Treatment Option For Ovarian Cancer Research Articles

Promising approach for targeting ROBO1 with CAR NK cells to combat ovarian cancer primary tumor cells and organoids.

Aim: This study aimed to explore using peripheral blood mononuclear cell (PBMC)-derived chimeric antigen receptor (CAR) NK cells targeting ROBO1 as a personalized medicine approach for ovarian cancer. Methods: A two-step strategy generated ROBO1-targeted CAR NK cells from PBMCs of ovarian cancer patients. Efficacy was evaluated using xCELLigence RTCA, CCK-8 and Live/Dead fluorescence assays. Results: ROBO1-NK cells exhibited higher efficiency in eradicating primary ovarian cancer cells and lysing ovarian tumor organoids compared with primary NK cells without ROBO1-CAR modification. Conclusion: These findings highlight the potential of developing ROBO1-targeted CAR-NK cells from patients' PBMCs as a personalized treatment option for ovarian cancer.

Contribution of sphingomyelin phosphodiesterase acid-like 3B to the proliferation, migration, and invasion of ovarian cancer cells.

Cancer has the highest mortality rate among gynecological cancers and poses a serious threat to women's lives. However, the treatment options for ovarian cancer are still limited, and exploring effective targeted biomarkers is particularly important for predicting and treating ovarian cancer. Therefore, it is necessary to explore the molecular mechanisms of the occurrence and development of ovarian cancer. This investigation encompassed the analysis of gene expression profiles, measurement of transcription levels of potential target genes in peripheral blood samples from ovarian cancer patients and characterization of the ovarian cancer-related secretory protein sphingomyelin phosphodiesterase acid-like 3B (SMPDL3B). Through bioinformatics analysis, potential target genes were identified, and their association with overall survival (OS) and progression-free survival (PFS) in ovarian cancer patients was assessed utilizing relevant databases. Subsequently, differences in target gene expression in ovarian cancer tissue samples were validated through protein blotting and quantitative real-time PCR (qRT-qPCR). Cell proliferation assays using the cell count kit-8 (CCK-8) method, as well as transwell chamber assay and pre coated matrix gel chamber assay were employed to elucidate the role of SMPDL3B in ovarian cancer cell migration and invasion. This study revealed a substantial upregulation of SMPDL3B in the serum of ovarian cancer patients, correlating with an unfavorable prognosis. High SMPDL3B expression was linked not only to increased proliferation of ovarian cancer cells, but also enhanced migration and invasion. Remarkably, the knockdown the human alkaline ceramidase 2 (ACER2) gene in cancer cells with heightened SMPDL3B expression significantly inhibited cell proliferation, migration, and invasion induced by SMPDL3B activation (P<0.05), highlighting the functional interplay between ACER2 and SMPDL3B in ovarian cancer. In summary, this study proposes SMPDL3B as a prognostic marker for ovarian cancer, with implications for potential therapeutic intervention targeting the ACER2-SMPDL3B axis.

Abstract 644: PKC-iota specific inhibitor ICA-1S causes the degradation of mutant p53 in ovarian cancer cell lines

Abstract Ovarian cancer is the most lethal malignant disease of female. Treatment options for ovarian cancer are mostly the use of chemotherapeutics, surgery, or radiotherapy. However, due to resistance to drugs, relapse occurs and thus 5 years survival rate is only 47%. The tumor suppressor protein p53 works as a transcription factor to transcribe several proteins such as p21, p16 and PUMA that lead to halt cell cycle and also induce apoptosis when there is a damage in DNA. Mutation in several regions of p53 (mutp53) is quite common in cancers and can lead to the accumulation of p53 with loss of functions or sometimes gain of oncogenic functions. Thus there is a search for drugs that can degrade the mut53 and can restore the functions of normal p53. In this research, it was observed that the treatment of ovarian cancer cell lines (ES-2, HEY and OVCAR3) with atypical protein kinase C-iota (aPKCɩ) specific inhibitors ICA-1S can cause the degradation of mutp53 (53.6%, N=6 trials). Treatment with ICA-1S also lowered the level of phosphorylated p53 (ser15, 87%, N=3 trials). However, the level of MDM2 protein (murine double minute 2), a known p53 E3 ligase was not significantly (98%, N=2 trials) affected by ICA-1S in ES-2 cell line with mut p53 as well as p21 was also not affected. However level of PUMA was decreased both in ES-2 and HEY cell lines. Immunoprecipitation (IP) with aPKCɩ specific beads showed the aPKCɩ is associated with p53, though reverse IP with p53 beads was not able to show the association. Application of proteasome inhibitor MG-132 at a single dose of 0.5µM could not completely inhibit the degradation of mut53 and WTp53 in ICA-1S treated ES-2 cell line and HEY cell line, respectively, indicating the drug may be affecting the transcription of p53 as well. It is therefore postulated that aPKCɩ can phosphorylate p53, stabilizing it and may be affecting the transcription of p53 as well in those cell lines. Further research (kinase activity assay, immunoprecipitation, immunofluorescence) is going on to reveal the mode of this degradation. Citation Format: Mahfuza Marzan, Nuzhat Nowshin Oishee, Abigail Olatunji, Mildred Acevedo-Duncan. PKC-iota specific inhibitor ICA-1S causes the degradation of mutant p53 in ovarian cancer cell lines [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 644.

