Apoptosis In Epithelial Ovarian Cancer Cells Research Articles

Abstract A008: Pre-diabetic D-glucose exposure promotes EOC progression and cisplatin resistance: Role of BAD associated pathway and potential therapeutic strategy

Abstract Prediabetes denotes a condition when blood sugar levels exceed normal thresholds (>7mmol) but have not reached the diagnostic criteria for type 2 diabetes (<11mmol). It positively correlates with diminished progression-free survival and overall survival among women with epithelial ovarian cancer (EOC). This suggests a potential metabolic state associated with prediabetes that may facilitate tumor survival and progression. Moreover, prediabetes is also associated with an increased risk of recurrence and poorer survival outcomes of EOC patients, possibly promoting tumor aggressiveness and resistance to treatment, although the precise mechanisms remain unclear and warrant additional investigation. In this study, we aimed to explore whether prediabetic D-glucose levels accelerate EOC progression and elucidate underlying mechanisms. We also aimed to propose a viable and effective therapy strategy for EOC progression. Various in vitro and ex vivo oncogenic assays were used to assess the effects of prediabetic levels of D-glucose in EOC cells. It was found to stimulate oncogenic phenotypes in EOC cells in a dose-dependent manner. EOC cells exposed to prediabetic levels of D-glucose (8mM) exhibited increased cell survival, enhanced foci formation on monolayer, growth in soft agar, spheroid formation capacity in 3D Matrigel (ex-vivo culture), increased migration and invasion, and resistance to cisplatin compared to those exposed to lower D-glucose doses (4mM). Exposure to 8mM D-glucose led to metabolic alterations associated with cisplatin resistance, including increased D-glucose consumption, elevated ATP production, increased thermogenesis, enhanced glycolytic capacity, and augmented mitochondrial activity. RNA sequencing analysis showed the BCL-2-associated death promoter (BAD) pathway positively correlates with metabolic alterations of EOC cells in 8mM. Prediabetic levels of D-glucose upregulated phosphorylation of BAD at serine (S) 99 residue along with key metabolic enzymes such as ALDH1A1, HK2, PFKP, G6PD, and LDHA. Inhibition of glycolysis with 2-deoxy-D-glucose (2-DG) attenuated 8mM D-glucose effects. Furthermore, forced expression of phosphorylated BADS99 increased oncogenic phenotypes of EOC. The elevated activities of metabolic enzymes associated with BADS99 phosphorylation were observed in EOCs, while this effect was diminished with dephosphorylated BADS99. High-throughput screening identified a combination therapy involving a BADS99 phosphorylation inhibitor and HDAC inhibitors demonstrated higher synergy to stimulate apoptosis in EOC cells. The combined BADS99-HDAC inhibition synergistically enhanced the efficacy of HDAC inhibitors, significantly reducing their IC50 values. It impaired cell survival, viability, anchorage-independent growth, mitochondrial activity, energy production, growth in 3D Matrigel and successfully overcome cisplatin resistance of EOC cell lines and a patient-derived cell line (AFC). This synergistic therapeutic approach offers a promising strategy for exploiting synthetic lethality in treating EOC patients. Citation Format: Jing Huang, Xi Zhang, Peng Huang, Basappa Basappa, Tao Zhu, Peter E. Lobie, Vijay Pandey. Pre-diabetic D-glucose exposure promotes EOC progression and cisplatin resistance: Role of BAD associated pathway and potential therapeutic strategy [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Expanding and Translating Cancer Synthetic Vulnerabilities; 2024 Jun 10-13; Montreal, Quebec, Canada. Philadelphia (PA): AACR; Mol Cancer Ther 2024;23(6 Suppl):Abstract nr A008.

Drug repositioning of disulfiram induces endometrioid epithelial ovarian cancer cell death via the both apoptosis and cuproptosis pathways.

