High-grade Ovarian Tumors Research Articles

Potential of AKNA as a Predictive Biomarker for Ovarian Cancer and Its Relationship to Tumor Grading.

Ovarian cancer exhibits a significant prevalence and incidence on a global scale. Low-grade or high-grade epithelial-type ovarian cancer can be classified by using the dualistic model. Inflammation has been associated with AKNA protein by cancer researchers. The potential of AKNA as a cancer biomarker is supported by its significance and association with ovarian carcinoma. Uninvestigated is this enormous potential. This study examines the correlation between AKNA expression in low-grade and high-grade ovarian tumors and its utility as a predictive biomarker for ovarian cancer. This study examined a total of thirty-one samples, which were classified into three groups: cyst, low-grade, and high-grade ovarian carcinoma. The departmental archive was accessed for the following information: age, tumor size, nuclear grade, mitosis, ovary volume, implant tumor status, lymph vascular invasion status, lymph node metastasis, and tumor-infiltrating lymphocyte. The expression of AKNA was determined using IHC staining. The information was collected and analyzed via analysis of variance. The AKNA H-score shows the mean difference between all three groups (P < 0.001). Cysts had the highest AKNA expression, followed by low-grade and high-grade ovarian carcinoma. Higher-grade ovarian cancer expressed less AKNA compared to cysts or low-grade forms of the disease. This considerable difference suggests that AKNA might predict ovarian cancer tumor grade.

Abstract B001: Identification of monoallelic ATM loss-of-function and homologous recombination deficiency (HRD) in high-grade ovarian tumor with prolonged response to camonsertib and low-dose gemcitabine combination therapy

Abstract Intra-tumor heterogeneity and the prevalent loss-of-function mutations within DNA damage repair (DDR) genes constitute salient hallmarks of high-grade ovarian malignancies. However, the etiological drivers beyond BRCA1/2 mutations, as well as the chronology of tumor evolutionary processes, remain enigmatic. Here, we present the case of a 60-year-old female with high-grade serous ovarian cancer, initially treated with primary debulking surgery followed by 6 cycles of adjuvant intraperitoneal cisplatin and paclitaxel. After a 16-month platinum-free interval, the patient (pt) developed recurrent disease and subsequently received 5 weeks of neoadjuvant olaparib followed by secondary debulking surgery and adjuvant carboplatin as part of a clinical trial (NCT02489006). The pt became platinum refractory after 4 cycles of carboplatin, then received weekly paclitaxel and biweekly bevacizumab with stable disease as best response and eventual progression after 17 cycles. Molecular profiling of the metastatic biopsies at the time of initial recurrence identified a pathogenic ATM (c.4910-1G&amp;gt;A) alteration for which the pt was then enrolled onto the Phase Ib TRESR trial (NCT04497116). The trial enrolled pts ≥18 years, ECOG PS 0-1, with advanced solid tumors with deleterious DDR alterations. The pt received a starting dose of 1000mg/m2 gemcitabine (gem) with 80mg of the ATR inhibitor camonsertib (cam; 3 days [d] on/4d off) on a 21d cycle (2 weeks [w] on/2w off). The pt had a partial RECIST 1.1 response at 4 months (mo) and remains on treatment after 18mo. Due to toxicities (primarily neutropenia) the pt had a series of dose reductions to 200mg/m2 gem with 50mg cam (2d on/5d off) on a 28d cycle (1w on/1w off). Circulating tumor fraction (TF), measured by methylation-based profiling, remained at or below the limit of quantitation of the assay through 11mo (0.01% TF, testing of later timepoints ongoing). At 13mo, the target lesions began increasing in size (-50% to -43%) prompting a dose increase of cam to 80mg (same gem dose), after which the target lesions decreased to nadir (-52%) at 76w with concomitant CA-125 decrease. Retrospective whole-genome sequencing (WGS) of the secondary debulking surgery specimen as well as targeted sequencing (SyNthetic lethal Interactions for Precision Diagnostics [SNiPDx]) and immunohistochemistry of the metastatic biopsy revealed ATM protein loss only in a portion of the tumor and a monoallelic ATM mutation. Genomic signature analysis of WGS indicated presence of single-base substitution signatures 3+8 (HRD-related) and HRD positivity (BRCA1-type; CHORD algorithm). In contrast, while HRD+ was also detected in the primary tumor sample, the ATM alteration was absent and ATM protein expression was uniform, suggesting that ATM loss was a late event in tumor evolution. This case highlights the complexity of intra-tumor heterogeneity and clonal evolution in ovarian tumors and importance of “functional” HRD as no apparent mutational driver was identified. Citation Format: Stephanie Lheureux, Joseph D. Schonhoft, Ian M. Silverman, Julia Yang, Adrienne Johnson, Brooke Grant, Alexander Fortuna, Trevor J. Pugh, Parham Nejad, Bernard Lam, Sahaj Arora, Ashley Adile, Stephenie D. Prokopec, Jeffrey Bruce, Danielle Ulanet, Maria Koehler, Ezra Rosen, Victoria Rimkunas. Identification of monoallelic ATM loss-of-function and homologous recombination deficiency (HRD) in high-grade ovarian tumor with prolonged response to camonsertib and low-dose gemcitabine combination therapy [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: DNA Damage Repair: From Basic Science to Future Clinical Application; 2024 Jan 9-11; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2024;84(1 Suppl):Abstract nr B001.

