Human Epithelial Ovarian Carcinoma Cell Research Articles

Rhamnetin, a nutraceutical flavonoid arrests cell cycle progression of human ovarian cancer (SKOV3) cells by inhibiting the histone deacetylase 2 protein

Overexpression of HDAC 2 promotes cell proliferation in ovarian cancer. HDAC 2 is involved in chromatin remodeling, transcriptional repression, and the formation of condensed chromatin structures. Targeting HDAC 2 presents a promising therapeutic approach for correcting cancer-associated epigenetic abnormalities. Consequently, HDAC 2 inhibitors have evolved as an attractive class of anti-cancer agents. This work intended to investigate the anti-cancer abilities and underlying molecular mechanisms of Rhamnetin in human epithelial ovarian carcinoma cells (SKOV3), which remain largely unexplored. We employed various in vitro methods, including MTT, apoptosis study, cell cycle analysis, fluorescence microscopy imaging, and in vitro enzymatic HDAC 2 protein inhibition, to examine the chemotherapeutic sensitivity of Rhamnetin in SKOV3 cells. Additionally, we conducted in silico studies using molecular docking, MD simulation, MM-GBSA, DFT, and pharmacokinetic analysis to investigate the binding interaction mechanism within Rhamnetin and HDAC 2, alongside the compound’s prospective as a lead candidate. The in vitro assay confirmed the cytotoxic effects of Rhamnetin on SKOV3 cells, through its inhibition of HDAC 2 activity. Rhamnetin, a nutraceutical flavonoid, halted at the G1 phase of the cell cycle and triggered apoptosis in SKOV3 cells. Furthermore, computational studies provided additional evidence of its stable binding to the HDAC 2 protein’s binding site cavity. Based on our findings, we conclude that Rhamnetin effectively promotes apoptosis and mitigates the proliferation of SKOV3 cells through HDAC 2 inhibition. These results highlight Rhamnetin as a potential lead compound, opening a new therapeutic strategy for human epithelial ovarian cancer. Communicated by Ramaswamy H. Sarma

Cytotoxic Properties of C17 Polyacetylenes from the Fresh Roots of Panax ginseng on Human Epithelial Ovarian Cancer Cells.

Although C17 polyacetylenes from Panax ginseng exhibit cytotoxic properties against various tumor cells, there have been few experiments on epithelial ovarian carcinoma cells. This study aimed to investigate the cytotoxic effects of C17 polyacetylenes from P. ginseng against ovarian cancer cell lines. Four unreported (1–4) and fifteen known (5–19) C17 polyacetylenes were obtained from the roots of P. ginseng using repeated chromatography (open column, MPLC, and preparative HPLC). The chemical structures of all the compounds were determined by analyzing their spectroscopic data (NMR, IR, and optical rotation) and HR-MS. The structures of new polyacetylenes were elucidated as (3S,8S,9R,10R)-(-)-heptadeca-9,10-epoxy-4,6-diyne-3,8-diyl diacetate (1), (3S,8S,9R,10R)-(−)-heptadeca-1-en-9,10-epoxy-4,6-diyne-3,8-diyl diacetate (2), (−)-haptadeca-9,10-epoxy-8-methoxy-4,6-diyne-3,11-diol (3), and (3R,9R,10R)-(+)-3-acetoxy-9,10-dihydroxyheptadeca-1-en-4,6-diyne (4), named ginsenoynes O, P, and Q, and 3-acetyl panaxytriol, respectively. Subsequently, in vitro experiments on A2780 and SKOV3 human epithelial ovarian carcinoma cells were performed to assess the cytotoxic properties of the isolates. Among the isolates, panaquinquecol 4 (15) exhibited the most remarkable cytotoxic effects on both human ovarian cancer cells A2780 (IC50 value of 7.60 μM) and SKOV3 (IC50 value of 27.53 μM). Therefore, C17 polyacetylenes derived from P. ginseng may warrant further investigation for their therapeutic potential in epithelial ovarian cancer.

