Treatment Of Epithelial Ovarian Cancer Research Articles

CircBNC2 affects epithelial ovarian cancer progression through the miR-223-3p/ LARP4 axis.

Epithelial ovarian cancer (EOC) is one of the most serious cancer. Circular RNA BNC2 (circBNC2) expression was decreased in EOC tissues. However, the molecular mechanism of circBNC2 remains unknown. The expression of circBNC2, microRNA-223-3p (miR-223-3p), and La-related proteins 4 ( LARP4 ) were detected by quantitative real-time fluorescence PCR (qRT-PCR). A series of in-vitro experiments were designed to explore the function of circBNC2 in EOC cells and the regulatory mechanism between circBNC2 and miR-223-3p and LARP4 in EOC cells. Western blot examined the protein levels of Snail1, Slug, and LARP4 . The relationship between miR-223-3p and circBNC2 or LARP4 was verified by Dual-luciferase reporter assays. The xenotransplantation model was established to study the role of circBNC2 in vivo . The expression of circBNC2 and LARP4 was decreased in EOC tissues, while the expression of miR-223-3p was increased. CircBNC2 can sponge miR-223-3p, and LARP4 is the target of miR-223-3p. In-vitro complement experiments showed that overexpression of circBNC2 significantly decreased the malignant behavior of EOC, while co-transfection of miR-223-3p mimics partially upregulated this change. In addition, LARP4 knockdown increased the proliferation, migration, and invasion of EOC cells inhibited by miR-223-3p inhibitor. Mechanically, circBNC2 regulates LARP4 expression in EOC cells by spongy miR-223-3p. In addition, in-vivo studies have shown that overexpression of circBNC2 inhibits tumor growth. Overexpression of circBNC2 decreased proliferation, migration, and invasion of EOC cells by regulating the miR-223-3p/ LARP4 axis, suggesting that circBNC2/miR-223-3p/ LARP4 axis may be a potential regulatory mechanism for the treatment of EOC.

Transfusion use and effect on progression-free, overall survival, and quality of life in upfront treatment of advanced epithelial ovarian cancer: evaluation of the European Organization for Research and Treatment EORTC-55971 Cohort

BackgroundThe impact of blood transfusion on ovarian cancer survival is uncertain.ObjectiveTo investigate whether peri-operative blood transfusion negatively impacted progression-free survival, overall survival, and quality of life in patients with advanced...

PARP Inhibitor for Ovarian Cancer Therapy

Almost all ovarian cancers are comprised of epithelial ovarian cancer (EOC). Approximately 80% of patients with EOC initially respond to standard cytoreductive therapy and postoperative platinum-based chemotherapy. However, due to drug resistance in high-grade serous ovarian cancer (HGSOC), recurrence is almost inevitable. Recently, the nuclear enzyme poly (ADP ribose) polymerase (PARP) represents a surprisingly new target in EOC therapy. Inhibitors of PARP have demonstrated promising efficacy in the treatment of EOC. Studies on Olaparib, in particular, hastened its approval in the USA and Europe. The main topics of this study are the pre-clinical evidence, ongoing clinical studies, recent advancements in PARP inhibitor technology, and their potential future roles in clinical care for EOC patients.

Resistance to Poly (ADP-Ribose) Polymerase Inhibitors (PARPi): Mechanisms and Potential to Reverse.

This review will focus on the most common mechanisms for poly (ADP-ribose) polymerase inhibitors' (PARPi) resistance and the main strategies for overcoming acquired or de novo PARPi resistance. Initial approvals for PARPi as part of treatment for advanced epithelial ovarian cancer (EOC) started in 2014 with patient with recurrent cancer characterized by BRCA mutations in the 3rd and 4th line and now have approvals for front-line maintenance in both the BRCA mutated and BRCAwt populations. As with all therapies, patients will eventually develop resistance to treatment. The most common mechanisms for PARPi resistance include reversion mutations, methylation events, and restoration of homologous recombination deficiency (HRD) through combinations and targeting replication stress. As more and more patients receive initial treatment (and potential retreatment with PARPi), we need to better understand the mechanisms in which tumors acquire PARPi resistance.

Systematic Pan-Cancer Analysis and Experimental Verification Identify FOXA1 as an Immunological and Prognostic Biomarker in Epithelial Ovarian Cancer.