Abstract 2429: Tumor and stromal AXL expression regulate ovarian cancer metastasis

Abstract Objective: Over 75% of patients with ovarian cancer present with widely metastatic disease. We have previously published that AXL is highly expressed in primary ovarian cancer tumors. However, it is unknown whether AXL expression in metastatic tumors correlates with outcome. Additionally, the role of stromally expressed AXL in metastasis has not been fully evaluated. Thus, the objective of this study is to evaluate the role of tumor and stromal AXL in the key steps of tumor metastasis. Methods: Immunohistochemistry was used to measure AXL expression in a tissue microarray with primary and metastatic high grade ovarian tumors. Attachment assays as well as transwell and spheroid invasion assays were performed on established ovarian cancer cell lines. Mesothelial cell clearance assays utilizing human omentum-cultured mesothelial cells (HPMC) and additional invasion assays utilizing normal omental fibroblasts (NOF) were performed. Results: 214 tumor samples were included from 139 patients: 122 primary and 92 metastatic sites, contributing to 85 matched samples. Most had high-grade serous histology (79%) and stage III-IV disease (79%). High AXL expression in metastatic tumors was associated with decreased overall survival (HRadj 1.8, 95% CI 1.03-3.1), but expression in primary tumors was not (1.1, 0.61-2.0). High vs. low AXL expression in metastases was associated with a decreased platinum-free interval (5.92 vs 15.9 months, P=0.03) and decreased progression-free survival (11.6 vs 18.8 months, P=0.02).Tumor AXL expression correlated with stromal AXL expression (R2=0.50, P&amp;lt;0.001). Human ovarian tumor cells depleted of AXL had decreased attachment (OVCAR3-TPMES, 0.55-fold decrease P&amp;lt;0.001) and invasion in transwell (OVCAR5, 173 vs 262 invasive tumor cells/hpf, P&amp;lt;0.01) and spheroid (ES2, 87% vs 31% area invaded, P&amp;lt;0.0001) invasion assays. Human ovarian cancer cells plated on AXL-deficient HPMCs had less cell clearance than those plated on AXL-expressing HPMCs (ES2, 6.0 vs 3.9 normalized area cleared, P&amp;lt;0.001). Further, human ovarian cancer cells plated on AXL-deficient NOFs had less invasion than tumor cells plated on AXL expressing NOFs (OVCAR5, 173 vs 262 invasive tumor cells/hpf, P&amp;lt;0.01). Conclusions: High AXL expression in metastatic ovarian cancer cells correlates with worse survival and worse response to chemotherapy. Further, AXL expression in both tumor and stromal cells contributes to the steps of ovarian cancer metastasis. Citation Format: Mary Margaret Mullen, Lillian N. van Biljon, Jeanne Quinn, Molly Greenwade, Gregory Opara, Hollie Noia, Ian S. Hagemann, Andrea R. Hagemann, Lindsay M. Kuroki, Carolyn K. McCourt, Premal H. Thaker, Matthew A. Powell, David G. Mutch, Dineo Khabele, Katherine C. Fuh. Tumor and stromal AXL expression regulate ovarian cancer metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2429.

Precision Oncology of High-Grade Ovarian Cancer Defined through Targeted Sequencing.

Simple SummaryOvarian cancer is a rare and deadly gynaecologic cancer, with a relatively large hereditary component. Genomic analysis of tumour material can potentially provide information regarding therapy and identify hereditary carriers and their families. The aim of our prospective study was to apply genomic characterization to tumour material from women with ovarian cancer to identify women that might benefit from PARP inhibitor therapy, as well as to detect and triage women to genetic counselling. We used next generation sequencing using a targeted panel to prospectively analyse 274 tumours and identified 50 with a BRCA1/2 pathogenic variant. Twenty patients received olaparib based on these results, and 16 previously unknown hereditary carriers were identified. In addition, in a subset examined by an extended sequencing panel, actionable mutations were found in 84/88 tumours. This study demonstrates that personalized medicine approaches can be useful for women with ovarian cancer and can help with therapy selection and identification of at risk families. Background: We examined whether molecular characterization of high-grade epithelial ovarian cancer can inform the diagnosis and/or identify potential actionable targets. Methods: All of the consecutively sequenced high-grade ovarian tumours with consent between 2014 until 2019 were included. A total of 274 tumours underwent next generation sequencing using a targeted panel. Results: Patients with high-grade ovarian epithelial cancer were consented to prospective molecular characterization. Clinical information was extracted from their medical record. Tumour DNA was subjected to sequencing, and selected patients received PARP inhibitor therapy. Conclusions: Tumours from 274 women were sequenced, including high-grade serous carcinoma (n = 252), clear cell carcinoma (n = 4), carcinosarcoma (n = 9), endometrioid carcinoma (n = 3), undifferentiated carcinoma (n = 1), and mixed tumours (n = 5). Genomic profiling did not influence histologic diagnosis. Mutations were identified in TP53, BRCA1, BRCA2, as well as additional homologous recombination repair pathway genes BARD1, ATR, CHEK2, PALB2, RAD51D, RAD50, SLX4, FANCA, RAD51C, and RAD54L. In addition, mutations in PTEN and CDKN2A were identified. Several somatic mutations with implications for germline testing were identified, including RMI1, STK11, and CDH1. Germline testing identified 16 previously unknown BRCA1/2 carriers. Finally, 20 patients were treated with the PARP inhibitor olaparib based on the sequencing results.

