Cellular and molecular processes in ovarian cancer metastasis. A Review in the Theme: Cell and Molecular Processes in Cancer Metastasis

Muscle weakness and mitochondrial stress occur before severe metastasis in a novel mouse model of ovarian cancer cachexia

OBJECTIVES

A high proportion of women with advanced epithelial ovarian cancer (EOC) experience weakness and cachexia. This relationship is associated with increased morbidity and mortality. EOC is the most lethal gynecological cancer, yet no preclinical cachexia model has demonstrated the combined hallmark features of metastasis, ascites development, muscle loss and weakness in adult immunocompetent mice.

METHODS

Here, we evaluated a new model of ovarian cancer-induced cachexia with the advantages of inducing cancer in adult immunocompetent C57BL/6J mice through orthotopic injections of EOC cells in the ovarian bursa. We characterized the development of metastasis, ascites, muscle atrophy, muscle weakness, markers of inflammation, and mitochondrial stress in the tibialis anterior (TA) and diaphragm ∼45, ∼75 and ∼90 days after EOC injection.

RESULTS

Primary ovarian tumour sizes were progressively larger at each time point while severe metastasis, ascites development, and reductions in body, fat and muscle weights occurred by 90 Days. There were no changes in certain inflammatory (TNFα), atrogene (MURF1 and Atrogin) or GDF15 markers within both muscles whereas IL-6 was increased at 45 and 90 Day groups in the diaphragm. TA weakness in 45 Day preceded atrophy and metastasis that were observed later (75 and 90 Day, respectively). The diaphragm demonstrated both weakness and atrophy in 45 Day. In both muscles, this pre-severe-metastatic muscle weakness corresponded with considerable reprogramming of gene pathways related to mitochondrial bioenergetics as well as reduced functional measures of mitochondrial pyruvate oxidation and creatine-dependent ADP/ATP cycling as well as increased reactive oxygen species emission (hydrogen peroxide). Remarkably, muscle force per unit mass at 90 days was partially restored in the TA despite the presence of atrophy and severe metastasis. In contrast, the diaphragm demonstrated progressive weakness. At this advanced stage, mitochondrial pyruvate oxidation in both muscles exceeded control mice suggesting an apparent metabolic super-compensation corresponding with restored indices of creatine-dependent adenylate cycling.

CONCLUSIONS

This mouse model demonstrates the concurrent development of cachexia and metastasis that occurs in women with EOC. The model provides physiologically relevant advantages of inducing tumour development within the ovarian bursa in immunocompetent adult mice. Moreover, the model reveals that muscle weakness in both TA and diaphragm precedes severe metastasis while weakness also precedes atrophy in the TA. An underlying mitochondrial bioenergetic stress corresponded with this early weakness. Collectively, these discoveries can direct new research towards the development of therapies that target pre-atrophy and pre-severe-metastatic weakness during EOC in addition to therapies targeting cachexia.

Injectable Nanocomposite Hydrogels Improve Intraperitoneal Co-delivery of Chemotherapeutics and Immune Checkpoint Inhibitors for Enhanced Peritoneal Metastasis Therapy

Intraperitoneal co-delivery of chemotherapeutic drugs (CDs) and immune checkpoint inhibitors (ICIs) brings hope to improve treatment outcomes in patients with peritoneal metastasis from ovarian cancer (OC). However, current intraperitoneal drug delivery systems face issues such as rapid drug clearance from lymphatic drainage, heterogeneous drug distribution, and uncontrolled release of therapeutic agents into the peritoneal cavity. Herein, we developed an injectable nanohydrogel by combining carboxymethyl chitosan (CMCS) with bioadhesive nanoparticles (BNPs) based on polylactic acid-hyperbranched polyglycerol. This system enables the codelivery of CD and ICI into the intraperitoneal space to extend drug retention. The nanohydrogel is formed by cross-linking of aldehyde groups on BNPs with amine groups on CMCS via reversible Schiff base bonds, with CD and ICI loaded separately into BNPs and CMCS network. BNP/CMCS nanohydrogel maintained the activity of the biomolecules and released drugs in a sustained manner over a 7 day period. The adhesive property, through the formation of Schiff bases with peritoneal tissues, confers BNPs with an extended residence time in the peritoneal cavity after being released from the nanohydrogel. In a mouse model, BNP/CMCS nanohydrogel loaded with paclitaxel (PTX) and anti-PD-1 antibodies (αPD-1) significantly suppressed peritoneal metastasis of OC compared to all other tested groups. In addition, no systemic toxicity of nanohydrogel-loaded PTX and αPD-1 was observed during the treatment, which supports potential translational applications of this delivery system.

Covalent Organic Frameworks as Potential Drug Carriers and Chemotherapeutic Agents for Ovarian Cancers

Anticancer drugs are often associated with limitations such as poor stability in aqueous solutions, limited cell membrane permeability, nonspecific targeting, and irregular drug release when taken orally. One possible solution to these problems is the use of nanocarriers of drug molecules, particularly those with targeting ability, stimuli-responsive properties, and high drug loading capacity. These nanocarriers can improve drug stability, increase cellular uptake, allow specific targeting of cancer cells, and provide controlled drug release. While improving the therapeutic efficacy of cancer drugs, contemporary researchers also aim to reduce their associated side effects, such that cancer patients are offered with a more effective and targeted treatment strategy. Herein, a set of nine porous covalent organic frameworks (COFs) were tested as drug delivery nanocarriers. Among these, paclitaxel loaded in COF-3 was most effective against the proliferation of ovarian cancer cells. This study highlights the emerging potential of COFs in the field of therapeutic drug delivery. Due to their biocompatibility, these porous COFs provide a viable substrate for controlled drug release, making them attractive candidates for improving drug delivery systems. This work also demonstrates the potential of COFs as efficient drug delivery agents, thereby opening up new opportunities in the field of sarcoma therapy.

From monocyte-derived macrophages to resident macrophages-how metabolism leads their way in cancer

Macrophages are innate immune cells that play key roles during both homeostasis and disease. Depending on the microenvironmental cues sensed in different tissues, macrophages are known to acquire specific phenotypes and exhibit unique features that, ultimately, orchestrate tissue homeostasis, defense, and repair. Within the tumor microenvironment, macrophages are referred to as tumor-associated macrophages (TAMs) and constitute a heterogeneous population. Like their tissue resident counterpart, TAMs are plastic and can switch function and phenotype according to the niche-derived stimuli sensed. While changes in TAM phenotype are known to be accompanied by adaptive alterations in their cell metabolism, it is reported that metabolic reprogramming of macrophages can dictate their activation state and function. In line with these observations, recent research efforts have been focused on defining the metabolic traits of TAM subsets in different tumor malignancies and understanding their role in cancer progression and metastasis formation. This knowledge will pave the way to novel therapeutic strategies tailored to cancer subtype-specific metabolic landscapes. This review outlines the metabolic characteristics of distinct TAM subsets and their implications in tumorigenesis across multiple cancer types.

Bone Marrow Mesenchymal Stem Cells Promote Ovarian Cancer Cell Proliferation via Cytokine Interactions

Bone marrow mesenchymal stem cells (BMSCs) are key players in promoting ovarian cancer cell proliferation, orchestrated by the dynamic interplay between cytokines and their interactions with immune cells; however, the intricate crosstalk among BMSCs and cytokines has not yet been elucidated. Here, we aimed to investigate interactions between BMSCs and ovarian cancer cells. We established BMSCs with a characterized morphology, surface marker expression, and tri-lineage differentiation potential. Ovarian cancer cells (SKOV3) cultured with conditioned medium from BMSCs showed increased migration, invasion, and colony formation, indicating the role of the tumor microenvironment in influencing cancer cell behavior. BMSCs promoted SKOV3 tumorigenesis in nonobese diabetic/severe combined immunodeficiency mice, increasing tumor growth. The co-injection of BMSCs increased the phosphorylation of p38 MAPK and GSK-3β in SKOV3 tumors. Co-culturing SKOV3 cells with BMSCs led to an increase in the expression of cytokines, especially MCP-1 and IL-6. These findings highlight the influence of BMSCs on ovarian cancer cell behavior and the potential involvement of specific cytokines in mediating these effects. Understanding these mechanisms will highlight potential therapeutic avenues that may halt ovarian cancer progression.

Comparative Review on Cancer Pathology from Aberrant Histone Chaperone Activity

Histone chaperones are integral to chromatin dynamics, facilitating the assembly and disassembly of nucleosomes, thereby playing a crucial role in regulating gene expression and maintaining genomic stability. Moreover, they prevent aberrant histone interactions prior to chromatin assembly. Disruption in histone chaperone function may result in genomic instability, which is implicated in pathogenesis. This review aims to elucidate the role of histone chaperones in cancer pathologies and explore their potential as therapeutic targets. Histone chaperones have been found to be dysregulated in various cancers, with alterations in expression levels, mutations, or aberrant interactions leading to tumorigenesis and cancer progression. In addition, this review intends to highlight the molecular mechanisms of interactions between histone chaperones and oncogenic factors, underscoring their roles in cancer cell survival and proliferation. The dysregulation of histone chaperones is significantly correlated with cancer development, establishing them as active contributors to cancer pathology and viable targets for therapeutic intervention. This review advocates for continued research into histone chaperone-targeted therapies, which hold potential for precision medicine in oncology. Future advancements in understanding chaperone functions and interactions are anticipated to lead to novel cancer treatments, enhancing patient care and outcomes.

