Ovarian Cancer Tumor Microenvironment Research Articles

Homologous Recombination Deficiency and Cyclin E1 Amplification Are Correlated with Immune Cell Infiltration and Survival in High-Grade Serous Ovarian Cancer.

How molecular profiles are associated with tumor microenvironment (TME) in high-grade serous ovarian cancer (HGSOC) is incompletely understood. Therefore, we analyzed the TME and molecular profiles of HGSOC and assessed their associations with overall survival (OS). Patients with advanced-stage HGSOC treated in three Dutch hospitals between 2008-2015 were included. Patient data were collected from medical records. BRCA1/2 mutation, BRCA1 promotor methylation analyses, and copy number variations were used to define molecular profiles. Immune cells were assessed with immunohistochemical staining. 348 patients were categorized as BRCA mutation (BRCAm) (BRCAm or promotor methylation) (30%), non-BRCA mutated HRD (19%), Cyclin E1 (CCNE1)-amplification (13%), non-BRCAmut HRD and CCNE1-amplification (double classifier) (20%), and no specific molecular profile (NSMP) (18%). BRCAm showed highest immune cell densities and CCNE1-amplification lowest. BRCAm showed the most favorable OS (52.5 months), compared to non-BRCAmut HRD (41.0 months), CCNE1-amplification (28.0 months), double classifier (27.8 months), and NSMP (35.4 months). Higher immune cell densities showed a favorable OS compared to lower, also within the profiles. CD8+, CD20+, and CD103+ cells remained associated with OS in multivariable analysis. Molecular profiles and TME are associated with OS. TME differs per profile, with higher immune cell densities showing a favorable OS, even within the profiles. HGSOC does not reflect one entity but comprises different entities based on molecular profiles and TME.

Erastin enhances metastatic potential of ferroptosis-resistant ovarian cancer cells by M2 polarization through STAT3/IL-8 axis.

Erastin is a small molecule identified in chemical screen that is capable of inducing ferropotosis. There is collective evidence proving that erastin-induced ferroptosis exhibits anti-tumor potential within diverse caners, such as ovarian cancer (OC). However, most OC cells show relative resistance to ferroptosis induced by erastin. M2-polarized tumor-associated macrophages (TAMs) have an important effect on the OC tumor microenvironment (TME), which makes M2 polarization a noticeable part in the context of OC therapy. The immunomodulatory effects of erastin on ferroptosis-resistant OC cells remain poorly understood. Here, we found that low concentration of erastin greatly promoted ferroptosis-resistant OC cell invasion and migration via STAT3-mediated M2 polarization of macrophages. As revealed by in-vitro experimental results, erastin significantly increased metastases of ferroptosis-resistant OC, and the percentage of M2 macrophage infiltration was also raised after erastin treatment. Furthermore, erastin augmented IL-8 production of macrophages, and pharmacological blockage of IL-8 partially abrogated the stimulatory effect of erastin on ferroptosis-resistant OC cells. This study demonstrates a new mechanism undering the tumor-promoting activity of erastin and has implications for the STAT3/IL-8 axis as a potential target for ferroptosis-resistant OC cells to improve overall anti-tumor efficacy.

Longitudinal Modulation of Loco-Regional Immunity in Ovarian Cancer Patients Receiving Intraperitoneal Chemotherapy.

The immune tumor microenvironment (TME) of epithelial ovarian cancer (EOC) carries both effector and suppressive functions. To define immune correlates of chemotherapy-induced tumor involution, we performed longitudinal evaluation of biomarker expression on serial biological specimens collected during intraperitoneal (IP) platinum-based chemotherapy. Serial biological samples were collected at several time points during IP chemotherapy. RNA from IP fluid cells and tumor tissue was analyzed via NanoString. Meso Scale Discovery (MSD) multiplex assay and ELISA for MUC1 antibodies were performed on plasma and IP fluid. Differentially expressed genes in IP fluid demonstrate an upregulation of B cell function and activation of Th2 immune response along with dampening of Th1 immunity during chemotherapy. MSD analysis of IP fluid and gene expression analysis of tumor tissue revealed activation of Th2 immunity and the complement system. Anti-MUC1 antibodies were detected in IP fluid samples. IP fluid analysis in a secondary cohort also identified chemotherapy-induced B cell function genes. This study shows that serial IP fluid sampling is an effective method to capture changes in the immune TME during chemotherapy and reveals treatment induced changes in B cell function and Th2 immunity.