Epithelial ovarian cancer (EOC) has the lowest survival rate among female reproductive cancers present with symptoms of aggressive malignancies, poor prognosis, drug resistance and postoperative recurrence. The majority of patients with EOC are diagnosed at an advanced stage due to the therapeutic challenges including lack of early diagnosis and effective therapeutic targets for EOC. Pan-cancer analyses were performed to explore the features of forkhead-box (FOX) A1 (FOXA1) using data from TCGA and GTEx databases. R package "clusterprofiler" was used to perform the enrichment analysis of FOXA1 in EOC. Data downloaded from Drug Sensitivity in Cancer (GDSC) database were used to evaluate the association between FOXA1 and antitumor drug sensitivity. In experimental verification, FOXA1 expression was detected using qRT-PCR and western blot assays. Western blot, immunofluorescence staining, and Transwell assays were used to assess the influence of FOXA1 silencing on epithelial-mesenchymal transition (EMT) of EOC cells. We found that FOXA1 was highly expressed in EOC and predicted poorer survival of EOC patients. We observed that FOXA1 expression was positively correlated EMT-related pathways. Through experimental verification, we found the underlying function of FOXA1 to promote EMT in ovarian cancers. The results from western blot, immunofluorescence staining, and Transwell assays showed that FOXA1 silencing impeded the progression of EMT and invasiveness of the cancer cells. Furthermore, CCK-8 and invasion assays suggested that siRNA-FOXA1 attenuated the ability of cancer cells to metastasize and proliferate. Dual-luciferase reporter assays confirmed the binding activity of FOXA1 to the promoter of connective tissue growth factor (CTGF). In addition, we found that FOXA1 was closely correlated immunosuppressive microenvironment of EOC. High FOXA1 expression may contribute to the resistance of many anticancer drugs. Our results predict and validate the function of FOXA1 in promoting EMT and the progression of disease in EOC. Targeting FOXA1 may improve the sensitivity of EOC treatment.

Patterns of Treatment and Outcomes in Epithelial Ovarian Cancer: A Retrospective North Indian Single-Institution Experience.

Ovarian cancer (OC) is ranked as the third most common gynecologic cancer in various Indian cancer registries. In India, OC is seen in the younger age group, with a median age < 55 years being reported by most of the studies. The majority of patients are diagnosed in advanced stage (70%-80%), where the long-term (10-year) survival rate is poor, estimated at 15%-30%. The aim of this study was to evaluate clinical epidemiology, treatment patterns, and survival outcomes in patients with epithelial OC. This was a retrospective analysis of patients with epithelial OC who were treated at Sher-i-Kashmir Institute of Medical Sciences, Srinagar, over a period of 9 years, from January 2010 to December 2018. OC constituted 2.94% of all cancers registered. Epithelial OC constituted 88.4% of all OCs, with a median age 50 years. More than two third of patients belonged to rural background and the majority (76.9%) of the patients were in stage III or IV at the time of diagnosis. The main presenting symptoms were abdominal distension/bloating (46.5%) and gastrointestinal disturbances (35.2%). The most common histologic types were serous (65.9%) followed by mucinous carcinoma (15%). Median overall survival for the whole study cohort was 30 months (95% CI, 28.0 to 31.9). Median overall survival for stage I, II, III, and IV was 72, 60, 30, and 20 months, respectively. Most of the patients presented in advanced stage of the disease and have poor outcome. Delay in diagnosis and improper management before registering in tertiary cancer center and lack of tertiary care facilities are the root causes of poor outcomes. The general population and primary care physicians need to be made aware of OC symptoms.

