Human Ovarian Cancer SKOV3 Cells Research Articles

Oxytocin inhibits ovarian cancer metastasis by repressing the expression of MMP-2 and VEGF.

Breastfeeding is associated with a decreased risk of ovarian cancer. However, the mechanism underlying this apparent clinical benefit is unknown. Oxytocin (OXT), a hypothalamic nonapetide, plays a crucial role in many reproductive and behavioural functions. In recent year, OXT acts as a growth regulator in many kind of tumor tissues, through the activation of a specific G-coupled transmembrane receptor, the oxytocin receptor (OXTR). OXT has been proved to inhibit the proliferation, migration and invasion of ovarian cancer SKOV3 cells in vitro. But, the underlying mechanisms remain unknown. Here, we found OXT inhibited proliferation, and critically migration and invasion of human ovarian cancer cells SKOV3 and A2780. Strikingly, OXT inhibited ovarian cancer metastasis by repressing the expressions of MMP-2 and VEGF. Moreover, OXT inhibited vascular endothelial cell tube formation by reducing the VEGF production from ovarian cancer cells. Our findings may provide a possible explanation for breastfeeding-associated protective effects and suggest new therapeutic opportunities for ovarian cancer.

The protective role of melatonin in cadmium-induced proliferation of ovarian cancer cells.

Cadmium (Cd), a ubiquitous environmental and occupational pollutant, acts as a metalloestrogen to induce cell proliferation. It is suggested that Cd may also contribute to the development of estrogen-related cancers like ovarian cancer which is the most lethal cancer in women. Furthermore, it was shown that melatonin has antiproliferative effect on estradiol (E2)-induced proliferation. The aim of the present study was to evaluate whether melatonin inhibits Cd-induced proliferation in ovarian cancer cell lines and also whether Cd and melatonin can modulate estrogen receptor α (ERα) expression. OVCAR3 and SKOV3 human ovarian cancer cell lines were treated with CdCl2 (1-100 nM) and melatonin (1 μM) for 48 h. Cell proliferation evaluation was carried out by bromodeoxyuridine (BrdU) incorporation assay. ERα expression was detected by western blotting method 24 h after cell treatment. The results were demonstrated that Cd increased proliferation of ovarian cancer cell lines in a dose dependent manner. Melatonin inhibited Cd-induced proliferation of OVCAR3 and SKOV3 cell lines. Moreover, CdCl2 significantly increased ERα expression in both OVCAR3 and SKOV3 cell lines compared to control. Melatonin significantly inhibited Cd inducing effect on ERα expression of OVCAR3 and SKOV3 cell. In conclusion, due to the proliferative effect on ovarian cancer cell lines, Cd could play an important role in the etiology of ovarian cancer by inducing cells ERα expression. Furthermore, melatonin has the protective role on Cd-induced cell proliferation by inhibition of ERα expression.

Bcl-2 overexpression reduces cisplatin cytotoxicity by decreasing ER-mitochondrial Ca2+ signaling in SKOV3 cells.

Recent studies have revealed that a small amount of cisplatin can penetrate into the nucleus and induce intranuclear DNA damage. Specifically, most cisplatin accumulates in and stresses different organelles, including mitochondria, endoplasmic reticulum (ER) and the cytosol, where apoptosis signaling is activated and magnified. Bcl-2, which is mainly localized to ER and mitochondria, is identified as a key regulator of survival and apoptosis. Bcl-2 is reported to block cisplatin-induced apoptosis via regulating Ca2+ signaling in a variety of cancer cell lines. However, its target molecule and the mechanism responsible for its inhibitory effect in ovarian cancer are undefined. The present study revealed that Bcl-2 overexpression reduced cisplatin-induced growth inhibition and apoptosis in SKOV3 human ovarian cancer cells. Furthermore, Bcl-2 inhibited cisplatin-induced Ca2+ release from the ER to the cytoplasm and mitochondria, which reduced cisplatin-induced ER stress-mediated apoptosis through the mitochondrial apoptotic pathway. The overexpression of Bcl-2 inhibited the cisplatin-induced increase in the number of ER-mitochondrial contact sites in SKOV3 human ovarian cancer cells. In addition, the present study provided evidence that Bcl-2 reduced the anticancer activity of cisplatin towards ovarian cancer cells in vivo. These results revealed that Bcl-2 attenuates cisplatin cytotoxicity via downregulating ER-mitochondrial Ca2+ signaling transduction. Thus, Bcl-2 which may be a potential therapeutic target for ovarian cancer.

