SKOV3 Ovarian Cancer Cells Research Articles

Bcl2l10 induces metabolic alterations in ovarian cancer cells by regulating the TCA cycle enzymes SDHD and IDH1.

Bcl2-like-10 (Bcl2l10) has both oncogenic and tumor suppressor functions depending on the type of cancer. It has been previously demonstrated that the suppression of Bcl2l10 in ovarian cancer SKOV3 and A2780 cells causes cell cycle arrest and enhances cell proliferation, indicating that Bcl2l10 is a tumor suppressor gene in ovarian cancer cells. The aim of the present study was to identify possible downstream target genes and investigate the underlying mechanisms of action of Bcl2l10 in ovarian cancer cells. RNA sequencing (RNA-Seq) was performed to obtain a list of differentially expressed genes (DEGs) in Bcl2l10-suppressed SKOV3 and A2780 cells. The RNA-Seq data were validated by reverse transcription-quantitative PCR (RT-qPCR) and western blot analysis, and the levels of metabolites after Bcl2l10-knockdown were measured using colorimetric assay kits. Pathway enrichment analysis revealed that the commonly downregulated genes in SKOV3 and A2780 cells after Bcl2l10-knockdown were significantly enriched in metabolic pathways. The analysis of the DEGs identified from RNA-Seq and validated by RT-qPCR revealed that succinate dehydrogenase complex subunit D (SDHD) and isocitrate dehydrogenase 1 (IDH1), which are key enzymes of the TCA cycle that regulate oncometabolite production, may be potential downstream targets of Bcl2l10. Furthermore, Bcl2l10-knockdown induced the accumulation of succinate and isocitrate through the downregulation of SDHD and IDH1. The present study was the first to elucidate the metabolic regulatory functions of Bcl2l10 in ovarian cancer cells, and the results indicated that Bcl2l10 may serve as a potential therapeutic target in ovarian cancer.

STAT3 Inhibitor Napabucasin Inhibits Tumor Growth and Cooperates with Proteasome Inhibition in Human Ovarian Cancer Cells.

Ovarian cancer is a disease with the highest mortality in gynecologic malignancies. Activation of STAT3 pathway is well known to be associated with tumor progression and metastasis in a number of cancers, including ovarian cancer. Therefore, STAT3 may be an ideal target for ovarian cancer treatment. The present study aims to determine the antitumor activity of STAT3 inhibitor Napabucasin as a single agent or in combination with proteasome inhibitor MG-132 in ovarian cancer cells. MTT was performed to determine the anti-proliferative effect of Napabucasin on ovarian cancer SKOV-3 cells. The involved anti-tumor mechanism was explored by flow cytometry, qRTPCR and western blot. MDC staining and tandem mRFP-GFP-LC3 fluorescence microscopy were used to analyze the autophagy-inducing capability of Napabucasin with or without MG-132. The combinational anticancer effect of Napabucasin and MG-132 was evaluated according to Chou and Talalay's method (1984). Napabucasin showed obvious tumor-inhibitory effects against SKOV-3 cells. Treatment by Napabucasin arrested cell cycle progression in G2/M phase. Mechanistically, elevated expression of p21 may contribute to the blockade of the cell cycle. Moreover, we demonstrated that Napabucasin induced autophagy in SKOV-3 cells by using various assays, including MDC staining, autophagic flux examination, and detection of the autophagy markers. In addition, a combination of Napabucaisin with MG-132 exhibited a significant synergistic anti-proliferative effect, probably by inducing apoptosis through a mitochondria-dependent pathway. The two compounds induced pro-survival autophagies, and co-treatment with autophagy inhibiter might further enhance their antitumor effects. Napabucasin alone or in combination with MG-132 might be promising treatment strategy for ovarian cancer patients.