Inhibiting DNA methylation and RNA editing upregulates immunogenic RNA to transform the tumor microenvironment and prolong survival in ovarian cancer

BackgroundNovel therapies are urgently needed for ovarian cancer (OC), the fifth deadliest cancer in women. Preclinical work has shown that DNA methyltransferase inhibitors (DNMTis) can reverse the immunosuppressive tumor microenvironment...

Molecular subtypes based on cuproptosis-related genes and tumor microenvironment infiltration characterization in ovarian cancer

BackgroundCuproptosis (copper death) is a recently found cell death type produced by copper iron; nonetheless, the properties of cuproptosis molecular subtypes and possible involvement of cuproptosis-related genes (CRGs) in the tumor microenvironment (TME) in ovarian cancer (OC) remain unknown.MethodsCRG changes were characterized at the genomic and transcriptional levels in 656 OC samples, and their expression patterns were investigated using three different datasets.ResultsWe identified three distinct molecular subtypes, and discovered that variations in molecular subtypes were linked to patient prognosis, TME cell infiltration characteristics, malignancy, and immune-related pathways. Then, in order to predict overall survival (OS), we created a risk score and tested its predictive potential in OC patients. As a result, we created a very accurate nomogram to increase risk score clinical applicability. Better OS, younger age, early stage, and immune activity were all associated with a low risk score. The hallmarks of a high-risk score are older age, advanced stage, immunosuppression, and a bad prognosis. Furthermore, risk score was linked to immune checkpoint expression (including PD-L1, CTLA4), targeted therapy gene expression (PARP, PDGFRA), cancer stem cell (CSC), chemotherapy and targeted medication sensitivity.ConclusionsOur comprehensive analysis of CRGs in OC showed their potential role in TME, clinicopathological characteristics, chemotherapy and targeted drug screening and prognosis. These discoveries could help us better understand CRGs in OC, as well as pave the path for novel ways to assess prognosis and design more effective immunotherapy strategies.

Extracellular vesicle-packaged miR-181c-5p from epithelial ovarian cancer cells promotes M2 polarization of tumor-associated macrophages via the KAT2B/HOXA10 axis.

The molecular mechanistic actions of tumor-derived extracellular vesicles (EVs) in modulating macrophage polarization in the tumor microenvironment of epithelial ovarian cancer (EOC) is largely unknown. The study was performed to clarify the effect and downstream mechanism of microRNA-181c-5p (miR-181c-5p)-containing EVs from EOC cells in the M2 polarization of tumor-associated macrophages (TAMs). EVs were isolated from normoxic and hypoxic human EOC cells SKOV3. Human mononuclear cell THP-1 was induced by phorbol-12-myristate-13-acetate to differentiate into TAMs. The targeting relationship between miR-181c-5p and KAT2B was verified by dual luciferase reporter gene assay. The interaction between KAT2B and HOXA10 was detected by immunofluorescence, Co-IP and ChIP assays. EdU staining, the scratch test and Transwell assay were used to assess the resultant cell proliferation, migration and invasion. The mouse xenograft model and the pulmonary metastasis model were developed through intraperitoneal injection of SKOV3 cells and tail vein injection of THP-1 cells, respectively. Hypoxic SKOV3 cell-derived EVs could be internalized by TAMs. SKOV3 cell-derived EVs induced by hypoxia (H-EVs) promoted M2 polarization of TAMs and facilitated the proliferation, migration and invasion of SKOV3 cells. miR-181c-5p was highly expressed in H-EVs and promoted the M2 polarization of TAMs. Further, miR-181c-5p targeted KAT2B, upregulated HOXA10 and activated the JAK1/STAT3 pathway, thereby promoting the M2 polarization of TAMs. In both mouse models, H-EV-derived miR-181c-5p promoted growth and metastasis of EOC cells. The miR-181c-5p-containing EVs from hypoxic EOC cells may upregulate HOXA10 by targeting KAT2B and activate the JAK1/STAT3 pathway to promote the M2 polarization of TAMs, ultimately promoting growth and metastasis of EOC cells in vitro and in vivo.

The Tumor Microenvironment of Clear-Cell Ovarian Cancer.