Intrinsic STING expression inversely associates with survival in ovarian cancer patients

<h3>Objectives:</h3> The DNA sensing cGAS-STING signaling pathway plays a dual role of anti-tumor immunity and tumorigenesis. Chemoradiotherapy and PARPi induce DNA damage leading to activation of the cGAS-STING pathway, robust anti-tumor responses and improved clinical outcomes. Chronic activation of STING signaling creates an immunosuppressive TME and promotes metastases. Studies show that ovarian cancer cells have defective STING signaling. Current therapeutic strategies are focused on harnessing the beneficial effects of PARPi, IC blockade and STING agonists. However, the role for intrinsic ovarian tumor cGAS-STING levels in treatment responses and patient survival is unknown. The goal of this study is to determine the effect of tumor-specific cGAS-STING expression on survival in ovarian cancer patients. <h3>Methods:</h3> Using the Roswell Park Cancer Registry (RPCR), TMAs were generated from 488 patients treated for ovarian, fallopian tube or primary peritoneal cancer from 1991-2012. TMAs were stained for cGAS, STING and CD8 by IHC. cGAS and STING were scored based on the staining intensity (0-3) and the percent of positive cells (0-3) with a maximum combined score of 6 (0=no expression, 6=strong staining in >50% of cells). Additionally, the OS, PFS and cGAS-STING expression in 558 ovarian cancer patients from TCGA were analyzed. Clinico-pathologic data (age, demographics, histopathology, stage, tumor grade, treatment response, recurrence and survival) were retrieved from the electronic health records. <h3>Results:</h3> TCGA ovarian cancer patients with tumors expressing cGAShighSTINGhigh compared to cGASlowSTINGlow had OS of 38.4 months vs. 31.18 months (p=0.05). There was a significant positive correlation between gene and protein expression for cGAS (r=0.39, p=0.01) and STING (r=0.62, p<0.0001). Of the 488 patients in the RPCR, 95.3% were Caucasian with a median age at diagnosis of 63 years (range 20-93) and a median follow up of 44 months (range 0-279). The majority were diagnosed at an advanced surgical stage (68% and 14% at stage III and IV respectively), serous histology in 72% and high grade in 90.6% of cases. 72% received optimal and 27% had suboptimal debulking surgery. All patients received adjuvant platinum and taxane chemotherapy and the initial recurrence rate was 52%. In addition, 42.2% were platinum sensitive, 30% were refractory and 18% were platinum resistant. During the first 60 months of follow up, there was a trend toward improved OS and PFS in patients with cGASlowSTINGlow compared to cGAShighSTINGhigh tumors. Independently, cGAS did not associate with OS or PFS. Interestingly, STING high tumors correlated positively with CD8+ TILs (r=0.05, p=0.0002) but associated with decreased PFS (p=0.016). <h3>Conclusions:</h3> TCGA dataset revealed cGAShighSTINGhigh expressing tumors correlated with improved OS. By contrast, high grade ovarian tumors with intrinsically high levels of STING correlate with increased CD8+ TILs and decreased PFS.

Does dual-energy CT differentiate benign and malignant ovarian tumours?

To assess the ability of dual-energy computed tomography (DECT) to distinguish benign from malignant ovarian tumours (OTs). Following approval of the institutional review board, the institutional database was mined for treatment-naive patients who underwent primary cytoreduction for OT. Thirty-seven patients were included and divided into those with benign OTs (n=11) and malignant OTs (n=26), including high-grade (n=20) and low-grade (n=6) malignant OTs. Advanced processing and region of interest delineation on the ovarian mass were performed using the preoperative staging DECT examination using the Advantage Workstation. The pixel-level data of the CT attenuation values at 50, 70, and 120 keV and the effective atomic number (Zeff), water content (WC), and iodine content (IC) in the ovarian mass were recorded. The Wilcoxon rank-sum test was used to compare CT attenuation data at different voltages, Zeff, and WC and IC levels between benign and malignant OTs and between high- and low-grade malignant OTs. Simple logistic regression was used to correlate the imaging characteristics with malignant status and grade. Malignant OTs had significantly higher Zeff and IC compared with benign OTs. The threshold values for the diagnosis of malignant OT were IC≥9.74 (100 μg/cm3) with 81% sensitivity and 73% specificity and Zeff ≥8.16 with 85% sensitivity and 73% specificity. High-grade OTs had significantly higher WC compared with low-grade OTs, and a threshold of ≥1,013.92 mg/cm3 differentiated them with 80% sensitivity and 83% specificity. DECT may be a tool to help distinguish malignant and benign OTs and predict tumour grade.