α3 integrin-binding peptide-functionalized polymersomes loaded with volasertib for dually-targeted molecular therapy for ovarian cancer

Ovarian cancer (OC) is a high-mortality malignancy in women with a five-year survival rate of 30-40%. There is an urgent need to develop high-efficacy and low toxic treatments for OC. Herein, we report an appealing strategy that combines α3 integrin targeted polymersomes (A3-Ps) and targeted molecular drug, polo-like kinase 1 (PLK1) inhibitor volasertib (Vol) for dually targeted molecular therapy of OC in vivo. A3-Ps had good Vol loading of 7.7-8.0 wt.% and small size of 25-32 nm, depending on the density of α3 integrin binding peptide A3. Interestingly, cellular uptake studies using FITC-labeled Vol revealed that A3-Ps with 20% peptide gave 2.3 and 3.3-fold better internalization in SKOV-3 OC cells compared with non-targeted Ps and free Vol, respectively. Accordingly, Vol loaded in A3-Ps showed the best inhibitory activity to SKOV-3 cells with an IC50 of 49 nM, which was 3.5 times lower than free Vol. Importantly, the in vivo experiments demonstrated that A3-Ps-Vol proficiently repressed the growth of SKOV-3 tumors in mice while continuous tumor growth was observed for Ps-Vol and free Vol-treated mice. A3-Ps-Vol besides boosting anti-OC activity also reduced the systemic toxicity of Vol. This dually targeted molecular drug nanoformulation has appeared to be an especially potent and low toxic treatment modality for human ovarian cancers. Statement of significanceVolasertib provides a potential molecular therapy for PLK1-positive advanced OC patients. The initial clinical outcomes, nevertheless, showed a suboptimal efficacy, possibly resulting from its fast clearance, deficient tumor deposition and dose-limiting toxicities. Here, we show for the first time that dually targeted molecular therapy of OC using α3 integrin-binding peptide-modified polymersomes as a vehicle gives markedly improved potency, better toleration, and depleted adverse effects in SKOV-3 tumor models, greatly outperforming free volasertib. This dually targeted strategy has emerged as an appealing treatment for malignant PLK1-positive ovarian tumors.

CircRAB11FIP1 promoted autophagy flux of ovarian cancer through DSC1 and miR-129

At present, no systematic and in-depth study is available on the function and potential mechanisms of circular RNA in autophagy. This study aimed to screen the expression profiles of circRNA, miRNA, and mRNA of ovarian cancer cells induced by Torin 1 (10 µM). The expression profiles of circRNA, miRNA, and mRNA were analyzed with next-generation sequencing technology. CircRAB11FIP1 expression was elevated in epithelial ovarian cancer (EOC) tissues than in normal ovarian tissues. Silencing circRAB11FIP1 inhibited the autophagic flux of ovarian cancer SKOV3 cells. However, circRAB11FIP1 overexpression activated the autophagic flux of ovarian cancer A2780 cells. CircRAB11FIP1-induced autophagy accelerated EOC proliferation and invasion. Also, circRAB11FIP1 directly bound to miR-129 and regulated its targets ATG7 and ATG14. CircRAB11FIP1 bound to desmocollin 1to facilitate its interaction with ATG101. Also, circRAB11FIP1 directly bound to the mRNA of fat mass and obesity-associated protein and promoted its expression. Then, circRAB11FIP1 mediated mRNA expression levels of ATG5 and ATG7 depending on m6A. In general, this study demonstrated that circRAB11FIP1 regulated ATG7 and ATG14 by sponging miR-129. The data suggested that circRAB11FIP1 might serve as a candidate biomarker for EOC diagnosis and treatment.

Design and development of folate-chitosan/CD nanogel: An efficient fluorescent platform for Cancer-specific delivery of AntimiR-21

Advances in the field of simultaneous diagnosis and treatment of cancer have introduced “nanotheranostic” systems that enable targeted co-delivery of imaging probes and therapeutic compounds. In this study, a simply designed fluorescent construction has been developed as a novel antimiR-21 nanocarrier for targeted imaging of SKOV3 cells. Fluorescent green carbon dots (CD) were synthesized from grapefruit extract through hydrothermal reaction. Folic acid-chitosan (FA-CS) conjugate was prepared according to the covalent chemistry for simultaneous loading of CD and antimiR-21 sequence in order to design FA-CS(CD/antimiR-21) nanoparticles. The FA-CS(CD/antimiR-21) nanoparticles showed uniform size distribution of 104.9 ± 30.68 nm. Nanoparticles with negligible toxicity and good serum stability transferred antimiR-21 sequence to cancer cells with 80–90% entrapment efficiency. In vitro cellular imaging and distribution studies were investigated by fluorescence microscopy that revealed higher cellular uptake of FA-CS(CD/antimiR-21) hybrid nanogel by SKOV3 ovarian cancer cells, which highly express folate receptors compared to fibroblast folate negative (FR−) (NIH3T3) cell lines. Ultimately, this investigation demonstrates that CD-loaded FA-CS nanogels provide a unique construction for cancer-specific fluorescent imaging capable of loading therapeutic agents.

