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Purpose: While numerous epidemiological studies have indicated that omega-3 polyunsaturated fatty acids have anticancer properties in various cancers, the effects and mechanisms of eicosapentaenoic acid (EPA) in ovarian cancer cell growth are poorly understood., Materials and Methods: ES2 ovarian clear cell carcinoma cells and SKOV3 adenocarcinoma cells were treated with palmitic acid or EPA, followed by flow cytometry and cell counting to measure apoptosis and proliferation, respectively. A modified protein lipid overlay assay was used to further verify whether EPA was a ligand of G protein-coupled receptor 30 (GPR30) in ES2 cells. The levels of apoptosis-related genes, phosphorylated AKT, and phosphorylated ERK1/2 were detected to explore the underlying mechanism. Finally, inhibitory effect of EPA on tumor growth via GPR30 was determined in vitro and in vivo., Results: EPA suppressed ES2 ovarian clear cell carcinoma cells growth via GPR30, a novel EPA receptor, by inducing apoptosis. As a ligand of GPR30, EPA activated the GPR30-cAMP- protein kinase A signaling pathway. When GPR30 was suppressed by siRNA or its inhibitor G15, the antiproliferative action of EPA was impaired. Furthermore, EPA inhibited tumor growth by blocking the activation of AKT and ERK. In the mouse xenograft model, EPA decreased tumor volume and weight through GPR30 by blocking tumor cell proliferation., Conclusion: These results confirm that EPA is a tumor suppressor in human ovarian clear cell carcinoma cells and functions through a novel fatty acid receptor, GPR30, indicating a mechanistic linkage between omega-3 fatty acids and cancers.

Patients with ovarian cancer frequently develop acquired drug resistance after the long-term chemotherapy, leading to disease progression. Enhanced epithelial-mesenchymal transition (EMT) has been implicated in chemoresistance of ovarian cancer cells; however, the molecular mechanisms involved are largely undefined. Pyruvate dehydrogenase kinase 1 (PDK1), a key regulatory enzyme in glucose metabolism, has been recognized as a gatekeeper of the Warburg effect, a hallmark of cancer. In this study, the function of PDK1 in cisplatin resistance of ovarian cancer in terms of growth and EMT was investigated. PDK1 was upregulated in cisplatin-resistant ovarian cancer cells. PDK1 knockdown in resistant cells led to increased sensitivity to cisplatin-induced cell death and apoptosis. PDK1 downregulation also reversed the EMT and cell motility in cisplatin-resistant cells. In a mouse xenograft model, tumors derived from PDK1-silenced ovarian cancer cells exhibited decreased tumor growth and EMT compared with control after the cisplatin treatment. Mechanistically, PDK1 overexpression led to increased phosphorylation of EGFR, and blocking EGFR kinase activity by erlotinib reversed cisplatin resistance induced by PDK1 overexpression. Furthermore, in patients with ovarian cancer, higher PDK1 and p-EGFR levels were associated with chemoresistance. These results supported that PDK1 contributes to chemoresistance of ovarian cancer by activating EGFR. Therefore, PDK1 may serve as a promising target to combat chemoresistance of ovarian cancer., (© 2018 Wiley Periodicals, Inc.)

The distinct hormone molecules and receptors, such as follicle-stimulating hormone receptor (FSHR) in ovarian cancer, provide opportunities for more precisely targeted therapy. We previously developed FSHR-mediated nanoparticles and found that FSH peptides on the surface of nanoparticles improved the delivery of short interfering RNA (siRNA) into ovarian cancer cells. However, the high toxicity of the nanoparticles and the transient silencing of the siRNA in vivo limited further study. Here, we developed FSH peptide-conjugated nanoparticles with an increased amount of polyethylene glycol (PEG) grafting and encapsulated short hairpin RNA (shRNA) to silence the target gene, growth-regulated oncogene α (gro-α). The nanoparticle complexes exhibited good stability over three weeks. Expression of the target gene, gro-α, was significantly down-regulated by gro-α shRNA-loaded nanoparticles conjugated with FSH peptides (FSH33-G-NP) in FSHR-positive HEY cells. Cell proliferation, migration, and invasion were also inhibited by FSH33-G-NP. Tumor growth was delayed significantly in the mice treated with FSH33-G-NP. No significant loss of body weight or severe toxic effects were observed in any groups. In conclusion, gro-α shRNA-loaded nanoparticles conjugated with FSH peptides overcame the drawbacks of the in vivo application of RNAi therapeutics and polymer-based nanocarriers and showed safe antitumor efficacy. Our study might contribute to the application of FSHR-based targeted therapy and imaging in cancer.

