Human Ovarian Surface Epithelial Cells Research Articles

Abstract A054: Interleukin-16 is a novel target to prevent age-associated epigenetic changes leading to malignant transformation associated with ovarian high-grade serous carcinoma (HGSOC)

Abstract Low-grade chronic inflammation and persistent oxidative stress are hallmarks of malignant transformation. High-grade serous ovarian carcinoma (HGSOC) is a fatal malignancy of women, and the median age of its incidence is 60-65 years. Our earlier studies showed enhanced expression of interleukin 16 (IL-16, an inflammatory cytokine), its receptor CD9, and glucose-regulated protein (GRP78, a marker of cellular stress and inhibitor of DNA damage repair mechanism) in postmenopausal ovaries and patients with HGSOC as compared with premenopausal subjects. It is possible that these age-associated increases in IL-16, CD9, and GRP78 expression may contribute to HGSOC-related epigenetic modifications of gH2A histone family member X (gH2AX, a marker for double-stranded DNA breaks), and histone deacetylase 1 (HDAC1), involved in DNA repair. The goal of this study was to examine if age-associated such changes lead to HGSOC-associated malignant transformation and if so, to determine mechanisms involved in such transformation. Materials and Methods: Exploratory study: Archived tissue specimens were selected for immunohistochemical, immunoblotting, genomic studies, and immunoassays based on the review of their hematoxylin and eosin staining and final pathological reports. Specimens were grouped as normal premenopausal women (30-50 years old), normal postmenopausal women (55-85 years old), and ovarian high-grade serous carcinoma (HGSC). In vitro study: human ovarian surface epithelium (HOSE) cells were treated with or without recombinant human IL-16 (rhIL-16) and recombinant human GRP78 (rhGRP78), and small interfering RNA-GRP78 (siGRP78) for 24 hours or 48 hours. Nuclear fractionations from treated- or untreated HOSE cells or OVCAR3 (HGSOC cell line) cells were extracted. Results: Compared to premenopausal women, a subset of postmenopausal women exhibited significantly elevated expression (P<0.01) of inflammatory markers IL-16, and its receptor CD9, as well as a marker of oxidative stress (GRP78). Additionally, markers of epigenetic changes, including gH2AX and HDAC1, presented similar patterns of increase in their expression. These observations were also consistent in HGSOC patients. Enhanced expression of GRP78, gH2AX, HDAC1, and CD9 in rhIL-16 treated HOSE cells like OVCAR3 cells and their reduction in siGRP78 treated HOSE cells suggests that age-associated increase in IL-16 in postmenopausal women may be a risk factor for malignant transformation and GRP78 may be a mechanism for IL-16-induced HGSOC development. Thus, IL-16 and GRP78 represent novel targets that may be used to develop novel targeted therapies to prevent HGSOC. Expression of gH2AX and HDAC1 increased in rhGRP78-treated HOSE cells. Conclusion: The results of this study suggest that age-associated increases in IL-16 (a marker of chronic inflammation) and GRP78 (a marker of oxidative stress) may contribute to the predisposition for HGSOC-associated malignant transformation. IL-16 and GRP78 offer potential targets for the prevention of HGSOC in women. Support: The Portes Foundation Citation Format: Jessica Ramirez, Animesh Barua. Interleukin-16 is a novel target to prevent age-associated epigenetic changes leading to malignant transformation associated with ovarian high-grade serous carcinoma (HGSOC) [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr A054.

Abstract A033: Anti-proliferative effects of lentinan, a beta-glucan from shiitake mushroom (lentinula edodes)

Abstract Cancer is one of the most significant health challenges worldwide. Lentinan, a β-glucan from shiitake mushroom, Lentinula edodes, has been demonstrated to have an inhibitory effect on selected cancer cells, but results are inconclusive. The aim of the present study was to investigate the anti-proliferative effect of lentinan on breast adenocarcinoma cells (MCF-7), prostate carcinoma (DU-145), and ovarian carcinoma (SKOV3) using MTS (3-(4,5-dimethylthiazol-2-yl)-5—(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay and explore possible mechanisms of action of this compound. In the MCF-7 cells that were used as a positive control, lentinan without phenol red resulted in a significant inhibition of cell viability by 96% while in the presence of phenol red, the weak estrogen effect attributable to phenol red eliminated the significant inhibitory effect of lentinan. Treatment of DU-145 cells with different doses of lentinan resulted in up to a 42% inhibition in cell growth. In SKOV3 cells, lentinan induced a biphasic response where doses of 800 µg/ml or less increased cell viability by 76% – 148%; however, a dose of 1.6 mg/ml inhibited cell proliferation significantly by 87%. When SKOV3 cells were co-treated with lentinan (800 µg/ml or less) and laminarin (a Dectin-1 receptor antagonist), the proliferation-promoting effect of lentinan was dominant over the proliferation-inhibiting effect of laminarin. However, when lentinan was presented at significant higher levels (1600 µg/ml), the inhibitory effect of the two agents became additive in suppressing SKOV3 cell proliferation. Lentinan induced a biphasic response in human ovarian surface epithelial cells (HOSEpC) similar to SKOV3 cells, where the highest dose (1600 µg/ml) resulted in the inhibition of cell growth by 53%. Western blots after treatment of SKOV3 cells with 1600 µg/ml of lentinan demonstrated caspase-3 activation and a decreased anti-apoptotic protein Bcl-2 levels. Our findings reveal that lentinan can be considered as a potential anti-cancer drug for effective treatment of breast and prostate cancer. Citation Format: Titus Sombuor, Kenneth Shane Broughton, Michael Bergel. Anti-proliferative effects of lentinan, a beta-glucan from shiitake mushroom (lentinula edodes) [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr A033.