Physicochemical Factors That Influence the Biocompatibility of Cationic Liposomes and Their Ability to Deliver DNA to the Nuclei of Ovarian Cancer SK-OV-3 Cells

Cationic liposomes composed of 3-[N-(N’,N’-dimethylaminoethane)-carbamoyl] cholesterol (DC-chol) and dioleoylphosphatidylethanolamine (DOPE) have previously been shown to have applications in gene delivery. Our study aims to explore the effects of inclusion of polyethylene glycol (PEG) and using different molar ratios of DC-chol/DOPE on size, zeta potential, cytotoxicity and DNA delivery of DC-chol/DOPE liposomes. Our results show that PEGylation reduces the cytotoxicity of DC-chol/DOPE liposomes, and, furthermore, PEGylated liposome-DNA lipoplexes are smaller in size and more uniform in size distribution than those that are not PEGylated. Additionally, toxicity against ovarian cancer SKOV-3 cells decreases with the amount of cationic DC-chol present in the formulation; however, decreased delivery of DNA to cellular nuclei is also observed. Transfection with the PEGylated liposomes was successfully demonstrated using plasmid DNA with a known functional outcome. These results offer further insight into physicochemical properties important for cationic liposomes as vehicles for DNA delivery and demonstrate the potential of PEGylated DC-chol/DOPE liposomes as systemic delivery carriers for DNA-mediated ovarian cancer therapy.

Ceramide synthase 2-C24:1 -ceramide axis limits the metastatic potential of ovarian cancer cells.

Regulation of sphingolipid metabolism plays a role in cellular homeostasis, and dysregulation of these pathways is involved in cancer progression. Previously, our reports identified ceramide as an anti-metastatic lipid. In the present study, we investigated the biochemical alterations in ceramide-centered metabolism of sphingolipids that were associated with metastatic potential. We established metastasis-prone sublines of SKOV3 ovarian cancer cells using an in vivo selection method. These cells showed decreases in ceramide levels and ceramide synthase (CerS) 2 expression. Moreover, CerS2 downregulation in ovarian cancer cells promoted metastasis in vivo and potentiated cell motility and invasiveness. Moreover, CerS2 knock-in suppressed the formation of lamellipodia required for cell motility in this cell line. In order to define specific roles of ceramide species in cell motility controlled by CerS2, the effect of exogenous long- and very long-chain ceramide species on the formation of lamellipodia was evaluated. Treatment with distinct ceramides increased cellular ceramides and had inhibitory effects on the formation of lamellipodia. Interestingly, blocking the recycling pathway of ceramides by a CerS inhibitor was ineffective in the suppression of exogenous C24:1 -ceramide for the formation of lamellipodia. These results suggested that C24:1 -ceramide, a CerS2 metabolite, predominantly suppresses the formation of lamellipodia without the requirement for deacylation/reacylation. Moreover, knockdown of neutral ceramidase suppressed the formation of lamellipodia concomitant with upregulation of C24:1 -ceramide. Collectively, the CerS2-C24:1 -ceramide axis, which may be countered by neutral ceramidase, is suggested to limit cell motility and metastatic potential. These findings may provide insights that lead to further development of ceramide-based therapy and biomarkers for metastatic ovarian cancer.

Pterostilbene induces cell apoptosis and inhibits lipogenesis in SKOV3 ovarian cancer cells by activation of AMPK-induced inhibition of Akt/mTOR signaling cascade

