The intratumoral microbiota biomarkers for predicting survival and efficacy of immunotherapy in patients with ovarian serous cystadenocarcinoma.

BACKGROUND: Ovarian serous cystadenocarcinoma, accounting for about 90% of ovarian cancers, is frequently diagnosed at advanced stages, leading to suboptimal treatment outcomes. Given the malignant nature of the disease, effective biomarkers for accurate prediction and personalized treatment remain an urgent clinical need. METHODS: In this study, we analyzed the microbial contents of 453 ovarian serous cystadenocarcinoma and 68 adjacent non-cancerous samples. A univariate Cox regression model was used to identify microorganisms significantly associated with survival and a prognostic risk score model constructed using LASSO Cox regression analysis. Patients were subsequently categorized into high-risk and low-risk groups based on their risk scores. RESULTS: Survival analysis revealed that patients in the low-risk group had a higher overall survival rate. A nomogram was constructed for easy visualization of the prognostic model. Analysis of immune cell infiltration and immune checkpoint gene expression in both groups showed that both parameters were positively correlated with the risk level, indicating an increased immune response in higher risk groups. CONCLUSION: Our findings suggest that microbial profiles in ovarian serous cystadenocarcinoma may serve as viable clinical prognostic indicators. This study provides novel insights into the potential impact of intratumoral microbial communities on disease prognosis and opens avenues for future therapeutic interventions targeting these microorganisms.

Impact of fludarabine and treosulfan on ovarian tumor cells and mesothelin chimeric antigen receptor T cells.

In addition to their immunosuppressive effect, cytostatics conditioning prior to adoptive therapy such as chimeric antigen receptor (CAR) T cells may play a role in debulking and remodeling the tumor microenvironment. We investigated in vitro the killing efficacy and impact of treosulfan and fludarabine on ovarian cancer cells expressing mesothelin (MSLN) and effect on MSLN-targeting CAR T cells. Treosulfan and fludarabine had a synergetic effect on killing of SKOV3 and OVCAR4 cells. Sensitivity to the combination of treosulfan and fludarabine was increased when SKOV3 cells expressed MSLN and when OVCAR4 cells were tested in hypoxia, while MSLN cells surface expression by SKOV3 and OVCAR4 cells was not altered after treosulfan or fludarabine exposure. Exposure to treosulfan or fludarabine (10 µM) neither impacted MSLN-CAR T cells degranulation, cytokines production upon challenge with MSLN + OVCAR3 cells, nor induced mitochondrial defects. Combination of treosulfan and fludarabine decreased MSLN-CAR T cells anti-tumor killing in normoxia but not hypoxia. In conclusion, treosulfan and fludarabine killed MSLN + ovarian cancer cells without altering MSLN-CAR T cells functions (at low cytostatics concentration) even in hypoxic conditions, and our data support the use of treosulfan and fludarabine as conditioning drugs prior to MSLN-CAR T cell therapy.

CAR memory-like NK cells targeting the membrane proximal domain of mesothelin demonstrate promising activity in ovarian cancer.

Epithelial ovarian cancer (EOC) remains one of the most lethal gynecological cancers. Cytokine-induced memory-like (CIML) natural killer (NK) cells have shown promising results in preclinical and early-phase clinical trials. In the current study, CIML NK cells demonstrated superior antitumor responses against a panel of EOC cell lines, increased expression of activation receptors, and up-regulation of genes involved in cell cycle/proliferation and down-regulation of inhibitory/suppressive genes. CIML NK cells transduced with a chimeric antigen receptor (CAR) targeting the membrane-proximal domain of mesothelin (MSLN) further improved the antitumor responses against MSLN-expressing EOC cells and patient-derived xenograft tumor cells. CAR arming of the CIML NK cells subtanstially reduced their dysfunction in patient-derived ascites fluid with transcriptomic changes related to altered metabolism and tonic signaling as potential mechanisms. Lastly, the adoptive transfer of MSLN-CAR CIML NK cells demonstrated remarkable inhibition of tumor growth and prevented metastatic spread in xenograft mice, supporting their potential as an effective therapeutic strategy in EOC.

Prognostic Impact of Tumor-Infiltrating Immune Cells on Efficacy of Neoadjuvant Chemotherapy in Patients with Advanced or Metastatic Ovarian Cancer: A Retrospective Study.