Some patients with advanced clear-cell ovarian cancer (CCOC) respond to immunotherapy; however, little is known about the tumor microenvironment (TME) of this relatively rare disease. Here, we describe a comprehensive quantitative and topographical analysis of biopsies from 45 patients, 9 with Federation Internationale des Gynaecologistes et Obstetristes (FIGO) stage I/II (early CCOC) and 36 with FIGO stage III/IV (advanced CCOC). We investigated 14 immune cell phenotype markers, PD-1 and ligands, and collagen structure and texture. We interrogated a microarray data set from a second cohort of 29 patients and compared the TMEs of ARID1A-wildtype (ARID1Awt) versus ARID1A-mutant (ARID1Amut) disease. We found significant variations in immune cell frequency and phenotype, checkpoint expression, and collagen matrix between the malignant cell area (MCA), leading edge (LE), and stroma. The MCA had the largest population of CD138+ plasma cells, the LE had more CD20+ B cells and T cells, whereas the stroma had more mast cells and αSMA+ fibroblasts. PD-L2 was expressed predominantly on malignant cells and was the dominant PD-1 ligand. Compared with early CCOC, advanced-stage disease had significantly more fibroblasts and a more complex collagen matrix, with microarray analysis indicating "TGFβ remodeling of the extracellular matrix" as the most significantly enriched pathway. Data showed significant differences in immune cell populations, collagen matrix, and cytokine expression between ARID1Awt and ARID1Amut CCOC, which may reflect different paths of tumorigenesis and the relationship to endometriosis. Increased infiltration of CD8+ T cells within the MCA and CD4+ T cells at the LE and stroma significantly associated with decreased overall survival.

Targeting oxidative phosphorylation as an approach for the treatment of ovarian cancer.

Ovarian cancer is an aggressive tumor that remains to be the most lethal gynecological malignancy in women. Metabolic adaptation is an emerging hallmark of tumors. It is important to exploit metabolic vulnerabilities of tumors as promising strategies to develop more effective anti-tumor regimens. Tumor cells reprogram the metabolic pathways to meet the bioenergetic, biosynthetic, and mitigate oxidative stress required for tumor cell proliferation and survival. Oxidative phosphorylation has been found to be altered in ovarian cancer, and oxidative phosphorylation is proposed as a therapeutic target for management of ovarian cancer. Herein, we initially introduced the overview of oxidative phosphorylation in cancer. Furthermore, we discussed the role of oxidative phosphorylation and chemotherapeutic resistance of ovarian cancer. The role of oxidative phosphorylation in other components of tumor microenvironment of ovarian cancer has also been discussed.

Omentum-on-a-chip: A multicellular, vascularized microfluidic model of the human peritoneum for the study of ovarian cancer metastases

Epithelial ovarian cancer has the highest mortality rate of any gynecologic malignancy and most frequently metastasizes to the peritoneal cavity. Intraperitoneal metastases are highly associated with ascites, the pathologic accumulation of peritoneal fluid due to impaired drainage, increased peritoneal permeability, and tumor and stromal cytokine secretion. However, the relationship between ascites, vascular and mesothelial permeability, and ovarian cancer intraperitoneal metastases remains poorly understood. In this study, a vascularized in vitro model of the human peritoneal omentum and ovarian tumor microenvironment (TME) was employed to study stromal cell effects on tumor cell (TC) attachment and growth, as well as TC effects on vascular and mesothelial permeability in models of both early- and late-stage metastases. Control over the number of TCs seeded in the vascularized peritoneum revealed a critical cell density requirement for tumor growth, which was further enhanced by stromal adipocytes and endothelial cells found in the peritoneal omentum. This tumor growth resulted in both a physically-mediated decrease and cytokine-mediated increase in microvascular permeability, emphasizing the important and potentially opposing roles of tumor cells in ascites formation. This system provides a robust platform to elucidate TC-stromal cell interactions during intraperitoneal metastasis of ovarian cancer and presents the first in vitro vascularized model of the human peritoneum and ovarian cancer TME.