Ovarian cancer is the leading cause of cancer death among gynecological malignancies. The high mortality rate has not been significantly reduced despite advances in surgery and chemotherapy. Gene therapy shows therapeutic potential, but several key issues must be resolved before clinical application. To minimize toxicity in noncancerous tissues, tumor-specific ligands are conjugated to vectors to increase the selectivity of drug delivery. The expression pattern of follicle-stimulating hormone (FSH) receptor in normal and cancer tissues provides an opportunity for highly selective drug delivery in ovarian cancer. Furthermore, tumor-specific promoters can conditionally regulate therapeutic gene expression in tumor or normal tissues. The mucin 16 (MUC16) promoter might be a potential tool to drive ovarian cancer-localized gene expression since MUC16/CA125 is overexpressed in most ovarian carcinomas. Here, we screened the possible MUC16 promoter sequences and constructed MUC16 promoter-driven gro-α shRNA plasmid vectors. The vectors were specifically delivered into ovarian cancer cells via FSH peptide-conjugated nanoparticles. The predicted promoter sequence with TAAA repeats showed high transcriptional activity. The nanoparticle complex containing MUC16 promoter-driven gro-α shRNA and FSH peptides had the ability to decrease gro-α protein secretion in ovarian cancer cells and block tumor growth without obvious toxic effects in a nude mouse model bearing ovarian cancer. Our study provides a novel gene delivery system using a MUC16 promoter trigger and FSH peptide-mediated active targeting in ovarian cancer, and this system may be a promising strategy for specific genetic therapeutic delivery.

The high mortality rate of ovarian cancer is connected with the development of acquired resistance to multiple cancer drugs, especially cisplatin. Activation of cytoprotective autophagy has been implicated as a contributing mechanism for acquired cisplatin resistance in ovarian cancer cells. Hexokinase 2 (HK2) phosphorylates glucose to generate glucose-6-phosphate, the rate-limiting step in glycolysis. Higher HK2 expression has been associated with chemoresistance in ovarian cancer. However, whether HK2 functionally contributes to cisplatin resistance in ovarian cancer is unclear. In this study, we investigated the role of HK2 in regulating ovarian cancer cisplatin resistance. Increased HK2 levels were detected in drug-resistant human ovarian cancer cells and tissues. Cisplatin downregulated HK2 in cisplatin-sensitive but not in resistant ovarian cancer cells. HK2 knockdown sensitized resistant ovarian cancer cells to cisplatin-induced cell death and apoptosis. Conversely, HK2 overexpression in cisplatin-sensitive cells induced cisplatin resistance. Mechanistically, cisplatin increased ERK1/2 phosphorylation as well as autophagic activity. Blocking autophagy with the autophagy inhibitor 3-MA sensitized resistant ovarian cancer cells to cisplatin. HK2 overexpression enhanced cisplatin-induced ERK1/2 phosphorylation and autophagy while HK2 knockdown showed the opposite effects. Blocking the MEK/ERK pathway using the MEK inhibitor U0126 prevented cisplatin-induced autophagy enhanced by HK2 overexpression. Furthermore, HK2 knockdown sensitized resistance ovarian tumor xenografts to cisplatin in vivo. In conclusion, our data supported that HK2 promotes cisplatin resistance in ovarian cancer by enhancing drug-induced, ERK-mediated autophagy. Therefore, targeting HK2 may be a new therapeutic strategy to combat chemoresistance in ovarian cancer., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Objective: This review aimed to update the progress of microRNA (miRNA) in early detection of ovarian cancer. We discussed the current clinical diagnosis methods and biomarkers of ovarian cancer, especially the methods of miRNA in early detection of ovarian cancer., Data Sources: We collected all relevant studies about miRNA and ovarian cancer in PubMed and CNKI from 1995 to 2015., Study Selection: We included all relevant studies concerning miRNA in early detection of ovarian cancer, and excluded the duplicated articles., Results: miRNAs play a key role in various biological processes of ovarian cancer, such as development, proliferation, differentiation, apoptosis and metastasis, and these phenomena appear in the early-stage. Therefore, miRNA can be used as a new biomarker for early diagnosis of ovarian cancer, intervention on miRNA expression of known target genes, and potential target genes can achieve the effect of early prevention. With the development of nanoscience and technology, analysis methods of miRNA are also quickly developed, which may provide better characterization of early detection of ovarian cancer., Conclusions: In the near future, miRNA therapy could be a powerful tool for ovarian cancer prevention and treatment, and combining with the new analysis technology and new nanomaterials, point-of-care tests for miRNA with high throughput, high sensitivity, and strong specificity are developed to achieve the application of diagnostic kits in screening of early ovarian cancer.