Zinc Finger Protein 90 Knockdown Promotes Cisplatin Sensitivity via Nrf2/HO-1 Pathway in Ovarian Cancer Cell.

Our study discussed the role of Zfp90 in ovarian cancer (OC) cell lines' sensitivity to cisplatin. We used two OC cell lines, SK-OV-3 and ES-2, to evaluate their role in cisplatin sensitization. The protein levels of p-Akt, ERK, caspase 3, Bcl-2, Bax, E-cadherin, MMP-2, MMP-9 and other drug resistance-related molecules, including Nrf2/HO-1, were discovered in the SK-OV-3 and ES-2 cells. We also used a human ovarian surface epithelial cell to compare the effect of Zfp90. Our outcomes indicated that cisplatin treatment generates reactive oxygen species (ROS) that modulate apoptotic protein expression. The anti-oxidative signal was also stimulated, which could hinder cell migration. The intervention of Zfp90 could greatly improve the apoptosis pathway and block the migrative pathway to regulate the cisplatin sensitivity in the OC cells. This study implies that the loss of function of Zfp90 might promote cisplatin sensitization in OC cells via regulating the Nrf2/HO-1 pathway to enhance cell apoptosis and inhibit the migrative effect in both SK-OV-3 and ES-2 cells.

Upregulation of ryanodine receptor-1 dependent calcium signaling contributes to the malignance of high-grade serous ovarian cancer (HGSOC).

Ca2+ signaling plays crucial roles in cancer metastasis and progression. We analyzed RNAseq data from TCGA database and our patient samples; and identified over-expression of ryanodine receptor 1 (RYR1), the target of the FDA-approved drug dantrolene, is associated with poor survival of HGSOC patients. RYR1 expression is also markedly higher in several HGSOC cell lines compared to normal human ovarian surface epithelial cells (HOSE) and fallopian tube epithelial cells. Suppression of RYR1 expression/activity by shRNA or dantrolene significantly inhibited proliferation and migration of HGSOC cells (OVCA432, OVCA433, OV90). Ca2+ fluorescence measurement showed that the resting [Ca2+] and Ca2+ release triggered by the RYR-agonist 4-chloro-m-cresol (4-cmc) were significantly higher in HGSOC cells than the HOSE cells. Store-operated Ca2+ entry (SOCE) induced by 4-cmc was also enhanced in HGSOC cells. The elevated resting [Ca2+], the 4-cmc-induced Ca2+ release and SOCE in the HGSOC cells were reduced to the control level by shRNA against RYR1; and were significantly potentiated by over-expression of RYR1. RYR-dependent endoplasmic reticulum (ER)-mitochondrial Ca2+ transfer was examined by expressing the ER specific Ca2+ biosensor G-CEPIA1er and mitochondria Ca2+ biosensor CEPIA2mt in HGSOC cells. Activation of RYR by 4-cmc triggered a large reduction in ER [Ca2+], which was associated with a robust increase in mitochondrial [Ca2+]. Activation of RYRs by photorelease of caged cADP-ribose in a subcellular region caused an immediate transient local reduction in ER [Ca2+] and a fast transient local increase in mitochondria [Ca2+]. In contrast, RyR-dependent ER-mitochondrial Ca2+ transfer was not observed in the HOSE cells. These observations are the first direct evidence of enhanced RYR-mediated ER-mitochondrial Ca2+ transfer in ovarian cancer cells, and upregulation of RYR1-dependent Ca2+-signaling pathway contributes to the malignant phenotypes of HGSOC cells.