Kaempferol Sensitizes Human Ovarian Cancer Cells-OVCAR-3 and SKOV-3 to Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand (TRAIL)-Induced Apoptosis via JNK/ERK-CHOP Pathway and Up-Regulation of Death Receptors 4 and 5.

BackgroundOvarian cancer is the most common gynecological malignancies in women, with high mortality rates worldwide. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a member of the tumor necrosis factor (TNF) superfamily which preferentially induces apoptosis of cancer cells. However, acquired resistance to TRAIL hampers its therapeutic application. Identification of compounds that sensitize cancer cells to TRAIL is vital in combating resistance to TRAIL. The effect of kaempferol, a flavonoid enhancing TRAIL-induced apoptosis in ovarian cancer cells, was investigated in this study.Material/MethodsThe cytotoxic effects of TRAIL (25 ng/mL) and kaempferol (20–100 μM) on human ovarian cancer cells OVCAR-3 and SKOV-3 were assessed. Effect of kaempferol on the expression patterns of cell survival proteins (Bcl-xL, Bcl-2, survivin, XIAP, c-FLIP) and apoptotic proteins (caspase-3, caspase-8, caspase-9, Bax) were studied. The influence of kaempferol on expression of DR4 and DR5 death receptors on the cell surface and protein and mRNA levels was also analyzed. Apoptosis following silencing of DR5 and CHOP by small interfering RNA (siRNA), and activation of MAP kinases were analyzed as well.ResultsKaempferol enhanced apoptosis and drastically up-regulated DR4, DR5, CHOP, JNK, ERK1/2, p38 and apoptotic protein expression with decline in the expression of anti-apoptotic proteins. Further transfection with siRNA specific to CHOP and DR5 indicated the involvement of CHOP in DR5 up-regulation and also the contribution of DR5 in kaempferol-enhanced TRAIL-induced apoptosis.ConclusionsKaempferol sensitized ovarian cancer cells to TRAIL-induced apoptosis via up-regulation of DR4 and DR5 through ERK/JNK/CHOP pathways.

New compounds from the roots of Coriaria nepalensis

One new sesquiterpene lactone, corialactone E (1), one new neolignan, coriarianeolignan A (2), together with three known apocarotenoids (3-5) and one known neolignan (6) have been isolated from a CHCl3 extract of the roots of Coriaria nepalensis. The structures including absolute configurations of 1-6 were elucidated through extensive NMR, HR-ESIMS, and CD data analysis. Structurally, compound 1 possessed novel variations in the structure, including the newly formed ether ring of C-3/O/C-9 and the lactone ring connecting C-13 and C-5. Compound 5 showed cytotoxic activity against SKOV3 (human ovarian cancer) cells with IC50 values of 4.67μmol/L. In vivo system, compound 3 showed anti-convulsant activity by 34% at the dose of 5mg/kg.

Three Combined Treatments, a Novel HDAC Inhibitor OBP-801/YM753, 5-Fluorouracil, and Paclitaxel, Induce G₂ Phase Arrest Through the p38 Pathway in Human Ovarian Cancer Cells.