Bispecific antibodies enhance tumor-infiltrating T cell cytotoxicity against autologous HER-2-expressing high-grade ovarian tumors

Epithelial ovarian cancer displays the highest mortality of all gynecological tumors. A relapse of the disease even after successful surgical treatment is a significant problem. Resistance against the current platinum‐based chemotherapeutic standard regime requires a detailed ex vivo immune profiling of tumor‐infiltrating cells and the development of new therapeutic strategies.In this study, we phenotypically and functionally characterize tumor cells and autologous tumor‐derived αβ and γδ T lymphocyte subsets. Tumor‐infiltrating (TIL) and tumor‐ascites lymphocytes (TAL) were ex vivo isolated out of tumor tissue and ascites, respectively, from high‐grade ovarian carcinoma patients (FIGO‐stage IIIa‐IV). We observed an increased γδ T cell percentage in ascites compared to tumor‐tissue and blood of these patients, whereas CD8+ αβ T cells were increased within TAL and TIL. The number of Vδ1 and non‐Vδ1/Vδ2‐expressing γδ T cells was increased in the ascites and in the tumor tissue compared to the blood of the same donors. Commonly in PBL, the Vγ9 chain of the γδ T cell receptor is usually associated exclusively with the Vδ2 chain. Interestingly, we detected Vδ1 and non‐Vδ1/Vδ2 T cells co‐expressing Vγ9, which is so far not described for TAL and TIL.Importantly, our data demonstrated an expression of human epidermal growth factor receptor (HER)‐2 on high‐grade ovarian tumors, which can serve as an efficient tumor antigen to target CD3 TIL or selectively Vγ9‐expressing γδ T cells by bispecific antibodies (bsAbs) to ovarian cancer cells. Our bsAbs efficiently enhance cytotoxicity of TIL and TAL against autologous HER‐2‐expressing ovarian cells.

Migration dynamics of ovarian epithelial cells on micro-fabricated image-based models of normal and malignant stroma

A profound remodeling of the collagen in the extracellular matrix (ECM) occurs in human ovarian cancer but it is unknown how this affects migration dynamics and ultimately tumor growth. Here, we investigate the influence of collagen morphology on ovarian cell migration through the use of second harmonic generation (SHG) image-based models of ovarian tumors. The scaffolds are fabricated by multiphoton excited (MPE) polymerization, where the process is akin to 3D printing except it achieves much greater resolution (∼0.5 µm) and utilizes collagen and collagen analogs. We used this technique to create scaffolds with complex 3D submicron features representing the collagen fiber morphology in normal stroma, high risk stroma, benign tumors, and high grade ovarian tumors. We found the highly aligned malignant stromal structure promoted enhanced motility and also increased cell and f-Actin alignment relative to the other tissues. However, using models based on fiber crimping characteristics, we found cells seeded on linear fibers based on normal stromal models yielded the highest degree of alignment but least motility. These results show that both the fiber properties themselves and as well as their overall alignment govern the resulting migration dynamics. These models cannot be synthesized by other conventional fabrication methods and we suggest the MPE image-based fabrication method will enable a variety of studies in cancer biology. Statement of significanceThe extracellular matrix collagen in ovarian cancer is highly remodeled but the consequences on cell function remain unknown. It is important to understand the operative cell matrix interactions, as this could lead to better prognostics and better prediction of therapeutic efficacy. We probe migration dynamics using high resolution (∼0.5 µm) multiphoton excited fabrication to synthesize scaffolds whose designs are derived directly from Second Harmonic Generation microscope images of the collagen in normal ovarian tissues as well as benign and malignant tumors. Collectively our results show the importance of the matrix morphology (fiber shape and alignment) on driving cell motility, cell shape and f-Actin alignment. These collagen-based models have complex fiber morphology and cannot be created by conventional fabrication technologies.

A data science approach for the classification of low-grade and high-grade ovarian serous carcinomas

BackgroundCopy Number Alternations (CNAs) is defined as somatic gain or loss of DNA regions. The profiles of CNAs may provide a fingerprint specific to a tumor type or tumor grade. Low-coverage sequencing for reporting CNAs has recently gained interest since successfully translated into clinical applications. Ovarian serous carcinomas can be classified into two largely mutually exclusive grades, low grade and high grade, based on their histologic features. The grade classification based on the genomics may provide valuable clue on how to best manage these patients in clinic. Based on the study of ovarian serous carcinomas, we explore the methodology of combining CNAs reporting from low-coverage sequencing with machine learning techniques to stratify tumor biospecimens of different grades.ResultsWe have developed a data-driven methodology for tumor classification using the profiles of CNAs reported by low-coverage sequencing. The proposed method called Bag-of-Segments is used to summarize fixed-length CNA features predictive of tumor grades. These features are further processed by machine learning techniques to obtain classification models.High accuracy is obtained for classifying ovarian serous carcinoma into high and low grades based on leave-one-out cross-validation experiments. The models that are weakly influenced by the sequence coverage and the purity of the sample can also be built, which would be of higher relevance for clinical applications. The patterns captured by Bag-of-Segments features correlate with current clinical knowledge: low grade ovarian tumors being related to aneuploidy events associated to mitotic errors while high grade ovarian tumors are induced by DNA repair gene malfunction.ConclusionsThe proposed data-driven method obtains high accuracy with various parametrizations for the ovarian serous carcinoma study, indicating that it has good generalization potential towards other CNA classification problems. This method could be applied to the more difficult task of classifying ovarian serous carcinomas with ambiguous histology or in those with low grade tumor co-existing with high grade tumor. The closer genomic relationship of these tumor samples to low or high grade may provide important clinical value.