Glycosylation-related genes mediated prognostic signature contribute to prognostic prediction and treatment options in ovarian cancer: based on bulk and single‑cell RNA sequencing data

BackgroundOvarian cancer (OC) is a complex disease with significant tumor heterogeneity with the worst prognosis and highest mortality among all gynecological cancers. Glycosylation is a specific post-translational modification that plays an important role in tumor progression, immune escape and metastatic spread. The aim of this work was to identify the major glycosylation-related genes (GRGs) in OC and construct an effective GRGs signature to predict prognosis and immunotherapy.MethodsAUCell algorithm was used to identify glycosylation-related genes (GRGs) based on the scRNA-seq and bulk RNA-seq data. An effective GRGs signature was conducted using COX and LASSO regression algorithm. The texting dataset and clinical sample data were used to assessed the accuracy of GRGs signature. We evaluated the differences in immune cell infiltration, enrichment of immune checkpoints, immunotherapy response, and gene mutation status among different risk groups. Finally, RT-qPCR, Wound-healing assay, Transwell assay were performed to verify the effect of the CYBRD1 on OC.ResultsA total of 1187 GRGs were obtained and a GRGs signature including 16 genes was established. The OC patients were divided into high- and low- risk group based on the median riskscore and the patients in high-risk group have poor outcome. We also found that the patients in low-risk group have higher immune cell infiltration, enrichment of immune checkpoints and immunotherapy response. The results of laboratory test showed that CYBRD1 can promote the invasion, and migration of OC and is closely related to the poor prognosis of OC patients.ConclusionsOur study established a GRGs signature consisting of 16 genes based on the scRNA-seq and bulk RNA-seq data, which provides a new perspective on the prognosis prediction and treatment strategy for OC.

Selinexor in Combination with Decitabine Attenuates Ovarian Cancer in Mice.

High-grade serous ovarian cancer is a lethal gynecologic disease. Conventional therapies, such as platinum-based chemotherapy, are rendered inadequate for disease management as most advanced disease patients develop resistance to this therapy and soon relapse, leading to poor prognosis. Novel immunotherapy and targeted therapy are currently under investigation as treatment options for ovarian cancer, but so far with little success. Epigenetic changes, such as aberrant DNA methylation, have been reported in resistance to platinum-based therapy. Decitabine is a hypomethylating agent which is effective against platinum-resistant disease and also exhibits several anti-tumor immune functions. Selinexor is a selective inhibitor of nuclear protein export. It restored platinum sensitivity in patient-derived ovarian cancer cell lines and is currently in clinical trials for the treatment of platinum-resistant ovarian cancer. We hypothesized that these two agents used in combination could elicit more potent anti-tumor immune responses in vivo than either agent used alone. These studies were designed to investigate the efficacy of these two agents used in combination to treat ovarian cancer by assessing murine models for changes in disease pathology and in anti-tumor responses. Decitabine priming followed by selinexor treatment significantly limited ascites formation and tumor size. This combination of agents also promoted T cell effector function as measured by granzyme B secretion. Treatment of mice with decitabine and selinexor led to the significant release of a broader range of macrophage and T cell cytokines and chemokines above control PBS and vehicle and above decitabine or selinexor treatment alone. These results reveal crucial information for the design of clinical trials which may advance therapy outcomes in ovarian cancer.

Abstract 3189: Pre-clinical evaluation of novel folate receptor 1 directed CAR T cells for high grade serous ovarian cancer

Abstract Purpose: Treatment of ovarian cancer remains challenging. A high unmet clinical need for targeted, efficient, and persisting drugs still is a major issue for clinicians and patients diagnosed with ovarian cancer, particularly platinum-resistant and-refractory, recurrent disease. Genetically modified T cells expressing chimeric antigen receptors (CARs) have shown efficient, as well as persisting anti-tumor functionality in hematological malignancies. However, solid cancers have not yet been as efficiently treated with CAR T cells, potentially due to the lack of appropriate targets. Therefore, we thoroughly characterized FOLR1 as CAR T cell target for ovarian cancer, designed novel CAR T cells, and assessed these drug candidates preclinically in vitro and in vivo. Experimental Design: We performed ultra-high content imaging on high-grade serous epithelial ovarian cancer as well as healthy tissue samples to profile the expression of the tumor-associated antigen FOLR1. Subsequently, we designed a series of CAR T cell candidates based on different monoclonal antibodies targeting FOLR1, in order to leverage on clinical experience with these binders, particularly safety aspects. The CAR designs differed in the VL-VH orientation and the spacer domain of the CAR construct. The preclinical assessment of various FOLR1-directed CAR T cell constructs was evaluated against various ovarian cancer cell lines in vitro and in vivo. Results: In this study we show high and consistent expression of the tumor-associated antigen FOLR1 on primary ovarian cancer samples, namely high-grade serous ovarian cancer. Moreover, FOLR1 expression is low, restricted, and polarized in healthy tissues. We generated diverse FOLR1-specific CAR T cells and characterized their efficacy and specificity in vitro as well as in an ovarian cancer xenograft model. CAR T cells rapidly and efficiently eradicate xenograft tumors. This anti-tumor response is accompanied by CAR T cell expansion, FOLR1-dependent cytokine secretion, and infiltration of CAR T cells into the tumor. Conclusions: These findings demonstrate the feasibility of a preclinical CAR T cell approach targeting FOLR1 as treatment option for ovarian cancer and potentially other FOLR1-expressing tumors. Citation Format: Christoph Herbel, Julie Daigre, Manuel Martinez-Osuna, Maria Bethke, Larissa Steiner, Janina Brauner, Jens Kopatz, Paurush Praveen, Dominik Eckardt, Andreas Bosio. Pre-clinical evaluation of novel folate receptor 1 directed CAR T cells for high grade serous ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3189.