Ovarian cancer is the most lethal disease among gynecological malignancies. More effective therapy is required to counter high recurrence rates and chemotherapy resistance. We investigated the efficacy and molecular mechanisms of three combined treatments (TCTs)—a novel histone deacetylase (HDAC) inhibitor OBP-801/YM753, 5-fluorouracil (5-FU), and paclitaxel (PTX)—in human ovarian cancer SKOV-3 and OVCAR-3 cells. The inhibition of cell growth was stronger with TCTs than with each single agent and with two combined treatments. The TCTs significantly induce G2 phase arrest in both cell lines. We then analyzed the molecular mechanisms and found that the TCTs increased the phosphorylation of p38 (Thr180/Tyr182), decreased the expression of CDC25C, and increased the phosphorylation of CDC2 (Tyr15), an inactive form of CDC2. To examine the responsibilities of the p38 pathway for G2 phase arrest induced by the TCTs, we employed the p38 inhibitor SB203580. SB203580 inhibited G2 phase arrest, suppression of CDC25C, and phosphorylation of CDC2 (Tyr15) induced by the TCTs. These results suggest that the TCTs can induce G2 phase arrest through activation of the p38 signaling pathway. We therefore believe that this combination is promising as a novel therapeutic strategy against ovarian cancer.

Charactor of JNK and P53 in Taxol-Induced Apoptotic Signaling in SKOV3 Human Ovarian Cancer Cell Proliferation

C-Jun N-terminal kinase (JNK) represents a group of mitogen-activated protein kinases (MAPKs) involved in many cellular responses including apoptosis. We have previously reported that taxol, a microtubule-interfering therapeutic agent widely used against various cancers, induces caspase-independent but apoptotic inducing factor (AIF)-dependent apoptosis in human ovarian cancer cell line SKOV3 cells. In the present study, we add to this report a detailed analysis of the taxol-induced apoptotic mechanisms in SKOV3 cells, particularly focusing on JNK and p53. In line with the previous report, we found that taxol induced caspase-independent apoptosis with concurrent activation of JNK, phosphorylation of Bcl-2, Bax translocation to the mitochondria, and AIF release from the mitochondria. Restoration of p53 functionality into SKOV3 cells, which are p53-null cells, by transfection of wild-type p53, however, induced caspase-dependent apoptosis in response to taxol treatment as evidenced by increasing PARP cleavage and the emergence of processed, active caspase-3 and -7. More to the point, treatment with a JNK inhibitor SP600125 blocked taxol-induced apoptotic cell death in both parental SKOV3 cells (p53-deficient) and p53-transfectant cells. Collectively, the aforementioned findings lend support to the view that taxol-induced apoptotic cell death in SKOV3 cells is executed by different mechanisms depending on the presence of p53 but commonly mediated by ASK1-JNK and/or -p38 axes.

A new natural product from the leaves of Olinia usambarensis and evaluation of its constituents for cytotoxicity against human ovarian cancer cells

Natural products play a significant role in cancer therapy and prevention; with considerable number of anticancer in use are either natural products or their derivatives. In this study, chromatographic separation of CH2Cl2/CH3OH (1:1, v/v) extract of the leaves of Olinia usambarensis gave four compounds among which compound 1, caffeoyloxy-5,6-dihydro-4-methyl-(2H)-pyran-2-one is a new natural product. The structures of the identified compounds were established using spectroscopic and mass spectrometric analyses. The crude extract and isolated compounds were evaluated against the human ovarian cancer cell lines, A2780 and SKOV3, and showed IC50 of 79–170 and 74–136μM, respectively. The crude extract and isolated compounds were also tested against normal cell, an immortalized ovarian surface epithelial (IOSE) cells, but did not show activity up to 100μM.

