SKOV3 Ovarian Cancer Cells Research Articles

Engineered multifunctional biodegradable hybrid microparticles for paclitaxel delivery in cancer therapy

Ovarian cancer is one of the most lethal gynecologic malignancies due to its rapid proliferation, frequent acquisition of chemoresistance, and widespread metastasis within the peritoneal cavity. Intraperitoneal (IP) chemotherapy has demonstrated significant anti-cancer potential but its broad clinical application is hindered by several drug delivery limitations. Herein, we engineer paclitaxel (PTX) laden hybrid microparticles (PTX-Hyb-MPs) for improved delivery of chemotherapy in ovarian cancer. The PTX-Hyb-MPs are comprised of a lipid-coated shell of poly (lactic acid-co-glycolic acid) (PLGA) encapsulating hydrophobic PTX. A co-axial electrohydrodynamic (CEH) process is used for one-step and scalable production of the PTX-Hyb-MP agent with controlled particles size, uniform size distribution, tunable thickness, and high encapsulation rate (92.17 ± 6.9%). The multi-layered structure of the PTX-Hyb-MPs is verified by transmission electron microscopy and confocal fluorescence microscopy. The effect of lipid coating on the enhancement of particle interactions with cancer cells is studied by flow cytometry and confocal fluorescence microscopy. The anti-cancer effect of the PTX-Hyb-MPs is evaluated in SKOV-3 ovarian cancer cells in vitro and a cancer xenograft model in vivo, in comparison with conventional drug delivery methods. Our studies reveal that the PTX-Hyb-MP agent can be potentially used for locoregional treatment of ovarian cancer and other tissue malignancies with sustained drug release, tunable release profiles, enhanced drug uptake, and reduced systemic toxicity.

Targeting slug-mediated non-canonical activation of c-Met to overcome chemo-resistance in metastatic ovarian cancer cells

Metastasis-associated drug resistance accounts for high mortality in ovarian cancer and remains to be a major barrier for effective treatment. In this study, SKOV3/T4, a metastatic subpopulation of ovarian cancer SKOV3 cells, was enriched to explore potential interventions against metastatic-associated drug resistance. Quantitative genomic and functional analyses were performed and found that slug was significantly increased in the SKOV3/T4 subpopulation and contributed to the high resistance of SKOV3/T4. Further studies showed that slug activated c-Met in a ligand-independent manner due to elevated levels of fibronectin and provoked integrin α V function, which was confirmed by the significant correlation of slug and p-Met levels in 121 ovarian cancer patient samples. Intriguingly, c-Met inhibitor(s) exhibited greatly enhanced anti-cancer effects in slug-positive ovarian cancer models both in vitro and in vivo. Additionally, IHC analyses revealed that slug levels were highly correlated with reduced survival of ovarian cancer patients. Taken together, this study not only uncovers the critical roles of slug in drug resistance in ovarian cancer but also highlights a promising therapeutic strategy by targeting the noncanonical activation of c-Met in slug-positive ovarian cancer patients with poor prognosis.

MiR-1180 from bone marrow-derived mesenchymal stem cells induces glycolysis and chemoresistance in ovarian cancer cells by upregulating the Wnt signaling pathway.

