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Despite having similar histologic features, patients with high-grade serous ovarian carcinoma (HGSC) often experience highly variable outcomes. The underlying determinants for long-term survival (LTS, ≥10 years) versus short-term survival (STS, 2; false discovery rate < 0.01). In the subsequent validation cohort, transmembrane protein 62 (TMEM62) was found to be related to LTS. CIBERSORT analysis showed that T cells (follicular helper) were found at higher levels in tumors from LTS than STS groups. In vitro data using OVCAR5 and OVCAR8 cells showed decreased proliferation with TMEM62 overexpression and positive correlation with a longevity-regulating pathway (KEGG HSA04213) at the RNA level. In vivo analysis using the OVCAR8-TMEM62-TetON model showed decreased tumor burden in mice with high- vs. low-expressing TMEM62 tumors. Our results demonstrate that restoring TMEM62 may be a novel approach for treatment of HGSC. These findings may have implications for biomarker and intervention strategies to help improve patient outcomes

Exosome cargoes are highly varied and include proteins, small RNAs, and genomic DNA (gDNA). The presence of gDNA suggests that different intracellular compartments contribute to exosome loading, resulting in distinct exosome subpopulations. However, the loading of gDNA and other nuclear contents into exosomes (nExo) remains poorly understood. Here, we identify the relationship between cancer cell micronuclei (MN), which are markers of genomic instability, and nExo formation. Imaging flow cytometry analyses reveal that 10% of exosomes derived from cancer cells and

Ovarian cancer presents as an aggressive, advanced stage cancer with widespread metastases that depend primarily on multicellular spheroids in the peritoneal fluid. To identify new druggable pathways related to metastatic progression and spheroid formation, we integrated microRNA and mRNA sequencing data from 293 tumors from The Cancer Genome Atlas (TCGA) ovarian cancer cohort. We identified miR-509-3p as a clinically significant microRNA that is more abundant in patients with favorable survival in both the TCGA cohort (P = 2.3E-3), and, by in situ hybridization (ISH), in an independent cohort of 157 tumors (P < 1.0E-3). We found that miR-509-3p attenuated migration and disrupted multi-cellular spheroids in HEYA8, OVCAR8, SKOV3, OVCAR3, OVCAR4 and OVCAR5 cell lines. Consistent with disrupted spheroid formation, in TCGA data miR-509-3p's most strongly anti-correlated predicted targets were enriched in components of the extracellular matrix (ECM). We validated the Hippo pathway effector YAP1 as a direct miR-509-3p target. We showed that siRNA to YAP1 replicated 90% of miR-509-3p-mediated migration attenuation in OVCAR8, which contained high levels of YAP1 protein, but not in the other cell lines, in which levels of this protein were moderate to low. Our data suggest that the miR-509-3p/YAP1 axis may be a new druggable target in cancers with high YAP1, and we propose that therapeutically targeting the miR-509-3p/YAP1/ECM axis may disrupt early steps in multi-cellular spheroid formation, and so inhibit metastasis in epithelial ovarian cancer and potentially in other cancers.

In this study, we investigated the metabolic alterations associated with clinical response to chemotherapy in patients with ovarian cancer. Pre- and post-neoadjuvant chemotherapy (NACT) tissues from patients with high-grade serous ovarian cancer (HGSC) who had poor response (PR) or excellent response (ER) to NACT were examined. Desorption electrospray ionization mass spectrometry (DESI-MS) was performed on sections of HGSC tissues collected according to a rigorous laparoscopic triage algorithm. Quantitative MS-based proteomics and phosphoproteomics were performed on a subgroup of pre-NACT samples. Highly abundant metabolites in the pre-NACT PR tumors were related to pyrimidine metabolism in the epithelial regions and oxygen-dependent proline hydroxylation of hypoxia-inducible factor alpha in the stromal regions. Metabolites more abundant in the epithelial regions of post-NACT PR tumors were involved in the metabolism of nucleotides, and metabolites more abundant in the stromal regions of post-NACT PR tumors were related to aspartate and asparagine metabolism, phenylalanine and tyrosine metabolism, nucleotide biosynthesis, and the urea cycle. A predictive model built on ions with differential abundances allowed the classification of patients' tumor responses as ER or PR with 75% accuracy (10-fold cross-validation ridge regression model). These findings offer new insights related to differential responses to chemotherapy and could lead to novel actionable targets. [ABSTRACT FROM AUTHOR]

