Epithelial ovarian cancer

Cul4B promotes the progression of ovarian cancer by upregulating the expression of CDK2 and CyclinD1

Background

Ovarian cancer is one of the most common malignant tumors in the female reproductive system with the highest mortality rate. Cul4B participates in the oncogenesis and progression of several malignant tumors. However, the role of Cul4B in ovarian cancer has not been studied.

Results

High expression of intratumor Cul4B was associated with poor patient survival. Cul4B expression was associated with FIGO stage and Cul4B was independent risk factor of ovarian cancer disease-free survival and overall survival. In vitro studies revealed that overexpression of Cul4B promoted tumor proliferation while knockdown of Cul4B significantly inhibited the proliferation capacity of ovarian cancer cells. Mechanistically, Cul4B was found to promotes cell entering S phase from G0/G1 phase by regulating the expression of CDK2 and CyclinD1. Cul4B regulates the expression of CDK2 and CyclinD1 by repressing miR-372.

Conclusions

The results revealed that high expression of Cul4B is associated with poor ovarian cancer prognosis and Cul4B may serve as a potential treating target for an adjuvant therapy.

Signaling within the epithelial ovarian cancer tumor microenvironment: the challenge of tumor heterogeneity

Epithelial ovarian cancer (EOC) is a leading cause of cancer death in women. Standard of care treatment has remained platinum-containing cytotoxic chemotherapy for over three decades. Among the central challenges in treating ovarian CA are disease recurrence and the development of chemoresistance. Survival is uniformly poor for patients with chemoresistant recurrent disease and effective therapeutic options are limited. As such, delineating the mechanisms of chemoresistance and developing targeted therapies to prevent chemoresistance from occurring are of vital importance to improving survival for patients with EOC. Attempts to characterize mechanisms of chemoresistance have implicated numerous cellular pathways, but a rift remains between pre-clinical findings and translation to improving patient survival. More recently, the interplay among different cell types within the tumor microenvironment has become central to understanding how chemoresistance may develop and may be sustained. An improved understanding of how tumor cell-intrinsic and -extrinsic pathways converge during the development of chemoresistance may improve the likelihood of successful clinical translation. This review focuses on the roles of the EOC tumor microenvironment and tumor cell heterogeneity in the development of chemoresistance. We review recent studies into mechanisms of chemoresistance as they relate to tumor microenvironment and development of novel therapeutic approaches that exploit these mechanisms to prevent or reverse chemoresistance. This review attempts to cast these latest discoveries in a clinical context by summarizing trends in ongoing clinical trials for patients with EOC.

Mitomycin C plus cisplatin for systemic treatment of recurrent BRCA1-associated ovarian cancer

Background Previous studies on neoadjuvant therapy for BRCA1-driven ovarian cancer (OC) demonstrated higher efficacy of mitomycin C plus cisplatin combination as compared to standard drug schemes. These data call for evaluation of the utility of this regimen for the treatment of recurrent BRCA1-associated OC. Methods The study included 12 BRCA1 germ-line mutation carriers, whose disease relapsed after one (n = 4) or two (n = 8) lines of chemotherapy. The patients received cisplatin 100 mg/m² and mitomycin C 10 mg/m², given every four weeks, for 6 (n = 10), 8 (n = 1) or 5 (n = 1) cycles. Retrospective data on conventional treatment of OC relapses in BRCA1 heterozygotes (n = 47) served as a control. Results Grade 3-4 toxicities were observed in 4/12 (33%) cases. There were 6 complete responses (CR), 4 partial responses (PR) and 2 instances of stable disease (SD). Comparison of patients receiving mitomycin C plus cisplatin (n = 4) or conventional therapy (n = 44) at first relapse demonstrated marginal improvement of the progression-free survival (PFS) (16.6 months vs. 10.2 months, P = .067). Use of mitomycin C plus cisplatin (n = 8) for the treatment of second relapse resulted in significant prolongation of PFS as compared to standard regimens (n = 31) (14.8 months vs. 4.8 months, P = .002). Conclusions Mitomycin C plus cisplatin shows promising activity in recurrent BRCA1-driven ovarian cancer.

Emerging drugs for the treatment of ovarian cancer: a focused review of PARP inhibitors

INTRODUCTION

Poly (ADP-ribose) polymerase (PARP) inhibitors have demonstrated significant anticancer activity in cancers harboring homologous recombination deficiency (HRD), exemplified by high grade serous ovarian cancer (HGSC). PARP inhibitors (PARPi) are being used in women with newly diagnosed ovarian cancer as well as in the recurrent setting. PARPi combination therapies are in development.

AREAS COVERED

This review discusses the treatment of ovarian cancer, key PARPi clinical trials, mechanisms of action of PARPi, and novel PARPi combination regimens under investigation. PubMed and ClinicalTrials.gov were searched for PARPi trials. Active development was confirmed via PharmaProjects.

EXPERT OPINION

PARPi have shown to improve progression-free survival (PFS) for women with HGSC as monotherapy in both frontline and recurrent maintenance settings and as monotherapy as treatment for recurrence. These benefits are greatest in HGSC with underlying HRD, in particular for those with deleterious BRCA mutations, and with the least benefit in cancers that are HR proficient (HRP) and BRCA wild-type (wt). Thus far, an improvement in overall survival has only been demonstrated in patients with BRCA mutated EOC treated with olaparib maintenance in the platinum sensitive recurrence setting. Novel combinations of PARPi are undergoing testing in an effort to increase PARPi efficacy in HRP or PARPi-resistant cancers.

Subsequent Development of Epithelial Ovarian Cancer After Ovarian Surgery for Benign Ovarian Tumor: A Population-Based Cohort Study

Purpose

The goal of the current study is to determine the risk of subsequent development of epithelial ovarian cancer (EOC) in women after ovarian surgery for benign ovarian tumors.

Patients and Methods

We conducted the nationwide population-based historic cohort study using the National Health Insurance Research Database (NHIRD) of Taiwan. Eleven thousand six hundred twenty women who underwent ovarian surgery for ovarian benign diseases were analyzed. The collected data included age, types of ovarian surgery, medical history by Charlson comorbidity index (CCI), infertility (yes/no), pelvic inflammatory disease (PID) (yes/no), tubal ligation (yes/no), total/subtotal hysterectomy (TH/STH) (yes/no), and endometrioma (yes/no). We used the Kaplan-Meier method and the Log-rank test to evaluate the risk factors. Cox proportional hazard methods were used to evaluate risk factors for the subsequent development of EOC. Multivariate analysis using Cox stepwise forward regression was conducted for the covariate selected in univariate analysis. Hazard ratio (HR) and 95% confidence interval (CI) were calculated using the Wald test.

Results

Subsequent EOC incidence rate (IR, incidence per 10,000 person-years) of women after ovarian surgery for benign ovarian tumors was 2.98. Separating into four groups based on different age, IR of EOC was 1.57 (<30 years), 4.71 (30-39 years), 3.59 (40-49 years) and 0.94 (≥50 years), respectively. Univariate and multivariate analyses identified only high level of CCI (≥2 or more) as an independent risk factor for subsequent development of EOC in women after ovarian surgery for benign ovarian tumors (HR 59.17, 95% CI 7.50-466.80 in women with CCI level of 2 and HR 190.68, 95% CI 24.33-2494.19, in women with CCI level ≥3, respectively).

Conclusion

Our results, if confirmed, suggest that women with other comorbidities (CCI) should be well informed that they may have a higher risk of subsequent development of EOC when ovarian surgery is planned even though the final pathology showed a benign ovarian tumor.

Overcoming Platinum and PARP-Inhibitor Resistance in Ovarian Cancer

Platinum chemotherapy remains the cornerstone of treatment for epithelial ovarian cancer (OC) and Poly (ADP-ribose) polymerase inhibitors (PARPi) now have an established role as maintenance therapy. The mechanisms of action of these agents is, in many ways, complementary, and crucially reliant on the intracellular DNA Damage Repair (DDR) response. Here, we review mechanisms of primary and acquired resistance to treatment with platinum and PARPi, examining the interplay between both classes of agents. A key resistance mechanism appears to be the restoration of the Homologous Recombination (HR) repair pathway, through BRCA reversion mutations and epigenetic upregulation of BRCA1. Alterations in non-homologous end-joint (NHEJ) repair, replication fork protection, upregulation of cellular drug efflux pumps, reduction in PARP1 activity and alterations to the tumour microenvironment have also been described. These resistance mechanisms reveal molecular vulnerabilities, which may be targeted to re-sensitise OC to platinum or PARPi treatment. Promising therapeutic strategies include ATR inhibition, epigenetic re-sensitisation through DNMT inhibition, cell cycle checkpoint inhibition, combination with anti-angiogenic therapy, BET inhibition and G-quadruplex stabilisation. Translational studies to elucidate mechanisms of treatment resistance should be incorporated into future clinical trials, as understanding these biologic mechanisms is crucial to developing new and effective therapeutic approaches in advanced OC.