Bone marrow-derived mesenchymal stem cells (BM-MSCs) play an important role in cancer development and progression. However, the mechanism by which they enhance the chemoresistance of ovarian cancer is unknown. Conditioned media of BM-MSCs (BM-MSC-CM) were analyzed using a technique based on microRNA arrays. The most highly expressed microRNAs were selected for testing their effects on glycolysis and chemoresistance in SKOV3 and COC1 ovarian cancer cells. The targeted gene and related signaling pathway were investigated using in silico analysis and in vitro cancer cell models. Kaplan-Merier survival analysis was performed on a population of 59 patients enrolled to analyze the clinical significance of microRNA findings in the prognosis of ovarian cancer. MiR-1180 was the most abundant microRNA detected in BM-MSC-CM, which simultaneously induces glycolysis and chemoresistance (against cisplatin) in ovarian cancer cells. The secreted frizzled-related protein 1 (SFRP1) gene was identified as a major target of miR-1180. The overexpression of miR-1180 led to the activation of Wnt signaling and its downstream components, namely Wnt5a, β-catenin, c-Myc, and CyclinD1, which are responsible for glycolysis-induced chemoresistance. The miR-1180 level was inversely correlated with SFRP1 mRNA expression in ovarian cancer tissue. The overexpressed miR-1180 was associated with a poor prognosis for the long-term (96-month) survival of ovarian cancer patients. BM-MSCs enhance the chemoresistance of ovarian cancer by releasing miR-1180. The released miR-1180 activates the Wnt signaling pathway in cancer cells by targeting SFRP1. The enhanced Wnt signaling upregulates the glycolytic level (i.e. Warburg effect), which reinforces the chemoresistance property of ovarian cancer cells.

Follicle-stimulating hormone promoted pyruvate kinase isozyme type M2-induced glycolysis and proliferation of ovarian cancer cells.

Reprogramming of cell metabolism is essential for tumor progression and the best-studied metabolic phenomenon of cancer cells is aerobic glycolysis, in which pyruvate kinase isozyme type M2 (PKM2) plays a critical role. Follicle-stimulating hormone (FSH) contributes to epithelial ovarian cancer progression and has been shown to regulate cell metabolism in ovaries. The aim of this study was to investigate the interaction between FSH and PKM2 and their effect on aerobic glycolysis and cell proliferation in ovarian cancer. SKOV3 and OVCAR3 ovarian cancer cells were treated with FSH at various doses to investigate its effect on cell proliferation and PKM2 expression. siRNA-PKM2-transfected SKOV3 and OVCAR3 cells were treated with FSH to examine whether the changes induced by FSH could be altered by siRNA-PKM2. Glucose and lactate levels were evaluated to observe the change in glycolysis in these cells. In the current study, FSH upregulated the expression of PKM2 and glycolysis in SKOV3 and OVCAR3 cells. PKM2 knockdown reduced FSH-induced cell growth and glycolysis. Moreover, FSH attenuated apoptosis that was induced by the inhibition of PKM2. Collectively, the findings of this study indicated that FSH promoted glycolysis in epithelial ovarian cancer cells. Knockdown of PKM2 inhibited aerobic glycolysis and cell proliferation induced by FSH.

Resveratrol induces cell death through ROS‑dependent downregulation of Notch1/PTEN/Akt signaling in ovarian cancer cells.

Resveratrol, a natural polyphenol compound, has been reported to exert anticancer activity in various cancer cells. The present study investigated the effect and underlying mechanisms of resveratrol in the human ovarian cancer cell lines, A2780 and SKOV3. Treatment with resveratrol induced apoptotic cell death in dose‑ and time‑dependent manners, as well as a transient increase of reactive oxygen species(ROS) generation. Resveratrol‑induced cell death was attenuated by the antioxidant, N‑acetylcysteine(NAC), suggesting that ROS were involved in the observed cell death. Treatment with resveratrol resulted in a ROS‑dependent decrease of Notch1 signaling. When cells were transfected to overexpress Notch1 using EF.hlCN1.CMV.GFP, resveratrol‑induced cell death was blocked. Western blot analysis demonstrated that resveratrol also upregulated phospho‑phosphatase and tensin homolog(p‑PTEN) and downregulated phospho‑Akt(p‑Akt). Overexpression of p‑Akt by transfection with a constitutively active form(caAkt), and the p‑PTEN inhibitor SF1670 prevented resveratrol‑induced cell death. The caspase‑3 inhibitor z‑DEVD‑FMK significantly attenuated the resveratrol‑induced caspase‑3 cleavage. Taken together, the results of the present study suggest that resveratrol induces caspase‑dependent cell death through suppression of Notch1 and PTEN/Akt signaling and it is mediated by increased ROS generation in human ovarian cancer cells.