Various therapeutic strategies have been developed to overcome ovarian cancer. However, the prognoses resulting from these strategies are still unclear. In the present work, we screened 54 small molecule compounds approved by the FDA to identify novel agents that could inhibit the viability of human epithelial ovarian cancer cells. Among these, we identified disulfiram (DSF), an old alcohol-abuse drug, as a potential inducer of cell death in ovarian cancer. Mechanistically, DSF treatment significantly reduced the expression of the anti-apoptosis marker B-cell lymphoma/leukemia-2 (Bcl-2) and increase the expression of the apoptotic molecules Bcl2 associated X (Bax) and cleaved caspase-3 to promote human epithelial ovarian cancer cell apoptosis. Furthermore, DSF is a newly identified effective copper ionophore, thus the combination of DSF and copper was used to reduce ovarian cancer viability than DSF single treatment. Combination treatment with DSF and copper also led to the reduced expression of ferredoxin 1 and loss of Fe-S cluster proteins (biomarkers of cuproptosis). In vivo, DSF and copper gluconate significantly decreased the tumor volume and increased the survival rate in a murine ovarian cancer xenograft model. Thus, the role of DSF revealed its potential for used as a viable therapeutic agent for the ovarian cancer.

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.

Binding of Intracellular Myeloperoxidase to αV/β1 Integrin Serves as a Mechanism of Survival in Epithelial Ovarian Cancer.

We were the first to report that epithelial ovarian cancer (EOC) cells and tissues express myeloperoxidase (MPO) that is known to play a role in immune surveillance and inflammation by myeloid cells. Additionally, we reported that MPO is colocalized with inducible nitric oxide synthase (iNOS), a key pro-oxidant enzyme, and plays a key role in regulating apoptosis in EOC cells. Whereas myeloid cells express MPO in a dimeric form, intriguingly, here we report the unique expression of only the monomeric form of MPO in EOC cells, tissues, and blood of an ovarian cancer patient. Additionally, we have identified a cell membrane receptor, αV/β1 integrin, that is uniquely expressed by both chemosensitive and chemoresistant EOC cells with significantly higher expression in chemoresistant EOC cells. More importantly, we have demonstrated that monoclonal antibodies against αV/β1 integrin induced cytotoxicity in EOC cells, but not in normal cells, that is also synergistic with conventional chemotherapies. Cytotoxicity of αV/β1 antibodies is due to conformational changes in αV/β1 integrin which prevents monomeric MPO binding to αV/β1 integrin inhibiting the activation of MPO, leading to increased apoptosis. Since normal epithelial cells and macrophages lack monomeric MPO and αV/β1 integrin system, targeting this unique MPO-dependent survival mechanism will selectively eliminate EOC cells and will be the target for developing specific ovarian cancer therapies.

Down-regulation of PSMD4 can attenuate autophagy, enhance the accumulation of intracellular ROS, and increase the sensitivity of epithelial ovarian cancer to carboplatin by inhibiting the NF-κB pathway.

BackgroundThe incidence of ovarian cancer ranks third among female gynecological cancers in the world, and more than 90% of patients are epithelial ovarian cancer (EOC). Carboplatin is the first-line chemotherapy drug for the treatment of EOC patients. However, patients who are resistant to carboplatin often do not benefit from it. Therefore, finding a key molecule that affects carboplatin sensitivity is expected to enhance the efficacy of carboplatin in EOC treatment.MethodsThe human EOC cell line SK-OV-3 and TOV-21G were used in this study. The second-generation sequencing technology was used to sequence the transcripts of carboplatin-resistant EOC cells and parental EOC cells. The bioinformatic analysis of the differentially expressed genes was performed by Gene Ontology (GO) enrichment, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. The EOC tissue chip in the Gene Expression Omnibus (GEO) database was also analyzed to screen the target gene. Flow cytometry, Hoechst staining, Western blot, MTS, mitochondrial specific reducing agent (Mito Tempo), and nuclear factor kappa-B (NF-κB) pathway inhibitor (BAY 11-7082) were used to explore the effect of proteasome 26S subunit, non-ATPase 4 (PSMD4) on the autophagy, apoptosis, and reactive oxygen species (ROS) accumulation of carboplatin-resistant EOC cells treated with carboplatin. In vivo, the carboplatin-resistant EOC cell lines treated with PSMD4 knockdown were injected subcutaneously into mice (twelve female BALB/c nude mice) to construct EOC subcutaneous xenograft tumor models.ResultsBased on second-generation sequencing technology and bioinformatics analysis, it was found that PSMD4 is the core molecule in the carboplatin resistance regulatory network in EOC, and its expression is up-regulated in EOC carboplatin-resistant tissues and cells. In vitro and in vivo experimental results show that the down-regulated expression of PSMD4 is closely related to the increase in sensitivity of EOC to carboplatin. Mechanically, we found that inhibiting PSMD4 expression may inhibit the activation of the NF-κB pathway, promote carboplatin-induced ROS accumulation in EOC cells, inhibit EOC cell autophagy, and enhance the sensitivity of EOC to carboplatin.ConclusionsDown-regulation of PSMD4 may inhibit the activation of the NF-κB pathway and autophagy, and up-regulate the level of intracellular ROS accumulation, thereby promoting carboplatin-mediated EOC cell apoptosis and enhancing carboplatin sensitivity.