The Effects of Quercetin and Hyperthermia on OVCAR-3 Cells

INTRODUCTION: This study aims to exhibit the growth inhibitory effect of quercetin on the human ovarian epithelial carcinoma cells (OVCAR-3) and scrutinize the effect of hyperthermia. METHODS: OVCAR-3 cells were exposed to different concentrations of quercetin and apoptotic changes were recorded with confocal microscopy and transmission electron microscopy. Also Annexin-V and reactive oxygen species (ROS) measurement were analyzed. Cytotoxicity was tested on quercetin exposed OVCAR-3 cells with hyperthermia. RESULTS: Quercetin has good anticancerous activities in vitro by inhibiting the proliferation of OVCAR-3 cells. The recorded IC50 value of quercetin was 122 μM for 48 hours. Hyperthermia didnot influence significantly on the growth inhibition of OVCAR-3 cells applied with quercetin. DISCUSSION and CONCLUSION: Our results demonstrated that quercetin could induce apoptosis in a time and concentration-dependent manner in OVCAR-3 cells.

Mechanism of resistin-induced enhancement of proliferation and migration of ovarian cancer cells

IntroductionResistin, a novel hormone secreted by human adipocytes and mononuclear cells, is associated with obesity, insulin resistance, and inflammation. Recent studies showed that resistin plays a key role in ovarian cancer cells. In this study, we investigated the potential of resistin to regulate the proliferation and migration of ovarian cancer cells.Material and methodsA series of in vitro functional experiments were carried out to elucidate the role of resistin in ovarian cancer progression and the molecular mechanisms underlying its role.ResultsResistin enhanced the proliferation of human ovarian epithelial carcinoma cells (HO-8910) in a time- and dose-dependent manner (30–100 ng/ml). Furthermore, HO-8910 cells cultured in adipocyte-conditioned medium showed dramatically increased rates of proliferation. Resistin knockout during adipocyte culture attenuated the proliferation of HO-8910 cells treated with adipocyte-conditioned media, indicating that resistin may promote HO-8910 cell proliferation via the mechanistic target of a rapamycin (mTOR)-mediated signaling pathway. Resistin (30–100 ng/ml) also enhanced wound-healing rates in a time- and concentration-dependent manner. Co-culturing HO-8910 cells with adipocytes also increased the wound-healing rates. Resistin expression was inhibited by miR-124-1 transcriptional activity, and resistin-mediated HO-8910 cell migration was also regulated by miR-124-1. Furthermore, we also confirmed the role of resistin in promoting tumor growth in vivo.ConclusionsThese findings suggest that resistin may serve as an effective therapeutic target for ovarian epithelial carcinoma, especially in patients who are obese.

MicroRNA‑195 suppresses cell proliferation, migration and invasion in epithelial ovarian carcinoma via inhibition of the CDC42/CCND1 pathway

Epithelial ovarian carcinoma (EOC) is the most common cause of gynecological cancer mortality, and poses a threat to women. MicroRNA-195 (miR-195) has been reported to induce apoptosis of human OVCAR-3 cells by inhibiting the VEGFR2/AKT pathway. However, the role of miR-195 in EOC remains unknown. A previous study reported that cell division cycle 42 (CDC42) can serve as a target gene of miR-195 and mediate malignant progression of esophageal squamous cell carcinoma (ESCC). The aim of the present study was to investigate the role of miR-195 in EOC and the regulation in CDC42/CCND1 pathway. Tissues samples and clinical materials were collected from 78 enrolled patients with EOC to analyze the expression and clinical significance of miR-195, CDC42 and cyclin D1 (CCND1). Human EOC cell lines OVCA420, OVCAR-3, A2780 and SKOV3 cell lines were used to assess the expression and function of miR-195, CDC42 and CCND1 in vitro. Cell proliferation, the cell cycle and apoptosis, as well as the cell migratory and invasive abilities were detected in vitro using BrdU incorporation, colony formation, wound healing and Transwell invasion assays, along with flow cytometry. miR-195 was downregulated, while CDC42 and CCND1 were upregulated in human EOC tissues and cells, and the aberrant expression of both was associated with increased EOC malignancy. Moreover, miR-195 expression was negatively correlated with CDC42 and CCND1 expression levels, and negatively regulated these expression levels. Thus, it was suggested that miR-195 functions as a tumor suppressor, but CDC42 and CCND1 act as tumor promoters based their abilities to enhance cell proliferation, cell cycle entry, migration and invasion, as well as decrease apoptosis in OVCAR-3 cells. the present results demonstrated that miR-195 inhibited human EOC progression by downregulating CDC42 and CCND1 expression. Furthermore, it was identified that miR-195, CDC42 and CCND1 may be effective biomarkers for EOC diagnosis and treatment.