Abstract LB004: Upregulation of STAT3 signaling in tumor cells fosters a TME-dependent secondary resistance of BRCA1-deficient HGSOC to PARP inhibition

Abstract PARP inhibitors (PARPi) have demonstrated potent therapeutic efficacy in patients with ovarian cancer. However, acquired resistance to PARPi is a major challenge in the clinic. Therefore, understanding the resistance mechanism and developing new treatment approaches are important to overcome therapeutic resistance to PARP inhibition. By using our GEM of Brca1-deficient ovarian tumor model, we uncovered a new mechanism underlying a secondary resistance to PARP inhibition mediated by tumor associated macrophages (TAMs) in the tumor microenvironment (TME). Mechanistically, PARP inhibition induced the STAT3 signaling pathway in tumor cells, which in turn promoted pro-tumor polarization of TAMs in the TME of ovarian cancer. Ablation of STAT3 in tumor cells mitigated polarization of M2-like pro-tumor macrophages in the TME and increased tumor infiltration T cells in response to PARP inhibition. Furthermore, we demonstrated that STING agonists reprogramed myeloid cells in the TME of ovarian tumor into antitumor M1-like macrophages and activated dendritic cells (DCs) in a myeloid cell STING-dependent manner. These findings were recapitulated in patient-derived PARPi-resistant ovarian tumor models. Finally, we show that STING agonism was able to overcome the secondary resistance to PARPi in ovarian cancer rendered by immunosuppressive TME. Our study elucidates a new mechanism of PARPi resistance and provides a new treatment strategy to overcome the TME-induced therapeutic resistance to PARP inhibition in ovarian cancers. Citation Format: Liya Ding, Qiwei Wang, Michael Kearns, Tao Jiang, Xin Cheng, Changli Qian, Jean Zhao. Upregulation of STAT3 signaling in tumor cells fosters a TME-dependent secondary resistance of BRCA1-deficient HGSOC to PARP inhibition [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr LB004.

Abstract 585: AB-1015, a novel integrated circuit T cells containing an ALPG/MSLN logic gate and FAS/PTPN2 shRNA-miR, demonstrates specific and potent activity against ALPG/MSLN tumors

Abstract In solid tumors, CAR T cell efficacy is limited by off-tumor toxicity, poor persistence, and suppression by the tumor microenvironment (TME). To address these challenges we have engineered AB-1015, an integrated circuit T cell (ICT cell) intended for the treatment of ovarian cancer. The AB-1015 transgene cassette encodes an “AND” logic gate designed to limit off-tumor toxicity through dual tumor antigen recognition and a dual shRNA-miR to resist TME suppression and improve ICT cell function and persistence. The AB-1015 DNA cassette is inserted into the T cell genome at a defined novel genomic site via CRISPR-based gene editing. The AB-1015 logic gate consists of a priming receptor that induces expression of an anti-mesothelin (MSLN) CAR upon engagement of a ALPG/P (alkaline phosphatase germ-line/placental). The dual-antigen specificity of the logic gate was assessed in mice engrafted with MSLN+ and ALPG/P+MSLN+ K562 tumors established on contralateral flanks. AB-1015 ICT cells eliminated ALPG/P+MSLN+ tumors, while sparing tumors that lacked ALPG/P. To assess the ability of AB-1015 to mediate killing of MSLN+ tumor cells in the context of heterogeneous cultures, we utilized an admixed co-culture system where ALPG/P+ target cells were spiked into cultures that were otherwise MSLN+. AB-1015 was able to eliminate admixed co-cultures where as few as 5-15% of the target cells expressed ALPG/P.The AB-1015 also contains a dual shRNA-miR that targets FAS and PTPN2, two critical mediators of T cells survival and function. FASL, the cognate ligand for FAS receptor, is expressed on the surface of activated T cells and is significantly overexpressed in the ovarian cancer TME. In vitro, AB-1015 demonstrated resistance to FAS-mediated apoptosis. Knockdown of PTPN2, a phosphatase involved in T cell proliferation and functional persistence, resulted in enhanced AB-1015 ICT cell expansion during repetitive stimulation over a period of 14 days, as well as a 30-fold reduction in tumor outgrowth compared with logic gated T cells alone. In summary, AB-1015 ICT cells are specific for ALPG/P+MSLN+, demonstrate superior potency, expansion, and persistence compared with logic gated T cells alone, and are resistant to ovarian TME suppression. These results support further evaluation of AB-1015 as a novel therapy for indications including ovarian, fallopian tube, or primary peritoneal cancer. Citation Format: Stephen Santoro, Aaron Cooper, Natalie Bezman, Jun Feng, Kanika Chawla, Jennifer McDevitt, Tarjei Mikkelsen, Susie Jun, W. Nicholas Haining. AB-1015, a novel integrated circuit T cells containing an ALPG/MSLN logic gate and FAS/PTPN2 shRNA-miR, demonstrates specific and potent activity against ALPG/MSLN tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 585.