Aspirin inhibits tumor progression and enhances cisplatin sensitivity in epithelial ovarian cancer.

BackgroundOvarian cancer is the most common gynecological malignancy and is difficult to manage due to the emergence of resistance to various chemotherapeutic drugs. New efforts are urgently awaited. Aspirin, which is traditionally considered a nonsteroidal anti-inflammatory drug (NSAID), has been reported to exert potential chemopreventive effects. Therefore, we aimed to investigate the anticancer effect and explore the underlying molecular mechanisms of aspirin on epithelial ovarian cancer (EOC) cells.MethodsWe conducted wound healing, transwell migration, EdU cell proliferation, colony formation and apoptosis detection assays to observe the effects of aspirin on the migration, proliferation and apoptosis of EOC cells (A2870, Caov-3, and SK-OV-3). EOC cells were treated with a combination of aspirin and cisplatin (CDDP) to observe the effect of aspirin on enhancing CDDP sensitivity. Orthotopic xenograft models of ovarian cancer established with A2780-Luciferase-GFP cells were applied to compare tumor growth inhibition in the control, CDDP and CDDP plus aspirin groups through in vivo imaging, which can be used to continuously monitor tumor growth. The expression and acetylation levels of p53 in EOC cells treated with aspirin were determined using western blotting, and p53 acetylation levels were examined in tumors harvested from the transplanted mice. Quantitative real-time PCR was used to assess the mRNA expression of p53 target genes.ResultsAspirin inhibited migration and proliferation and induced apoptosis in EOC cell lines in a concentration-dependent manner. In vitro, aspirin enhanced the sensitivity of EOC cells to CDDP by increasing its inhibitory effect on proliferation and its effect on inducing apoptosis. In vivo, the differences in the tumor growth inhibition rates among the different CDDP experimental groups were statistically significant (p < 0.05). Aspirin did not affect p53 protein expression but increased the p53 acetylation level in a concentration-dependent manner. In addition, the mRNA levels of CDKN1A, BAX, FOXF1, PUMA, and RRAD in EOC cells were significantly increased by the aspirin treatment.ConclusionsAspirin inhibits tumor progression and enhances the CDDP sensitivity of EOC cells. These antitumor effects of aspirin might be mediated by p53 acetylation and subsequent activation of p53 target genes.

Preclinical assessment of the VEGFR inhibitor axitinib as a therapeutic agent for epithelial ovarian cancer