Core-Shell Imidazoline-Functionalized Mesoporous SilicaSuperparamagnetic Hybrid Nanoparticles as a Potential Theranostic Agent for Controlled Delivery of Platinum(II) Compound.

IntroductionAs widely used chemotherapeutic agents, platinum compounds have several therapeutic challenges, such as drug resistance and adverse effects. Theranostic systems, macromolecular or colloidal therapeutics with companion diagnostics, not only address controlled drug delivery but also enable real-time monitoring of tumor sites.MethodsSynthesis of magnetic mesoporous silica nanoparticles (MMSNs) was performed for dual magnetic resonance imaging and drug delivery. MMSN surfaces were modified by imidazoline groups (MMSN-Imi) for cisplatin (Cis-Pt) conjugation via free N-termini to achieve well-controlled drug-release kinetics. Cis-Pt adsorption isotherms and drug-release profile at pH 5 and 7.4 were investigated using inductively coupled plasma atomic emission spectroscopy.ResultsMMSN-Imi showed a specific surface area of 517.6 m2 g−1, mean pore diameter of 3.26 nm, and saturated magnetization of 53.63 emu/g. A relatively high r2/r1 relaxivity value was obtained for MMSN-Imi. The nanoparticles provided high Cis-Pt loading with acceptable loading capacity (~30% w:w). Sustained release of Cis-Pt under acidic conditions led to specific inhibitory effects on the growth of human epithelial ovarian carcinoma cells, determined using MTT assays. Dual acridine orange–propidium iodide staining was investigated, confirming induction of apoptosis and necrotic cell death.ConclusionMMSN-Imi exhibited potential for applications in cancer chemotherapy and combined imaging.

Abstract 4296: Identification of cancer specific protein 80 (CSP-80), a novel 80 kDa MAP1a-like protein in ovarian carcinoma cells

Abstract Background: Although interfering with the actions of microtubule-associated proteins (MAP’s) is successful against ovarian epithelial carcinoma (OVCA), knowledge of the MAP’s in OVCA cells is lacking. We sought to identify cancer-specific MAP’s in OVCA cells.Methods: Four human OVCA cell lines, primary OVCA tissue, ascitic cells and metastases from 9 patients and normal ovarian tissue from six women were compared to control human and rat brain tissue, uterine myomas (benign tumors) and rat and human non-neural organs. Modified Western blotting using panels of anti-microtubule-associated protein monoclonal antibodies were used. An in-vitro brain and OVCA mixing and recovery experiment was carried out to assess possible degradation of MAP1a by OVCA. A paclitaxel-driven tubulin assembly assay was performed to determine whether the OVCA protein has microtubule-associated protein properties. The transcriptome of CSP-80 was sequenced using primer extension sequencing. Results: (1) In contradistinction to the 350 kDa MAP1a present in control brain extracts, only an 80 kDa molecule with MAP1a immune-reactivity was found in OVCA cell lines and tissues. No immune-reactivity was present in the negative controls. (2)Following the mixing experiments there was no increase of CSP-80; CSP-80 is not a degradation artifact of MAP1a. (3) The paclitaxel-driven tubulin assembly assay showed that CSP-80 bound to microtubules during tubulin polymerization. (4) No CSP-80 was identified in human or rat non-malignant tissues including normal human and rat brain or normal human ovary, placenta or uterine myomas, or normal rat liver, spleen or lung. (5) cDNA sequencing shows a 2603 bp fragment at a 5’ terminal of p80 to be homologous with the analogous segment of MAP1a. (6) Further testing showed that CSP-80 was present in other reproductive and non-reproductive carcinomas. Again, no 350 kDa MAP1a was present. Studies are underway to determine whether CSP-80 is a mutated protein or the product of post-transcriptional modification. Conclusion: CSP-80 is a novel cancer-related protein that appears to be limited to an 80 kDa sequence of the MAP1a gene, or a post-transcriptionally modified product. Since CSP-80 exhibits tubulin-binding activity, this may explain the efficacy of taxane derivatives. CSP-80 may disclose some aspects of carcinogenesis, be a valuable marker of cancer and therapeutic efficacy, and offer new avenues for cancer treatment. Citation Format: Ahmed Fadiel, Viswam S. Nair, Peter Aceto, Frederick Naftolin. Identification of cancer specific protein 80 (CSP-80), a novel 80 kDa MAP1a-like protein in ovarian carcinoma cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4296.

