Tumor microenvironment in ovarian cancer peritoneal metastasis

THEMIS2 contributes to ovarian cancer metastasis via DOCK4-mediated activation of Rap1 signaling

PURPOSE

Ovarian cancer (OC) is the most lethal gynecological malignancy, with widespread metastasis and ascites being the leading causes of patient mortality. However, the mechanisms driving OC metastasis have not been sufficiently studied. This study aimed to investigate the mechanisms and key molecules promoting OC metastasis.

METHODS

Public databases (StemChecker, GeneCards, GEO, and TCGA) were screened to identify metastasis-associated genes. Immunohistochemical staining and western blotting were employed to evaluate THEMIS2 expression and epithelial-mesenchymal transition (EMT) marker profiles across experimental groups. RNA sequencing coupled with pathway enrichment analysis revealed THEMIS2-regulated signaling pathways, while immunoprecipitation-mass spectrometry was utilized to identify THEMIS2 interaction partners. GST pull-down assays for active Rap1 quantified Rap1-GTP levels under varying THEMIS2 expression conditions. Wound healing and transwell invasion assays respectively assessed migratory and invasive capacities of OC cells following THEMIS2 expression perturbations in vitro. Abdominal cavity implantation metastasis model was established to evaluate OC cell colonization and invasive potential in vivo.

RESULTS

THEMIS2 expression is significantly elevated in OC tissues compared to normal ovarian tissues, and its high expression correlates with poor prognosis and malignant features. Experimental manipulation of THEMIS2 levels revealed that knockdown impended the migratory and invasive capacities of OC cells both in vitro and in vivo, while its overexpression exacerbated metastasis. THEMIS2 is involved in EMT and cytoskeleton rearrangement. RNA-seq analysis revealed that THEMIS2 positively correlates with Rap1 signaling pathway. Inhibition of Rap1 activity reversed the metastasis-promoting effects induced by THEMIS2 overexpression both in vitro and in vivo. Mechanistically, we uncovered that THEMIS2 functions as a molecular scaffold that recruits TBK1 (TANK Binding Kinase 1) to DOCK4 (Dedicator of Cytokinesis 4), facilitating site-specific phosphorylation at serine 1787 (S1787). This post-translational modification enables DOCK4 to engage with CRKII, subsequently triggering Rap1 signaling activation. These findings suggest that THEMIS2 promotes the metastatic potential of OC cells via DOCK4-mediated activation of Rap1 signaling.

CONCLUSION

THEMIS2 may serve as a predictive biomarker for OC prognosis, and targeting the Rap1 signaling pathway with specific inhibitors represents a promising therapeutic strategy for OC treatment.

Inhibition of Ovarian Cancer Growth, Metastasis and Reverse the Tumor Microenvironment by Dual Drug-Loaded Polymer Micelle Targeting Tumor Microenvironment

Introduction

Ovarian cancer is a malignant tumor that arises in the female reproductive system and is associated with a very high mortality rate. This is primarily due to the highly invasive nature of metastasis and recurrence. Transforming the immune environment from an immunosuppressive state to an anti-tumor state through the phenotypic transformation of tumor-associated macrophages is crucial for inhibiting the growth, metastasis, and recurrence of ovarian cancer.

Methods

A polymer micelle (RC-PH-Ms) containing paclitaxel (PTX) and honokiol (HNK) was designed based on high expression of reactive oxygen species in the tumor microenvironment. Once the micelles are actively targeted to the tumor microenvironment characterized by elevated levels of reactive oxygen species, the responsive bond is cleaved, thereby exposing the secondary targeting ligand C7R. The released PTX and HNK facilitate the transformation of relevant macrophages in the tumor microenvironment from an M2 phenotype to an M1 phenotype, which in turn inhibits tumor growth, invasion and metastasis, inhibit angiogenesis and reduce tumor recurrence.

Results

The effects of RC-PH-Ms on modulating the immune microenvironment and inhibiting tumor growth, invasion and metastasis, vascularization and recurrence were investigated both in vivo and in vitro.

Conclusion

RC-PH-Ms can significantly inhibit the metastasis and recurrence of ovarian cancer, which provides a new perspective for clinical treatment.

Repurposing the anti-parasitic agent pentamidine for cancer therapy; a novel approach with promising anti-tumor properties

Pentamidine (PTM) is an aromatic diamidine administered for infectious diseases, e.g. sleeping sickness, malaria, and Pneumocystis jirovecii pneumonia. Due to similarities of cellular mechanisms between human cells and such infections, PTM has also been proposed for repurposing in non-infectious diseases such as cancer. Indeed, by modulating different signaling pathways such as PI3K/AKT, MAPK/ERK, p53, PD-1/PD-L1, etc., PTM has been shown to inhibit different properties of cancer, including proliferation, invasion, migration, hypoxia, and angiogenesis, while inducing anti-tumor immune responses and apoptosis. Given the promising implications of PTM for cancer treatment, however, the clinical translation of PTM in cancer is not without certain challenges. In fact, clinical trials have shown that systemic administration of PTM can be concurrent with serious adverse effects, e.g. hypoglycemia. Therefore, to reduce the administered doses of PTM, lower the risk of adverse effects, and prevent any potential drug resistance, while maintaining the anti-tumor efficacy, two main strategies have been suggested. One is combination therapy that employs PTM in conjunction with other anti-cancer modalities, such as chemotherapy and radiotherapy, and attacks tumor cells with significant additive or synergistic anti-tumor effects. The other is developing PTM-loaded nanocarrier drug delivery systems e.g. pegylated liposomes, chitosan-coated niosomes, squalene-based nanoparticles, hyaluronated lipid-polymer hybrid nanoparticles, etc., that offer enhanced pharmacokinetic characteristics, including increased bioavailability, sit-targeting, and controlled/sustained drug release. This review highlights the anti-tumor properties of PTM that favor its repurposing for cancer treatment, as well as, PTM-based combination therapies and nanocarrier delivery systems which can enhance therapeutic efficacy and simultaneously reduce toxicity.