BACKGROUND Tumor-infiltrating immune cells (TIICs) are implicated in the survival of ovarian cancer (OVCA) patients, but their prognostic significance in advanced or metastatic OVCA patients treated with neoadjuvant chemotherapy (NCAT) has not been well documented, particularly in the Chinese population. MATERIAL AND METHODS A total of 31 advanced or metastatic OVCA patients who underwent NACT were included. The density and positive rate of tumor-infiltrating immune cells (TIICs) within cancer cell nests and in cancer stroma were explored. The correlations of pre- or post-NACT TIICs with the efficacy of NACT and the changes in TIIC subpopulation with NACT were examined. RESULTS Compared with patients with partial benefit from NACT, significantly decreased pre-NACT intratumoral CD68⁺CD163⁺ cells (P=0.0043) and increased pre-NACT intratumoral CD56⁺ cells (P=0.038) were observed in patients with benefit. The high level of pre-NACT intratumoral CD68⁺CD163⁻ M1 macrophage (P=0.075) and stromal CD3⁺PD-1⁺ cells (P=0.085) predicated improved progression-free survival, respectively. Increased post-NACT stromal CD68⁺CD163⁻ M1 macrophage (P=0.01), stromal CD8⁺ T cells (P=0.073), and stromal CD8⁺PD-1⁺ cells (P=0.072) were associated with benefit from NACT. Moreover, NACT increased intratumoral CD3⁺ (P=0.031), CD8+ (P=0.031), and CD3⁺CD8⁺ cells (P=0.031). CONCLUSIONS High intratumoral CD68⁺CD163⁻, intratumoral CD56⁺ cells, and stromal CD3⁺PD-1⁺ cells pre-NACT predicted good prognosis. Intratumoral CD3⁺, CD8⁺, and CD3⁺CD8⁺ cells were increased after NACT. Evaluation of immune profiles may help to identify patients who might benefit from NACT and allow us to further stratify advanced or metastatic OVCA patients treated with NACT for disease management.

Immunomic longitudinal profiling of the NeoPembrOv trial identifies drivers of immunoresistance in high-grade ovarian carcinoma.

PD-1/PD-L1 blockade has so far shown limited survival benefit for high-grade ovarian carcinomas. By using paired samples from the NeoPembrOv randomized phase II trial (NCT03275506), for which primary outcomes are published, and by combining RNA-seq and multiplexed immunofluorescence staining, we explore the impact of NeoAdjuvant ChemoTherapy (NACT) ± Pembrolizumab (P) on the tumor environment, and identify parameters that correlated with response to immunotherapy as a pre-planned exploratory analysis. Indeed, i) combination therapy results in a significant increase in intraepithelial CD8+PD-1+ T cells, ii) combining endothelial and monocyte gene signatures with the CD8B/FOXP3 expression ratio is predictive of response to NACT + P with an area under the curve of 0.93 (95% CI 0.85-1.00) and iii) high CD8B/FOXP3 and high CD8B/ENTPD1 ratios are significantly associated with positive response to NACT + P, while KDR and VEGFR2 expression are associated with resistance. These results indicate that targeting regulatory T cells and endothelial cells, especially VEGFR2+ endothelial cells, could overcome immune resistance of ovarian cancers.

Acetylation model predicts prognosis of patients and affects immune microenvironment infiltration in epithelial ovarian carcinoma.

