Epithelial Ovarian Cancer Progression Research Articles

Identification of two theranostic biomarker panels for epithelial ovarian cancer.

Epithelial Ovarian cancer (EOC) is the leading cause of death associated with gynecologic tumors. Because the disease is asymptomatic in early-stage, the majority of patients are not diagnosed until late stages, highlighting the need for the development of novel diagnostic biomarkers. Mediators of tumoral microenvironment may affect EOC progression and resistance to treatment. Analysis of serum proteins to identify a panel of theranostic biomarkers for EOC. Serum levels of 65 analytes were determined in EOC patients, and healthy controls with the ProcartaPlex Human Immune Monitoring 65-Plex Panel. Twenty-one analytes: 7 cytokines (IFN-γ, IL-12p70, IL-13, IL-18 and TSLP), 7 chemokines (Eotaxin, eotaxin-2, IP-10, BLC, I-TAC, SDF-1α, and fractalkine), 2 growth factors (MMP-1, VEGF-α), and 5 soluble receptors (APRIL, CD40L, TWEAK, CD30 and TNFRII; were significantly differentially expressed between the two groups. ROC curves showed that only seven of them (IL-9, TNF-α, Eotaxin, IP-10, BLC, Fractalkine, and Tweak) had AUC values greater than 0.70 and thus had potential clinical utility. Moreover, five cytokines: IFN-γ, IL-1 β, IL-8, MIP-1β, and TNF-α are positively associated with patients who developed resistance to taxol-platinum-based chemotherapy (CT). This study has revealed a first panel of 7 analytes (IL-9, TNF-α, Eotaxin, IP-10, BLC, Fractalkine and Tweak) that can be used for early detection of EOC and a second panel of five cytokines (IFN-γ, IL-1β, IL-8, MIP-1β, TNF-α) that can help clinicians to identify EOC patients who are at higher risk to develop resistance to CT of EOC.

NUF2 overexpression contributes to epithelial ovarian cancer progression via ERBB3-mediated PI3K-AKT and MAPK signaling axes.

NDC80 kinetochore complex component (NUF2) is upregulated and plays an important role in various human cancers. However, the function and mechanism of NUF2 in epithelial ovarian cancer (EOC) remain unclear. NUF2 expression was detected in EOC tissues and cell lines. The effects of NUF2 downregulation on cell proliferation, migration and invasion in EOC were analyzed by CCK-8 and Transwell assays. Meanwhile, the effect of NUF2 downregulation on tumor growth in vivo was determined by xenograft tumor models. The mechanisms by which NUF2 regulates EOC progression were detected by RNA sequencing and a series of in vitro assays. We showed that NUF2 was significantly upregulated in EOC tissues and cell lines, and high NUF2 expression was associated with FIGO stage, pathological grade and poor EOC prognosis. NUF2 downregulation decreased cell proliferation, migration, invasion and tumor growth in nude mice. RNA sequencing studies showed that NUF2 knockdown inhibited several genes enriched in the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)-AKT serine/threonine kinase (AKT) and mitogen-activated protein kinase (MAPK) signaling pathways. Erb-B2 receptor tyrosine kinase 3 (ERBB3) was the key factor involved in both of the above pathways. We found that ERBB3 silencing could inhibit EOC progression and repress activation of the PI3K-AKT and MAPK signaling pathways. Furthermore, the exogenous overexpression of ERBB3 partially reversed the inhibitory effects on EOC progression induced by NUF2 downregulation, while LY294002 and PD98059 partially reversed the effects of ERBB3 upregulation. These results showed that NUF2 promotes EOC progression through ERBB3-induced activation of the PI3K-AKT and MAPK signaling axes. These findings suggest that NUF2 might be a potential therapeutic target for EOC.

Extracellular Vesicle-Packaged circATP2B4 Mediates M2 Macrophage Polarization via miR-532-3p/SREBF1 Axis to Promote Epithelial Ovarian Cancer Metastasis.