Overlapping gene dependencies for PARP inhibitors and carboplatin response identified by functional CRISPR-Cas9 screening in ovarian cancer

PARP inhibitors (PARPi) have revolutionized the therapeutic landscape of epithelial ovarian cancer (EOC) treatment with outstanding benefits in regard to progression-free survival, especially in patients either carrying BRCA1/2 mutations or harboring defects in the homologous recombination repair system. Yet, it remains uncertain which PARPi to apply and how to predict responders when platinum sensitivity is unknown. To shed light on the predictive power of genes previously suggested to be associated with PARPi response, we systematically reviewed the literature and identified 79 publications investigating a total of 93 genes. The top candidate genes were further tested using a comprehensive CRISPR-Cas9 mutagenesis screening in combination with olaparib treatment. Therefore, we generated six constitutive Cas9+ EOC cell lines and profiled 33 genes in a CRISPR-Cas9 cell competition assay using non-essential (AAVS1) and essential (RPA3 and PCNA) genes for cell fitness as negative and positive controls, respectively. We identified only ATM, MUS81, NBN, BRCA2, and RAD51B as predictive markers for olaparib response. As the major survival benefit of PARPi treatment was reported in platinum-sensitive tumors, we next assessed nine top candidate genes in combination with three PARPi and carboplatin. Interestingly, we observed similar dropout rates in a gene and compound independent manner, supporting the strong correlation of cancer cell response to compounds that rely on DNA repair for their effectiveness. In addition, we report on CDK12 as a common vulnerability for EOC cell survival and proliferation without altering the olaparib response, highlighting its potential as a therapeutic target in EOC.

Endogenous Propionibacterium acnes Promotes Ovarian Cancer Progression via Regulating Hedgehog Signalling Pathway.

The oncogenesis and progression of epithelial ovarian cancer (EOC) is a complicated process involving several key molecules and factors, yet whether microbiota are present in EOC, and their role in the development of EOC, remains greatly unknown. In this study, 30 patients were enrolled to compare the similarities and differences of intratumour microbiota among patients with epithelial benign ovarian tumours (EBOTs) and patients with EOC based on the high-throughput sequencing method. Subsequently, we further isolated the specific EOC-related bacteria and defined Propionibacterium acnes as a key strain in facilitating EOC progression. More importantly, we constructed a mouse EOC model to evaluate the effect of the P. acnes strain on EOC using immunohistochemistry, Western blotting, and RT-qPCR. The high-throughput sequencing showed that the intratumour microbiota in EOC tissues had a higher microbial diversity and richness compared to EBOT tissues. The abundance of previously considered pathogens, Actinomycetales, Acinetobacter, Streptococcus, Ochrobacterium, and Pseudomonadaceae Pseudomonas, was increased in the EOC tissues. Meanwhile, we discovered the facilitating role of the P. acnes strain in the progression of EOC, which may be partially associated with the increased inflammatory response to activate the hedgehog (Hh) signalling pathway. This microbial-induced EOC progression mechanism is further confirmed using the inhibitor GANT61. This study profiled the intratumour microbiota of EBOT and EOC tissues and demonstrated that the diversity and composition of the intratumour microbiota were significantly different. Furthermore, through in vivo and in vitro experiments, we confirmed the molecular mechanism of intratumour microbiota promotion of EOC progression in mice, which induces inflammation to activate the Hh signalling pathway. This could provide us clues for improving EOC treatment.

RNA sequencing and bioinformatics analysis revealed PACSIN3 as a potential novel biomarker for platinum resistance in epithelial ovarian cancer

Failure to respond to treatment in epithelial ovarian cancer can often be attributed to platinum-based chemotherapy resistance. However, the possible mechanisms or candidate biomarkers associated with platinum resistance are yet to be elucidated, even though many researchers have performed related studies. We performed RNA sequencing of clinical specimens obtained from patients with platinum-sensitive or resistant epithelial ovarian cancer (EOC). Furthermore, various bioinformatics approaches, including spatial analysis of functional enrichment, were used to identify key regulators and associated underlying mechanisms of platinum resistance in EOC. Through RNA-sequencing, we identified 263 differentially expressed genes (98 upregulated and 165 downregulated) and subjected them to Gene Oncology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses, which were characterized to the traditional platinum-resistant characteristics. Subsequently, the gene interaction network and module analysis by spatial analysis of functional enrichment software demonstrated protein kinase C and casein kinase substrate in neurons 3 (PACSIN3) as the only upregulated hub gene, and neurotensin (NTS) and KIAA0319 as downregulated hub genes in platinum-resistant EOC. We selected PACSIN3 for further analysis because it has not been studied in relation to response to platinum-based chemotherapy. PACSIN3 was significantly upregulated in ovarian cancer cells compared to immortalized human ovarian surface epithelial cells. In addition, cisplatin-induced apoptosis was measured in PACSIN3 knockout OVCA433 and BRCA-mutated EOC cell line, SNU251, by a fluorescence-activated cell sorting-based Annexin-V/propium iodide double staining assay, which revealed a significant increase in apoptosis. Taken together, the present study presents PACSIN3 as a promising predictive biomarker associated with platinum resistance, especially in BRCA-mutated epithelial ovarian cancers.