Low glucose and metformin-induced apoptosis of human ovarian cancer cells is connected to ASK1 via mitochondrial and endoplasmic reticulum stress-associated pathways

BackgroundMetformin, a first-line drug for type 2 diabetes, could induce apoptosis in cancer cells. However, the concentration of glucose affects the effect of metformin, especially low glucose in the culture medium can enhance the cytotoxicity of metformin on cancer cells. Since mitochondria and endoplasmic reticulum is vital for maintaining cell homeostasis, we speculate that low glucose and metformin-induced cell apoptosis may be associated with mitochondria and endoplasmic reticulum. ASK1, as apoptosis signaling regulating kinase 1, is associated with cell apoptosis and mitochondrial damage. This study was designed to investigate the functional significance of ASK1, mitochondria and endoplasmic reticulum and underlying mechanism in low glucose and metformin-induced cell apoptosis.MethodsAn MTT assay was used to evaluate cell viability in SKOV3, OVCAR3 and HO8910 human ovarian cancer cells. Cell apoptosis was analyzed by flow cytometry. The expression of ASK1 was inhibited using a specific pharmacological inhibitor or ASK1-siRNA. Immunofluorescence was used to detect mitochondrial damage and ER stress. Nude mouse xenograft models were given metformin or/and NQDI-1, and ASK1 expression was detected using immunoblotting. In addition, subcellular fractionation of mitochondria was performed to assay the internal connection between ASK1 and mitochondria.ResultsThe present study found that low glucose in culture medium enhanced the anticancer effect of metformin in human ovarian cancer cells. Utilization of a specific pharmacological inhibitor or ASK1-siRNA identified a potential role for ASK1 as an apoptotic protein in the regulation of low glucose and metformin-induced cell apoptosis via ASK1-mediated mitochondrial damage through the ASK1/Noxa pathway and via ER stress through the ROS/ASK1/JNK pathway. Moreover, ASK1 inhibition weakened the antitumor activity of metformin in vivo. Thus, mitochondrial damage and ER stress play a crucial role in low glucose–enhanced metformin cytotoxicity in human ovarian cancer cells.ConclusionsThese data suggested that low glucose and metformin induce cell apoptosis via ASK1-mediated mitochondrial damage and ER stress. These findings indicated that the effect of metformin in anticancer treatment may be related to cell culture conditions.

Inhibition of Ca2+ -activated chloride channel ANO1 suppresses ovarian cancer through inactivating PI3K/Akt signaling.

Most common ovarian cancers are epithelial carcinoma in which the etiology for carcinogenesis remains elusive. ANO1/TMEM16A, a member of Ca2+ -activated Cl- channels (CaCCs), has been demonstrated to promote epithelium-originated cancers and whether it plays a role in the pathogenesis of ovarian cancer is unknown. In our study we found that ANO1 proteins were overexpressed in human epithelial ovarian cancer cells and tissue samples. ANO1 protein upregulation was correlated with the clinical FIGO (International Federation of Gynecology and Obstetrics) staging and poor grade in ovarian cancer tissues. Interestingly, the upregulation of ANO1 gene expression was also detected in the peripheral blood mononuclear cells (PBMCs) from preoperative patients with ovarian tumors, and the down-regulation of ANO1 in the PBMCs from postoperative patients. Silencing of ANO1 inhibited proliferation and invasion of ovarian cancer cells. Mechanistically, ANO1 knockdown attenuated phosphorylation of PI3K/Akt, and inhibition of PI3K/Akt signaling by specific inhibitor LY294002 resulted in suppression of ovarian cancer cells growth promoted by ANO1 expression. Furthermore, intratumoral injection of ANO1 siRNA suppressed subcutaneous xenograft tumor growth in nude mice implanted with ovarian cancer SKOV3 cells. Taken together, our findings demonstrate that ANO1 overexpression is involved in the pathogenesis of human epithelial ovarian cancer. Inhibition of ANO1 upregulation or inactivating PI3K/Akt signaling may have therapeutic potential for epithelial ovarian cancer, and the detection of ANO1 expression level in PBMCs from patients may also serve as a biomarker for diagnosis and prognosis of epithelial ovarian cancers.

