Studies indicate that estrogen receptor (ER) alpha mediates breast cancer-promoting effects of estrogens. The role ERbeta in cancer is unknown. Elucidating the pathogenesis important because many human tumors express both ERalpha and ERbeta. We show adenovirus-mediated expression changes phenotype ERalpha-positive MCF-7 cells. Estradiol increases cell proliferation causes tumor formation cells expressing only ERalpha. In contrast, introducing into an inhibition vitro prevents a mouse...

An atrial natriuretic factor (ANF) receptor from rat lung was solubilized with Lubrol-PX and purified by sequential chromatographic steps on GTP-agarose, DEAE-Sephacel, phenyl-agarose, wheat germ agglutinin-agarose.The ANF enriched 19,000-fold.The has a binding profile properties that correspond to the affinity specificity found in membranes crude detergent extracts.Polyacrylamide gel electrophoresis of preparation presence sodium dodecyl sulfate dithiothreitol showed one major protein band...

Vascular endothelial growth factor (VEGF) mediates angiogenic activity in a variety of estrogen target tissues. To determine whether has direct transcriptional effect on VEGF gene expression, we developed model system by transiently transfecting human promoter-luciferase reporter constructs into primary endometrial cells and Ishikawa cells, derived from well-differentiated adenocarcinoma. In epithelial treatment with 17β-estradiol (E 2 ) resulted 3.8-fold increase luciferase activity,...

Estrogens used in hormone replacement therapy regimens may increase the risk of developing breast cancer. Paradoxically, high consumption plant-derived phytoestrogens, particularly soybean isoflavones, is associated with a low incidence To explore molecular basis for these potential different clinical outcomes, we investigated whether isoflavones elicit distinct transcriptional actions from estrogens. Our results demonstrate that estrogen 17beta-estradiol effectively triggers activation and...

Estrogens and selective estrogen receptor modulators (SERMs) interact with (ER) alpha beta to activate or repress gene transcription. To understand how estrogens SERMs exert tissue-specific effects, we performed microarray analysis determine whether ERalpha ERbeta regulate different target genes in response SERMs. We prepared human U2OS osteosarcoma cells that are stably transfected a tetracycline-inducible vector express ERbeta. Western blotting, immunohistochemistry, immunoprecipitation...

In a previous study, we found that atriopeptin I was much weaker (EC50 greater than 500 nM) atrial natriuretic factor (ANF-(8-33)) = 0.3 at increasing cyclic GMP in cultured endothelial cells. this used the cross-linking reagent disuccinimidyl suberate to investigate whether differences activity were due presence of multiple ANF receptors. When 98% ANF-binding sites on cells occupied by tyrosine-atriopeptin after cross-linking, there no difference concentration-response curve ANF-(8-33) with...

Members of the mammalian p160 family, such as GRIP1, are known glucocorticoid receptor (GR) coactivators; at certain response elements (GREs), however, GRIP1 acts a GR corepressor. We characterized functional interactions and in repression complex where tethers to DNA-bound activator protein-1 (AP-1), human collagenase-3 gene, tested whether identified were similar or different other elements. At AP-1 tethering GRE, we mapped corepressor activity domain distinct from two activation domains;...

The tumor necrosis factor-alpha (TNF-alpha) promoter was used to explore the molecular mechanisms of estradiol (E(2))-dependent repression gene transcription. E(2) inhibited basal activity and abolished TNF-alpha activation promoter. E(2)-inhibitory element mapped -125 -82 region promoter, known as TNF-responsive (TNF-RE). An AP-1-like site in TNF-RE is essential for activity. Estrogen receptor (ER) beta more potent than ERalpha at repressing -1044 upstream herpes simplex virus thymidine...

The stimulation of cyclic GMP accumulation and particulate guanylate cyclase activity by atrial natriuretic peptide (ANP) was compared to the affinity number ANP receptors in eight cultured cell types. At 100 nM, increased 13-fold bovine adrenal cortical, 35-fold human lung fibroblast, 58-fold canine kidney epithelial, 60-fold aortic smooth muscle, 120-fold rat mammary 260-fold Leydig, 300-fold 475-fold endothelial cells. (1 microM) 1.5-, 2.5-, 3.1-, 3.2-, 5.0-, 7.0-, 7.8-, 8.0-fold cells,...