Moderate-Risk Genes for Hereditary Ovarian Cancers Involved in the Homologous Recombination Repair Pathway.

Approximately 20% of cases of epithelial ovarian cancer (EOC) are hereditary, sharing many causative genes with breast cancer. The lower frequency of EOC compared to breast cancer makes it challenging to estimate absolute or relative risk and verify the efficacy of risk-reducing surgery in individuals harboring germline pathogenic variants (GPV) in EOC predisposition genes, particularly those with relatively low penetrance. Here, we review the molecular features and hereditary tumor risk associated with several moderate-penetrance genes in EOC that are involved in the homologous recombination repair pathway, i.e., ATM, BRIP1, NBN, PALB2, and RAD51C/D. Understanding the molecular mechanisms underlying the expression and function of these genes may elucidate trends in the development and progression of hereditary tumors, including EOC. A fundamental understanding of the genes driving EOC can help us accurately estimate the genetic risk of developing EOC and select appropriate prevention and treatment strategies for hereditary EOC. Therefore, we summarize the functions of the candidate predisposition genes for EOC and discuss the clinical management of individuals carrying GPV in these genes.

Deciphering the expression patterns of homologous recombination-related lncRNAs identifies new molecular subtypes and emerging therapeutic opportunities in epithelial ovarian cancer.

Epithelial ovarian cancer (EOC) is the leading killer among women with gynecologic malignancies. Homologous recombination deficiency (HRD) has attracted increasing attention due to its significant implication in the prediction of prognosis and response to treatments. In addition to the germline and somatic mutations of homologous recombination (HR) repair genes, to widely and deeply understand the molecular characteristics of HRD, we sought to screen the long non-coding RNAs (lncRNAs) with regard to HR repair genes and to establish a prognostic risk model for EOC. Herein, we retrieved the transcriptome data from the Genotype-Tissue Expression Project (GTEx) and The Cancer Genome Atlas (TCGA) databases. HR-related lncRNAs (HRRlncRNAs) associated with prognosis were identified by co-expression and univariate Cox regression analyses. The least absolute shrinkage and selection operator (LASSO) and multivariate stepwise Cox regression were performed to construct an HRRlncRNA risk model containing AC138904.1, AP001001.1, AL603832.1, AC138932.1, and AC040169.1. Next, Kaplan−Meier analysis, time-dependent receiver operating characteristics (ROC), nomogram, calibration, and DCA curves were made to verify and evaluate the model. Gene set enrichment analysis (GSEA), immune analysis, and prediction of the half-maximal inhibitory concentration (IC50) in the risk groups were also analyzed. The calibration plots showed a good concordance with the prognosis prediction. ROCs of 1-, 3-, and 5-year survival confirmed the well-predictive efficacy of this model in EOC. The risk score was used to divide the patients into high-risk and low-risk subgroups. The low-risk group patients tended to exhibit a lower immune infiltration status and a higher HRD score. Furthermore, consensus clustering analysis was employed to divide patients with EOC into three clusters based on the expression of the five HRRlncRNAs, which exhibited a significant difference in checkpoints’ expression levels and the tumor microenvironment (TME) status. Taken together, the results of this project supported that the five HRRlncRNA models might function as a biomarker and prognostic indicator with respect to predicting the PARP inhibitor and immune treatment in EOC.

Molecular Mechanisms of Cassia fistula against Epithelial Ovarian Cancer Using Network Pharmacology and Molecular Docking Approaches.