Abstract 875: Chemical biology approach to phenotypic intra-tumor heterogeneity in high-grade serous ovarian cancer

Abstract Objective: High-grade serous ovarian cancer (HGSOC) remains the most lethal gynecologic malignancy. More than 50% of high-grade serous ovarian cancer (HGSOC) patients die due to recurrent disease within 5 years. Recurrent tumor clones are selected by chemotherapy treatment from heterogeneous subpopulations of cancer cells, and differ phenotypically. The objective of current study is to develop a high-throughput chemical biology approach to analyze phenotypic heterogeneity in HGSOC following progression of the disease. Methods: We utilize the Drug Sensitivity and Resistance Testing (DSRT) platform to assess the effects of 528 approved and investigational anti-cancer agents on primary HGSOC isolates. Samples are collected from ascites and/or solid high-grade ovarian tumors from the patients at different disease stages. DSRT profiling of the samples integrates viability and toxicity readouts with high-content imaging in order to assess the drug responses of phenotypically different cell subpopulations of epithelial cancer cells and stromal component. Results: Drug sensitivity profiling of ten primary and six relapse patient samples revealed heterogeneous drug sensitivity profiles characterized by common responsiveness to HDAC inhibitors, CDK inhibitors, and PI3K/mTOR inhibitors (mean drug sensitivity score (DSS) &amp;gt; 10). Relapse HGSOC samples demonstrated general trend towards resistance to a broad spectrum of chemotherapeutics and targeted drugs. Imaging-based DSRT profiling revealed that in both primary and relapse ascites-derived cancer cells the response to platinum drugs and DNA damaging agents associated with upregulation of transcriptional regulators of stemness, including BMI1, SOX2 and NANOG. The ascites-derived CK18-expressing epithelial cells collected from the same patient a) before chemotherapy, b) after 6 cycles of Carboplatin treatment and c) at the relapse demonstrated an increasing sensitivity to aldehyde dehydrogenase inhibitor disulfiram. These preliminary findings suggest that increase in a subpopulation of cancer cells with stem-like characteristics may accompany recurrence in HGSOC. Conclusions: Compound sensitivity testing combined with high-content imaging appears an informative tool to explore therapeutic vulnerabilities in chemoresistant subpopulations of ovarian cancer cells, and improves the accuracy of drug sensitivity profiling. Chemical biology screening of prospectively collected primary HGSOC samples can also help identifying phenotypic changes associated with chemoresistance development. Citation Format: Daria R. Bulanova, Katja Kaipio, Tarja Lamminen, Aleksandr Ianevski, Tero Aittokallio, Olli Carpen, Krister Wennerberg. Chemical biology approach to phenotypic intra-tumor heterogeneity in high-grade serous ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 875.

HPIP promotes epithelial-mesenchymal transition and cisplatin resistance in ovarian cancer cells through PI3K/AKT pathway activation.

Hematopoietic PBX interacting protein (HPIP), a scaffold protein, is known to regulate the proliferation, migration and invasion in different cancer cell types. The aim of this study was to assess the role of HPIP in ovarian cancer cell migration, invasion and epithelial-mesenchymal transition (EMT), and to unravel the mechanism by which it regulates these processes. HPIP expression was assessed by immunohistochemistry of tissue microarrays containing primary ovarian tumor samples of different grades. OAW42, an ovarian carcinoma-derived cell line exhibiting a high HPIP expression, was used to study the role of HPIP in cell migration, invasion and EMT. HPIP knockdown in these cells was achieved using a small hairpin RNA (shRNA) approach. Cell migration and invasion were assessed using scratch wound and transwell invasion assays, respectively. The extent of EMT was assessed by determining the expression levels of Snail, Vimentin and E-cadherin using Western blotting. The effect of HPIP expression on AKT and MAPK activation was also investigated by Western blotting. Cell viabilities in response to cisplatin treatment were assessed using a MTT assay, whereas apoptosis was assessed by determining caspase-3 and PARP cleavage in ovarian carcinoma-derived SKOV3 cells. We found that HPIP is highly expressed in high-grade primary ovarian tumors. In addition, we found that HPIP promotes the migration, invasion and EMT in OAW42 cells and induces EMT in these cells via activation of the PI3K/AKT pathway. The latter was found to lead to stabilization of the Snail protein and to repression of E-cadherin expression through inactivation of GSK-3β. We also found that HPIP expression confers cisplatin resistance to SKOV3 cells after prolonged exposure and that its subsequent knockdown decreases the viability of these cells and increases caspase-3 activation and PARP proteolysis in these cells following cisplatin treatment. From these results we conclude that HPIP expression is associated with high-grade ovarian tumors and may promote their migration, invasion and EMT, a process that is associated with metastasis. In addition, we conclude that HPIP may serve as a potential therapeutic target for cisplatin resistant ovarian tumors.