Ovarian cancer is one of the most common gynecologic malignancies with a highly immunosuppressive tumor microenvironment (TME) and poor prognosis. Circular RNA (circRNA) is a type of noncoding RNA with high stability, which has been shown to play an important role in biological processes and TME reprogramming in a variety of tumors. The biological function of a novel circRNA, circATP2B4, in epithelial ovarian cancer (EOC) was detected and evaluated. Transmission electron microscopy, differential ultracentrifugation and qRT-PCR were used to verify the existence of extracellular vesicles (EV)-packaged circATP2B4. Macrophage uptake of circATP2B4 was determined by EVs tracing. Dual luciferase reporter, FISH, Western blotting, and flow cytometry assays were used to investigate the interactions between circATP2B4 and miR-532-3p as well as sterol regulatory element-binding factor 1 (SREBF1) expression in macrophages. CircATP2B4 was upregulated in EOC tissues and positively correlated with ovarian cancer progression. Functionally, circATP2B4 promoted carcinogenic progression and metastasis of EOC both in vitro and in vivo. Mechanistically, EV-packaged circATP2B4 in EOC could be transmitted to infiltrated macrophages and acted as competing endogenous RNA of miR-532-3p to relieve the repressive effect of miR-532-3p on its target SREBF1. Furthermore, circATP2B4 induced macrophage M2 polarization by regulating the miR-532-3p/SREBF1/PI3Kα/AKT axis, thereby leading to immunosuppression and ovarian cancer metastasis. Collectively, these data indicate that circATP2B4-containing EVs generated by EOC cells promoted M2 macrophages polarization and malignant behaviors of EOC cells. Thus, targeting EVs-packaged circATP2B4 may provide a potential diagnosis and treatment strategy for ovarian cancer.

Single-Cell Sequencing of Malignant Ascites Reveals Transcriptomic Remodeling of the Tumor Microenvironment during the Progression of Epithelial Ovarian Cancer

Epithelial ovarian cancer (EOC) is the main cause of mortality among gynecological malignancies worldwide. Although patients with EOC undergo aggregate treatment, the prognosis is often poor. Peritoneal malignant ascites is a distinguishable clinical feature in EOC patients and plays a pivotal role in tumor progression and recurrence. The mechanisms of the tumor microenvironment (TME) in ascites in the regulation of tumor progression need to be explored. We comprehensively analyzed the transcriptomes of 4680 single cells from five EOC patients (three diagnostic samples and two recurrent samples) derived from Gene Expression Omnibus (GEO) databases. Batch effects between different samples were removed using an unsupervised deep embedding single-cell cluster algorithm. Subcluster analysis identified the different phenotypes of cells. The transition of a malignant cell state was confirmed using pseudotime analysis. The landscape of TME in malignant ascites was profiled during EOC progression. The transformation of epithelial cancer cells into mesenchymal cells was observed to lead to the emergence of related anti-chemotherapy and immune escape phenotypes. We found the activation of multiple biological pathways with the transition of tumor-associated macrophages and fibroblasts, and we identified the infiltration of CD4+CD25+ T regulatory cells in recurrent samples. The cell adhesion molecules mediated by integrin might be associated with the formation of the tumorsphere. Our study provides novel insights into the remodeling of the TME heterogeneity in malignant ascites during EOC progression, which provides evidence for identifying novel therapeutic targets and promotes the development of ovarian cancer treatment.

CircBNC2 affects epithelial ovarian cancer progression through the miR-223-3p/ LARP4 axis.

Epithelial ovarian cancer (EOC) is one of the most serious cancer. Circular RNA BNC2 (circBNC2) expression was decreased in EOC tissues. However, the molecular mechanism of circBNC2 remains unknown. The expression of circBNC2, microRNA-223-3p (miR-223-3p), and La-related proteins 4 ( LARP4 ) were detected by quantitative real-time fluorescence PCR (qRT-PCR). A series of in-vitro experiments were designed to explore the function of circBNC2 in EOC cells and the regulatory mechanism between circBNC2 and miR-223-3p and LARP4 in EOC cells. Western blot examined the protein levels of Snail1, Slug, and LARP4 . The relationship between miR-223-3p and circBNC2 or LARP4 was verified by Dual-luciferase reporter assays. The xenotransplantation model was established to study the role of circBNC2 in vivo . The expression of circBNC2 and LARP4 was decreased in EOC tissues, while the expression of miR-223-3p was increased. CircBNC2 can sponge miR-223-3p, and LARP4 is the target of miR-223-3p. In-vitro complement experiments showed that overexpression of circBNC2 significantly decreased the malignant behavior of EOC, while co-transfection of miR-223-3p mimics partially upregulated this change. In addition, LARP4 knockdown increased the proliferation, migration, and invasion of EOC cells inhibited by miR-223-3p inhibitor. Mechanically, circBNC2 regulates LARP4 expression in EOC cells by spongy miR-223-3p. In addition, in-vivo studies have shown that overexpression of circBNC2 inhibits tumor growth. Overexpression of circBNC2 decreased proliferation, migration, and invasion of EOC cells by regulating the miR-223-3p/ LARP4 axis, suggesting that circBNC2/miR-223-3p/ LARP4 axis may be a potential regulatory mechanism for the treatment of EOC.

FTO Inhibits Epithelial Ovarian Cancer Progression by Destabilising SNAI1 mRNA through IGF2BP2.

