Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 56
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Br J Cancer ; 105(10): 1574-81, 2011 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-22067903

RESUMO

BACKGROUND: Formalin-fixed, paraffin-embedded (FFPE) tumour tissue represents an immense but mainly untapped resource with respect to molecular profiling. The DASL (cDNA-mediated Annealing, Selection, extension, and Ligation) assay is a recently described, RT-PCR-based, highly multiplexed high-throughput gene expression platform developed by Illumina specifically for fragmented RNA typically obtained from FFPE specimens, which enables expression profiling. In order to extend the utility of the DASL assay for breast cancer, we have custom designed and validated a 512-gene human breast cancer panel. METHODS: The RNA from FFPE breast tumour specimens were analysed using the DASL assay. Breast cancer subtype was defined from pathology immunohistochemical (IHC) staining. Differentially expressed genes between the IHC-defined subtypes were assessed by prediction analysis of microarrays (PAM) and then used in the analysis of two published data sets with clinical outcome data. RESULTS: Gene expression signatures on our custom breast cancer panel were very reproducible between replicates (average Pearson's R²=0.962) and the 152 genes common to both the standard cancer DASL panel (Illumina) and our breast cancer DASL panel were similarly expressed for samples run on both panels (average R²=0.877). Moreover, expression of ESR1, PGR and ERBB2 corresponded well with their respective pathology-defined IHC status. A 30-gene set indicative of IHC-defined breast cancer subtypes was found to segregate samples based on their subtype in our data sets and published data sets. Furthermore, several of these genes were significantly associated with overall survival (OS) and relapse-free survival (RFS) in these previously published data sets, indicating that they are biomarkers of the different breast cancer subtypes and the prognostic outcomes associated with these subtypes. CONCLUSION: We have demonstrated the ability to expression profile degraded RNA transcripts derived from FFPE tissues on the DASL platform. Importantly, we have identified a 30-biomarker gene set that can classify breast cancer into subtypes and have shown that a subset of these markers is prognostic of OS and RFS.


Assuntos
Neoplasias da Mama/genética , Análise de Sequência com Séries de Oligonucleotídeos , Inclusão em Parafina , Sequência de Bases , Neoplasias da Mama/patologia , Estudos de Coortes , Primers do DNA , Feminino , Perfilação da Expressão Gênica , Humanos , Imuno-Histoquímica , Reação em Cadeia da Polimerase
2.
Br J Cancer ; 102(3): 570-6, 2010 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-20068566

RESUMO

BACKGROUND: Recent studies have indicated that prostate cancer patients with the TMPRSS2-ERG gene fusion have a higher risk of recurrence. To identify markers associated with TMPRSS2-ERG fusion and prognostic of biochemical recurrence, we analysed a cohort of 139 men with prostate cancer for 502 molecular markers. METHODS: RNA from radical prostatectomy tumour specimens was analysed using cDNA-mediated, annealing, selection, extension and ligation (DASL) to determine mRNAs associated with TMPRSS2-ERG T1/E4 fusion and prognostic of biochemical recurrence. Differentially expressed mRNAs in T1/E4-positive tumours were determined using significance analysis of microarrays (false discovery rate (FDR) <5%). Univariate and multivariate Cox regression determined genes, gene signatures and clinical factors prognostic of recurrence (P-value <0.05, log-rank test). Analysis of two prostate microarray studies (GSE1065 and GSE8402) validated the findings. RESULTS: In the 139 patients from this study and from a 455-patient Swedish cohort, 15 genes in common were differentially regulated in T1/E4 fusion-positive tumours (FDR <0.05). The most significant mRNAs in both cohorts coded ERG. Nine genes were found prognostic of recurrence in this study and in a 596-patient Minnesota cohort. A molecular recurrence score was significant in prognosticating recurrence (P-value 0.000167) and remained significant in multivariate analysis of a mixed clinical model considering Gleason score and TMPRSS2-ERG fusion status. CONCLUSIONS: TMPRSS2-ERG T1/E4 fusion-positive tumours had differentially regulated mRNAs observed in multiple studies, the most significant one coded for ERG. Several mRNAs were consistently associated with biochemical recurrence and have potential clinical utility but will require further validation for successful translation.