Pt(II)-PLGA Hybrid in a pH-Responsive Nanoparticle System Targeting Ovarian Cancer.

Platinum-based agents are the main treatment option in ovarian cancer (OC). Herein, we report a poly(lactic-co-glycolic acid) (PLGA) nanoparticle (NP) encapsulating platinum (II), which is targeted to a cell-spanning protein overexpressed in above 90% of late-stage OC, mucin 1 (MUC1). The NP is coated with phospholipid-DNA aptamers against MUC1 and a pH-sensitive PEG derivative containing an acid-labile hydrazone linkage. The pH-sensitive PEG serves as an off-on switch that provides shielding effects at the physiological pH and is shed at lower pH, thus exposing the MUC1 ligands. The pH-MUC1-Pt NPs are stable in the serum and display pH-dependent PEG cleavage and drug release. Moreover, the NPs effectively internalize in OC cells with higher accumulation at lower pH. The Pt (II) loading into the NP was accomplished via PLGA-Pt (II) coordination chemistry and was found to be 1.62 wt.%. In vitro screening using a panel of OC cell lines revealed that pH-MUC1-Pt NP has a greater effect in reducing cellular viability than carboplatin, a clinically relevant drug analogue. Biodistribution studies have demonstrated NP accumulation at tumor sites with effective Pt (II) delivery. Together, these results demonstrate a potential for pH-MUC1-Pt NP for the enhanced Pt (II) therapy of OC and other solid tumors currently treated with platinum agents.

Corrected Allele Frequency of BRCA1/2 Mutations Is an Independent Prognostic Factor for Treatment Response to PARP-Inhibitors in Ovarian Cancer Patients.

PARP inhibitors (PARPi) have increased treatment options in ovarian cancer, particularly in patients with BRCA1/2 mutations, although there are still marked differences in the duration of patients’ response to this targeted therapy. BRCA testing is routinely performed in tumor tissue of ovarian cancer patients. The resulting molecular pathological findings include the genetic nomenclature of the mutation, the frequency of the mutated allele (variant allele frequency, VAF), and the tumor cell content. VAF measures the percentage of mutated alleles from the total alleles in the cells of the examined tissue. The aim of this study was to investigate the significance of VAF on the therapeutic response to PARPis in ovarian cancer patients. Epithelial ovarian cancer patients harboring BRCA1/2 tumor mutations, who underwent germline testing and received PARPi therapy at the Medical University of Vienna (n = 41) were included in the study. Corrected VAF (cVAF) was calculated based on VAF, tumor cell content, and germline mutation. Patients were divided into two groups based on their cVAF. Median PFS under PARPi in patients with low cVAF was 13.0 months (IQR [10.3-not reached]) and was not reached in the high cVAF group. High cVAF was significantly associated with longer PFS in the multivariate analysis (HR = 0.07; 95% CI [0.01–0.63]; p = 0.017). In conclusion, high cVAF was associated with a significantly better response to PARPi in this study population.

42P Real-life data on treatment with poly (ADP-ribose) polymerase inhibitor (iPARP), in patients over 65 years of age with ovarian cancer: A current need

