76 research outputs found

    WAP four-disulfide core domain protein 2 gene(WFDC2) is a target of estrogen in ovarian cancer cells

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    BACKGROUND: WAP four-disulfide core domain protein 2 (WFDC2) shows a tumor-restricted upregulated pattern of expression in ovarian cancer. METHODS: We investigated the role of estradiol (E2) on cell growth in estrogen-sensitive or estrogen-insensitive ovarian cancer cell lines. Real-time (RT)-PCR and western blotting were used to examine the expression of WFDC2 at RNA and protein levels. Growth traits of cells transfected with WFDC2-shRNA or blank control were assessed using MMT arrays. Cell apoptosis was analyzed using annexin V-FITC/PI and flow cytometry. Estrogen receptor expression was evaluated using RT-PCR and flow cytometry. Apoptosis-related proteins induced by E2 directly and indirectly were determined using an antibody array comparing cells transfected with WFDC2- shRNA or a blank control. RESULTS: High-dose (625 ng/ml) E2 increased the expression of WFDC2 in HO8910 cells at both the mRNA and protein levels. However, E2 had no effect on WFDC2 expression in estrogen-insensitive SKOV3 cells. Of interest, knockdown of WFDC2 enabled a considerable estrogen response in SKOV3 cells in terms of proliferation, similar to estrogen-responsive HO8910 cells. This transformation of SKOV3 cells into an estrogen-responsive phenotype was accompanied by upregulation of estrogen receptor beta (ERß) and an effect on cell apoptosis under E2 treatment by regulating genes related to cell proliferation and apoptosis. CONCLUSIONS: We postulate that increased WFDC2 expression plays an important role in altering the estrogen pathway in ovarian cancer, and the identification of WFDC2 as a new player in endocrine-related cancer encourages further studies on the significance of this gene in cancer development and therapy. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13048-015-0210-y) contains supplementary material, which is available to authorized users

    Hypoxia-inducible Factor-1 Activation in Nonhypoxic Conditions: The Essential Role of Mitochondrial-derived Reactive Oxygen Species

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    Hypoxia-inducible factor-1 (HIF-1) is a key transcription factor for responses to low oxygen. Here we report that the generation of mitochondrial reactive oxygen species are essential for regulating HIF-1 in normal oxygen conditions in the vasculature

    Polyphenols Sensitization Potentiates Susceptibility of MCF-7 and MDA MB-231 Cells to Centchroman

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    Polyphenols as “sensitizers” together with cytotoxic drugs as “inducers” cooperate to trigger apoptosis in various cancer cells. Hence, their combination having similar mode of mechanism may be a novel approach to enhance the efficacy of inducers. Additionally, this will also enable to achieve the physiological concentrations facilitating significant increase in the activity at concentrations which the compound can individually provide. Here we propose that polyphenols (Resveratrol (RES) and Curcumin (CUR)) pre-treatment may sensitize MCF-7/MDA MB-231 (Human Breast Cancer Cells, HBCCs) to Centchroman (CC, antineoplastic agent). 6 h pre-treated cells with 10 µM RES/CUR and 100 µM RES/30 µM CUR doses, followed by 10 µM CC for 18 h were investigated for Ser-167 ER-phosphorylation, cell cycle arrest, redox homeostasis, stress activated protein kinase (SAPKs: JNK and p38 MAPK) pathways and downstream apoptosis effectors. Low dose RES/CUR enhances the CC action through ROS mediated JNK/p38 as well as mitochondrial pathway in MCF-7 cells. However, RES/CUR sensitization enhanced apoptosis in p53 mutant MDA MB-231 cells without/with involvement of ROS mediated JNK/p38 adjunct to Caspase-9. Contrarily, through high dose sensitization in CC treated cells, the parameters remained unaltered as in polyphenols alone. We conclude that differential sensitization of HBCCs with low dose polyphenol augments apoptotic efficacy of CC. This may offer a novel approach to achieve enhanced action of CC with concomitant reduction of side effects enabling improved management of hormone-dependent breast cancer