BACKGROUND: Epithelial ovarian carcinoma (EOC) is a prevalent gynaecological malignancy. The prognosis of patients with EOC is related to acetylation modifications and immune responses in the tumour microenvironment (TME). However, the relationships between acetylation-related genes, patient prognosis, and the tumour immune microenvironment (TIME) are not yet understood. Our research aims to investigate the link between acetylation and the tumour microenvironment, with the goal of identifying new biomarkers for estimating survival of patients with EOC. METHODS: Using data downloaded from the tumour genome atlas (TCGA), genotypic tissue expression (GTEx), and gene expression master table (GEO), we comprehensively evaluated acetylation-related genes in 375 ovarian cancer specimens and identified molecular subtypes using unsupervised clustering. The prognosis, TIME, stem cell index and functional concentration analysis were compared among the three groups. A risk model based on differential expression of acetylation-related genes was established through minimum absolute contraction and selection operator (LASSO) regression analysis, and the predictive validity of this feature was validated using GEO data sets. A nomogram is used to predict a patient's likelihood of survival. In addition, different EOC risk groups were evaluated for timing, tumour immune dysfunction and exclusion (TIDE) score, stemness index, somatic mutation, and drug sensitivity. RESULTS: We used the mRNA levels of the differentially expressed genes related to acetylation to classify them into three distinct clusters. Patients with increased immune cell infiltration and lower stemness scores in cluster 2 (C2) exhibited poorer prognosis. Immunity and tumourigenesis-related pathways were highly abundant in cluster 3 (C3). We developed a prognostic model for ten differentially expressed acetylation-related genes. Kaplan-Meier analysis demonstrated significantly worse overall survival (OS) in high-risk patients. Furthermore, the TIME, tumour immune dysfunction and exclusion (TIDE) score, stemness index, tumour mutation burden (TMB), immunotherapy response, and drug sensitivity all showed significant correlations with the risk scores. CONCLUSIONS: Our study demonstrated a complex regulatory mechanism of acetylation in EOC. The assessment of acetylation patterns could provide new therapeutic strategies for EOC immunotherapy to improve the prognosis of patients.

Preoperative Immune Cell Dysregulation Accompanies Ovarian Cancer Patients into the Postoperative Period.

Ovarian cancer (OC) poses a significant global health challenge with high mortality rates, emphasizing the need for improved treatment strategies. The immune system's role in OC progression and treatment response is increasingly recognized, particularly regarding peripheral blood mononuclear cells (PBMCs) and cytokine production. This study aimed to investigate PBMC subpopulations (T and B lymphocytes, natural killer cells, monocytes) and cytokine production, specifically interleukin-1 beta (IL-1ß), interleukin-4 (IL-4), interleukin-6 (IL-6), interleukin-10 (IL-10), interleukin-12 (IL-12), and tumor necrosis factor alpha (TNFα), in monocytes of OC patients both preoperatively and during the early postoperative period. Thirteen OC patients and 23 controls were enrolled. Preoperatively, OC patients exhibited changes in PBMC subpopulations, including decreased cytotoxic T cells, increased M2 monocytes, and the disbalance of monocyte cytokine production. These alterations persisted after surgery with subtle additional changes observed in PBMC subpopulations and cytokine expression in monocytes. Considering the pivotal role of these altered cells and cytokines in OC progression, our findings suggest that OC patients experience an enhanced pro-tumorigenic environment, which persists into the early postoperative period. These findings highlight the impact of surgery on the complex interaction between the immune system and OC progression. Further investigation is needed to clarify the underlying mechanisms during this early postoperative period, which may hold potential for interventions aimed at improving OC management.

Immune cell landscapes are associated with high-grade serous ovarian cancer survival.

High-grade serous ovarian cancer (HGSOC) is an aggressive disease known to develop resistance to chemotherapy. We investigated the prognostic significance of tumor cell states and potential mechanisms underlying chemotherapy resistance in HGSOC. Transcriptome deconvolution was performed to address cellular heterogeneity. Kaplan-Meier survival curves were plotted to illustrate the outcomes of patients with varying cellular abundances. The association between gene expression and chemotherapy response was tested. After adjusting for surgery status and grading, several cell states exhibited a significant correlation with patient survival. Cell states can organize into carcinoma ecotypes (CE). CE9 and CE10 were proinflammatory, characterized by higher immunoreactivity, and were associated with favorable survival outcomes. Ratios of cell states and ecotypes had better prognostic abilities than a single cell state or ecotype. A total of 1265 differentially expressed genes were identified between samples with high and low levels of C9 or CE10. These genes were partitioned into three co-expressed modules, which were associated with tumor cells and immune cells. Pogz was identified to be linked with immune cell genes and the chemotherapy response of paclitaxel. Collectively, the survival of HGSOC patients is correlated with specific cell states and ecotypes.

Unique immune characteristics and differential anti-PD-1-mediated reinvigoration potential of CD8+ TILs based on BRCA1/2 mutation status in epithelial ovarian cancers.