Cancer-Associated Fibroblasts in Intrahepatic Cholangiocarcinoma: Insights into Origins, Heterogeneity, Lymphangiogenesis, and Peritoneal Metastasis

Intrahepatic cholangiocarcinoma (iCCA) denotes a rare, highly malignant, and heterogeneous class of primary liver adenocarcinomas exhibiting phenotypic characteristics of cholangiocyte differentiation. Among the distinctive pathological features of iCCA, one that differentiates the most common macroscopic subtype (eg, mass-forming type) of this hepatic tumor from conventional hepatocellular carcinoma is a prominent desmoplastic reaction manifested as a dense fibro-collagenous-enriched tumor stroma. Cancer-associated fibroblasts (CAFs) represent the most abundant mesenchymal cell type in the desmoplastic reaction. Although the protumor effects of CAFs in iCCA have been increasingly recognized, more recent cell lineage tracing studies, advanced single-cell RNA sequencing, and expanded biomarker analyses have provided new awareness into their ontogeny, as well as underscored their biological complexity as reflected by the presence of multiple subtypes. In addition, evidence supports CAFs' potential to display cancer-restrictive roles, including immunosuppression. However, CAFs also play important roles in facilitating metastasis, as exemplified by lymph node metastasis and peritoneal carcinomatosis, which are common in iCCA. Herein, the authors provide a timely appraisal of the origins and phenotypic and functional complexity of CAFs in iCCA, together with providing mechanistic insights into lymphangiogenesis and peritoneal metastasis relevant to this lethal human cancer.

PLIN2 Promotes Lipid Accumulation in Ascites-Associated Macrophages and Ovarian Cancer Progression by HIF1α/SPP1 Signaling

A major characteristic of ovarian cancer (OC) is its unique route of metastasis via ascites. The immune microenvironment in ascites remains understudied, leaving the mechanism of ascites-mediated abdominal metastasis obscure. Here, a single-cell transcriptomic landscape of CD45+ immune cells across multiple anatomical sites is depicted, including primary tumors, metastatic lesions, and ascites, from patients diagnosed with high-grade serous ovarian carcinoma (HGSOC). A novel subset of perilipin 2 high (PLIN2hi) macrophages are identified that are enriched in ascites and positively correlated with OC progression, hence being designated as "ascites-associated macrophages (AAMs)". AAMs are lipid-loaded with overexpression of the lipid droplet protein PLIN2. Overexpression or suppression of PLIN2 can enhance or inhibit tumor cell migration, invasion, and vascular permeability in vitro, which is also confirmed in vivo. Mechanistically, it is demonstrated that PLIN2 boosts HIF1α/SPP1 signaling in macrophages, thereby exerting pro-tumor functions. Finally, a PLIN2-targeting liposome is designed to efficiently suppress ascites production and tumor metastasis. Taken together, this work provides a comprehensive characterization of the cancer-promoting function and lipid-rich property of ascites-enriched PLIN2hi macrophages, establishes a link between lipid metabolism and hypoxia within the context of the ascites microenvironment, and elucidates the pivotal role of ascites in trans-coelomic metastasis of OC.

Advanced Therapeutic Approaches for Metastatic Ovarian Cancer

Ovarian cancer is the fifth leading cause of cancer-related death among women, which is one of the most common gynecological cancers worldwide. Although several cytoreductive surgeries and chemotherapies have been attempted to address ovarian cancer, the disease still shows poor prognosis and survival rates due to prevalent metastasis. Peritoneal metastasis is recognized as the primary route of metastatic progression in ovarian cancer. It causes severe symptoms in patients, but it is generally difficult to detect at an early stage. Current anti-cancer therapy is insufficient to completely treat metastatic ovarian cancer due to its high rates of recurrence and resistance. Therefore, developing strategies for treating metastatic ovarian cancer requires a deeper understanding of the tumor microenvironment (TME) and the identification of effective therapeutic targets through precision oncology. Given that various signaling pathways, including TGF-β, NF-κB, and PI3K/AKT/mTOR pathways, influence cancer progression, their activity and significance can vary depending on the cancer type. In ovarian cancer, these pathways are particularly important, as they not only drive tumor progression but also impact the TME, which contributes to the metastatic potential. The TME plays a critical role in driving metastatic features in ovarian cancer through altered immunologic interactions. Recent therapeutic advances have focused on targeting these distinct features to improve treatment outcomes. Deciphering the complex interaction between signaling pathways and immune populations contributing to metastatic ovarian cancer provides an opportunity to enhance anti-cancer efficacy. Hereby, this review highlights the mechanisms of signaling pathways in metastatic ovarian cancer and immunological interactions to understand improved immunotherapy against ovarian cancer.

The Role of Douglasectomy Instead of Random Biopsies in the Surgical Treatment of Presumed FIGO Stage I Ovarian Cancer

Background/Objectives: Douglasectomy is defined as the removal of the pelvic peritoneum of the entire pouch of Douglas. In presumed FIGO stage I ovarian cancer, isolated microscopic cancer cells might disseminate from the ovaries to their neighboring pelvic peritoneum. However, a simple hysterectomy with bilateral salpingo-oophorectomy and a staging procedure is the standard of care. This study aims to investigate the safety and feasibility of douglasectomy compared to random pelvic biopsies, and it is based on the survival of patients with early ovarian cancer. Methods: We retrospectively analyzed the records of patients with presumed 2018 FIGO stage I ovarian cancer who underwent surgery in the 1st Department of Obstetrics and Gynecology Clinic from 2012 to 2022. Patient characteristics and oncological and follow-up information were collected. Results: A total of 88 patients were categorized into two groups, namely Group A (27 patients) with douglasectomy and Group B (61 patients) with random biopsies. There was no statistically significant difference in age, BMI, comorbidities, FIGO stage, intraoperative blood loss, and ICU admittance between the two groups. Conversely, patients with en bloc hysterectomy-douglasectomy had statistically significant higher pre-operative CA-125 values, surgery duration, rate of postoperative complications, and hospital stay. Concerning survival rates, there was a statistically significant difference in disease-free survival (p = 0.033), but no difference was observed in overall survival (p = 0.66). Conclusions: En bloc removal of the pelvic peritoneum of the entire pouch of Douglas with the uterus is a safe and feasible technique during surgery for early ovarian cancer, which leads to improved disease-free survival and local control.