Construction of ROS-Responsive Hyaluronic Acid Modified Paclitaxel and Diosgenin Liposomes and Study on Synergistic Enhancement of Anti-Ovarian Cancer Efficacy

Purpose

Ovarian cancer is a fatal gynecologic malignancy with a high rate of abdominal metastasis. Chemotherapy still has a poor clinical prognosis for ovarian cancer patients, with cell proliferation and angiogenesis leading to invasion, migration, and recurrence. To overcome these obstacles, we constructed a novel HA-modified paclitaxel and diosgenin liposome (PEG-TK-HA-PDLPs) using two novel functional materials, DSPE-PEG2000-HA and DSPE-PEG2000-TK-PEG5000, to specifically deliver the drugs to the tumor site in order to reduce OC cell proliferation and anti-angiogenic generation, thereby inhibiting invasion and migration.

Methods and Results

PEG-TK-HA-PDLPs were prepared by film dispersion, with ideal physicochemical properties and exhibits active targeting for enhanced cellular uptake. The ZIP synergy score for PTX and Dios was calculated using the online SynergyFinder software to be 3.15, indicating synergy. In vitro results showed that PEG-TK-HA-PDLPs were highly cytotoxic to ID8 cells, induced ID8 cell apoptosis, and inhibited ID8 cell migration and invasion. In vivo studies showed that PEG-TK-HA-PDLPs could prolong the circulation time in the blood, accumulate significantly in the tumor site, and effectively fight against angiogenesis with significant anti-tumor effects.

Conclusion

The production of PEG-TK-HA-PDLPs is an effective strategy for the treatment of OC.

Targeting tumour markers in ovarian cancer treatment

Ovarian cancers (OC) are the most common, lethal, and stage-dependent cancers at the global level, specifically in female patients. Targeted therapies involve the administration of drugs that specifically target the alterations in tumour cells responsible for their growth, proliferation, and metastasis, with the aim of treating particular patients. Presently, within the realm of gynaecological malignancies, specifically in breast and OCs, there exist various prospective therapeutic targets encompassing tumour-intrinsic signalling pathways, angiogenesis, homologous-recombination deficit, hormone receptors, and immunologic components. Breast cancers are often detected in advanced stages, primarily due to the lack of a reliable screening method. However, various tumour markers have been extensively researched and employed to evaluate the condition, progression, and effectiveness of medication treatments for this ailment. The emergence of recent technological advancements in the domains of bioinformatics, genomics, proteomics, and metabolomics has facilitated the exploration and identification of hitherto unknown biomarkers. The primary objective of this comprehensive review is to meticulously investigate and analyze both established and emerging methodologies employed in the identification of tumour markers associated with OC.

The β-arrestin1/endothelin axis bolsters ovarian fibroblast-dependent invadosome activity and cancer cell metastatic potential

Recruitment of fibroblasts to tumors and their activation into cancer-associated fibroblasts (CAFs) is a strategy used by tumor cells to direct extracellular matrix (ECM) remodeling, invasion, and metastasis, highlighting the need to investigate the molecular mechanisms driving CAF function. Endothelin-1 (ET-1) regulates the communication between cancer and stroma and facilitates the progression of serous ovarian cancer (SOC). By binding to Endothelin A (ETA) and B (ETB) receptors, ET-1 enables the recruitment of β-arrestin1 (β-arr1) and the formation of signaling complexes that coordinate tumor progression. However, how ET-1 receptors might "educate" human ovarian fibroblasts (HOFs) to produce altered ECM and promote metastasis remains to be elucidated. This study identifies ET-1 as a pivotal factor in the activation of CAFs capable of proteolytic ECM remodeling and the generation of heterotypic spheroids containing cancer cells with a propensity to metastasize. An autocrine/paracrine ET-1/ETA/BR/β-arr1 loop enhances HOF proliferation, upregulates CAF marker expression, secretes pro-inflammatory cytokines, and increases collagen contractility, and cell motility. Furthermore, ET-1 facilitates ECM remodeling by promoting the lytic activity of invadosome and activation of integrin β1. In addition, ET-1 signaling supports the formation of heterotypic HOF/SOC spheroids with enhanced ability to migrate through the mesothelial monolayer, and invade, representing metastatic units. The blockade of ETA/BR or β-arr1 silencing prevents CAF activation, invadosome function, mesothelial clearance, and the invasive ability of heterotypic spheroids. In vivo, therapeutic inhibition of ETA/BR using bosentan (BOS) significantly reduces the metastatic potential of combined HOFs/SOC cells, associated with enhanced apoptotic effects on tumor cells and stromal components. These findings support a model in which ET-1/β-arr1 reinforces tumor/stroma interaction through CAF activation and fosters the survival and metastatic properties of SOC cells, which could be counteracted by ETA/BR antagonists.

ROR2/Wnt5a Signaling Regulates Directional Cell Migration and Early Tumor Cell Invasion in Ovarian Cancer

Adhesion to and clearance of the mesothelial monolayer are key early events in metastatic seeding of ovarian cancer. ROR2 is a receptor tyrosine kinase that interacts with Wnt5a ligand to activate noncanonical Wnt signaling and has been previously shown to be upregulated in ovarian cancer tissue. However, no prior study has evaluated the mechanistic role of ROR2 in ovarian cancer. Through a cellular high-throughput genetic screen, we independently identified ROR2 as a driver of ovarian tumor cell adhesion and invasion. ROR2 expression in ovarian tumor cells serves to drive directed cell migration preferentially toward areas of high Wnt5a ligand, such as the mesothelial lined omentum. In addition, ROR2 promotes ovarian tumor cell adhesion and clearance of a mesothelial monolayer. Depletion of ROR2, in tumor cells, reduces metastatic tumor burden in a syngeneic model of ovarian cancer. These findings support the role of ROR2 in ovarian tumor cells as a critical factor contributing to the early steps of metastasis. Therapeutic targeting of the ROR2/Wnt5a signaling axis could provide a means of improving treatment for patients with advanced ovarian cancer.

IMPLICATIONS

This study demonstrates that ROR2 in ovarian cancer cells is important for directed migration to the metastatic niche and provides a potential signaling axis of interest for therapeutic targeting in ovarian cancer.

Circulating tumor cells help differentiate benign ovarian lesions from cancer before surgery: A literature review and proof of concept study using flow cytometry with fluorescence imaging

Current tools are insufficient for distinguishing patients with ovarian cancer from those with benign ovarian lesions before extensive surgery. The present study utilized a readily accessible platform employing a negative selection strategy, followed by flow cytometry, to enumerate circulating tumor cells (CTCs) in patients with ovarian cancer. These counts were compared with those from patients with benign ovarian lesions. CTC counts at baseline, before and after anticancer therapy, and across various clinical scenarios involving ovarian lesions were assessed. A negative-selection protocol we proposed was applied to patients with suspected ovarian cancer and prospectively utilized in those subsequently confirmed to have malignancy. The protocol was implemented before anticancer therapy and at months 3, 6, 9 and 12 post-treatment. A cut-off value for CTC number at 4.75 cells/ml was established to distinguish ovarian malignancy from benign lesions, with an area under the curve of 0.900 (P<0.001). In patients with ovarian cancer, multivariate Cox regression analysis revealed that baseline CTC counts and the decline in CTCs within the first three months post-therapy were significant predictors of prolonged progression-free survival. Additionally, baseline CTC counts independently prognosticated overall survival. CTC counts obtained with the proposed platform, used in the present study, suggest that pre-operative CTC testing may be able to differentiate between malignant and benign tumors. Moreover, CTC counts may indicate oncologic outcomes in patients with ovarian cancer who have undergone cancer therapies.

Senolytic drugs dasatinib and quercetin combined with Carboplatin or Olaparib reduced the peritoneal and adipose tissue metastasis of ovarian cancer

Chemotherapy and targeted drugs-induced senescent ovarian cancer cells that accumulate in peritoneal adipose tissue contribute significantly to chronic inflammation, disrupt homeostasis, and may fuel various aspects of cancer progression. However, the pro-senescence effects of chemotherapy and targeted drugs on adipose derived stem cells (ADSCs) within peritoneal adipose tissue remain poorly understood. In this study, we show that the first-line chemotherapy and targeted drugs can induce the cellular senescence of ADSCs in vitro and increase the aging of peritoneal adipose tissue in vivo. These treatments significantly promoted the dysregulation of glucose and lipid metabolism, including insulin resistance and liver lipid accumulation. Our study shows that dasatinib and quercetin, as senolytics, effectively restore glucose homeostasis in mice with ovarian cancer and significantly reduce adipose tissue aging. Importantly, combining these drugs with Carboplatin or Olaparib results in a marked decrease in both peritoneal and adipose tissue metastasis of ovarian cancer cells. Mechanistically, we revealed that there is crosstalk between ovarian cancer cells and senescent ADSCs. The crosstalk increases inflammatory cytokines and chemokines production in ADSCs and notably upregulates chemokine receptors on cancer cells. Collectively, these data indicate that senescent ADSCs induced by chemotherapy and targeted therapy drugs impair adipose tissue function. However, the senolytic drugs dasatinib and quercetin, can significantly ameliorate organ aging and damage induced by these treatments. Notably, dasatinib and quercetin combined with Carboplatin or Olaparib reduced the peritoneal and adipose tissue metastasis of ovarian cancer, ultimately benefiting the mice undergoing chemotherapy and targeted therapy.