This study investigates if the anti-tumor effect of Pterostilbene in the SKOV3 ovarian cancer (OC) cell line involves inhibition of cell metabolism and tested in this effect involves modulating AMPK and Akt-induced regulation of mTORC1. Initially, SKOV3 cells were cultured in the humidified conditions in DMEM media for 24 h with or without increasing concentration of Pterostilbene. Then, the cells were incubated with Pterostilbene (IC50 = 50 µM) under similar conditions with or without pre-incubation with Dorsomorphin, an AMPK inhibitor. In a dose-dependent manner, Pterostilbene inhibited SKOV3 cell survival and increased their lysate levels of lactate dehydrogenase (LDH) and single-stranded DNA (ssDNA). When SKOV3 cells were treated with 50 µM Pterostilbene, Pterostilbene significantly suppressed cell migration and invasion, reduced lysate levels of lactic acid and the optical density of Oil Red O staining, and increased lysate glucose levels. It also increased levels of malondialdehyde (MDA), reactive oxygen species (ROS), and induced intrinsic cell apoptosis by upregulating protein levels of Bax and cleaved caspase-3 and reducing protein levels of Bcl-2. Besides, Pterostilbene reduced mRNA levels of sterol regulatory element-binding protein 1 (SREBP-1), fatty acid synthase (FAS), acetyl CoA carboxylase-1 (ACC-1), and AMP-activated protein kinase (AMPK). Furthermore, Pterostilbene increased the protein levels of p-AMPK, p-p53, p-raptor, p-TSC-2, but significantly decreased protein levels of p-Akt, p-TSC-2, p-mTOR, p-S6K1, and p-4E-BP. Treatment with Dorsomorphin (CC) abolished all the anti-tumorigenesis effects afforded by Pterostilbene and prevented Pterostilbene-induced phosphorylation of Akt, p53, and mTOR. In conclusion, the tumorsuppressive effect of Pterostilbene in SKOV3 cells involves the induction of ROS and inhibition of dysregulation cell metabolism mainly due to AMPK-induced Akt-dependent or independent suppression of mTOR.

LncRNA HOTAIR regulates anoikis-resistance capacity and spheroid formation of ovarian cancer cells by recruiting EZH2 and influencing H3K27 methylation

This study aims to investigate the role of the long non-coding RNA (lncRNA) HOX transcript antisense RNA (HOTAIR) in the regulation of anoikis resistance of ovarian cancer cells, a prerequisite for metastasis and chemoresistance in ovarian cancer cells. Ovarian cancer SKOV3 cells were cultured in an ultra-low attachment system to establish an anoikis model. The relationship between cellular anoikis capability and HOTAIR expression level was studied by flow cytometry and RT-PCR. The ability of spheroid formation, migration, and invasion of the suspended cells was assessed following the knockdown of HOTAIR expression. The expression of EZH2, H3K27me3, representative targets of EZH2, and anoikis-related biomarkers was also detected. An increase in the duration of suspension culture time rendered the SKOV3 cells anoikis-resistant with a significantly lower apoptotic rate compared to the adherent cells. HOTAIR expression in the suspension cells increased significantly, while that in the adherent cells did not. Following small interfering RNA (siRNA)-mediated knockdown of HOTAIR expression, the abilities of anoikis resistance, migration, and invasion decreased in the suspension cells. Knockdown of HOTAIR levels also reduced the spheroid forming ability of the tumor cells in continuous suspension cultures. Moreover, EZH2 expression correlated with HOTAIR expression, thus regulating the expression of miR-193a and DOK2 via introducing H3K27me3. Western blot analysis of anoikis-related markers showed that N-cadherin, ZEB1, and TWIST1 were downregulated following inhibition of HOTAIR, while E-cadherin and ErbB3 were upregulated. In conclusion, HOTAIR enhances the anoikis resistance and spheroid forming ability of ovarian cancer cells by recruiting EZH2 and influencing H3K27 methylation that may contribute to migration, invasion, and chemoresistance of ovarian cancer cells.

Effect of icaritin on proliferation and apoptosis of human ovarian cancer cells SKOV3