Epithelial ovarian cancer (EOC) is one of the deadliest reproductive tract malignancies that form on the external tissue covering of an ovary. Cassia fistula is popular for its anti-inflammatory and anticarcinogenic properties in conventional medications. Nevertheless, its molecular mechanisms are still unclear. The current study evaluated the potential of C. fistula for the treatment of EOC using network pharmacology approach integrated with molecular docking. Eight active constituents of C. fistula were obtained from two independent databases and the literature, and their targets were retrieved from the SwissTargetPrediction. In total, 1077 EOC associated genes were retrieved from DisGeNET and GeneCardsSuite databases, and 800 potential targets of eight active constituents of C. fistula were mapped to the 1077 EOC targets and intersected targets from two databases. Ultimately, 98 potential targets were found from C. fistula for EOC. Finally, the protein–protein interaction network (PPI) topological interpretation revealed AKT1, CTNNB1, ESR1, and CASP3 as key targets. This is the first time four genes have been found against EOC from C. fistula. The major enriched pathways of these candidate genes were established by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) investigations. To confirm the network pharmacology findings, the molecular docking approach demonstrated that active molecules have higher affinity for binding to putative targets for EOC suppression. More pharmacological and clinical research is required for the development of a drug to treat EOC.

SLC7A1 Overexpression Is Involved in Energy Metabolism Reprogramming to Induce Tumor Progression in Epithelial Ovarian Cancer and Is Associated with Immune-Infiltrating Cells.

Cationic amino acid transporters (SLC7A1/CAT1) are highly expressed in human ovarian cancer (OC) tissues. However, the specific biological functions and mechanisms involved remain unclear. We used bioinformatics analysis to explore SLC7A1 expression level, prognostic value, and tumor mutation burden (TMB) in ovarian cancer (OC) tissues. We performed in vitro experiments to identify the expression and biological function of SLC7A1 in epithelial ovarian cancer (EOC) tissues and cells. An amino acid autoanalyzer was used to detect the effect of SLC7A1 on amino acid metabolism in EOC cells. Finally, SLC7A1 in OC was evaluated for cell-to-cell signalling and immune infiltration using online databases. We found that increased SLC7A1 expression in EOC cells and tissues was associated with poorer survival outcomes (P < 0.05) but not with tumor stage or grade of OC (P > 0.05). SLC7A1 is involved in the transport of phenylalanine and arginine in EOC cells, and its knockdown reduced the proliferation and migration of EOC cells and the resistance of cells to cisplatin. Furthermore, the TIMER database indicated that SLC7A1 overexpression was significantly positively correlated with levels of CD4+ memory resting cells, CD8+ effector memory cells, M0 macrophages, and cancer-associated fibroblasts (CAFs) in OC (P < 0.05) and significantly negatively correlated with CD4+ memory-activated cells (P < 0.05). Cell immunofluorescence indicated that SLC7A1 overexpression may affect the distribution of immune-infiltrating lymphocytes in tumors by inhibiting the expression of CCL4. Therefore, we concluded that SLC7A1 is involved in the metabolic remodelling of amino acids in EOC to promote tumor development and cisplatin resistance and is related to the tumor-infiltrating immune microenvironment of OC. SLC7A1 is a biomarker for predicting EOC progression and cisplatin resistance and represents a promising target for EOC treatment.

Comparing Intraperitoneal and Intravenous Personalized ErbB2CAR-T for the Treatment of Epithelial Ovarian Cancer.

High-grade serous ovarian carcinoma (HGSOC) is the most common type of epithelial ovarian cancer. The majority of cases are diagnosed at advanced stages, when intraperitoneal (IP) spread has already occurred. Despite significant surgical and chemotherapeutic advances in HGSOC treatment over the past decades, survival rates with HGSOC have only modestly improved. Chimeric antigen receptor (CAR)-T cells enable T cells to directly bind to tumor-associated antigens in a major histocompatibility complex-independent manner, thereby inducing tumor rejection. While CAR-T cell therapy shows great promise in hematological malignancies, its use in solid tumors is limited. Therefore, innovative approaches are needed to increase the specificity of CAR-modified T cells against solid tumors. The aim of this study was to assess the efficacy and safety of intraperitoneal (IP) versus intravenous (IV) CAR-T cell therapy in the treatment of HGSOC. We constructed a CAR that targets the ErbB2/HER2 protein (ErbB2CAR), which is overexpressed in HGSOC, and evaluated the functionality of ErbB2CAR on ovarian cancer cell lines (OVCAR8, SKOV3, and NAR). Our findings show that an IP injection of ErbB2CAR-T cells to tumor-bearing mice led to disease remission and increased survival compared to the IV route. Moreover, we found that IP-injected ErbB2CART cells circulate to a lesser extent, making them safer for non-tumor tissues than IV-injected cells. Further supporting our findings, we show that the effect of ErbB2CAR-T cells on primary HGSOC tumors is correlated with ErbB2 expression. Together, these data demonstrate the advantages of an IP administration of CAR-T cells over IV administration, offering not only a safer strategy but also the potential for counteracting the effect of ErbB2CAR in HGSOC. Significance: IP-injected ErbB2CAR-T cells led to disease remission and increased survival compared to the IV route. These findings demonstrate the advantages of IP administration, offering a safe treatment strategy with the potential for counteracting the effect of ErbB2CAR in HGSOC.

