naphthoquinones and Ovarian-Neoplasms

In this study, eight naphthoquinone derivatives were synthesized in yields ranging from 52 to 96% using easy, fast, and low-cost methodologies. All naphthoquinone derivatives were screened for their in vitro anti-proliferative activities against OVCA A2780 cancer cell lines. Amongst all analysed compounds, derivatives 3-5 presented the most prominent cytotoxic potential. Naphthoquinones 3 and 4, bearing sulfur-containing groups, were identified as having high potential for ROS production, in particular the superoxide anion. Furthermore, 3 and 4 compounds caused a decrease in the cell population in G0/G1 and induced more than 90% of the cell population to apoptosis. Compound 5 did not act in any of these processes. Finally, compounds 3-5 were tested for their inhibitory ability against PI3K and MAPK. Compounds 3 and 4 do not inhibit the PI3K enzyme. On the other hand, the naphthoquinone-polyphenol 5 was only able to inhibit the percentage of cells expressing pERK.

Topics: Antineoplastic Agents; Cell Line, Tumor; Cell Proliferation; Female; Humans; Naphthoquinones; Ovarian Neoplasms; Phosphatidylinositol 3-Kinases; Structure-Activity Relationship

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

Topics: Apoptosis; Benzofurans; Carcinoma, Ovarian Epithelial; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; Cell Survival; Cysteine Proteinase Inhibitors; Drug Synergism; Female; G2 Phase Cell Cycle Checkpoints; Humans; Leupeptins; Naphthoquinones; Ovarian Neoplasms; Proteasome Endopeptidase Complex; Proteasome Inhibitors; STAT3 Transcription Factor

This study will investigate the effect of shikonin on the proliferation and apoptosis of human ovarian cancer cell SKOV3 (HOCC-SKOV3).. We will retrieve potential studies from inception to the March 1, 2020 in Cochrane Library, MEDLINE, EMBASE, Scopus, Cumulative Index to Nursing and Allied Health Literature, WANGFANG, and China National Knowledge In-frastructure. There are not restrictions related to the language and publication status. This study will include case-controlled studies (CCSs) or randomized controlled studies (RCSs) that examine the effect of shikonin on the proliferation and apoptosis of HOCC-SKOV3. Two researchers will independently identify literatures, extract data, and appraise study quality. Any disagreements will be resolved by discussion with another researcher. RevMan 5.3 software will be placed to perform statistical analysis.. This study will summarize the present evidence to test the effect of shikonin on the proliferation and apoptosis of HOCC-SKOV3.. It will provide evidence to investigate the effect of shikonin on the proliferation and apoptosis of HOCC-SKOV3, and will supply reference for further study.Systematic review registration: INPLASY202040146.

Topics: Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Cell Proliferation; Cystadenocarcinoma, Serous; Female; Humans; Meta-Analysis as Topic; Naphthoquinones; Ovarian Neoplasms; Systematic Reviews as Topic

Synthesis of a novel theranostic molecule for targeted cancer intervention. A reaction between curcumin and lawsone was carried out to yield the novel curcumin naphthoquinone (CurNQ) molecule (2,2'-((((1E,3Z,6E)-3-hydroxy-5-oxohepta-1,3,6-triene-1,7-diyl) bis(2-methoxy-4,1-phenylene))bis(oxy))bis(naphthalene-1,4-dione). CurNQ's structure was elucidated and was fully characterized. CurNQ was demonstrated to have pH specific solubility, its saturation solubility increased from 11.15 µM at pH 7.4 to 20.7 µM at pH 6.8. This pH responsivity allows for cancer targeting (Warburg effect). Moreover, CurNQ displayed intrinsic fluorescence, thus enabling imaging and detection applications. In vitro cytotoxicity assays demonstrated the chemotherapeutic properties of CurNQ as CurNQ reduced cell viability to below 50% in OVCAR-5 and SKOV3 ovarian cancer cell lines. CurNQ is a novel theranostic molecule for potential targeted cancer detection and treatment.