Similarities in Mechanisms of Ovarian Cancer Metastasis and Brain Glioblastoma Multiforme Invasion Suggest Common Therapeutic Targets

Epithelial-to-mesenchymal transition (EMT) is a critical process in malignant ovarian cancer metastasis. EMT involves the conversion of epithelial cells to mesenchymal cells, conferring enhanced migratory and invasive capabilities. Glioblastoma multiforme (GBM) is the most common malignant primary brain tumor and exhibits an aggressive invasive phenotype that mimics some steps of EMT but does not undergo true metastasis, i.e., the invasion of other organ systems. This study conducts a comparative genomic analysis of EMT in ovarian cancer and invasion in GBM-two malignancies characterized by poor prognosis and limited therapies. Investigating the molecular biology in ovarian cancer and GBM demonstrates shared mechanisms of tumor progression, such as similar genetic and molecular pathways influencing cell plasticity, invasion, and resistance to therapy. The comparative analysis reveals commonalities and differences in the regulatory networks and gene expression profiles associated with EMT and invasion in these cancers. Key findings include the identification of core EMT regulators, such as TWIST1, SNAIL, and ZEB1, which are upregulated in both ovarian cancer and GBM, promoting mesenchymal phenotypes and metastasis. Additionally, the analysis uncovers EMT-related pathways, such as the PI3K/AKT and TGF-β signaling, which are critical in both cancers but exhibit distinct regulatory dynamics. Understanding the intricacies of EMT in ovarian cancer and invasion in GBM provides valuable insights into their aggressive behavior and identifies potential common therapeutic targets. The findings stress the importance of targeting EMT/invasion transitions to develop effective treatments to halt progression and improve patient outcomes in these malignancies.

Adipocyte-derived CXCL10 in obesity promotes the migration and invasion of ovarian cancer cells

BACKGROUND

As a widespread epidemic, obesity poses a significant risk to health and leads to physiological abnormalities, including diabetes mellitus and inflammation. Obesity-induced inflammation can accelerate the development of various cancers; however, the role of obesity in the migration of ovarian carcinoma is still unclear.

RESULTS

Twenty-four commonly upregulated genes were identified from single-cell RNA sequencing datasets of both ovarian carcinoma and adipose tissue of obese humans, with the chemokine CXCL10 showing a significant increase in adipose tissues associated with obesity. And CXCL10 treated primed macrophages exhibit both direct and indirect effects on the proliferation, apoptosis, migration, and invasion of ovarian adenocarcinoma cells. The treatment of CXCL10 on the SKOV3 cells enhances FAK expression and phosphorylation, thereby accelerating the migration and invasion of ovarian cancer cells. Conditioned medium-derived from CXCL10-treated THP-1 cells significantly promoted ovarian cancer cell migration and invasion, which may be attributed to the increased expression of C1QA, C1QC, CCL24, and IL4R in macrophages.

CONCLUSIONS

Obesity exacerbates the production of CXCL10 from adipose tissues in obese women. CXCL10 is a key hub factor between developments of ovarian cancer and adipose tissues in obese. Targeting adipose-derived CXCL10 or its downstream macrophages may be a potential strategy to alleviate ovarian cancer accompanied by obesity.

Is There a Correlation Between Platelet Count, Mesenteric Lymph Node Involvement, and Hematogenous Metastases in Advanced Stage Ovarian Cancer?

BACKGROUND/AIM

Ovarian cancer remains a major cause of death in women worldwide, mainly due to late diagnosis and the lack of a reliable screening test for early detection of the disease. In this context, attention has been focused on the identification of other prognostic factors that might allow a better identification of cases with worse long-term outcome.

PATIENTS AND METHODS

Data of patients who underwent cytoreductive surgery between 2014-2019 were retrospectively reviewed and 57 patients were considered eligible for this study. These cases were further classified according to preoperative platelet count, with a cut-off value of 335,000/μl as a positive predictive value for long-term survival.

RESULTS

According to this value, there were 27 cases with a preoperative platelet count lower than 335,000/μl and 30 cases with a preoperative platelet count higher than 335,000/μl. Cases in the second group had a significantly higher peritoneal carcinomatosis index (p=0.002), a higher proportion of digestive serosa involvement (p<0.001), and a higher proportion of mesenteric lymph node involvement and hematogenous metastases (p=0.005 and p=0.001, respectively). When analyzing long-term outcomes, all these factors had a significant impact on overall survival.

CONCLUSION

Preoperative thrombocytosis appears to be positively associated with gastrointestinal serosa involvement, mesenteric lymph node invasion, and the presence of hematogenous metastases, thus significantly influencing the long-term outcome of patients with advanced ovarian cancer.

Role of exosomal non‑coding RNAs in ovarian cancer (Review)

Ovarian cancer (OC) is a common gynecological disease with a high mortality rate worldwide due to its insidious nature and undetectability at an early stage. The standard treatment, combining platinum‑based chemotherapy with cytoreductive surgery, has suboptimal results. Therefore, early diagnosis of OC is crucial. All cell types secrete extracellular vesicles, particularly exosomes. Exosomes, which contain lipids, proteins, DNA and non‑coding RNAs (ncRNAs), are novel methods of intercellular communication that participate in tumor development and progression. ncRNAs are categorized by size into long ncRNAs (lncRNAs) and small ncRNAs (sncRNAs). sncRNAs further include transfer RNAs, small nucleolar RNAs, PIWI‑interacting RNAs and microRNAs (miRNAs). miRNAs inhibit protein translation and promote messenger RNA (mRNA) cleavage to suppress gene expression. By sponging downstream miRNAs, lncRNAs and circular RNAs can regulate target gene expression, thereby weakening the interactions between miRNAs and mRNAs. Exosomes and exosomal ncRNAs, commonly present in human biological fluids, are promising biomarkers for OC. The present article aimed to review the potential role of exosomal ncRNAs in the diagnosis and prognosis of OC by summarizing the characteristics, processes, roles and isolation methods of exosomes and exosomal ncRNAs.

Malignancy of Malignant Ascites: A Comprehensive Review of Interplay between Biochemical Variables, Tumor Microenvironment and Growth Factors

Malignant ascites, a buildup of fluid in the abdominal cavity, is a serious consequence of many malignancies. This review aims to comprehend the biochemical makeup of malignant ascites, such as pH, cholesterol, protein, etc., which is crucial to developing therapeutics with better treatment outcomes and hence correlate with corresponding prognostic value. The unique tumour microenvironment exhibited by malignant ascites and the crosstalk between inflammatory cells, cytokines and chemokines, interactions between tumour and non-tumour cell types, activation of vital cell signalling pathways within the TME for VEGF-regulated sustained angiogenesis, cancer progression and metastasis is highlighted. This review addresses the need to develop comprehensive assay platforms to identify various biochemical aspects of ascites, to discover the interactions of the tumour microenvironment and to study VEGF-regulated permeability that can expedite early diagnosis and progression of ascites.