LeY (Lewis Y) is a difucosylated oligosaccharide carried by glycoconjugates on the cell surface. Elevation of LeY is frequently observed in epithelial-derived cancers and is correlated to pathological staging and prognosis. To study the role of LeY on cancer cells, a stably LeY-overexpressing cell line, RMG-I-H, was developed previously by transfection of the α1,2-fucosyltransferase gene, a key enzyme that catalyzes the synthesis of LeY, into ovarian carcinoma-derived RMG-I cells. Our studies have shown that LeY is involved in the changes in biological behavior of RMG-I-H cells. However, the mechanism is still largely unknown. In this study, we determined the structural relationship and co-localization between LeY and TβRI/TβRII, respectively, and the potential cellular signaling mechanism was also investigated. We found that both TβRI and TβRII contain the LeY structure, and the level of LeY in TβRI and TβRII in RMG-I-H cells was significantly increased. Overexpression of LeY up-regulates the phosphorylation of ERK, Akt and down-regulates the phosphorylation of Smad2/3. In addition, the phosphorylation intensity was attenuated significantly by LeY monoantibody. These findings suggest that LeY is involved in the changes in biological behavior through TGF‑β receptors via Smad, ERK/MAPK and PI3K/Akt signaling pathways. We suggest that LeY may be an important composition of growth factor receptors and could be an attractive candidate for cancer diagnosis and treatment.

Objective: To observe the gene expression of herpes simplex virus type 1 thymidine kinase (HSVl-tk) in rat malignant ovarian tumor tissues and the therapeutic effect of ganciclovior (GCV) after intra-arterial infusion of HSVl-tk gene therapy mediated by GE7-delivery system., Methods: A GE7-polylysine/pCMV-HSV1-tk/polylysine-HA20 4-element complex was constructed. Eighteen rats with DMBA-induced ovarian tumor were divided into 3 groups as Atk, ANS and Vtk groups. The 4-element complex GE7-polylysine/pCMV-HSV1-tk/polylysine-HA20 was injected via the ovarian artery into the rats of Atk group, saline buffer was injected in the ANS groups, and the 4-element complex was injected via the tail vein into the rats of Vtk group. All rats received intraperitoneal injection of GCV in a dose of 50 mg/kg daily for 10 days. The rats were sacrificed 3 days after the final dose of GCV, and the tumor weight was measured and tumor growth inhibition rate was calculated. Flow cytometry was used to assess the cell cycle and apoptosis., Results: The tumor weight in the rats of Atk group was (4.77 ± 2.31) g, significantly lower than that of ANS group [(14.66 ± 6.26) g, P < 0.01] and Vtk group [(17.53 ± 7.19) g, P < 0.01]. The tumor growth inhibition rate of the Atk group was 67.5%, while that of Vtk group was -19.6%. The flow cytometry showed that S-phase tumor cells in the Atk group were (54.32 ± 9.65)%, significantly higher than that in the ANS (27.43 ± 9.22)% and (30.16 ± 11.57)% in the Vtk group (both P < 0.01). The tumor cell apoptosis rate in the Atk group was (39.15 ± 12.16)%, significantly higher than that in the ANS group [(11.86 ± 5.28)%, P < 0.01] and Vtk group [(14.32 ± 6.43)%, P < 0.01]., Conclusion: HSV1-tk/GCV gene therapy system mediated by GE7 non-viral delivery system via ovarian arterial infusion effectively causes cell cycle arrest at S phase and enhances cell apoptosis, therefore, exerts an inhibitory effect on tumor growth.