Assuntos
Fusão Gênica , Proteínas de Fusão Oncogênica/genética , Neoplasias da Próstata/genética , Estudos de Coortes , Humanos , Masculino , Recidiva Local de Neoplasia , Análise de Sequência com Séries de Oligonucleotídeos , Prognóstico , Antígeno Prostático Específico/sangue , RNA Mensageiro/análise
3.
Science ; 284(5423): 2184-8, 1999 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-10381885

RESUMO

Motilin is a 22-amino acid peptide hormone expressed throughout the gastrointestinal (GI) tract of humans and other species. It affects gastric motility by stimulating interdigestive antrum and duodenal contractions. A heterotrimeric guanosine triphosphate-binding protein (G protein)-coupled receptor for motilin was isolated from human stomach, and its amino acid sequence was found to be 52 percent identical to the human receptor for growth hormone secretagogues. The macrolide antibiotic erythromycin also interacted with the cloned motilin receptor, providing a molecular basis for its effects on the human GI tract. The motilin receptor is expressed in enteric neurons of the human duodenum and colon. Development of motilin receptor agonists and antagonists may be useful in the treatment of multiple disorders of GI motility.


Assuntos
Colo/metabolismo , Mucosa Gástrica/metabolismo , Intestino Delgado/metabolismo , Motilina/metabolismo , Receptores dos Hormônios Gastrointestinais/química , Receptores dos Hormônios Gastrointestinais/genética , Receptores de Neuropeptídeos/química , Receptores de Neuropeptídeos/genética , Processamento Alternativo , Sequência de Aminoácidos , Sequência de Bases , Sítios de Ligação , Cálcio/metabolismo , Linhagem Celular , Mapeamento Cromossômico , Cromossomos Humanos Par 13 , Clonagem Molecular , Eritromicina/metabolismo , Proteínas de Ligação ao GTP/metabolismo , Humanos , Hibridização In Situ , Ligantes , Dados de Sequência Molecular , Motilina/análogos & derivados , Receptores dos Hormônios Gastrointestinais/metabolismo , Receptores de Neuropeptídeos/metabolismo , Glândula Tireoide/metabolismo , Transfecção
4.
Biochim Biophys Acta ; 1483(2): 285-93, 2000 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-10634944

RESUMO

Stable cell lines that individually express the eight known human prostanoid receptors (EP(1), EP(2), EP(3), EP(4), DP, FP, IP and TP) have been established using human embryonic kidney (HEK) 293(EBNA) cells. These recombinant cell lines have been employed in radioligand binding assays to determine the equilibrium inhibitor constants of known prostanoid receptor ligands at these eight receptors. This has allowed, for the first time, an assessment of the affinity and selectivity of several novel compounds at the individual human prostanoid receptors. This information should facilitate interpretation of pharmacological studies that employ these ligands as tools to study human tissues and cell lines and should, therefore, result in a greater understanding of prostanoid receptor biology.


Assuntos
Membrana Celular/metabolismo , Prostaglandinas/metabolismo , Receptores de Prostaglandina/metabolismo , Ligação Competitiva , Linhagem Celular , Humanos , Ligantes , Ensaio Radioligante , Receptores de Prostaglandina/agonistas , Receptores de Prostaglandina/antagonistas & inibidores , Proteínas Recombinantes/metabolismo
5.
J Clin Endocrinol Metab ; 54(3): 563-8, 1982 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-6948817

RESUMO

Since cortisol (F) can influence fetal lung maturation, alterations in its intracellular metabolism may be important. In fetal lung at midgestation, both the in vivo studies of Pasqualini et al. and the in vitro studies of Murphy showed the activity of the enzyme 11 beta-hydroxysteroid dehydrogenase (EC 1.1.1.146) to be strongly oxidative, converting F to its inactive analog cortisone (E). By contrast, Smith et al. observed only reductive activity (E to F) in monolayer cultures. The object of this study was to resolve this discrepancy. Human fetal lung (HFL) of gestational age 9-13 weeks was grown in monolayer cultures or as explants on grids in Ham's F-10 medium plus 10% fetal calf serum and [3H]F and [14C]E (12-20 ng/ml of each). Extracts of media were chromatographed to separate the steroids, and the percent conversion was calculated. Explants converted F to E 20-40% and maintained day 1 levels for at least 7 days of culture. E to F conversion was initially low (1-5%) and rose to 14-20% by the end of culture, corresponding to fibroblast-like outgrowth. In monolayer cultures, which appeared to consist almost entirely of fibroblast-like cells, F to E conversion was less than 10% by 5 days, while E to F conversion steadily increased to 20-85% and plateaued at confluence. Homogenates of fresh tissue demonstrated F to E but no E to F conversion, even in the presence of cofactors. Thus, it appears that when tissue structure is maintained as in the explants, HFL cells oxidize F to E by a unidirectional enzyme; activation of E to F is only expressed by HFL fibroblast-like cells in culture and does not reflect the in vivo situation.