Expression of p53 and CD34 in Surface Epithelial Tumors of Ovary

Ovarian cancer accounts for 3 % of all cancers in females (1) . Owing to diagnostic difficulty of ovarian cancers at early stage, most of them are diagnosed when they are at metastatic stage, thus they account for increased number of deaths occurring in women due to genital tract tumors. Ovarian Carcinomas are currently divided into Type I ( low grade) and Type II ( high grade ) tumours. (1) p53 and CD34 have been reported to play an important role in the progression of ovarian cancer. However, only few studies focus on their expression in benign surface epithelial tumors compared to malignant surface epithelial tumors and further low grade tumors compared to high grade tumors in the malignant category. Tumour angiogenesis, evaluated by CD34 expression as intratumoral microvessel density and CD34 intensity index could be an important predictor of the aggressive nature of high grade ovarian carcinoma. Overexpression of p53 in ovarian tumors of both low-grade and high-grade ovarian tumors has been found to be associated with poor prognosis in most but not all studies. (2) In present study, Mean microvessel density, CD34 intensity index and p53 proportion scoring of High grade tumors was statistically significantly higher than Low grade tumors (p value <0.05). Infact, immunohistochemical staining for p53 has been utilized as a surrogate marker for mutational analysis in the diagnostic workup of carcinomas of multiple sites including ovarian cancers. (3) Implication of p53 and CD34 in predicting the metastatic potential of ovarian surface epithelial carcinomas has to be further analysed with larger sample size.

Ovarian Neuroendocrine Carcinoma-Case Report

This paper refers to a case of high-grade ovarian tumor with neuroendocrine differentiation in University General Hospital of Castellon. The gynaecologic literature refers to this tumor an incidence less than 0.1% of all ovarian tumors, and represents nearly 3% of all neuroendocrine tumors. We present the case of a 70-year-old woman who presented an ovarian neuroendocrine carcinoma with associated carcinomatosis.

PKCiota promotes ovarian tumor progression through deregulation of cyclin E.

The high frequency of relapse of epithelial ovarian tumors treated with standard chemotherapy has highlighted the necessity to identify targeted therapies that can improve patient outcomes. The dynamic relationship between Cyclin E and PKCiota frequent overexpression in high-grade ovarian tumors poses a novel pathway for therapeutic investigation. We hypothesized that a PI3K dependent signaling pathway activating PKCiota perpetuates cyclin E deregulation during ovarian tumorigenesis. We observed a positive correlation between PKCiota and cyclin E in a panel of 19 ovarian cancer cell lines. Modulation of cyclin E had no effect on PKCiota knockdown/overexpression however PKCiota differentially regulated cyclin E expression. In the serous ovarian cancer cells (IGROV, OVCAR-3), shPKCiota decreased proliferation, caused a G1 arrest, and significantly prolonged overall survival in xenograft mouse models. In vitro shPKCiota decreased the ability of IGROV cells to grow under anchorage independent conditions and form aberrant acini, which was dependent upon Ad-cyclin E or Ad-LMW-E expression. RPPA analysis of PKCiota wild-type, catalytic active, dominant negative protein isoforms strengthened the association between phospho-PKCiota levels and PI3K pathway activation. Inhibitors of PI3K coordinately decreased phospho-PKCiota and Cyclin E protein levels. In conclusion, we have identified a PI3K/PKCiota/Cyclin E signaling pathway as a therapeutic target during ovarian tumorigenesis.

Use of homologous recombination deficiency (HRD) score to enrich for niraparib sensitive high grade ovarian tumors.

5532 Background: The therapeutic potential of PARP inhibitors is predicted to extend beyond patients with germline BRCA mutations (BRCAmut) to those with homologous recombination deficient (HRD) ca...

MET nucleotide variations and amplification in advanced ovarian cancer: characteristics and outcomes with c-Met inhibitors.

MET alterations including amplifications and nucleotide variations have been associated with resistance to therapy and aggressive clinical behavior. The medical records of patients presenting to the University of Texas MD Anderson Cancer Center Phase I Clinic with relapsed or metastatic ovarian cancers and known MET nucleotide variation or amplification status were reviewed retrospectively (n=178). Categorical and continuous clinical and molecular characteristics were compared using Fisher's exact and Wilcoxon rank-sum tests, respectively. Univariate and multivariate survival were assessed via Kaplan-Meier and Cox regression analysis, respectively. MET amplification occurred in 4 (3.5%) of 113 patients, whereas nonsynonomous nucleotide variations were present in 9 (7.4%) of 122 patients. No patients exhibited concomitant amplification and variation. MET variations were observed only in white women with high-grade ovarian tumors, whereas amplifications were observed in both black and white women with high-grade serous ovarian primary tumors. No patients (n=4) exhibiting a MET alteration achieved an objective response when treated on a c-Met inhibitor phase I trial. In addition, ovarian cancer patients treated with a c-Met inhibitor with multikinase activity trended towards a longer time-to-failure compared with those treated with a c-Met-specific inhibitor (median: 1.5 vs. 4.5 months, p=0.07). MET alterations occur in a minority of patients with ovarian cancer. c-Met inhibitors with multikinase activity may exhibit less activity in ovarian cancer than c-Met specific drugs. These findings warrant further investigation.

