Agent For Treatment Of Ovarian Cancer Research Articles

Agrimonolide inhibits glycolysis in ovarian cancer cells by regulating HIF1A

BackgroundOvarian cancer is one of the most common tumors affecting females, significantly disrupting their quality of life. Agrimonolide, an extract derived from Agrimony (Agrimonia pilosa Ledeb.), has been shown to exert various regulatory effects on several diseases. Notably, recent studies indicate that Agrimonolide may attenuate the progression of ovarian cancer. However, the detailed regulatory mechanisms of Agrimonolide in this context require further investigation. PurposeTo determine the significance of HIF1A as a key target in ovarian cancer and its potential underlying signaling pathway. MethodsCell viability and proliferation were assessed using CCK-8 and colony formation assays. Glucose uptake and lactate production were measured using commercial kits, and the extracellular acidification rate (ECAR) was evaluated. Protein expression levels were analyzed through western blotting. ResultsOur network pharmacology analysis identified HIF1A as a crucial target and signaling pathway in ovarian cancer. Furthermore, treatment with Agrimonolide (20μM and 40μM) inhibited the growth of ovarian cancer cells. Agrimonolide also reduced glycolytic activity in these cells. Additionally, Agrimonolide treatment led to decreased expression levels of HIF1A, HK2, and LDHA in ovarian cancer cells. Rescue assays revealed that glucose uptake and lactate production were diminished following Agrimonolide treatment; however, these effects were reversed upon overexpression of HIF1A. ConclusionThis study showed that Agrimonolide can suppress glycolysis in ovarian cancer cells by modulating HIF1A, supporting Agrimonolide as a promising therapeutic agent for ovarian cancer treatment.

Salinomycin-Loaded High-Density Lipoprotein Exerts Promising Anti-Ovarian Cancer Effects by Inhibiting Epithelial-Mesenchymal Transition.

BackgroundEffective treatments for ovarian cancer remain elusive, and survival rates have long been considered grim. Ovarian cancer stem cells (OCSCs) and epithelial–mesenchymal transition (EMT) are associated with cancer progression and metastasis, as well as drug resistance and eventual treatment failure. Salinomycin (Sal) has an extensive effect on a variety of cancer stem cells (CSCs); however, its poor water solubility and toxicity to healthy tissues at high doses limit further research into its potential as an anti-cancer drug. We proposed a therapeutic strategy by constructing a tumor-targeting carrier that mimics high-density lipoprotein (HDL) to synthesize salinomycin-loaded high-density lipoprotein (S-HDL). This strategy helps reduce the side effects of salinomycin, thereby improving its clinical benefits.MethodsOCSCs were isolated from ovarian cancer cells (OCCs) and the uptake of HDL nanoparticles was observed using laser confocal microscopes. After the cell viability analysis revealed the inhibitory effect of S-HDL on OCCs and OCSCs, the main biological processes influenced by S-HDL were predicted with a transcriptome sequencing analysis and verified in vitro and in vivo.ResultsCellular uptake analysis showed that the HDL delivery system was able to significantly enhance the uptake of Sal by OCCs, tentatively validating the targeting role of recombinant HDL, so that S-HDL could reduce the toxicity of Sal and increase its anti-ovarian cancer effects. Conversely, S-HDL could exert anti-ovarian cancer effects by inhibiting the proliferation of OCCs and OCSCs, promoting apoptosis, blocking EMT, and suppressing stemness and angiogenesis-related protein expression in vitro and in vivo.ConclusionS-HDL had stronger anti-ovarian cancer effects than unencapsulated Sal. Thus, it may be a potential agent for ovarian cancer treatment in the future.

Polyphyllin E Inhibits Proliferation, Migration and Invasion of Ovarian Cancer Cells by Down-Regulating the AKT/NF-κB Pathway.

