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Sample records for cyclooxygenase 2-thromboxane pathway

  1. Involvement of COX2-thromboxane pathway in TCDD-induced precardiac edema in developing zebrafish.

    Science.gov (United States)

    Teraoka, Hiroki; Okuno, Yuki; Nijoukubo, Daisuke; Yamakoshi, Ayumi; Peterson, Richard E; Stegeman, John J; Kitazawa, Takio; Hiraga, Takeo; Kubota, Akira

    2014-09-01

    The cardiovascular system is one of the most characteristic and important targets for developmental toxicity by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in fish larvae. However, knowledge of the mechanism of TCDD-induced edema after heterodimerization of aryl hydrocarbon receptor type 2 (AHR2) and AHR nuclear translocator type 1 (ARNT1) is still limited. In the present study, microscopic analysis with a high-speed camera revealed that TCDD increased the size of a small cavity between the heart and body wall in early eleutheroembryos, a toxic effect that we designate as precardiac edema. A concentration-response curve for precardiac edema at 2 days post fertilization (dpf) showed close similarity to that for conventional pericardial edema at 3 dpf. Precardiac edema caused by TCDD was reduced by morpholino knockdown of AHR2 and ARNT1, as well as by an antioxidant (ascorbic acid). A selective inhibitor of cyclooxygenase type 2 (COX2), NS398, also markedly inhibited TCDD-induced precardiac edema. A thromboxane receptor (TP) antagonist, ICI-192,605 almost abolished TCDD-induced precardiac edema and this effect was canceled by U46619, a TP agonist, which was not influential in the action of TCDD by itself. Knockdown of COX2b and thromboxane A synthase 1 (TBXS), but not COX2a, strongly reduced TCDD-induced precardiac edema. Knockdown of COX2b was without effect on mesencephalic circulation failure caused by TCDD. The edema by TCDD was also inhibited by knockdown of c-mpl, a thrombopoietin receptor necessary for thromobocyte production. Finally, induction of COX2b, but not COX2a, by TCDD was seen in eleutheroembryos at 3 dpf. These results suggest a role of the COX2b-thromboxane pathway in precardiac edema formation following TCDD exposure in developing zebrafish.

  2. The role of cyclooxygenase-2/prostanoid pathway in visceral pain induced liver stress response in rats

    Institute of Scientific and Technical Information of China (English)

    PISTON Donald; WANG Shan; FENG Yi; YE Ying-jiang; ZHOU Jing; JIANG Ke-wei; XU Feng; ZHAO Yong; CUI Zhi-rong

    2007-01-01

    Background Cyclooxygenase (COX) is the rate-limiting enzyme in the production of prostanoids from arachidonic acid.COX-2 is the inducible enzyme in the COX family, together with the prostanoids forms the COX-2/prostanoid pathway.Research showed that the COX-2/prostanoid pathway is activated in hepatic diseases and liver stress reaction, such as fibrogenesis, portal hypertension, carcinogenesis, and ischemic/reperfusion injury. But there was no report on visceral pain induced liver stress. This study was to investigate the role of the COX-2/prostanoid pathway in liver stress response in rat acute colitis visceral pain liver stress model.Methods Fifty-three male SD rats were randomly divided into Naive, Model, NS398 treatment, and Morphine treatment groups. The rat acute colitis visceral pain liver stress model was established under anesthesia by the colonic administration of 0.5 ml of 6% acetic acid using a urethral catheter. NS398 and morphine were administrated 30 minutes prior to model establishment in NS398 and Morphine treatment groups respectively. Spontaneous activities and pain behavior were counted and the extent of colonic inflammation was assessed histologically. Liver tissue levels of Glutathione-S-Transferase (GST) activity, COX-2 mRNA, prostaglandin E2 (PGE2), thromboxane B2 (TXB2) and 6-Ketone-prostaglandin F1α (6-K-PGF1α) contents were assessed.Results Thirty minutes after the colonic administration of acetic acid, a significant decrease in spontaneous activities and an increase in pain behaviors were observed in Model group (P<0.01 and P<0.05 respectively), accompanied by colonic inflammation. Liver GST activity levels significantly dropped (P<0.05). Liver COX-2 mRNA expression significantly increased, accompanied by an increase in liver concentrations of PGE2 and TXB2, but no obvious change in 6-K-PGF1α concentrations. NS398 and morphine both ameliorated post-stress liver GST activity (P<0.05 and P<0.01respectively), decreased stress

  3. Intermittent hypoxia-activated cyclooxygenase pathway: role in atherosclerosis.

    Science.gov (United States)

    Gautier-Veyret, Elodie; Arnaud, Claire; Bäck, Magnus; Pépin, Jean-Louis; Petri, Marcelo H; Baguet, Jean-Philippe; Tamisier, Renaud; Lévy, Patrick; Stanke-Labesque, Françoise

    2013-08-01

    Intermittent hypoxia, the main stimulus of obstructive sleep apnoea (OSA), induces inflammation, leading to early atherosclerosis. Whether the cyclooxygenase (COX) pathway contributes to intermittent hypoxia-induced atherosclerosis remains to be determined. We studied the effects of 8-weeks of intermittent hypoxia exposure on COX-pathway gene expression and atherosclerosis, and the influence of COX-1 inhibition by SC-560 on atherosclerosis progression in aortas of apolipoprotein E(-/-) mice. Urinary 11-dehydrothromboxane B2 (11-dTXB2) was assessed in 50 OSA subjects free of cardiovascular risk factor matched for age and body mass index with 25 controls, and 56 OSA with cardiovascular risk factor. Intermittent hypoxia significantly increased atherosclerotic lesion sizes, mRNA levels of COX-1 and thromboxane synthase (TXBS). Lesion sizes correlated to COX-1 (r = 0.654, p = 0.0003) and TXBS (r = 0.693, pintermittent hypoxia mice only (p = 0.04). Urinary 11-dTXB2 was similar in OSA subjects free of cardiovascular risk factor and controls, but was increased by 13% (p = 0.007) in OSA subjects with cardiovascular risk factor compared with those without. Although OSA itself was not associated with increased urinary 11-dTXB2 concentration, the COX-1 pathway was activated in intermittent hypoxia-exposed mice and in OSA subjects presenting with cardiovascular risk factor, and may contribute to intermittent hypoxia-induced atherogenesis. COX-1 inhibition could be of clinical interest in the prevention of cardiovascular morbidity in OSA.

  4. Cyclooxygenase-2 inhibitor, celecoxib, inhibits leiomyoma cell proliferation through the nuclear factor κB pathway.

    Science.gov (United States)

    Park, Seung Bin; Jee, Byung Chul; Kim, Seok Hyun; Cho, Yeon Jean; Han, Myoungseok

    2014-09-01

    Our aim was to investigate whether celecoxib, a cyclooxygenase 2 (COX-2) inhibitor, decreases the in vitro proliferation of leiomyoma cells if the inflammatory pathway is blocked. Menstruation is an inflammation of uterus that produces cytokines and prostanoids, but the inflammatory mechanism underlying the growth of leiomyoma remains unexplained. Using in vitro cultures of leiomyoma cells obtained from 5 patients who underwent hysterectomy, cell proliferation, inflammatory signaling, transcription factors, growth factors, and extracellular matrix were examined by (4,5-dimethylthiaxol-2-yi)-2,5-diphenyltetraxolium bromide assay, immunoblotting, and quantitative polymerase chain reaction. Prostaglandin E2 was used to induce menstruation-like condition in the cells. We found that celecoxib inhibited COX-2 through the expression of nuclear factor κB in the cells. Celcoxib also decreased the gene expression of interleukin 6, tumor necrosis factor α, collagen A, fibronectin, platelet-derived growth factor, epidermal growth factor, and transforming growth factor β. In conclusion, the present study indicated that celecoxib could inhibit leiomyoma cell proliferation through blocking the inflammatory pathway that is probably one of the mechanisms underlying its pathogenesis.

  5. Signal transduction pathways regulating cyclooxygenase-2 expression: potential molecular targets for chemoprevention.

    Science.gov (United States)

    Chun, Kyung-Soo; Surh, Young-Joon

    2004-09-15

    Expression of cyclooxygenase-2 (COX-2) has been reported to be elevated in human colorectal adenocarcinoma and other tumors, including those of breast, cervical, prostate, and lung. Genetic knock-out or pharmacological inhibition of COX-2 has been shown to protect against experimentally-induced carcinogenesis. Results from epidemiological and laboratory studies indicate that regular intake of selective COX-2 inhibitors reduces the risk of several forms of human malignancies. Thus, it is conceivable that targeted inhibition of abnormally or improperly elevated COX-2 provides one of the most effective and promising strategies for cancer chemoprevention. The COX-2 promoter contains a TATA box and binding sites for several transcription factors including nuclear factor-kappaB (NF-kappaB), nuclear factor for interleukin-6/CCAAT enhancer-binding protein (NF-IL6/C/EBP) and cyclic AMP response element (CRE) binding protein. Upregulation of COX-2 is mediated by a variety of stimuli including tumor promoters, oncogenes, and growth factors. Stimulation of either protein kinase C (PKC) or Ras signaling enhances mitogen-activated protein kinase (MAPK) activity, which, in turn, activates transcription of cox-2. Celecoxib, the first US FDA approved selective COX-2 inhibitor, initially developed for the treatment of adult rheumatoid arthritis and osteoarthritis, has been reported to reduce the formation of polyps in patients with familial adenomatous polyposis. This COX-2 specific inhibitor also protects against experimentally-induced carcinogenesis, but the underlying molecular mechanisms are poorly understood. The present review covers the signal transduction pathways responsible for regulating COX-2 expression as novel molecular targets of chemopreventive agents with celecoxib as a specific example.

  6. Role of cyclooxygenase-2 signaling pathway dysfunction in unexplained recurrent spontaneous abortion

    Institute of Scientific and Technical Information of China (English)

    WANG Yu; ZHAO Ai-min; LIN Qi-de

    2010-01-01

    Background Experimental evidence indicates that cyclooxygenase-2 (COX-2) plays a critical role in blastocyst implantation; however, little is known of the role of COX-2 in unexplained recurrent spontaneous abortion (URSA).Methods We evaluated the expression level and potential signaling pathway of COX-2 in 30 cases of URSA who were excluded the abnormality of chromosomes, anatomy, endocrine, infectious, autoimmune diseases and in 30 normal pregnancies.Results The mRNA and the protein expression level of COX-2 in the URSA group (-0.238±0.848, 0.368±0.089,respectively) were significantly lower than that in the control group (1.943±3.845, 1.046±0.108, respectively) (both, P<0.01). The expression of prostaglandins PGF2a, PGD2, PGE2, and PGI2, in the URSA group ((2326.0±295.6) pg/ml,(2164.0±240.5) pg/ml, (238.7±26.4) pg/ml, (2337.0±263.0) pg/ml, respectively) were significantly lower than that in the control group ((3450.0±421.7) pg/ml, (3174.0±415.6) pg/ml, (323.5±43.8) pg/ml, (3623.0±460.4) pg/ml, respectively) (P<0.05). The mRNA expression level of PPARβ and RXRa (0.859±0.653, -0.172±0.752, respectively) in URSA group was significantly lower than that in the control group (1.554±1.735, 0.777±2.482, respectively) (both P <0.05). The mRNA and protein expression levels of vascular endothelial growth factor-A (VEGF-A) in the URSA group (2.010±1.522, 0.35±0.46)was significantly lower than that in the control group (4.569±2.430, 0.750±0.350) (both P <0.05).Conclusions COX-2 and the COX-2-derived PGI2 signaling pathway possibly play an important role in successful embryo implantation, and their decreased expression may result in URSA. The decreased expression may influence the expression of VEGF-A which interferes with placental angiogenesis causing failure of embryo implantation, leading to spontaneous abortion.

  7. MAPK pathway activation by chronic lead-exposure increases vascular reactivity through oxidative stress/cyclooxygenase-2-dependent pathways

    Energy Technology Data Exchange (ETDEWEB)

    Simões, Maylla Ronacher, E-mail: yllars@hotmail.com [Dept. of Physiological Sciences, Federal University of Espirito Santo, Vitória, ES CEP 29040-091 (Brazil); Department of Pharmacology, Universidad Autonoma de Madrid, Instituto de Investigación Hospital Universitario La Paz (IdiPAZ), Madrid (Spain); Aguado, Andrea [Department of Pharmacology, Universidad Autonoma de Madrid, Instituto de Investigación Hospital Universitario La Paz (IdiPAZ), Madrid (Spain); Fiorim, Jonaína; Silveira, Edna Aparecida; Azevedo, Bruna Fernandes; Toscano, Cindy Medice [Dept. of Physiological Sciences, Federal University of Espirito Santo, Vitória, ES CEP 29040-091 (Brazil); Zhenyukh, Olha; Briones, Ana María [Department of Pharmacology, Universidad Autonoma de Madrid, Instituto de Investigación Hospital Universitario La Paz (IdiPAZ), Madrid (Spain); Alonso, María Jesús [Dept. of Biochemistry, Physiology and Molecular Genetics, Universidad Rey Juan Carlos, Alcorcón (Spain); Vassallo, Dalton Valentim [Dept. of Physiological Sciences, Federal University of Espirito Santo, Vitória, ES CEP 29040-091 (Brazil); Health Science Center of Vitória-EMESCAM, Vitória, ES CEP 29045-402 (Brazil); Salaices, Mercedes, E-mail: mercedes.salaices@uam.es [Department of Pharmacology, Universidad Autonoma de Madrid, Instituto de Investigación Hospital Universitario La Paz (IdiPAZ), Madrid (Spain)

    2015-03-01

    Chronic exposure to low lead concentration produces hypertension; however, the underlying mechanisms remain unclear. We analyzed the role of oxidative stress, cyclooxygenase-2-dependent pathways and MAPK in the vascular alterations induced by chronic lead exposure. Aortas from lead-treated Wistar rats (1st dose: 10 μg/100 g; subsequent doses: 0.125 μg/100 g, intramuscular, 30 days) and cultured aortic vascular smooth muscle cells (VSMCs) from Sprague Dawley rats stimulated with lead (20 μg/dL) were used. Lead blood levels of treated rats attained 21.7 ± 2.38 μg/dL. Lead exposure increased systolic blood pressure and aortic ring contractile response to phenylephrine, reduced acetylcholine-induced relaxation and did not affect sodium nitroprusside relaxation. Endothelium removal and L-NAME left-shifted the response to phenylephrine more in untreated than in lead-treated rats. Apocynin and indomethacin decreased more the response to phenylephrine in treated than in untreated rats. Aortic protein expression of gp91(phox), Cu/Zn-SOD, Mn-SOD and COX-2 increased after lead exposure. In cultured VSMCs lead 1) increased superoxide anion production, NADPH oxidase activity and gene and/or protein levels of NOX-1, NOX-4, Mn-SOD, EC-SOD and COX-2 and 2) activated ERK1/2 and p38 MAPK. Both antioxidants and COX-2 inhibitors normalized superoxide anion production, NADPH oxidase activity and mRNA levels of NOX-1, NOX-4 and COX-2. Blockade of the ERK1/2 and p38 signaling pathways abolished lead-induced NOX-1, NOX-4 and COX-2 expression. Results show that lead activation of the MAPK signaling pathways activates inflammatory proteins such as NADPH oxidase and COX-2, suggesting a reciprocal interplay and contribution to vascular dysfunction as an underlying mechanisms for lead-induced hypertension. - Highlights: • Lead-exposure increases oxidative stress, COX-2 expression and vascular reactivity. • Lead exposure activates MAPK signaling pathway. • ROS and COX-2 activation by

  8. Expression of the aryl hydrocarbon receptor pathway and cyclooxygenase-2 in dog tumors.

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    Giantin, M; Vascellari, M; Lopparelli, R M; Ariani, P; Vercelli, A; Morello, E M; Cristofori, P; Granato, A; Buracco, P; Mutinelli, F; Dacasto, M

    2013-02-01

    In humans, the aryl hydrocarbon receptor (AHR) gene battery constitutes a set of contaminant-responsive genes, which have been recently shown to be involved in the regulation of several patho-physiological conditions, including tumorigenesis. As the domestic dog represents a valuable animal model in comparative oncology, mRNA levels of cytochromes P450 1A1, 1A2 and 1B1 (CYP1A1, 1A2 and 1B1), AHR, AHR nuclear translocator (ARNT), AHR repressor (AHRR, whose partial sequence was here obtained) and cyclooxygenase-2 (COX2) were measured in dog control tissues (liver, skin, mammary gland and bone), in 47 mast cell tumors (MCTs), 32 mammary tumors (MTs), 5 osteosarcoma (OSA) and related surgical margins. Target genes were constitutively expressed in the dog, confirming the available human data. Furthermore, their pattern of expression in tumor biopsies was comparable to that already described in a variety of human cancers; in particular, both AHR and COX2 genes were up-regulated and positively correlated, while CYP1A1 and CYP1A2 mRNAs were generally poorly expressed. This work demonstrated for the first time that target mRNAs are expressed in neoplastic tissues of dogs, thereby increasing the knowledge about dog cancer biology and confirming this species as an useful animal model for comparative studies on human oncology.

  9. Mercury induces proliferation and reduces cell size in vascular smooth muscle cells through MAPK, oxidative stress and cyclooxygenase-2 pathways

    Energy Technology Data Exchange (ETDEWEB)

    Aguado, Andrea; Galán, María; Zhenyukh, Olha; Wiggers, Giulia A.; Roque, Fernanda R. [Departamento de Farmacología, Facultad de Medicina, Universidad Autónoma de Madrid, Instituto de Investigación Hospital Universitario La Paz (IdiPAZ), 28029, Madrid (Spain); Redondo, Santiago [Departamento de Farmacología, Facultad de Medicina, Universidad Complutense, 28040, Madrid (Spain); Peçanha, Franck [Departamento de Farmacología, Facultad de Medicina, Universidad Autónoma de Madrid, Instituto de Investigación Hospital Universitario La Paz (IdiPAZ), 28029, Madrid (Spain); Martín, Angela [Departamento de Bioquímica, Fisiología y Genética Molecular, Universidad Rey Juan Carlos, 28922, Alcorcón (Spain); Fortuño, Ana [Área de Ciencias Cardiovasculares, Centro de Investigación Médica Aplicada, Universidad de Navarra, 31008, Pamplona (Spain); Cachofeiro, Victoria [Departamento de Fisiología, Facultad de Medicina, Universidad Complutense, 28040, Madrid (Spain); Tejerina, Teresa [Departamento de Farmacología, Facultad de Medicina, Universidad Complutense, 28040, Madrid (Spain); Salaices, Mercedes, E-mail: mercedes.salaices@uam.es [Departamento de Farmacología, Facultad de Medicina, Universidad Autónoma de Madrid, Instituto de Investigación Hospital Universitario La Paz (IdiPAZ), 28029, Madrid (Spain); and others

    2013-04-15

    Mercury exposure is known to increase cardiovascular risk but the underlying cellular mechanisms remain undetermined. We analyzed whether chronic exposure to HgCl{sub 2} affects vascular structure and the functional properties of vascular smooth muscle cells (VSMC) through oxidative stress/cyclooxygenase-2 dependent pathways. Mesenteric resistance arteries and aortas from Wistar rats treated with HgCl{sub 2} (first dose 4.6 mg kg{sup −1}, subsequent doses 0.07 mg kg{sup −1} day{sup −1}, 30 days) and cultured aortic VSMC stimulated with HgCl{sub 2} (0.05–5 μg/ml) were used. Treatment of rats with HgCl{sub 2} decreased wall thickness of the resistance and conductance vasculature, increased the number of SMC within the media and decreased SMC nucleus size. In VSMCs, exposure to HgCl{sub 2}: 1) induced a proliferative response and a reduction in cell size; 2) increased superoxide anion production, NADPH oxidase activity, gene and/or protein levels of the NADPH oxidase subunit NOX-1, the EC- and Mn-superoxide dismutases and cyclooxygenase-2 (COX-2); 3) induced activation of ERK1/2 and p38 MAPK. Both antioxidants and COX-2 inhibitors normalized the proliferative response and the altered cell size induced by HgCl{sub 2}. Blockade of ERK1/2 and p38 signaling pathways abolished the HgCl{sub 2}-induced Nox1 and COX-2 expression and normalized the alterations induced by mercury in cell proliferation and size. In conclusion, long exposure of VSMC to low doses of mercury activates MAPK signaling pathways that result in activation of inflammatory proteins such as NADPH oxidase and COX-2 that in turn induce proliferation of VSMC and changes in cell size. These findings offer further evidence that mercury might be considered an environmental risk factor for cardiovascular disease. - Highlights: ► Chronic HgCl{sub 2} exposure induces vascular remodeling. ► HgCl{sub 2} induces proliferation and decreased cell size in vascular smooth muscle cells. ► HgCl{sub 2} induces

  10. Prostaglandin E2, thromboxane B2, and leukotriene B4 release from peritoneal macrophages by different osmotic agents in nonuremic guinea pigs.

    Science.gov (United States)

    Hain, H; Jörres, A; Kögel, B; Mahiout, A; Gahl, G M; Kessel, M

    1988-01-01

    Interleukin-1 (Il-1), prostaglandins, and leukotrienes have been identified as inflammatory parameters in the setting of peritoneal dialysis. Recently, it was postulated that chronic overstimulation of peritoneal macrophages (PM) may result in fibrosis and loss of ultrafiltration. The aim of the present study was to investigate whether alternative osmotic agents (polyglucose, amino acids, glycerol, bicarbonate/glucose, gelatine, hydroxyethyl starch) provoke greater eicosanoid release by PMs than glucose. Fifty milliliters of sterile dialysate containing different osmotic agents were injected intraperitoneally into nonuremic guinea pigs. After 4 hours of dwell time, prostaglandin E2 (PGE2), thromboxane B2 (TXB2), and leukotriene B4 (LTB4) production was analyzed in peritoneal effluents using specific radioimmunoassays (RIA) after liquid extraction. Cyclooxygenase products were generated with all osmotic agents: PGE2 concentrations ranged from 0.9 to 2.8 ng/4h, and TXB2 levels ranged from 39 to 49 ng/4h. In addition, the lipoxygenase product LTB4 was found in concentrations between 1.8 and 3.5 ng/4h. There were no significant differences in eicosanoid release among the osmotic agents. Thus, in this experimental setting, the capacity of PM to release inflammatory mediators did not correlate with the chemical composition of the dialysis solutions.

  11. Anti-inflammatory effects of essential oils from Chamaecyparis obtusa via the cyclooxygenase-2 pathway in rats.

    Science.gov (United States)

    An, Beum-Soo; Kang, Ji-Houn; Yang, Hyun; Jung, Eui-Man; Kang, Hong-Seok; Choi, In-Gyu; Park, Mi-Jin; Jeung, Eui-Bae

    2013-07-01

    Essential oils are concentrated hydrophobic liquids containing volatile aromatic compounds from plants. In the present study, the essential oil of Chamaecyparis obtusa (C. obtusa), which is commercially used in soap, toothpaste and cosmetics, was extracted. Essential oil extracted from C. obtusa contains several types of terpenes, which have been shown to have anti-oxidative and anti-inflammatory effects. In the present study, we examined the anti-inflammatory effects of C. obtusa essential oil in vivo and in vitro following the induction of inflammation by lipopolysaccharides (LPS) in rats. While LPS induced an inflammatory response through the production of prostaglandin E2 (PGE2) in the blood and peripheral blood mononuclear cells (PMNCs), these levels were reduced when essential oil was pre-administered. Additionally, the mechanism of action underlying the anti-inflammatory effects of C. obtusa essential oil was investigated by measuring the mRNA expression of inflammation‑associated genes. LPS treatment significantly induced the expression of transforming growth factor α (TNFα) and cyclooxygenase-2 (COX-2) in rats, while C. obtusa essential oil inhibited this effect. Taken together, our results demonstrate that C. obtusa essential oil exerts anti‑inflammatory effects by regulating the production of PGE2 and TNFα gene expression through the COX-2 pathway. These findings suggest that C. obtusa essential oil may constitute a novel source of anti-inflammatory drugs.

  12. Simultaneous inhibition of EGFR/VEGFR and cyclooxygenase-2 targets stemness-related pathways in colorectal cancer cells.

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    Araceli Valverde

    Full Text Available Despite the demonstrated benefits of anti-EGFR/VEGF targeted therapies in metastatic colorectal cancer (mCRC, many patients initially respond, but then show evidence of disease progression. New therapeutic strategies are needed to make the action of available drugs more efficient. Our study aimed to explore whether simultaneous targeting of EGFR/VEGF and cyclooxygenase-2 (COX-2 may aid the treatment and management of mCRC patients. The dual tyrosine kinase inhibitor AEE788 and celecoxib were used to inhibit EGFR/VEGFR and COX-2, respectively, in colorectal cancer cells. COX-2 inhibition with celecoxib augmented the antitumoral and antiangiogenic efficacy of AEE788, as indicated by the inhibition of cell proliferation, induction of apoptosis and G1 cell cycle arrest, down-regulation of VEGF production by cancer cells and reduction of cell migration. These effects were related with a blockade in the EGFR/VEGFR signaling axis. Notably, the combined AEE788/celecoxib treatment prevented β-catenin nuclear accumulation in tumor cells. This effect was associated with a significant downregulation of FOXM1 protein levels and an impairment in the interaction of this transcription factor with β-catenin, which is required for its nuclear localization. Furthermore, the combined treatment also reduced the expression of the stem cell markers Oct 3/4, Nanog, Sox-2 and Snail in cancer cells, and contributed to the diminution of the CSC subpopulation, as indicated by colonosphere formation assays. In conclusion, the combined treatment of AEE788 and celecoxib not only demonstrated enhanced anti-tumoral efficacy in colorectal cancer cells, but also reduced colon CSCs subpopulation by targeting stemness-related pathways. Therefore, the simultaneous targeting of EGFR/VEGF and COX-2 may aid in blocking mCRC progression and improve the efficacy of existing therapies in colorectal cancer.

  13. Simultaneous Inhibition of EGFR/VEGFR and Cyclooxygenase-2 Targets Stemness-Related Pathways in Colorectal Cancer Cells

    Science.gov (United States)

    Valverde, Araceli; Peñarando, Jon; Cañas, Amanda; López-Sánchez, Laura M.; Conde, Francisco; Hernández, Vanessa; Peralbo, Esther; López-Pedrera, Chary; de la Haba-Rodríguez, Juan; Aranda, Enrique; Rodríguez-Ariza, Antonio

    2015-01-01

    Despite the demonstrated benefits of anti-EGFR/VEGF targeted therapies in metastatic colorectal cancer (mCRC), many patients initially respond, but then show evidence of disease progression. New therapeutic strategies are needed to make the action of available drugs more efficient. Our study aimed to explore whether simultaneous targeting of EGFR/VEGF and cyclooxygenase-2 (COX-2) may aid the treatment and management of mCRC patients. The dual tyrosine kinase inhibitor AEE788 and celecoxib were used to inhibit EGFR/VEGFR and COX-2, respectively, in colorectal cancer cells. COX-2 inhibition with celecoxib augmented the antitumoral and antiangiogenic efficacy of AEE788, as indicated by the inhibition of cell proliferation, induction of apoptosis and G1 cell cycle arrest, down-regulation of VEGF production by cancer cells and reduction of cell migration. These effects were related with a blockade in the EGFR/VEGFR signaling axis. Notably, the combined AEE788/celecoxib treatment prevented β-catenin nuclear accumulation in tumor cells. This effect was associated with a significant downregulation of FOXM1 protein levels and an impairment in the interaction of this transcription factor with β-catenin, which is required for its nuclear localization. Furthermore, the combined treatment also reduced the expression of the stem cell markers Oct 3/4, Nanog, Sox-2 and Snail in cancer cells, and contributed to the diminution of the CSC subpopulation, as indicated by colonosphere formation assays. In conclusion, the combined treatment of AEE788 and celecoxib not only demonstrated enhanced anti-tumoral efficacy in colorectal cancer cells, but also reduced colon CSCs subpopulation by targeting stemness-related pathways. Therefore, the simultaneous targeting of EGFR/VEGF and COX-2 may aid in blocking mCRC progression and improve the efficacy of existing therapies in colorectal cancer. PMID:26107817

  14. Investigation of cyclooxygenase and signaling pathways involved in human platelet aggregation mediated by synergistic interaction of various agonists.

    Science.gov (United States)

    Khan, Nadia; Farooq, Ahsana Dar; Sadek, Bassem

    2015-01-01

    In the present study, the mechanism(s) of synergistic interaction of various platelet mediators such as arachidonic acid (AA) when combined with 5-hydroxytryptamine (5-HT) or adenosine diphosphate (ADP) on human platelet aggregation were examined. The results demonstrated that 5-HT had no or negligible effect on aggregation but it did potentiate the aggregation response of AA. Similarly, the combination of subeffective concentrations of ADP and AA exhibited noticeable rise in platelet aggregation. Moreover, the observed synergistic effect of AA with 5-HT on platelets was inhibited by different cyclooxygenase (COX) inhibitors, namely ibuprofen and celecoxib, with half maximal inhibitory effect (IC50) values of 18.0 ± 1.8 and 15.6 ± 3.4 μmol/L, respectively. Interestingly, the synergistic effect observed for AA with 5-HT was, also, blocked by the 5-HT receptor blockers cyproheptadine (IC50=22.0 ± 7 μmol/L), ketanserin (IC50=152 ± 23 μmol/L), phospholipase C (PLC) inhibitor (U73122; IC50=6.1 ± 0.8 μmol/L), and mitogen activated protein kinase (MAPK) inhibitor (PD98059; IC50=3.8 ± 0.5 μmol/L). Likewise, the synergism of AA and ADP was, also, attenuated by COX inhibitors (ibuprofen; IC50=20 ± 4 μmol/L and celecoxib; IC50=24 ± 7 μmol/L), PLC inhibitor (U73122; IC50=3.7 ± 0.3 μmol/L), and MAPK inhibitor (PD98059; IC50=2.8 ± 1.1 μmol/L). Our observed data demonstrate that the combination of subthreshold concentrations of agonists amplifies platelet aggregation and that these synergistic effects largely depend on activation of COX/thromboxane A2, receptor-operated Ca(2+) channels, Gq/PLC, and MAPK signaling pathways. Moreover, our data revealed that inhibition of COX pathways by using both selective and/or non-selective COX inhibitors blocks not only AA metabolism and thromboxane A2 formation, but also its binding to Gq receptors and activation of receptor-operated Ca(2+) channels in platelets. Overall, our results show that PLC and MAPK inhibitors proved

  15. Derivation and evaluation of adverse outcome pathways for the effects of cyclooxygenase inhibitors on reproductive processes in fish

    Science.gov (United States)

    Cyclooxygenase (COX) inhibition is of concern in fish because COX inhibitors (e.g., ibuprofen) are ubiquitous in aquatic systems/fish tissues, and can disrupt synthesis of prostaglandins that modulate a variety of essential biological functions (e.g., reproduction). This study ut...

  16. Celecoxib Inhibits Proliferation and Induces Apoptosis via Cyclooxygen-ase-2 Pathway in Human Pancreatic Carcinoma Cells

    Institute of Scientific and Technical Information of China (English)

    WU Gaosong; YI Jilin; DI Fang; ZOU Shengquan; LI Xingrui

    2005-01-01

    In order to evaluate the effects and mechanisms of celecoxib in inhibiting proliferation and inducing apoptosis on human pancreatic carcinoma cells, the anti-proliferative effect was measured by using methabenzthiazuron (MTT) assay. Cell cycle and apoptosis were analyzed by using flow cytometry (FCM), and the PGE2 levels in the supernatant of cultured pancreatic carcinoma cells were quantitated by enzyme-linked immunoabsordent assay (ELISA). Our results showed that celecoxib suppressed the production of PGE2 and inhibited the growth of JF-305 cells, and the anti-proliferative effect of celecoxib could be abolished by addition of PGE2. FCM revealed that celecoxib could inhibit proliferation and induce apoptosis by G1-S cell cycle arrest. It was concluded that cyclooxygenase-2 specific inhibitor celecoxib could inhibit proliferation and induced apoptosis of human pancreatic carcinoma cells via suppression of PGE2 production in vitro.

  17. [Jianpi jiedu recipe inhibited Helicobacter pylori-induced the expression of cyclooxygenase-2 via p38MAPK/ATF-2 signal transduction pathway in human gastric cancer cells].

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    Liu, Ning-ning; Wang, Yan; Wu, Qiong

    2011-07-01

    To study the effect of Jianpi Jiedu Recipe (JJR) on the expression of cyclooxygenase (COX-2) in Helicobacter pylori (Hp) infected gastric cancer cell line MKN 45, and its regulatory mechanism of p38MAPK signal transduction. The expressions of COX-2 mRNA and protein in human gastric cancer cell line MKN 45 infected by Hp type strain NCTC 11637 and the regulatory effect of JJR containing serum were detected using Real-time fluorescent quantitative polymerase chain reaction (RFQ-PCR) and Western blot. The effects of Hp on COX-2 mRNA and protein expressions in human gastric cancer cell line MKN 45 were observed using blocking p38MAPK signal transduction pathway by p38MAPK specific inhibitor SB203580. The effects of JJR on Hp-infection activated p38MAPK signal transduction pathway and its downstream activating transcription factor 2 (ATF-2) were observed. COX-2 mRNA and protein expressions were obviously higher after human gastric cancer cell line MKN 45 were infected by Hp (PATF-2. Hp infection induced COX-2 expressions of gastric cancer cells via p38MAPK signal transduction pathway. JJR inhibited Hp-induced the expression of COX-2 through regulating p38MAPK/ATF-2 signal transduction pathway, which may be one of its mechanisms in prevention and treatment of Hp-induced gastric cancer.

  18. Inhibition of the Akt, cyclooxygenase-2, and matrix metalloproteinase-9 pathways in combination with androgen deprivation therapy: potential therapeutic approaches for prostate cancer.

    Science.gov (United States)

    Miyamoto, Hiroshi; Altuwaijri, Saleh; Cai, Yi; Messing, Edward M; Chang, Chawnshang

    2005-09-01

    Prostate cancer cells are generally dependent on androgen stimulation mediated by the androgen receptor (AR) for growth and survival, and, therefore, hormonal manipulation, such as castration and/or the use of AR antagonists, results in a regression of the cancer. However, this treatment very rarely leads to the "cure" of advanced disease, and cancers eventually become androgen-independent. A number of genes/pathways have been reported to be activated in prostate cancer, most of which are possibly associated with disease progression. In this article, among them, we focus on Akt (also known as protein kinase B), cyclooxygenase (COX)-2, and matrix metalloproteinase (MMP)-9, whose activities or expressions have been found to be regulated by androgens/AR. Previous studies by us and others, with androgen-sensitive prostate cancer cell lines, have demonstrated that androgen deprivation results in activation/overexpression of Akt, COX-2, and MMP-9 in cells. This suggests that androgen deprivation in clinical settings activates the Akt, COX-2, and MMP-9 pathways in prostate cancer, which may increase cell growth and in turn promote the transition to the androgen-independent state. We hypothesize that androgen deprivation, in combination with inhibition of the Akt, COX-2, and MMP-9 pathways, delays the androgen-independent transition and has more beneficial effects than hormonal therapy alone.

  19. Paracrine effects of bone marrow-derived endothelial progenitor cells: cyclooxygenase-2/prostacyclin pathway in pulmonary arterial hypertension.

    Directory of Open Access Journals (Sweden)

    Dong-Mei Jiang

    Full Text Available BACKGROUND: Endothelial dysfunction is the pathophysiological characteristic of pulmonary arterial hypertension (PAH. Some paracrine factors secreted by bone marrow-derived endothelial progenitor cells (BMEPCs have the potential to strengthen endothelial integrity and function. This study investigated whether BMEPCs have the therapeutic potential to improve monocrotaline (MCT-induced PAH via producing vasoprotective substances in a paracrine fashion. METHODS AND RESULTS: Bone marrow-derived mononuclear cells were cultured for 7 days to yield BMEPCs. 24 hours or 3 weeks after exposure to BMEPCs in vitro or in vivo, the vascular reactivity, cyclooxygenase-2 (COX-2 expression, prostacyclin (PGI2 and cAMP release in isolated pulmonary arteries were examined respectively. Treatment with BMEPCs could improve the relaxation of pulmonary arteries in MCT-induced PAH and BMEPCs were grafted into the pulmonary bed. The COX-2/prostacyclin synthase (PGIS and its progenies PGI2/cAMP were found to be significantly increased in BMEPCs treated pulmonary arteries, and this action was reversed by a selective COX-2 inhibitor, NS398. Moreover, the same effect was also observed in conditioned medium obtained from BMEPCs culture. CONCLUSIONS: Implantation of BMEPCs effectively ameliorates MCT-induced PAH. Factors secreted in a paracrine fashion from BMEPCs promote vasoprotection by increasing the release of PGI2 and level of cAMP.

  20. Aspirin inhibits the proliferation of tobacco-related esophageal squamous carcinomas cell lines through cyclooxygenase 2 pathway

    Institute of Scientific and Technical Information of China (English)

    ZHOU Qiao-Zhi; LIU Hai-bo; DING Xin-chun; LI Peng; ZHANG Shu-tian; YU Zhong-lin

    2007-01-01

    Background Cigarette smoking has been verified as the risk factor of esophageal squamous cell carcinoma(ESCC).Overexpression of cyclooxygenase 2(COX-2)is shown in ESCC.The objective of this study was to investigate the effects of cigarette smoking ethanol extract(EE)on the proliferation of the human ESCC cell Iines,and to explore the correlation between the proliferation rate of human ESCC cell lines and the expression pattern of COX-2.Whether aspirin can inhibit the proliferation of the ESCC cell lines pretreated with EE.and regulate the mRNA expression levels of COX-2 are also examined.Methods Two human ESCC cell Iines were selected.EC109 was poorly differentiated and EC9706 was highly differentiated.EC109 and EC9706 were treated with EE and aspirin for different time course.The cell growth of ESCC was measured by MTT reduction assay and the expression of COX-2 was measured by RT-PCR and Western blot analysis.Results EE promoted the proliferation of EC109 and EC9706 in dose- and time-dependent manners.In the concentration range (10-100 μg/ml for EE)and in the time range(24-72 hours)after addition of EE,the cell proliferation was prominent in an up-scaled manner respectively.Aspirin could inhibit the proliferation of cell lines EC109 and EC9706.pretreated with EE for 5 hours,in a dose-dependent manner.In the concentration range (0.5-8.0 mmol/L for aspirin),the cell growth inhibition was prominent in an up-scaled manner accordingly (P<0.05).The effect of EE on cell proliferation was correlated with the up-regulation of COX-2 gene.However,the cell growth inhibition of aspirin was correlated with the down-regulation of COX-2 gene.Conclusions EE can stimulate the proliferation of human ESCC cell lines EC109 and EC9706,most likely through up-regulating the expression of COX-2.Aspirin can inhibit the proliferation of ESCC cell lines induced by EE,which suggests it may be advantageous in the chemoprevention and therapy of human tobacco-related ESCC.And its effect is

  1. Disruption of Rb/E2F pathway results in increased cyclooxygenase-2 expression and activity in prostate epithelial cells.

    Science.gov (United States)

    Davis, Joanne N; McCabe, Michael T; Hayward, Simon W; Park, John M; Day, Mark L

    2005-05-01

    The loss of the retinoblastoma tumor suppressor gene (RB) is common in many human cancers, including prostate. We previously reported that engineered deletion of RB in prostate epithelial cells results in sustained cell growth in serum-free media, a predisposition to develop hyperplasia and dysplasia in prostate tissue recombinant grafts, and sensitization to hormonal carcinogenesis. Examining the molecular consequence of RB loss in this system, we show that cyclooxygenase-2 (COX-2) is significantly up-regulated following RB deletion in prostate tissue recombinants. To study the effect of RB deletion on COX-2 regulation, we generated wild-type (PrE) and Rb-/- (Rb-/-PrE) prostate epithelial cell lines rescued by tissue recombination. We show elevated COX-2 mRNA and protein expression in Rb-/-PrE cell lines with increased prostaglandin synthesis. We also find that loss of Rb leads to deregulated E2F activity, with increased expression of E2F target genes, and that exogenous expression of E2F1 results in elevated COX-2 mRNA and protein levels. COX-2 promoter studies reveal that E2F1 transcriptionally activates COX-2, which is dependent on the transactivation and DNA-binding domains of E2F1. Further analysis revealed that the E2F1 target gene, c-myb, is elevated in Rb-/-PrE cells and E2F1-overexpressing cells, whereas ectopic overexpression of c-myb activates the COX-2 promoter in prostate epithelial cells. Additionally, cotransfection with E2F1 and a dominant-negative c-myb inhibited E2F1 activation of the COX-2 promoter. Taken together, these results suggest activation of a transcriptional cascade by which E2F1 regulates COX-2 expression through the c-myb oncogene. This study reports a novel finding describing that deregulation of the Rb/E2F complex results in increased COX-2 expression and activity.

  2. Rhizoma Paridis Saponins Suppresses Tumor Growth in a Rat Model of N-Nitrosomethylbenzylamine-Induced Esophageal Cancer by Inhibiting Cyclooxygenases-2 Pathway.

    Science.gov (United States)

    Yan, Shu; Tian, Shuxia; Kang, Qingwei; Xia, Yafei; Li, Caixia; Chen, Qing; Zhang, Shukun; Li, Zhigang

    2015-01-01

    Rhizoma Paridis Saponins (RPS), a natural compound purified from Rhizoma Paridis, has been found to inhibit cancer growth in vitro and in animal models of cancer. However, its effects on esophageal cancer remain unexplored. The purpose of this study was to investigate the effects of RPS on tumor growth in a rat model of esophageal cancer and the molecular mechanism underlying the effects. A rat model of esophageal cancer was established by subcutaneous injection of N-nitrosomethylbenzylamine (NMBA, 1 mg/kg) for 10 weeks. RPS (350 mg/kg or 100 mg/kg) was administered by oral gavage once daily for 24 weeks starting at the first NMBA injection. RPS significantly reduced the size and number of tumors in the esophagus of rats exposed to NMBA and inhibited the viability, migration, and invasion of esophageal cancer cells EC9706 and KYSE150 in a dose dependent manner (all P induced apoptosis and cell cycle G2/M arrest in the esophageal cancer cells. The expression of cyclooxygenases-2 (COX-2) and Cyclin D1 in rat esophageal tissues and the esophageal cancer cells were also significantly reduced by RPS (all P cancer development by promoting apoptosis and cell cycle arrest and inhibiting the COX-2 pathway. RPS might be a promising therapeutic agent for esophageal cancer.

  3. Cyclooxygenase-2 enhances alpha2beta1 integrin expression and cell migration via EP1 dependent signaling pathway in human chondrosarcoma cells.

    Science.gov (United States)

    Liu, Ju-Fang; Fong, Yi-Chin; Chang, Chih-Shiang; Huang, Chun-Yin; Chen, Hsien-Te; Yang, Wei-Hung; Hsu, Chin-Jung; Jeng, Long-Bin; Chen, Chih-Yi; Tang, Chih-Hsin

    2010-02-23

    Cyclooxygenase (COX)-2, the inducible isoform of prostaglandin (PG) synthase, has been implicated in tumor metastasis. Interaction of COX-2 with its specific EP receptors on the surface of cancer cells has been reported to induce cancer invasion. However, the effects of COX-2 on migration activity in human chondrosarcoma cells are mostly unknown. In this study, we examined whether COX-2 and EP interaction are involved in metastasis of human chondrosarcoma. We found that over-expression of COX-2 or exogenous PGE2 increased the migration of human chondrosarcoma cells. We also found that human chondrosarcoma tissues and chondrosarcoma cell lines had significant expression of the COX-2 which was higher than that in normal cartilage. By using pharmacological inhibitors or activators or genetic inhibition by the EP receptors, we discovered that the EP1 receptor but not other PGE receptors is involved in PGE2-mediated cell migration and alpha2beta1 integrin expression. Furthermore, we found that human chondrosarcoma tissues expressed a higher level of EP1 receptor than normal cartilage. PGE2-mediated migration and integrin up-regulation were attenuated by phospholipase C (PLC), protein kinase C (PKC) and c-Src inhibitor. Activation of the PLCbeta, PKCalpha, c-Src and NF-kappaB signaling pathway after PGE2 treatment was demonstrated, and PGE2-induced expression of integrin and migration activity were inhibited by the specific inhibitor, siRNA and mutants of PLC, PKC, c-Src and NF-kappaB cascades. Our results indicated that PGE2 enhances the migration of chondrosarcoma cells by increasing alpha2beta1 integrin expression through the EP1/PLC/PKCalpha/c-Src/NF-kappaB signal transduction pathway.

  4. Cyclooxygenase-2 Pathway Correlates with VEGF Expression in Head and Neck Cancer. Implications for Tumor Angiogenesis and Metastasis

    Directory of Open Access Journals (Sweden)

    Oreste Gallo

    2001-01-01

    Full Text Available We evaluated the role of COX-2 pathway in 35 head and neck cancers (HNCs by analyzing COX-2 expression and prostaglandin E2 (PGE2 production in relation to tumor angiogenesis and lymph node metastasis. COX-2 activity was also correlated to vascular endothelial growth factor (VEGF mRNA and protein expression. COX-2 mRNA and protein expression was higher in tumor samples than in normal mucosa. PGE2 levels were higher in the tumor front zone in comparison with tumor core and normal mucosa (P<0001. Specimens from patients with lymph node metastasis exhibited higher COX-2 protein expression (P=.0074, PGEZ levels (P=.0011 and microvessel density (P<.0001 than specimens from patients without metastasis. A significant correlation between COX-2 and tumor vascularization (rs=0.450, P=.007 as well as between COX-2 and microvessel density with VEGF expression in tumor tissues was found (rs=0.450, P=.007; rs=0.620, P=.0001, respectively. The induction of COX-2 mRNA and PGE2 synthesis by EGF and Escherichia coli lipopolysaccharide (LPS in A-431 and SCC-9 cell lines, resulted in an increase in VEGF mRNA and protein production. Indomethacin and celecoxib reversed the EGF- and LPS-dependent COX-2, VEGF, and PGE2 increases. This study suggests a central role of COX-2 pathway in HNC angiogenesis by modulating VEGF production and indicates that COX-2 inhibitors may be useful in HNC treatment.

  5. Quercetin induces apoptosis by activating caspase-3 and regulating Bcl-2 and cyclooxygenase-2 pathways in human HL-60 cells.

    Science.gov (United States)

    Niu, Guomin; Yin, Songmei; Xie, Shuangfeng; Li, Yiqing; Nie, Danian; Ma, Liping; Wang, Xiuju; Wu, Yudan

    2011-01-01

    Quercetin is one of the naturally occurring dietary flavonol compounds. It is present abundantly in plants and has chemopreventive and anticancer effects. To investigate its anticancer mechanism, we examined the activity of quercetin against acute leukemia cell line, HL-60. Our results showed that quercetin inhibited cell proliferation and induced apoptosis in a time- and dose-dependent manner. Furthermore, quercetin down-regulated the expression of anti-apoptosis protein Bcl-2 and up-regulated the expression of pro-apoptosis protein Bax. Caspase-3 was also activated by quercetin, which started a caspase-3-depended mitochodrial pathway to induce apoptosis. It was also found that quercetin inhibited the expression of the cycloocygenase-2 (Cox-2) mRNA and Cox-2 protein. Taken together, these findings suggested that quercetin induces apoptosis in a caspase-3-dependent pathway by inhibiting Cox-2 expression and regulates the expression of downstream apoptotic components, including Bcl-2 and Bax. Quercetin can be a potent and promising medicine which might be safely used in leukemia therapy.

  6. Quercetin induces apoptosis by activating caspase-3 and regulating Bcl-2 and cyclooxygenase-2 pathways in human HL-60 cells

    Institute of Scientific and Technical Information of China (English)

    Guomin Niu; Songmei Yin; Shuangfeng Xie; Yiqing Li; Danian Nie; Liping Ma; Xiuju Wang; Yudan Wu

    2011-01-01

    Quercetin is one of the naturally occurring dietary flavo-nol compounds. It is present abundantly in plants and has chemopreventive and anticancer effects. To investigate its anticancer mechanism, we examined the activity of quercetin against acute leukemia cell line, HL-60. Our results showed that quercetin inhibited cell proliferation and induced apoptosis in a time- and dose-dependent manner. Furthermore, quercetin down-regulated the expression of anti-apoptosis protein Bcl-2 and up-regulated the expression of pro-apoptosis protein Bax. Caspase-3 was also activated by quercetin, which started a caspase-3-depended mitochodrial pathway to induce apoptosis. It was also found that quercetin inhibited the expression of the cycloocygenase-2 (Cox-2) mRNA and Cox-2 protein. Taken together, these findings suggested that quercetin induces apoptosis in a caspase-3-dependent pathway by inhibiting Cox-2 expression and regulates the expression of downstream apoptotic components, including Bcl-2 and Bax. Quercetin can be a potent and promising medicine which might be safely used in leukemia therapy.

  7. Formation of prostaglandins E2 and D2 via the isoprostane pathway: a mechanism for the generation of bioactive prostaglandins independent of cyclooxygenase.

    Science.gov (United States)

    Gao, Ling; Zackert, William E; Hasford, Justin J; Danekis, Michael E; Milne, Ginger L; Remmert, Catha; Reese, Jeff; Yin, Huiyong; Tai, Hsin-Hsiung; Dey, Sudhansu K; Porter, Ned A; Morrow, Jason D

    2003-08-01

    It has heretofore been assumed that the cyclooxygenases (COXs) are solely responsible for peostaglandin (PG) synthesis in vivo. An important structural feature of PGH2 formed by COX is the trans-configuration of side chains relative to the prostane ring. Previously, we reported that a series of PG-like compounds termed isoprostanes (IsoPs) are formed in vivo in humans from the free radical-catalyzed peroxidation of arachidonate independent of COX. A major difference between these compounds and PGs is that IsoPs are formed from endoperoxide intermediates, the vast majority of which contain side chains that are cis relative to the prostane ring. In addition, unlike the formation of eicosanoids from COX, IsoPs are formed as racemic mixtures because they are generated nonenzymatically. IsoPs containing E- and D-type prostane rings (E2/D2-IsoPs) are one class of IsoPs formed, and we have reported previously that one of the major IsoPs generated is 15-E2t-IsoP (8-iso-PGE2). Unlike PGE2, 15-E2t-IsoP is significantly more unstable in buffered solutions in vitro and undergoes epimerization to PGE2. Analogously, the D-ring IsoP (15-D2c-IsoP) would be predicted to rearrange to PGD2. We now report that compounds identical in all respects to PGE2 and PGD2 and their respective enantiomers are generated in vivo via the IsoP pathway, presumably by epimerization of racemic 15-E2t-IsoP and 15-D2c-IsoP, respectively. Racemic PGE2 and PGD2 were present esterified in phospholipids derived from liver tissue from rats exposed to oxidant stress at levels of 24 +/- 16 and 37 +/- 12 ng/g of tissue, respectively. In addition, racemic PGs, particularly PGD2, were present unesterified in urine from normal animals and humans and represented up to 10% of the total PG detected. Levels of racemic PGD2 increased 35-fold after treatment of rats with carbon tetrachloride to induce oxidant stress. In this setting, PGD2 and its enantiomer generated by the IsoP pathway represented approximately 30% of

  8. Evaluation of the role of the cyclooxygenase signaling pathway during inflammation in skin and muscle tissues of ball pythons (Python regius).

    Science.gov (United States)

    Sadler, Ryan A; Schumacher, Juergen P; Rathore, Kusum; Newkirk, Kim M; Cole, Grayson; Seibert, Rachel; Cekanova, Maria

    2016-05-01

    OBJECTIVE To determine degrees of production of cyclooxygenase (COX)-1 and -2 and other mediators of inflammation in noninflamed and inflamed skin and muscle tissues in ball pythons (Python regius). ANIMALS 6 healthy adult male ball pythons. PROCEDURES Biopsy specimens of noninflamed skin and muscle tissue were collected from anesthetized snakes on day 0. A 2-cm skin and muscle incision was then made 5 cm distal to the biopsy sites with a CO2 laser to induce inflammation. On day 7, biopsy specimens of skin and muscle tissues were collected from the incision sites. Inflamed and noninflamed tissue specimens were evaluated for production of COX-1, COX-2, phosphorylated protein kinase B (AKT), total AKT, nuclear factor κ-light-chain-enhancer of activated B cells, phosphorylated extracellular receptor kinases (ERKs) 1 and 2, and total ERK proteins by western blot analysis. Histologic evaluation was performed on H&E-stained tissue sections. RESULTS All biopsy specimens of inflamed skin and muscle tissues had higher histologic inflammation scores than did specimens of noninflamed tissue. Inflamed skin specimens had significantly greater production of COX-1 and phosphorylated ERK than did noninflamed skin specimens. Inflamed muscle specimens had significantly greater production of phosphorylated ERK and phosphorylated AKT, significantly lower production of COX-1, and no difference in production of COX-2, compared with production in noninflamed muscle specimens. CONCLUSIONS AND CLINICAL RELEVANCE Production of COX-1, but not COX-2, was significantly greater in inflamed versus noninflamed skin specimens from ball pythons. Additional research into the reptilian COX signaling pathway is warranted.

  9. Prostaglandins from Cytosolic Phospholipase A2α/Cyclooxygenase-1 Pathway and Mitogen-activated Protein Kinases Regulate Gene Expression in Candida albicans-infected Macrophages.

    Science.gov (United States)

    Yun, Bogeon; Lee, HeeJung; Jayaraja, Sabarirajan; Suram, Saritha; Murphy, Robert C; Leslie, Christina C

    2016-03-25

    In Candida albicans-infected resident peritoneal macrophages, activation of group IVA cytosolic phospholipase A2(cPLA2α) by calcium- and mitogen-activated protein kinases triggers the rapid production of prostaglandins I2 and E2 through cyclooxygenase (COX)-1 and regulates gene expression by increasing cAMP. InC. albicans-infected cPLA2α(-/-)or COX-1(-/-)macrophages, expression ofI l10,Nr4a2, and Ptgs2 was lower, and expression ofTnfα was higher, than in wild type macrophages. Expression was reconstituted with 8-bromo-cAMP, the PKA activator 6-benzoyl-cAMP, and agonists for prostaglandin receptors IP, EP2, and EP4 in infected but not uninfected cPLA2α(-/-)or COX-1(-/-)macrophages. InC. albicans-infected cPLA2α(+/+)macrophages, COX-2 expression was blocked by IP, EP2, and EP4 receptor antagonists, indicating a role for both prostaglandin I2 and E2 Activation of ERKs and p38, but not JNKs, by C. albicansacted synergistically with prostaglandins to induce expression of Il10,Nr4a2, and Ptgs2. Tnfα expression required activation of ERKs and p38 but was suppressed by cAMP. Results using cAMP analogues that activate PKA or Epacs suggested that cAMP regulates gene expression through PKA. However, phosphorylation of cAMP-response element-binding protein (CREB), the cAMP-regulated transcription factor involved inIl10,Nr4a2,Ptgs2, andTnfα expression, was not mediated by cAMP/PKA because it was similar inC. albicans-infected wild type and cPLA2α(-/-)or COX-1(-/-)macrophages. CREB phosphorylation was blocked by p38 inhibitors and induced by the p38 activator anisomycin but not by the PKA activator 6-benzoyl-cAMP. Therefore, MAPK activation inC. albicans-infected macrophages plays a dual role by promoting the cPLA2α/prostaglandin/cAMP/PKA pathway and CREB phosphorylation that coordinately regulate immediate early gene expression.

  10. The bitter barricading of prostaglandin biosynthesis pathway: understanding the molecular mechanism of selective cyclooxygenase-2 inhibition by amarogentin, a secoiridoid glycoside from Swertia chirayita.

    Directory of Open Access Journals (Sweden)

    Shantanu Shukla

    Full Text Available Swertia chirayita, a medicinal herb inhabiting the challenging terrains and high altitudes of the Himalayas, is a rich source of essential phytochemical isolates. Amarogentin, a bitter secoiridoid glycoside from S. chirayita, shows varied activity in several patho-physiological conditions, predominantly in leishmaniasis and carcinogenesis. Experimental analysis has revealed that amarogentin downregulates the cyclooxygenase-2 (COX-2 activity and helps to curtail skin carcinogenesis in mouse models; however, there exists no account on selective inhibition of the inducible cyclooxygenase (COX isoform by amarogentin. Hence the computer-aided drug discovery methods were used to unravel the COX-2 inhibitory mechanism of amarogentin and to check its selectivity for the inducible isoform over the constitutive one. The generated theoretical models of both isoforms were subjected to molecular docking analysis with amarogentin and twenty-one other Food and Drug Authority (FDA approved lead molecules. The post-docking binding energy profile of amarogentin was comparable to the binding energy profiles of the FDA approved selective COX-2 inhibitors. Subsequent molecular dynamics simulation analysis delineated the difference in the stability of both complexes, with amarogentin-COX-2 complex being more stable after 40ns simulation. The total binding free energy calculated by MMGBSA for the amarogentin-COX-2 complex was -52.35 KCal/mol against a binding free energy of -8.57 KCal/mol for amarogentin-COX-1 complex, suggesting a possible selective inhibition of the COX-2 protein by the natural inhibitor. Amarogentin achieves this potential selectivity by small, yet significant, structural differences inherent to the binding cavities of the two isoforms. Hypothetically, it might block the entry of the natural substrates in the hydrophobic binding channel of the COX-2, inhibiting the cyclooxygenation step. To sum up briefly, this work highlights the mechanism of the

  11. Salvianolic Acid B Inhibits Growth of Head and Neck Squamous Cell Carcinoma in vitro and in vivo via Cyclooxygenase-2 and Apoptotic Pathways

    Science.gov (United States)

    Hao, Yubin; Xie, Tianpei; Korotcov, Alexandru; Zhou, Yanfei; Pang, Xiaowu; Shan, Liang; Ji, Hongguang; Sridhar, Rajagopalan; Wang, Paul; Califano, Joseph; Gu, Xinbin

    2010-01-01

    Overexpression of cyclooxygenase-2 (COX-2) in oral mucosa has been associated with increased risk of head and neck squamous cell carcinoma (HNSCC). Celecoxib is a non steroidal anti-inflammatory drug, which inhibits COX-2 but not COX-1. This selective COX-2 inhibitor holds promise as a cancer preventive agent. Concerns about cardiotoxicity of celecoxib, limits its use in long term chemoprevention and therapy. Salvianolic acid B (Sal-B) is a leading bioactive component of Salvia miltiorrhiza Bge, which is used for treating neoplastic and chronic inflammatory diseases in China. The purpose of this study was to investigate the mechanisms by which Sal-B inhibits HNSCC growth. Sal-B was isolated from Salvia miltiorrhiza Bge by solvent extraction followed by two chromatographic steps. Pharmacological activity of Sal-B was assessed in HNSCC and other cell lines by estimating COX-2 expression, cell viability and caspase-dependent apoptosis. Sal-B inhibited growth of HNSCC JHU-022 and JHU-013 cells with IC50 of 18 and 50 µM respectively. Nude mice with HNSCC solid tumor xenografts were treated with Sal-B (80mg/kg/day) or celecoxib (5mg/kg/day) for 25 days to investigate in vivo effects of the COX-2 inhibitors. Tumor volumes in Sal-B treated group were significantly lower than those in celecoxib treated or untreated control groups (p<0.05). Sal-B inhibited COX-2 expression in cultured HNSCC cells and in HNSCC cells isolated from tumor xenografts. Sal-B also caused dose-dependent inhibition of prostaglandin E2 synthesis, either with or without lipopolysaccharide stimulation. Taken together, Sal-B shows promise as a COX-2 targeted anticancer agent for HNSCC prevention and treatment. PMID:19123475

  12. The shunt from the cyclooxygenase to lipoxygenase pathway in human osteoarthritic subchondral osteoblasts is linked with a variable expression of the 5-lipoxygenase-activating protein.

    Science.gov (United States)

    Maxis, Kelitha; Delalandre, Aline; Martel-Pelletier, Johanne; Pelletier, Jean-Pierre; Duval, Nicolas; Lajeunesse, Daniel

    2006-01-01

    Osteoarthritis (OA) is characterized by articular cartilage degradation and hypertrophic bone changes with osteophyte formation and abnormal bone remodeling. Two groups of OA patients were identified via the production of variable and opposite levels of prostaglandin E2 (PGE2) or leukotriene B4 (LTB4) by subchondral osteoblasts, PGE2 levels discriminating between low and high subgroups. We studied whether the expression of 5-lipoxygenase (5-LO) or 5-LO-activating protein (FLAP) is responsible for the shunt from prostaglandins to leukotrienes. FLAP mRNA levels varied in low and high OA groups compared with normal, whereas mRNA levels of 5-LO were similar in all osteoblasts. Selective inhibition of cyclooxygenase-2 (COX-2) with NS-398-stimulated FLAP expression in the high OA osteoblasts subgroup, whereas it was without effect in the low OA osteoblasts subgroup. The addition of PGE2 to the low OA osteoblasts subgroup decreased FLAP expression but failed to affect it in the high OA osteoblasts subgroup. LTB4 levels in OA osteoblasts were stimulated about twofold by 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) plus transforming growth factor-beta (TGF-beta), a situation corresponding to their effect on FLAP mRNA levels. Treatments with 1,25(OH)2D3 and TGF-beta also modulated PGE2 production. TGF-beta stimulated PGE2 production in both OA osteoblast groups, whereas 1,25(OH)2D3 alone had a limited effect but decreased the effect of TGF-beta in the low OA osteoblasts subgroup. This modulation of PGE2 production was mirrored by the synthesis of COX-2. IL-18 levels were only slightly increased in a subgroup of OA osteoblasts compared with normal; however, no relationship was observed overall between IL-18 and PGE2 levels in normal and OA osteoblasts. These results suggest that the shunt from the production of PGE2 to LTB4 is through regulation of the expression of FLAP, not 5-LO, in OA osteoblasts. The expression of FLAP in OA osteoblasts is also modulated differently by 1,25(OH

  13. Pharmacogenomics of cyclooxygenases.

    Science.gov (United States)

    Agúndez, José A G; Blanca, Miguel; Cornejo-García, José A; García-Martín, Elena

    2015-01-01

    Cyclooxygenases (COX-1 and COX-2) are key enzymes in several physiopathological processes. Many adverse drugs reactions to NSAIDs are attributable to COX-inhibition. The genes coding for these enzymes (PTGS1 and PTGS2) are highly variable, and variations in these genes may underlie the risk of developing, or the clinical evolution of, several diseases and adverse drug reactions. We analyze major variations in the PTGS1 and PTGS2 genes, allele frequencies, functional consequences and population genetics. The most salient clinical associations of PTGS gene variations are related to colorectal cancer and stroke. In many studies, the SNPs interact with NSAIDs use, dietary or environmental factors. We provide an up-to-date catalog of PTGS clinical associations based on case-control studies and genome-wide association studies, and future research suggestions.

  14. DNA-hypomethylating agent, 5'-azacytidine, induces cyclooxygenase-2 expression via the PI3-kinase/Akt and extracellular signal-regulated kinase-1/2 pathways in human HT1080 fibrosarcoma cells.

    Science.gov (United States)

    Yu, Seon-Mi; Kim, Song-Ja

    2015-10-01

    The cytosine analogue 5'-azacytidine (5'-aza) induces DNA hypomethylation by inhibiting DNA methyltransferase. In clinical trials, 5'-aza is widely used in epigenetic anticancer treatments. Accumulated evidence shows that cyclooxygenase-2 (COX-2) is overexpressed in various cancers, indicating that it may play a critical role in carcinogenesis. However, few studies have been performed to explore the molecular mechanism underlying the increased COX-2 expression. Therefore, we tested the hypothesis that 5'-aza regulates COX-2 expression and prostaglandin E2 (PGE2) production. The human fibrosarcoma cell line HT1080, was treated with various concentrations of 5'-aza for different time periods. Protein expressions of COX-2, DNA (cytosine-5)-methyltransferase 1 (DNMT1), pAkt, Akt, extracellular signal-regulated kinase (ERK), and phosphorylated ERK (pERK) were determined using western blot analysis, and COX-2 mRNA expression was determined using RT-PCR. PGE2 production was evaluated using the PGE2 assay kit. The localization and expression of COX-2 were determined using immunofluorescence staining. Treatment with 5'-aza induces protein and mRNA expression of COX-2. We also observed that 5'-aza-induced COX-2 expression and PGE2 production were inhibited by S-adenosylmethionine (SAM), a methyl donor. Treatment with 5'-aza phosphorylates PI3-kinase/Akt and ERK-1/2; inhibition of these pathways by LY294002, an inhibitor of PI3-kinase/Akt, or PD98059, an inhibitor of ERK-1/2, respectively, prevents 5'-aza-induced COX-2 expression and PGE2 production. Overall, these observations indicate that the hypomethylating agent 5'-aza modulates COX-2 expression via the PI3-kinase/Akt and ERK-1/2 pathways in human HT1080 fibrosarcoma cells.

  15. Cyclooxygenases in hepatocellular carcinoma

    Institute of Scientific and Technical Information of China (English)

    Melchiorre Cervello; Giuseppe Montalto

    2006-01-01

    Many epidemiological studies demonstrate that treatment with non-steroidal anti-inflammatory drugs (NSAIDs) reduce the incidence and mortality of certain malignancies, especially gastrointestinal cancer. The cyclooxygenase (COX) enzymes are well-known targets of NSAIDs. However, conventional NSAIDs nonselectively inhibit both the constitutive form COX-1, and the inducible form COX-2. Recent evidence indicates that COX-2 is an important molecular target for anticancer therapies. Its expression is undetectable in most normal tissues, and is highly induced by proinflammatory cytokines, mitogens, tumor promoters and growth factors. It is now well-established that COX-2 is chronically overexpressed in many premalignant, malignant, and metastastic cancers, including hepatocellular carcinoma (HCC). Overexpression of COX-2 in patients with HCC is generally higher in welldifferentiated HCCs compared with less-differentiated HCCs or histologically normal liver, suggesting that COX-2 may be involved in the early stages of hepatocarcinogenesis, and increased expression of COX-2 in noncancerous liver tissue has been significantly associated with shorter disease-free survival in patients with HCC.In tumors, overexpression of COX-2 leads to an increase in prostaglandin (PG) levels, which affect many mechanisms involved in carcinogenesis, such as angiogenesis, inhibition of apoptosis, stimulation of cell growth as well as the invasiveness and metastatic potential of tumor ceils. The availability of novel agents that selectively inhibit COX-2 (COXIB), has contributed to shedding light on the role of this molecule. Experimental studies on animal models of liver cancer have shown that NSAIDs, including both selective and non-selective COX-2 inhibitors, exert chemopreventive as well as therapeutic effects. However, the key mechanism by which COX-2 inhibitors affect HCC cell growth is as yet not fully understood. Increasing evidence suggests the involvement of molecular targets other

  16. Impact of Wines and Wine Constituents on Cyclooxygenase-1, Cyclooxygenase-2, and 5-Lipoxygenase Catalytic Activity

    Directory of Open Access Journals (Sweden)

    Zsofia Kutil

    2014-01-01

    Full Text Available Cyclooxygenases and lipoxygenases are proinflammatory enzymes; the former affects platelet aggregation, vasoconstriction, vasodilatation and later the development of atherosclerosis. Red wines from Georgia and central and western Europe inhibited cyclooxygenase-1 (COX-1 activity in the range of 63–94%, cyclooxygenase-2 (COX-2 activity in the range of 20–44% (tested at a concentration of 5 mL/L, and 5-lipoxygenase (5-LOX activity in the range of 72–84% (at a concentration of 18.87 mL/L. White wines inhibited 5-LOX in the range of 41–68% at a concentration of 18.87 mL/L and did not inhibit COX-1 and COX-2. Piceatannol (IC50 = 0.76 μM was identified as a strong inhibitor of 5-LOX followed by luteolin (IC50 = 2.25 μM, quercetin (IC50 = 3.29 μM, and myricetin (IC50 = 4.02 μM. trans-Resveratrol was identified as an inhibitor of COX-1 (IC50 = 2.27 μM and COX-2 (IC50 = 3.40 μM. Red wine as a complex mixture is a powerful inhibitor of COX-1, COX-2, and 5-LOX, the enzymes involved in eicosanoid biosynthetic pathway.

  17. Leukotriene B(4) BLT receptor signaling regulates the level and stability of cyclooxygenase-2 (COX-2) mRNA through restricted activation of Ras/Raf/ERK/p42 AUF1 pathway.

    Science.gov (United States)

    Zhai, Beibei; Yang, Huiqing; Mancini, Arturo; He, QingWen; Antoniou, John; Di Battista, John A

    2010-07-30

    Recent studies suggest that active resolution of the inflammatory response in animal models of arthritis may involve leukotriene B(4) (LTB(4))-dependent stimulation of "intermediate" prostaglandin production, which in turn favors the synthesis of "downstream" anti-inflammatory and pro-resolving lipoxins, resolvins, and protectins. We explored a putative mechanism involving LTB(4)-dependent control of cyclooxygenase-2 (COX-2) expression, the rate-limiting step in inflammatory prostaglandin biosynthesis. Indeed, LTB(4) potently up-regulated/stabilized interleukin-1beta-induced COX-2 mRNA and protein expression under conditions of COX-2 inhibitor-dependent blockade of PGE(2) release in human synovial fibroblasts (EC(50) = 16.5 + or - 1.7 nm for mRNA; 19 + or - 2.4 nm for protein, n = 4). The latter response was pertussis toxin-sensitive, and semi-quantitative reverse transcription-PCR confirmed the quantitative predominance of the BLT2 receptor. Transfection experiments, using human COX-2 promoter plasmids and chimeric luciferase-COX-2 mRNA 3'-untranslated region (3'-UTR) reporter constructs, revealed that LTB(4) exerted its stabilizing effect at the post-transcriptional level through a 116-bp adenylate/uridylate-rich sequence in the proximal region of the COX-2 3'-UTR. Using luciferase-COX-2 mRNA 3'-UTR reporter constructs and Ras/c-Raf expression and mutant constructs, we showed that the Ras/c-Raf/MEK1/2/ERK1/2 signaling pathway mediated LTB(4)-dependent COX-2 mRNA stabilization. Knockdown experiments with specific short hairpin RNAs confirmed that LTB(4) stabilization of COX-2 mRNA was apparently mediated through the RNA-binding protein, p42 AUF1. The nuclear export of p42 AUF1 was driven by c-Raf/MEK1/2/ERK1/2 signaling and sensitive to leptomycin B treatment, suggesting a CRM1-dependent mechanism. We conclude that LTB(4) may support the resolution phase of the inflammatory response by stabilizing COX-2, ensuring a reservoir of ambient pro-resolution lipid

  18. Linoleic acid-induced expression of inducible nitric oxide synthase and cyclooxygenase II via p42/44 mitogen-activated protein kinase and nuclear factor-kappaB pathway in retinal pigment epithelial cells.

    Science.gov (United States)

    Fang, I-Mo; Yang, Chang-Hao; Yang, Chung-May; Chen, Muh-Shy

    2007-11-01

    High linoleic acid (LA) intake is known to correlate with age-related macular degeneration (AMD), but the molecular mechanisms remain unclear. This study was conducted to investigate the effects of LA on expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase II (COX-2) and their associated signaling pathways in human retinal pigment epithelial (RPE) cells. ARPE-19 cells were treated with different concentrations of LA. Expressions of iNOS and COX-2 were examined using semiquantitative reverse transcription polymerase chain reaction (RT-PCR) and Western blot analysis. Concentrations of nitric oxide (NO) and prostaglandin E(2) (PGE(2)) in the culture medium were determined by enzyme-link immunosorbent assay (ELISA). Activation of p42/44, p38, JNK mitogen-activated protein kinase (MAPK) and nuclear factors (NF)-kappaB were evaluated by Western blot analysis and electrophoretic mobility shift assay (EMSA). We found that LA induced expression of iNOS and COX-2 in RPE cells at the mRNA and protein levels in a time-and dose-dependent manner. Upregulation of iNOS and COX-2 resulted in increased production of NO and PGE(2). Moreover, LA caused degradation of IkappaB and increased NF-kappaB DNA binding activity. Effects of LA-induced iNOS and COX-2 expression were inhibited by a NF-kappaB inhibitor, pyrrolidine dithiocarbamate (PDTC). LA activated p42/44, but not p38 or JNK MAPK. Inhibition of p42/44 activity by PD98059 significantly reduced LA-induced activation of NF-kappaB. Linoleic acid-induced expression of iNOS and COX-2 as well as PGE(2) and NO release in RPE cells were sequentially mediated through activation of p42/p44, MAPK, then NF-kappaB. These results may provide new insights into both mechanisms of LA action on RPE cells and pathogenesis of age-related macular degeneration.

  19. Cyclooxygenase-2-dependent prostacyclin formation and blood pressure homeostasis: targeted exchange of cyclooxygenase isoforms in mice

    DEFF Research Database (Denmark)

    Yu, Ying; Stubbe, Jane; Ibrahim, Salam

    2010-01-01

    pressure. OBJECTIVE: To elucidate the role of COX-2 in blood pressure homeostasis using COX-1>COX-2 mice, in which the COX-1 expression is controlled by COX-2 regulatory elements. METHODS AND RESULTS: COX-1>COX-2 mice developed systolic hypertension relative to wild types (WTs) on a high-salt diet (HSD......RATIONALE: Cyclooxygenase (COX)-derived prostanoids (PGs) are involved in blood pressure homeostasis. Both traditional nonsteroidal antiinflammatory drugs (NSAIDs) that inhibit COX-1 and COX-2 and NSAIDs designed to be selective for inhibition of COX-2 cause sodium retention and elevate blood......, PGI(2) biosynthesis/response pathway in the renal inner renal medulla undermines the homeostatic response to a HSD. Inhibition of this pathway may contribute directly to the hypertensive response to NSAIDs....

  20. Effects of ozone on lung mechanics and cyclooxygenase metabolites in dogs

    Energy Technology Data Exchange (ETDEWEB)

    Fouke, J.M.; Wolin, A.D.; McFadden, E.R. Jr. (Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH (United States))

    1991-10-01

    To determine if acute exposure to ozone can cause changes in the production of cyclooxygenase metabolites of arachidonic acid (AA) in the lung which are associated with changes in lung mechanics, we exposed mongrel dogs to 0.5 ppm ozone for two hours. We measured pulmonary resistance (RL) and dynamic compliance (Cdyn) and obtained methacholine dose response curves and bronchoalveolar lavagate (BAL) before and after the exposures. We calculated the provocative dose of methacholine necessary to increase RL 50% (PD50) and analyzed the BAL for four cyclooxygenase metabolites of AA: a stable hydrolysis product of prostacyclin, 6-keto-prostaglandin F1 alpha (6-keto-PgF1 alpha); prostaglandin E2 (PgE2); a stable hydrolysis product of thromboxane A2, thromboxane B2 (TxB2); and prostaglandin F2 alpha (PgF2 alpha). Following ozone exposure, RL increased from 4.75 +/- 1.06 to 6.08 +/- 1.3 cm H2O/L/sec (SEM) (p less than 0.05), Cdyn decreased from 0.0348 +/- 0.0109 TO .0217 +/- .0101 L/cm H2O (p less than 0.05), and PD50 decreased from 4.32 +/- 2.41 to 0.81 +/- 0.49 mg/cc (p less than 0.05). The baseline metabolite levels were as follows: 6-keto PgF1 alpha: 96.1 +/- 28.8 pg/ml; PgE2: 395.8 +/- 67.1 pg/ml; TxB2: 48.5 +/- 11.1 pg/ml; PgF2 alpha: 101.5 +/- 22.6 pg/ml. Ozone had no effect on any of these prostanoids. These studies quantify the magnitude of cyclooxygenase products of AA metabolism in BAL from dog lungs and demonstrate that changes in their levels are not prerequisites for ozone-induced changes in lung mechanics or airway reactivity.

  1. [Pharmacology and classification of cyclooxygenase inhibitors].

    Science.gov (United States)

    Jouzeau, Jean-Yves; Daouphars, Mikaël; Benani, Alexandre; Netter, Patrick

    2004-04-01

    The discovery of at least two cyclooxygenase (COX) isoenzymes had two major consequences: i) to give a new impetus to the research on lipid metabolism, giving rise to the crystallization of these peculiar membrane enzymes, the characterization of their active sites and their gene regulation, and the identification of new metabolic pathways; ii) the development of new NSAIDs aimed to have an improved safety profile, the coxibs. These drugs are defined by their COX-2 selectivity which is supported by a negligible inhibitory potency on platelet COX-1 in vitro and ex vivo after oral intake of maximal therapeutic doses. However, the coxibs marketed in France (celecoxib, rofecoxib, parecoxib) are not equivalent in terms of selectivity and some drugs developed by pharmaceutical companies (etoricoxib, lumiracoxib) will be even more selective for COX-2. These "new" coxibs are the final step in the theory of COX-2 selectivity and they will probably be helpful to better define the limitations of the therapeutic concept based on a selective inhibition of this iso-enzyme.

  2. Manassantin B isolated from Saururus chinensis inhibits cyclooxygenase-2-dependent prostaglandin D2 generation by blocking Fyn-mediated nuclear factor-kappaB and mitogen activated protein kinase pathways in bone marrow derived-mast cells.

    Science.gov (United States)

    Lu, Yue; Hwang, Seung-Lark; Son, Jong Keun; Chang, Hyeun Wook

    2013-01-01

    The authors investigated the effect of manassantin B (Man B) isolated from Saururus chinensis (S. chinensis) on cyclooxygenase-2 (COX-2)-dependent prostaglandin D2 (PGD2) generation in mouse bone marrow derived-mast cells (BMMCs). Man B inhibited the generation of PGD2 dose-dependently by inhibiting COX-2 expression in immunoglobulin E (IgE)/Ag-stimulated BMMCs. To elucidate the mechanism responsible for the inhibition of COX-2 expression by Man B, the effects of Man B on the activation of nuclear factor-kappaB (NF-κB), a transcription factor essential and mitogen-activated protein kinases (MAPKs) for COX-2 induction, were examined. Man B attenuated the nuclear translocation of NF-κB p65 and its DNA-binding activity by inhibiting inhibitors of kappa Bα (IκBα) degradation and concomitantly suppressing IκB kinase (IKK) phosphorylation. In addition, Man B suppressed phosphorylation of MAPKs including extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun NH2-terminal kinase (JNK) and p38. It was also found that Man B suppressed Fyn kinase activation and consequent downstream signaling processes, including those involving Syk, Gab2, and Akt. Taken together, the present results suggest that Man B suppresses COX-2 dependent PGD2 generation by primarily inhibiting Fyn kinase in FcεRI-mediated mast cells.

  3. Using gait analysis to assess weight bearing in rats with Freund׳s complete adjuvant-induced monoarthritis to improve predictivity: Interfering with the cyclooxygenase and nerve growth factor pathways.

    Science.gov (United States)

    Ängeby Möller, Kristina; Berge, Odd-Geir; Finn, Anja; Stenfors, Carina; Svensson, Camilla I

    2015-06-01

    Lack of predictive power for drug effects has been a major criticism against animal pain models. It is therefore important to define the utility and limitations of different models. The aim of this study was to extend previous work on gait analysis as a tool to investigate pharmacological effects in monoarthritic rats, specifically to test the hypothesis that monoarthritis induced by Freund׳s complete adjuvant (FCA) provides a better estimate of overall analgesic efficacy of established, and novel, clinically effective and ineffective therapeutic approaches. Male rats injected intra-articularly into one ankle joint with FCA (1.0mg/ml) were treated with the monoclonal antibody to nerve growth factor (NGF), MEDI-578, the inhibitors of tropomyosin receptor kinases A, B and C (pan-Trk) AZ6623 or AZ7092, the transient receptor potential vanilloid 1 (TRPV1) inhibitor AZD1386, or the cyclooxygenase (COX) inhibitors naproxen, ibuprofen, valdecoxib or rofecoxib. Effects on weight bearing during locomotion were tested using video capture of print images. The apparent efficacy in this model was Trk inhibitors≥anti-NGF antibody>COX inhibitors. The TRPV1 inhibitor was ineffective. Together with previous data, the results support using gait-related parameters in the monoarthritis model. FCA as induction agent seems to provide a good overall prediction of analgesic efficacy in disorders with inflammatory joint pain.

  4. Cyclooxygenase/lipoxygenase shunting lowers the anti-cancer effect of cyclooxygenase-2 inhibition in colorectal cancer cells

    Directory of Open Access Journals (Sweden)

    Ganesh Radhakrishnan

    2012-09-01

    Full Text Available Abstract Background Arachidonic acid metabolite, generated by cyclooxygenase (COX, is implicated in the colorectal cancer (CRC pathogenesis. Inhibiting COX may therefore have anti-carcinogenic effects. Results from use of non-steroidal anti-inflammatory drugs inhibiting only COX have been conflicting. It has been postulated that this might result from the shunting of arachidonic acid metabolism to the 5-lipoxygenase (5-LOX pathway. Cancer cell viability is promoted by 5-LOX through several mechanisms that are similar to those of cyclooxygenase-2 (COX-2. Expression of 5-LOX is upregulated in colorectal adenoma and cancer. The aim of this study was to investigate the shunting of arachidonic acid metabolism to the 5-LOX pathway by cyclooxygenase inhibition and to determine if this process antagonizes the anti-cancer effect in colorectal cancer cells. Methods Three colorectal cancer cell lines (HCA7, HT-29 & LoVo expressing 5-LOX and different levels of COX-2 expression were used. The effects of aspirin (a non-selective COX inhibitor and rofecoxib (COX-2 selective on prostaglandin E2 (PGE2 and leukotriene B4 (LTB4 secretion were quantified by ELISA. Proliferation and viability were studied by quantifying double-stranded DNA (dsDNA content and metabolic activity. Apoptosis was determined by annexin V and propidium iodide staining using confocal microscopy, and caspase-3/7 activity by fluorescent substrate assay. Results COX inhibitors suppressed PGE2 production but enhanced LTB4 secretion in COX-2 expressing cell lines (P  Conclusions This study provides evidence of shunting between COX and 5-LOX pathways in the presence of unilateral inhibition, and may explain the conflicting anti-carcinogenic effects reported with use of COX inhibitors.

  5. Inhibition of cyclooxygenase activity reduces rotavirus infection at a postbinding step.

    NARCIS (Netherlands)

    J.W. Rossen (John); J. Bouma (Janneke); R.H. Raatgeep (Rolien); H.A. Büller (Hans); A.W.C. Einerhand (Sandra)

    2004-01-01

    textabstractElevated levels of prostaglandins (PGs), products of cyclooxygenases (COXs), are found in the plasma and stool of rotavirus-infected children. We sought to determine the role of COXs, PGs, and the signal transduction pathways involved in rotavirus infection to elucidate

  6. Inhibition of cyclooxygenase activity reduces rotavirus infection at a postbinding step

    NARCIS (Netherlands)

    Rossen, John W A; Bouma, Janneke; Raatgeep, Rolien H C; Büller, Hans A; Einerhand, Alexandra W C

    2004-01-01

    Elevated levels of prostaglandins (PGs), products of cyclooxygenases (COXs), are found in the plasma and stool of rotavirus-infected children. We sought to determine the role of COXs, PGs, and the signal transduction pathways involved in rotavirus infection to elucidate possible new targets for anti

  7. Inhibition of cyclooxygenase activity reduces rotavirus infection at a postbinding step

    NARCIS (Netherlands)

    Rossen, John W A; Bouma, Janneke; Raatgeep, Rolien H C; Büller, Hans A; Einerhand, Alexandra W C

    Elevated levels of prostaglandins (PGs), products of cyclooxygenases (COXs), are found in the plasma and stool of rotavirus-infected children. We sought to determine the role of COXs, PGs, and the signal transduction pathways involved in rotavirus infection to elucidate possible new targets for

  8. Inhibition of cyclooxygenase activity reduces rotavirus infection at a postbinding step.

    NARCIS (Netherlands)

    J.W. Rossen (John); J. Bouma (Janneke); R.H. Raatgeep (Rolien); H.A. Büller (Hans); A.W.C. Einerhand (Sandra)

    2004-01-01

    textabstractElevated levels of prostaglandins (PGs), products of cyclooxygenases (COXs), are found in the plasma and stool of rotavirus-infected children. We sought to determine the role of COXs, PGs, and the signal transduction pathways involved in rotavirus infection to elucidate

  9. Cyclooxygenase-2 and prostate carcinogenesis.

    Science.gov (United States)

    Hussain, Tajamul; Gupta, Sanjay; Mukhtar, Hasan

    2003-03-10

    In recent years a dramatic surge has occurred on studies defining to the role of cyclooxygenase (COX)-2 in causation and prevention of cancer. Prostaglandin (PG) endoperoxidase synthase also commonly referred to as COX is a key enzyme involved in the conversion of arachidonic acid to PGs and other eicosanoids. COX exists as two isoforms, namely COX-1 and COX-2 with distinct tissue distribution and physiological functions. COX-1 is constitutively expressed in many tissues and cell types and is involved in normal cellular physiological functions whereas COX-2 is pro-inflammatory in nature and is inducible by mitogens, cytokines, tumor promoters and growth factors. A large volume of data exists showing that COX-2 is overexpressed in a large number of human cancers and cancer cell lines. The possibility of COX-2 as a candidate player in cancer development and progression evolved from the epidemiological studies which suggest that regular use of aspirin or other non-steroidal anti-inflammatory drugs could significantly decrease the risk of developing cancers in experimental animals and in humans. In our recently published study (Prostate, 42 2000 73-78), we provided the first evidence that COX-2 is overexpressed in human prostate adenocarcinoma. Many other studies verified our initial observation and reported that compared to normal tissue, COX-2 is overexpressed in human prostate cancer. It should be noted that some recent work has suggested that COX-2 is only up-regulated in proliferative inflammatory atrophy of the prostate, but not in prostate carcinoma. In this scenario, COX-2 inhibitors could afford their effects against prostate carcinogenesis by modulating COX-2 activity in other cells in prostate. An exciting corollary to this ongoing work is that selective COX-2 inhibitors may exhibit chemopreventive and even chemotherapeutic effects against prostate carcinogenesis in humans.

  10. TGF-β1 stimulates cyclooxygenase-2 expression and PGE2 production of human dental pulp cells: Role of ALK5/Smad2 and MEK/ERK signal transduction pathways

    Directory of Open Access Journals (Sweden)

    Po-Shuen Lin

    2017-10-01

    Conclusion: TGF-β1 increased the COX-2 and PGE2 level of cultured pulp cells. The effect of TGF-β1 on COX-2 protein expression was associated with ALK5/Smad2/3 and MEK/ERK pathways. These events are important in the early inflammation, repair and regeneration of dental pulp in response to injury.

  11. Cyclooxygenase and Neuroinflammation in Parkinson's Disease Neurodegeneration

    NARCIS (Netherlands)

    Bartels, Anna L.; Leenders, Klaus L.

    2010-01-01

    Cyclooxygenase (COX) expression in the brain is associated with pro-inflammatory activities, which are instrumental in neurodegenerative processes such as Parkinson's disease (PD). It is discussed that drugs with the capacity to rescue dopaminergic neurons from microglia toxicity and neuroinflammato

  12. Mechanisms underlying sodium nitroprusside-induced tolerance in the mouse aorta: Role of ROS and cyclooxygenase-derived prostanoids.