Based on the PI3K/Akt signaling pathway, this study aimed to observe the proliferation and apoptosis of ovarian cancer SKOV3 cells at different concentrations of icaritin, in order to explore the possible molecular mechanisms. The research object was ovarian cancer SKOV3 cells. The cells were divided into the control group and icaritin groups(5, 10, 20 μmol·L~(-1)), and administrated with drugs for 48 hours. The cell counting kit-8(CCK-8)assay was used to detect the inhibitory effect of icaritin on the proliferation of ovarian cancer SKOV3 cells. The proliferation ability of the SKOV3 cells was detected by EdU assay. Hoechst 33342 fluorescence staining was used to observe the apoptotic morphology of SKOV3 cells in each group. The distribution of cell cycle and the apoptosis rate of each group were detected by flow cytometry. Quantitative Real-time PCR was used to detect mRNA expressions of PTEN, PI3K, Akt in each group of cells. Protein expressions of PTEN, PI3K, Akt and p-Akt were measured by Western blot. The results showed that the cell inhibition rates of icaritin groups were significantly increased compared with the control group(P<0.05). The rates of EdU-positive cells of icaritin groups were significantly decreased(P<0.05). SKOV3 cells in icaritin groups showed morphological changes of apoptosis. Apoptosis rates of icaritin groups were significantly increased(P<0.05). The proportions of cells in G_0/G_1 phase of icaritin groups were decreased(P<0.05), while the proportions of S phase cells were increased(P<0.05). The gene and protein expressions of PTEN in icaritin groups were elevated(P<0.05). The gene expressions of PI3K and Akt in icaritin groups were down-regulated(P<0.05). The protein expression of PI3K and p-Akt in icaritin groups were reduced(P<0.05). These results indicated that icarin may inhibit the proliferation of ovarian cancer SKOV3 cells in vitro, induce cell apoptosis and affect the cycle distribution of cells by inhibiting the PI3K/Akt signaling pathway.

Computational Methods for Structure-to-Function Analysis of Diet-Derived Catechins-Mediated Targeting of In Vitro Vasculogenic Mimicry.

Background:Vasculogenic mimicry (VM) is an adaptive biological phenomenon wherein cancer cells spontaneously self-organize into 3-dimensional (3D) branching network structures. This emergent behavior is considered central in promoting an invasive, metastatic, and therapy resistance molecular signature to cancer cells. The quantitative analysis of such complex phenotypic systems could require the use of computational approaches including machine learning algorithms originating from complexity science.Procedures:In vitro 3D VM was performed with SKOV3 and ES2 ovarian cancer cells cultured on Matrigel. Diet-derived catechins disruption of VM was monitored at 24 hours with pictures taken with an inverted microscope. Three computational algorithms for complex feature extraction relevant for 3D VM, including 2D wavelet analysis, fractal dimension, and percolation clustering scores were assessed coupled with machine learning classifiers.Results:These algorithms demonstrated the structure-to-function galloyl moiety impact on VM for each of the gallated catechin tested, and shown applicable in quantifying the drug-mediated structural changes in VM processes.Conclusions:Our study provides evidence of how appropriate 3D VM compression and feature extractors coupled with classification/regression methods could be efficient to study in vitro drug-induced perturbation of complex processes. Such approaches could be exploited in the development and characterization of drugs targeting VM.

Mitochondrial Dynamics Mediated by DRP1 and MFN2 Contributes to Cisplatin Chemoresistance in Human Ovarian Cancer SKOV3 cells.

Cisplatin (DDP) is the first-line chemotherapeutic agent for ovarian cancer. However, the development of DDP resistance seriously influences the chemotherapeutic effect and prognosis of ovarian cancer. It was reported that DDP can directly impinge on the mitochondria and activate the intrinsic apoptotic pathway. Herein, the role of mitochondrial dynamics in DDP chemoresistance in human ovarian cancer SKOV3 cells was investigated. In DDP-resistant SKOV3/DDP cells, mitochondrial fission protein DRP1 was down-regulated, while mitochondrial fusion protein MFN2 was up-regulated. In accordance with the expression of DRP1 and MFN2, the average mitochondrial length was significantly increased in SKOV3/DDP cells. In DDP-sensitive parental SKOV3 cells, downregulation of DRP1 and upregulation of mitochondrial fusion proteins including MFN1,2 and OPA1 occurred at day 2~6 under cisplatin stress. Knockdown of DRP1 or overexpression of MFN2 promoted the resistance of SKOV3 cells to cisplatin. Intriguingly, weaker migration capability and lower ATP level were detected in SKOV3/DDP cells. Respective knockdown of DRP1 in parental SKOV3 cells or MFN2 in SKOV3/DDP cells using siRNA efficiently reversed mitochondrial dynamics, migration capability and ATP level. Moreover, MFN2 siRNA significantly aggravated the DDP-induced ROS production, mitochondrial membrane potential disruption, expression of pro-apoptotic protein BAX and Cleaved Caspase-3/9 in SKOV3/DDP cells. In contrast, DRP1 siRNA alleviated DDP-induced ROS production, mitochondrial membrane potential disruption, expression of pro-apoptotic protein BAX and Cleaved Caspase-3/9 in SKOV3 cells. Thus, these results indicate that mitochondrial dynamics mediated by DRP1 and MFN2 contributes to the development of DDP resistance in ovarian cancer cells, and will also provide a new strategy to prevent chemoresistance in ovarian cancer by targeting mitochondrial dynamics.