Ovarian cancer has long been considered the second-highest cancer threat to women's reproductive system with high mortality. This is ascribed to the absence of highly efficient therapy and cancer metastasis. Accordingly, there is an urgent need for the development of new agents. Recently, Traditional Chinese medicine has gained extensive interest because of its safe use, validity, and distinct pharmacological effects. Polyphyllin E (PPE), as a major constituent in Rhizoma Paridis, is a promising cancer-fighting agent. However, the effect of PPE on ovarian cancers as well as associated latent mechanisms is still not completely understood. In this study, PPE was found to prohibit the proliferation of SK-OV-3 and OVCAR-3 ovarian cancer cells, causing marked cell death. Additionally, low-dose PPE could also inhibit motility and invasion of ovarian cancer cells. The mechanistic assessment revealed PPE-mediated matrix metalloproteinases, i.e., MMP2 and MMP9, inhibition via the AKT-nuclear factor kappa B (AKT/NF-κB) signaling pathway. Rescue experiments with transfection of AKT lentiviral particles remarkably reversed PPE inhibitory effects against ovarian cancer cells. In conclusion, PPE could inhibit proliferation of ovarian cancer cell migration and invasion by down-regulating the AKT/NF-κB pathway. Moreover, it has the potential to act as a novel agent for ovarian cancer treatment.

Apigenin Inhibits the Histamine-Induced Proliferation of Ovarian Cancer Cells by Downregulating ERα/ERβExpression.

BackgroundApigenin (APG), a natural flavonoid, can affect the development of a variety of tumors, but its role in ovarian cancer remains unclear. There has been an increasing amount of evidence supporting the vital role played by mast cells and the bioactive mediators they release, as components of the tumor microenvironment, in the progression of ovarian cancer (OC); however, the mechanism warrants further exploration.Methods and ResultsIn this study, a combination of transcriptomics analysis and application of TCGA database was performed, and we found that the expression of genes related to mast cell degranulation in ovarian cancer tissues changed remarkably. We then explored whether histamine, a major constituent of mast cell degranulation, could affect the development of ovarian cancer through immunohistochemistry analysis and cell proliferation assays. The results showed that a certain concentration of histamine promoted the proliferation of ovarian cancer cells by upregulating the expression of estrogen receptor α (ERα)/estrogen receptor β (ERβ). Additionally, we found that the inhibition of ERα or the activation of ERβ could inhibit the proliferation of ovarian cancer cells induced by histamine through real-time PCR and western blot assays. Finally, we demonstrated the attenuation effect imparted by apigenin in histamine-mediated ovarian cancer via the PI3K/AKT/mTOR signaling pathway.ConclusionOur research revealed that apigenin decelerated ovarian cancer development by downregulating ER-mediated PI3K/AKT/mTOR expression, thus providing evidence of its applicability as a potentially effective therapeutic agent for ovarian cancer treatment.

Abstract 1012: In vitro antitumor effect of AZD4547 in ovarian cancer cell lines

Abstract Of all the gynecological cancer, ovarian cancer is the most fatal malignancy. In particular, strong chemotherapy resistance in ovarian cancer raises the need for new therapeutic strategy. Since fibroblast growth factor (FGF) signaling pays an important role in malignant transformation, tumor growth, angiogenesis, and chemoresistance, fibroblast growth factor receptor (FGFR) inhibitors are being assessed in clinical trials for several FGFR-driven cancer. FGFRs is known to be highly dysregulated in ovarian cancer, however the effect of FGFR inhibition in ovarian cancer has not been elucidated. In this study, we investigated the anti-tumor effects of AZD4547, an FGFR1-4 inhibitor, in various types of ovarian cancer cell line. AZD4547 markedly inhibited proliferation and stimulated apoptosis of ovarian cancer cells. In addition, AZD4547 inhibited cell migration and invasion under non-toxic condition. Moreover, AZD4547 reduced the sphere forming ability and the self-renewal capacities of ovarian cancer stem cells (CSCs) which are strongly resistant to paclitaxel. Furthermore, AZD4547 exhibited anti-angiogenic effect on human umbilical vein endothelial cells. Based on these anti-tumor effect of AZD4547 in ovarian cancer cell lines, we suggests AZD4547 as a promising agent for ovarian cancer treatment. Citation Format: Ji Hae Seo, Seungmee Lee, Chi-Heum Cho, So-Jin Shin. In vitro antitumor effect of AZD4547 in ovarian cancer cell lines [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1012.