Abstract 2527: Ovarian cancer ascites display altered immune environment featured by enhanced soluble factors and suppressive cellular context

Abstract Background: Tumor microenvironment (TME) of epithelial ovarian cancer is unique among solid tumors as tumor cells create their "malignant ascites" TME. These ascites, acting as a complex mixture of soluble factors and cell components, are known to be rich in macrophages which were suggested to skew to a M2-like phenotype involved in resistance and metastases. However, while macrophages can adopt different phenotypes, it's now postulated that tumor-associated macrophages (TAM) from ovarian cancer patient ascites may even acquire mixed M1/M2 properties, providing a particular pro-inflammatory and tumor-promoting microenvironment. Characterization of cell composition along with the growth factors present in the microenvironment is thus crucial to understand ovarian cancer biology and more particularly the immunosuppressive pathways that would underlie the altered immune cell activity. Methods & Results: Through flow cytometry-based marker expression analysis and quantitation of soluble mediators in ovarian cancer ascites, we investigated here the cell component nature as well as the presence of several growth factors. While these ascites were interestingly enriched in major "immunosuppressive" cell subsets including T and myeloid populations, TAM were intriguingly shown to display a mixed phenotype characterized by high expression of CD163, unrelated to M1/M2 categorization since also expressing Arg1, CD80, and iNOS markers. The immunosuppressive phenotype was also linked to IL6, LIF and IL10 among other factors present in the ascitic environment. In order to assess their role in the occurrence of such an immunosuppressive cell status, soluble mediators were then investigated on healthy monocytes undergoing M1 polarization. We demonstrated that, while LIF did not directly affect IL6 and IL10 levels released by the cells, interestingly IL6 alone or in co-presence with LIF decreased IL6 supernatant content, with respect to the control. These changes were concomitant with a decrease and increase in the expression of CD80 and CD163, respectively. Furthermore, CD14 and CD206 were found to increase in the presence of IL6+/-LIF. Conclusion: All these data highlight a switching activity of IL6 skewing cells from M1 polarization and resulting in a proper macrophage phenotype exhibiting a mixed M1/M2 status and would suggest these ascite-containing factors as keys conferring an immunosuppressive cell phenotype. Altogether, these translational findings highlight ovarian patient-derived ascites as a valuable tool to understand the mechanisms of suppression and to allow for the identification of novel markers to develop innovative targeted therapies. Citation Format: Imane Nafia, Assia Chaibi, Christophe Rey, Jean-Philippe Guegan, Alban Bessede, Coriolan Lebreton, Antoine Italiano. Ovarian cancer ascites display altered immune environment featured by enhanced soluble factors and suppressive cellular context [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2527.

Abstract 4262: Immunotherapy of ovarian cancer targeting FSHR by innate and adaptive immunity

