Tumour progression and chemoresistance is generally associated with major metabolic alterations, notably altered mitochondrial function(s). Here, we report for the first time that the expression of the mitochondrial regulators PGC1α and TFAM varies between EOC subtypes; furthermore, we have identified a profile in clear-cell carcinoma consisting of undetectability of PGC1α/TFAM, and low ERα/Ki-67. By contrast, high-grade serous carcinomas were characterised by a converse state of PGC1α/TFAM, ERα positivity and a high Ki-67 index. Interestingly, loss of PGC1α/TFAM and ERα was found also in a non-clear cell EOC cell line made highly resistant to platinum in vitro. Similar to clear-cell carcinomas, these resistant cells also showed accumulation of glycogen. Altogether, our data provide mechanistic insights into the chemoresistant nature of ovarian clear-cell carcinomas. Furthermore, these findings corroborate the need to take into account the diversity of EOC and to develop subtype specific treatment strategies.

Abstract B32: The role of the glucocorticoid receptor (GR) in inhibiting chemotherapy-induced apoptosis in high-grade serous ovarian carcinoma (HGS-OvCa)

Abstract Background: Ovarian cancer is the leading cause of death from gynecologic malignancies in developed countries. High-grade serous ovarian cancer (HGS-OvCa) is often initially sensitive to platinum-based therapy, but relapse rates remain high. The TCGA recently found that HGS-OvCas have a gene expression and mutational profile similar to that of triple negative breast cancer (TNBC). Previously, our group demonstrated that dexamethasone treatment decreased chemotherapy-induced tumor cell apoptosis in TNBC and HGS-OvCa cell lines. We have also shown that glucocorticoid receptor (GR) activation induces expression of anti-apoptotic genes SGK1 and MKP1/DUSP1 in both HGS-OvCa and TNBC cell lines and in primary human ovarian and TNBC tumors. Methods: We examined glucocorticoid receptor (GR), estrogen receptor (ER), and progesterone receptor (PR) expression in a panel of HGS-OvCa cell lines by Western analysis and qRT-PCR. We evaluated GR target genes SGK1, MKP1/ DUSP1, and GILZ to determine if there is a difference in expression of the anti-apoptotic genes when exposed to glucocorticoids versus glucocorticoid antagonist. We also performed apoptosis assays with and without mifepristone, glucocorticoid and/or chemotherapy treatment using IncuCyte™ live-cell imaging technology in order to measure the effect of GR modulation in chemotherapy sensitivity. In addition, we examined human tissue microarrays of various subtypes of epithelial ovarian carcinoma using immunohistochemical stain (IHC) to examine the tumors for ER, PR, and GR expression. Results: HGS-OvCa cell lines (including CAOV3, HeyA8, SKOV3, Monty-1) all had detectable GR expression; HeyA8, SKOV3, and Monty-1 cell lines expressed very low levels of ER-alpha while all other HGS-OvCa cell lines did not express any detectable ER-alpha. Furthermore, none of the HGS-OvCa cell lines tested expressed PR. Similar findings of GR and PR expression were also demonstrated in the primary ovarian cancer tissue microarrays. Known GR target genes SGK1, MKP1, and GILZ were upregulated in the presence of the glucocorticoid agonist dexamethasone and the addition of mifepristone inhibited this response. Apoptosis assays revealed that GR activation significantly inhibited carboplatin/gemcitabine-induced apoptosis in HGS-OvCa cell lines and that mifepristone could inhibit this cell survival effect, presumably through GR antagonism. Conclusions: These results suggest that treatment with mifepristone, a GR antagonist, reverses GR-mediated cell survival signaling in HGS-OvCa and increases chemotherapy-induced tumor cell death. This preliminary data may suggest that the glucocorticoid receptor may potentially be a good target for future therapeutics. To further investigate the role of GR activity in HGS-OvCas in vivo, we are currently performing xenograft experiments with chemotherapy +/- mifepristone treatment and exploring phase I clinical trials. Citation Format: Erica M. Stringer, Maxell N. Skor, Lei Zhao, Katja Gwin, Ernst Lengyel, Gini F. Fleming, Suzanne D. Conzen. The role of the glucocorticoid receptor (GR) in inhibiting chemotherapy-induced apoptosis in high-grade serous ovarian carcinoma (HGS-OvCa). [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: From Concept to Clinic; Sep 18-21, 2013; Miami, FL. Philadelphia (PA): AACR; Clin Cancer Res 2013;19(19 Suppl):Abstract nr B32.