Design, synthesis and biological evaluation of novel C-29 carbamate celastrol derivatives as potent and selective cytotoxic compounds

Celastrol and its derivatives have been reported for their potent anticancer activity. Among other celastrol analogues, novel carbamate derivatives were designed and synthesised, and their biological activity on the viability of human cancer cell lines was evaluated. Additionally, a preliminary structure–activity relationship study was conducted. Derivative 18 showed the highest activity on cancer cell viability, combined with the best selectivity between malignant cells and non-malignant fibroblasts. Preliminary mechanistic studies of its anti-tumour action indicated that compound 18 has an antiproliferative effect on SKOV-3 human ovarian cancer cells (IC50 = 0.54 μM). The results also suggested that its potent anticancer activity is mediated by apoptosis, and that this process was mainly the result of the activation of the extrinsic apoptotic pathway. Moreover, our results demonstrated the potential of derivative 18 as a new agent for combinatorial drug therapy for ovarian cancer.

Ginsenoside Rb1 inhibits hypoxia-induced epithelial-mesenchymal transition in ovarian cancer cells by regulating microRNA-25.

Metastasis frequently occurs in advanced ovarian cancer, which not only leads to substantial mortality but also becomes a major challenge to effective treatment. Epithelial-mesenchymal transition (EMT) is a key mechanism facilitating cancer metastasis. Targeting the EMT process with more efficacious and less toxic agents to prevent metastasis is of significant therapeutic value for ovarian cancer treatment. The anti-EMT function and mechanism of ginsenoside Rb1, a monomer composition extracted from the traditional Chinese herb Panax ginseng or P. notoginseng, was investigated in the present study. Western blotting demonstrated that treatment with ginsenoside Rb1 antagonized hypoxia-induced E-cadherin downregulation and vimentin upregulation in SKOV3 and 3AO human ovarian cancer cells. Wound healing assays and in vitro migration assays indicated that ginsenoside Rb1 weakened hypoxia-enhanced cell migration ability. Furthermore, it was demonstrated that microRNA (miR)-25 is upregulated by hypoxia in ovarian cancer cells, which was attenuated by ginsenoside Rb1 treatment. Additionally, forced expression of miR-25 in ovarian cancer cells was identified to not only trigger EMT, but also block the suppressive effects of ginsenoside Rb1 on hypoxia-induced EMT by negatively targeting the E-cadherin transactivator, EP300. In conclusion, ginsenoside Rb1 may reverse hypoxia-induced EMT by abrogating the suppression of miR-25 on EP300 and E-cadherin, which suggests that ginsenoside Rb1 may be a potential therapeutic candidate for the treatment of ovarian cancer.

In Vivo Quantification of ERβ Expression by Pharmacokinetic Modeling: Studies with 18F-FHNP PET.

The estrogen receptor (ER) is a target for endocrine therapy in breast cancer patients. Individual quantification of ERα and ERβ expression, rather than total ER levels, might enable better prediction of the response to treatment. We recently developed the tracer 2-18F-fluoro-6-(6-hydroxynaphthalen-2-yl)pyridin-3-ol (18F-FHNP) for assessment of ERβ levels with PET. In the current study, we investigated several pharmacokinetic analysis methods to quantify changes in ERβ availability with 18F-FHNP PET. Methods: Male nude rats were subcutaneously inoculated in the shoulder with ERα/ERβ-expressing SKOV3 human ovarian cancer cells. Two weeks after tumor inoculation, a dynamic 18F-FHNP PET scan with arterial blood sampling was acquired from rats treated with vehicle or various concentrations of estradiol (nonspecific ER agonist) or genistein (ERβ-selective agonist). Different pharmacokinetic models were applied to quantify ERβ availability in the tumor. Results: Irreversible-uptake compartmental models fitted the kinetics of 18F-FHNP uptake better than reversible models. The irreversible 3-tissue-compartment model, which included both the parent and the metabolite input function, gave results comparable to those of the irreversible 2-tissue-compartment model with only a parent input function, indicating that radioactive metabolites contributed little to the tumor uptake. Patlak graphical analysis gave metabolic rates (Ki, the irreversible uptake rate constant) comparable to compartment modeling. The Ki values correlated well with ERβ expression but not with ERα, confirming that Ki is a suitable parameter to quantify ERβ expression. SUVs at 60 min after tracer injection also correlated (r2 = 0.47; P = 0.04) with ERβ expression. A reduction in 18F-FHNP tumor uptake and Ki values was observed in the presence of estradiol or genistein. Conclusion:18F-FHNP PET enables assessment of ERβ availability in tumor-bearing rats. The most suitable parameter to quantify ERβ expression is the Ki However, a simplified static imaging protocol for determining the SUVs can be applied to assess ERβ levels.