CD164 regulates the tumorigenesis of ovarian surface epithelial cells through the SDF-1α/CXCR4 axis

BackgroundCD164 (endolyn), a sialomucin, has been reported to play a role in the proliferation, adhesion, and differentiation of hematopoietic stem cells. The potential association of CD164 with tumorigenicity remains unclear.MethodsThe clinicopathological correlation of ovarian cancer with CD164 was assessed in a 97-patient tumor tissue microarray. Overexpression or silence CD164 was to analyze the effect of CD164 on the proliferation, colony formation and apoptosis via a mouse xenograft and western blotting analysis. The subcellular localization of CD164 was collected in the immunohistochemical and confocal analysis.ResultsOur data demonstrated that higher expression levels of CD164 were identified in malignant ovarian cancer cell lines, such as SKOV3 and HeyA8. The clinicopathological correlation analysis showed that the upregulation of CD164 protein was significantly associated with tumor grade and metastasis. The overexpression of CD164 in human ovarian epithelial surface cells promoted cellular proliferation and colony formation and suppressed apoptosis. These tumorigenicity effects of CD164 were reconfirmed in a mouse xenograft model. We also found that the overexpression of CD164 proteins increased the amounts of CXCR4 and SDF-1α and activated the SDF-1α/CXCR4 axis, inducing colony and sphere formation. Finally, we identified the subcellular localization of CD164 in the nucleus and cytosol and found that nuclear CD164 might be involved in the regulation of the activity of the CXCR4 promoter.ConclusionsOur findings suggest that the increased expression of CD164 is involved in ovarian cancer progression via the SDF-1α/CXCR4 axis, which promotes tumorigenicity. Thus, targeting CD164 may serve as a potential ovarian cancer biomarker, and targeting CD164 may serve as a therapeutic modality in the management of high-grade ovarian tumors.

Abstract A48: Anti-tumor activity of the MEK inhibitor pimasertib in combination with the PI3K/mTOR inhibitor SAR245409 in low-grade serous ovarian cancer

Abstract Low-grade serous ovarian carcinoma is a distinct neoplasm from high-grade serous ovarian carcinoma and is chemo-resistant, both in the first line setting as well as in subsequent lines of therapy. Serous ovarian tumors of low malignant potential and low grade serous ovarian cancer (LGSOC) appear to be dependent, in part, on the activation of the mitogen-activated protein kinase (MAPK) survival signaling pathway, and furthermore display significantly higher prevalence of KRAS or BRAF mutations in contrast to high-grade serous carcinomas. The PI3K/AKT/mTOR and Ras/Raf/MEK/ERK (MAPK) survival pathways are interlinked survival signaling pathways, where compensatory activation of one of the pathways in response to the inhibition of the other has been observed. Given their ability to cross-talk, simultaneous inhibition of the MAPK and PI3K/PTEN signaling cascades may significantly enhance anti-tumor activity as compared with inhibition of either cascade alone. Preclinical studies have shown that the combination of MEK and PI3K inhibitors, both in vitro and in vivo, enhanced anti-tumor effects and induced apoptosis in cell lines and primary patient-derived models across a range of cancer types. In the present series of studies, we report: 1- the anti-tumor activity of the combination of two investigational drugs, a phosphatidylinositol 3-kinase (PI3K) and mTOR inhibitor, SAR245409 (XL765) with the selective allosteric inhibitor of MEK1/2, pimasertib (AS703026; MSC1936369B) against patient-derived ovarian cancer xenograft models harboring KRAS mutations from low, intermediate and high grade ovarian tumors), and 2- the preliminary clinical activity of the combination in ovarian patients. In patient-derived xenografts of low and intermediate grade ovarian cancer, the combination led to significantly greater antitumor activity than that of single agent treatments. In the high grade model of ovarian cancer, no additive effects on antitumor activity were observed in the combination as compared to pimasertib as a single agent. The combination of pimasertib and SAR245409 is currently being investigated in patients with refractory solid tumors in an ongoing Phase Ib Trial (EMR200066-006; NCT01390818), where objective responses have been reported in 2 out of 4 evaluable patients with low-grade serous ovarian carcinoma. A phase 2 study (EMR200066-012, EudraCT Number 2013-000902-40) will investigate the activity of the combination pimasertib and SAR245409 in subjects with recurrent or metastatic low grade ovarian cancer, a patient population which has a high unmet medical need. Citation Format: Sukhvinder S. Sidhu, Frank Campana, Coumaran Egile, Karl Hsu, Samantha Goodstal, Ekaterine Asatiani, Lars Damstrup, Joanne Lager, Janet Ogden, Loic Vincent. Anti-tumor activity of the MEK inhibitor pimasertib in combination with the PI3K/mTOR inhibitor SAR245409 in low-grade serous ovarian cancer. [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 A48.