BACKGROUND: We aimed to investigate the distinct immunological characteristics of the tumor immune microenvironment in epithelial ovarian cancer (EOC) according to BRCA1/2 mutations status and differential PD-1 expression levels. METHODS: Tumor-infiltrating lymphocytes (TILs) were collected from patients with newly diagnosed advanced-stage EOC (YUHS cohort, n=117). This YUHS cohort was compared with The Cancer Genome Atlas (TCGA) data for ovarian serous cystadenocarcinoma (n=482), in terms of survival outcomes and immune-related gene profiles according to BRCA1/2 status. We used multicolor flow cytometry to characterize the immune phenotypes and heterogeneity of TILs with or without BRCA1/2 mutations. In vitro functional assays were conducted to evaluate the reinvigorating ability of CD8+ TILs on anti-PD-1 treatment. RESULTS: We found that EOC patients with BRCA1/2 mutations (BRCA1/2mt) exhibited better survival outcomes and significantly higher tumor mutation burden (TMB), compared with BRCA1/2 non-mutated (BRCA1/2wt) patients. Furthermore, CD8+ TILs within BRCA1/2mt tumors displayed characteristics indicating more severe T-cell exhaustion than their BRCA1/2wt counterparts. Notably, the capacity for anti-PD-1-mediated reinvigoration of CD8+ TILs was significantly greater in BRCA1/2wt tumors compared with BRCA1/2mt tumors. Additionally, within the BRCA1/2wt group, the frequency of PD-1highCD8+ TILs was positively correlated with the reinvigoration capacity of CD8+ TILs after anti-PD-1 treatment. CONCLUSION: Our results highlight unique immune features of CD8+ TILs in EOC and a differential response to anti-PD-1 treatment, contingent on BRCA1/2 mutation status. These findings suggest that immune checkpoint blockade may be a promising frontline therapeutic option for selected BRCA1/2wt EOC patients.

New immune phenotypes for treatment response in high-grade serous ovarian carcinoma patients.

Despite advances in surgical and therapeutic approaches, high-grade serous ovarian carcinoma (HGSOC) prognosis remains poor. Surgery is an indispensable component of therapeutic protocols, as removal of all visible tumor lesions (cytoreduction) profoundly improves the overall survival. Enhanced predictive tools for assessing cytoreduction are essential to optimize therapeutic precision. Patients' immune status broadly reflects the tumor cell biological behavior and the patient responses to disease and treatment. Serum cytokine profiling is a sensitive measure of immune adaption and deviation, yet its integration into treatment paradigms is underexplored. This study is part of the IMPACT trial (NCT03378297) and aimed to characterize immune responses before and during primary treatment for HGSOC to identify biomarkers for treatment selection and prognosis. Longitudinal serum samples from 22 patients were collected from diagnosis until response evaluation. Patients underwent primary cytoreductive surgery or neoadjuvant chemotherapy (NACT) based on laparoscopy scoring. Twenty-seven serum cytokines analyzed by Bio-Plex 200, revealed two immune phenotypes at diagnosis: Immune High with marked higher serum cytokine levels than Immune Low. The immune phenotypes reflected the laparoscopy scoring and allocation to surgical treatment. The five Immune High patients undergoing primary cytoreductive surgery exhibited immune mobilization and extended progression-free survival, compared to the Immune Low patients undergoing the same treatment. Both laparoscopy and cytoreductive surgery induced substantial and transient changes in serum cytokines, with upregulation of the inflammatory cytokine IL-6 and downregulation of the multifunctional cytokines IP-10, Eotaxin, IL-4, and IL-7. Over the study period, cytokine levels uniformly decreased in all patients, leading to the elimination of the initial immune phenotypes regardless of treatment choice. This study reveals distinct pre-treatment immune phenotypes in HGSOC patients that might be informative for treatment stratification and prognosis. This potential novel biomarker holds promise as a foundation for improved assessment of treatment responses in patients with HGSOC. ClinicalTrials.gov Identifier: NCT03378297.

Immunogenicity of Non-Mutated Ovarian Cancer-Specific Antigens.