Objective: To assess the clinical outcomes of fertility-sparing treatments in young patients with epithelial ovarian carcinoma (EOC)., Methods: A retrospective study of young EOC inpatients (≤40 years old) was performed during January 1994 and December 2010 in eight institutions., Results: Data were analyzed from 94 patients treated with fertility-sparing surgery with a median follow-up time of 58.7 months. As histologic grade increased, overall survival (OS) and disease-free survival (DFS) of patients receiving fertility-sparing surgery declined. Neither staging surgery nor laparoscopy of early stage EOC with conservative surgery had a significant effect on OS or DFS. Normal menstruation recommenced after chemotherapy in 89% of the fertility-sparing group. Seventeen pregnancies among twelve patients were achieved by the end of the follow-ups., Conclusions: Fertility-sparing treatment for patients with EOC Stage I Grade 1 could be cautiously considered for young patients. The surgical procedure and surgical route might not significantly influence the prognosis. Standard chemotherapy is not likely to have an evident impact on ovarian function or fertility in young patients.

Objective: To observe the gene and protein expression of herpes simplex virus type I-thymidine kinase (HSV(1)-tk) in the ovarian tumor tissues and other organs after arterial infusion of HSV(1)-tk gene mediated by GE7 delivery system., Methods: GE7-polylysine/pCMV-HSV(1)-tk/polylysine-HA20 complexes were constructed. Nine rats with induced ovarian tumor were divided into 3 groups, injecting the 4-element complexes or saline buffer through the ovarian artery and complexes through the tail vein, respectively. The ovarian tumors, hearts, livers, spleens, lungs and kidneys were obtained at 72 hours after injection. RT-PCR and Western Blot were preceeded to determine the expression of HSV(1)-tk gene and protein in the tumor tissues and other organs., Results: In the group of arterial injection with 4-element complexes, the HSV(1)-tk gene and protein were expressed strongly in the tumor tissues, while little or none was detected in other organs. In the group of arterial injection with saline buffer, no HSV(1)-tk gene and protein was detected in both tumor tissues and other organs. In the group of tail vein injection, none was detected in tumor tissues and only little was found in the livers, spleens, lungs and kidneys., Conclusion: High target and gene transfer rates can be obtained when HSV(1)-tk gene is transferred via the artery route mediated by GE7 delivery system. HSV(1)-tk protein can be expressed after the gene transfer. The results may provide a new strategy for target killing of HSV(1)-tk/GCV system in ovarian tumors.

Chemotherapy is an important treatment for ovarian cancer. However, conventional chemotherapy has inevitable drawbacks due to side effects from nonspecific biodistribution of the chemotherapeutic drugs. To solve such problem, targeted delivery approaches were developed. The targeted delivery approaches combine drug carriers with the targeting system and can preferentially bring drugs to the targeted sites. Follicle-stimulating hormone receptor (FSHR) is an ovarian cancer-specific receptor. By using a peptide derived from FSH (amino acids 33-53 of the FSH beta chain, named as FSH33), we developed a conjugated nanoparticle, FSH33-NP, to target FSHR in ovarian cancer. FSH33-NP was tested for recognition specificity and uptake efficiency on FSHR-expressing cells. Then, the antitumor efficiency of paclitaxel (PTX)-loaded FSH33-NP (FSH33-NP-PTX) was determined. FSH33-NP-PTX displayed stronger antiproliferation and antitumor effects compared with free PTX or naked PTX-loaded nanoparticles (NP-PTX) both in vitro and in vivo. In summary, this novel FSH33-NP delivery system showed very high selectivity and efficacy for FSHR-expressing tumor tissues. Therefore, it has good potential to become a new therapeutic approach for patients with ovarian cancer.

Gene-directed enzyme prodrug therapy (GDEPT) is a strategy developed to selectively target cancer cells. However, the clinical benefit is limited due to its poor gene transfer efficiency. To overcome this obstacle, we took advantage of piggyBac (PB) transposon, a natural non-viral gene vector that can induce stable chromosomal integration and persistent gene expression in vertebrate cells, including human cells. To determine whether the vector can also mediate stable gene expression in ovarian cancer cells, we constructed a PB transposon system that simultaneously expresses the Herpes simplex virus thymidine kinase (HSV-tk) gene and the monomeric red fluorescent protein (mRFP1) reporter gene. The recombinant plasmid, pPB/TK, was transfected into ovarian adenocarcinoma cells SKOV3 with FuGENE HD reagent, and the efficiency was given by the percentage of mRFP1-positive cells detected by flow cytometry and confocal microscopy. The specific expression of HSV-tk in transfected cells was confirmed by RT-PCR and western blotting. The sensitivity of transfected cells to pro-drug ganciclovir (GCV) was determined by methylthiazoletetrazolium (MTT) assay. A total of 56.4 +/- 8.4% cells transfected with pPB/TK were mRFP1 positive, compared to no measurable mRFP1 expression in pORF-HSVtk-transfected cells. The expression level of HSV-tk in pPB/TK-transfected cells was 10 times higher than in pORF-HSVtk-transfected cells. The results show that pPB/TK transfection increases the sensitivity of cells to GCV in a dose-dependent manner. Our data indicate that the PB transposon system could enhance the anti-tumor efficiency of GDEPT in ovarian cancer.