A Perspective Review: Analyzing Collagen Alterations in Ovarian Cancer by High-Resolution Optical Microscopy

High-grade serous ovarian cancer (HGSOC) is the predominant subtype of ovarian cancer (OC), occurring in more than 80% of patients diagnosed with this malignancy. Histological and genetic analysis have confirmed the secretory epithelial of the fallopian tube (FT) as a major site of origin of HGSOC. Although there have been significant strides in our understanding of this disease, early stage detection and diagnosis are still rare. Current clinical imaging modalities lack the ability to detect early stage pathogenesis in the fallopian tubes and the ovaries. However, there are several microscopic imaging techniques used to analyze the structural modifications in the extracellular matrix (ECM) protein collagen in ex vivo FT and ovarian tissues that potentially can be modified to fit the clinical setting. In this perspective, we evaluate and compare the myriad of optical tools available to visualize these alterations and the invaluable insights these data provide on HGSOC initiation. We also discuss the clinical implications of these findings and how these data may help novel tools for early diagnosis of HGSOC.

Muscle weakness and mitochondrial stress occur before metastasis in a novel mouse model of ovarian cancer cachexia

Objectives

A high proportion of women with advanced epithelial ovarian cancer (EOC) experience weakness and cachexia. This relationship is associated with increased morbidity and mortality. EOC is the most lethal gynecological cancer, yet no preclinical cachexia model has demonstrated the combined hallmark features of metastasis, ascites development, muscle loss and weakness in adult immunocompetent mice.

Methods

Here, we evaluated a new model of ovarian cancer-induced cachexia with the advantages of inducing cancer in adult immunocompetent C57BL/6J mice through orthotopic injections of EOC cells in the ovarian bursa. We characterized the development of metastasis, ascites, muscle atrophy, muscle weakness, markers of inflammation, and mitochondrial stress in the tibialis anterior (TA) and diaphragm ~45, ~75 and ~90 days after EOC injection.

Results

Primary ovarian tumour sizes were progressively larger at each time point while robust metastasis, ascites development, and reductions in body, fat and muscle weights occurred by 90 Days. There were no changes in certain inflammatory (TNFα), atrogene (MURF1 and Atrogin) or GDF15 markers within both muscles whereas IL-6 was increased at 45 and 90 Day groups in the diaphragm. TA weakness in 45 Day preceded atrophy and metastasis that were observed later (75 and 90 Day, respectively). The diaphragm demonstrated both weakness and atrophy in 45 Day. In both muscles, this pre-metastatic muscle weakness corresponded with considerable reprogramming of gene pathways related to mitochondrial bioenergetics as well as reduced functional measures of mitochondrial pyruvate oxidation and creatine-dependent ADP/ATP cycling as well as increased reactive oxygen species emission (hydrogen peroxide). Remarkably, muscle force per unit mass at 90 days was partially restored in the TA despite the presence of atrophy and metastasis. In contrast, the diaphragm demonstrated progressive weakness. At this advanced stage, mitochondrial pyruvate oxidation in both muscles exceeded control mice suggesting an apparent metabolic super-compensation corresponding with restored indices of creatine-dependent adenylate cycling.

Conclusion

This mouse model demonstrates the concurrent development of cachexia and metastasis that occurs in women with EOC. The model provides physiologically relevant advantages of inducing tumour development within the ovarian bursa in immunocompetent adult mice. Moreover, the model reveals that muscle weakness in both TA and diaphragm precedes metastasis while weakness also precedes atrophy in the TA. An underlying mitochondrial bioenergetic stress corresponded with this early weakness. Collectively, these discoveries can direct new research towards the development of therapies that target pre-atrophy and pre-metastatic weakness during EOC in addition to therapies targeting cachexia.

Chemotherapy induces myeloid-driven spatial T-cell exhaustion in ovarian cancer

To uncover the intricate, chemotherapy-induced spatiotemporal remodeling of the tumor microenvironment, we conducted integrative spatial and molecular characterization of 97 high-grade serous ovarian cancer (HGSC) samples collected before and after chemotherapy. Using single-cell and spatial analyses, we identify increasingly versatile immune cell states, which form spatiotemporally dynamic microcommunities at the tumor-stroma interface. We demonstrate that chemotherapy triggers spatial redistribution and exhaustion of CD8+ T cells due to prolonged antigen presentation by macrophages, both within interconnected myeloid networks termed "Myelonets" and at the tumor stroma interface. Single-cell and spatial transcriptomics identifies prominent TIGIT-NECTIN2 ligand-receptor interactions induced by chemotherapy. Using a functional patient-derived immuno-oncology platform, we show that CD8+T-cell activity can be boosted by combining immune checkpoint blockade with chemotherapy. Our discovery of chemotherapy-induced myeloid-driven spatial T-cell exhaustion paves the way for novel immunotherapeutic strategies to unleash CD8+ T-cell-mediated anti-tumor immunity in HGSC.

Targeting endogenous fatty acid synthesis stimulates the migration of ovarian cancer cells to adipocytes and promotes the transport of fatty acids from adipocytes to cancer cells

Despite significant advances in oncology, 1 of 108 female patients succumb to ovarian cancer (OC) each year. Improved novel treatments against this aggressive disease would be a major improvement. The growth of OC cells has been demonstrated to be highly dependent on lipids. OC cells are abundantly present in the abdominal cavity and omentum, the main sites of OC expansion. Accordingly, it has been attempted not only to block the hyperactive synthesis of fatty acids (FAs) in cancer cells, but also to disrupt lipid supply. While either strategy has yielded promising results as monotherapy, the induction of resistance pathways diminishing the anticancer effects is yet conceivable. The endogenous regulation of lipid biosynthesis in OC has been extensively studied. However, the role of stromal cells in the modulation of the effects of anti‑lipogenic drugs has not yet been well documented. The present study thus examined the interaction between OC cells and associated stromal cells, when de novo FA synthesis was blocked. It has recently been revealed by the authors that when FA are provided to OC cells in monoculture, the lipid deficiency induced by pharmacological inhibition of FA synthase (FASN), the key enzyme of endogenous FA synthesis, cannot be compensated through an increased FA uptake by OC cells. In the present study, OC cells were co‑cultured with adipocytes preloaded with fluorescent FA and the effects of FASN‑inhibition on OC homing to adipocytes and the transcellular delivery of fluorescent FA from adipocytes to OC cells were examined. The FASN inhibitors, G28UCM and Fasnall, stimulated the spontaneous migration of A2780 OC cells in a concentration‑dependent manner and stimulated the transfer of FA from adipocytes to OC cells. Similar effects were observed with all types of adipocytes tested. The models applied in the present study demonstrated that co‑cultured cancer‑associated adipocytes may attenuate the anticancer effects of FASN inhibitors by attracting tumor cells and by supplying the cells with FA. This lipid‑mediated dependency may provide a rationale for the design of new treatment approaches for the treatment of OC.

NLRC5 overexpression in ovarian tumors remodels the tumor microenvironment and increases T-cell reactivity toward autologous tumor-associated antigens

Introduction

Epithelial ovarian cancer (OC) stands as one of the deadliest gynecologic malignancies, urgently necessitating novel therapeutic strategies. Approximately 60% of ovarian tumors exhibit reduced expression of major histocompatibility complex class I (MHC I), intensifying immune evasion mechanisms and rendering immunotherapies ineffective. NOD-like receptor CARD domain containing 5 (NLRC5) transcriptionally regulates MHC I genes and many antigen presentation machinery components. We therefore explored the therapeutic potential of NLRC5 in OC.

Methods

We generated OC cells overexpressing NLRC5 to rescue MHC I expression and antigen presentation and then assessed their capability to respond to PD-L1 blockade and an infected cell vaccine.

Results

Analysis of microarray datasets revealed a correlation between elevated NLRC5 expression and extended survival in OC patients; however, NLRC5 was scarcely detected in the OC tumor microenvironment. OC cells overexpressing NLRC5 exhibited slower tumor growth and resulted in higher recruitment of leukocytes in the TME with lower CD4/CD8 T-cell ratios and increased activation of T cells. Immune cells from peripheral blood, spleen, and ascites from these mice displayed heightened activation and interferon-gamma production when exposed to autologous tumor-associated antigens. Finally, as a proof of concept, NLRC5 overexpression within an infected cell vaccine platform enhanced responses and prolonged survival in comparison with control groups when challenged with parental tumors.

Discussion

These findings provide a compelling rationale for utilizing NLRC5 overexpression in "cold" tumor models to enhance tumor susceptibility to T-cell recognition and elimination by boosting the presentation of endogenous tumor antigens. This approach holds promise for improving antitumoral immune responses in OC.