Regulation of Survivin Isoform Expression by GLI Proteins in Ovarian Cancer.

Ovarian cancer (OC) is the most lethal female gynecological malignancy, mostly due to diagnosis in late stages when treatment options are limited. Hedgehog-GLI (HH-GLI) signaling is a major developmental pathway involved in organogenesis and stem cell maintenance, and is activated in OC. One of its targets is survivin (BIRC5), an inhibitor of apoptosis protein (IAP) that plays a role in multiple processes, including proliferation and cell survival. We wanted to investigate the role of different GLI proteins in the regulation of survivin isoform expression (WT, 2α, 2B, 3B, and Δex3) in the SKOV-3 OC cell line. We demonstrated that survivin isoforms are downregulated in GLI1 and GLI2 knock-out cell lines, but not in the GLI3 knock-out. Treatment of GLI1 knock-out cells with GANT-61 shows an additional inhibitory effect on several isoforms. Additionally, we examined the expression of survivin isoforms in OC samples and the potential role of BIRC5 polymorphisms in isoform expression. Clinical samples showed the same pattern of survivin isoform expression as in the cell line, and several BIRC5 polymorphisms showed the correlation with isoform expression. Our results showed that survivin isoforms are regulated both by different GLI proteins and BIRC5 polymorphisms in OC.

Interactions of ficolin-3 with ovarian cancer cells

BackgroundFicolin-3 is a pattern-recognition molecule with the ability to activate the lectin pathway of complement. It is found in lung, liver and blood, but its physiological role is unclear. We have investigated interaction of recombinant ficolin-3 with malignant cells and tissues. Material and MethodsCells of various lines of human origin as well as ovarian tissue sections have been studied with the use of flow cytometry and immunohistochemistry. ResultsRecombinant (but not serum-derived) ficolin-3 was found to bind strongly to the ovarian cancer cell lines, SKOV-3, OVCAR-3 and ES-2, at concentrations of 2.5 μg/ml and above. Moreover, His-tagged recombinant ficolin-3 (10 μg/ml) preferentially stained ovarian tissue sections from patients with malignant tumours compared with those from patients without. Binding to cell lines was inhibited by EDTA and specific carbohydrate ligands, indicating involvement of the fibrinogen-like domain. Binding was enhanced under mildly acidic conditions and at physiological pH after pre-incubation of cells with mildly acidic buffer. ConclusionBasing on data concerning recombinant protein, it may be suggested that ficolin-3 is involved in immune response in ovarian cancer. However, unidentified serum factor(s) seem(s) to protect cancer cells from recognition by natural or rficolin-3.

Synthesis of Ag@Fe3O4 Nanoparticles for Photothermal Treatment of Ovarian Cancer

Photothermal therapy is a promising approach for cancer treatment. In our study, we investigate the photothermal effect of different concentrations of the Ag@Fe3O4 nanoparticles on apoptosis and proliferation in the human epithelial ovarian cancer cells SKOV3. Ovarian cancer cells SKOV3 were treated with the Ag@Fe3O4 nanoparticles under an 808 nm near-infrared (NIR) laser irradiation at different concentrations. The cell proliferation was measured by the cell counting kit-8 (CCK-8) assay. The results show that the Ag@Fe3O4 nanoparticles with NIR laser irradiation could markedly inhibit the proliferation of the ovarian cancer cells SKOV3 independent of a concentration-time manner. Meanwhile, the cell morphology was also seriously damaged under the treatment of high-concentration nanoparticles. However, Ag@Fe3O4 nanoparticles have almost no obvious effect on the growth of SKOV3 cells without NIR laser illumination treatment. Therefore, it is reasonable to believe that the Ag@Fe3O4 nanoparticles have promising applications in photothermal treatment of cancer cells.

Wheat straw extracted lignin in silver nanoparticles synthesis: Expanding its prophecy towards antineoplastic potency and hydrogen peroxide sensing ability.