    Science.gov (United States)

    Diniz, Mariana C; Olivon, Vania C; Tavares, Lívia D; Simplicio, Janaina A; Gonzaga, Natália A; de Souza, Daniele G; Bendhack, Lusiane M; Tirapelli, Carlos R; Bonaventura, Daniella

    2017-05-01

    To determine the role of reactive oxygen species (ROS) on sodium nitroprusside (SNP)-induced tolerance. Additionally, we evaluated the role of ROS on NF-κB activation and pro-inflammatory cytokines production during SNP-induced tolerance. To induce in vitro tolerance, endothelium-intact or -denuded aortic rings isolated from male Balb-c mice were incubated for 15, 30, 45 or 60min with SNP (10nmol/L). Tolerance to SNP was observed after incubation of endothelium-denuded, but not endothelium-intact aortas for 60min with this inorganic nitrate. Pre-incubation of denuded rings with tiron (superoxide anion (O2(-)) scavenger), and the NADPH oxidase inhibitors apocynin and atorvastatin reversed SNP-induced tolerance. l-NAME (non-selective NOS inhibitor) and l-arginine (NOS substrate) also prevented SNP-induced tolerance. Similarly, ibuprofen (non-selective cyclooxygenase (COX) inhibitor), nimesulide (selective COX-2 inhibitor), AH6809 (prostaglandin PGF2α receptor antagonist) or SQ29584 [PGH2/thromboxane TXA2 receptor antagonist] reversed SNP-induced tolerance. Increased ROS generation was detected in tolerant arteries and both tiron and atorvastatin reversed this response. Tiron prevented tolerance-induced increase on O2(-) and hydrogen peroxide (H2O2) levels. The increase onp65/NF-κB expression and TNF-α production in tolerant arteries was prevented by tiron. The major new finding of our study is that SNP-induced tolerance is mediated by NADPH-oxidase derived ROS and vasoconstrictor prostanoids derived from COX-2, which are capable of reducing the vasorelaxation induced by SNP. Additionally, we found that ROS mediate the activation of NF-κB and the production of TNF-α in tolerant arteries. These findings identify putative molecular mechanisms whereby SNP induces tolerance in the vasculature. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Cyclooxygenase (COX) Inhibitors and the Newborn Kidney

    OpenAIRE

    Wei Qi; Smith, Francine G.; Megan L. Lewis; Wade, Andrew W

    2012-01-01

    This review summarizes our current understanding of the role of cyclo-oxygenase inhibitors (COXI) in influencing the structural development as well as the function of the developing kidney. COXI administered either during pregnancy or after birth can influence kidney development including nephronogenesis, and can decrease renal perfusion and ultrafiltration potentially leading to acute kidney injury in the newborn period. To date, which COX isoform (COX-1 or COX-2) plays a more important role...

  14. Cyclooxygenase-2 immunoreactivity in collagenous colitis

    DEFF Research Database (Denmark)

    Wildt, Signe; Rumessen, Jüri J; Csillag, Claudio

    2009-01-01

    Collagenous colitis (CC) is an inflammatory bowel disease of unknown aetiology and pathogenesis. In ulcerative colitis and Crohn's disease, prostaglandins may be involved in the pathogenesis of inflammation, and increased expression of cyclo-oxygenase-2 (COX-2) has been detected. The purpose...... with samples from eight normal controls, and samples from eight patients with ulcerative colitis or Crohn's disease. Specimens from patients with CC expressed COX-2 protein in increased amounts compared with controls, but similar to patients with ulcerative colitis and Crohn's disease. COX-2 expression...

  15. Cyclooxygenase- and cytochrome P450-derived eicosanoids in stroke.

    Science.gov (United States)

    Huang, Hui; Al-Shabrawey, Mohamed; Wang, Mong-Heng

    2016-01-01

    Arachidonic acid (AA) is metabolized by cyclooxygenase (COX) and cytochrome P450 (CYP) enzymes into eicosanoids, which are involved in cardiovascular diseases and stroke. Evidence has demonstrated the important functions of these eicosanoids in regulating cerebral vascular tone, cerebral blood flow, and autoregulation of cerebral circulation. Although COX-2 inhibitors have been suggested as potential treatments for stroke, adverse events, including an increased risk of stroke, occur following long-term use of coxibs. It is important to note that prolonged treatment with rofecoxib increased circulating levels of 20-hydroxyeicosatetraenoic acid (20-HETE), and 20-HETE blockade is a possible strategy to prevent coxib-induced stroke events. It appears that 20-HETE has detrimental effects in the brain, and that its blockade exerts cerebroprotection against ischemic stroke and subarachnoid hemorrhage (SAH). There is clear evidence that activation of EP2 and EP4 receptors exerts cerebroprotection against ischemic stroke. Several elegant studies have contributed to defining the importance of stabilizing the levels of epoxyeicosatrienoic acids (EETs), by inhibiting or deleting soluble epoxide hydrolase (sEH), in stroke research. These reports support the notion that sEH blockade is cerebroprotective against ischemic stroke and SAH. Here, we summarize recent findings implicating these eicosanoid pathways in cerebral vascular function and stroke. We also discuss the development of animal models with targeted gene deletion and specific enzymatic inhibitors in each pathway to identify potential targets for the treatment of ischemic stroke and SAH.

  16. Cyclooxygenase (COX Inhibitors and the Newborn Kidney

    Directory of Open Access Journals (Sweden)

    Wei Qi

    2012-10-01

    Full Text Available This review summarizes our current understanding of the role of cyclo-oxygenase inhibitors (COXI in influencing the structural development as well as the function of the developing kidney. COXI administered either during pregnancy or after birth can influence kidney development including nephronogenesis, and can decrease renal perfusion and ultrafiltration potentially leading to acute kidney injury in the newborn period. To date, which COX isoform (COX-1 or COX-2 plays a more important role in during fetal development and influences kidney function early in life is not known, though evidence points to a predominant role for COX-2. Clinical implications of the use of COXI in pregnancy and in the newborn infant are also evaluated herein, with specific reference to the potential effects of COXI on nephronogenesis as well as newborn kidney function.

  17. Assay of Endocannabinoid Oxidation by Cyclooxygenase-2

    Science.gov (United States)

    Kudalkar, Shalley N.; Kingsley, Philip J.; Marnett, Lawrence J.

    2017-01-01

    Summary The endocannabinoids, 2-arachidonoylglycerol (2-AG) and arachidonylethanolamide (AEA) are endogenous ligands for the cannabinoid receptors (CB1 and CB2) and are implicated in a wide array of physiological processes. These neutral arachidonic acid (AA) derivatives have been identified as efficient substrates for the second isoform of the cyclooxygenase enzyme (COX-2). A diverse family of prostaglandin glycerol esters (PG-Gs) and prostaglandin ethanolamides (PG-EAs) is generated by the action of COX-2 (and downstream prostaglandin synthases) on 2-AG and AEA. As the biological importance of the endocannabinoid system becomes more apparent, there is a tremendous need for robust, sensitive and efficient analytical methodology for the endocannabinoids and their metabolites. In this chapter we describe methodology suitable for carrying out oxygenation of endocannabinoids by COX-2, and analysis of products of endocannabinoid oxygenation by COX-2 and of endocannabinoids themselves from in-vitro and cell assays. PMID:27245906

  18. Cyclooxygenase-2 inhibitors in colorectal cancer prevention: point.

    Science.gov (United States)

    Arber, Nadir

    2008-08-01

    The limited success of current treatments for most advanced common malignancies highlights the importance of cancer prevention. Clinical trials on cyclooxygenase (COX) inhibitor drugs showed the potential of chemoprevention as a strategy for reducing cancer incidence, although not without associated side effects. The attractiveness of these drugs partly stems from an ability to engage multiple mechanisms of action by their potential to influence multiple components of the carcinogenesis pathway, from initiation to progression. There are two isoforms of the COX enzymes. COX-1 is constitutively expressed in normal tissues and serves as a "housekeeper" of mucosal integrity, whereas COX-2 is an immediate early response gene that is highly inducible by neoplastic and inflammatory stimuli. COX-2 is significantly overexpressed in colorectal neoplasms, making it an attractive therapeutic target. The drug market has been revolutionized by the development of preparations targeted selectively against COX-2, and a proof of concept has been achieved. Chemoprevention of colorectal cancer is already possible with celecoxib, but it is still not the ultimate drug of choice especially because of the cardiovascular risk associated with COX-2 inhibitors. Better patient selection and more effective and safer drugs are needed. Celecoxib is probably best used in a subset of individuals at moderate to high colorectal cancer risk and low risk of cardiovascular disease.

  19. Local osteogenic expression of cyclooxygenase-2 and systemic response in porcine models of osteomyelitis

    DEFF Research Database (Denmark)

    Johansen, Louise K.; Iburg, Tine M.; Nielsen, Ole L.;

    2012-01-01

    It is suggested that cyclooxygenase 2 (COX-2) derived prostaglandins contributes to the progressive bone loss seen in osteomyelitis lesions. In the present study we examined the expression of COX-2 in bones from 23 pigs with experimental osteomyelitis. Osteomyelitis was induced with Staphylococcus...... in vivo study showing an early wave of COX-2 mediated bone resorption during osteomyelitis. Therefore, treatment aiming to reduce the break down of bone tissue directed by the COX-2 pathway might be suggested early in the course of the disease....

  20. ETORICOXIB IS A NEW SELECTIVE CYCLOOXYGENASE-2 INHIBITOR

    Directory of Open Access Journals (Sweden)

    A E Karateev

    2009-01-01

    Full Text Available The paper provides the clinical characteristics of etoricoxib (Arcoxia, a new selective cyclooxygenase-2 inhibitor having unique properties, which permits it to be distinguished among other nonsteroidal anti-inflammatory agents.

  1. ETORICOXIB IS A NEW SELECTIVE CYCLOOXYGENASE-2 INHIBITOR

    Directory of Open Access Journals (Sweden)

    A E Karateev

    2009-06-01

    Full Text Available The paper provides the clinical characteristics of etoricoxib (Arcoxia, a new selective cyclooxygenase-2 inhibitor having unique properties, which permits it to be distinguished among other nonsteroidal anti-inflammatory agents.

  2. Aspirin, cyclooxygenase inhibition and colorectal cancer

    Institute of Scientific and Technical Information of China (English)

    Carlos; Sostres; Carla; Jerusalen; Gargallo; Angel; Lanas

    2014-01-01

    Colorectal cancer(CRC)is the third most common type of cancer worldwide.Screening measures are far from adequate and not widely available in resourcepoor settings.Primary prevention strategies therefore remain necessary to reduce the risk of developing CRC.Increasing evidence from epidemiological studies,randomized clinical trials and basic science supports the effectiveness of aspirin,as well as other non-steroidal anti-inflammatory drugs,for chemoprevention of several types of cancer,including CRC.This includes the prevention of adenoma recurrence and reduction of CRC incidence and mortality.The detectable benefit of daily low-dose aspirin(at least 75 mg),as used to prevent cardiovascular disease events,strongly suggests that its antiplatelet action is central to explaining its antitumor efficacy.Daily low-dose aspirin achieves complete and persistent inhibition of cyclooxygenase(COX)-1 in platelets(in pre-systemic circulation)while causing alimited and rapidly reversible inhibitory effect on COX-2and/or COX-1 expressed in nucleated cells.Aspirin has a short half-life in human circulation(about 20 minutes);nucleated cells have the ability to resynthesize acetylated COX isozymes within a few hours,while platelets do not.COX-independent mechanisms of aspirin have been suggested to explain its chemopreventive effects but this concept remains to be demonstrated in vivo at clinical doses.

  3. Cyclooxygenase-2 expression in cervical cancer

    Directory of Open Access Journals (Sweden)

    Mandić Aljoša

    2014-01-01

    Full Text Available Background/Aim. Cyclooxygenase (COX or prostaglandin H2 synthase is the first enzyme that catalyzes the first two steps in the biosynthesis of prostaglandins from arachidonic acid. The aim of the study was to determine the expression level of COX-2 in patients with cervical cancer and compare it with that in the control group with no cervical pathology. Methods. The study included 76 patients divided into two groups: the control group - 30 patients without histopathological changes and the group A - 46 patients with cervical cancer, FIGO stage IB-IIA. Histopathological and immunohistochemical analyses were performed in these two groups of patients. Results. In the control group, the expression of COX-2 was not confirmed compared to the group A of 26 (56.52% patients. The expression of COX-2 showed a statistically significant difference in the presence of lymphocytic stromal infiltration (p = 0.0053. The expression of COX-2 was more pronounced in the stromal tissue without lymphocytic infiltration (80% vs 20%. Conclusion. A higher expression of COX-2 in cervical carcinoma without stromal lymphocytic infiltration suggests a possible paradoxical effect of COX-2 in immunosuppression. Frequent COX- 2 expression in the subgroup with poor prognostic histological parameters in the group A indicates the importance of COX-2 expression in the carcinogenesis of cervical cancer.

  4. Crystallization of recombinant cyclo-oxygenase-2

    Science.gov (United States)

    Stevens, Anna M.; Pawlitz, Jennifer L.; Kurumbail, Ravi G.; Gierse, James K.; Moreland, Kirby T.; Stegeman, Roderick A.; Loduca, Jina Y.; Stallings, William C.

    1999-01-01

    The integral membrane protein, prostaglandin H 2 synthase, or cyclo-oxygenase (COX), catalyses the first step in the conversion of arachidonic acid to prostaglandins (PGs) and is the target of nonsteroidal anti-inflammatory drugs (NSAIDs). Two isoforms are known. The constitutive enzyme, COX-1, is present in most tissues and is responsible for the physiological production of PGs. The isoform responsible for the elevated production of PGs during inflammation is COX-2 which is induced specifically at inflammatory sites. Three-dimensional structures of inhibitor complexes of COX-2, and of site variants of COX-2 which mimic COX-1, provide insight into the structural basis for selective inhibition of COX-2. Additionally, structures of COX-2 mutants and complexes with the substrate can provide a clearer understanding of the catalytic mechanism of the reaction. A crystallization protocol has been developed for COX-2 which reproducibly yields diffraction quality crystals. Polyethyleneglycol 550 monomethylether (MMP550) and MgCl 2 were systematically varied and used in conjunction with the detergent β- D-octylglucopyranoside ( β-OG). As a result of many crystallization trials, we determined that the initial β-OG concentration should be held constant, allowing the salt concentration to modulate the critical micelle concentration (CMC) of the detergent. Over 25 crystal structures have been solved using crystals generated from this system. Most crystals belong to the space group P2 12 12, with lattice constants of a=180, b=134, c=120 Å in a pseudo body-centered lattice.

  5. Aspirin, cyclooxygenase inhibition and colorectal cancer.

    Science.gov (United States)

    Sostres, Carlos; Gargallo, Carla Jerusalen; Lanas, Angel

    2014-02-01

    Colorectal cancer (CRC) is the third most common type of cancer worldwide. Screening measures are far from adequate and not widely available in resource-poor settings. Primary prevention strategies therefore remain necessary to reduce the risk of developing CRC. Increasing evidence from epidemiological studies, randomized clinical trials and basic science supports the effectiveness of aspirin, as well as other non-steroidal anti-inflammatory drugs, for chemoprevention of several types of cancer, including CRC. This includes the prevention of adenoma recurrence and reduction of CRC incidence and mortality. The detectable benefit of daily low-dose aspirin (at least 75 mg), as used to prevent cardiovascular disease events, strongly suggests that its antiplatelet action is central to explaining its antitumor efficacy. Daily low-dose aspirin achieves complete and persistent inhibition of cyclooxygenase (COX)-1 in platelets (in pre-systemic circulation) while causing a limited and rapidly reversible inhibitory effect on COX-2 and/or COX-1 expressed in nucleated cells. Aspirin has a short half-life in human circulation (about 20 minutes); nucleated cells have the ability to resynthesize acetylated COX isozymes within a few hours, while platelets do not. COX-independent mechanisms of aspirin have been suggested to explain its chemopreventive effects but this concept remains to be demonstrated in vivo at clinical doses.

  6. Antitumor Activity of Cytotoxic Cyclooxygenase-2 Inhibitors

    Science.gov (United States)

    Uddin, Md. Jashim; Crews, Brenda C.; Xu, Shu; Ghebreselasie, Kebreab; Daniel, Cristina K.; Kingsley, Philip J.; Banerjee, Surajit; Marnett, Lawrence J.

    2017-01-01

    Targeted delivery of chemotherapeutic agents to tumors has been explored as a means to increase the selectivity and potency of cytotoxicity. Most efforts in this area have exploited the molecular recognition of proteins highly expressed on the surface of cancer cells followed by internalization. A related approach that has received less attention is the targeting of intracellular proteins by ligands conjugated to anti-cancer drugs. An attractive target for this approach is the enzyme cyclooxygenase-2 (COX-2), which is highly expressed in a range of malignant tumors. Herein, we describe the synthesis and evaluation of a series of chemotherapeutic agents targeted to COX-2 by conjugation to indomethacin. Detailed characterization of compound 12, a conjugate of indomethacin with podophyllotoxin, revealed highly potent and selective COX-2 inhibition in vitro and in intact cells. Kinetics and X-ray crystallographic studies demonstrated that compound 12 is a slow, tight-binding inhibitor that likely binds to COX-2’s allosteric site with its indomethacin moiety in a conformation similar to that of indomethacin. Compound 12 exhibited cytotoxicity in cell culture similar to that of podophyllotoxin with no evidence of COX-2-dependent selectivity. However, in vivo, compound 12 accumulated selectively in and more effectively inhibited the growth of a COX-2-expressing xenograft compared to a xenograft that did not express COX-2. Compound 12, which we have named chemocoxib A, provides proof-of-concept for the in vivo targeting of chemotherapeutic agents to COX-2, but suggests that COX-2-dependent selectivity may not be evident in cell culture-based assays. PMID:27588346

  7. Role of cyclooxygenase-2 in breast cancer.

    Science.gov (United States)

    Singh, Balraj; Lucci, Anthony

    2002-11-01

    Cyclooxygenase-2 (COX-2), the enzyme that converts arachidonic acid to prostaglandin H2, is expressed in normal brain and kidney, activated macrophages, synoviocytes during inflammation, and malignant epithelial cells. COX-2 expression is stimulated by a number of inflammatory cytokines, growth factors, oncogenes, lipopolysaccharides, and tumor promoters. There is evidence that COX-2 plays a key role in tumorigenesis through stimulating epithelial cell proliferation, inhibiting apoptosis, stimulating angiogenesis, enhancing cell invasiveness, mediating immune suppression, and by increasing the production of mutagens. Results of several studies using mouse models of colon cancer and the results of clinical trials have shown COX-2 to be a useful target for the prevention and treatment of colon cancer. Studies with several other epithelial cancers involving different organ sites, e.g., breast, prostate, bladder, lung, and pancreas, suggest that COX-2 plays an important role in the pathogenesis of these cancers. In this review, we summarize the studies that pertain to the involvement of COX-2 in breast cancer. COX-2 overexpression affects the physiological processes at different organ sites in a similar manner, although specific effectors and targets of COX-2 may differ at different sites. Thus in reviewing the data on the involvement of COX-2 in breast cancer, we have also considered the findings regarding the role of COX-2 in other organ sites. Studies from mouse models of mammary tumorigenesis and from human breast cancer cell lines provide evidence that COX-2 overexpression plays an important role in the pathogenesis of malignant breast cancer in humans. Because of availability of effective and relatively safe COX-2 inhibitors, it should be soon possible to evaluate their effectiveness in the clinic for the prevention and treatment of breast cancer. It is likely that the COX-2 inhibitors will be effective in the treatment regimens involving combination

  8. Characterization of Eicosanoids Produced by Adipocyte Lipolysis: IMPLICATION OF CYCLOOXYGENASE-2 IN ADIPOSE INFLAMMATION.

    Science.gov (United States)

    Gartung, Allison; Zhao, Jiawei; Chen, Simon; Mottillo, Emilio; VanHecke, Garrett C; Ahn, Young-Hoon; Maddipati, Krishna Rao; Sorokin, Andrey; Granneman, James; Lee, Menq-Jer

    2016-07-29

    Excessive adipocyte lipolysis generates lipid mediators and triggers inflammation in adipose tissue. However, the specific roles of lipolysis-generated mediators in adipose inflammation remain to be elucidated. In the present study, cultured 3T3-L1 adipocytes were treated with isoproterenol to activate lipolysis and the fatty acyl lipidome of released lipids was determined by using LC-MS/MS. We observed that β-adrenergic activation elevated levels of approximately fifty lipid species, including metabolites of cyclooxygenases, lipoxygenases, epoxygenases, and other sources. Moreover, we found that β-adrenergic activation induced cyclooxygenase 2 (COX-2), not COX-1, expression in a manner that depended on activation of hormone-sensitive lipase (HSL) in cultured adipocytes and in the epididymal white adipose tissue (EWAT) of C57BL/6 mice. We found that lipolysis activates the JNK/NFκB signaling pathway and inhibition of the JNK/NFκB axis abrogated the lipolysis-stimulated COX-2 expression. In addition, pharmacological inhibition of COX-2 activity diminished levels of COX-2 metabolites during lipolytic activation. Inhibition of COX-2 abrogated the induction of CCL2/MCP-1 expression by β-adrenergic activation and prevented recruitment of macrophage/monocyte to adipose tissue. Collectively, our data indicate that excessive adipocyte lipolysis activates the JNK/NFκB pathway leading to the up-regulation of COX-2 expression and recruitment of inflammatory macrophages. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  9. Inhibition of Cyclooxygenase-2 Prevents Chronic and Recurrent Cystitis.

    Science.gov (United States)

    Hannan, Thomas J; Roberts, Pacita L; Riehl, Terrence E; van der Post, Sjoerd; Binkley, Jana M; Schwartz, Drew J; Miyoshi, Hiroyuki; Mack, Matthias; Schwendener, Reto A; Hooton, Thomas M; Stappenbeck, Thaddeus S; Hansson, Gunnar C; Stenson, William F; Colonna, Marco; Stapleton, Ann E; Hultgren, Scott J

    2014-11-01

    The spread of multidrug-resistant microorganisms globally has created an urgent need for novel therapeutic strategies to combat urinary tract infections (UTIs). Immunomodulatory therapy may provide benefit, as treatment of mice with dexamethasone during acute UTI improved outcome by reducing the development of chronic cystitis, which predisposes to recurrent infection. Here we discovered soluble biomarkers engaged in myeloid cell development and chemotaxis that were predictive of future UTI recurrence when elevated in the sera of young women with UTI. Translation of these findings revealed that temperance of the neutrophil response early during UTI, and specifically disruption of bladder epithelial transmigration of neutrophils by inhibition of cyclooxygenase-2, protected mice against chronic and recurrent cystitis. Further, proteomics identified bladder epithelial remodeling consequent to chronic infection that enhances sensitivity to neutrophil damage. Thus, cyclooxygenase-2 expression during acute UTI is a critical molecular trigger determining disease outcome and drugs targeting cyclooxygenase-2 could prevent recurrent UTI.

  10. Discovery of potential cyclooxygenase inhibitors using in silico docking studies

    Directory of Open Access Journals (Sweden)

    Arumugam Madeswaran

    2012-03-01

    Full Text Available This study deals with the evaluation of the cyclooxygenase inhibitory activity of flavonoids (tangeritin, morin, rhamnetin, theaflavin, pachypodol, eriodictyol, homoeriodictyol, aromadedrin, okanin using in silico docking studies. In silico docking studies were carried out using AutoDock 4.2. Three important parameters like binding energy, inhibition constant and intermolecular energy were determined. The results showed that all the selected flavonoids showed binding energy ranging between -8.77 kcalmol-1 to -6.10 kcalmol-1 when compared with that of the standard (-8.30 kcalmol-1. Intermolecular energy (-10.56 kcalmol-1 to -7.89 kcalmol-1 and inhibition constant (373.91 nM to 34.03 µM of the ligands also coincide with the binding energy. All the selected flavonoids contributed cyclooxygenase inhibitory activity because of its structural parameters. These molecular docking analyses could lead to the further development of potent cyclooxygenase inhibitors.

  11. Inhibition of Cyclooxygenase-2 Prevents Chronic and Recurrent Cystitis

    Directory of Open Access Journals (Sweden)

    Thomas J. Hannan

    2014-11-01

    Full Text Available The spread of multidrug-resistant microorganisms globally has created an urgent need for novel therapeutic strategies to combat urinary tract infections (UTIs. Immunomodulatory therapy may provide benefit, as treatment of mice with dexamethasone during acute UTI improved outcome by reducing the development of chronic cystitis, which predisposes to recurrent infection. Here we discovered soluble biomarkers engaged in myeloid cell development and chemotaxis that were predictive of future UTI recurrence when elevated in the sera of young women with UTI. Translation of these findings revealed that temperance of the neutrophil response early during UTI, and specifically disruption of bladder epithelial transmigration of neutrophils by inhibition of cyclooxygenase-2, protected mice against chronic and recurrent cystitis. Further, proteomics identified bladder epithelial remodeling consequent to chronic infection that enhances sensitivity to neutrophil damage. Thus, cyclooxygenase-2 expression during acute UTI is a critical molecular trigger determining disease outcome and drugs targeting cyclooxygenase-2 could prevent recurrent UTI.

  12. Cyclooxygenases and lipoxygenases in prostate and breast cancers.

    Science.gov (United States)

    Nie, Daotai

    2007-01-01

    Oxidative metabolism of polyunsaturated fatty acids through cyclooxygenases or lipoxygenases can generate various lipid peroxides and bioactive lipids, and regulate cellular proliferation, apoptosis, differentiation and senescence. The role of the second cyclooxygenase isoform (COX-2) has been demonstrated in a number of studies and is regarded as a promising target for chemoprevention and treatment. The involvement for lipoxygenases in tumor initiation and progression has been implicated in several studies but remains controversial. Among the many members of lipoxygenase family, both tumor promoting and suppressing activities have been described. For example, 15-lipoxygenase-1 has been implicated as a tumor promoter in prostate cancer, but it suppresses colon cancer. In this review, the role of cyclooxygenases and lipoxygenases in cancer will be described, with the hope of attracting further research to define their functions in cancer.

  13. Acceleration of cardiovascular disease by a dysfunctional prostacyclin receptor mutation - Potential implications for cyclooxygenase-2 inhibition

    NARCIS (Netherlands)

    Arehart, Eric; Stitham, Jeremiah; Asselbergs, Folkert W.; Douville, Karen; MacKenzie, Todd; Fetalvero, Kristina M.; Gleim, Scott; Kasza, Zsolt; Rao, Yamini; Martel, Laurie; Segel, Sharon; Robb, John; Kaplan, Aaron; Simons, Michael; Powell, Richard J.; Moore, Jason H.; Rimm, Eric B.; Martin, Kathleen A.; Hwa, John

    2008-01-01

    Recent increased adverse cardiovascular events observed with selective cyclooxygenase-2 inhibition led to the withdrawal of rofecoxib ( Vioxx) and valdecoxib ( Bextra), but the mechanisms underlying these atherothrombotic events remain unclear. Prostacyclin is the major end product of cyclooxygenase

  14. Expression of Prostaglandin-Synthesizing Enzymes (Cyclooxygenase 1, Cyclooxygenase 2) in the Ovary of the Quail (Coturnix japonica).

    Science.gov (United States)

    Rodler, D; Sinowatz, F

    2015-01-01

    Cyclooxygenase is known to be the ratelimiting enzyme in the production of prostaglandins. So far, in different bird species there have been found two isoforms of cyclooxygenases (COX), cyclooxygenase 1 (COX-1) and cyclooxygenase 2 (COX-2). These isoforms along with prostaglandins are regarded to possess a determining influence on the success in female reproduction. Only in a few bird species the expression sites of cyclooxygenases have been investigated. In this study we report on the expression of COX-1 and COX-2 in the ovary of the quail (Coturnix japonica) using PCR, immunohistochemistry and non-radioactive in situ hybridization techniques. Using real time-polymerase chain reaction (RT-PCR), a distinct signal for COX-1 and COX-2 could be shown in small and large follicles of quail ovary. Antibodies to COX-1 distinctly labelled smooth muscle cells of the stroma, whereas COX-2 showed marked immunostaining in the thecal glands and the ovarian surface epithelium. In the same location, a signal of the corresponding mRNAs of COX-1 and COX-2 was found using in situ hybridization. This expression pattern in the quail is therefore completely different from the localization of COX-1 and COX-2 in the hen and ostrich, which suggests different functions of the cyclooxygenases in this small galliform avian species. According to our results, in quails COX-2 is involved in the synthesis of prostaglandins in the ovary's interstitial glands, which until now have been considered mainly as steroid-secreting cells. COX-1, which is expressed in the smooth muscles of the stroma, possibly plays a role in ovulation.

  15. Targeted deletions of cyclooxygenase-2 and atherogenesis in mice

    DEFF Research Database (Denmark)

    Hui, Yiqun; Ricciotti, Emanuela; Crichton, Irene;

    2010-01-01

    BACKGROUND: Although the dominant product of vascular Cyclooxygenase-2 (COX-2), prostacyclin (PGI(2)), restrains atherogenesis, inhibition and deletion of COX-2 have yielded conflicting results in mouse models of atherosclerosis. Floxed mice were used to parse distinct cellular contributions of C...

  16. Cyclooxygenase products sensitize muscle mechanoreceptors in humans with heart failure.

    Science.gov (United States)

    Middlekauff, Holly R; Chiu, Josephine; Hamilton, Michele A; Fonarow, Gregg C; Maclellan, W Robb; Hage, Antoine; Moriguchi, Jaime; Patel, Jignesh

    2008-04-01

    Prior work in animals and humans suggests that muscle mechanoreceptor control of sympathetic activation [muscle sympathetic nerve activity (MSNA)] during exercise in heart failure (HF) patients is heightened compared with that of healthy humans and that muscle mechanoreceptors are sensitized by metabolic by-products. We sought to determine whether cyclooxygenase products and/or endogenous adenosine, two metabolites of ischemic exercise, sensitize muscle mechanoreceptors during rhythmic handgrip (RHG) exercise in HF patients. Indomethacin, which inhibits the production of prostaglandins, and saline control were infused in 12 HF patients. In a different protocol, aminophylline, which inhibits adenosine receptors, and saline control were infused in 12 different HF patients. MSNA was recorded (microneurography). During exercise following saline, MSNA increased in the first minute of exercise, consistent with baseline heightened mechanoreceptor sensitivity. MSNA continued to increase during 3 min of RHG, indicative that muscle mechanoreceptors are sensitized by ischemia metabolites. Indomethacin, but not aminophylline, markedly attenuated the increase in MSNA during the entire 3 min of low-level rhythmic exercise, consistent with the sensitization of muscle mechanoreceptors by cyclooxygenase products. Interestingly, even the early increase in MSNA was abolished by indomethacin infusion, indicative of the very early generation of cyclooxygenase products after the onset of exercise in HF patients. In conclusion, muscle mechanoreceptors mediate the increase in MSNA during low-level RHG exercise in HF. Cyclooxygenase products, but not endogenous adenosine, play a central role in muscle mechanoreceptor sensitization. Finally, muscle mechanoreceptors in patients with HF have heightened basal sensitivity to mechanical stimuli, which also appears to be mediated by the early generation of cyclooxygenase products, resulting in exaggerated early increases in MSNA.

  17. The Role of Cyclooxygenase-2 in Cell Proliferation and Cell Death in Human Malignancies

    Directory of Open Access Journals (Sweden)

    Cyril Sobolewski

    2010-01-01

    Full Text Available It is well admitted that the link between chronic inflammation and cancer involves cytokines and mediators of inflammatory pathways, which act during the different steps of tumorigenesis. The cyclooxygenases (COXs are a family of enzymes, which catalyze the rate-limiting step of prostaglandin biosynthesis. This family contains three members: ubiquitously expressed COX-1, which is involved in homeostasis; the inducible COX-2 isoform, which is upregulated during both inflammation and cancer; and COX-3, expressed in brain and spinal cord, whose functions remain to be elucidated. COX-2 was described to modulate cell proliferation and apoptosis mainly in solid tumors, that is, colorectal, breast, and prostate cancers, and, more recently, in hematological malignancies. These findings prompt us to analyze here the effects of a combination of COX-2 inhibitors together with different clinically used therapeutic strategies in order to further improve the efficiency of future anticancer treatments. COX-2 modulation is a promising field investigated by many research groups.

  18. Eicosanoids Derived From Arachidonic Acid and Their Family Prostaglandins and Cyclooxygenase in Psychiatric Disorders.

    Science.gov (United States)

    Yui, Kunio; Imataka, George; Nakamura, Hiroyuki; Ohara, Naoki; Naito, Yukiko

    2015-01-01

    Arachidonic acid (AA)-derived lipid mediators are called eicosanoids. Eicosanoids have emerged as key regulators of a wide variety of physiological responses and pathological processes, and control important cellular processes. AA can be converted into biologically active compounds by metabolism by cyclooxygenases (COX). Beneficial effect of COX-2 inhibitor celecoxib add-on therapy has been reported in early stage of schizophrenia. Moreover, add-on treatment of celecoxib attenuated refractory depression and bipolar depression. Further, the COX/prostaglandin E pathway play an important role in synaptic plasticity and may be included in pathophysiology in autism spectrum disorders (ASD). In this regard, plasma transferrin, which is an iron mediator related to eicosanoid signaling, may be related to social impairment of ASD. COX-2 is typically induced by inflammatory stimuli in the majority of tissues, and the only isoform responsible for propagating the inflammatory response. Thus, COX-2 inhibitors considered as the best target for Alzheimer's disease.

  19. PI-3K and p38MAPK Pathways Upregulate the Epidermal Growth Factor Induced Cyclooxygenase-2 Expression in PC-3 Cells%PI-3K和p38MAPK通路在EGF诱导PC-3细胞环氧化酶-2表达上调中的作用

    Institute of Scientific and Technical Information of China (English)

    贾瑞鹏; 林建中; 刘军; 苏江浩; 包卿兵; 朱佳庚

    2008-01-01

    目的:研究p38丝裂原激活蛋白激酶(p38MAPK)和磷脂酰肌醇-3激酶(PI/3K)通路在表皮生长因子(EGF)诱导的激素非依赖性前列腺癌(hormone-refractory prostate cancer,HRPC)PC-3细胞环氧化酶2(cyclooxygenase-2,COX-2)表达上调中的作用. 方法:MTT法检测EGF(0μg/L)、EGF(10 μg/L)、EGF(10μg/L)+PI-3K阻断剂(LY294002,20μmol/L)、EGF(10μg/L)+p38MAPK阻断剂(SC203580,20μmol/L)处理后的细胞增殖情况.RT-PCR和Western印迹测定上述处理24 h后PC-3细胞COX-2的表达变化,ELISA测定细胞培养液中前列腺素E2(PGE2)的变化. 结果:LY294002和SC203580明显抑制EGF刺激后的PC-3细胞增殖(P<0.05)及EGF诱导的COX-2上调和PGE2生成(P<0.05). 结论:PI-3K通路和p38MAPK通路可能参与了EGF诱导的PC-3细胞COX-2的表达上调.

  20. [Cyclooxygenase 2 inhibitors and urologic and gynaecologic cancers].

    Science.gov (United States)

    Eschwege, Pascal

    2004-05-01

    PGE2 is one of the most important prostaglandin involved in the oncogenesis. PGE2 is found at high concentration level in the most of epithelial cancer. Urologic and gynaecologic cancer express the enzyme which are at the origin of PGE2: cyclooxygenase 2. Cox2 inhibitors present anticancer properties demonstrated in wide varieties of cellular and animal models. Human applications are currently tested in many clinical trials for bladder, prostate and uterine carcinomas.

  1. Expression of Cyclooxygenase-2 in Ovarian Cancer Cell Lines

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    To investigate the expression of cyclooxygenase-2 (COX-2) in ovarian cancer cell lines,RT-PCR and immunocytochemistry were used to detect the expression of COX-2 in 5 ovarian cancer cell lines. The expression of COX-2 mRNA and protein was detected in all 5 cell lines. It is suggested that COX-2 is expressed in ovarian cancer cell lines, which provides a basis for the chemoprevention of ovarian cancer.

  2. Follicle-stimulating hormone enhances alveolar bone resorption via upregulation of cyclooxygenase-2

    Science.gov (United States)

    Zhu, Chunxia; Ji, Yaoting; Liu, Shengbo; Bian, Zhuan

    2016-01-01

    This study aimed to investigate whether follicle-stimulating hormone (FSH)-induced alveolar bone resorption was mediated by a cyclooxygenase 2 (COX-2) enzyme related mechanism. Experimental periodontitis was induced in bilateral ovariectomized (OVX) rats, some of which were injected with triptorelin, an FSH inhibitor. After mandibles were collected, we performed micro-computed tomography to evaluate alveolar bone loss and immunohistochemical staining to assess COX-2 expression. As well, human periodontal ligament cells (PDLCs) were treated with FSH (30 ng/ml), and the COX-2 mRNA and protein expression levels were measured by quantitative real-time polymerase chain reaction (qPCR) and Western blotting, respectively; prostaglandin E2 (PGE2) levels were measured by enzyme-linked immunosorbent assay (ELISA). The results indicated that FSH significantly increased alveolar bone resorption and the expression of COX-2 in the bilateral OVX + Ligatured rats compared with the other treatment groups. FSH also increased the mRNA and protein expression of COX-2 and PGE2 (P < 0.01) in human PDLCs. Further, the analysis of signaling pathways revealed the activation of COX-2-mediated pathways including Erk, p38, and Akt. These data suggest that FSH aggravates alveolar bone loss via a COX-2-upregulation mechanism and that the Erk, p38, and Akt pathways are involved in this pathological process. PMID:27725865

  3. Cyclooxygenase-1 and -2 in the different stages of Alzheimer's disease pathology.

    Science.gov (United States)

    Hoozemans, J J M; Rozemuller, J M; van Haastert, E S; Veerhuis, R; Eikelenboom, P

    2008-01-01

    Alzheimer's disease (AD) is a neurodegenerative disorder characterized by the deposition of beta amyloid (Abeta) protein and the formation of neurofibrillary tangles. In addition, there is an increase of inflammatory proteins in the brains of AD patients. Epidemiological studies, indicating that non-steroidal anti-inflammatory drugs (NSAIDs) decrease the risk of developing AD, have encouraged the study on the role of inflammation in AD. The best-characterized action of most NSAIDs is the inhibition of cyclooxygenase (COX). The expression of the constitutively expressed COX-1 and the inflammatory induced COX-2 has been intensively investigated in AD brain and different disease models for AD. Despite these studies, clinical trials with NSAIDs or selective COX-2 inhibitors showed little or no effect on clinical progression of AD. The expression levels of COX-1 and COX-2 change in the different stages of AD pathology. In an early stage, when low-fibrillar Abeta deposits are present and only very few neurofibrillary tangles are observed in the cortical areas, COX-2 is increased in neurons. The increased neuronal COX-2 expression parallels and colocalizes with the expression of cell cycle proteins. COX-1 is primarily expressed in microglia, which are associated with fibrillar Abeta deposits. This suggests that in AD brain COX-1 and COX-2 are involved in inflammatory and regenerating pathways respectively. In this review we will discuss the role of COX-1 and COX-2 in the different stages of AD pathology. Understanding the physiological and pathological role of cyclooxygenase in AD pathology may facilitate the design of therapeutics for the treatment or prevention of AD.

  4. Coxibs interfere with the action of aspirin by binding tightly to one monomer of cyclooxygenase-1

    Energy Technology Data Exchange (ETDEWEB)

    Rimon, Gilad; Sidhu, Ranjinder S.; Lauver, D. Adam; Lee, Jullia Y.; Sharma, Narayan P.; Yuan, Chong; Frieler, Ryan A.; Trievel, Raymond C.; Lucchesi, Benedict R.; Smith, William L. (Michigan)

    2010-02-11

    Pain associated with inflammation involves prostaglandins synthesized from arachidonic acid (AA) through cyclooxygenase-2 (COX-2) pathways while thromboxane A{sub 2} formed by platelets from AA via cyclooxygenase-1 (COX-1) mediates thrombosis. COX-1 and COX-2 are both targets of nonselective nonsteroidal antiinflammatory drugs (nsNSAIDs) including aspirin whereas COX-2 activity is preferentially blocked by COX-2 inhibitors called coxibs. COXs are homodimers composed of identical subunits, but we have shown that only one subunit is active at a time during catalysis; moreover, many nsNSAIDS bind to a single subunit of a COX dimer to inhibit the COX activity of the entire dimer. Here, we report the surprising observation that celecoxib and other coxibs bind tightly to a subunit of COX-1. Although celecoxib binding to one monomer of COX-1 does not affect the normal catalytic processing of AA by the second, partner subunit, celecoxib does interfere with the inhibition of COX-1 by aspirin in vitro. X-ray crystallographic results obtained with a celecoxib/COX-1 complex show how celecoxib can bind to one of the two available COX sites of the COX-1 dimer. Finally, we find that administration of celecoxib to dogs interferes with the ability of a low dose of aspirin to inhibit AA-induced ex vivo platelet aggregation. COX-2 inhibitors such as celecoxib are widely used for pain relief. Because coxibs exhibit cardiovascular side effects, they are often prescribed in combination with low-dose aspirin to prevent thrombosis. Our studies predict that the cardioprotective effect of low-dose aspirin on COX-1 may be blunted when taken with coxibs.

  5. Cardiovascular risk and inhibition of cyclooxygenase: traditional nonsteroidal anti-inflammatory drugs and cyclooxygenase-2 inhibitors

    Directory of Open Access Journals (Sweden)

    M. Campanini

    2013-05-01

    Full Text Available BACKGROUND The development of non-selective nonsteroidal anti-inflammatory drugs (tNSAIDs and, more recently, of selective inhibitors of the cycloooxygenase-2 isoform (COXIBs, has contributed greatly towards the effective management of patients with arthritis and pain complaints. Although COXIBs have demonstrated an improved gastrointestinal tolerability compared with tNSAIDs, the cardiovascular effects of the two drugs types are much controversial. By blocking prostacyclin formation but leaving platelet-derived thromboxane A2 generation unopposed, the potential gastrointestinal benefit of COXIBs may come at cost of increased thrombotic risk. AIM OF THE STUDY This review aims at analysing the cardiovascular effects of the tNSAIDs and COXIBs. METHOD This review addresses the controversy of effects of COXIBs and tNSAIDs in 4 segments. It begins with a discussion about pathophysiological effects of cyclooxygenase inhibition on cardiovascular system. This is followed by a systematic review and meta-analysis of a control, randomized, double blind study and population-based matched case-control study to compare the risk of serious cardiovascular events with tNSAIDs and COXIBs. Then it answers to key questions with the aim to assist the clinicians for a systematic approach to evaluate the risk-benefit-ratio of NSAIDs in the clinical practice. Finally we analyse the open questions associated with the use of NSAIDs and the cardiovascular events. RESULTS The use of rofecoxib demonstrated an increase in adverse cardiovascular events. This toxic effect is not dose-related. The relationship between celecoxib and cardiovascular risk is less clear. The results of different clinical trials are conflicting: some didn’t demonstrate increase in cardiovascular toxicity but the APC study and recently a metanalysis reported a significant incidence of adverse cardiovascular events. Also valdecoxib and parecoxib appear to have increased risk for cardiovascular

  6. Epigenetic Regulations of Inflammatory Cyclooxygenase-Derived Prostanoids: Molecular Basis and Pathophysiological Consequences

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    Hedi Harizi

    2015-01-01

    Full Text Available The potential relevance of prostanoid signaling in immunity and immunological disorders, or disease susceptibility and individual variations in drug responses, is an important area for investigation. The deregulation of Cyclooxygenase- (COX- derived prostanoids has been reported in several immunoinflammatory disorders such as asthma, rheumatoid arthritis, cancer, and autoimmune diseases. In addition to the environmental factors and the genetic background to diseases, epigenetic mechanisms involved in the fine regulation of prostanoid biosynthesis and/or receptor signaling appeared to be an additional level of complexity in the understanding of prostanoid biology and crucial in controlling the different components of the COX pathways. Epigenetic alterations targeting inflammatory components of prostanoid biosynthesis and signaling pathways may be important in the process of neoplasia, depending on the tissue microenvironment and target genes. Here, we focused on the epigenetic modifications of inflammatory prostanoids in physiological immune response and immunological disorders. We described how major prostanoids and their receptors can be functionally regulated epigenetically and consequently the impact of these processes in the pathogenesis inflammatory diseases and the development of therapeutic approaches that may have important clinical applications.

  7. Contribution of Cyclooxygenase End Products and Oxidative Stress to Intrahepatic Endothelial Dysfunction in Early Non-Alcoholic Fatty Liver Disease.

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    Francisco Javier Gonzalez-Paredes

    Full Text Available Metabolic syndrome induces endothelial dysfunction, a surrogate marker of cardiovascular disease. In parallel, metabolic syndrome is frequently associated with non-alcoholic fatty liver disease (NAFLD, which may progress to cirrhosis. The aim of the present study was to evaluate intrahepatic endothelial dysfunction related to cyclooxygenase end products and oxidative stress as possible mechanisms involved in the pathophysiology of NAFLD.Sprague-Dawley rats were fed standard diet (control-diet, CD or high-fat-diet (HFD for 6 weeks. Metabolic syndrome was assessed by recording arterial pressure, lipids, glycemia and rat body weight. Splanchnic hemodynamics were measured, and endothelial dysfunction was evaluated using concentration-effect curves to acetylcholine. Response was assessed with either vehicle, L-NG-Nitroarginine (L-NNA, indomethacin, tempol, or a thromboxane receptor antagonist, SQ 29548. We quantified inflammation, fibrosis, oxidative stress, nitric oxide (NO bioavailability and thromboxane B2 levels.HFD rats exhibited metabolic syndrome together with the presence of NAFLD. Compared to control-diet livers, HFD livers showed increased hepatic vascular resistance unrelated to inflammation or fibrosis, but with decreased NO activity and increased oxidative stress. Endothelial dysfunction was observed in HFD livers compared with CD rats and improved after cyclooxygenase inhibition or tempol pre-incubation. However, pre-incubation with SQ 29548 did not modify acetylcholine response.Our study provides evidence that endothelial dysfunction at an early stage of NAFLD is associated with reduced NO bioavailability together with increased cyclooxygenase end products and oxidative stress, which suggests that both pathways are involved in the pathophysiology and may be worth exploring as therapeutic targets to prevent progression of the disease.

  8. Contribution of Cyclooxygenase End Products and Oxidative Stress to Intrahepatic Endothelial Dysfunction in Early Non-Alcoholic Fatty Liver Disease

    Science.gov (United States)

    Morales Arraez, Dalia; Marcelino Reyes, Raquel; Abrante, Beatriz; Diaz-Flores, Felicitas; Salido, Eduardo; Quintero, Enrique; Hernández-Guerra, Manuel

    2016-01-01

    Introduction Metabolic syndrome induces endothelial dysfunction, a surrogate marker of cardiovascular disease. In parallel, metabolic syndrome is frequently associated with non-alcoholic fatty liver disease (NAFLD), which may progress to cirrhosis. The aim of the present study was to evaluate intrahepatic endothelial dysfunction related to cyclooxygenase end products and oxidative stress as possible mechanisms involved in the pathophysiology of NAFLD. Materials and Methods Sprague-Dawley rats were fed standard diet (control-diet, CD) or high-fat-diet (HFD) for 6 weeks. Metabolic syndrome was assessed by recording arterial pressure, lipids, glycemia and rat body weight. Splanchnic hemodynamics were measured, and endothelial dysfunction was evaluated using concentration-effect curves to acetylcholine. Response was assessed with either vehicle, L-NG-Nitroarginine (L-NNA), indomethacin, tempol, or a thromboxane receptor antagonist, SQ 29548. We quantified inflammation, fibrosis, oxidative stress, nitric oxide (NO) bioavailability and thromboxane B2 levels. Results HFD rats exhibited metabolic syndrome together with the presence of NAFLD. Compared to control-diet livers, HFD livers showed increased hepatic vascular resistance unrelated to inflammation or fibrosis, but with decreased NO activity and increased oxidative stress. Endothelial dysfunction was observed in HFD livers compared with CD rats and improved after cyclooxygenase inhibition or tempol pre-incubation. However, pre-incubation with SQ 29548 did not modify acetylcholine response. Conclusions Our study provides evidence that endothelial dysfunction at an early stage of NAFLD is associated with reduced NO bioavailability together with increased cyclooxygenase end products and oxidative stress, which suggests that both pathways are involved in the pathophysiology and may be worth exploring as therapeutic targets to prevent progression of the disease. PMID:27227672

  9. Regulation of bombesin-stimulated cyclooxygenase-2 expression in prostate cancer cells

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    Ives Kirk

    2011-07-01

    Full Text Available Abstract Background Cyclooxygenase-2 (COX-2 and the bombesin (BBS-like peptide, gastrin-releasing peptide (GRP, have been implicated in the progression of hormone-refractory prostate cancer; however, a mechanistic link between the bioactive peptide and COX-2 expression in prostate cells has not been made. Results We report that BBS stimulates COX-2 mRNA and protein expression, and the release of prostaglandin E2 from the GRP receptor (GRPR-positive, androgen-insensitive prostate cancer cell line, PC-3. BBS-stimulated COX-2 expression is mediated, in part, by p38MAPK and PI3 kinase (PI3K/Akt pathways, and blocked by a GRPR antagonist. The PI3K/Akt pathway couples GRPR to the transcription factor, activator protein-1 (AP-1, and enhanced COX-2 promoter activity. Although BBS stimulates nuclear factor-kappaB (NF-κB in PC-3, NF-κB does not regulate GRPR-mediated COX-2 expression. The p38MAPK pathway increases BBS-stimulated COX-2 expression by slowing the degradation of COX-2 mRNA. Expression of recombinant GRPR in the androgen-sensitive cell line LNCaP is sufficient to confer BBS-stimulated COX-2 expression via the p38MAPK and PI3K/Akt pathways. Conclusions Our study establishes a mechanistic link between GRPR activation and enhanced COX-2 expression in prostate cancer cell lines, and suggests that inhibiting GRPR may, in the future, provide an effective therapeutic alternative to non-steroidal anti-inflammatory drugs for inhibiting COX-2 in patients with recurrent prostate cancer.

  10. Crystal structure of rofecoxib bound to human cyclooxygenase-2

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    Orlando, Benjamin J.; Malkowski, Michael G. (Buffalo)

    2016-10-26

    Rofecoxib (Vioxx) was one of the first selective cyclooxygenase-2 (COX-2) inhibitors (coxibs) to be approved for use in humans. Within five years after its release to the public, Vioxx was withdrawn from the market owing to the adverse cardiovascular effects of the drug. Despite the widespread knowledge of the development and withdrawal of Vioxx, relatively little is known at the molecular level about how the inhibitor binds to COX-2. Vioxx is unique in that the inhibitor contains a methyl sulfone moiety in place of the sulfonamide moiety found in other coxibs such as celecoxib and valdecoxib. Here, new crystallization conditions were identified that allowed the structural determination of human COX-2 in complex with Vioxx and the structure was subsequently determined to 2.7- Å resolution. The crystal structure provides the first atomic level details of the binding of Vioxx to COX-2. As anticipated, Vioxx binds with its methyl sulfone moiety located in the side pocket of the cyclooxygenase channel, providing support for the isoform selectivity of this drug.

  11. Crystal structure of rofecoxib bound to human cyclooxygenase-2.

    Science.gov (United States)

    Orlando, Benjamin J; Malkowski, Michael G

    2016-10-01

    Rofecoxib (Vioxx) was one of the first selective cyclooxygenase-2 (COX-2) inhibitors (coxibs) to be approved for use in humans. Within five years after its release to the public, Vioxx was withdrawn from the market owing to the adverse cardiovascular effects of the drug. Despite the widespread knowledge of the development and withdrawal of Vioxx, relatively little is known at the molecular level about how the inhibitor binds to COX-2. Vioxx is unique in that the inhibitor contains a methyl sulfone moiety in place of the sulfonamide moiety found in other coxibs such as celecoxib and valdecoxib. Here, new crystallization conditions were identified that allowed the structural determination of human COX-2 in complex with Vioxx and the structure was subsequently determined to 2.7 Å resolution. The crystal structure provides the first atomic level details of the binding of Vioxx to COX-2. As anticipated, Vioxx binds with its methyl sulfone moiety located in the side pocket of the cyclooxygenase channel, providing support for the isoform selectivity of this drug.

  12. Elevated spinal cyclooxygenase and prostaglandin release during hyperalgesia in diabetic rats.

    Science.gov (United States)

    Freshwater, Jason D; Svensson, Camilla I; Malmberg, Annika B; Calcutt, Nigel A

    2002-07-01

    Diabetic rats display exaggerated hyperalgesic behavior in response to noxious stimuli that may model aspects of painful diabetic neuropathy. This study examined the contribution of spinal prostaglandin production to this exaggerated hyperalgesic behavior. Rats were implanted with spinal dialysis probes and received noxious stimulation to the hind paw by subcutaneous injection of 0.5% formalin solution. Prostaglandin E(2) (PGE(2)) was measured in dialysates of lumbar spinal cerebrospinal fluid concurrent with behavioral responses to formalin injection. In separate experiments, formalin-evoked behavioral responses were measured after intrathecal delivery of either a cyclooxygenase inhibitor or an EP(1) receptor antagonist, and cyclooxygenase protein was measured in spinal cord homogenates. Diabetic rats exhibited exaggerated behavioral responses to paw formalin injection and a concurrent prolongation of formalin-evoked PGE(2) release. Formalin-evoked behavioral responses were dose-dependently reduced in diabetic rats by spinal delivery of a cyclooxygenase inhibitor or an EP(1) receptor antagonist. Protein levels of cyclooxygenase-2 were elevated in the spinal cord of diabetic rats, whereas cyclooxygenase-1 protein was reduced. Hyperalgesic behavior in diabetic rats is associated with both increased cyclooxygenase-2 protein and cyclooxygenase-mediated PGE(2) release. Spinal delivery of selective inhibitors of cyclooxygenase-2 or antagonists of prostaglandin receptors may have therapeutic potential for treating painful diabetic neuropathy.

  13. Acetaminophen-induced liver injury: Implications for temporal homeostasis of lipid metabolism and eicosanoid signaling pathway.

    Science.gov (United States)

    Suciu, Maria; Gruia, Alexandra T; Nica, Dragos V; Azghadi, Seyed M R; Mic, Ani A; Mic, Felix A

    2015-12-05

    Acetaminophen is a commonly used drug that induces serious hepatotoxicity when overdosed, leading to increased levels of serum aminotransferases. However, little knowledge exists linking acetaminophen to liver free fatty acids and the eicosanoid-mediated signaling pathway. To this end, adult NMRI mice injected with a dose of 400 mg/kg acetaminophen were monitored for one week post-treatment. Consistent changes were observed in serum transaminases, profile of hepatic free fatty acids, expression of cyclooxygenase, elongase, lipogenesis, and lipolysis genes; as well as in expression patterns of cyclooxygenase-1 and -2 in the liver. Both linoleic acid and arachidonic acid--substrates in eicosanoid biosynthesis--were significantly influenced by overdose, and the latter peaked first among the free fatty acids examined here. There was a close similarity between the temporal dynamics of linoleic acid and aspartate aminotransferases. Moreover, serum transaminases were reduced by cyclooxygenase-2 inhibitors, but not by cyclooxygenase-1 inhibitors. Our results hence attest to the hazard of acetaminophen overdose on the temporal homeostasis of hepatic concentrations of free fatty acids and expression of key genes underlying liver lipid metabolism. There is also evidence for activation of a cyclooxygenase-mediated signaling pathway, especially the cyclooxygenase 2-prostanoid pathway, during acetaminophen-induced liver injury. Therefore, the results of the present study should provide valuable information to a wide audience, working to understand the health hazard of this drug and the implications of the eicosanoid signaling pathway in liver pathophysiology.

  14. Piroxicam and other cyclooxygenase inhibitors: potential for cancer chemoprevention.

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    Earnest, D L; Hixson, L J; Alberts, D S

    1992-01-01

    Piroxicam is a nonsteroidal anti-inflammatory drug (NSAID) widely used for treatment of inflammatory arthritis. Recent experimental and clinical studies suggest that piroxicam, as well as other NSAIDs, may be useful for chemoprevention of colon cancer. While there is less information regarding NSAIDs for chemoprevention of urinary bladder malignancy, there are compelling data which suggest that this should be evaluated. A major effect of NSAIDs is inhibition of cyclooxygenase, the rate-limiting enzyme for conversion of arachidonic acid to important signal molecules, including prostaglandins, which profoundly affect cellular functions in many tissues. The initial enzyme reaction leading to formation of prostaglandin H can be accompanied by cooxidation of xenobiotics resulting in extrahepatic and local tissue production of reactive products which are carcinogenic. The end product prostaglandins, especially prostaglandin E2 (PGE2), are biological modifiers which can significantly affect cell proliferation and tumor growth. High levels of PGE2 stimulate growth of certain tumor cell lines while inhibition of prostaglandin synthesis with indomethacin or piroxicam can cause suppression. The mechanisms for this effect are unclear. Studies in cultured cells exposed to indomethacin show inhibition of G1-to-S phase progression of the cell cycle and a reduction in overall DNA synthesis. It is unclear whether this effect on cell growth results from some direct action of the NSAID or a reduction in prostaglandins or indirectly from modulation of important control signals, such as calcium flux. In addition to cyclooxygenase, NSAIDs can inhibit activity of other enzymes, including phosphodiesterases and cyclic GMP-AMP protein kinases, which may be central to cancer initiation and promotion. NSAIDs can also interfere with transmembrane ion fluxes and with cell-to-cell binding. Prostaglandins can modulate a variety of immunological responses and thereby play an important role in

  15. CYCLOOXYGENASE-2 AND HEPATOCELLULAR CARCINOMA: THE PROTEOMICS OF ASSOCIATION

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    Jaya Gandhi

    2011-12-01

    Full Text Available Hepatocellular carcinoma represents one of the most common malignancies worldwide with a rising incidence in western countries. Chronic inflammation is recognised as a threat factor for cancer progression. Cyclooxygenase-2 is the major mediator of inflammation. Various studies on Cox-2 suggest its possible association with HCC differentiation. Sufficient genetic and pharmacologic evidences implicate its crucial role in neoplasia and it is also now clear that Cox-2 plays a crucial role in tumor progression. Cox-2 overexpression is associated with maintaining tumor microenvironment and has crucial implication for angiogenesis. Cox-2 operates in multifactorial fashion. Cox-2 selective inhibition has been reported as a successful tool in suppressing angiogenesis and metastasis. The pharmacological suppression of Cox-2 represents a bright future as a therapeutic tool for treatment of various malignancies. This review is an attempt to discuss the critical issue of overexpression of Cox-2 and its role in the development of HCC in particular and cancer in general.

  16. Targeting cyclooxygenase-2 in hematological malignancies: rationale and promise.

    Science.gov (United States)

    Bernard, M P; Bancos, S; Sime, P J; Phipps, R P

    2008-01-01

    There is much interest in the potential use of Cox-2 selective inhibitors in combination with other cancer therapeutics. Malignancies of hematopoietic and non-hematopoietic origin often have increased expression of cyclooxygenase-2 (Cox-2), a key modulator of inflammation. For example, hematological malignancies such as chronic lymphocytic leukemia, chronic myeloid leukemia, Hodgkin's lymphoma, non-Hodgkin's lymphoma and multiple myeloma often highly express Cox-2, which correlates with poor patient prognosis. Expression of Cox-2 enhances survival and proliferation of malignant cells, while negatively influencing anti-tumor immunity. Hematological malignancies expressing elevated levels of Cox-2 potentially avoid immune responses by producing factors that enhance angiogenesis and metastasis. Cellular immune responses regulated by natural killer cells, cytotoxic T lymphocytes, and T regulatory cells are also influenced by Cox-2 expression. Therefore, Cox-2 selective inhibitors have promising therapeutic potential in patients suffering from certain hematological malignancies.

  17. A STUDY ON CYCLOOXYGENASE -2 PROTEIN EXPRESSION IN ESOPHAGEAL CAICONOGENESIS

    Institute of Scientific and Technical Information of China (English)

    王立峰; 张伟; 王吾如; 王洪平; 韩双廷; 曲平; 刘义; 李茉; 刘伯齐; 林培中

    2001-01-01

    To investigate cyclooxygenase- 2(Cox-2) protein expression in esophageal cancer and precancerous lesions. Methods: One hundred twenty biopsy specimens from esophageal carcinoma and 113 from patients with esophageal premalingnant lesions, 27 from individuals with normal esophageal mucosa and 3 from Barrett's esophagus were examined for Cox-2 protein expression by immunohistochemistry. Results: Cox-2 protein was not observed in normal esophageal squamous and glandular epithelium, hyperplasia from mild to severe dysplasia lesions and carcinoma in situ. Positive Cox-2 protein expression was found in 4 of 60 specimens of invasive squamous-cell carcinomas, 21 of 30 specimens of esophageal adenocarcinomas and in 3 of 3 Barret's esophageal tissues. Conclusion: The Cox-2 protein expression may be associated with the development of the esophageal adenocarcinomas but not esophageal squamous-cell carcinomas.

  18. Expression of cyclooxygenase-2 in human esophageal squamous cell carcinomas

    Institute of Scientific and Technical Information of China (English)

    Jian-Gang Jiang; Dao-Wen Wang; Jiang-Bo Tang; Chun-Lian Chen; Bao-Xing Liu; Xiang-Ning Fu; Zhi-Hui Zhu; Wei Qu; Katherine Cianflone; Michael P. Waalkes

    2004-01-01

    AIM: To determine whether cyclooxygenase-2 (COX-2) was expressed in human esophageal squamous cell carcinoma.METHODS: Quantitative reverse transcription-polymerase chain reaction (RT-PCR), western blotting, immunohistochemistry and immunofluorescence were used to assess the expression level of COX-2 in esophageal tissue.RESULTS: COX-2 mRNA levels were increased by >80-fold in esophageal squamous cell carcinoma when compared to adjacent noncancerous tissue. COX-2 protein was present in 21 of 30 cases of esophageal squamous cell carcinoma tissues, but was undetectable in noncancerous tissue. Immunohistochemistry was performed to directly show expression of COX-2 in tumor tissue.CONCLUSION: These results suggest that COX-2 may be an important factor for esophageal cancer and inhibition of COX-2 may be helpful for prevention and possibly treatment of this cancer.

  19. Molecular Dynamic Screening Sesquiterpenoid Pogostemon Herba as Suggested Cyclooxygenase Inhibitor.

    Science.gov (United States)

    Raharjo, Sentot Joko; Kikuchi, Takeshi

    2016-10-01

    Virtual molecular dynamic sesquiterpenoid Pogostemon Herba (CID56928117, CID94275, CID107152, and CID519743) have screening as cyclooxygenase (COX-1/COX-2) selective inhibitor. Molecular interaction studies sesquiterpenoid compounds with COX-1 and COX-2 were using the molecular docking tools by Hex 8.0 and interactions were further visualized using by Discovery Studio Client 3.5 software tool and Virtual Molecular Dynamic 1.9.1 software. The binding energy calculation of molecular dynamic interaction was calculated by AMBER12 software. The analysis of the sesquiterpenoid compounds showed that CID56928117, CID94275, CID107152, and CID519743 have suggested as inhibitor of COX-1 and COX-2. Collectively, the scoring binding energy calculation (with PBSA Model Solvent) sesquiterpenoid compounds: CID519743 had suggested as candidate for non-selective inhibitor; CID56928117 and CID94275 had suggested as candidate for a selective COX-1 inhibitor; and CID107152 had suggested as candidate for a selective COX-2 inhibitor.

  20. Effects of nimesulide, acetylsalicylic acid, ibuprofen and nabumetone on cyclooxygenase-1- and cyclooxygenase-2-mediated prostanoid production in healthy volunteers ex vivo.

    Science.gov (United States)

    Kerola, Markku; Vuolteenaho, Katriina; Kosonen, Outi; Kankaanranta, Hannu; Sarna, Seppo; Moilanen, Eeva

    2009-01-01

    : The beneficial actions of non-steroidal anti-inflammatory drugs (NSAIDs) have been associated with inhibition of cyclooxygenase-2 (COX-2), whereas some of their adverse effects are associated mainly with inhibition of COX-1. Selective COX-2 inhibitors reduce the risk of gastrointestinal adverse events, but increase the risk of thromboembolic events pointing to importance of optimal COX-1/COX-2 inhibition in drug safety. We compared the effects of acetylsalicylic acid, ibuprofen, nabumetone and nimesulide on COX-1 and COX-2 pathways in healthy volunteers in an ex vivo set-up using single oral doses commonly used to treat acute pain. In a randomized, double-blind four-phase cross-over study, 15 healthy volunteers were given orally a single dose of either acetylsalicylic acid 500 mg, ibuprofen 400 mg, nabumetone 1 g or nimesulide 100 mg. Blood samples were drawn before and 1, 3, 6, 24 and 48 hr after the drug for the assessment of COX-1 and COX-2 activity. COX-1 activity was measured as thromboxane(2) production during blood clotting and COX-2 activity as endotoxin-induced prostaglandin E(2) synthesis in blood leucocytes. The data show that after a single oral dose these four NSAIDs have different profiles of action on COX-1 and COX-2. As expected, acetylsalicylic acid appeared to be COX-1-selective and ibuprofen effectively inhibited both COX-1 and COX-2. Nabumetone showed only a slight inhibitory effect on COX-1 and COX-2. Nimesulide caused almost complete suppression of COX-2 activity and a partial reduction of COX-1 activity. This confirms the relative COX-2 selectivity of nimesulide.

  1. Bryostatin-1 stimulates the transcription of cyclooxygenase-2: evidence for an activator protein-1-dependent mechanism.

    Science.gov (United States)

    De Lorenzo, Mariana S; Yamaguchi, Kentaro; Subbaramaiah, Kotha; Dannenberg, Andrew J

    2003-10-15

    Bryostatin-1 (bryostatin) is a macrocyclic lactone derived from Bugula neritina, a marine bryozoan. On the basis of the strength of in vitro and animal studies, bryostatin is being investigated as a possible treatment for a variety of human malignancies. Severe myalgias are a common dose-limiting side effect. Because cyclooxygenase-2 (COX-2)-derived prostaglandins can cause pain, we investigated whether bryostatin induced COX-2. Bryostatin (1-10 nM) induced COX-2 mRNA, COX-2 protein, and prostaglandin biosynthesis. These effects were observed in macrophages as well as in a series of human cancer cell lines. Transient transfections localized the stimulatory effects of bryostatin to the cyclic AMP response element of the COX-2 promoter. Electrophoretic mobility shift assays and supershift experiments revealed a marked increase in the binding of activator protein-1 (AP-1)(c-Jun/c-Fos) to the cyclic AMP response element of the COX-2 promoter. Pharmacological and transient transfection studies indicated that bryostatin stimulated COX-2 transcription via the protein kinase C-->mitogen-activated protein kinase-->AP-1 pathway. All-trans-retinoic acid, a prototypic AP-1 antagonist, blocked bryostatin-mediated induction of COX-2. Taken together, these results suggest that bryostatin-mediated induction of COX-2 can help to explain the myalgias that are commonly associated with treatment. Moreover, it will be worthwhile to evaluate whether the addition of a selective COX-2 inhibitor can increase the antitumor activity of bryostatin.

  2. Cyclooxygenase-2 regulates TGFβ-induced cancer stemness in triple-negative breast cancer

    Science.gov (United States)

    Tian, Jun; Hachim, Mahmood Y.; Hachim, Ibrahim Y.; Dai, Meiou; Lo, Chieh; Raffa, Fatmah Al; Ali, Suhad; Lebrun, Jean Jacques

    2017-01-01

    Triple negative breast cancer (TNBC), an aggressive subtype of breast cancer, display poor prognosis and exhibit resistance to conventional therapies, partly due to an enrichment in breast cancer stem cells (BCSCs). Here, we investigated the role of the cyclooxygenase-2 (COX-2), a downstream target of TGFβ, in regulating BCSCs in TNBC. Bioinformatics analysis revealed that COX-2 is highly expressed in TNBC and that its expression correlated with poor survival outcome in basal subtype of breast cancer. We also found TGFβ-mediated COX-2 expression to be Smad3-dependent and to be required for BCSC self-renewal and expansion in TNBCs. Knocking down COX-2 expression strikingly blocked TGFβ-induced tumorsphere formation and TGFβ-induced enrichment of the two stem-like cell populations, CD24lowCD44high and ALDH+ BCSCs. Blocking COX-2 activity, using a pharmacological inhibitor also prevented TGFβ-induced BCSC self-renewal. Moreover, we found COX-2 to be required for TGFβ-induced expression of mesenchymal and basal breast cancer markers. In particular, we found that TGFβ-induced expression of fibronectin plays a central role in TGFβ-mediated breast cancer stemness. Together, our results describe a novel role for COX-2 in mediating the TGFβ effects on BCSC properties and imply that targeting the COX-2 pathway may prove useful for the treatment of TNBC by eliminating BCSCs. PMID:28054666

  3. Connexins and cyclooxygenase-2 crosstalk in the expression of radiation-induced bystander effects

    Science.gov (United States)

    Zhao, Y; de Toledo, S M; Hu, G; Hei, T K; Azzam, E I

    2014-01-01

    Background: Signalling events mediated by connexins and cyclooxygenase-2 (COX-2) have important roles in bystander effects induced by ionising radiation. However, whether these proteins mediate bystander effects independently or cooperatively has not been investigated. Methods: Bystander normal human fibroblasts were cocultured with irradiated adenocarcinoma HeLa cells in which specific connexins (Cx) are expressed in the absence of endogenous Cx, before and after COX-2 knockdown, to investigate DNA damage in bystander cells and their progeny. Results: Inducible expression of gap junctions composed of connexin26 (Cx26) in irradiated HeLa cells enhanced the induction of micronuclei in bystander cells (Pbystander response due to connexin expression. However, COX-2 knockdown resulted in enhanced micronucleus formation in the progeny of the bystander cells (P<0.001). COX-2 knockdown delayed junctional communication in HeLa Cx26 cells, and reduced, in the plasma membrane, the physical interaction of Cx26 with MAPKKK, a controller of the MAPK pathway that regulates COX-2 and connexin. Conclusions: Junctional communication and COX-2 cooperatively mediate the propagation of radiation-induced non-targeted effects. Characterising the mediating events affected by both mechanisms may lead to new approaches that mitigate secondary debilitating effects of cancer radiotherapy. PMID:24867691

  4. [Cyclooxygenases inhibitors and other compounds with antiinflammatory potential in osteoarthrosis--part II].

    Science.gov (United States)

    Dzielska-Olczak, Małgorzata

    2011-01-01

    NO-NSAIDs (or CINODs that is COX-inhibiting nitric oxide donors) are new class of antiinflammatory drugs and have a multi-pathway mechanism of action that involves cyclooxygenases (COXs) inhibition and nitric oxide (NO) donation. The first drug of this group is naproxcinod, which exerts rarely adverse effects of stomach, gut and less cardiovascular toxicity with naproxen. NO is an important mediator of endothelial function acting as a vasodilator and plays role in inflammation and pain perception that may be of relevance in osteoarthritis and in healing injures in stomach and gut. Lipoxins (LX, LXs): LXA4, LXB4 are group of lipid mediators leading to resolution of inflammation and protective influence on gastrointestinal mucosa. ATL (AT mean aspirin triggered therefore "depend on aspirin") synthesis, via COX-2, reduces the severity of damage gastrointestinal tract induced by NSAIDs. ATL also plays role in gastric adaptation during chronic aspirin administration. Antiinflammatory drugs hydrogen sulfide-releasing (H2S) (ATB-337 that consist of diclofenac linked to a hydrogen sulfide-releasing moiety) may show better efficacy and less toxicity. COX/5-LOX inhibitors and NO-NSAIDs heals symptoms of osteoarthrosis.

  5. Induction of Cyclooxygenase 2 by Streptococcus pyogenes Is Mediated by Cytolysins.

    Science.gov (United States)

    Blaschke, Ulrike; Beineke, Andreas; Klemens, Johanna; Medina, Eva; Goldmann, Oliver

    2017-08-17

    Prostaglandin E2 (PGE2), an arachidonic acid metabolite regulating a broad range of physiological activities, is an important modulator of the severity of infection caused by Streptococcus pyogenes. Here, we investigated the role of streptococcal cytolysin S (SLS) and streptococcal cytolysin O (SLO) in the induction of cyclooxygenase-2 (COX-2), the rate-limiting enzyme in the synthesis of prostaglandins, in in vitro cultured macrophages and during in vivo infection. Macrophages were infected with S. pyogenes wild type or with the isogenic mutant strains deficient in SLS (ΔSLS), SLO (ΔSLO), or both (ΔSLS/ΔSLO), and the expression of COX-2 was determined at the transcriptional and the protein level. The results indicated that S. pyogenes induced expression of COX-2 and concomitant synthesis of PGE2 in macrophages mediated by the synergistic activity of both SLS and SLO, and involved calcium and the PKC/JNK signaling pathway. These results were validated using recombinant cytolysins. In a murine skin infection model, COX-2-positive cells were found more abundant at the site of S. pyogenes wild-type infection than at the site of infection with ΔSLS/ΔSLO mutant strain. These findings suggest that inhibitory targeting of SLS and SLO could ameliorate the adverse effects of high levels of prostaglandins during S. pyogenes infection. © 2017 S. Karger AG, Basel.

  6. Non-small cell lung cancer cyclooxygenase-2-dependent invasion is mediated by CD44.

    Science.gov (United States)

    Dohadwala, M; Luo, J; Zhu, L; Lin, Y; Dougherty, G J; Sharma, S; Huang, M; Pold, M; Batra, R K; Dubinett, S M

    2001-06-15

    Elevated tumor cyclooxygenase (COX-2) expression is associated with increased angiogenesis, tumor invasion, and suppression of host immunity. We have previously shown that genetic inhibition of tumor COX-2 expression reverses the immunosuppression induced by non-small cell lung cancer (NSCLC). To assess the impact of COX-2 expression in lung cancer invasiveness, NSCLC cell lines were transduced with a retroviral vector expressing the human COX-2 cDNA in the sense (COX-2-S) and antisense (COX-2-AS) orientations. COX-2-S clones expressed significantly more COX-2 protein, produced 10-fold more prostaglandin E(2), and demonstrated an enhanced invasive capacity compared with control vector-transduced or parental cells. CD44, the cell surface receptor for hyaluronate, was overexpressed in COX-2-S cells, and specific blockade of CD44 significantly decreased tumor cell invasion. In contrast, COX-2-AS clones had a very limited capacity for invasion and showed diminished expression of CD44. These findings suggest that a COX-2-mediated, CD44-dependent pathway is operative in NSCLC invasion. Because tumor COX-2 expression appears to have a multifaceted role in conferring the malignant phenotype, COX-2 may be an important target for gene or pharmacologic therapy in NSCLC.

  7. Arachidonic acid metabolism and inhibition of cyclooxygenase in platelets from asthmatic subjects with aspirin intolerance.

    Science.gov (United States)

    Bonne, C; Moneret-Vautrin, D A; Wayoff, M; Descharmes, A; Gazel, P; Legrand, A; Kalt, C

    1985-02-01

    Exaggerated inhibition of cyclooxygenase has been proposed as a mechanism of drug-induced bronchospasm in aspirin-intolerant patients. This study, using platelets, shows that inhibition of prostaglandin biosynthesis by aspirin is unmodified in patients when compared with healthy subjects. The ratio of cyclooxygenase:lipoxygenase products is similar in platelets from patients and control subjects. We conclude that the cyclooxygenase alteration observed in cells from the respiratory tract is not generalised to other cells such as platelets. We also propose that the major abnormality in NSAID-intolerant patients would affect receptivity to lipoxygenase products more than their biosynthesis.

  8. Lipoxygenase and cyclooxygenase metabolism: new insights in treatment and chemoprevention of pancreatic cancer

    Directory of Open Access Journals (Sweden)

    Adrian Thomas E

    2003-01-01

    Full Text Available Abstract The essential fatty acids, linoleic acid and arachidonic acid play an important role in pancreatic cancer development and progression. These fatty acids are metabolized to eicosanoids by cyclooxygenases and lipoxygenases. Abnormal expression and activities of both cyclooxygenases and lipoxygenases have been reported in pancreatic cancer. In this article, we aim to provide a brief summary of (1 our understanding of the roles of these enzymes in pancreatic cancer tumorigenesis and progression; and (2 the potential of using cyclooxygenase and lipoxygenase inhibitors for pancreatic cancer treatment and prevention.

  9. Effect of Dietary Stilbenes on 5-Lipoxygenase and Cyclooxygenases Activities In Vitro

    OpenAIRE

    Kutil, Z. (Zsófia); Kvasnicová, M.; Temml, V.; Schuster, D; Maršík, P. (Petr); Cusimamani, E.F.; Lou, J.D.; Vaněk, T. (Tomáš); Landa, P.

    2015-01-01

    Stilbenes contained in various foods are associated with health beneficial effects. In this study six natural and one synthetic stilbene were tested for their potential to regulate the activity of lipoxygenase and cyclooxygenase in vitro. The most potent inhibitor of 5-lipoxygenase was pterostilbene (IC50 = 9.32 mu M), whereas the strongest inhibitor of cyclooxygenase-1 and cyclooxygenase-2 was pinostilbene (IC50s = 1.90 and 0.35 mu M, respectively). Pterostilbene (IC50s = 11.70 and 27.04 mu ...

  10. The prostaglandin E2 receptor EP2 is required for cyclooxygenase 2-mediated mammary hyperplasia.

    Science.gov (United States)

    Chang, Sung-Hee; Ai, Youxi; Breyer, Richard M; Lane, Timothy F; Hla, Timothy

    2005-06-01

    Expression of cyclooxygenase 2 (COX-2) in breast cancer correlates with poor prognosis, and COX-2 enzyme inhibitors reduce breast cancer incidence in humans. We recently showed that COX-2 overexpression in the mammary gland of transgenic mice induced mammary cancer. Because prostaglandin E2 (PGE2) is the major eicosanoid and because the EP2 subtype of the PGE2 receptor is highly expressed in the mammary tumors, we tested if this G protein-coupled receptor is required for tumorigenesis. We crossed the MMTV-COX-2 transgenic mice with Ep2-/- mice and studied tumor development in bigenic mice. Lack of EP2 receptor strongly suppressed COX-2-induced effects such as precocious development of the mammary gland in virgins and the development of mammary hyperplasia in multiparous female mice. Interestingly, the expression of amphiregulin, a potent mammary epithelial cell growth factor was down regulated in mammary glands of Ep2-/- mice. Total cyclic AMP (cAMP) levels were reduced in Ep2-/- mammary glands suggesting that PGE2 signaling via the EP2 receptor activates the Gs/cAMP/protein kinase A pathway. In mammary tumor cell lines, expression of the EP2 receptor followed by treatment with CAY10399, an EP2-specific agonist, strongly induced amphiregulin mRNA levels in a protein kinase A-dependent manner. These data suggest that PGE2 signaling via the EP2 receptor in mammary epithelial cells regulate mammary gland hyperplasia by the cAMP-dependent induction of amphiregulin. Inhibition of the EP2 pathway in the mammary gland may be a novel approach in the prevention and/or treatment of mammary cancer.

  11. Changes in extracellular matrix composition regulate cyclooxygenase-2 expression in human mesangial cells.

    Science.gov (United States)

    Alique, Matilde; Calleros, Laura; Luengo, Alicia; Griera, Mercedes; Iñiguez, Miguel Ángel; Punzón, Carmen; Fresno, Manuel; Rodríguez-Puyol, Manuel; Rodríguez-Puyol, Diego

    2011-04-01

    Glomerular diseases are characterized by a sustained synthesis and accumulation of abnormal extracellular matrix proteins, such as collagen type I. The extracellular matrix transmits information to cells through interactions with membrane components, which directly activate many intracellular signaling events. Moreover, accumulating evidence suggests that eicosanoids derived from cyclooxygenase (COX)-2 participate in a number of pathological processes in immune-mediated renal diseases, and it is known that protein kinase B (AKT) may act through different transcription factors in the regulation of the COX-2 promoter. The present results show that progressive accumulation of collagen I in the extracellular medium induces a significant increase of COX-2 expression in human mesangial cells, resulting in an enhancement in PGE(2) production. COX-2 overexpression is due to increased COX-2 mRNA levels. The study of the mechanism implicated in COX-2 upregulation by collagen I showed focal adhesion kinase (FAK) activation. Furthermore, we observed that the activation of the phosphatidylinositol 3-kinase (PI3K)/AKT pathway by collagen I and collagen I-induced COX-2 overexpression was abolished by PI3K and AKT inhibitors. Additionally, we showed that the cAMP response element (CRE) transcription factor is implicated. Finally, we studied COX-2 expression in an animal model, N(G)-nitro-l-arginine methyl ester hypertensive rats. In renal tissue and vascular walls, COX-2 and collagen type I content were upregulated. In summary, our results provide evidence that collagen type I increases COX-2 expression via the FAK/PI3K/AKT/cAMP response element binding protein signaling pathway.

  12. Endocannabinoids and their oxygenation by cyclo-oxygenases, lipoxygenases and other oxygenases.

    Science.gov (United States)

    Urquhart, P; Nicolaou, A; Woodward, D F

    2015-04-01

    The naturally occurring mammalian endocannabinoids possess biological attributes that extend beyond interaction with cannabinoid receptors. These extended biological properties are the result of oxidative metabolism of the principal mammalian endocannabinoids arachidonoyl ethanolamide (anandamide; A-EA) and 2-arachidonoylglycerol (2-AG). Both endocannabinoids are oxidized by cyclo-oxygenase-2 (COX-2), but not by COX-1, to a series of prostaglandin derivatives (PGs) with quite different biological properties from those of the parent substrates. PG ethanolamides (prostamides, PG-EAs) and PG glyceryl esters (PG-Gs) are not only pharmacologically distinct from their parent endocannabinoids, they are distinct from the corresponding acidic PGs, and are differentiated from each other. Ethanolamides and glyceryl esters of the major prostanoids PGD2, PGE2, PGF2α, and PGI2 are formed by the various PG synthases, and thromboxane ethanolamides and glyceryl esters are not similarly produced. COX-2 is also of interest by virtue of its corollary central role in modulating endocannabinoid tone, providing a new therapeutic approach for treating pain and anxiety. Other major oxidative conversion pathways are provided for both A-EA and 2-AG by several lipoxygenases (LOXs), resulting in the formation of numerous hydroxyl metabolites. These do not necessarily represent inactivation pathways for endocannabinoids but may mimic or modulate the endocannabinoids or even display alternative pharmacology. Similarly, A-EA and 2-AG may be oxidized by P450 enzymes. Again a very diverse number of metabolites are formed, with either cannabinoid-like biological properties or an introduction of disparate pharmacology. The biological activity of epoxy and hydroxyl derivatives of the endocannabinoids remains to be fully elucidated. This review attempts to consolidate and compare the findings obtained to date in an increasingly important research area. This article is part of a Special Issue entitled

  13. DOCKING OF 1-PHENYLSULFONAMIDE-3-TRIFLUOROMETHYL-5-PARABROMOPHENYL-PYRAZOLE TO CYCLOOXYGENASE-2 USING PLANTS

    Directory of Open Access Journals (Sweden)

    Stefanus Layli Prasojo

    2010-12-01

    Full Text Available The docking protocols to virtually screen selective cyclooxygenase-2 (COX-2 ligands using PLANTS docking software were developed and validated. The crystal structure of 1-phenylsulfonamide-3-trifluoromethyl-5-parabromophenyl-pyrazole (S58 binds to cyclooxygenase-2 (COX-2 was used as the reference structure. The developed protocols could predict the binding pose of S58 to COX-2 accurately (RMSD is 1.2 Ǻ.

  14. DOCKING OF 1-PHENYLSULFONAMIDE-3-TRIFLUOROMETHYL-5-PARABROMOPHENYL-PYRAZOLE TO CYCLOOXYGENASE-2 USING PLANTS

    OpenAIRE

    Stefanus Layli Prasojo; Fajar Agung Dwi Hartanto; Nunung Yuniarti; Zullies Ikawati; Enade Perdana Istyastono

    2010-01-01

    The docking protocols to virtually screen selective cyclooxygenase-2 (COX-2) ligands using PLANTS docking software were developed and validated. The crystal structure of 1-phenylsulfonamide-3-trifluoromethyl-5-parabromophenyl-pyrazole (S58) binds to cyclooxygenase-2 (COX-2) was used as the reference structure. The developed protocols could predict the binding pose of S58 to COX-2 accurately (RMSD is 1.2 Ǻ).

  15. Changes in the Expression of Cyclooxygenase-2 in Polycystic Ovary Syndrome in Wistar Rats

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    Karimzadeh L

    2011-12-01

    Full Text Available Background: Cyclooxygenase 2 is a key enzyme which converts arachidonic acid into prostaglandins. Cyclooxygenase 2 is triggered by inflammatory stimuli, such as cytokines. Its expression increases in tumors and Alzheimer's disease and ovarian hyperstimulation syndrome. Polycystic ovarian syndrome is a heterogeneous disease characterized by pathological angiogenesis and chronic anovulation. In the present study, the probable role of cyclooxygenase 2 in Wistar rats with polycystic ovarian syndrome was investigated.Methods: Thirty female Wistar rats (170-200 gr were equally divided into three groups: 2 mg estradiol valerate was intramuscularly administered to each rat in the experiment group or group 1; the rats in group 2 were regarded as the sham group and received sesame oil injections and group 3 or the control group received no injections. After 60 days of treatment, animals were anaesthetized with chloroform and killed by decapitation. Ovaries were collected for histological and immunohistochemical evaluations. All the experiments were repeated three times.Results: Morphologically, ovaries from the control group exhibited follicles in various stages of development and many fresh corpus luteum. In estradiol valerate group small follicles in early development were observed in addition to follicles showing evidence of atresia and many large cysts with thickened theca cell layer. Corpus luteum was rare or absent in group 2. The immunohistochemical analysis for cyclooxygenase 2 expression showed an increased expression of cyclooxygenase 2 enzyme in group 1.Conclusion: The results suggested the involvement of cyclooxygenase 2 in the progression to polycystic ovarian syndrome in a rat model.