Hyperthermic Intraperitoneal Chemotherapy (HIPEC): An Overview of the Molecular and Cellular Mechanisms of Actions and Effects on Epithelial Ovarian Cancers.

Most patients with epithelial ovarian cancers (EOCs) are at advanced stages (stage III–IV), for which the recurrence rate is high and the 5-year survival rate is low. The most effective treatment for advanced diseases involves a debulking surgery followed by adjuvant intravenous chemotherapy with carboplatin and paclitaxel. Nevertheless, systemic treatment with intravenous chemotherapeutic agents for peritoneal metastasis appears to be less effective due to the poor blood supply to the peritoneal surface with low drug penetration into tumor nodules. Based on this reason, hyperthermic intraperitoneal chemotherapy (HIPEC) emerges as a new therapeutic alternative. By convection and diffusion, the hyperthermic chemotherapeutic agents can directly contact intraperitoneal tumors and produce cytotoxicity. In a two-compartment model, the peritoneal–plasma barrier blocks the leakage of chemotherapeutic agents from peritoneal cavity and tumor tissues to local vessels, thus maintaining a higher concentration of chemotherapeutic agents within the tumor tissues to facilitate tumor apoptosis and a lower concentration of chemotherapeutic agents within the local vessels to decrease systemic toxicity. In this review, we discuss the molecular and cellular mechanisms of HIPEC actions and the effects on EOCs, including the progression-free survival (PFS), disease-free survival (DFS) and overall survival (OS). For primary advanced ovarian cancers, more studies are agreeing that patients undergoing HIPEC have better surgical and clinical (PFS; OS) outcomes than those not, although one study reported no differences in the PFS and OS. For recurrent ovarian cancers, studies have revealed better DFS and OS in patients undergoing HIPEC than those in patients not undergoing HIPEC, although one study reported no differences in the PFS. HIPEC appears comparable to traditional intravenous chemotherapy in treating advanced EOCs. Overall, HIPEC has demonstrated some therapeutic benefits in many randomized phase III trials when combined with the standard cytoreductive surgeries for advanced EOCs. Nevertheless, many unknown aspects of HIPEC, including detailed mechanisms of actions, along with the effectiveness and safety for the treatment of EOCs, warrant further investigation.

528MO Is re-introduction or continuation of PARP inhibitors after local therapy for oligo-metastatic progression in patients with relapsed ovarian cancer relevant?

PARP inhibitors (PARPi) have revolutionized the management of High-grade epithelial ovarian cancer (HGEOC) treatment. However, a significant number of patients relapse or progress under PARPi leading to the introduction of a new line of systemic therapy as chemotherapy. In patient with a limited number of metastatic sites in progression, -referred to as the oligo metastatic progression- a potential indication for local therapy followed by re introduction or continuation of PARPi treatment rather than initiating a new line of chemotherapy could be proposed. However, the impact of local treatment on progression free survival (PFS) in these patients remains unknown. This international multicenter retrospective study evaluated the efficacy of PARPi continuation or reintroduction in patients with HGEOC after local treatment for oligometastatic progression. The main objective was to assess PFS under PARPi after local therapy (PFS post-LT). Secondary objectives included safety and OS. 74 patients were identified in 20 centers between 04/20 and 11/21. 65% of patients were BRCA mutated and 92% had received ≥ 2 lines of prior systemic chemotherapy before the initial introduction of PARPi. Main progression sites were lymph nodes (42%), peritoneum (20%), liver (11%), other visceral (9%) and other (18%). Local therapy included radiotherapy (44%), surgery (43%), both (7%), cryotherapy or radiofrequency (3%) and other (3%). Median PFS post-LT was 11.5 months [95% CI 7.4; 17.2]. After median follow up of 14.8 months, 5 patients (6.8%) discontinued PARPi due to toxicity. The 1-year overall survival rate was 90.7% [95% CI 79.1; 96.0]. With close to one year without progression or introduction new line of systemic therapy, this study reports the feasibility and potential benefit of this original strategy in patients with oligometastatic progression under PARPi.