Assuntos
Cortisona/metabolismo , Hidrocortisona/metabolismo , Hidroxiesteroide Desidrogenases/metabolismo , Pulmão/embriologia , 11-beta-Hidroxiesteroide Desidrogenases , Técnicas de Cultura , Fibroblastos/enzimologia , Idade Gestacional , Humanos , Cinética , Pulmão/enzimologia , Oxirredução
6.
FEBS Lett ; 318(3): 277-81, 1993 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-8440384

RESUMO

5-Lipoxygenase-activating protein (FLAP) is an 18-kDa integral membrane protein which is essential for cellular leukotriene (LT) synthesis, and is the target of LT biosynthesis inhibitors. However, the mechanism by which FLAP activates 5-LO has not been determined. We have expressed high levels of human FLAP in Spodoptera frugiperda (Sf9) insect cells infected with recombinant baculovirus, and used this system to demonstrate that FLAP specifically binds [125I]L-739,059, a novel photoaffinity analog of arachidonic acid. This binding is inhibited by both arachidonic acid and MK-886, an LT biosynthesis inhibitor which specifically interacts with FLAP. These studies suggest that FLAP may activate 5-LO by specifically binding arachidonic acid and transferring this substrate to the enzyme.


Assuntos
Proteínas de Transporte/metabolismo , Proteínas de Membrana/metabolismo , Proteínas Ativadoras de 5-Lipoxigenase , Marcadores de Afinidade , Animais , Araquidonato 5-Lipoxigenase/metabolismo , Ácidos Araquidônicos/metabolismo , Baculoviridae/genética , Proteínas de Transporte/genética , Linhagem Celular , Ativação Enzimática , Expressão Gênica , Humanos , Indóis/metabolismo , Radioisótopos do Iodo/metabolismo , Proteínas de Membrana/genética , Mariposas/metabolismo , Fotoquímica , Quinolinas/metabolismo , Proteínas Recombinantes/metabolismo , Transfecção
7.
FEBS Lett ; 338(2): 170-4, 1994 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-8307176

RESUMO

Functional cDNA clones coding for three isoforms of the human prostaglandin E receptor EP3 subtype have been isolated from kidney and uterus cDNA libraries. The three isoforms, designated hEP3-I, hEP3-II and hEP3-III, have open reading frames corresponding to 390, 388 and 365 amino acids, respectively. They differ only in the length and amino acid composition of their carboxy-terminal regions, beginning at position 360. The human EP3 receptor has seven predicted transmembrane spanning domains and therefore belongs to the G-protein-coupled receptor family. The rank order of potency for prostaglandins and related analogs in competition for [3H]PGE2 specific binding to membranes prepared from transfected COS cells was comparable for all three isoforms, and as predicted for the EP3 receptor, with PGE2 = PGE1 >> PGF2 alpha = iloprost > PGD2 >> U46619. In addition, the EP3-selective agonist MB28767 was a potent competing ligand with an IC50 value of 0.3 nM, whereas the EP1-selective antagonist AH6909 gave IC50 values of 2-7 microM and the EP2-selective agonist butaprost was inactive. In summary, we have cloned three isoforms of the human EP3 receptor having comparable ligand binding properties.


Assuntos
Clonagem Molecular , Expressão Gênica , Receptores de Prostaglandina E/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Bovinos , Linhagem Celular , Sondas de DNA , Humanos , Camundongos , Dados de Sequência Molecular , Peso Molecular , Reação em Cadeia da Polimerase , Ratos , Receptores de Prostaglandina E/química , Homologia de Sequência de Aminoácidos , Transfecção
8.
Bone ; 28(3): 275-81, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11248657