  16. Molecular Dynamic Screening Sesquiterpenoid Pogostemon Herba as Suggested Cyclooxygenase Inhibitor

    Science.gov (United States)

    Raharjo, Sentot Joko; Kikuchi, Takeshi

    2016-01-01

    Objective: Virtual molecular dynamic sesquiterpenoid Pogostemon Herba (CID56928117, CID94275, CID107152, and CID519743) have screening as cyclooxygenase (COX-1/COX-2) selective inhibitor. Methods: Molecular interaction studies sesquiterpenoid compounds with COX-1 and COX-2 were using the molecular docking tools by Hex 8.0 and interactions were further visualized using by Discovery Studio Client 3.5 software tool and Virtual Molecular Dynamic 1.9.1 software. The binding energy calculation of molecular dynamic interaction was calculated by AMBER12 software. Result: The analysis of the sesquiterpenoid compounds showed that CID56928117, CID94275, CID107152, and CID519743 have suggested as inhibitor of COX-1 and COX-2. Conclusion: Collectively, the scoring binding energy calculation (with PBSA Model Solvent) sesquiterpenoid compounds: CID519743 had suggested as candidate for non-selective inhibitor; CID56928117 and CID94275 had suggested as candidate for a selective COX-1 inhibitor; and CID107152 had suggested as candidate for a selective COX-2 inhibitor. PMID:28077888

  17. Consistent inhibition of cyclooxygenase drives macrophages towards the inflammatory phenotype.

    Directory of Open Access Journals (Sweden)

    Yi Rang Na

    Full Text Available Macrophages play important roles in defense against infection, as well as in homeostasis maintenance. Thus alterations of macrophage function can have unexpected pathological results. Cyclooxygenase (COX inhibitors are widely used to relieve pain, but the effects of long-term usage on macrophage function remain to be elucidated. Using bone marrow-derived macrophage culture and long-term COX inhibitor treatments in BALB/c mice and zebrafish, we showed that chronic COX inhibition drives macrophages into an inflammatory state. Macrophages differentiated in the presence of SC-560 (COX-1 inhibitor, NS-398 (COX-2 inhibitor or indomethacin (COX-1/2 inhibitor for 7 days produced more TNFα or IL-12p70 with enhanced p65/IκB phosphoylation. YmI and IRF4 expression was reduced significantly, indicative of a more inflammatory phenotype. We further observed that indomethacin or NS-398 delivery accelerated zebrafish death rates during LPS induced sepsis. When COX inhibitors were released over 30 days from an osmotic pump implant in mice, macrophages from peritoneal cavities and adipose tissue produced more TNFα in both the basal state and under LPS stimulation. Consequently, indomethacin-exposed mice showed accelerated systemic inflammation after LPS injection. Our findings suggest that macrophages exhibit a more inflammatory phenotype when COX activities are chronically inhibited.

  18. Cyclooxygenase-2 Expression in Hamster and Human Pancreatic Neoplasia

    Directory of Open Access Journals (Sweden)

    Pamela L. Crowell

    2006-06-01

    Full Text Available Cyclooxygenase-2 (COX-2 has been implicated in the development of gastrointestinal malignancies. The aim of the present study was to determine COX-2 expression/activity throughout stages of experimental and human pancreatic neoplasia. COX-2 immunohistochemistry was performed in pancreata of hamsters subjected to the carcinogen N-nitrosobis-(2-oxopropylamine (BOP and in human pancreatic tumors. COX-2 activity was determined by prostaglandin E2 assay in tumor versus matched normal pancreatic tissues. The activity of the COX inhibitor sulindac was tested in the PC-1 hamster pancreatic cancer model. COX-2 expression was elevated in all pancreatic intraepithelial neoplasias (PanINs and adenocarcinomas. In BOP-treated hamsters, there were significant progressive elevations in COX-2 expression throughout pancreatic tumorigenesis. In human samples, peak COX-2 expression occurred in PanIN2 lesions and remained moderately elevated in PanIN3 and adenocarcinoma tissues. COX-2 activity was significantly elevated in hamster and human pancreatic cancers compared to pair-matched normal pancreas. Furthermore, hamster pancreatic tumor engraftment/formation in the PC-1 hamster pancreatic cancer model was reduced 4.9-fold by oral administration of sulindac. Increased COX-2 expression is an early event in pancreatic carcinogeneses. The BOP-induced hamster carcinogenesis model is a representative model used to study the role of COX-2 in well-differentiated pancreatic tumorigenesis. COX inhibitors may have a role in preventing tumor engraftment/formation.

  19. Prokaryotic expression, purification and characterization of human cyclooxygenase-2.

    Science.gov (United States)

    Liao, Xiangzhi; Wang, Wenhan; Fan, Chuanxi; Yang, Ning; Zhao, Jialiang; Zhang, Ying; Gao, Ruijuan; Shen, Guannan; Xia, Simin; Li, Guiying

    2017-07-01

    Cyclooxygenase-2 (COX-2) is a key enzyme which catalyzes the conversion of arachidonic acid (AA) into prostaglandins (PGs). It plays an important role in pathophysiological processes, such as tumorigenesis, angiogenesis, inflammation and tumor cell drug resistance. Therefore, COX-2 has been viewed as an important target for cancer therapy. The preparation of COX-2 protein is an important initial step for the subsequent development of COX-2 inhibitors. In this study, we report a strategy to heterologously express truncated human COX-2 (trCOX-2) in Escherichia coli (E. coli) BL21(DE3) host cells. Following denaturation, purification and renaturation, we successfully obtained enzymatically active trCOX-2 containing 257 residues of the C-terminus. Homology modeling and molecular docking analyses revealed that trCOX-2 retained the predicted 3D catalytic domain structure and AA could still bind to its hydrophobic groove. Western blot analysis and ELISA indicated that the trCOX-2 still retained its characteristic antigenicity and binding activity, while COX assays revealed that trCOX-2 maintained its enzyme activity. On the whole, in this study, we provided a novel method to isolate trCOX-2 possessing AA binding and catalytic activities. This study thus lays a foundation to facilitate further investigations of COX-2 and offers a valuable method with which to achieve the prokaryotic expression of a eukaryotic membrane protein.

  20. Cyclooxygenase 2 genotypes influence prostate cancer susceptibility in Japanese Men.

    Science.gov (United States)

    Sugie, Satoru; Tsukino, Hiromasa; Mukai, Shoichiro; Akioka, Takahiro; Shibata, Norihiko; Nagano, Masafumi; Kamoto, Toshiyuki

    2014-03-01

    This study aims to evaluate the relationship between the cyclooxygenase 2 (COX2) G1195A (rs689465) polymorphism and the risk of prostate cancer in a Japanese population and the associations between COX2 polymorphisms and clinicopathological characteristics, including Gleason grade and prostate-specific antigen (PSA) grade. We recruited 134 patients with prostate cancer and 86 healthy controls matched for age and smoking status. The COX2 G1195A polymorphism status was determined by polymerase chain reaction and restriction fragment length polymorphism analysis. Genotype distributions (p = 0.028) and allelic frequencies (p = 0.014) differed significantly between prostate cancer and control groups in terms of the COX2 G1195A polymorphism (Pearson's χ (2) test). Logistic regression analysis of case and control outcomes showed an odds ratio between the GG and AA genotypes of 3.15 (95% confidence interval = 1.27-8.08, p = 0.014), indicating an increased risk of prostate cancer associated with the AA genotype. Subset analysis revealed no significant associations between this polymorphism and clinicopathological characteristics of prostate cancer. This study demonstrated a relationship between the COX2 G1195A variant and prostate cancer risk. This polymorphism may merit further investigation as a potential genomic marker for the early detection of prostate cancer. Our results support the hypothesis that rs689465 influences susceptibility to prostate cancer; however, prostate cancer progression was not associated with rs689465 in a Japanese population.

  1. The role of cyclooxygenase-2 in prostate cancer.

    Science.gov (United States)

    Kirschenbaum, A; Liu, X; Yao, S; Levine, A C

    2001-08-01

    Cyclooxygenase-2 (COX-2) is the inducible isozyme of COX, a key enzyme in the conversion of arachidonic acid to prostaglandins and other eicosanoids. COX-2 is highly expressed in a number of human cancers and cancer cell lines, including prostate cancer. We studied the immunohistochemical expression of COX-2 in the human prostate gland. The enzyme is strongly expressed in smooth muscle cells of both the normal and cancerous prostate. Its expression in noncancerous epithelial cells is limited to the basal cell layer. In prostatic inflammation, luminal epithelial cells surrounded by lymphocytes are induced to express the enzyme. COX-2 is expressed in the epithelial cells of high-grade prostatic intraepithelial neoplasia and cancer. We have demonstrated that treatment of human prostate-cancer cell lines with a selective COX-2 inhibitor induces apoptosis both in vitro and in vivo. The in vivo results also indicate that the COX-2 inhibitor decreases tumor microvessel density and angiogenesis. COX-2 inhibitors can prevent the hypoxic upregulation of a potent angiogenic factor, vascular endothelial growth factor. These results indicate that COX-2 inhibitors may, therefore, serve as effective chemopreventive and therapeutic agents in cancer of the prostate.

  2. Over-expression of cyclooxygenase-2 in human prostate adenocarcinoma.

    Science.gov (United States)

    Gupta, S; Srivastava, M; Ahmad, N; Bostwick, D G; Mukhtar, H

    2000-01-01

    Aberrant or increased expression of cyclooxygenase (COX)-2 has been implicated in the pathogenesis of many diseases including carcinogenesis. COX-2 has been shown to be over-expressed in some human cancers. Employing semi-quantitative reverse transcription-PCR, immunoblotting, and immunohistochemistry we assessed COX-2 expression in samples of pair-matched benign and cancer tissue obtained from the same prostate cancer patient. Mean levels of COX-2 mRNA were 3.4-fold higher in prostate cancer tissue (n = 12) compared with the paired benign tissue. The immunoblot analysis demonstrated that as compared to benign tissue COX-2 protein was over-expressed in 10 of 12 samples examined. Immunohistochemical analysis also verified COX-2 over-expression in cancer than in benign tissue. To our knowledge, this is the first in vivo study showing an over-expression of COX-2 in prostate cancer. These data suggest that COX-2 inhibitors may be useful for prevention or therapy of prostate cancer in humans.

  3. The effects of cyclooxygenase-2 inhibitors on urological cancer cells.

    Science.gov (United States)

    Yoshimura, Rikio; Matsuyama, Masahide; Kawahito, Yutaka; Takemoto, Yoshiaki; Tsuchida, Kenji; Kuratsukuri, Katsuyuki; Segawa, Yoshihiro; Shinnka, Toshiaki; Sano, Hajime; Nakatani, Tatsuya

    2004-06-01

    Cyclooxygenase (COX)-2 plays an important role in the development of various cancers due to its angiogenic function. We have demonstrated that the expression of COX-2 was up-regulated in human renal cell carcinoma (RCC), bladder tumor (BT) and prostate cancer (PC). In this study, we examined the effects of COX-2 inhibitors on cell proliferation in RCC, BT and PC-derived cell lines using MTT assay and Hoechst staining. COX-2 inhibitors did not induce a reduction of cell viability with the half-maximal concentration of growth inhibition of RCC, BT and PC cell lines. Furthermore, counting cells at days 1, 2 and 3, showed no inhibition of cell proliferation using COX-2 inhibitors. COX-2 inhibitors could not stop the growth of RCC, BT and PC cells. Typical characteristics of apoptosis, i.e. chromatin condensation, cellular shrinkage, small membrane-bound bodies (apoptotic bodies) and cytoplasmic condensation, did not occur. Although the expression of COX-2 was up-regulated in human RCC, BT and PC tissues, COX-2 inhibitors have only slight anti-proliferative effects against RCC, BT and PC cells through differentiation. Thus, using only down-regulation of arachidonic acid (AA) metabolizing enzyme, COX may be an unsuccessful approach in providing new anti-cancer therapies.

  4. Antiangiogenic and antitumor activities of cyclooxygenase-2 inhibitors.

    Science.gov (United States)

    Masferrer, J L; Leahy, K M; Koki, A T; Zweifel, B S; Settle, S L; Woerner, B M; Edwards, D A; Flickinger, A G; Moore, R J; Seibert, K

    2000-03-01

    We provide evidence that cyclooxygenase (COX)-2-derived prostaglandins contribute to tumor growth by inducing newly formed blood vessels (neoangiogenesis) that sustain tumor cell viability and growth. COX-2 is expressed within human tumor neovasculature as well as in neoplastic cells present in human colon, breast, prostate, and lung cancer biopsy tissue. COX-1 is broadly distributed in normal, as well as in neoplastic, tissues. The contribution of COX-2 to human tumor growth was indicated by the ability of celecoxib, an agent that inhibits the COX-2 enzyme, to suppress growth of lung and colon tumors implanted into recipient mice. Mechanistically, celecoxib demonstrated a potent antiangiogenic activity. In a rat model of angiogenesis, we observe that corneal blood vessel formation is suppressed by celecoxib, but not by a COX-1 inhibitor. These and other data indicate that COX-2 and COX-2-derived prostaglandins may play a major role in development of cancer through numerous biochemical mechanisms, including stimulation of tumor cell growth and neovascularization. The ability of celecoxib to block angiogenesis and suppress tumor growth suggests a novel application of this anti-inflammatory drug in the treatment of human cancer.

  5. Novel selective inhibitors of hydroxyxanthone derivatives for human cyclooxygenase-2

    Institute of Scientific and Technical Information of China (English)

    Yu-chian CHEN; Kun-tze CHEN

    2007-01-01

    Aim: To screen the selective inhibitors for human cyclooxygenase-2 ((h)COX-2) utilizing molecular simulation. Methods: Eight xanthone derivatives, compounds A-H, were employed by the structure-based research methodology. Resveratrol and NS-398 were selected as the control compounds for COX-1 and COX-2, respectively. The docking results were scored and the interaction energies of the complexes were calculated by CHARMm forcefield. Results: NS-398 could not dock into the active site of COX-1. However, resveratrol, the specific selective compound for COX-1, gained lower interaction energy while docked in COX-1. The lower interaction energies were investigated, while compound B and F were docked into the catalytic sites of COX-1 and COX-2, respectively. Compound A, 1,3,6,7-tetrahydroxyxanthone, revealed high inhibitory potency to both COX-1 and COX-2. Conclusion: The conformations of the docking would influence the values of interaction energies. The hydrogen bond could also increase the stabi- lity of the whole complex, which might suggest that compound B had a suitable conformation in the tunnel-like active site of COX-1. Compound F, a potent agent for COX-2, revealed a strong hydrogen bond with Set516 in human COX-2 to form a stable complex.

  6. Polymorphisms in cyclooxygenase-2 gene in endometrial cancer patients.

    Science.gov (United States)

    Torricelli, Federica; Mandato, Vincenzo Dario; Farnetti, Enrico; Abrate, Martino; Casali, Bruno; Ciarlini, Gino; Pirillo, Debora; Gelli, Maria Carolina; Costagliola, Luigi; Nicoli, Davide; Palomba, Stefano; La Sala, Giovanni Battista

    2015-09-01

    The enzyme cyclooxygenase 2 is an inducible enzyme expressed at sites of inflammation and in a variety of malignant solid tumors such as endometrial cancer (EC). In EC patients, its over-expression is correlated with progressive disease and poor prognosis. The expression is encoded by a polymorphic gene, called PTGS2. The aim of the current study was to test the hypothesis that rs5275 polymorphism of PTGS2 influence the prognosis of EC patients. This paper is a retrospective cohort study. Clinical and pathological data were extrapolated and genotypes were assessed on formalin-fixed and paraffin-embedded non-tumor tissues. A total of 159 type I EC patients were included in the final analysis. Univariate analysis indicated that patients with rs5275 genotype CC have a lower risk to develop a grade (G) 2-3 endometrial cancer. rs5275 effect on EC grading was confirmed by multivariate analysis also after data adjusting for age, BMI, parity, hypertension, and diabetes. Adjusted odds ratio (OR) confirmed that patients with rs5275 genotype CC have a risk 80 % lower (OR = 0.20, P = 0.009) to develop a G2 and/or G3 EC in comparison with patients with TT or TC genotype. Differentiation of the type 1 EC is significantly and independently influenced by rs5275 polymorphism. rs5275 CC patients have a lower risk to present a G2-G3 EC.

  7. In silico docking analysis of piperine with cyclooxygenases

    Directory of Open Access Journals (Sweden)

    Prashantha Karunakar

    2012-08-01

    Full Text Available The structure of 1-[5-(1,3-benzodioxol- 5-yl-1-oxo-2,4-pentadienyl]piperidine (Piperine, C17H19O3N, a versatile bioactive molecule has been redetermined at 100(2 K by X-raycrystallography to explore their potential utilization in inhibition of prostaglandin release. The crystal structure is stabilized by weaknonclassical intermolecular C-H…O hydrogen bonds and also intermolecular C-H…π interactions. The crystallographiccoordinates of the compound were extrapolated to docking studies to elucidate the action of piperine against the enzymes,cyclooxygenases (COX-1 and COX-2 involved in biosynthesis of prostaglandin release. Using AutoDock suite, piperine was docked at the binding site of COX-1 and COX-2 enzyme and a strong affinity (-9.06kcal/mol, Ki =227.73nM and -8.77kcal/mol, Ki = 375.62nM, respectively was formed by Hydrogen bonds and hydrophobic interactions. These results suggest that piperine can be a promising lead for the development of COX family inhibitors.

  8. Eicosanoid pathway in colorectal cancer: Recent updates

    OpenAIRE

    Tuncer, Sinem; Banerjee, Sreeparna

    2015-01-01

    Enzymatic metabolism of the 20C polyunsaturated fatty acid (PUFA) arachidonic acid (AA) occurs via the cyclooxygenase (COX) and lipoxygenase (LOX) pathways, and leads to the production of various bioactive lipids termed eicosanoids. These eicosanoids have a variety of functions, including stimulation of homeostatic responses in the cardiovascular system, induction and resolution of inflammation, and modulation of immune responses against diseases associated with chronic inflammation, such as ...

  9. Immunohistochemical localization of cyclooxygenase-1 and cyclooxygenase-2 in the human fetal and adult male reproductive tracts.

    Science.gov (United States)

    Kirschenbaum, A; Liotta, D R; Yao, S; Liu, X H; Klausner, A P; Unger, P; Shapiro, E; Leav, I; Levine, A C

    2000-09-01

    The first rate-limiting step in the conversion of arachidonic acid to PGs is catalyzed by cyclooxygenase (Cox). Two isoforms of Cox have been identified, Cox-1 (constitutively expressed) and Cox-2 (inducible form), which are the products of two different genes. In this study we describe the immunohistochemical localization of Cox-1 and -2 in the human male fetal and adult reproductive tracts. There was no Cox-1 expression in fetal samples (prostate, seminal vesicles, or ejaculatory ducts), and only minimal expression in adult tissues. There was no expression of Cox-2 in the fetal prostate. In a prepubertal prostate there was some Cox-2 expression that localized exclusively to the smooth muscle cells of the transition zone. In adult hyperplastic prostates, Cox-2 was strongly expressed in smooth muscle cells, with no expression in the luminal epithelial cells. Cox-2 was strongly expressed in epithelial cells of both fetal and adult seminal vesicles and ejaculatory ducts. The Cox-2 staining intensity in the fetal ejaculatory ducts during various times of gestation correlated with previously reported testosterone production rates by the fetal testis. These data indicate that Cox-2 is the predominant isoform expressed in the fetal male reproductive tract, and its expression may be regulated by androgens. The distinct cell type-specific expression patterns of Cox-2 in the prostate (smooth muscle) vs. the seminal vesicles and ejaculatory ducts (epithelium) may reflect the different roles of PGs in these tissues.

  10. Competition and allostery govern substrate selectivity of cyclooxygenase-2

    Science.gov (United States)

    Mitchener, Michelle M.; Hermanson, Daniel J.; Shockley, Erin M.; Brown, H. Alex; Lindsley, Craig W.; Reese, Jeff; Rouzer, Carol A.; Lopez, Carlos F.; Marnett, Lawrence J.

    2015-01-01

    Cyclooxygenase-2 (COX-2) oxygenates arachidonic acid (AA) and its ester analog, 2-arachidonoylglycerol (2-AG), to prostaglandins (PGs) and prostaglandin glyceryl esters (PG-Gs), respectively. Although the efficiency of oxygenation of these substrates by COX-2 in vitro is similar, cellular biosynthesis of PGs far exceeds that of PG-Gs. Evidence that the COX enzymes are functional heterodimers suggests that competitive interaction of AA and 2-AG at the allosteric site of COX-2 might result in differential regulation of the oxygenation of the two substrates when both are present. Modulation of AA levels in RAW264.7 macrophages uncovered an inverse correlation between cellular AA levels and PG-G biosynthesis. In vitro kinetic analysis using purified protein demonstrated that the inhibition of 2-AG oxygenation by high concentrations of AA far exceeded the inhibition of AA oxygenation by high concentrations of 2-AG. An unbiased systems-based mechanistic model of the kinetic data revealed that binding of AA or 2-AG at the allosteric site of COX-2 results in a decreased catalytic efficiency of the enzyme toward 2-AG, whereas 2-AG binding at the allosteric site increases COX-2’s efficiency toward AA. The results suggest that substrates interact with COX-2 via multiple potential complexes involving binding to both the catalytic and allosteric sites. Competition between AA and 2-AG for these sites, combined with differential allosteric modulation, gives rise to a complex interplay between the substrates, leading to preferential oxygenation of AA. PMID:26392530

  11. Effects of cyclooxygenase-2 on human esophageal squamous cell carcinoma

    Institute of Scientific and Technical Information of China (English)

    Li Zhang; Yong-Dong Wu; Peng Li; Jun Tu; Ying-Lin Niu; Cai-Min Xu; Shu-Tian Zhang

    2011-01-01

    AIM: To study the relationship between the cyclooxygenase (COX)-2 gene and the proliferation and apoptosis of esophageal squamous carcinoma EC109 cells.METHODS: The techniques of RNA interference (RNAi) and cell transfection, as well as the levels of oncogenicity in nude mice, were used to study the role of COX-2 in the esophageal squamous carcinoma cell (ESCC) line EC109. Following RNAi and transfection, Western blotting analysis was used to determine the expression of the COX-2 protein. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) reduction assay was used to evaluate cell growth, and flow cytometry was used to detect cell apoptosis.RESULTS: Western blotting analysis demonstrated that COX-2 expression was significantly reduced in EC109 cells treated with COX-2-specific short interfering RNA (siRNA) but was increased in EC109 cells transfected with COX-2. Furthermore, COX-2 siRNA treatment inhibited cell proliferation (P < 0.01) and induced apoptosis in EC109 cells, as determined by an MTT assay and by flow cytometry, respectively. In contrast, transfected COX-2 led to increased cell proliferation (P < 0.05) and decreased apoptosis in EC109 cells. In addition, combination treatment of cells with COX-2 siRNA and aspirin had a synergistic effect (P < 0.01). For experiments measuring tumorigenicity, xenograft tumors of a greater volume and weight were found in the COX-2 group compared with other groups (P < 0.05). A large dose of aspirin inhibited tumor growth in nude mice effectively (P < 0.05), and the rate of tumor suppression was 51.8% in the high-dose aspirin group.CONCLUSION: COX-2 plays a very critical role in ESCC carcinogenesis, and COX-2 siRNA combined with aspirin has the potential to be an anticancer therapy for the treatment of ESCC.

  12. Cyclooxygenase 2: its regulation, role and impact in airway inflammation.

    Science.gov (United States)

    Rumzhum, N N; Ammit, A J

    2016-03-01

    Cyclooxygenase 2 (COX-2: official gene symbol - PTGS2) has long been regarded as playing a pivotal role in the pathogenesis of airway inflammation in respiratory diseases including asthma. COX-2 can be rapidly and robustly expressed in response to a diverse range of pro-inflammatory cytokines and mediators. Thus, increased levels of COX-2 protein and prostanoid metabolites serve as key contributors to pathobiology in respiratory diseases typified by dysregulated inflammation. But COX-2 products may not be all bad: prostanoids can exert anti-inflammatory/bronchoprotective functions in airways in addition to their pro-inflammatory actions. Herein, we outline COX-2 regulation and review the diverse stimuli known to induce COX-2 in the context of airway inflammation. We discuss some of the positive and negative effects that COX-2/prostanoids can exert in in vitro and in vivo models of airway inflammation, and suggest that inhibiting COX-2 expression to repress airway inflammation may be too blunt an approach; because although it might reduce the unwanted effects of COX-2 activation, it may also negate the positive effects. Evidence suggests that prostanoids produced via COX-2 upregulation show diverse actions (and herein we focus on prostaglandin E2 as a key example); these can be either beneficial or deleterious and their impact on respiratory disease can be dictated by local concentration and specific interaction with individual receptors. We propose that understanding the regulation of COX-2 expression and associated receptor-mediated functional outcomes may reveal number of critical steps amenable to pharmacological intervention. These may prove invaluable in our quest towards future development of novel anti-inflammatory pharmacotherapeutic strategies for the treatment of airway diseases. © 2015 John Wiley & Sons Ltd.

  13. Chronic elevation of IL-1β induces diuresis via a cyclooxygenase 2-mediated mechanism.

    Science.gov (United States)

    Boesen, E I

    2013-07-15

    Chronic renal inflammation is an increasingly recognized phenomenon in multiple disease states, but the impact of specific cytokines on renal function is unclear. Previously, we found that 14-day interleukin-1β (IL-1β) infusion increased urine flow in mice. To determine the mechanism by which this occurs, the current study tested the possible involvement of three classical prodiuretic pathways. Chronic IL-1β infusion significantly increased urine flow (6.5 ± 1 ml/day at day 14 vs. 2.3 ± 0.3 ml/day in vehicle group; P < 0.05) and expression of cyclooxygenase (COX)-2, all three nitric oxide synthase (NOS) isoforms, and endothelin (ET)-1 in the kidney (P < 0.05 in all cases). Urinary prostaglandin E metabolite (PGEM) excretion was also significantly increased at day 14 of IL-1β infusion (1.21 ± 0.26 vs. 0.29 ± 0.06 ng/day in vehicle-infused mice; P = 0.001). The selective COX-2 inhibitor celecoxib markedly attenuated urinary PGEM excretion and abolished the diuretic response to chronic IL-1β infusion. In contrast, deletion of NOS3, or inhibition of NOS1 with L-VNIO, did not blunt the diuretic effect of IL-1β, nor did pharmacological blockade of endothelin ETA and ETB receptors with A-182086. Consistent with a primary effect on water transport, IL-1β infusion markedly reduced inner medullary aquaporin-2 expression (P < 0.05) and did not alter urinary Na⁺ or K⁺ excretion. These data indicate a critical role for COX-2 in mediating the effects of chronic IL-1β elevation on the kidney.

  14. Cyclooxygenase-2 is a target of microRNA-16 in human hepatoma cells.

    Directory of Open Access Journals (Sweden)

    Noelia Agra Andrieu

    Full Text Available Cyclooxygenase-2 (COX-2 expression has been detected in human hepatoma cell lines and in human hepatocellular carcinoma (HCC; however, the contribution of COX-2 to the development of HCC remains controversial. COX-2 expression is higher in the non-tumoral tissue and inversely correlates with the differentiation grade of the tumor. COX-2 expression depends on the interplay between different cellular pathways involving both transcriptional and post-transcriptional regulation. The aim of this work was to assess whether COX-2 could be regulated by microRNAs in human hepatoma cell lines and in human HCC specimens since these molecules contribute to the regulation of genes implicated in cell growth and differentiation. Our results show that miR-16 silences COX-2 expression in hepatoma cells by two mechanisms: a by binding directly to the microRNA response element (MRE in the COX-2 3'-UTR promoting translational suppression of COX-2 mRNA; b by decreasing the levels of the RNA-binding protein Human Antigen R (HuR. Furthermore, ectopic expression of miR-16 inhibits cell proliferation, promotes cell apoptosis and suppresses the ability of hepatoma cells to develop tumors in nude mice, partially through targeting COX-2. Moreover a reduced miR-16 expression tends to correlate to high levels of COX-2 protein in liver from patients affected by HCC. Our data show an important role for miR-16 as a post-transcriptional regulator of COX-2 in HCC and suggest the potential therapeutic application of miR-16 in those HCC with a high COX-2 expression.

  15. Localization of Cyclo-Oxygenase and Prostaglandin E2 in the Secretory Granule of the Mast Cell

    Science.gov (United States)

    1989-01-01

    cascade during exocytosis. Keywords: Cyclo-oxygenase; Prostaglandin E2; Secretory granules; Mast cell ; Exocytosis; Lipid mediators; Inflammation; Arachidonic acid; Eicosanoids; Immunocytochemistry; Reprints. (KT)

  16. Cyclooxygenase-2 and Ki67 Expression in Oral Leukoplakia: a Clinicopathological Study

    Directory of Open Access Journals (Sweden)

    Alper Sinanoglu

    2015-06-01

    Full Text Available Objectives: Oral leukoplakia is a precancerous lesion of the oral mucosa. The upregulation of Ki67 and cyclooxygenase-2 has been reported in both dysplastic and non-dysplastic tissues. The aim of this clinicopathological study was to investigate the prognostic value of Ki67 and cyclooxygenase-2 expression for oral leukoplakia. Material and Methods: A total of 50 samples were investigated and the study group consisted of 30 oral leukoplakia samples. Samples of 10 intact oral mucosa and 10 squamous cell carcinoma were included as negative and positive control groups, respectively. Epithelial dysplasia was defined as oral intraepithelial neoplasia (OIN and classified into subgroups 1 - 3. Tissue samples were assessed immunohistochemically for Ki67 and cyclooxygenase-2 expression. Clinicopathological correlations of oral leukoplakia patients were also investigated. Results: All OIN 3 patients were non-smokers (P < 0.05, and homogeneous oral leukoplakia lesions also presented OIN. Both cyclooxygenase-2 and Ki67 expression increased with the severity of lesions, which defined different subgroups (P < 0.05, except there was no significant difference between the hyperkeratosis and OIN groups for Ki67 expression. Conclusions: Cyclooxygenase-2 and Ki67 expression may have a prognostic value for the malignant transformation of oral leukoplakia.

  17. Investigating Immunohistochemical Expression of cyclooxygenase-2 in oral lichen planus

    Directory of Open Access Journals (Sweden)

    Maryam Seyedmajidi

    2016-06-01

    Full Text Available Background and goal: (cox2 Cyclooxygenase -2 as an enzyme is not present in normal tissues and in fact is a type of inductive enzyme during pathological phenomena such as inflammation and cancer are significantly increased. Increased expression of cox-2 in gastric carcinoma, pancreatic, lung and oral squamous cell carcinoma has been shown and seems to be one of the performance mechanisms of the inhibition of apoptosis in tumor cells. Regarding the role of cox-2 in apoptosis mechanisms and the creation of dysplastic changes and malignant, the study aimed to evaluate the immunohistochemical expression of cox-2 in oral lichen planus and were compared with normal mucosa and gingivitis. Methods: The study was performed on 30 paraffin blocks related to patients referred to oral and maxillofacial pathology department in Dental School of Babol with confirmed diagnosis of oral lichen planus was done. The same number of samples of normal mucosa and samples of gingivitis were studied. Slices prepared from the above blocks bycoloring immunostaining cox-2 were stained and after reviewing the slides obtained, data using statistical software spss20 and x2 tests, Mann-Whitney and parametric tests such as T test was analyzed and P ˂0.05 was considered significant Results: In this study, significantly percentage of stained cells and staining intensity of cells in the basal layer of lichen planus was higher than normal mucosa (p <0.001. In parabasal layer the results were similar (p <0.001. This results in comparison to lichen planus and gingivitis in basal layer (p <0.001 and parabasal was seen (p <10.0. On the other hand, significantly the percentage of stained cells and staining intensity of cells in the basal layer of gingivitis was more than normal mucosa (p <0.001. In above comparison, similar result in the parabasal layer was seen (p <0.001. The percentage of stained cells and staining intensity of cells in lymphocytic infiltration was significantly higher

  18. Cyclooxygenase-2 expression in oligodendrocytes increases sensitivity to excitotoxic death

    Directory of Open Access Journals (Sweden)

    Rojas Monica A

    2010-04-01

    Full Text Available Abstract Background We previously found that cyclooxygenase 2 (COX-2 was expressed in dying oligodendrocytes at the onset of demyelination in the Theiler's murine encephalomyelitis virus-induced demyelinating disease (TMEV-IDD model of multiple sclerosis (MS (Carlson et al. J.Neuroimmunology 2006, 149:40. This suggests that COX-2 may contribute to death of oligodendrocytes. Objective The goal of this study was to examine whether COX-2 contributes to excitotoxic death of oligodendrocytes and potentially contributes to demyelination. Methods The potential link between COX-2 and oligodendrocyte death was approached using histopathology of MS lesions to examine whether COX-2 was expressed in dying oligodendrocytes. COX-2 inhibitors were examined for their ability to limit demyelination in the TMEV-IDD model of MS and to limit excitotoxic death of oligodendrocytes in vitro. Genetic manipulation of COX-2 expression was used to determine whether COX-2 contributes to excitotoxic death of oligodendrocytes. A transgenic mouse line was generated that overexpressed COX-2 in oligodendrocytes. Oligodendrocyte cultures derived from these transgenic mice were used to examine whether increased expression of COX-2 enhanced the vulnerability of oligodendrocytes to excitotoxic death. Oligodendrocytes derived from COX-2 knockout mice were evaluated to determine if decreased COX-2 expression promotes a greater resistance to excitotoxic death. Results COX-2 was expressed in dying oligodendrocytes in MS lesions. COX-2 inhibitors limited demyelination in the TMEV-IDD model of MS and protected oligodendrocytes against excitotoxic death in vitro. COX-2 expression was increased in wild-type oligodendrocytes following treatment with Kainic acid (KA. Overexpression of COX-2 in oligodendrocytes increased the sensitivity of oligodendrocytes to KA-induced excitotoxic death eight-fold compared to wild-type. Conversely, oligodendrocytes prepared from COX-2 knockout mice showed a

  19. Piroxicam inhibits Masitinib-induced cyclooxygenase 2 expression in oral squamous cell carcinoma cells in vitro.

    Science.gov (United States)

    Rathore, Kusum; Alexander, Mary; Cekanova, Maria

    2014-08-01

    Development and characterization of animal models for human cancers is important for the improvement of diagnosis and therapy. The oral squamous cell carcinoma (OSCC) of domestic animals resembles human OSCC in many aspects; thus, cell lines derived from OSCC of cats and dogs are a valuable model for human OSCC. We characterized 1 feline OSCC (FeOSCC-Sidney) and 1 canine OSCC (K9OSCC-Abby) cell line and compared their characteristics with human OSCC cell line hSCC-25. We calculated the doubling time of the new OSCC cell lines and evaluated the expression profiles of cancer-related markers and cell-cycle proteins such as c-kit, platelet-derived growth factor receptor, vascular endothelial growth factor receptor, epidermal growth factor receptor, cyclooxygenase (COX)-1, COX-2, and p27 by immunocytochemistry and Western blot analysis. We evaluated the effects of novel receptor tyrosine kinase inhibitor (Masitinib, AB1010) and the nonsteroidal anti-inflammatory drug piroxicam on the previously mentioned OSCC cells. Interestingly, AB1010 increased expression levels of COX-2 in all tested OSCCs. Cotreatment of piroxicam with Masitinib significantly inhibited cell proliferation of OSCC as compared to either drug alone through the c-kit and AKT signaling pathways. Piroxicam inhibited Masitinib-induced COX-2 expression in all tested OSCCs. Therefore, targeting these two signaling pathways simultaneously was more efficient for inhibition of OSCCs across these species.

  20. Down regulation of cyclooxygenase-2 is involved in delayed neuroprotec-tion by ischemic preconditioning in rats

    Institute of Scientific and Technical Information of China (English)

    Liang XIAO; Fei-li ZHAO; Xing-zu ZHU

    2005-01-01

    Aim: To examine whether the prostaglandins (PGs) pathway is involved in triggering delayed neuroprotection by ischemic preconditioning (IPC) and evaluate the effects of IPC on cyclooxygenase-2 (COX-2) expression following focal cerebral ischemia and reperfusion in rats. Methods: IPC was induced by 10 min of saline infusion into the left internal carotid artery with the right common carotid artery clamped at the same time. Middle cerebral artery occlusion (MCAO) and reperfusion model was produced using intraluminal filament method. Results: IPC 48 h prior to MCAO significantly reduced infarct area as compared with MCAO alone. A nonselective inhibitor of COX indomethacin (3 mg/kg ip) applied 1 h prior to or 1 h after IPC failed to affect its protective effects. IPC had no direct effect on the cortex COX-2 mRNA and protein expression 72 h later, but decreased the expres sion of COX-2 mRNA and protein following ischemia and reperfusion insult. Conclusion: PGs pathways was not involved in triggering delayed neuroprotection by IPC, and IPC induced down-regulation of COX-2 following focal cerebral ischemia and reperfusion in rats in vivo.

  1. Role of Cyclooxygenase-2 on Intermittent Hypoxia-Induced Lung Tumor Malignancy in a Mouse Model of Sleep Apnea

    Science.gov (United States)

    Campillo, Noelia; Torres, Marta; Vilaseca, Antoni; Nonaka, Paula Naomi; Gozal, David; Roca-Ferrer, Jordi; Picado, César; Montserrat, Josep Maria; Farré, Ramon; Navajas, Daniel; Almendros, Isaac

    2017-01-01

    An adverse role for obstructive sleep apnea (OSA) in cancer epidemiology and outcomes has recently emerged from clinical and animal studies. In animals, intermittent hypoxia (IH) mimicking OSA promotes tumor malignancy both directly and via host immune alterations. We hypothesized that IH could potentiate cancer aggressiveness through activation of the cyclooxygenase-2 (COX-2) pathway and the concomitant increases in prostaglandin E2 (PGE2). The contribution of the COX-2 in IH-induced enhanced tumor malignancy was assessed using celecoxib as a COX-2 specific inhibitor in a murine model of OSA bearing Lewis lung carcinoma (LLC1) tumors. Exposures to IH accelerated tumor progression with a tumor associated macrophages (TAMs) shift towards a pro-tumoral M2 phenotype. Treatment with celecoxib prevented IH-induced adverse tumor outcomes by inhibiting IH-induced M2 polarization of TAMs. Furthermore, TAMs isolated from IH-exposed mice treated with celecoxib reduced the proliferation of LLC1 naïve cells, while the opposite occurred with placebo-treated IH-exposed mice. Finally, in vitro IH exposures of murine macrophages and LLC1 cells showed that both cell types increased PGE2 release in response to IH. These results suggest a crucial role for the COX-2 signaling pathway in the IH-exacerbated malignant processes, and designate macrophages and lung adenocarcinoma cells, as potential sources of PGE2. PMID:28300223

  2. DNA damage drives an activin a-dependent induction of cyclooxygenase-2 in premalignant cells and lesions.

    Science.gov (United States)

    Fordyce, Colleen; Fessenden, Tim; Pickering, Curtis; Jung, Jason; Singla, Veena; Berman, Hal; Tlsty, Thea

    2010-02-01

    Cyclooxygenase-2 (COX-2) catalyzes the rate-limiting step in the synthesis of prostaglandins. Its overexpression induces numerous tumor-promoting phenotypes and is associated with cancer metastasis and poor clinical outcome. Although COX-2 inhibitors are promising chemotherapeutic and chemopreventative agents for cancer, the risk of significant cardiovascular and gastrointestinal complications currently outweighs their potential benefits. Systemic complications of COX-2 inhibition could be avoided by specifically decreasing COX-2 expression in epithelial cells. To that end, we have investigated the signal transduction pathway regulating the COX-2 expression in response to DNA damage in breast epithelial cells. In variant human mammary epithelial cells that have silenced p16 (vHMEC), double-strand DNA damage or telomere malfunction results in a p53- and activin A-dependent induction of COX-2 and continued proliferation. In contrast, telomere malfunction in HMEC with an intact p16/Rb pathway induces cell cycle arrest. Importantly, in ductal carcinoma in situ lesions, high COX-2 expression is associated with high gammaH2AX, TRF2, activin A, and telomere malfunction. These data show that DNA damage and telomere malfunction can have both cell-autonomous and cell-nonautonomous consequences and can provide a novel mechanism for the propagation of tumorigenesis.

  3. Antiaggregatory effects of flavonoids in vivo and their influence on lipoxygenase and cyclooxygenase in vitro.

    Science.gov (United States)

    Swies, J; Robak, J; Dabrowski, L; Duniec, Z; Michalska, Z; Gryglewski, R J

    1984-01-01

    Quercetin, rutin and troxerutin were found to inhibit platelet aggregation on collagen strip superfused with blood of anesthetized cats. Quercetin was the most potent acting at the dose of 1 micrograms/kg. Its effect was shortlasting. Troxerutin was a weak inhibitor of platelet aggregation and its effect was delayed. Quercetin inhibited in 50% 15-lipoxygenase and 12-lipoxygenase in vitro at the concentration of 1.3 microm and 13 microM respectively. It stimulated cyclooxygenase when 100 microM of arachidonic acid was applied. Quercetin inhibited cyclooxygenase in the presence of 1.6 microM of substrate. Rutin was a weaker inhibitor of lipoxygenase. Troxerutin was inactive in all experiments in vitro. It is concluded that unusually strong effect of quercetin in vivo can be explained neither by its influence on cyclooxygenase nor on lipoxygenase because the effects in vitro were observed in much higher concentrations.

  4. [Cyclooxygenases inhibitors and other compounds with antiinflammatory potential in osteoarthrosis--part I].

    Science.gov (United States)

    Dzielska-Olczak, Małgorzata

    2011-01-01

    Nonsteroidal antiinflammatory drugs (NSAIDs) contain conventional nonselective drugs and selective inhibitors cyclooxygenase-2 (ICOX-2). NSAIDs frequently cause adverse effects tied with cyclooxygenases (COX, COXs) inhibition and prostaglandins (PG, PGs) synthesis, which exerts different physiological effects and are involved in the patophysiology of osteoarthritis. NSAIDs don't inhibit leucotriens (LT LTs) generation. Nonselective drugs cause detrimental results in the gastrointestinal tract. Selective COX-2 inhibitors exert thrombotic cardiovascular events and other negative effects in cardiovascular system. NSAIDs can intensify symptoms of OA and accelerate its progress. Analgetic and antiinflammatory properties possess also licofelone, a competitive inhibitor of cyclooxygenases and 5-lipooxygenase (5-LOX), which presents well gastrointestinal tract tolerability in contrast to NSAIDs. Licofelone decreases the production of proinflammatory leucotrienes and prostaglandins. Moreover inhibition of 5-lipooxygenase activity can delay of cartilago degradation.

  5. Cyclooxygenase-2 expression in the normal human eye and its expression pattern in selected eye tumours

    DEFF Research Database (Denmark)

    Wang, Jinmei; Wu, Yazhen; Heegaard, Steffen;

    2011-01-01

    using antibodies against COX-2 was performed on paraffin sections of normal human eyes and selected eye tumours arising from cells expressing COX-2. Results: Cyclooxygenase-2 expression was found in various structures of the normal eye. Abundant expression was seen in the cornea, iris, ciliary body......Purpose: Cyclooxygenase-2 (COX-2) is an enzyme involved in neoplastic processes. The purpose of the present study is to investigate COX-2 expression in the normal human eye and the expression pattern in selected eye tumours involving COX-2 expressing cells. Methods: Immunohistochemical staining...... and retina. The COX-2 expression was less in tumours deriving from the ciliary epithelium and also in retinoblastoma. Conclusion: Cyclooxygenase-2 is constitutively expressed in normal human eyes. The expression of COX-2 is much lower in selected eye tumours involving COX-2 expressing cells....

  6. Cyclooxygenase-2 expression is dependent upon epidermal growth factor receptor expression or activation in androgen independent prostate cancer

    Institute of Scientific and Technical Information of China (English)

    Rui-Peng Jia; Lu-Wei Xu; Qi Su; Jian-Hua Zhao; Wen-Cheng Li; Feng Wang; Zheng Xu

    2008-01-01

    Aim: To investigate the expression of cyclooxygenase-2 (COX-2) and epidermal growth factor receptor (EGFR) and the possible mechanism in the development in androgen independent prostate cancer (AIPC). Methods: Immunohis- tochemistry was performed on paraffin-embedded sections with goat polyclonal against COX-2 and mouse mono- clonal antibody against EGFR in 30 AIPC and 18 androgen dependent prostate cancer (ADPC) specimens. The effect of epidermal growth factor (EGF) treatments on the expression of COX-2 and signal pathway in PC-3 and DU-145 cells was studied using reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis. ELISA was used to measure prostaglandin E2 (PGE2) levels in the media of PC-3 and DU-145 incubated with EGF for 24 h. Results: COX-2 was positively expressed in AIPC and ADPC, which were predominantly in endochylema of prostate cancer (Pca) cells. Intense staining was seen in AIPC (80%) and in ADPC (55.5%), but there was no significant association between the two groups. EGFR expression was also positive in the two groups (61.8% in ADPC and 90% in AIPC, P < 0.01). A significant association was found between EGFR expression and a higher Gleason score (P < 0.05) or tumor stage (P < 0.05). The expression of PGE2 was increased in PC-3 and DU-145 cells after being incubated with EGF. Both p38MAPK and PI-3K pathway were involved in the PC-3 cell COX-2 upregulation course. In DU- 145, only p38MAPK pathway was associated with COX-2 upregulation. Conclusion: EGFR activation induces COX-2 expression through PI-3K and/or p38MAPK pathways. COX-2 and EGFR inhibitors might have a cooperative anti-tumor effect in Pca.

  7. In vitro and In Silico Studies on Curcumin and Its Analogues as Dual Inhibitors for cyclooxygenase-1 (COX-1 and cyclooxygenase-2 (COX-2

    Directory of Open Access Journals (Sweden)

    Nunung Yuniarti

    2012-03-01

    Full Text Available Curcumin has been widely reported as an anti-inflammatory agent isolated from the plant Curcuma longa L. (turmeric. This anti-inflammatory activity was associated with the ability of this compound to inhibit the activity of both cyclooxygenase-1 (COX-1 and cyclooxygenase-2 (COX-2 in arachidonic acid metabolism. Dual COX-1 and COX-2 inhibitors are preferred to be employed in the therapy of chronic inflammatory diseases compared to selective inhibitors, since it was reported that the use of selective inhibitors led to severe adverse side effect. In the present study, in vitro and in silico assays on curcumin and its analogues as dual inhibitors for both COX-1 and COX-2 were performed. The results provide theoretical contribution in understanding the ligand-protein interactions at the molecular level to develop new curcumin analogues which possess better anti-inflammatory activity as well as to avoid unsolicited side effects.

  8. Imaging of cyclooxygenase-2 (COX-2) expression : Potential use in diagnosis and drug evaluation

    NARCIS (Netherlands)

    de Vries, E. F. J.

    2006-01-01

    Cyclooxygenase is an enzyme that catalyzes the first two steps in the biosynthesis of prostanoids. The constitutively expressed isoform COX-1 is regarded as a housekeeping enzyme that is responsible for the normal production of prostanoids. The inducible isoform COX-2, on the other hand, is transien

  9. Expression of cyclooxygenase-2 in intestine of pigs of different ages and hygiene status

    DEFF Research Database (Denmark)

    Lauridsen, Charlotte; Whiting, C; Lewis, M;

    2010-01-01

    Prostaglandins (PG) are bioactive lipids derived from the metabolism of membrane polyunsaturated fatty acids (PUFA), and play important roles in a number of biological processes including cell division, immune responses and wound healing. Cyclooxygenase (COX) is the key enzyme in PG synthesis fro...

  10. Aromatase, cyclooxygenase 2, HER-2/neu, and p53 as prognostic factors in endometrioid endometrial cancer

    NARCIS (Netherlands)

    Jongen, Vincent H. W. M.; Briet, Justine M.; de Jong, Renske A.; Joppe, Erna; ten Hoor, Klaske A.; Boezen, H. M.; Evans, Dean B.; Hollema, Harry; van der Zee, Ate G. J.; Nijman, Hans W.

    2009-01-01

    The prognostic value of aromatase, cyclooxygenase 2 (COX-2), HER-2/neu, and p53 expression was determined in endometrioid endometrial cancer. Tissue microarrays were constructed comprising samples from 315 endometrioid endometrial cancer patients. Expression of aromatase, COX-2, HER-2/neu, and p53 w

  11. β-Adrenergic-mediated vasodilation in young men and women: cyclooxygenase restrains nitric oxide synthase.

    Science.gov (United States)

    Limberg, Jacqueline K; Johansson, Rebecca E; Peltonen, Garrett L; Harrell, John W; Kellawan, J Mikhail; Eldridge, Marlowe W; Sebranek, Joshua J; Schrage, William G

    2016-03-15

    We tested the hypothesis that women exhibit greater vasodilator responses to β-adrenoceptor stimulation compared with men. We further hypothesized women exhibit a greater contribution of nitric oxide synthase and cyclooxygenase to β-adrenergic-mediated vasodilation compared with men. Forearm blood flow (Doppler ultrasound) was measured in young men (n = 29, 26 ± 1 yr) and women (n = 33, 25 ± 1 yr) during intra-arterial infusion of isoproterenol (β-adrenergic agonist). In subset of subjects, isoproterenol responses were examined before and after local inhibition of nitric oxide synthase [N(G)-monomethyl-l-arginine (l-NMMA); 6 male/10 female] and/or cyclooxygenase (ketorolac; 5 male/5 female). Vascular conductance (blood flow ÷ mean arterial pressure) was calculated to assess vasodilation. Vascular conductance increased with isoproterenol infusion (P 0.99) or women (P = 0.21). In contrast, ketorolac infusion markedly increased isoproterenol-mediated responses in both men (P vasodilation is not different between men and women and sex differences in the independent contribution of nitric oxide synthase and cyclooxygenase to β-mediated vasodilation are not present. However, these data are the first to demonstrate β-adrenoceptor activation of cyclooxygenase suppresses nitric oxide synthase signaling in human forearm microcirculation and may have important implications for neurovascular control in both health and disease.

  12. Differential regulation of renal cyclooxygenase mRNA by dietary salt intake

    DEFF Research Database (Denmark)

    Jensen, B L; Kurtz, A

    1997-01-01

    RNA correlated directly with salt intake. We conclude that dietary salt intake influences renal cyclooxygenase mRNAs zone-specifically with opposite responses between cortex and medulla. Cortical COX II-mediated prostaglandin formation is probably important in low salt states whereas medullary COX I...

  13. Disruption of cyclooxygenase type 2 exacerbates apoptosis and renal damage during obstructive nephropathy

    DEFF Research Database (Denmark)

    Nilsson, Line; Madsen, Kirsten; Krag, Søren Rasmus Palmelund;

    2015-01-01

    Renal oxidative stress is increased in response to ureteral obstruction. In vitro, cyclooxygenase (COX)-2 activity contributes to protection against oxidants. In the present study, we tested the hypothesis that COX-2 activity counters oxidative stress and apoptosis in an in vivo model...

  14. Cyclooxygenase-2 inhibitory and antioxidant compounds from the truffle Elaphomyces granulatus

    Science.gov (United States)

    Rita Stanikunaite; Shabana I. Khan; James M. Trappe; Samir A. Ross

    2009-01-01

    The ethanol extract of fruiting bodies of Elaphomyces granulatus, a truffle-like fungus, was evaluated for cyclooxygenase-2 (COX-2) enzyme inhibitory and antioxidant activities. Inhibition of COX-2 activity was evaluated in mouse macrophages (RAW 264.7). The extract of E. granulatus caused a 68% inhibition of COX-2 activity at...

  15. Cyclooxygenase-2 expression in the normal human eye and its expression pattern in selected eye tumours

    DEFF Research Database (Denmark)

    Wang, Jinmei; Wu, Yazhen; Heegaard, Steffen;

    2011-01-01

    and retina. The COX-2 expression was less in tumours deriving from the ciliary epithelium and also in retinoblastoma. Conclusion: Cyclooxygenase-2 is constitutively expressed in normal human eyes. The expression of COX-2 is much lower in selected eye tumours involving COX-2 expressing cells....

  16. Cyclooxygenase-2 contributes to elevated renin in the early postnatal period in rats

    DEFF Research Database (Denmark)

    Stubbe, Jane; Jensen, Boye L; Bachmann, Sebastian;

    2003-01-01

    We asked whether cyclooxygenase (COX) activity controls the renin-angiotensin system in the postnatal period. During kidney development, renin peaked at postnatal days 0-1 at the mRNA, tissue protein [renal renin concentration (RRC)], and plasma renin concentration (PRC) levels and was widely...

  17. Cyclooxygenase-2 inhibitor is a robust enhancer of anticancer agents against hepatocellular carcinoma multicellular spheroids

    Directory of Open Access Journals (Sweden)

    Cui J

    2014-02-01

    Full Text Available Jie Cui,1,2 Ya-Huan Guo,3 Hong-Yi Zhang,4 Li-Li Jiang,1 Jie-Qun Ma,1 Wen-Juan Wang,1 Min-Cong Wang,1 Cheng-Cheng Yang,1 Ke-Jun Nan,1 Li-Ping Song5 1Department of Oncology, First Affiliated Hospital, College of Medicine of Xi'an Jiaotong University, Xi'an, 2Department of Oncology, Yan'an University Affiliated Hospital, Yan'an, 3Department of Oncology, Shaanxi Province Cancer Hospital, Xi'an, 4Department of Urology, Yan'an University Affiliated Hospital, Yan'an, 5Department of Radiotherapy, First Affiliated Hospital, College of Medicine of Xi'an Jiaotong University, Xi'an, People's Republic of China Purpose: Celecoxib, an inhibitor of cyclooxygenase-2 (COX2, was investigated for enhancement of chemotherapeutic efficacy in cancer clinical trials. This study aimed to determine whether celecoxib combined with 5-fluorouracil or sorafenib or gefitinib is beneficial in HepG2 multicellular spheroids (MCSs, as well as elucidate the underlying mechanisms. Methods: The human hepatocellular carcinoma cell line HepG2 MCSs were used as in vitro models to investigate the effects of celecoxib combined with 5-fluorouracil or sorafenib or gefitinib treatment on cell growth, apoptosis, and signaling pathway. Results: MCSs showed resistance to drugs compared with monolayer cells. Celecoxib combined with 5-fluorouracil or sorafenib exhibited a synergistic action. Exposure to celecoxib (21.8 µmol/L plus 5-fluorouracil (8.1 × 10-3 g/L or sorafenib (4.4 µmol/L increased apoptosis but exerted no effect on COX2, phosphorylated epidermal growth-factor receptor (p-EGFR and phosphorylated (p-AKT expression. Gefitinib (5 µmol/L, which exhibits no growth-inhibition activity as a single agent, increased the inhibitory effect of celecoxib. Gefitinib (5 µmol/L plus celecoxib (21.8 µmol/L increased apoptosis. COX2, p-EGFR, and p-AKT were inhibited. Conclusion: Celecoxib combined with 5-fluorouracil or sorafenib or gefitinib may be superior to single-agent therapy in HepG2

  18. Hypoxia stimulates prostacyclin synthesis in newborn pulmonary artery endothelium by increasing cyclooxygenase-1 protein.

    Science.gov (United States)

    North, A J; Brannon, T S; Wells, L B; Campbell, W B; Shaul, P W

    1994-07-01

    In newborn lambs, pulmonary prostacyclin (PGI2) production increases acutely in response to low oxygen. We tested the hypothesis that decreased oxygenation directly stimulates PGI2 synthesis in arterial segments and cultured endothelial cells from newborn lamb intrapulmonary arteries. In segments studied at PO2 of 680 mm Hg, the synthesis of PGI2 exceeded prostaglandin E2 (PGE2) by 73%. Endothelium removal lowered PGI2 by 77% and PGE2 by 66%. At low oxygen tension (PO2, 40 mm Hg), PGI2 and PGE2 synthesis rose by 96% and 102%, respectively. Similarly, in endothelial cells studied at PO2 of 680 mm Hg, the synthesis of PGI2 exceeded PGE2 by 50%, and at low oxygen tension both PGI2 and PGE2 increased (89% and 64%, respectively). Endothelial cell PGI2 synthesis maximally stimulated by bradykinin, A23187, or arachidonic acid was also increased at low PO2 by 50%, 66%, and 48%, respectively. PGE2 synthesis was similarly altered, increasing by 33%, 37%, and 41%, respectively. In contrast, lowering oxygen had minimal effect on PGI2 and PGE2 synthesis with exogenous PGH2, which is the product of cyclooxygenase. Immunoblot analyses revealed that there was a 2.6-fold greater abundance of cyclooxygenase-1 protein at PO2 of 40 versus 680 mm Hg, and the increase at lower oxygen tension was inhibited by cycloheximide. The cyclooxygenase-2 isoform was not detected. Thus, attenuated oxygenation directly stimulates PGI2 and PGE2 synthesis in intrapulmonary arterial segments and endothelial cells from newborn lambs. This process is due to enhanced cyclooxygenase activity related to increased abundance of the cyclooxygenase-1 protein, and this effect may be due to increased synthesis of the enzyme protein.

  19. The Target of 5-Lipoxygenase is a Novel Strategy over Human Urological Tumors than the Target of Cyclooxygenase-2

    Directory of Open Access Journals (Sweden)

    Masahide Matsuyama

    2008-01-01

    Full Text Available The metabolism of arachidonic acid by either the cyclooxygenase (COX or lipoxygenase (LOX pathway generates eicosanoids, which have been implicated in the pathogenesis of a variety of human diseases, including cancer. It is now considered that they play important roles in tumor promotion, progression, and metastasis, also, the involvement of COX and LOX expression and function in tumor growth and metastasis has been reported in human tumor cell lines. In this study, we examined the expression of COX and LOX in human urological tumors (renal cell carcinoma, bladder tumor, prostate cancer, testicular cancer by immunohistochemistry and RT-PCR, and we also examined the effects of COX and LOX (5- and 12-LOX inhibitors in those cells by MTT assay, hoechest staining, and flow cytometry. COX-2, 5-LOX and 12-LOX expressions were significantly more extensive and intense in malignant tissues than in normal tissues. Furthermore, 5-LOX inhibitor induced the reduction of malignant cell viability through early apoptosis. These results demonstrated COX-2 and LOX were induced in urological tumors, and 5-LOX inhibitor may mediate potent antiproliferative effects against urological tumors cells. Thus, 5-LOX may become a new target in the treatment of urological tumors.

  20. A novel sulindac derivative lacking cyclooxygenase-inhibitory activities suppresses carcinogenesis in the transgenic adenocarcinoma of mouse prostate model.

    Science.gov (United States)

    Zhang, Yong; Zhang, Jinhui; Wang, Lei; Quealy, Emily; Gary, Bernard D; Reynolds, Robert C; Piazza, Gary A; Lü, Junxuan

    2010-07-01

    Nonsteroidal anti-inflammatory drugs including sulindac are well documented to be highly effective for cancer chemoprevention. However, their cyclooxygenase (COX)-inhibitory activities cause severe gastrointestinal, renal, and cardiovascular toxicities, limiting their chronic use. Recent studies suggest that COX-independent mechanisms may be responsible for the chemopreventive benefits of nonsteroidal anti-inflammatory drugs and support the potential for the development of a novel generation of sulindac derivatives lacking COX inhibition for cancer chemoprevention. A prototypic sulindac derivative with a N,N-dimethylammonium substitution called sulindac sulfide amide (SSA) was recently identified to be devoid of COX-inhibitory activity yet displays much more potent tumor cell growth-inhibitory activity in vitro compared with sulindac sulfide. In this study, we investigated the androgen receptor (AR) signaling pathway as a potential target for its COX-independent antineoplastic mechanism and evaluated its chemopreventive efficacy against prostate carcinogenesis using the transgenic adenocarcinoma of mouse prostate model. The results showed that SSA significantly suppressed the growth of human and mouse prostate cancer cells expressing AR in strong association with G(1) arrest, and decreased AR level and AR-dependent transactivation. Dietary SSA consumption dramatically attenuated prostatic growth and suppressed AR-dependent glandular epithelial lesion progression through repressing cell proliferation in the transgenic adenocarcinoma of mouse prostate mice, whereas it did not significantly affect neuroendocrine carcinoma growth. Overall, the results suggest that SSA may be a chemopreventive candidate against prostate glandular epithelial carcinogenesis.

  1. The Target of 5-Lipoxygenase is a Novel Strategy over Human Urological Tumors than the Target of Cyclooxygenase-2

    Directory of Open Access Journals (Sweden)

    Masahide Matsuyama

    2008-06-01

    Full Text Available The metabolism of arachidonic acid by either the cyclooxygenase (COX or lipoxygenase (LOX pathway generates eicosanoids, which have been implicated in the pathogenesis of a variety of human diseases, including cancer. It is now considered that they play important roles in tumor promotion, progression, and metastasis, also, the involvement of COX and LOX expression and function in tumor growth and metastasis has been reported in human tumor cell lines. In this study, we examined the expression of COX and LOX in human urological tumors (renal cell carcinoma, bladder tumor, prostate cancer, testicular cancer by immunohistochemistry and RT-PCR, and we also examined the effects of COX and LOX (5- and 12-LOX inhibitors in those cells by MTT assay, hoechest staining, and flow cytometry. COX-2, 5-LOX and 12-LOX expressions were significantly more extensive and intense in malignant tissues than in normal tissues. Furthermore, 5-LOX inhibitor induced the reduction of malignant cell viability through early apoptosis. These results demonstrated COX-2 and LOX were induced in urological tumors, and 5-LOX inhibitor may mediate potent antiproliferative effects against urological tumors cells. Thus, 5-LOX may become a new target in the treatment of urological tumors.

  2. New analogues of 13-hydroxyocatdecadienoic acid and 12-hydroxyeicosatetraenoic acid block human blood platelet aggregation and cyclooxygenase-1 activity

    Directory of Open Access Journals (Sweden)

    Hirz Taghreed

    2012-12-01

    Full Text Available Abstract Background Thromboxane A2 is derived from arachidonic acid through the action of cyclooxygenases and thromboxane synthase. It is mainly formed in blood platelets upon activation and plays an important role in aggregation. Aspirin is effective in reducing the incidence of complications following acute coronary syndrome and stroke. The anti-thrombotic effect of aspirin is obtained through the irreversible inhibition of cyclooxygenases. Analogues of 12-hydroxyeicosatetraenoic acid and 13-hydroxyocatdecadienoic acid were shown previously to modulate platelet activation and to block thromboxane receptors. Results and discussion We synthesized 10 compounds based on the structures of analogues of 12-hydroxyeicosatetraenoic acid and 13-hydroxyocatdecadienoic acid and evaluated their effect on platelet aggregation triggered by arachidonic acid. The structure activity relationship was evaluated. Five compounds showed a significant inhibition of platelet aggregation and highlighted the importance of the lipidic hydrophobic hydrocarbon chain and the phenol group. Their IC50 ranged from 7.5 ± 0.8 to 14.2 ± 5.7 μM (Mean ± S.E.M.. All five compounds decreased platelet aggregation and thromboxane synthesis in response to collagen whereas no modification of platelet aggregation in response to thromboxane receptor agonist, U46619, was observed. Using COS-7 cells overexpressing human cyclooxygenase-1, we showed that these compounds are specific inhibitors of cyclooxygenase-1 with IC50 ranging from 1.3 to 12 μM. Docking observation of human recombinant cyclooxygenase-1 supported a role of the phenol group in the fitting of cyclooxygenase-1, most likely related to hydrogen bonding with the Tyr 355 of cyclooxygenase-1. Conclusions In conclusion, the compounds we synthesized at first based on the structures of analogues of 12 lipoxygenase metabolites showed a role of the phenol group in the anti-platelet and anti-cyclooxygenase-1 activities

  3. HEMOSTATIC FUNCTION OF ASPIRIN-TREATED PLATELETS VULNERABLE TO CARDIOPULMONARY BYPASS - ALTERED SHEAR-INDUCED PATHWAY

    NARCIS (Netherlands)

    TABUCHI, N; HUET, RCGG; STURK, A; EIJSMAN, L; WILDEVUUR, CRH

    1995-01-01

    The impaired hemostasis of aspirin-treated patients is an annoying problem during and after cardiopulmonary bypass, The hemostatic function of platelets comprises two mechanisms: the shear-induced and the cyclooxygenase pathways, Because the latter is inhibited in aspirin-treated patients, the hemos

  4. Involvement of cyclooxygenase-1 and cyclooxygenase-2 activity in the therapeutic effect of ghrelin in the course of ethanol-induced gastric ulcers in rats.

    Science.gov (United States)

    Warzecha, Z; Ceranowicz, P; Dembinski, M; Cieszkowski, J; Ginter, G; Ptak-Belowska, A; Dembinski, A

    2014-02-01

    Previous studies have shown that treatment with ghrelin exhibits protective and therapeutic effects in the gut. Aim of our present investigation was to examine the influence of ghrelin administration on the healing of ethanol-induced gastric ulcers and determine the role of cyclooxygenase-1 and cyclooxygenase-2 in this effect. Our studies were performed on male Wistar rats. Gastric ulcers were induced by intragastric administration of 75% ethanol. Ghrelin alone or in combination with cyclooxygenase inhibitors was administered twice, 1 and 13 hours after ethanol application. Cyclooxygenase-1 (COX-1) inhibitor (SC-560, 10 mg/kg/dose) or COX-2 inhibitor (celecoxib, 10 mg/kg/dose) were given 30 min prior to ghrelin. Twelve or 24 hours after administration of ethanol, rats were anesthetized and experiments were terminated. The study revealed that administration of ethanol induced gastric ulcers in all animals and this effect was accompanied by the reduction in gastric blood flow and mucosal DNA synthesis. Moreover induction of gastric ulcer by ethanol significantly increased mucosal expression of mRNA for COX-2, IL-1β and TNF-α. Treatment with ghrelin significantly accelerated gastric ulcer healing. Therapeutic effect of ghrelin was associated with significant reversion of the ulcer-evoked decrease in mucosal blood flow and DNA synthesis. Ghrelin administration also caused the reduction in mucosal expression of mRNA for IL-1β and TNF-α. Addition of SC-560 slightly reduced the therapeutic effect of ghrelin in the healing of ethanol-induced ulcer and the ulcer area in rats treated SC-560 plus ghrelin was significantly smaller than that observed in rats treated with saline or SC-560 alone. Pretreatment with celecoxib, a COX-2 inhibitor, abolished therapeutic effect of ghrelin. We concluded that treatment with ghrelin increases healing rate of gastric ulcers evoked by ethanol and this effect is related to improvement in mucosal blood flow, an increase in mucosal cell

  5. Opposing Effects of Cyclooxygenase-2 (COX-2) on Estrogen Receptor β (ERβ) Response to 5α-Reductase Inhibition in Prostate Epithelial Cells.

    Science.gov (United States)

    Liu, Teresa T; Grubisha, Melanie J; Frahm, Krystle A; Wendell, Stacy G; Liu, Jiayan; Ricke, William A; Auchus, Richard J; DeFranco, Donald B

    2016-07-08

    Current pharmacotherapies for symptomatic benign prostatic hyperplasia (BPH), an androgen receptor-driven, inflammatory disorder affecting elderly men, include 5α-reductase (5AR) inhibitors (i.e. dutasteride and finasteride) to block the conversion of testosterone to the more potent androgen receptor ligand dihydrotestosterone. Because dihydrotestosterone is the precursor for estrogen receptor β (ERβ) ligands, 5AR inhibitors could potentially limit ERβ activation, which maintains prostate tissue homeostasis. We have uncovered signaling pathways in BPH-derived prostate epithelial cells (BPH-1) that are impacted by 5AR inhibition. The induction of apoptosis and repression of the cell adhesion protein E-cadherin by the 5AR inhibitor dutasteride requires both ERβ and TGFβ. Dutasteride also induces cyclooxygenase type 2 (COX-2), which functions in a negative feedback loop in TGFβ and ERβ signaling pathways as evidenced by the potentiation of apoptosis induced by dutasteride or finasteride upon pharmacological inhibition or shRNA-mediated ablation of COX-2. Concurrently, COX-2 positively impacts ERβ action through its effect on the expression of a number of steroidogenic enzymes in the ERβ ligand metabolic pathway. Therefore, effective combination pharmacotherapies, which have included non-steroidal anti-inflammatory drugs, must take into account biochemical pathways affected by 5AR inhibition and opposing effects of COX-2 on the tissue-protective action of ERβ.

  6. Phosphorylation of STAT3 mediates the induction of cyclooxygenase-2 by cortisol in the human amnion at parturition.

    Science.gov (United States)

    Wang, Wangsheng; Guo, Chunming; Zhu, Ping; Lu, Jiangwen; Li, Wenjiao; Liu, Chao; Xie, Huiliang; Myatt, Leslie; Chen, Zi-Jiang; Sun, Kang

    2015-10-27

    The induction of cyclooxygenase-2 (COX-2) and subsequent production of prostaglandin E2 (PGE2) by cortisol in the amnion contrast with the effect of cortisol on most other tissues, but this proinflammatory effect of cortisol may be a key event in human parturition (labor). We evaluated the underlying mechanism activated by cortisol in primary human amnion fibroblasts. Exposure of the amnion fibroblasts to cortisol led to the activation of the cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA) pathway, which induced the phosphorylation of the kinase SRC and STAT3 (signal transducer and activator of transcription 3). STAT3 interacted with the glucocorticoid receptor (GR) and the transcription factor CREB-1 (cAMP response element-binding protein 1) at the promoter of the gene encoding COX-2, which promoted the production of the secreted prostaglandin PGE2. PGE2 activates the prostaglandin receptors EP2 and EP4, which stimulate cAMP-PKA signaling. Thus, cortisol reinforced the activation of cAMP-PKA signaling through an SRC-STAT3-COX-2-PGE2-mediated feedback loop. Inhibiting STAT3, SRC, or the cAMP-PKA pathway attenuated the cortisol-stimulated induction of COX-2 and PGE2 production in amnion fibroblasts. In human amnion tissue, the amount of phosphorylated STAT3 correlated positively with that of cortisol, COX-2, and PGE2, and all were more abundant in tissue obtained after active labor than in tissue obtained from cesarean surgeries in the absence of labor. These results indicated that the coordinated recruitment of STAT3, CREB-1, and GR to the promoter of the gene encoding COX-2 contributes to the feed-forward induction of COX-2 activity and prostaglandin synthesis in the amnion during parturition.

  7. Evaluation of 2 celecoxib derivatives: analgesic effect and selectivity to cyclooxygenase-2/1

    Institute of Scientific and Technical Information of China (English)

    Zhi-hong LU; Xiao-yun XIONG; Bang-le ZHANG; Guo-cheng LIN; Yu-xiang SHI; Zhen-guo LIU; Jing-ru MENG; Yu-mei ZHOU; Qi-bing MEI

    2005-01-01

    Aim: To evaluate the analgesic effects of 2 celecoxib derivatives and their inhibitory effects on cyclooxygenase (COX). Methods: Four antinociceptive assays were used: the acetic acid-induced writhing test, hot plate test, hot tail-flick test and formalin test. Three doses were used in the analgesic assays and ED50 values were calculated. For the selectivity assay, macrophages were incubated with test compounds at various concentrations and then stimulated with calcimycin or lipopolysaccharide (LPS). The amounts of 6-keto-prostaglandin F1α (6-keto-PGF1α)and prostaglandin E2 (PGE2) in the supernatant were examined by radioimmunoassay (RIA). The selectivity of the test compounds was expressed as the IC50,COX-1/IC50,COX-2 value. Results: Celecoxib and its 2 derivatives had a significant analgesic effect. The ED50 values of celecoxib, PC-406 and PC-407 were 94.2, 67.9, and 63.3mg/kg, respectively, for the acetic acid-induced writhing test; 104.7, 89.1, and 30.0mg/kg, respectively, for the hot tail-flick response test; 60.7, 56.7, and 86.2 mg/kg,respectively, for the hot plate response test; 67.1,55.8, and 68.8 mg/kg, respectively,for the formalin-induced response. That is, the ED50 of PC-406 was the lowest for the formalin and hot plate tests, which focus on changes above the spinal cord level; however, the ED50 of PC-407 was lowest for the tail-flick and writhing tests,which focus on changes at the spinal cord level. Celecoxib and PC-407 inhibited COX-1 with IC50 values of 39.8 and 27.5 nmol/L, respectively. PC-406 inhibited COX-1 with an IC50 value of more than 1000 nmol/L. The IC50 values for the effect of celecoxib, PC-406 and PC-407 on COX-2 were 4.8, 8.9, and 1.9 nmol/L respectively.The IC50,COX-1/IC50,COX-2 ratios for celecoxib and PC-407 were 8.3 and 14.4, respectively. For PC-406, the ratio was greater than 112.2. Conclusion: Derivatives of celecoxib via substitution with an isopropyl or naphthyl group at the 5 position in the pyrazole ring still have

  8. Oxidative stress and cyclooxygenase activity in prostate carcinogenesis: targets for chemopreventive strategies.

    Science.gov (United States)

    Pathak, S K; Sharma, R A; Steward, W P; Mellon, J K; Griffiths, T R L; Gescher, A J

    2005-01-01

    Over the last decade, epidemiological, experimental and clinical studies have implicated oxidative stress in the development and progression of prostate cancer. Oxidative stress may be linked to the effects of androgens, anti-oxidant systems and the pre-malignant condition, high-grade prostatic intraepithelial neoplasia. Cyclooxygenase-2 activity has been linked with prostate carcinogenesis. Evidence suggests that oxidative stress and cyclo-oxygenase-2 activity may be mechanistically linked. Agents such as anti-oxidants and cyclo-oxgenase-2 inhibitors may be of value in the chemoprevention of prostate cancer. The feasibility of intervention with such agents will depend on the development and validation of biomarkers for clinical trials, particularly markers of oxidative damage caused by reactive oxygen species (ROS). A greater understanding of the molecular events associated with oxidative stress will enhance the development of such biomarkers and should result in better strategies for the chemoprevention of prostate cancer.

  9. Evaluation of anticonvulsant effect of celecoxib, a selective cyclooxygenase-2 inhibitor in experimentally induced convulsions in albino rats

    OpenAIRE

    Mohammed Naseeruddin Nadeem; Maliha Maqdoom

    2016-01-01

    Background: Cyclooxygenase-2 (COX-2) exists as the inducible form of the cyclooxygenase enzyme, the levels of which are elevated in inflammatory conditions. COX-2 is located in regions of brain like hippocampus and cerebral cortex. When induced, COX-2 forms prostaglandin E2 (PGE2), which is responsible for CNS excitation, in turn leading to generation of seizures. COX-2 inhibitors by preventing the formation of PGE2 may serve as effective anticonvulsants. Since none of the anti-epileptics in ...

  10. Inhibition of Cyclooxygenase-2 Reduces Hypothalamic Excitation in Rats with Adriamycin-Induced Heart Failure

    OpenAIRE

    2012-01-01

    BACKGROUND: The paraventricular nucleus (PVN) of the hypothalamus plays an important role in the progression of heart failure (HF). We investigated whether cyclooxygenase-2 (COX-2) inhibition in the PVN attenuates the activities of sympathetic nervous system (SNS) and renin-angiotensin system (RAS) in rats with adriamycin-induced heart failure. METHODOLOGY/PRINCIPAL FINDING: Heart failure was induced by intraperitoneal injection of adriamycin over a period of 2 weeks (cumulative dose of 15 mg...

  11. Cyclo-Oxygenase 2 Modulates Chemoresistance in Breast Cancer Cells Involving NF-κB

    Directory of Open Access Journals (Sweden)

    Maria Chiara Zatelli

    2009-01-01

    Full Text Available Background: Breast cancer cells can develop chemoresistance after prolonged exposure to cytotoxic drugs due to expression of the multi drug resistance (MDR 1 gene. Type 2 cyclo-oxygenase (COX-2 inhibitors reverse the chemoresistance phenotype of a medullary thyroid carcinoma cell line, TT, and of a breast cancer cell line, MCF7, by inhibiting MDR1 expression and P-gp function.

  12. The relationship between angiogenesis and cyclooxygenase-2 expression in prostate cancer

    OpenAIRE

    Mukherjee, R.; Edwards, J; Underwood, M.A.; Bartlett, J M S

    2005-01-01

    OBJECTIVE: To test the hypothesis that angiogenesis in prostate cancer is associated with tumour invasion and metastasis, and that this is mediated through increased cyclooxygenase-2 (COX-2) expression.\\ud \\ud PATIENTS AND METHODS: Angiogenesis was assessed in 105 patients with either prostate cancer (79) or benign prostatic hyperplasia (BPH, 26) and these data correlated with levels of COX-2 expression in the same dataset. The mean microvessel density (MVD) was analysed as a marker of angiog...

  13. Regulation of bombesin-stimulated cyclooxygenase-2 expression in prostate cancer cells

    OpenAIRE

    Ives Kirk; Chao Celia; Wen Xiaodong; Hellmich Mark R

    2011-01-01

    Abstract Background Cyclooxygenase-2 (COX-2) and the bombesin (BBS)-like peptide, gastrin-releasing peptide (GRP), have been implicated in the progression of hormone-refractory prostate cancer; however, a mechanistic link between the bioactive peptide and COX-2 expression in prostate cells has not been made. Results We report that BBS stimulates COX-2 mRNA and protein expression, and the release of prostaglandin E2 from the GRP receptor (GRPR)-positive, androgen-insensitive prostate cancer ce...

  14. Synthesis and biological evaluation of 3-amino-2-pyrones as selective cyclooxygenase-1 (COX-1) inhibitors

    Institute of Scientific and Technical Information of China (English)

    Xue-Ping Chu; Qing-Fa Zhou; Shen Zhao; Fei-Fei Ge; Mian Fu; Jia-Peng Chen; Tao Lu

    2013-01-01

    A group of 3-amino-2-pyrones were synthesized and their biological activities were evaluated for inhibiting cyclooxygenase (COX) activity.This study has led to the identification of COX-1-selective inhibitors.Among the tested compounds,the compound 5j exhibited the most potent COX-1 inhibitory activity (IC50 =19.32 μg/mL) and COX-1 selectivity index (SI =41.98).

  15. Reduced esophageal cancer incidence in statin users,particularly with cyclo-oxygenase inhibition

    Institute of Scientific and Technical Information of China (English)

    Ian; Leonard; Phillip; Beales; Abigail; Hensley; Yoon; Loke

    2013-01-01

    AIM:To examine the association between statin use and the development of esophageal cancer METHODS:We performed a systematic review and meta-analysis.Multiple databases(Pubmed,EMBASE,Cochrane Library,Web of Science,Wiley Interscience and Google Scholar) were systematically searched for studies reporting the association of statin use and the development of esophageal cancer.Literature searching and data abstraction were performed independently by two separate researchers.The quality of studies reviewed was evaluated using the Newcastle-Ottawa Quality assessment scale.Meta-analysis on the relationship between statin use and cancer incidence was performed.The effect of the combination of statin plus a cyclo-oxygenase inhibitor was also examined.RESULTS:Eleven studies met eligibility criteria,9 high and 2 medium quality.All were observational studies.Studies examining adenocarcinoma development in Barrett’s esophagus included 317 cancers and 1999 controls,population-based studies examining all esophageal cancers included 371203 cancers and 6083150 controls.In the Barrett’s population the use of statins(OR = 0.57;95%CI:0.43-0.75) and cyclo-oxygenase inhibitors(OR = 0.59;95%CI:0.45-0.77) were independently associated with a reduced incidence of adenocarcinoma.Combined use of a statin plus cyclooxygenase inhibitor was associated with an even lower adenocarcinoma incidence(OR = 0.26;95%CI:0.1-0.68).There was more heterogeneity in the population-based studies but pooled adjusted data showed that statin use was associated with a lower incidence of all combined esophageal cancers(OR = 0.81;95%CI:0.75-0.88).CONCLUSION:Statin use in patients with Barrett’s oesophagus is associated with a significantly lower incidence of adenocarcinoma.The chemopreventive actions of statins,especially combined with cyclooxygenase inhibitors deserve further exploration.

  16. Expression of cyclooxygenase-1 and -2 in normal and glaucomatous human eyes

    OpenAIRE

    Maihöfner, C; Schlötzer-Schrehardt, U; Gühring, H; Zeilhofer, H U; Naumann, G O; Pahl, A; Mardin, C.; Tamm, E R; Brune, K

    2001-01-01

    PURPOSE: Primary open-angle glaucoma (POAG) is the predominant form of chronic glaucoma, but the underlying pathologic mechanisms are largely unknown. Because prostaglandins (PGs) have been introduced into POAG treatment with remarkable success, this study was undertaken to investigate whether a change in the expression of the PG-synthesizing enzymes cyclooxygenase (COX)-1 and -2 might be involved in the pathogenesis of POAG. METHODS: Expression of COX-1 and -2 was assessed by confocal laser ...

  17. Comparative analysis of clinicopathological correlations of cyclooxygenase-2 expression in resectable pancreatic cancer

    Institute of Scientific and Technical Information of China (English)

    Marketa; Hermanova; Petr; Karasek; Jiri; Tomasek; Jiri; Lenz; Jiri; Jarkovsky; Petr; Dite

    2010-01-01

    AIM:To perform a comparative analysis of clinicopathological correlations of cyclooxygenase2 (COX2) expression in pancreatic cancer, examined by monoclonal and polyclonal antibodies.METHODS: The COX2 expression in 85 resection specimens of pancreatic ductal adenocarcinoma was immunohistochemically examined using both monoclonal and polyclonal antibodies. The final immunoscores were obtained by multiplying the percentage of positive cells with the numeric score reflecting the staining intensity.COX2 expressi...

  18. Selective cyclooxygenase-2 inhibition protects against myocardial damage in experimental acute ischemia

    Directory of Open Access Journals (Sweden)

    Alberto Carnieto Jr.

    2009-03-01

    Full Text Available BACKGROUND: Acute myocardial infarction is associated with tissue inflammation. Early coronary reperfusion clearly improves the outcome but may help propagate the inflammatory response and enhance tissue damage. Cyclooxygenase-2 is an enzyme that catalyzes the initial step in the formation of inflammatory prostaglandins from arachidonic acid. Cyclooxygenase-2 levels are increased when ischemic cardiac events occur. The overall function of COX-2 in the inflammatory process generated by myocardial ischemic damage has not yet been elucidated. GOAL: The objective of this study was to determine whether a selective cyclooxygenase-2 inhibitor (rofecoxib could alter the evolution of acute myocardial infarction after reperfusion. METHODS AND RESULTS: This study was performed with 48 mongrel dogs divided into two groups: controls and those treated with the drug. All animals were prepared for left anterior descending coronary artery occlusion. The dogs then underwent 180 minutes of coronary occlusion, followed by 30 minutes of reperfusion. Blood samples were collected from the venous sinus immediately before coronary occlusion and after 30 minutes of reperfusion for measurements of CPK-MB, CPK-MBm and troponin I. During the experiment we observed the mean blood pressure, heart rate and coronary flow. The coronary flow and heart rate did not change, but in the control group, there was blood pressure instability, in addition to maximal levels of CPK-MB post-infarction. The same results were observed for CPK-MBm and troponin I. CONCLUSION: In a canine model of myocardial ischemia-reperfusion, selective inhibition of Cyclooxygenase-2 with rofecoxib was not associated with early detrimental effects on the hemodynamic profile or the gross extent of infarction; in fact, it may be beneficial by limiting cell necrosis.

  19. Expression and enzyme activity determination of human cyclooxygenase-1 and -2 in a baculovirus-insect cell system

    Institute of Scientific and Technical Information of China (English)

    Wei-yu ZHANG; Xin-ning YANG; Dao-zhong JIN; Xing-zu ZHU

    2004-01-01

    AIM: To develop an in vitro intact cell-based assay for screening selective cyclooxygenase inhibitors. METHODS:Human cyclooxygenase-1 (hCOX-1) and cyclooxygenase-2 (hCOX-2) genes were cloned from human monocyte cell line THP-1 cells and expressed in Spodopterafrugiperda (sf9) insect cell line by Bac-to-Bac baculovirus expression systems. Infected sr9 cells were harvested 24 h post-infection (hpi), and distributed to a 24-well plate,preincubated with various nonsteroidal anti-inflammatory drugs, and challenged with 10 mmol/L arachidonic acid;the cyclooxygenase activity was assessed indirectly by prostaglandin E2-specific radioimmunoassay. RESULTS:Polymerase chain reaction detection demonstrated that hCOX-1 and hCOX-2 were transposed to the bacmid.Western blot analysis showed that infected sf9 cells could express hCOX-1 and hCOX-2 proteins. Radioimmunoassay demonstrated that both recombinant proteins functioned well in sf9 cells. CONCLUSION: Human cyclooxygenase-1 and cyclooxygenase-2 were successfully expressed in sf9 insect cell line. It can be utilized for the identification of potent and selective inhibitors of hCOX- 1 and/or hCOX-2.

  20. CD40 engagement on dendritic cells induces cyclooxygenase-2 and EP2 receptor via p38 and ERK MAPKs.

    Science.gov (United States)

    Harizi, Hedi; Limem, Ilef; Gualde, Norbert

    2011-02-01

    We have previously reported that cyclooxygenase (COX)-2-derived prostaglandin (PG)E2 critically regulates dendritic cell (DC) inflammatory phenotype and function through EP2/EP4 receptor subtypes. As genes activated by CD40 engagement are directly relevant to inflammation, we examined the effects of CD40 activation on inflammatory PGs in murine bone marrow-derived DC (mBM-DC). We showed for the first time that activation of mBM-DC with agonist anti-CD40 monoclonal antibody (anti-CD40 mAb) dose dependently induces the synthesis of significant amounts of PGE2 via inducible expression of COX-2 enzyme, as NS-398, a COX-2-selective inhibitor reduces this upregulation. In contrast to lipopolysaccharide, which upregulates mBM-DC surface levels of EP2 and EP4 receptors, CD40 crosslinking on mBM-DC increases EP2, but not EP4, receptor expression. Flow cytometry analysis and radioligand-binding assay showed that EP2 was the major EP receptor subtype, which binds to PGE2 at the surface of anti-CD40-activated mBM-DC. Upregulation of COX-2 and EP2 levels by CD40 engagement was accompanied by dose-dependent phosphorylation of p38 and ERK1/2 mitogen-activated protein kinase (MAPK) and was abrogated by inhibitors of both pathways. Collectively, we demonstrated that CD40 engagement on mBM-DC upregulates COX-2 and EP2 receptor expression through activation of p38 and ERK1/2 MAPK signaling. Triggering the PGE2/EP2 pathway by anti-CD40 mAb resulted on the induction of Th2 immune response. Thus, CD40-induced production of PGE2 by mBM-DC could represent a negative feedback mechanism involving EP2 receptor and limiting the propagation of Th1 responses. Blocking CD40 pathway may represent a novel therapeutic pathway of inhibiting COX-2-derived prostanoids in chronically inflamed tissues (that is, arthritis).

  1. MDMA increases glutamate release and reduces parvalbumin-positive GABAergic cells in the dorsal hippocampus of the rat: role of cyclooxygenase.

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    Anneken, John H; Cunningham, Jacobi I; Collins, Stuart A; Yamamoto, Bryan K; Gudelsky, Gary A

    2013-03-01

    3,4-Methylenedioxymethamphetamine (MDMA; Ecstasy) is a popular drug of abuse with well-documented acute effects on serotonergic, dopaminergic, and cholinergic transmitter systems, as well as evidence of long-term disruption of serotoninergic systems in the rat brain. Recently, it was demonstrated that MDMA evokes a delayed and sustained increase in glutamate release in the hippocampus. The purpose of the present study was to determine the role of inflammatory mediators in the MDMA-induced increase in glutamate release, as well as the contribution of inflammatory pathways in the persistent neurochemical toxicity associated with repeated MDMA treatment. Treatment with the non-selective cyclooxygenase (COX) inhibitor ketoprofen and the COX-2 selective inhibitor nimesulide attenuated the increase in extracellular glutamate in the hippocampus evoked by repeated MDMA exposure (10 mg/kg, i.p., every 2 h); no attenuation was observed in rats treated with the COX-1 selective inhibitor piroxicam. Reverse dialysis of a major product of COX activity, prostaglandin E2, also resulted in a significant increase in extracellular glutamate in the hippocampus . Repeated exposure to MDMA diminished the number of parvalbumin-positive GABA interneurons in the dentate gyrus of the hippocampus, an effect that was attenuated by ketoprofen treatment. However, COX inhibition with ketoprofen did not prevent the long-term depletion of 5-HT in the hippocampus evoked by MDMA treatment. These data are supportive of the view that cyclooxygenase activity contributes to the mechanism underlying both the increased release of glutamate and decreased number of GABA interneurons in the rat hippocampus produced by repeated MDMA exposure.