Objective: To prepare follicle stimulating hormone (FSH) polypeptide modified nanoparticles (NP) in order to achieve specific ovarian tumor targeting., Methods: Expression of FSH receptor protein in human liver cancer and ovarian cancer cell lines BEL-7402, SKOV-3 and Caov-3 was detected by immunocytochemistry. The polypeptide fragment of FSH beta 81-95 amino acids (FSHL81-95) was synthesized and covalently coupled to NP. The specific binding of FSHL81-95 and FSHL81-95-NP was examined by fluorescence microscopy and flow cytometry., Results: BEL-7402 and SKOV-3 cells were negative for FSH receptor staining, while Caov-3 cells were positive. The diameters of NP were about 100 nm, with a Zeta potential of -25 mV or so. Caov-3 cells showed a more specific interaction with FSHL81-95-NP than SKOV-3 cells (4.17 +/- 0.86 and 2.30 +/- 0.21; P < 0.05). The uptake of FSHL81-95-NP was more than NP in Caov-3 cells (4.17 +/- 0.86 and 0.41 +/- 0.32; P < 0.05). FSHL81-95-NP showed a selective targeting at Caov-3 cells compared with control NP., Conclusion: FSH polypeptide modified NP could selectively target ovarian cancer cells expressing FSH receptor, which might contribute to specific endocytosis mediated by FSH receptor.

A few highly aggressive and malignant tumor cells could acquire identities by turning on genes expressed by endothelial cells and recruit blood vessels to sustain tumor growth. Hypoxia was reported recently to play an essential role in these events. These 'plastic' tumor-cell phenotypes and the exact mechanism driving transendothelial differentiation by hypoxia-inducible factor (HIF)-1alpha is unclear. In this study, epithelial ovarian carcinoma cells were exposed to hypoxia and the tumor cells were transformed into endothelial cells-like (ECs-like). Typical endothelial features such as cell markers and uptaking of acetylated low density lipoprotein were identified constantly. Small interference RNA was used to block the expression of HIF-1alpha. Analysis revealed that hypoxia promotes transendothelial differentiation through stimulating HIF-1-dependent transcriptional expression of vascular endothelial growth factor (VEGF), VEGF receptor-2 (Flk-1) and P53, and through decreasing HIF-1-independent transcriptional expression of Cyclin D1. These results demonstrate that ECs-like derived from epithelial ovarian cancer cells are similar to endothelial progenitor cells rather than endothelial cells. HIF-1alpha is crucial but not unique in alternation of tumor cells towards ECs-like.

Objective: To develop a polymeric drug delivery system for paclitaxel and determine whether paclitaxel can inhibit the growth of ovarian carcinoma xenografts in F344 rats by intraperitoneal administration., Methods: Paclitaxel loading nanoparticles (PLA) were synthesized by ultrasonic emulsification; rat ovarian carcinoma cells were injected into the peritoneal cavity of F344 rats. The antitumor effect of paclitaxel nanoparticles in vivo has been evaluated by measuring tumor weight and ascite volume. At the end of the procedure the rats were killed, tumors were excised and processed for PCNA staining, tissue terminal deoxynucleotide transferase-mediated dUTP nick and labeling (TUNEL) assay. Paclitaxel concentration in plasma, pelvic lymph nodes, liver, heart were determined by high-performance liquid chromatography (HPLC)., Results: In the implanted carcinoma cells, paclitaxel nanoparticles significantly reduced tumor weight [(4.55 +/- 0.11) g vs (10.13 +/- 0.52) g]and ascites volume [(3.55 +/- 0.50) mL vs (30.45 +/- 1.55) mL], and induced apoptosis of tumor cells [(105 +/- 15) vs (55 +/- 10)]. The paclitaxel concentration of pelvic lymph nodes in PLA treated animals was significantly higher than that of free PTX treated animals 48 h after intraperitoneal administration [(0.75 +/- 0.05) microg/g vs (0.188 +/- 0.045) microg/g]., Conclusion: The intraperitoneal administration of paclitaxel nanoparticles can significantly inhibit the progression of ovarian carcinoma in peritoneal cavity of female F344 rats. The paclitaxel nanoparticle is safe and lymphatic targeting.