Research progress of extracellular vesicles in the treatment of ovarian diseases (Review)

The ovary is an essential reproductive organ in the female organism and its development seriously affects the physical and mental health of female patients. Ovarian diseases include ovarian cancer, premature ovarian insufficiency (POI) and polycystic ovary syndrome (PCOS). Women should pay attention to the most effective treatments for this condition because it is one of the most prevalent gynecological illnesses at present. Extracellular vesicles (EVs), which are smaller vesicles that mediate the exchange of cellular information, include the three categories of exosomes, microvesicles and apoptotic bodies. They are able to transport proteins, RNA and other substances to adjacent or distal cells, thus allowing cellular and tissue homeostasis to be maintained. Numerous previous studies have revealed that EVs are crucial for the treatment of ovarian diseases. They are known to transport its contents to ovarian cancer cells as well as other ovarian cells such as granulosa cells, affecting the development of ovarian disease processes. Therefore, this extracellular vesicle may be involved as a target in the therapeutic process of ovarian disease and may have great potential in the treatment of ovarian disease. In the present review, the role of EVs in the development of three ovarian diseases, including ovarian cancer, POI and PCOS, was mainly summarizes. It is expected that this will provide some theoretical support for the treatment of ovarian disease.

Rescue of p53 functions by in vitro-transcribed mRNA impedes the growth of high-grade serous ovarian cancer

BACKGROUND

The cellular tumor protein p53 (TP53) is a tumor suppressor gene that is frequently mutated in human cancers. Among various cancer types, the very aggressive high-grade serous ovarian carcinoma (HGSOC) exhibits the highest prevalence of TP53 mutations, present in >96% of cases. Despite intensive efforts to reactivate p53, no clinical drug has been approved to rescue p53 function. In this study, our primary objective was to administer in vitro-transcribed (IVT) wild-type (WT) p53-mRNA to HGSOC cell lines, primary cells, and orthotopic mouse models, with the aim of exploring its impact on inhibiting tumor growth and dissemination, both in vitro and in vivo.

METHODS

To restore the activity of p53, WT p53 was exogenously expressed in HGSOC cell lines using a mammalian vector system. Moreover, IVT WT p53 mRNA was delivered into different HGSOC model systems (primary cells and patient-derived organoids) using liposomes and studied for proliferation, cell cycle progression, apoptosis, colony formation, and chromosomal instability. Transcriptomic alterations induced by p53 mRNA were analyzed using RNA sequencing in OVCAR-8 and primary HGSOC cells, followed by ingenuity pathway analysis. In vivo effects on tumor growth and metastasis were studied using orthotopic xenografts and metastatic intraperitoneal mouse models.

RESULTS

Reactivation of the TP53 tumor suppressor gene was explored in different HGSOC model systems using newly designed IVT mRNA-based methods. The introduction of WT p53 mRNA triggered dose-dependent apoptosis, cell cycle arrest, and potent long-lasting inhibition of HGSOC cell proliferation. Transcriptome analysis of OVCAR-8 cells upon mRNA-based p53 reactivation revealed significant alterations in gene expression related to p53 signaling, such as apoptosis, cell cycle regulation, and DNA damage. Restoring p53 function concurrently reduces chromosomal instability within the HGSOC cells, underscoring its crucial contribution in safeguarding genomic integrity by moderating the baseline occurrence of double-strand breaks arising from replication stress. Furthermore, in various mouse models, treatment with p53 mRNA reduced tumor growth and inhibited tumor cell dissemination in the peritoneal cavity in a dose-dependent manner.

CONCLUSIONS

The IVT mRNA-based reactivation of p53 holds promise as a potential therapeutic strategy for HGSOC, providing valuable insights into the molecular mechanisms underlying p53 function and its relevance in ovarian cancer treatment.

The role and function of autophagy through signaling and pathogenetic pathways and lncRNAs in ovarian cancer

Lysosomal-driven autophagy is a tightly controlled cellular catabolic process that breaks down and recycles broken or superfluous cell parts. It is involved in several illnesses, including cancer, and is essential in preserving cellular homeostasis. Autophagy prevents DNA mutation and cancer development by actively eliminating pro-oxidative mitochondria and protein aggregates from healthy cells. Oncosuppressor and oncogene gene mutations cause dysregulation of autophagy. Increased autophagy may offer cancer cells a pro-survival advantage when oxygen and nutrients are scarce and resistance to chemotherapy and radiation. This finding justifies the use of autophagy inhibitors in addition to anti-neoplastic treatments. Excessive autophagy levels can potentially kill cells. The diagnosis and treatment of ovarian cancer present many difficulties due to its complexity and heterogeneity. Understanding the role of autophagy, a cellular process involved in the breakdown and recycling of cellular components, in ovarian cancer has garnered increasing attention in recent years. Of particular note is the increasing amount of data indicating a close relationship between autophagy and ovarian cancer. Autophagy either promotes or restricts tumor growth in ovarian cancer. Dysregulation of autophagy signaling pathways in ovarian cancers can affect the development, metastasis, and response to tumor treatment. The precise mechanism underlying autophagy concerning ovarian cancer remains unclear, as does the role autophagy plays in ovarian carcinoma. In this review, we tried to encapsulate and evaluate current findings in investigating autophagy in ovarian cancer.

Characterization of candidate factors associated with the metastasis and progression of high-grade serous ovarian cancer

BACKGROUND

High-grade serous ovarian cancer (HGSOC) is the biggest cause of gynecological cancer-related mortality because of its extremely metastatic nature. This study aimed to explore and evaluate the characteristics of candidate factors associated with the metastasis and progression of HGSOC.

METHODS

Transcriptomic data of HGSOC patients' samples collected from primary tumors and matched omental metastatic tumors were obtained from three independent studies in the National Center for Biotechnology Information (NCBI) Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were selected to evaluate the effects on the prognosis and progression of ovarian cancer using data from The Cancer Genome Atlas (TCGA) database. Hub genes' immune landscapes were estimated by the Tumor Immune Estimation Resource (TIMER) database. Finally, using 25 HGSOC patients' cancer tissues and 10 normal fallopian tube tissues, immunohistochemistry (IHC) was performed to quantify the expression levels of hub genes associated with International Federation of Gynecology and Obstetrics (FIGO) stages.

RESULTS

Fourteen DEGs, ADIPOQ , ALPK2 , BARX1 , CD37 , CNR2 , COL5A3 , FABP4 , FAP , GPR68 , ITGBL1 , MOXD1 , PODNL1 , SFRP2 , and TRAF3IP3 , were upregulated in metastatic tumors in every database while CADPS , GATA4 , STAR , and TSPAN8 were downregulated. ALPK2 , FAP , SFRP2 , GATA4 , STAR , and TSPAN8 were selected as hub genes significantly associated with survival and recurrence. All hub genes were correlated with tumor microenvironment infiltration, especially cancer-associated fibroblasts and natural killer (NK) cells. Furthermore, the expression of FAP and SFRP2 was positively correlated with the International Federation of Gynecology and Obstetrics (FIGO) stage, and their increased protein expression levels in metastatic samples compared with primary tumor samples and normal tissues were confirmed by IHC ( P = 0.0002 and P = 0.0001, respectively).

CONCLUSIONS

This study describes screening for DEGs in HGSOC primary tumors and matched metastasis tumors using integrated bioinformatics analyses. We identified six hub genes that were correlated with the progression of HGSOC, particularly FAP and SFRP2 , which might provide effective targets to predict prognosis and provide novel insights into individual therapeutic strategies for HGSOC.

Defining the Role of Metastasis-Initiating Cells in Promoting Carcinogenesis in Ovarian Cancer

Ovarian cancer is the deadliest gynecological malignancy with a high prevalence of transcoelomic metastasis. Metastasis is a multi-step process and only a small percentage of cancer cells, metastasis-initiating cells (MICs), have the capacity to finally establish metastatic lesions. These MICs maintain a certain level of stemness that allows them to differentiate into other cell types with distinct transcriptomic profiles and swiftly adapt to external stresses. Furthermore, they can coordinate with the microenvironment, through reciprocal interactions, to invade and establish metastases. Therefore, identifying, characterizing, and targeting MICs is a promising strategy to counter the spread of ovarian cancer. In this review, we provided an overview of OC MICs in the context of characterization, identification through cell surface markers, and their interactions with the metastatic niche to promote metastatic colonization.

PINK1-PTEN axis promotes metastasis and chemoresistance in ovarian cancer via non-canonical pathway

BACKGROUND

Ovarian cancer is commonly associated with a poor prognosis due to metastasis and chemoresistance. PINK1 (PTEN-induced kinase 1) is a serine/threonine kinase that plays a crucial part in regulating various physiological and pathophysiological processes in cancer cells.

METHODS

The ATdb database and "CuratedOvarianData" were used to evaluate the effect of kinases on ovarian cancer survival. The gene expression in ovarian cancer cells was detected by Western blot and quantitative real-time PCR. The effects of gene knockdown or overexpression in vitro were evaluated by wound healing assay, cell transwell assay, immunofluorescence staining, immunohistochemistry, and flow cytometry analysis. Mass spectrometry analysis, protein structure analysis, co-immunoprecipitation assay, nuclear-cytoplasmic separation, and in vitro kinase assay were applied to demonstrate the PINK1-PTEN (phosphatase and tensin homolog) interaction and the effect of this interaction. The metastasis experiments for ovarian cancer xenografts were performed in female BALB/c nude mice.