Lignin, is the most abundant, renewable and degradable biopolymer available in the nature. The present study exploited purified lignin from wheat straw as reducing, capping and stabilizing agent for the green synthesis of silver nanoparticles (Li-AgNPs) under optimized conditions. The analytical studies revealed synthesized Li-AgNPs having a face centered cubic crystalline structure, size ranging ~15-20 nm and the biomolecules comprising majorly phenolic, hydroxyl and carboxylic group of lignin coated on the surface of AgNPs. Li-AgNPs showed significant antimicrobial efficacy against human pathogens namely; Staphylococcus aureus and Escherichia coli and also determined their minimum inhibitory and minimum bactericidal concentration (MIC and MBC). Li-AgNPs also displayed substantial antioxidant activity in terms of well-known enzyme marker viz.; ABTS and DPPH free radical scavenging assay relative to commercial AgNPs. In vitro cytotoxicity assay of Li-AgNPs demonstrated dose-dependent toxicity effects in SKOV3 ovarian cancer cell line (LD50; 150 μg/mL) indicative of promising anticancer agent. Further, H2O2 sensing ability of stabilized Li-AgNPs exhibited its vital role in determining reactive oxygen species. Synthesis of Li-AgNPs is a cheap green technology and could exhibit its commercial use in biomedical, cosmetic, and pharmaceutical industry.

MicroRNA-16 inhibits migration and invasion via regulation of the Wnt/β-catenin signaling pathway in ovarian cancer.

As small non-coding RNA molecules, microRNAs (miRs) function in the regulation of tumorigenesis. Proliferation in ovarian cancer is considered to be associated with miR-16; however, the role of miR-16 in the migration and invasion of ovarian cancer cells remains unclear. The results of the present study demonstrated that miR-16 expression is downregulated in the ovarian cancer SKOV3 and OVCAR3 cell lines compared with that in normal ovarian epithelial cells (OECs). miR-16 overexpression inhibited the proliferation, migration and invasion of SKOV3 and OVCAR3 cells, and decreased the expression of matrix metallopeptidase (MMP)2 and MMP9. Additionally, miR-16 upregulated the expression of cadherin 1, an intercellular adhesion molecule, and downregulated the expression of some mesenchymal markers, including snail family transcriptional repressor 2, snail family transcriptional repressor 1, Vimentin, twist family BHLH transcription factor 1 and cadherin 2 in SKOV3 and OVCAR3 cells. Furthermore, it was indicated that miR-16 overexpression in SKOV3 and OVCAR3 cells resulted in a significant increase in anti-glycogen synthase kinase 3 β expression and a decrease in the expression of Wnt family member 3A, β-catenin, MYC proto-oncogene, BHLH transcription factor and cyclin D1 compared with the NC group. The results of the present study indicated that miR-16 exerts a suppressive effect on cell migration and invasion in ovarian cancer in vitro, through inactivation of the Wnt/β-catenin signaling pathway. The data suggest that miR-16 may be a potential therapeutic agent for the treatment and prevention of ovarian cancer.

MiR-142-5p enhances cisplatin-induced apoptosis in ovarian cancer cells by targeting multiple anti-apoptotic genes