Objective: To study the anti-tumor immunotherapeutic effect induced by the suicidalcancer vaccine FC/TK, and to evaluate the safety of this vaccine., Methods: The suicidal cancer vaccine, named FC/TK, was prepared by fusion of suicide gene (HSVI,-TK gene) -modified ovarian carcinoma NuTu-19 cells with rat bone marrow-derived dendritic cells (DCs). The morphology of FC/TK was evaluated by scanning electron microscopy. The stimulatory effect of FC/TK on T cells was determined by T cell proliferation assay. In immunotherapeutic studies in vivo, Fischer344 rats were injected subcutaneously with NuTu-19 cells, followed by treatment of FC/TK on days 7 and 14, compared to controls treated with irradiated FC/TK, FC or PBS, respectively. Tumor incidence and volume were measured in 90 days after challenge. To determine the killing effect of FC/TK in vivo, TUNEL assays were applied to detect apoptotic cell death in spleen of vaccinated rats with prodrug ganciclovir administration., Results: FC/TK cells were of irregular shape with surface membrane processes. Compared to the control groups, FC/TK significantly promoted T cell proliferation (P <0.01). The rats vaccinated with FC/TK and FC significantly inhibited the tumor growth compared to rats vaccinated with irradiated FC/TK (P <0.05) or with PBS ( P <0.01). The immunotherapeutic effect induced by FC/TK was similar to that using FC. Fluorescence microscopy showed that fluorescein-stained FC/TK cells migrated into spleen also showed to be TUNEL-positive, suggesting that the FC/TK cells were killed by ganciclovir in vivo., Conclusion: Our data indicate that suicidal cancer vaccine is an effective and safe therapy for ovarian carcinoma and may serve as a broadly applicable approach for other cancer vaccines in the future.

Fusing dendritic cells (DCs) with tumor cells is a powerful vaccine to increase tumor immunogenicity. To develop more effective and safer therapeutic vaccine, we fused rat bone marrow-derived DCs with ovarian tumor cell line NuTu-19 modified by suicide gene (HSV1-TK gene) to obtain live vaccine against ovarian cancer. Our data showed that immunization of rats with such live vaccine solicited stronger ovarian tumor-specific cytotoxic T lymphocyte responses and induced immunopreventive and immunotherapeutic effects against parental tumor cells in vivo. Live vaccine could be induced to death after ganciclovir administration in vitro and in vivo. Our researches suggest that live vaccine modified with suicide gene might be effective and controllable in the therapy of ovarian cancer.

Both the morbidity and mortality of ovarian cancer, among malignant tumors ot temale genital organs, are quite high. The traditional therapeutic methods on ovarian cancer are surgical operation, chemotherapy, radiotherapy and combination of these methods mentioned above. In recent years, some components of traditional Chinese medicine, such as genistein, semen Coicis, phytosterols, curcumin, quercetin, ginsenoside, etc. have been found to exert anticancer actions of inhibiting proliferation and inducing apoptosis of cancer cells, increasing the sensitivity of patients to chemotherapeutic agents in viva and/or in vitro, the mechanisms involve such aspects as inhibiting activity of key enzymes in cell metabolism, affecting gene expression, antioxidation, and inhibiting tumor angiogenesis, etc. As an adjuvant therapeutic means, the bioactive components of traditional Chinese medicine have broad future of clinical application.

Transfer of the herpes simplex virus type I-thymidine kinase gene, followed by the administration of ganciclovir (HSV1-tk/GCV) into ovarian cancer-derived cell line either in vitro or transplanted into nude mice has been shown to provide a potential strategy for the gene therapy of ovarian cancer. We investigated the antitumor effects of HSV1-tk/GCV strategy with a chemically induced rat ovarian cancer model and a tumor-selective gene delivery by a novel nonviral gene delivery system (GE7) through the ovarian artery and tail vein. We demonstrated the expression of a reporter gene, beta-gal gene, as well as HSV1-tk gene in tumors and other organs, evaluated the overall antitumor effects after the GCV treatment and analyzed the tumor cell cycle phase distribution. Via the ovarian artery route, the expressions of beta-gal and HSV1-tk in tumors were significantly stronger than those expressed in such organs as the hearts, livers, spleens, lungs and kidneys. However, no beta-gal and HSV1-tk were detected in the tumor tissues when administrated via the tail vein, and little was found in other organs. The cell cycle analysis showed that the total S-phase of tumor cells in the test intra-arterial treatment group was considerably higher than that of the controls. The weight of the tumor tissues in the group treated by the intra-arterial route (4.06+/-2.12 g) was much less than the group treated intravenously (18.25+/-8.34 g) (P<.01). These findings indicated that the administration of GE7/HSV1-tk complex via the ovarian artery route could be a promising avenue of future human ovarian cancer treatment.