Topics: Animals; Cell Line, Tumor; Cell Shape; Cell Survival; Curcumin; Female; Fibroblasts; Humans; Hydrogen-Ion Concentration; Inhibitory Concentration 50; Mice; Naphthoquinones; NIH 3T3 Cells; Ovarian Neoplasms; Proton Magnetic Resonance Spectroscopy; Spectrometry, Fluorescence; Theranostic Nanomedicine

Pyruvate kinase M2 (PKM2) regulates glycolysis and oxidative phosphorylation; however, the role of PKM2 in ovarian cancer remains largely unknown. We investigated whether ovarian cancer metabolism could provide insight into the development of therapeutic strategies. We performed immunohistochemical staining for PKM2 on a tissue microarray for multivariate analysis. It revealed that patients exhibiting higher PKM2 expression were significantly associated with malignancy groups (p < 0.001) and pathogenesis models (p < 0.001), had poor progression-free survival rates (p = 0.01) as compared with patients exhibiting lower PKM2 levels, and yielded a hazard ratio of death of 2.02 (95% confidence interval: 0.70-5.85). In cell lines, PKM2 inhibitor significantly inhibited the glycolytic rate according to cellular glucose consumption (p < 0.001). We also utilized Seahorse assays to assess metabolism-related cell-specific factors and the impact of PKM2 inhibitors. Energy shifts as per Seahorse analysis showed attenuation of the extracellular acidification rate (p < 0.05) and no significant difference in oxygen-consumption rate in SKOV3 cells. Treatment with PKM2 inhibitor suppressed ovarian cancer growth and cell migration in vitro and inhibited tumor growth without significant toxicity in a xenograft study. PKM2 inhibition disturbed Warburg effects and inhibited ovarian cancer cell growth. Targeting PKM2 may constitute a promising therapy for patients with ovarian cancer, and clinical trials involving shikonin are warranted.

Topics: Animals; Biomarkers; Cell Line, Tumor; Cell Survival; Disease-Free Survival; Enzyme Inhibitors; Female; Glucose; Humans; Immunohistochemistry; Lactic Acid; Mice, SCID; Naphthoquinones; Ovarian Neoplasms; Positron-Emission Tomography; Prognosis; Pyruvate Kinase; Tissue Array Analysis; Xenograft Model Antitumor Assays

Melittin is well known to possess cytolytic activity with wide-spectrum lytic properties and its potential use as an agent to treat several types of cancer has been tested. Due to the non-specific toxicity, melittin can impair not only cancer cells but also normal tissue. Thus, tumor-targeted toxins may be helpful for developing novel anticancer therapeutics. The urokinase-type plasminogen activator (uPA) plays a central role in tissue remodelling events occurring in normal physiology and in pathophysiology, including cancer invasion and metastasis. Heartening findings showed that uPA receptor is predominantly expressed on many types of cancer. Therefore, the amino-terminal fragment (ATF) of uPA which was able to identify and bond with cancer cells was used as the cell-targeting domain to make up tumor-targeted toxin in this study. In the present study, pPICZαC-ATF-melittin eukaryotic expression vector was successfully constructed. After transformed into P. pastoris and induced by methanol, rATF-mellitin was detected by SDS-PAGE and western blot analysis. After induction with methanol, the expression level of rATF-mellitin was 312 mg/l in 80-l fermentor. rATF‑mellitin was purified to >95% purity using SP Sepharose ion exchange chromatography and source™ 30 RPC with 67.2% recovery. Cell proliferation assay showed that rATF-melittin inhibited growth of SKOV3 cells and had no cytotoxicity effect on normal cells. For the first time, we established a stable and effective rATF-mellitin P. pastoris expression system to obtain a high level of expression of secreted rATF-mellitin which was purified by a highly efficient purification procedure.

Topics: Antineoplastic Agents; Cell Line, Tumor; Drug Screening Assays, Antitumor; Female; Gene Expression; Genes, Synthetic; Genetic Vectors; Humans; Methanol; Molecular Targeted Therapy; Naphthoquinones; Neoplasm Proteins; Ovarian Neoplasms; Pichia; Plasmids; Receptors, Urokinase Plasminogen Activator; Recombinant Fusion Proteins; Transformation, Genetic

The objective of this study is to chemosensitize ovarian cancer (OVCa) cells to cisplatin (CDDP) using an inhibitor of Survivin, YM155. The efficacy of YM155 in combination with CDDP was determined in vitro, ex vivo and in vivo.. Human OVCa cell lines A2780p and their cisplatin-resistant derivative A2780cis, were treated with CDDP, YM155, and the combined treatment (YM155+CDDP), and cell viability, mRNA and protein expression levels, cell-cycle distribution, and DNA damage were then evaluated. Furthermore, the efficacy of YM155 combined with CDDP was further examined in established primary cell cultures and xenograft models.. The combination of YM155 with CDDP induced G2/M cell cycle arrest and apoptosis, increased DNA damage, and decreased Survivin levels, especially in A2780cis CDDP-resistant cells. Additionally, YM155 in combination with CDDP sensitized primary cell cultures to CDDP. Studies in vivo showed how this combination significantly decreased the tumor size of OVCa xenografts.. Our results demonstrate that in OVCa cells the expression of Survivin did not affect their sensitivity to YM155, suggesting that Survivin was not the only target of YM155. The combination of YM155 with CDDP could be a good option for therapy of CDDP-resistant OVCa, independently of p53 status.