Abstract A015: Age-associated molecular changes may predispose the ovary to malignant transformation leading to ovarian cancer (OVCA)

Abstract Background: Ovarian cancer (OVCA) is a fatal malignancy of women which in most cases is a disease of postmenopausal women. Thus, age-associated changes in women may predispose them to malignancy. Persistent high levels of follicle stimulating hormone (FSH) is a feature of aging and we have shown that aging was associated with increased expression of inflammatory cytokine interleukin 16 (IL-16) and glucose regulatory protein (GRP78), a marker of cellular stress. It is possible that age-associated increased expression of IL-16 and GRP78 might be involved in production of mutagenic 8-OXO-2dG or its cognate enzyme OGG1 and malondialdehyde (MDA) as well as markers of DNA repair mechanisms. The goal of this study was to determine the mechanism of age-associated malignant transformation in the ovary. Materials and Methods: Exploratory study: Archived tissue specimens were selected for immunohistochemical, immunoblotting, genomic studies and immunoassays based on the review of their hematoxylin and eosin staining and final Pathological reports. Specimens were grouped as normal premenopausal women (30-50 years old), normal postmenopausal women (55-85 years old) and ovarian high grade serous carcinoma (HGSC). In vitro study: human ovarian surface epithelium (HOSE) cells were treated with or without FSH for 24 hours, and their cytoplasmic and nuclear fractionations together with that of OVCAR3 (HGSC cell line) cells were extracted. Expression of markers of inflammation (IL-16), oxidative stress (SOD2, GRP78), DNA adducts (8-OXO-2dG/OGG1, MDA) and epigenetics (HDAC1, gH2AX) and were examined. Significant differences in expression of different markers among different age groups and ovarian HGSC, and treated or control OVCAR3 cells were determined by ANOVA and t-tests. Results: Compared with premenopausal women, expression of markers of inflammation and oxidative stress including IL-16, GRP78, SOD2, 8-OXO-2dG/OGG1, MDA as well as markers of epigenetic changes including HDAC1 and gH2AX was significantly higher (<0.0001) in a subset of postmenopausal women. Similar patterns of expression were also observed in patients with ovarian HGSC. Nuclear expression of mutagenic DNA adducts (OGG1, MDA) and inhibitor of DNA damage repair mechanism (GRP78) enhanced during aging. Thus, age-associated inflammation and oxidative stress are predispositions to malignant transformation. This assumption is based on the observation from the treatment of HOSE cells with FSH which showed increased expression of the above markers as also observed in OVCAR3 cells. Conclusion: Expression of IL-16, GRP78, SOD2, 8-OXO-2dG/OGG1, MDA and HDAC1 increased in ovary during aging. These results suggest that aging is associated with persistent inflammation and oxidative stress in ovarian tissues, which predisposes these tissues to malignant transformation leading to OVCA development. Support: NIH/NCI: CA210370 Citation Format: Jessica Ramirez, Elizabeth Paris, Sanjib Basu, Animesh Barua. Age-associated molecular changes may predispose the ovary to malignant transformation leading to ovarian cancer (OVCA) [abstract]. In: Proceedings of the AACR Special Conference: Aging and Cancer; 2022 Nov 17-20; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2022;83(2 Suppl_1):Abstract nr A015.

RNA sequencing and bioinformatics analysis revealed PACSIN3 as a potential novel biomarker for platinum resistance in epithelial ovarian cancer

Failure to respond to treatment in epithelial ovarian cancer can often be attributed to platinum-based chemotherapy resistance. However, the possible mechanisms or candidate biomarkers associated with platinum resistance are yet to be elucidated, even though many researchers have performed related studies. We performed RNA sequencing of clinical specimens obtained from patients with platinum-sensitive or resistant epithelial ovarian cancer (EOC). Furthermore, various bioinformatics approaches, including spatial analysis of functional enrichment, were used to identify key regulators and associated underlying mechanisms of platinum resistance in EOC. Through RNA-sequencing, we identified 263 differentially expressed genes (98 upregulated and 165 downregulated) and subjected them to Gene Oncology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses, which were characterized to the traditional platinum-resistant characteristics. Subsequently, the gene interaction network and module analysis by spatial analysis of functional enrichment software demonstrated protein kinase C and casein kinase substrate in neurons 3 (PACSIN3) as the only upregulated hub gene, and neurotensin (NTS) and KIAA0319 as downregulated hub genes in platinum-resistant EOC. We selected PACSIN3 for further analysis because it has not been studied in relation to response to platinum-based chemotherapy. PACSIN3 was significantly upregulated in ovarian cancer cells compared to immortalized human ovarian surface epithelial cells. In addition, cisplatin-induced apoptosis was measured in PACSIN3 knockout OVCA433 and BRCA-mutated EOC cell line, SNU251, by a fluorescence-activated cell sorting-based Annexin-V/propium iodide double staining assay, which revealed a significant increase in apoptosis. Taken together, the present study presents PACSIN3 as a promising predictive biomarker associated with platinum resistance, especially in BRCA-mutated epithelial ovarian cancers.