Mid-infrared spectroscopic imaging (MIRSI) is an emerging class of label-free techniques being leveraged for digital histopathology. Modern histopathologic identification of ovarian cancer involves tissue staining followed by morphological pattern recognition. This process is time-consuming and subjective and requires extensive expertise. This paper presents the first label-free, quantitative, and automated histological recognition of ovarian tissue subtypes using a new MIRSI technique. This optical photothermal infrared (O-PTIR) imaging technique provides a 10× enhancement in spatial resolution relative to prior instruments. It enables sub-cellular spectroscopic investigation of tissue at biochemically important fingerprint wavelengths. We demonstrate that the enhanced resolution of sub-cellular features, combined with spectroscopic information, enables reliable classification of ovarian cell subtypes achieving a classification accuracy of 0.98. Moreover, we present a statistically robust analysis from 78 patient samples with over 60 million data points. We show that sub-cellular resolution from five wavenumbers is sufficient to outperform state-of-the-art diffraction-limited techniques with up to 235 wavenumbers. We also propose two quantitative biomarkers based on the relative quantities of epithelia and stroma that exhibit efficacy in early cancer diagnosis. This paper demonstrates that combining deep learning with intrinsic biochemical MIRSI measurements enables quantitative evaluation of cancerous tissue, improving the rigor and reproducibility of histopathology. [ABSTRACT FROM AUTHOR]

Simple Summary: One-third of patients with ovarian cancer have elevated platelet counts associated with a poor prognosis. We found that platelets increase the expression of immune checkpoint (PD-L1) in ovarian cancer in mice and patients. Reducing platelet counts or inhibiting platelet function reduced the expression of PD-L1 in tumors. We investigated the mechanism of platelet-induced PD-L1 and showed that platelets increase PD-L1 on cancer cells both directly (contact-dependent through NF-κB signaling) and indirectly (contact-independent via TFGβ released from platelets through TFGβR1/Smad signaling). Our results show that platelets dampen the antitumor immune response in the tumor microenvironment. Based on our preclinical results, we speculate that platelet counts might be a predictive biomarker for immunotherapy, i.e., patients with thrombocytosis respond better to anti-PD1/PDL-1 therapy. On the other hand, the use of aspirin or other antiplatelet reagents may impact the effectiveness of immunotherapy. These speculations need to be examined in clinical trials. The interactions between platelets and cancer cells activate platelets and enhance tumor growth. Platelets increase proliferation and epithelial–mesenchymal transition in cancer cells, inhibit anoikis, enhance the extravasation of cancer cells, and protect circulating tumor cells against natural killer cells. Here, we have identified another mechanism by which platelets dampen the immune attack on cancer cells. We found that platelets can blunt the antitumor immune response by increasing the expression of inhibitory immune checkpoint (PD-L1) on ovarian cancer cells in vitro and in vivo. Platelets increased PD-L1 in cancer cells via contact-dependent (through NF-κB signaling) and contact-independent (through TFGβR1/Smad signaling) pathways. Inhibition of NF-κB or TGFβR1 signaling in ovarian cancer cells abrogated platelet-induced PD-L1 expression. Reducing platelet counts or inhibiting platelet functions reduced the expression of PD-L1 in ovarian cancer. On the other hand, an increase in platelet counts increased the expression of PD-L1 in tumor-bearing mice. [ABSTRACT FROM AUTHOR]

Purpose: An in-depth analysis of the tumor microenvironment of ovarian cancer is needed. The purpose of this study was to elucidate the architecture of the immune microenvironment of high-grade serous ovarian cancers (HGSCs) with or without BRCA1 and BRCA2 mutations. Methods: A cohort of highly annotated HGSC patients with known germline BRCA1 and BRCA2 status was selected, and pretreatment tumor tissue specimens were analyzed with a multiplexed staining technique aimed at detecting lymphocytes, macrophages, and fibroblasts in the whole tumor area and in specific regions including epithelium, stroma, and perivascular areas. Results: BRCA1- or BRCA2-mutated tumors showed a more immunogenic microenvironment, characterized by a higher abundance of CD8+ and PD-L1+ cells, than did tumors with wild-type BRCA1 and BRCA2. High numbers of PD-L1+ and PD-L1+CD8+ cells were prognostic for event-free survival (hazard ratio [HR]: 0.41, 95% CI 0.21–0.79, p = 0.008 and HR 0.49, 95% CI 0.26–0.91, p = 0.025, respectively), as were high numbers of epithelial PD-L1+ and FAP+PD-L1+ cells (HR 0.52, 95% CI 0.28–0.96, p = 0.037 and HR 0.27, 95% CI 0.08–0.87, p = 0.029) and CD8+ cells (HR 0.51, 95% CI 0.28–0.93, p = 0.027). Conclusions: This study reveals substantial differences between the immune microenvironment composition of germline BRCA-mutated and BRCA wild-type HGSC. [ABSTRACT FROM AUTHOR]