The role of the MAD2-TLR4-MyD88 axis in paclitaxel resistance in ovarian cancer.

Despite the use of front-line anticancer drugs such as paclitaxel for ovarian cancer treatment, mortality rates have remained almost unchanged for the past three decades and the majority of patients will develop recurrent chemoresistant disease which remains largely untreatable. Overcoming chemoresistance or preventing its onset in the first instance remains one of the major challenges for ovarian cancer research. In this study, we demonstrate a key link between senescence and inflammation and how this complex network involving the biomarkers MAD2, TLR4 and MyD88 drives paclitaxel resistance in ovarian cancer. This was investigated using siRNA knockdown of MAD2, TLR4 and MyD88 in two ovarian cancer cell lines, A2780 and SKOV-3 cells and overexpression of MyD88 in A2780 cells. Interestingly, siRNA knockdown of MAD2 led to a significant increase in TLR4 gene expression, this was coupled with the development of a highly paclitaxel-resistant cell phenotype. Additionally, siRNA knockdown of MAD2 or TLR4 in the serous ovarian cell model OVCAR-3 resulted in a significant increase in TLR4 or MAD2 expression respectively. Microarray analysis of SKOV-3 cells following knockdown of TLR4 or MAD2 highlighted a number of significantly altered biological processes including EMT, complement, coagulation, proliferation and survival, ECM remodelling, olfactory receptor signalling, ErbB signalling, DNA packaging, Insulin-like growth factor signalling, ion transport and alteration of components of the cytoskeleton. Cross comparison of the microarray data sets identified 7 overlapping genes including MMP13, ACTBL2, AMTN, PLXDC2, LYZL1, CCBE1 and CKS2. These results demonstrate an important link between these biomarkers, which to our knowledge has never before been shown in ovarian cancer. In the future, we hope that triaging patients into alterative treatment groups based on the expression of these three biomarkers or therapeutic targeting of the mechanisms they are involved in will lead to improvements in patient outcome and prevent the development of chemoresistance.

Optimized Icariin Cubosomes Exhibit Augmented Cytotoxicity against SKOV-3 Ovarian Cancer Cells.

Clinical application of icariin (ICA) is limited, despite its activity against cancer growth, because of the low solubility of ICA in an aqueous environment. Therefore, the present study attempted to develop and optimize ICA-loaded cubosome delivery and to explore its efficacy and possible mechanism of action against ovarian cancer. The optimization of the cubosome formulation was performed using the Box‒Behnken statistical design; during the characterization, the particle sizes were in the range of 73 to 183 nm and the entrapment efficiency was 78.3% to 97.3%. Optimized ICA-loaded cubosomes (ICA-Cubs) exhibited enhanced cytotoxicity and apoptotic potential, compared with ICA-raw, against ovarian cancer cell lines (SKOV-3 and Caov 3). The optimized ICA-Cubs showed a relatively non-cytotoxic effect on normal EA.hy926 endothelial cells. Further analysis of cell cycle arrest suggested a potential role in the pre-G1 and G2/M phases for ICA-Cubs in comparison with ICA-raw. ICA-Cubs increased the generation of reactive oxygen species (ROS) and the overexpression of p53 and caspase-3 in the SKOV-3 cell line. In conclusion, the cubosomal delivery of ICA might provide a prospective approach towards the superior control of ovarian cancer cell growth. Its improved efficacy compared with that of the free drug might be due to the improved solubility and cellular permeability of ICA.