Topics: Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Cisplatin; Disease Progression; DNA Damage; Female; Humans; Imidazoles; Inhibitor of Apoptosis Proteins; Naphthoquinones; Ovarian Neoplasms; Survivin

Conventional chemotherapy of ovarian cancer often fails because of initiation of drug resistance and/or side effects and trace of untouched remaining cancerous cells. This highlights an urgent need for advanced targeted therapies for effective remediation of the disease using a cytotoxic agent with immunomodulatory effects, such as shikonin (SHK). Based on preliminary experiments, we found SHK to be profoundly toxic in ovarian epithelial cancer cells (OVCAR-5 and ID8 cells) as well as in normal ovarian IOSE-398 cells, endothelial MS1 cells, and lymphocytes. To limit its cytotoxic impact solely to tumor cells within the tumor microenvironment (TME), we aimed to engineer SHK as polymeric nanoparticles (NPs) with targeting moiety toward tumor microvasculature. To this end, using single/double emulsion solvent evaporation/diffusion technique with sonication, we formulated biodegradable NPs of poly(lactic-co-glycolic acid) (PLGA) loaded with SHK. The surface of NPs was further decorated with solubilizing agent polyethylene glycol (PEG) and tumor endothelial marker 1 (TEM1)/endosialin-targeting antibody (Ab) through carbodiimide/N-hydroxysuccinimide chemistry. Having characterized the physicochemical and morphological properties of NPs, we studied their drug-release profiles using various kinetic models. The biological impact of NPs was also evaluated in tumor-associated endothelial MS1 cells, primary lymphocytes, and epithelial ovarian cancer OVCAR-5 cells. Based on particle size analysis and electron microscopy, the engineered NPs showed a smooth spherical shape with size range of 120 to 250 nm and zeta potential value of -30 to -40 mV. Drug entrapment efficiency was ~80%-90%, which was reduced to ~50%-60% upon surface decoration with PEG and Ab. The liberation of SHK from NPs showed a sustained-release profile that was best fitted with Wagner log-probability model. Fluorescence microscopy and flow cytometry analysis showed active interaction of Ab-armed NPs with TEM1-positive MS1 cells, but not with TEM1-negative MS1 cells. While exposure of the PEGylated NPs for 2 hours was not toxic to lymphocytes, long-term exposure of the Ab-armed and PEGylated NPs was significantly toxic to TEM1-positive MS1 cells and OVCAR-5 cells. Based on these findings, we propose SHK-loaded Ab-armed PEGylated PLGA NPs as a novel nanomedicine for targeted therapy of solid tumors.

Topics: Antibodies, Monoclonal; Antigens, CD; Antigens, Neoplasm; Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Cell Survival; Diffusion; Drugs, Chinese Herbal; Female; Humans; Molecular Targeted Therapy; Nanocapsules; Nanocomposites; Naphthoquinones; Ovarian Neoplasms; Particle Size; Treatment Outcome

To study the effect of beta-hydroxyisovaleryl shikonin (beta-HIVS) combined cisplatin on activities of ovarian cancer cell line SKOV3 in vivo and its possible mechanisms.. Cells were divided into the blank control group and six beta-HIVS groups (2 - 30 micromol/L). Effect of beta-HIVS at different concentrations on the activities of ovarian cancer cell line SKOV3 was detected using MTT assay. SKOV3 cells were treated with cisplatin (10, 20, and 40 micromol/L) and beta-HIVS (0.25, 1, and 2.5 micromol/L) combined cisplatin. Effect of beta-HIVS combined cisplatin on the activities of ovarian cancer cell line SKOV3 was determined by MTT assay. The expression of Bcl-2 and Bax after treated by different concentrations of beta-HIVS was detected by Western blot.. The activities of SKOV3 were inhibited by different concentrations of beta-HIVS dose-dependently. The 50% inhibition rate (IC50) was 7.37 micromol/L. There was statistical difference in IC50 between each concentration beta-HIVS group and the blank control group (P < 0.05). There was statistical difference in IC50 between the beta-HIVS (1 and 2.5 micromol/L) combined cisplatin groups and the cisplatin group (P < 0.05, P < 0.01). The synergistic effect on beta-HIVS showed dose-dependent manner. Results of Western blot showed beta-HIVS at different concentrations (5, 7.5, and 10 micromol/L) could obviously up-regulate the expression level of Bax protein and inhibit the expression level of Bcl-2 protein, showing statistical difference when compared with the control group (P < 0.01). CONCLUSIONS; HIVS could obviously inhibit in vitro growth of SKOV3 in a dose-dependent manner. With the range of concentration, beta-HIVS showed synergetic effect with cisplatin. Besides, along with increasing beta-HIVS concentrations, the synergetic effect was more significant. The synergetic effect might accelerate the apoptosis of SKOV3 through up-regulating Bax expression and inhibiting Bcl-2 expression.