RESULTS

PINK1 was strongly associated with a poor prognosis in ovarian cancer patients and promoted metastasis and chemoresistance in ovarian cancer cells. Although the canonical PINK1/PRKN (parkin RBR E3 ubiquitin protein ligase) pathway showed weak effects in ovarian cancer, PINK1 was identified to interact with PTEN and phosphorylate it at Serine179. Remarkably, the phosphorylation of PTEN resulted in the inactivation of the phosphatase activity, leading to an increase in AKT (AKT serine/threonine kinase) activity. Moreover, PINK1-mediated phosphorylation of PTEN impaired the nuclear import of PTEN, thereby enhancing the cancer cells' ability to resist chemotherapy and metastasize.

CONCLUSIONS

PINK1 interacts with and phosphorylates PTEN at Serine179, resulting in the activation of AKT and the inhibition of PTEN nuclear import. PINK1 promotes ovarian cancer metastasis and chemotherapy resistance through the regulation of PTEN. These findings offer new potential therapeutic targets for ovarian cancer management.

The recent advancements of ferroptosis in the diagnosis, treatment and prognosis of ovarian cancer

Ovarian cancer affects the female reproductive system and is the primary cause of cancer related mortality globally. The imprecise and non-specific nature of ovarian cancer symptoms often results in patients being diagnosed at an advanced stage, with metastatic lesions extending beyond the ovary. This presents a significant clinical challenge and imposes a substantial economic burden on both patients and society. Despite advancements in surgery, chemotherapy, and immunotherapy, the prognosis for most patients with ovarian cancer remains unsatisfactory. Therefore, the development of novel treatment strategies is imperative. Ferroptosis, a distinct form of regulated cell death, characterized by iron-dependent lipid peroxidation, differs from autophagy, apoptosis, and necrosis, and may hold promise as a novel cell death. Numerous studies have demonstrated the involvement of ferroptosis in various conventional signaling pathways and biological processes. Recent investigations have revealed the significant contribution of ferroptosis in the initiation, progression, and metastasis of diverse malignant tumors, including ovarian cancer. Moreover, ferroptosis exhibits a synergistic effect with chemotherapy, radiotherapy, and immunotherapy in restraining the proliferation of ovarian cancer cells. The aforementioned implies that ferroptosis holds considerable importance in the management of ovarian cancer and has the potential to serve as a novel therapeutic target. The present review provides a comprehensive overview of the salient features of ferroptosis, encompassing its underlying mechanisms and functional role in ovarian cancer, along with the associated signaling pathways and genes. Furthermore, the review highlights the prospective utility of ferroptosis in the treatment of ovarian cancer.

Roles of salt‑inducible kinases in cancer (Review)

Salt inducible kinases (SIKs) with three subtypes SIK1, SIK2 and SIK3, belong to the AMP‑activated protein kinase family. They are expressed ubiquitously in humans. Under normal circumstances, SIK1 regulates adrenocortical function in response to high salt or adrenocorticotropic hormone stimulation, SIK2 is involved in cell metabolism, controlling insulin signaling and gluconeogenesis and SIK3 coordinates with the mTOR complex, promoting cancer. The dysregulation of SIKs has been widely detected in various types of cancers. Based on most of the existing studies, SIK1 is mostly considered a tumor inhibitor, SIK2 and SIK3 are usually associated with tumor promotion. However, the functions of SIKs have shown contradictory in certain tumors, suggesting that SIKs cannot be simply classified as oncogenes or tumor suppressor genes. The present review provided a comprehensive summary of the roles of SIKs in the initiation and progression of different cancers, aiming to elucidate their clinical value and discuss potential strategies for targeting SIKs in cancer therapy.

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.

MicroRNAs Can Influence Ovarian Cancer Progression by Dysregulating Integrin Activity

Ovarian cancer is a deadly disease that affects thousands of women worldwide. Integrins, transmembrane receptors that mediate cell adhesion and signaling, play important roles in ovarian cancer progression, metastasis, and drug resistance. Dysregulated expression of integrins is implicated in various cellular processes, such as cell migration, invasion, and proliferation. Emerging evidence suggests that microRNAs (miRNAs) can regulate integrin expression and function, thus affecting various physiological and pathological processes, including ovarian cancer. In this article, we review the current understanding of integrin-mediated cellular processes in ovarian cancer and the roles of miRNAs in regulating integrins. We also discuss the therapeutic potential of targeting miRNAs that regulate integrins for the treatment of ovarian cancer. Targeting miRNAs that regulate integrins or downstream signaling pathways of integrins may provide novel therapeutic strategies for inhibiting integrin-mediated ovarian cancer progression.

Cardiovascular Mortality in Ovarian Cancer Patients: An Analysis of Patient Characteristics Using the SEER Database

Background and Objectives: Cardiovascular disease (CVD) is a major contributor to the high mortality rate among individuals with ovarian cancer. Nevertheless, there is limited understanding regarding the specific patient attributes that might impact the risk of CVD in this group. Materials and Methods: A retrospective cohort study was performed using the SEER database to analyze primary ovarian cancer cases from 2000 to 2019. Multivariable logistic regression analysis was employed to identify patient characteristics linked to cardiovascular mortality. Results: The cohort included 41,930 cases of patients who were alive, 54,829 cases of cancer-related deaths, 3003 cases of cardiovascular-related deaths, and 10,238 cases with other causes of death. Poorly differentiated cancer cells and distant metastasis were associated with a higher risk of cardiovascular mortality. Logistic regression analysis identified age, year of diagnosis, race, laterality, and staging as significant risk factors for cardiovascular cause of death. The risk of cardiovascular cause of death was lower in patients aged 31-60 and higher in those aged over 60 years old, and the risk also increased with a later year of diagnosis. Patients who were not white were at a higher risk of cardiovascular cause of death. Additionally, bilateral ovarian cancer and distant staging disease were linked to elevated risks of cardiovascular cause of death. Conclusion: Cardiovascular mortality is a significant concern in ovarian cancer patients, and several patient characteristics are associated with an increased risk. Our study suggests that targeted interventions to improve cardiovascular health in high-risk patients, such as those with comorbidities or an advanced stage at diagnosis, may improve survival in this population.

LGALS1 regulates cell adhesion to promote the progression of ovarian cancer

The present study aimed to explore the significance and molecular mechanisms of galectin-1 (LGALS1) in ovarian cancer (OC). Using the Gene Expression Omnibus database and The Cancer Genome Atlas database, the results of the present study demonstrated that LGALS1 mRNA expression was markedly increased in OC and associated with advanced tumor, lymphatic metastasis and residual lesions. In Kaplan-Meier analysis, patients who expressed LGALS1 highly had a poor prognosis. Furthermore, using The Cancer Genome Atlas database, differentially expressed genes that are potentially regulated by LGALS1 in OC were determined. Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, and Gene Set Enrichment Analysis were used to build a biological network of upregulated differentially expressed genes. The results of the enrichment analysis revealed that the upregulated differentially expressed genes were primarily associated with 'ECM-receptor interaction', 'cell-matrix adhesion' and 'focal adhesion', which are closely associated with the metastasis of cancer cells. Subsequently, cell adhesion was selected for further analysis. The results demonstrated that LGALS1 was co-expressed with the candidate genes. Subsequently, the elevated expression levels of candidate genes were verified in OC tissues, and survival analysis indicated that high expression of candidate genes was associated with shortened overall survival of patients with OC. In the present study, OC samples were also collected to verify the high protein expression levels of LGALS1 and fibronectin 1. The results of the present study highlighted that LGALS1 may regulate cell adhesion and participate in the development of OC. Therefore, LGALS1 exhibits potential as a therapeutic target in OC.

Interferon-ε is a tumour suppressor and restricts ovarian cancer

High-grade serous ovarian cancers have low survival rates because of their late presentation with extensive peritoneal metastases and frequent chemoresistance1, and require new treatments guided by novel insights into pathogenesis. Here we describe the intrinsic tumour-suppressive activities of interferon-ε (IFNε). IFNε is constitutively expressed in epithelial cells of the fallopian tube, the cell of origin of high-grade serous ovarian cancers, and is then lost during development of these tumours. We characterize its anti-tumour activity in several preclinical models: ovarian cancer patient-derived xenografts, orthotopic and disseminated syngeneic models, and tumour cell lines with or without mutations in Trp53 and Brca genes. We use manipulation of the IFNε receptor IFNAR1 in different cell compartments, differential exposure status to IFNε and global measures of IFN signalling to show that the mechanism of the anti-tumour activity of IFNε involves direct action on tumour cells and, crucially, activation of anti-tumour immunity. IFNε activated anti-tumour T and natural killer cells and prevented the accumulation and activation of myeloid-derived suppressor cells and regulatory T cells. Thus, we demonstrate that IFNε is an intrinsic tumour suppressor in the female reproductive tract whose activities in models of established and advanced ovarian cancer, distinct from other type I IFNs, are compelling indications of potential new therapeutic approaches for ovarian cancer.