Cationic liposomes overcome neutralizing antibodies and enhance reovirus efficacy in ovarian cancer

Reovirus (Reo) has shown promising potential in specifically killing tumor cells, and offering new possibilities for ovarian cancer (OC) treatment. However, neutralizing antibodies in the ascites from OC patients greatly limit the further application of Reo. In this study, we employed cationic liposomes (Lipo) to deliver Reo, significantly enhancing its ability to enter OC cells and its effectiveness in killing these cells under ascitic conditions. Pre-treatment with the MβCD inhibitor notably decreased Reo-mediated tumor cell death, indicating that Lipo primarily enables Reo's cellular uptake through caveolin-mediated endocytosis. Our results demonstrate that Lipo effectively facilitates the entry of Reo into the cytoplasm and triggers cell apoptosis. The above findings provide a new strategy to overcome the obstacle of neutralizing antibodies in the clinical application of Reo.

Intraperitoneal drug delivery systems for peritoneal carcinomatosis: Bridging the gap between research and clinical implementation

Several abdominal-located cancers develop metastasis within the peritoneum, what is called peritoneal carcinomatosis (PC), constituting a clinical challenge in their therapeutical management, often leading to poor prognoses. Current multidisciplinary strategies, including cytoreductive surgery (CRS), hyperthermic intraperitoneal chemotherapy (HIPEC), and pressurized intraperitoneal aerosol chemotherapy (PIPAC), demonstrate efficacy but have limitations. In response, alternative strategies are explored in the drug delivery field for intraperitoneal chemotherapy. Controlled drug delivery offers a promising avenue, maintaining localized drug concentrations for optimal PC management. Drug delivery systems (DDS), including hydrogels, implants, nanoparticles, and hybrid systems, show potential for sustained and region-specific drug release. The present review aims to offer an overview of the advances and current designs of DDS for PC chemotherapy administration, focusing on their composition, main characteristics, and principal experimental outcomes, highlighting the importance of biomaterial rationale design and in vitro/vivo models for their testing. Moreover, since clinical data for human subjects are scarce, we offer a critical discussion of the gap between bench and bedside in DDS translation, emphasizing the need for further research.

Research progress of epithelial-mesenchymal transformation-related transcription factors in peritoneal metastases

Metastasis is the leading cause of mortality in patients with malignant tumors, particularly characterized by peritoneal metastases originating from gastric, ovarian, and colorectal cancers. Regarded as the terminal phase of tumor progression, peritoneal metastasis presents limited therapeutic avenues and is associated with a dismal prognosis for patients. The epithelial-mesenchymal transition (EMT) is a crucial phenomenon in which epithelial cells undergo significant changes in both morphology and functionality, transitioning to a mesenchymal-like phenotype. This transition plays a pivotal role in facilitating tumor metastasis, with transcription factors being key mediators of EMT's effects. Consequently, we provide a retrospective summary of the efforts to identify specific targets among EMT-related transcription factors, aimed at modulating the onset and progression of peritoneal metastatic cancer. This summary offers vital theoretical underpinnings for developing treatment strategies against peritoneal metastasis.

Cancer metastasis through the lymphatic versus blood vessels

Whether cancer cells metastasize from the primary site to the distant sites via the lymphatic vessels or the blood vessels directly into the circulation is still under intense study. In this review article, we follow the journey of cancer cells metastasizing to the sentinel lymph nodes and beyond to the distant sites. We emphasize cancer heterogeneity and microenvironment as major determinants of cancer metastasis. Multiple molecules have been found to be associated with the complicated process of metastasis. Based on the large sentinel lymph node data, it is reasonable to conclude that cancer cells may metastasize through the blood vessels in some cases but in most cases, they use the sentinel lymph nodes as the major gateway to enter the circulation to distant sites.

CAR-T therapy for ovarian cancer: Recent advances and future directions

Ovarian cancer (OC) is a common gynecological tumor with high mortality, which is difficult to control its progression with conventional treatments and is prone to recurrence. Recent studies have identified OC as an immunogenic tumor that can be recognized by the host immune system. Immunotherapy for OC is being evaluated, but approaches such as immune checkpoint inhibitors have limited efficacy, adoptive cell therapy is an alternative therapy, in which CAR(chimeric antigen receptor)-T therapy has been applied to the clinical treatment of hematological malignancies. In addition, CAR-NK and CAR-macrophage (CAR-M) have also shown great potential in the treatment of solid tumors. Here, we discuss recent advances in preclinical and clinical studies of CAR-T for OC treatment, introduce the efforts made by researchers to modify the structure of CAR in order to achieve effective OC immunotherapy, as well as the research status of CAR-NK and CAR-M, and highlight emerging therapeutic opportunities that can be utilized to improve the survival of patients with OC using CAR-based adoptive cell therapy.

The prion-like protein Doppel: A soluble biomarker steering ovarian cancer's peritoneal to circulatory dissemination

Detecting ovarian cancer (OC) early using existing biomarkers, e.g., cancer antigen 125 (CA125), is challenging due to its ubiquitous expression in many tissues. Doppel, a prion-like protein, expresses in male reproductive organ but absent in female reproductive systems and healthy tissues, but plays an important role in neoangiogenesis. Here, we have shown two platforms, soluble Doppel in sera/ascites and Doppel expressed circulating tumor cells ( Dpl+ CTC) in the whole blood, to detect subsets of epithelial OC (EOC). Increased level of Doppel in the sera of OC patients, in three different cohorts, confirm Doppel as OC specific biomarker. Serum Doppel level distinguishes EOC subtypes and early stages HGSOCs from non-cancerous conditions with high sensitivity and specificity. Stratifying the EOCs based on Doppel level, we categorized them into Doppel-high (Dpl hi ) and Doppel-low (Dpl low ) groups. Using ascites-derived organoids and single cell sequencing of whole ascites of Dpl hi and Dpl low patients, we identify that Doppel induces epithelial-mesenchymal transition (EMT) and creates an immunosuppressive microenvironment, respectively. Doppel levels in the sera/ascites correlate with the changes of Dpl+ CTC number in whole blood, highlighting the association of Doppel-induced EMT with CTC dissemination in circulation. Thus, Doppel-based detection of EOC subtypes could be a promising platform as clinical biomarker and link Doppel-axis with OC dissemination.

Cancer-associated adipocytes in the ovarian cancer microenvironment

The tumor microenvironment (TME) plays a critical role in high energy metabolism during tumorigenesis, progression and metastasis. Among them, adipocytes, as an important component of the TME, can transform into cancer-associated adipocytes (CAAs) through dedifferentiation via interactions with tumor cells. These CAAs provide nutrients, growth factors, cytokines and metabolites to the tumor and later transdifferentiate into other stromal cells at a later stage to alter tumor growth, metastasis and the drug response and ultimately influence the treatment and prognosis of ovarian cancer. This review outlines the physiological functions of CAAs and discusses the progress in the use of CAAs as therapeutic targets in ovarian cancer.