Objective: Establishing an accurate histologic diagnosis is essential for determining the appropriate course of therapy for ovarian cancer. This study sought to investigate and describe nonovarian cancer pathologies discovered during the systematic laparoscopic workup of presumed advanced ovarian cancer. Methods: A retrospective cohort of patients with presumed advanced ovarian cancer (based on elevated CA125 and/or imaging) presenting to our center without confirmed pathologic diagnosis were identified and characterized. Patients without ovarian cancer on final pathology were described and compared with those with confirmed epithelial ovarian cancer using standard statistical methods. Results: Nonovarian cancer was found in 26 (7.1%) of 365 cases over 3.5 years of study, and included benign ovarian pathology, and metastatic uterine, breast, and gastrointestinal cancers. Most nonovarian cancer cases could not be diagnosed with percutaneous biopsy, and instead used diagnostic laparoscopy or assessment at the time of laparotomy for diagnosis (58%). No patient received inappropriate treatment. Nonovarian cancer cases were more likely to be nonwhite (P = 0.003), have a better Eastern Cooperative Oncology Group performance status (P < 0.001), and have a lower CA125 value (P < 0.001), and were less likely to have pleural effusions (P = 0.04). Conclusions: A systematic laparoscopic triage approach to advanced-stage ovarian cancer eliminates incorrect neoadjuvant chemotherapy administration and inappropriate laparotomy. This algorithm identified a population of women who are more likely to have nonovarian cancer pathology. Increasing screening efforts should be focused on conclusive diagnosis with the least invasive testing possible. [ABSTRACT FROM AUTHOR]

Among the 3 GTPases in the DIRAS family, DIRAS3/ARHI is the best characterized. DIRAS3 is an imprinted tumor suppressor gene that encodes a 26-kDa GTPase that shares 60% homology to RAS and RAP. DIRAS3 is downregulated in many tumor types, including ovarian cancer, where re-expression inhibits cancer cell growth, reduces motility, promotes tumor dormancy and induces macroautophagy/autophagy. Previously, we demonstrated that DIRAS3 is required for autophagy in human cells. Diras3 has been lost from the mouse genome during evolutionary re-arrangement, but murine cells can still undergo autophagy. We have tested whether DIRAS1 and DIRAS2, which are homologs found in both human and murine cells, could serve as surrogates to DIRAS3 in the murine genome affecting autophagy and cancer cell growth. Similar to DIRAS3, these 2 GTPases share 40-50% homology to RAS and RAP, but differ from DIRAS3 primarily in the lengths of their N-terminal extensions. We found that DIRAS1 and DIRAS2 are downregulated in ovarian cancer and are associated with decreased disease-free and overall survival. Re-expression of these genes suppressed growth of human and murine ovarian cancer cells by inducing autophagy-mediated cell death. Mechanistically, DIRAS1 and DIRAS2 induce and regulate autophagy by inhibition of the AKT1-MTOR and RAS-MAPK signaling pathways and modulating nuclear localization of the autophagy-related transcription factors FOXO3/FOXO3A and TFEB. Taken together, these data suggest that DIRAS1 and DIRAS2 likely serve as surrogates in the murine genome for DIRAS3, and may function as a backup system to fine-tune autophagy in humans. [ABSTRACT FROM AUTHOR]

Background: p16 INK4A (p16) functions as a tumor suppressor gene in various malignancies. Aberrant p16 methylation has been proposed to be essential in ovarian carcinogenesis. However, it is unclear whether p16 can be used as a diagnostic marker owing to the small sample sizes in previous studies.Methods: To determine whether p16 promoter methylation is associated with epithelial ovarian cancer and can thus be used as a diagnostic marker, we performed a meta-analysis of published studies. The following databases were searched using a systematic search method: PubMed, Web of Science, EMBASE, and Chinese National Knowledge Infrastructure. We used a random-effects model to analyze the relative risk (RR); we also evaluated between-study heterogeneity, subgroup heterogeneity, and publication bias.Results: Our meta-analysis included eight eligible studies, with 428 ovarian cancers and 278 normal tissue samples and benign neoplasms. p16 promoter methylation was identified in 5.4 to 43.2% (median 27.86%) of ovarian cancers and 0 to 37.5% (median 15.8%) of normal tissue and benign neoplasms indicating that no significant association exists between p16 promoter methylation and epithelial ovarian cancer. However, the pooled results also showed that the RR was 1.52 (95% CI 0.80-2.87) in the ovarian cancer cases versus the corresponding normal and benign cases under the random-effects model. Between-study heterogeneity was determined through a sensitivity analysis; the I 2 value did not change when one study was excluded.Conclusions: Our study showed that p16 promoter methylation cannot be used to differentiate benign from malignant epithelial ovarian tumors. Therefore, p16 promoter methylation cannot be used as a marker for diagnosing the early stage of ovarian cancer. [ABSTRACT FROM AUTHOR]