  2. The role of arachidonic acid/cyclooxygenase cascade, phosphodiesterase IV and Rho-kinase in H2S-induced relaxation in the mouse corpus cavernosum.

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    Aydinoglu, Fatma; Ogulener, Nuran

    2017-08-01

    Penile corpus cavernosum is an extremely vascularized tissue and cavernosal smooth muscle tone is regulated by the balance between contractile and relaxant factor. We investigated the possible role of arachidonic acid/cyclooxygenase cascade, phosphodiesterase IV (PDEIV) and Rho-kinase in exogenous hydrogen sulfide (H2S)-induced relaxation in mouse corpus cavernosum. The relaxant response to H2S (NaHS as exogenous H2S; 1-1000μM) were obtained in isolated mouse corpus cavernosum tissues which pre-contracted by phenylephrine (5μM). The effects of 4-(4-octadecylphenyl)-4-oxobutenoic acid (OBAA; 10μM), a selective phospholipase A2 (PLA2) inhibitor, indomethacin (1μM), a non-selective cyclooxygenase (COX) inhibitor, baicalein (10μM), a lipoxygenase (LOX) inhibitor, and proadifen (10μM), cytochrome P450 inhibitor, on the relaxant responses to H2S were investigated. Furthermore, the effects of theophylline (500μM) and rolipram (1μM), a non-selective and selective PDEIV inhibitor, and fasudil (3μM), a specific Rho-kinase inhibitor, were studied on H2S-induced relaxation. H2S-induced relaxations were significantly reduced by OBAA, indomethacin and proadifen but not baicalein. Furthermore, theophylline, rolipram and fasudil reduced H2S-induced relaxations. These results suggest that PLA2, COX, cytochrome P450, PDEIV and Rho-kinase pathway may involve in H2S-induced relaxation in mouse corpus cavernosum tissues. Copyright © 2017 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  3. Prostaglandin receptor EP2 is responsible for cyclooxygenase-2 induction by prostaglandin E2 in mouse skin.

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    Ansari, Kausar M; Sung, You Me; He, Guobin; Fischer, Susan M

    2007-10-01

    The EP2 prostanoid receptor is one of the four subtypes of receptors for prostaglandin E2 (PGE2). We previously reported that deletion of EP2 led to resistance to chemically induced mouse skin carcinogenesis, whereas overexpression of EP2 resulted in enhanced tumor development. The purpose of this study was to investigate the underlying molecular mechanisms. We found that EP2 knockout mice had reduced cyclooxygenase-2 (COX-2) expression after 12-O-tetradecanoylphorbol-13-acetate (TPA) treatment compared with wild-type (WT) mice. Further, primary keratinocytes from EP2 transgenic mice had increased COX-2 expression after either TPA or PGE2 treatment and COX-2 expression was blocked by 10 microM SQ 22,536, an adenylate cyclase inhibitor. EP2 knockout mice had significantly decreased, whereas EP2 transgenic mice had significantly increased PGE2 production in response to a single treatment of TPA. Cyclic AMP response element-binding protein (CREB) phosphorylation was elevated to a greater extent in keratinocytes from EP2 transgenic mice compared with those of WT mice following PGE2 treatment. A protein kinase A (PKA) inhibitor reduced PGE2-mediated CREB phosphorylation in keratinocytes from EP2 transgenic mice. Furthermore, we found that there was no CREB phosphorylation in EP2 knockout mice following PGE2 treatment. PGE2-induced DNA synthesis (cell proliferation) was significantly decreased in keratinocytes from EP2 knockout mice following pretreatment with 10 microM SQ 22,536. Taken together, EP2 activation of the PKA/CREB-signaling pathway is responsible for keratinocyte proliferation and our findings reveal a positive feedback loop between COX-2 and PGE2 that is mediated by the EP2 receptor.

  4. Sphingosine 1-phosphate in amniotic fluid modulates cyclooxygenase-2 expression in human amnion-derived WISH cells.

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    Kim, Jung Im; Jo, Eun Jin; Lee, Ha-Young; Cha, Moon Seok; Min, Jung Kee; Choi, Chang Hwan; Lee, Yong Moon; Choi, Young-Ae; Baek, Suk-Hwan; Ryu, Sung Ho; Lee, Kyu Sup; Kwak, Jong-Young; Bae, Yoe-Sik

    2003-08-22

    The metabolism of arachidonic acid, in particular the generation of prostaglandins (PGs), has been proposed to play a key role in the regulation of labor. Moreover, several extracellular proteins have been reported to modulate PG synthesis in amnion cells. In this study, we found that lipid components dissolved in the amniotic fluid modulate PG synthesis in WISH human amnion cells and identified one of these components as a sphingosine 1-phosphate (S1P). WISH cells express several S1P receptors including S1P1, S1P2, and S1P3. When WISH cells were stimulated with S1P, PGE2 synthesis increased in a concentration-dependent manner, showing maximal activity at around 100 nM. S1P treatment also caused the up-regulation of cyclooxygenase-2 (COX-2) mRNA and protein, which was apparent within 3-12 h of stimulation. In terms of the intracellular signaling pathway of S1P-induced WISH cell activation, we found that S1P stimulated two kinds of MAPK, ERK, and p38 kinase. We examined the roles of these two MAPKs in S1P-induced COX-2 expression. S1P-induced COX-2 expression was blocked completely by PD-98059 but not by SB-203580, suggesting that ERK has a critical role in the process. Transfection of S1P1 or S1P3 but not of S1P2 antisense oligonucleotide inhibited S1P-induced COX-2 expression and PGE2 production in WISH cells, indicating the involvements of S1P1 and S1P3 in the processes. This study demonstrates the physiological role of S1P in amniotic fluid and its effect on the modulation of COX-2 expression and PGs synthesis in WISH cells.

  5. Cyclooxygenase-2 is up-regulated in proliferative inflammatory atrophy of the prostate, but not in prostate carcinoma.

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    Zha, S; Gage, W R; Sauvageot, J; Saria, E A; Putzi, M J; Ewing, C M; Faith, D A; Nelson, W G; De Marzo, A M; Isaacs, W B

    2001-12-15

    Cyclooxygenase-2 (COX-2) is the inducible isoform of the rate-limiting enzymes that convert arachidonic acid to proinflammatory prostaglandins as well as a primary target for nonsteroidal anti-inflammatory drugs. Accumulating evidence suggests that up-regulation of COX-2 is associated with carcinogenesis in multiple organ systems including the large bowel, lung, breast, and prostate. In this report, we examine the expression of COX-2 protein and mRNA in prostate tissue containing various lesions and in prostate cancer cell lines. In the cell lines, LNCaP, DU145, PC-3, and TSU, COX-2 protein expression was undetectable under basal conditions but could be induced transiently by phorbol ester treatment in PC-3 and TSU cells, but not in DU145 and LNCaP cells. Immunohistochemical analysis of 144 human prostate cancer cases suggested that, in contrast to several previous reports, there was no consistent overexpression of COX-2 in established prostate cancer or high-grade prostatic intraepithelial neoplasia, as compared with adjacent normal prostate tissue. Positive staining was seen only in scattered cells (prostatic carcinogenesis. Staining was also seen at times in macrophages. Western blotting and quantitative RT-PCR analyses confirmed these patterns of expression. These results suggest that if nonsteroidal anti-inflammatory drugs are indeed chemopreventive and/or chemotherapeutic for prostate cancer, their effects are likely to be mediated by modulating COX-2 activity in non-PCa cells (either inflammatory cells or atrophic epithelial cells) or by affecting a COX-2-independent pathway.

  6. Inhibitors of cyclo-oxygenase-2 and secretory phospholipase A2 preserve bone architecture following ovariectomy in adult rats.

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    Gregory, Laura S; Kelly, Wendy L; Reid, Robert C; Fairlie, David P; Forwood, Mark R

    2006-07-01

    Epidemiological evidence and in vitro data suggest that COX-2 is a key regulator of accelerated remodeling. Accelerated states of osteoblast and osteoclast activity are regulated by prostaglandins in vitro, but experimental evidence for specific roles of cyclooxygenase-2 (COX-2) and secretory phospholipase A2 (sPLA2) in activated states of remodeling in vivo is lacking. The aim of this study was to determine the effect of specific inhibitors of sPLA2-IIa and COX-2 on bone remodeling activated by estrogen deficiency in adult female rats. One hundred and twenty-four adult female Wistar rats were ovariectomized (OVX) or sham-operated. Rats commenced treatment 14 days after surgery with either vehicle, a COX-2 inhibitor (DFU at 0.02 mg/kg/day and 2.0 mg/kg/day) or a sPLA2-group-IIa inhibitor (KH064 at 0.4 mg/kg/day and 4.0 mg/kg/day). Treatment continued daily until rats were sacrificed at 70 days or 98 days post-OVX. The right tibiae were harvested, fixed and embedded in methylmethacrylate for structural histomorphometric bone analysis at the proximal tibial metaphysis. The specific COX-2 or sPLA2 inhibitors prevented ovariectomy-induced (OVX-induced) decreases in trabecular connectivity (Pbone resorption; and maintained bone turnover at SHAM levels following OVX in the rat. The sPLA2 inhibitor significantly suppressed increases in osteoclast surface induced by OVX (Pbone loss in the adult rat by conserving trabecular bone mass and architecture through reduced bone remodeling and decreased resorptive activity. Moreover, we report an important role of sPLA2-IIa in osteoclastogenesis that may be independent of the COX-2 metabolic pathway in the OVX rat in vivo.

  7. Genomic, Lipidomic and Metabolomic Analysis of Cyclooxygenase-null Cells: Eicosanoid Storm, Cross Talk, and Compensation by COX-1.

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    Islam, Abul B M M K; Dave, Mandar; Amin, Sonia; Jensen, Roderick V; Amin, Ashok R

    2016-04-01

    The constitutively-expressed cyclooxygenase 1 (COX-1) and the inducible COX-2 are both involved in the conversion of arachidonic acid (AA) to prostaglandins (PGs). However, the functional roles of COX-1 at the cellular level remain unclear. We hypothesized that by comparing differential gene expression and eicosanoid metabolism in lung fibroblasts from wild-type (WT) mice and COX-2(-/-) or COX-1(-/-) mice may help address the functional roles of COX-1 in inflammation and other cellular functions. Compared to WT, the number of specifically-induced transcripts were altered descendingly as follows: COX-2(-/-)>COX-1(-/-)>WT+IL-1β. COX-1(-/-) or COX-2(-/-) cells shared about 50% of the induced transcripts with WT cells treated with IL-1β, respectively. An interactive "anti-inflammatory, proinflammatory, and redox-activated" signature in the protein-protein interactome map was observed in COX-2(-/-) cells. The augmented COX-1 mRNA (in COX-2(-/-) cells) was associated with the upregulation of mRNAs for glutathione S-transferase (GST), superoxide dismutase (SOD), NAD(P)H dehydrogenase quinone 1 (NQO1), aryl hydrocarbon receptor (AhR), peroxiredoxin, phospholipase, prostacyclin synthase, and prostaglandin E synthase, resulting in a significant increase in the levels of PGE2, PGD2, leukotriene B4 (LTB4), PGF1α, thromboxane B2 (TXB2), and PGF2α. The COX-1 plays a dominant role in shifting AA toward the LTB4 pathway and anti-inflammatory activities. Compared to WT, the upregulated COX-1 mRNA in COX-2(-/-) cells generated an "eicosanoid storm". The genomic characteristics of COX-2(-/-) is similar to that of proinflammatory cells as observed in IL-1β induced WT cells. COX-1(-/-) and COX-2(-/-) cells exhibited compensation of various eicosanoids at the genomic and metabolic levels.

  8. Genomic, Lipidomic and Metabolomic Analysis of Cyclooxygenase-null Cells: Eicosanoid Storm, Cross Talk, and Compensation by COX-1

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    Abul B.M.M.K. Islam

    2016-04-01

    Full Text Available The constitutively-expressed cyclooxygenase 1 (COX-1 and the inducible COX-2 are both involved in the conversion of arachidonic acid (AA to prostaglandins (PGs. However, the functional roles of COX-1 at the cellular level remain unclear. We hypothesized that by comparing differential gene expression and eicosanoid metabolism in lung fibroblasts from wild-type (WT mice and COX-2-/- or COX-1-/- mice may help address the functional roles of COX-1 in inflammation and other cellular functions. Compared to WT, the number of specifically-induced transcripts were altered descendingly as follows: COX-2-/- > COX-1-/- > WT + IL-1β. COX-1-/- or COX-2-/- cells shared about 50% of the induced transcripts with WT cells treated with IL-1β, respectively. An interactive “anti-inflammatory, proinflammatory, and redox-activated” signature in the protein–protein interactome map was observed in COX-2-/- cells. The augmented COX-1 mRNA (in COX-2-/- cells was associated with the upregulation of mRNAs for glutathione S-transferase (GST, superoxide dismutase (SOD, NAD(PH dehydrogenase quinone 1 (NQO1, aryl hydrocarbon receptor (AhR, peroxiredoxin, phospholipase, prostacyclin synthase, and prostaglandin E synthase, resulting in a significant increase in the levels of PGE2, PGD2, leukotriene B4 (LTB4, PGF1α, thromboxane B2 (TXB2, and PGF2α. The COX-1 plays a dominant role in shifting AA toward the LTB4 pathway and anti-inflammatory activities. Compared to WT, the upregulated COX-1 mRNA in COX-2-/- cells generated an “eicosanoid storm”. The genomic characteristics of COX-2-/- is similar to that of proinflammatory cells as observed in IL-1β induced WT cells. COX-1-/- and COX-2-/- cells exhibited compensation of various eicosanoids at the genomic and metabolic levels.

  9. Galphaq signaling is required for Rho-dependent transcriptional activation of the cyclooxygenase-2 promoter in fibroblasts.

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    Slice, Lee W; Han, Sang-Kyou; Simon, Melvin I

    2003-02-01

    Previously, we demonstrated that the gastrin releasing peptide (GRP) induces cyclooxygenase-2 (COX-2) expression through a Rho-dependent, protein kinase C (PKC)-independent signaling pathway in fibroblasts (Slice et al., 1999, J Biol Chem 274:27562-27566). However, the specific role of heterotrimeric guanine nucleotide binding regulatory proteins (G-proteins) that are coupled to the GRP receptor in Rho-dependent COX-2 expression has not been elucidated. In this report, we utilize embryonic fibroblasts from transgenic mice containing double gene knock-outs (DKO) for Galpha(q/11) and Galpha(12/13) to demonstrate that COX-2 promoter activation by GRP requires Galpha(q). Furthermore, we show that GRP-dependent COX-2 gene expression, as assessed by a COX-2 reporter luciferase assay, was induced in cells lacking Galpha(12/13) but was blocked in cells that did not express Galpha(q/11). GRP-dependent COX-2 promoter induction in Galpha(q/11) deficient cells was rescued by expression of wild type Galpha(q) but blocked by inhibition of calcium signaling in calcium-free media or in cells treated with 2-aminoethoxydiphenylborate (2-APB). Co-stimulation of transfected Galpha(q/11) deficient cells with GRP and thapsigargin (TG) induced the COX-2 promoter. Activation of endogenous Rho by expression of Onco-lbc or expression of Rho A Q63L resulted in COX-2 promoter activation in Galpha(q/11) deficient cells. Inhibition of Rho by Clostridium botulinum C3 toxin blocked COX-2 promoter induction. Expression of Galpha(q) Q209L in the well-characterized fibroblast cell line, NIH3T3, induced the COX-2 promoter which was blocked by expression of C3 toxin. These results demonstrate that calcium signaling mediated by Galpha(q) and Rho play critical roles in GRP-dependent COX-2 expression in fibroblasts.

  10. Cyclooxygenase-2, a Potential Therapeutic Target, Is Regulated by miR-101 in Esophageal Squamous Cell Carcinoma.

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    Ying Shao

    Full Text Available Cyclooxygenase-2 (COX-2 is known to promote the carcinogenesis of esophageal squamous cell carcinoma (ESCC. There are no reports on whether microRNAs (miRNAs regulate COX-2 expression in ESCC. This study investigated the effect of miR-101 on ESCC through modulating COX-2 expression in ESCC.Real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR was used to quantify miR-101 expression in ESCC clinical tissues and cell lines. The effects of miR-101 on ESCC progression were evaluated by cell counting kit-8 (CCK8, transwell migration and invasion assays, as well as by flow cytometry. The COX-2 and PEG2 levels were determined by western blot and enzyme-linked immunosorbent assays (ELISA. The luciferase reporter assay was used to verify COX-2 as a direct target of miR-101. The anti-tumor activity of miR-101 in vivo was investigated in a xenograft nude mouse model of ESCC.Downregulation of miR-101 was confirmed through comparison of 30 pairs of ESCC tumor and adjacent normal tissues (P < 0.001, as well as in 11 ESCC cell lines and a human immortalized esophageal cell line (P < 0.001. Transfection of miR-101 in ESCC cell lines significantly suppressed cell proliferation, migration, and invasion (all P < 0.001. The antitumor effect of miR-101 was verified in a xenograft model. Furthermore, COX-2 was shown to be a target of miR-101.Overexpression of miR-101 in ESCC inhibits proliferation and metastasis. Therefore, the miR-101/COX-2 pathway might be a therapeutic target in ESCC.

  11. Suppression of cyclooxygenase-2 gene transcription by humulon of beer hop extract studied with reference to glucocorticoid.

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    Yamamoto, K; Wang, J; Yamamoto, S; Tobe, H

    2000-01-14

    In murine osteoblastic MC3T3-E1 cells which produced prostaglandin E2 as a bone resorption factor, the cyclooxygenase-2 induction by tumor necrosis factor alpha (TNFalpha) was suppressed by dexamethasone with an IC(50) of 1 nM. Humulon isolated from hop extract for beer brewing was reported previously as an inhibitor of bone resorption [Tobe, H. et al. (1997) Biosci. Biotech. Biochem. 61, 158-159]. We showed that the compound suppressed the TNFalpha-dependent cyclooxygenase-2 induction with an IC(50) of as low as about 30 nM as demonstrated experimentally by catalytic activity assay, Northern blot analysis and promoter analysis. Reporter gene experiments suggested that humulon blocked the cyclooxygenase-2 expression mediated by NFkappaB and NF-IL6, but the intracellular glucocorticoid receptor was not involved. The catalytic activity of cyclooxygenase-2 was inhibited by humulon with an IC(50) of as high as 1.6 microM. These results showed that humulon suppressed cyclooxygenase-2 induction at the step of transcription.

  12. Inhibition of Cyclooxygenase Type 1 and 2 Enzyme by Aqueous Extract of Elaeagnus Angustifolia in Mice

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    Shahedeh Farahbakhsh

    2011-09-01

    Full Text Available  Introduction: It has been shown that the extract of Elaeagnus angustifolia can inhibit inflammation and pain induced by formalin in mice and rats. The aim of the present study is to reach evaluations of possible cellular and molecular mechanisms of Elaeagnus angustifolia extract in reducing pain and inflammation through examining the extract ability for inhibition of cyclooxygenase (Cox type 1 and 2 enzymes and corticosterone release from adrenal glands in mice. Methods: Male Swiss Webster mice were evaluated through the injection of 2 μliters to the plantar part of right foot. Elaeagnus angustifolia extract was injected to the animals 30 minutes before formalin. In order to evaluate the mechanism of extract, naloxone and memantine were administered intrapretonealy 30 minutes before the extract administration. In separate groups, after injection of extract, blood samples were taken from animals and corticosterone concentrations were measured. In an in vitro study the effect of extract on the activity of cyclooxygenase type 1 and 2 was assessed. Results: the research data showed the ineffectiveness of the extract on acute phase of pain induced by formalin but it completely inhibits the chronic phase. Naloxone and Memantine administration had no effect on the efficacy of extract in the chronic phase. Also the extract administration did not increase the plasma concentration of corticosterone in mice, but in vitro inhibited Cox1 and Cox 2 enzymes. Discussion: These results indicate that Elaeagnus angustifolia extract probably reducesww pain and inflammation caused by formalin in mice by inhibiting cyclooxygenase type 1 and 2 enzymes.

  13. Analysis of angiogenic factors and cyclooxygenase-2 expression in cartilaginous tumors: clinical and histological correlation

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    Francisco Fontes Cintra

    2011-01-01

    Full Text Available OBJECTIVES: To study the role of angiogenesis and cyclooxygenase-2 expression in cartilaginous tumors and correlate these factors with prognosis. INTRODUCTION: For chondrosarcoma, the histological grade is the current standard for predicting tumor outcome. However, a low-grade chondrosarcoma can follow an aggressive course-as monitored by sequential imaging techniques-even when it is histologically indistinguishable from an enchondroma. Therefore, additional tools are needed to help identify the biological potential of these tumors. The degree of angiogenesis that is induced by the tumor could assist in this task. Angiogenesis can be quantified by measuring the expression of vascular endothelial growth factor and CD34, and cyclooxygenase-2 can induce angiogenesis by stimulating the production of proangiogenic factors. METHODS: In total, 21 enchondromas and 58 conventional chondrosarcomas were studied by examining the clinical and histopathological findings in conjunction with the immunostaining markers of angiogenesis and cyclooxygenase- 2 expression. RESULTS: The significant variables that were associated with poor outcome were 1 higher-grade chondrosarcomas, 2 tumors that developed in flat bones, and 3 over-expression of CD34 (with a median count that was higher than 5.9 vessels in 5 high power fields. Moreover, CD34 expression (measured using the Chalkley method revealed significantly higher microvessel density in flat bone chondrosarcomas. DISCUSSION: Previous studies have shown a positive correlation between Chalkley microvessel density and histological grade; however, in our sample, we found that the former is predictive of the outcome. Chondrosarcomas in flat bones have been shown to correlate with a poor prognosis. We also found that CD34 microvessel density values were significantly higher in flat-bone chondrosarcomas. This could explain-at least in part-the more aggressive biological course that is taken by these tumors. CONCLUSIONS

  14. The role of cyclooxygenase-2 inhibition for the prevention and treatment of prostate carcinoma.

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    Lin, Daniel W; Nelson, Peter S

    2003-09-01

    Experimental and epidemiologic studies have demonstrated that nonsteroidal antiinflammatory drugs (NSAIDs) are effective in the prevention of human cancers. Nonsteroidal antiinflammatory drugs inhibit the cyclooxygenase (COX) enzyme that functions to convert arachidonic acid to prostaglandins (PGs). Cyclooxygenase-2, a key COX isoenzyme, is rapidly induced in response to inflammatory stimuli, growth factors, cytokines, and promoters of neoplastic growth. Cyclooxygenase-2-catalyzed reactions may be involved in carcinogenesis via 2 distinct mechanisms: (1). DNA damage and (2). PG-mediated effects. Reactions mediated by COX-2 form reactive oxygen species that can directly induce the oxidation of DNA or instigate the bioactivation of carcinogens. Prostaglandin E2, a byproduct of COX-2-mediated arachidonic acid metabolism, exhibits several biologic actions that have been shown to promote tumorigenesis and tumor progression. These actions include increased cell proliferation, promotion of angiogenesis, and the elevated expression of the antiapoptotic protein Bcl-2. In addition, PGE2 decreases natural killer cell activity and alters immune surveillance. In vitro experimental studies find that COX-2 inhibitors decrease cellular proliferation, increase apoptosis, and modulate genes involved in cell cycle regulation. Evidence from animal studies supports a role for NSAIDs in prostate cancer (CaP) prevention. Population-based studies have observed a reduced incidence of CaP among men using NSAIDs. Because CaP evolves slowly and rarely strikes men before the sixth or seventh decade of life, any strategy to delay or lengthen the time to development of clinically evident CaP, such as chemoprevention strategies, would greatly impact the natural history of this disease. Recent progress and critical analyses in the roles of COX-2 inhibition on prostate carcinogenesis and CaP prevention will be presented.

  15. A cyclooxygenase (COX) inhibitory biflavonoid from the seeds of Semecarpus anacardium.

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    Selvam, C; Jachak, Sanjay M

    2004-12-01

    Semecarpus anacardium Linn., Anacardiaceae, is being most commonly used in India for the treatment of rheumatoid arthritis and other inflammatory disorders. Bioactivity guided fractionation of ethyl acetate extract led to the isolation of major active principle, tetrahydroamentoflavone (THA), a biflavonoid. The in vitro cyclooxygenase (COX-1) catalyzed prostaglandin biosynthesis assay of THA gave an IC(50) value of 29.5 microM (COX-1) and 40.5% inhibition at 100 microg/mL (COX-2). The in vivo carrageenan induced paw edema assay resulted in dose dependent anti-inflammatory effect of THA and the activity was comparable to that of ibuprofen, one of the well known NSAIDs.

  16. 1-Bromopropane up-regulates cyclooxygenase-2 expression via NF-κB and C/EBP activation in murine macrophages.

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    Han, Eun Hee; Yang, Ji Hye; Kim, Hyung-Kyun; Choi, Jae Ho; Khanal, Tilak; Do, Minh Truong; Chung, Young Chul; Lee, Kwang Youl; Jeong, Tae Cheon; Jeong, Hye Gwang

    2012-05-01

    1-Bromopropane (1-BP) has been used in industry as an alternative to ozone-depleting solvents. In the present study, we examined the effect of 1-BP on cyclooxygenase-2 (COX-2) gene expression and analyzed the molecular mechanism of its activity in murine RAW 264.7 macrophages. 1-BP dose-dependently increased COX-2 protein and mRNA levels, as well as COX-2 promoter-driven luciferase activity in macrophages. Additionally, exposure to 1-BP markedly enhanced the production of prostaglandin E(2) (PGE(2)), a major COX-2 metabolite, in macrophages. Transfection experiments with several human COX-2 promoter constructs revealed that 1-BP activated the transcription factors nuclear factor-κB (NF-κB) and CCAAT/enhancer-binding protein (C/EBP), but not AP-1 or the cyclic AMP response element binding protein. Furthermore, Akt and mitogen-activated protein (MAP) kinases were significantly activated by 1-BP. These results demonstrated that 1-BP induced COX-2 expression via NF-κB and C/EBP activation through the Akt/ERK and p38 MAP kinase pathways. These findings provide further insight into the signal transduction pathways involved in the inflammatory effects of 1-BP.

  17. Cyclooxygenase-2 overexpression is common in serrated and non-serrated colorectal adenoma, but uncommon in hyperplastic polyp and sessile serrated polyp/adenoma

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    Kirkner Gregory J

    2008-01-01

    Full Text Available Abstract Background Cyclooxygenase-2 (COX-2, PTGS2 plays an important role in colorectal carcinogenesis. COX-2 overexpression in colorectal cancer is inversely associated with microsatellite instability (MSI and the CpG island methylator phenotype (CIMP. Evidence suggests that MSI/CIMP+ colorectal cancer may arise through the serrated tumorigenic pathway through various forms of serrated neoplasias. Therefore, we hypothesized that COX-2 may play a less important role in the serrated pathway. Methods By immunohistochemistry, we assessed COX-2 expression in 24 hyperplastic polyps, 7 sessile serrated polyp/adenomas (SSA, 5 mixed polyps with SSA and adenoma, 27 traditional serrated adenomas, 515 non-serrated adenomas (tubular adenoma, tubulovillous adenoma and villous adenoma, 33 adenomas with intramucosal carcinomas, 96 adenocarcinomas with serration (corkscrew gland and 111 adenocarcinomas without serration. Results Strong (2+ COX-2 overexpression was more common in non-serrated adenomas (28% = 143/515 than in hyperplastic polyps (4.2% = 1/24, p = 0.008 and serrated polyps (7 SSAs and 5 mixed polyps (0% = 0/12, p = 0.04. Furthermore, any (1+/2+ COX-2 overexpression was more frequent in non-serrated adenomas (60% = 307/515 than in hyperplastic polyps (13% = 3/24, p Conclusion COX-2 overexpression is infrequent in hyperplastic polyp, SSA and mixed polyp with SSA and adenoma, compared to non-serrated and serrated adenoma. COX-2 overexpression becomes more frequent as tumors progress to higher grade neoplasias. Our observations suggest that COX-2 may play a less significant role in the serrated pathway of tumorigenesis; however, COX-2 may still play a role in later stage of the serrated pathway.

  18. Cyclooxygenase-2 inhibition attenuates abdominal aortic aneurysm progression in hyperlipidemic mice.

    Directory of Open Access Journals (Sweden)

    Sarbani Ghoshal

    Full Text Available Abdominal aortic aneurysms (AAAs are a chronic inflammatory disease that increase the risk of life-threatening aortic rupture. In humans, AAAs have been characterized by increased expression of cyclooxygenase-2 and the inactivation of COX-2 prior to disease initiation reduces AAA incidence in a mouse model of the disease. The current study examined the effectiveness of selective cyclooxygenase-2 (COX-2 inhibition on reducing AAA progression when administered after the initiation of AAA formation. AAAs were induced in hyperlipidemic apolipoprotein E-deficient mice by chronic angiotensin II (AngII infusion and the effect of treatment with the COX-2 inhibitor celecoxib was examined when initiated at different stages of the disease. Celecoxib treatment that was started 1 week after initiating AngII infusion reduced AAA incidence by 61% and significantly decreased AAA severity. Mice treated with celecoxib also showed significantly reduced aortic rupture and mortality. Treatment with celecoxib that was started at a late stage of AAA development also significantly reduced AAA incidence and severity. Celecoxib treatment significantly increased smooth muscle alpha-actin expression in the abdominal aorta and did not reduce expression of markers of macrophage-dependent inflammation. These findings indicate that COX-2 inhibitor treatment initiated after formation of AngII-induced AAAs effectively reduces progression of the disease in hyperlipidemic mice.

  19. Imrecoxib:a novel and selective cyclooxygenase 2 inhibitor with anti-inflammatory effect

    Institute of Scientific and Technical Information of China (English)

    Xiao-hong CHEN; Jin-ye BAI; Fang SHEN; Ai-ping BAI; Zong-ru GUO; Gui-fang CHENG

    2004-01-01

    AIM: To investigate the inhibitory effect of imrecoxib, a synthetic compound of completely new structure, on cyclooxygenase 1 (COX-1) and 2 (COX-2) and its anti-inflammatory effect in vivo. METHODS: The inhibitory effects of imrecoxib on cyclooxygenase 1 and 2 were studied using whole cell assay with murine peritoneal macrophages induced by calcimycin and LPS. The inhibitory effects of imrecoxib on mRNA level of COX- 1 and COX2 in human macrophage cell line U937 were detected by reverse transcription polymerase chain reaction (RT-PCR)analysis. Effects of imrecoxib on acute and chronic inflammation were evaluated in rat carrageenan induced edema model and rat adjuvant-induced arthritis model, respectively. RESULTS: Imrecoxib was found to inhibit COX-1and COX-2 with IC50 value of 115+28 nmol/L and 18+4 nmol/L, respectively. Imrecoxib was shown to selectively and dose-dependently inhibit COX-2 mRNA level. Imrecoxib effectively inhibited carrageenan-induced acute inflammation at the doses of 5, 10, and 20 mg.kg-1 ig and adjuvant-induced chronic inflammation at the doses of 10and 20 rmg.kg-1.d-1 ig. CONCLUSION: Imrecoxib is a novel and moderately selective COX-2 inhibitor that possesses anti-inflammatory effect by inhibition of COX-2 mRNA expression.

  20. Increased expression of cyclooxygenase-2 and nitric oxide synthase-2 in human prostate cancer.

    Science.gov (United States)

    Uotila, P; Valve, E; Martikainen, P; Nevalainen, M; Nurmi, M; Härkönen, P

    2001-02-01

    Cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase-2 (NOS-2) each have an important role in angiogenesis. The expression of these genes was investigated in human prostate cancer by immunohistochemistry, the expression of COX-1 and COX-2 being confirmed by mRNA analysis. Prostate cancer specimens from 12 patients were compared to control prostates from 13 patients operated on for bladder carcinoma. The intensity of COX-2 and NOS-2 immunostaining was significantly stronger in prostate cancer cells than in the non-malignant glandular epithelium of the control prostates. COX-2 and NOS-2 were clearly also expressed in the lesions of prostatic intraepithelial neoplasia (PIN) in control prostates. COX-2 was detected in the muscle fibres of the hyperplastic stroma of some control prostates. No significant difference was detected in COX-1 expression between control and cancer prostates. These results indicate that the expression of COX-2 and NOS-2 is elevated in prostatic adenocarcinoma and in PIN.

  1. Lung edema due to hydrogen peroxide is independent of cyclooxygenase products

    Energy Technology Data Exchange (ETDEWEB)

    Burghuber, O.; Mathias, M.M.; McMurtry, I.F.; Reeves, J.T.; Voelkel, N.F.

    1984-01-01

    Active oxygen species can cause lung injury. Although a direct action on endothelial cells is proposed, the possibility exists that they might cause injury via mediators. We considered that active oxygen species would stimulate the generation of cyclooxygenase metabolites, which then alter pulmonary vasoreactivity and cause edema. We chemically produced hydrogen peroxide by adding glucose oxidase to a plasma- and cell-free, but ..beta..-D-glucose-containing, solution, which perfused isolated rat lungs. Addition of glucose oxidase to the perfusate caused a marked decrease in pulmonary vasoreactivity, accompanied by an increase in the concentrations of prostacyclin, thromboxane A/sub 2/, and prostaglandin F/sub 2..cap alpha../. Pretreatment with catalase, a specific scavenger of hydrogen peroxide, preserved pulomonary vasoreactivity, inhibited the increase of the concentration of the measured prostaglandins, and prevented edema formation. Indomethacin effectively blocked lung prostaglandin production but neither prevented the decrease in vasoreactivity nor inhibited edema formation. From these data we conclude the hydrogen peroxide impaired pulmonary vasoreactivity and subsequently caused edema. Depsite the fact that hydrogen peroxide stimulated lung prostaglandin production, cyclooxygenase-derived products neither caused the decrease in vasoreactivity nor the development of edema.

  2. The regulation of interferon production by aspirin, other inhibitors of the cyclooxygenase pathway and agents influencing calcium channel flux.

    OpenAIRE

    1989-01-01

    Interferon is a family of potent antiviral agents which can activate macrophages, enhance cell surface markers, or influence antibody production. Three major types of human interferon are known to exist and have been designated interferons alpha, beta, and gamma. Because of its unique antiviral properties and its ability to influence the immune response, interferon has long been considered a potential therapeutic intervention in the treatment of infections and possibly neoplastic diseases. Tw...

  3. EFFECTS OF p53 GENE THERAPY COMBINED WITH CYCLOOXYGENASE-2 INHIBITOR ON CYCLOOXYGENASE-2 GENE EXPRESSION AND GROWTH INHIBITION OF HUMAN LUNG CANCER CELLS

    Institute of Scientific and Technical Information of China (English)

    WANG Zhao-Xia; LU Bin-Bin; WANG Teng; YIN Yong-Mei; DE Wei; SHU Yong-Qian

    2007-01-01

    Background Gene therapy by adenovirus-mediated wild-type p53 gene transfer has been shown to inhibit lung cancer growth in vitro, in animal models, and in human clinical trials. The antitumor effect of selective cyclooxygenase (COX)-2 inhibitors has been demonstrated in preclinical studies. However, no information is available on the effects of p53 gene therapy combined with selective COX-2 inhibitor on COX-2 gene expression and growth inhibition of human lung cancer cells. Methods We evaluated the effects of recombinant adenovirus-p53 (Ad-p53) gene therapy combined with selective COX-2 inhibitor on the proliferation, apoptosis, cell cycle arrest of human lung adenocarcinoma A549 cell line, and the effects of tumor suppressor exogenous wild type p53 on COX-2 gene expression. Results Ad-p53 gene therapy combined with selective COX-2 inhibitor celecoxib shows significant synergistic inhibition effects on the growth of human lung adenocarcinoma A549 cell line. Exogenous p53 gene can suppress COX-2 gene expression. Conclusions Significant synergistic inhibition effects of A549 cell line by the combined Ad-p53 and selective COX-2 inhibitor celecoxib may be achieved by enhancement of growth inhibition, apoptosis induction and suppression of COX-2 gene expression. This study provides first evidence that the administration of p53 gene therapy in combination with COX-2 inhibitors might be a new clinical strategy for the treatment or prevention of NSCLC.

  4. Vascular endothelial growth factor and not cyclooxygenase 2 promotes endothelial cell viability in the pancreatic tumor microenvironment.

    LENUS (Irish Health Repository)

    Toomey, Desmond P

    2010-07-01

    Cyclooxygenase 2 (COX-2) and vascular endothelial growth factor (VEGF), often coexpressed in cancer, are associated with poor prognosis. However, results from pancreatic cancer trials of their inhibitors were disappointing. This study delineated the role of COX-2 and nonsteroidal anti-inflammatory drugs in angiogenesis and VEGF regulation.

  5. Cyclo-oxygenase-2 inhibitors or nonselective NSAIDs plus gastroprotective agents: What to prescribe in daily clinical practice?

    NARCIS (Netherlands)

    G.M.C. Masclee (Gwen); V.E. Valkhoff (Vera); E.M. van Soest; R. Schade (René); G. Mazzaglia (Giampiero); M. Molokhia (Mariam); G. Trifiro (Gianluca); J.L. Goldstein; S. Hernández-Díaz (Sonia); E.J. Kuipers (Ernst); M.C.J.M. Sturkenboom (Miriam)

    2013-01-01

    textabstractBackground Two strategies for prevention of upper gastrointestinal (UGI) events for nonselective nonsteroidal anti-inflammatory drug (nsNSAID) users are replacement of the nsNSAID by a cyclo-oxygenase-2-selective inhibitor (coxib) or co-prescription of a gastroprotective agent (GPA). Aim

  6. NS-398, a selective cyclooxygenase-2 inhibitor, reduces experimental bladder carcinoma outgrowth by inhibiting tumor cell proliferation.

    NARCIS (Netherlands)

    Smakman, N.; Schaap, N.P.M.; Snijckers, C.M.; Rinkes, M.J.; Kranenburg, O.

    2005-01-01

    OBJECTIVES: To evaluate the efficacy of the selective cyclooxygenase-2 (COX-2) inhibitor NS-398 in treating experimental T24 bladder carcinoma, and to assess its effect on tumor cell proliferation and survival and tumor vascularization. COX-2 overexpression is frequently observed in bladder carcinom

  7. Cyclo-oxygenase-2 inhibitors or nonselective NSAIDs plus gastroprotective agents: What to prescribe in daily clinical practice?

    NARCIS (Netherlands)

    G.M.C. Masclee (Gwen); V.E. Valkhoff (Vera); E.M. van Soest; R. Schade (René); G. Mazzaglia (Giampiero); M. Molokhia (Mariam); G. Trifiro (Gianluca); J.L. Goldstein; S. Hernández-Díaz (Sonia); E.J. Kuipers (Ernst); M.C.J.M. Sturkenboom (Miriam)

    2013-01-01

    textabstractBackground Two strategies for prevention of upper gastrointestinal (UGI) events for nonselective nonsteroidal anti-inflammatory drug (nsNSAID) users are replacement of the nsNSAID by a cyclo-oxygenase-2-selective inhibitor (coxib) or co-prescription of a gastroprotective agent (GPA). Aim

  8. Cyclooxygenase activity is important for efficient replication of mouse hepatitis virus at an early stage of infection

    NARCIS (Netherlands)

    Raaben, Matthijs; Einerhand, Alexandra W. C.; Taminiau, Lucas J. A.; van Houdt, Michel; Bouma, Janneke; Raatgeep, Rolien H.; Buller, Hans A.; de Haan, Cornelis A. M.; Rossen, John W. A.

    2007-01-01

    Cyclooxygenases (COXs) play a significant role in many different viral infections with respect to replication and pathogenesis. Here we investigated the role of COXs in the mouse hepatitis coronavirus (MHV) infection cycle. Blocking COX activity by different inhibitors or by RNA interference affecte

  9. Exacerbation of inflammatory bowel disease by nonsteroidal anti-inflammatory drugs and cyclooxygenase-2 inhibitors:Fact or fiction?

    Institute of Scientific and Technical Information of China (English)

    Mario Guslandi

    2006-01-01

    The existence of a possible link between inflammatory bowel disease (IBD) and nonsteroidal anti-inflammatory drugs (NSAIDs) has been repeatedly suggested. Recently, a few studies have addressed the issue of a possible,similar effect by selective cyclooxygenase-2 inhibitors (COXIBs). The present article reviews the available scientific evidence for this controversial subject.

  10. Cyclooxygenase 2: understanding the pathophysiological role through genetically altered mouse models.

    Science.gov (United States)

    Martín Sanz, Paloma; Hortelano, Sonsoles; Bosca, Lisardo; Casado, Marta

    2006-09-01

    Cyclooxygenase (COX) -1 and -2 catalyze the first step in the biosynthesis of prostanoids. COX-1 is constitutively expressed in many tissues and seems to be involved in the housekeeping function of prostanoids. COX-2, the inducible isoform, accounts for the elevated production of prostaglandins in response to various inflammatory stimuli, hormones and growth factors. COX-2 expression has been also associated with cell growth regulation, tissue remodelling and carcinogenesis. More of these characteristics have been elucidate through using COX selective inhibitors. Recent advances in transgenic and gene-targeting approaches allow a sophisticated manipulation of the mouse genome by gene addition, gene deletion or gene modifications. The development of COX-2 genetically altered mice has provided models to elucidate the physiological and pathophysiological roles of this enzyme.

  11. Cyclooxygenase-2 inhibitor enhances the efficacy of a breast cancer vaccine: role of IDO.

    Science.gov (United States)

    Basu, Gargi D; Tinder, Teresa L; Bradley, Judy M; Tu, Tony; Hattrup, Christine L; Pockaj, Barbara A; Mukherjee, Pinku

    2006-08-15

    We report that administration of celecoxib, a specific cyclooxygenase-2 (COX-2) inhibitor, in combination with a dendritic cell-based cancer vaccine significantly augments vaccine efficacy in reducing primary tumor burden, preventing metastasis, and increasing survival. This combination treatment was tested in MMTV-PyV MT mice that develop spontaneous mammary gland tumors with metastasis to the lungs and bone marrow. Improved vaccine potency was associated with an increase in tumor-specific CTLs. Enhanced CTL activity was attributed to a significant decrease in levels of tumor-associated IDO, a negative regulator of T cell activity. We present data suggesting that inhibiting COX-2 activity in vivo regulates IDO expression within the tumor microenvironment; this is further corroborated in the MDA-MB-231 human breast cancer cell line. Thus, a novel mechanism of COX-2-induced immunosuppression via regulation of IDO has emerged that may have implications in designing future cancer vaccines.

  12. Fluorocoxib A enables targeted detection of cyclooxygenase-2 in laser-induced choroidal neovascularization

    Science.gov (United States)

    Uddin, Md. Jashim; Moore, Chauca E.; Crews, Brenda C.; Daniel, Cristina K.; Ghebreselasie, Kebreab; McIntyre, J. Oliver; Marnett, Lawrence J.; Jayagopal, Ashwath

    2016-09-01

    Ocular angiogenesis is a blinding complication of age-related macular degeneration and other retinal vascular diseases. Clinical imaging approaches to detect inflammation prior to the onset of neovascularization in these diseases may enable early detection and timely therapeutic intervention. We demonstrate the feasibility of a previously developed cyclooxygenase-2 (COX-2) targeted molecular imaging probe, fluorocoxib A, for imaging retinal inflammation in a mouse model of laser-induced choroidal neovascularization. This imaging probe exhibited focal accumulation within laser-induced neovascular lesions, with minimal detection in proximal healthy tissue. The selectivity of the probe for COX-2 was validated in vitro and by in vivo retinal imaging with nontargeted 5-carboxy-X-rhodamine dye, and by blockade of the COX-2 active site with nonfluorescent celecoxib prior to injection of fluorocoxib A. Fluorocoxib A can be utilized for imaging COX-2 expression in vivo for further validation as an imaging biomarker in retinal diseases.

  13. Lipoperoxidation and cyclooxygenase enzyme inhibitory piperidine alkaloids from Cassia spectabilis green fruits.

    Science.gov (United States)

    Viegas, Cláudio; Silva, Dulce H S; Pivatto, Marcos; de Rezende, Amanda; Castro-Gambôa, Ian; Bolzani, Vanderlan S; Nair, Muraleedharan G

    2007-12-01

    Phytochemical work in the search for bioactive metabolites from the methanolic extract of Senna spectabilis green fruits led to the isolation of a new piperidine alkaloid, (+)-3- O-feruloylcassine ( 1), in addition to the known (-)-spectaline ( 2) and (-)-3- O-acetylspectaline ( 3). The isolates were submitted to in vitro evaluation of lipoperoxidation (LPO) and cyclooxygenase enzymes (COX-1 and -2) inhibitory properties and showed moderate antioxidant activities (40-70%) at 100 ppm when compared to commercial standards BHT and vitamin E and moderate inhibition of COX-1 (ca . 40%) and marginal inhibition of COX-2 enzymes (<10%) at 100 ppm when compared to nonsteroidal anti-inflammatory drugs (NSAIDs) aspirin, rofecoxib, and celecoxib, respectively.

  14. Immunoexpression of cyclooxygenase-2 in primary gastric carcinomas and lymph node metastases

    Institute of Scientific and Technical Information of China (English)

    Paulo RC Almeida; Francisco VA Ferreira; Cássio C Santos; Francisco D Rocha-Filho; Raul RP Feitosa; Esther AA Falc(a)o; Belise K Cavada; Roberto CP Lima-Júnior; Ronaldo A Ribeiro

    2012-01-01

    AIM:To evaluate immunoexpression of cyclooxygenase-2 (COX-2) in primary gastric carcinomas and respective lymph node metastases.METHODS:Immunohistochemistry to analyze COX-2 expression was performed on tissue microarray slices obtained from 36 specimens of gastrectomy and satellite lymph nodes from patients with gastric carcinoma.RESULTS:Immunostaining was seen in most cases,and COX-2 expression was higher in lymph node metastases than in corresponding primary gastric tumors of intestinal,diffuse and mixed carcinomas,with a statistically significant difference in the diffuse histotype (P=0.0108).CONCLUSION:COX-2 immunoexpression occurs frequently in primary gastric carcinomas,but higher expression of this enzyme is observed in lymph node metastases of the diffuse histotype.

  15. Up-regulation of cyclooxygenase-2 by product-prostaglandin E2

    Science.gov (United States)

    Tjandrawinata, R. R.; Hughes-Fulford, M.

    1997-01-01

    The development of prostate cancer has been linked to high level of dietary fat intake. Our laboratory investigates the connection between cancer cell growth and fatty acid products. Studying human prostatic carcinoma PC-3 cells, we found that prostaglandin E2 (PGE2) increased cell growth and up-regulated the gene expression of its own synthesizing enzyme, cyclooxygenase-2 (COX-2). PGE2 increased COX-2 mRNA expression dose-dependently with the highest levels of stimulation seen at the 3-hour period following PGE2 addition. The NSAID flurbiprofen (5 microM), in the presence of exogenous PGE2, inhibited the up-regulation of COX-2 mRNA and cell growth. These data suggest that the levels of local intracellular PGE2 play a major role in the growth of prostate cancer cells through an activation of COX-2 gene expression.

  16. Expression of cyclooxygenase-2 in prostate adenocarcinoma and benign prostatic hyperplasia.

    Science.gov (United States)

    Lee, L M; Pan, C C; Cheng, C J; Chi, C W; Liu, T Y

    2001-01-01

    Elevated expression of cyclo-oxygenase (COX)-2 has been found in several human cancers, including prostate adenocarcinoma. To evaluate the potential prognostic role of COX-2 in prostate cancer, we assessed the expression of COX-2 in benign prostatic hyperplasia (BPH) and prostate cancer samples employing immunohistochemistry. COX-2 was over-expressed in 15 out of 18 (83%) prostate cancer samples whereas it was detected in only 22% (4 of 18) paired benign tissues. The intensity of immunostaining correlated with the tumor grading. In addition, COX-2 was expressed in 7 of the 22 (32%) BPH samples examined. The significance a COX-2 expression in the BPH samples is not known at present. This data suggest that COX-2 is over-expressed in prostate cancer and COX-2 inhibitors may be useful in combination chemotherapy or chemoprevention for prostate cancer.

  17. Estrogen-dependent induction of cyclooxygenase-2 in the canine prostate in vivo.

    Science.gov (United States)

    Doré, M; Chevalier, S; Sirois, J

    2005-01-01

    Cyclooxygenase (COX)-2 is involved in several physiologic and pathologic processes. COX-2 is overexpressed in human and canine prostate cancer, but little is known about COX-2 inducers in the prostate. Our objective was to investigate the effect of sex steroid hormones on COX-2 expression in the canine prostate in vivo. COX-2 expression was evaluated by immunohistochemistry in intact and castrated dogs treated with exogenous androgen or estrogen. Results showed that no COX-2 staining was observed in prostates of untreated or androgen-treated castrated or intact dogs. However, treatment of intact and castrated dogs with estrogen resulted in squamous metaplasia with intense COX-2 expression observed in both squamous epithelial cells and in cells of acini without metaplasia. This is the first report to demonstrate the induction of COX-2 by estrogen in the prostate in vivo.

  18. Cyclooxygenase-2 inhibitors and free flap complications after autologous breast reconstruction

    DEFF Research Database (Denmark)

    Bonde, Christian; Khorasani, Hoda; Højvig, Jens

    2017-01-01

    because of the well-known side effects of NSAID treatment (bleeding/gastrointestinal ulcers). However, COX-2 inhibitors have been suggested to increase flap failure rates. We report our experience in using COX-2 inhibitors as part of our post-operative MOSA after ABR using free flaps. MATERIALS......BACKGROUND: A key component of modern analgesics is the use of multimodal opioid-sparing analgesia (MOSA). In the past, our analgesic regime after autologous breast reconstruction (ABR) included either NSAID or a selective cyclooxygenase-2 (COX-2) inhibitor. COX-2 inhibitors are superior to NSAIDs...... focus on reoperations due to bleeding/haematomas and flap thrombosis/failure. Comparisons between the COX-2 inhibitor and NSAID were made. RESULTS: Median age, ischaemia time, blood loss and operating time were similar in the two periods. Significantly, more patients were re-operated because of post...

  19. Low expression of cyclooxygenase-2 in chronic kidney disease in young dogs.

    Science.gov (United States)

    Yabuki, Akira; Miyazaki, Akiko; Ichii, Osamu; Kohyama, Moeko; Sawa, Mariko; Yamato, Osamu

    2016-12-01

    Chronic kidney disease (CKD) often results in end-stage renal failure in young dogs; however, the pathogenesis of this disease is not established. This study investigated renal expression of cyclooxygenase (COX)-1 and COX-2 proteins in three dogs with chronic kidney disease by immunohistochemistry. Histopathology showed asynchronous differentiation of renal tissues, including immature glomeruli. COX-1 signals were not detected in diseased or normal kidneys. COX-2 signals were low or undetectable in diseased kidneys, while normal kidneys showed clear positive signals in the macula densa (MD). Quantitative scores of COX-2 in diseased kidneys were significantly lower than those in normal kidneys. These findings demonstrate low renal COX-2 expression in CKD in young dogs, but whether this is correlated with disease pathogenesis remains unclear.

  20. TTF-1 action on the transcriptional regulation of cyclooxygenase-2 gene in the rat brain.

    Directory of Open Access Journals (Sweden)

    Chang Ho Yun

    Full Text Available We have recently found that thyroid transcription factor-1 (TTF-1, a homeodomain-containing transcription factor, is postnatally expressed in discrete areas of the hypothalamus and closely involved in neuroendocrine functions. We now report that transcription of cyclooxygenase-2 (COX-2, the rate limiting enzyme in prostaglandin biosynthesis, was inhibited by TTF-1. Double immunohistochemistry demonstrated that TTF-1 was expressed in the astrocytes and endothelial cells of blood vessel in the hypothalamus. Promoter assays and electrophoretic mobility shift assays showed that TTF-1 inhibited COX-2 transcription by binding to specific binding domains in the COX-2 promoter. Furthermore, blocking TTF-1 synthesis by intracerebroventricular injection of an antisense oligomer induced an increase of COX-2 synthesis in non-neuronal cells of the rat hypothalamus, and resulted in animals' hyperthermia. These results suggest that TTF-1 is physiologically involved in the control of thermogenesis by regulating COX-2 transcription in the brain.

  1. Cyclooxygenase active bioflavonoids from Balaton tart cherry and their structure activity relationships.

    Science.gov (United States)

    Wang, H; Nair, M G; Strasburg, G M; Booren, A M; Gray, I; Dewitt, D L

    2000-03-01

    Several flavonoids and isoflavonoids isolated from Balaton tart cherry were assayed for prostaglandin H endoperoxide synthase (PGHS-1) enzyme or cyclooxygenase isoform-1 (COX-1) activity. Genistein showed the highest COX-1 inhibitory activity among the isoflavonoids studied, with an IC50 value of 80 microM. Kaempferol gave the highest COX-1 inhibitory activity among the flavonoids tested, with an IC50 value of 180 microM. The structure-activity relationships of flavonoids and isoflavonoids revealed that hydroxyl groups at C4', C5 and C7 in isoflavonoids were essential for appreciable COX-1 inhibitory activity. Also, the C2-C3 double bond in flavonoids is important for COX-1 inhibitory activity. However, a hydroxyl group at the position decreased COX-1 inhibitory activity by flavonoids.

  2. Prognostic relevance of cyclooxygenase-2 (COX-2) expression in Chinese patients with prostate cancer.

    Science.gov (United States)

    Bin, Wu; He, Wang; Feng, Zhang; Xiangdong, Lu; Yong, Chen; Lele, Kou; Hongbin, Zhang; Honglin, Guo

    2011-02-01

    Cyclooxygenase-2 (COX-2), an inducible isoform of cyclooxygenase, has been reported to be correlated with tumorigenesis, tumor progression and metastasis. The present study was designed to investigate the clinicopathological and prognostic significance of COX-2 in Chinese patients with prostate cancer. Firstly, RT-PCR and Western blot assays were performed to detect the expression of COX-2 mRNA and protein in prostate cancer cell lines and 20 tissue samples (tumor or corresponding non-tumor). Next, immunohistochemistry was performed to detect the expression of COX-2 protein in 88 prostate cancer tissue samples. Finally, the correlation between COX-2 expression and clinicopathological factors and patient survival was evaluated. We found that the expression levels of COX-2 mRNA and protein showed significant difference among four prostate cancer cell lines. Moreover, the levels of COX-2 mRNA and protein were significantly higher in prostate cancer tissues than in corresponding non-tumor tissues. COX-2 staining was positive in the cytoplasm of prostate cancer cells. High-COX-2 expression was correlated with the Gleason score (P=0.009), tumor stage (P=0.012), and lymph-node status (P=0.036). Furthermore, patients with high-COX-2 expression showed lower disease-free (P=0.014) and overall survival (P=0.047) rates than those with low-COX-2 expression. Univariate and multivariate analyses suggested that the status of COX-2 protein expression was an independent prognostic indicator for patients' survival. Taken together, higher COX-2 protein expression might provide an independent prognostic marker for Chinese patients with prostate cancer who have undergone surgery.

  3. G-Protein–Coupled Receptors Signaling Pathways in New Antiplatelet Drug Development

    OpenAIRE

    Gurbel, Paul A.; Kuliopulos, Athan; Tantry, Udaya S.

    2015-01-01

    Platelet G-protein–coupled receptors influence platelet function by mediating the response to various agonists, including ADP, thromboxane A2, and thrombin. Blockade of the ADP receptor, P2Y12, in combination with cyclooxygenase-1 inhibition by aspirin has been among the most widely used pharmacological strategies to reduce cardiovascular event occurrence in high-risk patients. The latter dual pathway blockade strategy is one of the greatest advances in the field of cardiovascular medicine. I...

  4. Persisting eicosanoid pathways in rheumatic diseases.

    Science.gov (United States)

    Korotkova, Marina; Jakobsson, Per-Johan

    2014-04-01

    An unmet clinical need exists for early treatment of rheumatic diseases and improved treatment strategies that can better maintain remission with reduced ongoing subclinical inflammation and bone destruction. Eicosanoids form one of the most complex networks in the body controlling many physiological and pathophysiological processes, including inflammation, autoimmunity and cancer. Persisting eicosanoid pathways are thought to be involved in the development of rheumatic diseases, and targeting this pathway might enable improved treatment strategies. Several enzymes of the arachidonic acid cascade as well as eicosanoid receptors (all part of the eicosanoid pathway) are today well-recognized targets for anti-inflammatory drugs that can reduce symptoms of inflammation in rheumatic diseases. In this Review, we outline the evidence supporting pivotal roles of eicosanoid signalling in the pathogenesis of rheumatic diseases and discuss findings from studies in animals and humans. We focus first on rheumatoid arthritis and discuss the upregulation of the cyclooxygenase and lipoxygenase pathways as most data are available in this condition. Research into the roles of eicosanoids in other rheumatic diseases (osteoarthritis, idiopathic inflammatory myopathies, systemic lupus erythematosus and gout) is also progressing rapidly and is discussed. Finally, we summarize the prospects of targeting eicosanoid pathways as anti-inflammatory treatment strategies for patients with rheumatic diseases.

  5. miR-144 and targets, c-fos and cyclooxygenase-2 (COX2), modulate synthesis of PGE2 in the amnion during pregnancy and labor.

    Science.gov (United States)

    Li, Huanan; Zhou, Jiawei; Wei, Xiajie; Chen, Ran; Geng, Junnan; Zheng, Rong; Chai, Jin; Li, Fenge; Jiang, Siwen

    2016-06-14

    Labor is initiated as a result of hormonal changes that are induced by the activation of the inflammatory response and a series of biochemical events. The amnion, which is the primary source of prostaglandin E2 (PGE2), plays an important role in the process of labor. In the present study, we uncovered a pathway in which c-fos, cyclooxygenase-2 (COX2) and miR-144 function as hormonal modulators in the amnions of pregnant mice and humans. miR-144 down-regulated the synthesis of PGE2 during pregnancy by directly and indirectly inhibiting COX2 expression and by directly inhibiting the expression of c-fos, a transcriptional activator of COX2 and miR-144. Estrogen (E2) activated c-fos, thus promoting the expression of miR-144 and COX2 during labor. However, the increase in COX2 resulted in the partial inhibition of COX2 expression by miR-144, thereby slightly reducing the secretion of PGE2. These observations suggest that miR-144 inhibits PGE2 secretion by section to prevent the initiation of premature labor. Up-regulated expression of miR-144, c-fos and COX2 was also observed both in preterm mice and in mice undergoing normal labor. In summary, miR-144, c-fos and COX2 play important roles in regulating PGE2 secretion in the amnion during pregnancy and labor.

  6. Inhibition of breast cancer cell motility with a non-cyclooxygenase inhibitory derivative of sulindac by suppressing TGFβ/miR-21 signaling.

    Science.gov (United States)

    Yi, Bin; Chang, Hong; Ma, Ruixia; Feng, Xiangling; Li, Wei; Piazza, Gary A; Xi, Yaguang

    2016-02-16

    Compelling efficacy on intervention of tumorigenesis by nonsteroidal anti-inflammatory drugs (NSAIDs) has been documented intensively. However, the toxicities related to cyclooxygenase (COX) inhibition resulting in suppression of physiologically important prostaglandins limit their clinical use for human cancer chemoprevention. A novel derivative of the NSAID sulindac sulfide (SS), referred as sulindac sulfide amide (SSA), was recently developed, which lacks COX inhibitory activity, yet shows greater suppressive effect than SS on growth of various cancer cells. In this study, we focus on the inhibitory activity of SSA on breast tumor cell motility, which has not been studied previously. Our results show that SSA treatment at non-cytotoxic concentrations can specifically reduce breast tumor cell motility without influencing tumor cell growth, and the mechanism of action involves the suppression of TGFβ signaling by directly blocking Smad2/3 phosphorylation. Moreover, miR-21, a well-documented oncogenic miRNA for promoting tumor cell metastasis, was also found to be involved in inhibitory activity of SSA in breast tumor cell motility through the modulation of TGFβ pathway. In conclusion, we demonstrate that a non-COX inhibitory derivative of sulindac can inhibit breast tumor metastasis by a mechanism involving the TGFβ/miR-21 signaling axis.

  7. Tumor cyclooxygenase-2/prostaglandin E2-dependent promotion of FOXP3 expression and CD4+ CD25+ T regulatory cell activities in lung cancer.

    Science.gov (United States)

    Sharma, Sherven; Yang, Seok-Chul; Zhu, Li; Reckamp, Karen; Gardner, Brian; Baratelli, Felicita; Huang, Min; Batra, Raj K; Dubinett, Steven M

    2005-06-15

    Cyclooxygenase (COX)-2 and its product prostaglandin (PG) E2 underlie an immunosuppressive network that is important in the pathogenesis of non-small cell lung cancer. CD4+ CD25+ T regulatory (Treg) cells play an important role in maintenance of immunologic self-tolerance. CD4+ CD25+ Treg cell activities increase in lung cancer and appear to play a role in suppressing antitumor immune responses. Definition of the pathways controlling Treg cell activities will enhance our understanding of limitation of the host antitumor immune responses. Tumor-derived COX-2/PGE2 induced expression of the Treg cell-specific transcription factor, Foxp3, and increased Treg cell activity. Assessment of E-prostanoid (EP) receptor requirements revealed that PGE2-mediated induction of Treg cell Foxp3 gene expression was significantly reduced in the absence of the EP4 receptor and ablated in the absence of the EP2 receptor expression. In vivo, COX-2 inhibition reduced Treg cell frequency and activity, attenuated Foxp3 expression in tumor-infiltrating lymphocytes, and decreased tumor burden. Transfer of Treg cells or administration of PGE2 to mice receiving COX-2 inhibitors reversed these effects. We conclude that inhibition of COX-2/PGE2 suppresses Treg cell activity and enhances antitumor responses.

  8. Flavocoxid Inhibits Phospholipase A2, Peroxidase Moieties of the Cyclooxygenases (COX, and 5-Lipoxygenase, Modifies COX-2 Gene Expression, and Acts as an Antioxidant

    Directory of Open Access Journals (Sweden)

    Bruce P. Burnett

    2011-01-01

    Full Text Available The multiple mechanisms of action for flavocoxid relating to arachidonic acid (AA formation and metabolism were studied in vitro. Flavocoxid titrated into rat peritoneal macrophage cultures inhibited cellular phospholipase A2 (PLA2 (IC50 = 60 μg/mL. In in vitro enzyme assays, flavocoxid showed little anti-cyclooxygenase (CO activity on COX-1/-2 enzymes, but inhibited the COX-1 (IC50 = 12.3 and COX-2 (IC50 = 11.3 μg/mL peroxidase (PO moieties as well as 5-lipoxygenase (5-LOX (IC50 = 110 μg/mL. No detectable 5-LOX inhibition was found for multiple traditional and COX-2 selective NSAIDs. Flavocoxid also exhibited strong and varied antioxidant capacities in vitro and decreased nitrite levels (IC50 = 38 μg/mL in rat peritoneal macrophages. Finally, in contrast to celecoxib and ibuprofen, which upregulated the cox-2 gene, flavocoxid strongly decreased expression. This work suggests that clinically favourable effects of flavocoxid for management of osteoarthritis (OA are achieved by simultaneous modification of multiple molecular pathways relating to AA metabolism, oxidative induction of inflammation, and neutralization of reactive oxygen species (ROS.

  9. Effects of genetic deficiency of cyclooxygenase-1 or cyclooxygenase-2 on functional and histological outcomes following traumatic brain injury in mice

    Directory of Open Access Journals (Sweden)

    Scheff Stephen W

    2009-08-01

    Full Text Available Abstract Background Neuroinflammation contributes to the pathophysiology of acute CNS injury, including traumatic brain injury (TBI. Although prostaglandin lipid mediators of inflammation contribute to a variety of inflammatory responses, their importance in neuroinflammation is not clear. There are conflicting reports as to the efficacy of inhibiting the enzymes required for prostaglandin formation, cyclooxygenase (COX -1 and COX-2, for improving outcomes following TBI. The purpose of the current study was to determine the role of the COX isoforms in contributing to pathological processes resulting from TBI by utilizing mice deficient in COX-1 or COX-2. Results Following a mild controlled cortical impact injury, the amount of cortical tissue loss, the level of microglial activation, and the capacity for functional recovery was compared between COX-1-deficient mice or COX-2-deficient mice, and their matching wild-type controls. The deficiency of COX-2 resulted in a minor (6%, although statistically significant, increase in the sparing of cortical tissue following TBI. The deficiency of COX-1 resulted in no detectable effect on cortical tissue loss following TBI. As determined by 3[H]-PK11195 autoradiography, TBI produced a similar increase in microglial activation in multiple brain regions of both COX-1 wild-type and COX-1-deficient mice. In COX-2 wild-type and COX-2-deficient mice, TBI increased 3[H]-PK11195 binding in all brain regions that were analyzed. Following injury, 3[H]-PK11195 binding in the dentate gyrus and CA1 region of the hippocampus was greater in COX-2-deficient mice, as compared to COX-2 wild-type mice. Cognitive assessment was performed in the wild-type, COX-1-deficient and COX-2-deficient mice following 4 days of recovery from TBI. There was no significant cognitive effect that resulted from the deficiency of either COX-1 or COX-2, as determined by acquisition and spatial memory retention testing in a Morris water maze

  10. Regulation of cyclooxygenase-2 expression in rat oviductal epithelial cells: Evidence for involvement of GPR30/Src kinase-mediated EGFR signaling.

    Science.gov (United States)

    Popli, Pooja; Sirohi, Vijay Kumar; Manohar, Murli; Shukla, Vinay; Kaushal, Jyoti Bala; Gupta, Kanchan; Dwivedi, Anila

    2015-11-01

    The oviduct plays a crucial role in female reproduction by regulating gamete transport, providing a specific microenvironment for fertilization and early embryonic development. Cyclooxygenase (COX)-derived prostaglandins play essential role in carrying out these oviduct-specific functions. Estrogen upregulates COX-2 expression in rat oviduct; however, the mechanisms responsible for regulation of COX-2 expression in rat oviductal epithelial cells (OECs) remain unclear. In the present study, we proposed that estrogen induces COX-2 expression via G-protein coupled receptor i.e., GPR30 in OECs. To investigate this hypothesis, we examined the effects of E2-BSA, ICI 182,780, GPR30 agonist and GPR30 antagonist on COX-2 expression and explored potential signaling pathway leading to COX-2 expression. Co-localization experiments revealed GPR30 to be primarily located in the peri-nuclear space, which was also the site of E2-BSA-fluorescein isothiocyanate (E2-BSA-FITC) binding. The E2-BSA induced-COX-2 and prostaglandin release were subjected to regulation by both EGFR and PI3K signaling as inhibitors of c-Src kinase (PP2), EGFR (EGFR inhibitor) and PI-3 kinase (LY294002) attenuated E2-BSA mediated effect. These results suggest that EGFR transactivation leading to activation of PI-3K/Akt pathway participates in COX-2 expression in rat OECs. Interestingly, E2-BSA induced COX-2 expression and subsequent prostaglandin release were abolished by NF-κB inhibitor. In addition, E2-BSA induced the nuclear translocation of p65-NF-κB and up-regulated the NF-κB promoter activity in rat OECs. Taken together, results demonstrated that E2-BSA induced the COX-2 expression and consequent PGE2 and PGF2α release in rat OECs. These effects are mediated through GPR30-derived EGFR transactivation and PI-3K/Akt cascade leading to NF-κB activation.

  11. Correlation of β-Catenin Localization with Cyclooxygenase-2 Expression and CpG Island Methylator Phenotype (CIMP in Colorectal Cancer

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    Takako Kawasaki

    2007-07-01

    Full Text Available The WNT/β-catenin (CTNNB1 pathway is commonly activated in the carcinogenic process. Cross-talks between the WNT and cyclooxygenase-2 (COX-2 or PTGS2/prostaglandin pathways have been suggested. The relationship between (3-catenin activation and microsatellite instability (MSI in colorectal cancer has been controversial. The CpG island methylator phenotype (CIMP or CIMP-high with widespread promoter methylation is a distinct epigenetic phenotype in colorectal cancer, which is associated with MSI-high. However, no study has examined the relationship between (β-catenin activation and CIMP status. Using 832 population-based colorectal cancer specimens, we assessed (3-catenin localization by immunohistochemistry. We quantified DNA methylation in eight CIMP-specific promoters [CACNA1G, CDKN2A(p16, CRABP1, IGF2, MLH1, NEUROG1, RUNX3, and SOCS1] by real-time polymerase chain reaction (MethyLight. MSI-high, CIMP-high, and BRAF mutation were associated inversely with cytoplasmic and nuclear (β-catenin expressions (i.e., β-catenin activation and associated positively with membrane expression. The inverse relation between (β-catenin activation and CIMP was independent of MSI. COX-2 overexpression correlated with cytoplasmic (β-catenin expression (even after tumors were stratified by CIMP status, but did not correlate significantly with nuclear or membrane expression. In conclusion, β-catenin activation is inversely associated with CIMP-high independent of MSI status. Cytoplasmic β-catenin is associated with COX-2 overexpression, supporting the role of cytoplasmic β-catenin in stabilizing PTGS2(COX-2 mRNA.

  12. Prostate Tumor Growth Can Be Modulated by Dietarily Targeting the 15-Lipoxygenase-1 and Cyclooxygenase-2 Enzymes

    Directory of Open Access Journals (Sweden)

    Uddhav P. Kelavkar

    2009-07-01

    Full Text Available The main objectives of our study were to determine the bioavailability of omega-3 (ω-3 to the tumor, to understand its mechanisms, and to determine the feasibility of targeting the ω-6 polyunsaturated fatty acids (PUFAs metabolizing 15-lipoxygenase-1 (15-LO-1 and cyclooxygenase-2 (COX-2 pathways. Nude mice injected subcutaneously with LAPC-4 prostate cancer cells were randomly divided into three different isocaloric (and same percent [%] of total fat diet groups: high ω-6 linoleic acid (LA, high ω-3 stearidonic acid (SDA PUFAs, and normal (control diets. Tumor growth and apoptosis were examined as end points after administration of short-term (5 weeks ω-3 and ω-6 fatty acid diets. Tumor tissue membranes were examined for growth, lipids, enzyme activities, apoptosis, and proliferation. Tumors from the LA diet-fed mice exhibited the most rapid growth compared with tumors from the control and SDA diet-fed mice. Moreover, a diet switch from LA to SDA caused a dramatic decrease in the growth of tumors in 5 weeks, whereas tumors grew more aggressively when mice were switched from an SDA to an LA diet. Evaluating tumor proliferation (Ki-67 and apoptosis (caspase-3 in mice fed the LA and SDA diets suggested increased percentage proliferation index from the ω-6 diet-fed mice compared with the tumors from the ω-3 SDA-fed mice. Further, increased apoptosis was observed in tumors from ω-3 SDA diet-fed mice versus tumors from ω-6 diet-fed mice. Levels of membrane phospholipids of red blood cells reflected dietary changes and correlated with the levels observed in tumors. Linoleic or arachidonic acid and metabolites (eicosanoid/prostaglandins were analyzed for 15-LO-1 and COX-2 activities by high-performance liquid chromatography. We also examined the percent unsaturated or saturated fatty acids in the total phospholipids, PUFA ω-6/ω-3 ratios, and other major enzymes (elongase, Delta [Δ]-5-desaturase, and Δ-6-desaturase of ω-6 catabolic

  13. Efficacy of cyclo-oxygenase-2 inhibition by etoricoxib and naproxen on the axial manifestations of ankylosing spondylitis in the presence of peripheral arthritis

    OpenAIRE

    Gossec, L; van der Heijde, D.; Melian, A; Krupa, D.; James, M.; Cavanaugh, P; Reicin, A; Dougados, M.

    2005-01-01

    Objective: The combined efficacy of selective and non-selective cyclo-oxygenase-2 (COX-2) inhibition on the axial manifestations of ankylosing spondylitis (AS) in the presence or absence of chronic peripheral arthritis was evaluated.

  14. Regulation of cyclooxygenase-2 expression by cAMP response element and mRNA stability in a human airway epithelial cell line exposed to zinc

    Science.gov (United States)

    Exposure to zinc-laden particulate matter in ambient and occupational settings has been associated with proinflammatory responses in the lung. Cyclooxygenase 2-derived eicosanoids are important modulators of airway inflammation. In this study, we characterized the transcriptional...

  15. Cyclooxygenase-2 (COX-2) Polymorphisms and Risk of Inflammatory Bowel Disease in a Scottish and Danish Case–Control Study

    DEFF Research Database (Denmark)

    Andersen, Vibeke; Nimmo, Elaine; Krarup, Henrik B.;

    2011-01-01

    Background: Inflammatory bowel diseases (IBDs) are a result of interactions between luminal pathogens and the intestinal immune response. Cyclooxygenase-2 (COX-2) plays a key role in the regulation of the inflammatory response upon stimulation by luminal pathogens via Toll-like receptors. Methods...... among never-smokers, suggesting that low activity of COX-2 may predispose to UC. Our results suggest that inclusion of smoking status may be essential for the evaluation of the role of genetic predisposition to IBD....

  16. Role of mast cells and protease-activated receptor-2 in cyclooxygenase-2 expression in urothelial cells

    OpenAIRE

    Wang, Zun-Yi; Wang, Peiqing; Bjorling, Dale E.

    2009-01-01

    Mast cells have been shown to play a role in development and persistence of various inflammatory bladder disorders. Mast cell-derived tryptase specifically activates protease-activated receptor-2 (PAR-2), and PAR-2 is known to be involved in inflammation. We investigated whether mast cells participate in increase of cyclooxygenase-2 (COX-2) protein abundance in urothelium/suburothelium of bladders of mice subsequent to cyclophosphamide (CYP)-induced bladder inflammation. We also used primary ...

  17. Mechanism of the irreversible inhibition of human cyclooxygenase-1 by aspirin as predicted by QM/MM calculations.

    Science.gov (United States)

    Tóth, L; Muszbek, L; Komáromi, I

    2013-03-01

    Acetylsalicylic acid (aspirin) suppresses the generation of prostaglandin H2, which is the precursor of thromboxane A2. Aspirin acts as an acetylating agent in which its acetyl group is covalently attached to a serine residue (S530) in the active site of the cyclooxygenase-1 enzyme. The exact reaction mechanism has not been revealed by experimental methods. In this study the putative structure of human cyclooxygenase-1 was constructed from ovine cyclooxygenase-1 by homology modeling, and the acetylsalicylic acid was docked into the arachidonic acid binding cavity of the enzyme. To characterize the shape of the potential energy surface of the acetylating reaction and to determine the relative energies of the stationary points on the surface, a series of ONIOM-type quantum mechanical/molecular mechanical (QM/MM) calculations were carried out at different QM levels of theories applying electronic embedding approximations. The acetylsalicylic acid and the surrounding amino acids were included in these calculations. Frequency analyses were performed to prove the existence of first order saddle points (representing transition states) and local minima on the potential energy surface. It was found that all levels of theories predicted similar transition state geometries. The activation energy values, however, demonstrated significant dependence on the methods that were applied. All the applied "dependable" ab initio and DFT methods predicted that the breakage of the S530 Oγ--Hγ and formation of the Oγ--C(acetylsalicylic acid carbonyl) bonds occur in a single elementary step. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. Virtual and in vitro bioassay screening of phytochemical inhibitors from flavonoids and isoflavones against xanthine oxidase and cyclooxygenase-2 for gout treatment.

    Science.gov (United States)

    Li, Yadi; Frenz, Christopher M; Li, Zhiwen; Chen, Mianhua; Wang, Yurong; Li, Fengjuan; Luo, Cheng; Sun, Jian; bohlin, Lars; Li, Zhenjing; Yang, Hua; Wang, Changlu

    2013-04-01

    Synthetic drugs such as allopurinol and benzbromarone are commonly used to treat the complex pathogenesis of gout, a metabolic disease that results from an inflammation of the joints caused by precipitation of uric acid. We seek to discover novel phytochemicals that could treat gout, by targeting the xanthine oxidase and cyclooxygenase-2 enzymes. In this study, we report the screening of nine compounds of flavonoids from the ZINC and PubChem databases (containing 2092 flavonoids) using the IGEMDOCK software tool against the xanthine oxidase and cyclooxygenase-2 3D protein structures. Each compound was also evaluated by an in vitro bioassay testing the inhibition of xanthine oxidase and cyclooxygenase-2. Myricetin and luteolin were found to be the potential dual inhibitors of xanthine oxidase and cyclooxygenase-2 as demonstrated by IC(50): 62.7 and 3.29 μg/mL (xanthine oxidase)/70.8 and 16.38 μg/mL (cyclooxygenase-2), respectively. In addition, structure-activity relationships and other important factors of the flavonoids binding to the active site of xanthine oxidase and cyclooxygenase-2 were discussed, which is expected for further rational drug design.

  19. Characterization of the effects of cyclooxygenase-2 inhibition in the regulation of apoptosis in human small and non-small cell lung cancer cell lines.

    LENUS (Irish Health Repository)

    Alam, Mahmood

    2012-02-03

    BACKGROUND: Cyclooxygenase-2 enzyme (COX-2) is overexpressed in human non-small cell lung cancer (NSCLC) but is not expressed in small cell lung cancer. Selective COX-2 inhibitors have been shown to induce apoptosis in NSCLC cells, an effect which is associated with the regulation of intracellular MAP kinase (MAPK) signal pathways. Our aims were to characterize the effects of COX-2 inhibition by rofecoxib on apoptosis in human NSCLC and small cell lung cancer cell lines. METHODS: The human NSCLC cell line NCI-H2126 and small cell lung cancer cell line DMS-79 were used. Constitutive COX-2 protein levels were first determined by Western blot test. Levels of apoptosis were evaluated by using propidium iodide staining on FACScan analysis after incubation of NCI-H2126 and DMS-79 with p38 MAPK inhibitor SB202190 (25 ?microM), NF-kappaB inhibitor SN50 (75 microg\\/mL), and rofecoxib at 100 and 250 microM. All statistical analysis was performed by analysis of variance. RESULTS: Western blot test confirmed the presence of COX-2 enzyme in NCI-H2126 and absence in DMS-79. Interestingly, rofecoxib treatment demonstrated a dose-dependent increase in apoptosis in both cell lines. Given this finding, the effect of rofecoxib on NF-kappaB and p38 MAPK pathways was also examined. Apoptosis in both cell lines was unaltered by SN50, either alone or in combination with rofecoxib. A similar phenomenon was observed in NCI-H2126 cells treated with SB202190, either alone or in combination with rofecoxib. In contrast, p38 MAPK inhibition greatly upregulated DMS-79 apoptosis in a manner that was unaltered by the addition of rofecoxib. CONCLUSIONS: Rofecoxib led to a dose-dependent increase in apoptosis in both tumor cell lines. This effect occurred independently of COX-2, NF-kappaB, and p38 MAPK pathways in DMS-79 cells. As such, rofecoxib must act on alternative pathways to regulate apoptosis in human small cell lung cancer cells.

  20. IN SILICO STUDIES ON Tithonia Diversifolia DERIVED PHYTOCHEMICALS AS POTENT INHIBITOR OF CYCLOOXYGENASE

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    OLUWAMODUPE CECILIA EJELONU

    2016-04-01

    Full Text Available Objectives: Prostaglandins released by the activity of the bifunctional enzyme, cyclooxygenase (COX are involved in physiological functions such as protection of the stomach mucosa, aggregation of platelets and regulation of kidney function. Conversely, prostaglandins have been implicated in inflammation, thereby representing an important target for non-steroidal anti-inflammatory drugs.Material and methods: In this study, natural compounds from Tithonia diversifolia (a known anti-inflammatory plant have been evaluated for their interaction with COX in comparison with ibuprofen using computational methods. T. diversifolia phytocompounds were docked into COX active site using Autodock/Vina Plugin in PyMol.Result: All phytocompounds from T. diversifolia show better interactions than ibuprofen with myricetin and quercetin having the highest binding energy of -9.1 Kcal/mol (ibuprofen -6.2 Kcal/mol.Conclusion: These phytocompounds can be considered as potential COX inhibitor thereby leading credence to the use of T. diversifolia as an anti-inflammatory plant.

  1. Curcumin-attenuated trinitrobenzene sulphonic acid induces chronic colitis by inhibiting expression of cyclooxygenase-2

    Institute of Scientific and Technical Information of China (English)

    Hua Jiang; Chang-Sheng Deng; Ming Zhang; Jian Xia

    2006-01-01

    AIM: To explore the possible mechanisms of curcumin in rat colitis induced by trinitrobenzene sulfonic (TNBS) acid. METHODS: Rats with TNBS acid-induced colitis were treated with curcumin (30 mg/kg or 60 mg/kg per day ip). Changes of body weight and histological scores as well as survival rate were evaluated. Leukocyte infiltration was detected by myeloperoxidase (MPO)activity assay. The expression of cyclooxygenase-2(COX-2) was detected by RT-PCR and Western blot.Inflammation cytokines were determined by RT-PCR.Local concentration of prostaglandin E2 (PGE2) in colon mucosa was determined by ELISA.RESULTS: Curcumin improved survival rate and histological image, decreased the macroscopic scores and MPO activity. Also curcumin reduced the expression of COX-2 and inflammation cytokines. In addition,treatment with curcumin increased the PGE2 level.CONCLUSION: Curcumin has therapeutic effects on TNBS acid-induced colitis, the mechanisms seem to be related to COX-2 inhibition and PGE2 improvement.

  2. Increased expression of cyclooxygenase-2 in first-degree relatives of gastric cancer patients

    Institute of Scientific and Technical Information of China (English)

    Jin-Ting Zhang; Ming-Wei Wang; Zhen-Long Zhu; Xiao-Hui Huo; Jian-Kun Chu; Dong-Sheng Cui; Liang Qiao; Jun Yu

    2005-01-01

    AIM: To study the expression of cyclooxygenase-2 (COX-2)in human gastric cancer tissues and their paired adjacent mucosa, as well as mucosa from gastric antrum and corpus of the first-degree relatives of the recruited cancer patients.METHODS: The expression of COX-2 mRNA in 38 patients with gastric cancer and their 29 first-degree relatives and 18 healthy controls was assessed by the real time RT-PCR.The expression of COX-2 protein was determined by Western blot.RESULTS: A marked increase in COX-2 mRNA expression was found in 20 of 37 (54%) cancerous tissues compared to their respective paired normal mucosa (P<0.001).Interestingly, increased COX-2 mRNA expression was also found in mucosa of the corpus (6/29) and antrum (13/29)of their first-degree relatives. Increased COX-2 mRNA expression was more frequently observed in the antrum biopsies from cancer patients than in the antrum biopsies from healthy controls (P<0.05). In addition, 3 of 23 (13%)patients with atrophic mucosa and 6 of 35 (17%) patients with intestinal metaplasia showed increased COX-2 mRNA expression. Furthermore, COX-2 expression increased in H pylori-positive tissues, especially in antrum mucosa.CONCLUSION: Increased COX-2 expression is involved in gastric carcinogenesis, and may be necessary for maintenance of the malignant phenotype and contribute to Helicobacterpylori-associated malignant transformation.

  3. Cyclooxygenase-2 inhibitor inhibits hippocampal synaptic reorganization in pilocarpine-induced status epilepticus rats

    Institute of Scientific and Technical Information of China (English)

    Hai-ju ZHANG; Ruo-peng SUN; Ge-fei LEI; Lu YANG; Chun-xi LIU

    2008-01-01

    Objective: To examine modulations caused by cyclooxygenase-2 (COX-2) inhibitors on altered microenvironments and overbalanced neurotransmitters in pilocarpine-induced epileptic status rats and to investigate possible mechanisms. Methods:Celecoxib (a COX-2 inhibitor) was administered 45 min prior to pilocarpine administration. The effects of COX-2 inhibitors on mIPSCs (miniature GABAergic inhibitory postsynaptic currents) of CA3 pyramidal cells in the hippocampus were recorded. Expressions of COX-2, c-Fos, newly generated neurons, and activated microgliosis wore analyzed by immunohistochemistry, and expressions of α-subunit of γ-amino butyric acid (GABAA) receptors and mitogen-activated protein kinase/extracellular sig-nal-regulated protein kinase (MAPK/ERK) activity were detected by Western blotting. Results: Pretreatment with celecoxib showed protection against pilocarpine-induced seizures. Celecoxib prevented microglia activation in the hilus and inhibited the abnormal neurogenesis and astrogliosis in the hippocampus by inhibiting MAPK/ERK activity and c-Fos transcription. Celecoxib also up-regulated the expression of GABAA receptors. NS-398 (N-2-cyclohexyloxy-4-nitrophenyl-methanesuifonamide), another COX-2 inhibitor, enhanced the frequency and decay time of mIPSCs. Conclusion: The COX-2 inhibitor celecoxib decreased neuronal excitability and prevented epileptogenesis in pilocarpine-induced status epilepticus rats. Celecoxib regulates synaptic reorganization by inhibiting astrogliosis and ectopic neurogenesis by attenuating MAPK/ERK signal activity, mediated by a GABAergic mechanism.

  4. Study of Osteoarthritis Treatment with Anti-Inflammatory Drugs: Cyclooxygenase-2 Inhibitor and Steroids

    Directory of Open Access Journals (Sweden)

    Hongsik Cho

    2015-01-01

    Full Text Available Patients with osteoarthritis (OA, a condition characterized by cartilage degradation, are often treated with steroids, nonsteroidal anti-inflammatory drugs (NSAIDs, and cyclooxygenase-2 (COX-2 selective NSAIDs. Due to their inhibition of the inflammatory cascade, the drugs affect the balance of matrix metalloproteinases (MMPs and inflammatory cytokines, resulting in preservation of extracellular matrix (ECM. To compare the effects of these treatments on chondrocyte metabolism, TNF-α was incubated with cultured chondrocytes to mimic a proinflammatory environment with increasing production of MMP-1 and prostaglandin E2 (PGE2. The chondrocytes were then treated with either a steroid (prednisone, a nonspecific COX inhibitor NSAID (piroxicam, or a COX-2 selective NSAID (celecoxib. Both prednisone and celecoxib decreased MMP-1 and PGE-2 production while the nonspecific piroxicam decreased only the latter. Both prednisone and celecoxib decreased gene expression of MMP-1 and increased expression of aggrecan. Increased gene expression of type II collagen was also noted with celecoxib. The nonspecific piroxicam did not show these effects. The efficacy of celecoxib in vivo was investigated using a posttraumatic OA (PTOA mouse model. In vivo, celecoxib increases aggrecan synthesis and suppresses MMP-1. In conclusion, this study demonstrates that celecoxib and steroids exert similar effects on MMP-1 and PGE2 production in vitro and that celecoxib may demonstrate beneficial effects on anabolic metabolism in vivo.