RESUMO

Prostaglandins E (especially PGE(2)) stimulate bone formation and increase bone mass in several species including man. The mechanism for this effect, the target cells, and the receptors involved are not known. Specific cell-surface receptors for PGE(2) (EP(1-4)) have been cloned and characterized. EP(4) was reported to be the major receptor in embryonic and neonatal bone tissue in mice, especially in preosteoblasts; however, no data are available regarding its expression in adult bone. This study examines the expression of EP(4) in bone tissue of young adult rats, in which PGE(2) is markedly anabolic, and in various osteoblastic cell lines. Using northern blot analysis, we found that osteoblastic cell lines RCT-1, RCT-3, TRAB-11, and RP-1, primary osteoblastic cells harvested from fetal rat calvaria, as well as tibiae and calvariae of 5-week-old rats express 3.8 kb EP(4) messenger RNA (mRNA). Treatment of periosteal cells (RP-1) in vitro with 10(-6) mol/L PGE(2) increased the levels of both EP(4) mRNA and EP(4) protein, peaking at 1-2 h. Similarly, systemic administration of an anabolic dose of PGE(2) (3-6 mg/kg) to young adult rats upregulated the expression of EP(4) in the tibia and calvaria, also peaking at 1-2 h. Using in situ hybridization, we found increased expression of EP(4) in bone marrow cells of the tibial metaphysis in response to systemic PGE(2) treatment. The preosteoblastic nature of these EP(4)-expressing cells was suggested by the fact that dexamethasone-treated bone marrow stromal cells in culture express EP(4) mRNA, which is upregulated by PGE(2). Northern blot analysis failed to detect both basal and PGE(2)-induced EP(2) mRNA in the bone samples or cell lines tested. Taken together, these data implicate EP(4) as the major cyclic AMP-related PGE(2) receptor subtype expressed in bone tissue and osteoblastic cells and indicate that this receptor is upregulated by its ligand, PGE(2).


Assuntos
Dinoprostona/fisiologia , Regulação da Expressão Gênica/fisiologia , Receptores de Prostaglandina E/metabolismo , Animais , Northern Blotting , Células da Medula Óssea/metabolismo , Linhagem Celular , Dinoprostona/metabolismo , Osteoblastos/metabolismo , RNA Mensageiro/genética , Ratos , Receptores de Prostaglandina E/genética , Receptores de Prostaglandina E Subtipo EP4 , Células Estromais/metabolismo
9.
Br J Pharmacol ; 123(7): 1317-24, 1998 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9579725

RESUMO

1. A human embryonic kidney cell line [HEK 293(EBNA)] stably expressing the human recombinant prostaglandin D2 (PGD2) receptor (hDP) has been characterized with respect to radioligand binding and signal transduction properties by use of prostanoids and prostanoid analogues. Radioligand binding studies included saturation analyses, the effects of nucleotide analogues, the initial rate of ligand-receptor association and equilibrium competition assays. In addition, adenosine 3':5'-cyclic monophosphate (cyclic AMP) generation in response to ligand challenge was also measured, as this is the predominant hDP signalling pathway. 2. L-644,698 ((4-(3-(3-(3-hydroxyoctyl)-4-oxo-2-thiazolidinyl) propyl) benzoic acid) (racemate)) was identified as a novel ligand having high affinity for hDP with an inhibitor constant (Ki) of 0.9 nM. This Ki value was comparable to the Ki values obtained in this study for ligands that have previously shown high affinity for DP: PGD2 (0.6 nM), ZK 110841 (0.3 nM), BW245C (0.4 nM), and BW A868C (2.3 nM). 3. L-644,698 was found to be a full agonist with an EC50 value of 0.5 nM in generating cyclic AMP following activation of hDP. L-644,698 is, therefore, comparable to those agonists with known efficacy at the DP receptor (EC50): PGD2 (0.5 nM), ZK 110841 (0.2 nM) and BW245C (0.3 nM). 4. L-644,698 displayed a high degree of selectivity for hDP when compared to the family of cloned human prostanoid receptors: EP1 (> 25,400 fold), EP2 (approximately 300 fold), EP3-III (approximately 4100 fold), EP4 (approximately 10000 fold), FP (> 25,400 fold), IP (> 25,400 fold) and TP (> 25,400 fold). L-644,698 is, therefore, one of the most selective DP agonists as yet described. 5. PGJ2 and delta12-PGJ2, two endogenous metabolites of PGD2, were also tested in this system and shown to be effective agonists with Ki and EC50 values in the nanomolar range for both compounds. In particular, PGJ2 was equipotent to known DP specific agonists with a Ki value of 0.9 nM and an EC50 value of 1.2 nM.