Chemotherapy is the preferred treatment for advanced ovarian cancer, but the 5-year survival rate remains low partly because of the development of drug resistance. Although it has been reported that X-linked inhibitor of apoptosis (XIAP) causes more severe chemoresistance in ovarian cancer cells and is highly expressed in chemoresistant ovarian cancer, the molecular mechanism underlying this dysregulation is unknown. The purpose of this study was to identify microRNAs (miRNAs) that bind to the 3′ untranslated region (3′UTR) of XIAP and have a role in chemoresistance in ovarian cancer. Using in silico analysis and literature review, a panel of miRNAs dysregulated in chemoresistant ovarian cancer was generated from hundreds of miRNAs that were predicted to target the XIAP 3′UTR. Using a dual luciferase reporter assay and cellular co-transfection of a miRNA expression vector and a luciferase reporter fused to the XIAP 3′UTR cognate miRNA binding site, we identified three miRNAs of which miR-142-5p had the greatest inhibitory effect. We found that overexpression of miR-142-5p suppressed XIAP expression by binding to its 3′UTR in OVCAR3 and SKOV3 cells. Using a chemosensitivity assay, we found that in OVCAR3, SKOV3, and primary epithelial ovarian cancer (EOC) cells, overexpression or inhibition of miR-142-5p increased or suppressed their sensitivities to cisplatin respectively. In contrast, introducing XIAP without a 3′UTR counteracted the effect of overexpressed miR-142-5p on cisplatin-induced apoptosis in OVCAR3 ovarian cancer cells. Furthermore, we found a negative correlation between miR-142-5p expression and XIAP protein levels in clinical samples from patients with EOC. Using clinical and miRNA expression data of more than 200 ovarian cancer patients treated with platinum-based chemotherapy from The Cancer Genome Atlas (TCGA) database, we found ovarian cancer patients with higher expression levels of miR-142-5p had longer median progression-free survival as compared to patients with lower miR-142-5p levels. We demonstrated that miR-142-5p also targeted four other anti-apoptotic genes, baculoviral IAP repeat-containing 3 (BIRC3), B-cell lymphoma-2 (BCL2), BCL2 like 2 (BCL2L2), and myeloid cell leukemia sequence 1 (MCL1) specifically. Transcriptome sequencing shed light on the essential apoptosis-related pathway in which miR-142-5p may be involved. To conclude, our findings illustrate that miR-142-5p sensitizes ovarian cancer cells to cisplatin-induced apoptosis by targeting multiple anti-apoptotic genes including XIAP, and may also suggest the therapeutic potential of miR-142-5p in ovarian cancer treatment.

UNBS5162 inhibits SKOV3 ovarian cancer cell proliferation by regulating the PI3K/AKT signalling pathway.

Ovarian cancer is the gynaecological malignancy with the highest mortality rate worldwide, and effective and safe therapeutic methods are limited. UNBS5162, a derivative of naphthalimide, has a clear inhibitory effect on the proliferation of various tumour cells in vitro and in vivo as a pan-antagonist of CXC chemokine ligand expression, but whether it serves a function in ovarian cancer remains unclear. The aim of the present study was to determine the effects of UNBS5162 on the proliferation, migration and invasion of ovarian cancer cells. The cell viability was detected using a Cell Counting Kit-8 (CCK-8) assay. The invasion and migration of SKOV3 cells were determined using Transwell assays. Cell apoptosis was determined using flow cytometry. The apoptosis-associated proteins and associated factors, such as phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signalling pathway members, were detected using western blot analysis. The CCK-8 assay revealed that SKOV3 cell viability was affected by UNBS5162 in a dose- and time-dependent manner. In Transwell assays, UNBS5162 inhibited cell invasion and migration. Furthermore, it was identified that UNBS5162 markedly increased the apoptosis rate of SKOV3 cells. Simultaneously, the expression of the anti-apoptotic protein B-cell lymphoma 2 (Bcl-2) was decreased and the expression of the pro-apoptotic proteins active caspase-3 and Bcl-2-associated X protein were increased in SKOV3 cells treated with UNBS5162. In addition, the expression levels of phospho (p-)AKT/total AKT, p-mammalian target of rapamycin (mTOR)/total mTOR, p-p70 S6 kinase (p70S6K)/total p70S6K and cyclin D1 were decreased in the UNBS5162-treated group. The results of the present study indicated that UNBS5162 inhibits proliferation, migration and invasion, and induces apoptosis in ovarian cancer cells, which may be regulated by the PI3K/AKT signalling pathway. These results suggest that UNBS5162 may be a potential novel drug for clinical ovarian cancer treatment.