Suppressive activities of mangiferin on human epithelial ovarian cancer

BACKGROUND

Epithelial carcinoma is a subtype of ovarian cancers, with the highest lethality among all ovarian cancer subtypes. Hitherto surgical excision combined with chemotherapy has been the most extensively employed method in clinical treatment. However, the disease relapses very frequently, calling for more effective therapies. Mangiferin, a natural xanthone glucoside, has displayed promising anti-cancer activities by in vitro studies, but its therapeutic value in epithelial ovarian cancer treatment, either by in vivo or in vitro studies, remained to be known.

PURPOSE

This study aimed to determine the suppressive activities of mangiferin on human epithelial ovarian cancer and elucidate the underlying molecular mechanisms.

STUDY DESIGN AND METHODS

We employed the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and the crystal violet assay to determine the half maximal inhibitory concentration (IC50) values of mangiferin with paclitaxel as a positive control and the inhibitory effects of mangiferin on the proliferation of two human epithelial ovarian cancer cell lines. Wound healing and Transwell assays were used to determine anti-metastastic activities of mangiferin. ES-2 xenograft nude mouse model was used for the in vivo experiments. Western blotting, enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry (IHC) assays were carried out for evaluating the expression level of matrix metalloproteinase 2 (MMP2) and matrix metalloproteinase 9 (MMP9).

RESULTS

In the present study, we demonstrated by both in vitro and in vivo assays that mangiferin suppressed the progress of epithelial ovarian cancer in a dose-dependent manner. In the animals treated with mangiferin, the tumor volume and weight were reduced significantly. Analyses of involved molecular events demonstrated that mangiferin down-regulated the expression of metastasis-associated proteins MMP2 and MMP9.

CONCLUSION

Mangiferin strongly inhibited the progression of human epithelial ovarian cancer by down-regulating MMP2 and MMP9.

YLZ-F5, a novel polo-like kinase 4 inhibitor, inhibits human ovarian cancer cell growth by inducing apoptosis and mitotic defects

PURPOSE

Polo-like kinase 4 (PLK4), a member of the polo-like kinase family, plays several important roles in mitotic regulation, including centrosome duplication, spindle formation, and cytokinesis. PLK4 overexpression is frequently detected in many human cancers, including ovarian cancer, and the inhibition of PLK4 activity results in cancer cell mitotic arrest and apoptosis. Therefore, PLK4 might be a valid therapeutic target for antitumor therapy. In the present study, we aimed to determine if YLZ-F5, a potent small-molecule inhibitor of PLK4, inhibits ovarian cancer cell growth.

METHODS AND RESULTS

MTT assay showed that YLZ-F5 inhibited ovarian cancer cell proliferation in a concentration- and time-dependent manner. The results of colony formation assays were consistent with those of the MTT assay results. In addition, YLZ-F5 induced ovarian cancer cell apoptosis that was associated with activation of caspase-3/caspase-9. Moreover, YLZ-F5 caused aberrant in centriole duplication that was associated with the inhibition of PLK4 phosphorylation. Notably, we showed that YLZ-F5 promoted the accumulation of ovarian cancer cells with mitotic defects (> 4 N DNA content) in a concentration-dependent manner. Furthermore, YLZ-F5 markedly inhibited the migration of A2780 cells.

CONCLUSION

Taken together, these findings suggest that YLZ-F5 is a potential drug candidate for human ovarian cancer.

Expressions and clinical significances of STAT3 and Grim19 in epithelial ovarian cancer

This study aimed to explore the expressions of signal transducer and activator of transcription 3 (STAT3) and a gene associated with retinoid-interferon induced mortality (Grim19) in epithelial ovarian cancer (EOC), and to determine their correlations with tumor progression and metastasis as well as the related mechanism. Ovarian tissue specimens resected through operation in our hospital were collected, and the correlations of Grim19 and STAT3 expressions with clinicopathological indexes were detected via immunohistochemistry (IHC) and Western blotting. Their positions in cells were observed through immunofluorescence. IHC assay results showed that STAT3 had the lowest expression level in the normal ovary, followed by those in benign ovarian tumor and borderline ovarian tumor (BOT), but it had high expression in EOC; The expression level of Grim19 was the lowest in EOC, followed by those in BOT and benign ovarian tumor successively, while it was highly expressed in the normal ovary; The expressions of STAT3 and Grim19 presented negative correlations in all kinds of ovarian tissues (p < 0.05). The expression level of STAT3 in EOC had no obvious correlations with FIGO staging or WHO classification (p > 0.05). The expression level of Grim19 in EOC in stage FIGO III-IV was higher than that in stage FIGO I-II (p < 0.05), Grim19 expression was not obviously associated with WHO classification (p > 0.05). The expressions of Grim19 and STAT3 in lymphatic metastasis lesion had significantly positive correlations with the primary lesion (p < 0.05). The Western blotting assay results were identical with the IHC results. The immunofluorescence demonstrated that STAT3 and Grim19 were mainly localized in the cytoplasm and they were colocalized in mitochondria. In conclusion, STAT3 presents high expression in EOC tissues while Grim19 is expressed in EOC tissues at a low level, which may be related to its interaction with STAT3 as well as progression, metastasis and poor prognosis of ovarian cancer.

Role of the Exosome Secretion Machinery in Ovarian Carcinoma: In Vitro and In Vivo Models

Objective. We recently reported on the expression and clinical role of molecules that mediate exosome secretion in high-grade serous carcinoma. In the present study, the biological role of these molecules was analyzed. Methods. OVCAR8 and ES-2 ovarian carcinoma cells were studied using a combination of CRISPR/Cas9 technology and two 3D in vitro models—spheroids emulating effusions and alginate scaffolds representing solid lesions. Isolation of exosomes was validated by electron microscopy. TSAP6, NSMASE2, RAB27A, and RAB27B mRNA and protein levels were analyzed using qRT-PCR and Western blotting, respectively. Tumor aggressiveness was studied in vitro using scratch assay, invasion assay, and matrix metalloproteinase (MMP) activity assay and in vivo using a mouse model. Results. In OVCAR8 cells, mRNA expression of TSAP6 and RAB27A was significantly higher in spheroids compared to scaffolds, whereas the opposite was true for NSMASE2 mRNA. In ES-2 cells, TSAP6 and RAB27B mRNA expression was significantly higher in spheroids versus scaffolds. In addition, nSMase2 and TSAP6 protein expression was significantly higher in scaffolds compared to spheroids. CRISPR-edited cells with silencing of NSMASE2, TSAP6, and RAB27A/B had reduced migration, invasion, and MMP activity. Additionally, knockout (KO) of these molecules resulted in significantly diminished exosome secretion. In vivo assay showed that when injected to mice, OVCAR8 RAB27A/B KO cells, as opposed to control OVCAR8 cells, did not form ascites or visible tumor lesions and had reduced MMP expression. Conclusion. The present study provides evidence that different models for culturing ovarian carcinoma cells affect the expression of molecules mediating exosome secretion and that these molecules have a tumor-promoting role. Silencing these molecules may consequently have therapeutic relevance in this cancer.

Epithelial-mesenchymal interconversions in ovarian cancer: The levels and functions of E-cadherin in intraabdominal dissemination

The metastatic process of ovarian cancer (OC) is almost exclusively defined by direct shedding of tumor cells into the abdominal cavity, followed by clustering into multicellular aggregates and posterior peritoneal anchorage. This process relies on dynamic intercellular interactions which are modified by epithelial- mesenchymal interconversions and, therefore, E-cadherin expression variability. Although widely accepted as a tumor suppressor in many types of cancer, E-cadherin is currently known to have a dynamic expression and a much more complex role in OC. First, high E-cadherin expression is considered a sign of metaplasia in the normal ovarian epithelium, due to its association with epithelial growth factor receptor (EGFR) mediated cell proliferation. Subsequently, it is the decreased expression of E-cadherin that allows the acquisition of a more invasive phenotype, leading to the spread of primary tumor cells into the peritoneal fluid. This downregulation seems to depend on complex regulatory mechanisms, from molecular proteolysis to microenvironment interference and epigenetic regulation. E-cadherin cleavage and its resulting fragments appear to be essential to the process of dissemination and even to the formation of multicellular aggregates. Paradoxically, the maintenance of some E-cadherin expression seems to promote intercellular adhesion, resistance, and survival while decreasing cancer response to chemotherapy. Multiple studies have shown that reversing epithelial-mesenchymal transaction (EMT) and increasing E-cadherin expression prevents OC intraperitoneal dissemination, but findings that simultaneously correlate E-cadherin downregulation to higher chemotherapy sensitivity should not be ignored. Nevertheless, EMT and E-cadherin seem to have a potential interest as therapeutic targets in novel approaches to OC treatment.