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.

Single-cell transcriptomics reveals the aggressive landscape of high-grade serous carcinoma and therapeutic targets in tumor microenvironment

High-grade serous carcinoma (HGSC) is characterized by early abdominal metastasis, leading to a dismal prognosis. In this study, we conducted single-cell RNA sequencing on 109,573 cells from 34 tumor samples of 18 HGSC patients, including both primary tumors and their metastatic sites. Our analysis revealed a distinct S100A9+ tumor cell subtype present in both primary and metastatic sites, strongly associated with poor overall survival. This subtype exhibited high expression of S100A8, S100A9, ADGRF1, CEACAM6, CST6, NDRG2, MUC4, PI3, SDC1, and C15orf48. Individual knockdown of these ten marker genes, validated through in vitro and in vivo models, significantly inhibited ovarian cancer growth and invasion. Around S100A9+ tumor cells, a population of HK2+_CAF was identified, characterized by activated glycolysis metabolism, correlating with shorter overall survival in patients. Notably, similar to CAFs, immunosuppressive tumor-associated macrophage (TAM) subtypes underwent glycolipid metabolism reprogramming via PPARgamma regulation, promoting tumor metastasis. These findings shed light on the mechanisms driving the aggressiveness of HGSC, offering crucial insights for the development of novel therapeutic targets against this formidable cancer.

ASS1 enhances anoikis resistance via AMPK/CPT1A-mediated fatty acid metabolism in ovarian cancer

Metastasis is the leading cause of death in ovarian carcinoma (OC), whereas anoikis resistance is a critical step for the survival of the detached OC cells. Despite extensive research, targeting anoikis resistance remains a challenge. Here, we first identified that argininosuccinate synthase 1 (ASS1), a key enzyme in urea cycle markedly upregulated in OC cells of detached culture, is associated with increased anoikis resistance and metastasis. Disruption of the AMP/ATP balance by overexpressing ASS1 activates AMPK and the downstream factor CPT1A. Then, we further found that ASS1 enhances FAO, leading to higher ATP generation and lipid utilization. Inhibition of CPT1A reverses the ASS1-induced FAO, which interrupts the AMP/ATP balance and the activation of AMPK. These results extend ASS1's relevance beyond nitrogen and fatty acid metabolisms, and may provide some new insights into OC metabolism and represent a shift from traditional views. In conclusion, our study reveals a mechanism that the ASS1/AMPK/CPT1A axis is crucial for anoikis resistance and metastasis, which may open up a new avenue for the intervention of OC.

GSK3β and UCHL3 govern RIPK4 homeostasis via deubiquitination to enhance tumor metastasis in ovarian cancer

Receptor-interacting protein kinase 4 (RIPK4) is increasingly recognized as a pivotal player in ovarian cancer, promoting tumorigenesis and disease progression. Despite its significance, the posttranslational modifications dictating RIPK4 stability in ovarian cancer remain largely uncharted. In this study, we first established that RIPK4 levels are markedly higher in metastatic than in primary ovarian cancer tissues through single-cell sequencing. Subsequently, we identified UCHL3 as a key deubiquitinase that regulates RIPK4. We elucidate the mechanism that UCHL3 interacts with and deubiquitinates RIPK4 at the K469 site, removing the K48-linked ubiquitin chain and thus enhancing RIPK4 stabilization. Intriguingly, inhibition of UCHL3 activity using TCID leads to increased RIPK4 ubiquitination and degradation. Furthermore, we discovered that GSK3β-mediated phosphorylation of RIPK4 at Ser420 enhances its interaction with UCHL3, facilitating further deubiquitination and stabilization. Functionally, RIPK4 was found to drive the proliferation and metastasis of ovarian cancer in a UCHL3-dependent manner both in vitro and in vivo. Importantly, positive correlations between RIPK4 and UCHL3 protein expression levels were observed, with both serving as indicators of poor prognosis in ovarian cancer patients. Overall, this study uncovers a novel pathway wherein GSK3β-induced phosphorylation of RIPK4 strengthens its interaction with UCHL3, leading to increased deubiquitination and stabilization of RIPK4, thereby promoting ovarian cancer metastasis. These findings offer new insights into the molecular underpinnings of ovarian cancer and highlight potential therapeutic targets for enhancing antitumor efficacy.

Phosphoproteomics Reveals Selective Regulation of Signaling Pathways by Lysophosphatidic Acid Species in Macrophages

Lysophosphatidic acid (LPA) species, prevalent in the tumor microenvironment (TME), adversely impact various cancers. In ovarian cancer, the 18:0 and 20:4 LPA species are selectively associated with shorter relapse-free survival, indicating distinct effects on cellular signaling networks. Macrophages represent a cell type of high relevance in the TME, but the impact of LPA on these cells remains obscure. Here, we uncovered distinct LPA-species-specific responses in human monocyte-derived macrophages through unbiased phosphoproteomics, with 87 and 161 phosphosites upregulated by 20:4 and 18:0 LPA, respectively, and only 24 shared sites. Specificity was even more pronounced for downregulated phosphosites (163 versus 5 sites). Considering the high levels 20:4 LPA in the TME and its selective association with poor survival, this finding may hold significant implications. Pathway analysis pinpointed RHO/RAC1 GTPase signaling as the predominantly impacted target, including AHRGEF and DOCK guanine exchange factors, ARHGAP GTPase activating proteins, and regulatory protein kinases. Consistent with these findings, exposure to 20:4 resulted in strong alterations to the actin filament network and a consequent enhancement of macrophage migration. Moreover, 20:4 LPA induced p38 phosphorylation, a response not mirrored by 18:0 LPA, whereas the pattern for AKT was reversed. Furthermore, RNA profiling identified genes involved in cholesterol/lipid metabolism as selective targets of 20:4 LPA. These findings imply that the two LPA species cooperatively regulate different pathways to support functions essential for pro-tumorigenic macrophages within the TME. These include cellular survival via AKT activation and migration through RHO/RAC1 and p38 signaling.

Knockdown of CENPM activates cGAS-STING pathway to inhibit ovarian cancer by promoting pyroptosis

OBJECTIVE

We aimed to screen novel gene signatures for ovarian cancer (OC) and explore the role of biomarkers in OC via regulating pyroptosis using bioinformatics analysis.