IL-6 promotes nuclear translocation of HIF-1α to aggravate chemoresistance of ovarian cancer cells

The inflammatory milieu in tumor modulates the resistance to the conventional antitumoral therapies. Interleukin-6 (IL-6), a pleiotropic pro-inflammatory cytokine and a crucial mediator of tumor development, has been targeted as a therapeutic strategy to overcome chemoresistance in the treatment of tumors. The protein levels and nuclear translocation of HIFs (hypoxia-inducible factors), such as HIF-1α, are linked to the drug resistance of tumor cells. However, whether IL-6 promotes the nuclear translocation of HIF-1α and the related mechanism remain to be investigated. We applied two ovarian cancer (OvCa) cell lines, A2780 cells and SKOV3 cells for the in vivo and in vitro studies. We found that IL-6 up-regulates the HIF-1α expression via the signal transducer and activator of transcription 3 (STAT3) signaling under hypoxia in either endogenous or exogenous way, and then we proved that IL-6 enhances the transcriptional activity of HIF-1α via the STAT3 signaling. Further mechanism research revealed that IL-6 promotes the nuclear translocation of HIF-1α through the STAT3 signaling under hypoxia. Proliferation assay and apoptosis assay were applied and proved that IL-6 enhances the chemoresistance of OvCa cells against cisplatin through the upregulation of HIF-1α via the STAT3 signaling in vitro. The In vivo studies confirmed the effect of IL-6 in increasing the chemoresistance of OvCa cells against cisplatin through the IL-6/STAT3/HIF-1α loop in the animal models. Our data elucidates the explicit mechanism of IL-6/STAT3/HIF-1α loop in OvCa and also provides new insights into the development of different approaches for the inflammation-induced and hypoxia-induced resistance in tumor therapies.

Chimeric Antigen receptor-T (CAR-T) cells targeting Epithelial cell adhesion molecule (EpCAM) can inhibit tumor growth in ovarian cancer mouse model.

Ovarian cancer (OC) is one of the most lethal solid tumors with poor prognosis. In 2017, two chimeric antigen receptor-T (CAR-T) cell drugs were approved by the U.S. Food and Drug Administration (FDA), and continuously optimized CAR-T cells therapy might be the novel hope for OC patient. EpCAM are known to be over-expressed in OC cells and could be targeted by CAR-T cells. However, the feasibility of using EpCAM-CAR-T cells to treat OC still needs to be verified. We engineered the 3rd-generation EpCAM-CAR containing a single-chain variable fragment (scFv) EpCAM-scFv that targeting EpCAM, a CD8 transmembrane domain, the costimulatory domains from both CD28 and 4-1BB, and activating domain CD3ζ and then transduced the CAR into T-cells via lentivirus. In addition, the cytotoxicity and cytokine releasing ability of the EpCAM-CAR-T cells against OC cell SKOV3 were verified in vitro. The in vivo data also showed that EpCAM-CAR-T cells significantly reduced the tumor size in OC xenograft mouse models. The anti-tumor activity of EpCAM-CAR-T cells against OC in vitro and in vivo indicated that the CAR-T might provide a promising therapeutic approach to OC.

Lidocaine inhibits the metastatic potential of ovarian cancer by blocking NaV 1.5-mediated EMT and FAK/Paxillin signaling pathway.

Lidocaine, one of the most commonly used local anesthetics during surgery, has been reported to suppress cancer cell growth via blocking voltage‐gated sodium channels (VGSCs). VGSC 1.5 (NaV1.5) is highly expressed in invasive cancers including ovarian cancer. This study aims to investigate whether lidocaine inhibits the malignancy of ovarian cancer through NaV1.5 blockage. Human ovarian cancer, its metastatic cancer and normal ovarian tissues were probed with anti‐NaV1.5 antibody in situ. Human ovarian cancer A2780 and SKOV3 cells were cultured and their growth, epithelial‐mesenchymal transition (EMT), migration, and invasion in the presence or absence of lidocaine together with underlying molecular mechanisms were assessed. Murine syngeneic ovarian cancer (ID8) model was also used to determine the chemotherapeutic efficiency of cisplatin in combination with lidocaine. The high level of NaV1.5 expression was found in human ovarian cancer and even higher in its metastatic cancer but not in normal ovarian tissues. Lidocaine decreased the growth, EMT, migration, and invasion of human ovarian cancer A2780 and SKOV3 cells. Lidocaine enhanced the chemotherapeutic efficiency of cisplatin in both ovarian cancer cell cultures and a murine ovarian metastatic model. Furthermore, a downregulation of NaV1.5 by siRNA transfection, or FAK inhibitor application, inhibited the malignant properties of SKOV3 cells through inactivating FAK/Paxillin signaling pathway. Our data may indicate that lidocaine suppresses the metastasis of ovarian cancer and sensitizes cisplatin through blocking NaV1.5‐mediated EMT and FAK/paxillin signaling pathway. The translational value of lidocaine local application as an ovarian cancer adjuvant treatment warrants further study.