Topics: Apoptosis; bcl-2-Associated X Protein; Cell Line, Tumor; Cisplatin; Female; Humans; Naphthoquinones; Ovarian Neoplasms; Proto-Oncogene Proteins c-bcl-2

It has been shown earlier that plumbagin, a naturally occurring naphthaquinone has specific anticancer activity in BRCA1 blocked ovarian cancer cells. Plumbagin can induce estrogen dependent cell signaling and apoptosis in BRCA1 blocked ovarian cancer cells. Being a reactive oxygen species (ROS) generator and apoptosis inducing agent, plumbagin has immense potential as a promising anticancer agent. In this study we analyzed whether there would be increased anticancer activity if the positions of the functional groups on plumbagin were altered and further to analyze the detailed molecular mechanism of action of the lead molecule. Methods like MTT assay, apoptosis analysis by flow cytometry, assessment of mitochondrial membrane potential-Δψm , suppression subtractive hybridization, microarray, molecular docking and estrogen receptor-DNA binding activity by electrophoresis mobility shift assay (EMSA) were adopted for assessing the anticancer activity. Consequently we found that, plumbagin was the most potent anticancer agent when compared to structurally related compounds. The anti-cancer activities were in the order plumbagin > 1,4-naphthaquinone > juglone > lawsone > menadione. Molecular docking studies showed that plumbagin could be well docked in the receptor ligand complex of TRAIL-DR5 complexes to activate the extrinsic pathway of apoptosis. Since the antiproliferative activity of plumbagin could be reduced by inhibiting ERα, we speculated that plumbagin interferes with the binding of ERα to ERE and we confirmed this by EMSA. This study clearly indicates that plumbagin can induce multiple pathways of apoptosis and cell cycle arrest in BRCA1 blocked cells compared to unblocked cells.

Topics: Antineoplastic Agents, Phytogenic; BRCA1 Protein; Breast Neoplasms; Cell Cycle Checkpoints; Drug Screening Assays, Antitumor; Estrogen Receptor alpha; Female; Gene Knockout Techniques; Humans; Membrane Potential, Mitochondrial; Molecular Docking Simulation; Naphthoquinones; Ovarian Neoplasms; Poly(ADP-ribose) Polymerases; Response Elements; Structure-Activity Relationship; Transcriptome

Angiogenesis is a hallmark of tumor development and metastatic progression, and anti-angiogenic drugs targeting the VEGF pathway have shown to decrease the disease progression in cancer patients. In this study, we have analyzed the anti-proliferative and anti-angiogenic property of plumbagin in cisplatin sensitive, BRCA2 deficient, PEO-1 and cisplatin resistant, BRCA2 proficient PEO-4 ovarian cancer cells. Both PEO-1 and PEO-4 ovarian cancer cells are sensitive to plumbagin irrespective of BRCA2 status in both normoxia and hypoxia. Importantly, plumbagin treatment effectively inhibits VEGF-A and Glut-1 in PEO-1 and PEO-4 ovarian cancer cells. We have also analyzed the p53 mutant, cisplatin resistant, and BRCA2 proficient OVCAR-5 cells. Plumbagin challenge also restricts the VEGF induced pro-angiogenic signaling in HUVECs and subsequently endothelial cell proliferation. In addition, we observe a significant effect on tumor regression among OVCAR-5 tumor-bearing mice treated with plumbagin, which is associated with significant inhibition of Ki67 and vWF expressions. Plumbagin also significantly reduces CD31 expression in an ear angiogenesis assay. Collectively, our studies indicate that plumbagin, as an anti-cancer agent disrupts growth of ovarian cancer cells through the inhibition of proliferation as well as angiogenesis.