Catalase Deficiency Compromises Survival in Extracellular Matrix-Detached SKOV3 Ovarian Cancer Cells

For epithelial ovarian cancer cells to survive during the metastatic cascade, cells must be able to evade anoikis, a caspase-dependent cell death mechanism initiated by extracellular matrix (ECM) detachment. However, many of the details behind this phenomenon have yet to be unveiled. Here, we examined the role of the antioxidant enzyme, catalase, in the survival and proliferation of anchorage-independent SKOV3 ovarian cancer cells. Catalase deficiency severely compromises cell viability and anchorage-independent growth in ECM-detached SKOV3 cells. Notably, cellviability and proliferation were unaffected in ECM-attached catalase-deficient SKOV3 cells. In aggregate, we discovered that catalase plays a prominent role in protection from ECM-detachment-induced cell death in SKOV3 cells. Furthermore, these findings imply that catalase may be an effective therapeutic target for epithelial ovarian cancer cells that survive the ECM-bereft metastatic cascade.

Elimination of Peroxiredoxin 1 Abrogates Proliferation and Viability in Extracellular Matrix-Detached SKOV3 Ovarian Cancer Cells

Epithelial ovarian carcinoma has a relatively low survival rate due to the fact that this disease is often diagnosed after it has already progressed to stage III or stage IV, thus making the disease more difficult to treat. In order to successfully metastasize to these regional and distant sites, tumor cells must be able to overcome extracellular matrix (ECM)-detachment-induced effects, including combatting increased reactive oxygen species (ROS). Here, we investigate peroxiredoxin 1 (PRDX1) and find that PRDX1 plays an important role in proliferation in ECM-attached and ECM-detached SKOV3 cells, an epithelial ovarian carcinoma cell line. Furthermore, we find that PRDX1 deficiency in SKOV3 cells promotes a substantial decrease in cell viability in ECM detachment contributing to abrogated cell growth in anchorage independence. Thus, our study finds that PRDX1 deficiency uniquely compromises cell viability in ECM-detached cells, suggesting that PRDX1 could be a potential therapeutic target for late-stage epithelial ovarian carcinoma.

Elimination of Sestrin 2 Compromises Viability in Extracellular Matrix-Detached SKOV3 Ovarian Cancer Cells

Epithelial ovarian carcinoma (EOC) is considered the deadliest gynecological cancer, largely due to the fact that it is often diagnosed once the cancer has already metastasized, thus making the disease more difficult to treat. Throughout metastasis, ovarian epithelial cancer cells must overcome many feats, including surviving in extracellular matrix (ECM) detachment. ECM-detached cancer cells must evade a number of insults, including increased intracellular reactive oxygen species (ROS). Recent evidence suggests ECM-detached cancer cells rely on antioxidant enzymes to combat these increasing levels of ROS to promote survival; however, the specific antioxidant enzymes involved in this process have yet to be fully elucidated. Sestrin 2 (SESN2) is a multi-functional protein that has been found to be instrumental in many different signaling pathways; notably, it has been recognized to play a critical role in eliminating ROS. Here, we show that SESN2 plays a unique role in maintaining the viability of ECM-detached metastatic ovarian epithelial cancer cells, and elimination of this critical protein results in compromised viability. Thus, these data identify SESN2 as a potentially interesting therapeutic target for treating this deadly metastatic disease.

Antitumor effects of BMS-777607 on ovarian cancer cells with constitutively activated c-MET