Overexpression of thymic stromal lymphopoietin is correlated with poor prognosis in epithelial ovarian carcinoma.

Thymic stromal lymphopoietin (TSLP) is an IL-7-like cytokine that has been reported to be associated with several malignant tumors. The present study aimed to evaluate its role in epithelial ovarian carcinoma (EOC). The mRNA levels of TSLP in human EOC samples and EOC cell lines were determined. Then, the expression of TSLP was examined in 144 clinical tissue microarray samples and correlated with clinicopathological factors. Finally, the correlation between TSLP overexpression and prognosis of EOC patients was analyzed. Our data show that mRNA levels of TSLP were significantly higher in EOC tissues and cell lines. Chi-square tests revealed that TSLP overexpression in EOC was significantly associated with age, histological type, Federation of Gynecology and Obstetrics (FIGO) stage, histological differentiation, pelvic involvement, and lymphatic metastasis. Kaplan–Meier survival analysis revealed that poor prognosis was significantly correlated with older age, advanced FIGO stage, poor histological differentiation, pelvic involvement, lymphatic involvement, or TSLP overexpression (P<0.05). Additionally, multivariate Cox regression analysis confirmed pelvic involvement and TSLP overexpression as independent prognostic factors for both overall and disease-free survival. Taken altogether, TSLP overexpression reflects a more malignant phenotype and TSLP may be a novel biomarker for EOC.

MAL gene overexpression as a marker of high-grade serous ovarian carcinoma stem-like cells that predicts chemoresistance and poor prognosis

BackgroundThe existence of cancer stem cells (CSCs) within a tumor bulk has been demonstrated for many solid tumors including epithelial ovarian carcinoma (EOC). CSCs have been associated to tumor invasion, metastasis and development of chemoresistant recurrences. In this context, we aim to characterize EOC CSCs from the molecular point of view in order to identify potential biomarkers associated with chemoresistance.MethodsWe isolated a population of cells with stem-like characteristics (OVA-BS4 spheroids) from a primary human EOC cell line under selective conditions. OVA-BS4 spheroids were characterized for drug response by cytotoxicity assays and their molecular profile was investigated by microarray and RT-qPCR. Finally, we performed a gene expression study in a cohort of 74 high-grade serous EOC (HGSOC) patients by RT-qPCR.ResultsSpheroids exhibited properties of self-renewal and a pronounced expression of well-known stem cell genes. Moreover, they demonstrated greater resistance towards several anticancer drugs compared to parent cell line, consistent with their higher ABCG2 gene expression. From microarray studies MAL (T-cell differentiation protein) emerged as the most up-regulated gene in spheroids, compared to parent cell line. In HGSOC patients, MAL was significantly overexpressed in platinum-resistant compared to platinum-sensitive patients and resulted as an independent prognostic marker of survival.ConclusionsThis investigation provides an important contribution to the identification of molecular markers of ovarian CSCs and chemoresistance. Successful translation of molecular findings would lead to a better comprehension of the mechanisms triggering chemoresistant recurrences, to the individuation of novel therapeutic targets and to the personalization of treatment regimens.