Methiothepin Suppresses Human Ovarian Cancer Cell Growth by Repressing Mitochondrion-Mediated Metabolism and Inhibiting Angiogenesis In Vivo.

Ovarian cancer is the fifth leading cause of cancer-related deaths in women. Despite treatment, most patients experience relapse and the 5-year survival rate of ovarian cancer is less than 50%. Serotonin has cell growth-promoting functions in a variety of carcinomas, but the effect of serotonin receptor antagonists on ovarian cancer cells is unknown. In this study, it was confirmed that methiothepin, a serotonin receptor antagonist, suppresses the viability of, and induces apoptosis in, ovarian cancer cells. Methiothepin also induces mitochondrial dysfunction, represented by depolarization of the mitochondrial membrane and increased mitochondrion-specific Ca2+ levels, and causes metabolic disruption in cancer cells such as decreased ATP production and oxidative phosphorylation. Methiothepin also interferes with vascular development in transgenic zebrafish embryos. Combination treatment with methiothepin improves the anti-cancer effect of paclitaxel, a standard chemotherapeutic agent. In conclusion, this study revealed that methiothepin is a potential novel therapeutic agent for ovarian cancer treatment.

Fucoxanthin inhibits cell proliferation and stimulates apoptosis through downregulation of PI3K/AKT/mTOR signaling pathway in human ovarian cancer cells

Background: Fucoxanthin is rich in seaweed and considered the most efficient anticancer drug because of its powerful antioxidant properties. The aim of this study was to elucidate the role of fucoxanthin on apoptosis via signaling pathway in ovarian cancer cells. First, fucoxanthin exhibited obvious cytotoxicity against A2780 human ovarian cancer cells. Materials and Methods: We established the action potential of fucoxanthin on cell proliferation in addition to apoptosis in A2780 cells, which were measured using reactive oxygen species (ROS) generation and the mitochondrial membrane potential (MMP). Apoptotic-related morphological alterations were inspected by acridine orange/EtBr dual staining. In addition, we analyzed caspase family protein expression by enzyme-linked immunosorbent assay analysis. Results: Our results established that fucoxanthin stimulates apoptosis as confirmed through reduced cell viability, improved production of ROS, and altered MMP in A2780 cells. Further, the fucoxanthin upregulates the expression of caspase (3, 8, and 9) protein experimentally in A2780 cell. In addition, we uncovered upstream signaling cascade (Akt/mTOR) induced by incubation A2780 cell lines with fucoxanthin that mediated cell apoptosis, migration, and invasion process. Conclusion: These findings suggest that fucoxanthin augments apoptosis; reduces cell proliferation, migration, and invasion; and reveals a potential mechanism of fucoxanthin-mediated Akt/mTOR suppression in human ovarian cancer cell line. Hence, fucoxanthin could be reflected as a potential therapeutic agent for ovarian cancer treatment.

Hedyotis Diffusa Willd. Extracts Inhibit the Proliferation and Migration of Ovarian Cancer Cells by Modulating the AKT/ERK Signaling Pathway

Hedyotis diffusa Willd. (HDW) is a traditional Chinese medicine used for the treatment of colorectal cancer. The aim of this study was to investigate the molecular mechanism of inhibitory effects of HDW on the growth of ovarian cancer cells. Treatment of ovarian cancer cells with increasing doses of HDW for 48 or 72 h resulted in a significant reduction in the viability and colony formation of cancer cells. In HDW-treated cancer cells, the cell cycle was blocked at the G0/G1 phase and cell apoptosis was 4- to 5-fold higher than that of control group. HDW treatment also markedly inhibited the migration and invasion of ovarian cancer cells. Mechanistically, the phosphorylation levels of AKT and ERK were down-regulated in HDW-treated ovarian cancer cells. Therefore, HDW is likely to become a promising therapeutic agent for ovarian cancer treatment.