Background & Objective: Live tumor vaccines could achieve better immunotherapeutic effects than irradiated tumor vaccines; however, the tumorigenicity is the crucial drawback incurred by the current procedures for vaccine preparation. This study was to explore the application of herpes simplex virus type 1 thymidine kinase/ganciclovir (HSV1-TK/GCV) system as "in vivo death switch" to control the survival status of cancer vaccines under certain circumstances., Methods: Suicide gene HSV(1)-TK was transferred into ovarian cancer cell line NuTu-19 with a retrovirus vector, followed by G418 selection to obtain HSV(1)-TK-transfected NuTu-19 cells (NuTu-19/TK). Dendritic cells (DCs) derived from Fischer344 rat bone marrow were fused with NuTu-19/TK cells to construct live tumor vaccine FC/TK. The expression of HSV(1)-TK in FC/TK cells was determined by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. The cytotoxic efficacy of GCV on FC/TK cells was evaluated by XTT assay. The apoptosis of FC/TK cells was analyzed by flow cytometry and Hoechst33258 staining after GCV treatment. Rats were vaccinated with FC/TK cells and divided into 2 groups: GCV group (5 rats) were intraperitoneally treated with GCV for 7 days, control group (5 rats) were treated with normal saline. The tumorigenesis and tumor metastasis in the rats were observed 90 days after inoculation., Results: HSV1-TK was specifically expressed in FC/TK cells. GCV showed in vitro cytotoxicity to FC/TK cells in a dose-dependent manner, and 86.25% of the FC/TK cells were killed by GCV at a concentration of 100 microg/ml; the apoptosis rate of FC/TK cells was over 80%, and apoptotic morphology, including cell shrinkage, chromatin condensation, was observed. In the rat models, the tumor was developed at the injection site in 3 rats of control group, while no tumor was observed in the rats of GCV group., Conclusion: HSV(1)-TK/GCV could act as the "death switch" of tumor vaccines by triggering apoptosis of tumor vaccines both in vitro and in vivo.

Objective: To investigate the efficiency of antitumor immune responses induced by a controlled live dendritic cell (DC) vaccine., Methods: DC precursors were isolated from Fischer 344 rat bone marrow and cultured with granulocyte-macrophage colony-stimulating factor and interleukin-4. The rat ovarian tumor cell line NuTu-19 was genetically modified by retroviral-mediated suicide gene (HSV(1)-TK), and the positive clones were selected using G418. Live DC vaccine was then fused with DC and NuTu-19/TK cell by polyethylene glycol. The characteristics of live DC vaccine were assayed with flow cytometry and confocal laser scanning microscopy. The specific expression of HSV(1)-TK gene in live DC vaccine was evaluated by RT-PCR and western blot. The sensitivity of live DC vaccine to ganciclovir (GCV) was evaluated by methylthiazoletetrazolium assay. In vivo, rats vaccinated twice with live DC vaccine were compared to those vaccinated with killed DC vaccine, unfused DC and NuTu-19/TK cell or phosphate buffered saline. Seven days following the last immunization, the rats were sacrificed to test the specific cytotoxic T lymphocyte (CTL) activity by lactate dehydrogenase release assay, or challenged with NuTu-19 and tumor incidence was observed., Results: The fusion efficiency was approximately (23 +/- 14). Live DC vaccine displayed an up-regulated expression of major histocompatibility complex (MHC)-IIOX6 (87.6 +/- 3.4)%, costimulatory molecule B(1 - 2) (71.1 +/- 9.3)%, integrin OX 62 (68.0 +/- 7.4)%, and adhesion ICAM-1 (77.1 +/- 2.0)%, and specifically expressed HSV(1)-TK gene. Our data showed that spleen T lymphocytes from rats vaccinated with live vaccine displayed enhanced CTL activity (61.8 +/- 8.3)% contrast to that of rats vaccinated with killed vaccines (26.0 +/- 3.8)% (P < 0.05). Compared to the control groups, rats immunized with live DC vaccine demonstrated a significant delay in tumor development [(39 +/- 8) d vs (70 +/- 16) d], reduced tumor incidence (100% vs 80%) and decreased tumor volume [(806 +/- 553) mm(3) vs (89 +/- 53) mm(3), P < 0.05]. Seventy-three percent of TK-transduced live DC vaccine was killed after 7 of GCV treatment by a functional assay., Conclusion: The results demonstrate that DC live vaccine modified by HSV(1)-TK gene can induce efficient protective immunity and be killed by GCV.