Glutamine can play a critical role in cellular growth in multiple cancers. Glutamine-addicted cancer cells are dependent on glutamine for viability, and their metabolism is reprogrammed for glutamine utilization through the tricarboxylic acid ( TCA) cycle. Here, we have uncovered a missing link between cancer invasiveness and glutamine dependence. Using isotope tracer and bioenergetic analysis, we found that low-invasive ovarian cancer ( OVCA) cells are glutamine independent, whereas high-invasive OVCA cells are markedly glutamine dependent. Consistent with our findings, OVCA patients' microarray data suggest that glutaminolysis correlates with poor survival. Notably, the ratio of gene expression associated with glutamine anabolism versus catabolism has emerged as a novel biomarker for patient prognosis. Significantly, we found that glutamine regulates the activation of STAT3, a mediator of signaling pathways which regulates cancer hallmarks in invasive OVCA cells. Our findings suggest that a combined approach of targeting high-invasive OVCA cells by blocking glutamine's entry into the TCA cycle, along with targeting low-invasive OVCA cells by inhibiting glutamine synthesis and STAT3 may lead to potential therapeutic approaches for treating OVCAs. [ABSTRACT FROM AUTHOR]

Background We previously found focal adhesion kinase (FAK) inhibition sensitizes ovarian cancer to taxanes; however, the mechanisms are not well understood. Methods We characterized the biologic response of taxane-resistant and taxane-sensitive ovarian cancer models to a novel FAK inhibitor (VS-6063). We used reverse-phase protein arrays (RPPA) to identify novel downstream targets in taxane-resistant cell lines. Furthermore, we correlated clinical and pathological data with nuclear and cytoplasmic expression of FAK and YB-1 in 105 ovarian cancer samples. Statistical tests were two-sided, and P values were calculated with Student t test or Fisher exact test. Results We found that VS-6063 inhibited FAK phosphorylation at the Tyr397 site in a time- and dose-dependent manner. The combination of VS-6063 and paclitaxel markedly decreased proliferation and increased apoptosis, which resulted in 92.7% to 97.9% reductions in tumor weight. RPPA data showed that VS-6063 reduced levels of AKT and YB-1 in taxane-resistant cell lines. FAK inhibition enhanced chemosensitivity in taxane-resistant cells by decreasing YB-1 phosphorylation and subsequently CD44 in an AKT-dependent manner. In human ovarian cancer samples, nuclear FAK expression was associated with increased nuclear YB-1 expression (χ2 = 37.7; P < .001). Coexpression of nuclear FAK and YB-1 was associated with statistically significantly worse median overall survival (24.9 vs 67.3 months; hazard ratio = 2.64; 95% confidence interval = 1.38 to 5.05; P = .006). Conclusions We have identified a novel pathway whereby FAK inhibition with VS-6063 overcomes YB-1–mediated paclitaxel resistance by an AKT-dependent pathway. These findings have implications for clinical trials aimed at targeting FAK. [ABSTRACT FROM PUBLISHER]

Single-chain glycoprotein CD44 is a major cell surface receptor for hyaluronan and mediates epithelial cell adhesion by its involvement in cell-cell and cell-matrix interactions. Recently, CD44 has been identified as a biomarker of cancer stem cells in many malignancies including ovarian carcinoma. However, its clinical significance in human ovarian carcinoma has been controversial until recently. The aim of our current study was to clarify the clinical role of CD44 expression in human ovarian carcinoma. Immunohistochemical staining of 483 primary ovarian carcinoma and 27 paired primary and recurrent ovarian carcinoma samples for CD44 standard form (CD44s) was performed using tissue microarray. The associations between CD44s expression and clinical factors (histologic types, tumor grade, International Federation of Gynecology and Obstetrics stage, and response to chemotherapy), and overall or diseasefree survivals were analyzed. We observed CD44s expression in 38% of the ovarian carcinoma samples. Results of the Fisher exact test suggested that CD44s expression was associated with high-grade carcinoma (P = .013), advanced International Federation of Gynecology and Obstetrics stage (III-IV; P b .001), age at diagnosis less than 60 years (P = .011), and transitional cell carcinoma (P = .039). However, CD44s expression was not associated with overall survival (P = .529) or disease-free survival (P = .218) by the log-rank test. Moreover, there was no statistical difference in CD44s expression between the primary and recurrent ovarian carcinomas. Our results showed that CD44s expression is not a prognostic predictor in ovarian cancer. © 2013 Elsevier Inc. All rights reserved. [ABSTRACT FROM AUTHOR]