Effect of procyanidin-rich extract from natural cocoa powder on cellular viability, cell cycle progression, and chemoresistance in human epithelial ovarian carcinoma cell lines

Effect of procyanidin-rich extract from natural cocoa powder on cellular viability, cell cycle progression, and chemoresistance in human epithelial ovarian carcinoma cell lines

Effect of Procyanidin-rich Extract from Natural Cocoa Powder on Cellular Viability, Cell Cycle Progression, and Chemoresistance in Human Epithelial Ovarian Carcinoma Cell Lines.

Background:Over the last 400 years, cocoa and chocolate have been described as having potential medicinal value, being consumed as a beverage or eaten as food. Concentration–dependant, antiproliferation, and cytotoxic effects of some of their polyphenolic constituents have been demonstrated against various cancers. Such an effect remains to be demonstrated in ovarian cancerObjective:To investigate the effect of cocoa procyanidins against ovarian cancer in vitro using OAW42 and OVCAR3 cell lines.Materials and Methods:Cocoa procyanidins were extracted and enriched from non alkalized cocoa powder. The polyphenolic content and antioxidant activity were determined. Effect on cell viability was determined after the treatment with ≤1000 μg/mL cocoa procyanidin-rich extract on OAW42 and OVCAR3 and normal human dermal fibroblasts. Similarly, chemosensitization effect was determined by pretreating cancer cell lines with extract followed by doxorubicin hydrochloride treatment. The effect of treatment on cell cycle and P-glycoprotein (P-gp) expression was determined using flow cytometry.Results:The cocoa extract showed high polyphenolic content and antioxidant activity. Treatment with extract caused cytotoxicity and chemosensitization in OAW42 and OVCAR3 cell lines. Normal dermal fibroblasts showed an increase in cell viability post treatment with extract. Treatment with extract affected the cell cycle and an increasing percentage of cells in hypodiploid sub-G1/G0 phase was observed. Treatment of OVCAR3 with the extract caused reduction of P-gp expression.Conclusion:Cocoa procyanidins were found to be selectively cytotoxic against epithelial ovarian cancer, interfered with the normal cell cycle and sensitized cells to subsequent chemotherapeutic treatment. Chemosensitization was found to be associated with P-gp reduction in OVCAR3 cells.SUMMARY Among the naturally occurring flavonoids, procyanidins have been shown to be effective against cancersNon alkalized cocoa powder is one of the richest sources of procyanidinsCocoa procyanidin-rich extract (CPRE) caused cytotoxicity and chemosensitization in ovarian carcinoma cell lines OAW42 and OVCAR3CPRE affected normal cell cycle progressionCPRE also downregulated P-glycoprotein, which mediates chemoresistance in multidrug-resistant OVCAR3 cell line. Abbreviations used: P-gp: P-glycoprotein, CPRE: Cocoa procyanidin rich extract, DMAC: 4-dimethylaminocinnamaldehyde, DPPH: Diphenylpicrylhydrazyl, ABTS: 2,2’;-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid), PI: Propidium iodide, FITC: Fluorescein isothiocyanate, MTT: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, TLC: Thin layer chromatography, HPTLC: High-performance thin layer chromatography.

The expression and function of toll-like receptors (TLRs) in ovarian cancer cell lines

Meeting abstracts This study is to investigate which Toll Like Receptors (TLRs) are expressed on human ovarian cancer cell lines and to evaluate the effect of TLR expression on the growth of ovarian cancer cells. Four human ovarian epithelial carcinoma cell lines SKOV3 (clear), OVCAR3 (serous

Adrenomedullin Up-regulates the Expression of Vascular Endothelial Growth Factor in Epithelial Ovarian Carcinoma Cells via JNK/AP-1 Pathway.