Endoplasmic reticulum stress regulates proliferation, migration and invasion of human ovarian cancer SKOV3 cells through PI3K/AKT/mTOR signaling pathway.

The study is to explore the role of tunicamycin-induced endoplasmic reticulum stress (ERS) in human ovarian cancer (OC) SKOV3 cells proliferation, migration and invasion by modulating the activity of PI3K/AKT/mTOR pathway. The collected human OC SKOV3 cells were randomly separated into three groups: The control group, the Tun group (treated with tunicamycin to induce ERS) and the CHOP-si group (transfected with CHOP-siRNA before tunicamycin treatment). CCK-8 method was applied for testing cell proliferation, while flow cytometry was conducted to detect cell apoptosis. Scratch test and Transwell test were used to determine the level of cell migration and invasion, respectively. Western blotting was performed to determine the related proteins expressions in ERS and PI3K/AKT/mTOR pathway. The cell survival rate in the Tun group was enhanced than that in the CHOP-si group, both of which were declined with the passage of time. The cell apoptosis rate in the Tun group was increased compared to the CHOP-si group, both of which were significantly elevated. The horizontal migration distance and the number of invasive cells in the Tun and CHOP-si groups were inhibited; however, the horizontal migration distance and the number of invasive cells in the CHOP-si group were enhanced than that in the Tun group. In comparison with the control group, the expressions of CHOP and TRB3 were increased in the Tun group but decreased in the CHOP-si group. The PI3K, p-AKT and p-mTOR expressions were remarkably declined in the Tun group than those in the control group (P< 0.05). The study provides strong evidence that tunicamycin-induced ERS induces the apoptosis of human OC SKOV3 cells through inhibiting PI3K/AKT/mTOR signaling pathway.

Abstract 3197: Splicing factors and the role of Navitoclax in drug-resistant ovarian cancer

Abstract Alternative RNA splicing allows processing of a pre-mRNA into various mature mRNAs. In this way multiple protein products can be derived from a single gene. In cancer it is known that specific splice variants may facilitate malignant transformation and therapeutic resistance. Our current studies focus on the problem of drug resistance in ovarian cancer and we have approached this in a variety of ways. Following sequencing analysis of a panel of ovarian cancer cell lines we identified the RNA splicing factors TCERG and SRSF2 as being reduced in drug resistant ovarian cancer cell lines, compared with their drug sensitive counterpart. TCERG is important in regulating the splicing of variant forms of the BClx gene: BClxL (long form) and BClxs (short form). There are clear implications for drug resistance whereby low TCERG results in reduced BClx splicing to yield the pro-apoptotic BClxs form. In the SKOV-3 human ovarian cancer cell line panel both paclitaxel resistant SKOV-3TaxR and SKOV-3CR carboplatin resistant cells showed reduced levels of TCERG mRNA using qPCR analysis. In addition, qPCR analysis for BClxl and BClxs levels indicated increased ratio of long:short form with drug resistance: SKOV-3 parent line ratio 1.0; SKOV-3TaxR 1.8; SKOV-3CR 1.65. Western immunoblotting showed relatively decreased levels of Bax protein in drug resistant versus drug sensitive cell line in line with a reduced apoptotic reduced. We then explored the use of Navitoclax (ABT0263), the small-molecule Bcl-2 family protein inhibitor for Bcl-xL, Bcl-2 and Bcl-w in our cell line panel. Navitoclax in combination with paclitaxel for 48h gave rise to significantly increased apoptotic response in drug-resistant versus drug sensitive ovarian cancer cell line counterparts, using the Annexin V assay with PI, indicative of re-sensitisation to paclitaxel. Synergistic effects were also seen for the parental cell line but the effects were more marked for the resistant cell lines. Our future work will also involve the use of clinical biopsies of ovarian cancer cases. Citation Format: Helen M. Coley, Laura Lattanzio, Ornella Garrone, Marco Merlano, Daniela Vivenza, Cristiana Lo Nigro, Nelofer Syed, Alistair Thompson, Bhavya Rao, Tim Crook. Splicing factors and the role of Navitoclax in drug-resistant ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3197. doi:10.1158/1538-7445.AM2017-3197