Sedum middendorffianum Maxim Induces Apoptosis and Inhibits the Invasion of Human Ovarian Cancer Cells via Oxidative Stress Regulation

Sedum middendorffianum Maxim (SMM) is a Korean endemic plant belonging to the Crassulaceae family. This study aimed to investigate the antitumor effects of the SMM extract on human ovarian cancer cells. Among five endemic plants grown in Korea, the SMM extract showed the most potent cytotoxicity in ovarian cancer cells and had little effect on normal ovarian surface epithelial cells. Furthermore, we revealed that the SMM extract dose-dependently induced apoptosis in human ovarian cancer A2780 and SKOV3 cells. The SMM extract markedly stimulated the activation of caspase-3/8, while the broad-spectrum caspase inhibitor and caspase-8 selective inhibitor significantly reversed SMM extract-induced apoptosis. In addition, the SMM extract significantly inhibited cell invasion and the expression levels of matrix metalloproteinase (MMP)-2 and MMP-9 in ovarian cancer cells. Notably, the SMM extract increased the generation of intracellular ROS, and pretreatment with antioxidant N-acetyl-L-cysteine (NAC) significantly suppressed SMM-induced cytotoxicity and anti-invasive activity. Moreover, NAC treatment reversed the SMM-induced inhibition of MMP-2/9 expression. Taken together, these data suggest that the SMM extract induces caspase-dependent apoptotic cell death and inhibits MMP-dependent invasion via ROS regulation.

"DEPHENCE" system-a novel regimen of therapy that is urgently needed in the high-grade serous ovarian cancer-a focus on anti-cancer stem cell and anti-tumor microenvironment targeted therapies

Ovarian cancer, especially high-grade serous type, is the most lethal gynecological malignancy. The lack of screening programs and the scarcity of symptomatology result in the late diagnosis in about 75% of affected women. Despite very demanding and aggressive surgical treatment, multiple-line chemotherapy regimens and both approved and clinically tested targeted therapies, the overall survival of patients is still unsatisfactory and disappointing. Research studies have recently brought some more understanding of the molecular diversity of the ovarian cancer, its unique intraperitoneal biology, the role of cancer stem cells, and the complexity of tumor microenvironment. There is a growing body of evidence that individualization of the treatment adjusted to the molecular and biochemical signature of the tumor as well as to the medical status of the patient should replace or supplement the foregoing therapy. In this review, we have proposed the principles of the novel regimen of the therapy that we called the "DEPHENCE" system, and we have extensively discussed the results of the studies focused on the ovarian cancer stem cells, other components of cancer metastatic niche, and, finally, clinical trials targeting these two environments. Through this, we have tried to present the evolving landscape of treatment options and put flesh on the experimental approach to attack the high-grade serous ovarian cancer multidirectionally, corresponding to the "DEPHENCE" system postulates.

Deciphering Common Traits of Breast and Ovarian Cancer Stem Cells and Possible Therapeutic Approaches

Breast cancer (BC) and ovarian cancer (OC) are among the most common and deadly cancers affecting women worldwide. Both are complex diseases with marked heterogeneity. Despite the induction of screening programs that increase the frequency of earlier diagnosis of BC, at a stage when the cancer is more likely to respond to therapy, which does not exist for OC, more than 50% of both cancers are diagnosed at an advanced stage. Initial therapy can put the cancer into remission. However, recurrences occur frequently in both BC and OC, which are highly cancer-subtype dependent. Therapy resistance is mainly attributed to a rare subpopulation of cells, named cancer stem cells (CSC) or tumor-initiating cells, as they are capable of self-renewal, tumor initiation, and regrowth of tumor bulk. In this review, we will discuss the distinctive markers and signaling pathways that characterize CSC, their interactions with the tumor microenvironment, and the strategies they employ to evade immune surveillance. Our focus will be on identifying the common features of breast cancer stem cells (BCSC) and ovarian cancer stem cells (OCSC) and suggesting potential therapeutic approaches.

Spatial Transcriptomics Depict Ligand-Receptor Cross-talk Heterogeneity at the Tumor-Stroma Interface in Long-Term Ovarian Cancer Survivors

Advanced high-grade serous ovarian cancer (HGSC) is an aggressive disease that accounts for 70% of all ovarian cancer deaths. Nevertheless, 15% of patients diagnosed with advanced HGSC survive more than 10 years. The elucidation of predictive markers of these long-term survivors (LTS) could help identify therapeutic targets for the disease, and thus improve patient survival rates. To investigate the stromal heterogeneity of the tumor microenvironment (TME) in ovarian cancer, we used spatial transcriptomics to generate spatially resolved transcript profiles in treatment-naïve advanced HGSC from LTS and short-term survivors (STS) and determined the association between cancer-associated fibroblasts (CAF) heterogeneity and survival in patients with advanced HGSC. Spatial transcriptomics and single-cell RNA-sequencing data were integrated to distinguish tumor and stroma regions, and a computational method was developed to investigate spatially resolved ligand-receptor interactions between various tumor and CAF subtypes in the TME. A specific subtype of CAFs and its spatial location relative to a particular ovarian cancer cell subtype in the TME correlated with long-term survival in patients with advanced HGSC. Also, increased APOE-LRP5 cross-talk occurred at the stroma-tumor interface in tumor tissues from STS compared with LTS. These findings were validated using multiplex IHC. Overall, this spatial transcriptomics analysis revealed spatially resolved CAF-tumor cross-talk signaling networks in the ovarian TME that are associated with long-term survival of patients with HGSC. Further studies to confirm whether such cross-talk plays a role in modulating the malignant phenotype of HGSC and could serve as a predictive biomarker of patient survival are warranted.

SIGNIFICANCE

Generation of spatially resolved gene expression patterns in tumors from patients with ovarian cancer surviving more than 10 years allows the identification of novel predictive biomarkers and therapeutic targets for better patient management. See related commentary by Kelliher and Lengyel, p. 1383.

Surgical efficacy and quality of wide resection of the pelvic peritoneum in patients with epithelial ovarian cancer

PURPOSE

The aim of the study was to evaluate the impact of adding an extensive pelvic peritoneal stripping procedure, termed "wide resection of the pelvic peritoneum," (WRPP) to standard surgery for epithelial ovarian cancer on survival effectiveness and to investigate the role of ovarian cancer stem cells (CSCs) in the pelvic peritoneum.

METHODS

A total of 166 patients with ovarian cancer undergoing surgical treatment at Kumamoto University Hospital between 2002 and 2018 were retrospectively analyzed. Eligible patients were divided into three groups based on the surgical approach: standard surgery (SS) group (n = 36), WRPP group (standard surgery plus WRPP, n = 100), and rectosigmoidectomy (RS) group (standard surgery plus RS, n = 30). Survival outcomes were compared between the three groups. CD44 variant 6 (CD44v6) and EpCAM expression, as markers of ovarian CSCs, in peritoneal disseminated tumors were evaluated using immunofluorescence staining.

RESULTS

With respect to patients with stage IIIA-IVB ovarian cancer, there were significant differences in overall and progression-free survival between the WRPP and SS groups, as revealed by univariate (hazard ratio [HR], 0.35; 95% confidence interval [CI], 0.17-0.69; P = 0.003 and HR, 0.54; 95% CI, 0.31-0.95; P = 0.032, respectively) and multivariate Cox proportional hazards models (HR, 0.35; 95% CI, 0.17-0.70; P = 0.003 and HR, 0.54; 95% CI, 0.31-0.95; P = 0.032, respectively). Further, no significant differences were observed in survival outcomes between the RS group and the SS or WRPP group. Regarding the safety of WRPP, no significant differences in major intraoperative and postoperative complications were found between the three groups. Immunofluorescence analysis revealed a high percentage of CD44v6/EpCAM double-positive ovarian cancer cells in peritoneal disseminated tumors.

CONCLUSION

The present study demonstrates that WRPP significantly contributes to improved survival in patients with stage IIIA-IVB ovarian cancer. WRPP could result in eradicating ovarian CSCs and disrupting the CSC niche microenvironment in the pelvic peritoneum.

Extra-abdominal Lymph Node Metastases as the First Presentation in Ovarian and Fallopian Tube Carcinomas

Revision of ovarian and fallopian tube cancer presentation as extra-abdominal lymph nodes to understand the diagnostic challenges and prognostic features of these situations. Literature review in PubMed and Cochrane databases using the terms "ovarian cancer," "fallopian tube cancer," "extrapelvic lymph nodes," extra-abdominal lymph nodes," "distant lymph nodes," "initial presentation," "metastases," and "unusual presentation of ovarian cancer/unusual presentation of fallopian tube cancer" isolated and in conjunction. Articles in English were analyzed regarding revision's purpose, inclusion, and exclusion criteria and 65 were included in the final document. Statistical data was obtained with Microsoft Excel software analysis. Distant manifestations of ovarian cancer may occur through the lymphatic system and, less frequently, through hematogenous spread. These forms of spread may exist with almost no symptoms related to the primary cancer location and can justify distant disease at the initial presentation. Extra-abdominal lymph node involvement poses a clinical challenge for oncologists and oncologic gynecologists because it may occur with no or mild symptoms, and even in situations where no macroscopic disease is seen in the pelvic cavity. Histology and immunohistochemistry analyses together with a high level of suspicion are paramount to help in the diagnostic workup decisions and in finding a correct diagnosis when an extra-abdominal lymph node is the first manifested sign. Given its rarity and scarcity of information dispersed in a few case reports and small case series, further investigation is needed to understand the particularities of these tumors and their prognostic relevance.