A graph-based multi-sample test for identifying pathways associated with cancer progression

Cancer is in general not a result of an abnormality of a single gene but a consequence of changes in many genes, it is therefore of great importance to understand the roles of different oncogenic and tumor suppressor pathways in tumorigenesis. In recent years, there have been many computational models developed to study the genetic alterations of different pathways in the evolutionary process of cancer. However, most of the methods are knowledge-based enrichment analyses and inflexible to analyze user-defined pathways or gene sets. In this paper, we develop a nonparametric and data-driven approach to testing for the dynamic changes of pathways over the cancer progression. Our method is based on an expansion and refinement of the pathway being studied, followed by a graph-based multivariate test, which is very easy to implement in practice. The new test is applied to the rich Cancer Genome Atlas data to study the (epi)genetic alterations of 186 KEGG pathways in the development of serous ovarian cancer. To make use of the comprehensive data, we incorporate three data types in the analysis representing gene expression level, copy number and DNA methylation level. Our analysis suggests a list of nine pathways that are closely associated with serous ovarian cancer progression, including cell cycle, ERBB, JAK-STAT signaling and p53 signaling pathways. By pairwise tests, we found that most of the identified pathways contribute only to a particular transition step. For instance, the cell cycle and ERBB pathways play key roles in the early-stage transition, while the ECM receptor and apoptosis pathways contribute to the progression from stage III to stage IV. The proposed computational pipeline is powerful in detecting important pathways and gene sets that drive cancers at certain stage(s). It offers new insights into the understanding of molecular mechanism of cancer initiation and progression.

Bim, Puma and Noxa upregulation by Naftopidil sensitizes ovarian cancer to the BH3-mimetic ABT-737 and the MEK inhibitor Trametinib

Ovarian cancer represents the first cause of mortality from gynecologic malignancies due to frequent chemoresistance occurrence. Increasing the [BH3-only Bim, Puma, Noxa proapoptotic]/[Bcl-x_L, Mcl-1 antiapoptotic] proteins ratio was proven to efficiently kill ovarian carcinoma cells and development of new molecules to imbalance Bcl-2 member equilibrium are strongly required. Drug repurposing constitutes an innovative approach to rapidly develop therapeutic strategies through exploitation of established drugs already approved for the treatment of noncancerous diseases. This strategy allowed a renewed interest for Naftopidil, an α₁-adrenergic receptor antagonist commercialized in Japan for benign prostatic hyperplasia. Naftopidil was reported to decrease the incidence of prostate cancer and its derivative was described to increase BH3-only protein expression in some cancer models. Based on these arguments, we evaluated the effects of Naftopidil on ovarian carcinoma and showed that Naftopidil reduced cell growth and increased the expression of the BH3-only proteins Bim, Puma and Noxa. This effect was independent of α₁-adrenergic receptors blocking and involved ATF4 or JNK pathway depending on cellular context. Finally, Naftopidil-induced BH3-only members sensitized our models to ABT-737 and Trametinib treatments, in vitro as well as ex vivo, in patient-derived organoid models.

Eukaryotic initiation factor 3B is overexpressed and correlates with larger tumor size, advanced FIGO stage, and shorter overall survival in epithelial ovarian cancer patients

Background

This study aimed to detect the eukaryotic initiation factor 3B (EIF3B) expression and explore its correlation with clinical features and prognosis in epithelial ovarian cancer (EOC) patients.

Methods

A total of 230 primary EOC patients underwent surgery treatment were retrospectively reviewed. Immunohistochemical (IHC) assay was used to determine EIF3B expression in tumor and adjacent tissue specimens of all patients. According to the total IHC score, the expression of EIF3B was classified as low expression and high expression, and the latter was further divided into 3 grades: high+, high++, and high+++ expressions. Overall survival (OS) was calculated.

Results

Eukaryotic initiation factor 3B expression was increased in tumor tissue compared with adjacent tissue. Tumor EIF3B high expression correlated with larger tumor size (>10 cm), lymphatic metastasis, and advanced International Federation of Gynecology and Obstetrics stage (FIGO) (III/IV). Besides, OS was decreased in patients with tumor EIF3B high expression compared with patients with tumor EIF3B low expression, and further analysis showed that the OS was shortest in patients with tumor EIF3B high+++ expression, followed by patients with tumor EIF3B high++ expression and patients with tumor EIF3B high + expression, and the longest in patients with tumor EIF3B low expression. Additionally, higher tumor EIF3B expression, peritoneal cytology (positive), ascites volume (>100 mL), differentiation (poor vs. well/moderate), tumor size (>10 cm), FIGO stage (III/IV vs. I/II), and cancer antigen 125 (>1000 U/mL) independently predicted shorter OS.

Conclusion

Eukaryotic initiation factor 3B exhibits a clinical value for monitoring disease progression and predicting prognosis in EOC patients.

A novel role for NUAK1 in promoting ovarian cancer metastasis through regulation of fibronectin production in spheroids

Epithelial ovarian cancer (EOC) has a unique mode of metastasis, where cells shed from the primary tumour, form aggregates called spheroids to evade anoikis, spread through the peritoneal cavity, and adhere to secondary sites. We previously showed that the master kinase Liver kinase B1 (LKB1) is required for EOC spheroid viability and metastasis. We have identified novel (nua) kinase 1 (NUAK1) as a top candidate LKB1 substrate in EOC cells and spheroids using a multiplex inhibitor beads-mass spectrometry approach. We confirmed that LKB1 maintains NUAK1 phosphorylation and promotes its stabilization. We next investigated NUAK1 function in EOC cells. Ectopic NUAK1-overexpressing EOC cell lines had increased adhesion, whereas the reverse was seen in OVCAR8-NUAK1KO cells. In fact, cells with NUAK1 loss generate spheroids with reduced integrity, leading to increased cell death after long-term culture. Following transcriptome analysis, we identified reduced enrichment for cell interaction gene expression pathways in OVCAR8-NUAK1KO spheroids. In fact, the FN1 gene, encoding fibronectin, exhibited a 745-fold decreased expression in NUAK1KO spheroids. Fibronectin expression was induced during native spheroid formation, yet this was completely lost in NUAK1KO spheroids. Co-incubation with soluble fibronectin restored the compact spheroid phenotype to OVCAR8-NUAK1KO cells. In a xenograft model of intraperitoneal metastasis, NUAK1 loss extended survival and reduced fibronectin expression in tumours. Thus, we have identified a new mechanism controlling EOC metastasis, through which LKB1-NUAK1 activity promotes spheroid formation and secondary tumours via fibronectin production.

Activated CAMKKβ-AMPK signaling promotes autophagy in a spheroid model of ovarian tumour metastasis

Background

A hallmark of epithelial ovarian cancer (EOC) metastasis is the process of spheroid formation, whereby tumour cells aggregate into 3D structures while in suspension in the peritoneal cavity. EOC spheroids are subjected to bioenergetic stress, thereby activating AMP-activated protein kinase (AMPK) signaling to enter a metabolically quiescent state, which can facilitate cell survival under nutrient-limiting conditions. Independently, we have also demonstrated that EOC spheroids induce autophagy, a process that degrades and recycles intracellular components to restore energy and metabolites. Herein, we sought to examine whether AMPK controls autophagy induction as a cell survival mechanism in EOC spheroids.

Results

We observed a co-ordinate increase in phosphorylated AMPK and the autophagy marker LC3-II during EOC spheroid formation. Reduced AMPK expression by siRNA-mediated knockdown of PRKAA1 and PRKAA2 blocked autophagic flux in EOC spheroids as visualized by fluorescence microscopy using the mCherry-eGFP-LC3B reporter. A complementary approach using pharmacologic agents Compound C and CAMKKβ inhibitor STO-609 to inhibit AMPK activity both yielded a potent blockade of autophagic flux as well. However, direct activation of AMPK in EOC cells using oligomycin and metformin was insufficient to induce autophagy. STO-609 treatment of EOC spheroids resulted in reduced viability in 7 out of 9 cell lines, but with no observed effect in non-malignant FT190 cell spheroids.

Conclusions

Our results support the premise that CAMKKβ-mediated AMPK activity is required, at least in part, to regulate autophagy induction in EOC spheroids and support cell viability in this in vitro model of EOC metastasis.