COPS5 Conferred the Platinum Resistance in Epithelial Ovarian Cancer.

Development of platinum resistance is one of the major causes of epithelial ovarian cancer (EOC) treatment failure. COP9 signalosome subunit 5 (COPS5) was found to take part in the progression of EOC in our previous study. Herein, we aim to uncover the potential utility of COPS5 in EOC chemoresistance. COPS5 levels were analyzed to define clinic pathologic correlates using a matched tissue microarray and online datasets. The effect of COPS5 inhibition by the lentivirus-mediated short hairpin RNA on cell viability, proliferation and migration was accessed in vitro and in vivo. Results showed that COPS5 was upregulated in patients after platinum resistance. Kaplan–Meier survival curves revealed that COPS5 overexpression was correlated with shorter PFS and OS. COPS5 downregulation inhibited the cell proliferation, migration, and reduced the sensitivity of EOC to platinum. Overall, our data indicated that COPS5 inhibition might represent a new therapeutic strategy for overcoming platinum resistance in patients with EOC.

Patterns of First-Line Systemic Therapy Delivery and Outcomes in Advanced Epithelial Ovarian Cancer in Ontario.

Background: First-line treatment of epithelial ovarian cancer (EOC) consists of a combination of cytoreductive surgery and platinum-based chemotherapy. Recently, targeted therapies such as bevacizumab have been shown to improve oncologic outcomes in a subset of a high-risk population. The objective of this study is to evaluate the patterns of practice and outcomes of first-line systemic treatment of advanced EOC, focusing on the adoption of bevacizumab. Methods: A population cohort study was conducted using administrative data in Ontario, Canada. Patients diagnosed with advanced stage non-mucinous EOC between 2014 and 2018 were identified. Datasets were linked to obtaining information on first-line treatment including surgery, systemic therapy, providers of care, systemic therapy facilities, and acute care utilization (emergency department (ED) visits and hospitalizations) during systemic treatment. Multivariate logistic regression was used to determine factors associated with systemic therapy utilization. Results: Among 3726 patients with advanced EOC, 2838 (76%) received chemotherapy: 1316 (47%) received neoadjuvant chemotherapy, 1060 (37%) underwent primary cytoreductive surgery followed by chemotherapy, and 462 (16%) received chemotherapy only. The median age was 67 (range: 20–100). Most chemotherapies were prescribed by gynecologic oncologists (60%) and in level 1 academic cancer centres (58%). Only 54 patients (3.1%) received bevacizumab in the first-line setting after its approval in Ontario in 2016. Bevacizumab was more likely to be administered by medical oncologists compared to gynecologic oncologists (OR 3.95, 95% CI 2.11–7.14). In total, 1561 (55%) and 1594 (56%) patients had at least one ED visit and/or hospitalization during systemic treatment, respectively. The most common reasons for ED visits were fever and bowel obstruction. Conclusion: Patterns of care for EOC in Ontario differed between care providers. The uptake of bevacizumab for first-line treatment of EOC was low. Acute care utilization related to EOC was high.

HER-2-mediated nano-delivery of molecular targeted drug potently suppresses orthotopic epithelial ovarian cancer and metastasis