  5. New sterols with anti-inflammatory potentials against cyclooxygenase-2 and 5-lipoxygenase from Paphia malabarica.

    Science.gov (United States)

    Joy, Minju; Chakraborty, Kajal; Raola, Vamshi Krishna

    2017-06-01

    Marine bivalves occupy a leading share in the total edible molluscs at the coastline regions of south-eastern Asia, and are found to possess significant nutritional and biological potential. Various in vitro evaluation (antioxidant and anti-inflammatory) guided purification of ethyl acetate-methanol (EtOAc-MeOH) extract of bivalve clam, Paphia malabarica characterised two new sterol derivatives as 23-gem-dimethylcholesta-5-en-3β-ol (1) and (22E)-24(1),24(2)-methyldihomocholest-5,22-dien-3β-ol (2) collected from the south-west coast of Arabian Sea. Their structures were unambiguously assigned on the basis of 1D, 2D NMR spectroscopy and mass spectrometry. The antioxidant and anti-inflammatory activities of 2 as determined by DPPH/ABTS(+) radical scavenging and anti-cyclooxygenase-2/5-lipoxygenase assays were significantly greater (IC50  1 mg/mL). Structure-activity relationship analysis revealed that the bioactivities of these compounds were directly proportional to the electronic and lipophilic parameters. This is the first report of the occurrence and characterisation of 23-gem-dimethyl-3β-hydroxy-Δ(5)-cholestane nucleus and C-30 dihomosterol from marine organisms.

  6. Silkworm Thorn Stem Extract Targets RSK2 and Suppresses Solar UV-Induced Cyclooxygenase-2 Expression

    Directory of Open Access Journals (Sweden)

    Jong-Eun Kim

    2015-10-01

    Full Text Available Excessive exposure to solar UV (sUV is associated with numerous human skin disorders, such as carcinogenesis, skin photoaging and skin inflammation. Silkworm Thorn (Cudraniatricuspidata, SW is a plant belonging to the Moraceae family and widely present throughout Korea, China, and Japan. Most parts of the tree (including the fruit, leaf, stem, root, and bark is consumable as a functional food or tea. In this study, we found that SW extract (SWE inhibited the elevated expression of sUV-induced cyclooxygenase (COX-2 levels in both HaCaT and JB6 cells. Levels of nuclear factor-κB and activator protein-1, two crucial transcription factors involved in COX-2 expression, were elevated by sUV treatment. Treatment with SWE abolished this activation. SWE also inhibited sUV-induced histone H3 phosphorylation. However, sUV-induced phosphorylation of Akt, c-Jun N-terminal kinase and p38 kinase remained unchanged in the presence of SWE. SWE inhibited RSK2 activity, and pull-down assays using SWE-Sepharose beads revealed that SWE binds directly with RSK2 in an ATP-competitive manner. These results suggest a potential for SWE to be developed as a cosmeceutical material and functional food constituent for the promotion of skin health.

  7. The effects of cyclo-oxygenase inhibitors on bile-injured and normal equine colon.

    Science.gov (United States)

    Campbell, N B; Jones, S L; Blikslager, A T

    2002-07-01

    A potential adverse effect of cyclo-oxygenase (COX) inhibitors (nonsteroidal anti-inflammatory drugs [NSAIDs]) in horses is colitis. In addition, we have previously shown an important role for COX-produced prostanoids in recovery of ischaemic-injured equine jejunum. It was hypothesised that the nonselective COX inhibitor flunixin would retard repair of bile-injured colon by preventing production of reparative prostaglandins, whereas the selective COX-2 inhibitor, etodolac would not inhibit repair as a result of continued COX-1 activity. Segments of the pelvic flexure were exposed to 1.5 mmol/l deoxycholate for 30 min, after which they were recovered for 4 h in Ussing chambers. Contrary to the proposed hypothesis, recovery of bile-injured colonic mucosa was not affected by flunixin or etodolac, despite significantly depressed prostanoid production. However, treatment of control tissue with flunixin led to increases in mucosal permeability, whereas treatment with etodolac had no significant effect. Therefore, although recovery from bile-induced colonic injury maybe independent of COX-elaborated prostanoids, treatment of control tissues with nonselective COX inhibitors may lead to marked increases in permeability. Alternatively, selective inhibition of COX-2 may reduce the incidence of adverse effects in horses requiring NSAID therapy.

  8. Cyclooxygenase-1-selective inhibitors based on the (E)-2'-des-methyl-sulindac sulfide scaffold.

    Science.gov (United States)

    Liedtke, Andy J; Crews, Brenda C; Daniel, Cristina M; Blobaum, Anna L; Kingsley, Philip J; Ghebreselasie, Kebreab; Marnett, Lawrence J

    2012-03-08

    Prostaglandins (PGs) are powerful lipid mediators in many physiological and pathophysiological responses. They are produced by oxidation of arachidonic acid (AA) by cyclooxygenases (COX-1 and COX-2) followed by metabolism of endoperoxide intermediates by terminal PG synthases. PG biosynthesis is inhibited by nonsteroidal anti-inflammatory drugs (NSAIDs). Specific inhibition of COX-2 has been extensively investigated, but relatively few COX-1-selective inhibitors have been described. Recent reports of a possible contribution of COX-1 in analgesia, neuroinflammation, or carcinogenesis suggest that COX-1 is a potential therapeutic target. We designed, synthesized, and evaluated a series of (E)-2'-des-methyl-sulindac sulfide (E-DMSS) analogues for inhibition of COX-1. Several potent and selective inhibitors were discovered, and the most promising compounds were active against COX-1 in intact ovarian carcinoma cells (OVCAR-3). The compounds inhibited tumor cell proliferation but only at concentrations >100-fold higher than the concentrations that inhibit COX-1 activity. E-DMSS analogues may be useful probes of COX-1 biology in vivo and promising leads for COX-1-targeted therapeutic agents.

  9. Review: molecular pathology of cyclooxygenase-2 in cancer-induced angiogenesis.

    Science.gov (United States)

    Fosslien, E

    2001-10-01

    Cancer-induced angiogenesis is the result of increased expression of angiogenic factors, or decreased expression of anti-angiogenic factors, or a combination of both events. For instance, in colon cancer, the malignant cells, the stromal fibroblasts, and the endothelial cells all exhibit strong staining for cyclooxygenase-2 (COX-2), the rate-controlling enzyme in prostaglandin (PG) synthesis. In various cancer tissues, vascular endothelial growth factor (VEGF) and transforming growth factor beta (TGF-beta) co-localize with COX-2. Strong COX-2 and VEGF expression is highly correlated with increased tumor microvascular density (MCD); new vessels proliferate in areas of the tumor that express COX-2. Moreover, high MVD is a predictor of poor prognosis in breast and cervical cancers. COX-2 and VEGF expression are elevated in breast and prostate cancer tissues and their cell-lines. In vitro, PGE2 induces VEGE Supernatants of cultured cells from breast, prostate, and squamous cell cancers contain angiogenic proteins such as COX-2 and VEGF that induce in vitro angiogenesis. A selective COX-2 inhibitor, NS-398, restores tumor cell apoptosis, reduces microvascular density, and reduces tumor growth of PC-3 prostate carcinoma cells xenografted into nude mice. The COX-2 produced by a malignant tumor and COX-2 produced by the surrounding host tissue both contribute to new vessel formation, which explains how selective COX-2 inhibition reduces tumor growth where the tumor COX-2 gene has been silenced by methylation.

  10. Induction of apoptosis by cyclooxygenase-2 inhibitors in prostate cancer cell lines.

    Science.gov (United States)

    Kamijo, T; Sato, T; Nagatomi, Y; Kitamura, T

    2001-07-01

    Prostaglandins are thought to play an important role in the proliferation of prostate cancer and are highly expressed in prostate cancer tissue. Cyclooxygenase-2 (COX-2), or prostaglandin endoperoxide synthase, is a key enzyme in the conversion of arachidonic acid into prostaglandin. In several cancers, COX-2 contributes to the proliferation and metastasis of cancer cells. To assess the role of COX-2 in prostate cancer, we investigated whether the inhibition of COX-2 affected the proliferation of prostate cancer cells. The human prostate cancer cell lines, LNCaP and PC 3, and a normal prostate stromal cell line (PrSC) were treated with COX-2 inhibitors NS 398 and Etodolac. The proliferation rate of the cell lines was examined using 3(4,5-dimethylethiazoly 1-2-) 2,5-diphonyl tetrazolium bromide (MTT) assays. A DNA fragmentation assay was also used for proof of apoptosis. COX-2 inhibitors could suppress the proliferation of LNCaP and PC 3 cells. In contrast, PrSC was not affected by COX-2 inhibitors. These suppressive effects occurred in a time- and dose-dependent manner. One of mechanisms responsible for cell death was apoptosis. COX-2 seems to play a significant role in the progression of prostate cancer. COX-2 may be a therapeutic target for prostate cancer. Since COX-2 inhibitors suppress proliferation and induce apoptosis in prostate cancer cells, and have no effect in normal prostate stromal cells, COX-2 inhibitors will be useful for the treatment of prostate cancer.

  11. Cyclooxygenase-2: A Role in Cancer Stem Cell Survival and Repopulation of Cancer Cells during Therapy

    Directory of Open Access Journals (Sweden)

    Lisa Y. Pang

    2016-01-01

    Full Text Available Cyclooxygenase-2 (COX-2 is an inducible form of the enzyme that catalyses the synthesis of prostanoids, including prostaglandin E2 (PGE2, a major mediator of inflammation and angiogenesis. COX-2 is overexpressed in cancer cells and is associated with progressive tumour growth, as well as resistance of cancer cells to conventional chemotherapy and radiotherapy. These therapies are often delivered in multiple doses, which are spaced out to allow the recovery of normal tissues between treatments. However, surviving cancer cells also proliferate during treatment intervals, leading to repopulation of the tumour and limiting the effectiveness of the treatment. Tumour cell repopulation is a major cause of treatment failure. The central dogma is that conventional chemotherapy and radiotherapy selects resistant cancer cells that are able to reinitiate tumour growth. However, there is compelling evidence of an active proliferative response, driven by increased COX-2 expression and downstream PGE2 release, which contribute to the repopulation of tumours and poor patient outcome. In this review, we will examine the evidence for a role of COX-2 in cancer stem cell biology and as a mediator of tumour repopulation that can be molecularly targeted to overcome resistance to therapy.

  12. Prospective performance evaluation of selected common virtual screening tools. Case study: Cyclooxygenase (COX) 1 and 2.

    Science.gov (United States)

    Kaserer, Teresa; Temml, Veronika; Kutil, Zsofia; Vanek, Tomas; Landa, Premysl; Schuster, Daniela

    2015-01-01

    Computational methods can be applied in drug development for the identification of novel lead candidates, but also for the prediction of pharmacokinetic properties and potential adverse effects, thereby aiding to prioritize and identify the most promising compounds. In principle, several techniques are available for this purpose, however, which one is the most suitable for a specific research objective still requires further investigation. Within this study, the performance of several programs, representing common virtual screening methods, was compared in a prospective manner. First, we selected top-ranked virtual screening hits from the three methods pharmacophore modeling, shape-based modeling, and docking. For comparison, these hits were then additionally predicted by external pharmacophore- and 2D similarity-based bioactivity profiling tools. Subsequently, the biological activities of the selected hits were assessed in vitro, which allowed for evaluating and comparing the prospective performance of the applied tools. Although all methods performed well, considerable differences were observed concerning hit rates, true positive and true negative hits, and hitlist composition. Our results suggest that a rational selection of the applied method represents a powerful strategy to maximize the success of a research project, tightly linked to its aims. We employed cyclooxygenase as application example, however, the focus of this study lied on highlighting the differences in the virtual screening tool performances and not in the identification of novel COX-inhibitors.

  13. Cyclooxygenase-2 polymorphisms and the risk of esophageal adeno- or squamous cell carcinoma

    Institute of Scientific and Technical Information of China (English)

    Jón O Kristinsson; Paul van Westerveld; Rene HM te Morsche; Hennie MJ Roelofs; T Wobbes; Ben JM Witteman; Adriaan CITL Tan; Martijn GH van Oijen; Jan BMJ Jansen; Wilbert HM Peters

    2009-01-01

    AIM: To determine whether - 1195 A→ G and/or - 765 G→ C polymorphisms in Cyclooxygenase-2 ( COX-2) may have a risk modifying effect on the development of esophageal carcinoma in a Dutch Caucasian population. METHODS: Two study groups were recruited, 252 patients with esophageal carcinoma and 240 healthy controls, matched for race, age, gender and recruiting area. DNA was isolated from whole blood and used for genotyping. PCR products were digested with restriction enzymes and products were analyzed by agarose gel electrophoresis. Odds ratios (OR) and 95% confidence intervals (CI) were estimated. RESULTS: The dist r ibut ion of the - 1195 A→ G polymorphism was significantly different in esophageal cancer patients compared to controls. The - 1195 GG genotype resulted in a higher risk of developing esophageal adenocarcinoma (OR = 3.85, 95% CI: 1.45-10.3) compared with the - 1195 AA genotype as a reference. The - 765 G→ C genotype distribution was not different between the two groups. The GG/ GG haplotype was present more often in esophageal adenocarcinoma patients than in controls (OR = 3.45, 95% CI: 1.24-9.58; with AG/AG as a reference). The same trends were observed in patients with squamous cell carcinomas, however, the results did not reach statistical significance. CONCLUSION: Presence of the COX-2 -1195 GG genotype and of the GG/GG haplotype may result in a higher risk of developing esophageal carcinoma.

  14. Fluorocoxib A loaded nanoparticles enable targeted visualization of cyclooxygenase-2 in inflammation and cancer.

    Science.gov (United States)

    Uddin, Md Jashim; Werfel, Thomas A; Crews, Brenda C; Gupta, Mukesh K; Kavanaugh, Taylor E; Kingsley, Philip J; Boyd, Kelli; Marnett, Lawrence J; Duvall, Craig L

    2016-06-01

    Cyclooxygenase-2 (COX-2) is expressed in virtually all solid tumors and its overexpression is a hallmark of inflammation. Thus, it is a potentially powerful biomarker for the early clinical detection of inflammatory disease and human cancers. We report a reactive oxygen species (ROS) responsive micellar nanoparticle, PPS-b-POEGA, that solubilizes the first fluorescent COX-2-selective inhibitor fluorocoxib A (FA) for COX-2 visualization in vivo. Pharmacokinetics and biodistribution of FA-PPS-b-POEGA nanoparticles (FA-NPs) were assessed after a fully-aqueous intravenous (i.v.) administration in wild-type mice and revealed 4-8 h post-injection as an optimal fluorescent imaging window. Carrageenan-induced inflammation in the rat and mouse footpads and 1483 HNSCC tumor xenografts were successfully visualized by FA-NPs with fluorescence up to 10-fold higher than that of normal tissues. The targeted binding of the FA cargo was blocked by pretreatment with the COX-2 inhibitor indomethacin, confirming COX-2-specific binding and local retention of FA at pathological sites. Our collective data indicate that FA-NPs are the first i.v.-ready FA formulation, provide high signal-to-noise in inflamed, premalignant, and malignant tissues, and will uniquely enable clinical translation of the poorly water-soluble FA compound.

  15. Progressive Metaplastic and Dysplastic Changes in Mouse Pancreas Induced by Cyclooxygenase-2 Overexpression

    Directory of Open Access Journals (Sweden)

    Jennifer K.L. Colby

    2008-08-01

    Full Text Available Cyclooxygenase-2 (COX-2 overexpression is an established factor linking chronic inflammation with metaplastic and neoplastic change in various tissues. We generated transgenic mice (BK5.COX-2 in which elevation of COX-2 and its effectors trigger a metaplasia-dysplasia sequence in exocrine pancreas. Histologic evaluation revealed a chronic pancreatitis-like state characterized by acinar-to-ductal metaplasia and a well-vascularized fibroinflammatory stroma that develops by 3 months. By 6 to 8 months, strongly dysplastic features suggestive of pancreatic ductal adenocarcinoma emerge in the metaplastic ducts. Increased proliferation, cellular atypia, and loss of normal cell/tissue organization are typical features in transgenic pancreata. Alterations in biomarkers associated with human inflammatory and neoplastic pancreatic disease were detected using immunohistochemistry. The abnormal pancreatic phenotype can be completely prevented by maintaining mice on a diet containing celecoxib, a well-characterized COX-2 inhibitor. Despite the high degree of atypia, only limited evidence of invasion to adjacent tissues was observed, with no evidence of distant metastases. However, cell lines derived from spontaneous lesions are aggressively tumorigenic when injected into syngeneic or nude mice. The progressive nature of the metaplastic/dysplastic changes observed in this model make it a valuable tool for examining the transition from chronic inflammation to neoplasia.

  16. Isoorientin, a Selective Inhibitor of Cyclooxygenase-2 (COX-2) from the Tubers of Pueraria tuberosa.

    Science.gov (United States)

    Sumalatha, Manne; Munikishore, Rachakunta; Rammohan, Aluru; Gunasekar, Duvvuru; Kumar, Kotha Anil; Reddy, Kakularam Kumar; Azad, Rajaram; Reddanna, Pallu; Bodo, Bernard

    2015-10-01

    Bioassay-guided fraction of the methanol extract of the roots of Pueraria tuberose DC yielded puerarin, an isoflavone C-glycoside (PT-1), isoorientin, a flavone C-glycoside (PT-2) and mangiferin, a xanthone C-glycoside (PT-3). The extracts and the isolated compounds were screened for potent anti-inflammatory components inhibiting the cyclooxygenases (COX-1 and COX-2) and 5-lipoxygenase (5-LOX), the target enzymes of inflammation, by employing spectroscopic/polorographic methods. Among these, isoorientin was found to be a potent inhibitor of COX-2with an IC50 value of 39 μM. Docking studies were carried out to understand the interactions of isorientin (PT-2) with COX-2.The structures of the isolates were determined by mass spectrometry and 2D-NMR techniques including HSQC, HMBC, NOESY and 1H-1H COSY experiments. Although isoorientin and mangiferin have been reported from several plant sources, this is the first report of their isolation from a Pueraria species.

  17. Pharmacoeconomics of Surgical Interventions vs. Cyclooxygenase Inhibitors for the Treatment of Patent Ductus Arteriosus

    Science.gov (United States)

    Turck, Charles J; Marsh, Wallace; Stevenson, James G.; York, John M.; Miller, Henry; Patel, Snehal

    2007-01-01

    Management of neonatal patent ductus arteriosus (PDA) often is resource-intensive and costly. Therefore, it is in hospitals' best interests to ensure the most cost-efficient use of associated resources. Clinical status, comorbidities, and response to prior therapy are considered in selecting the most appropriate intervention for PDA management. Currently, supportive measures (e.g., fluid restriction), surgical ligation, and pharmacologically based medical therapy are the primary treatment modalities for correcting PDA. Medical therapy, which comprises a small percentage (2.0%–5.0%)1 of overall PDA treatment expenses in the United States, consists of either of the 2 intravenous (IV) cyclooxygenase (COX) inhibitors: IV indomethacin and the newly available IV ibuprofen lysine. Although IV COX inhibitors represent a small portion of medical expenses, their benefits appear to be considerable. Pharmacoeconomic studies have evaluated indomethacin's beneficial impact on cost-effectiveness per quality-adjusted life year in PDA prophylaxis; however, no analysis to date prospectively assesses the effect of COX inhibitors on resource use or expenses in treating PDA. Such analysis is desirable and should consider efficacy and safety outcomes, impact on health care resource use and length of stay (LOS), and any differential effects of the agents' safety profiles; notably, IV indomethacin adversely affects renal and mesenteric blood flow and increases serum creatinine and oliguria significantly more than IV ibuprofen. These observations lay the foundation to conduct studies assessing the influence of these differences on resource use, LOS and expenses associated with PDA management. PMID:23055853

  18. Differential expression of cyclooxygenase-2 in metastatic melanoma affects progression free survival.

    Science.gov (United States)

    Panza, Elisabetta; De Cicco, Paola; Ercolano, Giuseppe; Armogida, Chiara; Scognamiglio, Giosuè; Anniciello, Anna Maria; Botti, Gerardo; Cirino, Giuseppe; Ianaro, Angela

    2016-08-30

    The possible correlation between cyclooxygenase-2 (COX-2) expression and disease progression in melanoma is still a matter of debate. Analysis of COX-2 expression in 45 lymph node melanoma metastases demonstrates a significant correlation between the percent of expression and progression free survival (PFS). A positive COX-2 expression ≥10% (COX-2high), as opposite to a positive expression ≤9% (COX-2low), translated into a striking significant reduction of PFS of about 3 years. The reduction in PFS correlated neither with BRAFV600E nor with NRASQ61 expression in the analyzed samples. This concept was reinforced by the finding that tumour development in COX-2-/- mice was almost blunted. Similarly, inhibition of COX-2 protein expression in human melanoma cell lines, by using siRNAs technology as well as selective inhibition of COX-2 activity by celecoxib, reduced cellular proliferation and invasiveness. In conclusion we show that COX-2high is a negative prognostic factor in metastatic melanoma. Our study also clarifies that the uncertainty about the role of COX-2 in metastatic malignant melanoma, found in the current relevant literature, is probably due to the fact that a threshold in COX-2 expression has to be reached in order to impact on cancer malignancy. Our findings suggest that COX-2 expression may become an useful diagnostic tool in defining melanoma malignancy as well as argue for a possible therapeutic use of NSAID as add on therapy in selected cases.

  19. Biological Evaluation and Docking Analysis of Daturaolone as Potential Cyclooxygenase Inhibitor

    Directory of Open Access Journals (Sweden)

    Abdur Rauf

    2016-01-01

    Full Text Available This study deals with the isolation of the active constituent(s from a methanolic extract of Pistacia integerrima J. L. Stewart barks and it was also oriented to evaluate the in vivo and in silico anti-inflammatory activity. By NMR and crystallography techniques, we have isolated a triterpenoid identified as daturaolone (compound 1. This compound showed in vivo a significant and dose dependent (1–30 mg/kg anti-inflammatory activity on carrageenan-induced mouse paw oedema (ED50 = 10.1 mg/kg and on acetic acid-induced writhing responses in mice (ED50 = 13.8 mg/kg. In the in vivo experiments, the effect of tested compound was also evaluated in presence of the reference drug diclofenac (1–30 mg/kg. Moreover, in silico analysis of receptor ligand complex shows that compound 1 interacts with cyclooxygenases (COXs binding sites displaying an interesting interaction with COX-1. These findings suggest that compound 1 isolated from P. integerrima possesses in vivo anti-inflammatory and antinociceptive potentials, which are supported in silico by an interaction with COXs receptors.

  20. Interleukin-1β, cyclooxygenase-2, and hypoxia-inducible factor-1α in asthenozoospermia.

    Science.gov (United States)

    Salvolini, Eleonora; Buldreghini, Eddi; Lucarini, Guendalina; Vignini, Arianna; Giulietti, Alessia; Lenzi, Andrea; Mazzanti, Laura; Di Primio, Roberto; Balercia, Giancarlo

    2014-11-01

    Impaired male fertility may have a variety of causes, among which asthenozoospermia. In its etiology, several bioactive substances, such as cytokines may be involved. In this context, our aim was to evaluate the expression of interleukin-1β, cyclooxygenase-2, and hypoxia-inducible factor-1α, in spermatozoa isolated from normospermic fertile donors and asthenozoospermic infertile patients. We evaluated twenty-eight infertile patients affected by idiopathic asthenozoospermia and twenty-three normospermic fertile donors, age-matched. Sperm parameters were evaluated; immunohistochemical analysis and enzyme-linked immunosorbent assay were then performed in isolated spermatozoa. Spermatozoa from the asthenozoospermic group presented an increased expression of IL-1β, COX-2, and HIF-1α compared with the normospermic fertile subjects. Our results can lead us to speculate that the increased expression of these substances may influence sperm motility. Nevertheless, further studies are needed in order to assess whether these bioactive mediators have a potential relevance as targets in future therapeutic strategies for the treatment of male infertility.

  1. Nucleobindin co-localizes and associates with cyclooxygenase (COX-2 in human neutrophils.

    Directory of Open Access Journals (Sweden)

    Patrick Leclerc

    Full Text Available The inducible cyclooxygenase isoform (COX-2 is associated with inflammation, tumorigenesis, as well as with physiological events. Despite efforts deployed in order to understand the biology of this multi-faceted enzyme, much remains to be understood. Nucleobindin (Nuc, a ubiquitous Ca(2+-binding protein, possesses a putative COX-binding domain. In this study, we investigated its expression and subcellular localization in human neutrophils, its affinity for COX-2 as well as its possible impact on PGE(2 biosynthesis. Complementary subcellular localization approaches including nitrogen cavitation coupled to Percoll fractionation, immunofluorescence, confocal and electron microscopy collectively placed Nuc, COX-2, and all of the main enzymes involved in prostanoid synthesis, in the Golgi apparatus and endoplasmic reticulum of human neutrophils. Immunoprecipitation experiments indicated a high affinity between Nuc and COX-2. Addition of human recombinant (hr Nuc to purified hrCOX-2 dose-dependently caused an increase in PGE(2 biosynthesis in response to arachidonic acid. Co-incubation of Nuc with COX-2-expressing neutrophil lysates also increased their capacity to produce PGE(2. Moreover, neutrophil transfection with hrNuc specifically enhanced PGE(2 biosynthesis. Together, these results identify a COX-2-associated protein which may have an impact in prostanoid biosynthesis.

  2. The influence of cyclo-oxygenase inhibitors on the cardiovascular effects of hydralazine in rats.

    Science.gov (United States)

    Vidrio, H; Garcia-Marquez, F

    1985-01-01

    In order to explore the postulated role of prostaglandins in the vasodilator effects of hydralazine, blood pressure and heart rate responses to the drug were determined in anesthetized and conscious rats with and without pretreatment with indomethacin or aspirin. Changes in rectal temperature were also measured. In control animals, hydralazine produced an almost immediate fall in blood pressure and a slowly developing tachycardia which bore no temporal relation with the hypotension. These effects were accompanied by a moderate increase in temperature. Pretreatment with the cyclo-oxygenase inhibitors did not reduce the blood pressure response, but completely blocked and in some cases reversed the tachycardia. The hyperthermic response was also reversed. These results can be taken as evidence for a role of prostaglandins in the tachycardia and hyperthermia, but not in the hypotension elicited by hydralazine in rats. In the absence of direct measurements of prostaglandin synthesis and release, however, no firm support for this possibility is offered by the present findings and alternative explanations are considered.

  3. Inhibition of cyclooxygenase-2 prevents inflammation-mediated preterm labor in the mouse.

    Science.gov (United States)

    Gross, G; Imamura, T; Vogt, S K; Wozniak, D F; Nelson, D M; Sadovsky, Y; Muglia, L J

    2000-06-01

    Prostaglandins (PGs) have proven important during parturition, but inhibition of PG production treating preterm labor (PTL) results in significant maternal and fetal side effects. We hypothesize that specific inhibition of either cyclooxygenase (COX)-1 or -2 may result in separation of therapeutic and toxic effects. We demonstrate that COX-2, but not COX-1, is induced during inflammation-mediated PTL caused by lipopolysaccharide (LPS) administration. A two- to threefold increase in uterine and ovarian PG concentrations coincides with this induction of COX-2. The COX-2-selective inhibitor SC-236 proved effective in stopping preterm delivery and the increases in PGs. The COX-1-selective inhibitor SC-560 also attenuated uterine and ovarian PG production after LPS but did not inhibit PTL as efficiently as SC-236. COX-1-deficient mice, which show delay in the onset of term labor, exhibited no delay in onset of PTL after LPS. These findings suggest that the mechanisms for initiation of inflammation-mediated PTL and term labor differ and that selective COX-2 inhibition may provide a means of stopping inflammation-induced PTL in humans.

  4. Expression of p63 and Cyclooxygenase-2 and Their Correlation in Skin Tumors

    Institute of Scientific and Technical Information of China (English)

    WU Yan; LIU Houjun; LI Jiawen

    2007-01-01

    To study the expression of p63 and cyclooxygenase-2 (cox-2) in skin tumors and evaluate the correlation between p63 and cox-2, the expressions of cox-2 and p63 were measured by streptavidin-peroxidase complex immunohistochemical technique in 17 cases of skin squamous cell carcinoma (SCC), 19 cases of Bowen's disease(Bowen), 11 cases of actinic keratosis(AK), 12 cases of seborreic keratosis(SK) and 13 specimens of normal skin. Our results showed that the expression of p63 in skin squamous cell carcinoma, Bowen's disease and actinic keratosis were significantly higher than that in seborreic keratosis, while the expression of p63 in seborreic keratosis was significantly higher than that in normal skin. The expression of cox-2 in skin squamous cell carcinoma,Bowen's disease and actinic keratosis were significantly higher than that in seborreic keratosis, while no statistical difference was noted in the expression of cox-2 between seborreic keratosis and normal skin. Cox-2 expression was positively correlated with the high p63 expression in malignant skin tumors. The increased expression of cox-2 and p63 may play an important role in the development of skin tumors and work synergetically in malignant skin tumors.

  5. Chronic inhibition of cyclooxygenase-2 attenuates antibody responses against vaccinia infection.

    Science.gov (United States)

    Bernard, Matthew P; Bancos, Simona; Chapman, Timothy J; Ryan, Elizabeth P; Treanor, John J; Rose, Robert C; Topham, David J; Phipps, Richard P

    2010-02-01

    Generation of optimal humoral immunity to vaccination is essential to protect against devastating infectious agents such as the variola virus that causes smallpox. Vaccinia virus (VV), employed as a vaccine against smallpox, provides an important model of infection. Herein, we evaluated the importance cyclooxygenase-2 (Cox-2) in immunity to VV using Cox-2 deficient mice and Cox-2 selective inhibitory drugs. The effects of Cox-2 inhibition on antibody responses to live viruses such as vaccinia have not been previously described. Here, we used VV infection in Cox-2 deficient mice and in mice chronically treated with Cox-2 selective inhibitors and show that the frequency of VV-specific B cells was reduced, as well as the production of neutralizing IgG. VV titers were approximately 70 times higher in mice treated with a Cox-2 selective inhibitor. Interestingly, Cox-2 inhibition also reduced the frequency of IFN-gamma producing CD4(+) T helper cells, important for class switching. The significance of these results is that the chronic use of non-steroidal anti-inflammatory drugs (NSAIDs), and other drugs that inhibit Cox-2 activity or expression, blunt the ability of B cells to produce anti-viral antibodies, thereby making vaccines less effective and possibly increasing susceptibility to viral infection. These new findings support an essential role for Cox-2 in regulating humoral immunity.

  6. Inhibition of cyclooxygenase activity by standardized hydroalcoholic extracts of four Asteraceae species from the Argentine Puna

    Directory of Open Access Journals (Sweden)

    M.R. Alberto

    2009-09-01

    Full Text Available We determined the anti-inflammatory activity of standardized extracts of four medicinal plant species (Baccharis incarum, B. boliviensis, Chuquiraga atacamensis, Parastrephia lucida that grow in the Argentine Puna (3800 m above sea level and that are used to reduce oxidative stress and alleviate gout and arthritic pain. The extracts of plant aerial parts were standardized in terms of total phenolic compounds and flavone/flavanone content and free radical scavenging activity. All extracts showed high phenolic compound concentration (0.5-1.6 mg/mL, mainly flavones and flavonols (0.1-0.8 mg/mL. The extracts showed hydrogen donating ability (DPPH and ABTS and reactive oxygen species scavenging activity (O2●-, OH-, H2O2. The ability of the extracts to inhibit cyclooxygenase enzymes (COX-1 and COX-2 was determined by calculating percent inhibition of PGE2 production measured by enzyme immunoassay. All extracts inhibited both enzymes with IC50 values of 2.0 to 16.7 µg/mL. The anti-inflammatory activity of B. incarum and C. atacamensis extracts was higher than that of B. boliviensis and P. lucida. The IC50 values obtained for indomethacin were 0.11 and 0.78 µM for COX-1 and COX-2, respectively. The present results are consistent with the anecdotal use of these species in phytotherapic preparations.

  7. Inhibition of cyclooxygenase activity by standardized hydroalcoholic extracts of four Asteraceae species from the Argentine Puna.

    Science.gov (United States)

    Alberto, M R; Zampini, I C; Isla, M I

    2009-09-01

    We determined the anti-inflammatory activity of standardized extracts of four medicinal plant species (Baccharis incarum, B. boliviensis, Chuquiraga atacamensis, Parastrephia lucida) that grow in the Argentine Puna (3800 m above sea level) and that are used to reduce oxidative stress and alleviate gout and arthritic pain. The extracts of plant aerial parts were standardized in terms of total phenolic compounds and flavone/flavanone content and free radical scavenging activity. All extracts showed high phenolic compound concentration (0.5-1.6 mg/mL), mainly flavones and flavonols (0.1-0.8 mg/mL). The extracts showed hydrogen donating ability (DPPH and ABTS) and reactive oxygen species scavenging activity (O2-, OH-, H2O2). The ability of the extracts to inhibit cyclooxygenase enzymes (COX-1 and COX-2) was determined by calculating percent inhibition of PGE2 production measured by enzyme immunoassay. All extracts inhibited both enzymes with IC50 values of 2.0 to 16.7 microg/mL. The anti-inflammatory activity of B. incarum and C. atacamensis extracts was higher than that of B. boliviensis and P. lucida. The IC50 values obtained for indomethacin were 0.11 and 0.78 microM for COX-1 and COX-2, respectively. The present results are consistent with the anecdotal use of these species in phytotherapic preparations.

  8. Differential regulation of renal cyclooxygenase mRNA by dietary salt intake

    DEFF Research Database (Denmark)

    Jensen, B L; Kurtz, A

    1997-01-01

    Experiments were done to investigate the influence of dietary salt intake on renal cyclooxygenase (COX) I and II mRNA levels. To this end rats were fed either a low NaCl diet (LS; 0.02% NaCl wt/wt) or a high NaCl diet (HS diet; 4% NaCl wt/wt) for 5, 10 and 20 days. After 10 days Na excretion...... differed 760-fold, plasma renin activity and renin mRNA were increased eight- and threefold in LS compared to HS animals. Total renal COX I mRNA decreased 50% following the LS diet and did not change after the HS diet. Conversely, COX II mRNA declined after HS intake and transiently increased after salt...... depletion. COX I and II mRNAs were unevenly distributed along the cortical-medullary axis with ratios of the cortex:outer medulla:papilla of 1:3:23 and 1:1:2, respectively. Cortical COX mRNAs were inversely regulated by salt intake with eightfold changes in COX II. Conversely, in medullary zones, COX I m...

  9. Antiinflammatory and antinociceptive activities of gossypin and procumbentin--cyclooxygenase-2 (COX-2) inhibition studies.

    Science.gov (United States)

    Mada, Sripal Reddy; Metukuri, Mallikarjuna Reddy; Burugula, Laxminarayana; Reddanna, Pallu; Krishna, Devarakonda Rama

    2009-06-01

    In the present study the antiinflammatory and antinociceptive activities of a few selected flavonoids were investigated. Procumbentin, gossypin, chrysin and methylhespiridin were studied for antiinflammatory and antinociceptive activities using in vitro enzymatic assays and in animal models utilizing acetic acid-induced writhing in mice and hind paw edema in rats. In vitro studies were performed using TMPD (NNN'N'-tetramethyl-p-phenylene diamine) and oxygraphic methods for COX-1 (cyclooxygenase-1), COX-2, 5-LOX (5-lipoxygenase) and 15-LOX. Gossypin and procumbentin showed COX-2 inhibitory activity and exhibited IC(50) (COX-2/COX-1) ratios of 0.14 and 0.11, respectively. None of the flavonoids tested in this study showed LOX inhibitory activity. Four groups were studied for each test compound following intraperitoneal (i.p.) administration of doses of 10, 30 and 100 mg/kg. Antiinflammatory activity was measured by the carrageenin-induced rat hind paw edema model and antinociceptive activity by acetic acid-induced writhing. Procumbentin and gossypin showed antinociceptive activity at the 100 mg/kg dose. Gossypin showed antiinflammatory activity at doses of 10, 30, 100 mg/kg. Procumbentin and gossypin exhibited COX-2 inhibitory activity when tested by in vitro methods. Procumbentin and gossypin showed antinociceptive, and gossypin showed antiinflammatory, activities.

  10. The prognostic importance of cyclooxygenase 2 and HER2 expression in epithelial ovarian cancer

    DEFF Research Database (Denmark)

    Dahl Steffensen, Karina; Waldstrøm, M; Jeppesen, U;

    2007-01-01

    Both cyclooxygenase 2 (COX2) and human epidermal growth factor receptor 2 (HER2, also called c-erbB-2) overexpression have been related to a worse prognosis in epithelial ovarian cancer (EOC), but the data are conflicting and the percentage of tumors with overexpression varies widely in different......) and immunohistochemistry (IHC) for evaluation of the HER2 status in EOC. Immunostaining was performed for COX2/HER2 together with FISH analysis for HER2 gene amplification in 160 patients with EOC, FIGO stages IIB-IV. Follow-up was more than 10 years. COX2 overexpression was found in 20.0% of the tumors. With HER2...... staining, 64.4% were scored as 0, 24.4% as 1+, 6.9% as 2+, and 4.4% as 3+. Median survival time for COX2-negative tumors was 21.6 versus 36 months for COX2-positive tumors. The longer survival for COX2 positive was significant by both univariate analysis (P= 0.015) and multivariate analysis (P= 0...

  11. Cyclo-oxygenase 2 inhibitor, nabumetone, inhibits proliferation in chronic myeloid leukemia cell lines.

    Science.gov (United States)

    Vural, Filiz; Ozcan, Mehmet Ali; Ozsan, Güner Hayri; Ateş, Halil; Demirkan, Fatih; Pişkin, Ozden; Undar, Bülent

    2005-05-01

    The anti-tumor effect of cyclo-oxygenase (COX) inhibitors has been documented in several studies. COX2 inhibitors have attracted more attention because of the fewer side-effects and the more prominent anti-tumor effects. However, experience with these drugs in hematological malignancies is limited. In our study, a potent COX2 inhibitor, nabumetone (NBT), was investigated for its anti-proliferative and apoptotic effects in K-562 and Meg-01 chronic myeloid leukemia blastic cell lines as a single agent or in combination with adriamycin (ADR) and interferon alpha (IFN-a). In these cell lines, a dose-dependent inhibition of proliferation was observed with NBT. We observed no significant apoptotic effect of NBT. However, NBT potentiated the apoptotic effect of ADR in the K-562 cell line. Bcl-2 expression was reduced by NBT (11% vs. 2%). The combination of NBT with IFN did not have any significant effect on the K-562 cell line. We suggest that NBT inhibits proliferation and potentiates the apoptotic effect of ADR in chronic myeloid leukemia cell lines.

  12. Does uterine prolapse alter endometrial cyclooxygenase 2 expression and promote the development of premalignant lesions?

    Science.gov (United States)

    Genc, Mine; Sivrikoz, Oya Nermin; Sahin, Nur; Celik, Esin; Turan, Guluzar Arzu; Guclu, Serkan

    2015-01-01

    The aim of this study was to evaluate the expression of cyclooxygenase 2 (COX-2) and its association with the development of premalignant lesions in gland structures of the endometrium in patients with uterine prolapse, a condition which exposes the uterus to mechanical and infectious stress. The study included 102 patients who underwent hysterectomy to correct grade 3-4 uterine prolapse and 105 patients who underwent hysterectomy for other causes. Endometrial gland structures underwent immunohistochemical staining and COX-2 expression was graded. Grades 0 and 1 represent low expression; grades 2 and 3 correspond to high levels of COX-2 expression. The prevalence of grade 2-3 COX-2 expression was significantly higher in the endometrial gland structures of patients with prolapse and hyperplasia compared to the remaining patients (p = 0.014). Grade 0-1 COX-2 expression was significantly more common in the endometrial gland structures of patients without uterine prolapse or hyperplasia (p = 0.004). Among the patients without endometrial hyperplasia, COX-2 expression was elevated in the endometrial gland structures of those with uterine prolapse compared to those without prolapse. Elevated COX-2 expression may explain the presence of unexpected premalignant lesions of the endometrium in patients with uterine prolapse. © 2015 S. Karger AG, Basel.

  13. Oral gold compound auranofin triggers arachidonate release and cyclooxygenase metabolism in the alveolar macrophage

    Energy Technology Data Exchange (ETDEWEB)

    Peters-Golden, M.; Shelly, C.

    1988-12-01

    We examined the effect of in vitro incubation with the oral gold compound auranofin (AF) on arachidonic acid (AA) release and metabolism by rat alveolar macrophages (AMs). AF stimulated dose- and time-dependent release of /sup 14/C-AA from prelabeled AMs, which reached 4.7 +/- 0.3% (mean +/- SEM) of incorporated radioactivity at 10 micrograms/ml for 90 min, as compared to 0.5 +/- 0.1% release following control incubation for 90 min (p less than 0.001). Similar dose- and time-dependent synthesis of thromboxane (Tx) A2 (measured as TxB2) and prostaglandin (PG) E2 was demonstrated by radioimmunoassay of medium from unlabeled cultures, reaching 18-fold and 9-fold, respectively, of the control values at 10 micrograms/ml AF for 90 min (p less than 0.001 for both). AF-induced TxB2 and PGE2 synthesis was inhibited by indomethacin as well as by pretreatment with methylprednisolone. No increase in the synthesis of immunoreactive leukotrienes (LT) B4 or C4 was noted at any dose or time of AF. High performance liquid chromatographic separation of /sup 14/C-eicosanoids synthesized by prelabeled AMs confirmed that AF induced the release of free AA and its metabolism to cyclooxygenase, but not 5-lipoxygenase, metabolites. The ability of AF to trigger macrophage AA metabolism may be relevant to the exacerbation of certain inflammatory processes which sometimes accompany gold therapy.

  14. Inhibition of cyclooxygenase-2 by diallyl sulfides (DAS) in HEK 293T cells.

    Science.gov (United States)

    Elango, Erode M; Asita, Hag; Nidhi, Gunapalan; Seema, Parvathy; Banerji, Asoke; Kuriakose, Moni A

    2004-01-01

    Cyclooxygenase (COX) is involved in modulating inflammatory response through the synthesis of prostaglandins. The inducible isoform of the enzyme, COX-2, is overexpressed in some malignant and premalignant lesions. Several preclinical and clinical studies have reported COX-2 inhibition as an effective strategy for chemoprevention. Nonsteroidal anitinflammatory drugs (NASIDs) such as celecoxib, are the most widely investigated COX-2 inhibitors. The oil-soluble diallyl sulfides (DAS) include monosulfides (DAMS), disulfides (DADS) and trisulfides (DATS). They were found to be effective against canine and human tumors, the mechanism of which remains unresolved. We attempted a comparative evaluation of the antiproliferative effect of DAS in HEK 293T cells. The cells were treated with increasing concentrations of DAMS, DADS and DATS. There were significant differences between the IC50 values of DAMS, DADS and DATS. RT-PCR was performed and the expression of COX-2 was compared with that of b actin. DATS inhibited COX-2 gene expression significantly stronger than DAMS and DADS. The data are suggestive of antineoplastic effect of DAS, mediated by controlling COX-2 expression.

  15. Hemicrania continua changed to chronic paroxysmal hemicrania after treatment with cyclooxygenase-2 inhibitor.

    Science.gov (United States)

    Müller, Kai Ivar; Bekkelund, Svein Ivar

    2011-02-01

    Remission of hemicrania continua (HC) and transformation from HC to chronic paroxysmal hemicrania (CPH) are unusual. We report a patient with left-sided HC who, after a period of remission, presented as CPH. The continuous HC headache disappeared completely after initiating treatment with cyclooxygenase (COX)-2 inhibitor, but reappeared on the same side after 14 months remission with paroxysmal, frequent, intense and short-lasting headache attacks accompanied by ipsilateral cranial autonomic symptoms. This happened shortly after the treatment was discontinued because of withdrawal of the COX-2 inhibitor from the market. The response to indomethacin was prompt, and the patient became completely free from her paroxysmal headache with a dose of 50 mg 2 times daily. This case questions a possible modification effect on the course of HC by use of COX-2 inhibitor, as well as further supporting that some aspects of the pathophysiology of HC may resemble those of CPH, and may argue for common biological mechanisms in HC and CPH.

  16. Cyclooxygenase-2 inhibition blocks M2 macrophage differentiation and suppresses metastasis in murine breast cancer model.

    Directory of Open Access Journals (Sweden)

    Yi-Rang Na

    Full Text Available Tumor cells are often associated with abundant macrophages that resemble the alternatively activated M2 subset. Tumor-associated macrophages (TAMs inhibit anti-tumor immune responses and promote metastasis. Cyclooxygenase-2 (COX-2 inhibition is known to prevent breast cancer metastasis. This study hypothesized that COX-2 inhibition affects TAM characteristics potentially relevant to tumor cell metastasis. We found that the specific COX-2 inhibitor, etodolac, inhibited human M2 macrophage differentiation, as determined by decreased CD14 and CD163 expressions and increased TNFα production. Several key metastasis-related mediators, such as vascular endothelial growth factor-A, vascular endothelial growth factor-C, and matrix metalloproteinase-9, were inhibited in the presence of etodolac as compared to untreated M2 macrophages. Murine bone marrow derived M2 macrophages also showed enhanced surface MHCII IA/IE and CD80, CD86 expressions together with enhanced TNFα expressions with etodolac treatment during differentiation. Using a BALB/c breast cancer model, we found that etodolac significantly reduced lung metastasis, possibly due to macrophages expressing increased IA/IE and TNFα, but decreased M2 macrophage-related genes expressions (Ym1, TGFβ. In conclusion, COX-2 inhibition caused loss of the M2 macrophage characteristics of TAMs and may assist prevention of breast cancer metastasis.

  17. Cyclooxygenase-2 contributes to VX-induced cell death in cultured cortical neurons.

    Science.gov (United States)

    Tenn, Catherine C; Weiss, M Tracy; Beaup, Claire; Peinnequin, Andre; Wang, Yushan; Dorandeu, Frederic

    2012-04-05

    The link between cell death and increased cyclooxygenases-2 (COX-2) activity has not been clearly established. In this study, we examined whether COX-2 activation contributed to the mechanism of neurotoxicity produced by an organophosphorous nerve agent in cultured rat cortical neurons. Exposure of neuronal cells to the nerve agent, VX resulted in an increase in COX enzyme activity in the culture media. A concentration dependent increase in the activity levels of COX-2 enzyme was observed while there was little to no effect on COX-1. In addition, COX-2 mRNA and protein levels increased several hours post-VX exposure. Pre-treatment of the cortical cells with the COX-2 selective inhibitor, NS 398 resulted in a decrease in both the enzyme activity and prostaglandin (PGE(2) and PGF(2α)) release, as well as in a reduction in cell death. These findings indicate that the increase in COX-2 activity may contribute to the mechanism of VX-induced neurotoxicity in cultured rat cortical neuron.

  18. Tumor cyclooxygenase-2 levels correlate with tumor invasiveness in human hepatocellular carcinoma

    Institute of Scientific and Technical Information of China (English)

    Terence C. Tang; Ronnie T. Poon; Cecilia P. Lau; Dan Xie; Sheung Tat Fan

    2005-01-01

    AIM: Recent studies suggested that cyclooxygenase-2(COX-2) enhances tumor angiogenesis via upregulationof vascular endothelial growth factor (VEGF). AlthoughCOX-2 expression has been demonstrated in hepatocellularcarcinoma (HCC), the significance of COX-2 in progressionof HCC remains unclear. This study evaluated the clinico-pathological correlation of COX-2 level and its relationshipwith VEGF level in HCC.METHODS: Fresh tumor tissues were obtained from 100patients who underwent resection of HCC. COX-2 proteinexpression was examined by immunohistochemistry, andquantitatively by an enzyme immunometric assay (EIA)of tumor cytosolic COX-2 levels. Tumor cytosolic VEGFlevels were measured by an ELISA.RESULTS: Immunostaining showed expression of COX-2in tumor cells. Tumor cytosolic COX-2 levels correlatedwith VEGF levels (r = 0.469, P<0.001). Correlation withclinicopathological features showed significantly highertumor cytosolic COX-2 levels in the presence of multipletumors (P = 0.027), venous invasion (P = 0.030),microsatellite lesions (P = 0.037) and advanced tumorstage (P = 0.008). Higher tumor cytosolic COX-2 levelswere associated with worse patient survival.CONCLUSION: This study shows that elevated tumorCOX-2 levels correlate with elevated VEGF levels andinvasiveness in HCC, suggesting that COX-2 plays a significantrole in the progression of HCC.

  19. An immunohistochemical study of cyclooxygenase-2 expression in various feline neoplasms.

    Science.gov (United States)

    Beam, S L; Rassnick, K M; Moore, A S; McDonough, S P

    2003-09-01

    Cyclooxygenase (COX) enzymes catalyze the synthesis of prostaglandins and exist as two isoforms, COX-1 and COX-2. COX-2 is a potent inducible mediator of inflammation. COX-2 is also upregulated in several human tumors and in canine squamous cell, renal cell, and transitional cell carcinomas, prostatic adenocarcinoma, and intestinal neoplasia. The purpose of this study was to determine whether COX-2 is expressed in various feline tumors. Results of this study may help determine whether COX-2 is a potential target for therapeutic and preventive strategies in cats. Immunohistochemical studies were performed on paraffin-embedded tissues using the amplified streptavidin-biotin-horseradish peroxidase system. COX-2 was found in 7 of 19 (37%) feline transitional cell carcinomas and in 2 of 21 (9%) feline oral squamous cell carcinomas. No COX-2 immunoreactivity was detected in cutaneous squamous cell carcinomas (6), adenocarcinomas (nine mammary, eight pulmonary, seven intestinal), lymphomas (six nasal, six intestinal), or 10 vaccine-associated sarcomas. The widespread absence of COX-2 expression in most feline neoplasms might suggest that COX-2 inhibitors would have a low potential as anticancer agents.

  20. Progress of Cyclooxygenase-2 Expression in Tumors and Its Inhibitors Application in Anti-tumor%环氧合酶-2在肿瘤中的表达及其抑制剂在肿瘤中的应用进展

    Institute of Scientific and Technical Information of China (English)

    李巨仕; 汤恢焕

    2011-01-01

    环氧合酶-2(Cyclooxygenase-2,COX-2)是前列腺素合成过程中一重要的限速酶,COX-2的过度表达及其前列腺素产物与多种肿瘤的发生、发展关系密切,COX-2抑制剂通过抑制肿瘤细胞增殖,诱导肿瘤细胞凋亡,阻断致癌物的代谢,减弱肿瘤介导的免疫抑制,调节抑制血管生成,抑制肿瘤细胞侵袭,环氧合酶非依赖抑癌途径,对原癌基因及抑癌基因的影响等途径影响肿瘤的发生发展,这方面的研究为针对COX-2的抗肿瘤策略打开新的视野,提供新的线索.%Cyclooxygenase-2 (COX-2) is the process of prostaglandin synthesis is an important rate-limiting enzyme, COX-2 over-expression of prostaglandin products with a variety of tumors, the development of close.COX-2 inhibiting tumor cell added induce tumor cell apoptosis,blocking the metabolism of carcinogens, decreased tumor-mediated immunosuppression, inhibition of angiogenesis regulation, inhibition of tumor cell invasion, cyclooxygenase-independent tumor suppressor pathway, and suppression of oncogene the impact of cancer genes affect the tumor development pathway, esearch in this area is for COX-2 anti-tumor strategy to open new horizons and provide new clues.

  1. Improved quantification of 8-epi-prostaglandin F2 alpha and F2-isoprostanes by gas chromatography/triple-stage quadrupole mass spectrometry: partial cyclooxygenase-dependent formation of 8-epi-prostaglandin F2 alpha in humans.

    Science.gov (United States)

    Schweer, H; Watzer, B; Seyberth, H W; Nüsing, R M

    1997-12-01

    -epi-PGF2 alpha. However, the suppression of F2-isoprostanes and 8-epi-PGF2 alpha excretion rates was less pronounced in comparison with the classical prostanoids. An improved and reliable method for the determination of F2-isoprostanes and especially 8-epi-PGF2 alpha has been developed. The data obtained on human urine samples indicates a contribution of the cyclooxygenase pathway to the formation of isoprostanes.

  2. Effects of phenylbutazone on gene expression of cyclooxygenase-1 and -2 in the oral, glandular gastric, and bladder mucosae of healthy horses.

    Science.gov (United States)

    Nieto, Jorge E; Aleman, Monica; Anderson, Jonathan D; Fiack, Ciara; Snyder, Jack R

    2012-01-01

    To assess gene expressions of cyclooxygenase-1 and -2 in oral, glandular gastric, and urinary bladder mucosae and determine the effect of oral administration of phenylbutazone on those gene expressions in horses. 12 healthy horses. Horses were allocated to receive phenylbutazone or placebo (6 horses/group); 1 placebo-treated horse with a cystic calculus was subsequently removed from the study, and those data were not analyzed. In each horse, the stomach and urinary bladder were evaluated for ulceration via endoscopy before and after experimental treatment. Oral, glandular gastric, and urinary bladder mucosa biopsy specimens were collected by use of a skin punch biopsy instrument (oral) or transendoscopically (stomach and bladder) before and after administration of phenylbutazone (4.4 mg/kg, p.o., q 12 h) in corn syrup or placebo (corn syrup alone) for 7 days. Cyclooxygenase-1 and -2 gene expressions were determined (via quantitative PCR techniques) in specimens collected before and after the 7-day treatment period and compared within and between groups. Prior to commencement of treatment, biopsy specimens from 7 horses were used to compare gene expressions among tissues. The cyclooxygenase-1 gene was expressed in all tissues collected. The cyclooxygenase-2 gene was expressed in the glandular gastric and bladder mucosae but not in the oral mucosa. Cyclooxygenase gene expressions were unaffected by phenylbutazone administration. Cyclooxygenase-2 was constitutively expressed in glandular gastric and bladder mucosae but not in the oral mucosa of healthy horses. Oral administration of phenylbutazone at the maximum recommended dosage daily for 7 days did not affect cyclooxygenase-1 or -2 gene expression.

  3. Quercetin suppresses cyclooxygenase-2 expression and angiogenesis through inactivation of P300 signaling.

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    Xiangsheng Xiao

    Full Text Available Quercetin, a polyphenolic bioflavonoid, possesses multiple pharmacological actions including anti-inflammatory and antitumor properties. However, the precise action mechanisms of quercetin remain unclear. Here, we reported the regulatory actions of quercetin on cyclooxygenase-2 (COX-2, an important mediator in inflammation and tumor promotion, and revealed the underlying mechanisms. Quercetin significantly suppressed COX-2 mRNA and protein expression and prostaglandin (PG E(2 production, as well as COX-2 promoter activation in breast cancer cells. Quercetin also significantly inhibited COX-2-mediated angiogenesis in human endothelial cells in a dose-dependent manner. The in vitro streptavidin-agarose pulldown assay and in vivo chromatin immunoprecipitation assay showed that quercetin considerably inhibited the binding of the transactivators CREB2, C-Jun, C/EBPβ and NF-κB and blocked the recruitment of the coactivator p300 to COX-2 promoter. Moreover, quercetin effectively inhibited p300 histone acetyltransferase (HAT activity, thereby attenuating the p300-mediated acetylation of NF-κB. Treatment of cells with p300 HAT inhibitor roscovitine was as effective as quercetin at inhibiting p300 HAT activity. Addition of quercetin to roscovitine-treated cells did not change the roscovitine-induced inhibition of p300 HAT activity. Conversely, gene delivery of constitutively active p300 significantly reversed the quercetin-mediated inhibition of endogenous HAT activity. These results indicate that quercetin suppresses COX-2 expression by inhibiting the p300 signaling and blocking the binding of multiple transactivators to COX-2 promoter. Our findings therefore reveal a novel mechanism of action of quercetin and suggest a potential use for quercetin in the treatment of COX-2-mediated diseases such as breast cancers.

  4. Roles of cyclooxygenase-2 in microvascular endothelial cell proliferation induced by basic fibroblast growth factor

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Background The level of basic fibroblast growth factor (bFGF) increases rapidly after cerebral ischemia. However, the molecular mechanisms for the effects of bFGF on cerebral microvascular endothelial cells (cMVECs) have not yet been fully elucidated. In this study, a murine cMVEC line, bend.3, was employed to study the effects of bFGF on cyclooxygenase (COX) expression and its downstream effects in cMVECs. Methods After treatment with bFGF, RT-PCR and Western blotting analyses were carried out to evaluate the changes in COX-2 mRNA and protein expression, respectively. Ml-r assays were performed to measure cell proliferation. The prostaglandin E2 (PGE2) and vascular endothelial growth factor (VEGF) concentrations in the culture medium were measured by enzyme-linked immunosorbent assay (ELISA). Results COX-2 mRNA and protein expressions in bEnd.3 cells were induced by bFGF in time- and dose-dependent manners. The bFGF-induced COX-2 upregulation led to enhanced PGE2 production by bEnd.3 cells, and this effect was abolished by the selective COX-2 inhibitor NS-398. bFGF also increased VEGF production by bend.3 cells, and this effect was blocked by NS-398 and the EP1/2 (PGE2 receptors) antagonist AH6809. Furthermore, exogenous PGE2 increased VEGF production in bend.3 cells, and AH6809 blocked this effect. Conclusion bFGF increases VEGF production in an autocrine manner by increasing COX-2-generated PGE2 in cMVECs and subsequently stimulates MVEC proliferation and angiogenesis.

  5. Cancer-induced anorexia in tumor-bearing mice is dependent on cyclooxygenase-1.

    Science.gov (United States)

    Ruud, Johan; Nilsson, Anna; Engström Ruud, Linda; Wang, Wenhua; Nilsberth, Camilla; Iresjö, Britt-Marie; Lundholm, Kent; Engblom, David; Blomqvist, Anders

    2013-03-01

    It is well-established that prostaglandins (PGs) affect tumorigenesis, and evidence indicates that PGs also are important for the reduced food intake and body weight loss, the anorexia-cachexia syndrome, in malignant cancer. However, the identity of the PGs and the PG producing cyclooxygenase (COX) species responsible for cancer anorexia-cachexia is unknown. Here, we addressed this issue by transplanting mice with a tumor that elicits anorexia. Meal pattern analysis revealed that the anorexia in the tumor-bearing mice was due to decreased meal frequency. Treatment with a non-selective COX inhibitor attenuated the anorexia, and also tumor growth. When given at manifest anorexia, non-selective COX-inhibitors restored appetite and prevented body weight loss without affecting tumor size. Despite COX-2 induction in the cerebral blood vessels of tumor-bearing mice, a selective COX-2 inhibitor had no effect on the anorexia, whereas selective COX-1 inhibition delayed its onset. Tumor growth was associated with robust increase of PGE(2) levels in plasma - a response blocked both by non-selective COX-inhibition and by selective COX-1 inhibition, but not by COX-2 inhibition. However, there was no increase in PGE(2)-levels in the cerebrospinal fluid. Neutralization of plasma PGE(2) with specific antibodies did not ameliorate the anorexia, and genetic deletion of microsomal PGE synthase-1 (mPGES-1) affected neither anorexia nor tumor growth. Furthermore, tumor-bearing mice lacking EP(4) receptors selectively in the nervous system developed anorexia. These observations suggest that COX-enzymes, most likely COX-1, are involved in cancer-elicited anorexia and weight loss, but that these phenomena occur independently of host mPGES-1, PGE(2) and neuronal EP(4) signaling.

  6. Cyclooxygenase-derived vasoconstriction restrains hypoxia-mediated cerebral vasodilation in young adults with metabolic syndrome.

    Science.gov (United States)

    Harrell, John W; Schrage, William G

    2014-01-15

    Poor cerebrovascular function in metabolic syndrome (MetSyn) likely contributes to elevated risk of cerebrovascular disease in this growing clinical population. Younger MetSyn adults without clinical evidence of cerebrovascular disease exhibit preserved hypercapnic vasodilation yet markedly impaired hypoxic vasodilation, but the mechanisms behind reduced hypoxic vasodilation are unknown. Based on data from rats, we tested the hypothesis that younger adults with MetSyn exhibit reduced cerebral hypoxic vasodilation due to loss of vasodilating prostaglandins. Middle cerebral artery velocity (MCAv) was measured with transcranial Doppler ultrasound in adults with MetSyn (n = 13, 33 ± 3 yr) and healthy controls (n = 15, 31 ± 2 yr). Isocapnic hypoxia was induced by titrating inspired oxygen to lower arterial saturation to 90% and 80% for 5 min each. Separately, hypercapnia was induced by increasing end-tidal CO2 10 mmHg above baseline levels. Cyclooxygenase inhibition (100 mg indomethacin) was conducted in a randomized double-blind, placebo controlled design. MCAv was normalized for group differences in blood pressure (healthy: 89 ± 2 mmHg vs. MetSyn: 102 ± 2 mmHg) as cerebrovascular conductance index (CVCi), and used to assess cerebral vasodilation. Hypoxia increased CVCi in both groups; however, vasodilation was ∼55% lower in MetSyn at SpO2 = 80% (P vasodilation in healthy controls, and unexpectedly increased dilation in MetSyn (P vasodilation was similar between groups, as was the decrease in vasodilation with indomethacin. These data indicate increased production of vasoconstrictor prostaglandins restrains hypoxic cerebral vasodilation in MetSyn, preventing them from responding appropriately to this important physiological stressor.

  7. Epigenetic regulation of cyclooxygenase-2 by methylation of c8orf4 in pulmonary fibrosis.

    Science.gov (United States)

    Evans, Iona C; Barnes, Josephine L; Garner, Ian M; Pearce, David R; Maher, Toby M; Shiwen, Xu; Renzoni, Elisabetta A; Wells, Athol U; Denton, Christopher P; Laurent, Geoffrey J; Abraham, David J; McAnulty, Robin J

    2016-04-01

    Fibroblasts derived from the lungs of patients with idiopathic pulmonary fibrosis (IPF) and systemic sclerosis (SSc) produce low levels of prostaglandin (PG) E2, due to a limited capacity to up-regulate cyclooxygenase-2 (COX-2). This deficiency contributes functionally to the fibroproliferative state, however the mechanisms responsible are incompletely understood. In the present study, we examined whether the reduced level of COX-2 mRNA expression observed in fibrotic lung fibroblasts is regulated epigenetically. The DNA methylation inhibitor, 5-aza-2'-deoxycytidine (5AZA) restored COX-2 mRNA expression by fibrotic lung fibroblasts dose dependently. Functionally, this resulted in normalization of fibroblast phenotype in terms of PGE2 production, collagen mRNA expression and sensitivity to apoptosis. COX-2 methylation assessed by bisulfite sequencing and methylation microarrays was not different in fibrotic fibroblasts compared with controls. However, further analysis of the methylation array data identified a transcriptional regulator, chromosome 8 open reading frame 4 (thyroid cancer protein 1, TC-1) (c8orf4), which is hypermethylated and down-regulated in fibrotic fibroblasts compared with controls. siRNA knockdown of c8orf4 in control fibroblasts down-regulated COX-2 and PGE2 production generating a phenotype similar to that observed in fibrotic lung fibroblasts. Chromatin immunoprecipitation demonstrated that c8orf4 regulates COX-2 expression in lung fibroblasts through binding of the proximal promoter. We conclude that the decreased capacity of fibrotic lung fibroblasts to up-regulate COX-2 expression and COX-2-derived PGE2 synthesis is due to an indirect epigenetic mechanism involving hypermethylation of the transcriptional regulator, c8orf4.

  8. Expression of cyclooxygenase-2 is associated with p53 accumulation in premalignant and malignant gallbladder lesions

    Institute of Scientific and Technical Information of China (English)

    Mateja Legan; Bo(s)tjan Luzar; Vera Ferlan Marolt; Andrej C(o)r

    2006-01-01

    AIM: To examine the relationship between cyclooxygenase-2 (COX-2) overexpression and p53 accumulation in gallbladder carcinoma and its precursor lesions.METHODS: Sixty-eight gallbladder tissue samples comprising 14 cases of normal gallblader epithelium,27 cases of dysplasia (11 low-grade dyplasia and 16 high-grade dysplasia) and 27 adenocarcinomas were evaluated by immunohistochemistry for COX-2 expression and p53 accumulation. The relationship among COX-2 expression, p53 accumulation and clinicopathological characteristics was analysed.RESULTS: COX-2 was expressed in 14.3% of normal gallbladder epithelium, 70.3% of dysplastic epite hiium,and 59.2% of adenocarcinomas. When divided into low- and high-grade dysplasia, COX-2 was positive in 5 (45.4%) cases of low-grade and 14 (87.5%) of highgrade dysplasia (P = 0.019). Accumulation of p53 was detected in 5 (31.2%) cases of high-grade dysplasia and in 13 (48.1%) of carcinomas. No p53 accumulation was found in normal epithelium or low-grade dysplasia. COX-2 overexpression was observed in 17 of 18 (94.4%) cases with p53-accumulation in comparison with 20 (40.0%)out of 50 cases without p53 accumulation (P < 0.001).CONCLUSION: The significant differences in COX-2 expression among normal epithelium, low-grade dysplasia and high-grade dysplasia suggest that overexpression of COX-2 enzyme is an early event in gallbladder carcinogenensis. Furthermore, since accumulation of p53 correlates with COX-2 expression, COX-2 overexpression observed in gallbladder high-grade dysplasia and carcinoma might be partly due to the dysfunction of p53.

  9. Effect of cyclooxygenase inhibitors on gentamicin-induced nephrotoxicity in rats

    Directory of Open Access Journals (Sweden)

    Hosaka E.M.

    2004-01-01

    Full Text Available The frequent use of nonsteroidal anti-inflammatory drugs (NSAID in combination with gentamicin poses the additional risk of nephrotoxic renal failure. Cyclooxygenase-1 (COX-1 is the main enzyme responsible for the synthesis of renal vasodilator prostaglandins, while COX-2 participates predominantly in the inflammatory process. Both are inhibited by non-selective NSAID such as indomethacin. Selective COX-2 inhibitors such as rofecoxib seem to have fewer renal side effects than non-selective inhibitors. The objective of the present study was to determine whether the combined use of rofecoxib and gentamicin can prevent the increased renal injury caused by gentamicin and indomethacin. Male Wistar rats (250-300 g were treated with gentamicin (100 mg/kg body weight, ip, N = 7, indomethacin (5 mg/kg, orally, N = 7, rofecoxib (1.4 mg/kg, orally, N = 7, gentamicin + rofecoxib (100 and 1.4 mg/kg, respectively or gentamicin + indomethacin (100 and 5 mg/kg, respectively, N = 8 for 5 days. Creatinine clearance and alpha-glutathione-S-transferase concentrations were used as markers of renal injury. Animals were anesthetized with ether and sacrificed for blood collection. The use of gentamicin plus indomethacin led to worsened renal function (0.199 ± 0.019 ml/min, as opposed to the absence of a nephrotoxic effect of rofecoxib when gentamicin plus rofexicob was used (0.242 ± 0.011 ml/min. These results indicate that COX-2-selective inhibitors can be used as an alternative treatment to conventional NSAID, especially in situations in which risk factors for nephrotoxicity are present.

  10. Zoledronic acid cooperates with a cyclooxygenase-2 inhibitor and gefitinib in inhibiting breast and prostate cancer.

    Science.gov (United States)

    Melisi, Davide; Caputo, Rosa; Damiano, Vincenzo; Bianco, Roberto; Veneziani, Bianca Maria; Bianco, A Raffaele; De Placido, Sabino; Ciardiello, Fortunato; Tortora, Giampaolo

    2005-12-01

    Biphosphonates (BPs) are widely used to inhibit osteoclastic activity in malignant diseases such as bone metastatic breast and prostate carcinoma. Recent studies reported that BPs could also cause a direct antitumor effect, probably due to their ability to interfere with several intracellular signalling molecules. The enzyme cyclooxygenase-2 (COX-2) and the epidermal growth factor receptor (EGFR) play an important role in the control of cancer cell growth and inhibitors of COX-2 and EGFR have shown antitumor activity in vitro and in vivo in several tumor types. We, and others, have previously shown that EGFR and COX-2 may be directly related to each other and that their selective inhibitors may have a cooperative effect. In the present study we have evaluated the combined effect of zoledronic acid, the most potent nitrogen-containing BP, with the COX-2 inhibitor SC-236 and the selective EGFR-tyrosine kinase inhibitor gefitinib, on breast and prostate cancer models in vitro and in xenografted nude mice. We show that combination of zoledronic acid with SC-236 and gefitinib causes a cooperative antitumor effect accompanied by induction of apoptosis and regulation of the expression of mitogenic factors, proangiogenic factors and cell cycle controllers both in vitro and in xenografted nude mice. The modulatory effect on protein expression and the inhibitory effect on tumor growth is much more potent when the three agents are used together. Since studies are ongoing to explore the antitumor effect of zoledronic acid, our results provide new insights into the mechanism of action of these agents and a novel rationale to translate this feasible combination treatment strategy into a clinical setting.

  11. Interferon-α and cyclooxygenase-2 inhibitor cooperatively mediates TRAIL-induced apoptosis in hepatocellular carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Zuo, Chaohui, E-mail: zuochaohui@vip.sina.com [Department of Gastroduodenal and Pancreatic Surgery, Translation Medicine Research Center of Liver Cancer, Hunan Province Tumor Hospital & Affiliated Tumor Hospital of Xiangya Medical School, Central South University, Changsha, Hunan Province (China); Department of Pathology, Immunology and Laboratory Medicine and Shands Cancer Center, University of Florida, Gainesville, FL (United States); Qiu, Xiaoxin [Department of Gastroduodenal and Pancreatic Surgery, Translation Medicine Research Center of Liver Cancer, Hunan Province Tumor Hospital & Affiliated Tumor Hospital of Xiangya Medical School, Central South University, Changsha, Hunan Province (China); Cancer Research Institute, University of South China, Hengyang, Hunan Province (China); Liu, Nianli; Yang, Darong [Cancer Research Institute, University of South China, Hengyang, Hunan Province (China); Xia, Man [Department of Gastroduodenal and Pancreatic Surgery, Translation Medicine Research Center of Liver Cancer, Hunan Province Tumor Hospital & Affiliated Tumor Hospital of Xiangya Medical School, Central South University, Changsha, Hunan Province (China); Department of Pathology, Immunology and Laboratory Medicine and Shands Cancer Center, University of Florida, Gainesville, FL (United States); Liu, Jingshi [Department of Gastroduodenal and Pancreatic Surgery, Translation Medicine Research Center of Liver Cancer, Hunan Province Tumor Hospital & Affiliated Tumor Hospital of Xiangya Medical School, Central South University, Changsha, Hunan Province (China); Wang, Xiaohong [Cancer Research Institute, University of South China, Hengyang, Hunan Province (China); and others

    2015-05-01

    Hepatocellular carcinoma (HCC) is a leading cause of cancer-related mortality worldwide. Interferon-alpha (IFN-α) has recently been recognized to harbor therapeutic potential in the prevention and treatment of HCC, but it remains controversial as to whether IFN-α exerts direct cytotoxicity against HCC. Cyclooxygenase-2 (COX-2) is overexpressed in HCC and is considered to play a role in hepatocarcinogenesis. Therefore, we aimed to elucidate the combined effect of a COX-2 inhibitor, celecoxib, and IFN-α on in vitro growth suppression of HCC using the hepatoma cell line HLCZ01 and the in vivo nude mouse xenotransplantation model using HLCZ01 cells. Treatment with celecoxib and IFN-α synergistically inhibited cell proliferation in a dose- and time-dependent manner. Apoptosis was identified by 4',6-diamidino-2-phenylindole dihydrochloride and fluorescent staining. IFN-α upregulated the expression of TRAIL, while celecoxib increased the expression of TRAIL receptors. The combined regimen with celecoxib and IFN-α reduced the growth of xenotransplanted HCCs in nude mice. The regulation of IFN-α- and COX-2 inhibitor-induced cell death is impaired in a subset of TRAIL-resistant cells. The molecular mechanisms of HCC cells resistant to TRAIL-induced apoptosis were explored using molecular biological and immunological methods. Interferon-α and the COX-2 inhibitor celecoxib synergistically increased TRAIL-induced apoptosis in hepatocellular carcinoma. These data suggest that IFN-α and celecoxib may offer a novel role with important implications in designing new therapeutics for TRAIL-resistant tumors. - Highlights: ●The cytotoxic effect of TRAIL on a developed HCC HLCZ01 cells infected with HBV. ●IFN-α and celecoxib induced apoptosis in HLCZ01 cells infected with HBV. ●The combined regime reduced the growth of xenotransplanted HCCs in nude mice model.

  12. Peroxisome proliferator-activated receptor-gamma suppresses cyclooxygenase-2 expression in human prostate cells.

    Science.gov (United States)

    Sabichi, Anita L; Subbarayan, Vemparala; Llansa, Norma; Lippman, Scott M; Menter, David G

    2004-11-01

    Recent studies have found that cyclooxygenase-2 (COX-2) protein expression was low and inducible with cytokines in prostate cancer cells (in the absence of serum) and that, in contrast, COX-2 expression was high in normal prostate epithelial cells (EC). Peroxisome proliferator-activated receptor-gamma (PPAR-gamma) was expressed at high levels in the prostate cancer cell line PC-3 but not in ECs. In contrast to previous findings by others, PPAR-gamma ligands did not induce PPAR-gamma expression in EC or PC-3. The present study examined the relationship between PPAR-gamma and COX-2 expression patterns in EC and PC-3 in the presence and absence of serum and/or the PPAR-gamma agonist 15-deoxy-Delta12,14-prostaglandin J(2) (15d-PGJ(2)). We also evaluated the effects that the forced expression of PPAR-gamma1 and PPAR-gamma2 had on COX-2 in ECs. We found that expression of PPAR-gamma and COX-2 protein was inversely correlated in ECs and PC-3. Low COX-2 expression in PC-3 was up-regulated by serum, and 15d-PGJ(2) blocked serum-induced COX-2 expression and activity in a dose-dependent manner. 15d-PGJ(2) had no effect on COX-2 expression in ECs or PPAR-gamma expression in either cell type. However, forced expression of PPAR-gamma1 or PPAR-gamma2 in ECs suppressed the high level of endogenous COX-2. This effect was not isoform specific and was augmented by 15d-PGJ(2). The present study showed that PPAR-gamma activation can be an important regulator of COX-2 in prostate cells and may be an important target for prostate cancer chemoprevention.

  13. Effect of selective inhibition of cyclooxygenase-2 on lipopolysaccharide-induced hyperalgesia.

    Science.gov (United States)

    Satyanarayana, Padi S V; Jain, Naveen K; Singh, Sukhjeet; Kulkarni, Shrinivas K

    2004-01-01

    Lipopolysaccharide (LPS) is known to increase the expression and release of various pro-inflammatory mediators, including cyclooxygenase-2 (COX-2) and produce hyperalgesia. It is also well known that prostaglandins (PGs), synthesised both in the periphery and centrally by COX isoforms, play a key role in sensitisation of nociceptors and nociceptive processing. To investigate the role of COX-2 in LPS-induced hyperalgesia, parecoxib, a selective COX-2-inhibiting pro-drug, was injected intravenously 30 min before assessing hyperalgesia induced by intraperitoneal or subcutaneous administration of LPS (50 microg/mouse or 25 microg/paw of rat, respectively). Acetic acid-induced writhing and tail immersion assay in mice and paw withdrawal response to thermal and mechanical stimuli in rats were used to assess the effect of inhibition of COX-2 on LPSinduced hyperalgesia. Animals showed significant hyperalgesic behavior 8 h after LPS injection. Parecoxib (up to 20 mg/kg, i.v.) had no effect in the two acute nociceptive assays but showed marked antinociceptive activity in writhing and tail immersion assay in LPS-pretreated mice. Similarly, parecoxib reversed the hyperalgesia in the LPS-injected paw but not in the contralateral paw of rats. Pre-treatment with dexamethasone, an inhibitor of COX-2 expression before LPS injection significantly affected the development of hyperalgesia in both mice and rats. These findings suggest that inducible COX-2 derived PGs are involved in central nociceptive processing, which resulted in hyperalgesic behavior following LPS administration and inhibition of COX-2 or its expression attenuated LPS-induced hyperalgesia.

  14. Genetic ablation of cyclooxygenase-2 in keratinocytes produces a cell-autonomous defect in tumor formation

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    Langenbach, Robert

    2012-01-01

    Using a mouse skin tumor model, we reported previously that cyclooxygenase-2 (COX-2) deficiency reduced papilloma formation. However, this model did not differentiate between the effects of systemic COX-2-deficiency and keratinocyte-specific COX-2 deficiency on tumor formation. To determine whether keratinocyte-specific COX-2 deficiency reduced papilloma formation, v-H-ras-transformed COX-2+/+ and COX-2−/− keratinocytes were grafted onto nude mice and tumor development was compared. Transformed COX-2+/+ and COX-2−/− keratinocytes expressed similar levels of H-ras, epidermal growth factor receptor and phospho-extracellular signal-regulated kinase1/2 in vitro; and COX-2-deficiency did not reduce uninfected or v-H-ras infected keratinocyte replication. In contrast, tumors arising from grafted transformed COX-2+/+ and COX-2−/− keratinocytes expressed similar levels of H-ras, but COX-2 deficiency reduced phospho-extracellular signal-regulated kinase 1/2 and epidermal growth factor receptor levels 50–60% and tumor volume by 80% at 3 weeks. Two factors appeared to account for the reduced papilloma size. First, papillomas derived from COX-2−/− keratinocytes showed about 70% decreased proliferation, as measured by bromodeoxyuridine incorporation, compared with papillomas derived from COX-2+/+ keratinocytes. Second, keratin 1 immunostaining of papillomas indicated that COX-2−/− keratinocytes prematurely initiated terminal differentiation. Differences in the levels of apoptosis and vascularization did not appear to be contributing factors as their levels were similar in tumors derived from COX-2−/− and COX-2+/+ keratinocytes. Overall, the data are in agreement with our previous observations that decreased papilloma number and size on COX-2−/− mice resulted from reduced keratinocyte proliferation and accelerated keratinocyte differentiation. Furthermore, the data indicate that deficiency/inhibition of COX-2 in the initiated keratinocyte is an

  15. Selective Cyclooxygenase-2 Inhibitor Prevents Cisplatin-induced Tumorigenesis in A/J Mice

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    Okada,Toshiaki

    2012-06-01

    Full Text Available Cisplatin is used to treat lung cancer;however, it is also a known carcinogen. Cyclooxygenase-2 (COX-2 inhibitors have been shown to prevent carcinogen-induced experimental tumors. We investigated the effect of a COX-2 inhibitor, celecoxib, on cisplatin-induced lung tumors. One hundred twenty 4-week-old A/J mice were divided into 6 groups:group 1, no treatment;group 2, low-dose celecoxib (150mg/kg;group 3, high-dose celecoxib (1,500mg/kg;group 4, cisplatin alone;group 5, cisplatin plus low-dose celecoxib;and group 6, cisplatin plus high-dose celecoxib. Mice in groups 4-6 were administered cisplatin (1.62mg/kg, i.p. once a week for 10 weeks between 7 and 16 weeks of age. All mice were sacrificed at week 30. Tumor incidence was 15.8% in group 1, 25% in group 2, 26.3% in group 3, 60% in group 4, 50% in group 5, and 50% in group 6. Tumor multiplicity was 0.2, 0.3, 0.3, 1.3, 1.0, and 0.6 in groups 1-6, respectively. Tumor multiplicity in the cisplatin-treated mice was reduced by celecoxib treatment in a dose-dependent manner (p<0.05, group 4 vs. group 6. Celecoxib significantly reduced COX-2 expression in cisplatin-induced tumors (p<0.01, group 4 vs. group 6.

  16. Quantitative analysis of cyclooxygenase 2 in the posterior longitudinal ligament of cervical spondylotic myelopathy

    Institute of Scientific and Technical Information of China (English)

    SONG Hong-xing; Michael Scarpatetti; Wolfgang Kreil; SHEN Hui-liang; Koppany Bodo; Birgit Ebner; Heribert Schr(o)ttner; Michael Mokry

    2011-01-01

    Background Cervical spondylotic myelopathy (CSM), in part, results from degeneration of the posterior longitudinal ligament (PLL), which mechanically compresses the spinal cord. Much research was done on the ossification of PLL, but not concerning the non-ossifying degeneration of cervical PLL. The degeneration of cervical PLL may be related to inflammation. The aim of this study was to elucidate the pathological features of the PLL and the role of cyclooxygenase 2 (COX-2) in the degeneration of the PLL in CSM.Methods A total of 23 PLL specimens were collected during surgery from patients with CSM for the histological and immunohistochemical (type Ⅱ collagen and Ki-67) study. For the control group 14 cervical PLL autopsy specimens were investigated in the same manner. mRNA expression of COX-2 was quantitatively measured by real-time reverse transcription-polymerase chain reaction (RT-PCR) from 18 PLL specimens of patients with CSM and 18 PLL specimens of autopsy cases. Immunohistochemistry was used to evaluate the cellular location of COX-2 in PLL.Results A distinct amount of fibrotic area, chondrometaplastic tissue and calcification were found in the PLL of the patient group, compared with the control group. Type Ⅱ collagen was apparent around chondrometaplastic cells. Ki-67 positive reaction was less than 5%. A COX-2 positive reaction was found in 9 of the patient specimens (39.1%) in which the COX-2 was released from vascular endothelial cells in the PLL. However, such reactions were not found in the control group. Real-time PCR showed that the mRNA expression level of COX-2 in the patient group was significantly higher than that in the control group (P <0.01).Conclusions Chondrometaplastic tissue producing type Ⅱ collagen was identified as the most predominant pathological feature in the degenerative PLL. The higher expression of COX-2 might be related to degeneration of the PLL in CSM.

  17. Effects of aspirin on atherosclerosis and the cyclooxygenase-2 expression in atherosclerotic rabbits

    Institute of Scientific and Technical Information of China (English)

    GUO Yi; WANG Qi-zhang; TANG Bing-shan; ZUO Yan-fang; LI Fang-ming; JIANG Xin; WANG Ling; MA Ke-fu

    2006-01-01

    Background Atherosclerosis is a complex vascular inflammatory disease. Aspirin is a mainstay in the prevention of vascular complications of atherosclerosis. In this study, the effectiveness of aspirin in suppressing atherosclerosis and the inflammation process was evaluated in rabbits fed with a high fat diet.Methods Eighteen male New Zealand rabbits were randomly divided into 3 groups: control group, untreated cholesterol-fed group, aspirin treated cholesterol-fed group, which were fed for 12 weeks. After 12 weeks, the aorta was harvested for pathologic morphology observation. Immunohistochemical analysis of cyclooxygenase-2 (COX-2), macrophage and vascular smooth muscle cell (VSMC) was performed. The statistical analysis was performed by the statistical program SPSS 10.0.Results The aorta plaque/intima size (P/I) by pathologic morphology observation was 0%, (59.6± 13.7)% and (36.3± 16.5)% in the control, untreated cholesterol-fed group and aspirin treated group, respectively. The maximum plaque thickness, the degree of artery stenosis and the proportion of the intimal circumference occupied by atheroma of the 3 groups were significantly different from each other (P<0.01). The expression of COX-2 and macrophage in plaque of the aspirin treated group were decreased compared with that in untreated cholesterol-fed group. However, no difference was found in the expression of VSMC between the aspirin treated and the untreated cholesterol-fed group.Conclusion The mechanism of atherosclerosis suppression by aspirin in cholesterol-fed rabbits is related to the inhibition of COX-2 expression together with the reduced inflammation followed by, but not related to the hypolipidemic effects.

  18. Identification of novel Cyclooxygenase-2-dependent genes in Helicobacter pylori infection in vivo

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    Wiedenmann Bertram

    2009-03-01

    Full Text Available Abstract Background Helicobacter pylori is a crucial determining factor in the pathogenesis of benign and neoplastic gastric diseases. Cyclooxygenase-2 (Cox-2 is the inducible key enzyme of arachidonic acid metabolism and is a central mediator in inflammation and cancer. Expression of the Cox-2 gene is up-regulated in the gastric mucosa during H. pylori infection but the pathobiological consequences of this enhanced Cox-2 expression are not yet characterized. The aim of this study was to identify novel genes down-stream of Cox-2 in an in vivo model, thereby identifying potential targets for the study of the role of Cox- 2 in H. pylori pathogenesis and the initiation of pre- cancerous changes. Results Gene expression profiles in the gastric mucosa of mice treated with a specific Cox-2 inhibitor (NS398 or vehicle were analysed at different time points (6, 13 and 19 wk after H. pylori infection. H. pylori infection affected the expression of 385 genes over the experimental period, including regulators of gastric physiology, proliferation, apoptosis and mucosal defence. Under conditions of Cox-2 inhibition, 160 target genes were regulated as a result of H. pylori infection. The Cox-2 dependent subset included those influencing gastric physiology (Gastrin, Galr1, epithelial barrier function (Tjp1, connexin45, Aqp5, inflammation (Icam1, apoptosis (Clu and proliferation (Gdf3, Igf2. Treatment with NS398 alone caused differential expression of 140 genes, 97 of which were unique, indicating that these genes are regulated under conditions of basal Cox-2 expression. Conclusion This study has identified a panel of novel Cox-2 dependent genes influenced under both normal and the inflammatory conditions induced by H. pylori infection. These data provide important new links between Cox-2 and inflammatory processes, epithelial repair and integrity.

  19. A cyclooxygenase-2-dependent prostaglandin E2 biosynthetic system in the Golgi apparatus.

    Science.gov (United States)

    Yuan, Chong; Smith, William L

    2015-02-27

    Cyclooxygenases (COXs) catalyze the committed step in prostaglandin (PG) biosynthesis. COX-1 is constitutively expressed and stable, whereas COX-2 is inducible and short lived. COX-2 is degraded via endoplasmic reticulum (ER)-associated degradation (ERAD) following post-translational glycosylation of Asn-594. COX-1 and COX-2 are found in abundance on the luminal surfaces of the ER and inner membrane of the nuclear envelope. Using confocal immunocytofluorescence, we detected both COX-2 and microsomal PGE synthase-1 (mPGES-1) but not COX-1 in the Golgi apparatus. Inhibition of trafficking between the ER and Golgi retarded COX-2 ERAD. COX-2 has a C-terminal STEL sequence, which is an inefficient ER retention signal. Substituting this sequence with KDEL, a robust ER retention signal, concentrated COX-2 in the ER where it was stable and slowly glycosylated on Asn-594. Native COX-2 and a recombinant COX-2 having a Golgi targeting signal but not native COX-1 exhibited efficient catalytic coupling to mPGES-1. We conclude that N-glycosylation of Asn-594 of COX-2 occurs in the ER, leading to anterograde movement of COX-2 to the Golgi where the Asn-594-linked glycan is trimmed prior to retrograde COX-2 transport to the ER for ERAD. Having an inefficient ER retention signal leads to sluggish Golgi to ER transit of COX-2. This permits significant Golgi residence time during which COX-2 can function catalytically. Cytosolic phospholipase A2α, which mobilizes arachidonic acid for PG synthesis, preferentially translocates to the Golgi in response to physiologic Ca(2+) mobilization. We propose that cytosolic phospholipase A2α, COX-2, and mPGES-1 in the Golgi comprise a dedicated system for COX-2-dependent PGE2 biosynthesis.