Oncologic outcomes and morbidity following heated intraperitoneal chemotherapy at cytoreductive surgery for primary epithelial ovarian cancer: A systematic review and meta-analysis

OBJECTIVES

Heated intraperitoneal chemotherapy (HIPEC) has not been universally adopted at the time of interval cytoreductive surgery for primary epithelial ovarian cancer (EOC) despite evidence of a 12-month overall survival (OS) benefit in a recent landmark randomized trial. We performed a systematic review and meta-analysis to assess oncologic outcomes and perioperative morbidity following HIPEC among primary EOC patients.

METHODS

We searched MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, and the Cochrane Database of Systematic Reviews, from inception to August 2019, for observational and randomized studies of primary EOC patients undergoing HIPEC. We assessed risk of bias using the Institute of Health Economics Quality Appraisal Checklist for single-arm cohort studies, Newcastle-Ottawa Scale for comparative cohort studies, and Cochrane Collaboration's Tool for randomized trials. We qualitatively summarized survival outcomes and calculated the pooled proportion of 30-day grade III-IV morbidity and postoperative death.

RESULTS

We identified 35 articles including 2252 primary EOC patients; one study was a randomized trial, and only six studies included a comparator group of surgery alone. The timing, temperature, and chemotherapeutic agents used for HIPEC differed across studies. Reported OS was highly variable (3-year OS range: 46-77%); three comparative cohort studies and the sole randomized trial reported statistically significant survival benefits for HIPEC over surgery alone, while two comparative cohort studies did not. The pooled proportions for grade III-IV morbidity and postoperative death at 30 days were 34% (95% CI 20-52) and 0% (95% CI 0-5) respectively.

CONCLUSION

One randomized trial suggests that HIPEC at time of interval cytoreductive surgery should be considered in patients with primary EOC. However, there is significant heterogeneity in literature with respect to an appropriate HIPEC regimen, short- and long-term outcomes. High-quality prospective randomized trials are urgently needed to clarify the role of HIPEC in the first-line treatment of primary EOC.

CD38 Predicts Favorable Prognosis by Enhancing Immune Infiltration and Antitumor Immunity in the Epithelial Ovarian Cancer Microenvironment

The identification of predictive biomarkers and novel targets to optimize immunotherapy strategies for epithelial ovarian cancer (EOC) is urgently needed. CD38 is a multifunctional glycoprotein that acts as an ectoenzyme and immune receptor. However, the underlying immunological mechanisms and prognostic value of CD38 in EOC remain unclear. CD38 gene expression in EOC was evaluated by using Gene Expression Profiling Interactive Analysis (GEPIA) and TISIDB database. The prognostic value was calculated using GEPIA and Kaplan-Meier plotter. Gene set enrichment analysis was conducted to study the roles of CD38 in the EOC microenvironment. Furthermore, the relationship between CD38 expression level and immune cell infiltration was analyzed by the Tumor Immune Estimation Resource and TISIDB. The GEPIA and TISIDB databases showed that CD38 expression in EOC was higher than that in normal tissue and was highest in the immunoreactive subtype among the four molecular types. A total of 424 cases from GEPIA revealed that high levels of CD38 were associated with longer disease-free survival [hazard ratio (HR) = 0.66, P = 0.00089] and increased overall survival rate (HR = 0.67, P = 0.0016). Kaplan-Meier plotter also confirmed the prognostic value of CD38 in EOC. Data from The Cancer Genome Atlas database demonstrated that gene signatures in many categories, such as immune response and adaptive immune response, were enriched in EOC samples with high CD38 expression. In addition, CD38 was positively correlated with immune cell infiltration, especially infiltration of activated CD8+ T cells, CD4+ T cells, and B cells. CD38 is positively correlated with prognosis and immune cell infiltration in the EOC microenvironment and contributes to the regulation of antitumor immunity. CD38 could be used as a prognostic biomarker and potential immunotherapy target.

Non-canonical signaling pathway of SNAI2 induces EMT in ovarian cancer cells by suppressing miR-222-3p transcription and upregulating PDCD10

Background: Epithelial ovarian cancer (EOC) is one of the most lethal malignancies in women worldwide. Many studies showed the transcription factor SNAI2-induced Epithelial-Mesenchymal Transition (EMT) through inhibiting E-cadherin (E-cad) expression. Our previous study reported that miR-222-3p was an important tumor-suppressive miRNA for EOC development and dissemination. The present study aimed to acquire a deeper mechanistic understanding of the role of miR-222-3p regulation that might contribute to improving current anti-metastasis strategies in EOC. Methods: A variety of techniques were used to measure mRNA and protein expression levels, including quantitative real-time polymerase chain reaction (qRT-PCR), Western blot, immunohistochemical (IHC) staining, and immunofluorescence (IF). Four different microRNA (miRNA) target prediction databases were used to predict the target genes of miR-222. Luciferase assay was performed to determine the direct binding of miR-222-3p to the untranslated region (3'-UTR) of PDCD10. The biological effects of PDCD10 and miR-222-3p were also investigated in vitro by Transwell and wound healing assays, as well as in vivo by a xenograft mice model. Combining UCSC and JASPAR, as well as ENCODE public databases, we predicted that the transcription factor SNAI2 could affect miR-222-3p expression. Luciferase assay was utilized to examine the validity of putative SNAI2 binding sites for miR-222-3p regulation. Chromatin immunoprecipitation (ChIP) was used to explore the SNAI2's occupancy on the miR-222-3p promoter. Results: We observed the inhibitory effect of SNAI2 on miR-222-3p transcription and confirmed the tumor-suppressive function of miR-222-3p both in EOC cells and tissues. PDCD10 was upregulated and inversely correlated with miR-222-3p, both in vitro and in vivo, which was consistent with the information in bioinformatics databases. Furthermore, We observed direct binding of miR-222-3p to the 3'-UTR of PDCD10 and inhibition of PDCD10 translation, which, in turn, inhibited EOC cell migration in vitro and repressed EOC xenografted tumor metastasis in vivo. We found that genetic overexpression of PDCD10 (OE-PDCD10) increased cancer metastasis by down-regulating E-cad and enhancing Vimentin (VIM) thereby inducing EMT and promoting β-catenin/Wnt-mediated cell migration.

Splicing factor proline- and glutamine-rich (SFPQ) protein regulates platinum response in ovarian cancer-modulating SRSF2 activity

In epithelial ovarian cancer (EOC), response to platinum (PT)-based chemotherapy dictates subsequent treatments and predicts patients' prognosis. Alternative splicing is often deregulated in human cancers and can be altered by chemotherapy. Whether and how changes in alternative splicing regulation could impact on the response of EOC to PT-based chemotherapy is still not clarified. We identified the splicing factor proline and glutamine rich (SFPQ) as a critical mediator of response to PT in an unbiased functional genomic screening in EOC cells and, using a large cohort of primary and recurrent EOC samples, we observed that it is frequently overexpressed in recurrent PT-treated samples and that its overexpression correlates with PT resistance. At mechanistic level, we show that, under PT treatment, SFPQ, in complex with p54^nrb, binds and regulates the activity of the splicing factor SRSF2. SFPQ/p54^nrb complex decreases SRSF2 binding to caspase-9 RNA, favoring the expression of its alternative spliced antiapoptotic form. As a consequence, SFPQ/p54^nrb protects cells from PT-induced death, eventually contributing to chemoresistance. Overall, our work unveils a previously unreported SFPQ/p54^nrb/SRSF2 pathway that in EOC cells plays a central role in regulating alternative splicing and PT-induced apoptosis and that could result in the design of new possible ways of intervention to overcome PT resistance.

Rapid decrease in serum VEGF-A levels may be a worse prognostic biomarker for patients with platinum-resistant recurrent ovarian cancer treated with bevacizumab and gemcitabine

PURPOSE

The aim of this study was to investigate the association between changes in the levels of vascular endothelial growth factors (VEGFs) after treatment with bevacizumab and gemcitabine (Bev-Gem) and the clinical outcome.

METHODS

Platinum-resistant ovarian cancer patients treated with Bev-Gem therapy at our hospital between 2014 and 2018 were identified. Serum VEGF levels at the first and second treatment cycle were measured by ELISA. All patients were categorized into two groups-patients with > 50% decrease in serum VEGF-A levels (Group A) and patients with < 50% decrease serum VEGF-A levels (Group B). The association between clinical outcome and serum VEGF levels was investigated between the two groups.