Axitinib, small molecule tyrosine kinase inhibitor, demonstrates anti-cancer activity for various solid tumors. We investigated anti-cancer effect of axitinib in epithelial ovarian cancer (EOC). We treated EOC cells (A2780, HeyA8, RMG1, and HeyA8-MDR) with axitinib to evaluate its effects on cell viabilty, apoptosis and migration. Western blots were performed to assess VEGFR2, ERK, and AKT levels, and ELISA and FACS to evaluate apoptosis according to axitinib treatment. In addition, in vivo experiments in xenografts using A2780, RMG1, and HeyA8-MDR cell lines were performed. We repeated the experiment with patient-derived xenograft models (PDX) of EOC. Axitinib significantly inhibited cell survival and migration, and increased apoptosis in EOC cells. The expression of VEGFR2 and phosphorylation of AKT and ERK in A2780, RMG1, and HeyA8 were decreased with axitinib treatment in dose-dependent manner, but not in HeyA8-MDR. In in vivo experiments, axitinib significantly decreased tumor weight in xenograft models of drug-sensitive (A2780), and clear cell carcinoma (RMG1) and PDX models for platinum sensitive EOC compared to control, but was not effective in drug-resistant cell line (HeyA8-MDR) or heavily pretreated refractory PDX model. Axitinib showed significant anti-cancer effects in drug-sensitive or clear cell EOC cells via inhibition of VEGFR signals associated with cell proliferation, apoptosis and migration, but not in drug-resistant cells.

Clinical significance of SLP-2 in epithelial ovarian cancer and its regulatory effect on the Notch signaling pathway.

To explore the expression of Stomatin-like protein 2 (SLP-2) and its clinical significance in epithelial ovarian cancer (EOC). Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the differential expression of SLP-2 in EOC tissues and cell lines. The relationship between SLP-2 expression and clinical pathological data of EOC patients was analyzed. QRT-PCR results suggested that the SLP-2 was up-regulated in both EOC tissues and EOC cells by comparing with normal control. SLP-2 expression was a correlation with tumor pathological grade, distant metastasis, and TNM stage in EOC patients. Down-regulation of SLP-2 could significantly inhibit proliferation and promote apoptosis of EOC cells by activating the Notch signaling pathway. Knockdown of SLP-2 markedly downregulated Notch1 and Hes1. SLP-2 was a novel factor involved in EOC progression, and could be utilized as a potential biomarker and therapeutic target for the EOC patients.

CDK7 is a reliable prognostic factor and novel therapeutic target in epithelial ovarian cancer

ObjectiveCyclin-dependent kinase 7 (CDK7) engages tumor growth by acting as a direct link between the regulation of transcription and the cell cycle. Here, we investigated the clinical significance of CDK7 expression and its potential as a therapeutic target in epithelial ovarian cancer (EOC). MethodsCDK7 expression was examined in 436 ovarian tissues including normal to metastatic ovarian tumors using immunohistochemistry, and its clinical implications were analyzed. Furthermore, we performed in vitro and in vivo experiments using CDK7 siRNA or a covalent CDK7 inhibitor (THZ1) to elucidate the effect of CDK7 inhibition on tumorigenesis in EOC cells. ResultsThe patient incidence of high CDK7 expression (CDK7High) gradually increased from normal ovarian epithelium to EOC (P < 0.001). Moreover, CDK7High was associated with an advanced stage and high-grade histology (P = 0.035 and P = 0.011, respectively) in EOC patients and had an independent prognostic significance in EOC recurrence (P = 0.034). CDK7 inhibition with siRNA or THZ1 decreased cell proliferation and migration, and increased apoptosis in EOC cells, and this anti-cancer mechanism is caused by G0/G1 cell cycle arrest. In in vivo therapeutic experiments using cell-line xenograft and PDX models, CDK7 inhibition significantly decreased the tumor weight, which was mediated by cell proliferation and apoptosis. ConclusionMechanistic interrogation of CDK7 revealed that it is significantly associated with an aggressive phenotype of EOC, and it has independent prognostic power for EOC recurrence. Furthermore, CDK7 may be a potential therapeutic target for patients with EOC, whether platinum sensitive or resistant.

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.

CHTOP in Chemoresistant Epithelial Ovarian Cancer: A Novel and Potential Therapeutic Target.