Assuntos
Benzoatos/farmacologia , Receptores Imunológicos , Receptores de Prostaglandina/metabolismo , Tiazóis/farmacologia , Nucleotídeos de Adenina/farmacologia , Ligação Competitiva , Linhagem Celular , AMP Cíclico/biossíntese , Dinoprostona/metabolismo , Nucleotídeos de Guanina/farmacologia , Humanos , Cinética , Receptores de Prostaglandina/agonistas , Receptores de Prostaglandina/genética , Proteínas Recombinantes/agonistas , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Tiazolidinas , Trítio
10.
Biochem Pharmacol ; 62(9): 1193-200, 2001 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-11705452

RESUMO

We sought to clone and characterize the murine cysteinyl-leukotriene D(4) receptor (mCysLT(1)R) to complement our studies with leukotriene-deficient mice. A cDNA, cloned from trachea mRNA by reverse transcriptase-polymerase chain reaction, has two potential initiator ATG codons that would encode for polypeptides of 352 and 339 amino acids, respectively. These two potential forms, predicted to be seven transmembrane-spanning domain proteins, have 87% amino acid identity with the human CysLT(1) receptor (hCysLT(1)R). Membrane fractions of Cos-7 cells transiently expressing the short mCysLT(1)R demonstrated high affinity and specific binding for leukotriene D(4) (LTD(4), K(d) = 0.25 +/- 0.04 nM). In competition binding experiments, LTD(4) was the most potent competitor (K(i) = 0.8 +/- 0.2 nM) followed by LTE(4) and LTC(4) (K(i) = 86.6 +/- 24.5 and 100.1 +/- 17.1 nM, respectively) and LTB(4) (K(i) > 1.5 microM). Binding of LTD(4) was competitively inhibited by the specific CysLT(1) receptor antagonists MK-571 [(+)-3-(((3-(2-(7-chloro-2-quinolinyl)ethenyl)phenyl) ((3-(dimethylamino)-3-oxopropyl)thio)methyl)thio)propanoic acid], pranlukast (Onon), and zafirlukast (Accolate), while the CysLT(1)/CysLT(2) receptor antagonist BAY-u9773 [6(R)-(4'-carboxyphenylthio)-5(S)-hydroxy-7(E),9(E),11(Z),14(Z)-eicosatetrenoic acid] was 1000 times less potent than LTD(4). In transiently transfected HEK293-T cells expressing either the long or short form of mCysLT(1)R, LTD(4) induced an increase of intracellular calcium. In Xenopus laevis melanophores transiently expressing either isoform, LTD(4) induced the dispersion of pigment granules, consistent with the activation by LTD(4) of a G(alphaq) (calcium) pathway. Functional elucidation of mCysLT(1)R properties as described here will enable further experiments to clarify the selective role of LTD(4) in murine models of inflammation and asthma.


Assuntos
Proteínas de Membrana , Receptores de Leucotrienos/genética , Equorina/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Células Cultivadas , Clonagem Molecular , DNA Complementar/análise , Humanos , Medições Luminescentes , Melanóforos/metabolismo , Camundongos , Dados de Sequência Molecular , Ensaio Radioligante , Receptores de Leucotrienos/metabolismo , Análise de Sequência de Proteína , Homologia de Sequência de Aminoácidos , Xenopus laevis/metabolismo
11.
Biochem Pharmacol ; 62(8): 997-1012, 2001 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-11597569

RESUMO

The prostaglandin E2 (PGE2) EP4 subtype is one of four prostanoid receptors that use PGE2 as the preferred ligand. We have investigated the agonist-mediated regulation of EP4 using a multifaceted approach. Short-term (30 min) agonist challenge of recombinant EP4 expressed in human embryonic kidney 293 cells (EP4-HEK293 cells) with PGE2 (1 microM) resulted in the desensitization of intracellular cyclic AMP (cAMP) accumulation and a reduction in cell surface [3H]PGE2 specific binding sites. These events correlated with sequestration of EP4, as visualized by immunofluorescence confocal microscopy and phosphorylation, as shown by [32P]orthophosphate labeling of the receptor. Stimulation of protein kinase A activity in EP4-HEK293 cells (10 microM forskolin or 1 mM 8-bromo-cAMP) did not induce EP4 desensitization, sequestration, or phosphorylation. In contrast, stimulation of protein kinase C activity (100 nM phorbol 12-myristate 13-acetate) attenuated PGE2-induced adenylyl cyclase activity and increased EP4 phosphorylation, but did not induce sequestration or a reduction in [3H]PGE2 specific binding sites. EP4 receptors containing a third intracellular loop deletion [EP4 (del. 215-263)] or a carboxyl-terminal tail truncation [EP4 (del. 355)] of EP4 were used to demonstrate that the C-terminal tail governs sequestration as well as phosphorylation of the receptor.