BackgroundIPARPs are the latest advance in ovarian cancer treatment and have been shown and have been shown in clinical trials to be an effective and safe treatment. The increase in life expectancy implies an increase in the age of the patients treated, so the development of effective drugs with few adverse effects is becoming more important every day. The objective of the study was to establish the clinical and toxicity differences of iPARP treatment between patients older and younger than 65 years.MethodsA retrospective, single-center study was conducted. All patients diagnosed of high-grade serous or endometrioid ovarian cancer, primary peritoneal cancer, or fallopian tube cancer treated with iPARPs between 2017 and 2021 in Puerta de Hierro Hospital were included. Epidemiological and clinical data were registered.ResultsTable: 42PCharacteristics<65 years (41)>65 years (19)Comorbidities:HypertensionDiabetesHypercholesterolemiaIschemic eventHeart failure7.3%2.4%14.6%2.4%0%26.3%10.5%21.0%0%5.26%Smoking habitCurrentFormer14.6%29.3%1%36.8%Stage at diagnosisI-II: 14.6%III-IV: 86.4%I-II: 15.8III-IV: 84.4%Toxicity (any)43.9%63.2%p=0.165Grade >G314.6%5.3%P=0.293ToxicityGastrointestinalCardiologicalHematologicalOthers:33%22.2%33.4%5.5%50%25%21%4%Median treatment duration (months)11.57Discontinuation:9.8%21.0%P= 0.231Delays:9.8%15.8%P=0.498Subsequent treatment68.2%71.4%P=0.333 Open table in a new tab ConclusionsPatients >65 years treated with iPARPs did not experience higher rates of adverse events or treatment interruptions/discontinuations. iPARPs should be a valid treatment option for ovarian cancer in this increasingly frequent subgroup of patients.Legal entity responsible for the studyThe authors.FundingHas not received any funding.DisclosureAll authors have declared no conflicts of interest. BackgroundIPARPs are the latest advance in ovarian cancer treatment and have been shown and have been shown in clinical trials to be an effective and safe treatment. The increase in life expectancy implies an increase in the age of the patients treated, so the development of effective drugs with few adverse effects is becoming more important every day. The objective of the study was to establish the clinical and toxicity differences of iPARP treatment between patients older and younger than 65 years. IPARPs are the latest advance in ovarian cancer treatment and have been shown and have been shown in clinical trials to be an effective and safe treatment. The increase in life expectancy implies an increase in the age of the patients treated, so the development of effective drugs with few adverse effects is becoming more important every day. The objective of the study was to establish the clinical and toxicity differences of iPARP treatment between patients older and younger than 65 years. MethodsA retrospective, single-center study was conducted. All patients diagnosed of high-grade serous or endometrioid ovarian cancer, primary peritoneal cancer, or fallopian tube cancer treated with iPARPs between 2017 and 2021 in Puerta de Hierro Hospital were included. Epidemiological and clinical data were registered. A retrospective, single-center study was conducted. All patients diagnosed of high-grade serous or endometrioid ovarian cancer, primary peritoneal cancer, or fallopian tube cancer treated with iPARPs between 2017 and 2021 in Puerta de Hierro Hospital were included. Epidemiological and clinical data were registered. ResultsTable: 42PCharacteristics<65 years (41)>65 years (19)Comorbidities:HypertensionDiabetesHypercholesterolemiaIschemic eventHeart failure7.3%2.4%14.6%2.4%0%26.3%10.5%21.0%0%5.26%Smoking habitCurrentFormer14.6%29.3%1%36.8%Stage at diagnosisI-II: 14.6%III-IV: 86.4%I-II: 15.8III-IV: 84.4%Toxicity (any)43.9%63.2%p=0.165Grade >G314.6%5.3%P=0.293ToxicityGastrointestinalCardiologicalHematologicalOthers:33%22.2%33.4%5.5%50%25%21%4%Median treatment duration (months)11.57Discontinuation:9.8%21.0%P= 0.231Delays:9.8%15.8%P=0.498Subsequent treatment68.2%71.4%P=0.333 Open table in a new tab ConclusionsPatients >65 years treated with iPARPs did not experience higher rates of adverse events or treatment interruptions/discontinuations. iPARPs should be a valid treatment option for ovarian cancer in this increasingly frequent subgroup of patients. Patients >65 years treated with iPARPs did not experience higher rates of adverse events or treatment interruptions/discontinuations. iPARPs should be a valid treatment option for ovarian cancer in this increasingly frequent subgroup of patients.

Echinacoside inhibits the proliferation, migration, invasion and angiogenesis of ovarian cancer cells through PI3K/AKT pathway.

Echinacoside is a group of natural compounds extracted from medicinal plants Cistanche and Echinacea, which has neuroprotective, antiaging, immunomodulatory and anticancer effects, but its specific role and mechanism in tumor remains partially unclear. To our knowledge, it was the first time to reported the effect of Echinacoside in ovarian cancer. Colony formation, TUNEL staining, Transwell and tube formation assays were conducted to analyze the proliferation, apoptosis, invasion and tube formation abilities of serous ovarian carcinoma cells (SKOV3 and OVCAR-3), respectively. The expressions of apoptosis-, invasion- and PI3K/AKT pathway-related proteins were measured by western blotting. In addition, PI3K agonist (740Y-P) was used to assess the regulatory effect of Echinacoside on PI3K/AKT signaling in ovarian cancer. Finally, the anti-tumor effect of Echinacoside on SKOV3-xenografted mice was evaluated by xenograft tumor mouse model. Our results demonstrated Echinacoside concentration-dependently reduced the proliferation, migration and angiogenesis of ovarian cancer cells, whereas promoted apoptosis. Moreover, western blotting revealed that Echinacoside suppressed the growth of ovarian cancer cells by downregulating the phosphorylation levels of PI3K, AKT and mTOR, which could be partially reversed by 740Y-P. Further, in vivo results showed that Echinacoside could effectively alleviate the tumor growth of xenograft mice, accompanied by the decrease of PI3K/AKT signaling. In general, our results demonstrate that Echinacoside could reduce the ovarian cancer progression through inhibition of PI3K/AKT pathway, suggesting that Echinacoside may be a new treatment option for ovarian cancer.