Abstract A7: Targeting mutant p53 and cell-cell adhesion in ovarian cancer

Abstract One of the most important challenges in the ovarian cancer research is to identify new molecular pathways that can be targeted to kill ovarian cancer cells. High-grade serous ovarian cancer (HGS-OvCa) cells survive, proliferate, and assemble into multicellular clusters that have a capacity to disseminate within the peritoneum. Therefore, it is important to identify specific molecular mechanisms that can be targeted to block survival, growth, and assembly of ovarian cancer multicellular clusters that metastasize within peritoneum. High-grade ovarian tumors originate from the fallopian tube epithelium (FTE) and almost all have mutations in theTP53 gene. The contribution of various mutant p53 proteins (m-p53) to ovarian cancer and whether targeting mutant p53 –dependent molecular mechanisms in ovarian cancer is poorly understood and of clinical significance. We have developed new methodologies and used them to identify m-p53-dependent pathways that support HGS-OvCa survival, proliferation and assembly of multicellular aggregates under condition mimicking peritoneal suspension. To determine whether mutations in TP53 contribute to the ability of HGS-OvCa cells to survive, proliferate, and assemble into multicellular clusters we introduced different variants of mutant p53 (m-p53) into normal human non-transformed FTE cells. We found that expression of m-p53 variants (R175H; R249S; R273H) in FTE cells promoted survival, growth, and assembly of multicellular clusters under conditions mimicking peritoneal suspension. Interestingly m-p53-driven phenotypes were not induced by the loss of p53 expression; and more importantly, these phenotypes were blocked by the reactivation of p53 pathway with small molecule inhibitor NSC319726. We further found that m-p53 induced phenotypes were dependent on the expression of integrin β 1 (ITGB1). The evidence that activated ITGB1 is enriched at cell's surface of precursors of HGS-OvCa within the fallopian tube and HGS-OvCa isolated from ovarian cancer patients highlighted the relevance of these findings to ovarian cancer. We hypothesize that mutant p53 supports survival, growth, and assembly of multicellular HGS-OvCa clusters through mechanisms in which ITGB1 plays a critical role. Our data indicate that observed phenotypes are the consequence of the m-p53 gain of function mechanisms that are amenable to therapeutic inhibitions and targeting m-p53 in HGS-OvCa might be of clinical significance. Citation Format: Marcin P. Iwanicki, Marian Novak, Ioannis K. Zervantonakis, Tan A. Ince, Ronny Drapkin, Joan S. Brugge. Targeting mutant p53 and cell-cell adhesion in ovarian cancer. [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 A7.

Analysis of the levels of lysine-specific demethylase 1 (LSD1) mRNA in human ovarian tumors and the effects of chemical LSD1 inhibitors in ovarian cancer cell lines

BackgroundLysine-specific demethylase 1 (LSD1, also known as KDM1A and AOF2) is a chromatin-modifying activity that catalyzes the removal of methyl groups from lysine residues in histone and non-histone proteins, regulating gene transcription. LSD1 is overexpressed in several cancer types, and chemical inhibition of the LSD1 activity has been proposed as a candidate cancer therapy. Here, we examine the levels of LSD1 mRNA in human ovarian tumors and the cytotoxicity of several chemical LSD1 inhibitors in a panel of ovarian cancer cell lines.MethodsWe measured LSD1 mRNA levels in a cohort of n = 177 normal and heterogeneous tumor specimens by quantitative real time-PCR (qRT-PCR). Tumors were classified by FIGO stage, FIGO grade, and histological subtypes. We tested the robustness of our analyses in an independent cohort of n = 573 serous tumor specimens (source: TCGA, based on microarray). Statistical analyses were based on Kruskal-Wallis/Dunn’s and Mann Whitney tests. Changes in LSD1 mRNA levels were also correlated with transcriptomic alterations at genome-wide scale. Effects on cell viability (MTS/PMS assay) of six LSD1 inhibitors (pargyline, TCP, RN-1, S2101, CAS 927019-63-4, and CBB1007) were also evaluated in a panel of ovarian cancer cell lines (SKOV3, OVCAR3, A2780 and cisplatin-resistant A2780cis).ResultsWe found moderate but consistent LSD1 mRNA overexpression in stage IIIC and high-grade ovarian tumors. LSD1 mRNA overexpression correlated with a transcriptomic signature of up-regulated genes involved in cell cycle and down-regulated genes involved in the immune/inflammatory response, a signature previously observed in aggressive tumors. In fact, some ovarian tumors showing high levels of LSD1 mRNA are associated with poor patient survival. Chemical LSD1 inhibition induced cytotoxicity in ovarian cancer lines, which roughly correlated with their reported LSD1 inhibitory potential (RN-1,S2101 >> pargyline,TCP).ConclusionsOur findings may suggest a role of LSD1 in the biology of some ovarian tumors. It is of special interest to find a correlation of LSD1 mRNA overexpression with a transcriptomic signature relevant to cancer. Our findings, therefore, prompt further investigation of the role of LSD1 in ovarian cancer, as well as the study of its enzymatic inhibition in animal models for potential therapeutic purposes in the context of this disease.