RESULTS

Among 18 patients, 10 were in Group A and 8 in Group B. Group A exhibited a lower response rate (0% vs.75% p < 0.01) and clinical benefit rate (60% vs.100% p = 0.02) than Group B. The median serum VEGF-A level of Group A before the first cycle of Bev-Gem therapy was higher than that in Group B (61.2 vs. 3.7 pg/mL, p < 0.01). Group A exhibited worse PFS (7 vs., 10 months, p < 0.01) and OS (17 vs. 26 months, p = 0.04) than Group B. There were more patients with > 10% increase in serum VEGF-B levels in Group A than in Group B (p < 0.01).

CONCLUSION

The rapid decrease in VEGF-A levels and the resultant increase in serum VEGF-B levels might be associated with an unfavorable clinical outcome. Large-scale studies are needed to further examine these results.

Targeting the PI3K pathway and DNA damage response as a therapeutic strategy in ovarian cancer

Ovarian cancer is the most lethal gynecological malignancy worldwide although exponential progress has been made in its treatment over the last decade. New agents and novel combination treatments are on the horizon. Among many new drugs, a series of PI3K/AKT/mTOR pathway (referred to as the PI3K pathway) inhibitors are under development or already in clinical testing. The PI3K pathway is frequently upregulated in ovarian cancer and activated PI3K signaling contributes to increased cell survival and chemoresistance. However, no significant clinical success has been achieved with the PI3K pathway inhibitor(s) to date, reflecting the complex biology and also highlighting the need for combination treatment strategies. DNA damage repair pathways have been active therapeutic targets in ovarian cancer. Emerging data suggest the PI3K pathway is also involved in DNA replication and genome stability, making DNA damage response (DDR) inhibitors as an attractive combination treatment for PI3K pathway blockades. This review describes an expanded role for the PI3K pathway in the context of DDR and cell cycle regulation. We also present the novel treatment strategies combining PI3K pathway inhibitors with DDR blockades to improve the efficacy of these inhibitors for ovarian cancer.

Intraoperative Capsule Rupture, Postoperative Chemotherapy, and Survival of Women With Stage I Epithelial Ovarian Cancer

The incidence and prognostic significance of intraoperative capsule rupture in apparent stage IA-B ovarian cancer varies across histologies, and postoperative chemotherapy was not associated with improved survival.

To examine the incidence and prognostic effects of intraoperative capsule rupture and to assess the effectiveness of postoperative chemotherapy for intraoperative tumor rupture in apparent stage I epithelial ovarian cancer.

Low expression of NCALD is associated with chemotherapy resistance and poor prognosis in epithelial ovarian cancer

Background

Low expression of NCALD(neurocalcin delta) in peripheral blood of ovarian cancer patients predicts poor prognosis. However, the molecular mechanism of NCALD in ovarian cancer and its relationship with chemotherapy outcomes is unclear. The aim of this study was to investigate the potential signaling pathways of NCALD and to evaluate its ability to predict chemotherapy outcomes and prognosis.

Methods

High-throughput RNA sequencing data were downloaded from TCGA. GSEA explored the potential signaling pathways of NCALD. The expression of NCALD in chemotherapy sensitive and chemotherapy resistant ovarian cancer patients was detected by TCGA data and clinical samples. ROC analysis confirmed the ability of NCALD to predict chemotherapy outcomes. The association between NCALD expression and prognosis in ovarian cancer patients was assessed using Kaplan-Meier plotter.

Results

In patients with NCALD overexpression, genes expression related to ERK1 / 2 signaling pathway, NF-kappaB signaling pathway, TGF-β signaling pathway and immune response pathway was increased, especially ERK1 / 2 signaling pathway. The expression of NCALD in chemoresistant patients was significantly lower than chemosensitive patients. In TCGA data and immunohistochemical samples, the AUC of NCALD expression predicting chemotherapy outcome was 0.59 and 0.64, respectively. In clinical samples, low expression of NCALD was associated with poor OS and PFS.

Conclusions

NCALD may activate the ERK1 / 2 signaling pathway in ovarian cancer. As a new biomarker of chemotherapy sensitivity, NCALD was significantly down-regulated in chemotherapy resistance ovarian cancer patients. Low expression of NCALD in ovarian cancer is associated with poor OS and PFS. In the future, further research will be needed on the potential mechanism and clinical application value of NCALD in ovarian cancer.

Comparing Paclitaxel-Carboplatin with Paclitaxel-Cisplatin as the Front-Line Chemotherapy for Patients with FIGO IIIC Serous-Type Tubo-Ovarian Cancer

The use of weekly chemotherapy for the treatment of patients with advanced-stage serous-type epithelial Tubo-ovarian cancer (ETOC), and primary peritoneal serous carcinoma (PPSC) is acceptable as the front-line postoperative chemotherapy after primary cytoreductive surgery (PCS). The main component of dose-dense chemotherapy is weekly paclitaxel (80 mg/m²), but it would be interesting to know what is the difference between combination of triweekly cisplatin (20 mg/m²) or triweekly carboplatin (carboplatin area under the curve 5-7 mg/mL per min [AUC 5-7]) in the dose-dense paclitaxel regimen. Therefore, we compared the outcomes of women with Gynecology and Obstetrics (FIGO) stage IIIC ETOC and PPSC treated with PCS and a subsequent combination of dose-dense weekly paclitaxel and triweekly cisplatin (paclitaxel–cisplatin) or triweekly carboplatin using AUC 5 (paclitaxel–carboplatin). Between January 2010 and December 2016, 40 women with International Federation of Gynecology and Obstetrics (FIGO) stage IIIC EOC, FTC, or PPSC were enrolled, including 18 treated with paclitaxel–cisplatin and the remaining 22 treated with paclitaxel–carboplatin. There were no statistically significant differences in disease characteristics of patients between two groups. Outcomes in paclitaxel–cisplatin group seemed to be little better than those in paclitaxel–carboplatin (median progression-free survival [PFS] 30 versus 25 months as well as median overall survival [OS] 58.5 versus 55.0 months); however, neither reached a statistically significant difference. In terms of adverse events (AEs), patients in paclitaxel–carboplatin group had more AEs, with a higher risk of neutropenia and grade 3/4 neutropenia, and the need for a longer period to complete the front-line chemotherapy, and the latter was associated with worse outcome for patients. We found that a period between the first-time chemotherapy to the last dose (6 cycles) of chemotherapy >21 weeks was associated with a worse prognosis in patients compared to that ≤21 weeks, with hazard ratio (HR) of 81.24 for PFS and 9.57 for OS. As predicted, suboptimal debulking surgery (>1 cm) also contributed to a worse outcome than optimal debulking surgery (≤1 cm) with HR of 14.38 for PFS and 11.83 for OS. Based on the aforementioned findings, both regimens were feasible and effective, but maximal efforts should be made to achieve optimal debulking surgery and following the on-schedule administration of dose-dense weekly paclitaxel plus triweekly platinum compounds. Randomized trials validating the findings are warranted.

The tubal epigenome - An emerging target for ovarian cancer

Ovarian cancer is the most lethal gynecologic malignancy in the United States. The mortality of this disease is primarily attributed to challenges in early detection and therapeutic resistance. Recent studies indicate that the majority of high-grade serous ovarian carcinomas (HGSCs) originate from aberrant fallopian tube epithelial (FTE) cells. This shift in thinking about ovarian cancer pathogenesis has been met with an effort to identify the early genetic and epigenetic changes that underlie the transformation of normal FTE cells and prompt them to migrate and colonize the ovary, ultimately giving rise to aggressive HGSC. While identification of these early changes is important for biomarker discovery, the emergence of epigenetic alterations in FTE chromatin may also provide new opportunities for early detection, prevention, and therapeutic intervention. Here we provide a comprehensive overview of the current knowledge regarding early epigenetic reprogramming that precedes HGSC tumor development, the way that these alterations affect both intrinsic and extrinsic tumor properties, and how the epigenome may be targeted to thwart HGSC tumorigenesis.

Lack of evidence for CDK12 as an ovarian cancer predisposing gene

CDK12 variants were investigated as a genetic susceptibility to ovarian cancer in a series of 416 unrelated and consecutive patients with ovarian carcinoma and who carry neither germline BRCA1 nor BRCA2 pathogenic variant. The presence of CDK12 variants was searched in germline DNA by massive parallel sequencing on pooled DNAs. The lack of detection of deleterious variants and the observed proportion of missense variants in the series of ovarian carcinoma patients as compared with all human populations strongly suggests that CDK12 is not an ovarian cancer predisposing gene.