Engineered EV-Mimetic Nanoparticles as Therapeutic Delivery Vehicles for High-Grade Serous Ovarian Cancer

Simple SummaryIn this review, we begin with the role of natural extracellular vesicles (EVs) in high-grade serous ovarian cancer (HGSOC). Then, we narrow our focus on the advantages of using EV-mimetic nanoparticles as a delivery vehicle for RNAi therapy and other chemotherapeutics. Furthermore, we discuss the challenges of the clinical translation of engineering EV mimetic drug delivery systems and the promising directions of further development.High-grade serous ovarian cancer (HGSOC) is the most lethal gynecological malignancy among women. Several obstacles impede the early diagnosis and effective treatment options for ovarian cancer (OC) patients, which most importantly include the development of platinum-drug-resistant strains. Currently, extensive efforts are being put into the development of strategies capable of effectively circumventing the physical and biological barriers present in the peritoneal cavity of metastatic OC patients, representing a late stage of gastrointestinal and gynecological cancer with an extremely poor prognosis. Naturally occurring extracellular vesicles (EVs) have been shown to play a pivotal role in progression of OC and are now being harnessed as a delivery vehicle for cancer chemotherapeutics. However, there are limitations to their clinical application due to current challenges in their preparation techniques. Intriguingly, there is a recent drive towards the use of engineered synthetic EVs for the delivery of chemotherapeutics and RNA interference therapy (RNAi), as they show the promise of overcoming the obstacles in the treatment of OC patients. This review discusses the therapeutic application of EVs in OC and elucidates the potential use of engineered EV-mimetic nanoparticles as a delivery vehicle for RNAi therapy and other chemotherapeutics, which would potentially improve clinical outcomes of OC patients.

Expression profiles and prognostic values of BolA family members in ovarian cancer

BackgroundThe BOLA gene family, comprising three members, is mainly involved in regulating intracellular iron homeostasis. Emerging evidence suggests that BolA family member 2 plays a vital role in tumorigenesis and hepatic cellular carcinoma progression. However, there was less known about its role in ovarian cancer.MethodsIn the present study, we investigated the expression profiles, prognostic roles, and genetic alterations of three BolA family members in patients with ovarian cancer through several public databases, containing Oncomine and Gene Expression Profiling Interactive Analysis, Human Protein Atlas, Kaplan–Meier plotter and cBioPortal. Then, we constructed the protein-protein interaction networks of BOLA proteins and their interactors by using the String database and Cytoscape software. In addition, we performed the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment by the Annotation, Visualization, and Integrated Discovery database. Finally, we explored the mechanisms underlying BolA family members’ involvement in OC by using gene set enrichment analysis.ResultsThe mRNA and protein expression levels of BOLA2 and BOLA3 were heavily higher in ovarian cancer tissues than in normal ovarian tissues. Dysregulated mRNA expressions of three BolA family members were significantly associated with prognosis in overall or subgroup analysis. Moreover, genetic alterations also occurred in three BolA family members in ovarian cancer. GO analysis indicated that BolA family members might regulate the function of metal ion binding and protein disulfide oxidoreductase activity. Gene set enrichment analysis indicated that BolA family members were mainly associated with oxidative phosphorylation, proteasome, protein export, and glutathione metabolism in ovarian cancer.ConclusionIn brief, our finding may contribute to increasing currently limited prognostic biomarkers and treatment options for ovarian cancer.

Association of homologous recombination deficiency in ovarian cancer with neoantigen load and expression of immune checkpoints.

5536 Background: Immune checkpoint blockade (ICB) is being explored as a treatment option in ovarian cancer, but objective response rates for single agent ICB are modest at around 10-15%. Validated biomarkers are needed to predict which patients will respond to ICB. BRCA mutations and homologous recombination deficiency (HRD) status are the only validated integral biomarkers in ovarian cancer. HRD tumors exhibit defective DNA repair mechanisms that promote increased mutational burden, which we postulate may correlate with higher neoantigen load and increased expression of targetable immune checkpoints. Methods: The Cancer Genome Atlas (TCGA) ovarian cancer dataset was evaluated and previously published, well annotated samples were obtained for HRD status. HLA type was determined with OptiType. Nonsynonymous mutations were annotated with Ensembl VEP. pVAC-Seq using NetMHCpan algorithm predicted neoepitopes 9 amino acids in length for MHC class I, reporting only those with a predicted IC50 less than 500 nM. Immune checkpoint gene expression counts were normalized with TCGAbiolinks. Correlation between HRD status and neoantigen load was assessed by Wilcoxon test. After log2 transformation, Wilcoxon tests evaluated for association between HRD status and expression of immune checkpoints. The relationship between HRD status and PD-L1 protein abundance with reverse phase protein array was measured. Results: Data from 154 HRD positive and 198 HRD negative tumors were analyzed. HRD positive status correlated with higher neoantigen load (p = 0.038) and increased expression of the immune checkpoints CTLA4 (p = 0.024), TIGIT (p = 0.027), and PVR (p = 0.002), but not PD-L1 (p = 0.238), LAG3 (p = 0.583), HVEM (p = 0.805), GAL9 (p = 0.750), NECTIN2 (p = 0.874), VSIG3 (p = 0.438), PSGL1 (p = 0.205) or VISTA (p = 0.531). TIM3 (p = 0.064) and B7H3 (p = 0.052) both demonstrated a trend towards increased expression in HRD tumors. Interestingly, HRD status showed a negative association with PVRIG (p = 0.028). There was no association between PD-L1 protein abundance and HRD status. Conclusions: HRD positive ovarian tumors demonstrate higher neoantigen load than HRD negative tumors, as well as increased expression of certain immune checkpoints. This supports the hypothesis that increased neoantigen load leads to compensatory induction of immune checkpoints, and suggests that HRD status may predict response to ICB, particularly to drugs that target CTLA4, TIGIT, PVR, TIM3 and B7H4.