Organochlorine pesticides induce epithelial as well as inflammatory mediators following exposure to human ovarian surface epithelial cells: An in vitro study.

Although studies have suggested organochlorine pesticides (OCPs) exposure increased the risk of epithelial ovarian cancer, the mechanisms underlying its potential tumorigenic effects in the human ovary are not well understood. In this study, we investigated the impact of dichlorodiphenyldichloroethylene (DDE), endosulfan, and heptachlor exposure on epithelial cadherin (E-cadherin) and proinflammatory mediators in human ovary surface epithelial (HOSE) cells. We found that DDE, endosulfan, and heptachlor exposure resulted in epithelial differentiation accompanied by upregulation of E-cadherin expression and overexpression of proinflammatory cytokines (TNFα,IL-1β, and IL-6) in HOSE cells. The epithelial differentiation may accelerate HOSE cells to inclusion body formation, a common site for ovarian cancer initiation and persistent exposure to OCPs creates a chronic inflammatory microenvironment that may promote the neoplastic transformation of HOSE cells within the inclusion cyst.

Sulfated Polysaccharide From Undaria Pinnatifida Induces Apoptosis and Inhibits Proliferation, Migration, and Invasion in Ovarian Cancer via Suppressing the Hedgehog Signaling Pathway

Objective: To investigate the effects of sulfured polysaccharide from Undaria pinnatifida (SPUP) on the biological behaviors of ovarian cancer (OC) cells and its potential mechanism.Methods: Sulfated polysaccharide from Undaria pinnatifida (SPUP) was extracted and characterized through a combination of chemical analysis, IR spectra, UV-Vis, gas chromatography, and high-performance gel permeation chromatography. OC and human ovarian surface epithelial cells were used as working model in vitro for evaluation of SPUP’s therapeutic effects. A combination of CCK-8, Transwell, and flow cytometry assay was used to measure the proliferation, migration, invasion, and apoptosis of OC cells, respectively. In addition, the protein expression levels of cells were also measured by Western blot.Results: SPUP suppressed OC development from three different perspectives: 1) SPUP treatment significantly inhibited the proliferation of OC in a dosage-dependent manner (p < 0.05); 2) SPUP inhibited the migration and invasion of OC cells confirmed by scratch and Transwell experiments (p < 0.05); 3) SPUP induced apoptosis in OC cells and thus further inhibited the growth of OC cells evaluated using flow cytometry (p < 0.05). The underlying mechanism of the suppressing effects of SPUP might be related to the inhibition of the hedgehog (Hh) signaling pathway in OC cells after SPUP treatment. With additional suppression of the Hh signaling pathway, the anticancer effects of SPUP were enhanced (p < 0.05).Conclusion: Taken together, SPUP could inhibit the proliferation, migration, and invasion and induce apoptosis of OC cells by inhibiting the activation of the Hh signaling pathway, which proposes SPUP as a novel drug to treat OC clinically.

A pancancer overview of FBN1, asprosin and its cognate receptor OR4M1 with detailed expression profiling in ovarian cancer.

Ovarian cancer affects >295,000 women worldwide and is the most lethal of gynaecological malignancies. Often diagnosed at a late stage, current research efforts seek to further the molecular understanding of its aetiopathogenesis and the development of novel biomarkers. The present study investigated the expression levels of the glucogenic hormone asprosin [encoded by fibrillin-1 (FBN1)], and its cognate receptor, olfactory receptor 4M1 (OR4M1), in ovarian cancer. A blend of in silico open access The Cancer Genome Atlas data, as well as in vitro reverse transcription-quantitative PCR (RT-qPCR), immunohistochemistry and immunofluorescence data were used. RT-qPCR revealed expression levels of OR4M1 and FBN1 in clinical samples and in ovarian cancer cell lines (SKOV-3, PEO1, PEO4 and MDAH-2774), as well as the normal human ovarian surface epithelial cell line (HOSEpiC). Immunohistochemical staining of a tissue microarray was used to identify the expression levels of OR4M1 and asprosin in ovarian cancer samples of varying histological subtype and grade, including clear cell carcinoma, serous ovarian cancer and mucinous adenocarcinoma. Immunofluorescence analysis revealed asprosin expression in SKOV-3 and HOSEpiC cells. These results demonstrated the expression of both asprosin and OR4M1 in normal and malignant human ovarian tissues. This research invokes further investigation to advance the understanding of the role of asprosin and OR4M1 within the ovarian tumour microenvironment.