Icariin suppresses cell cycle transition and cell migration in ovarian cancer cells.

Ovarian cancer is the third most common type of gynecological tumor, in addition to being the most lethal. Cytoreductive surgery with chemotherapy is the standard treatment for ovarian cancer. It is necessary to identify novel chemotherapeutic methods, since current chemotherapy treatments are rarely effective for patients with advanced‑stage or recurrent ovarian cancer and may cause acute systemic toxicity. Icariin (ICA) is a prenylated flavonol glycoside derived from Herba Epimedii, a medicinal plant with a variety of pharmacological activities, including anticancer, antidiabetic and anti‑obesity effects. By analyzing cell viability, cell cycle and cell migration, the present study demonstrated that ICA inhibited the cell viability of the ovarian cancer cell line, SKOV3, and blocked cell cycle transition. ICA inhibited the expression of fuse binding protein 1 (FBP1), a critical regulator of proliferation and tumorigenesis through binding to the c‑Myc promoter, as well as β‑catenin, a key regulator in ovarian cancer initiation, metastasis, chemoresistance and recurrence. Furthermore, it was indicated that ICA inhibited the migration of SKOV3 cells. In accordance with our previous findings on high FBP1 expression in ovarian cancer, FBP1 was a potential target of ICA in ovarian cancer cells. Based on these results, the present study demonstrated that ICA may be a potential therapeutic agent for ovarian cancer treatment.

Abstract A65: Combination of a thioxodihydroquinazolinone compound with cisplatin eliminates ovarian cancer stem cell-like cells (CSC-LCs) and shows preclinical potential

Abstract Cancer stem cell-like cells (CSC-LCs) contribute to drug resistance and recurrence of ovarian cancer. Strategies that can eradicate CSC-LCs are expected to substantially improve the outcome of ovarian cancer treatments. We have previously identified a class of thioxodihydroquinazolinone small molecules, which have strong synergistic antitumor activity with platinum drugs, the standard chemotherapeutic agents for ovarian cancer treatment. In the current study, using the activity of aldehyde dehydrogenase (ALDH) as a marker of CSC-LCs, we demonstrated that the combination of thioxodihydroquinazolinone compound 19 with cisplatin is able to deplete ALDH-high CSC-LC population in both established platinum-resistant ovarian cancer cell lines and primary ovarian cancer cells from metastatic ascites of a cisplatin-resistant patient. Compound 19 enhanced the accumulation of intracellular cisplatin in ALDH-high ovarian cancer cells. The combination of compound 19 with cisplatin was also able to reduce the sphere-forming capability of cisplatin-resistant ovarian cancer cells. Using a spheroid-based in vitro metastasis model of ovarian cancer, we demonstrated that the combination of compound 19 with cisplatin prevents spheroid ovarian cancer cells from attaching to substratum and spreading. In vivo, the treatment by the combination of compound 19 with cisplatin significantly reduced tumor burden in a cisplatin-resistant intraperitoneal ovarian cancer xenograft mouse model, as compared to cisplatin-alone treatment. Taken together, our study demonstrated that the thioxodihydroquinazolinone compounds are a new class of agents that in combination with cisplatin are capable of eliminating CSC-LCs in ovarian cancer. Further development of thioxodihydroquinazolinone small molecules may yield a more effective treatment for cisplatin-resistant metastatic ovarian cancer. Citation Format: Jing Ma, Joseph Salamoun, Peter Wipf, Robert Edwards, Bennett Van Houten, Wei Qian. Combination of a thioxodihydroquinazolinone compound with cisplatin eliminates ovarian cancer stem cell-like cells (CSC-LCs) and shows preclinical potential. [abstract]. In: Proceedings of the AACR Conference: Addressing Critical Questions in Ovarian Cancer Research and Treatment; Oct 1-4, 2017; Pittsburgh, PA. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(15_Suppl):Abstract nr A65.