Most patients with epithelial ovarian cancer achieve a complete clinical remission (CCR) with normal CA-125 but will still relapse and die from their disease. The present study was designed to determine whether CA-125 levels before, during, and after primary treatment provide prognostic information for both type I and type II ovarian cancer.In this retrospective study, we identified 410 patients with epithelial ovarian cancer who had achieved a CCR between 1984 and 2011. A Cox proportional hazards model and log-rank test were used to assess associations between the nadir CA-125, histotype, and prognosis.The baseline serum CA-125 concentration was higher in patients with type II ovarian cancer than in those with type I ovarian cancer (P < 0.001). The nadir CA-125 was an independent predictor of progression-free survival (PFS; P < 0.001) and overall survival (OS; P = 0.035) duration. The PFS and OS durations were 21.7 and 79.4 months in patients with CA-125 of 10 U/mL or less and 13.6 and 64.6 months in those with CA-125 of 11 to 35 U/mL, respectively (P = 0.01 and P = 0.002, respectively). Histotype was an independent predictor of PFS (P = 0.041): the PFS and OS durations of the patients with type I ovarian cancer were longer than those of the patients with type II ovarian cancer (P < 0.001 and P < 0.001, respectively).The nadir CA-125 and histotype are predictive of PFS and OS durations in patients with ovarian cancers who experienced a CCR. Progression-free survival and OS durations were shorter in the patients with CA-125 levels of 11 to 35 U/mL and type II disease than in those with CA-125 levels of 10 U/mL or less and type I ovarian cancer. [ABSTRACT FROM AUTHOR]

Abstract: Serous carcinoma is the most common type of epithelial ovarian cancer. In this review, we provide a comprehensive picture of ovarian serous cancers from multiple aspects: the first part of this review summarizes the morphological, histological, and immunological signatures of ovarian serous carcinoma; subsequently, we review the history of the evolvement of different grading systems used in ovarian serous cancer; in the end, we focus on characterizing the genetics that underlie the 2-tiered pathways through which ovarian serous cancers are believed to arise: the low-grade and the high-grade pathways. [Copyright &y& Elsevier]

Abstract: Border cell migration is a process that occurs during Drosophila ovarian development in which cells derived from a simple epithelium migrate and invade neighboring tissue. This process resembles the behavior of cancerous cells that derive from the simple epithelium of the human ovary. One important regulator of border cell migration is Taiman, a homolog of steroid receptor coactivator-3 (SRC-3). Because increasing evidence indicates that similarities exist between the molecular control of migration of border cells and of cancer cells, we investigated whether SRC-3 controls ovarian cancer cell migration. Little or no SRC-3 expression was detected in normal ovarian surface epithelium, ovarian cysts and borderline ovarian tumors that lack stromal invasion. In contrast, SRC-3 was abundantly expressed in high-grade ovarian carcinomas. Inhibiting SRC-3 expression in ovarian cancer cells markedly reduced cell spreading and migration, and altered intracellular localization of focal adhesion kinase. This inhibitory effect on cell migration was independent of the estrogen receptor (ER) status of the cells. These studies reveal a novel role for SRC-3 in ovarian cancer progression by promoting cell migration, independently of its role in estrogen receptor signaling. [Copyright &y& Elsevier]

Background: Insulin-like growth factor binding protein 2 (IGFBP2) is overexpressed in ovarian malignant tissues and in the serum and cystic fluid of ovarian cancer patients, suggesting an important role of IGFBP2 in the biology of ovarian cancer. The purpose of this study was to assess the role of increased IGFBP2 in ovarian cancer cells. Results: Using western blotting and tissue microarray analyses, we showed that IGFBP2 was frequently overexpressed in ovarian carcinomas compared with normal ovarian tissues. Furthermore, IGFBP2 was significantly overexpressed in invasive serous ovarian carcinomas compared with borderline serous ovarian tumors. To test whether increased IGFBP2 contributes to the highly invasive nature of ovarian cancer cells, we generated IGFBP2-overexpressing cells from an SKOV3 ovarian cancer cell line, which has a very low level of endogenous IGFBP2. A Matrigel invasion assay showed that these IGFBP2-overexpressing cells were more invasive than the control cells. We then designed small interference RNA (siRNA) molecules that attenuated IGFBP2 expression in PA-1 ovarian cancer cells, which have a high level of endogenous IGFBP2. The Matrigel invasion assay showed that the attenuation of IGFBP2 expression indeed decreased the invasiveness of PA-1 cells. Conclusions: We therefore showed that IGFBP2 enhances the invasion capacity of ovarian cancer cells. Blockage of IGFBP2 may thus constitute a viable strategy for targeted cancer therapy. [ABSTRACT FROM AUTHOR]