ObjectiveTyrosine-protein kinase MET (c-MET) has been reported to be a prognostic marker and suitable therapeutic target for ovarian cancer. BMS-777607, a small molecule, can inhibit MET and other protein kinase activities. The present study was conducted to investigate the mechanism of action and antitumor effect of BMS-777607 on ovarian cancer cells with constitutively activated c-MET. Materials and methodsOvarian cancer cells with constitutively activated c-MET were first identified through Western blot analysis. Bio-behaviors, including signal transduction, proliferation, apoptosis, and migration, of the cells with constitutively activated c-MET were evaluated after BMS-777607 treatment. Liu's stain and immunological staining of α-tubuline were performed to evaluate the ploidy of the cells. A xenograft mouse model was also used to evaluate the antitumor effects of BMS-777607 on ovarian cancer cells with constitutively activated c-MET. ResultsBMS-777607 could induce the highest inhibition of cell growth in ovarian cancer cells constitutively expressing c-MET. Treating SKOV3 cells with BMS-777607 could reduce c-MET activation and inhibit downstream cell signaling, thus causing cell apoptosis and polyploidy as well as cell cycle and cell migration inhibition. This molecule also inhibited tumor growth in a mouse xenograft model of SKOV3 ovarian cancer cells in vivo. ConclusionBMS-777607 exhibits antitumor effects on ovarian cancer cells that constitutively express c-MET through c-MET signaling blockade and the inhibition of Aurora B activity. Combination treatments to enhance the effects of BMS-777607 warrant investigation in the future.

Effect of Dioscorea Pills on Immunity of Mice Receiving Chemotherapy for Ovarian Cancer

Objective: To observe the effect of Dioscorea pills on the immunity of mice with ovarian cancer after chemotherapy and its mechanism of action. Methods: BALB/C mice were randomly divided into blank group, ovarian cancer model group, chemotherapy group and chemotherapy plus TCM (Traditional Chinese Medicine) group with 20 mice in each group. Except the blank group, 60 mice in other groups were subcutaneously injected with SKOV-3 ovarian cancer cell suspension at the right buttock to build a tumor-bearing mouse model. After tumor formation, the chemotherapy group and the chemotherapy plus TCM group were intraperitoneally injected with Docetaxel. Next day, the chemotherapy plus TCM group was given Dioscorea pills by gavage, while the other three groups were given equal quantity of normal saline. All mice were sacrificed 21 days after treatment. The white blood cell count and serum levels of IL-2 and TNF-α were measured. Results: Compared with the model group and the ovarian cancer model group, the levels of IL-2 and white blood cell count of the chemotherapy group and the chemotherapy plus TCM group were significantly decreased (P 0.05). Conclusions: Dioscorea pills can improve the immunity of mice with ovarian cancer after chemotherapy.

Upregulation of sulfatase-1 decreases metastatic potential of SKOV3 human ovarian cancer cells in vitro and in vivo.

Sulfatase-1 (SULF-1) is one of the genes associated with the inhibition of several signaling pathways by desulfating HSPG in cancer cells. The aim of this study is to investigate the effect of SULF-1 upregulation on SKOV3 ovarian cancer cell line and its influence on cell proliferation, migration, invasion in vitro, and lymph node metastasis in 615 inbred mice in vivo. In in vitro study, we upregulated SULF-1 in SKOV3 cells using SULF-1 expression plasmid. Quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR) and western blotting were used to measure SULF-1 expression levels after stable upregulation. CCK-8, flow cytometry, Boyden Transwell-chamber, and scratch-wound healing assay were performed to explore the effect of SULF-1 on the proliferation, migration, and invasion. In in vivo study, immunohistochemistry and eosin stain (H and E) were used to evaluate the expression level of SULF-1 gene and to measure the lymph node metastatic rate of mice inoculated with SULF-1-SKOV3-expressed plasmid, SKOV3, and Nc-SKOV3 cells. qRT-PCR and western blot assay confirmed that SULF-1 was upregulated both in mRNA and protein levels. Following SULF-1 stable upregulation, the cell proliferation, migration, and invasion were significantly reduced in the SULF-1 upregulated cells (SULF-1-SKOV3) compared with the nontransfected (SKOV3) and the nonspecific sequence transfected cells (Nc-SKOV3). IHC results showed that SULF-1 was highly expressed after stably upregulation in SKOV3 cells, and H and E stain confirmed that the mice inoculated with SULF-1-SKOV3 cells decreased lymph node metastatic rate compared to the two control groups. Our findings showed that overexpression of SULF-1 in SKOV3 results in a decrease in ovarian cancer cell proliferation, migration, and invasion in vitro and decreased lymph node metastasis in vivo. This finding could have a potential therapeutic window in the management of ovarian cancer.