MicroRNA-21 inhibits ovarian granulosa cell proliferation by targeting SNHG7 in premature ovarian failure with polycystic ovary syndrome

microRNA (miRs or miRNAs) is a type of non-coding RNA which plays the role of a regulator in gene expression. A number of miRNAs has been found by the researchers for its critical role in the pathogenesis of polycystic ovary syndrome (PCOS). But there is a no clear information available about the biological role played by miR-21 in PCOS prognosis. So, the aim of the current study is to determine the role played by miR-21 in the progression of PCOS. In order to achieve this aim, the researcher examined miR-21 expression levels in ovarian tissue samples collected from PCOS patients as well as their KGN cells (human granulosa-like tumor cell line). The study results inferred downregulation in the expression levels of miR-21 in ovarian tissues of PCOS patients and KGN cells, when compared with unaffected ovarian tissues and IOSE80 (human ovarian surface epithelial cell line). With the overexpression of miR-21, the proliferation of KGN cells was prevented and apoptosis was induced among these cells. The authors used StarBase analysis for predicting the direct binding target of miR-21. As per the assay results attained from luciferase reporter assay and western blot analysis, it was found that SNHG7 acted as a target gene for miR-21 while the latter downregulated the former. To conclude, the current study revealed the contribution of miR-21/SNHG7 axis in the regulation of Granulosa Cell (GC) proliferation and apoptosis. It further suggested a new molecular mechanism for GC dysregulation while the finding presents a new promising target for PCOS treatment procedure.

Phytochemical Profile, Antioxidant and Anti Proliferative Studies in Different Extracts of Artocarpus kemando Miq. Bark

In this study, the stem bark of Artocarpus kemando was used to find alternative antioxidants from natural sources with fewer side effects. A. kemando wasextracted successively using hexane, chloroform and methanol solvents, and evaluated for antioxidant, cytotoxic, and antiproliferative activities. The extracts were investigated for determination of their total phenolic content (TPC) and total flavonoid content (TFC). Then, the antioxidant activities were evaluated using chemical based assays such as ferric reducing antioxidant power (FRAP), total antioxidant capacity, radical scavenging of 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) and 2,2’-azino-bis (3-ethylbenzothia zoline-6-sulphonic) (ABTS), β-carotene-linoleic acid (BC) assay, oxygen radical absorbance capacity (ORAC), and cell based assay. The cytotoxic study was done using four different cell lines namely human estrogen receptor positive (ER+) breast cancer cell line (MCF7), human ovarian cancer cell line (CAOV-3), human promyelocytic leukemia cell line (HL60), and normal immortalised human ovarian surface epithelial cell line (TI074), and were evaluated using microculture tetrazolium salt (MTT) before morphological change study was done on CAOV-3 cell. In this study, methanol extract displayed the most promising antioxidant activity compared to other extracts when tested with DPPH, FRAP, ABTS, TAOC, BC,ORAC, and cytoprotective assays. The remarkable activity showed by the methanol extract might be due to its high content of phenolic and flavonoid compounds at 855.5 ± 0.01 GAE μg/mL and 145.45 ± 0.06 QAE μg/mL, respectively. Nevertheless, the chloroform extract displayed better scavenging activity compared to other extracts with IC50 value of 618 ± 0.04 μg/mL in DPPH assay. Each extract was analysed using Gas Chromatography Mass Spectrophotometry and the chemical constituents obtained were then analysed. In the cytoprotective activity, the methanol extract showed a comparable cytoprotection with ascorbic acid against the free radicals at the lowest effective concentration (EC50) value of 21.48 μg/mL. However, in the cytotoxicity study, only chloroform extract displayed significant toxicity against the cancer cells with IC50 value of 27.9 ± 0.03, 24.1 ± 0.02 and 9.0 ± 0.04 μg/mL after treatment at 24, 48, and 72 h, respectively. The chloroform extract of A. kemando was found capable of inducing apoptosis as shown with cell membrane blebbing, chromatin condensation and formation of apoptotic bodies. The results obtained from the study showed that A. kemando bark could be a potential antioxidant and antitumor agents particularly on human ovarian cancer cells.

Newly developed dual topoisomerase inhibitor P8-D6 is highly active in ovarian cancer

Background:Ovarian cancer (OvCa) constitutes a rare and highly aggressive malignancy and is one of the most lethal of all gynaecologic neoplasms. Due to chemotherapy resistance and treatment limitations because of side effects, OvCa is still not sufficiently treatable. Hence, new drugs for OvCa therapy such as P8-D6 with promising antitumour properties have a high clinical need. The benzo[c]phenanthridine P8-D6 is an effective inductor of apoptosis by acting as a dual topoisomerase I/II inhibitor.Methods:In the present study, the effectiveness of P8-D6 on OvCa was investigated in vitro. In various OvCa cell lines and ex vivo primary cells, the apoptosis induction compared with standard therapeutic agents was determined in two-dimensional monolayers. Expanded by three-dimensional and co-culture, the P8-D6 treated cells were examined for changes in cytotoxicity, apoptosis rate and membrane integrity via scanning electron microscopy (SEM). Likewise, the effects of P8-D6 on non-cancer human ovarian surface epithelial cells and primary human hepatocytes were determined.Results:This study shows a significant P8-D6-induced increase in apoptosis and cytotoxicity in OvCa cells which surpasses the efficacy of well-established drugs like cisplatin or the topoisomerase inhibitors etoposide and topotecan. Non-cancer cells were affected only slightly by P8-D6. Moreover, no hepatotoxic effect in in vitro studies was detected.Conclusion:P8-D6 is a strong and rapid inductor of apoptosis and might be a novel treatment option for OvCa therapy.