Free fatty acid receptor (FFAR) agonists inhibit proliferation of human ovarian cancer cells

Many cellular actions of omega-3 fatty acids are mediated by two G protein-coupled receptors, FFA1 and FFA4, free fatty acid receptor (FFAR) family members that are activated by these dietary constituents. FFAR agonists inhibit proliferation of human prostate and breast cancer cells. Since omega-3 fatty acids can inhibit ovarian cancer cell growth, the current study tested the potential role of FFARs in the response. OVCAR3 and SKOV3 human ovarian cancer cell lines express mRNA for FFA1; FFA4 mRNA was detected at low levels in SKOV3 but not OVCAR3. Lysophosphatidic acid (LPA) and epidermal growth factor (EGF) stimulated proliferation of both cell lines; these responses were inhibited by eicosopentaneoic acid (EPA) and by GW9508, a synthetic FFAR agonist. The LPA antagonist Ki16425 also inhibited LPA- and EGF-induced proliferation; FFAR agonists had no further effect when added with Ki16425. The results suggest that FFARs are potential targets for ovarian cancer therapy.

In vivo inhibitory effect of lentivirus-mediated RNA interference targeting RhoC on growth of SKOV3 cells

To investigate the inhibitory effect of lentivirus-mendiated RNA interference targeting RhoC on the growth of SKOV3 cells(ovarian cancer SKOV3 cells) in vivo, the vector expressing RNA interference targeting RhoC gene(LV-shRhoC) was constructed and the virus particles were packaged. The infection effiency of SKOV3 cells by the virus was estimated by green fluorescent protein expression on a fluorescence microscope and the expression of RhoC gene in the SKOV3 cells was detected by reverse transcription real time polymerase chain reaction(PCR). Furthermore, human ovarian cancer SKOV3 cells, empty vector infected SKOV3 cells and interfered-vector infected SKOV3 cells were respectively seeded into nude mice, and the shape, mass, volume and histophathological changes of the transplanted tumors were observed 20 d later the mice were sacrified. The results show that lentivirus packaging particles can effectively infect SKOV3 cells and the lentivirus-mediated RNA interference can significantly inhibit the expression of RhoC gene in SKOV3 cells, the mass and volume of the transplanted tumor in the mice of the specific-control group(Lv-shRhoC) are all lower than the corresponding ones in the mice of negative- and blank-control groups(Lv-NC and SKOV3). Moreover, the histopathlosical secion investigation shows that the nuclear Karyotype and histopathologic mitotic figure of SKOV3 cells in mice of the specific-control group are clearly lower than those in the mice of the negative-control group.Thus it is concluded that silencing RhoC gene by means of lentivirus-mediated RNA interference targeting RhoC can obviously inhibit the growth of ovarian cancer cells(SKOV3) in vivo, which is a new strategy for the gene therapy of ovarian cancers.

Ginsenoside 20(S)-Rg3 suppresses ovarian cancer migration via hypoxia-inducible factor 1 alpha and nuclear factor-kappa B signals.