Assuntos
Dinoprostona/metabolismo , Receptores de Prostaglandina E/metabolismo , Sequência de Aminoácidos , Células Cultivadas , AMP Cíclico/metabolismo , Ativação Enzimática , Imunofluorescência , Humanos , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Dados de Sequência Molecular , Mutação , Fosforilação , Proteína Quinase C/metabolismo , Estrutura Terciária de Proteína , Receptores de Prostaglandina E/genética , Receptores de Prostaglandina E Subtipo EP4 , Sistemas do Segundo Mensageiro/fisiologia , Transfecção
12.
Brain Res Mol Brain Res ; 28(1): 37-46, 1995 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-7707876

RESUMO

To gain insight into mechanisms of cell type-specific transcription of class mu-glutathione S-transferase genes, the gene encoding the Yb3 subunit was cloned. Yb3 subunits are selectively expressed at high levels in rat brain and testis but not in liver or kidney. The Yb3 subunit gene spans over 6 kb and consists of 8 exons and 7 introns and a sequence consisting of tandem direct repeat consensus octamer DNA binding motifs separated by a 6 base pair (bp) spacer was identified in its 5'-flanking region. Gel shift assays with a 40 bp segment of DNA containing the two consensus octamer sequences, revealed the presence of specific binding proteins in nuclear extracts of rat brain, testis and C6 glioma cells. DNA binding activity was greatly reduced in liver, kidney and HTC cells. Reporter vectors carrying segments of the 5'-flanking region of the Yb3 subunit gene fused to a luciferase gene were introduced into C6 glioma cells which express high levels of Yb3 subunits, and into HTC cells which do not. The plasmids consisting of the Yb3 gene promoter up to, but not including, the octamer motifs did not support luciferase transcription in the C6 glioma cells, but larger fragments that included the octamer repeat sequences, effectively directed transcription in the C6 glioma cells. With mutated octameric sequences transcriptional activity was greatly reduced, and none of the same Yb3 constructs directed substantial luciferase transcription in the HTC cells. The results show that octamer motifs in the 5'-flanking region of the Yb3 subunit gene are functional and are the principal cis-acting elements that account for its discrete cell type-selective expression. This gene is one of the few known targets for octamer DNA binding transcription factors in brain.


Assuntos
Encéfalo/metabolismo , Glutationa Transferase/biossíntese , Testículo/metabolismo , Animais , Sequência de Bases , Sondas de DNA , Éxons , Expressão Gênica , Glioma/metabolismo , Glutationa Transferase/genética , Íntrons , Luciferases/biossíntese , Masculino , Dados de Sequência Molecular , Ratos , Transcrição Gênica
13.
Science ; 174(4008): 481-3, 1971 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-17745738
14.
Eur J Pharmacol ; 340(2-3): 227-41, 1997 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-9537820

RESUMO

We have characterized the rat prostanoid EP1, EP2, EP3alpha and EP4 receptor subtypes cloned from spleen, hepatocyte and/or kidney cDNA libraries. Comparison of the deduced amino acid sequences of the rat EP receptors with their respective homologues from mouse and human showed 91% to 98% and 82% to 89% identity, respectively. Radioreceptor binding assays and functional assays were performed on EP receptor expressing human embryonic kidney (HEK) 293 cells. The KD values obtained with prostaglandin E2 for the prostanoid receptor subtypes EP1, EP2, EP3alpha and EP4 were approximately 24, 5, 1 and 1 nM, respectively. The rank order of affinities for various prostanoids at the prostanoid receptor subtypes EP2, EP3alpha and EP4 receptor subtypes was prostaglandin E2 = prostaglandin E1 > iloprost > prostaglandin F2alpha > prostaglandin D2 > U46619. The rank order at the prostanoid EP1 receptor was essentially the same except that iloprost had the highest affinity of the prostanoids tested. Of the selective ligands, butaprost was selective for prostanoid EP2, M&B28767 and sulprostone were selective for EP3alpha and enprostil displayed dual selectivity, interacting with both prostanoid receptor subtypes EP1 and EP3alpha. All four receptors coupled to their predominant signal transduction pathways in HEK 293 cells. Notably, using a novel aequorin luminescence assay to monitor prostanoid EP1 mediated increases in intracellular calcium, both iloprost and sulprostone were identified as partial agonists. Finally, by Northern blot analysis EP3 transcripts were most abundant in liver and kidney whereas prostanoid EP2 receptor mRNA was expressed in spleen, lung and testis and prostanoid EP1 receptor mRNA transcripts were predominantly expressed in the kidney. The rat prostanoid EP1 probes also detected additional and abundant transcripts present in all the tissues examined. These were found to be related to the expression of a novel protein kinase gene and not the prostanoid EP1 gene [Batshake, B., Sundelin, J., 1996. The mouse genes for the EP1 prostanoid receptor and the novel protein kinase overlap. Biochem. Biophys. Res. Commun. 227. 1329-1333].