Objective: Chemoresistance is a major challenge in epithelial ovarian cancer (EOC) treatment. Chromatin target of protein arginine methyltransferase (CHTOP) was identified as a potential biomarker in chemoresistant EOC cell lines using label-free LC-MS/MS quantitative proteomics. Thus, the aim of this study is to investigate the role of CHTOP in chemoresistant EOC and the underlying mechanism.Methods: The expression of CHTOP in human ovarian cancer cells and tissues was detected using immunofluorescence (IF), western blot (WB), and immunohistochemistry (IHC), respectively. Flow cytometry and TUNEL assay were employed to detect the effect of CHTOP knockdown (KD) in chemoresistant EOC cell apoptosis, while colony and sphere formation assays were used to evaluate its effect on cell stemness. The association of CHTOP with cell metastasis was determined using Matrigel invasion and wound-healing assays.Results: The higher level expression of CHTOP protein was found in chemoresistant EOC cells as compared to their sensitive parental cells or normal epithelial ovarian cells. Results from IHC and bioinformatic analysis showed CHTOP was highly expressed in human ovarian cancer tissues and associated with a poor progression-free survival in patients. In addition, CHTOP KD significantly enhanced cisplatin-induced apoptosis, reduced the stemness of chemoresistant EOC cells, and decreased their metastatic potential.Conclusion: Our findings suggest that CHTOP is associated with apoptosis, stemness, and metastasis in chemoresistant EOC cells and might be a promising target to overcome chemoresistance in EOC treatment.

Songorine suppresses cell growth and metastasis in epithelial ovarian cancer via the Bcl‑2/Bax and GSK3β/β‑catenin signaling pathways.

Epithelial ovarian cancer (EOC) is the most frequent cause of cancer‑associated mortality among all types of gynecological cancer. The high recurrence rate and the poor 5‑year survival rate indicate that more effective therapeutic strategies are required. The aim of the present study was to investigate the role and potential mechanisms of songorine in treating EOC. EOC cells were cultured with different concentrations of songorine, following which MTT and flow cytometric analyses were conducted to measure cell viability and apoptosis. Wound healing and Transwell assays were used to detect cell migration and invasion abilities. Furthermore, associated molecules in the glycogen synthase kinase (GSK)‑3β/β‑catenin and B‑cell lymphoma 2 (Bcl‑2)/Bcl‑2‑associated X (Bax) signaling pathways were semi‑quantified by western blotting. Finally, tumor size measurements, pathological observations, western blot analysis and toxicological evaluations were performed in SKOV‑3 tumor‑bearing BALB/c nude mice to investigate the efficacy and safety of songorine. As expected, songorine inhibited EOC cell survival, invasion and migration, promoted EOC cell apoptosis and suppressed mammalian EOC tumorigenic behavior. In particular, GSK3β inhibitor treatment restored the songorine‑induced regulation of the GSK3β/β‑catenin signaling pathway. Furthermore, in the in vitro and in vivo experiments, songorine consistently downregulated the expression of N‑cadherin, vimentin, matrix metalloproteinase (MMP)‑2, MMP‑9, phosphorylated‑GSK3β, β‑catenin and Bcl‑2, and upregulated the expression of E‑cadherin, cleaved caspase‑3, cleaved caspase‑9 and Bax. In conclusion, songorine exerted its anticancer effect through the GSK3β/β‑catenin and Bcl‑2/Bax signaling pathways. These results highlight the potential use of songorine as a novel therapeutic agent for EOC.

TRIP13 promotes proliferation and invasion of epithelial ovarian cancer cells through Notch signaling pathway.

Growing evidence supports the involvement of Thyroid hormone Receptor Interactor 13 (TRIP13) in the progression and metastasis of multiple cancers. However, the roles of TRIP13 in epithelial ovarian cancer (EOC) remains unknown. The present study aimed to investigate the expression pattern and biological function as well as the underlying molecular mechanism. The expression patterns of genes in EOC tissues and normal ovarian tissues via microarray from GEO and TCGA datasets. The expression levels of TRIP13 in EOC cell lines were detected by Real Time-Polymerase Chain Reaction (RT-PCR). Next, we investigated the effect of TRIP13 on the proliferation, apoptosis, migration and invasion in the EOC cells. Western blot assay was used to explore the role of TRIP13 on the Notch signaling pathway proteins (Notch1, P21, Hes1). Bioinformatics analysis showed that TRIP13 was one of the most significantly upregulated in EOC. The results of RT-PCR also indicated that TRIP13 expression was markedly upregulated in EOC cell lines (SKOV-3, HEY and OVCAR-3) compared to normal ovarian cell lines. Functionally, our data revealed that silencing TRIP13 in EOC cells inhibits cell proliferation, decreases cell invasion and migration, and stimulates EOC cell apoptosis in vitro. Mechanistically, the knockdown of TRIP13 suppressed the Notch signaling pathway activation and subsequently inhibited EMT progression. The present study provided the first evidence that TRIP13 acted as an onco-promotive regulator in EOC development by modulating the Notch signaling pathway. Our findings enlarged our knowledge in the molecular pathology of TRIP13 tumorigenesis.