ARID1A Mutations and PI3K/AKT Pathway Alterations in Endometriosis and Endometriosis-Associated Ovarian Carcinomas

Endometriosis is a common gynecological disease affecting 6%–10% of women of reproductive age and is characterized by the presence of endometrial-like tissue in localizations outside of the uterine cavity as, e.g., endometriotic ovarian cysts. Mainly, two epithelial ovarian carcinoma subtypes, the ovarian clear cell carcinomas (OCCC) and the endometrioid ovarian carcinomas (EnOC), have been molecularly and epidemiologically linked to endometriosis. Mutations in the gene encoding the AT-rich interacting domain containing protein 1A (ARID1A) have been found to occur in high frequency in OCCC and EnOC. The majority of these mutations lead to a loss of expression of the ARID1A protein, which is a subunit of the SWI/SNF chromatin remodeling complex and considered as a bona fide tumor suppressor. ARID1A mutations frequently co-occur with mutations, leading to an activation of the phosphatidylinositol 3-kinase (PI3K)/AKT pathway, such as mutations in PIK3CA encoding the catalytic subunit, p110α, of PI3K. In combination with recent functional observations, these findings strongly suggest cooperating mechanisms between the two pathways. The occurrence of ARID1A mutations and alterations in the PI3K/AKT pathway in endometriosis and endometriosis-associated ovarian carcinomas, as well as the possible functional and clinical implications are discussed in this review.

Immunoexpression and prognostic role of p53 in different subtypes of epithelial ovarian carcinoma

We sought to investigate the significance of p53 expression for epithelial ovarian carcinoma. In this study, we used immunohistochemical method to investigate the expression patterns of p53 in different subtypes of epithelial ovarian carcinoma. We found that the expressions of p53 protein in epithelial ovarian cancer (pituita, serosity and intima) were 88.9%, 75% and 100%, respectively, while the recurrence rates among three cancer subtypes were significantly different (33.3%, 12.5% and 0%, respectively; P < 0.05). Compared with patients without lymph node metastasis, the expression of p53 in patients with lymph node metastasis was significantly strong (68.75% and 100%, respectively; P < 0.05). However, the recurrence rate in the patients with lymph node metastasis (40%) was higher than that without lymph node metastasis (6.25%, P < 0.05). The expressions of p53 protein in ovarian cancer between I-II (25%) stage and II – IV stage (100%) were significantly different (P < 0.05), and the recur-rence rates between the two groups were significantly different (0% and 31.25%, respectively, P < 0.05). There-fore, p53 protein has an intimate relationship with the malignant degree and the prognosis of ovarian cancer.

Prognosis of ovarian clear cell carcinoma compared to other histological subtypes: A meta-analysis

Objective To compare the survival outcome between clear cell carcinoma (CCC) and other histological subtypes in epithelial ovarian carcinoma (EOC). Methods From January 1974 to February 2011, we identified a total of 31,800 (CCC; 2152, non-CCC; 29648) patients from 12 studies meeting the inclusion criteria. Results Heterogeneity tests demonstrated significant between-study variation ( I 2 = 92.1%) with no significant difference in hazard ratio (HR) for death between CCC and non-CCC (HR; 1.16, 95% CI; 0.85–1.57, random-effects model). Comparing the HR based on stage I + II, and stage III + IV, between CCC and non-CCC, showed that CCC patients had a higher hazard rate for death than those with non-CCC of the ovary (stage I + II; HR; 1.17, 95% CI; 1.01–1.36, stage III + IV; HR; 1.65, 95% CI; 1.52–1.79). In a comparison of CCC and serous EOC, advanced stage (III and IV) CCC only showed a poorer hazard rate for death than serous EOC (HR; 1.71, 95% CI; 1.57–1.86). Conclusion This analysis suggests that ovarian CCC patients had poorer prognosis than those with other histological subtypes of EOC, especially in advanced EOC stages. Different treatment strategies may be needed for patients with ovarian CCC.