Abstract Ovarian cancer (OC) represents the deadliest gynecologic malignancy. Despite important advances in the field of OC therapy, recurrent OC still has very poor prognosis with a median survival of 1 year. Due to the close interaction between the ovarian cancer cells and tumor microenvironment, development of treatment strategies which not only target the tumor cells but also the components of the tumor microenvironment hold significance. Notably, a prime obstacle in the development of therapies is to identify targets with specific expression limited to the tumor surface and not the healthy tissues. The follicle-stimulating hormone receptor (FSHR) is one such target with selective expression in ovarian granulosa cells and thus, a potentially important therapeutic target in OC. Therefore, we developed monoclonal antibodies against FSHR and focused on studies of the most potent of these reagents. Anti-FSHR antibody bound to diverse FSHR expressing ovarian serous and clear cell adenocarcinoma cells suggesting these antibodies could be used to specifically target OC. We then designed a novel DNA encoded bispecific T cell engager targeting FSHR (FSHRxCD3) and evaluated this bispecific in therapeutic models for the treatment of OC. FSHRxCD3 bispecific in the presence of human PBMCs was highly specific in killing FSHR positive ovarian tumor lines. However, T cell approaches alone may not be fully effective in treating OC, referred as Immunologically “Cold” Tumors. Hence, we hypothesized that engaging the other components of immune system, would provide better tumor control. Increasing lines of evidence suggest that OC is receptive to Natural killer (NK) cell attack. We designed antibodies against human Siglec-7, an inhibitory receptor present on human NK cells and showed they could bind to NK cells. We then used these to create a novel class of bispecific NK engager (NKE) that simultaneously targets both Siglec-7 and FSHR (Siglec-7xFSHR). This NKE was potent at killing FSHR positive OC targets in both in vitro and in vivo assays. Multiple Ovarian tumors including BRCA mutated and PARPi resistant ovarian cancer cells could be targeted by this immune therapy. Our data demonstrate the therapeutic potential of these two novel bispecific molecules and initial studies suggest that their combination may be valuable in patients with OC. Citation Format: Devivasha Bordoloi, Pratik Bhojnagarwala, Abhijeet J. Kulkarni, Opeyemi S. Adeniji, Alfredo Perales-Puchalt, Ryan P. O’Connell, Xizhou Zhu, Elizabeth M. Parzych, Rugang Zhang, Mohamed Abdel-Mohsen, David B. Weiner. Immunotherapy of ovarian cancer targeting FSHR by innate and adaptive immunity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 4262.

The Role of Cancer-Associated Fibroblasts in Ovarian Cancer.

Simple SummaryOvarian cancer is a lethal gynecologic tumor and is generally resistant to conventional treatments. Stable cancer-associated fibroblasts (CAFs) are important cellular components in the ovarian cancer tumor microenvironment and may provide novel resources for future treatment strategies. Different subtypes of CAFs display specific functions in tumor pathogenesis and various CAF markers suggest potential treatment targets. Several clinical or preclinical trials have targeted stromal fibroblasts and focused on the properties of CAFs to enhance ovarian cancer treatment efficacy. This review concentrates on the origins, subtypes, and activation of CAFs, as well as specific roles of CAFs in regulating tumor development and drug resistance, and aims to provide potential and prospective targets for improving the therapeutic efficacy of ovarian cancer treatment.Ovarian cancer is a lethal gynecologic tumor and is generally resistant to conventional treatments. Stable cancer-associated fibroblasts (CAFs) are important cellular components in the ovarian cancer tumor microenvironment and may provide novel resources for future treatment strategies. Different subtypes of CAFs display specific functions in tumor pathogenesis and various CAF markers suggest potential treatment targets, such as FAP and GPR77. Both autocrine and paracrine cytokines play important roles in the CAF activation process and regulate tumor progression. Downstream mediators and pathways, including IL-6, TGF-β, NF-κB, mitogen-activated protein kinase (MAPK), and AKT/mTOR/(p70S6K), play important roles in the initiation, proliferation, invasiveness, and metastasis of ovarian cancer cells and also participate in angiogenesis, therapeutic resistance, and other biological processes. Several clinical or preclinical trials have targeted stromal fibroblasts and focused on the properties of CAFs to enhance ovarian cancer treatment outcomes. This review concentrates on the origins, subtypes, and activation of CAFs, as well as specific roles of CAFs in regulating tumor development and drug resistance, and aims to provide potential and prospective targets for improving the therapeutic efficacy of ovarian cancer treatment.

Regulatory Role of the Adipose Microenvironment on Ovarian Cancer Progression

Simple SummaryAdipocytes or fat cells are integral part of the ovarian tumor microenvironment. Secreted factors from adipocytes, as well as direct cell-to-cell interaction with ovarian cancer cells have been shown to directly support ovarian tumor progression. Elucidating the molecular pathways involved is crucial in the identification of relevant targets.The tumor microenvironment of ovarian cancer is the peritoneal cavity wherein adipose tissue is a major component. The role of the adipose tissue in support of ovarian cancer progression has been elucidated in several studies from the past decades. The adipocytes, in particular, are a major source of factors, which regulate all facets of ovarian cancer progression such as acquisition of chemoresistance, enhanced metastatic potential, and metabolic reprogramming. In this review, we summarize the relevant studies, which highlight the role of adipocytes in ovarian cancer progression and offer insights into unanswered questions and possible future directions of research.