METHODS

Differentially expressed genes (DEGs) of OC were screened from GSE12470 and GSE16709 datasets. Hub genes were determined from protein-protein interaction networks after bioinformatics analysis. The role of Centromeric protein M (CENPM) in OC was assessed by subcutaneous tumor experiment using hematoxylin-eosin and immunohistochemical staining. Tumor metastasis was evaluated by detecting epithelial-mesenchymal transition-related proteins. The proliferation, migration, and invasion were determined using cell counting kit and transwell assay. Enzyme-linked immunosorbent assay was applied to measure inflammatory factors. The mRNA and protein expression were detected using real-time quantitative PCR and western blot.

RESULTS

We determined 9 hub genes (KIFC1, PCLAF, CDCA5, KNTC1, MCM3, OIP5, CENPM, KIF15, and ASF1B) with high prediction value for OC. In SKOV3 and A2780 cells, the expression levels of hub genes were significantly up-regulated, compared with normal ovarian cells. CENPM was selected as a key gene. Knockdown of CENPM suppressed proliferation, migration, and invasion of OC cells. Subcutaneous tumor experiment revealed that CENPM knockdown significantly suppressed tumor growth and metastasis. Additionally, pyroptosis was promoted in OC cells and xenograft tumors after CENPM knockdown. Furthermore, CENPM knockdown activated cGAS-STING pathway and the pathway inhibitor reversed the inhibitory effect of CENPM knockdown on viability, migration, and invasion of OC cells.

CONCLUSION

CENPM was a novel biomarker of OC, and knockdown of CENPM inhibited OC progression by promoting pyroptosis and activating cGAS-STING pathway.

Targeting interleukin-6 as a treatment approach for peritoneal carcinomatosis

Peritoneal carcinomatosis (PC) is a complex manifestation of abdominal cancers, with a poor prognosis and limited treatment options. Recent work identifying high concentrations of the cytokine interleukin-6 (IL-6) and its soluble receptor (sIL-6-Rα) in the peritoneal cavity of patients with PC has highlighted this pathway as an emerging potential therapeutic target. This review article provides a comprehensive overview of the current understanding of the potential role of IL-6 in the development and progression of PC. We discuss mechansims by which the IL-6 pathway may contribute to peritoneal tumor dissemination, mesothelial adhesion and invasion, stromal invasion and proliferation, and immune response modulation. Finally, we review the prospects for targeting the IL-6 pathway in the treatment of PC, focusing on common sites of origin, including ovarian, gastric, pancreatic, colorectal and appendiceal cancer, and mesothelioma.

Deregulated circRNAs in Epithelial Ovarian Cancer With Activity in Preclinical In Vivo Models: Identification of Targets and New Modalities for Therapeutic Intervention

Epithelial ovarian cancer (EOC) is associated with a dismal prognosis due to development of resistance to chemotherapy and metastasis in the peritoneal cavity and distant organs. In order to identify new targets and treatment modalities we searched the literature for up- and and down-regulated circRNAs with efficacy in preclinical EOC-related in vivo systems. Our search yielded circRNAs falling into the following categories: cisplatin and paclitaxel resistance, transmembrane receptors, secreted factors, transcription factors, RNA splicing and processing factors, RAS pathway-related components, proteolysis and cell-cycle regulation, signaling-related proteins, and circRNAs regulating proteins in additional categories. These findings can be potentially translated by validation and manipulation of the corresponding targets, inhibition of circRNAs with antisense oligonucleotides (ASO), small interfering RNAs (siRNA) or small hairpin RNA (shRNA) or by reconstituting their activity.

Sindbis Virus Vaccine Platform: A Promising Oncolytic Virus-Mediated Approach for Ovarian Cancer Treatment

This review article provides a comprehensive overview of a novel Sindbis virus vaccine platform as potential immunotherapy for ovarian cancer patients. Ovarian cancer is the most lethal of all gynecological malignancies. The majority of high-grade serous ovarian cancer (HGSOC) patients are diagnosed with advanced disease. Current treatment options are very aggressive and limited, resulting in tumor recurrences and 50-60% patient mortality within 5 years. The unique properties of armed oncolytic Sindbis virus vectors (SV) in vivo have garnered significant interest in recent years to potently target and treat ovarian cancer. We discuss the molecular biology of Sindbis virus, its mechanisms of action against ovarian cancer cells, preclinical in vivo studies, and future perspectives. The potential of Sindbis virus-based therapies for ovarian cancer treatment holds great promise and warrants further investigation. Investigations using other oncolytic viruses in preclinical studies and clinical trials are also presented.

Mechanisms of carboplatin- and paclitaxel-dependent induction of premature senescence and pro-cancerogenic conversion of normal peritoneal mesothelium and fibroblasts

Carboplatin (CPT) and paclitaxel (PCT) are the optimal non-surgical treatment of epithelial ovarian cancer (EOC). Although their growth-restricting influence on EOC cells is well known, their impact on normal peritoneal cells, including mesothelium (PMCs) and fibroblasts (PFBs), is poorly understood. Here, we investigated whether, and if so, by what mechanism, CPT and PCT induce senescence of omental PMCs and PFBs. In addition, we tested whether PMC and PFB exposure to the drugs promotes the development of a pro-cancerogenic phenotype. The results showed that CPT and PCT induce G2/M growth arrest-associated senescence of normal peritoneal cells and that the strongest induction occurs when the drugs act together. PMCs senesce telomere-independently with an elevated p16 level and via activation of AKT and STAT3. In PFBs, telomeres shorten along with an induction of p21 and p53, and their senescence proceeds via the activation of ERK1/2. Oxidative stress in CPT + PCT-treated PMCs and PFBs is extensive and contributes causatively to their premature senescence. Both PMCs and PFBs exposed to CPT + PCT fuel the proliferation, migration, and invasion of established (A2780, OVCAR-3, SKOV-3) and primary EOCs, and this activity is linked with an overproduction of multiple cytokines altering the cancer cell transcriptome and controlled by p38 MAPK, NF-κB, STAT3, Notch1, and JAK1. Collectively, our findings indicate that CPT and PCT lead to iatrogenic senescence of normal peritoneal cells, which paradoxically and opposing therapeutic needs alters their phenotype towards pro-cancerogenic. It cannot be excluded that these adverse outcomes of chemotherapy may contribute to EOC relapse in the case of incomplete tumor eradication and residual disease initiation. © 2023 The Pathological Society of Great Britain and Ireland.