  20. Hepatic cyclooxygenase-2 expression protects against diet-induced steatosis, obesity, and insulin resistance.

    Science.gov (United States)

    Francés, Daniel E; Motiño, Omar; Agrá, Noelia; González-Rodríguez, Águeda; Fernández-Álvarez, Ana; Cucarella, Carme; Mayoral, Rafael; Castro-Sánchez, Luis; García-Casarrubios, Ester; Boscá, Lisardo; Carnovale, Cristina E; Casado, Marta; Valverde, Ángela M; Martín-Sanz, Paloma

    2015-05-01

    Accumulation evidence links obesity-induced inflammation as an important contributor to the development of insulin resistance, which plays a key role in the pathophysiology of obesity-related diseases such as type 2 diabetes and nonalcoholic fatty liver disease. Cyclooxygenase (COX)-1 and -2 catalyze the first step in prostanoid biosynthesis. Because adult hepatocytes fail to induce COX-2 expression regardless of the proinflammatory stimuli used, we have evaluated whether this lack of expression under mild proinflammatory conditions might constitute a permissive condition for the onset of insulin resistance. Our results show that constitutive expression of human COX-2 (hCOX-2) in hepatocytes protects against adiposity, inflammation, and, hence, insulin resistance induced by a high-fat diet, as demonstrated by decreased hepatic steatosis, adiposity, plasmatic and hepatic triglycerides and free fatty acids, increased adiponectin-to-leptin ratio, and decreased levels of proinflammatory cytokines, together with an enhancement of insulin sensitivity and glucose tolerance. Furthermore, hCOX-2 transgenic mice exhibited increased whole-body energy expenditure due in part by induction of thermogenesis and fatty acid oxidation. The analysis of hepatic insulin signaling revealed an increase in insulin receptor-mediated Akt phosphorylation in hCOX-2 transgenic mice. In conclusion, our results point to COX-2 as a potential therapeutic target against obesity-associated metabolic dysfunction. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  1. The blockade of cyclooxygenases-1 and -2 reduces the effects of hypoxia on endothelial cells

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    Gloria M.A.

    2006-01-01

    Full Text Available Hypoxia activates endothelial cells by the action of reactive oxygen species generated in part by cyclooxygenases (COX production enhancing leukocyte transmigration. We investigated the effect of specific COX inhibition on the function of endothelial cells exposed to hypoxia. Mouse immortalized endothelial cells were subjected to 30 min of oxygen deprivation by gas exchange. Acridine orange/ethidium bromide dyes and lactate dehydrogenase activity were used to monitor cell viability. The mRNA of COX-1 and -2 was amplified and semi-quantified before and after hypoxia in cells treated or not with indomethacin, a non-selective COX inhibitor. Expression of RANTES (regulated upon activation, normal T cell expressed and secreted protein and the protective role of heme oxygenase-1 (HO-1 were also investigated by PCR. Gas exchange decreased partial oxygen pressure (PaO2 by 45.12 ± 5.85% (from 162 ± 10 to 73 ± 7.4 mmHg. Thirty minutes of hypoxia decreased cell viability and enhanced lactate dehydrogenase levels compared to control (73.1 ± 2.7 vs 91.2 ± 0.9%, P < 0.02; 35.96 ± 11.64 vs 22.19 ± 9.65%, P = 0.002, respectively. COX-2 and HO-1 mRNA were up-regulated after hypoxia. Indomethacin (300 µM decreased COX-2, HO-1, hypoxia-inducible factor-1alpha and RANTES mRNA and increased cell viability after hypoxia. We conclude that blockade of COX up-regulation can ameliorate endothelial injury, resulting in reduced production of chemokines.

  2. Synthesis and evaluation of a radioiodinated lumiracoxib derivative for the imaging of cyclooxygenase-2 expression

    Energy Technology Data Exchange (ETDEWEB)

    Kuge, Yuji [Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501 (Japan); Department of Tracer Kinetics and Bioanalysis, Graduate School of Medicine, Hokkaido University, Sapporo 060-8638 (Japan)], E-mail: kuge@med.hokudai.ac.jp; Obokata, Naoyuki; Kimura, Hiroyuki; Katada, Yumiko; Temma, Takashi [Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501 (Japan); Sugimoto, Yukihiko [Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501 (Japan); Aita, Kazuki [Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501 (Japan); Central Institute of Isotope Science, Hokkaido University, Sapporo 060-8638 (Japan); Seki, Koh-ichi [Central Institute of Isotope Science, Hokkaido University, Sapporo 060-8638 (Japan); Tamaki, Nagara [Department of Nuclear Medicine, Graduate School of Medicine, Hokkaido University, Sapporo 060-8638 (Japan); Saji, Hideo [Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501 (Japan)

    2009-11-15

    Introduction: Despite extensive attempts to develop cyclooxygenase (COX)-2 imaging radiotracers, no suitable positron emission tomography (PET)/single photon emission computed tomography (SPECT) tracers are currently available for in vivo imaging of COX-2 expression. The aims of this study were to synthesize and evaluate a radioiodinated derivative of lumiracoxib, 2-[(2-fluoro-6-iodophenyl)-amino]-5-methylphenylacetic acid (FIMA), which is structurally distinct from other drugs in the class and has weakly acidic properties, as a SPECT tracer for imaging COX-2 expression. Methods: The COX inhibitory potency was assessed by measuring COX-catalyzed oxidation with hydrogen peroxide. Cell uptake characteristics of {sup 125}I-FIMA were assessed in control and linterfero/interferon-{gamma}-stimulated macrophages. The biodistribution of {sup 125}I-FIMA was determined by the ex vivo tissue counting method in rats. Results: The COX-2 inhibitory potency of FIMA (IC{sub 50}=2.46 {mu}M) was higher than that of indomethacin (IC{sub 50}=20.9 {mu}M) and was comparable to lumiracoxib (IC{sub 50}=0.77 {mu}M) and diclofenac (IC{sub 50}=0.98 {mu}M). The IC{sub 50} ratio (COX-1/COX-2=182) indicated FIMA has a high isoform selectivity for COX-2. {sup 125}I-FIMA showed a significantly higher accumulation in COX-2 induced macrophages than in control macrophages, which decreased with nonradioactive FIMA in a concentration dependent manner. The biodistribution study showed rapid clearance of {sup 125}I-FIMA from the blood and most organs including the liver and kidneys. No significant in vivo deiodination was observed with radioiodinated FIMA. Conclusions: FIMA showed high inhibitory potency and selectivity for COX-2. Radioiodinated FIMA showed specific accumulation into COX-2 induced macrophages, no significant in vivo deiodination and rapid blood clearance. Radioiodinated FIMA deserves further investigation as a SPECT radiopharmaceutical for imaging COX-2 expression.

  3. Effect of flunixin meglumine and firocoxib on ex vivo cyclooxygenase activity in horses undergoing elective surgery.

    Science.gov (United States)

    Duz, Marco; Parkin, Tim D; Cullander, Rose M; Marshall, John F

    2015-03-01

    To evaluate ex vivo cyclooxygenase (COX) inhibition and compare in vitro and ex vivo COX-1 inhibition by flunixin meglumine and firocoxib in horses. 4 healthy horses for in vitro experiments and 12 healthy horses (6 males and 6 females; 5 Thoroughbreds, 5 Warmbloods, and 2 ponies) undergoing elective surgery for ex vivo experiments. 12 horses received flunixin meglumine (1.1 mg/kg, IV, q 12 h) or firocoxib (0.09 mg/kg, IV, q 24 h). Blood samples were collected before (baseline) and 2 and 24 hours after NSAID administration. Prostanoids (thromboxane B2, prostaglandin E2, and prostaglandin E metabolites) served as indicators of COX activity, and serum drug concentrations were measured by use of high-performance liquid chromatography. An in vitro coagulation-induced thromboxane B2 assay was used to calculate drug concentration-COX-1 inhibition curves. Effect of time and treatment on COX activity was determined. Agreement between in vitro and ex vivo measurement of COX activity was assessed with Bland-Altman analysis. At 2 and 24 hours after NSAID administration, COX-1 activity was reduced, compared with baseline activity, for the flunixin meglumine group only and relative COX-1 activity was significantly greater for the firocoxib group, compared with that for the flunixin meglumine group. There was no significant change in COX-2 activity after surgery for either group. Bland-Altman analysis revealed poor agreement between in vitro and ex vivo measurement of COX-1 activity. Compared with flunixin meglumine, firocoxib had COX-1-sparing effects ex vivo in equine patients that underwent elective surgery.

  4. Cyclooxygenase I and II inhibitors distinctly enhance hippocampal- and cortex-dependent cognitive functions in mice.

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    Syed, Huma; Ikram, Muhammad Faisal; Yaqinuddin, Ahmed; Ahmed, Touqeer

    2015-11-01

    Cyclooxygenase (COX) enzymes are expressed in the brain; however, their role in hippocampus-dependent and cortex-dependent cognitive functions remains to be fully elucidated. The aim of the present study was to comparatively investigate the effects of piroxicam, a selective COX-I inhibitor, and celecoxib, a selective COX‑II inhibitor, on cognitive functions in an AlCl3‑induced neurotoxicity mouse model to understand the specific role of each COX enzyme in the hippocampus and cortex. The AlCl3 (250 mg/kg) was administered to the mice in drinking water and the drugs were administered in feed for 30 days. Assessments of memory, including a Morris water maze, social behavior and nesting behavior were performed in control and treated mice. The RNA expression of the COX enzymes were analyzed using reverse transcription‑quantitative polymerase chain reaction analysis. An ex‑vivo 2,2‑Diphenyl‑1‑picrylhydrazyl assay was performed in the hippocampus and cortex. Following 30 days of treatment with thedrugs, the mice in the celecoxib‑ and piroxicam‑treated groups exhibited enhanced learning (6.84 ± 0.76 and 9.20 ± 1.08, respectively), compared with the AlCl3‑induced neurotoxicity group (21.14 ± 0.76) on the fifth day of the Morris water maze test. Celecoxib treatment improved social affiliation in the AlCl3‑induced neurotoxicity group, the results of which were superior to piroxicam. Piroxicam led to better improvement in nesting score in the AlCl3‑induced neurotoxicity group. Both drugs decreased the expression levels of COX‑I and COX‑II in the hippocampus and cortex, and rescued oxidative stress levels. These findings suggested that each drug distinctly affected cognitive functions, highlighting the distinctive roles of COX-I and COX-II in learning and memory.

  5. Effect of Propyl Gallate on Activity of Cyclooxygenase 1 and 2 in Mice's Peritoneal Macrophages

    Institute of Scientific and Technical Information of China (English)

    殷惠军; 蒋跃绒; 吴晓华; 陈晓红; 陈可冀

    2004-01-01

    Objective: To investigate the effect of Red Peony 801 (propyl gallate,PrG) on cyclooxygenase (COX) activity in murine peritoneal macrophages. Methods: A screening model for COX inhibitors in vitro based on murine peritoneal macrophages was used. COX-1 activity was reflected by the level of 6-ketoprostaglandin F1α (6-keto-PGF1α) in supernatants of cultured macrophages which were stimulated with calcium ionophore A23187 for a short-term, while COX-2 activity was reflected by the level of prostaglandin E2(PGE2) in supernatants of cultured macrophages which were stimulated with lipopolysaccharide (LPS) for a long-term. Results: PrG did not affect A23187-induced, COX-1-derived 6-keto-PGF1α synthesis at the concentrations of 1 × 10-5, 5 × 10 6 mol/L (P>0.05), but enhanced 6-keto-PGF1α synthesis at the concentrations of 1×10-6, 5×10-7, 1×10-7 mol/L (P<0.01) in vitro, and showed a good dose-dependent manner. It inhibited LPS-induced, COX-2-derived PGE2 synthesis at the concentrations of 1 × 10-5 , 1 × 10-6 mol/L ( P<0.05). Conclusion: Within the range of 1 × 10-5 to 1 × 10-7 mol/L, PrG activated COX-1 at lower concentrations and inhibited COX-2 at higher concentrations in murine peritoneal macrophages.

  6. Cellular Expression of Cyclooxygenase, Aromatase, Adipokines, Inflammation and Cell Proliferation Markers in Breast Cancer Specimen.

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    Samar Basu

    Full Text Available Current evidences suggest that expression of Ki67, cyclooxygenase (COX, aromatase, adipokines, prostaglandins, free radicals, β-catenin and α-SMA might be involved in breast cancer pathogenesis. The main objective of this study was to compare expression/localization of these potential compounds in breast cancer tissues with tissues collected adjacent to the tumor using immunohistochemistry and correlated with clinical pathology. The breast cancer specimens were collected from 30 women aged between 49 and 89 years who underwent breast surgery following cancer diagnosis. Expression levels of molecules by different stainings were graded as a score on a scale based upon staining intensity and proportion of positive cells/area or individually. AdipoR1, adiponectin, Ob-R, leptin, COX-1, COX-2, aromatase, PGF2α, F2-isoprostanes and α-SMA were localised on higher levels in the breast tissues adjacent to the tumor compared to tumor specimens when considering either score or staining area whereas COX-2 and AdipoR2 were found to be higher considering staining intensity and Ki67 on score level in the tumor tissue. There was no significant difference observed on β-catenin either on score nor on staining area and intensity between tissues adjacent to the tumor and tumor tissues. A positive correlation was found between COX-1 and COX-2 in the tumor tissues. In conclusion, these suggest that Ki67, COXs, aromatase, prostaglandin, free radicals, adipokines, β-catenin and α-SMA are involved in breast cancer. These further focus the need of examination of tissues adjacent to tumor, tumor itself and compare them with normal or benign breast tissues for a better understanding of breast cancer pathology and future evaluation of therapeutic benefit.

  7. Cyclooxygenase-2 expression as a predictor of outcome in colorectal carcinoma

    Institute of Scientific and Technical Information of China (English)

    Jaudah AI-Maghrabi; Abdelbaset Buhrneida; Eman Emam; Kari Syrj(a)nen; Abdulrahman Sibiany; Mohmmad AI-Qahtani; Mahmoud AI-Ahwal

    2012-01-01

    AIM:To correlate cyclooxygenase-2 (COX-2) expression profile with clinical and pathological variables to assess their prognostic/predictive value in colorectal carcinoma (CRC).METHODS:Archival tumor samples were analyzed using immunohistochemistry for COX-2 expression in 94patients with CRC.Patients were diagnosed and treated at the Departments of Surgery and Oncology,King Abdulaziz University Hospital,Saudi Arabia.RESULTS:Fifty-six percent of the tumors showed positive cytoplasmic COX-2 expression,whereas 44% of cases were completely COX-2-negative.There were no significant correlations between COX-2 expression and sex,age,grade or tumor location.However,COX-2 expression revealed a significant correlation with tumor stage (P =0.01) and distant metastasis (P =0.02),and a borderline association with lymph node involvement (P=0.07).Tumors with high COX-2 expression showed a higher recurrence rate than tumors with no expression (P < 0.009).In univariate Kaplan-Meier survival analysis,there was a significant (P =0.026) difference in disease-free survival between COX-2-positive and negative tumors in favor of the latter.COX-2 expression did not significantly predict disease-specific survival,which was much shorter for COX-2-positive tumors.In multivariate (COX) models,COX-2 did not appear among the independent predictors of disease-free survival or disease-specific survival.CONCLUSION:COX-2 expression seems to provide useful prognostic information in CRC,while predicting the patients at high risk for recurrent disease.

  8. Reduction in the risk of human breast cancer by selective cyclooxygenase-2 (COX-2 inhibitors

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    Alshafie Galal A

    2006-01-01

    Full Text Available Abstract Background Epidemiologic and laboratory investigations suggest that nonsteroidal anti-inflammatory drugs (NSAIDs have chemopreventive effects against breast cancer due to their activity against cyclooxygenase-2 (COX-2, the rate-limiting enzyme of the prostaglandin cascade. Methods We conducted a case control study of breast cancer designed to compare effects of selective and non-selective COX-2 inhibitors. A total of 323 incident breast cancer patients were ascertained from the James Cancer Hospital, Columbus, Ohio, during 2003–2004 and compared with 649 cancer free controls matched to the cases at a 2:1 ratio on age, race, and county of residence. Data on the past and current use of prescription and over the counter medications and breast cancer risk factors were ascertained using a standardized risk factor questionnaire. Effects of COX-2 inhibiting agents were quantified by calculating odds ratios (OR and 95% confidence intervals. Results Results showed significant risk reductions for selective COX-2 inhibitors as a group (OR = 0.29, 95% CI = 0.14–0.59, regular aspirin (OR = 0.49, 95% CI = 0.26–0.94, and ibuprofen or naproxen (0.36, 95% CI = 0.18–0.72. Acetaminophen, a compound with negligible COX-2 activity and low dose aspirin (81 mg produced no significant change in the risk of breast cancer. Conclusion Selective COX-2 inhibitors (celecoxib and rofecoxib were only recently approved for use in 1999, and rofecoxib (Vioxx was withdrawn from the marketplace in 2004. Nevertheless, even in the short window of exposure to these compounds, the selective COX-2 inhibitors produced a significant (71% reduction in the risk of breast cancer, underscoring their strong potential for breast cancer chemoprevention.

  9. Ozone inhibits endothelial cell cyclooxygenase activity through formation of hydrogen peroxide

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    Madden, M.C.; Eling, T.E.; Friedman, M.

    1987-09-01

    We have previously demonstrated that a 2H exposure of cultured pulmonary endothelial cells to ozone (0.0-1.0 ppm) in-vitro resulted in a concentration-dependent reduction of endothelial prostacyclin production (90% decrease at the 1.0 ppm level). Ozone-exposed endothelial cells, incubated with 20 uM arachidonate, also demonstrated a significant inhibition of prostacyclin synthesis. To further examine the mechanisms of the inhibition of prostacyclin synthesis, bovine pulmonary endothelial cells were exposed to 1.0 ppm ozone for 2H. A significant decrease in prostacyclin synthesis was found within 5 min of exposure (77 +/- 36% of air-exposed control values, p less than 0.05). Endothelial prostacyclin synthesis returned to baseline levels by 12H after ozone exposure, a time point which was similar to the recovery time of unexposed endothelium treated with 0.5 uM acetylsalicylic acid. Incubation of endothelial cells, previously exposed to 1.0 ppm ozone for 2 hours, with 4 uM PGH2 resulted in restoration of essentially normal prostacyclin synthesis. When endothelial cells were co-incubated with catalase (5 U/ml) during ozone exposure, no inhibition of prostacyclin synthesis was observed. Co-incubation with either heat-inactivated catalase or superoxide dismutase (10 U/ml) did not affect the ozone-induced inhibition of prostacyclin synthesis. These data suggest that H/sub 2/O/sub 2/ is a major toxic species produced in endothelial cells during ozone exposure and responsible for the inhibition of endothelial cyclooxygenase activity.

  10. Cyclooxygenase-2 suppresses the anabolic response to PTH infusion in mice.

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    Shilpa Choudhary

    Full Text Available We previously reported that the ability of continuously elevated PTH to stimulate osteoblastic differentiation in bone marrow stromal cell cultures was abrogated by an osteoclastic factor secreted in response to cyclooxygenase-2 (Cox2-produced prostaglandin E2. We now examine the impact of Cox2 (Ptgs2 knockout (KO on the anabolic response to continuously elevated PTH in vivo. PTH (40 μg/kg/d or vehicle was infused for 12 or 21 days in 3-mo-old male wild type (WT and KO mice in the outbred CD-1 background. Changes in bone phenotype were assessed by bone mineral density (BMD, μCT and histomorphometry. PTH infusion for both 12 and 21 days increased femoral BMD in Cox2 KO mice and decreased BMD in WT mice. Femoral and vertebral trabecular bone volume fractions were increased in KO mice, but not in WT mice, by PTH infusion. In the femoral diaphysis, PTH infusion increased cortical area in Cox2 KO, but not WT, femurs. PTH infusion markedly increased trabecular bone formation rate in the femur, serum markers of bone formation, and expression of bone formation-related genes, growth factors, and Wnt target genes in KO mice relative to WT mice, and decreased gene expression of Wnt antagonists only in KO mice. In contrast to the differential effects of PTH on anabolic factors in WT and KO mice, PTH infusion increased serum markers of resorption, expression of resorption-related genes, and the percent bone surface covered by osteoclasts similarly in both WT and KO mice. We conclude that Cox2 inhibits the anabolic, but not the catabolic, effects of continuous PTH. These data suggest that the bone loss with continuously infused PTH in mice is due largely to suppression of bone formation and that this suppression is mediated by Cox2.

  11. A novel gliotic P2 receptor mediating cyclooxygenase-2 induction in rat and human astrocytes.

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    Brambilla, R; Ceruti, S; Malorni, W; Cattabeni, F; Abbracchio, M P

    2000-07-01

    In astrocytic cultures maintained in vitro, a brief challenge with the ATP analog alpha,beta methyleneATP (alpha,betameATP) results, 3 days later, in marked elongation of astrocytic processes, an event that resembles the astrocytic hypertrophy known to occur in vivo during reactive astrogliosis. alpha,beta meATP-induced effects were observed in primary astrocytes obtained from both rat striatum and cortex (a brain area highly involved in chronic neurodegenerative pathologies), as well as in human astrocytoma cells (ADF cells). Purine-induced gliosis could be reversed by the non-selective P2X/P2Y receptor antagonist pyridoxalphosphate-6-azophenyl-2', 4'-disulphonic acid (PPADS), but not by oxidized ATP (an antagonist of the P2X(7) receptor), in line with previous studies of our laboratory suggesting the involvement of a P2Y receptor subtype. Induction of reactive gliosis was preceded by increased expression of cyclooxygenase-2 (COX-2), an enzyme whose excessive activation has been implicated in both acute and chronic neurodegenerative diseases. The selective COX-2 inhibitor NS-398 prevented both purine-induced astrogliosis and the associated COX-2 induction, suggesting that inhibition of the transcription of the COX-2 gene may also contribute to the anti-inflammatory properties of this agent. Significant blockade of both alpha,beta meATP-mediated reactive gliosis and COX-2 induction was also observed with PPADS. These data suggest that COX-2 mediates P2Y receptor-induced reactive astrogliosis, and that antagonists selective for this receptor subtype may represent a novel class of anti-inflammatory agents of potential interest in acute and chronic neurological disorders characterized by an inflammatory component and reactive gliosis.

  12. Clinical pharmacokinetics of nabumetone. The dawn of selective cyclo-oxygenase-2 inhibition?

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    Davies, N M

    1997-12-01

    Nabumetone is a nonsteroidal anti-inflammatory drug (NSAID) of the 2,6-disubstituted naphthyl-alkanone class. Nabumetone is metabolised to an active metabolite 6-methoxy-2-napthylacetic acid (6-MNA) which is a relatively selective cyclo-oxygenase-2 inhibitor that has anti-inflammatory and analgesic properties. Nabumetone and its metabolites bind extensively to plasma albumin. Nabumetone is eliminated following biotransformation to 6-MNA, which does not undergo enterohepatic circulation and the respective glucoroconjugated metabolites are excreted in urine. Substantial concentrations of 6-MNA are attained in synovial fluid, which is he proposed site of action in chronic inflammatory arthropathies. A smaller area under the plasma concentration-time curve (AUC) is evident at steady state as compared with a single dose; this is possibly due to an increase in the volume of distribution and saturation of protein binding. Relationships between 6-MNA concentrations and the therapeutic and toxicological effects have yet to be elucidated for this NSAID. Renal failure significantly reduces 6-MNA elimination but steady-state concentrations of 6-MNA are not increased, possibly because of nonlinear protein binding. Elderly patients with osteoarthritis demonstrate decreased elimination and increased plasma concentrations of nabumetone as compared with young healthy volunteers. Rheumatic disease activity also influences 6-MNA plasma concentrations, as patients with more active disease and lower serum albumin concentrations demonstrate a lower area under the plasma concentration versus time curve. A reduced bioavailability of 6-MNA in patients with severe hepatic impairment is also evident. Dosage adjustment may be required in the elderly, patients with active rheumatic disease and those with hepatic impairment, but not in patients with mild-to-moderate renal failure.

  13. The adverse effect of selective cyclooxygenase-2 inhibitor on random skin flap survival in rats.

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    Haiyong Ren

    Full Text Available BACKGROUND: Cyclooxygenase-2(COX-2 inhibitors provide desired analgesic effects after injury or surgery, but evidences suggested they also attenuate wound healing. The study is to investigate the effect of COX-2 inhibitor on random skin flap survival. METHODS: The McFarlane flap model was established in 40 rats and evaluated within two groups, each group gave the same volume of Parecoxib and saline injection for 7 days. The necrotic area of the flap was measured, the specimens of the flap were stained with haematoxylin-eosin(HE for histologic analysis. Immunohistochemical staining was performed to analyse the level of VEGF and COX-2 . RESULTS: 7 days after operation, the flap necrotic area ratio in study group (66.65 ± 2.81% was significantly enlarged than that of the control group(48.81 ± 2.33%(P <0.01. Histological analysis demonstrated angiogenesis with mean vessel density per mm(2 being lower in study group (15.4 ± 4.4 than in control group (27.2 ± 4.1 (P <0.05. To evaluate the expression of COX-2 and VEGF protein in the intermediate area II in the two groups by immunohistochemistry test .The expression of COX-2 in study group was (1022.45 ± 153.1, and in control group was (2638.05 ± 132.2 (P <0.01. The expression of VEGF in the study and control groups were (2779.45 ± 472.0 vs (4938.05 ± 123.6(P <0.01.In the COX-2 inhibitor group, the expressions of COX-2 and VEGF protein were remarkably down-regulated as compared with the control group. CONCLUSION: Selective COX-2 inhibitor had adverse effect on random skin flap survival. Suppression of neovascularization induced by low level of VEGF was supposed to be the biological mechanism.

  14. Inhibition of cyclooxygenase-2 reduces hypothalamic excitation in rats with adriamycin-induced heart failure.

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    Min Zheng

    Full Text Available BACKGROUND: The paraventricular nucleus (PVN of the hypothalamus plays an important role in the progression of heart failure (HF. We investigated whether cyclooxygenase-2 (COX-2 inhibition in the PVN attenuates the activities of sympathetic nervous system (SNS and renin-angiotensin system (RAS in rats with adriamycin-induced heart failure. METHODOLOGY/PRINCIPAL FINDING: Heart failure was induced by intraperitoneal injection of adriamycin over a period of 2 weeks (cumulative dose of 15 mg/kg. On day 19, rats received intragastric administration daily with either COX-2 inhibitor celecoxib (CLB or normal saline. Treatment with CLB reduced mortality and attenuated both myocardial atrophy and pulmonary congestion in HF rats. Compared with the HF rats, ventricle to body weight (VW/BW and lung to body weight (LW/BW ratios, heart rate (HR, left ventricular end-diastolic pressure (LVEDP, left ventricular peak systolic pressure (LVPSP and maximum rate of change in left ventricular pressure (LV±dp/dtmax were improved in HF+CLB rats. Angiotensin II (ANG II, norepinephrine (NE, COX-2 and glutamate (Glu in the PVN were increased in HF rats. HF rats had higher levels of ANG II and NE in plasma, higher level of ANG II in myocardium, and lower levels of ANP in plasma and myocardium. Treatment with CLB attenuated these HF-induced changes. HF rats had more COX-2-positive neurons and more corticotropin releasing hormone (CRH positive neurons in the PVN than did control rats. Treatment with CLB decreased COX-2-positive neurons and CRH positive neurons in the PVN of HF rats. CONCLUSIONS: These results suggest that PVN COX-2 may be an intermediary step for PVN neuronal activation and excitatory neurotransmitter release, which further contributes to sympathoexcitation and RAS activation in adriamycin-induced heart failure. Treatment with COX-2 inhibitor attenuates sympathoexcitation and RAS activation in adriamycin-induced heart failure.

  15. Expression and function of cyclooxygenase-2 is necessary for hamster blastocyst hatching.

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    Sen Roy, Shubhendu; Seshagiri, Polani B

    2013-12-01

    Blastocyst hatching is critical for successful implantation leading to pregnancy. Its failure causes infertility. The phenomenon of blastocyst hatching in humans is poorly understood and the available information on this stems from studies of rodents such as mice and hamsters. We and others showed that hamster blastocyst hatching is characterized by firstly blastocyst deflation followed by a dissolution of the zona pellucida (zona) and accompanied by trophectodermal projections (TEPs). We also showed that embryo-derived cathepsins (Cat) proteases, specifically Cat-L, -B and -P act as zonalysins and are responsible for hatching. In this study, we show the expression and function of one of the potential regulators of embryogenesis, cyclooxygenase (COX)-2 during blastocyst development and hatching. The expression of COX-2 mRNA and protein was observed in 8-cell through hatched blastocyst stages and it was also localized to blastocyst's TEPs. Specific COX-2 inhibitors, NS-398 and CAY-10404, inhibited blastocyst hatching; percentages achieved were only 28.4 ± 5.3 and 32.3 ± 5.4%, respectively, compared with >90% with untreated embryos. Interestingly, inhibitor-treated blastocysts failed to deflate, normally observed during hatching. Supplementation of prostaglandins (PGs)-E2 or -I2 to cultured embryos reversed the inhibitors' effect on hatching and also the deflation behavior. Importantly, the levels of mRNA and protein of Cat-L, -B and -P showed a significant reduction in the inhibitor-treated embryos compared with untreated embryos, although its mechanism remains to be examined. These data provide the first evidence that COX-2 is critical for blastocyst hatching in the golden hamster.

  16. Immunohistochemical Expression of Cyclooxygenase-2 in Urinary Bladder Transitional Cell Carcinomas

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    F Niki

    2012-07-01

    Full Text Available Background: Transitional Cell Carcinoma (TCC is the most common type of urinary bladder cancer. Cyclooxygenase-2 (COX-2, a key enzyme in prostaglandins biosynthesis, has been introduced as a new candidate for targeted therapy in this cancer. In this study, we investigated the expression of COX-2 in urinary bladder TCCs and its relationship with clinicopathological parameters such as tumor grade and stage. Methods: This cross-sectional study was performed in the Pathology department of Sina Hospital in Tehran, Iran during 2006-2011. Pathology reports of patients with definite diagnosis of urinary bladder TCCs who had undergone Transurethral Resection (TUR were reviewed and 40 cases were selected. Subsequently, COX-2 expression was assessed immunohistochemically by the examination of paraffin embedded tissue blocks. Staining in more than 5% of tumor cells was considered as positive expression. Results: COX-2 was expressed in 52.5% of the patients. High-grade tumors revealed a higher (87.5% COX-2 expression versus other grades of the lesions and there was a statistically significant difference in COX-2 expression between them (P<0.001. Patients age was also related to the expression of this marker (P=0.03. In contrast, this marker did not correlate with other characteristics including gender, lymphatic invasion or tumor stage. In addition, perineurial or vascular invasions were not detected in any of the patients. Conclusion: COX-2 expression was seen in more than half of our patients and it had a marked relation to tumor differentiation. Accordingly, this molecule may be a useful tumor marker in the assessment of urinary bladder cancers.

  17. Synergistic Induction of Cyclooxygenase-2 by Transforming Growth Factor-β1 and Epidermal Growth Factor Inhibits Apoptosis in Epithelial Cells

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    Debabrata Saha

    1999-12-01

    Full Text Available Increased expression of cyclooxygenase-2 (COX-2 expression has been observed in several human tumor types and in selected animal and cell culture models of carcinogenesis, including lung cancer. Increased expression of COX-2 and production of prostaglandins appear to provide a survival advantage to transformed cells through the inhibition of apoptosis, increased attachment to extracellular matrix, increased invasiveness, the stimulation of angiogenesis. In the present studies, we found that transforming growth factor β1 (TGF-β1 and epidermal growth factor (EGF synergistically induced the expression of COX-2 and prostaglandin E2 (PGE2 production in mink lung epithelial (Mvi Lu cells. EGF, but not PDGF or IGF-1, was able to inhibit TGF-β1-induced apoptosis in Mvi Lu cells and this effect was blocked by NS-398, a selective inhibitor of COX-2 activity, suggesting a possible role for COX-2 in the anti-apoptosic effect of EGF receptor ligands. The combination of TGF-β1 and EGF also significantly induced COX-2 expression in rat intestinal epithelial (RIE-1 cells and completely prevented sodium butyrate (NaBu-induced apoptosis. The synergistic induction of COX-2 by TGF-β1 and EGF was not observed in R1B-L17 cells, a line derived from Mvi Lu cells that lacks the TGF-β type-I receptor. AG1478, a selective inhibitor of EGF receptor tyrosine kinase activity, completely suppressed the induction of COX-2 expression by either EGF or TGF-β1+EGF. Also, PD98059, a specific inhibitor of MEK/ERK pathway, SB203580, a specific inhibitor of p38 MAPK activity, significantly inhibited the induction of COX-2 in response to combined EGF and TGF-β1. These results suggest an important collaborative interaction of TGF-β1 and EGF signaling in the induction of COX-2 and prostaglandin production in Mv1Lu cells.

  18. Hemin inhibits cyclooxygenase-2 expression through nuclear factor-kappa B activation and ornithine decarboxylase expression in 12-O-tetradecanoylphorbol-13-acetate-treated mouse skin

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    Park, Jae Hee; Lee, Chang Ki [Department of Oral Biology, Yonsei University College of Dentistry, 134 Shinchon-Dong, Seodaemoon-Ku, Seoul 120-752 (Korea, Republic of); Oral Cancer Research Institute, Yonsei University College of Dentistry, 134 Shinchon-Dong, Seodaemoon-Ku, Seoul 120-752 (Korea, Republic of); Hwang, Young Sun [Department of Applied Life Science and Brain Korea 21 Project, Yonsei University College of Dentistry, 134 Shinchon-Dong, Seodaemoon-Ku, Seoul 120-752 (Korea, Republic of); Park, Kwang-Kyun [Department of Oral Biology, Yonsei University College of Dentistry, 134 Shinchon-Dong, Seodaemoon-Ku, Seoul 120-752 (Korea, Republic of); Department of Applied Life Science and Brain Korea 21 Project, Yonsei University College of Dentistry, 134 Shinchon-Dong, Seodaemoon-Ku, Seoul 120-752 (Korea, Republic of); Chung, Won-Yoon [Department of Oral Biology, Yonsei University College of Dentistry, 134 Shinchon-Dong, Seodaemoon-Ku, Seoul 120-752 (Korea, Republic of); Department of Applied Life Science and Brain Korea 21 Project, Yonsei University College of Dentistry, 134 Shinchon-Dong, Seodaemoon-Ku, Seoul 120-752 (Korea, Republic of)], E-mail: wychung@yuhs.ac

    2008-07-03

    Inflammation induced by various stimuli has been found to be associated with increased risk for most types of human cancer. Inflammation facilitates the initiation of normal cells, as well as the growth of initiated cells and their progression to malignancy through production of proinflammatory cytokines and diverse reactive oxygen/nitrogen species. These also activate the signaling molecules that are involved in inflammation and carcinogenesis. Our previous studies have demonstrated that hemin inhibited 7,12-dimethylbenz[a]anthracene (DMBA)-induced bacterial mutagenesis and oxidative DNA damage, reduced the level of DNA-DMBA adduct and 12-O-tetradecanoylphorobl-13-acetate (TPA)-induced tumor formation in DMBA-initiated ICR mouse skin, and inhibited myeloperoxidase and ornithine decarboxylase (ODC) activity and H{sub 2}O{sub 2} formation in TPA-treated mouse skin. In the present study, to further elucidate the molecular mechanisms underlying the chemopreventive activity of hemin, its effect on the expression of ODC and cyclooxygenase (COX)-2, and the activation of nuclear factor-kappa B (NF-{kappa}B) and mitogen-activated protein kinases (MAPKs) regulating these proteins were explored in mouse skin with TPA-induced inflammation. Topically applied hemin inhibited ear edema and epidermal thickness in mice treated with TPA. Pretreatment with hemin reduced the expression of ODC and COX-2, and also reduced NF-{kappa}B activation in TPA-stimulated mouse skin. In addition, hemin suppressed the TPA-induced activation of extracellular signal-regulated protein kinase (ERK) and p38 MAPK in a dose-dependent manner. Taken together, hemin inhibited TPA-induced COX-2 expression by altering NF-{kappa}B signaling pathway via ERK and p38 MAPK, as well as TPA-induced ODC expression in mouse skin. Thereby, hemin may be an attractive candidate for a chemopreventive agent.

  19. 3-phosphoinositide-dependent protein kinase-1/Akt signaling represents a major cyclooxygenase-2-independent target for celecoxib in prostate cancer cells.

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    Kulp, Samuel K; Yang, Ya-Ting; Hung, Chin-Chun; Chen, Kuen-Feng; Lai, Ju-Ping; Tseng, Ping-Hui; Fowble, Joseph W; Ward, Patrick J; Chen, Ching-Shih

    2004-02-15

    Regarding the involvement of cyclooxygenase-2 (COX-2)-independent pathways in celecoxib-mediated antineoplastic effects, the following two issues remain outstanding: identity of the non-COX-2 targets and relative contributions of COX-2-dependent versus -independent mechanisms. We use a close celecoxib analog deficient in COX-2-inhibitory activity, DMC (4-[5-(2,5-dimethylphenyl)-3(trifluoromethyl)-1H-pyrazol-1-yl]benzene-sulfonamide), to examine the premise that Akt signaling represents a major non-COX-2 target. Celecoxib and DMC block Akt activation in PC-3 cells through the inhibition of phosphoinositide-dependent kinase-1 (PDK-1) with IC(50) of 48 and 38 micro M, respectively. The consequent effect on Akt activation is more pronounced (IC(50) values of 28 and 20 micro M, respectively), which might be attributed to the concomitant dephosphorylation by protein phosphatase 2A. In serum-supplemented medium, celecoxib and DMC cause G(1) arrest, and at higher concentrations, they induce apoptosis with relative potency comparable with that in blocking Akt activation. Moreover, the effect of daily oral celecoxib and DMC at 100 and 200 mg/kg on established PC-3 xenograft tumors is assessed. Celecoxib at both doses and DMC at 100 mg/kg had marginal impacts. However, a correlation exists between the in vitro potency of DMC and its ability at 200 mg/kg to inhibit xenograft tumor growth through the inhibition of Akt activation. Analysis of the tumor samples indicates that a differential reduction in the phospho-Akt/Akt ratio was noted in celecoxib- and DMC-treated groups vis-à-vis the control group. Together, these data underscore the role of 3-phosphoinositide-dependent protein kinase-1/Akt signaling in celecoxib-mediated in vitro antiproliferative effects in prostate cancer cells.

  20. AB154. Testosterone improves erectile function through regulation of nicotinamide adenine dinucleotide phosphate-oxidase and cyclooxygenase-2 expression in castrated rats

    Science.gov (United States)

    Li, Rui; Wang, Tao; Yang, Jun; Zhang, Yan; Niu, Yonghua; Wang, Shaogang; Ye, Zhangqun; Rao, Ke; Liu, Jihong

    2015-01-01

    Objective Testosterone significantly improves hypogonadal-related erectile dysfunction (ED). However, the molecular mechanisms are poorly understood. The purpose of this study was to explore the effect and mechanism of testosterone in castrated rats. Methods Forty male Sprague-Dawley rats were randomized to 4 groups (control, sham-operated, castration and castration-with-testosterone-replacement). After 2 months, reactive oxygen species (ROS) production was measured by dihydroethidium (DHE) staining. Erectile function was tested by recording intracavernosal pressure (ICP) and mean arterial blood pressure (MAP). Protein expression levels were examined by Western blot. Results Castration reduced erectile function, and testosterone restored it. The concentrations of testosterone, cyclic guanosine mono-phosphate (cGMP) and cyclic adenosine monophosphate (cAMP) were lower in castrated rats than in controls, and testosterone restored these decreases (each P<0.05). The expression levels of cyclooxygenase-2 (COX-2), prostacyclin synthase (PTGIS or PGIS), endothelial nitric oxide synthase (eNOS) and phospho-eNOS were reduced in castrated rats compared with controls. The expression levels were significantly elevated in rats treated with testosterone (each P<0.05). The expression levels of p40phox and p67phox were increased in castrated rats, and testosterone significantly reduced these increases (each P<0.05). ROS production was markedly enhanced in castrated rats, and testosterone administration reversed this effect (P<0.05). Conclusions Testosterone can ameliorate ED after castration by reducing ROS production and increasing activity of the eNOS/cGMP and COX-2/PTGIS/cAMP signaling pathways.

  1. Highly Selective Cyclooxygenase-1 Inhibitors P6 and Mofezolac Counteract Inflammatory State both In Vitro and In Vivo Models of Neuroinflammation

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    Rosa Calvello

    2017-06-01

    Full Text Available Activated microglia secrete an array of pro-inflammatory factors, such as prostaglandins, whose accumulation contributes to neuronal damages. Prostaglandin endoperoxide synthases or cyclooxygenases (COX-1 and COX-2, which play a critical role in the inflammation, are the pharmacological targets of non-steroidal anti-inflammatory drugs, used to treat pain and inflammation. Since it was reported that COX-1 is the major player in mediating the brain inflammatory response, the aim of this study was to evaluate the effects of highly selective COX-1 inhibitors, such as P6 and mofezolac, in neuroinflammation models. Lipopolysaccharide (LPS-activated mouse BV-2 microglial cells and LPS intracerebroventricular-injected mice as in vitro and in vivo neuroinflammation models, respectively, were used to probe the antiinflammatory efficacy of P6 and mofezolac. Both P6 and mofezolac reduce COX-1 expression in LPS-activated BV-2 cells. This reduction was accompanied with PGE2 release reduction and NF-kB activation downregulation. Coextensively, in the in vivo model, both glial fibrillary acidic protein and ionized calcium-binding adapter molecule-1 expression, two markers of inflammation, were reduced by mofezolac to a rank depending on the encephalon area analyzed. The increase of COX-1 expression observed in all the brain sections of LPS-treated mice was selectively downregulated by the in vivo treatment with mofezolac as well as PGE2 release and Ikβα phosphorylation amount assayed in the brain areas tested. These results indicate the capability of P6 and mofezolac to modulate the NF-kB signaling pathway, emphasizing the neuroprotective effect and therapeutic potential of COX-1 inhibitors in the control of neuroinflammatory diseases.

  2. Inhibition of lipopolysaccharide-induced cyclooxygenase-2 and inducible nitric oxide synthase expression by 4-[(2'-O-acetyl-α-L-rhamnosyloxy)benzyl]isothiocyanate from Moringa oleifera.

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    Park, Eun-Jung; Cheenpracha, Sarot; Chang, Leng Chee; Kondratyuk, Tamara P; Pezzuto, John M

    2011-01-01

    Moringa oleifera Lamarck is commonly consumed for nutritional or medicinal properties. We recently reported the isolation and structure elucidation of novel bioactive phenolic glycosides, including 4-[(2'-O-acetyl-α-L-rhamnosyloxy)benzyl]isothiocyanate (RBITC), which was found to suppress inducible nitric oxide synthase (iNOS) expression and nitric oxide (NO) production in lipopolysaccharide-stimulated RAW 264.7 mouse macrophage cells. Inhibitors of proteins such as cyclooxygenase-2 (COX-2) and iNOS are potential antiinflammatory and cancer chemopreventive agents. The inhibitory activity of RBITC on NO production (IC(50) = 0.96 ± 0.23 μM) was greater than that mediated by other well-known isothiocyanates such as sulforaphane (IC(50) = 2.86 ± 0.39 μM) and benzyl isothiocyanate (IC(50) = 2.08 ± 0.28 μM). RBITC inhibited expression of COX-2 and iNOS at both the protein and mRNA levels. Major upstream signaling pathways involved mitogen-activated protein kinases and nuclear factor-κB (NF-κB). RBITC inhibited phosphorylation of extracellular signal-regulated kinase and stress-activated protein kinase, as well as ubiquitin-dependent degradation of inhibitor κBα (IκBα). In accordance with IκBα degradation, nuclear accumulation of NF-κB and subsequent binding to NF-κB cis-acting element was attenuated by treatment with RBITC. These data suggest RBITC should be included in the dietary armamentarium of isothiocyanates potentially capable of mediating antiinflammatory or cancer chemopreventive activity.

  3. Genomic,Lipidomic,and Metabolomic Analysis ®CrossMark of Cyclooxygenase-null Cells:Eicosanoid Storm, Cross Talk, and Compensation by COX-1

    Institute of Scientific and Technical Information of China (English)

    Abul BMMK Islam; Mandar Dave; Sonia Amin; oderick V Jensen; Ashok R Amin

    2016-01-01

    The constitutively-expressed cyclooxygenase 1 (COX-1) and the inducible COX-2 are both involved in the conversion of arachidonic acid (AA) to prostaglandins (PGs). However, the functional roles of COX-1 at the cellular level remain unclear. We hypothesized that by comparing differential gene expression and eicosanoid metabolism in lung fibroblasts from wild-type (WT) mice and COX-2"^' or COX-1'^" mice may help address the functional roles of COX-1 in inflammation and other cellular functions. Compared to WT, the number of specifically-induced transcripts were altered descendingly as follows: COX-2-" > COX-1"^' > WT + IL-lp. COX-l /_ or COX-2'^" cells shared about 50% of the induced transcripts with WT cells treated with IL-lp, respectively. An interactive 4"anti-inflammatory, proinflammatory, and redox-activated” signature in the protein—protein interactome map was observed in COX-2'^' cells. The augmented COX-1 mRNA (in COX-2cells) was associated with the upregulation of mRNAs for glutathione 5-transferase (GST), superoxide dismutase (SOD), NAD(P)H dehydrogenase quinone 1 (NQOl),aryl hydrocarbon receptor (AhR), peroxiredoxin, phospholipase, prostacyclin synthase, and prostaglandin E synthase, resulting in a significant increase in the levels of PGE2, PGD2, leukotriene B4 (LTB4), PGF1a, thromboxane B2 (TXB2), and PGF2a. The COX-1 plays a dominant role in shifting AA toward the LTB4 pathway and anti-inflammatory activities. Compared to WT, the upregulated COX-1 mRNA in COX-2-/- cells generated an ‘‘eicosanoid storm”. The genomic characteristics of COX-2-/- is similar to that of proinflammatory cells as observed in IL-1b induced WT cells. COX-1-/- and COX-2-/- cells exhibited compensation of various eicosanoids at the genomic and metabolic levels.

  4. Divalent lead cations induce cyclooxygenase-2 gene expression by epidermal growth factor receptor/nuclear factor-kappa B signaling in A431carcinoma cells.

    Science.gov (United States)

    Chou, Yii-Her; Woon, Peng-Yeong; Huang, Wan-Chen; Shiurba, Robert; Tsai, Yao-Ting; Wang, Yu-Shiuan; Hsieh, Tusty-Jiuan; Chang, Wen-Chang; Chuang, Hung-Yi; Chang, Wei-Chiao

    2011-06-10

    Divalent lead cations (Pb²+) are toxic metal pollutants that may contribute to inflammatory diseases in people and animals. Human vascular smooth muscle cells in culture respond to low concentrations of Pb²+ ions by activating mediators of inflammation via the plasma membrane epidermal growth factor receptor (EGFR). These include cyclooxygenase-2 (COX-2) and cytosolic phospholipase A₂ as well as the hormone-like lipid compound prostaglandin E₂. To further clarify the mechanism by which Pb²+ induces such mediators of inflammation, we tested human epidermoid carcinoma cell line A431 that expresses high levels of EGFR. Reverse transcription PCR and western blots confirmed A431 cells treated with a low concentration (1 μM) of Pb²+ in the form of lead (II) nitrate increased expression of COX-2 mRNA and its encoded protein in a time-dependent manner. Promoter deletion analysis revealed the transcription factor known as nuclear factor-kappa B (NF-κB) was a necessary component of the COX-2 gene response. NF-κB inhibitor BAY 11-7082 suppressed Pb²+-induced COX-2 mRNA expression, and EGFR inhibitors AG1478 and PD153035 as well as EGFR small interfering RNA reduced the coincident nuclear translocation of NF-κB. Our findings support the hypothesis that low concentrations of Pb²+ ions incite inflammation by inducing COX-2 gene expression via the EGFR/NF-κB signal transduction pathway. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  5. Molecular pathways

    DEFF Research Database (Denmark)

    Cox, Thomas R; Erler, Janine Terra

    2014-01-01

    that 45% of deaths in the developed world are linked to fibrotic disease. Fibrosis and cancer are known to be inextricably linked; however, we are only just beginning to understand the common and overlapping molecular pathways between the two. Here, we discuss what is known about the intersection...... of fibrosis and cancer, with a focus on cancer metastasis, and highlight some of the exciting new potential clinical targets that are emerging from analysis of the molecular pathways associated with these two devastating diseases. Clin Cancer Res; 20(14); 3637-43. ©2014 AACR....

  6. Radiation Therapy Overcomes Adverse Prognostic Role of Cyclooxygenase-2 Expression on Reed-Sternberg Cells in Early Hodgkin Lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Mestre, Francisco [Service of Radiation Therapy, University Hospital Son Espases, Instituto de Investigación Sanitaria de Palma, Palma de Mallorca (Spain); Gutiérrez, Antonio, E-mail: antoniom.gutierrez@ssib.es [Service of Hematology, University Hospital Son Espases, Instituto de Investigación Sanitaria de Palma, Palma de Mallorca (Spain); Rodriguez, Jose [MD Anderson Cancer Center, Madrid (Spain); Ramos, Rafael [Service of Pathology, University Hospital Son Espases, Instituto de Investigación Sanitaria de Palma, Palma de Mallorca (Spain); Garcia, Juan Fernando [Spanish National Cancer Research Centre, Madrid (Spain); Martinez-Serra, Jordi [Service of Hematology, University Hospital Son Espases, Instituto de Investigación Sanitaria de Palma, Palma de Mallorca (Spain); Casasus, Marta; Nicolau, Cristina [Service of Radiation Therapy, Policlinica Miramar, Palma de Mallorca (Spain); Bento, Leyre; Herraez, Ines [Service of Hematology, University Hospital Son Espases, Instituto de Investigación Sanitaria de Palma, Palma de Mallorca (Spain); Lopez-Perezagua, Paloma [Service of Radiology, IDISPA, Palma de Mallorca (Spain); Daumal, Jaime [Service of Nuclear Medicine, IDISPA, Palma de Mallorca (Spain); Besalduch, Joan [Service of Hematology, University Hospital Son Espases, Instituto de Investigación Sanitaria de Palma, Palma de Mallorca (Spain)

    2015-05-01

    Purpose: To analyze the role of radiation therapy (RT) on the adverse prognostic influence of cyclooxygenase-2 (COX-2) expression on Reed-Sternberg (RS) cells, in the setting of early Hodgkin lymphoma (HL) treated with ABVD (adriamycin, vinblastine, bleomycin, dacarbazine). Methods and Materials: In the present study we retrospectively investigated the prognostic value of COX-2 expression in a large (n=143), uniformly treated early HL population from the Spanish Network of HL using tissue microarrays. Univariate and multivariate analyses were done, including the most recognized clinical variables and the potential role of administration of adjuvant RT. Results: Median age was 31 years; the expression of COX-2 defined a subgroup with significantly worse prognosis. Considering COX-2{sup +} patients, those who received RT had significantly better 5-year progression-free survival (PFS) (80% vs 54% if no RT; P=.008). In contrast, COX-2{sup −} patients only had a modest, nonsignificant benefit from RT in terms of 5-year PFS (90% vs 79%; P=.13). When we compared the outcome of patients receiving RT considering the expression of COX-2 on RS cells, we found a nonsignificant 10% difference in terms of PFS between COX-2{sup +} and COX-2{sup −} patients (P=.09), whereas the difference between the 2 groups was important (25%) in patients not receiving RT (P=.04). Conclusions: Cyclooxygenase-2 RS cell expression is an adverse independent prognostic factor in early HL. Radiation therapy overcomes the worse prognosis associated with COX-2 expression on RS cells, acting in a chemotherapy-independent way. Cyclooxygenase-2 RS cell expression may be useful for determining patient candidates with early HL to receive consolidation with RT.

  7. Prognostic role of host cyclooxygenase and cytokine genotypes in a Caucasian cohort of patients with gastric adenocarcinoma.

    Directory of Open Access Journals (Sweden)

    María Asunción García-González

    Full Text Available BACKGROUND: Genetic factors influencing the prognosis of gastric adenocarcinoma (GAC are not well known. Given the relevance of cytokines and other pro-inflammatory mediators in cancer progression and invasiveness, we aimed to assess the prognostic role of several functional cytokine and cyclooxygenase gene polymorphisms in patients with GAC. METHODOLOGY: Genomic DNA from 380 Spanish Caucasian patients with primary GAC was genotyped for 23 polymorphisms in pro-inflammatory (IL1B, TNFA, LTA, IL6, IL12p40, anti-inflammatory (IL4, IL1RN, IL10, TGFB1 cytokine, and cyclooxygenase (PTGS1 and PTGS2 genes by PCR, RFLP and TaqMan assays. Clinical and histological information was collected prospectively. Survival curves were estimated by the Kaplan-Meier method and compared using the log rank test. Outcome was determined by analysis of Cox proportional hazards, adjusting for confounding factors. RESULTS: The median follow-up period and median overall survival (OS time were 9.9 months (range 0.4-120.3 and 10.9 months (95% CI: 8.9-14.1, respectively. Multivariate analysis identified tumor stages III (HR, 3.23; 95% CI:2-5.22 and IV (HR, 5.5; 95% CI: 3.51-8.63 as independent factors associated with a significantly reduced OS, whereas surgical treatment (HR: 0.44; 95%CI: 0.3-0.6 was related to a better prognosis of the disease. Concerning genetic factors, none of the 23 polymorphisms evaluated in the current study did influence survival. Moreover, no gene-environment interactions on GAC prognosis were observed. CONCLUSIONS: Our results show that, in our population, the panel of selected pro- and anti-inflammatory cytokine, and cyclooxygenase gene polymorphisms are not relevant in determining the prognosis of gastric adenocarcinoma.

  8. Neuroinflammation and J2 prostaglandins: linking impairment of the ubiquitin-proteasome pathway and mitochondria to neurodegeneration

    Directory of Open Access Journals (Sweden)

    Maria Emilia Figueiredo-Pereira

    2015-01-01

    Full Text Available The immune response of the CNS is a defense mechanism activated upon injury to initiate repair mechanisms while chronic over-activation of the CNS immune system (termed neuroinflammation may exacerbate injury. The latter is implicated in a variety of neurological and neurodegenerative disorders such as Alzheimer and Parkinson diseases, amyotrophic lateral sclerosis, multiple sclerosis, traumatic brain injury, HIV dementia and prion diseases. Cyclooxygenases (COX -1 and COX-2, which are key enzymes in the conversion of arachidonic acid into bioactive prostanoids, play a central role in the inflammatory cascade. J2 prostaglandins are endogenous toxic products of cyclooxygenases, and because their levels are significantly increased upon brain injury, they are actively involved in neuronal dysfunction induced by pro-inflammatory stimuli. In this review, we highlight the mechanisms by which J2 prostaglandins (1 exert their actions, (2 potentially contribute to the transition from acute to chronic inflammation and to the spreading of neuropathology, (3 disturb the ubiquitin-proteasome pathway and mitochondrial function, and (4 contribute to neurodegenerative disorders such as Alzheimer and Parkinson diseases, and amyotrophic lateral sclerosis, as well as stroke, traumatic brain injury, and demyelination in Krabbe disease. We conclude by discussing the therapeutic potential of targeting the J2 prostaglandin pathway to prevent/delay neurodegeneration associated with neuroinflammation. In this context, we suggest a shift from the traditional view that cyclooxygenases are the most appropriate targets to treat neuroinflammation, to the notion that J2 prostaglandin pathways and other neurotoxic prostaglandins downstream from cyclooxygenases, would offer significant benefits as more effective therapeutic targets to treat chronic neurodegenerative diseases, while minimizing adverse side effects.

  9. Cyclooxygenase-2 and epithelial growth factor receptor up-regulation during progression of Barrett's esophagus to adenocarcinoma

    Institute of Scientific and Technical Information of China (English)

    Yan Li; John M Wo; Mukunda B Ray; Whitney Jones; Ruifeng R Su; Susan Ellis; Robert C G Martin

    2006-01-01

    AIM: To investigate the expression of cyclooxygenase-2(COX-2) and epithelial growth factor receptor (EGFR)throughout the progression of Barrett's esophagus (BE).METHODS: COX-2 and EGFR protein expressions were detected by using immunohistochemical method. A detailed cytomorphological changes were determined.Areas of COX-2 and EGFR expression were quantified by using computer Imaging System.RESULTS: The expressions of both COX-2 and EGFR increased along with the progression from BE to esophagus adenocarcinoma (EAC). A positive correlation was found between COX-2 expression and EGFR expression.CONCLUSION: COX-2 and EGFR may be cooperative in the stepwise progression from BE to EAC, thereby leading to carcinogenesis.

  10. Cyclo-oxygenase 2 expression is associated with angiogenesis and lymph node metastasis in human breast cancer

    OpenAIRE

    Costa, C; SOARES, R.; Reis-Filho, J S; Leitão, D; Amendoeira, I; Schmitt, F C

    2002-01-01

    Aims: Cyclo-oxygenases 1 and 2 (COX-1 and COX-2) are key enzymes in prostaglandin biosynthesis. COX-2 is induced by a wide variety of stimuli, and present during inflammation. COX-2 overexpression has been observed in colon, head and neck, lung, prostate, stomach, and breast cancer. In colon and gastric cancer, COX-2 expression was associated with angiogenesis. The aim of this study was to determine the relation between COX-2 expression and angiogenesis in breast cancer, and to correlate the ...

  11. Effects of macronutrient composition and cyclooxygenase-inhibition on diet-induced obesity, low grade inflammation and glucose homeostasis

    DEFF Research Database (Denmark)

    Fjære, Even

    - or protein based background, and supplemented with either corn- or fish oil. These experiments were conducted to determine whether macronutrient composition and type of dietary fat can modulate diet-induced obesity, and associated metabolic consequences. The use of non-steroidal anti-inflammatory drugs...... is escalating, and in view of the increased consumption of obesogenic diets with high levels of dietary carbohydrates and fat, the metabolic consequences of cyclooxygenase-inhibition warrants investigation. Results: High fat/high sucrose diets increased obesity development and expression of macrophage...

  12. Novel anti-inflammatory chalcone derivatives inhibit the induction of nitric oxide synthase and cyclooxygenase-2 in mouse peritoneal macrophages.

    Science.gov (United States)

    Herencia, F; Ferrándiz, M L; Ubeda, A; Guillén, I; Dominguez, J N; Charris, J E; Lobo, G M; Alcaraz, M J

    1999-06-18

    In a previous work, we tested a series of chalcone derivatives as possible anti-inflammatory compounds. We now investigate the effects of three of those compounds, CHI, CH8 and CH12, on nitric oxide and prostanoid generation in mouse peritoneal macrophages stimulated with lipopolysaccharide and in the mouse air pouch injected with zymosan, where they showed a dose-dependent inhibition with inhibitory concentration 50% values in the microM range. This effect was not the consequence of a direct inhibitory action on enzyme activities. Our results demonstrated that chalcone derivatives inhibited de novo inducible nitric oxide synthase and cyclooxygenase-2 synthesis, being a novel therapeutic approach for inflammatory diseases.

  13. Cardiovascular thrombotic events in arthritis trials of the cyclooxygenase-2 inhibitor celecoxib.

    Science.gov (United States)

    White, William B; Faich, Gerald; Borer, Jeffrey S; Makuch, Robert W

    2003-08-15

    To determine whether the cyclooxygenase-2 (COX-2) inhibitor celecoxib affects cardiovascular thrombotic risk, we analyzed the incidence of cardiovascular events for celecoxib, placebo, and nonsteroidal anti-inflammatory drugs (NSAIDs) in the entire controlled, arthritis clinical trial database for celecoxib. The primary analysis used the Antiplatelet Trialists' Collaboration end points, which include: (1) cardiovascular, hemorrhagic, and unknown deaths, (2) nonfatal myocardial infarction, and (3) nonfatal stroke. Other secondary thrombotic events were also examined. Separate analyses were performed for all patients and for those not taking aspirin. Data from all controlled, completed arthritis trials of > or =4 weeks duration, including 13 new drug application studies and 2 large post-marketing trials (CLASS and SUCCESS) were included for analyses. Patients were randomized to celecoxib at doses from 100 to 400 mg twice daily (18,942 patients; 5,668.2 patient-years of exposure), diclofenac 50 to 75 mg twice daily, ibuprofen 800 mg thrice daily, naproxen 500 mg twice daily (combined NSAID exposure of 11,143 patients; 3,612.2 patient-years), or placebo (1,794 subjects; 199.9 subject-years). Data from a long-term uncontrolled trial with 5,209 patients (6,950 patients-years) treated with celecoxib were included in a supplemental analysis. The entire 15-trial database was searched for possible serious thrombotic events as well as to identify all deaths. For these patients, detailed clinical data were obtained and reviewed by 2 of the investigators (WBW and JSB), who were independently and blinded to exposure, to classify the event as primary, secondary, or neither. All analyses were done using the intent-to-treat population, and time-to-event analyses were performed using per-patient data. To examine heterogeneity of results among studies, tests of interaction were performed using the Cox model. Incidences of the primary and secondary events were not significantly

  14. Do Different Cyclooxygenase Inhibitors Impair Rotator Cuff Healing in a Rabbit Model?

    Institute of Scientific and Technical Information of China (English)

    Yi Lu; Yue Li; Feng-Long Li; Xu Li; Hong-Wu Zhuo; Chun-Yan Jiang

    2015-01-01

    Background:The effect of selective and non-selective cyclooxygenase (COX) inhibitors on tendon healing was variable.The purpose of the study was to evaluate the influence of non-selective COX inhibitor,ibuprofen and flurbiprofen axetil and selective COX-2 inhibitor,celecoxib on the tendon healing process in a rabbit model.Methods:Ninety-six New Zealand rabbits were used as rotator cuff repair models.After surgery,they were divided randomly into four groups:Ibuprofen (10 mg·kg-1·d-1),celecoxib (8 mg·kg 1·d 1),flurbiprofen axetil (2 mg·kg 1·d-1),and control group (blank group).All drugs were provided for 7 days.Rabbits in each group were sacrificed at 3,6,and 12 weeks after tendon repair.Tendon biomechanical load failure tests were performed.The percentage of type Ⅰ collagen on the bone tendon insertion was calculated by Picric acid Sirius red staining and image analysis.All data were compared among the four groups at the same time point.All data in each group were also compared across the different time points.Qualitative histological evaluation of the bone tendon insertion was also performed among groups.Results:The load to failure increased significantly with time in each group.There were significantly lower failure loads in the celecoxib group than in the control group at 3 weeks (0.533 vs.0.700,P =0.002),6 weeks (0.607 vs.0.763,P =0.01),and 12 weeks (0.660 vs.0.803,P =0.002),and significantly lower percentage of type Ⅰ collagen at 3 weeks (l 1.5% vs.27.6%,P =0.001),6 weeks (40.5% vs.66.3%,P =0.005),and 12 weeks (59.5% vs.86.3%,P =0.001).Flurbiprofen axetil showed significant differences at 3 weeks (failure load:0.600 vs.0.700,P =0.024;percentage of type Ⅰ collagen:15.6% vs.27.6%,P =0.001),but no significant differences at 6 and 12 weeks comparing with control group,whereas the ibuprofen groups did not show any significant difference at each time point.Conclusions:Nonsteroidal anti-inflammatory drugs can delay tendon healing in the

  15. Alterations in Lipoxygenase and Cyclooxygenase-2 Catalytic Activity and mRNA Expression in Prostate Carcinoma

    Directory of Open Access Journals (Sweden)

    Scott B. Shappell

    2001-01-01

    Full Text Available Recent studies in prostate tissues and especially cell lines have suggested roles for arachidonic acid (AA metabolizing enzymes in prostate adenocarcinoma (Pca development or progression. The goal of this study was to more fully characterize lipoxygenase (LOX and cyclooxygenase-2 (COX-2 gene expression and AA metabolism in benign and malignant prostate using snap-frozen tissues obtained intraoperatively and mRNA analyses and enzyme assays. Formation of 15-hydroxyeicosatetraenoic acid (15-HETE was detected in 23/29 benign samples and 15-LOX-2 mRNA was detected in 21/25 benign samples. In pairs of pure benign and Pca from the same patients, 15-HETE production and 15-LOX-2 mRNA were reduced in Pca versus benign in 9/14 (P=.04 and 14/17 (P=.002, respectively. Under the same conditions, neither 5HETE nor 12-HETE formation was detectable in 29 benign and 24 tumor samples; with a more sensitive assay, traces were detected in some samples, but there was no clear association with tumor tissue. COX-2 mRNA was detected by nuclease protection assay in 7/16 benign samples and 5/16 tumors. In benign and tumor pairs from 10 patients, COX-2 was higher in tumor versus benign in only 2, with similar results by in situ hybridization. Paraffin immunoperoxidase for COX2 was performed in whole mount sections from 87 additional radical prostatectomy specimens, with strong expression in ejaculatory duct as a positive control and corroboration with in situ hybridization. No immunostaining was detected in benign prostate or tumor in 45% of cases. Greater immunostaining in tumor versus benign was present in only 17% of cases, and correlated with high tumor grade (Gleason score 8 and 9 vs. 5 to 7. In conclusion, reduced 15-LOX-2 expression and 15-HETE formation is the most characteristic alteration of AA metabolism in Pca. Increased 12-HETE and 5-HETE formation in Pca were not discernible. Increased COX-2 expression is not a typical abnormality in Pca in general, but

  16. Alterations in lipoxygenase and cyclooxygenase-2 catalytic activity and mRNA expression in prostate carcinoma.

    Science.gov (United States)

    Shappell, S B; Manning, S; Boeglin, W E; Guan, Y F; Roberts, R L; Davis, L; Olson, S J; Jack, G S; Coffey, C S; Wheeler, T M; Breyer, M D; Brash, A R

    2001-01-01

    Recent studies in prostate tissues and especially cell lines have suggested roles for arachidonic acid (AA) metabolizing enzymes in prostate adenocarcinoma (Pca) development or progression. The goal of this study was to more fully characterize lipoxygenase (LOX) and cyclooxygenase-2 (COX-2) gene expression and AA metabolism in benign and malignant prostate using snap-frozen tissues obtained intraoperatively and mRNA analyses and enzyme assays. Formation of 15-hydroxyeicosatetraenoic acid (15-HETE) was detected in 23/29 benign samples and 15-LOX-2 mRNA was detected in 21/25 benign samples. In pairs of pure benign and Pca from the same patients, 15-HETE production and 15-LOX-2 mRNA were reduced in Pca versus benign in 9/14 (P=.04) and 14/17 (P=.002), respectively. Under the same conditions, neither 5-HETE nor 12-HETE formation was detectable in 29 benign and 24 tumor samples; with a more sensitive assay, traces were detected in some samples, but there was no clear association with tumor tissue. COX-2 mRNA was detected by nuclease protection assay in 7/16 benign samples and 5/16 tumors. In benign and tumor pairs from 10 patients, COX-2 was higher in tumor versus benign in only 2, with similar results by in situ hybridization. Paraffin immunoperoxidase for COX-2 was performed in whole mount sections from 87 additional radical prostatectomy specimens, with strong expression in ejaculatory duct as a positive control and corroboration with in situ hybridization. No immunostaining was detected in benign prostate or tumor in 45% of cases. Greater immunostaining in tumor versus benign was present in only 17% of cases, and correlated with high tumor grade (Gleason score 8 and 9 vs. 5 to 7). In conclusion, reduced 15-LOX-2 expression and 15-HETE formation is the most characteristic alteration of AA metabolism in Pca. Increased 12-HETE and 5-HETE formation in Pca were not discernible. Increased COX-2 expression is not a typical abnormality in Pca in general, but occurs in high

  17. [Cyclooxygenase 2 genetic variant interacting with tobacco smoking and the risk of lung cancer].

    Science.gov (United States)

    Zhang, Zhi; Liu, Rui; Yang, Zhao-huan; Wang, Guang-xia; Shao, Sha-sha; Song, Qin-qin; Zhang, Xue-mei

    2013-08-01

    To explore the association of -1195G > A genetic variant in the promoter region of cyclooxygenase 2 genetic (COX2) with the genetic susceptibility of lung cancer and its interaction with smoking. Totally, 956 lung cancer patients recruited between January 2000 and December 2008 at Cancer Hospital, Chinese Academy of Medical Science as the case group, and 994 frequency-matched controls were randomly selected from a pool of cancer-free subjects recruited from a nutritional survey. All subjects were ethnic Han Chinese. There was no sex, age restrictions. Case group and control group were matched. Informed consent was obtained and 2 ml peripheral blood was collected from each subject. All samples were genotyped by polymerase chain reaction-restriction fragment length polymorphism method, smoking status of the subjects was surveyed.While the OR and 95% CI were estimated by logistic regression to evaluate the relation of COX2 -1195G > A variant and the risk of lung cancer. The genetic allele COX2 -1195AA of control group and case group were 24.9% (247/994) and 28.3% (271/956) . Case-control analysis showed an increased risk of developing lung cancer for -1195AA genotype carriers (OR = 1.36, 95% CI: 1.03-1.79), compared with -1195GG carriers. When stratified by smoking status, the significant increased risk of lung cancer was found among smokers with COX2-1195AA genotype, with the OR (95%CI) was 1.56 (1.08-2.25); while among non-smokers, difference of lung cancer risk was not found among different genotypes (OR = 1.17; 95%CI: 0.77-1.61). Among heavy smokers (pack-year >20), -1195AA and -1195AG genotype carriers have significant increased risk of lung cancer with 1.85 (1.16-2.95) and 1.62(1.08-2.43) of OR (95%CI), respectively; among light smokers (pack-year ≤ 20), the OR (95%CI) of lung cancer risk in -1195AG and -1195AA genotype carriers were 0.78 (0.47-1.30) and 1.08 (0.60-1.94), respectively. Genetic polymorphism in the promoter of COX2 gene interacting with smoking

  18. Role of nitric oxide synthase and cyclooxygenase in hyperdynamic splanchnic circulation of por tal hyper tension

    Institute of Scientific and Technical Information of China (English)

    Jia Xu; Hui Cao; Hua Liu; Zhi-Yong Wu

    2008-01-01

    BACKGROUND:Nitric oxide (NO) and prostacyclin (PGI2) are both powerful vasoactive substances correlated with the hyperhemodynamics of portal hypertension (PHT), a common syndrome characterized by a pathological increase in portal venous pressure. The purpose of the present study was to evaluate the possible interaction between these two endothelial vasodilators, together with their respective roles in the hyperdynamic splanchnic circulation of PHT. METHODS:Ninety-six male Sprague-Dawley rats were randomly divided into three groups: intrahepatic portal hypertension (IHPH) induced by injection of CCl4 (n=31), prehepatic portal hypertension (PHPH) induced by partial stenosis of the portal vein (n=33), and sham-operated controls (SO) (n=32). Animals of each group received indomethacin (INDO), a cyclooxygenase (COX) inhibitor, either short-term (7 days) or long-term (15 days), with saline as control. Free portal pressure (FPP), together with the concentration of NO and PGI2 in serum were measured. The activity of constitutive nitric oxide synthase (cNOS) and inducible nitric oxide synthase (iNOS) in the abdominal aorta and small intestine were determined by spectrophotometry. RT-PCR was performed to measure the levels of cNOS and iNOS mRNA in the arteries and small intestines. RESULTS:Compared with SO rats, the concentrations of NO and PGI2 in PHT rats were elevated, which were consistent with the increased FPP (P0.05). Moreover, the changes of iNOS activity and mRNA expression were more marked than cNOS in PHT rats, and there was no difference in expression and activity of cNOS between PHT rats treated by short- and long-term INDO (P>0.05). CONCLUSIONS:iNOS plays an important role in the hemodynamic abnormalities of PHT induced by overproduction of NO. There is a possible interaction between PGI2 and NO in hyperhemodynamics of PHT, but PGI2 may not be a mediator in the formation and development of the hyperdynamic circulatory state in PHT rats.

  19. 11-Oxoeicosatetraenoic acid is a cyclooxygenase-2/15-hydroxyprostaglandin dehydrogenase-derived antiproliferative eicosanoid.

    Science.gov (United States)

    Liu, Xiaojing; Zhang, Suhong; Arora, Jasbir S; Snyder, Nathaniel W; Shah, Sumit J; Blair, Ian A

    2011-12-19

    Previously, we established that 11(R)-hydroxy-5,8,12,14-(Z,Z,E,Z)-eicosatetraenoic acid (HETE) was a significant cyclooxygenase (COX)-2-derived arachidonic acid (AA) metabolite in epithelial cells. Stable isotope dilution chiral liquid chromatography (LC)-electron capture atmospheric pressure chemical ionization (ECAPCI)/mass spectrometry (MS) was used to quantify COX-2-derived eicosanoids in the human colorectal adenocarcinoma (LoVo) epithelial cell line, which expresses both COX-2 and 15-hydroxyprostaglandin dehydrogenase (15-PGDH). 11(R)-HETE secretion reached peak concentrations within minutes after AA addition before rapidly diminishing, suggesting further metabolism had occurred. Surprisingly, recombinant 15-PGDH, which is normally specific for oxidation of eicosanoid 15(S)-hydroxyl groups, was found to convert 11(R)-HETE to 11-oxo-5,8,12,14-(Z,Z,E,Z)-eicosatetraenoic acid (ETE). Furthermore, LoVo cell lysates converted 11(R)-HETE to 11-oxo-ETE and inhibition of 15-PGDH with 5-[[4-(ethoxycarbonyl)phenyl]azo]-2-hydroxy-benzeneacetic acid (CAY10397) (50 μM) significantly suppressed endogenous 11-oxo-ETE production with a corresponding increase in 11(R)-HETE. These data confirmed COX-2 and 15-PGDH as enzymes responsible for 11-oxo-ETE biosynthesis. Finally, addition of AA to the LoVo cells resulted in rapid secretion of 11-oxo-ETE into the media, reaching peak levels within 20 min of starting the incubation. This was followed by a sharp decrease in 11-oxo-ETE levels. Glutathione (GSH) S-transferase (GST) was found to metabolize 11-oxo-ETE to the 11-oxo-ETE-GSH (OEG)-adduct in LoVo cells, as confirmed by LC-MS/MS analysis. Bromodeoxyuridine (BrdU)-based cell proliferation assays in human umbilical vein endothelial cells (HUVECs) revealed that the half-maximal inhibitory concentration (IC(50)) of 11-oxo-ETE for inhibition of HUVEC proliferation was 2.1 μM. These results show that 11-oxo-ETE is a novel COX-2/15-PGDH-derived eicosanoid, which inhibits endothelial

  20. Effects of ozone on cyclooxygenase metabolites in the baboon tracheobronchial tree

    Energy Technology Data Exchange (ETDEWEB)

    Fouke, J.M.; DeLemos, R.A.; Dunn, M.J.; McFadden, E.R. Jr. (Southwest Foundation for Biomedical Research, San Antonio, TX (USA))

    1990-07-01

    Short-term exposure to 0.5 parts per million (ppm) ozone has been shown to cause an increase in respiratory resistance in primates that can be diminished by 50% with pretreatment with cromolyn sodium. Because of the known membrane-stabilizing effects of cromolyn and the resultant inhibition of mediator production, we hypothesized a role for the products of arachidonic acid (AA) metabolism in these events. We exposed five adult male baboons to 0.5 ppm ozone on two occasions, once with cromolyn pretreatment and once without. Pulmonary resistance (RL) was monitored and bronchoalveolar lavage (BAL) was performed before and after each exposure. The BAL was analyzed for a stable hydrolysis product of prostacyclin, 6-keto-prostaglandin (PG) F1 alpha, PGE2, a stable hydrolysis product of thromboxane (Tx) A2, TxB2, and PGF2 alpha. RL increased after ozone exposure (1.62 +/- 0.23 to 3.77 +/- 0.51 cmH2O.l-1.s, difference 2.15; P less than 0.02), and this effect was partially blocked by cromolyn (1.93 +/- 0.09 to 3.18 +/- 0.40 cmH2O.l-1.s, difference 1.25; P less than 0.02). The base-line levels of the metabolites of AA in the BAL were as follows (in pg/ml): 6-keto-PGF1 alpha 72.78 +/- 12.6, PGE2 145.92 +/- 30.52, TxB2 52.52 +/- 9.56, and PGF2 alpha 22.28 +/- 5.42. Ozone exposure had no effect on the level of any of these prostanoids (P = NS). These studies quantify the magnitude of cyclooxygenase products of AA metabolism in BAL from baboon lungs and demonstrate that changes in the levels of these mediators in BAL are not prerequisites for ozone-induced increases in respiratory resistance.

  1. Nicotine impairs cyclooxygenase-2-dependent kinin-receptor-mediated murine airway relaxations

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yuan, E-mail: yuan.xu@ki.se; Cardell, Lars-Olaf

    2014-02-15

    Introduction: Cigarette smoke induces local inflammation and airway hyperreactivity. In asthmatics, it worsens the symptoms and increases the risk for exacerbation. The present study investigates the effects of nicotine on airway relaxations in isolated murine tracheal segments. Methods: Segments were cultured for 24 h in the presence of vehicle, nicotine (10 μM) and/or dexamethasone (1 μM). Airway relaxations were assessed in myographs after pre-contraction with carbachol (1 μM). Kinin receptors, cyclooxygenase (COX) and inflammatory mediator expressions were assessed by real-time PCR and confocal-microscopy-based immunohistochemistry. Results: The organ culture procedure markedly increased bradykinin- (selective B{sub 2} receptor agonist) and des-Arg{sup 9}-bradykinin- (selective B{sub 1} receptor agonist) induced relaxations, and slightly increased relaxation induced by isoprenaline, but not that induced by PGE{sub 2}. The kinin receptor mediated relaxations were epithelium-, COX-2- and EP2-receptor-dependent and accompanied by drastically enhanced mRNA levels of kinin receptors, as well as inflammatory mediators MCP-1 and iNOS. Increase in COX-2 and mPGES-1 was verified both at mRNA and protein levels. Nicotine selectively suppressed the organ-culture-enhanced relaxations induced by des-Arg{sup 9}-bradykinin and bradykinin, at the same time reducing mPGES-1 mRNA and protein expressions. α7-nicotinic acetylcholine receptor inhibitors α-bungarotoxin and MG624 both blocked the nicotine effects on kinin B{sub 2} receptors, but not those on B{sub 1}. Dexamethasone completely abolished kinin-induced relaxations. Conclusion: It is tempting to conclude that a local inflammatory process per se could have a bronchoprotective component by increasing COX-2 mediated airway relaxations and that nicotine could impede this safety mechanism. Dexamethasone further reduced airway inflammation together with relaxations. This might contribute to the steroid resistance seen in

  2. An Asp49 Phospholipase A2 from Snake Venom Induces Cyclooxygenase-2 Expression and Prostaglandin E2 Production via Activation of NF-κB, p38MAPK, and PKC in Macrophages

    Directory of Open Access Journals (Sweden)

    Vanessa Moreira

    2014-01-01

    Full Text Available Phospholipases A2 (PLA2 are key enzymes for production of lipid mediators. We previously demonstrated that a snake venom sPLA2 named MT-III leads to prostaglandin (PGE2 biosynthesis in macrophages by inducing the expression of cyclooxygenase-2 (COX-2. Herein, we explored the molecular mechanisms and signaling pathways leading to these MT-III-induced effects. Results demonstrated that MT-III induced activation of the transcription factor NF-κB in isolated macrophages. By using NF-κB selective inhibitors, the involvement of this factor in MT-III-induced COX-2 expression and PGE2 production was demonstrated. Moreover, MT-III-induced COX-2 protein expression and PGE2 release were attenuated by pretreatment of macrophages with SB202190, and Ly294002, and H-7-dihydro compounds, indicating the involvement of p38MAPK, PI3K, and PKC pathways, respectively. Consistent with this, MT-III triggered early phosphorylation of p38MAPK, PI3K, and PKC. Furthermore, SB202190, H-7-dihydro, but not Ly294002 treatment, abrogated activation of NF-κB induced by MT-III. Altogether, these results show for the first time that the induction of COX-2 protein expression and PGE2 release, which occur via NF-κB activation induced by the sPLA2-MT-III in macrophages, are modulated by p38MAPK and PKC, but not by PI3K signaling proteins.

  3. Eicosanoid pathway in colorectal cancer: Recent updates.

    Science.gov (United States)

    Tuncer, Sinem; Banerjee, Sreeparna

    2015-11-07

    Enzymatic metabolism of the 20C polyunsaturated fatty acid (PUFA) arachidonic acid (AA) occurs via the cyclooxygenase (COX) and lipoxygenase (LOX) pathways, and leads to the production of various bioactive lipids termed eicosanoids. These eicosanoids have a variety of functions, including stimulation of homeostatic responses in the cardiovascular system, induction and resolution of inflammation, and modulation of immune responses against diseases associated with chronic inflammation, such as cancer. Because chronic inflammation is essential for the development of colorectal cancer (CRC), it is not surprising that many eicosanoids are implicated in CRC. Oftentimes, these autacoids work in an antagonistic and highly temporal manner in inflammation; therefore, inhibition of the pro-inflammatory COX-2 or 5-LOX enzymes may subsequently inhibit the formation of their essential products, or shunt substrates from one pathway to another, leading to undesirable side-effects. A better understanding of these different enzymes and their products is essential not only for understanding the importance of eicosanoids, but also for designing more effective drugs that solely target the inflammatory molecules found in both chronic inflammation and cancer. In this review, we have evaluated the cancer promoting and anti-cancer roles of different eicosanoids in CRC, and highlighted the most recent literature which describes how those molecules affect not only tumor tissue, but also the tumor microenvironment. Additionally, we have attempted to delineate the roles that eicosanoids with opposing functions play in neoplastic transformation in CRC through their effects on proliferation, apoptosis, motility, metastasis, and angiogenesis.

  4. Immunoexpression of constitutive and inducible cyclooxygenase isoforms in distinguishing and accessory structures of synovial joints in rat foetuses.

    Science.gov (United States)

    Burdan, F; Szumiło, J; Dworzański, W; Szumiło, M; Podlodowska, J; Dyndor, K; Madej, B; Dworzański, J; Klepacz, R

    2009-05-01

    Joint formation is a developmental process regulated by various factors including bone morphogenetic proteins, transforming and growth factors, etc. Recently, a high expression of cyclooxygenase (COX) isoforms in the foetal cartilaginous elements was also revealed. On the other hand, various joint and skeletal abnormalities were seen in laboratory animal and human offspring, exposed in utero to several COX inhibitors. Immunoexpression of constitutive (COX-1) and inducible (COX-2) cyclooxygenase isoforms was evaluated in various articular structures of untreated and unfamiliar 21-day-old male rat foetuses. Both COX isoforms were detected in the articular cartilage and joint capsule, as well as in the intra-articular disc of the temporomandibular joint and meniscus of the knee joint. COX-1 immunostaining was revealed in the anterior and posterior cruciate ligament of the knee joint and the labrum of the hip and shoulder, whereas COX-2 immunoreactivity in those structures was not found. It could be concluded that both constitutive and inducible COX isoforms are physiologically expressed in various structures of synovial joints in rat foetuses at the end of prenatal development.

  5. Cyclooxygenase 2 (rs2745557) Polymorphism and the Susceptibility to Benign Prostate Hyperplasia and Prostate Cancer in Egyptians.

    Science.gov (United States)

    Fawzy, Mohamed S; Elfayoumi, Abdel-Rahman; Mohamed, Randa H; Fatah, Ihab R Abdel; Saadawy, Sara F

    2016-06-01

    Cyclooxygenase-2 (COX-2), an inducible isoform of cyclooxygenase, has been reported to be correlated with tumorigenesis, tumor progression, and metastasis. We aimed to evaluate the association between COX-2 (rs2745557) polymorphism and prostate cancer (PCa), benign prostate hyperplasia (BPH) risk. We also assessed the influence of other risk factors such as obesity, smoking, diabetes in modulating the risk of PCa in Egyptian men. COX-2 (rs2745557) was genotyped in 112 PC patients, 111 BPH and 120 subjects as a control group. COX-2 and PSA levels were measured by ELISA. We found that GG genotype was associated with a 17-fold increased risk for PCa and 20-fold increased the risk for BPH more than AA genotype. Also, G allele carriers of COX-2 were associated with metastatic cancer (OR = 1.3, P < 0.05) and disease aggressiveness (OR = 3.5, P < 0.001). The coexistence of obesity, smoking, or diabetes with GG genotype may lead to increasing the risk of developing BPH (OR = 3.3, 4, and 2.7, respectively) and of developing PCa (OR = 2.9, 4.9, and 3.2, respectively). Our results showed evidence suggesting the involvement of the COX-2 (rs2745557) polymorphism and its protein in PCa or BPH initiation and progression. Also, the coexistence of COX-2 (rs2745557) and obesity, smoking, or diabetes may lead to the development of PCa or BPH.

  6. Reversal of High dietary fructose-induced PPARα suppression by oral administration of lipoxygenase/cyclooxygenase inhibitors

    Directory of Open Access Journals (Sweden)

    Azhar Salman

    2005-08-01

    Full Text Available Abstract High fructose feeding causes diet-induced alterations of lipid metabolism and decreased insulin sensitivity, hallmark of which is a rapid and profound hypertriglyceridemia. One of the mechanisms that contribute to serum hypertriglyceridemia in this model is suppression of hepatic PPARα. HMG-CoA inhibitors, which reduce serum triglycerides in these animals, also elevate/restore hepatic PPARα. Previously we demonstrated that two known lipoxygenase/cyclooxygenase inhibitors reversed diet-induced hypertriglyceridemia in this model and that reversal of certain inflammatory markers in the liver correlated with the metabolic benefit. In this paper we extended these studies by examining the impact of these compounds on expression of PPARα, both at the level of transcription and expression. Our data show that diet-induced suppression of hepaic PPARα is reversed upon treatment with lipoxygenase/cyclooxygenase compounds. We then tested one of these compounds, BW-755c, over a range of doses from 10 mg/kg to 100 mg/kg to establish a dose-response relationship with the reduction of serum hypertriglyceridemia in this model. These experiments support the concept of using anti-inflammatory medications as one method to correct metabolic dysfunction.