Hypoxia-inducible factor 1 is believed to play a prominent role in the survival and developing progress of cancers. As a result, inhibiting α subunit of hypoxia-inducible factor 1 represents an attractive strategy against tumor. Although hypoxia-inducible factor 1α is a hypoxia-regulated subunit, increasing evidence indicates that hypoxia-inducible factor 1α could stable expression under normoxic conditions, regulated by non-hypoxia-mediated mechanisms. However, there are few strategies to target hypoxia-inducible factor 1α under normoxic conditions. Here, we report that ginsenoside 20(S)-Rg3, one of the main active ingredients in red ginseng, restrains hypoxia-inducible factor 1α expression under normal oxygen levels in human ovarian cancer cell lines, SKOV3 and 3AO, which leads to potently inhibits migration of ovarian cancer in vitro and in vivo. 20(S)-Rg3 could decrease the expression of hypoxia-inducible factor 1α by upregulation of prolyl hydroxylase domain protein 1 to promoting hypoxia-inducible factor 1α ubiquitin-proteasome degradation under normal oxygen levels. Furthermore, 20(S)-Rg3 could attenuate the expression of nuclear factor-κ B, which may be another possible mechanism for 20(S)-Rg3 to block ovarian cancer migration. Taken together, our study suggests that 20(S)-Rg3 is a strong inhibitor of hypoxia-inducible factor 1α, which may provide a novel agent for future treatments for ovarian cancer.

LFG-500, a newly synthesized flavonoid, induces apoptosis in human ovarian carcinoma SKOV3 cells with involvement of the reactive oxygen species-mitochondria pathway.

Ovarian cancer is the main cause of gynecologic malignancy-related mortality in women. Therefore, the disease requires improvements in treatment options and in the potency of chemotherapeutic drugs. The study of apoptosis in tumor cells is an important field for cancer therapy and cancer molecular biology. It has recently been established that LFG-500, a new synthesized flavonoid with a piperazine and benzyl group substitution, has strong anticancer activity. However, its exact molecular mechanism is not fully understood. The present study aimed to examine the effects of LFG-500 on human ovarian cancer SKOV3 cells, as well as to identify its underlying mechanisms. The data showed that LFG-500 inhibited the growth of SKOV3 cells in a concentration-dependent manner. It was found that LFG-500 induced apoptosis in SKOV3 cells, detected by DAPI staining and an Annexin V/PI double-staining assay. Moreover, LFG-500 reduced caspase-3 protein expression and increased the Bcl-2-associated X protein/B-cell lymphoma 2 protein ratio. Further findings revealed that LFG-500 treatment resulted in reactive oxygen species (ROS) accumulation and loss of mitochondrial transmembrane potential. Collectively, these results demonstrated that LFG-500 efficiently induced apoptosis in SKOV3 cells, an event possibly associated with the trigging of the mitochondrial apoptotic pathway through ROS accumulation. Therefore, LFG-500 shows potential as a potent anticancer agent for the treatment of ovarian cancer.

Wip1 regulates SKOV3 cell apoptosis through the p38 MAPK signaling pathway.

The aim of the present study was to explore the effect of silencing wild-type p53-induced phosphatase 1 (Wip1) on apoptosis of human ovarian cancer SKOV3 cells. SKOV3 cells cultured in vitro were divided into three groups: untreated cells, cells transfected with control small interfering RNA (siRNA) and cells transfected with siRNA targeting Wip1. Flow cytometry analysis was used to detect cell apoptosis. Western blot analysis was performed to determine expression of tumor protein 53 (p53), cleaved caspase-3, caspase-3, BCL2 associated X (Bax), BCL2 apoptosis regulator (Bcl-2), p38 mitogen-activated protein kinase (p38 MAPK) and phosphorylated (p)-p38 MAPK. Reverse transcription-quantitative polymerase chain reaction was used to detect expression of p53, Bax, Bcl-2 and caspase-3 mRNAs. Compared with control, apoptosis of SKOV3 cell was significantly increased following Wip1 siRNA silencing. Wip1 silencing also resulted in a significant increase of p53 and p-p38 MAPK expression, as well as increased cleaved caspase-3/caspase-3 and Bax/Bcl-2 protein ratios. No significant differences were observed in apoptosis and apoptosis-related protein expression in the control siRNA transfected cells. The present study demonstrated that Wip1 silencing promotes apoptosis of human ovarian cancer SKOV3 cells by activation of the p38 MAPK signaling pathways and through subsequent upregulation of p53, and cleaved caspase-3/caspase-3 and Bax/Bcl-2 protein ratios. Overall, the findings of the present study suggest that targeting Wip1 may be a potential therapeutic avenue for the treatment of human ovarian cancer in the future.