Fat mass and obesity-associated protein (FTO) regulates critical pathways in various diseases, including malignant tumours. However, the functional link between FTO and its target genes in epithelial ovarian cancer (EOC) development remains to be elucidated. In this study, the biological functions of FTO were verified in vitro and in vivo. The m6A modification and the binding sites of SNAI1 mRNA were confirmed by m6A RNA immunoprecipitation (MeRIP) and RIP experiments. The actinomycin D assay was used to test the stability of RNA. We found that FTO was downregulated with increased m6A levels in EOC. Reduced expression of FTO was associated with a higher FIGO stage in patients with EOC. Mechanistically, FTO decreased the m6A level and stability of SNAI1 mRNA, causing downregulation of SNAI1 and inhibiting epithelial-mesenchymal transition (EMT). Furthermore, FTO-mediated downregulation of SNAI1 expression depended on IGF2BP2, which acted as an m6A reader binding to the 3' UTR region of SNAI1 mRNA to promote its stability. In conclusion, FTO inhibits SNAI1 expression to attenuate the growth and metastasis of EOC cells in an m6A-IGF2BP2-dependent manner. Our findings suggest that the FTO-IGF2BP2-SNAI1 axis is a potential therapeutic target in EOC.

Endogenous Propionibacterium acnes Promotes Ovarian Cancer Progression via Regulating Hedgehog Signalling Pathway.

The oncogenesis and progression of epithelial ovarian cancer (EOC) is a complicated process involving several key molecules and factors, yet whether microbiota are present in EOC, and their role in the development of EOC, remains greatly unknown. In this study, 30 patients were enrolled to compare the similarities and differences of intratumour microbiota among patients with epithelial benign ovarian tumours (EBOTs) and patients with EOC based on the high-throughput sequencing method. Subsequently, we further isolated the specific EOC-related bacteria and defined Propionibacterium acnes as a key strain in facilitating EOC progression. More importantly, we constructed a mouse EOC model to evaluate the effect of the P. acnes strain on EOC using immunohistochemistry, Western blotting, and RT-qPCR. The high-throughput sequencing showed that the intratumour microbiota in EOC tissues had a higher microbial diversity and richness compared to EBOT tissues. The abundance of previously considered pathogens, Actinomycetales, Acinetobacter, Streptococcus, Ochrobacterium, and Pseudomonadaceae Pseudomonas, was increased in the EOC tissues. Meanwhile, we discovered the facilitating role of the P. acnes strain in the progression of EOC, which may be partially associated with the increased inflammatory response to activate the hedgehog (Hh) signalling pathway. This microbial-induced EOC progression mechanism is further confirmed using the inhibitor GANT61. This study profiled the intratumour microbiota of EBOT and EOC tissues and demonstrated that the diversity and composition of the intratumour microbiota were significantly different. Furthermore, through in vivo and in vitro experiments, we confirmed the molecular mechanism of intratumour microbiota promotion of EOC progression in mice, which induces inflammation to activate the Hh signalling pathway. This could provide us clues for improving EOC treatment.

Changes in subcellular localization of Lysyl-tRNA synthetase and the 67-kDa laminin receptor in epithelial ovarian cancer metastases.

Although lysyl-tRNA synthetase (KARS1) is predominantly located in the cytosol, it is also present in the plasma membrane where it stabilizes the 67-kDa laminin receptor (67LR). This physical interaction is strongly increased under metastatic conditions. However, the dynamic interaction of these two proteins and the turnover of KARS1 in the plasma membrane has not previously been investigated. Our objective in this study was to identify the membranous location of KARS1 and 67LR and investigate if this changes with the developmental stage of epithelial ovarian cancer (EOC) and treatment with the inhibitor BC-K01. In addition, we evaluated the therapeutic efficacy of BC-K01 in combination with paclitaxel, as the latter is frequently used to treat patients with EOC. Overall survival and prognostic significance were determined in EOC patients according to KARS1 and 67LR expression levels as determined by immunohistochemistry. Changes in the location and expression of KARS1 and 67LR were investigated in vitro after BC-K01 treatment. The effects of this compound on tumor growth and apoptosis were evaluated both in vitro and in vivo. EOC patients with high KARS1 and high 67LR expression had lower progression-free survival rates than those with low expression levels of these two markers. BC-K01 reduced cell viability and increased apoptosis in combination with paclitaxel in EOC cell xenograft mouse models. BC-K01 decreased membranous KARS1 expression, causing a reduction in 67LR membrane expression in EOC cell lines. BC-K01 significantly decreased in vivo tumor weight and number of nodules, especially when used in combination with paclitaxel. Co-localization of KARS1 and 67LR in the plasma membrane contributes to EOC progression. Inhibition of the KARS1-67LR interaction by BC-K01 suppresses metastasis in EOC.

NANOG regulates epithelial-mesenchymal transition via AMPK/mTOR signalling pathway in ovarian cancer SKOV-3 and A2780 cells.