PLGA nanoparticles co-delivering MDR1 and BCL2 siRNA for overcoming resistance of paclitaxel and cisplatin in recurrent or advanced ovarian cancer

The inherent or acquired resistance to paclitaxel and cisplatin, which are commonly used chemotherapeutic agents for ovarian cancer treatment, remains an important issue in chemotherapy of multidrug resistant ovarian cancer. Currently, it is still challenging to deal with the recurrent or advanced stage ovarian cancer. When drug efflux and anti-apoptotic pathways are highly interdependent and also involved in developing the resistance of multidrug resistant ovarian cancer, simultaneous inhibition of both pathways represents the potential targets to enhance the efficacy of chemotherapy. Here, we introduce PLGA nanoparticles system as a “dual RNAi delivery system” to contain both MDR1 and BCL2 siRNA, which is designed for simultaneous inhibition of drug efflux and cell death defense pathways. In the present studies, siRNA-loaded PLGA nanoparticles efficiently elicit the simultaneous suppression of both genes, which consequently shows more enhanced drug-sensitivity than sole suppression of drug efflux or anti-apoptosis in the resistant ovarian cancer cells, owing to the interdependence of both pathways. Our siRNA-loaded PLGA nanoparticles for co-delivering MDR1 and BCL2 siRNA provide an efficient combination therapy strategy to overcome the chemoresistance of paclitaxel and cisplatin on the paclitaxel-resistant SKOV3-TR and cisplatin-resistant A2780-CP20 ovarian cancer respectively.

Combination of a thioxodihydroquinazolinone with cisplatin eliminates ovarian cancer stem cell-like cells (CSC-LCs) and shows preclinical potential.

Cancer stem cell-like cells (CSC-LCs) contribute to drug resistance and recurrence of ovarian cancer. Strategies that can eradicate CSC-LCs are expected to substantially improve the outcome of ovarian cancer treatment. We have previously identified a class of thioxodihydroquinazolinone small molecules, which have strong synergistic antitumor activity with platinum drugs, the standard chemotherapeutic agents for ovarian cancer treatment. In the current study, using the activity of aldehyde dehydrogenase (ALDH) as a marker of CSC-LCs, we demonstrated that the combination of thioxodihydroquinazolinone compound 19 with cisplatin is able to diminish ALDH-high CSC-LC populations in both platinum-resistant ovarian cancer cell lines and primary ovarian cancer cells from metastatic ascites of a cisplatin-resistant patient. Compound 19 enhanced the accumulation of intracellular cisplatin in ALDH-high ovarian CSC-LCs. The combination of compound 19 with cisplatin was also able to reduce the sphere-forming capability of cisplatin-resistant ovarian cancer cells. Using a spheroid-based in vitro metastasis model of ovarian cancer, we demonstrated that the co-administration of compound 19 with cisplatin prevents ovarian cancer spheroid cells from attaching to substratum and spreading. In a cisplatin-resistant in vivo intraperitoneal xenograft mouse model, the combination of compound 19 with cisplatin significantly reduced tumor burden, as compared to cisplatin alone. Taken together, our study demonstrated that thioxodihydroquinazolinones represent a new class of agents that in combination with cisplatin are capable of eliminating CSC-LCs in ovarian cancer. Further development of thioxodihydroquinazolinone small molecules may yield a more effective treatment for cisplatin-resistant metastatic ovarian cancer.

Inhibitory Effects of Total Triterpenoid Saponins Isolated from the Seeds of the Tea Plant (Camellia sinensis) on Human Ovarian Cancer Cells.

Ovarian cancer is regarded as one of the most severe malignancies for women in the world. Death rates have remained steady over the past five decades, due to the undeniable inefficiency of the current treatment in preventing its recurrence and death. The development of new effective alternative agents for ovarian cancer treatment is becoming increasingly critical. Tea saponins (TS) are triterpenoidsaponins composed of sapogenins, glycosides, and organic acids, which possess a variety of pharmacological activities, and have shown promise in the anti-cancer field. Through cell CellTiter 96® Aqueous One Solution Cell Proliferation assay (MTS) assay, colony formation, Hoechst 33342 staining assay, caspase-3/7 activities, flow cytometry for apoptosis analysis, and Western blot, we observed that TS isolated from the seeds of tea plants, Camellia sinensis, exhibited strong anti-proliferation inhibitory effects on OVCAR-3 and A2780/CP70 ovarian cancer cell lines. Our results indicate that TS may selectivity inhibit human ovarian cancer cells by mediating apoptosis through the extrinsic pathway, and initiating anti-angiogenesis via decreased VEGF protein levels in a HIF-1α-dependent pathway. Our data suggests that, in the future, TS could be incorporated into a potential therapeutic agent against human ovarian cancer.