Associations between DNA Damage and PD-L1 Expression in Ovarian Cancer, a Potential Biomarker for Clinical Response.

Simple SummaryThis work establishes that ovarian tumors contain persistent oxidative DNA damage levels that can be measured using Repair Assisted Damage Detection (RADD). The persistent DNA damage correlates with increased protein expression of PD-L1, establishing a link between genomic instability and PD-L1 expression across ovarian tumors. DNA damage may be a potential biomarker for immunotherapy.Programmed death ligand-1 (PD-L1) inhibitors are currently under investigation as a potential treatment option for ovarian cancer. Although this therapy has shown promise, its efficacy is highly variable among patients. Evidence suggests that genomic instability influences the expression of PD-L1, but little is known about this relationship in ovarian cancer. To examine the relationship between PD-L1 expression and genomic instability, we measured DNA damage using Repair Assisted Damage Detection (RADD). We then correlated the presence of persistent DNA damage in the ovarian tumor with protein expression of PD-L1 using immunohistochemistry. Ovarian tumors showed a high prevalence of oxidative DNA damage. As the level of oxidative DNA damage increased, we saw a significant correlation with PD-L1 expression. The highest correlation between DNA damage and PD-L1 expression was observed for mucinous ovarian tumors (r = 0.82), but a strong correlation was also observed for high grade serous and endometrioid tumors (r = 0.67 and 0.69, respectively). These findings link genomic instability to PD-L1 protein expression in ovarian cancer and suggest that persistent DNA damage can be used as a potential biomarker for patient selection for immunotherapy treatment.

The latest first-line treatment options for ovarian cancer: focus on maintenance therapy

Ovarian cancer is one of the leading causes of death from gynecologic cancers in Russia: in 2018, 7616 women died from this disease and the proportion of patients who is under observation for 5 years or more was only 3.4%, which probably indicates very low 5-year survival. At the same time, there was is a tremendous paradigm shift in the treatment of BRCA-associated ovarian cancer. A number of large phase III trials have been published on the use of PARP inhibitors in this subtype of the disease. Their results demonstrated a marked reduction in the risk of disease progression or death with PARP inhibitors after first-line therapy for advanced ovarian cancer. Here we present a comparative analysis of the efficacy of various PARP inhibitors in BRCA-associated ovarian cancer. The relative risk reduction in disease progression or death for olaparib, niraparib and veliparib was 70%, 60% and 56%, respectively and advantage of using these drugs noted in all patient subgroups. Comparative analysis of the safety of various PARP inhibitors was carried out as well, the risks of developing various toxicity were assessed. Based on a comparison of published data on their safety profile, it was concluded that olaparib is the safest drug of this class, especially in the context of therapy on an outpatient basis. Possible ways to optimize the use of PARP inhibitors in disseminated ovarian cancer have been analyzed.

Increased canonical NF-kappaB signaling specifically in macrophages is sufficient to limit tumor progression in syngeneic murine models of ovarian cancer

BackgroundNew treatment options for ovarian cancer are urgently required. Tumor-associated macrophages (TAMs) are an attractive target for therapy; repolarizing TAMs from M2 (pro-tumor) to M1 (anti-tumor) phenotypes represents an important therapeutic goal. We have previously shown that upregulated NF-kappaB (NF-κB) signaling in macrophages promotes M1 polarization, but effects in the context of ovarian cancer are unknown. Therefore, we aimed to investigate the therapeutic potential of increasing macrophage NF-κB activity in immunocompetent mouse models of ovarian cancer.MethodsWe have generated a transgenic mouse model, termed IKFM, which allows doxycycline-inducible overexpression of a constitutively active form of IKK2 (cIKK2) specifically within macrophages. The IKFM model was used to evaluate effects of increasing macrophage NF-κB activity in syngeneic murine TBR5 and ID8-Luc models of ovarian cancer in two temporal windows: 1) in established tumors, and 2) during tumor implantation and early tumor growth. Tumor weight, ascites volume, ascites supernatant and cells, and solid tumor were collected at sacrifice. Populations of macrophages and T cells within solid tumor and/or ascites were analyzed by immunofluorescent staining and qPCR, and soluble factors in ascitic fluid were analyzed by ELISA. Comparisons of control versus IKFM groups were performed by 2-tailed Mann-Whitney test, and a P-value < 0.05 was considered statistically significant.ResultsIncreased expression of the cIKK2 transgene in TAMs from IKFM mice was confirmed at the mRNA and protein levels. Tumors from IKFM mice, regardless of the timing of doxycycline (dox) administration, demonstrated greater necrosis and immune infiltration than control tumors. Analysis of IKFM ascites and tumors showed sustained shifts in macrophage populations away from the M2 and towards the anti-tumor M1 phenotype. There were also increased tumor-infiltrating CD3+/CD8+ T cells in IKFM mice, accompanied by higher levels of CXCL9, a T cell activating factor secreted by macrophages, in IKFM ascitic fluid.ConclusionsIn syngeneic ovarian cancer models, increased canonical NF-κB signaling in macrophages promoted anti-tumor TAM phenotypes and increased cytotoxic T cell infiltration, which was sufficient to limit tumor progression. This may present a novel translational approach for ovarian cancer treatment, with the potential to increase responses to T cell-directed therapy in future studies.