Assuntos
Dinoprostona/metabolismo , Receptores de Prostaglandina E/química , Equorina , Sequência de Aminoácidos , Animais , Northern Blotting , Linhagem Celular , Membrana Celular/química , Clonagem Molecular , Humanos , Rim/metabolismo , Ligantes , Fígado/metabolismo , Medições Luminescentes , Masculino , Camundongos , Dados de Sequência Molecular , Ensaio Radioligante , Ratos , Baço/metabolismo
15.
Eur J Pharmacol ; 380(2-3): 203-13, 1999 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-10513580

RESUMO

A cDNA clone coding for the guinea pig leukotriene B4 (BLT) receptor has been isolated from a lung cDNA library. The guinea pig BLT receptor has an open reading frame corresponding to 348 amino acids and shares 73% and 70% identity with human and mouse BLT receptors, respectively. Scatchard analysis of membranes prepared from guinea pig and human BLT receptor-transfected human embryonic kidney (HEK) 293 EBNA (Epstein-Bar Virus Nuclear Antigen) cells showed that both receptors displayed high affinity for leukotriene B4 (Kd value of approximately 0.4 nM) and were expressed at high levels (Bmax values ranging from 9 to 12 pmol/mg protein). The rank order of potency for leukotrienes and related analogs in competition for [3H]leukotriene B4 specific binding at the recombinant guinea pig BLT receptor is leukotriene B4 > 20-OH-leukotriene B4 > 12(R)-HETE ((5Z,8Z,10E,12(R)14Z)-12-hydroxyeicosatetraen -1-oic acid) > 12(S)-HETE ((5Z,8Z,10E,12(S)14Z)-12-Hydroxyeicosatetraen -1-oic acid) > 20-COOH-leukotriene B4 > U75302 (6-(6-(3-hydroxy-1E,5Z-undecadienyl)-2-pyridinyl)-1,5-hexane diol) >> leukotriene C4 = leukotriene D4 = leukotriene E4. For the human receptor the rank order of 12(S)-HETE, 20-COOH-leukotriene B4 and U75302 was reversed. Xenopus melanophore and HEK aequorin-based reporter gene assays were used to demonstrate that the guinea pig and human BLT receptors can couple to both the cAMP inhibitory and intracellular Ca2+ mobilization signaling pathways. However, in the case of the aequorin-expressing HEK cells (designated AEQ17-293) transfected with either the guinea pig or human BLT receptor, expression of Galpha16 was required to achieve a robust Ca2+ driven response. Leukotriene B4 was a potent agonist in functional assays of both the guinea pig and human BLT receptors. U-75302 a leukotriene B4 analogue which possesses both agonistic and antagonistic properties behaved as a full agonist of the guinea pig and human BLT receptors in AEQ17-293 cells and not as an antagonist. The recombinant guinea pig BLT receptor will permit the comparison of the intrinsic potencies of leukotriene B4 receptor antagonists used in guinea pig in vivo models of allergic and inflammatory disorders.