Loss of PFKFB4 induces cell death in mitotically arrested ovarian cancer cells.

Taxanes represent some of the most commonly used chemotherapeutic agents for ovarian cancer treatment. However, they are only effective in approximately 40% of patients. Novel therapeutic strategies are required to potentiate their effect and improve patient outcome. A hallmark of many cancers is the constitutive activation of the PI3K/AKT pathway, which drives cell survival and metabolism. We discovered a striking decrease in AKT activity coupled with a significant reduction in glucose 6-phosphate and ATP levels during mitotic arrest in the majority of ovarian cancer cell lines tested, indicating a potential metabolic vulnerability. A high-content siRNA screen to detect novel metabolic targets in mitotically arrested ovarian cancer cells identified the glycolytic enzyme PFKFB4. PFKFB4 depletion increased caspase 3/7 activity, and levels of reactive oxygen species only in mitotically arrested cells, and significantly enhanced mitotic cell death after paclitaxel treatment. Depletion of PFKFB3 demonstrated a similar phenotype. The observation that some ovarian cancer cells lose AKT activity during mitotic arrest and become vulnerable to metabolic targeting is a new concept in cancer therapy. Thus, combining mitotic-targeted therapies with glycolytic inhibitors may act to potentiate the effects of antimitotics in ovarian cancer through mitosis-specific cell death.

Long Noncoding RNA Ceruloplasmin Promotes Cancer Growth by Altering Glycolysis.

Long noncoding RNAs (lncRNAs) significantly influence the development and regulation of genome expression in cells. Here, we demonstrate the role of lncRNA ceruloplasmin (NRCP) in cancer metabolism and elucidate functional effects leading to increased tumor progression. NRCP was highly upregulated in ovarian tumors, and knockdown of NRCP resulted in significantly increased apoptosis, decreased cell proliferation, and decreased glycolysis compared with control cancer cells. In an orthotopic mouse model of ovarian cancer, siNRCP delivered via a liposomal carrier significantly reduced tumor growth compared with control treatment. We identified NRCP as an intermediate binding partner between STAT1 and RNA polymerase II, leading to increased expression of downstream target genes such as glucose-6-phosphate isomerase. Collectively, we report a previously unrecognized role of the lncRNA NRCP in modulating cancer metabolism. As demonstrated, DOPC nanoparticle-incorporated siRNA-mediated silencing of this lncRNA in vivo provides therapeutic avenue toward modulating lncRNAs in cancer.

Abstract 2181: Dual targeting of phosphoinositide 3-kinase/mammalian target of rapamycin using NVP-BEZ235 suppressed tumor growth in a genetically engineered mouse model of serous ovarian cancer.