Construction of an Anticancer Fusion Peptide (ACFP) Derived from Milk Proteins and an Assay of Anti-ovarian Cancer Cells in vitro.

Some bioactive peptides derived from natural resources or synthesized by rational design have been shown to have very good anticancer effects. We designed an anticancer fusion peptide (ACFP) based on the structure of bovine lactoferricin (LfcinB) and hexapeptide (PGPIPN) derived from bovine milk protein. To prepare ACFP through genetic engineering and study its antiovarian cancer activity. ACFP gene was produced by a flexible link arm connecting LfcinB and PGPIPN. ACFP was inductively expressed in Escherichia coli by the recombinant plasmid pGEX-KG-ACFP. ACFP was prepared and purified by affinity chromatography, and identified by polyacrylamide gel electrophoresis (PAGE), high-performance liquid chromatography (HPLC) and mass spectrometry (MS). Recombinant lentivirus vectors were produced by cotransfecting 293T cells with constructed plasmid pLJM1-ACFP, envelope plasmid Δ8.91 and pVSVG using Lipofectamine. ACFP gene was transfected into ovarian cancer cells by pLJM1-ACFP lentivirus. Cell Viability was assayed by the methyl thiazolyl tetrazolium (MTT). The apoptosis of ovarian cancer SKOV3 cells was measured by flow cytometry and observed by Hoechst33258 staining. ACFP was successfully prepared and purified by genetic engineering. ACFP more effectively inhibited the viability of human ovarian cancer SKOV3 cells than the single parent peptides in vitro. ACFP was found to have no cytotoxicity towards untransformed cells. The ACFP gene in cancer cells infected with pLJM1-ACFP lentivirus could significantly inhibit the viability of SKOV3 cells and induce their apoptosis. ACFP is a potential therapeutic agent for the treatment of ovarian cancer.

The expression of Duffy antigen receptor for chemokines by epithelial ovarian cancer decreases growth potential.

Epithelial ovarian cancer (EOC) is one of the main causes of cancer-associated mortality in females with gynecological malignancies. Duffy antigen receptor for chemokines (DARC) has previously been reported to be involved in tumor growth and the inhibition of tumor metastasis. However, the association between DARC and EOC remains unknown. The aim of the present study was to investigate the expression of DARC in the SKOV3 human epithelial ovarian cancer cell line with the establishment of a subcutaneous model in nude mice. To investigate the effects of DARC on the tumorigenesis of human epithelial ovarian cancer cells, GV287-DARC-L.V lentiviral vectors containing a DARC overexpression construct were transfected into SKOV3 cells. The present study revealed that transfection with DARC reduced the viability of SKOV3 cells in vitro by performing an MTT assay. SKOV3-DARC and SKOV3-negative control (NC) cells cultured in vitro were injected into nude mice to establish a subcutaneous model. The ovarian tumor volumes and the tumor weights were observed. Immunohistochemistry to detect CD31 expression was used to determine the microvessel density (MVD) in SKOV3-DARC and SKOV3-NC tumors. The results of the present study revealed that DARC-induced inhibition of tumor growth was associated with MVD in xenograft tumors. This suggested that DARC was a negative regulator of tumor growth in EOC, primarily via the inhibition of tumor angiogenesis.