Topics: Angiogenesis Inhibitors; Animals; Antineoplastic Agents; Antineoplastic Agents, Phytogenic; BRCA2 Protein; Calcium; Cell Line, Tumor; Cell Proliferation; Cell Transformation, Neoplastic; Cisplatin; Endothelial Cells; Female; Glucose Transporter Type 1; Humans; Ki-67 Antigen; Mice; Mice, SCID; Naphthoquinones; Neovascularization, Pathologic; Ovarian Neoplasms; Platelet Endothelial Cell Adhesion Molecule-1; Random Allocation; Tumor Suppressor Protein p53; Vascular Endothelial Growth Factor A; Xenograft Model Antitumor Assays

The multifunctional enzyme apurinic endonuclease 1/redox enhancing factor 1 (Ape1/ref-1) maintains genetic fidelity through the repair of apurinic sites and regulates transcription through redox-dependent activation of transcription factors. Ape1 can therefore serve as a therapeutic target in either a DNA repair or transcriptional context. Inhibitors of the redox function can be used as either therapeutics or novel tools for separating the two functions for in vitro study. Presently there exist only a few compounds that have been reported to inhibit Ape1 redox activity; here we describe a series of quinones that exhibit micromolar inhibition of the redox function of Ape1. Benzoquinone and naphthoquinone analogues of the Ape1-inhibitor E3330 were designed and synthesized to explore structural effects on redox function and inhibition of cell growth. Most of the naphthoquinones were low micromolar inhibitors of Ape1 redox activity, and the most potent analogues inhibited tumor cell growth with IC(50) values in the 10-20 microM range.

Topics: Benzoquinones; Cell Line, Tumor; Cell Proliferation; DNA-(Apurinic or Apyrimidinic Site) Lyase; Drug Design; Electrophoretic Mobility Shift Assay; Enzyme Inhibitors; Female; Humans; Magnetic Resonance Spectroscopy; Methacrylates; Naphthoquinones; Ovarian Neoplasms; Oxidation-Reduction; Propionates

Cellular response to chemotherapeutic drugs in the absence of BRCA1 either completely or partially had drawn less attention. The present study evaluated whether there is a differential inhibition of cell growth by selected compounds with respect to BRCA1 status in estrogen receptor (ER)-positive ovarian cancer cells.. The BG1 ovarian cancer cells used in the experiments were antisensely blocked with BRCA1 gene. Growth inhibition and apoptotic induction were analyzed to evaluate the cytotoxic effects. Small interfering RNA (SiRNA) transfection, western blot analysis, RT-PCR analysis and molecular modeling were carried out to analyze the estrogen-dependent action of plumbagin.. Although we found that all the compounds studied induce apoptosis, the induction was in the order of plumbagin > doxorubicin > tamoxifen > cisplatin. Plumbagin can bind to the active site of ER-alpha. Plumbagin, however, induced ER-alpha 46 kDa truncated isoform, which was found abundantly preempted in the cytoplasm compared with a 66-kDa full-length isoform. The truncated isoform is known to inhibit classical ER-alpha signaling pathways. SiRNA-transfected cells for ER-alpha exhibited lower cytotoxicity upon plumbagin treatment than the control-transfected cells.. Taken together, this study indicates that plumbagin has chemotherapeutic potential in BRCA1-mutated/defective ER-positive cancers.

Topics: Actins; Adenocarcinoma; Antineoplastic Agents; Antineoplastic Agents, Phytogenic; Apoptosis; Biomarkers, Tumor; Blotting, Western; Cell Line, Tumor; Cisplatin; Doxorubicin; Estrogen Receptor alpha; Female; Genes, BRCA1; Humans; Lethal Dose 50; Naphthoquinones; Ovarian Neoplasms; Receptors, Estrogen; Reverse Transcriptase Polymerase Chain Reaction; RNA, Small Interfering; Signal Transduction; Tamoxifen; Transfection; Tumor Suppressor Protein p53; Tumor Suppressor Proteins; Ubiquitin-Protein Ligases