Neglected Anatomical Areas in Ovarian Cancer: Significance for Optimal Debulking Surgery

Ovarian cancer (OC), the most lethal gynecological malignancy, usually presents in advanced stages. Characterized by peritoneal and lymphatic dissemination, OC necessitates a complex surgical approach usually involving the upper abdomen with the aim of achieving optimal cytoreduction without visible macroscopic disease (R0). Failures in optimal cytoreduction, essential for prognosis, often stem from overlooking anatomical neglected sites that harbor residual tumor. Concealed OC metastases may be found in anatomical locations such as the omental bursa; Morison's pouch; the base of the round ligament and hepatic bridge; the splenic hilum; and suprarenal, retrocrural, cardiophrenic and inguinal lymph nodes. Hence, mastery of anatomy is crucial, given the necessity for maneuvers like liver mobilization, diaphragmatic peritonectomy and splenectomy, as well as dissection of suprarenal, celiac, and cardiophrenic lymph nodes in most cases. This article provides a meticulous anatomical description of neglected anatomical areas during OC surgery and describes surgical steps essential for the dissection of these "neglected" areas. This knowledge should equip clinicians with the tools needed for safe and complete cytoreduction in OC patients.

Ovarian cancer cells regulate their mitochondrial content and high mitochondrial content is associated with a poor prognosis

Most cancer patients ultimately die from the consequences of distant metastases. As metastasis formation consumes energy mitochondria play an important role during this process as they are the most important cellular organelle to synthesise the energy rich substrate ATP, which provides the necessary energy to enable distant metastasis formation. However, mitochondria are also important for the execution of apoptosis, a process which limits metastasis formation. We therefore wanted to investigate the mitochondrial content in ovarian cancer cells and link its presence to the patient's prognosis in order to analyse which of the two opposing functions of mitochondria dominates during the malignant progression of ovarian cancer. Monoclonal antibodies directed against different mitochondrial specific proteins, namely heat shock proteins 60 (HSP60), fumarase and succinic dehydrogenase, were used in immunohistochemistry in preliminary experiments to identify the antibody most suited to detect mitochondria in ovarian cancer cells in clinical tissue samples. The clearest staining pattern, which even delineated individual mitochondria, was seen with the anti-HSP60 antibody, which was used for the subsequent clinical study staining primary ovarian cancers (n = 155), borderline tumours (n = 24) and recurrent ovarian cancers (n = 26). The staining results were semi-quantitatively scored into three groups according to their mitochondrial content: low (n = 26), intermediate (n = 50) and high (n = 84). Survival analysis showed that high mitochondrial content correlated with a statistically significant overall reduced survival rate In addition to the clinical tissue samples, mitochondrial content was analysed in ovarian cancer cells grown in vitro (cell lines: OVCAR8, SKOV3, OVCAR3 and COV644) and in vivo in severe combined immunodeficiency (SCID) mice.In in vivo grown SKOV3 and OVCAR8 cells, the number of mitochondria positive cells was markedly down-regulated compared to the in vitro grown cells indicating that mitochondrial number is subject to regulatory processes. As high mitochondrial content is associated with a poor prognosis, the provision of high energy substrates by the mitochondria seems to be more important for metastasis formation than the inhibition of apoptotic cell death, which is also mediated by mitochondria. In vivo and in vitro grown human ovarian cancer cells showed that the mitochondrial content is highly adaptable to the growth condition of the cancer cells.

The high-grade serous ovarian cancer metastasis and chemoresistance in 3D models

High-grade serous ovarian cancer (HGSOC) is the most frequent and aggressive type of epithelial ovarian cancer, with high recurrence rate and chemoresistance being the main issues in its clinical management. HGSOC is specifically challenging due to the metastatic dissemination via spheroids in the ascitic fluid. The HGSOC spheroids represent the invasive and chemoresistant cellular fraction, which is impossible to investigate in conventional two-dimensional (2D) monolayer cell cultures lacking critical cell-to-cell and cell-extracellular matrix interactions. Three-dimensional (3D) HGSOC cultures, where cells aggregate and exhibit relevant interactions, offer a promising in vitro model of peritoneal metastasis and multicellular drug resistance. This review summarizes recent studies of HGSOC in 3D culture conditions and highlights the role of multicellular HGSOC spheroids and ascitic environment in HGSOC metastasis and chemoresistance.

Adipocyte Microenvironment in Ovarian Cancer: A Critical Contributor?

Ovarian cancer is one of the most common gynecological malignancies and has low survival rates. One of the main determinants of this unfavorable prognosis is the high rate of peritoneal metastasis at diagnosis, closely related to its morbidity and mortality. The mechanism underlying peritoneal carcinomatosis is not clearly defined, but a clear preference for omental spread has been described. Growing evidence suggests that adipose tissue plays a role in promoting cancer onset and progression. Moreover, obesity can lead to changes in the original functions of adipocytes, resulting in metabolic and inflammatory changes in the adipose tissue microenvironment, potentially increasing the risk of tumor growth. However, the specific roles of adipocytes in ovarian cancer have not yet been fully elucidated. Due to the undeniable link between obesity and cancer, the adipose tissue microenvironment could also present a promising therapeutic target that warrants further research. This review discusses the complex relationship between ovarian cancer and the adipose tissue microenvironment.

Aberrant expression of cuproptosis‑related gene LIPT1 is associated with metabolic dysregulation of fatty acid and prognosis in hepatocellular carcinoma

PURPOSE

Lipoyltransferase 1 (LIPT1) has been recently identified as a cuproptosis‑related gene. As a key enzyme of lipoic acid metabolism, LIPT1 has been revealed to play important roles in hereditary diseases involved with lipoic acid biosynthesis defects, while its roles in hepatocellular carcinoma (HCC) remain to be elucidated. Hence, we aimed to explore the roles and mechanisms of LIPT1 in HCC progression.

METHODS

The expression of LIPT1 in HCC tissues and its clinical significance for HCC were evaluated by bioinformatic analysis and in our patient cohort. The influences of LIPT1 on the growth, migration, and lipid metabolism of HCC cells were assessed in vitro. The underlying mechanisms were explored using gene set enrichment analysis (GSEA) and molecular experiments.

RESULTS

LIPT1 expression was significantly elevated in HCC tissues compared to the normal tissues, and such upregulation was associated with more malignant pathological features and poor prognosis of patients with HCC. LIPT1 silencing significantly inhibited cell proliferation, migration, and lipid content. GSEA revealed that LIPT1 upregulation was significantly associated with various cancer-associated signaling pathways, including the PI3K-AKT signaling pathway and the Wnt/β-catenin pathway. Further molecular experiments indicated that LIPT1 silencing repressed the expression of peroxisome proliferator-activated receptor gamma (PPARγ) and inactivated the AKT/GSK-3β/β-catenin signaling axis.