LINC01116 promotes the progression of epithelial ovarian cancer via regulating cell apoptosis.

To explore the biological function of LINC01116 in epithelial ovarian cancer (EOC) and its underlying mechanism. The expression level of LINC01116 in 60 EOC tissues, 30 normal ovarian tissues and EOC cells were detected by qRT-PCR (quantitative real-time polymerase chain reaction). Disease-free survival (DFS) and overall survival (OS) of enrolled EOC patients were recorded. The correlation between LINC01116 expression, DFS and OS of EOC patients was analyzed using ROC curve. Influencing factors for DFS and OS were analyzed by univariable and multivariable Cox regression model. For in vitro experiments, the effect of LINC01116 knockdown on proliferation, invasion and apoptosis of EOC cells were detected by CCK-8 (cell counting kit-8), transwell assay and flow cytometry, respectively. Protein expressions of apoptosis-related genes in EOC cells transfected with pc-DNA-LINC01116 or si-LINC01116 were detected by Western blot. LINC01116 was overexpressed in EOC tissues than that of paracancerous tissues. DFS and OS in EOC patients with higher expression of LINC01116 were remarkably shorter than those with lower expression. FIGO (International Federation of Gynecology and Obstetrics) clinical stage and LINC01116 expression were the independent factors that affected DFS and OS of EOC patients. Besides, LINC01116 expression was positively correlated to the diagnostic sensitivity of EOC patients. In vitro experiments found that LINC01116 overexpression promoted proliferation and invasion of EOC cells. Overexpressed LINC01116 resulted in upregulated Bcl-2, and downregulated cleaved Caspase-3 and cleaved Caspase-9 in EOC cells. Overexpressed LINC01116 promotes EOC progression via increasing proliferation and migration, and inhibiting cell apoptosis.

Anti-Müllerian hormone inhibits proliferation and induces apoptosis in epithelial ovarian cancer cells by regulating the cell cycle and decreasing the secretion of stem cell factor.

Anti-Müllerian hormone (AMH) has been demonstrated to exhibit an inhibitory effect on the proliferation, invasion, metastasis and drug resistance of ovarian cancer. However, the mechanisms underlying these effects remain unclear. In the present study, 10 µg/ml recombinant human AMH (rhAMH) was administered to human OVCAR3 and OVCAR8 epithelial ovarian cancer (EOC) cell lines. Cell proliferation, apoptosis and cell cycle were analyzed. The level of stem cell factor (SCF) was detected using a reverse transcription-quantitative polymerase chain reaction and an ELISA, respectively. The exogenous addition of rhAMH significantly reduced the proliferation of OVCAR3 and OVCAR8 cell lines compared with the control group (P<0.01). The apoptosis rate in the rhAMH treated group (48 h) significantly increased compared with in the control group (OVCAR3, P=0.035; OVCAR8, P=0.020). The apoptosis rate increased at 72 h but did not exhibit a significant difference when compared with the 48 h group (OVCAR3, P=0.145; OVCAR8, P=0.296). The percentage of cells in the G1 phase in the rhAMH treated group (48 h) increased but was not significantly different compared with the control group (OVCAR3, P=0.070; OVCAR8, P=0.051). However, there was a significant difference at 72 h compared with the control group (OVCAR3, P=0.016; OVCAR8, P=0.019). At 48 h, the rhAMH-treated group exhibited a statistically significant inhibition of SCF mRNA expression levels (P=0.008), but no significant difference in the protein expression levels (P=0.101) compared with the control, though a significant inhibition was exhibited at 72 h (mRNA expression levels, P=0.005; protein expression levels, P=0.036). The present study revealed that rhAMH may be able to inhibit the proliferation and induce the apoptosis of EOC cells via G1/S-phase cell cycle arrest and the decreased secretion of SCF.