Splenectomy in epithelial ovarian cancer surgery

OBJECTIVE

Splenectomy is performed in 4-32% of cytoreductive surgeries for ovarian cancer. The objective of our study was to assess splenectomy and evaluate its impact on overall and disease-free survival.

METHODS

We conducted a retrospective single-center study between January 2000 and December 2016. Patients who underwent a cytoreduction for epithelial ovarian cancer, regardless of stage and surgical approach, were eligible for the study. Patients deemed not operable were excluded from the study. Patients were stratified into two groups, splenectomy or no splenectomy. A univariate analysis followed by a multivariate analysis was conducted to evaluate the postoperative complications after splenectomy and the overall and disease-free survival.

RESULTS

This cohort included 464 patients. Disease stages, peritoneal carcinomatosis scores, and the rate of radical surgery (Pomel classification) were significantly higher in the splenectomy group, p=0.04, p<0.0001, and p<0.001, respectively. However, no significant difference was found in the rate of complete cytoreduction between the two groups (p=0.26) after multivariate analysis. In univariate analysis, splenectomy was significantly associated with extensive surgical procedures. In multivariate analysis, the two more prevalent complications in the splenectomy group were the risk of abdominopelvic lymphocele (overall response (OR) =4.2; p=0.01) and blood transfusion (OR=2.4; p=0.008). The average length of hospital stay was significantly longer in the splenectomy group, 17.4 vs 14.6 days (p<0.0001). The delay in adjuvant chemotherapy was longer in the splenectomy group (p=0.001). There was no significant difference in overall and disease-free survival (p=0.09) and (p=0.79), respectively.

CONCLUSION

Splenectomy may be considered an acceptable and safe procedure; however, with no impact on overall or disease-free survival. In addition, it is associated with longer hospital stay and longer time to chemotherapy.

A 3D multi-cellular tissue model of the human omentum to study the formation of ovarian cancer metastasis

Reliable and predictive experimental models are urgently needed to study metastatic mechanisms of ovarian cancer cells in the omentum. Although models for ovarian cancer cell adhesion and invasion were previously investigated, the lack of certain omental cell types, which influence the metastatic behavior of cancer cells, limits the application of these tissue models. Here, we describe a 3D multi-cellular human omentum tissue model, which considers the spatial arrangement of five omental cell types. Reproducible tissue models were fabricated combining permeable cell culture inserts and bioprinting technology to mimic metastatic processes of immortalized and patient-derived ovarian cancer cells. The implementation of an endothelial barrier further allowed studying the interaction between cancer and endothelial cells during hematogenous dissemination and the impact of chemotherapeutic drugs. This proof-of-concept study may serve as a platform for patient-specific investigations in personalized oncology in the future.

LMCD1-AS1 Facilitates Cell Proliferation and EMT by Sponging miR-873-3p in Cervical Cancer

Long non-coding RNA LMCD1 antisense RNA 1 (LMCD1-AS1) has recently been reported to participate in the pathogenesis of several tumors, including thyroid cancer and osteosarcoma. However, the clinical significance of LMCD1-AS1 and the related biological function have not been reported in cervical cancer (CC). In this study, we observed that LMCD1-AS1 expression was highly expressed in CC specimens compared with adjacent normal specimens using quantitative real-time PCR. Chi-square test showed that high LMCD1-AS1 expression was correlated with FIGO stage and lymph node metastasis. Kaplan-Meier survival analysis showed poor prognosis with high LMCD1-AS1 expression. Moreover, FIGO stage, lymph node metastasis and high LMCD1-AS1 expression could be independent prognostic factors for the patients with CC. Functionally, knockdown of LMCD1-AS1 suppressed the proliferation, migration and invasion of two CC cell lines (HeLa and CaSki) cells by CCK-8 assay, colony formation assay, and Transwell assay. Knockdown of LMCD1-AS1 upregulated E-cadherin expression and downregulated the expression of PCNA, N-cadherin, and imentin in HeLa and CaSki cells. Luciferase reporter assay and RIP assay were conducted to evaluate the downstream molecular mechanisms of LMCD1-AS1. LMCD1-AS1 possesses a putative miR-873-3p-binding site and confirmed the negative correlation between them in CC tissues. Moreover, overexpression of LMCD1-AS1 promoted CC cell proliferation and EMT process through the regulation of miR-873-3p. In addition, depletion of LMCD1-AS1 reduced tumor growth and Ki-67 protein expression. In summary, our findings indicate that LMCD1-AS1 might exert an oncogenic role in CC and targeting LMCD1-AS1 might be a promising therapeutic target for CC treatment.

Cholesterol Biosynthesis Inhibitor RO 48-8071 Suppresses Growth of Epithelial Ovarian Cancer Cells in Vitro and In Vivo

Introduction

Epithelial Ovarian Cancer (EOC) cells express enzymes in the cholesterol biosynthetic pathway, making this pathway an attractive therapeutic target for controlling ovarian cancer. Potent small molecule inhibitors of one biosynthetic enzyme, Oxidosqualene Cyclase (OSC), have been identified, and RO 48-8071 (4'-[6-(allylmethylamino)hexyloxy]-4-bromo-2'-fluorobenzophenone fumarate) (RO), has emerged as a useful chemotherapeutic agent for breast and prostate cancer.

Methods

Cell viability assays were performed to determine effects of RO 48-8071 on growth of EOC cells. Aldehyde Dehydrogenase (ALDH) assay was conducted to determine the effects of drug on reducing stem cell like properties of EOC cells. Finally, xenograft studies were performed to assess the ability of RO 48-8071 to inhibit the growth of EOC cells in vivo.

Results

We found that short-term (24-48 h) administration of pharmacological doses of RO effectively reduced the viability of drug-resistant EOC cells (SK-OV-3 and OVCAR-3), as determined with sulforhodamine B colorimetric assays. In 7-day assays, nanomolar concentrations of RO effectively inhibited the growth of EOC cells. RO also suppressed ALDH activity, a marker of stem cells. Importantly, RO significantly suppressed growth of xenografts derived from EOC cells when given to mice intraperitoneally (20-40 mg kg-1 day-1) for 27 days once tumors reached 100 mm3 (controls: 336 + 60 mm3; treated: 171 + 20 mm3) with no toxicity to the experimental animals. Mechanistically, RO induced apoptosis in tumor cells in vivo as shown with immunohistochemistry.

Conclusion

Cholesterol biosynthesis inhibitor RO 48-8071 is thus a novel and potent inhibitor of human EOC, including EOC stem cells.

A rare case of peritoneal metastases from oropharyngeal squamous cell carcinoma in a young male after completion of chemoradiotherapy

ABSTRACT

Distant metastases are frequent in head and neck squamous cell carcinomas (HNSCC), but they are limited to some organs like lungs, bone, mediastinum, liver and brain. Peritoneal metastases (PMs) from HNSCC are extremely rare. A 28-year-old chronic smoker and alcoholic was diagnosed with squamous cell carcinoma of oropharynx. Patient was admitted and was given six cycles of concurrent chemo and radiotherapy (CCRT) and was discharged. Two months later, he presented with abdominal pain and lump. Contrast-enhanced CT revealed ascites, peritoneal implants and subcutaneous deposit which were proved to be metastases by histopathology. The present case is the seventh reported case of PM from HNSCC. • Patients of HNSCC shall be screened for distant metastases. • Differential diagnosis of HNSCC needs consideration when encountered with peritoneal metastases. • Research is required to understand the basis of PM in HNSCC while on CCRT to suggest management modifications.

New Insights into Ferroptosis Initiating Therapies (FIT) by Targeting the Rewired Lipid Metabolism in Ovarian Cancer Peritoneal Metastases

Ovarian cancer is one of the most lethal gynecological cancers worldwide. The poor prognosis of this malignancy is substantially attributed to the inadequate symptomatic biomarkers for early diagnosis and effective remedies to cure the disease against chemoresistance and metastasis. Ovarian cancer metastasis is often relatively passive, and the single clusters of ovarian cancer cells detached from the primary ovarian tumor are transcoelomic spread by the peritoneal fluid throughout the peritoneum cavity and omentum. Our earlier studies revealed that lipid-enriched ascitic/omental microenvironment enforced metastatic ovarian cancer cells to undertake metabolic reprogramming and utilize free fatty acids as the main energy source for tumor progression and aggression. Intriguingly, cell susceptibility to ferroptosis has been tightly correlated with the dysregulated fatty acid metabolism (FAM), and enhanced iron uptake as the prominent features of ferroptosis are attributed to the strengthened lipid peroxidation and aberrant iron accumulation, suggesting that ferroptosis induction is a targetable vulnerability to prevent cancer metastasis. Therefore, the standpoints about tackling altered FAM in combination with ferroptosis initiation as a dual-targeted therapy against advanced ovarian cancer were highlighted herein. Furthermore, a discussion on the prospect and challenge of inducing ferroptosis as an innovative therapeutic approach for reversing remedial resistance in cancer interventions was included. It is hoped this proof-of-concept review will indicate appropriate directions for speeding up the translational application of ferroptosis-inducing compounds (FINs) to improve the efficacy of ovarian cancer treatment.