    Global analysis of estrogen receptor beta binding to breast cancer cell genome reveals an extensive interplay with estrogen receptor alpha for target gene regulation

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    Background: Estrogen receptors alpha (ERa) and beta (ERb) are transcription factors (TFs) that mediate estrogen signaling and define the hormone-responsive phenotype of breast cancer (BC). The two receptors can be found co-expressed and play specific, often opposite, roles, with ERb being able to modulate the effects of ERa on gene transcription and cell proliferation. ERb is frequently lost in BC, where its presence generally correlates with a better prognosis of the disease. The identification of the genomic targets of ERb in hormone-responsive BC cells is thus a critical step to elucidate the roles of this receptor in estrogen signaling and tumor cell biology. Results: Expression of full-length ERb in hormone-responsive, ERa-positive MCF-7 cells resulted in a marked reduction in cell proliferation in response to estrogen and marked effects on the cell transcriptome. By ChIP-Seq we identified 9702 ERb and 6024 ERa binding sites in estrogen-stimulated cells, comprising sites occupied by either ERb, ERa or both ER subtypes. A search for TF binding matrices revealed that the majority of the binding sites identified comprise one or more Estrogen Response Element and the remaining show binding matrixes for other TFs known to mediate ER interaction with chromatin by tethering, including AP2, E2F and SP1. Of 921 genes differentially regulated by estrogen in ERb+ vs ERb- cells, 424 showed one or more ERb site within 10 kb. These putative primary ERb target genes control cell proliferation, death, differentiation, motility and adhesion, signal transduction and transcription, key cellular processes that might explain the biological and clinical phenotype of tumors expressing this ER subtype. ERb binding in close proximity of several miRNA genes and in the mitochondrial genome, suggests the possible involvement of this receptor in small non-coding RNA biogenesis and mitochondrial genome functions. Conclusions: Results indicate that the vast majority of the genomic targets of ERb can bind also ERa, suggesting that the overall action of ERb on the genome of hormone-responsive BC cells depends mainly on the relative concentration of both ERs in the cell

    In vitro and in vivo evaluation of C-20- and C-23-modified derivatives of tylosin against veterinary pathogens.

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    Three series of semi-synthetic derivatives of tylosin-related macrolides were evaluated for utility in veterinary medicine. 23-Modified derivatives of 5-O-mycaminosyltylonolide (OMT) possessed potent activity in vitro against species of Pasteurella and Mycoplasma. An experimental infection in chicks caused by Pasteurella multocida was utilized to evaluate efficacy; several of these derivatives of OMT effectively treated the infection when given subcutaneously, but none were effective after oral administration in drinking water. Macrolides retaining the 4'-O-mycarosyl moiety (tylosin, DMT) had relatively poor activity against Pasteurella in vitro. Certain 20-modified derivatives of desmycosin demonstrated good oral bioavailability in chicks and a lead compound with oral efficacy in the Pasteurella infection model was discovered.info:eu-repo/semantics/publishe

    Estrogen-induced DNA synthesis in vascular endothelial cells is mediated by ROS signaling