Ovarian cancer-specific dysregulated genes with prognostic significance: scRNA-Seq with bulk RNA-Seq data and experimental validation.

A major cause of gynecological cancer -related deaths worldwide, ovarian cancer is characterized by heterogeneity in both tumor cells and the tumor microenvironment (TME). Our study aimed to characterize tumor cell heterogeneity and the infiltration of M2 tumor-associated macrophages (TAMs) in the ovarian cancer TME by single-cell RNA-Seq (scRNA-Seq) analysis combined with bulk RNA sequencing (bulk RNA-Seq). Several highly variable genes were identified in ovarian cancer tissues, and tumor cell heterogeneity and infiltrating immune tumor cell heterogeneity were characterized in ovarian cancer cells. M2 TAMs in the TME were the predominant phenotype of TAM. Further, M2 TAM infiltration in the TME was negatively correlated with poor prognosis of ovarian cancer patients. Four M2 TAM-associated genes (SLAMF7, GNAS, TBX2-AS1, and LYPD6) correlated with the prognostic survival of ovarian cancer patients. Knockdown of SLAMF7 or GNAS mRNA repressed malignancy and cisplatin resistance of ovarian cancer cells. ScRNA-Seq combined with bulk RNA-Seq identified the same four genes associated with M2 TAMs. The prognostic risk score model based on these four genes may hold favorable predictive value for the prognosis of ovarian cancer patients.

Genomic Instability Is Defined by Specific Tumor Microenvironment in Ovarian Cancer: A Subgroup Analysis of AGO OVAR 12 Trial.

Simple SummaryGiven the importance of genomic instability signatures in the management of ovarian cancer and the difficulties in defining the role of immunotherapy, our objective was to describe the tumor immune microenvironment in the light of genomic instability signatures. Intratumoral CD3+ T lymphocytes confirmed its prognostic value. HLA-E appears to be a robust prognostic biomarker and preferentially overexpressed in homologous recombination deficiency (HRD) ovarian cancers. Our data provide a rationale for future immunotherapy strategies targeting the inhibitory CD94/NKG2A receptor of HLA-E in HRD tumors.Background: Following disappointing results with PD-1/PD-L1 inhibitors in ovarian cancer, it is essential to explore other immune targets. The aim of this study is to describe the tumor immune microenvironment (TME) according to genomic instability in high grade serous ovarian carcinoma (HGSOC) patients receiving primary debulking surgery followed by carboplatin-paclitaxel chemotherapy +/− nintedanib. Methods: 103 HGSOC patients’ tumor samples from phase III AGO-OVAR-12 were analyzed. A comprehensive analysis of the TME was performed by immunohistochemistry on tissue microarray. Comparative genomic hybridization was carried out to evaluate genomic instability signatures through homologous recombination deficiency (HRD) score, genomic index, and somatic copy number alterations. The relationship between genomic instability and TME was explored. Results: Patients with high intratumoral CD3+ T lymphocytes had longer progression-free survival (32 vs. 19.6 months, p = 0.009) and overall survival (OS) (median not reached). High HLA-E expression on tumor cells was associated with a longer OS (median OS not reached vs. 52.9 months, p = 0.002). HRD profile was associated with high HLA-E expression on tumor cells and an improved OS. In the multivariate analysis, residual tumor, intratumoral CD3, and HLA-E on tumor cells were more predictive than other parameters. Conclusions: Our results suggest HLA-E/CD94-NKG2A/2C is a potential immune target particularly in the HRD positive ovarian carcinoma subgroup.

Fatty Acid Metabolism in Ovarian Cancer: Therapeutic Implications.

Ovarian cancer is the most malignant gynecological tumor. Previous studies have reported that metabolic alterations resulting from deregulated lipid metabolism promote ovarian cancer aggressiveness. Lipid metabolism involves the oxidation of fatty acids, which leads to energy generation or new lipid metabolite synthesis. The upregulation of fatty acid synthesis and related signaling promote tumor cell proliferation and migration, and, consequently, lead to poor prognosis. Fatty acid-mediated lipid metabolism in the tumor microenvironment (TME) modulates tumor cell immunity by regulating immune cells, including T cells, B cells, macrophages, and natural killer cells, which play essential roles in ovarian cancer cell survival. Here, the types and sources of fatty acids and their interactions with the TME of ovarian cancer have been reviewed. Additionally, this review focuses on the role of fatty acid metabolism in tumor immunity and suggests that fatty acid and related lipid metabolic pathways are potential therapeutic targets for ovarian cancer.