Abstract 5654: Affinity tuned Xmab®2+1 anti-mesothelin x anti-CD3 bispecific antibody induces selective T cell-dependent cellular cytotoxicity of human ovarian cancer cells

Abstract Mesothelin (MSLN) is a tumor-associated antigen highly expressed in ovarian tumors. Current treatment options for ovarian cancer have only modest efficacy and there remains a large unmet need for new targeted therapies. We generated targeted T cell engager bispecific antibodies that bind MSLN on tumor cells and CD3 on T cells. The humanized and affinity-optimized MSLN x CD3 bispecific antibodies are in an XmAb® 2+1 Fab2-scFv-Fc format that bind bivalently to MSLN and monovalently to CD3. The affinity of the MSLN-targeting arms was reduced to promote avid binding to MSLN expressing cancer cell lines and to minimize reactivity on normal surrogate cell lines. We correlated the expression of MSLN on cancer cell lines to 191 biopsy cores of serous and mucinous ovarian cancer tissues by IHC to identify surrogate cell lines to test for T cell-dependent cellular cytotoxicity (TDCC) activity. MSLN-transfected A549 cells were found to stain as intensely as ovarian cancer tumors expressing high amounts of MSLN. OVCAR-8 cancer cells were found to correlate with a medium MSLN level density on ovarian cancer tumors while ASPC-1 cells represented low MSLN-expressing tumors. Finally, we correlated expression of MSLN to non-cancer adjacent tissues and identified SKOV3, HT29, MCF7, and A549 (parental) cancer cells as appropriate surrogates of normal tissues. Reduction of MSLN affinity of MSLN x CD3 XmAb® 2+1 bispecific antibodies led to preferential killing of MSLN-high target cells, with up to 45-fold more potent TDCC activity on OVCAR8 and ASPC-1 cancer cells compared to the selected normal surrogate cell lines. Engineering of selective MSLN x CD3 bispecific antibodies allows for preferential killing of cancer cells, potentially minimizing on-target/off-tumor effects that may contribute to dose-limiting toxicities. Citation Format: Veronica G. Zeng, Matthew S. Faber, Matthew J. Bernett, Kendra N. Avery, John L. Zeytounian, Rumana Rashid, Umesh S. Muchhal, Gregory L. Moore, John R. Desjarlais, Michael Hedvat. Affinity tuned Xmab®2+1 anti-mesothelin x anti-CD3 bispecific antibody induces selective T cell-dependent cellular cytotoxicity of human ovarian cancer cells [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5654.

Dual targeting of GSK3B and HDACs reduces tumor growth and improves survival in an ovarian cancer mouse model

ObjectiveTo investigate the anti-tumor effect of a newly-developed dual inhibitor (APCS-540) of glycogen synthase kinase 3 beta (GSK3B) and histone deacetylases (HDACs) in ovarian cancer cells. MethodsThe effects of APCS-540 on cancer cell proliferation, migration, invasion and cancer stemness were investigated in vitro in human (KURAMOCHI, OVCA420, OVSAHO) and mouse (BR-Luc, ID8, MOSE-HRas-Myc) ovarian cancer cells. Cisplatin-sensitive (A2780) and cisplatin-resistant (A2780cis) cell lines were used to evaluate APCS-540's effect on chemoresistance. The immunocompetent syngeneic mouse model BR-Luc was used to test the effect of APCS-540 on ovarian cancer progression and survival. ResultsAPCS-540 showed significant anti-tumor effects in vitro in both human and mouse ovarian cancer cells. Importantly, APCS-540 demonstrated marked cytotoxicity against cisplatin-resistant cancer cells and reversed cisplatin-resistance when used in combination with platinum. APCS-540 significantly decreased cancer cell invasion. A significant 66% increase in survival was observed in mice treated with APCS-540 compared to control mice. ConclusionDual inhibition of GSK3B and HDACs via APCS-540 showed potent anti-tumor activity in vitro and in vivo, suggesting that APCS-540 may provide a novel treatment option for ovarian cancer, including the platinum-resistant disease.