  7. Mathematical modeling of the Phoenix Rising pathway.

    Directory of Open Access Journals (Sweden)

    Chad Liu

    2014-02-01

    Full Text Available Apoptosis is a tightly controlled process in mammalian cells. It is important for embryogenesis, tissue homoeostasis, and cancer treatment. Apoptosis not only induces cell death, but also leads to the release of signals that promote rapid proliferation of surrounding cells through the Phoenix Rising (PR pathway. To quantitatively understand the kinetics of interactions of different molecules in this pathway, we developed a mathematical model to simulate the effects of various changes in the PR pathway on the secretion of prostaglandin E2 (PGE2, a key factor for promoting cell proliferation. These changes include activation of caspase 3 (C3, caspase 7 (C7, and nuclear factor κB (NFκB. In addition, we simulated the effects of cyclooxygenase-2 (COX2 inhibition and C3 knockout on the level of secreted PGE2. The model predictions on PGE2 in MEF and 4T1 cells at 48 hours after 10-Gray radiation were quantitatively consistent with the experimental data in the literature. Compared to C7, the model predicted that C3 activation was more critical for PGE2 production. The model also predicted that PGE2 production could be significantly reduced when COX2 expression was blocked via either NFκB inactivation or treatment of cells with exogenous COX2 inhibitors, which led to a decrease in the rate of conversion from arachidonic acid to prostaglandin H2 in the PR pathway. In conclusion, the mathematical model developed in this study yielded new insights into the process of tissue regrowth stimulated by signals from apoptotic cells. In future studies, the model can be used for experimental data analysis and assisting development of novel strategies/drugs for improving cancer treatment or normal tissue regeneration.

  8. Designing pathways

    DEFF Research Database (Denmark)

    Scheuer, John Damm

    2010-01-01

    The theoretical background in this chapter is organizational studies and especially theories about design and design processes in organizations. The concept of design is defined as a particular kind of work aimed at making arrangements in order to change existing situations into desired ones....... The illustrative case example is the introduction of clinical pathways in a psychiatric department. The contribution to a general core of design research is the development of the concept of design work and a critical discussion of the role of technological rules in design work....

  9. Designing pathways

    DEFF Research Database (Denmark)

    2010-01-01

    The theoretical background in this chapter is organizational studies and especially theories about design and design processes in organizations. The concept of design is defined as a particular kind of work aimed at making arrangements in order to change existing situations into desired ones....... The illustrative case example is the introduction of clinical pathways in a psychiatric department. The contribution to a general core of design research is the development of the concept of design work and a critical discussion of the role of technological rules in design work....

  10. Pathway collages: personalized multi-pathway diagrams.

    Science.gov (United States)

    Paley, Suzanne; O'Maille, Paul E; Weaver, Daniel; Karp, Peter D

    2016-12-13

    Metabolic pathway diagrams are a classical way of visualizing a linked cascade of biochemical reactions. However, to understand some biochemical situations, viewing a single pathway is insufficient, whereas viewing the entire metabolic network results in information overload. How do we enable scientists to rapidly construct personalized multi-pathway diagrams that depict a desired collection of interacting pathways that emphasize particular pathway interactions? We define software for constructing personalized multi-pathway diagrams called pathway-collages using a combination of manual and automatic layouts. The user specifies a set of pathways of interest for the collage from a Pathway/Genome Database. Layouts for the individual pathways are generated by the Pathway Tools software, and are sent to a Javascript Pathway Collage application implemented using Cytoscape.js. That application allows the user to re-position pathways; define connections between pathways; change visual style parameters; and paint metabolomics, gene expression, and reaction flux data onto the collage to obtain a desired multi-pathway diagram. We demonstrate the use of pathway collages in two application areas: a metabolomics study of pathogen drug response, and an Escherichia coli metabolic model. Pathway collages enable facile construction of personalized multi-pathway diagrams.

  11. Clinical Implication of Cyclooxygenase-2 Expression for Rectal Cancer Patients with Lymph Node Involvement

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyung Sik; Choi, Young Min; Hur, Won Joo; Kim, Su Jin; Kim, Dae Cheol; Roh, Mee Sook; Hong, Young Seoub; Park, Ki Jae [Dona-A University School of Medicine, Busan (Korea, Republic of)

    2009-12-15

    To assess the influence of cyclooxygenase-2 (COX-2) expression on the survival of patients with a combination of rectal cancer and lymph node metastasis. The study included rectal cancer patients treated by radical surgery and postoperative radiotherapy at the Dong-A university hospital from 1998 to 2004. A retrospective analysis was performed on a subset of patients that also had lymph node metastasis. After excluding eight of 86 patients, due to missing tissue samples in three, malignant melanoma in one, treatment of gastric cancer around one year before diagnosis in one, detection of lung cancer after one year of diagnosis in one, liver metastasis in one, and refusal of radiotherapy after 720 cGy in one, 78 patients were analyzed. The immunohistochemistry for COX-2 was conducted with an autostainer (BenchMark; Ventana, Tucson, AZ, USA). An image analyzer (TissueMine; Bioimagene, Cupertino, CA, USA) was used for analysis after scanning (ScanScope; Aperio, Vista, CA, USA). A survival analysis was performed using the Kaplan Meier method and significance was evaluated using the log rank test. COX-2 was stained positively in 62 patients (79.5%) and negatively in 16 (20.5%). A total of 6 (7.7%), 15 (19.2%), and 41 (52.6%) patients were of grades 1, 2, and 3, respectively for COX-2 expression. No correlation was found between being positive of COX-2 patient characteristics, which include age (<60-year old vs. {>=}60), sex, operation methods (abdominoperineal resection vs. lower anterior resection), degrees of differentiation, tumor size (<5 cm vs. {>=}5 cm), T stages, N stages, and stages (IIIa, IIIb, IIIc). The 5-year overall and 5-year disease free survival rates for the entire patient population were 57.0% and 51.6%, respectively. The 5-year overall survival rates for the COX-2 positive and negative patients were 53.0% and 72.9%, respectively (p=0.146). Further, the 5-year disease free survival rates for the COX-2 positive and negative patients were 46.3% and 72

  12. Decreased cyclooxygenase inhibition by aspirin in polymorphic variants of human prostaglandin H synthase-1.

    Science.gov (United States)

    Liu, Wen; Poole, Elizabeth M; Ulrich, Cornelia M; Kulmacz, Richard J

    2012-07-01

    Aspirin (ASA), a major antiplatelet and cancer-preventing drug, irreversibly blocks the cyclooxygenase (COX) activity of prostaglandin H synthase-1 (PGHS-1). Considerable differences in ASA effectiveness are observed between individuals, and some of this variability may be due to PGHS-1 protein variants. Our overall aim is to determine which, if any, of the known variants in the mature PGHS-1 protein lead to functional alterations in COX catalysis or inhibition by ASA. The present study targeted four PGHS-1 variants: R53H, R108Q, L237M, and V481I. Wild-type human PGHS-1 and the four polymorphic variants were expressed as histidine-tagged, homodimeric proteins in insect cells using baculovirus vectors, solubilized with a detergent, and purified by affinity chromatography. The purified proteins were characterized in vitro to evaluate COX and peroxidase (POX) catalytic parameters and the kinetics of COX inhibition by ASA and NS-398. Compared with the wild type, several variants showed a higher COX/POX ratio (up to 1.5-fold, for R108Q), an elevated arachidonate Km (up to 1.9-fold, for R108Q), and/or a lower ASA reactivity (up to 60% less, for R108Q). The decreased ASA reactivity in R108Q reflected both a 70% increase in the Ki for ASA and a 30% decrease in the rate constant for acetyl group transfer to the protein. Computational modeling of the brief ASA pulses experienced by PGHS-1 in circulating platelets during daily ASA dosing predicted that the 60% lower ASA reactivity in R108Q yields a 15-fold increase in surviving COX activity; smaller, approximately two-fold increases in surviving COX activity were predicted for L237M and V481I. NS-398 competitively inhibited COX catalysis of the wild type (Ki=6 µmol/l) and inhibited COX inactivation by 1.0 mmol/l ASA in both the wild type (IC50=0.8 µmol/l) and R108Q (IC50=2.1 µmol/l). Of the four PGHS-1 variants examined, R108Q exerts the largest functional effects, with evidence for impaired interactions with a COX

  13. Indomethacin but not a selective cyclooxygenase-2 inhibitor inhibits esophageal adenocarcinogenesis in rats

    Institute of Scientific and Technical Information of China (English)

    Paula Esquivias; Antonio Morandeira; Alfredo Escartín; Carmelo Cebrián; Sonia Santander; Francisco Esteva; María Asunción García-González

    2012-01-01

    AIM:To evaluate the effects of indomethacin [dual cyclooxygenase (COX)-1/COX-2 inhibitor] and 3-(3,4-difluorophenyl)-4-(4-(methylsulfonyl) phenyl)-2-(5H)-furanone (MF-tricyclic) (COX-2 selective inhibitor) in a rat experimental model of Barrett's esophagus and esophageal adenocarcinoma.METHODS:A total of 112 surviving post-surgery rats were randomly divided into three groups:the control group (n =48),which did not receive any treatment; the indomethacin group (n =32),which were given 2mg/kg per day of the COX-1/COX-2 inhibitor; and the MF-tricyclic group (n =32),which received 10 mg/kg per day of the selective COX-2 inhibitor.Randomly selected rats were killed either 8 wk or 16 wk after surgery.The timing of the deaths was in accordance with a previous study performed in our group.Only rats that were killed at the times designated by the protocol were included in the study.We then assessed the histology and prostaglandin E2 (PGE2) expression levels in the rat esophagi.An additional group of eight animals that did not undergo esophagojejunostomy were included in order to obtain normal esophageal tissue as a control.RESULTS:Compared to a control group with no treatment (vehicle-treated rats),indomethacin treatment was associated with decreases in ulcerated esophageal mucosa (16% vs 35% and 14% vs 17%,2 mo and 4mo after surgery,respectively; P =0.021),length of intestinal metaplasia in continuity with anastomosis (2± 1.17 mm vs 2.29 ± 0.75 mm and 1.25 ± 0.42 mm vs 3.5 ± 1.54 mm,2 mo and 4 mo after surgery,respectively; P =0.007),presence of intestinal metaplasia beyond anastomosis (20% vs 71.4% and 0% vs 60%,2 mo and 4 mo after surgery,respectively; P =0.009),severity of dysplasia (0% vs 71.4% and 20% vs 85.7%high-grade dysplasia,2 mo and 4 mo after surgery,respectively; P =0.002),and adenocarcinoma incidence (0% vs 57.1% and 0% vs 60%,2 mo and 4 mo after surgery,respectively; P < 0.0001).Treatment with the selective COX-2

  14. Disruption of cyclooxygenase-2 prevents downregulation of cortical AQP2 and AQP3 in response to bilateral ureteral obstruction in the mouse

    DEFF Research Database (Denmark)

    Nilsson, Line; Madsen, Kirsten Morill; Topcu, Sukru Oguzkan

    2012-01-01

    Bilateral ureteral obstruction (BUO) in rats is associated with increased cyclooxygenase type 2 (COX-2) expression, and selective COX-2 inhibition prevents downregulation of aquaporins (AQPs) in response to BUO. It was hypothesized that a murine model would display similar changes in renal COX-2...

  15. Vasoactive intestinal peptide induces cyclooxygenase-2 expression through nuclear factor-κB in human prostate cell lines. Differential time-dependent responses in cancer progression

    OpenAIRE

    Fernández-Martínez, Ana B.; Collado, Beatriz; Bajo, Ana M.; Sánchez-Chapado, Manuel; Prieto,Juan C.; Carmena, María J.

    2007-01-01

    Vasoactive intestinal peptide induces cyclooxygenase-2 expression through nuclear factor-?B in human prostate cell lines. Differential time-dependent responses in cancer progression SPAIN (Fernandez-Martinez, Ana B.) SPAIN Received: 2006-09-11 Revised: 2007-01-11 Accepted: 2007-01-11

  16. Effect of cyclooxygenase-2 inhibition by meloxicam, on atrogin-1 and myogenic regulatory factors in skeletal muscle of rats injected with endotoxin.

    Science.gov (United States)

    Martin, A I; Nieto-Bona, M P; Castillero, E; Fernandez-Galaz, C; Lopez-Menduina, M; Gomez-Sanmiguel, A B; Gomez-Moreira, C; Villanua, M Angeles; Lopez-Calderon, A

    2012-12-01

    Cyclooxygenase-2-induction by inflammatory stimuli has been proposed as a mediator of inflammatory cachexia. We analyse whether cyclooxygenase-2 inhibition by meloxicam administration is able to modify the response of skeletal muscle to inflammation induced by lipopolysaccharide endotoxin (LPS). Male rats were injected with 1 mg kg(-1) LPS at 17:00 h and at 10:00 h the following day, and euthanized 4, 24 or 72 hours later. Atrogin-1, MuRF1, myogenic regulatory factors and cyclooxygenase-2 in the gastrocnemius were determined by real time-PCR (mRNA) and Western blot (protein). In a second experiment the effect of meloxicam administration (1 mg kg⁻¹) was analyzed. Meloxicam was administered either in a preventive manner, 1 hour before each endotoxin injection, or in a therapeutic manner, starting 2 hours after the second LPS injection and at 24 and 48 hours afterwards. There was a marked increase in MuRF1 mRNA (Pmeloxicam treatment blocked LPS-induced increase in atrogin-1. Preventive, but not therapeutic, meloxicam decreased myostatin (Pmeloxicam treatment decreased gastrocnemius myogenin. These data suggest that cyclooxygenase-2 inhibition by meloxicam administration can prevent the increase in atrogin-1 and the decrease in MyoD induced by LPS administration. However, prolonged therapeutic meloxicam treatment seems to be less effective, since it can inhibit myogenic regulatory factors.

  17. Use of selective cyclooxygenase-2 inhibitors and nonselective nonsteroidal antiinflammatory drugs in high doses increases mortality and risk of reinfarction in patients with prior myocardial infarction

    DEFF Research Database (Denmark)

    Sørensen, Rikke; Abildstrøm, Steen Zabell; Torp-Pedersen, C.

    2008-01-01

    The selective cyclooxygenase-2 (COX-2) inhibitors and other nonselective nonsteroidal antiinflammatory drugs (NSAIDs) have been associated with increased cardiovascular risk, but the risk in patients with established cardiovascular disease is unknown. In the present study, we analyzed the risk of...

  18. Effect of a specific cyclooxygenase-gene polymorphism (A-842G/C50T) on the occurrence of peptic ulcer hemorrhage.

    NARCIS (Netherlands)

    Oijen, M.G.H. van; Laheij, R.J.F.; Koetsier, M.I.A.; Kleine, E. de; Morsche, R.H.M. te; Kerkhoven, L.A.S. van; Jansen, J.B.M.J.; Drenth, J.P.H.

    2006-01-01

    Cyclooxygenases (COX) catalyze the conversion of arachidonic acid to prostaglandins (PGs). COX-inhibiting drugs, such as nonsteroidal anti-inflammatory drugs (NSAIDs), increase the risk for peptic ulcer disease. As a corollary, COX gene polymorphisms could be important in the pathogenesis of peptic

  19. Effects of polyunsaturated fatty acids on prostaglandin synthesis and cyclooxygenase-mediated DNA adduct formation by heterocyclic aromatic amines in human adenocarcinoma colon cells

    NARCIS (Netherlands)

    Moonen, H.J.J.; Dommels, Y.E.M.; Zwam, M.; Herwijnen, van M.H.M.; Kleinjans, J.C.S.; Alink, G.M.; Kok, de T.M.C.M.

    2004-01-01

    Dietary heterocyclic aromatic amines (HCA) and polyunsaturated fatty acids (PUFA) are both believed to play a role in colon carcinogenesis, and are both substrate for the enzyme cyclooxygenase (COX). In HCA-7 cells, highly expressing isoform COX-2, we investigated the effects of PUFA on prostaglandi

  20. Effect of a specific cyclooxygenase-gene polymorphism (A-842G/C50T) on the occurrence of peptic ulcer hemorrhage.

    NARCIS (Netherlands)

    Oijen, M.G.H. van; Laheij, R.J.F.; Koetsier, M.I.A.; Kleine, E. de; Morsche, R.H.M. te; Kerkhoven, L.A.S. van; Jansen, J.B.M.J.; Drenth, J.P.H.

    2006-01-01

    Cyclooxygenases (COX) catalyze the conversion of arachidonic acid to prostaglandins (PGs). COX-inhibiting drugs, such as nonsteroidal anti-inflammatory drugs (NSAIDs), increase the risk for peptic ulcer disease. As a corollary, COX gene polymorphisms could be important in the pathogenesis of peptic

  1. Misoprostol Reverse Hippocampal Neuron Cyclooxygenase-2 Downstream Signaling Imbalance in Aluminum-Overload Rats

    Science.gov (United States)

    Guo, Yuanxin; Lei, Wenjuan; Wang, Jianfeng; Hu, Xinyue; Wei, Yuling; Ji, Chaonan; Yang, Junqing

    2016-01-01

    Although COX-2 inhibition in animal models of neurodegenerative diseases has shown neuroprotection, recent studies have revealed some serious side effects (ulcers, bleeding, fatal cerebrovascular diseases etc.) and the limited benefits of COX-2 inhibitors. A more focused approach is necessary to explore the therapeutic effect of the COX downstream signaling pathway in neurological research. The aim of this study was to explore the alterations of the PGES-PGE2-EP signal pathway and the effect of misoprostol on neurodegeneration by chronic aluminum-overload in rats. Adult rats were treated by intragastric administration of aluminum gluconate. The PGE2 content and expression of PGES and EPs in the hippocampi of rats were detected using ELISA, q-PCR and Western blot analysis, respectively. The content of malondialdehyde (MDA) and the activity of superoxide dismutase (SOD) in the rat hippocampi were also detected. The misoprostol treatment dose-dependently improved spatial learning and memory function as well as healing after hippocampal neuron damage induced by chronic aluminum-overload in rats. Meanwhile, the administration of misoprostol resulted in a decrease in the PGE2 level and down-regulation of the mPGES-1, EP2 and EP4 expression levels, while there was a dose-dependent up-regulation of EP3 expression. These results suggest that misoprostol possesses a neuroprotective property, and the mechanism involves affecting the EP3 level and reducing the endogenous production of PGE2 through a negative feedback mechanism, increasing the EP3 expression level, decreasing the EP2 and EP4 expression levels, and rebuilding the mPGES-1-PGE2-EP1-4 signal pathway balance. In this way, misoprostol has a counteractive effect on oxidant stress and inflammation in the central nervous system. The PGES-PGE2-EPs signaling pathway is a potential therapeutic strategy for treating neurodegeneration in patients. PMID:27033056

  2. The Anti-Inflammatory Effects of Lipoxygenase and Cyclo-Oxygenase Inhibitors in Inflammation-Induced Human Fetal Glia Cells and the Aβ Degradation Capacity of Human Fetal Astrocytes in an Ex vivo Assay

    Directory of Open Access Journals (Sweden)

    Rea Pihlaja

    2017-05-01

    Full Text Available Chronic inflammation is a common phenomenon present in the background of multiple neurodegenerative diseases, including Alzheimer's disease (AD. The arachidonic acid pathway overproduces proinflammatory eicosanoids during these states and glial cells in the brain gradually lose their vital functions of protecting and supporting neurons. In this study, the role of different key enzymes of the eicosanoid pathway mediating inflammatory responses was examined in vitro and ex vivo using human fetal glial cells. Astrocytes and microglia were exposed to proinflammatory agents i.e., cytokines interleukin 1-β (IL-1β and tumor necrosis factor (TNF-α. ELISA assays were used to examine the effects of inhibitors of key enzymes in the eicosanoid pathway. Inhibitors for 5-lipoxygenase (5-LOX and cyclo-oxygenase 2 (COX-2 in both cell types and 5-, 12-, and 15-LOX-inhibitor in astrocytes reduced significantly IL-6 secretion, compared to exposed glial cells without inhibitors. The cytokine antibody array showed that especially treatments with 5, -12, and -15 LOX inhibitor in astrocytes, 5-LOX inhibitor in microglia and COX-2 inhibitor in both glial cell types significantly reduced the expression of multiple proinflammatory cytokines. Furthermore, human fetal astrocytes and microglia were cultured on top of AD-affected and control human brain sections for 30 h. According to the immunochemical evaluation of the level of total Aβ, astrocytes were very efficient at degrading Aβ from AD-affected brain sections ex vivo; simultaneously added enzyme inhibitors did not increase their Aβ degradation capabilities. Microglia were not able to reduce the level of total Aβ during the 30 h incubation time.

  3. Temporal expression of the PGE2 synthetic system in the kidney is associated with the time frame of renal developmental vulnerability to cyclooxygenase-2 inhibition.

    Science.gov (United States)

    Frölich, Stefanie; Olliges, Anke; Kern, Niklas; Schreiber, Yannik; Narumiya, Shuh; Nüsing, Rolf M

    2012-07-15

    Pharmacological blockade of cyclooxygenase-2 (COX-2) causes impairment of kidney development. The present study was aimed at determining temporal expression pattern and activity of the PGE(2) synthetic pathway during postnatal nephrogenesis in mice and its association to the time window sensitive to COX-2 inhibition. During the first 10 days after birth, we observed transient induction of mRNA and protein for microsomal PGE synthase (mPGES)-1 between postnatal days 4 (P4) and P8, but not for mPGES-2 or cytosolic PGE synthase (cPGES). PGE(2) synthetic activity using arachidonic acid and PGH(2) as substrates and also urinary excretion of PGE(2) were enhanced during this time frame. In parallel to the PGE(2) system, COX-2 but not COX-1 expression was also transiently induced. Studying glomerulogenesis in EP receptor knockout mice revealed a reduction in glomerular size in EP1(-/-), EP2(-/-), and EP4(-/-) mice, supporting the developmental role of PGE(2). The most vulnerable time window to COX-2 inhibition by SC-236 was found closely related to the temporal expression of COX-2 and mPGES-1. The strongest effects of COX-2 inhibition were achieved following 8 days of drug administration. Similar developmental damage was caused by application of rofecoxib, but not by the COX-1-selective inhibitor SC-560. COX-2 inhibition starting after P10 has had no effect on the size of glomeruli or on the relative number of superficial glomeruli; however, growth of the renal cortex was significantly diminished, indicating the requirement of COX-2 activity after P10. Effects of COX-2 inhibition on renal cell differentiation and on renal fibrosis needed a prolonged time of exposition of at least 10 days. In conclusion, temporal expression of the PGE(2) synthetic system coincides with the most vulnerable age interval for the induction of irreversible renal abnormalities. We assume that mPGES-1 is coregulated with COX-2 for PGE(2) synthesis to orchestrate postnatal kidney development and

  4. Cyclo-oxygenase-2 mediated prostaglandin release regulates blood flow in connective tissue during mechanical loading in humans

    DEFF Research Database (Denmark)

    Langberg, H; Boushel, Robert Christopher; Skovgaard, D

    2003-01-01

    Mechanical loading is known to increase connective tissue blood flow of human tendons and to cause local release of vasodilatory substances. The present study investigated the importance of prostaglandins (PG) formed by cyclo-oxygenase isoforms (COX-1 and 2) for the exercise-related increase...... in blood flow in connective tissue. Healthy individuals (n = 24, age: 23-31 years) underwent 30 min of intermittent, isometric, plantarflexion with both calf muscles either without (n = 6, Control, C) or with blockade of PG formation, either COX-2 specific (n = 10, Celecoxib 2 x 100 mg day-1 for 3 days.......2 +/- 2.0)(P tissue prostaglandin plays an important role for blood flow in peritendinous connective tissue during physical loading in vivo....

  5. UCP1 induction during recruitment of brown adipocytes in white adipose tissue is dependent on cyclooxygenase activity

    DEFF Research Database (Denmark)

    Madsen, Lise; Pedersen, Lone M; Lillefosse, Haldis Haukaas;

    2010-01-01

    -adrenergic induction of UCP1 expression in primary inguinal adipocytes. The use of PGE(2) receptor antagonists implicated EP(4) as a main PGE(2) receptor, and injection of the stable PGE(2) analog (EP(3/4) agonist) 16,16 dm PGE(2) induced UCP1 expression in inguinal white adipose tissue. Inhibition of COX activity......BACKGROUND: The uncoupling protein 1 (UCP1) is a hallmark of brown adipocytes and pivotal for cold- and diet-induced thermogenesis. METHODOLOGY/PRINCIPAL FINDINGS: Here we report that cyclooxygenase (COX) activity and prostaglandin E(2) (PGE(2)) are crucially involved in induction of UCP1...... expression in inguinal white adipocytes, but not in classic interscapular brown adipocytes. Cold-induced expression of UCP1 in inguinal white adipocytes was repressed in COX2 knockout (KO) mice and by administration of the COX inhibitor indomethacin in wild-type mice. Indomethacin repressed beta...

  6. Cyclooxygenase-2 modulates the insulin-like growth factor axis in non-small-cell lung cancer.

    Science.gov (United States)

    Põld, Mehis; Krysan, Kostyantyn; Põld, Anu; Dohadwala, Mariam; Heuze-Vourc'h, Nathalie; Mao, Jenny T; Riedl, Karen L; Sharma, Sherven; Dubinett, Steven M

    2004-09-15

    Constitutive overexpression of cyclooxygenase-2 (COX-2) occurs frequently in several different malignancies, including lung, colon, breast, and prostate cancer. Clinical studies have established elevated serum insulin-like growth factor (IGF-I) content and IGF-I:IGF-binding protein 3 (IGFBP-3) ratio as risk factors for these same malignancies. Therefore, we sought to determine the link between COX-2 expression and the IGF axis in COX-2 gene-modified human non-small-cell lung cancer (NSCLC) cells. Overexpression of COX-2 in NSCLC cells enhanced the antiapoptotic and mitogenic effects of IGF-I and IGF-II, facilitated the autophosphorylation of the type 1 IGF receptor, increased class IA phosphatidylinositol 3'-kinase activity, and decreased expression of IGFBP-3. Thus, these findings show that COX-2 augments the stimulatory arm of the IGF axis.

  7. Vascular endothelial growth factor, matrix metalloproteinases, and cyclooxygenase-2 influence prognosis of uterine cervical cancer in young women.

    Science.gov (United States)

    Noriyuki, Maiko; Sumi, Toshiyuki; Zhi, Xu; Misugi, Fumiko; Nobeyama, Hiroyuki; Yoshida, Hiroyuki; Matsumoto, Yoshinari; Yasui, Tomoyo; Honda, Ken-Ichi; Ishiko, Osamu

    2007-09-01

    Recent changes in the lifestyle of young women have led to an increase in the rate of uterine cervical cancer. We investigated the clinicopathological characteristics of uterine cervical cancer in young women, and examined the expression of vascular endothelial growth factor (VEGF), matrix metalloproteinases (MMPs) and cyclooxygenase-2 (COX-2). Tumor samples from 439 patients with uterine cervical cancer, who were initially treated at Osaka City University Medical School Hospital, Japan between 1995 and 2004, were stained immunohistochemically. The patients were classified into two groups according to age at onset: group Y included women aged or =36 years. Group Y had more cases of squamous cell carcinoma, while group O had more advanced cases (Pcervical cancer in young women.

  8. Effects of macronutrient composition and cyclooxygenase-inhibition on diet-induced obesity, low grade inflammation and glucose homeostasis

    DEFF Research Database (Denmark)

    Fjære, Even

    Background: Obesity and its related metabolic complications are an increasing problem worldwide. A high fat diet in combination with sucrose has been shown to induce obesity and development of glucose intolerance and insulin resistance in rodents. C57BL/6J mice were fed high fat diets with sucrose......- or protein based background, and supplemented with either corn- or fish oil. These experiments were conducted to determine whether macronutrient composition and type of dietary fat can modulate diet-induced obesity, and associated metabolic consequences. The use of non-steroidal anti-inflammatory drugs...... is escalating, and in view of the increased consumption of obesogenic diets with high levels of dietary carbohydrates and fat, the metabolic consequences of cyclooxygenase-inhibition warrants investigation. Results: High fat/high sucrose diets increased obesity development and expression of macrophage...

  9. UCP1 induction during recruitment of brown adipocytes in white adipose tissue is dependent on cyclooxygenase activity

    DEFF Research Database (Denmark)

    Madsen, Lise; Pedersen, Lone M; Lillefosse, Haldis Haukaas

    2010-01-01

    -adrenergic induction of UCP1 expression in primary inguinal adipocytes. The use of PGE(2) receptor antagonists implicated EP(4) as a main PGE(2) receptor, and injection of the stable PGE(2) analog (EP(3/4) agonist) 16,16 dm PGE(2) induced UCP1 expression in inguinal white adipose tissue. Inhibition of COX activity......BACKGROUND: The uncoupling protein 1 (UCP1) is a hallmark of brown adipocytes and pivotal for cold- and diet-induced thermogenesis. METHODOLOGY/PRINCIPAL FINDINGS: Here we report that cyclooxygenase (COX) activity and prostaglandin E(2) (PGE(2)) are crucially involved in induction of UCP1...... attenuated diet-induced UCP1 expression and increased energy efficiency and adipose tissue mass in obesity-resistant mice kept at thermoneutrality. CONCLUSIONS/SIGNIFICANCE: Our findings provide evidence that induction of UCP1 expression in white adipose tissue, but not in classic interscapular brown adipose...

  10. Temporal and topographic profiles of cyclooxygenase-2 expression during 24 h of focal brain ishemia in rats.

    Science.gov (United States)

    Yokota, Chiaki; Kaji, Tomohito; Kuge, Yuji; Inoue, Hiroyasu; Tamaki, Nagara; Minematsu, Kazuo

    2004-03-11

    Substantial increases in cyclooxygenase-2 (COX-2) mRNA and protein levels were demonstrated in the peri-infarct and focal ischemic areas after 3-24 and 12-24 h, respectively, in rats. In the ischemic core, significant increases in COX-2 mRNA followed 6 h of ischemia, though the peak level was about one-third of that in the peri-infarct area. Increases in COX-2 protein in the ischemic core were not observed during ischemic periods. Diffuse, neuronal COX-2 staining was found in peri-infarct areas as well as in discrete, immunoreactive neurons in the ischemic core. Robust increases in prostaglandin E2 levels in the peri-infarct area were demonstrated following 24 h of ischemia. Prostaglandin production as well as COX-2 expression in ischemic tissues depended on the degree and duration of the reduction in cerebral blood flow.

  11. Entamoeba histolytica: inflammatory process during amoebic liver abscess formation involves cyclooxygenase-2 expression in macrophages and trophozoites.

    Science.gov (United States)

    Gutiérrez-Alarcón, A; Moguel-Torres, M; Mata-Leyva, O; Cuellar-Nevárez, G; Siqueiros-Cendón, T; Erosa, G; Ramos-Martínez, E; Talamás-Rohana, P; Sánchez-Ramírez, B

    2006-11-01

    It has been demonstrated that expression of cyclooxygenase-2 (COX-2) isoform is induced by Entamoeba histolytica in macrophages and polymorphonuclear cells during amoebic liver abscess (ALA) formation in hamsters. Trophozoites present in the lesion were also positive for COX-2 signal. However, no cross reactivity of the anti-COX-2 antibody with protein extract of cultivated trophozoites was found. To clarify if trophozoites are involved in PGE(2) production during ALA development, COX-2 expression was detected by in situ hybridization and RT-PCR in liver tissue from intrahepatically infected hamsters. COX-2 mRNA was in polymorphonuclear cells since 4h postinfection, and subsequently, local macrophages expressed COX-2 mRNA in a similar way. Additionally, a positive signal for COX-2 mRNA expression was detected in E. histolytica trophozoites, suggesting that, in vivo, parasite COX expression may be an important mechanism to promote inflammation.

  12. Expression of gelatinases (MMP-2, MMP-9) and cyclooxygenases (COX-1, COX-2) in some benign salivary gland tumors.

    Science.gov (United States)

    Lipari, L; Mauro, A; Gallina, S; Tortorici, S; Buscemi, M; Tete, S; Gerbino, A

    2012-01-01

    Salivary gland tumors, most of which are rare benign tumors, represent a histologically heterogenous group with the greatest diversity of morphological and cellular features. The aim of this study is to analyse the expression and possible interactions between gelatinases (MMP-2, MMP-9) and cyclooxygenases (COX-1, COX-2) in some benign salivary gland tumors. We investigated the expression of gelatinases and cyclooxigenases in control salivary gland, Pleomorphic adenoma and Warthin's tumor through immunohistochemistry and Reverse Transcription - Polymerase Chain Reaction (PCR). We identified the expression of both classes of enzyme in normal samples and in the two types of pathological samples without any quantitative differences. From the present data no significant differences emerge in the expression of these enzymes among the different pathologies examined. Nevertheless, due to the small number of samples included in this study, general statements regarding correlation between the degree of severity of the tumoral pathology and the quantitative expression of these potential tumoral markers can not be made.

  13. Viscum album exerts anti-inflammatory effect by selectively inhibiting cytokine-induced expression of cyclooxygenase-2.

    Directory of Open Access Journals (Sweden)

    Pushpa Hegde

    Full Text Available Viscum album (VA preparations are extensively used as complementary therapy in cancer and are shown to exert anti-tumor activities which involve the cytotoxic properties, induction of apoptosis, inhibition of angiogenesis and several other immunomodulatory mechanisms. In addition to their application in cancer therapy, VA preparations have also been successfully utilized in the treatment of several inflammatory pathologies. Owing to the intricate association of inflammation and cancer and in view of the fact that several anti-tumor phytotherapeutics also exert a potent anti-inflammatory effect, we hypothesized that VA exerts an anti-inflammatory effect that is responsible for its therapeutic benefit. Since, inflammatory cytokine-induced cyclo-oxygenase-2 (COX-2 and prostaglandin E2 (PGE2 play a critical role in the pathogenesis of inflammatory diseases, we investigated the anti-inflammatory effect of VA on regulation of cyclo-oxygenase expression and PGE2 biosynthesis by using human lung adenocarcinoma cells (A549 cells as a model. A549 cells were stimulated with IL-1β and treated with VA preparation (VA Qu Spez for 18 hours. PGE2 was analysed in the culture supernatants by enzyme immunoassay. Expression of COX-2 and COX-1 proteins was analyzed by immunoblotting and the expression of COX-2 mRNA was assessed by semi-quantitative RT-PCR. We found that VA Qu Spez inhibit the secretion of IL-1β-induced PGE2 in a dose-dependent manner. Further, we also show that this inhibitory action was associated with a reduced expression of COX-2 without modulating the COX-1 expression. Together these results demonstrate a novel anti-inflammatory mechanism of action of VA preparations wherein VA exerts an anti-inflammatory effect by inhibiting cytokine-induced PGE2 via selective inhibition of COX-2.

  14. Crystal Structure of Aspirin-Acetylated Human Cyclooxygenase-2: Insight into the Formation of Products with Reversed Stereochemistry.

    Science.gov (United States)

    Lucido, Michael J; Orlando, Benjamin J; Vecchio, Alex J; Malkowski, Michael G

    2016-03-01

    Aspirin and other nonsteroidal anti-inflammatory drugs target the cyclooxygenase enzymes (COX-1 and COX-2) to block the formation of prostaglandins. Aspirin is unique in that it covalently modifies each enzyme by acetylating Ser-530 within the cyclooxygenase active site. Acetylation of COX-1 leads to complete loss of activity, while acetylation of COX-2 results in the generation of the monooxygenated product 15(R)-hydroxyeicosatetraenoic acid (15R-HETE). Ser-530 has also been shown to influence the stereochemistry for the addition of oxygen to the prostaglandin product. We determined the crystal structures of S530T murine (mu) COX-2, aspirin-acetylated human (hu) COX-2, and huCOX-2 in complex with salicylate to 1.9, 2.0, and 2.4 Å, respectively. The structures reveal that (1) the acetylated Ser-530 completely blocks access to the hydrophobic groove, (2) the observed binding pose of salicylate is reflective of the enzyme-inhibitor complex prior to acetylation, and (3) the observed Thr-530 rotamer in the S530T muCOX-2 crystal structure does not impede access to the hydrophobic groove. On the basis of these structural observations, along with functional analysis of the S530T/G533V double mutant, we propose a working hypothesis for the generation of 15R-HETE by aspirin-acetylated COX-2. We also observe differential acetylation of COX-2 purified in various detergent systems and nanodiscs, indicating that detergent and lipid binding within the membrane-binding domain of the enzyme alters the rate of the acetylation reaction in vitro.

  15. THE CRYSTAL STRUCTURE OF ASPIRIN ACETYLATED HUMAN CYCLOOXYGENASE-2: INSIGHT INTO THE FORMATION OF PRODUCTS WITH REVERSED STEREOCHEMISTRY

    Science.gov (United States)

    Lucido, Michael J.; Orlando, Benjamin J.; Vecchio, Alex J.; Malkowski, Michael G.

    2016-01-01

    Aspirin and other nonsterroidal anti-inflammatory drugs target the Cyclooxygenase enzymes (COX-1 and COX-2) to block the formation of prostaglandins. Aspirin is unique in that it covalently modifies each enzyme by acetylating Ser-530 within the cyclooxygenase active site. Acetylation of COX-1 leads to complete loss of activity, while acetylation of COX-2 results in the generation of the mono-oxygenated product 15(R)-hydroxyeicosatetraenoic acid (15R-HETE). Ser-530 has also been shown to influence the stereochemistry for oxygen addition into the prostaglandin product. We determined the crystal structures of S530T murine (mu) COX-2, aspirin-acetylated human (hu) COX-2, and huCOX-2 in complex with salicylate to 1.9Å, 2.0Å, and 2.4Å, respectively. The structures reveal that: 1) the acetylated Ser-530 completely blocks access to the hydrophobic groove; 2) the observed binding pose of salicylate is reflective of the enzyme-inhibitor complex prior to acetylation; and 3) the observed Thr-530 rotamer in the S530T muCOX-2 crystal structure does not impede access to the hydrophobic groove. Based on these structural observations, along with functional analysis of the S530T/G533V double mutant, we propose a working hypothesis for the generation of 15R-HETE by aspirin-acetylated COX-2. We also observe differential acetylation of COX-2 purified in various detergent systems and nanodiscs, indicating that detergent and lipid binding within the membrane-binding domain of the enzyme alters the rate of the acetylation reaction in vitro. PMID:26859324

  16. Novel functional association of rat testicular membrane-associated cytosolic glutathione S transferases and cyclooxygenase in vitro

    Institute of Scientific and Technical Information of China (English)

    S. Neeraja; B. Ramakrishna; A. S. Sreenath; G. V. Reddy; P. R. K. Reddy; P. Reddanna

    2005-01-01

    Aim: To analyze the role of cytosolic glutathione S-transferases (cGSTs) and membrane-associated cytosolic GSTs (macGSTs) in prostaglandin biosynthesis and to evaluate the possible interaction between glutathione S-transferases (GSTs) and cyclooxygenase (COX) in vitro. Methods: SDS-PAGE analysis was undertaken for characterization of GSTs, thin layer chromatography (TLC) to monitor the effect of GSTs on prostaglandin biosynthesis from arachidonic acid (AA) and spectrophotometric assays were done for measuring activity levels of COX and GSTs. Results:SDS-PAGE analysis indicates that macGSTs have molecular weights in the range of 25-28 kDa. In a coupled assay involving GSTs, arachidonic acid and cyclooxygenase-1, rat testicular macGSTs produced prostaglandin E2 and F2α,while the cGSTs caused the generation of prostaglandin D2, E2 and F2α. In vitro interaction studies on GSTs and COX at the protein level have shown dose-dependent inhibition of COX activity by macGSTs and vice versa. This effect,however, is not seen with cGSTs. The inhibitory effect of COX on macGST activity was relieved with increasing concentrations of reduced glutathione (GSH) but not with 1-chloro 2,4-dinitrobenzene (CDNB). The inhibition of COX by macGSTs, on the other hand, was potentiated by glutathione. Conclusion: We isolated and purified macGSTs and cGSTs from rat testis and analyzed their involvement in prostaglandin biosynthesis. These studies reveal a reversible functional interaction between macGSTs and COX in vitro, with possible interactions between them at the GSH binding site of macGSTs.

  17. Lack of association between the cyclooxygenase 2 -765G>C polymorphism and prostate cancer risk: a meta-analysis.

    Science.gov (United States)

    Feng, Y-Q; Li, Y U; Xiao, W-D; Wang, G-X; Li, Y O

    2015-10-28

    The aim of this study was to investigate the association between the cyclooxygenase 2 (COX2) -765G>C (rs20417) polymorphism and prostate cancer (PC) risk using meta-analysis. A systematic literature search was performed using the PubMed, Embase, Cochrane Library, and Google Scholar databases by using the terms "cyclooxygenase-2/COX-2/PTGs2", "polymorphism" or "variation", and "prostate" and "cancer" or "carcinoma" to identify relevant articles up to June 14, 2014. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were assessed for PC risk associated with COX2 -765G>C polymorphism using fixed- and random-effect models. We identified a total of nine publications, including 5952 cases and 5078 controls, to investigate the effect of COX2 -765G>C on PC risk, and found no significant association in any genetic model tested (CC vs GG: OR = 0.993, 95%CI = 0.923-1.068; GC+CC vs GG: OR = 1.041, 95%CI = 0.931-1.103; CC vs GC+GG: OR = 0.858, 95%CI = 0.689-1.067; CC vs GG: OR = 0.871, 95%CI = 0.689-1.086; GC vs GG: OR = 1.032, 95%CI = 0.945-1.127). Power analysis and tests for publication bias ensured the reliability of our results. This meta-analysis suggested that the functional COX2 -765G>C polymorphism, located in the COX2 gene promoter, is unlikely to be associated with PC risk. However, additional larger, well-designed studies are still required to reach a conclusive result on this issue.

  18. Induction of cyclo-oxygenase-2 mRNA by prostaglandin E2 in human prostatic carcinoma cells

    Science.gov (United States)

    Tjandrawinata, R. R.; Dahiya, R.; Hughes-Fulford, M.

    1997-01-01

    Prostaglandins are synthesized from arachidonic acid by the enzyme cyclo-oxygenase. There are two isoforms of cyclooxygenases: COX-1 (a constitutive form) and COX-2 (an inducible form). COX-2 has recently been categorized as an immediate-early gene and is associated with cellular growth and differentiation. The purpose of this study was to investigate the effects of exogenous dimethylprostaglandin E2 (dmPGE2) on prostate cancer cell growth. Results of these experiments demonstrate that administration of dmPGE2 to growing PC-3 cells significantly increased cellular proliferation (as measured by the cell number), total DNA content and endogenous PGE2 concentration. DmPGE2 also increased the steady-state mRNA levels of its own inducible synthesizing enzyme, COX-2, as well as cellular growth to levels similar to those seen with fetal calf serum and phorbol ester. The same results were observed in other human cancer cell types, such as the androgen-dependent LNCaP cells, breast cancer MDA-MB-134 cells and human colorectal carcinoma DiFi cells. In PC-3 cells, the dmPGE2 regulation of the COX-2 mRNA levels was both time dependent, with maximum stimulation seen 2 h after addition, and dose dependent on dmPGE2 concentration, with maximum stimulation seen at 5 microg ml(-1). The non-steroidal anti-inflammatory drug flurbiprofen (5 microM), in the presence of exogenous dmPGE2, inhibited the up-regulation of COX-2 mRNA and PC-3 cell growth. Taken together, these data suggest that PGE2 has a specific role in the maintenance of human cancer cell growth and that the activation of COX-2 expression depends primarily upon newly synthesized PGE2, perhaps resulting from changes in local cellular PGE2 concentrations.

  19. Induction of cyclo-oxygenase-2 mRNA by prostaglandin E2 in human prostatic carcinoma cells

    Science.gov (United States)

    Tjandrawinata, R. R.; Dahiya, R.; Hughes-Fulford, M.

    1997-01-01

    Prostaglandins are synthesized from arachidonic acid by the enzyme cyclo-oxygenase. There are two isoforms of cyclooxygenases: COX-1 (a constitutive form) and COX-2 (an inducible form). COX-2 has recently been categorized as an immediate-early gene and is associated with cellular growth and differentiation. The purpose of this study was to investigate the effects of exogenous dimethylprostaglandin E2 (dmPGE2) on prostate cancer cell growth. Results of these experiments demonstrate that administration of dmPGE2 to growing PC-3 cells significantly increased cellular proliferation (as measured by the cell number), total DNA content and endogenous PGE2 concentration. DmPGE2 also increased the steady-state mRNA levels of its own inducible synthesizing enzyme, COX-2, as well as cellular growth to levels similar to those seen with fetal calf serum and phorbol ester. The same results were observed in other human cancer cell types, such as the androgen-dependent LNCaP cells, breast cancer MDA-MB-134 cells and human colorectal carcinoma DiFi cells. In PC-3 cells, the dmPGE2 regulation of the COX-2 mRNA levels was both time dependent, with maximum stimulation seen 2 h after addition, and dose dependent on dmPGE2 concentration, with maximum stimulation seen at 5 microg ml(-1). The non-steroidal anti-inflammatory drug flurbiprofen (5 microM), in the presence of exogenous dmPGE2, inhibited the up-regulation of COX-2 mRNA and PC-3 cell growth. Taken together, these data suggest that PGE2 has a specific role in the maintenance of human cancer cell growth and that the activation of COX-2 expression depends primarily upon newly synthesized PGE2, perhaps resulting from changes in local cellular PGE2 concentrations.

  20. Brain-targeted angiotensin-converting enzyme 2 overexpression attenuates neurogenic hypertension by inhibiting cyclooxygenase-mediated inflammation.

    Science.gov (United States)

    Sriramula, Srinivas; Xia, Huijing; Xu, Ping; Lazartigues, Eric

    2015-03-01

    Overactivity of the renin-angiotensin system, oxidative stress, and cyclooxygenases (COX) in the brain are implicated in the pathogenesis of hypertension. We previously reported that angiotensin-converting enzyme 2 (ACE2) overexpression in the brain attenuates the development of deoxycorticosterone acetate-salt hypertension, a neurogenic hypertension model with enhanced brain renin-angiotensin system and sympathetic activity. To elucidate the mechanisms involved, we investigated whether oxidative stress, mitogen-activated protein kinase signaling and cyclooxygenase (COX) activation in the brain are modulated by ACE2 in neurogenic hypertension. Deoxycorticosterone acetate-salt hypertension significantly increased expression of Nox-2 (+61±5%), Nox-4 (+50±13%), and nitrotyrosine (+89±32%) and reduced activity of the antioxidant enzymes, catalase (-29±4%) and superoxide dismutase (-31±7%), indicating increased oxidative stress in the brain of nontransgenic mice. This increased oxidative stress was attenuated in transgenic mice overexpressing ACE2 in the brain. Deoxycorticosterone acetate-salt-induced reduction of neuronal nitric oxide synthase expression (-26±7%) and phosphorylated endothelial nitric oxide synthase/total endothelial nitric oxide synthase (-30±3%), and enhanced phosphorylation of protein kinase B and extracellular signal-regulated kinase 1/2 in the paraventricular nucleus, were reversed by ACE2 overexpression. In addition, ACE2 overexpression blunted the hypertension-mediated increase in gene and protein expression of COX-1 and COX-2 in the paraventricular nucleus. Furthermore, gene silencing of either COX-1 or COX-2 in the brain, reduced microglial activation and accompanied neuroinflammation, ultimately attenuating Deoxycorticosterone acetate-salt hypertension. Together, these data provide evidence that brain ACE2 overexpression reduces oxidative stress and COX-mediated neuroinflammation, improves antioxidant and nitric oxide signaling, and

  1. Acetylcholine produces contraction mediated by cyclooxigenase pathway in arterial vessels in the marine fish (Isacia conceptionis

    Directory of Open Access Journals (Sweden)

    FA. Moraga

    Full Text Available Preliminary studies showed that dorsal artery contraction mediated by acetylcholine (ACh is blocked with indomethacin in intertidal fish (G. laevifrons. Our objective was to characterize the cholinergic pathway in several artery vessels of the I. conceptionis. Afferent and efferent branchial, dorsal and mesenteric arteries were dissected of 6 juvenile specimens, isometric tension studies were done using doses response curves (DRC for Ach (10–13 to 10–3 M, and cholinergic pathways were obtained by blocking with atropine or indomethacin. CRC to ACh showed a pattern of high sensitivity only in efferente branchial artery and low sensibility in all vessels. Furthermore, these contractions were blocked in the presence of atropine and indomethacin in all vessels. Our results corroborate previous results observed in intertidal species that contraction induced by acetylcholine is mediated by receptors that activate a cyclooxygenase contraction pathway.

  2. Induction of cyclooxygenase-2 expression by prostaglandin E2 stimulation of the prostanoid EP4 receptor via coupling to Gαi and transactivation of the epidermal growth factor receptor in HCA-7 human colon cancer cells.

    Science.gov (United States)

    Yoshida, Kenji; Fujino, Hiromichi; Otake, Sho; Seira, Naofumi; Regan, John W; Murayama, Toshihiko

    2013-10-15

    Increased expressions of cyclooxygenase-2 (COX-2) and its downstream metabolite, prostaglandin E2 (PGE2), are well documented events in the development of colorectal cancer. Interestingly, PGE2 itself can induce the expression of COX-2 thereby creating the potential for positive feedback. Although evidence for such a positive feedback has been previously described, the specific E-type prostanoid (EP) receptor subtype that mediates this response, as well as the relevant signaling pathways, remain unclear. We now report that the PGE2 stimulated induction of COX-2 expression in human colon cancer HCA-7 cells is mediated by activation of the prostanoid EP4 receptor subtype and is followed by coupling of the receptor to Gαi and the activation of phosphatidylinositol 3-kinase. Subsequent activation of metalloproteinases releases membrane bound heparin-binding epidermal growth factor-like growth factor resulting in the transactivation of epidermal growth factor receptors and the activation of the extracellular signal-regulated kinases and induction of COX-2 expression. This induction of COX-2 expression by PGE2 stimulation of the prostanoid EP4 receptor may underlie the upregulation of COX-2 during colorectal cancer and appears to be an early event in the process of tumorigenesis. © 2013 Elsevier B.V. All rights reserved.

  3. Interaction between nitric oxide synthase and cyclooxygenase in the development of acetaminophen-induced hepatotoxicity

    Directory of Open Access Journals (Sweden)

    Meltem Kolgazi

    2015-03-01

    Results: AG and KET prevented the increase in liver malondialdehyde levels due to APAP toxicity. Decreased liver glutathione in APAP group was prevented by all treatments except NIM. Stimulated liver myeloperoxidase activity in APAP group was attenuated by all treatments except INDO and NIM. Elevation of liver chemiluminescence, nuclear factor (NF- and #61547;B expression and serum alanine transferase level due to APAP overdose were also suppressed by all treatments. Conclusions: NOS and COX pathways interact in the development of hepatotoxicity due to APAP overdose. [J Exp Integr Med 2015; 5(1.000: 16-22

  4. Safrole oxide induces human umbilical vein endothelial cell transdifferentiation to 5-hydroxytryptaminergic neuron-like cells through tropomyosin receptor kinase A/cyclooxygenase 2/nuclear factor-kappa B/interleukin 8 signaling.

    Science.gov (United States)

    Su, Le; Zhao, Jing; Zhao, Bao Xiang; Zhang, Shang Li; Miao, Jun Ying

    2011-10-01

    The phenomenon of endothelial-neural transdifferentiation has been observed for a long time, but the mechanism is not clear. We previously found that safrole oxide induced human umbilical vein endothelial cell transdifferentiation into neuron-like cells. In this study, we first validated that these cells induced by safrole oxide were functional 5-hydroxytryptaminergic neuron-like cells. Then, we performed microarray analysis of safrole oxide-treated and -untreated human umbilical vein endothelial cells. Safrole oxide elevated the levels of cyclooxygenase 2 (COX-2), interleukin-8 (IL-8) and reactive oxygen species (ROS), which was accompanied by nuclear factor-kappa B (NF-κB) nuclear translocation during the transdifferentiation. Blockade of tropomyosin receptor kinase A (TrkA) by an inhibitor or short hairpin RNA inhibited the levels of COX-2/IL-8 and the nuclear translocation of NF-κB but did not suppress the increased ROS level. As a result, cells underwent apoptosis. Therefore, via TrkA, safrole oxide may induce endothelial cell transdifferentiation into functional neuron-like cells. During this process, the increased levels of COX-2/IL-8 and the subsequent elevation of ROS production induced NF-κB nuclear translocation and IL-8 secretion. With the activity of TrkA inhibited, the inactive NF-κB regulated the ROS level in a negative feedback manner. Finally, the transdifferentiation pathway was blocked and cells became apoptotic. The TrkA/COX-2/IL-8 signal pathway may have an important role in endothelial-neural transdifferentiation, and safrole oxide may trigger this process by activating TrkA.

  5. Direct Lentiviral-Cyclooxygenase 2 Application to the Tendon-Bone Interface Promotes Osteointegration and Enhances Return of the Pull-Out Tensile Strength of the Tendon Graft in a Rat Model of Biceps Tenodesis: e98004

    National Research Council Canada - National Science Library

    Charles H Rundle; Shin-Tai Chen; Michael J Coen; Jon E Wergedal; Virginia Stiffel; Kin-Hing William Lau

    2014-01-01

      This study sought to determine if direct application of the lentiviral (LV)-cyclooxygenase 2 (COX2) vector to the tendon-bone interface would promote osteointegration of the tendon graft in a rat model of biceps tenodesis...

  6. Intrarenal dopamine attenuates deoxycorticosterone acetate/high salt-induced blood pressure elevation in part through activation of a medullary cyclooxygenase 2 pathway.

    Science.gov (United States)

    Yao, Bing; Harris, Raymond C; Zhang, Ming-Zhi

    2009-11-01

    Locally produced dopamine in the renal proximal tubule inhibits salt and fluid reabsorption, and a dysfunctional intrarenal dopaminergic system has been reported in essential hypertension and experimental hypertension models. Using catechol-O-methyl-transferase knockout (COMT(-/-)) mice, which have increased renal dopamine because of deletion of the major renal dopamine-metabolizing enzyme, we investigated the effect of intrarenal dopamine on the development of hypertension in the deoxycorticosterone acetate/high-salt (DOCA/HS) model. DOCA/HS led to significant increases in systolic blood pressure in wild-type mice (from 115+/-2 to 153+/-4 mm Hg), which was significantly attenuated in COMT(-/-) mice (from 114+/-2 to 135+/-3 mm Hg). In DOCA/HS COMT(-/-) mice, the D1-like receptor antagonist SCH-23390 increased systolic blood pressure (156+/-2 mm Hg). DOCA/HS COMT(-/-) mice also exhibited more urinary sodium excretion (COMT(-/-) versus wild-type: 3038+/-430 versus 659+/-102 micromol/L per 24 hours; Pdopamine stimulates medullary prostaglandin production. Renal medullary COX-2 expression and urinary prostaglandin E2 excretion were significantly higher in COMT(-/-) than in wild-type mice after DOCA/HS treatment. In DOCA/HS-treated COMT(-/-) mice, the COX-2 inhibitor SC-58236 reduced urinary sodium and prostaglandin E(2) excretion and increased systolic blood pressure (153+/-2 mm Hg). These studies indicate that an activated renal dopaminergic system attenuates the development of hypertension, at least in large part through activating medullary COX-2 expression/activity, and also decreases oxidative stress resulting from DOCA/HS.

  7. Overexpression of cyclooxygenase-2 in malignant peripheral nerve sheath tumor and selective cyclooxygenase-2 inhibitor-induced apoptosis by activating caspases in human malignant peripheral nerve sheath tumor cells.

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    Michiyuki Hakozaki

    Full Text Available BACKGROUND: Cyclooxygenase-2 (COX-2 is a key enzyme in the conversion of arachidonic acid to prostanoids, and its activation is associated with carcinogenesis as well as inflammation. The antitumor effect of selective COX-2 inhibitors has been noted in various malignancies. Malignant peripheral nerve sheath tumor (MPNST is a rare and aggressive soft tissue sarcoma for which effective treatments have not yet been established. The purpose of this study was to investigate a potential therapeutic role of COX-2 in MPNST. METHODS: We evaluated the expression of COX-2 in 44 cases of high-grade MPNST using immunohistochemical staining and compared the staining results with the characteristics and outcome of the patients. We also investigated the antitumor effect of etodolac, a selective COX-2 inhibitor, on MPNST cells in vitro using the MPNST cell line, FMS-1. RESULTS: Overexpression of COX-2 (≥50% positive cells was observed in 29 cases (65.9%, was significantly associated with a poor overall survival (P = 0.0495, and was considered an independent risk factor for a poor outcome by the results of both univariate and multivariate analysis. Etodolac induced apoptosis of FMS-1 cells through the activation of caspase-8, -9, and -3. Moreover, several caspase inhibitors significantly inhibited etodolac-induced apoptosis. CONCLUSIONS: Selective COX-2 inhibitors including etodolac had an antitumor effect on MPNST cells, and their use holds promise as a novel therapeutic strategy for patients with MPNST to improve their prognoses.

  8. Expression of cyclooxygenase-2 mRNA in drug-sensitive cell and drug-resistant strains of ovarian cancer cell lines

    Institute of Scientific and Technical Information of China (English)

    Xiaoyan Li; Zehua Wang

    2006-01-01

    Objective: To investigate the expression of cyclooxygenase-2 (COX-2) mRNA in drug-sensitive cell and drugresistant clones of ovarian cancer cell lines. Methods: RT-PCR and immunocytochemistry were used to investigate the expression of cyclooxygenase-2 in 3 clones drug-sensitive and 5 clones drug-resistant ovarian cancer cell. Results: Strong COX-2 mRNA expressions were detected in 3 clones of drug-sensitive cell and weak expressions were detected in 5 clones of drug-resistant cell. The protein expression of COX-2 in drug-sensitive cell was strongly positive reaction in immunocytochemistry stain and there was a weak positive reaction in 5clones of drug-resistant cell. Conclusion: The expression of COX-2 mRNA in drug-sensitive cell strains is much higher than that in drugresistant strains of ovarian cancer cell lines, providing a basis of the chemoprevention for ovarian cancer.

  9. Overexpression of Cyclooxygenase-2 in Noncancerous Liver Tissue Increases the Postoperative Recurrence of Hepatocellular Carcinoma in Patients with Hepatitis B Virus-Related Cirrhosis

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    Yi-Fu He

    2010-01-01

    Full Text Available BACKGROUND: Many previous studies have evaluated the histopathological features of tumours as risk factors for postoperative recurrence in hepatitis B virus (HBV-associated hepatocellular carcinoma (HCC. However, there have been few large studies investigating the relationship between cyclooxygenase-2 (COX-2 expression in non-cancerous regions of the liver and postoperative recurrence in the remnant liver, especially in HBV-related HCC.

  10. Citronellol and geraniol, components of rose oil, activate peroxisome proliferator-activated receptor α and γ and suppress cyclooxygenase-2 expression.

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    Katsukawa, Michiko; Nakata, Rieko; Koeji, Satomi; Hori, Kazuyuki; Takahashi, Saori; Inoue, Hiroyasu

    2011-01-01

    We evaluated the effects of rose oil on the peroxisome proliferator-activated receptor (PPAR) and cyclooxygenase-2 (COX-2). Citronellol and geraniol, the major components of rose oil, activated PPARα and γ, and suppressed LPS-induced COX-2 expression in cell culture assays, although the PPARγ-dependent suppression of COX-2 promoter activity was evident only with citronellol, indicating that citronellol and geraniol were the active components of rose oil.

  11. Identification of a cyclooxygenase gene from the red alga Gracilaria vermiculophylla and bioconversion of arachidonic acid to PGF(2α) in engineered Escherichia coli.

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    Kanamoto, Hirosuke; Takemura, Miho; Ohyama, Kanji

    2011-08-01

    Prostaglandins (PGs) are important local messenger molecules in many tissues and organs of animals including human. For applications in medicine and animal care, PGs are mostly purified from animal tissues or chemically synthesized. To generate a clean, reliable, and inexpensive source for PGs, we have now engineered expression of a suitable cyclooxygenase gene in Escherichia coli and achieved production levels of up to 2.7 mg l(-1) PGF(2α). The cyclooxygenase gene cloned from the red alga Gracilaria vermiculophylla appears to be fully functional without any eukaryotic modifications in E. coli. A crude extract of the recombinant E. coli cells is able to convert in vitro the substrate arachidonic acid (AA) to PGF(2α). Furthermore, these E. coli cells produced PGF(2α) in a medium supplemented with AA and secreted the PGF(2α) product. To our knowledge, this is the first report of the functional expression of a cyclooxygenase gene and concomitant production of PGF(2α) in E. coli. The successful microbial synthesis of PGs with reliable yields promises a novel pharmaceutical tool to produce PGF(2α) at significantly reduced prices and greater purity.

  12. Guggulsterone of Commiphora mukul resin reverses drug resistance in imatinib-resistant leukemic cells by inhibiting cyclooxygenase-2 and P-glycoprotein.

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    Xu, Hong-Bin; Xu, Lu-Zhong; Mao, Xia-Ping; Fu, Jun

    2014-06-15

    The purpose of this study was to investigate the effects of guggulsterone on cyclooxygenase-2 and P-glycoprotein mediated drug resistance in imatinib-resistant K562 cells (K562/IMA). MTT cytotoxicity assay, flow cytometry, western blot analysis, and ELISA were performed to investigate the anti-proliferative effect, the reversal action of drug resistance, and the inhibitory effect on cyclooxygenase-2, P-glycoprotein, BCR/ABL kinase, and PGE2 release in K562/IMA cells by guggulsterone. The results showed that co-administration of guggulsterone resulted in a significant increase in chemo-sensitivity of K562/IMA cells to imatinib, compared with imatinib treatment alone. Rhodamine123 accumulation in K562/IMA cells was significantly enhanced after incubation with guggulsterone (60, 120 μM), compared with untreated K562/IMA cells (pP-glycoprotein and prostaglandin E2. However, guggulsterone had little inhibitory effect on the activity of BCR/ABL kinase. The present study indicates guggulsterone induces apoptosis by inhibiting cyclooxygenase-2 and down-regulating P-glycoprotein expression in K562/IMA cells.

  13. Diallyl disulfide inhibits proliferation and transdifferentiation of lung fibroblasts through induction of cyclooxygenase and synthesis of prostaglandin E₂.

    Science.gov (United States)

    Wang, Yanhua; Cao, Rong; Wei, Bo; Chai, Xiaoyu; Sun, Dan; Guan, Y; Liu, Xin-min

    2014-08-01

    Platelet-derived growth factor-BB (PDGF-BB) and transforming growth factor-β1 (TGF-β1) are critically involved in idiopathic pulmonary fibrosis by inducing the proliferation and transdifferentiation of lung fibroblasts. In the present study, we examined the impact of diallyl disulfide (DADS), a garlic-derived compound, on such pathological conditions. DADS showed profound inhibitory effects on the PDGF-BB-induced proliferation of human and mouse lung fibroblasts. DADS also abrogated the TGF-β1-induced expression of α-smooth muscle actin, type I collagen and fibronectin. Following treatment with DADS, the expression of cyclooxygenase-2 (COX-2) and the synthesis of prostaglandin E₂ (PGE₂) were found to be markedly enhanced, which in turn led to elevated cAMP levels in lung fibroblasts. Notably, the effect of DADS was largely abolished in the presence of either COX inhibitor indomethacin or siRNA-targeting COX-2, or in the absence of the PGE₂ receptor EP2, supporting an essential role for the COX-2-PGE₂-cAMP autocrine loop. Furthermore, we demonstrated that the upregulated expression of COX-2 was a result of increased level of histone 3 acetylation at COX-2 locus in DADS-treated cells. Together, these results suggest that DADS, by inducing COX-2 expression, may have therapeutic potential in treating lung fibrosis.

  14. Expression of inducible nitric oxide synthase and cyclooxygenase-2 in pancreatic adenocarcinoma:Correlation with microvessel density

    Institute of Scientific and Technical Information of China (English)

    Hans U. Kasper; Hella Wolf; Uta Drebber; Helmut K. Wolf; Michael A. Kern

    2004-01-01

    AIM: Cyclooxygenases (COX) are key enzymes for conversion of arachidonic acid to prostaglandins. Nitric oxide synthase (NOS) is the enzyme responsible for formation of nitric oxide.Both have constitutive and inducible isoforms. The inducible isoforms (iNOS and COX-2) are of great interest as regulators of tumor angiogenesis, tumorigenesis and inflammatory processes. This study was to clarify their role in pancreatic adenocarcinomas.METHODS: We investigated the immunohistochemical iNOS and COX-2 expression in 40 pancreatic ducal adenocarcinomas of different grade and stage. The results were compared with microvessel density and clinicopathological data.RESULTS: Twenty-one (52.5%) of the cases showed iNOS expression, 15 (37.5%) of the cases were positive for COX-2.The immunoreaction was heterogeneously distributed within the tumors. Staining intensity was different between the tumors. No correlation between iNOS and COX-2 expression was seen. There was no relationship with microvessel density.However, iNOS positive tumors developed more often distant metastases and the more malignant tumors showed a higher COX-2 expression. There was no correlation with other clinicopathological data.CONCLUSION: Approximately half of the cases expressed iNOS and COX-2. These two enzymes do not seem to be the key step in angiogenesis or carcinogenesis of pancreatic adenocarcinomas. Due to a low prevalence of COX-2expression, chemoprevention of pancreatic carcinomas by COX-2 inhibitors can only achieve a limited success.

  15. Targeting the prostaglandin E2 EP1 receptor and cyclooxygenase-2 in the amygdala kindling model in mice.

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    Fischborn, Sarah Verena; Soerensen, Jonna; Potschka, Heidrun

    2010-09-01

    The prostaglandin E2 EP1 receptor as well as the inflammatory enzyme cyclooxygenase-2 have been suggested as targets for disease modulation, improvement of therapeutic response, and restoration of pharmacosensitivity in epilepsies. Translational development of respective add-on approaches requires careful analysis of putative effects on ictogenesis. Therefore we evaluated the impact of the EP1 receptor antagonist SC-51089, the EP1 receptor agonist misoprostol and the COX-2 inhibitors celecoxib and NS-398 in the mouse amygdala kindling model of temporal lobe epilepsy. Neither celecoxib nor NS-398 affected the generation, spread and termination of seizure activity. Whereas SC-51089 did not affect the seizure threshold, the highest dose (30mg/kg) significantly decreased the seizure severity when administered 60min before stimulation. Moreover, SC-51089 significantly prolonged seizure duration at the highest dose. The EP1 receptor agonist misoprostol exerted contrasting effects on seizure duration with a significant decrease in the duration of motor seizure activity. The data suggest that doses of COX-2 inhibitors and EP1 receptor antagonists which exert disease modulating or antiepileptic drug potentiating effects do not negatively affect seizure control in temporal lobe epilepsy. The contrasting impact of the EP1 receptor antagonist and agonist suggests that EP1 receptors can influence endogenous mechanisms involved in termination of seizure activity.

  16. Interactions of gallic acid, resveratrol, quercetin and aspirin at the platelet cyclooxygenase-1 level. Functional and modelling studies.

    Science.gov (United States)

    Crescente, Marilena; Jessen, Gisela; Momi, Stefania; Höltje, Hans-Dieter; Gresele, Paolo; Cerletti, Chiara; de Gaetano, Giovanni

    2009-08-01

    While resveratrol and quercetin possess antiplatelet activity, little is known on the effect of gallic acid on platelets. We studied the interactions of these three different polyphenols among themselves and with aspirin, at the level of platelet cyclooxygenase-1 (COX-1). Both functional (in vitro and in vivo) and molecular modelling approaches were used. All three polyphenols showed comparable antioxidant activity (arachidonic acid [AA]-induced intraplatelet ROS production); however, resveratrol and quercetin, but not gallic acid, inhibited AA-induced platelet aggregation. Gallic acid, similarly to salicylic acid, the major aspirin metabolite, prevented inhibition of AA-induced platelet function by aspirin but, at variance with salicylic acid, also prevented inhibition by the other two polyphenols. Molecular modelling studies, performed by in silico docking the polyphenols into the crystal structure of COX-1, suggested that all compounds form stable complexes into the COX-1 channel, with slightly different but functionally relevant interaction geometries. Experiments in mice showed that gallic acid administered before aspirin, resveratrol or quercetin fully prevented their inhibitory effect on serum TxB(2). Finally, a mixture of resveratrol, quercetin and gallic acid, at relative concentrations similar to those contained in most red wines, did not inhibit platelet aggregation, but potentiated sub-inhibitory concentrations of aspirin. Gallic acid interactions with other polyphenols or aspirin at the level of platelet COX-1 might partly explain the complex, and possibly contrasting, effects of wine and other components of the Mediterranean diet on platelets and on the pharmacologic effect of low-dose aspirin.

  17. Triptolide Inhibits Cyclooxygenase-2 and Inducible Nitric Oxide Synthase Expression in Human Colon Cancer and Leukemia Cells

    Institute of Scientific and Technical Information of China (English)

    Xiangmin TONG; Shui ZHENG; Jie JIN; Lifen ZHU; Yinjun LOU; Hangping YAO

    2007-01-01

    Triptolide (TP), a traditional Chinese medicine, has been reported to be effective in the treatment of autoimmune diseases and exerting antineoplastic activity in several human tumor cell lines. This study investigates the antitumor effect of TP in human colon cancer cells (SW114) and myelocytic leukemia (K562), and elucidates the possible molecular mechanism involved. SW114 and K562 cells were treated with different doses of TP (0, 5, 10, 20, or 50 ng/ml). The cell viability was assessed by 3-[4,5-dimethylthiazol2-yl]-2,5-diphenyltetrazolium bromide (MTT). Results demonstrated that TP inhibited the proliferation of both tumor cell lines in a dose-dependent manner. To further investigate its mechanisms, the products prostaglandin E2 (PGE2) and nitric oxide (NO) were measured by enzyme-linked immunosorbent assay (ELISA). Our data showed that TP strongly inhibited the production of NO and PGE2. Consistent with these results, the expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) was up-regulated both at the mRNA level and the protein expression level, as shown by real-time RT-PCR and Western blotting. These results indicated that the inhibition of the inflammatory factor COX-2 and iNOS activity could be involved in the antitumor mechanisms of TP.

  18. Quantitative assessment of the association of COX-2 (Cyclooxygenase-2 immunoexpression with prognosis in human osteosarcoma: a meta-analysis.

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    Zhe Wang

    Full Text Available BACKGROUND: Numerous studies examining the relationship between Cyclooxygenase-2 (COX-2 immunoexpression and clinical outcome in osteosarcoma patients have yielded inconclusive results. METHODS: We accordingly conducted a meta-analysis of 9 studies (442 patients that evaluated the correlation between COX-2 immunoexpression and clinical prognosis (death. Pooled odds ratios (OR and risk ratios (RR with 95% confidence intervals (95% CI were calculated using the random-effects or fixed-effects model. RESULTS: Meta-analysis showed no significant association between COX-2 positivity and age, gender, tumor location, histology, stage, metastasis or 90% necrosis. Conversely, COX-2 immunoexpression was associated with overall survival rate (RR=2.12; 95% CI: 1.10-3.74; P=0.009 and disease-free survival rate (RR=1.63; 95% CI: 1.17-2.28; P=0.004 at 2 years. Sensitivity analysis performed by omitting low quality studies showed that the pooled results were stable. CONCLUSIONS: COX-2 positivity was associated with a lower 2-year overall survival rate and disease-free survival rate. COX-2 expression change is an independent prognostic factor in patients with osteosarcoma.

  19. Interaction between cyclooxygenase-2 and insulin-like growth factor in breast cancer: A new field for prevention and treatment

    Science.gov (United States)

    TAROMARU, GIULIANA CÁSSIA MORRONE; DE OLIVEIRA, VILMAR MARQUES; SILVA, MARIA ANTONIETA LONGO GALVÃO; MONTOR, WAGNER RICARDO; BAGNOLI, FABIO; RINALDI, JOSÉ FRANCISCO; AOKI, TSUTOMU

    2011-01-01

    The objective of this study was to evaluate the correlation between cyclooxygenase-2 (COX-2) and markers of cell proliferation and apoptosis, including, Bcl-2, Bax, Ki-67 and the type I insulin-like growth factor (IGF) receptor (IGF1-R) in ductal carcinoma in situ (DCIS) and infiltrating ductal carcinoma (IDC), present in the same surgical specimen. A total of 110 cases were evaluated using tissue microarrays. Cases were classified in scores from 0 to 3 according to pre-defined methods. The results showed that the positivity rates were COX-2 in 87% of cases in DCIS and IDC; Bcl-2 in 55% of cases in DCIS and IDC; Bax in 23% of cases in IDC and 19% in DCIS, IGF-1 in 24% of cases in DCIS and IDC; and Ki-67 in 81% of cases in DCIS and IDC. We also observed a positive correlation between the expression of COX-2 and IGF1-R (p=0.045). Our results demonstrate a positive correlation between the expression of COX-2 and IGF1-R in DCIS and IDC, demonstrating that they are involved in breast cancer carcinogenesis. Further studies are required to prove the effectiveness of COX-2 and IGF1-R inhibitors for the prevention and treatment of breast cancer, as well as to explain their mechanism of action. PMID:22740976

  20. Constant expression of cyclooxygenase-2 gene in prostate and the lower urinary tract of estrogen-treated male rats.

    Science.gov (United States)

    Luo, C; Strauss, L; Ristimäki, A; Streng, T; Santti, R

    2001-01-01

    Expression of cyclooxygenase-2 (E. C. 1.14.99.1) in prostate and the lower urinary tract (LUT) of the neonatally estrogenized male rat has been studied by using a COX-2's PCR fragment of 724 nt spanning 3 introns and a 478nt internal standard for quantitative RT-PCR. The same fragment of 724 nt was used for RNA probe in Northern hybridization. Neonatal estrogenization (10 microg/day of diethylstilbestrol on days 1-5) had no effect on COX-2 expression in prostatic urethra, prostatic lobes, or bladder. Acute estrogen treatment of castrated animals did not induce COX-2 expression, either. In addition the differential expression of basal level of COX-2 in the different lobes of prostate in normal rat was demonstrated. Our results suggest a constant expression of COX-2 gene in prostate and the lower urinary tract of the neonatally estrogenized (neoDES) rats. The present study indicates that the increased expression of COX-2 is probably not essential for the estrogen-driven development of stromal inflammation or hyperplastic and dysplastic alterations in the prostate of neoDES rats.

  1. Effects of β-glucosidase hydrolyzed products of harpagide and harpagoside on cyclooxygenase-2 (COX-2) in vitro.

    Science.gov (United States)

    Zhang, Liuqiang; Feng, Li; Jia, Qi; Xu, Jinwen; Wang, Rui; Wang, Zhengtao; Wu, Yingchun; Li, Yiming

    2011-08-15

    Harpagide (1) and harpagoside (2) are two iridoid glycosides existing in many medicinal plants. Although they are believed to be the main bioactive compounds related to the anti-inflammatory efficacy of these plants, the mechanisms of their anti-inflammatory activities remain unclear. The results of our present study showed that 1 and 2 had no effects on inhibitions of cyclooxygenase (COX)-1/2 enzyme activity, tumor necrosis factor-α (TNF-α) release, and nitric oxide (NO) production in vitro. However, the hydrolyzed products of 1 and 2 with β-glucosidase treatment showed a significant inhibitory effect on COX-2 activity at 2.5-100 μM in a concentration-dependent manner. Our further study revealed that the hydrolyzed 2 product was structurally the same as the hydrolyzed 1 product (H-harpagide (3)). The structure of 3 was 2-(formylmethyl)-2,3,5-trihydroxy-5-methylcyclopentane carbaldehyde, with a backbone similar to prostaglandins and COX-2 inhibitors such as celecoxib. All of them have a pentatomic ring with two adjacent side chains. The result of molecular modeling and docking study showed that 3 could bind to the COX-2 active domain well through hydrophobic and hydrogen-bonding interactions, whereas 1 and 2 could not, implying that the hydrolysis of the glycosidic bond of 1 and 2 is a pre-requisite step for their COX-2 inhibitory activity.

  2. Isobolographic analysis of interaction between cyclooxygenase inhibitors and tramadol in acetic acid-induced writhing in mice.

    Science.gov (United States)

    Satyanarayana, Padi S V; Jain, Naveen K; Singh, Amarjit; Kulkarni, Shrinivas K

    2004-07-01

    Non-steroidal anti-inflammatory drugs (NSAIDs) and opioids are the most commonly used analgesics in the management of acute and chronic pain. Combined use of NSAIDs and opioids has been indicated for achieving better analgesia with reduced side effects. The present study was aimed at evaluating the combination of different NSAIDs, which inhibit cyclooxygenase (COX) enzymes and tramadol against acetic acid-induced writhing in mice. The expected beneficial effect of combination regimen was analyzed by isobolographic analysis. The oral and intrathecally administered tramadol, a mu-opioid and naproxen, a nonselective COX inhibitor produced dose-dependent antinociception, however, rofecoxib, a selective COX-2 inhibitor lacked analgesic efficacy in writhing test. Isobolographic analysis showed synergistic or supra-additive interactions for the combinations of naproxen and tramadol after oral and intrathecal administration. However, similar interaction was not observed when tramadol was combined with rofecoxib. Pretreatment with naloxone partially reversed the antinociceptive effect of tramadol per se and its combination with naproxen without modifying the per se effect of NSAID. The results demonstrated marked synergistic interaction between naproxen and tramadol and such interaction involved opioid as well as non-opioid mechanisms of tramadol and inhibition of COX-1 but not COX-2 by naproxen.

  3. Levuglandin forms adducts with histone h4 in a cyclooxygenase-2-dependent manner, altering its interaction with DNA.

    Science.gov (United States)

    Carrier, Erica J; Zagol-Ikapitte, Irene; Amarnath, Venkataraman; Boutaud, Olivier; Oates, John A

    2014-04-22

    Inflammation and subsequent cyclooxygenase-2 (COX-2) activity has long been linked with the development of cancer, although little is known about any epigenetic effects of COX-2. A product of COX-2 activation, levuglandin (LG) quickly forms covalent bonds with nearby primary amines, such as those in lysine, which leads to LG-protein adducts. Here, we demonstrate that COX-2 activity causes LG-histone adducts in cultured cells and liver tissue, detectable through LC-MS, with the highest incidence in histone H4. Adduction is blocked by a γ-ketoaldehyde scavenger, which has no effect on COX-2 activity as measured by PGE2 production. Formation of the LG-histone adduct is associated with an increased histone solubility in NaCl, indicating destabilization of the nucleosome structure; this is also reversed with scavenger treatment. These data demonstrate that COX-2 activity can cause histone adduction and loosening of the nucleosome complex, which could lead to altered transcription and contribute to carcinogenesis.

  4. Rebamipide induces the gastric mucosal protective factor, cyclooxygenase-2, via activation of 5'-AMP-activated protein kinase.

    Science.gov (United States)

    Lee, Sunyoung; Jeong, Seongkeun; Kim, Wooseong; Kim, Dohoon; Yang, Yejin; Yoon, Jeong-Hyun; Kim, Byung Joo; Min, Do Sik; Jung, Yunjin

    2017-01-29

    Rebamipide, an amino acid derivative of 2(1H)-quinolinone, has been used for mucosal protection, healing of gastroduodenal ulcers, and treatment of gastritis. Induction of cyclooxygenase (COX)-2, a gastric mucosal protective factor, by rebamipide has been suggested as the major mechanism of the drug action. However, how rebamipide induces COX-2 at the molecular level needs further investigation. In this study, the molecular mechanism underlying the induction of COX-2 by rebamipide was investigated. In gastric carcinoma cells and macrophage cells, rebamipide induced phosphorylation of AMP-activated protein kinase (AMPK), leading to phosphorylation of acetyl-CoA carboxylase (ACC), a substrate of AMPK. The induction of COX-2 by rebamipide was dependent on AMPK activation because compound C, an AMPK inhibitor, abolished COX-2 induction by rebamipide. In a mouse ulcer model, rebamipide protected against hydrochloric acid/ethanol-induced gastric ulcer, and these protective effects were deterred by co-administration of compound C. In parallel, in the gastric tissues, rebamipide increased the phosphorylation AMPK, whereas compound C reduced the levels of COX-2 and phosphorylated ACC, which were increased by rebamipide. Taken together, the activation of AMPK by rebamipide may be a molecular mechanism that contributes to induction of COX-2, probably resulting in protection against gastric ulcers. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Expression of Vascular Endothelial Growth Factor and Cyclooxygenase-2 in Laryngeal Squamous Cell Carcinoma and Its significance

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In order to study the expressions of vascular endothelial growth factor (VEGF) and cyclooxygenase-2 (COX-2) in human laryngeal squamous cell carcinoma (LSCC) and its significance,the expression of VEGF mRNA and COX-2 mRNA in 62 cases of LSCC and 54 adjacent noncancerous laryngeal tissues and 9 normal human laryngeal mucous tissues was detected by using techniques of semi-quantitative RT-PCR. It was found that the expression level of VEGF and COX-2 mRNA was significantly increased in LSCC as compared with that in the normal human laryngeal mucous tissues (both P<0.01), and the expression level of VEGF and COX-2 mRNA were significantly increased in stage Ⅲ + Ⅳ tissues of LSCC as compared with the stage Ⅰ + Ⅱ tissues of LSCC (P <0. 01). There was a high positive correlation between VEGF and COX-2 expression in LSCC (r=0. 756,P<0.01). These data raise the possibility that VEGF and COX-2 may play key roles in the growth, invasion and metastasis of LSCC.

  6. Cyclooxygenase-2-dependent phosphorylation of the pro-apoptotic protein Bad inhibits tonicity-induced apoptosis in renal medullary cells.

    Science.gov (United States)

    Küper, Christoph; Bartels, Helmut; Beck, Franz-X; Neuhofer, Wolfgang

    2011-11-01

    During antidiuresis, cell survival in the renal medulla requires cyclooxygenase-2 (COX-2) activity. We have recently found that prostaglandin E2 (PGE2) promotes cell survival by phosphorylation and, hence, inactivation of the pro-apoptotic protein Bad during hypertonic stress in Madin-Darby canine kidney (MDCK) cells in vitro. Here we determine the role of COX-2-derived PGE(2) on phosphorylation of Bad and medullary apoptosis in vivo using COX-2-deficient mice. Both wild-type and COX-2-knockout mice constitutively expressed Bad in tubular epithelial cells of the renal medulla. Dehydration caused a robust increase in papillary COX-2 expression, PGE2 excretion, and Bad phosphorylation in wild-type, but not in the knockout mice. The abundance of cleaved caspase-3, a marker of apoptosis, was significantly higher in papillary homogenates, especially in tubular epithelial cells of the knockout mice. Knockdown of Bad in MDCK cells decreased tonicity-induced caspase-3 activation. Furthermore, the addition of PGE2 to cells with knockdown of Bad had no effect on caspase-3 activation; however, PGE2 caused phosphorylation of Bad and substantially improved cell survival in mock-transfected cells. Thus, tonicity-induced COX-2 expression and PGE2 synthesis in the renal medulla entails phosphorylation and inactivation of the pro-apoptotic protein Bad, thereby counteracting apoptosis in renal medullary epithelial cells.

  7. Increased cyclooxygenase-2 and thromboxane synthase expression is implicated in diosgenin-induced megakaryocytic differentiation in human erythroleukemia cells.

    Science.gov (United States)

    Cailleteau, C; Liagre, B; Battu, S; Jayat-Vignoles, C; Beneytout, J L

    2008-09-01

    Differentiation induction as a therapeutic strategy has, so far, the greatest impact in hematopoietic malignancies, most notably leukemia. Diosgenin is a very interesting natural product because, depending on the specific dose used, its biological effect is very different in HEL (human erythroleukemia) cells. For example, at 10 microM, diosgenin induced megakaryocytic differentiation, in contrast to 40 microM diosgenin, which induced apoptosis in HEL cells previously demonstrated using sedimentation field-flow fractionation (SdFFF). The goal of this work focused on the correlation between cyclooxygenase-2 (COX-2) and thromboxane synthase (TxS) and megakaryocytic differentiation induced by diosgenin in HEL cells. Furthermore, the technique of SdFFF, having been validated in our models, was used in this new study as an analytical tool that provided us with more or less enriched differentiated cell fractions that could then be used for further analyses of enzyme protein expression and activity for the first time. In our study, we showed the implication of COX-2 and TxS in diosgenin-induced megakaryocytic differentiation in HEL cells. Furthermore, we showed that the analytical technique of SdFFF may be used as a tool to confirm our results as a function of the degree of cell differentiation.

  8. Inhibition of cyclo-oxygenase 2 reduces tumor metastasis and inflammatory signaling during blockade of vascular endothelial growth factor

    Directory of Open Access Journals (Sweden)

    Fisher Jason C

    2011-10-01

    Full Text Available Abstract Vascular endothelial growth factor (VEGF blockade is an effective therapy for human cancer, yet virtually all neoplasms resume primary tumor growth or metastasize during therapy. Mechanisms of progression have been proposed to include genes that control vascular remodeling and are elicited by hypoperfusion, such as the inducible enzyme cyclooxygenase-2 (COX-2. We have previously shown that COX-2 inhibition by the celecoxib analog SC236 attenuates perivascular stromal cell recruitment and tumor growth. We therefore examined the effect of combined SC236 and VEGF blockade, using the metastasizing orthotopic SKNEP1 model of pediatric cancer. Combined treatment perturbed tumor vessel remodeling and macrophage recruitment, but did not further limit primary tumor growth as compared to VEGF blockade alone. However, combining SC236 and VEGF inhibition significantly reduced the incidence of lung metastasis, suggesting a distinct effect on prometastatic mechanisms. We found that SC236 limited tumor cell viability and migration in vitro, with effects enhanced by hypoxia, but did not change tumor proliferation or matrix metalloproteinase expression in vivo. Gene set expression analysis (GSEA indicated that the addition of SC236 to VEGF inhibition significantly reduced expression of gene sets linked to macrophage mobilization. Perivascular recruitment of macrophages induced by VEGF blockade was disrupted in tumors treated with combined VEGF- and COX-2-inhibition. Collectively, these findings suggest that during VEGF blockade COX-2 may restrict metastasis by limiting both prometastatic behaviors in individual tumor cells and mobilization of macrophages to the tumor vasculature.

  9. Role of cyclooxygenase-2 in the carcinogenesis of gastrointestinal tract cancers: A review and report of personal experience

    Institute of Scientific and Technical Information of China (English)

    Takashi Fujimura; Tetsuo Ohta; Katsunobu Oyama; Tomoharu Miyashita; Koichi Miwa

    2006-01-01

    Selective cyclooxygenase (COX)-2 inhibitors (coxibs)were developed as one of the anti-inflammatory drugs to avoid the various side effects of non-steroidal anti-inflammatory drugs (NSAIDs). However, coxibs also have an ability to inhibit tumor development of various kinds the same way that NSAIDs do. Many experimental studies using cell lines and animal models demonstrated an ability to prevent tumor proliferation of COX-2 inhibitors. After performing a randomized study for polyp chemoprevention study in patients with familial adenomatous polyposis (FAP),which showed that the treatment with celecoxib,one of the coxibs, significantly reduced the number of colorectal polyps in 2000, the U.S. Food and Drug Administration (FDA) immediately approved the clinicai use of celecoxib for FAP patients. However, some coxibs were recently reported to increase the risk of serious cardiovascular events including heart attack and stroke. In this article we review a role of COX-2in carcinogenesis of gastrointestinal tract, such as the esophagus, stomach and colorectum, and also analyze the prospect of coxibs for chemoprevention of gastrointestinal tract tumors.