Modulating the tumor immune microenvironment with nanoparticles: A sword for improving the efficiency of ovarian cancer immunotherapy

With encouraging antitumor effects, immunotherapy represented by immune checkpoint blockade has developed into a mainstream cancer therapeutic modality. However, only a minority of ovarian cancer (OC) patients could benefit from immunotherapy. The main reason is that most OC harbor a suppressive tumor immune microenvironment (TIME). Emerging studies suggest that M2 tumor-associated macrophages (TAMs), T regulatory cells (Tregs), myeloid-derived suppressor cells (MDSCs), and cancer-associated fibroblasts (CAFs) are enriched in OC. Thus, reversing the suppressive TIME is considered an ideal candidate for improving the efficiency of immunotherapy. Nanoparticles encapsulating immunoregulatory agents can regulate immunocytes and improve the TIME to boost the antitumor immune response. In addition, some nanoparticle-mediated photodynamic and photothermal therapy can directly kill tumor cells and induce tumor immunogenic cell death to activate antigen-presenting cells and promote T cell infiltration. These advantages make nanoparticles promising candidates for modulating the TIME and improving OC immunotherapy. In this review, we analyzed the composition and function of the TIME in OC and summarized the current clinical progress of OC immunotherapy. Then, we expounded on the promising advances in nanomaterial-mediated immunotherapy for modulating the TIME in OC. Finally, we discussed the obstacles and challenges in the clinical translation of this novel combination treatment regimen. We believe this resourceful strategy will open the door to effective immunotherapy of OC and benefit numerous patients.

The Development of a Three-Dimensional Platform for Patient-Derived Ovarian Cancer Tissue Models: A Systematic Literature Review

There is an unmet biomedical need for ex vivo tumour models that would predict drug responses and in turn help determine treatment regimens and potentially predict resistance before clinical studies. Research has shown that three dimensional models of ovarian cancer (OvCa) are more realistic than two dimensional in vitro systems as they are able to capture patient in vivo conditions in more accurate manner. The vast majority of studies aiming to recapitulate the ovarian tumour morphology, behaviors, and study chemotherapy responses have been using ovarian cancer cell lines. However, despite the advantages of utilising cancer cell lines to set up a platform, they are not as informative as systems applying patient derived cells, as cell lines are not able to recapitulate differences between each individual patient characteristics. In this review we discussed the most recent advances in the creation of 3D ovarian cancer models that have used patient derived material, the challenges to overcome and future applications.

High HOXA9 gene expression predicts response to chemotherapy and prognosis of high-grade serous ovarian cancer patients

Objective

High-grade serous ovarian cancer (HGSOC) is a deadly malignancy. Homeobox protein A9 ( HOXA9) is linked with serous papillary histotype differentiation, and inappropriate HOXA9 expression is a step in ovarian cancer that induces aberrant differentiation. This study aimed to reveal the significance of HOXA9 in HGSOC.

Methods

HOXA9 mRNA and protein expression were examined by quantitative PCR and immunohistochemistry, respectively. The chi-square test was used to evaluate associations between HOXA9 expression and clinical characteristics. The prognostic value of HOXA9 was calculated by the Kaplan–Meier method. The Kaplan–Meier Plotter database was used to assess the prognostic value of HOXA9.

Results

The mRNA and protein expression of HOXA9 were significantly upregulated in chemotherapy-resistant HGSOC compared with chemotherapy-sensitive HGSOC. The chi-square test showed that high HOXA9 expression was significantly related with grade, clinical stage, and residual disease. High HOXA9 expression was significantly associated with poor prognosis. The Kaplan–Meier Plotter database further confirmed these results. Cox hazard regression showed that high HOXA9 expression was an independent prognostic factor for survival in HGSOC patients.

Conclusion

This study showed that HOXA9 expression was associated with chemotherapy resistance and poor outcomes in HGSOC patients. High HOXA9 expression might be a prognostic indicator for HGSOC.

Extracellular vesicle contents as non-invasive biomarkers in ovarian malignancies

Ovarian cancer most commonly presents at an advanced stage where survival is approximately 30% compared with >80% if diagnosed and treated before disease spreads. Diagnostic capabilities have progressed from surgical staging via laparotomy to image-guided biopsies and immunohistochemistry staining, along with advances in technology and medicine. Despite improvements in diagnostic capabilities, population-level screening for ovarian cancer is not recommended. Extracellular vesicles (EVs) are 40–150 nm structures formed when the cellular lipid bilayer invaginates. These structures function in cell signaling, immune responses, cancer progression, and establishing the tumor microenvironment. EVs are found in nearly every bodily fluid, including serum, plasma, ascites, urine, and effusion fluid, and contain molecular cargo from their cell of origin. This cargo can be analyzed to yield information about a possible malignancy. In this review we describe how the cargo of EVs has been studied as biomarkers in ovarian cancer. We bring together studies analyzing evidence for various cargos as ovarian cancer biomarkers. Then, we describe the role of EVs in modulation of the tumor microenvironment. This review also summarizes the therapeutic and translational potential of EVs for their optimal utilization as non-invasive biomarkers for novel treatments against cancer.

microRNA-26b inhibits growth and cellular invasion of ovarian cancer cells by targeting estrogen receptor α

The current study set out to elucidate the mechanism of miR-26b in OC cell proliferation and EMT via suppression of ERα. Initial findings illustrated that miR-26b was poorly expressed in OC tissues and cells. On the other hand, over-expression of miR-26b exerted a diminishing effect on SKOV3 cell proliferation, migration, invasion and EMT, whereas silencing of miR-26b conferred an enhancing effect on CAOV3 cell proliferation, migration, invasion and EMT. Subsequently, with help from the TargetScan database, a dual-luciferase reporter gene assay was carried out to verify the targeting relation between miR-26b and ERα, which revealed that miR-26b could negatively modulate ERα. Furthermore, the in vivo experimentation illustrated that over-expression of miR-26b led to down-regulation of ERα and suppression OC tumor growth and EMT. Meanwhile, silencing of ERα inhibited OC cell proliferation, migration, invasion and EMT. In conclusion, our findings indicated that miR-26b inhibited OC cell proliferation and EMT via negative-modulation of ERα. This investigation may offer potential strategy for OC treatment.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-022-03222-2.

DDR2 Expression in Cancer-Associated Fibroblasts Promotes Ovarian Cancer Tumor Invasion and Metastasis through Periostin-ITGB1

Ovarian cancer has the highest mortality of all gynecologic malignancies. As such, there is a need to identify molecular mechanisms that underlie tumor metastasis in ovarian cancer. Increased expression of receptor tyrosine kinase, DDR2, has been associated with worse patient survival. Identifying downstream targets of DDR2 may allow specific modulation of ovarian cancer metastatic pathways. Additionally, stromal cells play a critical role in metastasis. The crosstalk between tumor and stromal cells can lead to tumor progression. We first identified that tumor cells co-cultured with DDR2-expressing fibroblasts had lower periostin expression when compared to tumor cells co-cultured with DDR2-depleted fibroblasts. We confirmed that DDR2 regulates POSTN expression in ovarian cancer-associated fibroblasts (CAFs). We found that mesothelial cell clearance and invasion by tumor cells were enhanced three-fold when DDR2 and POSTN-expressing CAFs were present compared to DDR2 and POSTN-depleted CAFs. Furthermore, DDR2-depleted and POSTN-overexpressing CAFs co-injected with ovarian tumor cells had increased tumor burden compared to mice injected with tumor cells and DDR2 and POSTN-depleted CAFs. Furthermore, we demonstrated that DDR2 regulates periostin expression through integrin B1 (ITGB1). Stromal DDR2 is highly correlated with stromal POSTN expression in ovarian cancer patient tumors. Thus, DDR2 expression in CAFs regulates the steps of ovarian cancer metastasis through periostin.

Green Tea Epigallocatechin-3-Gallate Regulates Autophagy in Male and Female Reproductive Cancer

With a rich abundance of natural polyphenols, green tea has become one of the most popular and healthiest nonalcoholic beverages being consumed worldwide. Epigallocatechin-3-gallate (EGCG) is the predominant catechin found in green tea, which has been shown to promote numerous health benefits, including metabolic regulation, antioxidant, anti-inflammatory, and anticancer. Clinical studies have also shown the inhibitory effects of EGCG on cancers of the male and female reproductive system, including ovarian, cervical, endometrial, breast, testicular, and prostate cancers. Autophagy is a natural, self-degradation process that serves important functions in both tumor suppression and tumor cell survival. Naturally derived products have the potential to be an effective and safe alternative in balancing autophagy and maintaining homeostasis during tumor development. Although EGCG has been shown to play a critical role in the suppression of multiple cancers, its role as autophagy modulator in cancers of the male and female reproductive system remains to be fully discussed. Herein, we aim to provide an overview of the current knowledge of EGCG in targeting autophagy and its related signaling mechanism in reproductive cancers. Effects of EGCG on regulating autophagy toward reproductive cancers as a single therapy or cotreatment with other chemotherapies will be reviewed and compared. Additionally, the underlying mechanisms and crosstalk of EGCG between autophagy and other cellular processes, such as reactive oxidative stress, ER stress, angiogenesis, and apoptosis, will be summarized. The present review will help to shed light on the significance of green tea as a potential therapeutic treatment for reproductive cancers through regulating autophagy.