Therapeutic Inducers of Apoptosis in Ovarian Cancer.

Ovarian cancers remain one of the most common causes of gynecologic cancer-related death in women worldwide. The standard treatment comprises platinum-based chemotherapy, and most tumors develop resistance to therapeutic drugs. One mechanism of developing drug resistance is alterations of molecules involved in apoptosis, ultimately assisting in the cells’ capability to evade death. Thus, there is a need to focus on identifying potential drugs that restore apoptosis in cancer cells. Here, we discuss the major inducers of apoptosis mediated through various mechanisms and their usefulness as potential future treatment options for ovarian cancer. Broadly, they can target the apoptotic pathways directly or affect apoptosis indirectly through major cancer-pathways in cells. The direct apoptotic targets include the Bcl-2 family of proteins and the inhibitor of apoptotic proteins (IAPs). However, indirect targets include processes related to homologous recombination DNA repair, micro-RNA, and p53 mutation. Besides, apoptosis inducers may also disturb major pathways converging into apoptotic signals including janus kinase (JAK)/signal transducer and activator of transcription 3 (STAT3), wingless-related integration site (Wnt)/β-Catenin, mesenchymal-epithelial transition factor (MET)/hepatocyte growth factor (HGF), mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK), and phosphatidylinositol 3-kinase (PI3K)/v-AKT murine thymoma viral oncogene homologue (AKT)/mammalian target of rapamycin (mTOR) pathways. Several drugs in our review are undergoing clinical trials, for example, birinapant, DEBIO-1143, Alisertib, and other small molecules are in preclinical investigations showing promising results in combination with chemotherapy. Molecules that exhibit better efficacy in the treatment of chemo-resistant cancer cells are of interest but require more extensive preclinical and clinical evaluation.

Abstract 3242: Triple checkpoint blockade targeting PD-1, TIM-3, and LAG-3 reinvigorates ovarian cancer-infiltrating T cells by increasing T cell polyfunctionality and effector function

Abstract Co-expression of immune checkpoint receptors (ICRs) PD-1, TIM-3, and LAG-3 characterizes chronically activated and exhausted tumor-infiltrating T cells (TILs), suggesting their targeting may have applicability for the treatment of multiple cancer types. We previously reported improved tumor control in various syngeneic and humanized mouse models when treated with a combination of TSR-042 (αPD-1), TSR-022 (αTIM-3), and TSR-033 (αLAG-3) as compared to single or double combinations. Here, we are characterizing TILs from ovarian cancer tissues and their functional response to triple combination treatment. Immune profiling using flow cytometry confirmed expression of all three ICRs on TILs isolated from primary resections of ovarian cancer. Ex vivo re-stimulation of immune infiltrates with S. aureus enterotoxin B in presence of ICR-targeting antibodies led to increased secretion of IFN-γ and IL-2 when treated with TSR-042. Notably, triple combination of TSR-042, TSR-022, and TSR-033 further amplified cytokine release, indicating more effective TIL reinvigoration. To further understand the differential effects of triple combination treatment over PD-1 blockade, we analyzed αCD3/αCD28-stimulated and antibody-treated ovarian cancer TILs on a single cell level using a microfluidic IsoCode chip technology that allows for parallel detection and quantification of 32 secreted proteins from live single cells. Combining the amount of each protein secreted by polyfunctional T cells (co-secreting two or more proteins per cell) with the frequency of such cells results in a measurement of polyfunctional strength (PSI), a unique IsoCode-enabled metric that has been associated with improved response to ICR inhibition. TSR-042 increased the PSI of CD4+ and CD8+ TILs 1.4 and 1.5-fold over isotype control treatment. Importantly, triple combination treatment was able to significantly increase the PSI of both subsets by 2.9 and 3.7-fold, respectively (p &amp;lt; 0.001). For CD8+ TILs, this increase was mainly driven by an increase in the frequency of polyfunctional subsets, while for CD4+ TILs, the absolute amounts of secreted cytokines had a larger impact. Interestingly, both classical effector cytokines like Granzyme B and IFN-γ as well as other secreted factors like chemoattractant factors, implicated in the recruitment of multiple immune cell subsets to tumor tissue, contributed to T cell polyfunctionality. Taken together, triple ICR blockade targeting PD-1, TIM-3, and LAG-3 reinvigorated ovarian cancer TILs more effectively than PD-1 inhibition alone. This was mediated by increasing T cell polyfunctionality, which has been associated with improved anti-tumor activity and response to ICR inhibition. This data further supports the concept of triple combination checkpoint blockade as a treatment option for ovarian cancer. Citation Format: Johanna K. Kaufmann, Brianna Flynn, Kevin Morse, Maria C. Speranza, Jing Zhou, Sridhar Ramaswamy, Sean Mackay, Kevin G. Coleman. Triple checkpoint blockade targeting PD-1, TIM-3, and LAG-3 reinvigorates ovarian cancer-infiltrating T cells by increasing T cell polyfunctionality and effector function [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3242.