Objective: To investigate the efficiency and targeting of the GE7 system mediated gene transfer in the chemically induced ovarian tumor by intraarterial route., Methods: Animal models were chemically induced by 7,12-dimethylbenz[a]anthracene (DMBA). GE7-polylysine/beta-galactosidase (beta-gal)/polylysine-HA20 complexes were constructed. Fifteen rats with induced ovarian tumor were divided into three groups, the complexes were injected through ovarian artery and tail vein, respectively. The tumor, heart, liver, spleen, lung and kidney were obtained at 72 h. X-gal staining was used to check expression of beta-gal., Results: beta-gal was expressed strongly and well-distributed in tumor in the first group, and stained blue in the liver, spleen, lung and kidney, but much weaker than that of tumor. In the second group, beta-gal was expressed in the tumor, and weakly expressed in the liver, none was detected in the other organs. In the third group beta-gal was detected in the lung slightly, none was detected in the tumor and other organs., Conclusions: When GE7 complexes were administrated through ovarian artery, the introduced gene expressed preferentially in ovary. This result was the basis of intraarterial administration of therapeutic gene to treat ovarian cancer.

Objective: To investigate gene transfer efficiency of a novel target non-viral vector GE7 and effects of herpes simplex virus thymidine kinase (HSV(1)-tk)/ganciclovir (GCV) mediated by it in vitro., Methods: The epidermal growth factor receptor (EGF-R) target gene delivery system GE7 was constructed. Human ovarian cancer cell line CAOV3 was transfected in vitro with beta-galactosidase (beta-gal) as reporter gene and HSV(1)-tk gene as therapeutic gene using this gene delivery system. By means of the assay of X-gal staining, Northern blotting, cell growth-inhibiting curve and so on, the transferring efficiency of exogenous genes and killing effects are observed., Results: It showed that gene transfer efficiency is over 80%. When 10 mg/L GCV was put into ovarian cells transfected with HSV(1)-tk gene, 95% of cells were killed, and the apoptosis ratio reached up to 30., Conclusions: The GE7 gene delivery system is an effective and safe delivery system. GE7/HSV(1)-tk/GCV therapeutic gene system is appraising for ovarian cancer.

Purpose: While numerous epidemiological studies have indicated that omega-3 polyunsaturated fatty acids have anticancer properties in various cancers, the effects and mechanisms of eicosapentaenoic acid (EPA) in ovarian cancer cell growth are poorly understood. Materials and Methods: ES2 ovarian clear cell carcinoma cells and SKOV3 adenocarcinoma cells were treated with palmitic acid or EPA, followed by flow cytometry and cell counting to measure apoptosis and proliferation, respectively. A modified protein lipid overlay assay was used to further verify whether EPA was a ligand of G protein-coupled receptor 30 (GPR30) in ES2 cells. The levels of apoptosis-related genes, phosphorylated AKT, and phosphorylated ERK1/2 were detected to explore the underlying mechanism. Finally, inhibitory effect of EPA on tumor growth via GPR30 was determined in vitro and in vivo. Results: EPA suppressed ES2 ovarian clear cell carcinoma cells growth via GPR30, a novel EPA receptor, by inducing apoptosis. As a ligand of GPR30, EPA activated the GPR30-cAMP-protein kinase A signaling pathway. When GPR30 was suppressed by siRNA or its inhibitor G15, the antiproliferative action of EPA was impaired. Furthermore, EPA inhibited tumor growth by blocking the activation of AKT and ERK. In the mouse xenograft model, EPA decreased tumor volume and weight through GPR30 by blocking tumor cell proliferation. Conclusion: These results confirm that EPA is a tumor suppressor in human ovarian clear cell carcinoma cells and functions through a novel fatty acid receptor, GPR30, indicating a mechanistic linkage between omega-3 fatty acids and cancers. [ABSTRACT FROM AUTHOR]