NANOG engages with tumour initiation and metastasis by regulating the epithelial–mesenchymal transition (EMT) in epithelial ovarian cancer (EOC). However, its role in association with pAMPKα, and its clinical significance in EOC have not been elucidated even though AMPK is known to degrade NANOG in various human cancers. Hence, we investigated the role of pAMPKα and its association with NANOG as potential prognostic biomarkers in EOC. Both NANOG and pAMPKα expression were significantly overexpressed in EOCs comparing nonadjacent normal epithelial tissues, benign tissues, and borderline tumours. NANOG overexpression was significantly associated with poor disease‐free survival (DFS) and overall survival (OS), whereas pAMPKα overexpression was associated with good DFS and OS. Importantly, multivariate analysis revealed that the combination of high NANOG and low pAMPKα expression was a poor independent prognostic factor for DFS and was associated with platinum resistance. In ovarian cancer cell lines, siRNA‐mediated NANOG knockdown diminished migration and invasion properties by regulating the EMT process via the AMPK/mTOR signalling pathway. Furthermore, treatment with AMPK activator suppressed expression of stemness factors such as NANOG, Oct4 and Sox2. Collectively, these findings established that the combination of high NANOG and low pAMPKα expression was associated with EOC progression and platinum resistance, suggesting a potential prognostic biomarker for clinical management in EOC patients.

SLC7A1 Overexpression Is Involved in Energy Metabolism Reprogramming to Induce Tumor Progression in Epithelial Ovarian Cancer and Is Associated with Immune-Infiltrating Cells.

Cationic amino acid transporters (SLC7A1/CAT1) are highly expressed in human ovarian cancer (OC) tissues. However, the specific biological functions and mechanisms involved remain unclear. We used bioinformatics analysis to explore SLC7A1 expression level, prognostic value, and tumor mutation burden (TMB) in ovarian cancer (OC) tissues. We performed in vitro experiments to identify the expression and biological function of SLC7A1 in epithelial ovarian cancer (EOC) tissues and cells. An amino acid autoanalyzer was used to detect the effect of SLC7A1 on amino acid metabolism in EOC cells. Finally, SLC7A1 in OC was evaluated for cell-to-cell signalling and immune infiltration using online databases. We found that increased SLC7A1 expression in EOC cells and tissues was associated with poorer survival outcomes (P < 0.05) but not with tumor stage or grade of OC (P > 0.05). SLC7A1 is involved in the transport of phenylalanine and arginine in EOC cells, and its knockdown reduced the proliferation and migration of EOC cells and the resistance of cells to cisplatin. Furthermore, the TIMER database indicated that SLC7A1 overexpression was significantly positively correlated with levels of CD4+ memory resting cells, CD8+ effector memory cells, M0 macrophages, and cancer-associated fibroblasts (CAFs) in OC (P < 0.05) and significantly negatively correlated with CD4+ memory-activated cells (P < 0.05). Cell immunofluorescence indicated that SLC7A1 overexpression may affect the distribution of immune-infiltrating lymphocytes in tumors by inhibiting the expression of CCL4. Therefore, we concluded that SLC7A1 is involved in the metabolic remodelling of amino acids in EOC to promote tumor development and cisplatin resistance and is related to the tumor-infiltrating immune microenvironment of OC. SLC7A1 is a biomarker for predicting EOC progression and cisplatin resistance and represents a promising target for EOC treatment.

PHGDH Inhibitor CBR-5884 Inhibits Epithelial Ovarian Cancer Progression via ROS/Wnt/β-Catenin Pathway and Plays a Synergistic Role with PARP Inhibitor Olaparib

PHGDH attaches importance to serine biosynthesis in cancer cells and maintaining mitochondrial redox homeostasis. However, the role of PHGDH inhibitor CBR-5884 in cell ROS level and its downstream pathways has not been explored in epithelial ovarian cancer. Thus, we investigated the function and possible mechanism of PHGDH inhibitor CBR-5884 on epithelial ovarian cancer in vitro and in vivo. A2780, OVCAR3, and ES-2 were treated with CBR-5884 at different concentrations or different time points. Results showed that CBR-5884 inhibited epithelial ovarian cancer cell proliferation, migration, and invasion and increases cell ROS level. Meanwhile, CBR-5884 exerts antitumor effect through activating ROS/Wnt/β-catenin pathway. Besides, CBR-5884 exerts antitumor effect in vivo. What's more, we explored the effect of CBR-5884 with or without PARP inhibitor Olaparib, which showed that the two together had a larger effect. In conclusion, PHGDH inhibitor CBR-5884 inhibits epithelial ovarian cancer proliferation, migration, and invasion through activating ROS/Wnt/β-catenin pathway and plays a synergistic role with PARP inhibitor olaparib, which provided a theoretical basis for PHGDH inhibitor CBR-5884 in clinical treatment.

COPS5 Conferred the Platinum Resistance in Epithelial Ovarian Cancer.