ObjectiveAdrenomedullin (AM), a potent vasodilator peptide, presents in various kinds of tumors and promotes angiogenesis. We have previously reported that AM is expressed in epithelial ovarian carcinoma tissue. Here, we investigated the hypothesis that AM might regulate production of vascular endothelial growth factor (VEGF) in epithelial ovarian carcinoma and further promote angiogenic processes.MethodsThe messenger RNA expression of VEGF in human epithelial ovarian carcinoma cells (HO-8910) was examined by real-time polymerase chain reaction. Transcriptional control was analyzed by transient transfection assay of VEGF promoter-luciferase hybrid genes and chromatin immunoprecipitation assay. Activation of c-Jun N-terminal kinase (JNK) was detected by Western blotting. The formation of capillarylike structures by EA.hy926 cells cocultured with HO-8910 cells on Matrigel was also studied.ResultsWe found that in HO-8910 cells, AM (10−10 to 10−7 mol/L) enhanced VEGF messenger RNA expression in a time- and concentration-dependent manner, as well as promoter activity. Furthermore, JNK was activated by AM stimulation. The AM-induced increase in VEGF expression was significantly attenuated by SP600125, a specific JNK inhibitor. Chromatin immunoprecipitation assay and promoter activity analysis showed that VEGF expression induced by AM required the activator protein 1 motif on the VEGF promoter. In an in vitro angiogenesis system for endothelial cells (EA.hy926) cocultured with HO-8910 cells, we observed that the addition of AM stimulated endothelial cell tube formation, which could be abolished by VEGF neutralizing antibody.ConclusionsOur findings suggest that the JNK/Activator protein 1 pathway is involved in AM-induced VEGF expression in HO-8910 cells.

Combination of therapy with 5-fluorouracil and cisplatin with electroporation in human ovarian carcinoma model in vitro

High electric field, applied to plasma membrane, affects organization of the lipid molecules, generating transient hydrophilic electropores. The application of the cell membrane electroporation in combination with cytotoxic drugs could increase the drug transport into cells. This approach is known as electrochemotherapy (ECT). Our work shows new data concerning the influence of electrochemical reaction with cisplatin or with 5-fluorouracil (5-FU) on cancer ovarian cells resistant to standard therapy with cisplatin, in comparison to ECT effect on human primary fibroblasts. We investigated the effect of electroporation and electrochemotherapy with 5-FU and cisplatin on human ovarian clear-cell carcinoma cell line (OvBH-1) and epithelial ovarian carcinoma cell line (SKOV-3) – both resistant to cisplatin typically used in ovarian cancers. As control cells, human gingival fibroblasts (HGF's) from primary culture were used. Electropermeabilization efficiency was determined by FACS analysis with iodide propidium. Efficiency of electrochemotherapy was evaluated with viability assay. The cytotoxic effect was dependent on the electroporation parameters and on drug concentration. Electroporation alone only insignificantly decreased cells proliferation in OvBH-1 line; SKOV-3 line was more sensitive to the electrical field. Electrochemotherapy with cisplatin and 5-FU showed promising effects on both ovarian cell lines with recovery of normal cells revealed after 72hours.

Identification of candidate circulating cisplatin resistance biomarkers from epithelial ovarian carcinoma cell secretomes

Objectives: Most patients diagnosed with advanced epithelial ovarian carcinoma (EOC) relapse with resistant disease, and there are no clinically useful biomarkers to identify or monitor this resistance. This study sought to identify differential secreted proteins collected from human EOC cell lines of varying platinum sensitivity.