Overexpression of CAPG Is Associated with Poor Prognosis and Immunosuppressive Cell Infiltration in Ovarian Cancer.

Historically, immunotherapies have only resulted in a partial response from patients with advanced ovarian cancer, resulting in poor clinical efficacy. A full understanding of immune-related gene expression and immunocyte infiltration in ovarian cancer would be instrumental for the improved implementation of immunotherapy. The Capping Actin Protein, Gelsolin-Like (CAPG) gene encodes an actin-regulatory protein, which plays important roles in tumor progression and immune regulation. This study is aimed at identifying the potential therapeutic and prognostic roles of CAPG in ovarian cancer. CAPG expression and clinical information were investigated in the data collected from TCGA, Oncomine, GEPIA, UALCAN, and Kaplan-Meier plotter. CAPG coexpression networks were evaluated by LinkedOmics, GeneMANIA, and NetworkAnalyst. The correlation of CAPG with immune infiltrates was analyzed via TIMER, ImmuCellAI, and GEPIA. Our result showed that patients with high tumoral CAPG expression had significantly shorter 5-year overall survival. Functional enrichment analysis indicated that CAPG-related phenotypes were largely involved in inflammatory response, chemokine and cytokine signaling, cell adhesion, and Toll-like receptor signaling pathways. CAPG expression was positively correlated with infiltrating levels of regulatory T cells (Tregs), tumor-associated macrophages (TAMs), and exhausted T cells (Texs) while being negatively correlated with infiltrating levels of natural killer T cells (NKTs) and neutrophils in ovarian cancer. Moreover, the expression of FOXP3, CD25, CD127, CCR8, and TGFβ in respect to Tregs; CCL2 and CD68 in respect to TAM; CD163, VSIG4, and MS4A4A in respect to M2 macrophages; CD33 and CD11b in respect to myeloid-derived suppressor cells (MDSCs); and PD1, CTLA4, LAG3, TIM3, GZMB, 2B4, and TIGIT in respect to Texs was significantly correlated with CAPG expression in ovarian cancer. These findings suggest that CAPG may contribute to the immunosuppressive tumor microenvironment in ovarian cancer, leading to an exhausted T cell phenotype and tumor progression. Therefore, CAPG can be used as a potential biomarker for determining prognosis and immunotherapy effectiveness in ovarian cancer.

Integrated analysis of prognostic immune-related genes in the tumor microenvironment of ovarian cancer.

BackgroundOvarian cancer (OC) is a major cause of most gynecological cancer deaths, and the rates of incidence and mortality are increasing worldwide. However, factors in the tumor microenvironment (TME) related to OC and certain prognostic markers of OC are still unknown. We aimed to identify biomarkers connected to prognostic immunity based on clinical patients’ data from The Cancer Genome Atlas (TCGA).MethodsWe used the ESTIMATE algorithm to compute the immune and matrix scores of OC patients from TCGA. Next, differentially expressed genes (DEGs) according to the immune and matrix scores were obtained. Subsequently, genes (GZMB, C2orf37, CXCL13, and UBD) connected with prognostic immunity were determined. Moreover, functional enrichment analysis and the protein-protein interaction network showed that these genes were enriched in many biological processes related to immune function. The Tumor Immune Estimation Resource (TIMER) algorithm was also used to analyze the immune prognostic genes according to six immuno-infiltrating cells.ResultsAccording to high/low immune-scores and matrix-score groups, 682 common genes were identified, within 420 upregulated genes and 262 downregulated genes. Gene ontology (GO) analysis of biological process primarily enriched in T cell activation, regulation of lymphocyte activation and lymphocyte differentiation. OS analysis showed 45 genes (6.6%) were relevant in the final results. The Kaplan-Meier plotter database verified the top 10 genes related to prognosis, but only GZMB, C2orf37, CXCL13 and UBD were related to overall survival (OS).ConclusionsGZMB, CXCL13, and UBD may influence prognosis via their effects on the infiltration of immune cells and therefore represent potential targets for OC immunotherapy.