Development of platinum resistance is one of the major causes of epithelial ovarian cancer (EOC) treatment failure. COP9 signalosome subunit 5 (COPS5) was found to take part in the progression of EOC in our previous study. Herein, we aim to uncover the potential utility of COPS5 in EOC chemoresistance. COPS5 levels were analyzed to define clinic pathologic correlates using a matched tissue microarray and online datasets. The effect of COPS5 inhibition by the lentivirus-mediated short hairpin RNA on cell viability, proliferation and migration was accessed in vitro and in vivo. Results showed that COPS5 was upregulated in patients after platinum resistance. Kaplan–Meier survival curves revealed that COPS5 overexpression was correlated with shorter PFS and OS. COPS5 downregulation inhibited the cell proliferation, migration, and reduced the sensitivity of EOC to platinum. Overall, our data indicated that COPS5 inhibition might represent a new therapeutic strategy for overcoming platinum resistance in patients with EOC.

NANOG regulates tumor metastasis via AMPK/mTOR signaling pathway in patients with epithelial ovarian cancer (252)

<b>Objectives:</b> NANOG engages with tumor initiation and metastasis by regulating EMT (epithelial-mesenchymal transition) in epithelial ovarian cancer (EOC). However, its role in association with pAMPK and its clinical significance in EOC has not been elucidated, even though pAMPK is known to degrade NANOG in various human cancer. Therefore, here we investigated the role of pAMPK and its association with NANOG as a potential prognostic, predictive biomarker in EOC. <b>Methods:</b> Immunohistochemistry of NANOG and pAMPK in epithelial ovarian cancer tissues were performed to define the clinical significance with TMA. Moreover, ovarian cancer cell lines were used for functional studies to investigate the underlying mechanisms. <b>Results:</b> Both NANOG and pAMPK expression were significantly overexpressed in EOCs compared to nonadjacent normal epithelial tissues, benign tissues, and borderline tumors. NANOG overexpression was significantly associated with poor DFS and OS, whereas pAMPK overexpression was associated with good DFS and OS. Importantly, multivariate analysis revealed that combining high NANOG and low pAMPK expression was an independent prognostic factor for DFS and associated with poor platinum resistance. In ovarian cancer cell lines, NANOG knockdown diminished migration and invasion property by regulating the EMT process via the AMPK/mTOR signaling pathway. Furthermore, treatment of AMPK activator suppressed expression of stemness-related genes, such as <i>NANOG, Oct4</i>, and <i>Sox2</i>. <b>Conclusions:</b> Collectively, our findings established that a combination of high NANOG and low pAMPK expression was associated with EOC progression and platinum resistance, suggesting a potential predictive biomarker for clinical management in EOC patients. Also, NANOG knockdown inhibited tumor metastasis and invasion by regulating EMT via the AMPK/mTOR signaling pathway.

Ketogenic Diet Promotes Epithelial Ovarian Cancer Progression and Alters Tumor Gene Expression in-vivo (104)

<b>Objectives:</b> The ketogenic diet (KD) is hypothesized to impact tumor progression indirectly through altering the immune system as well as directly at the cellular level. Our studies were designed to assess changes in tumor resident immune cells and tumor gene expression in relation to epithelial ovarian cancer (EOC) progression in KD-fed mice. <b>Methods:</b> ID8 EOC cells, syngeneic with C57Bl/6J mouse strain, transfected with luciferase (ID8-Luc), were injected and monitored for tumor development via imaging with an <i>in vivo</i> Imaging System (IVIS) intraperitoneal D-luciferin. Tumor-bearing mice were fed a KD (10% protein, 0% carbohydrates, 90% fat), high fat diet (HFD) (10% protein, 15% carbohydrates, 75% fat), or control diet (CD) (10% protein, 77% carbohydrates, and 13% fat) (<i>n</i>=10 mice per group). EOC tumor growth was monitored weekly, and tumor burden was determined based on total flux recorded in photons/second measured. At the endpoint, tumors were collected and processed for flow cytometry and RNAseq analysis. Single-cell dissociated tumors (Papain System) were stained with an immune targeted antibody panel and analyzed on the BD Cytek Aurora. RNA was isolated (Qiagen), and sequencing was performed. Statistical tests included analysis of variance (ANOVA), permutational multivariate analysis (PERMANOVA), linear regression, and Wilcoxon test; a p-value of <0.05 was considered statistically significant. <b>Results:</b> Throughout the study, KD-fed mice exhibited a statistically significant increase in tumor progression. We observed a 9.1-fold increase in tumor volume from baseline in the KD-fed group compared to HFD and CD-fed groups (9.1 vs 2.0 vs 3.1-fold, respectively, p<0.001). At the endpoint, tumor-associated macrophages (TAM) were significantly enriched and activated lymphoid cells (NK cells) were significantly diminished in the KD group (p<0.001). There was a trend toward increased M2:M1 polarization in KD-fed mice. However, there was no significant difference in Treg cells or activated CD8+ cells among diet groups. EOC tumors in KD-fed mice exhibited a significant decrease in differential gene expression on RNA seq compared to CD- and HFD-fed tumors, with no significant difference between CD- and HFD-fed groups at the gene expression level. Gene set enrichment analysis (GSEA) demonstrated that EOC tumors from KD-fed mice had enhanced angiogenesis, inflammatory response, and epithelial to mesenchymal transition (EMT) phenotype, as well as altered lipid metabolism. Specifically, an increase in lipid catalytic activity and catabolism and decrease in lipid synthesis were noted among KD-fed mice versus HFD-fed mice. <b>Conclusions:</b> KD induced tumor progression in our murine EOC model compared to HFD and CD. KD was associated with an increase in TAM and a decrease in activated NK cells consistent with a protumorigenic immune environment. KD-fed mice exhibited markedly increased alterations in angiogenesis, inflammation, and EMT pathways with enhanced lipid catabolic activity. Further testing of KD in human EOC cells is needed to clarify the <i>in-vivo</i> effect of KD on EOC growth.Fig. 1

The impact of ketogenic diet on the gut microbiome and tumor growth in an in vivo epithelial ovarian cancer model (105)

<b>Objectives:</b> The ketogenic diet (KD) is hypothesized to protect against cancer progression due to metabolic reprogramming. Sustained dietary modifications alter the composition of the gut microbiome, which may influence tumor growth. Here, we present the impact of KD on the gut microbiome in relation to epithelial ovarian cancer (EOC) progression. <b>Methods:</b> C57Bl/6J ID8 (luciferase-tagged) tumor-bearing mice were fed a KD (10% protein, 0% carbohydrates, 90% fat), high fat diet (HFD) (10% protein, 15% carbohydrates, 75% fat), and control diet (CD) (10% protein, 77% carbohydrates, and 13% fat) (<i>n</i>=10 mice per group). Blood ketone and glucose levels were serially measured. EOC tumor growth was monitored with <i>in Vivo</i> Imaging System (IVIS) via intraperitoneal D-luciferin. Total tumor burden was measured in total flux (photons/second). Stool was collected at baseline, midpoint (four weeks after tumor cell injection), and endpoint (tumor mass of >150 mm³, ascites development, or weight loss >20%); 16S rDNA was isolated, and sequence reads were assigned to genus-level amplicon sequence variants (ASV) in DADA2 as well as analyzed for alpha and beta microbial diversity using Phyloseq. Statistical tests included analysis of variance (ANOVA), permutational multivariate analysis (PERMANOVA), linear regression, and Wilcoxon test. A p-value of <0.05 was considered statistically significant. <b>Results:</b> KD-fed mice exhibited an increase in ketone blood levels (2.22 mmol/L) compared to both HFD- (0.7 mmol/L, p<0.0001) and CD-fed mice (0.61 mmol/L, p<0.0001) at the endpoint. There was no significant difference in overall glucose levels or body mass composition between the groups. By day 42, there was a 9.1-fold increase in tumor growth from baseline in the KD-fed group compared to HFD-and CD-fed groups (9.1 vs 2.0 vs 3.1-fold, respectively, p<0.001 and p<0.001). By study endpoint, KD-fed mice exhibited a statistically significant increase in gut microbial alpha diversity in comparison to HFD and CD (p<0.01 at the midpoint and p<0.05 at the endpoint). Brays-Curtis dissimilarity based on microbial beta diversity demonstrated that the relative abundance of gut microbial species between the three groups was similar at baseline. However, KD-fed mice had significantly altered gut microbial composition than HFD-and CD-fed mice at both midpoint and endpoint (p = 0.001); 16S data analysis demonstrated a relative decrease in <i>Lactobacillus</i> and <i>Coriobacteriaceae</i> species and a relative increase in <i>Romboutsia</i> and <i>Akkermansia</i> species in the KD-fed mice. <b>Conclusions:</b> In our EOC murine model, KD was associated with increased EOC growth and distinct gut microbial alterations in comparison to HFD and CD. KD-fed mice exhibited increased gut microbial diversity over time, a relative depletion of bacterial species <i>Lactobacillus</i> and <i>Coriobacteriaceae</i>, and a relative enrichment of bacterial species <i>Romboutsia</i> and <i>Akkermansia</i>. Further studies are needed to understand the mechanisms underlying the relationship between KD, the gut microbiome, and EOC progression.Fig. 1

Glaucocalyxin A Inhibits the Malignant Progression of Epithelial Ovarian Cancer by Affecting the MicroRNA-374b-5p/HMGB3/Wnt-β-Catenin Pathway Axis.

ObjectiveGlaucocalyxin A (GLA) is an ent-kaurene diterpenoid from Rabdosia japonica var possessing anti-tumor activity. This study aimed to investigate effects of GLA on epithelial ovarian cancer (EOC) and elucidate underlying mechanisms.MethodsThe expression of HMGB3 in EOC tissues was analyzed by GEPIA and immunohistochemistry. Cell proliferation was determined using CCK-8 and colony formation assays. Cell invasion, migration, and apoptosis were detected using Transwell, wound healing, and flow cytometry assays, respectively. Interactions between HMGB3 and miRNAs were predicted using ENCORI and validated using a dual-luciferase assay. mRNA expression levels of HMGB3 and miRNAs were measured using qPCR. Protein expression levels of HMGB3, E-cadherin, N-cadherin, Wnt3a,β-catenin, Bcl-2, and Bax were measured by western blotting. A tumor xenograft model was established to validate the efficacy and mechanism of GLA in vivo.ResultsHMGB3 was upregulated in EOC tissues and cells. GLA dose-dependently inhibited EOC cell proliferation and epithelial-mesenchymal transition (EMT). HMGB3 overexpression promoted proliferation, invasion, migration, and EMT, and suppressed the apoptosis of EOC cells. In addition, miR-374b-5p was targeted by HMGB3, and its overexpression hindered malignant characteristics of EOC cells. HMGB3 overexpression weakened antitumor effects of GLA and miR-374b-5p in EOC cells. Moreover, the Wnt-β-catenin pathway was inhibited by the GLA-mediated miR-374b-5p/HMGB3 axis. In vivo experiments showed that GLA inhibited EOC tumor growth, meanwhile, upregulated the miR-374b-5p level and downregulated the expression of HMGB3, Wnt3a, and β-catenin in tumor tissues.ConclusionsGLA suppressed the malignant progression of EOC by regulating the miR-374b-5p/HMGB3/Wnt-β-catenin pathway axis.

Homo and Heterotypic Cellular Cross-Talk in Epithelial Ovarian Cancer Impart Pro-Tumorigenic Properties through Differential Activation of the Notch3 Pathway.

Simple SummaryThe omental metastatic spreading of epithelial ovarian cancer is spearheaded by complex cell–cell interactions present in the fluidic microenvironment (ascites), which is yet to be fully decoded. Using a unique co-culture model of SNFT (SKOV3 cells expressing a Notch3 luciferase reporter-sensor) and NIH3T3 cells (differentially overexpressing Jagged1 ligand), we demonstrated that incremental Jagged1 expression led to proportional Notch3 activation in SNFT. Differential Notch3 activation was also evident from co-culture of SNFT with other EOC cell lines and ascites-derived cancer-associated fibroblasts of HGSOC patients expressing varying levels of Jagged1. Amongst the top five modulated genes identified by the gene profiler array, both p21 and VEGFA showed enhanced expression (for p21)/secretion (for VEGFA) in SNFT when induced with Jagged1. Secreted VEGFA further reduced CSC differentiation in platinum-resistant A2780 cells. Pronounced VEGFA expression associated with Notch3 up-regulation in metastatic HGSOC tumors delineates an unknown role of the Notch3/VEGFA axis in EOC progression.An active fluidic microenvironment governs peritoneal metastasis in epithelial ovarian cancer (EOC), but its critical functional/molecular cues are not fully understood. Utilizing co-culture models of NIH3T3 cells (differentially overexpressing Jagged1) and SKOV3 cells expressing a Notch3 luciferase reporter-sensor (SNFT), we showed that incremental expression of Jagged1 led to proportional Notch3 activation in SNFT. With no basal luciferase activity, this system efficiently recorded dose-dependent Notch3 activation by rh-Jag1 peptide and the non-appearance of such induction in co-culture with NIH3T3Δjag1 cells indicates its sensitivity and specificity. Similar Notch3 modulation was shown for the first time in co-cultures with HGSOC patients’ ascites-derived cancer-associated fibroblasts and Jagged1-expressing EOC cell lines. NIH3T3J1-A and OVCAR3 co-cultured SNFT cells showed maximum proliferation, invasion, and cisplatin resistance among all the heterotypic/homotypic cellular partners. VEGFA and CDKN1A are the two most upregulated genes identified across co-cultures by the gene profiler array. Co-culture induced VEGFA secretion from SNFT cells which also reduced cancer stem cell differentiation in platinum-resistant A2780 cells. rh-Jag1-peptide promoted enhanced nuclear-cytoplasmic p21 expression. Additionally, metastatic HGSOC tumors had higher VEGFA than corresponding primary tumors. This study thus demonstrates the tumoral and non-tumoral cell-mediated differential Notch3 activation imparting its tumorigenic effects through two critical molecular regulators, VEGFA and p21, during EOC progression.