Abstract Introduction: The PI3K/Akt/mTOR pathway plays a central role in regulating cancer cell proliferation and survival, and activation of the PI3K/Akt/mTOR pathway is commonly seen in ovarian cancer. NVP-BEZ235 is a novel agent that targets two molecules in this pathway, PI3K and mTOR. Thus, we explored the effects of NVP-BEZ235 on proliferation in human ovarian cancer cell lines and inhibition of tumor growth in a genetically engineered mouse model of serous ovarian cancer. Methods: Four ovarian cancer cell lines (SKOV3, ES2, HEY, IGROV1) were treated with NVP-BEZ235 (NOVARTIS Pharmaceuticals) at different concentrations for up to 72 hours and proliferation was measured using the MTT assay. Cell cycle progression was evaluated by Cellometer. Apoptosis was determined by Annexin V-FITC assay. Phosphorylated (phos)-Akt, phos-S6 were evaluated by Western blot analysis. Adhesion was assessed by ELISA assay. The K18-gT121+/−;p53fl/fl;Brca1fl/fl (KpB) genetically engineered serous ovarian cancer mouse model was used for the in vivo studies. The KpB mice were subjected to a 60% calories-derived from fat in a high fat diet (HFD) versus 10% calories from fat in a low fat diet (LFD) to mimic diet-induced obesity and subsequently exposed to NVP-BEZ235 or placebo for 4 weeks. Results: NVP-BEZ235 inhibited proliferation in all four ovarian cancer cell lines, in both a dose and time dependent manner (IC50=30 nM for SKOV3, 42 nM for ES2, 7 nM for IGROV1, 30 nM for HEY, p=0.00001). Treatment with NVP-BEZ235 resulted in G1 cell cycle arrest but failed to induce apoptosis. Western blot analysis demonstrated that NVP-BEZ235 decreased phosphorylation of both Akt and S6 within 24 hours of exposure. Cellular adhesion was decreased by 34-51% in the ovarian cancer cell lines at a dose of 50 nM (p=0.00001). In the KpB mice fed a high fat diet (obese) and treated with NVP-BEZ235, tumor weight decreased by 77% (p=0.0015) when compared with control animals. Among KpB mice fed a low fat diet (non-obese), tumor weight decreased by 59% after treatment with NVP-BEZ235 (p=0.03). Conclusions: NVP-BEZ235 potently inhibited cell growth via G1 arrest and decreased cellular adhesion in human ovarian cancer cells. In vivo studies using the KpB mouse model found that treatment with NVP-BEZ235 inhibited tumor growth in both obese and non-obese mice, but was more efficacious in the obese mice. Given that alterations in the PI3K/Akt/mTOR parthway are common in both obeso- and onco-genesis disease processes, this may explain the enhanced effect of NVP-BEZ235 in the obese KpB mice. This work suggests that NVP-BEZ235 may be a novel chemotherapeutic agent for ovarian cancer treatment that is potentially more beneficial in the obese population. Citation Format: Yan Zhong, Chunxiao Zhou, Victoria Lin Bae-Jump. Dual targeting of phosphoinositide 3-kinase/mammalian target of rapamycin using NVP-BEZ235 suppressed tumor growth in a genetically engineered mouse model of serous ovarian cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2181. doi:10.1158/1538-7445.AM2013-2181

Abstract 2265: Embelin induces autophagy in ovarian cancer cells

Abstract Embelin is an active ingredient of traditional herbal medicine that exhibits cytotoxic effect and inhibits cell proliferation in various cancer cell types. It is a small molecular inhibitor of XIAP undergoing preclinical testing for its anticancer effects in many different cancer types. In this study we have investigated its role as a chemotherapeutic agent in a panel of ovarian cancer cell lines. Utilising the MTT assay and annexin staining we demonstrate that embelin exhibits a potent, dose dependent cytotoxic effect in human ovarian cancer cells. Surprisingly in contrast to the previously reported cytotoxicity of embelin in many other cancer cell types, treatment of ovarian cancer cells with embelin promoted autophagy and not apoptosis as evidenced by the death without caspase 3 activation and induces cellular swelling and cytoplasmic vacuolization with evident features of necrotic cell death. Treatment of ovarian cancer cells with embelin demonsrnstrated autophagic hallmarks, including an increased number of autophagosomes were observed through acridine orange staining. Embelin also induced cell autophagy, as demonstrated by the punctuate distribution of GFP-LC3, as well as the LC3 cleavage and beclin1 activation. Red green fluorescence in acridine orange stained cells by flowcyometry further confirmed the autophagy action by embelin treatment. Our findings demonstrate a new death pathway underlying the cytotoxic effect of embelin, but also suggest that targeting autophagy could augment the anticancer activity, providing the framework for further development of embelin as a new chemotherapeutic agent for ovarian cancer treatment. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2265. doi:1538-7445.AM2012-2265