Hyperthermia During Intraperitoneal Chemotherapy With Paclitaxel or Docetaxel for Ovarian Cancer: Is There Any Benefit?

Intraperitoneal chemotherapy with taxanes provides high locoregional drug concentrations. Regarding their synergy with hyperthermia, results have been inconclusive. In this in vitro study, the thermal enhancement of the effect of paclitaxel and docetaxel on ovarian cancer cells under conditions mimicking those during hyperthermic intraperitoneal chemotherapy (HIPEC) is evaluated. Cisplatin-resistant SKOV-3 and OVCAR-3 ovarian cancer cells were exposed for 2 h to 0.1, 1 and 3 μΜ of paclitaxel and docetaxel at 37°C (normothermia) and 41.5°C (hyperthermia). Cell proliferation and cell-cycle distribution were evaluated after 24 h, 3 days and 7 days. A concentration-dependent cytotoxic effect on cell proliferation was observed. Concurrent hyperthermia caused an increased arrest of cells in the G2/M phase. At 7 days, thermal enhancement of drug effect was shown only for treatment of OVCAR-3 cells with 1 μM paclitaxel. The concentration-dependent cytotoxic effect of paclitaxel and docetaxel supports their intraperitoneal use. Due to the lack of or only minimal thermal enhancement, normothermic may be as effective as hyperthermic intraoperative intraperitoneal chemotherapy with taxanes, avoiding, however, potential oncological and treatment-related adverse effects of concurrent hyperthermia.

Withdrawal: FGF16 promotes invasive behavior of SKOV-3 ovarian cancer cells through activation of mitogen-activated protein kinase (MAPK) signaling pathway.

Withdrawal: FGF16 promotes invasive behavior of SKOV-3 ovarian cancer cells through activation of mitogen-activated protein kinase (MAPK) signaling pathway.

IL-17A/lL-17RA reduces cisplatin sensitivity of ovarian cancer SKOV3 cells by regulating autophagy

To investigate the effect of interleukin-17A (IL-17A) on chemosensitivity of ovarian cancer cells to cisplatin (DDP) and explore the mechanism in light of autophagy regulation. Ovarian cancer SKOV3 cells cultured in vitro were treated with different concentrations of DDP (1-20 μg/mL). MTT assay was used to observe the changes in proliferation of the treated cells and the effect of treatment with 100 ng/mL IL-17A for 24 h on DDP-induced apoptosis of SKOV3 cells. We then examined the expression of IL-17A receptor (IL-17RA) in SKOV3 cells using flow cytometry. Annexin V-FITC/PI double staining was used to detect the cell apoptosis rate, and early apoptosis of the cells was detected with JC-1 assay. A neutralizing monoclonal antibody (mAb) against IL-17RA was used to block IL-17RA. We also observed the effects of IL-17RA silencing mediated by a siRNA targeting IL-17RA (siRNA-IL-17RA) and treatment with 3-methyladenine (3-MA) for inhibiting autophagy on DDP-induced apoptosis of SKOV3 cells. The expressions of apoptosis-related proteins (Bcl-2, Bax, and cleaved caspase-3) and autophagy-related proteins (P62 and Beclin-1) in the treated cells were detected using Western blotting. DDP increased the expression of IL-17RA in ovarian cancer SKOV3 cells. Treatment with IL-17A significantly reduced the susceptibility of SKOV3 cells to cisplatin-induced apoptosis (P < 0.05). DDP obviously augmented the expression of Beclin-1 and reduced the autophagy degradation substrate P62 protein in the cells (P < 0.05). IL-17A/IL-17RA strongly enhanced the DDPinducted autophagy of the cells (P < 0.05). Blocking autophagy with 3-MA significantly increased DDP- induced apoptosis of SKOV3 cells with IL-17RA silencing, lowered the expression of Bcl-2 and enhanced Bax expression in the cells (P < 0.05). IL-17A/IL-17RA can decrease chemosensitivity of SKOV3 cells to DDP by upregulating DDP-induced autophagy.