The treatment of epithelial ovarian cancer (EOC) has made slow progress due to absence of effective adjuvant chemotherapy that is capable of preventing tumor relapse and metastasis. Molecular targeted drugs such as PARP and PLK1 inhibitors appear to be promising new treatments for EOC. The low EOC cell uptake, poor selectivity and pronounced toxicity, however, greatly compromise their clinical efficacy. Herein, we report that HER-2-mediated nano-delivery of clinical PLK1-targeted drug, volasertib (Vol), while causing little toxicity potently suppresses orthotopic EOC and metastasis. Anti-HER-2 antibody, trastuzumab (Tra), was conjugated onto Vol-loaded polymersomes via click chemistry yielding Tra-PVol with a size of 33 nm and optimally about 5 Tra per polymersome. Tra-PVol exhibited clearly stronger uptake and anti-tumor activity (IC50 = 59 nM) in HER-2 overexpressing SKOV-3 cells than free Vol and non-targeted PVol controls. Both biodistribution and therapeutic studies in orthotopic SKOV-3-Luc tumor-bearing mice displayed that Tra-PVol induced significantly better tumor deposition and retardation than PVol and that intraperitoneal administration outperformed intravenous administration. More interestingly, Tra-PVol was shown to effectively suppress the intraperitoneal metastasis and to markedly prolong the survival time of SKOV-3-Luc tumor-bearing mice. This HER-2 directed molecular therapy emerges as a potential treatment strategy toward EOC.

Spatial oriented single-cell proteomic assay of low grade serous ovarian carcinoma identifies tumor oncogenic pathways associated with brain metastases (233)

Objectives: As the systemic treatment of epithelial ovarian cancer (EOC) has improved, and the survival is longer, the incidence of brain metastases (BM) in EOC patients has increased to about 2-6% and invariably results in death. In order to better understand the molecular mechanisms involved in the development of EOC BM and to characterize the BM architecture and heterogeneity, we recently used multiplex cyclic-immunofluorescence (Cyc-IF) to characterize a set of matched samples from a single ovarian cancer patient. Methods: The samples included a primary tumor, a peritoneal tumor collected at recurrence, and a BM. Cyc-IF is a spatial oriented single-cell proteomic assay that allows the quantification of over 60 proteins in a single FFPE slide. Results: Our analyses indicated that tumor architecture and heterogeneity were highly altered in the BM compared to the primary and recurrent tumors in this patient. Indeed, the primary and recurrent intraperitoneal tumors showed extensive heterogeneity with cancer cells in different cell states related to the cell cycle (cyclins), hormone receptors (PR and ER) and signaling pathways. In contrast, the BM was overall more homogeneous, with no PR receptor expression and low expression of cyclins. EOC cells from the BM harbor higher oncogenic MAPK and PI3K-AKT signaling pathway activity, higher estrogen receptor expression and displayed immunosuppressive properties including increased expression of PD1 and the presence of tumor-associated macrophages (TAM) and regulatory T cells (Tregs). Importantly, we were able to identify cell populations in the primary tumor that had phenotypes similar to that of cells found in the BM. Conclusions: These findings are consistent with the concept that EOC cells with a predilection for BM are present early during the disease course. Therefore, this represents an opportunity to develop a molecular signature for BM prevention and treatment. Objectives: As the systemic treatment of epithelial ovarian cancer (EOC) has improved, and the survival is longer, the incidence of brain metastases (BM) in EOC patients has increased to about 2-6% and invariably results in death. In order to better understand the molecular mechanisms involved in the development of EOC BM and to characterize the BM architecture and heterogeneity, we recently used multiplex cyclic-immunofluorescence (Cyc-IF) to characterize a set of matched samples from a single ovarian cancer patient. Methods: The samples included a primary tumor, a peritoneal tumor collected at recurrence, and a BM. Cyc-IF is a spatial oriented single-cell proteomic assay that allows the quantification of over 60 proteins in a single FFPE slide. Results: Our analyses indicated that tumor architecture and heterogeneity were highly altered in the BM compared to the primary and recurrent tumors in this patient. Indeed, the primary and recurrent intraperitoneal tumors showed extensive heterogeneity with cancer cells in different cell states related to the cell cycle (cyclins), hormone receptors (PR and ER) and signaling pathways. In contrast, the BM was overall more homogeneous, with no PR receptor expression and low expression of cyclins. EOC cells from the BM harbor higher oncogenic MAPK and PI3K-AKT signaling pathway activity, higher estrogen receptor expression and displayed immunosuppressive properties including increased expression of PD1 and the presence of tumor-associated macrophages (TAM) and regulatory T cells (Tregs). Importantly, we were able to identify cell populations in the primary tumor that had phenotypes similar to that of cells found in the BM. Conclusions: These findings are consistent with the concept that EOC cells with a predilection for BM are present early during the disease course. Therefore, this represents an opportunity to develop a molecular signature for BM prevention and treatment.