Epithelial ovarian cancer (EOC) has not significantly benefited from advances in immunotherapy, mainly because of the lack of well-defined actionable antigen targets. Using proteogenomic analyses of primary EOC tumors, we previously identified 91 aberrantly expressed tumor-specific antigens (TSAs) originating from unmutated genomic sequences. Most of these TSAs derive from non-exonic regions, and their expression results from cancer-specific epigenetic changes. The present study aimed to evaluate the immunogenicity of 48 TSAs selected according to two criteria: presentation by highly prevalent HLA allotypes and expression in a significant fraction of EOC tumors. Using targeted mass spectrometry analyses, we found that pulsing with synthetic TSA peptides leads to a high-level presentation on dendritic cells. TSA abundance correlated with the predicted binding affinity to the HLA allotype. We stimulated naïve CD8 T cells from healthy blood donors with TSA-pulsed dendritic cells and assessed their expansion with two assays: MHC-peptide tetramer staining and TCR Vß CDR3 sequencing. We report that these TSAs can expand sizeable populations of CD8 T cells and, therefore, represent attractive targets for EOC immunotherapy.

Mast Cell-related Prognosis Signature Characterizes Immune Landscape and Predicts Prognosis of Ovarian Cancer.

BACKGROUND/AIM: Ovarian cancer (OVC) is a common, aggressive, and heterogeneous malignancy, with a widely variable prognosis. With the advances of modern immunology, mast cells (MCs) have been shown to play a significant role in the prognosis of some malignant tumors. However, the role of mast cells in the prognosis of OVC is unknown. MATERIALS AND METHODS: In this study, MC-associated prognostic genes (MRGs) were used to classify OVC from The Cancer Genome Atlas (TCGA)-OVC cohort. Genes were evaluated using univariate cox regression analysis. Twenty-nine prognostic gene signatures were identified using LASSO-COX analysis. COX regression models and principal component analysis (PCA) algorithms were used to construct MRG scores and individual MRGs patterns. External validation was performed in the TCGA-breast cancer (BRCA) and IMvigor210 cohorts. Immunity analysis based on MRGs was performed using CIBERSORT, and GSVA methods, and immunotherapy response was evaluated using the TIDE website. RESULTS: Using TCGA-OVC data, we established a model for constructing MRG scores based on the twenty-nine identified prognostic gene signatures using the PCA algorithm. MRG scores were found to be strongly correlated with immune cell infiltration and were excellent predictors of prognosis in patients with OVC. Low MRG scores were associated with better prognosis and better response to immunotherapy and chemotherapy. CONCLUSION: MC-related prognosis signature characterizes the immune landscape and predicts the prognosis of OVC. Understanding the correlation between MC-related gene signatures and immunotherapy and chemotherapy may improve the development of personalized clinical treatment strategies.

Recent advances in understanding the immune microenvironment in ovarian cancer.

The occurrence of ovarian cancer (OC) is a major factor in women's mortality rates. Despite progress in medical treatments, like new drugs targeting homologous recombination deficiency, survival rates for OC patients are still not ideal. The tumor microenvironment (TME) includes cancer cells, fibroblasts linked to cancer (CAFs), immune-inflammatory cells, and the substances these cells secrete, along with non-cellular components in the extracellular matrix (ECM). First, the TME mainly plays a role in inhibiting tumor growth and protecting normal cell survival. As tumors progress, the TME gradually becomes a place to promote tumor cell progression. Immune cells in the TME have attracted much attention as targets for immunotherapy. Immune checkpoint inhibitor (ICI) therapy has the potential to regulate the TME, suppressing factors that facilitate tumor advancement, reactivating immune cells, managing tumor growth, and extending the survival of patients with advanced cancer. This review presents an outline of current studies on the distinct cellular elements within the OC TME, detailing their main functions and possible signaling pathways. Additionally, we examine immunotherapy rechallenge in OC, with a specific emphasis on the biological reasons behind resistance to ICIs.

The biological roles of CD47 in ovarian cancer progression.

Ovarian cancer is one of the most lethal malignant tumors, characterized by high incidence and poor prognosis. Patients relapse occurred in 65-80% after initial treatment. To date, no effective treatment has been established for these patients. Recently, CD47 has been considered as a promising immunotherapy target. In this paper, we reviewed the biological roles of CD47 in ovarian cancer and summarized the related mechanisms. For most types of cancers, the CD47/Sirpα immune checkpoint has attracted the most attention in immunotherapy. Notably, CD47 monoclonal antibodies and related molecules are promising in the immunotherapy of ovarian cancer, and further research is needed. In the future, new immunotherapy regimens targeting CD47 can be applied to the clinical treatment of ovarian cancer patients.