Poly(ADP-ribose) polymerase inhibitors as maintenance treatment in patients with newly diagnosed advanced ovarian cancer: a meta-analysis

Aim: Poly(ADP-ribose) polymerase inhibitors (PARPIs) improved progression-free survival among patients with recurrent ovarian cancer. This meta-analysis examined the effectiveness of PARPIs as maintenance strategy for newly diagnosed patients with advanced high-grade ovarian cancer with or without mutations. Materials & methods: Using defined selection criteria, a literature search identified four eligible randomized clinical trials involving 2386 patients. Results: Compared with placebo maintenance, PARPIs achieved a 46% reduction in the risk of progression or death as compared with placebo (hazard ratio: 0.54; 95% CI: 0.39-0.73; p < 0.0001). That benefit was shown in all clinical subgroups: among those with BRCA mutation, with negative/unknown BRCA mutation, and in those with homologous recombination deficient tumors. Data about the effect on overall survival are still premature. Conclusion: In patients with newly diagnosed advanced ovarian cancer, PARPIs maintenance after standard therapy achieved a significant improvement in progression-free survival as compared with placebo, overall and in all subgroups.

Long non-coding RNA RHPN1-AS1 promotes tumorigenesis and metastasis of ovarian cancer by acting as a ceRNA against miR-596 and upregulating LETM1

Background: In recent decades, long non-coding RNAs (lncRNAs) have been reported as crucial functional regulators involved in ovarian cancer. In the present study, we explored how lncRNA RHPN1-AS1 influences the progression of epithelial ovarian cancer (EOC) through tumor cell-dependent mechanisms.

Results: The expression of RHPN1-AS1 in EOC tissues was higher than that in para-cancerous control tissues. High expression of RHPN1-AS1 was closely associated with poor prognosis in EOC patients. N6-methyladenosine (m6A) improved the stability of RHPN1-AS1 methylation transcript by reducing RNA degradation, which resulted in upregulation of RHPN1-AS1 in EOC. In vitro and in vivo functional experiments showed that RHPN1-AS1 promoted EOC cell proliferation and metastasis. RHPN1-AS1 acted as a ceRNA to sponge miR-596, consequently increasing LETM1 expression and activating the FAK/PI3K/Akt signaling pathway.

Conclusion: RHPN1-AS1-miR-596-LETM1 axis plays a crucial role in EOC progression. Our findings may provide promising drug targets for EOC treatment.

Methods: We determined the aberrantly expressed lncRNAs in EOC via microarray analysis and validated RHPN1-AS1 expression by qRT-PCR. The RHPN1-AS1-miR-596-LETM1 axis was examined by dual-luciferase reporter assay and RIP assay. The mechanism of RHPN1-AS1 was investigated through gain- and loss-of-function studies both in vivo and in vitro.

Immune Checkpoint Inhibitors in Epithelial Ovarian Cancer: An Overview on Efficacy and Future Perspectives

Epithelial ovarian cancer (EOC) is the leading cause of death among gynecological cancers. Despite improvements in medical treatments, the prognosis for EOC remains poor, and there is an urgent need for new therapeutic strategies. Immune checkpoint inhibitors (CPIs) have dramatically improved survival of several cancers and are under evaluation in OC. Unfortunately, CPIs have shown globally unsatisfactory results. The aim of this manuscript is to critically review the results from early-phase trials with CPIs in terms of safety and activity, discuss the possible reasons for disappointing results and the new therapeutic approaches to improve patient outcomes.

Functionalized Folate-Modified Graphene Oxide/PEI siRNA Nanocomplexes for Targeted Ovarian Cancer Gene Therapy

Gene therapy is emerging as a valid method for the treatment of ovarian cancer, including small interfering RNA (siRNA). Although it is so powerful, few targeting efficient gene delivery systems seriously hindered the development of gene therapy. In this study, we synthesized a novel gene vector PEG-GO-PEI-FA by functionalized graphene oxide (GO), in which folic acid (FA) can specifically bind to the folate receptor (FR), which is overexpressed in ovarian cancer. Characterizations of the nanocomplexes were evaluated by dynamic light scattering (DLS), atomic force microscopy (AFM), and Fourier transform infrared spectroscopy (FTIR). The siRNA condensation ability and stability were assessed by agarose gel electrophoresis. Cellular uptake efficiency and lysosomal escape ability in ovarian cancer cells were investigated by confocal laser scanning microscopy. Furthermore, cellular biosafety of the system and inhibitory of the siRNA tolerability were evaluated by CCK-8 assay. The size of the PEG-GO-PEI-FA nanocomplexes was 216.1 ± 2.457 nm, exhibiting mild cytotoxicity in ovarian cancer cells. With high uptake efficiency, PEG-GO-PEI-FA can escape from the lysosome rapidly and release the gene. Moreover, PEG-GO-PEI-FA/siRNA can effectively inhibit the growth of ovarian cancer cells. By and large, the PEG-GO-PEI-FA/siRNA may offer a promising strategy for siRNA delivery in the treatment of FR-positive ovarian carcinoma or similar tumors.

Prophylactic salpingectomy for prevention of ovarian cancer at the time of elective laparoscopic cholecystectomy

Background

Most serous ovarian cancers are now understood to originate in the fallopian tubes. Removing the tubes (salpingectomy) likely reduces the risk of developing high‐grade serous ovarian cancer. Numerous gynaecological societies now recommend prophylactic (or opportunistic) salpingectomy at the time of gynaecological surgery in appropriate women, and this is widely done. Salpingectomy at the time of non‐gynaecological surgery has not been explored and may present an opportunity for primary prevention of ovarian cancer.

Methods

This study investigated whether prophylactic salpingectomy with the intention of reducing the risk of developing ovarian cancer would be accepted and could be accomplished at the time of elective laparoscopic cholecystectomy. Women aged at least 45 years scheduled for elective laparoscopic cholecystectomy were recruited. They were counselled and offered prophylactic bilateral salpingectomy at the time of cholecystectomy. Outcome measures were rate of accomplishment of salpingectomy, time and procedural steps needed for salpingectomy, and complications.

Results

A total of 105 patients were included in the study. The rate of acceptance of salpingectomy was approximately 60 per cent. Salpingectomy was performed in 98 of 105 laparoscopic cholecystectomies (93·3 per cent) and not accomplished because of poor visibility or adhesions in seven (6·7 per cent). Median additional operating time was 13 (range 4–45) min. There were no complications attributable to salpingectomy. One patient presented with ovarian cancer 28 months after prophylactic salpingectomy; histological re‐evaluation of the tubes showed a previously undetected, focal serous tubal intraepithelial carcinoma.

Conclusion

Prophylactic salpingectomy can be done during elective laparoscopic cholecystectomy.

MYC-regulated pseudogene HMGA1P6 promotes ovarian cancer malignancy via augmenting the oncogenic HMGA1/2

Pseudogenes have long been considered as nonfunctional genomic sequences. Recent studies have shown that they can potentially regulate the expression of protein-coding genes and are dysregulated in diseases including cancer. However, the potential roles of pseudogenes in ovarian cancer have not been well studied. Here we characterized the pseudogene expression profile in HGSOC (high-grade serous ovarian carcinoma) by microarray. We identified 577 dysregulated pseudogenes and most of them were up-regulated (538 of 577). HMGA1P6 (High mobility group AT-hook 1 pseudogene 6) was one of the overexpressed pseudogenes and its expression was inversely correlated with patient survival. Mechanistically, HMGA1P6 promoted ovarian cancer cell malignancy by acting as a ceRNA (competitive endogenous RNA) that led to enhanced HMGA1 and HMGA2 expression. Importantly, HMGA1P6 was transcriptionally activated by oncogene MYC in ovarian cancer. Our findings reveal that MYC may contribute to oncogenesis through transcriptional regulation of pseudogene HMGA1P6 in ovarian cancer.

Truncated Bid Regulates Cisplatin Response via Activation of Mitochondrial Apoptosis Pathway in Ovarian Cancer

Refractoriness to conventional chemotherapy is a major challenge in the treatment of advanced ovarian cancer (OC). There is increasing evidence that mitochondrial priming correlates with cisplatin response in various cancers. Notably, Bim and Bid, two of the proapoptotic BH3-only proteins, are recognized as the most effective inducers of mitochondrial priming in OC. In this study, we constructed two tumor-specific oncolytic adenoviruses (Ads) coding for Bim (Ad-Bim) or truncated Bid (Ad-tBid), respectively, and performed gain-of-function assays in nine OC cell lines. Ad-tBid exhibited significant antitumor efficacy than the controls. On addition of Ad-tBid pretreatment, mito-primed cells displayed more sensitivity to cisplatin both in vitro and ex vivo. We also found that Ad-tBid induced mitochondrial apoptosis in a Bak-dependent manner. Furthermore, a combined cisplatin plus Ad-tBid therapy markedly inhibited tumor growth in a subcutaneous xenotransplanted tumor model. In mice bearing peritoneal disseminated OC, intraperitoneal administration of Ad-tBid potentiated the antitumor effect of cisplatin. Our findings suggest that Ad-tBid enhances cisplatin response in OC cells, establishing the potential treatment of advanced OC via a combination of cisplatin and Ad-tBid.