Methylomic Signatures of High Grade Serous Ovarian Cancer

ABSTRACT High-grade serous ovarian cancer (HGSOC) harbours aberrant epigenetic features, including DNA methylation. In this study we delineate pathways and networks altered by DNA methylation and associated with HGSOC initiation and progression to a platinum-resistant state. By including tumours from patients who had been treated with the hypomethylating agent (HMA) guadecitabine, we also addressed the role of HMAs in treatment of HGSOC. Tumours from patients with primary (platinum-naïve) HGSOC (n = 20) were compared to patients with recurrent platinum-resistant HGSOC and enrolled in a recently completed clinical trial (NCT01696032). Human ovarian surface epithelial cells (HOSE; n = 5 samples) served as normal controls. Genome-wide methylation profiles were determined. DNA methyltransferase (DNMT) expression levels were examined by immunohistochemistry and correlated with clinical outcomes. Cancer-related and tumorigenesis networks were enriched among differentially methylated genes (DMGs) in primary OC vs. HOSE. When comparing platinum-resistant and primary tumours, 452 CpG island (CGI)-containing gene promoters acquired DNA methylation; of those loci, decreased (P < 0.01) methylation after HMA treatment was observed in 42% (n = 189 CGI). Stem cell pluripotency and cytokine networks were enriched in recurrent platinum-resistant OC tumours, while drug metabolism and transport-related networks were downregulated in tumours from HMA-treated patients compared to HOSE. Lower DNMT1 and 3B protein levels in pre-treatment tumours were associated with improved progression-free survival. The findings provide important insight into the DNA methylation landscape of HGSOC tumorigenesis, platinum resistance and epigenetic resensitization. Epigenetic reprogramming plays an important role in HGSOC aetiology and contributes to clinical outcomes.

NGF/TRKA Decrease miR-145-5p Levels in Epithelial Ovarian Cancer Cells.

Nerve Growth Factor (NGF) and its high-affinity receptor tropomyosin receptor kinase A (TRKA) increase their expression during the progression of epithelial ovarian cancer (EOC), promoting cell proliferation and angiogenesis through several oncogenic proteins, such as c-MYC and vascular endothelial growth factor (VEGF). The expression of these proteins is controlled by microRNAs (miRs), such as miR-145, whose dysregulation has been related to cancer. The aims of this work were to evaluate in EOC cells whether NGF/TRKA decreases miR-145 levels, and the effect of miR-145 upregulation. The levels of miR-145-5p were assessed by qPCR in ovarian biopsies and ovarian cell lines (human ovarian surface epithelial cells (HOSE), A2780 and SKOV3) stimulated with NGF. Overexpression of miR-145 in ovarian cells was used to evaluate cell proliferation, migration, invasion, c-MYC and VEGF protein levels, as well as tumor formation and metastasis in vivo. In EOC samples, miR-145-5p levels were lower than in epithelial ovarian tumors. Overexpression of miR-145 decreased cell proliferation, migration and invasion of EOC cells, changes that were concomitant with the decrease in c-MYC and VEGF protein levels. We observed decreased tumor formation and suppressed metastasis behavior in mice injected with EOC cells that overexpressed miR-145. As expected, ovarian cell lines stimulated with NGF diminished miR-145-5p transcription and abundance. These results suggest that the tumoral effects of NGF/TRKA depend on the regulation of miR-145-5p levels in EOC cells, and that its upregulation could be used as a possible therapeutic strategy for EOC.

Metformin Reduces NGF-Induced Tumour Promoter Effects in Epithelial Ovarian Cancer Cells.

Epithelial ovarian cancer (EOC) is a lethal gynaecological neoplasm characterized by rapid growth and angiogenesis. Nerve growth factor (NGF) and its high affinity receptor tropomyosin receptor kinase A (TRKA) contribute to EOC progression by increasing the expression of c-MYC, survivin and vascular endothelial growth factor (VEGF) along with a decrease in microRNAs (miR) 23b and 145. We previously reported that metformin prevents NGF-induced proliferation and angiogenic potential of EOC cells. In this study, we sought to obtain a better understanding of the mechanism(s) by which metformin blocks these NGF-induced effects in EOC cells. Human ovarian surface epithelial (HOSE) and EOC (A2780/SKOV3) cells were stimulated with NGF and/or metformin to assess the expression of c-MYC, β-catenin, survivin and VEGF and the abundance of the tumor suppressor miRs 23b and 145. Metformin decreased the NGF-induced transcriptional activity of MYC and β-catenin/T-cell factor/lymphoid enhancer-binding factor (TCF-Lef), as well as the expression of c-MYC, survivin and VEGF in EOC cells, while it increased miR-23b and miR-145 levels. The preliminary analysis of ovarian biopsies from women users or non-users of metformin was consistent with these in vitro results. Our observations shed light on the mechanisms by which metformin may suppress tumour growth in EOC and suggest that metformin should be considered as a possible complementary therapy in EOC treatment.