Mitochondria-targeted polyprodrug nanoparticles induce mitochondrial stress for immunogenic chemo-photodynamic therapy of ovarian cancer.

Hypoimmunogenicity and the immunosuppressive microenvironment of ovarian cancer severely restrict the capability of immune-mediated tumor killing. Immunogenic cell death (ICD) introduces a theoretical principle for antitumor immunity by increasing antigen exposure and presentation. Despite recent research progress, the currently available ICD inducers are still very limited, and many of them can hardly induce sufficient ICD based on traditional endoplasmic reticulum (ER) stress. Accumulating evidence indicates that inducing mitochondrial stress usually shows a higher efficiency in evoking large-scale ICD than that via ER stress. Inspired by this, herein, a mitochondria-targeted polyprodrug nanoparticle (named Mito-CMPN) serves as a much superior ICD inducer, effectively inducing chemo-photodynamic therapy-caused mitochondrial stress in tumor cells. The rationally designed stimuli-responsive polyprodrugs, which can self-assemble into nanoparticles, were functionalized with rhodamine B for mitochondrial targeting, cisplatin and mitoxantrone (MTO) for synergistic chemo-immunotherapy, and MTO also serves as a photosensitizer for photodynamic immunotherapy. The effectiveness and robustness of Mito-CMPNs in reversing the immunosuppressive microenvironment is verified in both an ovarian cancer subcutaneous model and a high-grade serous ovarian cancer model. Our results support that the induction of abundant ICD by focused mitochondrial stress is a highly effective strategy to improve the therapeutic efficacy of immunosuppressive ovarian cancer.

The potential value of cancer-testis antigens in ovarian cancer: Prognostic markers and targets for immunotherapy.

BACKGROUND: Tumor immunotherapy has become an important adjuvant therapy after surgery, radiotherapy, and chemotherapy. In recent years, the role of tumor-associated antigen (TAA) in tumor immunotherapy has become increasingly prominent. Cancer-testis antigen (CTA) is a kind of TAA that is highly restricted in a variety of tumors and can induce an immune response. AIMS: This review article aimed to evaluate the role of CTA on the progression of ovarian cancer, its diagnostic efficacy, and the potential for immunotherapy. METHODS: We analyzed publications and outlined a comprehensive of overview the regulatory mechanism, immunogenicity, clinical expression significance, tumorigenesis, and application prospects of CTA in ovarian cancer, with a particular focus on recent progress in CTA-based immunotherapy. RESULTS: The expression of CTA affects the occurrence, development, and prognosis of ovarian cancer and is closely related to tumor immunity. CONCLUSION: CTA can be used as a biomarker for the diagnosis and prognosis evaluation of ovarian cancer and is an ideal target for antitumor immunotherapy. These findings provide novel insights on CTA in the improvement of diagnosis and treatment for ovarian cancer. The successes, current challenges and future prospects were also discussed to portray its significant potential.

Structural and functional characterization of IgG- and non-IgG-based T-cell-engaging bispecific antibodies.

Bispecific T-cell-engaging antibodies are a growing class of therapeutics with numerous molecules being tested in clinical trials and, currently, seven of them have received market approval. They are structurally complex and function as adaptors to redirect the cytotoxicity of T cells to kill tumor cells. T-cell-engaging bispecific antibodies can be generally divided into two categories: IgG/IgG-like and non-IgG-like formats. Different formats may have different intrinsic potencies and physiochemical properties, and comprehensive studies are needed to gain a better understanding of how the differences in formats impact on structural and functional characteristics. In this study, we designed and generated bispecific T-cell-engaging antibodies with IgG-like (DVD-Ig) and non-IgG (BiTE) formats. Both target the same pair of antigens (EGFR and CD3) to minimize the possible influence of targets on functional characterization. We performed a side-by-side comparison to assess differences in the physiochemical and biological properties of these two bispecific T-cell-engaging antibodies using a variety of breast and ovarian cancer cell-based functional assays to delineate the structural-functional relationships and anti-tumor activities/potency. We found that the Fc portion of T-cell-engaging bispecific antibodies can significantly impact antigen binding activity, potency, and stability in addition to eliciting different mechanisms of action that contribute the killing of cancer cells.