Beta-hydroxyisovalerylshikonin (beta-HIVS), a compound isolated from the traditional oriental medicinal herb Lithospermum radix, is an ATP non-competitive inhibitor of protein-tyrosine kinases, such as v-Src and EGFR, and it induces apoptosis in some lines of human tumor cells. We investigated the effect of beta-HIVS on three endometrial cancer cell lines, two ovarian cancer cell lines, and normal human endometrial epithelial cells.. Endometrial and ovarian cancer cells were treated with various concentrations of beta-HIVS, and its effect on cell growth, cell cycle, apoptosis, and related measurements was investigated.. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay showed that all endometrial and ovarian cancer cell lines were sensitive to the growth-inhibitory effect of beta-HIVS, although normal endometrial epithelial cells were viable after treatment with the same doses of beta-HIVS that induced growth inhibition in endometrial and ovarian cancer cells. Cell-cycle analysis indicated that their exposure to beta-HIVS decreased the proportion of cells in the S phase and increased the proportion in the G0/G1 phases of the cell cycle. Induction of apoptosis was confirmed by annexin V staining of externalized phosphatidylserine and loss of the transmembrane potential of mitochondria. This induction occurred in concert with altered expression of genes related to cell growth, malignant phenotype, and apoptosis.. These results suggest that the anticancer activity of beta-HIVS may occur with higher sensitivity of cancer cells compared with normal healthy cells, when using low concentration, rising hopes that beta-HIVS may become a useful adjuvant therapy for endometrial and ovarian cancers.

Topics: Apoptosis; Cell Cycle; Cell Growth Processes; Cell Line, Tumor; Cyclin-Dependent Kinase Inhibitor p16; Cyclin-Dependent Kinase Inhibitor p21; Cyclin-Dependent Kinase Inhibitor p27; Endometrial Neoplasms; Female; Humans; Intracellular Signaling Peptides and Proteins; Membrane Potential, Mitochondrial; Naphthoquinones; Ovarian Neoplasms; Up-Regulation

Bioassay-guided fractionation of the root and stem extracts of Mendoncia cowanii led to the isolation of two new and two known naphthoquinones. The structures of the new compounds, avicequinones D and E (1 and 2), were determined using 1D and 2D NMR spectroscopy and by chemical conversion of compound 1 to 2. The new compounds were active in the A2780 human ovarian cancer cell line with IC50 values of 7.4 - 50 microM, respectively, and 1, 3, and 4 were subsequently found to be weakly active in an assay for inhibition of the kinase Akt.

Topics: Antineoplastic Agents, Phytogenic; Cell Line, Tumor; Female; Humans; Inhibitory Concentration 50; Madagascar; Magnoliopsida; Medicine, Traditional; Naphthoquinones; Ovarian Neoplasms; Phytotherapy; Plant Extracts; Plant Roots; Plant Stems; Trees

Previous studies have shown that reduction in BRCA1 mRNA and protein can result in increased proliferation of BG-1 ovarian cancer cells in both in vitro and in vivo conditions, suggesting that BRCA1 may normally act as a growth inhibitor in these cells. Also, there are other reports that suggest that wild-type BRCA1 protein may repress estrogen receptor (ER) function either directly or indirectly. However, response to antiestrogen drugs in BRCA1-blocked ER-positive ovarian cancer cells has not been reported, and this served as the rationale for this study. We analyzed the effect of tamoxifen, emodin, and plumbagin in BRCA1-blocked ER-positive BG-1 ovarian cancer cells. For all three drugs, BRCA1-blocked cells were more sensitive than the corresponding control cells as assessed by MTT assay; however, only plumbagin showed a statistically significant difference in mean viability (P < 0.05). All three drugs induced loss of mitochondrial membrane potential (DeltaPsi(m)), nuclear condensation, DNA fragmentation, and morphological changes, as observed after 6 h of drug treatment, suggesting apoptosis induction in both BRCA1-blocked and control cells. However, apoptosis induction was greater in BRCA1-blocked cells, the efficacy being in the order of plumbagin > tamoxifen > emodin. The dose of plumbagin needed to kill 50% was 5 microM in the control cells and 2.68 microM for the BRCA1-blocked cells, indicating that the latter was about twofold more sensitive to plumbagin than the wild-type cells. This throws light on the fact that plumbagin may have chemotherapeutic potential as an anticancer agent in BRCA1-mutated ovarian cancer patients.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; BRCA1 Protein; Cell Division; Emodin; Enzyme Inhibitors; Estrogen Antagonists; Female; Humans; In Situ Nick-End Labeling; Membrane Potentials; Mitochondria; Naphthoquinones; Neoplasms, Hormone-Dependent; Ovarian Neoplasms; RNA, Antisense; RNA, Messenger; Tamoxifen; Tumor Cells, Cultured