Estrogens exert their physiological effects on target tissues by interacting with the estrogen receptors, ERα and ERβ. Estrogen replacement is one most common effective strategies used to prevent osteoporosis in postmenopausal women. Whereas it was thought that estrogens work exclusively inhibiting bone resorption, our previous results show 17β-estradiol (E2) increases mouse morphogenetic protein (BMP)-2 mRNA, suggesting may also enhance formation. In this study, we quantitative real-time...

In addition to their role in the development and function of reproductive system, estrogens have significant anti-inflammatory properties. Although both estrogen receptors (ERs) can mediate actions, ERbeta is a more desirable therapeutic target because ERalpha mediates proliferative effects on mammary gland uterus. fact, selective agonists beneficial preclinical models involving inflammation without causing growth-promoting uterus or gland. However, mechanism action unclear. The purpose this...

Estrogen receptor β (ERβ) has potent antiproliferative and anti-inflammatory properties, suggesting that ERβ-selective agonists might be a new class of therapeutic chemopreventative agents. To understand how ERβ regulates genes, we identified genes regulated by the unliganded liganded forms ERα in U2OS cells. Microarray data demonstrated virtually no gene regulation occurred with ERα, whereas many were estradiol (E2). These results requires ligand to regulate single genes. In contrast, three...

Estrogen receptors (ERs) control transcription of genes important for normal human development and reproduction. The signaling networks are complex, there is a need molecular level understanding the roles receptor subtypes ERα ERβ in physiology as therapeutic targets. We synthesized two series ER ligands, based on common indene scaffold, an attempt to develop compounds that can selectively modulate ER-mediated transcription. 3-ethyl-1,2-diarylindenes, utilizing amide linker 1-aryl extension,...

Cultured rat lung fibroblasts were used to explore desensitization of guanylate cyclase nitrovasodilators. The effect pretreatment with glyceryl trinitrate (GTN) on the concentration-response curves GTN and sodium nitroprusside (SNP) for cyclic GMP accumulation in intact cells activation broken cell preparations was measured. Pretreatment 1 microM 3 h decreased induced by but had no SNP-induced accumulation. 100 efficacy SNP elevation 89% 40%, respectively. In contrast results obtained GTN,...

Background:Xenoestrogens are synthetic compounds that mimic endogenous estrogens by binding to and activating estrogen receptors. Exposure some xenoestrogens has been associated with cell proliferation an increased risk of breast cancer. Despite evidence estrogenicity, parabens among the most widely used in cosmetics personal-care products generally considered safe. However, previous cell-based studies do not take into account signaling cross-talk between receptor α (ERα) human epidermal...

The regulation by tumor necrosis factor alpha (TNF) of its own promoter has been investigated transient transfection and nuclear protein binding assays. In human K652 erythroleukemia cells TNF produced an 8-10-fold activation the linked to chloramphenicol acetyltransferase gene. TNF-responsive element was localized -125 -82 region examining in 5'-deletion or site-directed mutants demonstrating that fragment confers responsiveness thymidine kinase promoter. This contains a palindrome, 5'...

Novel estrogenic therapies are needed that ameliorate menopausal symptoms and have the bone-sparing effects of endogenous estrogens but do not promote breast or uterine cancer. Recent evidence suggests selective activation estrogen receptor (ER)-beta subtype inhibits cancer cell proliferation. To establish whether ERbeta-selective ligands represent a viable approach to improve hormone therapy, we investigated activities present in an herbal extract, MF101, used treat hot flashes, ERbeta...

We assessed glyceryl trinitrate (GTN) biotransformation and cyclic GMP accumulation in cultured rat lung fibroblasts (RLF), porcine kidney epithelial (PK1), bovine aortic endothelial (BAE) smooth muscle (BASM) cells. Biotransformation of 0.1 microM GTN was linear over 30 min the percentage dinitrate (GDN)/10(6) cells for BAE, BASM, RLF PK1 at 3.1, 2.3, 5.8 21.7%, respectively. At low concentration (0.01-0.1 microM) there a highly selective formation 1,2-GDN, whereas higher (greater than 1...

We used cultured rat lung fibroblasts to evaluate the role of particulate and soluble guanylate cyclase in atrial natriuretic factor (ANF)-induced stimulation cyclic GMP. ANF receptors were identified by binding 125I-ANF confluent cells at 37 degrees C. Specific was rapid saturable with increasing concentrations ANF. The equilibrium dissociation constant (KD) 0.66 +/- 0.077 nM Bmax. 216 33 fmol bound/10(6) cells, which corresponds 130,000 20,000 sites/cell. molecular characteristics sites...