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    <p>Abstract</p> <p>Background</p> <p>Since estrogen is known to increase vascular endothelial cell growth, elevated estrogen exposure from hormone replacement therapy or oral contraceptives has the potential to contribute in the development of abnormal proliferative vascular lesions and subsequent thickening of the vasculature. How estrogen may support or promote vascular lesions is not clear. We have examined in this study whether estrogen exposure to vascular endothelial cells increase the formation of reactive oxygen species (ROS), and estrogen-induced ROS is involved in the growth of endothelial cells.</p> <p>Methods</p> <p>The effect of estrogen on the production of intracellular oxidants and the role of estrogen-induced ROS on cell growth was studied in human umbilical vein endothelial cells. ROS were measured by monitoring the oxidation of 2'7'-dichlorofluorescin by spectrofluorometry. Endothelial cell growth was measured by a colorimetric immunoassay based on BrdU incorporation into DNA.</p> <p>Results</p> <p>Physiological concentrations of estrogen (367 fmol and 3.67 pmol) triggered a rapid 2-fold increase in intracellular oxidants in endothelial cells. E2-induced ROS formation was inhibited to basal levels by cotreatment with the mitochondrial inhibitor rotenone (2 μM) and xanthine oxidase inhibitor allopurinol (50 μM). Inhibitors of NAD(P)H oxidase, apocynin and DPI, did not block E2-induced ROS formation. Furthermore, the NOS inhibitor, L-NAME, did not prevent the increase in E2-induced ROS. These findings indicate both mitochondria and xanthine oxidase are the source of ROS in estrogen treated vascular endothelial cells. E2 treated cells showed a 2-fold induction of BrdU incorporation at 18 h which was not observed in cells exposed to vehicle alone. Cotreatment with ebselen (20 μM) and NAC (1 mM) inhibited E2-induced BrdU incorporation without affecting the basal levels of DNA synthesis. The observed inhibitory effect of NAC and ebselen on E2-induced DNA synthesis was also shown to be dose dependent.</p> <p>Conclusion</p> <p>We have shown that estrogen exposure stimulates the rapid production of intracellular ROS and they are involved in growth signaling of endothelial cells. It appears that the early estrogen signaling does not require estrogen receptor genomic signaling because we can inhibit estrogen-induced DNA synthesis by antioxidants. Findings of this study may further expand research defining the underlying mechanism of how estrogen may promote vascular lesions. It also provides important information for the design of new antioxidant-based drugs or new antioxidant gene therapy to protect the cardiovascular health of individuals sensitive to estrogen.</p

    Structure-activity studies of 20-deoxo-20-amino derivatives of tylosin-related macrolides.

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    Reductive amination of the C-20 aldehyde group of tylosin and related macrolides yielded a large series of derivatives with potentially useful antibiotic properties. Evaluation of these new compounds was conducted on the basis of: 1) Broad antimicrobial spectrum in vitro, with particular emphasis on inhibition of Pasteurella multocida and Pasteurella haemolytica; 2) in vivo efficacy, especially when given orally, against P. multocida in experimental infections in chicks; and 3) bioavailability after oral administration to laboratory animals. The most useful activity was found within a series of derivatives produced by reductive amination of desmycosin with secondary amines.info:eu-repo/semantics/publishe

    Synthesis, antimicrobial evaluation and structure-activity relationships within 23-modified derivatives of 5-O-mycaminosyltylonolide.

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    A large series of C-23-modified derivatives of 5-O-mycaminosyltylonolide were synthesized, in which the C-23 hydroxyl group was replaced by halo, aryl ether or thioether, azido, amino or dialkylamino substituents via SN2 displacement reactions. The majority of derivatives possessed excellent in vitro activity against a variety of aerobic and anaerobic bacteria. While some of the compounds treated experimental infections in rodents by parenteral administration, none showed any significant efficacy or bioavailability after oral dosing. Novel rearrangement products were obtained from some of the reactions; these were identified as 13,23-cyclopropyl-12,22-exomethylene and 13,23-cyclopropyl-12-alkoxy derivatives.info:eu-repo/semantics/publishe

    Synthesis and antimicrobial evaluation of acyl derivatives of 16-membered macrolide antibiotics related to tylosin.

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    A large number and wide variety of acyl derivatives of the tylosin-related macrolides 23-demycinosyltylosin (DMT), 23-demycinosyloxytylosin (DMOT) and 5-O-mycaminosyltylonolide (OMT) were synthesized and evaluated. This encompassed conversion of the hydroxyl groups at 2',4' and 23 of the appropriate macrolides to the corresponding esters, in which a variety of different substitution patterns were examined. A wide range of acyl substituents was investigated, particularly for 23-O-acyl derivatives of OMT, since these were substantially more active in vitro than OMT itself. However, the acyl derivatives which were prepared demonstrated no substantial improvement in oral efficacy or bioavailability over the parent macrolides.info:eu-repo/semantics/publishe
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