Live-attenuated measles virus vaccine confers cell contact loss and apoptosis of ovarian cancer cells via ROS-induced silencing of E-cadherin by methylation

Herein we present a novel molecular mechanism of the antitumor effects of live-attenuated measles virus (MV) vaccine in ovarian cancer. Using a 2-DE/MS-based comparative proteomics strategy, we identified 17 proteins differentially expressed in live-attenuated MV vaccine-treated SKOV-3 ovarian cancer cells, including oxidative stress-associated enzymes and cell contact-related proteins, which indicated that live-attenuated MV vaccine could induce aberrant ROS activation. It further mediated epigenetic silencing of E-cadherin via upregulating DNMT3a that conferred both cell–cell and cell–matrix contact loss and apoptosis of ovarian cancer cells. This process could be reversed through ROS inhibition. Our study lays the theoretical foundation for the clinical application of live-attenuated MV vaccine as a potential oncotherapeutic agent for ovarian cancer treatment.

FTY720 induces necrotic cell death and autophagy in ovarian cancer cells: A protective role of autophagy

FTY720, a sphingosine analog, is a novel immunosuppressant currently undergoing multiple clinical trials for the prevention of organ transplant rejection and treatment of various autoimmune diseases. Recent studies indicate an additional cytotoxic effect of FTY720 and its preclinical efficacy in a variety of cancer models, yet the underlying mechanisms remain unclear. We demonstrate here for the first time that FTY720 exhibits a potent, dose- and time-dependent cytotoxic effect in human ovarian cancer cells, even in the cells that are resistant to cisplatin, a commonly prescribed chemotherapeutic drug for treatment of ovarian cancer. In contrast to the previously reported cytotoxicity of FTY720 in many other cancer cell types, FTY720 kills ovarian cancer cells independent of caspase 3 activity and induces cellular swelling and cytoplasmic vacuolization with evident features of necrotic cell death. Furthermore, the presence of autophagic hallmarks, including an increased number of autophagosomes and the formation and accumulation of LC3-II, are observed in FTY720-treated cells before cell death. FTY720 treatment enhances autophagic flux as reflected in the increased LC3 turnover and p62 degradation. Notably, blockade of autophagy by either specific chemical inhibitors or siRNAs targeting Beclin 1 or LC3 resulted in aggravated necrotic cell death in response to FTY720, suggesting that FTY720-induced autophagy plays a self-protective role against its own cytotoxic effect. Thus, our findings not only demonstrate a new death pathway underlying the cytotoxic effect of FTY720, but also suggest that targeting autophagy could augment the anticancer potency, providing the framework for further development of FTY720 as a new chemotherapeutic agent for ovarian cancer treatment.

SU5416 inhibited VEGF and HIF-1α expression through the PI3K/AKT/p70S6K1 signaling pathway

Ovarian cancer has the highest mortality rate of any gynecological disease affecting women in Western countries. VEGF is a crucial inducer of angiogenesis both in vivo and in vitro. VEGF is commonly upregulated in ovarian cancer and is regulated by HIF-1. SU5416 is known to inhibit various stages of tumor growth. In this study, we show that SU5416 inhibited VEGF mRNA expression in ovarian cancer cells in a dose-dependent manner. SU5416 inhibited VEGF expression at the transcriptional level through the HIF-1 DNA binding site. HIF-1 is composed of HIF-1α and HIF-1β subunits. SU5416 specifically decreased HIF-1α, but not HIF-1β protein levels. To understand the signaling pathways regulating SU5416-inhibited VEGF and HIF-1α expression, we found that SU5416 inhibited PI3K activity. AKT is a downstream target of PI3K. We found that SU5416 also inhibited AKT and p70S6K1 activation and activity in a dose-dependent manner. These results demonstrate that SU5416 inhibited VEGF and HIF-1α expression through the inhibition of PI3K/AKT/p70S6K1 pathway in ovarian cancer cells. These results indicate that SU5416 may be an effective agent for ovarian cancer treatment through the inhibition of VEGF and HIF-1 expression, and the activation of PI3K/AKT/p70S6K1 signaling pathway.