Plasma Gelsolin Inhibits Natural Killer Cell Function and Confers Chemoresistance in Epithelial Ovarian Cancer.

Plasma gelsolin (pGSN) overexpression in ovarian cancer (OVCA) disarms immune function, contributing to chemoresistance. The aim of this study was to investigate the immunoregulatory effects of pGSN expression on natural killer (NK) cell function in OVCA. OVCA tissues from primary surgeries underwent immunofluorescent staining of pGSN and the activated NK cell marker natural cytotoxicity triggering receptor 1 to analyze the prognostic impact of pGSN expression and activated NK cell infiltration. The immunoregulatory effects of pGSN on NK cells were assessed using apoptosis assay, cytokine secretion, immune checkpoint-receptor expression, and phosphorylation of STAT3. In OVCA tissue analyses, activated NK cell infiltration provided survival advantages to patients. However, high pGSN expression attenuated the survival benefits of activated NK cell infiltration. In the in vitro experiment, pGSN in OVCA cells induced NK cell death through cell-to-cell contact. pGSN increased T-cell immunoglobulin and mucin-domain-containing-3 expression (TIM-3) on activated NK cells. Further, it decreased interferon-γ production in activated TIM-3+ NK cells, attenuating their anti-tumor effects. Thus, increased pGSN expression suppresses the anti-tumor functions of NK cells. The study provides insights into why immunotherapy is rarely effective in patients with OVCA and suggests novel treatment strategies.

Comprehensive single-cell and bulk RNA-seq analyses reveal a novel CD8+ T cell-associated prognostic signature in ovarian cancer.

CD8+ T cells play pivotal roles in combating intracellular pathogens and eliminating malignant cells in cancer. However, the prognostic role of CD8+ T cells in ovarian carcinoma is insufficiently exploited. Herein, through univariate Cox regression along with least absolute shrinkage and selection operator (LASSO) regression analyses, we developed a novel prognostic model based on CD8+ T cell markers identified by single-cell sequencing (scRNA-seq) analyses. Patient grouping by the median risk score reveals an excellent prognostic efficacy of this model in both training and validation cohorts. Of note, patients classified as low-risk group exhibit a dramatically improved prognosis. In addition, higher enrichment level of immune-related pathways and increased infiltration level of multiple immune cells are found in patients with lower risk score. Importantly, low-risk patients also exhibited higher response rate to immunotherapies. Summarily, this developed CD8+ T cell-associated prognostic model serves as an excellent predictor for clinical outcomes and aids in guiding therapeutic strategy choices for ovarian cancer patients.

Restoration of ARID1A Protein in ARID1A-deficient Clear Cell Carcinoma of the Ovary Attenuates Reactivity to Cytotoxic T Lymphocytes.

BACKGROUND/AIM: Clear cell carcinoma is a prevalent histological type of ovarian cancer in East Asia, particularly in Japan, known for its resistance to chemotherapeutic agents and poor prognosis. ARID1A gene mutations, commonly found in ovarian clear cell carcinoma (OCCC), contribute to its pathogenesis. Recent data revealed that the ARID1A mutation is related to better outcomes of cancer immunotherapy. Thus, this study aimed to investigate the immunotherapy treatment susceptibility of OCCC bearing ARID1A mutations. MATERIALS AND METHODS: Expression of ARID1A was analyzed using western blotting in ovarian cancer cell lines. OCCC cell lines JHOC-9 and RMG-V were engineered to overexpress NY-ESO-1, HLA-A*02:01, and ARID1A. Sensitivity to chemotherapy and T cell receptor-transduced T (TCR-T) cells specific for NY-ESO-1 was assessed in ARID1A-restored cells compared to ARID1A-deficient wild-type cells. RESULTS: JHOC-9 cells and RMG-V cells showed no expression of ARID1A protein. Overexpression of ARID1A in JHOC-9 and RMG-V cells did not impact sensitivity to gemcitabine. While ARID1A overexpression decreased sensitivity to cisplatin in RMG-V cells, it had no such effect in JHOC-9 cells. ARID1A overexpression reduced the reactivity of NY-ESO-1-specific TCR-T cells, as observed by the IFNγ ESLIPOT assay. CONCLUSION: Cancer immunotherapy is an effective approach to target ARID1A-deficient clear cell carcinoma of the ovary.