Long non-coding RNA taurine-upregulated gene 1 predicts unfavorable prognosis, promotes cells proliferation, and inhibits cells apoptosis in epithelial ovarian cancer.

The aim of this study was to evaluate the correlation of long non-coding RNAs (lncRNAs) taurine-upregulated gene 1 (TUG1) with clinicopathological characteristics as well as overall survival (OS) in epithelial ovarian cancer (EOC) patients, and investigate its function in EOC cells proliferation and apoptosis in vitro.LncRNA TUG1 expressions were detected in tumor tissues and paired adjacent tissues obtained from 96 EOC patients. Blank mimic, lncRNA TUG1 mimic, blank inhibitor, and lncRNA TUG1 inhibitor plasmids were transfected into SKOV3 cells. CKK-8, annexin V-FITC–propidium iodide, qPCR and western blot assays were performed to detect cells proliferation, cells apoptosis, RNA expression, and protein expression, respectively.LncRNA TUG1 expression was higher in tumor tissue compared to paired adjacent tissue (P < .001), and it was positively correlated with pathological grade (P = .022), tumor size (P = .011) and FIGO stage (P < .001). Kaplan-Meier curve showed that lncRNA TUG1 high expression was associated with worse OS (P = .003). Multivariate Cox analysis indicated that lncRNA TUG1 high expression (vs. low expression) (P = .035) was independently predictive factor for shorter OS. In vitro, cells proliferation was promoted after treatment with lncRNA TUG1 mimic and was suppressed after treatment with lncRNA TUG1 inhibitor. In addition, cells apoptosis rate was decreased in lncRNA TUG1 mimic group compared to NC1 mimic, and increased in lncRNA TUG1 inhibitor group compared to NC2 inhibitor.In conclusion, lncRNA TUG1 is positively correlated with advanced disease and poor prognosis, and it promotes cells proliferation and inhibits cells apoptosis in EOC cells.

Goserelin promotes the apoptosis of epithelial ovarian cancer cells by upregulating forkhead boxO1 through the PI3K/AKT signaling pathway.

Gonadotropins, including luteinizing hormone (LH) and follicle stimulating hormone (FSH), are conducive to the growth of ovarian cancer based on the ‘gonadotropin theory’ and are regulated by gonadotropin-releasing hormone (GnRH). The present study was carried out to investigate the effect of goserelin, a GnRH agonist, on the apoptosis of epithelial ovarian cancer (EOC) cells and the underlying in vitro and in vivo mechanisms. Through flow cytometry, Hoechst staining and TUNEL staining, we demonstrated that goserelin promoted the apoptosis of EOC cells both in vitro and in vivo. Through human apoptosis gene PCR array, we verified that the promotion of EOC cell apoptosis by goserelin was linked to the upregulation of members of the tumor necrosis factor (TNF) and TNF receptor superfamilies, which have been identified as downstream targets of forkhead box O1 (FOXO1). Goserelin enhanced FOXO1 expression, and siRNA-mediated knockdown of FOXO1 abrogated the induction of apoptosis by goserelin. Moreover, goserelin decreased AKT activity, and FOXO1 upregulation by goserelin was dependent on the phosphatidylinositol 3-kinase (PI3K)/AKT pathway. In vivo, the expression of key factors in the PI3K/AKT/FOXO1 pathway was consistent with that observed in vitro. In conclusion, our data suggested that goserelin may promote EOC cell apoptosis by upregulating FOXO1 through the PI3K/AKT signaling pathway. We believe that GnRH agonists may be potential antitumor agents, and key factors in the PI3K/AKT-FOXO1 pathway may also be novel therapeutic targets for the treatment of EOC.