The role of the CDCA gene family in ovarian cancer

Background

Ovarian cancer is a frequently-occurring reproductive system malignancy in females, which leads to an annual of over 100 thousand deaths worldwide.

Methods

The electronic databases, including GEPIA, ONCOMINE, Metascape, and Kaplan-Meier Plotter, were used to examine both survival and transcriptional data regarding the cell division cycle associated (CDCA) gene family among ovarian cancer patients.

Results

All CDCA genes expression levels were up-regulated in ovarian cancer tissues relative to those in non-carcinoma ovarian counterparts. Besides, CDCA5/7 expression levels were related to the late tumor stage. In addition, the Kaplan-Meier Plotter database was employed to carry out survival analysis, which suggested that ovarian cancer patients with increased CDCA2/3/5/7 expression levels had poor overall survival (OS) (P<0.05). Moreover, ovarian cancer patients that had up-regulated mRNA expression levels of CDCA2/5/8 had markedly reduced progression-free survival (PFS) (P<0.05); and up-regulated CDCA4 expression showed remarkable association with reduced post-progression survival (PPS) (P<0.05). Additionally, the following processes were affected by CDCA genes alterations, including R-HAS-2500257: resolution of sister chromatid cohesion; GO:0051301: cell division; CORUM: 1118: Chromosomal passenger complex (CPC, including CDCA8, INCENP, AURKB and BIRC5); CORUM: 127: NDC80 kinetochore complex; M129: PID PLK1 pathway; and GO: 0007080: mitotic metaphase plate congression, all of which were subjected to marked regulation since the alterations affected CDCA genes.

Conclusions

Up-regulated CDCA gene expression in ovarian cancer tissues probably played a crucial part in the occurrence of ovarian cancer. The up-regulated CDCA2/3/5/7 expression levels were used as the potential prognostic markers to improve the poor ovarian cancer survival and prognostic accuracy. Moreover, CDCA genes probably exerted their functions in tumorigenesis through the PLK1 pathway.

Clinical Implications of Circulating Tumor DNA from Ascites and Serial Plasma in Ovarian Cancer

Purpose

The purpose of this study was to identify the clinical utility of circulating tumor DNA (ctDNA) from ascites and serial plasma samples from epithelial ovarian cancer (EOC) patients.

Materials and Methods

Using targeted next-generation sequencing, we analyzed a total of 55 EOC samples including ctDNA from ascites and serial plasma and gDNA from tumor tissues. Tumor tissues and ascites were collected during debulking surgeries and plasma samples were collected before and after the surgeries. Because one EOC patient underwent secondary debulking surgery, a total of 11 tumor tissues, 33 plasma samples, and 11 ascites samples were obtained from the 10 patients.

Results

Of the 10 patients, nine (90%) contained somatic mutations in both tumor tissues and ascites ctDNA. This mutational concordance was confirmed through correlation analysis. The mutational concordance between ascites and tumor tissues was valid in recurrent/progressive ovarian cancer. TP53 was the most frequently detected gene with mutations. ctDNA from serial plasma samples identified EOC progression/recurrence at a similar time or even more rapidly than cancer antigen 125, an established serum protein tumor marker for EOC.

Conclusion

Our data suggest that ascites ctDNA can be used to identify the mutational landscape of ovarian cancer for therapeutic strategy planning.

Estrogen enhances the proliferation and migration of ovarian cancer cells by activating transient receptor potential channel C3

Background

Recent studies have suggested that estrogen (E2) plays an important role in epithelial ovarian cancer (EOC). However, the mechanism of E2 in ovarian cancers is unclear. The purpose of this study was to investigate the effect of E2 on ovarian cancers and illuminate the mechanism of E2 in promote ovarian cancers proliferation.

Results

We demonstrated that E2 stimulated the proliferation and invasion of ovarian cancer cells. In this study, ovarian cancer specimens were also analyzed for transient receptor potential channel C3 (TRPC3) expression; TRPC3 expression levels were higher in ovarian cancer samples than in normal ovarian tissue samples. Previous studies have shown that TRPC3 contributes to the progression of human ovarian cancer. In this study, we further investigated the interaction between E2 and TRPC3. We found that E2 stimulation enhanced the expression of TRPC3 at both the mRNA and protein levels. E2 stimulation enhanced the influx of Ca2⁺. Moreover, siRNA-mediated silencing of TRPC3 expression inhibited the ability of E2 to stimulate the influx of Ca2⁺.

Conclusions

In conclusion, TRPC3 plays a significant role in the stimulatory activity of E2 and could be a therapeutic target for the treatment of EOC. Furthermore, this study elucidates the molecular mechanism by which E2 promotes the proliferation and migration of EOC cells.

Plasma-activated Ringer's Lactate Solution Displays a Selective Cytotoxic Effect on Ovarian Cancer Cells

Epithelial Ovarian Cancer (EOC) is one of the leading causes of cancer-related deaths among women and is characterized by the diffusion of nodules or plaques from the ovary to the peritoneal surfaces. Conventional therapeutic options cannot eradicate the disease and show low efficacy against resistant tumor subclones. The treatment of liquids via cold atmospheric pressure plasma enables the production of plasma-activated liquids (PALs) containing reactive oxygen and nitrogen species (RONS) with selective anticancer activity. Thus, the delivery of RONS to cancer tissues by intraperitoneal washing with PALs might be an innovative strategy for the treatment of EOC. In this work, plasma-activated Ringer’s Lactate solution (PA-RL) was produced by exposing a liquid substrate to a multiwire plasma source. Subsequently, PA-RL dilutions are used for the treatment of EOC, non-cancer and fibroblast cell lines, revealing a selectivity of PA-RL, which induces a significantly higher cytotoxic effect in EOC with respect to non-cancer cells.

[Hereditary breast and ovarian cancer syndrome: Diagnosis and therapeutic implications]

Patients who carry the BReast Cancer 1 or 2 (BRCA) gene mutations have an underlying hereditary predisposition for breast and ovarian cancers. These deleterious genetic mutations are the most common ones implicated in hereditary breast and ovarian cancers. Oncogenetic counselling plays a key role in identifying patient for BRCA testing and for mutation identification. BRCA1/2 carriers have to be followed up regularly and may justify breast and/or adnexal prophylactic surgery, according to the French National Cancer Institute guidelines (INCa). Poly- (DNA-riboses) polymerases inhibitors, notably olaparib, have a major role in the management of epithelial ovarian cancer in patients with BRCA mutation and many studies are ongoing to expand their indications in a near future.

A living biobank of ovarian cancer ex vivo models reveals profound mitotic heterogeneity

High-grade serous ovarian carcinoma is characterised by TP53 mutation and extensive chromosome instability (CIN). Because our understanding of CIN mechanisms is based largely on analysing established cell lines, we developed a workflow for generating ex vivo cultures from patient biopsies to provide models that support interrogation of CIN mechanisms in cells not extensively cultured in vitro. Here, we describe a "living biobank" of ovarian cancer models with extensive replicative capacity, derived from both ascites and solid biopsies. Fifteen models are characterised by p53 profiling, exome sequencing and transcriptomics, and karyotyped using single-cell whole-genome sequencing. Time-lapse microscopy reveals catastrophic and highly heterogeneous mitoses, suggesting that analysis of established cell lines probably underestimates mitotic dysfunction in advanced human cancers. Drug profiling reveals cisplatin sensitivities consistent with patient responses, demonstrating that this workflow has potential to generate personalized avatars with advantages over current pre-clinical models and the potential to guide clinical decision making.