Assuntos
Receptores do Leucotrieno B4/genética , Equorina/análise , Equorina/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Ligação Competitiva , Linhagem Celular , Membrana Celular/metabolismo , Clonagem Molecular , DNA Complementar/química , DNA Complementar/genética , Cobaias , Humanos , Medições Luminescentes , Melanóforos/metabolismo , Dados de Sequência Molecular , Ensaio Radioligante , Receptores do Leucotrieno B4/metabolismo , Alinhamento de Sequência , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Transfecção , Xenopus
18.
Xenobiotica ; 35(7): 737-53, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16316932

RESUMO

The effects of different fibric acid derivatives (bezafibrate, clofibrate, clofibric acid, fenofibrate, fenofibric acid and gemfibrozil) on human organic anion transporting-polypeptide 1B1 (OATP2, OATP-C, SLC21A6), multidrug resistance protein 2 (MRP2/ABCC2) and MDR1-type P-glycoprotein (P-gp/ABCB1) were examined in vitro. Cyclosporin A (a known inhibitor of OATP1B1 and P-gp), MK-571 (a known inhibitor of MRP2) and cimetidine (an organic cation) were also tested. Bezafibrate, fenofibrate, fenofibric acid and gemfibrozil showed concentration-dependent inhibition of estradiol 17-beta-D-glucuronide uptake by OATP1B1-stably transfected HEK cells, whereas clofibrate and clofibric acid did not show any significant effects up to 100 microM. Inhibition kinetics of gemfibrozil, which exhibited the most significant inhibition on OATP1B1, was shown to be competitive with a Ki = 12.5 microM. None of the fibrates showed any significant inhibition of MRP2-mediated transport, which was evaluated by measuring the uptake of ethacrynic acid glutathione into MRP2-expressing Sf9 membrane vesicles. Only fenofibrate showed moderate P-gp inhibition as assessed by measuring cellular accumulation of vinblastine in a P-gp overexpressing cell-line. Cyclosporin A significantly inhibited OATP1B1 and P-gp, whereas only moderate inhibition was observed on MRP2. The rank order of inhibitory potency of MK-571 was determined as OATP1B1 (IC50: 0.3 microM) > MRP2 (4 microM) > P-gp (25 microM). Cimetidine did not show any effects on these transporters. In conclusion, neither MRP2- nor P-gp-mediated transport is inhibited significantly by the fibrates tested. Considering the plasma protein binding and IC50 values for OATP1B1, only gemfibrozil appeared to have a potential to cause drug-drug interactions by inhibiting OATP1B1 at clinically relevant concentrations.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Ácido Clofíbrico/farmacologia , Hipolipemiantes/farmacologia , Transportador 1 de Ânion Orgânico Específico do Fígado/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/antagonistas & inibidores , Transporte Biológico Ativo/efeitos dos fármacos , Linhagem Celular , Interações Medicamentosas , Ativação Enzimática/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Estradiol/análogos & derivados , Estradiol/farmacologia , Humanos , Transportador 1 de Ânion Orgânico Específico do Fígado/antagonistas & inibidores , Proteína 2 Associada à Farmacorresistência Múltipla , Proteínas Associadas à Resistência a Múltiplos Medicamentos/antagonistas & inibidores
19.
Soc Work ; 31(4): 257-64, 1986.
Artigo em Inglês | MEDLINE | ID: mdl-10300978

RESUMO

Although the privatization of social services is not new, its purpose, form, and content have changed over time. Under the Reagan Administration, it has meant a greater role for private enterprise in a scaled-down welfare state. Intervention in the economy was historically conceived to modify the market in behalf of social justice. In contrast, privatization channels public dollars into private hands, strengthens the two-class welfare state, and reproduces the inequalities of the free market.


Assuntos
Hospitais com Fins Lucrativos/provisão & distribuição , Hospitais/provisão & distribuição , Indústrias , Política Pública/tendências , Seguridade Social/tendências , Acessibilidade aos Serviços de Saúde/economia , Estados Unidos
20.
Soc Work ; 46(4): 297-308, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11682971

RESUMO

Most people have an inaccurate assessment of who is "on welfare." Two decades have passed since Social Work published the original version of this article, which applied Titmuss's framework of a three-tiered social welfare system and showed that nearly "everyone is on welfare." Based on new data and a more in-depth analysis, this article re-examines who benefits from and who pays for social, fiscal, and corporate welfare and concludes that all three welfare systems continue to serve and to favor the middle class, wealthy households, and large corporations. Social workers can work to transform the system from one that rewards power and privilege to one that ensures distributive justice for all.


Assuntos
Assistência Pública/estatística & dados numéricos , Política Pública , Seguridade Social/estatística & dados numéricos , Alocação de Recursos para a Atenção à Saúde , Humanos , Assistência Pública/normas , Justiça Social , Previdência Social/estatística & dados numéricos , Seguridade Social/economia , Impostos/estatística & dados numéricos , Estados Unidos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA