Tumor Growth In Epithelial Ovarian Cancer Research Articles

Polystyrene nanoparticle exposure accelerates ovarian cancer development in mice by altering the tumor microenvironment

Microplastics and nanoplastics are ubiquitous pollutants, widely spread in the living and natural environment. Although their potential impact on human health has been investigated, many doubts remain about their effects in carcinogenic processes. We investigated the potential effects and its molecular mechanisms of polystyrene nanoplastics (PS-NPs) on epithelial ovarian cancer (EOC) using the human EOC cell line HEY as an in vitro cell model and mice as a mammalian model. In vivo exposure to PS-NPs (100 nm; 10 mg/L) via drinking water significantly accelerated EOC tumor growth in mice. In in vitro tests the PS-NPs reduced the relative viability of EOC cells in a dose-dependent manner. Histological analysis showed increased mitotic counts in EOC tumor tissues of PS-NP exposed mice. PS-NP exposure significantly affected gene expression and disturbed many metabolic pathways in both cultured EOC cells and EOC tumor tissue in mice. Gene functional and pathway analysis indicated that immune-related responses and the tumor microenvironment pathway were significantly enriched, which may be attributed to disturbed expression of thrombomodulin (THBD) and its regulators. It may be concluded that PS-NP exposure caused a significant acceleration of EOC tumor growth in mice and a dose-dependent decrease in the relative viability of EOC cells by altering the tumor growth microenvironment. This offers new insights into the mechanisms underlying PS-NP effects on EOC.

Unrestricted Ketogenic Diet Feeding Enhances Epithelial Ovarian Cancer Growth In Vivo.

The ketogenic diet (KD) is hypothesized to impact tumor progression by altering tumor metabolism. In this study, we assessed the impact of an unrestricted KD on epithelial ovarian cancer (EOC) tumor growth, gene expression, and metabolite concentration in a mouse model. ID8 EOC cells, which were syngeneic with C57Bl/6J mouse strain and transfected with luciferase (ID8-luc), were injectedand monitored for tumor development. Female mice were fed either a strict KD, a high fat/low carbohydrate (HF/LC) diet, or a low fat/high carbohydrate (LF/HC) diet (n = 10 mice per group) ad libitum. EOC tumor growth was monitored weekly, and tumor burden was determined based on luciferase fluorescence (photons/second). At the endpoint (42 days), tumors were collected and processed for RNA sequencing. Plasma and tumor metabolites were evaluated using LC-MS. The KD-fed mice exhibited a statistically significant increase in tumor progression in comparison to the HF/LC- and LF/HC-fed groups (9.1 vs. 2.0 vs. 3.1-fold, respectively, p < 0.001). The EOC tumors of the KD-fed mice exhibited significant enrichment of the peroxisome proliferator-activated receptor (PPAR) signaling and fatty acid metabolism pathways based on the RNA sequencing analysis when compared to the LF/HC- and HF/LC-fed mice. Thus, unrestricted KD diet enhanced tumor progression in our mouse EOC model. KD was associated with the upregulation of fatty acid metabolism and regulation pathways, as well as enrichment of fatty acid and glutamine metabolites.

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.

High GNG13 expression is associated with poor survival in epithelial ovarian cancer and breast cancer.

Recently, change in the GNG13 expression has been shown to result in multiple congenital malformations and sexual reversal, and it was also found in the brain. The aim of this study was to measure the expression levels in epithelial ovarian cancer (EOC) and breast cancer (BC) and assess their value as a potential prognostic marker. The correlation of GNG13 protein expression was detected by immunohistochemistry (IHC) in 119 EOC and 125 BC tissues. Assessment of the associations between GNG13 levels and various clinicopathological features was identified, the relationship between GNG13 and prognosis in BC and EOC patients was analyzed using online resources of Oncomine and Kaplan-Meier plotter. Protein expression levels of GNG13 were both significantly lower in BC and EOC compared with normal tissues (p<0.0001 and p<0.001, respectively). Among the clinicopathological characteristics of BC, tumor grade (p=0.001) and TNM stage (p=0.001) were significantly associated with low expression of GNG13. While in EOC, low expression of GNG13 was significantly related to FIGO stage (p=0.001), presence of metastasis (p=0.001), and CA125 (p=0.001). Our data suggest that GNG13 expression maybe as a new inhibitor, which can strongly inhibit metastasis and partially attenuates tumor growth in EOC and BC.

LncRNA CDKN2A-AS1 facilitates tumorigenesis and progression of epithelial ovarian cancer via modulating the SOSTDC1-mediated BMP-SMAD signaling pathway

ABSTRACT Ovarian cancer (OC) is the fifth most common female malignant tumor and the leading cause of cancer-related death in women worldwide. Epithelial ovarian cancer (EOC) is the predominant type of OC. Investigating the mechanism underlying tumorigenesis and progression of EOC is urgent. Our previous research has shown that long non-coding RNAs (lncRNAs) CDKN2A-AS1 is upregulated in EOC tissues and cells. Furthermore, we have predicted that CDKN2A-AS1 is associated with the bone morphogenetic protein (BMP)-SMAD signaling pathway, which is negatively regulated by the sclerostin domain containing 1 (SOSTDC1). Therefore, we conjecture that the CDKN2A-AS1 regulate BMP-SMAD signaling pathway via interacting with SOSTDC1, which need more investigation. Moreover, the functions of the BMP-SMAD signaling pathway and the SOSTDC1 on EOC are still unclear. Herein, we unearthed that CDKN2A-AS1, BMP2/4/7, SMAD1/5/9 and phosphorylation of SMAD1/5/9 (p-SMAD1/5/9) were upregulated in EOC tissues and cells, whereas SOSTDC1 was downregulated in EOC tissues and cells. We firstly demonstrated that CDKN2A-AS1 bound directly with the SOSTDC1. CDKN2A-AS1 downregulated the expression of SOSTDC1, but upregulated the expression of BMP2/4/7, SMAD1/5/9, and p-SMAD1/5/9. CDKN2A-AS1 promoted the proliferation, migration, invasion of EOC cells and tumor growth in vivo, whereas SOSTDC1 inhibited the proliferation, migration, invasion of EOC cells. Knockdown SOSTDC1 rescued the inhibitory effect of si-lncRNA CDKN2A-AS1 on the EOC cells proliferation, migration and invasion. These results demonstrated that CDKN2A-AS1activated the BMP-SMAD signaling pathway by directly bind with SOSTDC1 to promote EOC tumor growth. CDKN2A-AS1/SOSTDC1 axis may provide a novel therapeutic strategy for EOC treatment.

Efficacy of Combination Therapy with Linalool and Doxorubicin Encapsulated by Liposomes as a Two-in-One Hybrid Carrier System for Epithelial Ovarian Carcinoma.

BackgroundEpithelial ovarian cancer (EOC) is a fatal gynecologic malignancy that is usually treated with chemotherapy after surgery. However, patients who receive chemotherapy experience severe side effects because of the inherent toxicity and high dose of chemotherapeutics. To overcome these issues, we suggest a combination therapeutic strategy using liposomes encapsulating linalool nanoemulsions (LN-NEs) and doxorubicin (DOX), a chemotherapeutic drug, to increase their synergistic antitumor efficacy and reduce the incidence of side effects from chemotherapeutics for EOC.MethodsThe physical properties of LN-NE-DOX-liposomes were characterized by light scattering with a particle size analyzer. Cell viability was determined by MTT assay. Therapeutic efficacy was evaluated in a mouse HeyA8 EOC tumor model of ovarian carcinoma. Additionally, biochemical toxicity was analyzed for levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and blood urea nitrogen (BUN) using BALB/c nude mice.ResultsThe size of the liposomes encapsulating LN-NEs and DOX (LN-NE-DOX-liposomes) was 267.0 ± 4.6 nm, with a loading efficiency of 55.1 ± 3.1% and 27.2 ± 0.9% for linalool and DOX, respectively. Cell viability after treatment with LN-NE-DOX-liposomes was significantly decreased compared to that of cells treated with DOX liposomes, and apoptosis was significantly increased. Additionally, LN-NE-DOX-liposomes significantly inhibited HeyA8 EOC tumor growth compared to that of the control (p < 0.01) and DOX-liposome-treated groups (p < 0.05), while decreasing cell proliferation (Ki67) and microvessel density (CD31), and promoting apoptosis (caspase-3) compared to the control (p < 0.05). Moreover, the liposomal formulations induced no significant differences in biochemical toxicity (AST, ALT, and BUN) compared to healthy control mice, indicating that the liposomal formulations showed no overt toxicity in mice.ConclusionThis study demonstrates that the production of LN-NE-DOX-liposomes is a pivotal approach for EOC treatment, suggesting a novel combination therapeutic strategy.

LINC01224 Exhibits Cancer-Promoting Activity in Epithelial Ovarian Cancer Through microRNA-485-5p-Mediated PAK4 Upregulation.

PurposeLong intergenic non-protein coding RNA 1224 (LINC01224) plays vital roles in the tumorigenesis and progression of hepatocellular carcinoma. Here, we determined LINC01224 expression in epithelial ovarian cancer (EOC) tissues and cells. We also assessed the effects of LINC01224 knockdown on the malignant phenotype of EOC cells both in vitro and in vivo. Furthermore, the detailed molecular mechanisms underlying the oncogenic actions of LINC01224 in EOC cells were elucidated.MethodsQuantitative real-time polymerase chain reaction (qRT-PCR) was used to detect LINC01224 expression in EOC tissues and cells. EOC cells were transfected with small interfering RNAs, and cell proliferation, apoptosis, migration, and invasion were assessed using Cell Counting Kit-8 assay, flow cytometry, cell migration assays, and cell invasion assays, respectively. Using tumor xenografts, the effects of LINC01224 silencing on EOC tumor growth were analyzed in vivo. The mechanism underlying LINC01224 regulation of malignant processes in EOC cells was explored using bioinformatics, RNA immunoprecipitation assay, qRT-PCR, Western blotting, and rescue experiments.ResultsLINC01224 expression was upregulated in EOC tissues and cells. LINC01224 upregulation was correlated to tumor size, the International Federation of Gynecology and Obstetrics stage, and lymph node metastasis. LINC01224 depletion in EOC cells suppressed cell proliferation, migration, and invasion and facilitated cell apoptosis in vitro. LINC01224 downregulation also hindered EOC tumor growth in vivo. Mechanistically, LINC01224 served as a competing endogenous RNA for microRNA-485-5p (miR-485-5p) and consequently increased p21-activated kinase 4 (PAK4) expression in EOC cells. Furthermore, miR-485-5p inhibition or PAK4 upregulation significantly abrogated the effects of LINC01224 depletion in EOC cells.ConclusionLINC01224/miR-485-5p/PAK4 formed a competing endogenous RNA network regulating the aggressive behavior of EOC. Therefore, targeting this pathway may be an attractive therapeutic strategy for EOC.

Silencing the long noncoding RNA, TINCR, a molecular sponge of miR‑335, inhibits the malignant phenotype of epithelial ovarian cancer via FGF2 suppression.

Aberrant terminal differentiation‑induced noncoding RNA (TINCR) expression has been identified in multiple human cancer types and is functionally significant in cancer progression. However, to the best of our knowledge, no reported studies have investigated the expression pattern and precise role of TINCR in epithelial ovarian cancer (EOC). Here, TINCR expression levels in EOC tissues and cell lines were determined by reverse transcription‑quantitative polymerase chain reaction. Cell Counting Kit‑8 assays, flow cytometric analysis, Transwell migration and invasion assays, and invivo xenograft experiments were performed to determine the influence of TINCR on the malignant phenotype of EOC cells invitro and invivo. The molecular mechanisms associated with the tumor‑promoting roles of TINCR during EOC progression were elucidated using a series of experiments. TINCR expression was higher in EOC tissues and cell lines compared with normal cells. An analysis of the association between TINCR expression and clinicopathological characteristics showed that increased TINCR expression was closely related to tumor size, FIGO stage, and lymphatic metastasis. In addition, the overall survival rates of EOC patients with high TINCR expression levels were lower than in those with low TINCR expression levels. Functional experiments showed that TINCR deficiency attenuated the proliferation, migration, and invasion of EOC cells invitro and hindered EOC tumor growth invivo. In addition, EOC cell apoptosis increased after TINCR knockdown. Mechanistically, TINCR was shown to function as a sponge of microRNA‑335 (miR‑335) in EOC cells, thereby regulating fibroblast growth factor 2 (FGF2) expression. miR‑335 inhibition partially counteracted the effect of TINCR knockdown on the aggressive behavior of EOC cells. This study showed, for the first time to the best of our knowledge, that silencing TINCR, which interacts with miR‑335, inhibited EOC progression invitro and invivo by decreasing FGF2 expression. Hence, this lncRNA could be a potential prognostic biomarker and effective target for therapeutic intervention in EOC.

Sphingosine kinase 2 inhibitor ABC294640 displays anti-epithelial ovarian cancer activities in vitro and in vivo.

Background: ABC294640 is a non-lipid competitive inhibitor of SphK2. It exhibited anti-proliferative activities in many human malignancies, including ovarian cancer. However, its potential mechanism of action remains poorly understood.Methods: In this paper, epithelial ovarian cancer (EOC) cell lines SKOV3 and HO8910 were treated with ABC294640. In order to explore the effect of ABC294640 on the behavior of ovarian cancer cells in vitro, we used cell counting kit-8 (CCK-8) assays, colony formation assays, flow cytometry, quantitative real-time PCR (qRT-PCR), Western blot analysis and immunohistochemistry to detect the effect of ABC294640 on cell proliferation, cell cycle distribution, cell apoptosis, the expression of related factors at mRNA levels, and the expression of related factors at protein level. An intra-abdominal xenograft tumor model of EOC was set up to assess the tumor growth in nude mice.Results: The results obtained indicate that EOC cell proliferation was noticeably inhibited in a concentration-dependent manner by ABC294640. ABC294640 caused cell cycle arrest in S phase and increased cell apoptosis rate in EOC cells. Also, the proteins, including phosphorylated retinoblastoma protein (P-Rb), cyclin D1, cyclin B1, and Bcl-2 were significantly inhibited, while cleaved-caspase 3 was activated. ABC294640 inhibited the expression of c-Myc in EOC. The in vivo assay showed an inhibitory effect of ABC294640 on tumor growth.Conclusions: ABC294640 could downregulate the expression of c-Myc in EOC both in vitro and in vivo. ABC294640 inhibited tumor growth in EOC via cell cycle arrest and inducing cell apoptosis both in vitro and in vivo, partially by decreasing the expression of cell cycle–associated proteins (such as P-Rb, cyclin B1, and cyclin D1) and promoting caspase 3 activation via downregulation expression of c-Myc. It suggested that ABC294640 had the potential to serve as an agent in EOC treatment.

LncRNA TPT1-AS1 promotes tumorigenesis and metastasis in epithelial ovarian cancer by inducing TPT1 expression.

Increasing numbers of studies have confirmed that long noncoding RNA (lncRNA) play a critical role in epithelial ovarian cancer (EOC) progression. However, the potential function of the lncRNA tumor protein translationally controlled 1 (TPT1) antisense RNA 1 (TPT1‐AS1) in EOC is unclear. In this study, we aimed to uncover the biological roles and regulatory mechanisms of TPT1‐AS1 in EOC progression and metastasis. First, TPT1‐AS1 expression was significantly higher in EOC metastatic tissue and cell lines than in their respective control counterparts. In addition, ectopic TPT1‐AS1 expression was strongly associated with unfavorable EOC clinicopathological features, including FIGO stage, tumor size and tumor differentiation. TPT1‐AS1 overexpression remarkably induced cell proliferation, migration and invasion, and significantly attenuated cell adhesion ability in vitro and facilitated nude mouse subcutaneous xenograft growth and intraperitoneal metastasis in vivo, while the downregulation of TPT1‐AS1 expression produced the opposite effect in vitro. Mechanistically, TPT1‐AS1 was proven to be primarily distributed in EOC cell nuclei and positively modulated TPT1 promoter activity and transcription. Moreover, the oncogenic effects of TPT1‐AS1 could be reversed by TPT1 depletion, and the PI3K/AKT signaling pathway downstream of TPT1 was also altered. These results suggested that TPT1‐AS1 induced EOC tumor growth and metastasis through TPT1 and downstream PI3K/AKT signaling and that TPT1‐AS1 may be a promising therapeutic target for EOC.

TNFAIP8 promotes cell growth by regulating the Hippo pathway in epithelial ovarian cancer.

Tumor necrosis factor-α-induced protein 8 (TNFAIP8) is an independent prognostic factor for cancer-specific and disease-free survival in patients with epithelial ovarian cancer (EOC). However, the exact mechanism of the biological role of TNFAIP8 in EOC remains unclear. In the present study, a siRNA specifically targeting TNFAIP8 was prepared to knock down TNFAIP8 in EOC cells. Cell growth, colony formation, apoptosis, and cell cycle distribution in TNFAIP8-deficient EOC cells were determined. In addition, the underlying molecular mechanisms were investigated by western blot analysis and reverse transcription quantitative polymerase chain reaction assays. It was demonstrated that the knockdown of TNFAIP8 inhibited EOC cell growth and colony formation, along with increased levels of apoptosis and cell cycle arrest. The results of the western blot analysis suggested that TNFAIP8 inhibited the expression of phosphorylated yes-associated protein 1 (YAP) while promoting total and nuclear YAP expression, followed by the regulation of apoptosis and cell cycle checkpoint protein expression in EOC. Overexpression of YAP in EOC cells efficiently attenuated cell growth inhibition in TNFAIP8-deficient EOC cells. In addition, knockdown of TNFAIP8 significantly impaired EOC tumor growth in vivo. Collectively, the data from the present study suggested that TNFAIP8 is an oncogene and a novel therapeutic target for EOC.

The expression of Duffy antigen receptor for chemokines by epithelial ovarian cancer decreases growth potential.

Epithelial ovarian cancer (EOC) is one of the main causes of cancer-associated mortality in females with gynecological malignancies. Duffy antigen receptor for chemokines (DARC) has previously been reported to be involved in tumor growth and the inhibition of tumor metastasis. However, the association between DARC and EOC remains unknown. The aim of the present study was to investigate the expression of DARC in the SKOV3 human epithelial ovarian cancer cell line with the establishment of a subcutaneous model in nude mice. To investigate the effects of DARC on the tumorigenesis of human epithelial ovarian cancer cells, GV287-DARC-L.V lentiviral vectors containing a DARC overexpression construct were transfected into SKOV3 cells. The present study revealed that transfection with DARC reduced the viability of SKOV3 cells in vitro by performing an MTT assay. SKOV3-DARC and SKOV3-negative control (NC) cells cultured in vitro were injected into nude mice to establish a subcutaneous model. The ovarian tumor volumes and the tumor weights were observed. Immunohistochemistry to detect CD31 expression was used to determine the microvessel density (MVD) in SKOV3-DARC and SKOV3-NC tumors. The results of the present study revealed that DARC-induced inhibition of tumor growth was associated with MVD in xenograft tumors. This suggested that DARC was a negative regulator of tumor growth in EOC, primarily via the inhibition of tumor angiogenesis.

Immunomodulatory action of the DNA methyltransferase inhibitor SGI-110 in epithelial ovarian cancer cells and xenografts

We aimed to determine the effect of SGI-110 on methylation and expression of the cancer testis antigens (CTAs) NY-ESO-1 and MAGE-A in epithelial ovarian cancer (EOC) cells in vitro and in vivo and to establish the impact of SGI-110 on expression of major histocompatibility (MHC) class I and Intracellular Adhesion Molecule 1 (ICAM-1) on EOC cells, and on recognition of EOC cells by NY-ESO-1-specific CD8+ T-cells. We also tested the impact of combined SGI-110 and NY-ESO-1-specific CD8+ T-cells on tumor growth and/or murine survival in a xenograft setting. EOC cells were treated with SGI-110 in vitro at various concentrations and as tumor xenografts with 3 distinct dose schedules. Effects on global methylation (using LINE-1), NY-ESO-1 and MAGE-A methylation, mRNA, and protein expression were determined and compared to controls. SGI-110 treated EOC cells were evaluated for expression of immune-modulatory genes using flow cytometry, and were co-cultured with NY-ESO-1 specific T-cell clones to determine immune recognition. In vivo administration of SGI-110 and CD8+ T-cells was performed to determine anti-tumor effects on EOC xenografts. SGI-110 treatment induced hypomethylation and CTA gene expression in a dose dependent manner both in vitro and in vivo, at levels generally superior to azacitidine or decitabine. SGI-110 enhanced the expression of MHC I and ICAM-1, and enhanced recognition of EOC cells by NY-ESO-1-specific CD8+ T-cells. Sequential SGI-110 and antigen-specific CD8+ cell treatment restricted EOC tumor growth and enhanced survival in a xenograft setting. SGI-110 is an effective hypomethylating agent and immune modulator and, thus, an attractive candidate for combination with CTA-directed vaccines in EOC.

Lurbinectedin (PM01183), a New DNA Minor Groove Binder, Inhibits Growth of Orthotopic Primary Graft of Cisplatin-Resistant Epithelial Ovarian Cancer

Epithelial ovarian cancer (EOC) is the fifth leading cause of death in women diagnosed with gynecologic malignancies. The low survival rate is because of its advanced-stage diagnosis and either intrinsic or acquired resistance to standard platinum-based chemotherapy. So, the development of effective innovative therapeutic strategies to overcome cisplatin resistance remains a high priority. To investigate new treatments in in vivo models reproducing EOCs tumor growth, we generated a preclinical model of ovarian cancer after orthotopic implantation of a primary serous tumor in nude mice. Further, matched model of acquired cisplatin-resistant tumor version was successfully derived in mice. Effectiveness of lurbinectedin (PM01183) treatment, a novel marine-derived DNA minor groove covalent binder, was assessed in both preclinical models as a single and a combined-cisplatin agent. Orthotopically perpetuated tumor grafts mimic the histopathological characteristics of primary patients' tumors and they also recapitulate in mice characteristic features of tumor response to cisplatin treatments. We showed that single lurbinectedin or cisplatin-combined therapies were effective in treating cisplatin-sensitive and cisplatin-resistant preclinical ovarian tumor models. Furthermore, the strongest in vivo synergistic effect was observed for combined treatments, especially in cisplatin-resistant tumors. Lurbinectedin tumor growth inhibition was associated with reduced proliferation, increased rate of aberrant mitosis, and subsequent induced apoptosis. Taken together, preclinical orthotopic ovarian tumor grafts are useful tools for drug development, providing hard evidence that lurbinectedin might be a useful therapy in the treatment of EOC by overcoming cisplatin resistance.