Bioassay-directed fractionation of extract of Arnebia euchroma led to the isolation of alkannin (1), shikonin (2), and their derivatives (3-8) as the active principles against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). The stereochemistry of alpha-methylbutyryl alkannin (8) is revealed for the first time, and the antimicrobial activity of 8 was compared with its corresponding diastereomer (9). The derivatives 3-9 showed stronger anti-MRSA activity [minimum inhibitory concentrations (MICs) ranged from 1.56 to 3.13 microg/mL] than alkannin or shikonin (MIC = 6.25 microg/mL). Anti-MRSA activity of derivatives was bactericidal with minimum bactericidal concentration (MBC)/MIC < or = 2. In a time-kill assay, the bactericidal activity against MRSA was achieved as rapidly as 2 h. The derivatives 3-9 were also active against vancomycin-resistant Enterococcus faecium (F935) and vancomycin-resistant Enterococcus faecalis (CKU-17) with MICs similar to those with MRSA. Aromatic ester derivatives were also synthesized for antimicrobial activity comparison. None of these compounds were active against Gram-negative bacteria tested. Their cytotoxicity was also evaluated on selected cancer cell lines, and they expressed their activity in the range 0.6-5.4 microg/mL (CD(50)). Our results indicate that the ester derivatives of alkannin are potential candidates of anti-MRSA and anti-VRE agents with antitumor activity.

Topics: Anti-Bacterial Agents; Boraginaceae; Carcinoma, Hepatocellular; China; Drug Screening Assays, Antitumor; Electron Spin Resonance Spectroscopy; Enterococcus faecalis; Female; HeLa Cells; Humans; Methicillin Resistance; Microbial Sensitivity Tests; Molecular Structure; Naphthoquinones; Nuclear Magnetic Resonance, Biomolecular; Ovarian Neoplasms; Plant Bark; Plants, Medicinal; Staphylococcus aureus; Stereoisomerism; Tumor Cells, Cultured; Vancomycin

The hollow fiber test has been developed for the preliminary in vivo assessment of cancer chemotherapeutic efficacy of selected natural products. Using this model, we have established growth conditions for HL-60, HUVEC, Ishikawa, KB, KB-V1, LNCaP, Lu1, MCF-7, Mel2, P-388, and SW626 cells implanted at the intraperitoneal (i.p.) and subcutaneous (s.c.) compartments of athymic mice. Five cytotoxic natural product isolates (2-6) were tested in this model, along with paclitaxel (taxol) (1). Among the compounds tested, dioscin (2) and 13-methoxy-15-oxozoapatlin (3) were found to be active, indicating their potential to function as cancer chemotherapeutic agents. On the other hand, ochraceolide A (4), alpha-lapachone (5), and 2-(1-hydroxyethyl)naphtha[2,3-b]furan-4,9-quinone (6), all of which were significantly cytotoxic to cultured mammalian cells, did not mediate significant responses with the hollow fiber model. In further xenograft studies using KB cells implanted at the subcutaneous site, compound 3 mediated a statistically significant response which was consistent with the response observed at the subcutaneous compartment in the hollow fiber tests. In sum, these studies illustrate the usefulness of the hollow fiber model in natural product drug discovery programs. Preliminary indications of potential therapeutic efficacy can be provided quickly at relatively low expense. Agents capable of mediating a response at the subcutaneous site would appear to warrant greatest attention.

Topics: Animals; Biological Factors; Colonic Neoplasms; Diosgenin; Disease Models, Animal; Diterpenes; Drug Screening Assays, Antitumor; Female; Heterocyclic Compounds, 3-Ring; HL-60 Cells; Humans; Inhibitory Concentration 50; KB Cells; Leukemia P388; Male; Melanoma; Mice; Molecular Structure; Naphthoquinones; Ovarian Neoplasms; Paclitaxel; Polymers; Prostatic Neoplasms; Triterpenes; Tumor Cells, Cultured