Human telomerase reverse transcriptase (hTERT), the catalytic subunit of human telomerase, is responsible for the synthesis and maintenance of the telomeric repeats at the distal ends of human chromosomes. Telomerase expression is repressed in normal human cells and is activated in immortal cells and during tumorigenesis, but the mechanism by which telomerase expression is regulated is not fully understood. Previous studies have shown that c-Myc stimulates hTERT transcription through the binding sites located on the hTERT promoter. In this study, we sought to determine whether BRCA1 inhibits hTERT transcription through its direct interaction with c-Myc. In ovarian cancer cells, c-Myc increased hTERT expression by threefold and BRCA1 completely abrogated this activity. A mutation in the c-Myc-binding site (E-box) of the hTERT promoter resulted in the loss of activation by c-Myc and in the loss of inhibition by BRCA1. Deletion of the c-Myc-binding domain in BRCA1 resulted in the loss of BRCA1’s ability to inhibit transcription of the hTERT promoter. In addition, BRCA1 associates with c-Myc and inhibits the binding activity of c-Myc to the hTERT promoter. Our data indicate that BRCA1 is involved in regulating cellular immortalization through the modulation of c-Myc on the hTERT promoter. [Copyright &y& Elsevier]

Polyploid giant cancer cells (PGCCs) are a morphologically distinct subgroup of human tumor cells with increased nuclear size or multiple nuclei, but they are generally considered unimportant because they are presumed to be nondividing and thus nonviable. We have recently shown that these large cancer cells are not only viable but also can divide asymmetrically and yield progeny cancer cells with cancer stem-like properties via budding division. To further understand the molecular events involved in the regulation of PGCCs and the generation of their progeny cancer cells, we comparatively analyzed the proteomic profiles of PGCCs, PGCCs with budding daughter cells, and regular control cancer cells from the HEY and SKOv3 human ovarian cancer cell lines with and without CoCl2. We used a high-throughput iTRAQ-based proteomic methodology coupled with liquid chromatography-electrospray ionization tandem mass spectroscopy to determine the differentiated regulated proteins. We performed Western blotting and immunohistochemical analyses to validate the differences in the expression patterns of a variety of proteins between PGCCs or budding PGCCs and regular cancer cells identified by iTRAQ approach and also a selected group of proteins from the literature. The differentially regulated proteins included proteins involved in response to hypoxia, stem cell generation, chromatin remodeling, cell-cycle regulation, and invasion and metastasis. In particular, we found that HIF-1alpha and its known target STC1 are upregulated in PGCCs. In addition, we found that a panel of stem cell-regulating factors and epithelial-to-mesenchymal transition regulatory transcription factors were upregulated in budding PGCCs, whereas expression of the histone 1 family of nucleosomal linker proteins was consistently lower in PGCCs than in control cells. Thus, proteomic expression patterns provide valuable insight into the underlying mechanisms of PGCC formation and the relationship between PGCCs and cancer stem cells in patients with ovarian cancers. [ABSTRACT FROM AUTHOR]