Menadione induces the formation of reactive oxygen species and depletion of GSH-mediated apoptosis and inhibits the FAK-mediated cell invasion

Menadione induces apoptosis in tumor cells. However, the mechanism of apoptosis in ovarian cancer cells exposed to menadione is not clear. In addition, it is unclear whether menadione-induced apoptosis is mediated by the depletion of glutathione (GSH) contents that is associated with the formation of reactive oxygen species. Furthermore, the effect of menadione on the invasion and migration of human epithelial ovarian cancer cells has not been studied. Therefore, we investigated the effects of menadione exposure on apoptosis, cell adhesion, and cell migration using the human epithelial ovarian carcinoma cell lines OVCAR-3 and SK-OV-3. The results suggest that menadione may induce apoptotic cell death in ovarian carcinoma cell lines by activating the mitochondrial pathway and the caspase-8- and Bid-dependent pathways. The apoptotic effect of menadione appears to be mediated by the formation of reactive oxygen species and the depletion of GSH. Menadione inhibited fetal-bovine-serum-induced cell adhesion and migration of OVCAR-3 cells, possibly through the suppression the focal adhesion kinase (FAK)-dependent activation of cytoskeletal-associated components. Therefore, menadione might be beneficial in the treatment of epithelial ovarian adenocarcinoma and combination therapy.

Evaluation of the mechanism of epithelial-mesenchymal transition in human ovarian cancer stem cells transfected with a WW domain-containing oxidoreductase gene.

The aim of the present study was to investigate the impact of the WW domain-containing oxidoreductase (WWOX) gene on the mechanisms underlying epithelial-mesenchymal transition (EMT) in human ovarian cancer stem cells. Western blot analysis was performed to detect the differences in the expression of the EMT markers, E-cadherin, β-catenin, N-cadherin, vimentin and fibronectin, between human ovarian cancer stem cells and the human epithelial ovarian carcinoma cell line, HO-8910. A pcDNA3.1-WWOX eukaryotic expression vector was subsequently transfected into the ovarian cancer stem cells (recombinant plasmid group) or an empty plasmid (empty plasmid group) and non-transfected ovarian cancer stem cells (blank control group) served as the controls. Following the transfection of the WWOX gene, methyl thiazolyl tetrazolium cell viability and Transwell® invasion assays, and western blot analysis were performed to detect changes in the proliferative capability and invasive capacity of ovarian cancer stem cells, as well as the expression of EMT markers and regulatory factors, Elf5 and Snail. The expression levels of E-cadherin and β-catenin in the ovarian cancer stem cells were identified to be significantly lower than those in the HO-8910 cells, whereas the expression levels of N-cadherin, vimentin and fibronectin in the ovarian cancer stem cells were found to be significantly higher than those in the HO-8910 cells. At each time point, the cellular proliferative capacity of the recombinant plasmid group was observed to be significantly lower than that of the empty plasmid or blank control groups (P<0.05 vs. the controls). The number of penetrating cells in the recombinant plasmid, empty plasmid and the blank control groups were 105.5±3.1, 199.7±3.4 and 191.4±4.1, respectively (mean ± standard error of the mean; P<0.05 vs. the controls). In addition, the protein expression of E-cadherin, β-catenin and Elf5 in the recombinant plasmid group was found to be significantly higher than that in the other two groups, whereas the protein expression of N-cadherin, vimentin, fibronectin and Snail in the recombinant plasmid group was significantly lower than that in the other two groups. An EMT exists in ovarian cancer stem cells, and the WWOX gene inhibits the cellular proliferation of ovarian cancer stem cells and reduces their invasive capability. Therefore, the WWOX gene may reverse the EMT in ovarian cancer stem cells by regulating the expression of the EMT regulatory factors, Elf5 and Snail.