Melatonin antagonizes ovarian aging via YTHDF2-MAPK-NF-κB pathway

Cellular senescence is closely associated with age-related diseases. Ovarian aging, a special type of organ senescence, is the pathophysiological foundation of the diseases of the reproductive system. It is characterized by the loss of integrity of the surface epithelium and a gradual decrease in the number of human ovarian surface epithelial cells (HOSEpiCs). To contribute to the research on delaying ovarian aging, we aimed to investigate the novel epigenetic mechanism of melatonin in protecting HOSEpiCs. We discovered that melatonin has antagonistic effects against the oncogene-induced senescence (OIS) of HOSEpiCs. Mechanistically, the oncogene Ras decreased the expression of YTHDF2, which is the reader of RNA-m6A, by stimulating the generation of reactive oxygen species (ROS). Moreover, we found that the suppression of YTHDF2 increased the expression of MAP2K4 and MAP4K4 by enhancing the stability of the transcription of their mRNAs, thereby upregulating the expression of the senescence-associated secretory phenotype (SASP) through the activation of the MAP2K4 and MAP4K4-dependent nuclear factor-κB (NF-κB) signaling pathways. We further determined that melatonin has antagonistic effects against the OIS of HOSEpiCs by inhibiting the ROS-YTHDF2-MAPK-NF-κB pathway. These findings provide key insights into the potential avenues for preventing and treating ovarian aging.

Examination of the relationship between viscoelastic properties and the invasion of ovarian cancer cells by atomic force microscopy.

The mechanical properties of cells could serve as an indicator for disease progression and early cancer diagnosis. This study utilized atomic force microscopy (AFM) to measure the viscoelastic properties of ovarian cancer cells and then examined the association with the invasion of ovarian cancer at the level of living single cells. Elasticity and viscosity of the ovarian cancer cells OVCAR-3 and HO-8910 are significantly lower than those of the human ovarian surface epithelial cell (HOSEpiC) control. Further examination found a dramatic increase of migration/invasion and an obvious decease of microfilament density in OVCAR-3 and HO-8910 cells. Also, there was a significant relationship between viscoelastic and biological properties among these cells. In addition, the elasticity was significantly increased in OVCAR-3 and HO-8910 cells after the treatment with the anticancer compound echinomycin (Ech), while no obvious change was found in HOSEpiC cells after Ech treatment. Interestingly, Ech seemed to have no effect on the viscosity of the cells. Ech significantly inhibited the migration/invasion and significantly increased the microfilament density in OVCAR-3 and HO-8910 cells, which was significantly related with the elasticity of the cells. An increase of elasticity and a decrease of invasion were found in OVCAR-3 and HO-8910 cells after Ech treatment. Together, this study clearly demonstrated the association of viscoelastic properties with the invasion of ovarian cancer cells and shed a light on the biomechanical changes for early diagnosis of tumor transformation and progression at single-cell level.

LncRNA MIAT Regulates Cell Growth, Migration, and Invasion Through Sponging miR-150-5p in Ovarian Cancer.

Background: MIAT (myocardial infarction-associated transcript) regulates cell proliferation, apoptosis, and metastasis in several cancers. In this study, the authors aimed to explore the role of MIAT in ovarian cancer. Materials and Methods: The expression of MIAT in ovarian cancer subtypes, normal human ovarian surface epithelial and ovarian cancer cell lines was measured by qualitative real-time polymerase chain reaction (qRT-PCR). OVCAR3 and SKOV3 cells were transfected with MIAT overexpression plasmid or siMIAT. The cell growth ability was then evaluated by CCK-8 and colony formation assays. The cell migration and invasion rate were separately measured by wound-healing and transwell assays. The levels of epithelial-mesenchymal transition (EMT)-associated markers were evaluated by Western blotting. MIAT sponging miR-150-5p was predicted by starBase and confirmed by dual-luciferase reporter assays. The expression of miR-150-5p in OVCAR3 and SKOV3 cells with MIAT overexpression or knockdown, and in ovarian cancer subtypes was also measured by qRT-PCR. Further analyses confirmed the role of MIAT sponging miR-150-5p in ovarian cancer cells. Results: MIAT was highly expressed in mesenchymal subtype ovarian cancer tissues and ovarian cancer cells. In OVCAR3 and SKOV3 cells, overexpression of MIAT promoted, and knockdown of MIAT suppressed the cell growth, migration, invasion, and EMT. miR-150-5p was sponged and regulated by MIAT. miR-150-5p was downregulated in mesenchymal subtype ovarian cancer. Suppression of cell migration, invasion, and EMT caused by miR-150-5p overexpression was rescued by MIAT overexpression. Conclusions: MIAT acts as an oncogene in ovarian cancer cells through sponging miR-150-5p. MIAT or miR-150-5p expression might be a potential prognostic biomarker for ovarian cancer patients. MIAT and miR-150-5p are potential therapeutic targets in treatment of ovarian cancer.