Objectives: Response rates to immune checkpoint inhibitors (ICI) in recurrent ovarian cancer have been disappointingly low. While emerging data suggest increased activity in patients with ovarian clear cell carcinomas (OCCC), only a minority of patients benefit even among this group. The objective of the current study was to investigate correlates of long-term survival in patients with OCCC treated with ICI. Methods: A review of medical records identified 28 patients with ovarian/peritoneal clear cell carcinoma who had been treated with CTLA4 and PD1/L1 ICI immunotherapy as part of two prospective RCTs. All patients except one received tremelimumab and durvalumab, either sequentially or in combination, and one additional patient received ipilimumab and nivolumab. Clinical-pathologic and tumor somatic mutation information (obtained from clinical next-generation sequencing) were correlated with overall survival (OS) using Kaplan-Meier and log-rank methodologies. Results: The evaluable patients were heavily pre-treated, with 1-9 prior lines of therapy (median: 2). The most common mutations were ARID1A (72%), PIK3CA (57%), and PPP2R1A (25%). The overall survival was significantly longer in patients whose tumors harbored a PPP2R1A hotspot mutation (n =7) compared to those without such mutation (n =21; median OS not reached vs 6.4 months, respectively, p=0.018; HR: 0.13 [95% CI: 0.02-0.95]; Figure 1). PPP2R1A mutations were also associated with more severe (≥grade 3) immune-related adverse events (57.1% vs 9.5% for non-carriers p=0.021). PPP2R1A mutations retained their prognostic significance within the subgroup of patients with ARID1A mutations (p=0.018). However, among patients without PPP2R1A mutations, there was no association between ARID1A mutations and OS (p=0.253). Increased survival resulted from prolonged stable disease and delayed responses, often following initial progression by RECIST v1.1. [Display omitted] Conclusions: These preliminary data suggest that PPP2R1A (rather than ARID1A) mutations may serve as a biomarker for long-term survival after ICI in OCCC, and ongoing research is aimed at determining a causal relationship. Given the benefit was delayed and often followed initial progression, harboring PPP2R1A mutations on ICI treatment beyond progression in patients with OCCC may be a consideration after appropriate counseling. [ABSTRACT FROM AUTHOR]

Despite similar histologic appearance amongst high-grade serous ovarian cancers (HGSOC), anecdotally there are differences in gross appearance. However, no systematic framework to classify morphologic differences exists. Therefore, we aimed to determine whether high-grade serous ovarian cancers (HGSOC) can be reliably divided into distinct gross morphologic subtypes and to assess clinical outcomes and molecular features of these subtypes. A retrospective review was performed of video-recordings from patients who underwent laparoscopic assessment of disease burden prior to primary debulking surgery (PDS) or neoadjuvant chemotherapy (NACT). Video recordings were reviewed by at least 2 physicians. A total of 4 sites (diaphragm, omentum, peritoneum, and pelvis) were assessed and classified as type I (deep, infiltrative disease with distortion of surrounding tissue) or type II (superficial, exophytic disease bordered by normal tissue). Tumor tissues from 16 of these chemotherapy-naïve patients were analyzed by multi-platform omics (RNA sequencing, proteomics). Clinical outcomes were assessed utilizing a prospectively collected database and compared by morphology using t-test or Fisher's exact test. Of the 99 evaluable patients, 60 exhibited uniform morphology at all involved metastatic sites (65% type I and 35% type II), and 81 exhibited a predominating morphology (58% type I and 42% type II). A total of 164 images were reviewed by a third physician with 83.5% inter-rater concordance (κ=0.6446). Patients with uniform type 1 (n=34)tumor morphology were more likely to exhibit an excellent response to NACT (defined as radiologic or CA-125 complete response) than those with type II (n=16) tumor morphology (47% vs 18%, p=0.13). Patients with type II predominant tumor morphology had a significantly higher estimated blood loss at the time of interval debulking surgery (p=0.008) as well as longer operative time (p=0.03) compared with type I tumor morphology. Patients with complete type II morphology were more likely to have a modified Fagotti score of <8 (p=0.026), and thus were more likely to be triaged to PDS. On histopathologic review of 7 type I cases and 4 type II cases, no obvious histo-pathological pattern dominated either type. We identified distinct molecular differences between the 2 types, including increased TGF-β expression in type I and increased MYC expression in type II. Type I tumors seem to have abundant stroma and are immunologically active, whereas type II tumors seem to be dominated by cancer cells, have little stroma, and are immunologically cold. There are at least two distinct gross morphological patterns of HGSOC with unique molecular differences and responses to chemotherapy. These findings could have major clinical implications for tailored therapeutic strategies. [Display omitted] [ABSTRACT FROM AUTHOR]

Summary: Integrated genomic analyses revealed a miRNA-regulatory network that further defined a robust integrated mesenchymal subtype associated with poor overall survival in 459 cases of serous ovarian cancer (OvCa) from The Cancer Genome Atlas and 560 cases from independent cohorts. Eight key miRNAs, including miR-506, miR-141, and miR-200a, were predicted to regulate 89% of the targets in this network. Follow-up functional experiments illustrate that miR-506 augmented E-cadherin expression, inhibited cell migration and invasion, and prevented TGFβ-induced epithelial-mesenchymal transition by targeting SNAI2, a transcriptional repressor of E-cadherin. In human OvCa, miR-506 expression was correlated with decreased SNAI2 and VIM, elevated E-cadherin, and beneficial prognosis. Nanoparticle delivery of miR-506 in orthotopic OvCa mouse models led to E-cadherin induction and reduced tumor growth. [ABSTRACT FROM AUTHOR]