Pyridoxine 5\u2032-phosphate oxidase is a novel therapeutic target and regulated by the TGF-\u03b2 signalling pathway in epithelial ovarian cancer

Pyridoxine 5′-phosphate oxidase (PNPO) is an enzyme that converts pyridoxine 5′-phosphate into pyridoxal 5′-phosphate (PLP), an active form of vitamin B6 implicated in several types of cancer. However, the role of PNPO and its regulatory mechanism in epithelial ovarian cancer (EOC) are unknown. In the present study, PNPO expression in human ovarian tumour tissue and its association with the clinicopathological features of patients with EOC were examined. Further, the biological function of PNPO in EOC cells and in xenograft was evaluated. We demonstrated for the first time that PNPO was overexpressed in human EOC. Knockdown of PNPO induced EOC cell apoptosis, arrested cell cycle at G2/M phase, decreased cell proliferation, migration and invasion. Xenografts of PNPO-shRNA-expressing cells into the nude mouse attenuated tumour growth. PNPO at mRNA and protein levels in EOC cells was decreased after transforming growth factor-β1 (TGF-β1) treatment. The inhibitory effect of TGF-β1 on PNPO expression was abolished in the presence of SB-431542, a TGF-β type I receptor kinase inhibitor. Moreover, we found that TGF-β1-mediated PNPO expression was at least in part through the upregulation of miR-143-3p. These data indicate a mechanism underlying PNPO regulation by the TGF-β signalling pathway. Furthermore, PLP administration reduced PNPO expression and decreased EOC cell proliferation, suggesting a feedback loop between PLP and PNPO. Thus, our findings reveal that PNPO can serve as a novel tissue biomarker of EOC and may be a potential target for therapeutic intervention.

Adipose‑derived mesenchymal stem cells attenuate cisplatin‑induced apoptosis in epithelial ovarian cancer cells.

Environment-mediated drug resistance (EMDR) serves an important role in tumor chemotherapy resistance. Adipose‑derived mesenchymal stem cells (ADSC) are an important component of the tumor microenvironment. However, the role of ADSC in EMDR remains unclear. Therefore, in order to clarify whether ADSCs contribute to the cisplatin‑mediated apoptosis in epithelial ovarian cancer (EOC), the present study isolated ADSCs from the omentum of women with benign disease and collected the ADSC culture medium as conditioned medium. Subsequently, it was revealed that ADSCs decreased the sensitivity of EOC cells to cisplatin via an MTT assay. In addition, it was revealed that ADSCs may reduce cisplatin-induced apoptosis in EOC cells, as determined by Hoechst staining and flow cytometric analysis. Additionally, a lower level of cleaved caspase‑3 was observed, accompanied with decreased intracellular platinum accumulation in EOC cells indirectly co‑cultured with ADSCs. In conclusion, the findings of the present study suggested that ADSCs reduced cisplatin‑induced apoptosis and the intracellular level of platinum in EOC cells, which in turn resulted in cisplatin resistance. Therefore, ADSCs may serve as a therapeutic target for recurrent EOC.

MiR-23a promotes IKKα expression but suppresses ST7L expression to contribute to the malignancy of epithelial ovarian cancer cells.

Background:Dysregulation of microRNAs (miRNAs) has been found in human epithelial ovarian cancer (EOC). However, the role and mechanism of action of miR-23a in EOC remain unclear.Methods:The roles of miR-23a, IKKα, and ST7L in EOC were determined by MTT, colony formation, wounding healing, transwell, flow cytometry, immunofluorescence, RT–qPCR, and western blotting experiments. miR-23a target genes were validated by EGFP reporter assays, RT–qPCR, and western blotting analysis.Results:miR-23a is upregulated and promotes tumorigenic activity by facilitating the progress of cell cycle and EMT and repressing apoptosis in EOC cells. miR-23a enhances the expression of IKKα but suppresses the expression of ST7L by binding the 3′UTR of each transcript in EOC cells. The proliferation, migration, and invasion of EOC cells are increased by IKKα and inhibited by ST7L. Furthermore, miR-23a activates NF-κB by upregulating IKKα and WNT/MAPK pathway by downregulating ST7L.Conclusions:miR-23a functions as an oncogene by targeting IKKα and ST7L, thus contributing to the malignancy of EOC cells.