Identification of candidate circulating cisplatin-resistant biomarkers from epithelial ovarian carcinoma cell secretomes

Background:The majority of patients diagnosed with advanced epithelial ovarian carcinoma (EOC) relapse with resistant disease, and there are no biomarkers that possess clinical utility to identify or monitor these patients. This study aimed to identify secreted proteins (‘secretome') collected from human EOC cell lines that differ in their inherent platinum sensitivity.Methods:Secreted proteins collected from conditioned medium from ovarian cancer cell lines that vary in their sensitivity to cisplatin were digested with trypsin and analysed by liquid chromatography-tandem mass spectrometry for peptide identification.Results:Of the 1688 proteins identified, 16 possessed significant differential abundances (P<0.05) between the platinum-resistant and -sensitive cell lines. A number of these were verified by immunoblot, including COL11A1, which was also found to be associated with worse progression-free survival (PFS; N=723) and overall survival (OS; N=1183) as assessed from publicly available transcript expression data from ovarian cancer tumour specimens.Conclusion:Secretome proteomics of EOC cells resulted in the identification of a novel candidate biomarker, COL11A1. The expression level of COL11A1 correlates to worse PFS and OS, and is predicted to reside in peripheral circulation making this an attractive candidate for validation in sera as a biomarker of cisplatin resistance and poor outcome.

Parthenolide induces apoptosis by activating the mitochondrial and death receptor pathways and inhibits FAK-mediated cell invasion

The natural product parthenolide induces apoptosis in cancer cells. However, the mechanism of apoptosis in ovarian cancer cells exposed to parthenolide is not clear. In addition, it is unclear whether parthenolide-induced apoptosis is mediated by the formation of reactive oxygen species and the depletion of GSH contents, and the effect of parthenolide on the invasion and migration of human epithelial ovarian cancer cells has not been studied. Therefore, we investigated the effects of parthenolide exposure on apoptosis, cell adhesion, and migration using the human epithelial ovarian carcinoma cell lines OVCAR-3 and SK-OV-3. The results suggest that parthenolide may induce apoptotic cell death in ovarian carcinoma cell lines by activating the mitochondrial pathway and the caspase-8- and Bid-dependent pathways. The apoptotic effect of parthenolide appears to be mediated by the formation of reactive oxygen species and the depletion of GSH. Parthenolide inhibited fetal bovine serum-induced cell adhesion and migration of OVCAR-3 cells, possibly through the suppression the focal adhesion kinase-dependent activation of cytoskeletal-associated components. Therefore, parthenolide might be beneficial in the treatment of epithelial ovarian adenocarcinoma and combination therapy.

Ghrelin inhibits ovarian epithelial carcinoma cell proliferation in vitro

The only orexigenic peptide, ghrelin, which is primarily produced by the gastrointestinal tract, has been implicated in malignant cell proliferation and invasion. Ghrelin is a natural ligand of the growth hormone secretagogue receptor 1a (GHSR1a). However, the role of ghrelin in ovarian epithelial carcinoma remains unknown since the expression of GHSR1a in ovary is not confirmed. The aim of the present study was to assess expression of ghrelin and its receptor in human ovarian epithelial carcinoma and to examine the effect of ghrelin on carcinoma cell proliferation. Frozen sections of ovarian samples and the human ovarian epithelial carcinoma cell line, HO-8910, were used to characterize the expression of ghrelin/GHSR1a axis and the effect of ghrelin on proliferation. We found that ghrelin and GHSR1a are expressed in ovarian epithelial carcinoma in vivo and in vitro. Ghrelin inhibits the proliferation and growth of HO-8910 cells by G1 phase arrest, and this inhibition may be abolished by the ghrelin receptor antagonist D-Lys-3-GH-releasing peptide-6 and ghrelin neutralizing antibody. Ghrelin enhances HO-8910 cell apoptosis and autophagy. The activation of mammalian target of rapamycin (mTOR) signaling pathway blocks the effects of ghrelin-induced autophagy and apoptosis, therefore reverses the inhibition of HO-8910 cell proliferation induced by ghrelin. In conclusion, the present study demonstrates that ghrelin inhibits the proliferation of human HO-8910 ovarian epithelial carcinoma cells by inducing apoptosis and autophagy via the mTOR signaling pathway. This study provides a novel regulatory signaling pathway of ghrelin-regulated ovarian epithelial carcinoma growth and may contribute to ovarian cancer prevention and therapy.