Influences of Gastrointestinal Microbiota Dysbiosis on Serum Proinflammatory Markers in Epithelial Ovarian Cancer Development and Progression.

Simple SummaryAdvanced epithelial ovarian cancer (EOC) is the deadliest gynecologic cancer due to the lack of available early screening methods that are available in clinical settings. Unique gastrointestinal (GI) microbiota have been detected in the ovaries and peritoneal fluid of women with EOC that are not found in women without disease. However, there are limited data available to determine possible links in GI microbiota composition and early ovarian cancer development while women are largely asymptomatic. This research utilizes an EOC animal model to investigate the effects of GI microbial disruption on systemic inflammation during early disease development and progression. The identification of distinct GI microbial communities that may potentially mediate systemic immune response during carcinogenesis can open new opportunities to disentangle the complex ovarian tumor microenvironment for the discovery of valid clinical tools for early EOC detection.GI microbiota has been implicated in producing the inflammatory tumor microenvironment of several cancers. Women with ovarian cancer often report GI-related symptoms at diagnosis although minimal is known about the possible GI bacteria that may trigger pro-tumorigenic immune responses in early EOC. The purpose of this study was to investigate the influences of GI microbiota dysbiosis on serum inflammatory markers during EOC utilizing a rodent model. This experimental design consisted of C57BL/6 mice randomly assigned to either the microbiota dysbiosis group (n = 6) or control group (n = 5). The CD7BL/6 mice assigned to the microbiota dysbiosis group were administered a mixture of broad-spectrum antibiotics (bacitracin and neomycin) for 2 weeks. Both groups were injected intraperitoneally with mouse ovarian epithelial cells that induce ovarian tumorigenesis. Levels of C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) were assessed in the serum, and the composition of the GI microbiota in fecal samples was measured using 16S rRNA gene sequencing. Overall CRP serum levels were significantly lower and TNFα levels were significantly higher in the microbiota dysbiosis group compared to the control group. The abundances of microbiota that correlated with CRP serum levels in the combined groups were genus Parabacteroides, Roseburia, and Emergencia and species Ruminococcus faecis, Parabacteroides distasonis, Roseburia Faecis, and Emergencia timonensis. This study provides evidence to support for further investigation of the GI microbial profiles in patients at risk of EOC.

CXCR4 knockdown enhances sensitivity of paclitaxel via the PI3K/Akt/mTOR pathway in ovarian carcinoma.

Epithelial ovarian cancer (EOC) is the deadliest gynecological malignancy. EOC control remains difficult, and EOC patients show poor prognosis regarding metastasis and chemotherapy resistance. The aim of this study was to estimate the effect of CXCR4 knockdown-mediated reduction of cancer stem cells (CSCs) and epithelial–mesenchymal transition (EMT) stemness and enhancement of chemotherapy sensitivity in EOC. Mechanisms contributing to these effects were also explored. Our data showed distinct contribution of CXCR4 overexpression by dependent PI3K/Akt/mTOR signaling pathway in EOC development. CXCR4 knockdown resulted in a reduction in CSCs and EMT formation and enhancement of chemotherapy sensitivity in tumor cells, which was further advanced by blocking CXCR4-PI3K/Akt/mTOR signaling. This study also documented the critical role of silencing CXCR4 in sensitizing ovarian CSCs to chemotherapy. Thus, targeting CXCR4 to suppress EOC progression, specifically in combination with paclitaxel (PTX) treatment, may have clinical application value.

Maelstrom promotes tumor metastasis through regulation of FGFR4 and epithelial-mesenchymal transition in epithelial ovarian cancer

BackgroundIncreasing evidence has indicated that Maelstrom (MAEL) plays an oncogenic role in various human carcinomas. However, the exact function and mechanisms by which MAEL acts in epithelial ovarian cancer (EOC) remain unclear.ResultsThis study demonstrated that MAEL was frequently overexpressed in EOC tissues and cell lines. Overexpression of MAEL was positively correlated with the histological grade of tumors, FIGO stage, and pT/pN/pM status (p < 0.05), and it also acted as an independent predictor of poor patient survival (p < 0.001). Ectopic overexpression of MAEL substantially promoted invasiveness/metastasis and induced epithelial-mesenchymal transition (EMT), whereas silencing MAEL by short hairpin RNA effectively inhibited its oncogenic function and attenuated EMT. Further study demonstrated that fibroblast growth factor receptor 4 (FGFR4) was a critical downstream target of MAEL in EOC, and the expression levels of FGFR4 were significantly associated with MAEL. (P < 0.05).ConclusionOur findings suggest that overexpression of MAEL plays a crucial oncogenic role in the development and progression of EOC through the upregulation of FGFR4 and subsequent induction of EMT, and also provide new insights on its potential as a therapeutic target for EOC.