Osthole inhibits ovarian carcinoma cells through LC3-mediated autophagy and GSDME-dependent pyroptosis except for apoptosis

Ovarian carcinoma (OC) begins in the ovaries and remains a highly lethal malignancy. Despite great efforts have been made to fight against OC, there still remain limited therapeutic options owing to chemotherapy drug resistance and serious side effects. Osthole is a derivative of coumarin and extracted from Cnidium monnieri (L.) Cusson, which has been drawn more attention due to its high biological activity in various disease. However, the underlying mechanism of osthole in OC is still unclear. In this study, we aim to evaluate the mechanism of osthole against OC cells. Methodologically, Cell Counting Kit-8 (CCK-8) and LIVE/DEAD™ Cell Imaging experiments were employed to assess cell viability. 2',7'-Dichlorofluorescin diacetate (DCFH-DA) staining, flow cytometry, Hoechst staining, JC-1 staining assay and western blotting were performed to study apoptosis. Transmission electron microscopy, western blotting and monodansyl cadaverine (MDC) staining assay were used to study autophagy. Western blotting and microscopy image were employed to determine pyroptosis. Our results demonstrated that osthole could significantly suppress OC cells growth in a dose-dependent manner. We further proved that osthole could inhibit OC cells growth by mitochondria-mediated apoptosis. Meanwhile, we also discovered that osthole could trigger cell autophagy and lead to cell death. Furthermore, our study revealed that osthole could lead to pyroptosis through inducing the cleavage of gasdermin E (c-GSDME) level. Taken together, Osthole could significantly suppress the growth of OC cells and induce OC cells death via apoptosis, pyroptosis and autophagy, which is a promising new drug for the treatment of OC.

Circular RNA PVT1 enhances cell proliferation but inhibits apoptosis through sponging microRNA-149 in epithelial ovarian cancer

AIM

This study aimed to investigate the influence of circular RNA PVT1 (circ-PVT1) on epithelial ovarian cancer (EOC) cell proliferation and apoptosis, more importantly, to identify the target microRNAs (miRNA) of circ-PVT1 in EOC.

METHODS

Circ-PVT1 expression in EOC cell lines and nonmalignant control cells was detected. Cell proliferation, apoptosis and candidate target miRNA (miR-149, miR-183 and miR-194) expressions were detected in circ-PVT1 overexpression treated CAOV3 cells and circ-PVT1 knock-down treated SKOV3 cells. Furthermore, miR-149 overexpression and miR-149 knock-down plasmids were transfected into circ-PVT1 dysregulated CAOV3 cells and SKOV3 cells, respectively, and cell proliferation as well as apoptosis were detected.

RESULTS

Circ-PVT1 expression was increased in human EOC cell lines (CAOV3, SKOV3, SNU119 and OVCAR3) compared to human normal ovary surface epithelial cell line (HOSEpiC). In SKOV3 cells, cell proliferation was reduced at 48 and 72 h but cell apoptosis rate was increased at 48 h by circ-PVT1 knock-down. In CAOV3 cells, cell proliferation was increased at 48 and 72 h but cell apoptosis rate was decreased at 48 h by circ-PVT1 overexpression. Besides, circ-PVT1 negatively regulated miR-149 but not miR-183 or miR-194 in SKOV3 and CAOV3 cells. Rescue experiments showed that miR-149 knock-down increased cell proliferation but decreased apoptosis in circ-PVT1 knock-down treated SKOV3 cells, while miR-149 overexpression reduced cell proliferation but enhanced apoptosis in circ-PVT1 overexpression treated CAOV3 cells.

CONCLUSION

Circ-PVT1 enhances cell proliferation but inhibits cell apoptosis through sponging miR-149 in EOC cells, which suggests that circ-PVT1 may serve as a treatment target in EOC.

Upregulation of long non‑coding RNA CCEPR is associated with poor prognosis and contributes to the progression of ovarian cancer through regulating the Wnt/β‑catenin signaling pathway

Accumulating evidence has demonstrated that the expression of long non‑coding RNAs (lncRNAs) is altered in various types of cancer, which may prove beneficial for their use as biomarkers. Cervical carcinoma expressed PCNA regulatory lncRNA (CCEPR) is a recently identified lncRNA, which has an important role in regulating cell proliferation and apoptosis in cervical and bladder cancer; however, whether CCEPR is involved in the progression of ovarian cancer (OC) remains largely unclear. The aim of the present study was to determine the clinical significance of CCEPR in OC and to investigate its biological roles. Cell Counting Kit‑8 assay was used to analyze cell proliferation, Transwell assay was used to assess invasion, flow cytometric analysis was used to analyze apoptosis, and western blotting was used to perform mechanistic studies. CCEPR expression levels were significantly elevated in OC tissues compared with adjacent non‑cancer tissues. Similarly, significant increases in CCEPR expression were observed in OC cell lines (SK‑OV‑3 and OVCAR‑3) compared with the ovarian surface epithelial cell line, HOSEpiC. The increased expression levels of CCEPR were associated with increased invasion, higher International Federation of Gynecology and Obstetrics stage and a poorer overall survival rate. In vitro, the genetic silencing of CCEPR decreased the cell proliferation rate and invasive ability of OC cells, and promoted apoptosis. CCEPR‑silenced OC cells also demonstrated decreased expression levels of four proteins involved in the Wnt/β‑catenin signaling pathway: Cyclin D1, β‑catenin, Myc and matrix metallopeptidase‑7. In conclusion, the present study demonstrated that increased expression levels of CCEPR may predict poor prognosis in patients with OC and contribute to the progression of OC through regulating the Wnt/β‑catenin signaling pathway.

Loss of Tenascin-X expression during tumor progression: A new pan-cancer marker

Cancer is a systemic disease involving multiple components produced from both tumor cells themselves and surrounding stromal cells. The pro- or anti-tumoral role of the stroma is still under debate. Indeed, it has long been considered the main physical barrier to the diffusion of chemotherapy by its dense and fibrous nature and its poor vascularization. However, in murine models, the depletion of fibroblasts, the main ExtraCellular Matrix (ECM)-producing cells, led to more aggressive tumors even though they were more susceptible to anti-angiogenic and immuno-modulators. Tenascin-C (TNC) is a multifunctional matricellular glycoprotein (i.e. an ECM protein also able to induce signaling pathway) and is considered as a marker of tumor expansion and metastasis. However, the status of other tenascin (TN) family members and particularly Tenascin-X (TNX) has been far less studied during this pathological process and is still controversial. Herein, through (1) in silico analyses of the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases and (2) immunohistochemistry staining of Tissue MicroArrays (TMA), we performed a large and extensive study of TNX expression at both mRNA and protein levels (1) in the 6 cancers with the highest incidence and mortality in the world (i.e. lung, breast, colorectal, prostate, stomach and liver) and (2) in the cancers for which sparse data regarding TNX expression already exist in the literature. We thus demonstrated that, in most cancers, TNX expression is significantly downregulated during cancer progression and we also highlighted, when data were available, that high TNXB mRNA expression in cancer is correlated with a good survival prognosis.

Evolving population-based statistics for rare epithelial ovarian cancers

OBJECTIVE

To describe how population-based statistics for rare epithelial ovarian cancers are evolving.

METHODS

This is a retrospective observational study examining the Surveillance, Epidemiology, and End Results Program from 1988 to 2016. Overall survival (OS) of clear cell (OCCC), mucinous (MOC), and low-grade serous (LGSOC) ovarian cancers were compared to high-grade serous ovarian cancer (HGSOC) by fitting a propensity score matching.

RESULTS

Among 113,365 ovarian malignancies, 5780 OCCCs (5.1%), 7561 MOCs (6.7%), and 2021 LGSOCs (1.8%) were compared to 38,199 HGSOCs. OCCCs and MOCs were more likely to be diagnosed with stage I disease compared to HGSOC (57.0-59.5% versus 8.6%, P<0.001). For early-stage disease, OCCC (hazard ratio [HR] 0.91, 95% confidence interval [CI] 0.82-1.01) and MOC (HR 0.94, 95%CI 0.85-1.04) had similar OS to HGSOC whereas LGSOC had superior OS (HR 0.93, 95%CI 0.89-0.97) versus HGSOC. Conversely, for advanced-stage disease, OCCC (HR 1.42, 95%CI 1.32-1.53) and MOC (HR 1.11, 95%CI 1.09-1.13) had poorer OS whereas LGSOC (HR 0.86, 95%CI 0.84-0.89) had superior OS compared to HGSOC. OCCC (HR range, 1.92-2.45) and MOC (HR range, 1.73-2.22) had particularly poorer OS in the first three years following diagnosis compared to HGSOC. Population-level statistics for advanced-stage disease showed that 5-year OS rates have increased in HGSOC (16.9% to 36.8%, P<0.001) and LGSOC (50.8% to 66.4%, P=0.010); but remain unchanged for OCCC (21.0% to 28.2%, P=0.174) and MOC (21.4% to 16.5%, P=0.102).

CONCLUSION

OCCC, MOC, and LGSOC comprise 2-7% of ovarian malignancies, have distinct characteristics and survival compared to HGSOC. While these rare tumors have a favorable to comparable prognosis in early-stage disease, disproportionally poor survival in advanced-stage OCCC and MOC highlights the need for further research into novel treatment strategies.