KILLER/DR5 is a death-domain-containing proapoptotic receptor that binds to the cytotoxic ligand TRAIL. It was originally reported that induction of KILLER/DR5 mRNA following DNA damage was p53-dependent, but some drugs that induce apoptosis can upregulate KILLER/DR5 mRNA expression in cell lines with mutated p53. We further extend those findings by classifying the capability of various apoptosis-inducing drugs to increase the expression of KILLER/DR5 mRNA in a p53-independent manner. beta-Lapachone, a topoisomerase inhibitor, increased KILLER/DR5 mRNA in colon cancer cell lines with wild-type p53 but not with mutant p53. In contrast, betulinic acid, a novel chemotherapeutic compound, induced apoptosis and KILLER/DR5 mRNA in melanoma and glioblastoma cells through a p53-independent mechanism. The synthetic glucocorticoid dexamethasone elevated KILLER/DR5 mRNA in glioblastoma, ovarian cancer, and colon cancer cell lines with mutant p53 undergoing apoptosis, and this induction was inhibited by the transcriptional inhibitor actinomycin D. Although another glucocorticoid, prednisolone, also induced apoptosis, it did not increase KILLER/DR5 mRNA. Finally, the cytokine interferon-gamma (IFN-gamma) induced apoptosis and KILLER/DR5 in cell lines with mutant p53, and the induction of KILLER/DR5 mRNA by IFN-gamma was delayed in cells lacking wild-type STAT1, a transcription factor implicated in IFN-gamma signaling. Similarly, the induction of KILLER/DR5 mRNA by the cytokine TNF-alpha was also delayed in cell lines with mutated STAT1. These findings suggest that KILLER/DR5 may play a role in p53-independent apoptosis induced by specific drugs and warrants further investigation as a novel target for chemotherapy of tumors lacking wild-type p53.

Topics: Antibiotics, Antineoplastic; Apoptosis; Betulinic Acid; Colonic Neoplasms; Dactinomycin; Dexamethasone; DNA-Binding Proteins; Female; Glioblastoma; Glucocorticoids; Humans; Interferon-gamma; Melanoma; Mutation; Naphthoquinones; Ovarian Neoplasms; Pentacyclic Triterpenes; Prednisolone; Receptors, TNF-Related Apoptosis-Inducing Ligand; Receptors, Tumor Necrosis Factor; RNA, Messenger; STAT1 Transcription Factor; Trans-Activators; Triterpenes; Tumor Cells, Cultured; Tumor Suppressor Protein p53; Up-Regulation

Ablation of tumor colonies was seen in a wide spectrum of human carcinoma cells in culture after treatment with the combination of beta-lapachone and taxol, two low molecular mass compounds. They synergistically induced death of cultured ovarian, breast, prostate, melanoma, lung, colon, and pancreatic cancer cells. This synergism is schedule dependent; namely, taxol must be added either simultaneously or after beta-lapachone. This combination therapy has unusually potent antitumor activity against human ovarian and prostate tumor prexenografted in mice. There is little host toxicity. Cells can commit to apoptosis at cell-cycle checkpoints, a mechanism that eliminates defective cells to ensure the integrity of the genome. We hypothesize that when cells are treated simultaneously with drugs activating more than one different cell-cycle checkpoint, the production of conflicting regulatory signaling molecules induces apoptosis in cancer cells. beta-Lapachone causes cell-cycle delays in late G(1) and S phase, and taxol arrests cells at G(2)/M. Cells treated with both drugs were delayed at multiple checkpoints before committing to apoptosis. Our findings suggest an avenue for developing anticancer therapy by exploiting apoptosis-prone "collisions" at cell-cycle checkpoints.

Topics: Animals; Antineoplastic Agents; Apoptosis; Cell Cycle; Cell Survival; Cyclin-Dependent Kinases; Drug Synergism; Female; Humans; Mice; Mice, Nude; Naphthoquinones; Ovarian Neoplasms; Paclitaxel; Tumor Cells, Cultured

Topics: Adenoma; Adult; Animals; Antineoplastic Agents; Carcinoma, Ehrlich Tumor; Cystadenoma; Female; Humans; Mammary Neoplasms, Experimental; Mice; Mice, Inbred Strains; Naphthoquinones; Neoplasm Transplantation; Ovarian Neoplasms

The in vitro interaction of modulators of topoisomerase I and II with cisplatin in human ovarian carcinoma cells might be synergistic. The interactions were evaluated by median effect analysis of survival data derived from continuous exposure to drug combinations for 10 days in colony-forming assays. The interaction between cisplatin and the topoisomerase I inhibitor camptothecin and the topoisomerase I activator beta-lapachone was additive, as was that between cisplatin and the topoisomerase II inhibitor novobiocin. Despite the clinical efficacy of the combination of etoposide (a topoisomerase II inhibitor) and cisplatin, the combination index at 50% cell kill indicated antagonism between these two drugs. Thus, biochemical synergism at the cellular level is not a prerequisite of improved therapeutic efficacy.

Topics: Antibiotics, Antineoplastic; Camptothecin; Cell Line; Cisplatin; DNA Topoisomerases, Type I; Drug Interactions; Etoposide; Female; Humans; Naphthoquinones; Novobiocin; Ovarian Neoplasms; Topoisomerase I Inhibitors; Topoisomerase II Inhibitors; Tumor Cells, Cultured