LncRNA LUCAT1 promotes proliferation of ovarian cancer cells by regulating miR-199a-5p expression.

To investigate the biological effect of long non-coding ribonucleic acid (lncRNA) lung cancer-associated transcript 1 (LUCAT1) in the development of ovarian cancer. Real-time quantitative polymerase chain reaction (RT-qPCR) was utilized to detect the expression levels of lncRNA LUCAT1 in three human ovarian cancer cell lines (CaoV-3, SK-OV-3 and HO-8910) and the normal human ovarian surface epithelial cell line (IOSE80). Small interfering RNAs against lncRNA LUCAT1 (si-LUCAT1) were transfected into SK-OV-3 cells. Transfection efficiency of si-LUCAT1 was verified via RT-qPCR. Cell Counting Kit-8 (CCK-8) and colony formation assays were performed to test the effect of silencing lncRNA LUCAT1 on SK-OV-3 cell proliferation. The apoptosis was measured by flow cytometry. The miRcode database was searched to predict potential microRNAs (miRNAs) binding lncRNA LUCAT1. It was found that lncRNA LUCAT1 contained a highly conserved binding site of miR-199a-5p in the 3'-untranslated region (3'-UTR). Subsequently, the targeting relationship between them was determined through Dual-Luciferase reporter gene assay and RT-qPCR analysis. LncRNA LUCAT1 was highly expressed in three human ovarian cancer cell lines compared to that in normal ovarian surface epithelial cell line (p<0.05). The cell proliferation rate in SK-OV-3 cells with lncRNA LUCAT1 knockdown was remarkably lower in comparison to that in control group. Moreover, colony formation assay also revealed that the number of cell clones decreased significantly after knockdown of lncRNA LUCAT1 compared to that in control group (p<0.05). In addition, the apoptosis rate was distinctly elevated in the lncRNA LUCAT1 silencing group (p<0.05). Furthermore, a highly conserved binding site of miR-199a-5p was found in the 3'-UTR of lncRNA LUCAT1. Dual-Luciferase reporter gene assay exhibited that the Luciferase activity of LUCAT1-wt was significantly reduced after overexpression of miR-199a-5p (p<0.05), while that of LUCAT1-mut was unchangeable. Further analysis via RT-qPCR suggested that miR-199a-5p overexpression significantly decreased the expression level of lncRNA LUCAT1 (p<0.05). LncRNA LUCAT1 is overexpressed in ovarian cancer cells, which may target miR-199a-5p to exert its effects on driving the malignant development of ovarian cancer.

ALDH1A2 Is a Candidate Tumor Suppressor Gene in Ovarian Cancer.

Aldehyde dehydrogenase 1 family member A2 (ALDH1A2) is a rate-limiting enzyme involved in cellular retinoic acid synthesis. However, its functional role in ovarian cancer remains elusive. Here, we found that ALDH1A2 was the most prominently downregulated gene among ALDH family members in ovarian cancer cells, according to complementary DNA microarray data. Low ALDH1A2 expression was associated with unfavorable prognosis and shorter disease-free and overall survival for ovarian cancer patients. Notably, hypermethylation of ALDH1A2 was significantly higher in ovarian cancer cell lines when compared to that in immortalized human ovarian surface epithelial cell lines. ALDH1A2 expression was restored in various ovarian cancer cell lines after treatment with the DNA methylation inhibitor 5-aza-2′-deoxycytidine. Furthermore, silencing DNA methyltransferase 1 (DNMT1) or 3B (DNMT3B) restored ALDH1A2 expression in ovarian cancer cell lines. Functional studies revealed that forced ALDH1A2 expression significantly impaired the proliferation of ovarian cancer cells and their invasive activity. To the best of our knowledge, this is the first study to show that ALDH1A2 expression is regulated by the epigenetic regulation of DNMTs, and subsequently that it might act as a tumor suppressor in ovarian cancer, further suggesting that enhancing ALDH1A2-linked signaling might provide new opportunities for therapeutic intervention in ovarian cancer.