Abstract: Paclitaxel is commonly used to treat multiple human malignancies, but its mechanism of action is still poorly defined. Human ovarian cancer SKOV3 cells (parental SKOV3) were treated with paclitaxel (1μM) for 2days, and the morphologic changes in the cells were monitored for more than 4months. Parental SKOV3 underwent a markedly morphologic transition from the epithelial to fibroblast-like phenotype following treatment with paclitaxel; the resulting cells were designated as SKOV3-P. The SKOV3-P cells’ proliferative ability was assessed via a 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay. The molecular characteristics of these cells were assessed via immunocytochemical staining and Western blot analysis. Their invasiveness and tumor formation ability was evaluated via wound-scratch and colony formation assays. The tumorigenicity of SKOV3-P cells was assessed in vivo after subcutaneous injection of tumor cells between injections of parental and paclitaxel-treated cells in nude mice. SKOV3-P cells have decreased the proliferation and invasion ability, decreased colony-forming ability when cultured in Matrigel and lost their tumor formation as compared with parental SKOV3 cells when injected in nude mice. SKOV3-P cells have decreased expression of E-cadherin, cytokeratin, Snail, PI3K, and P-Akt-Ser473, and increased expression of fibronectin, vimentin, Slug, P27, and PTEN. These results demonstrated that paclitaxel can inhibit tumor growth by inducing ovarian cancer epithelial cells toward a benign fibroblast-like phenotype through dysregulation of previously known pathways involved in the regulation of epithelial to mesenchymal transition (EMT), which may represent a novel mechanism for paclitaxel-induced tumor suppression. [Copyright &y& Elsevier]

Abstract: Mixed lineage kinase 3 (MLK3) is a mitogen-activated protein kinase kinase kinase (MAP3K) that activates MAPK signaling pathways and regulates cellular responses such as proliferation, migration and apoptosis. Here we report high levels of total and phospho-MLK3 in ovarian cancer cell lines in comparison to immortalized nontumorigenic ovarian epithelial cell lines. Using small interfering RNA (siRNA)-mediated gene silencing, we determined that MLK3 is required for the invasion of SKOV3 and HEY1B ovarian cancer cells. Furthermore, mlk3 silencing substantially reduced matrix metalloproteinase (MMP)-1, -2, -9 and -12 gene expression and MMP-2 and -9 activities in SKOV3 and HEY1B ovarian cancer cells. MMP-1, -2, -9 and-12 expression, and MLK3-induced activation of MMP-2 and MMP-9 requires both extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) activities. In addition, inhibition of activator protein-1 (AP-1) reduced MMP-1, MMP-9 and MMP-12 gene expression. Collectively, these findings establish MLK3 as an important regulator of MMP expression and invasion in ovarian cancer cells. [Copyright &y& Elsevier]

Abstract: Objective: Receptors for estrogen (ER), progesterone (PR), or androgen (AR) are predictive and prognostic markers of malignancy of multiple endocrine organs, including endometrial and breast cancer. However, the role of ERs, PRs, or ARs in the carcinogenesis of ovarian cancer, another sex hormone-dependent malignancy, is still controversial despite numerous studies that have attempted to determine their role. The disagreement in the findings may result from the fact that the numbers of tumor samples in studies have been small and that different immunohistochemical methods have been used that can introduce variation in the scoring of the histology. We therefore examined the pattern of expression of ERs, PRs, and ARs in a large number of samples of primary ovarian carcinoma by using a tissue microarray technique. Methods: We constructed a tissue microarray with 322 samples of primary ovarian carcinoma obtained at surgery performed at The University of Texas M. D. Anderson Cancer Center between 1990 and 2000. Immunohistochemistry studies were performed by using the immunoperoxidase technique against primary antibodies (ER, PR, and AR). Results: ERs, PRs, and ARs were differently expressed in different histotypes of ovarian cancer: ERs were expressed in 77.3% of all cases but more highly expressed in serous and endometrioid types; PRs were expressed in 26.2% of all cases but most highly expressed in the endometrioid type < 64.2%; and ARs were expressed in 43.7% of all cases but were most highly expressed in serous (47.5%) carcinomas. Of particular importance, the expression of PRs, but not ERs or ARs, was associated with better survival (P < 0.0001) in univariate and multivariate analyses. Conclusions: The PR is an independent marker, with its overexpression associated with a favorable prognosis in women with ovarian cancer. [Copyright &y& Elsevier]