CONCLUSIONS

Upregulation of LIPT1 is involved in metabolic dysregulation of fatty acid and poor prognosis of HCC patients, which suggests that LIPT1 plays an important role in reprogramming lipid metabolism and could act as a potential prognostic marker and therapeutic target for HCC.

Snail transcription factors as key regulators of chemoresistance, stemness and metastasis of ovarian cancer cells

Ovarian cancer is one of the deadliest gynecological malignancies among women. The reason for this outcome is the frequent acquisition of cancer cell resistance to platinum-based drugs and unresponsiveness to standard therapy. It has been increasingly recognized that the ability of ovarian cancer cells to adopt more aggressive behavior (mainly through the epithelial-to-mesenchymal transition, EMT), as well as dedifferentiation into cancer stem cells, significantly affects drug resistance acquisition. Transcription factors in the Snail family have been implicated in ovarian cancer chemoresistance and metastasis. In this article, we summarize published data that reveal Snail proteins not only as key inducers of the EMT in ovarian cancer but also as crucial links between the acquisition of ovarian cancer stem properties and spheroid formation. These Snail-related characteristics significantly affect the ovarian cancer cell response to treatment and are related to the acquisition of chemoresistance.

Image-Based Modeling of Drug Delivery during Intraperitoneal Chemotherapy in a Heterogeneous Tumor Nodule

Intraperitoneal (IP) chemotherapy is a promising treatment approach for patients diagnosed with peritoneal carcinomatosis, allowing the direct delivery of therapeutic agents to the tumor site within the abdominal cavity. Nevertheless, limited drug penetration into the tumor remains a primary drawback of this method. The process of delivering drugs to the tumor entails numerous complications, primarily stemming from the specific pathophysiology of the tumor. Investigating drug delivery during IP chemotherapy and studying the parameters affecting it are challenging due to the limitations of experimental studies. In contrast, mathematical modeling, with its capabilities such as enabling single-parameter studies, and cost and time efficiency, emerges as a potent tool for this purpose. In this study, we developed a numerical model to investigate IP chemotherapy by incorporating an actual image of a tumor with heterogeneous vasculature. The tumor's geometry is reconstructed using image processing techniques. The model also incorporates drug binding and uptake by cancer cells. After 60 min of IP treatment with Doxorubicin, the area under the curve (AUC) of the average free drug concentration versus time curve, serving as an indicator of drug availability to the tumor, reached 295.18 mol·m-3·s-1. Additionally, the half-width parameter W1/2, which reflects drug penetration into the tumor, ranged from 0.11 to 0.14 mm. Furthermore, the treatment resulted in a fraction of killed cells reaching 20.4% by the end of the procedure. Analyzing the spatial distribution of interstitial fluid velocity, pressure, and drug concentration in the tumor revealed that the heterogeneous distribution of tumor vasculature influences the drug delivery process. Our findings underscore the significance of considering the specific vascular network of a tumor when modeling intraperitoneal chemotherapy. The proposed methodology holds promise for application in patient-specific studies.

The Roles of Histone Deacetylases in the Regulation of Ovarian Cancer Metastasis

Ovarian cancer is the most lethal gynecologic malignancy, and metastasis is the major cause of death in patients with ovarian cancer, which is regulated by the coordinated interplay of genetic and epigenetic mechanisms. Histone deacetylases (HDACs) are enzymes that can catalyze the deacetylation of histone and some non-histone proteins and that are involved in the regulation of a variety of biological processes via the regulation of gene transcription and the functions of non-histone proteins such as transcription factors and enzymes. Aberrant expressions of HDACs are common in ovarian cancer. Many studies have found that HDACs are involved in regulating a variety of events associated with ovarian cancer metastasis, including cell migration, invasion, and the epithelial-mesenchymal transformation. Herein, we provide a brief overview of ovarian cancer metastasis and the dysregulated expression of HDACs in ovarian cancer. In addition, we discuss the roles of HDACs in the regulation of ovarian cancer metastasis. Finally, we discuss the development of compounds that target HDACs and highlight their importance in the future of ovarian cancer therapy.

The role of pyroptosis-related lncRNA risk signature in ovarian cancer prognosis and immune system

Ovarian cancer is a leading cause of death in females with gynecologic cancers. Pyroptosis is a relatively new discovered programmed cell death that is believed to be associated with inflammation. However, studies on pyroptosis-related lncRNAs in ovarian cancer are limited. In this study, we identified 29 pyroptosis-related genes and screened out 72 pyroptosis-related lncRNAs. Furthermore, the 72 lncRNAs were eliminated to 2 survival-related lncRNAs using Cox regression and Lasso regression to build an ovarian cancer prognostic prediction signature and were further validated on the test set. We adopted a riskscore from the two-gene signature, and the survival in low-risk group was higher than the high-risk group. Functional enrichment analysis indicated that the differentially expressed genes (DEGs) between two risk groups were associated with tumor immunity. This study implies that pyroptosis-related genes are closely related to tumor immunity and could be potential therapeutic factors for ovarian cancer treatment.

Targeting Oncometabolites in Peritoneal Cancers: Preclinical Insights and Therapeutic Strategies

Peritoneal cancers present significant clinical challenges with poor prognosis. Understanding the role of cancer cell metabolism and cancer-promoting metabolites in peritoneal cancers can provide new insights into the mechanisms that drive tumor progression and can identify novel therapeutic targets and biomarkers for early detection, prognosis, and treatment response. Cancer cells dynamically reprogram their metabolism to facilitate tumor growth and overcome metabolic stress, with cancer-promoting metabolites such as kynurenines, lactate, and sphingosine-1-phosphate promoting cell proliferation, angiogenesis, and immune evasion. Targeting cancer-promoting metabolites could also lead to the development of effective combinatorial and adjuvant therapies involving metabolic inhibitors for the treatment of peritoneal cancers. With the observed metabolomic heterogeneity in cancer patients, defining peritoneal cancer metabolome and cancer-promoting metabolites holds great promise for improving outcomes for patients with peritoneal tumors and advancing the field of precision cancer medicine. This review provides an overview of the metabolic signatures of peritoneal cancer cells, explores the role of cancer-promoting metabolites as potential therapeutic targets, and discusses the implications for advancing precision cancer medicine in peritoneal cancers.