  10. Cyclooxygenase 2 in Gastric Carcinoma Is Expressed in Doublecortin- and CaM Kinase-Like-1-Positive Tuft Cells

    Science.gov (United States)

    Mutoh, Hiroyuki; Sashikawa, Miho; Sakamoto, Hirotsugu; Tateno, Tomoko

    2014-01-01

    Background/Aims Doublecortin and CaM kinase-like-1 (DCAMKL1) is a marker of stem cells expressed predominantly in the crypt base in the intestine. However, DCAMKL1-positive cells have been shown to be differentiated tuft cells rather than quiescent progenitors. Tuft cells are the only epithelial cells that express cyclooxygenase 2 (COX-2) in the normal intestinal epithelium. We previously generated Cdx2-transgenic mice as model mice for intestinal metaplasia and gastric carcinoma. In the current study, we investigated the association between COX-2 and DCAMKL1 in gastric carcinoma. Methods We examined the association between COX-2 and DCAMKL1 expression in gastric carcinomas in clinical samples (early gastric well-differentiated adenocarcinoma) and Cdx2-transgenic mice; and the DCAMKL1-transgenic mouse stomach using immunohistochemistry and quantitative real-time polymerase chain reaction. Results The COX-2-expressing cells were scattered, not diffusely expressed, in gastric carcinomas from humans and Cdx2-transgenic mice. DCAMKL1-positive cells were also scattered in the gastric carcinomas, indicating that tuft cells could still be present in gastric carcinoma. COX-2 was expressed in DCAMKL1-positive tuft cells in Cdx2- and DCAMKL1-transgenic mouse stomachs, whereas the Sox9 transcription factor was ubiquitously expressed in gastric carcinomas, including COX-2-positive cells. Conclusions COX-2 is expressed in DCAMKL1-expressing quiescent tuft cells in gastric carcinoma. PMID:25228975

  11. Involvement of eicosanoids in the pathogenesis of pancreatic cancer: the roles of cyclooxygenase-2 and 5-lipoxygenase.

    Science.gov (United States)

    Knab, Lawrence M; Grippo, Paul J; Bentrem, David J

    2014-08-21

    The interplay between inflammation and cancer progression is a growing area of research. A combination of clinical, epidemiological, and basic science investigations indicate that there is a relationship between inflammatory changes in the pancreas and neoplastic progression. Diets high in ω-6 polyunsaturated fatty acids provide increased substrate for arachidonic acid metabolism by cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX) to form eicosanoids. These eicosanoids directly contribute to pancreatic cancer cell proliferation. Both COX-2 and 5-LOX are upregulated in multiple cancer types, including pancreatic cancer. In vitro studies using pancreatic cancer cell lines have demonstrated upregulation of COX-2 and 5-LOX at both the mRNA and protein levels. When COX-2 and 5-LOX are blocked via a variety of mechanisms, cancer cell proliferation is abrogated both in vitro and in vivo. The mechanism of COX-2 has been shown to include effects on apoptosis as well as angiogenesis. 5-LOX has been implicated in apoptosis. The use of COX-2 and 5-LOX inhibitors in clinical studies in patients with pancreatic cancer has been limited. Patient enrollment has been restricted to those with advanced disease which makes evaluation of these drugs as chemopreventive agents difficult. COX-2 and 5-LOX expression have been shown to be present during the early neoplastic changes of pancreatic cancer, well before progression to invasive disease. This indicates that the ideal role for these interventions is early in the disease process as preventive agents, perhaps in patients with chronic pancreatitis or hereditary pancreatitis.

  12. Prostaglandin cyclooxygenase products but not thromboxane A2 are involved in the pathogenesis of ewthromelalgia in thrombocythaemia

    Directory of Open Access Journals (Sweden)

    J. J. Michiels

    1993-01-01

    Full Text Available Fluid of artificial blisters from erythromelalgic skin areas in primary thrombocythaemia contained a high amount of prostaglandin-E-like activity. Dazoxiben did not alleviate the erythromelalgia in patients with primary thrombocythaemia despite complete inhibition of platelet malondialdehyde and thromboxane B2 synthesis and no inhibition of prostaglandin-E-like material. During a 10-day dazoxiben treatment period, persistent erythromelalgia was associated with a significant shortened mean platelet life span of 3.2 days. During subsequent treatment with low dose acetylsalicylic acid daily complete relief of erythromelalgia was associated with inhibition of platelet prostaglandin endoperoxide production and correction of platelet mean life span to normal, 7.9 days. These observations indicate that prostaglandin E2, or another prostaglandin endoperoxide metabolite, is involved in the pathogenesisof erythromelalgia. The presented study does not give one single clue as to the origin (platelet, vessel wall or other of the prostanoid, but very likely originates from platelets because a very low dose of acetylsalicylic acid (250 to 500 mg every other day, which irreversibly inhibits platelet cyclooxygenase, is highly effective in the prevention of erythromelalgia in thrombocythaemia.

  13. Nuclear factor κB and cyclooxygenase-2 immunoexpression in oral dysplasia and oral squamous cell carcinoma.

    Science.gov (United States)

    Pontes, Hélder Antônio Rebelo; Pontes, Flávia Sirotheau Corrêa; Fonseca, Felipe Paiva; de Carvalho, Pedro Luiz; Pereira, Erika Martins; de Abreu, Michelle Carvalho; de Freitas Silva, Brunno Santos; dos Santos Pinto, Décio

    2013-02-01

    Oral leukoplakia is the main potentially malignant oral lesion, and oral squamous cell carcinoma accounts for more than 95% of all malignant neoplasms in the oral cavity. Therefore, the aim of this study was to verify the immunoexpression of nuclear factor κB (NF-κB) and cyclooxygenase-2 (COX-2) proteins in dysplastic oral lesions and oral squamous cell carcinoma. Immunohistochemical reactions were performed on 6 inflammatory fibrous hyperplasia, 28 oral leukoplakia, and 15 oral squamous cell carcinoma paraffin-embedded samples. Immunoperoxidase reaction for NF-κB and COX-2 was applied on the specimens, and the positivity of the reactions was calculated for 1000 epithelial cells. Using the analysis of variance and the Tukey post hoc statistical analyses, a significantly increased immunoexpression for NF-κB was observed when oral squamous cell carcinoma samples were compared with the other groups studied. However, using the Kruskal-Wallis and the Dunn post hoc tests, a statistically significant result for COX-2 expression was obtained only when the moderate dysplasia group was compared with the inflammatory fibrous hyperplasia group. Nuclear factor κB may participate in the malignant phenotype acquisition process of the oral squamous cell carcinoma in its late stages, whereas COX-2 may be involved in the early stages of oral carcinogenesis process.

  14. Effect of diclofenac on cyclooxygenase-2 levels and early breaking strength of experimental colonic anastomoses and skin incisions

    DEFF Research Database (Denmark)

    Klein, M; Krarup, P-M; Ågren, M S

    2011-01-01

    of diclofenac 4 mg/kg/day on the cyclooxygenase-2 (COX-2) enzyme in the anastomotic tissue and on the breaking strength of anastomotic and incisional wounds. The operation was performed with colonic resection and hand-sewn anastomosis. After 3 days, the rats were sacrificed and the breaking strength and the COX......-2 content of the anastomosis were measured. Results: There was a significantly reduced level of COX-2 in the rats treated with diclofenac (p = 0.001); no significant differences in any of the breaking strength measurements and no significant correlation between COX-2 levels and breaking strength...... of the anastomotic or incisional wounds could be found (p = 0.073 and p = 0.727). Conclusion: This study for the first time showed that a diclofenac dose of 4 mg/kg/24 h was sufficient to reduce the level of COX-2 enzymes in the anastomotic tissue in rats. This inhibition of the inflammatory response did not lead...

  15. Prolactin (PRL) induction of cyclooxygenase 2 (COX2) expression and prostaglandin (PG) production in hamster Leydig cells.

    Science.gov (United States)

    Matzkin, María Eugenia; Ambao, Verónica; Carino, Mónica Herminia; Rossi, Soledad Paola; González, Lorena; Turyn, Daniel; Campo, Stella; Calandra, Ricardo Saúl; Frungieri, Mónica Beatriz

    2012-01-02

    Serum prolactin (PRL) variations play a crucial role in the photoperiodic-induced testicular regression-recrudescence transition in hamsters. We have previously shown that cyclooxygenase 2 (COX2), a key enzyme in the biosynthesis of prostaglandins (PGs), is expressed mostly in Leydig cells of reproductively active hamsters with considerable circulating and pituitary levels of PRL. In this study, we describe a stimulatory effect of PRL on COX2/PGs in hamster Leydig cells, which is mediated by IL-1β and prevented by P38-MAPK and JAK2 inhibitors. Furthermore, by preparative isoelectric focusing (IEF), we isolated PRL charge analogues from pituitaries of active [isoelectric points (pI): 5.16, 4.61, and 4.34] and regressed (pI: 5.44) hamsters. More acidic PRL charge analogues strongly induced COX2 expression, while less acidic ones had no effect. Our studies suggest that PRL induces COX2/PGs in hamster Leydig cells through IL-1β and activation of P38-MAPK and JAK2. PRL microheterogeneity detected in active/inactive hamsters may be responsible for the photoperiodic variations of COX2 expression in Leydig cells.

  16. Prostaglandins in human semen during fish oil ingestion: evidence for in vivo cyclooxygenase inhibition and appearance of novel trienoic compounds.

    Science.gov (United States)

    Knapp, H R

    1990-04-01

    Marine oils may offer cardiovascular benefits, but inhibition of prostaglandin E and prostaglandin F synthesis by fish oil has been found in animal studies, and such effects could alter physiological responses in man to a clinically significant degree. Since greater amounts of E and F-type prostaglandins are made in human seminal vesicles than in the rest of the body combined, the influence of n-3 supplements upon semen prostaglandins was assessed in 10 subjects before and after one month of taking 50 ml menhaden oil daily. Prostaglandins E1, E2 and their 19-hydroxy derivatives were measured by HPLC-UV as PGB's, and prostaglandin E3, 19-OH PGE3, and analogous PGF's by gas chromatography/mass spectrometry. Fish oil ingestion reduced concentrations of one- and two series prostaglandins (mean reduction in PGE's = 37%, in PGF's = 20%, p less than 0.05), while more than doubling the low amounts of PGE3 and PGF3 alpha, and their previously undescribed 19-hydroxy derivatives. Semen phospholipids were enriched in eicosapentaenoic acid after dietary fish oil, but sperm counts and motility were not altered during the study. Since dietary fish oil reduces prostaglandin concentration in semen, clinical trials of n-3 fatty acids should also evaluate other possible results of in vivo cyclooxygenase inhibition.

  17. Dietary Protein Source and Cyclooxygenase-Inhibition Influence Development of Diet-Induced Obesity, Glucose Homeostasis and Brown Adipose Tissue

    DEFF Research Database (Denmark)

    Aune, Ulrike Liisberg

    The prevalence of obesity and associated diseases, such as Type 2 diabetes, cardiovascular disease and non-alcoholic fatty liver disease, are accelerating worldwide and require urgent attention. Many of the obesity-related morbidities are likely to originate from a state of chronic low-grade infl......The prevalence of obesity and associated diseases, such as Type 2 diabetes, cardiovascular disease and non-alcoholic fatty liver disease, are accelerating worldwide and require urgent attention. Many of the obesity-related morbidities are likely to originate from a state of chronic low......-grade inflammation accompanying the increasing adipose mass. In order to investigate the relationship between obesity, inflammation and insulin resistance, we ran an experiment feeding mice a high fat/high sucrose diet supplemented with the antiinflammatory cyclooxygenase-inhibitor, indomethacin. We saw...... of endogenous n-3 PUFAs present in phospholipid fractions of the cod fillets was reflected in the red-blood cells and the livers of the mice. This subsequently caused an altered endocannabinoid tone in the mice. In addition to amino acids, changing protein sources also alters fat, which may affect the consumer...

  18. The Expression of Cyclooxygenase-2 in Cervical Cancers and Hela Cells Was Regulated by Estrogen/Progestogen

    Institute of Scientific and Technical Information of China (English)

    LI Yunguang; PU Demin; LI Yanli

    2007-01-01

    To investigate the relationship between the expression of cyclooxygenase-2 (COX-2) and menstrual cycle, the regulatory effects of 17-β-estradiol (E2) and medroxyprogesterone acetate (MPA) on the expression of COX-2 in cervical cancer Hela cells were examined. Cervical cancer specimens were obtained from 47 pre-menopausal patients. The phase of menstrual cycle was determined by case history and HE staining of uterine endometrium. COX-2 was immunohistochemically stained by SABC staining and the staining intensity was determined with computerized image analysis system.Hela cells were incubated with alcohol, E2, E2+MPA, MPA for 12, 24 and 48 h respectively. The expression of COX-2 in Hela cells was detected by Western blotting and reverse transcriptase-polymerase chain reaction (RT-PCR). Our results showed that the expression of COX-2 was significantly higher during proliferative phase than secretory phase (P<0.05), but there was no difference in the positive rate between proliferative phase and secretory phase (P>0.05). Incubation with E2 could significantly enhance the expression of COX-2 continually. On the contrary, E2+MPA and MPA alone could decrease the expression of COX-2 as compared with the control and E2 group (P<0.05 and P<0.01 respectively). It is concluded that the expression of COX-2 in cervical cancer of pre-menopausal patients and Hela cells was regulated by estrogen/progestogen.

  19. Ischemic preconditioning inhibits development of edematous cerulein-induced pancreatitis: Involvement of cyclooxygenases and heat shock protein 70

    Science.gov (United States)

    Warzecha, Zygmunt; Dembinski, Artur; Ceranowicz, Piotr; Konturek, Stanislaw J; Dembinski, Marcin; Pawlik, Wieslaw W; Tomaszewska, Romana; Stachura, Jerzy; Kusnierz-Cabala, Beata; Naskalski, Jerzy W; Konturek, Peter C

    2005-01-01

    AIM: To determine whether ischemic preconditioning (IP) affects the development of edematous cerulein-induced pancreatitis and to assess the role of cyclooxygenase-1 (COX-1), COX-2, and heat shock protein 70 (HSP 70) in this process. METHODS: In male Wistar rats, IP was performed by clamping of celiac artery (twice for 5 min at 5-min intervals). Thirty minutes after IP or sham operation, acute pancreatitis was induced by cerulein. Activity of COX-1 or COX-2 was inhibited by resveratrol or rofecoxib, respectively (10 mg/kg). RESULTS: IP significantly reduced pancreatic damage in cerulein-induced pancreatitis as demonstrated by the improvement of pancreas histology, reduction in serum lipase and poly-C ribonuclease activity, and serum concentration of pro-inflammatory interleukin (IL)-1β. Also, IP attenuated the pancreatitis-evoked fall in pancreatic blood flow and pancreatic DNA synthesis. Serum level of anti-inflammatory IL-10 was not affected by IP. Cerulein-induced pancreatitis and IP increased the content of HSP 70 in the pancreas. Maximal increase in HSP 70 was observed when IP was combined with cerulein-induced pancreatitis. Inhibition of COXs, especially COX-2, reduced the protective effect of IP in edematous pancreatitis. CONCLUSION: Our results indicate that IP reduces pancreatic damage in cerulein-induced pancreatitis and this effect, at least in part, depends on the activity of COXs and pancreatic production of HSP 70. PMID:16273606

  20. Ischemic preconditioning inhibits development of edematous cerulein-induced pancreatitis: Involvement of cyclooxygenases and heat shock protein 70

    Institute of Scientific and Technical Information of China (English)

    Zygmunt Warzecha; Jerzy W Naskalski; Peter C Konturek; Artur Dembinski; Piotr Ceranowicz; Stanislaw J Konturek; Marcin Dembinski; Wieslaw W Pawlik; Romana Tomaszewska; Jerzy Stachura; Beata Kusnierz-Cabala

    2005-01-01

    AIM: To determine whether ischemic preconditioning (IP)affects the development of edematous cerulein-induced pancreatitis and to assess the role of cyclooxygenase-1 (COX-1), COX-2, and heat shock protein 70 (HSP 70) in this process.METHODS: In male Wistar rats, IP was performed by damping of celiac artery (twice for 5 min at 5-min intervals).Thirty minutes after IP or sham operation, acute pancreatitis was induced by cerulein. Activity of COX-1 or COX-2 was inhibited by resveratrol or rofecoxib, respectively (10 mg/kg).RESULTS: IP significantly reduced pancreatic damage in cerulein-induced pancreatitis as demonstrated by the improvement of pancreas histology, reduction in serum lipase and poly-C ribonuclease activity, and serum concentration of pro-inflammatory interleukin (IL)-1β.Also, IP attenuated the pancreatitis-evoked fall in pancreatic blood flow and pancreatic DNA synthesis.Serum level of anti-inflammatory IL-10 was not affected by IP. Cerulein-induced pancreatitis and IP increased the content of HSP 70 in the pancreas. Maximal increase in HSP 70 was observed when IP was combined with cerulein-induced pancreatitis. Inhibition of COXs, especially COX-2, reduced the protective effect of IP in edematous pancreatitis.CONCLUSION: Our results indicate that IP reduces pancreatic damage in cerulein-induced pancreatitis and this effect, at least in part, depends on the activity of COXs and pancreatic production of HSP 70.

  1. Additive antithrombotic effect of ASP6537, a selective cyclooxygenase (COX)-1 inhibitor, in combination with clopidogrel in guinea pigs.

    Science.gov (United States)

    Sakata, Chinatsu; Suzuki, Ken-Ichi; Morita, Yoshiaki; Kawasaki, Tomihisa

    2017-03-05

    Clopidogrel (Plavix(®), Sanofi-Aventis), the adenosine diphosphate P2Y12 receptor antagonist, is reported to be effective in the prevention of cardiovascular events and is often used in combination with aspirin, particularly in high-risk patients. ASP6537 is a reversible cyclooxygenase (COX)-1 inhibitor that is under investigation as an anti-platelet agent. First, we investigated the reversibility of the antiplatelet effect of ASP6537 and its interaction with ibuprofen to compare the usability of ASP6537 with that of aspirin. We then evaluated the antithrombotic effect of ASP6537 in combination with clopidogrel using a FeCl3-induced thrombosis model in guinea pigs. ASP6537 exerted reversible antiplatelet activity, and no pharmacodynamic interaction with ibuprofen was noted. When administered as monotherapy, ASP6537 exerted a significant antithrombotic effect at ≥3mg/kg, while aspirin inhibited thrombosis at 100mg/kg. ASP6537 exerted significant additive effects in combination with clopidogrel, and the minimum antithrombotic dose was reduced by concomitant administration of clopidogrel. Our study showed that ASP6537 did not interact with ibuprofen and has clear additive effects in combination with clopidogrel. ASP6537 may therefore represent a promising antiplatelet agent for use in clinical settings in combination with clopidogrel.

  2. CYCLO-OXYGENASE 2 IS PRESENT IN THE MAJORITY OF LESIONAL SKIN FROM PATIENTS WITH AUTOINMUNE BLISTERING DISEASES

    Directory of Open Access Journals (Sweden)

    Ana Maria Abreu Velez

    2013-10-01

    Full Text Available Introduction: The in situ immune response within skin biopsies from patients affected by autoimmune skin blistering diseases (ABDs is not well characterized. Aim: Based on the fact that the ABD immune response is considered an adaptive immune response, both an innate immune response and inflammation would be expected in these diseases. Our investigation investigates the presence of cyclo-oxygenase-2 (COX-2, since this enzyme is commonly involved in innate immune responses. Methods: We utilized immunohistochemistry (IHC to evaluate the presence of COX-2 in lesional skin biopsies of patients affected by ABDs. We tested 30 patients with endemic pemphigus foliaceus (EPF, 15 controls from the endemic area, and 15 biopsies from healthy controls from the USA. We also tested archival biopsies from patients with selected ABDs, including 20 patients with bullous pemphigoid, 20 with pemphigus vulgaris, 8 with pemphigus foliaceus and 12 with dermatitis herpetiformis. Results: Most ABD biopsies stained positive for COX-2 in the lesional blister and/or the dermal inflammatory infiltrate, accentuated in the upper neurovascular plexus. In BP and EPF, the COX-2 staining was also seen in the sweat glands. All controls were negative. Conclusions: We document that COX-2 is expressed in lesional skin of patients with ABDs.

  3. Amygdalin suppresses lipopolysaccharide-induced expressions of cyclooxygenase-2 and inducible nitric oxide synthase in mouse BV2 microglial cells.

    Science.gov (United States)

    Yang, Hye-Young; Chang, Hyun-Kyung; Lee, Jin-Woo; Kim, Young-Sick; Kim, Hong; Lee, Myoung-Hwa; Shin, Mal-Soon; Ham, Dae-Hyun; Park, Hun-Kuk; Lee, Hyejung; Kim, Chang-Ju

    2007-01-01

    Amygdalin (D-mandelonitrile-beta-D-gentiobioside) is a cynogenic compound found in sweet and bitter almonds, Persicae semen and Armeniacae semen. Amygdalin has been used for the treatment of cancers and for the relief of the pain. We made an aqueous extraction of amygdalin from Armeniacae semen. In this study, the effect of amygdalin on the lipopolysaccharide (LPS)-induced inflammation was investigated. The effects of amygdalin extracted from Armeniacae semen on the LPS-stimulated mRNA expressions of cyclooxygenase (COX)-1, COX-2 and inducible nitric oxide synthase (iNOS) in the mouse BV2 microglial cells were investigated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, reverse transcription-polymerase chain reaction (RT-PCR). The effects of amygdalin on the prostaglandins E(2) synthesis and the nitric oxide production were also studied by performing prostaglandins E(2) immunoassay and by detecting nitric oxide. The present results showed that amygdalin suppressed the prostaglandin E(2) synthesis and the nitric oxide production by inhibiting the LPS-stimulated mRNA expressions of COX-2 and iNOS in the mouse BV2 cells. These results show that amygdalin exerts anti-inflammatory and analgesic effects and it dose so probably by suppressing the mRNA expressions of COX-2 and iNOS.

  4. Function of DNA methyltransferase 3a in lead (Pb(2+) )-Induced Cyclooxygenase-2 gene.

    Science.gov (United States)

    Tsai, Yao-Ting; Chang, Che-Mai; Wang, Jaw-Yuan; Hou, Ming-Feng; Wang, Ju-Ming; Shiurba, Robert; Chang, Wen-Chang; Chang, Wei-Chiao

    2015-09-01

    Lead ions (Pb(2+) ) are toxic industrial pollutants associated with chronic inflammatory diseases in humans and animals. Previously, we found that Pb(2+) ions induce COX-2 gene expression via the EGF receptor/nuclear factor-κB signal transduction pathway in epidermoid carcinoma cell line A431. In this study, to see whether Pb(2+) ions affect COX-2 expression by epigenetic mechanisms, we looked at the mRNAs of DNA methyltransferases (DNMTs) using real-time PCR of total RNA from these cells. Cells exposed to Pb(2+) had low levels of DNMT3a mRNA, whereas the levels of DNMT1 and DNMT3b mRNAs remained unchanged. Pretreatment of cells with DNMT inhibitor 5-aza-2'-deoxycytidine (5 μM) followed by Pb(2+) (1 μM) significantly increased levels of COX-2 mRNA compared with cells treated with Pb(2+) alone. Overexpression of tumor suppressor gene Rb correlated with an increase in COX-2 mRNA and a decrease in DNMT3a mRNA. Conversely, overexpression of transcription factor E2F1 correlated with a decrease in COX-2 mRNA and an increase in DMNT3a mRNA. Pretreatment with EGFR inhibitors AG1478 and PD153035 significantly limited Pb(2+) -induced reduction in DNMT3a mRNA. In addition, gene knockdown of DNMT3a with short hairpin RNA correlated with increased COX-2 mRNA induced by Pb(2+) . Our findings suggest Pb(2+) ions induce COX-2 expression indirectly by reducing DNMT3a methylation of the COX-2 promoter via transcription factors Rb and E2F1. © 2014 Wiley Periodicals, Inc.

  5. Extract from Nandina domestica inhibits lipopolysaccharide-induced cyclooxygenase-2 expression in human pulmonary epithelial A549 cells.

    Science.gov (United States)

    Ueki, Takuro; Akaishi, Tatsuhiro; Okumura, Hidenobu; Abe, Kazuho

    2012-01-01

    Extract from fruits of Nandina domestica THUNBERG (NDE) has been used to improve cough and breathing difficulty in Japan for many years. To explore whether NDE may alleviate respiratory inflammation, we investigated its effect on expression of cyclooxygenase-2 (COX-2) and production of prostaglandin E₂ (PGE₂) in human pulmonary epithelial A549 cells in culture. Treatment with lipopolysaccharide (LPS; 6 µg/mL) resulted in an increase of COX-2 expression and PGE₂ production in A549 cells. Both the LPS-induced COX-2 expression and PGE₂ production were significantly inhibited by NDE (1-10 µg/mL) in a concentration-dependent manner. NDE did not affect COX-1 expression nor COX activity. These results suggest that NDE downregulates LPS-induced COX-2 expression and inhibits PGE₂ production in pulmonary epithelial cells. Furthermore, higenamine and nantenine, two major constituents responsible for tracheal relaxing effect of NDE, did not mimic the inhibitory effect of NDE on LPS-induced COX-2 expression in A549 cells. To identify active constituent(s) of NDE responsible for the anti-inflammatory effect, NDE was introduced in a polyaromatic absorbent resin column and stepwise eluted to yield water fraction, 20% methanol fraction, 40% methanol fraction, 99.8% methanol fraction, and 99.5% acetone fraction. However, none of these five fractions alone inhibited LPS-induced COX-2 expression. On the other hand, exclusion of water fraction from NDE abolished the inhibitory effect of NDE on LPS-induced COX-2 expression. These results suggest that constituent(s) present in water fraction is required but not sufficient for the anti-inflammatory activity of NDE, which may result from interactions among multiple constituents.

  6. Antitumor activity of the selective cyclooxygenase-2 inhibitor, celecoxib, on breast cancer in Vitro and in Vivo

    Directory of Open Access Journals (Sweden)

    Dai Zhi-Jun

    2012-12-01

    Full Text Available Abstract Background Cyclooxygenase-2(COX-2 promotes carcinogenesis, tumor proliferation, angiogenesis, prevention of apoptosis, and immunosuppression. Meanwhile, COX-2 over-expression has been associated with tumor behavior and prognosis in several cancers. This study investigated the antitumor effects of the selective COX-2 inhibitor, Celecoxib, on breast cancer in vitro and in vivo. Methods Human breast cancer MCF-7 and MDA-MB-231 cells were cultured with different concentration (10, 20, 40 μmol/L of celecoxib after 0-96 hours in vitro. MTT assay was used to determine the growth inhibition of breast cancer cells in vitro. The expression of COX-2 on mRNA was measured by real-time quantitive PCR analysis. Flow cytometry was performed to analyze the cell cycle of MCF-7 cells. Levels of PGE2 were measured by ELISA method. The in vivo therapeutic effects of celecoxib were determined using rat breast cancer chemically induced by 7,12-dimethylben anthracene (DMBA. Results The inhibition of proliferation of both MCF-7 and MDA-MB-231 cells in vitro by celecoxib was observerd in time and dose dependent manner. Celecoxib effectively down-regulated the expression of COX-2. The cell cycle was arrested at G0/G1, and rate of cells in S phase was obviously decreased. Levels of PGE2 were inhibited by Celecoxib. The tumor incidence rate of the celecoxib group was lower than that of the control group. In addition, the tumor latency period of the celecoxib group was longer than that of the control group. Conclusions Celecoxib inhibited the proliferation of breast cancer cell lines in vitro, and prevented the occurrence of rat breast cancer chemically induced by DMBA. Therefore, celecoxib exhibits an antitumor activity and seems to be effective in anti-tumor therapy.

  7. Pulmonary oxidative stress is increased in cyclooxygenase-2 knockdown mice with mild pulmonary hypertension induced by monocrotaline.

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    Francesca Seta

    Full Text Available The aim of this study was to examine the role of cyclooxygenase-2 (COX-2 and downstream signaling of prostanoids in the pathogenesis of pulmonary hypertension (PH using mice with genetically manipulated COX-2 expression. COX-2 knockdown (KD mice, characterized by 80-90% suppression of COX-2, and wild-type (WT control mice were treated weekly with monocrotaline (MCT over 10 weeks. Mice were examined for cardiac hypertrophy/function and right ventricular pressure. Lung histopathological analysis was performed and various assays were carried out to examine oxidative stress, as well as gene, protein, cytokine and prostanoid expression. We found that MCT increased right ventricular systolic and pulmonary arterial pressures in comparison to saline-treated mice, with no evidence of cardiac remodeling. Gene expression of endothelin receptor A and thromboxane synthesis, regulators of vasoconstriction, were increased in MCT-treated lungs. Bronchoalveolar lavage fluid and lung sections demonstrated mild inflammation and perivascular edema but activation of inflammatory cells was not predominant under the experimental conditions. Heme oxygenase-1 (HO-1 expression and indicators of oxidative stress in lungs were significantly increased, especially in COX-2 KD MCT-treated mice. Gene expression of NOX-4, but not NOX-2, two NADPH oxidase subunits crucial for superoxide generation, was induced by ∼4-fold in both groups of mice by MCT. Vasodilatory and anti-aggregatory prostacyclin was reduced by ∼85% only in MCT-treated COX-2 KD mice. This study suggests that increased oxidative stress-derived endothelial dysfunction, vasoconstriction and mild inflammation, exacerbated by the lack of COX-2, contribute to the pathogenesis of early stages of PH when mild hemodynamic changes are evident and not yet accompanied by vascular and cardiac remodeling.

  8. Relationship between cyclooxygenase 8473T>C polymorphism and the risk of lung cancer: a case-control study

    Directory of Open Access Journals (Sweden)

    Kang Young

    2006-03-01

    Full Text Available Abstract Background Cyclooxygenase-2 (COX-2 plays an important role in the development of lung cancer. DNA sequence variations in the COX-2 gene may lead to altered COX-2 production and/or activity, and so they cause inter-individual differences in the susceptibility to lung cancer. To test this hypothesis, we investigated the association between the 8473T>C polymorphism in the 3'-untranslated region of the COX-2 gene and the risk of lung cancer in a Korean population. Methods The COX-2 genotypes were determined using PCR-based primer-introduced restriction analysis in 582 lung cancer patients and in 582 healthy controls that were frequency-matched for age and gender. Results The distribution of the COX-2 8473T>C genotypes was not significantly different between the overall lung cancer cases and the controls. However, when the cases were categorized by the tumor histology, the combined 8473 TC + CC genotype was associated with a significantly decreased risk of adenocarcinoma as compared with the 8473 TT genotype (adjusted OR = 0.64; 95% CI = 0.46–0.90, P = 0.01. On the stratification analysis, the protective effect of the combined 8473 TC + CC genotype against adenocarcinoma was statistically significant in the males, older individuals and ever-smokers (adjusted OR = 0.59; 95% CI = 0.39–0.91, P = 0.02; adjusted OR = 0.55; 95% CI = 0.33–0.93, P = 0.03; and adjusted OR = 0.57; 95% CI = 0.37–0.87, P = 0.01, respectively. Conclusion These findings suggest that the COX-2 8473T>C polymorphism could be used as a marker for the genetic susceptibility to adenocarcinoma of the lung.

  9. Involvement of hypothalamic cyclooxygenase-2, interleukin-1β and melanocortin in the development of docetaxel-induced anorexia in rats.

    Science.gov (United States)

    Yamamoto, Kouichi; Asano, Keiko; Ito, Yui; Matsukawa, Naoki; Kim, Seikou; Yamatodani, Atsushi

    2012-12-16

    Docetaxel, a taxane derivative, is frequently used for the treatment of advanced breast cancer, non-small cell lung cancer, and metastatic prostate cancer. Clinical reports demonstrated that docetaxel-based chemotherapy often induces anorexia, but the etiology is not completely understood. To elucidate possible mechanisms, we investigated the involvement of central interleukin (IL)-1β, cyclooxygenase (COX)-2, and pro-opiomelanocortin (POMC) in the development of docetaxel-induced anorexia in rats. Rats received docetaxel (10mg/kg, i.p.) with or without pretreatment with selective COX-2 inhibitors, NS-398 (10 and 30 mg/kg, i.g.) or celecoxib (10 and 30 mg/kg, i.g.), and a non-selective COX inhibitor, indomethacin (10mg/kg, i.g.), then food intake was monitored for 24h after administration. We also examined expression of IL-1β, COX-2, and POMC mRNA in hypothalamus of docetaxel-treated rats and the effect of a COX-2 inhibitor on docetaxel-induced POMC mRNA expression. Food consumption in rats was significantly decreased 24h after administration of docetaxel and anorexia was partially reversed by all COX inhibitors. Administration of docetaxel increased IL-1β, COX-2, and POMC mRNA expression in the hypothalamus of rats. The time required to increase these gene expressions was comparable to the latency period of docetaxel-induced anorexia in rats. In addition, pretreatment with COX-2 inhibitors suppressed docetaxel-induced expression of POMC mRNA. These results suggest that IL-1β and COX-2 mRNA expression and subsequent activation of POMC in the hypothalamus may contribute to the development of docetaxel-induced anorexia in rats. Copyright © 2012. Published by Elsevier Ireland Ltd.

  10. Radiation-induced cyclooxygenase 2 up-regulation is dependent on redox status in prostate cancer cells.

    Science.gov (United States)

    Li, Lingyun; Steinauer, Kirsten K; Dirks, Amie J; Husbeck, Bryan; Gibbs, Iris; Knox, Susan J

    2003-12-01

    Cyclooxygenase 2 (COX2) is the inducible isozyme of COX, a key enzyme in arachidonate metabolism and the conversion of arachidonic acid (AA) to prostaglandins (PGs) and other eicosanoids. Previous studies have demonstrated that the COX2 protein is up-regulated in prostate cancer cells after irradiation and that this results in elevated levels of PGE(2). In the present study, we further investigated whether radiation-induced COX2 up-regulation is dependent on the redox status of cells from the prostate cancer cell line PC-3. l-Buthionine sulfoximine (BSO), which inhibits gamma glutamyl cysteine synthetase (gammaGCS), and the antioxidants alpha-lipoic acid and N-acetyl-l-cysteine (NAC) were used to modulate the cellular redox status. BSO decreased the cellular GSH level and increased cellular reactive oxygen species (ROS) in PC-3 cells, whereas alpha-lipoic acid and NAC increased the GSH level and decreased cellular ROS. Both radiation and the oxidant H(2)O(2) had similar effects on COX2 up-regulation and PGE(2) production in PC-3 cells, suggesting that radiation-induced COX2 up-regulation is secondary to the production of ROS. The relative increases in COX2 expression and PGE(2) production induced by radiation and H(2)O(2) were even greater when PC-3 cells were pretreated with BSO. When the cells were pretreated with alpha-lipoic acid or NAC for 24 h, both radiation- and H(2)O(2)-induced COX2 up-regulation and PGE(2) production were markedly inhibited. These results demonstrate that radiation-induced COX2 up-regulation in prostate cancer cells is modulated by the cellular redox status. Radiation-induced increases in ROS levels contribute to the adaptive response of PC-3 cells, resulting in elevated levels of COX2.

  11. Differential expression of cyclooxygenase-2 and its regulation by tumor necrosis factor-alpha in normal and malignant prostate cells.

    Science.gov (United States)

    Subbarayan, V; Sabichi, A L; Llansa, N; Lippman, S M; Menter, D G

    2001-03-15

    Cyclooxygenase (COX)-2 expression is elevated in some malignancies; however, information is scarce regarding COX-2 contributions to the development of prostate cancer and its regulation by inflammatory cytokines. The present study compared and contrasted the expression levels and subcellular distribution patterns of COX-1 and COX-2 in normal prostate [prostate epithelial cell (PrEC), prostate smooth muscle (PrSM), and prostate stromal (PrSt)] primary cell cultures and prostatic carcinoma cell lines (PC-3, LNCaP, and DU145). The basal COX-2 mRNA and protein levels were high in normal PrEC and low in tumor cells, unlike many other normal cells and tumor cells. Because COX-2 levels were low in prostate smooth muscle cells, prostate stromal cells, and tumor cells, we also examined whether COX-1 and COX-2 gene expression was elevated in response to tumor necrosis factor-alpha (TNF-alpha), a strong inducer of COX-2 expression. Northern blot analysis and reverse transcription-PCR demonstrated different patterns and kinetics of expression for COX-1 and COX-2 among normal cells and tumor cells in response to TNF-alpha. In particular, COX-2 protein levels increased, and the subcellular distribution formed a distinct perinuclear ring in the normal cells at 4 h after TNF-alpha exposure. The COX-2 protein levels also increased in cancer cells, but the subcellular distribution was less organized; COX-2 protein appeared diffuse in some cells and accumulated as focal deposits in the cytoplasm of other cells. TNF-alpha induction of COX-2 and prostaglandin E2 correlated inversely with induction of apoptosis. We conclude that COX-2 expression may be important to PrEC cell function. Although it is low in stromal and tumor cells, COX-2 expression is induced by TNF-alpha in these cells, and this responsiveness may play an important role in prostate cancer progression.

  12. Overexpression of vasoactive intestinal peptide receptors and cyclooxygenase-2 in human prostate cancer. Analysis of potential prognostic relevance.

    Science.gov (United States)

    Fernández-Martínez, Ana B; Carmena, María J; Arenas, M Isabel; Bajo, Ana M; Prieto, Juan C; Sánchez-Chapado, Manuel

    2012-08-01

    Vasoactive intestinal peptide (VIP) is a potent inductor of cyclooxygenase-2 (COX-2) expression in human prostate cancer cell lines. There are conflicting data regarding the role of COX-2 in the progression of this disease. Here we examined the expression of VIP receptors (VPAC1 and VPAC2) and COX-2 in prostate cancer specimens. Correlations among protein levels and various clinicopathological factors and prognosis of patients were statistically analyzed. For these purposes, formaldehyde-fixed, paraffin-embedded prostate tissue specimens from 63 patients with prostate cancer and 9 control samples were used. The expression of VPAC1 and VPAC2 receptors and COX-2 was analyzed at mRNA levels by quantitative reverse transcriptase-PCR. The corresponding expression at protein level was studied by immunohistochemistry, scored as negative, weak, moderate, or strong, and correlated with different clinicopathological factors by means of multivariate analysis. 88% of prostate cancer tissues overexpressed VPAC1-receptor at mRNA level, 72% VPAC2-receptor and 77% COX-2. Simultaneous overexpression of the three genes was seen in 52% of patients. Similar overexpression patterns were observed at protein level. The correlation between VPAC1 and VPAC2 receptor protein levels was statistically significant. However, no significant correlations existed among protein levels of VPAC receptors and COX-2 with patient age, prostate-specific antigen (PSA) levels, tumor stage, Gleason score and survival time. The overexpression of VPAC1 and VPAC2 receptors and COX-2 in cancer tissue gives them a potential role as targets for diagnosis of prostate cancer but results do not support a clear value as biomarkers for the clinical prognosis of this disease.

  13. Evaluation of [{sup 11}C]rofecoxib as PET tracer for cyclooxygenase 2 overexpression in rat models of inflammation

    Energy Technology Data Exchange (ETDEWEB)

    Vries, Erik F.J. de [Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, P.O. Box 30.001, 9700 RB Groningen (Netherlands)], E-mail: e.f.j.de.vries@ngmb.umcg.nl; Doorduin, Janine; Dierckx, Rudi A.; Waarde, Aren van [Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, P.O. Box 30.001, 9700 RB Groningen (Netherlands)

    2008-01-15

    Background: Overexpression of cyclooxygenase type 2 (COX-2) is triggered by inflammatory stimuli, but it also plays a prominent role in the initiation and progression of various diseases. This study aims to investigate [{sup 11}C]rofecoxib as a positron emission tomography (PET) tracer for COX-2 expression. Methods: [{sup 11}C]Rofecoxib was prepared by methylation of its sulphinate precursor. Regional brain distribution and specific binding of [{sup 11}C]rofecoxib in healthy rats was studied by ex vivo biodistribution and autoradiography. Regional brain distribution and PET imaging studies were also performed on rats with severe encephalitis, caused by nasal infection with herpes simplex virus (HSV). Finally, ex vivo biodistribution and blocking studies were carried in rats with a sterile inflammation, induced by intramuscular turpentine injection. Results: [{sup 11}C]rofecoxib brain uptake in control animals corresponded with the known distribution of COX-2. Pretreatment with NS398 significantly reduced tracer uptake in the cingulate/frontopolar cortex, whereas the reduction in hippocampus approached significance. Ex vivo autoradiography also revealed preferential tracer uptake in hippocampus and cortical areas that could be blocked by NS398. In HSV-infected animals, [{sup 11}C]rofecoxib uptake was moderately increased in all brain regions, but it could not be blocked with indomethacin. Yet, some PET images revealed increased tracer uptake in brain areas with microglia activation. In turpentine-injected animals, [{sup 11}C]rofecoxib uptake in inflamed muscle was not higher than in control muscle and could not be blocked with NS398. Indomethacin caused a slight reduction in muscle uptake. Conclusions: Despite the apparent correlation between [{sup 11}C]rofecoxib uptake and COX-2 distribution in healthy rats, [{sup 11}C]rofecoxib could not unambiguously detect COX-2 overexpression in two rat models of inflammation.

  14. Lipopolysaccharide Enhances the Production of Nicotine-Induced Prostaglandin E2 by an Increase in Cyclooxygenase-2 Expression in Osteoblasts

    Institute of Scientific and Technical Information of China (English)

    Maiko SHOJI; Natsuko TANABE; Narihiro MITSUI; Naoto SUZUKI; Osamu TAKEICHI; Tomoko KATONO; Akira MOROZUMI; Masao MAENO

    2007-01-01

    Previous studies have indicated that lipopolysaccharide (LPS) from Gram-negative bacteria in plaque induces the release of prostaglandin E2 (PGE2),which promotes alveolar bone resorption in periodontitis,and that tobacco smoking might be an important risk factor for the development and severity of periodontitis.We determined the effect of nicotine and LPS on alkaline phosphatase (ALPase)activity,PGE2 production,and the expression of cyclooxygenase (COX-1,COX-2),PGE2 receptors Ep1-4,and macrophage colony stimulating factor(M-CSF)in human osteoblastic Saos-2 cells.The cells were cultured with 10-3 M nicotine in the presence of 0,1,or 10 μg/ml LPS,or with LPS alone.ALPase activity decreased in cells cultured with nicotine or LPS alone,and decreased further in those cultured with both nicotine and LPS,whereas PGE2 production significantly increased in the former and increased further in the latter.By itself,nicotine did not affect expression of COX-1,COX-2,any of the PGE2 receptors,or M-CSF,but when both nicotine and LPS were present,expression of COX-2,Ep3,Ep4,and M-CSF increased significantly.Simultaneous addition of 10-4 M indomethacin eliminated the effects of nicotine and LPS on ALPase activity,PGE2 production,and MCSF expression.Phosphorylation of protein kinase A was high in cells cultured with nicotine and LPS.These results suggest that LPS enhances the production of nicotine-induced PGE2 by an increase in COX-2 expression in osteoblasts,that nicotine-LPS-induced PGE2 interacts with the osteoblast Ep4 receptor primarily in autocrine or paracrine mode,and that the nicotine-LPS-induced PGE2 then decreases ALPase activity and increases M-CSF expression.

  15. Cyclooxygenases in human and mouse skin and cultured human keratinocytes: association of COX-2 expression with human keratinocyte differentiation

    Science.gov (United States)

    Leong, J.; Hughes-Fulford, M.; Rakhlin, N.; Habib, A.; Maclouf, J.; Goldyne, M. E.

    1996-01-01

    Epidermal expression of the two isoforms of the prostaglandin H-generating cyclooxygenase (COX-1 and COX-2) was evaluated both by immunohistochemistry performed on human and mouse skin biopsy sections and by Western blotting of protein extracts from cultured human neonatal foreskin keratinocytes. In normal human skin, COX-1 immunostaining is observed throughout the epidermis whereas COX-2 immunostaining increases in the more differentiated, suprabasilar keratinocytes. Basal cell carcinomas express little if any COX-1 or COX-2 immunostaining whereas both isozymes are strongly expressed in squamous cell carcinomas deriving from a more differentiated layer of the epidermis. In human keratinocyte cultures, raising the extracellular calcium concentration, a recognized stimulus for keratinocyte differentiation, leads to an increased expression of both COX-2 protein and mRNA; expression of COX-1 protein, however, shows no significant alteration in response to calcium. Because of a recent report that failed to show COX-2 in normal mouse epidermis, we also looked for COX-1 and COX-2 immunostaining in sections of normal and acetone-treated mouse skin. In agreement with a previous report, some COX-1, but no COX-2, immunostaining is seen in normal murine epidermis. However, following acetone treatment, there is a marked increase in COX-1 expression as well as the appearance of significant COX-2 immunostaining in the basal layer. These data suggest that in human epidermis as well as in human keratinocyte cultures, the expression of COX-2 occurs as a part of normal keratinocyte differentiation whereas in murine epidermis, its constitutive expression is absent, but inducible as previously published.

  16. Breast cancer cell cyclooxygenase-2 expression alters extracellular matrix structure and function and numbers of cancer associated fibroblasts.

    Science.gov (United States)

    Krishnamachary, Balaji; Stasinopoulos, Ioannis; Kakkad, Samata; Penet, Marie-France; Jacob, Desmond; Wildes, Flonne; Mironchik, Yelena; Pathak, Arvind P; Solaiyappan, Meiyappan; Bhujwalla, Zaver M

    2017-01-31

    Cyclooxygenase-2 (COX-2) is a critically important mediator of inflammation that significantly influences tumor angiogenesis, invasion, and metastasis. We investigated the role of COX-2 expressed by triple negative breast cancer cells in altering the structure and function of the extracellular matrix (ECM). COX-2 downregulation effects on ECM structure and function were investigated using magnetic resonance imaging (MRI) and second harmonic generation (SHG) microscopy of tumors derived from triple negative MDA-MB-231 breast cancer cells, and a derived clone stably expressing a short hairpin (shRNA) molecule downregulating COX-2. MRI of albumin-GdDTPA was used to characterize macromolecular fluid transport in vivo and SHG microscopy was used to quantify collagen 1 (Col1) fiber morphology. COX-2 downregulation decreased Col1 fiber density and altered macromolecular fluid transport. Immunohistochemistry identified significantly fewer activated cancer associated fibroblasts (CAFs) in low COX-2 expressing tumors. Metastatic lung nodules established by COX-2 downregulated cells were infrequent, smaller, and contained fewer Col1 fibers.COX-2 overexpression studies were performed with tumors derived from triple negative SUM-149 breast cancer cells lentivirally transduced to overexpress COX-2. SHG microscopy identified significantly higher Col1 fiber density in COX-2 overexpressing tumors with an increase of CAFs. These data expand upon the roles of COX-2 in shaping the structure and function of the ECM in primary and metastatic tumors, and identify the potential role of COX-2 in modifying the number of CAFs in tumors that may have contributed to the altered ECM.

  17. Two isoforms of cyclooxygenase contribute to augmented endothelium-dependent contractions in femoral arteries of 1-year-old rats

    Institute of Scientific and Technical Information of China (English)

    Yi SHI; Ricky YK MAN; Paul M VANHOUTTE

    2008-01-01

    Aim: The present experiments were designed to study the changes in endothe-lium-dependent contractions with aging. Methods: The rat femoral arteries of 20-week and 1-year-old rats with and without endothelium were suspended in organ chambers to record isometric tension. The production of oxygen-derived free radicals in the endothelium was measured with 2',7'-dichiorodihydrofluorescein diacetate (DCF) using confocal microscopy. Protein presences were determined by Western blotting. Results: In the arteries from the 1-year-old rats, endothe-lium-dependent relaxations to A23187 were reduced, but the endothelium-depen-dent contractions to A23187 (in the presence of Nω-nitro-L-arginine methyl ester hydrochloride [L-NAME; an inhibitor of nitric oxide synthase]) were augmented, demonstrating endothelial dysfunction with aging. Indomethacin normalized the responses, suggesting that a cyclooxygenase (COX)-dependent contraction is prominent in aging. The endothelium-dependent contractions were also prevented by terntroban (a blocker of thromboxane-prostanoid receptors), confirming the activation of thromboxane-prostanoid receptors on vascular smooth muscle. Valeryl salicylate and NS-398 (preferential inhibitors of COX-1 and COX-2, respectively) partially reduced the response, indicating that both COX-1 and COX-2 are involved. Western blotting confirmed the upregulation of both isoforms in the arteries of the 1-year-old rats. In the presence of L-NAME, A23187 increased the DCF fluores-cence in the endothelium, demonstrating that the production of oxygen-derived free radicals contributes to endothelium-dependent contractions. The activity of catalase was reduced in the arteries with endothelium of 1-year-old rats, indicating that hydrogen peroxide is the likely mediator of increased oxidative stress in the aging endothelium. Conclusion: Endothelium-dependent contractions are aug-mented with aging. Oxidative stress potentiates the response, and both COX-1 and COX-2 are

  18. Prostacyclin production in rat aortic smooth muscle cells: role of protein kinase C, phospholipase D and cyclooxygenase-2 expression.

    Science.gov (United States)

    Frias, Miguel A; Dubouloz, Frédérique; Rebsamen, Michela C; Lang, Ursula

    2003-11-01

    The present study was designed to investigate the role of protein kinase C (PKC) and phospholipase D (PLD) in angiotensin II (AngII)- and phorbol ester (PMA)-induced cyclooxygenase-2 (COX-2) expression and prostacyclin (PGI(2)) production in rat aortic smooth muscle cells (VSMC). Prostacyclin production in cultured VSMC was determined by radioimmunoassay. PKC activity was examined by measuring the transfer of 32P from (gamma-32P)ATP to histone III-S. COX-2 expression was determined by Western blotting. To measure PLD activity, thin layer chromatography was used. AngII (50 nM) and PMA (100 nM) promoted the translocation of PKC activity from the cytosol to the membranes within 30 min, followed by a strong increase in PLD activity as well as COX-2 expression and PGI(2) production. After 48 h exposure to PMA, PKC was downregulated resulting in a complete suppression of its activity. PKC-downregulation and the PKC inhibitor CGP41251 abolished PMA- and AngII-induced PLD activation, suppressed the stimulatory effect of PMA on COX-2 expression and PGI(2) production and strongly inhibited that of AngII. Furthermore, AngII- and PMA-induced PGI(2) production depended on protein synthesis and COX-2 but not COX-1 activity. Inhibition of PLD-mediated phosphatidic acid (PA) formation by 1% 1-butanol abolished AngII-induced COX-2 expression and PGI(2) secretion, while dioctanoyl PA increased COX-2 expression and PGI(2) production in a time- and concentration-dependent manner. Our results indicate that in VSMC, AngII promotes PGI(2) production to a large extent through a rise in COX-2 expression which is mediated by PA generated from increased PKC-dependent PLD activity.

  19. A tale of switched functions: from cyclooxygenase inhibition to M-channel modulation in new diphenylamine derivatives.

    Directory of Open Access Journals (Sweden)

    Asher Peretz

    Full Text Available Cyclooxygenase (COX enzymes are molecular targets of nonsteroidal anti-inflammatory drugs (NSAIDs, the most used medication worldwide. However, the COX enzymes are not the sole molecular targets of NSAIDs. Recently, we showed that two NSAIDs, diclofenac and meclofenamate, also act as openers of Kv7.2/3 K(+ channels underlying the neuronal M-current. Here we designed new derivatives of diphenylamine carboxylate to dissociate the M-channel opener property from COX inhibition. The carboxylate moiety was derivatized into amides or esters and linked to various alkyl and ether chains. Powerful M-channel openers were generated, provided that the diphenylamine moiety and a terminal hydroxyl group are preserved. In transfected CHO cells, they activated recombinant Kv7.2/3 K(+ channels, causing a hyperpolarizing shift of current activation as measured by whole-cell patch-clamp recording. In sensory dorsal root ganglion and hippocampal neurons, the openers hyperpolarized the membrane potential and robustly depressed evoked spike discharges. They also decreased hippocampal glutamate and GABA release by reducing the frequency of spontaneous excitatory and inhibitory post-synaptic currents. In vivo, the openers exhibited anti-convulsant activity, as measured in mice by the maximal electroshock seizure model. Conversion of the carboxylate function into amide abolished COX inhibition but preserved M-channel modulation. Remarkably, the very same template let us generating potent M-channel blockers. Our results reveal a new and crucial determinant of NSAID-mediated COX inhibition. They also provide a structural framework for designing novel M-channel modulators, including openers and blockers.

  20. Cyclooxygenases expression and distribution in the normal ovary and their role in ovarian cancer in the domestic hen (Gallus domesticus).

    Science.gov (United States)

    Hales, Dale Buchanan; Zhuge, Yan; Lagman, Jo Ann Jaen; Ansenberger, Kristine; Mahon, Cassandra; Barua, Animesh; Luborsky, Judith L; Bahr, Janice M

    2008-06-01

    Cyclooxygenase (COX) (PTGS) is the rate-limiting enzyme in the biosynthesis of prostaglandins. Two COX isoforms have been identified, COX-1 and COX-2, which show distinct cell-specific expression and regulation. Ovarian cancer is the most lethal gynecological malignancy and the disease is poorly understood due to the lack of suitable animal models. The laying hen spontaneously develops epithelial ovarian cancer with few or no symptoms until the cancer has progresses to a late stage, similar to the human disease. The purpose of this study was to examine the relative expression and distribution of COX-1 and COX-2 in the ovaries of normal hens and in hens with ovarian cancer. The results demonstrate that COX-1 was localized to the granulosa cell layer and cortical interstitium, ovarian surface epithelium (OSE) and postovulatory follicle (POF) of the normal ovary. In ovarian cancer, COX-1 mRNA was significantly increased and COX-1 protein was broadly distributed throughout the tumor stroma. COX-2 protein was localized to the granulosa cell layer in the follicle and the ovarian stroma. COX-2 mRNA expression did not change as a function of age or in ovarian cancer. There was significantly higher expression of COX-1 mRNA in the first POF (POF-1) compared to POF-2 and POF-3. COX-2 mRNA expression was not significantly different among POFs. There was no difference in COX-1 or COX-2 mRNA in the OSE isolated from individual follicles in the follicular hierarchy. The results confirm previous findings of the high expression of COX-1 in ovarian tumors further supporting the laying hen as a model for ovarian cancer, and demonstrate for the first time the high expression of COX-1 in POF-1 which is the source of prostaglandins needed for oviposition.

  1. The role of chemoprevention by selective cyclooxygenase-2 inhibitors in colorectal cancer patients - a population-based study

    Directory of Open Access Journals (Sweden)

    Yang Yi-Hsin

    2012-12-01

    Full Text Available Abstract Background There are limited population-based studies focusing on the chemopreventive effects of selective cyclooxygenase-2 (COX-2 inhibitors against colorectal cancer. The purpose of this study is to assess the trends and dose–response effects of various medication possession ratios (MPR of selective COX-2 inhibitor used for chemoprevention of colorectal cancer. Methods A population-based case–control study was conducted using the Taiwan Health Insurance Research Database (NHIRD. The study comprised 21,460 colorectal cancer patients and 79,331 controls. The conditional logistic regression was applied to estimate the odds ratios (ORs for COX-2 inhibitors used for several durations (5 years, 3 years, 1 year, 6 months and 3 months prior to the index date. Results In patients receiving selective COX-2 inhibitors, the OR was 0.51 (95% CI=0.29~0.90, p=0.021 for an estimated 5-year period in developing colorectal cancer. ORs showing significant protection effects were found in 10% of MPRs for 5-year, 3-year, and 1-year usage. Risk reduction against colorectal cancer by selective COX-2 inhibitors was observed as early as 6 months after usage. Conclusion Our results indicate that selective COX-2 inhibitors may reduce the development of colorectal cancer by at least 10% based on the MPRs evaluated. Given the limited number of clinical reports from general populations, our results add to the knowledge of chemopreventive effects of selective COX-2 inhibitors against cancer in individuals at no increased risk of colorectal cancer.

  2. Cyclooxygenase 2 polymorphism and colorectal cancer: -765G>C variant modifies risk associated with smoking and body mass index

    Institute of Scientific and Technical Information of China (English)

    Li-Li Xing; Zhen-Ning Wang; Li Jiang; Yong Zhang; Ying-Ying Xu; Juan Li; Yang Luo; Xue Zhang

    2008-01-01

    AIM: To explore whether cyclooxygenase 2 (COX-2) -765G>C polymorphism is associated with susceptibility of colorectal cancer (CRC) and to evaluate the risk of colorectal cancer in relation to environmental exposures and polymorphism.METHODS: We conducted a case-control study of 137 patients with colorectal cancer and 199 cancer-free controls in northeast China. Multivariate logistic regression analysis was performed to calculate the adjusted odds ratio (OR) and 95% confidence interval (95% CI).RESULTS: The -765G>C polymorphism was not independently associated with CRC risk. However, risk associated with the polymorphism differed by smoking and body mass index (BMI). Smoking and BMI associated risks were stronger among those with -765GG genotype, showing that smokers had a 2.682-fold greater risk of CRC than nonsmokers (51/43 vs 68/126, P = 0.006). Compared to those with a normal body mass index (BMI 18.5-22.9), those with overweight (BMI 23-24.9) had a 3.909-fold higher risk of CRC (OR = 3.909, 95% CI = 2.081-7.344; P < 0.001), while those with obesity (BMI > 25) had a 2.031- fold higher risk of CRC (OR = 1.107, 95% CI = 1.107-3.726; P = 0.022).CONCLUSION: Although COX-2 -765G>C polymorphism is not associated with an increased risk of CRC, -765GG genotype appears to be related to an increased risk in the presence of smoking and higher BMI.

  3. Similar reductions in the risk of human colon cancer by selective and nonselective cyclooxygenase-2 (COX-2 inhibitors

    Directory of Open Access Journals (Sweden)

    Alshafie Galal A

    2008-08-01

    Full Text Available Abstract Background Epidemiologic and laboratory investigations suggest that aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs have chemopreventive effects against colon cancer perhaps due at least in part to their activity against cyclooxygenase-2 (COX-2, the rate-limiting enzyme of the prostaglandin cascade. Methods We conducted a case control study of colon cancer designed to compare effects of selective and non-selective COX-2 inhibitors. A total of 326 incident colon cancer patients were ascertained from the James Cancer Hospital, Columbus, Ohio, during 2003–2004 and compared with 652 controls with no history of cancer and matched to the cases at a 2:1 ratio on age, race, and county of residence. Data on the past and current use of prescription and over the counter medications and colon cancer risk factors were ascertained using a standardized risk factor questionnaire. Effects of COX-2 inhibiting agents were quantified by calculating odds ratios (OR and 95% confidence intervals. Results Results showed significant risk reductions for selective COX-2 inhibitors (OR = 0.31, 95% CI = 0.16–0.57, regular aspirin (OR = 0.33, 95% CI = 0.20–0.56, and ibuprofen or naproxen (0.28, 95% CI = 0.15–0.54. Acetaminophen, a compound with negligible COX-2 activity and low dose aspirin (81 mg produced no significant change in the risk of colon cancer. Conclusion These results suggest that both non-selective and selective COX-2 inhibitors produce significant reductions in the risk of colon cancer, underscoring their strong potential for colon cancer chemoprevention.

  4. Effects of the estrous cycle, pregnancy and interferon tau on expression of cyclooxygenase two (COX-2 in ovine endometrium

    Directory of Open Access Journals (Sweden)

    Bazer Fuller W

    2003-08-01

    Full Text Available Abstract In sheep, the uterus produces luteolytic pulses of prostaglandin F2α (PGF on Days 15 to 16 of estrous cycle to regress the corpus luteum (CL. These PGF pulses are produced by the endometrial lumenal epithelium (LE and superficial ductal glandular epithelium (sGE in response to binding of pituitary and/or luteal oxytocin to oxytocin receptors (OTR and liberation of arachidonic acid, the precursor of PGF. Cyclooxygenase-one (COX-1 and COX-2 are rate-limiting enzymes in PGF synthesis, and COX-2 is the major form expressed in ovine endometrium. During pregnancy recognition, interferon tau (IFNτ, produced by the conceptus trophectoderm, acts in a paracrine manner to suppress development of the endometrial epithelial luteolytic mechanism by inhibiting transcription of estrogen receptor α (ERα (directly and OTR (indirectly genes. Conflicting studies indicate that IFNτ increases, decreases or has no effect on COX-2 expression in bovine and ovine endometrial cells. In Study One, COX-2 mRNA and protein were detected solely in endometrial LE and sGE of both cyclic and pregnant ewes. During the estrous cycle, COX-2 expression increased from Days 10 to 12 and then decreased to Day 16. During early pregnancy, COX-2 expression increased from Days 10 to 12 and remained higher than in cyclic ewes. In Study Two, intrauterine infusion of recombinant ovine IFNτ in cyclic ewes from Days 11 to 16 post-estrus did not affect COX-2 expression in the endometrial epithelium. These results clearly indicate that IFNτ has no effect on expression of the COX-2 gene in the ovine endometrium. Therefore, antiluteolytic effects of IFNτ are to inhibit ERα and OTR gene transcription, thereby preventing endometrial production of luteolytic pulses of PGF. Indeed, expression of COX-2 in the endometrial epithelia as well as conceptus is likely to have a beneficial regulatory role in implantation and development of the conceptus.

  5. Elucidation of the mechanism of inhibition of cyclooxygenases by acyl-coenzyme A and acylglucuronic conjugates of ketoprofen.

    Science.gov (United States)

    Levoin, Nicolas; Blondeau, Céline; Guillaume, Cécile; Grandcolas, Line; Chretien, Françoise; Jouzeau, Jean-Yves; Benoit, Etienne; Chapleur, Yves; Netter, Patrick; Lapicque, Françoise

    2004-11-15

    Nonsteroidal anti-inflammatory drugs (NSAIDs) inhibit the cyclooxygenase (COX) isoforms which accounts for their clinical effects. The differential inhibition of COX-1 and COX-2 is not sufficient to explain the absence of a correlation between in vitro and in vivo effects, especially for 2-aryl-propionates, thus indicating the participation of metabolites. Conjugates to glucuronic acid and to coenzyme-A are mainly produced, and have been shown to be chemically reactive. Therefore, we studied the interaction of the ketoprofen metabolites with the COX enzymes. After incubation with bovine pulmonary artery endothelial cells (BPAEC), COX-1 was inhibited stereoselectively by S-ketoprofen acylglucuronide, and more significantly by CoA-thioester. After washing-out the medium, COX-1 activity was essentially recovered, indicating a reversible inhibition. In LPS-stimulated J774.2 cells, COX activity (mainly inducible COX-2) was inhibited reversibly and stereospecifically by S-ketoprofen glucuronide, whereas it disappeared totally and was not recovered after incubation with CoA-thioester. Correspondingly, inhibition of purified COX-2 with this compound was observed to be rapid and irreversible. Using an anti-ketoprofen antibody, COX immunoprecipitated from cells exhibited adduct formation for COX-2 but not for COX-1. This was observed after incubation with CoA-thioester, and, surprisingly, also with glucuronide. Molecular docking gave support to explain this discrepancy: the glucuronide was found to establish a strong interaction with Y115 located in the membrane binding domain, whereas the thioester was preferentially bound to the active site of the enzyme. Overall, our results suggest a contribution of CoA-thioester metabolites of carboxylic NSAIDs to their pharmacological action by irreversibly and selectively inhibiting COX-2.

  6. Comparative study of vanadate- and phorbol ester-induced cyclo-oxygenase-2 expression in human endothelial cells.

    Science.gov (United States)

    Hirai, K; Ezumi, Y; Nishida, E; Uchiyama, T; Takayama, H

    1999-11-01

    Our previous study showed that vanadate, an inhibitor of protein tyrosine phosphatases, induced the expression of cyclo-oxygenase (COX)-2 in a protein-tyrosine-kinase (PTK)-dependent manner in human umbilical vein endothelial cells (HUVEC). Here, we further compared the actions of vanadate and phorbol 12-myristate 13-acetate (PMA), an activator of protein kinase C (PKC), on induction of COX-2 with special reference to mitogen-activated protein kinases (MAPKs) in HUVEC. Vanadate induced activation of three families of MAPKs, extracellular signal-regulated kinases 1 and 2 (ERK1/2), p38, and c-Jun amino-terminal kinase (JNK) 1, while activation of ERK 1/2 alone was induced by PMA. The former activation by vanadate and the latter one by PMA were inhibited by tyrphostin-47, an inhibitor of PTKs, and by Ro31-8220, a PKC inhibitor, respectively. Either tyrphostin-47, PD98059, a specific inhibitor of the upstream kinase toward ERK1/2, or SB203580, a specific inhibitor of p38, completely suppressed vanadate-induction of COX-2 mRNA and protein. On the other hand, PMA-induction of COX-2 mRNA and protein was abolished by Ro31-8220 or PD98059 but not by SB203580. These data indicate that PMA-induced and PKC-dependent expression of COX-2 requires mainly activation of ERK 1/2 among MAPKs, while activation of both ERK1/2 and p38 or possibly of all three families of MAPKs is necessary for vanadate-induced and PTK-dependent expression of COX-2.

  7. Purinergic signaling induces cyclooxygenase-1-dependent prostanoid synthesis in microglia: roles in the outcome of excitotoxic brain injury.

    Directory of Open Access Journals (Sweden)

    Josef Anrather

    Full Text Available Cyclooxygenases (COX are prostanoid synthesizing enzymes constitutively expressed in the brain that contribute to excitotoxic neuronal cell death. While the neurotoxic role of COX-2 is well established and has been linked to prostaglandin E(2 synthesis, the role of COX-1 is not clearly understood. In a model of N-Methyl-D-aspartic acid (NMDA induced excitotoxicity in the mouse cerebral cortex we found a distinctive temporal profile of COX-1 and COX-2 activation where COX-1, located in microglia, is responsible for the early phase of prostaglandin E(2 synthesis (10 minutes after NMDA, while both COX-1 and COX-2 contribute to the second phase (3-24 hours after NMDA. Microglial COX-1 is strongly activated by ATP but not excitatory neurotransmitters or the Toll-like receptor 4 ligand bacterial lipopolysaccharide. ATP induced microglial COX-1 dependent prostaglandin E(2 synthesis is dependent on P2X7 receptors, extracellular Ca(2+ and cytoplasmic phospholipase A2. NMDA receptor activation induces ATP release from cultured neurons leading to microglial P2X7 receptor activation and COX-1 dependent prostaglandin E(2 synthesis in mixed microglial-neuronal cultures. Pharmacological inhibition of COX-1 has no effect on the cortical lesion produced by NMDA, but counteracts the neuroprotection exerted by inhibition of COX-2 or observed in mice lacking the prostaglandin E(2 receptor type 1. Similarly, the neuroprotection exerted by the prostaglandin E(2 receptor type 2 agonist butaprost is not observed after COX-1 inhibition. P2X7 receptors contribute to NMDA induced prostaglandin E(2 production in vivo and blockage of P2X7 receptors reverses the neuroprotection offered by COX-2 inhibition. These findings suggest that purinergic signaling in microglia triggered by neuronal ATP modulates excitotoxic cortical lesion by regulating COX-1 dependent prostanoid production and unveil a previously unrecognized protective role of microglial COX-1 in excitotoxic brain

  8. Protective Role of Cyclooxygenase (COX)-2 in Experimental Lung Injury: Evidence of a Lipoxin A(4)-Mediated Effect.

    LENUS (Irish Health Repository)

    2012-02-01

    BACKGROUND: Polymorphoneutrophils (PMNs) are activated by inflammatory mediators following splanchnic ischemia\\/reperfusion (I\\/R), potentially injuring organs such as the lung. As a result, some patients develop respiratory failure following abdominal aortic aneurysm repair. Pulmonary cyclooxygenase (COX)-2 protects against acid aspiration and bacterial instillation via lipoxins, a family of potent anti-inflammatory lipid mediators. We explored the role of COX-2 and lipoxin A(4) in experimental I\\/R-mediated lung injury. MATERIALS AND METHODS: Sprague-Dawley rats were assigned to one of the following five groups: (1) controls; (2) aortic cross-clamping for 45 min and reperfusion for 4 h (I\\/R group); (3) I\\/R and SC236, a selective COX-2 inhibitor; (4) I\\/R and aspirin; and (5) I\\/R and iloprost, a prostacyclin (PGI(2)) analogue. Lung injury was assessed by wet\\/dry ratio, myeloperoxidase (MPO) activity, and bronchoalveolar lavage (BAL) neutrophil counts. BAL levels of thromboxane, PGE(2), 6-keto-PGF(1)alpha (a hydrolysis product of prostacyclin), lipoxin A(4), and 15-epi-lipoxin A(4) were analyzed by enzyme immunoassay (EIA). Immunostaining for COX-2 was performed. RESULTS: I\\/R significantly increased tissue MPO, the wet\\/dry lung ratio, and neutrophil counts. These measures were significantly further aggravated by SC236 and improved by iloprost. I\\/R increased COX-2 immunostaining and both PGE(2) and 6-keto-PGF(1alpha) levels in BAL. SC236 markedly reduced these prostanoids and lipoxin A(4) compared with I\\/R alone. Iloprost markedly increased lipoxin A(4) levels. The deleterious effect of SC236 and the beneficial effect of iloprost was associated with a reduction and an increase, respectively, in lipoxin A(4) levels. CONCLUSIONS: Lipoxin A(4) warrants further evaluation as a mediator of COX-2 regulated lung protection.

  9. No association between cyclooxygenase-2 and uridine diphosphate glucuronosyltransferase 1A6 genetic polymorphisms and colon cancer risk

    Institute of Scientific and Technical Information of China (English)

    Cheryl L Thompson; Sarah J Plummer; Alona Merkulova; Iona Cheng; Thomas C Tucker; Graham Casey; Li Li

    2009-01-01

    AIM: To investigate the association of variations in the cyclooxygenase-2 (COX2) and uridine diphosphate glucuronosyltransferase 1A6 (UGT1A6) genes and nonsteroidal anti-inflammatory drugs (NSAIDs) use with risk of colon cancer. METHODS: NSAIDs, which are known to reduce the risk of colon cancer, act directly on COX2 and reduce its activity. Epidemiological studies have associated variations in the COX2 gene with colon cancer risk, but others were unable to replicate this finding. Similarly, enzymes in the UGT1A6 gene have been demonstrated to modify the therapeutic effect of NSAIDs on colon adenomas. Polymorphisms in the UGT1A6 gene have been statistically shown to interact with NSAID intake to influence risk of developing colon adenomas, but not colon cancer. Here we examined the association of tagging single nucleotide polymorphisms (SNPs) in the COX2 and UGT1A6 genes, and their interaction with NSAID consumption, on risk of colon cancer in a population of 422 colon cancer cases and 481 population controls. RESULTS: No SNP in either gene was individually statistically significantly associated with colon cancer, nor did they statistically significantly change the protective effect of NSAID consumption in our sample. Like others, we were unable to replicate the association of variants in the COX2 gene with colon cancer risk ( P > 0.05), and we did not observe that these variants modify the protective effect of NSAIDs ( P > 0.05). We were able to confirm the lack of association of variants in UGT1A6 with colon cancer risk, although further studies will have to be conducted to confirm the association of these variants with colon adenomas. CONCLUSION: Our study does not support a role of COX2 and UGT1A6 genetic variations in the development of colon cancer.

  10. Mechanisms underlying aspirin-mediated growth inhibition and apoptosis induction of cyclooxygenase-2 negative colon cancer cell line SW480

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    AIM: To investigate the effects of aspirin (acetylsalicylic acid) on proliferation and apoptosis of colorectal can- cer cell line $W480 and its mechanism. METHODS: Cyclooxygenase (COX)-2 negative colorec- tal cancer cell line SW480 was treated with aspirin at concentrations of 2.5 retool/L, 5.0 retool/L, 10.0 mmol/L for different periods in vitro. Anti-proliferation effect of aspirin on SW480 was detected by 3-(4,5-dimeth- ylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cell cycle and apoptosis were observed by flow cytometry (FCM). Transmission electron microscope (TEM) was used for morphological study. Apoptosis-as- sociated genes were detected by immunohistochemical staining and Western blotting. RESULTS: Aspirin inhibited SW480 proliferation and induced apoptosis in a dose- and time-dependent manner. Treatment with different concentrations of aspirin significantly increased the proportions of cells at the G0/G1 phase and decreased the proportions of cells at the S- and G2/M phases in a concentration- dependent manner. Aspirin not only induced apoptosis but also caused cell necrosis at a high concentration as well. After treatment with aspirin, SW480 cells displayed typically morphological features of apoptosis and necrosis under TEM, and increased the Bcl-2 expression in cells, but the expression of Bax was down regulated. CONCLUSION: Aspirin inhibits proliferation and induces apoptosis of SW480 cells. Its anti-tumor mechanism may arrest cell cycle and shift Bax/Bcl-2 balance in cells.

  11. Tumour necrosis factor alpha mediates transient receptor potential vanilloid 1-dependent bilateral thermal hyperalgesia with distinct peripheral roles of interleukin-1beta, protein kinase C and cyclooxygenase-2 signalling.

    Science.gov (United States)

    Russell, Fiona A; Fernandes, Elizabeth S; Courade, Jean-Philippe; Keeble, Julie E; Brain, Susan D

    2009-04-01

    TNFalpha plays a pivotal role in rheumatoid arthritis (RA) but little is known of the mechanisms that link the inflammatory and nociceptive effects of TNFalpha. We have established a murine model of TNFalpha-induced TRPV1-dependent bilateral thermal hyperalgesia that then allowed us to identify distinct peripheral mechanisms involved in mediating TNFalpha-induced ipsilateral and contralateral hyperalgesia. Thermal hyperalgesia and inflammation were assessed in both hindpaws following unilateral intraplantar (i.pl.) TNFalpha. The hyperalgesic mechanisms were analysed through pharmacogenetic approaches involving TRPV1(-/-) mice and TRPV1 antagonists. To study the mediators downstream of TNFalpha, cyclooxygenase (COX) and PKC inhibitors were utilised and cytokine and prostaglandin levels assessed. The role of neutrophils was determined through use of the selectin inhibitor, fucoidan. We show that TNFalpha (10pmol) causes thermal hyperalgesia (1-4h) in the ipsilateral inflamed and contralateral uninjured hindpaws, which is TRPV1-dependent. GF109203X, a PKC inhibitor, suppressed the hyperalgesia indicating that PKC is involved in TRPV1 sensitisation. Ipsilateral COX-2-derived prostaglandins were also crucial to the development of the bilateral hyperalgesia. The prevention of neutrophil accumulation with fucoidan attenuated hyperalgesia at 4 but not at 1h, indicating a role in the maintenance but not in the induction of bilateral hyperalgesia. However, TNFalpha-induced IL-1beta generation in both paws and the presence of local IL-1beta in the contralateral paw were essential for the development of bilateral hyperalgesia. These results identify a series of peripheral events through which TNFalpha triggers and maintains bilateral inflammatory pain. This potentially allows a better understanding of mechanisms involved in TNFalpha-dependent pain pathways in symmetrical diseases such as arthritis.

  12. Oxidized low-density lipoprotein-induced periodontal inflammation is associated with the up-regulation of cyclooxygenase-2 and microsomal prostaglandin synthase 1 in human gingival epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Nagahama, Yu [Department of Periodontology, School of Dentistry, Showa University Dental Hospital, Tokyo (Japan); Department of Biological Chemistry, Showa University School of Pharmacy, Tokyo (Japan); Obama, Takashi [Department of Biological Chemistry, Showa University School of Pharmacy, Tokyo (Japan); Usui, Michihiko [Department of Periodontology, School of Dentistry, Showa University Dental Hospital, Tokyo (Japan); Kanazawa, Yukari [Department of Biological Chemistry, Showa University School of Pharmacy, Tokyo (Japan); Iwamoto, Sanju [Department of Biochemistry, Showa University School of Medicine, Tokyo (Japan); Suzuki, Kazushige [Department of Periodontology, School of Dentistry, Showa University Dental Hospital, Tokyo (Japan); Miyazaki, Akira [Department of Biochemistry, Showa University School of Medicine, Tokyo (Japan); Yamaguchi, Tomohiro [Department of Biological Chemistry, Showa University School of Pharmacy, Tokyo (Japan); Yamamoto, Matsuo [Department of Periodontology, School of Dentistry, Showa University Dental Hospital, Tokyo (Japan); Itabe, Hiroyuki, E-mail: h-itabe@pharm.showa-u.ac.jp [Department of Biological Chemistry, Showa University School of Pharmacy, Tokyo (Japan)

    2011-10-07

    Highlights: {yields} OxLDL-induced responses in human gingival epithelial cells were studied. {yields} OxLDL enhanced the production of IL-8, IL-1{beta} and PGE{sub 2} in Ca9-22 cells. {yields} An NF-{kappa}B inhibitor suppressed the expression of COX-2 and mPGES1 induced by oxLDL. {yields} Unlike the case in macrophages, oxLDL did not increase the CD36 level. -- Abstract: Periodontitis is characterized by chronic gingival tissue inflammation, and inflammatory mediators such as IL-8 and prostaglandin E{sub 2} (PGE{sub 2}) are associated with disease progression. Previously we showed that oxidatively modified low-density lipoprotein (oxLDL) was present in gingival crevicular fluid. In this study, the role of oxLDL in the gingival epithelial cell inflammatory response was further investigated using Ca9-22 cells and primary human oral keratinocytes (HOK). Treatment of Ca9-22 cells and HOK with oxLDL induced an up-regulation of IL-8 and the PGE{sub 2}-producing enzymes, cyclooxygenase-2 and microsomal PGE{sub 2} synthase-1. These responses induced by oxLDL were significantly suppressed by a nuclear factor-kappa B (NF-{kappa}B) inhibitor. However, unlike the result in macrophages, oxLDL did not lead to an increase in CD36 expression in these two cells. These results suggest that oxLDL elicits gingival epithelial cell inflammatory responses through an activation of the NF-{kappa}B pathway. These data suggest a mechanistic link between periodontal disease and lipid metabolism-related disorders, including atherosclerosis.

  13. Inhibition of fatty acid amide hydrolase and cyclooxygenase-2 increases levels of endocannabinoid related molecules and produces analgesia via peroxisome proliferator-activated receptor-alpha in a model of inflammatory pain.

    Science.gov (United States)

    Jhaveri, Maulik D; Richardson, Denise; Robinson, Ian; Garle, Michael J; Patel, Annie; Sun, Yan; Sagar, Devi R; Bennett, Andrew J; Alexander, Stephen P H; Kendall, David A; Barrett, David A; Chapman, Victoria

    2008-07-01

    The antinociceptive effects of the endocannabinoids (ECs) are enhanced by inhibiting catabolic enzymes such as fatty acid amide hydrolase (FAAH). The physiological relevance of the metabolism of ECs by other pathways, such as cyclooxygenase-2 (COX2) is less clear. To address this question we compared the effects of local inhibition of FAAH versus COX2 (URB597 and nimesulide, respectively) on inflammatory hyperalgesia and levels of endocannabinoids and related molecules in the hindpaw. Inflammatory hyperalgesia was measured following intraplantar injection of carrageenan. Effects of intraplantar injection of URB597 (25 microg and 100 microg) or nimesulide (50 microg) on hyperalgesia and hindpaw levels of anandamide (AEA), 2-arachidonoylglycerol (2AG) and N-palmitoylethanolamine (PEA) were determined. Although both doses of URB597 increased levels of AEA and 2AG in the carrageenan inflamed hindpaw, only the lower dose of URB597 attenuated hyperalgesia (P<0.05). Nimesulide attenuated both hyperalgesia and hindpaw oedema (P<0.001, P<0.01, respectively) and increased levels of PEA (P<0.05) in the hindpaw. Since both AEA and PEA are ligands for peroxisome proliferator-activated receptor-alpha (PPARalpha), the effects of the PPARalpha antagonist GW6471 on nimesulide- and URB597-mediated effects were studied. GW6471, but not a PPARgamma antagonist, blocked the inhibitory effects of nimesulide and URB597 on hyperalgesia. Our data suggest that both COX2 and FAAH play a role in the metabolism of endocannabinoids and related molecules. The finding that PPARalpha antagonism blocked the inhibitory effects of nimesulide and URB597 suggests that PPARalpha contributes to their antinociceptive effects in the carrageenan model of inflammatory hyperalgesia.

  14. The target of arachidonic acid pathway is a new anticancer strategy for human prostate cancer

    Directory of Open Access Journals (Sweden)

    Masahide Matsuyama

    2008-07-01

    Full Text Available Masahide Matsuyama, Rikio YoshimuraDepartment of Urology, Osaka City University Graduate School of Medicine, Osaka, JapanAbstract: Recent epidemiological studies and animal experiments have demonstrated that nonsteroidal anti-inflammatory drugs (NSAIDs reduce the incidence of colorectal carcinoma. Cyclooxygenase (COX is the principal target of NSAIDs. COX is the first oxidase in the process of prostaglandin production from arachidonic acid. COX enzyme may be involved in the initiation and/or the promotion of carcinogenesis due to NSAIDs inhibition of COX. Lipoxygenase (LOX is also an initial enzyme in the pathway for producing leukotrienes from arachidonic acid. Similar to COX, LOX enzyme may also be involved in the initiation and/or promotion of carcinogenesis. Peroxisome proliferator activator-receptor (PPAR-γ is a ligand-activated transcriptional factor belonging to the steroid receptor superfamily. PPAR-γ plays a role in both adipocyte differentiation and carcinogenesis. PPAR-γ is one target for cell growth modulation of NSAIDs. In this review, we report the expression of COX-2, LOX and PPAR-γ in human prostate cancer tissues as well as the effects of COX-2 and LOX inhibitors and PPAR-γ ligand.Keywords: cyclooxygenase, lipoxygenase, peroxisome proliferator activator-receptor-γ, prostate cancer

  15. Overexpression of cyclooxygenase-2 in human HepG2, Bel-7402 and SMMC-7721 hepatoma cell lines and mechanism of cyclooxygenase-2 selective inhibitor celecoxib-induced cell growth inhibition and apoptosis

    Institute of Scientific and Technical Information of China (English)

    Ning-Bo Liu; Tao Peng; Chao Pan; Yu-Yu Yao; Bo Shen; Jing Leng

    2005-01-01

    AIM: To investigate the cyclooxygenase-2 (COX-2)expression level in human HepG2, Bel-7402 and SMMC-7721hepatoma cell lines and the molecular mechanism of COX-2 selective inhibitor celecoxib-induced cell growth inhibition and cell apoptosis.METHODS: Hepatoma cells were cultured and treated with celecoxib. Cell in situ hybridization (ISH) and immunocytochemistry were used to detect COX-2 mRNA and protein expression. Proliferating cell nuclear antigen and phosphorylated Akt were also detected by immunocytochemistry assay. Cell growth rates were assessed by 3-(4, 5-dimethylthiazol-2-yl-2, 5-diphenyltetrazolium (MTT) bromide colorimetric assay. Celecoxibinduced cell apoptosis was measured by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) and flow cytometry (FCM). The phosphorylated Akt and activated fragments of caspase-9, caspase-3 were examined by Western blotting analysis.RESULTS: Increased COX-2 mRNA and protein expression were detected in all three hepatoma cell lines. Celecoxib could significantly inhibit cell growth and the inhibitory effect was in a dose- and time-dependent manner evidenced by MTr assays and morphological changes.The apoptotic index measured by TUNEL increased correspondingly with the increased concentration of celecoxib and the reaction time. With 50 μmol/L celecoxib treatment for 24 h, the apoptotic index of HepG2, BEL-7402and SMMC-7721 cells was 25.01±3.08%, 26.40±3.05%,and 30.60±2.89%, respectively. Western blotting analysis showed remarkable activation of caspase-9, caspase-3and dephosphorylation of Akt (Thr308). Immunocytochemistry also showed the reduction of PCNA expression and phosphorylation Akt (Thr308) after treatment with celecoxib.CONCLUSION: COX-2 mRNA and protein overexpression in HepG2, Bel-7402 and SMMC-7721 cell lines correlate with the increased cell growth rate. Celecoxib can inhibit proliferation and induce apoptosis of hepatoma cell strains in a dose- and time-dependent manner.

  16. The superoxide anion donor, potassium superoxide, induces pain and inflammation in mice through production of reactive oxygen species and cyclooxygenase-2.

    Science.gov (United States)

    Maioli, N A; Zarpelon, A C; Mizokami, S S; Calixto-Campos, C; Guazelli, C F S; Hohmann, M S N; Pinho-Ribeiro, F A; Carvalho, T T; Manchope, M F; Ferraz, C R; Casagrande, R; Verri, W A

    2015-04-01

    It is currently accepted that superoxide anion (O2•-) is an important mediator in pain and inflammation. The role of superoxide anion in pain and inflammation has been mainly determined indirectly by modulating its production and inactivation. Direct evidence using potassium superoxide (KO2), a superoxide anion donor, demonstrated that it induced thermal hyperalgesia, as assessed by the Hargreaves method. However, it remains to be determined whether KO2 is capable of inducing other inflammatory and nociceptive responses attributed to superoxide anion. Therefore, in the present study, we investigated the nociceptive and inflammatory effects of KO2. The KO2-induced inflammatory responses evaluated in mice were: mechanical hyperalgesia (electronic version of von Frey filaments), thermal hyperalgesia (hot plate), edema (caliper rule), myeloperoxidase activity (colorimetric assay), overt pain-like behaviors (flinches, time spent licking and writhing score), leukocyte recruitment, oxidative stress, and cyclooxygenase-2 mRNA expression (quantitative PCR). Administration of KO2 induced mechanical hyperalgesia, thermal hyperalgesia, paw edema, leukocyte recruitment, the writhing response, paw flinching, and paw licking in a dose-dependent manner. KO2 also induced time-dependent cyclooxygenase-2 mRNA expression in the paw skin. The nociceptive, inflammatory, and oxidative stress components of KO2-induced responses were responsive to morphine (analgesic opioid), quercetin (antioxidant flavonoid), and/or celecoxib (anti-inflammatory cyclooxygenase-2 inhibitor) treatment. In conclusion, the well-established superoxide anion donor KO2 is a valuable tool for studying the mechanisms and pharmacological susceptibilities of superoxide anion-triggered nociceptive and inflammatory responses ranging from mechanical and thermal hyperalgesia to overt pain-like behaviors, edema, and leukocyte recruitment.

  17. COMPARISON OF SELECTIVE AND NON SELECTIVE CYCLO-OXYGENASE 2 INHIBITORS IN EXPERIMENTAL COLITIS EXACERBATION: role of leukotriene B4 and superoxide dismutase

    Directory of Open Access Journals (Sweden)

    José Wander BREGANÓ

    2014-09-01

    Full Text Available Context Nonsteroidal anti-inflammatory drugs are considered one of the most important causes of reactivation of inflammatory bowel disease. With regard to selective cyclo-oxygenase 2 inhibitors, the results are controversial in experimental colitis as well as in human studies. Objectives The aim this study is to compare nonsteroidal anti-inflammatory drugs effects, selective and non selective cyclo-oxygenase 2 inhibitors, in experimental colitis and contribute to the understanding of the mechanisms which nonsteroidal anti-inflammatory drugs provoke colitis exacerbation. Methods Six groups of rats: without colitis, with colitis, and colitis treated with celecoxib, ketoprofen, indometacin or diclofenac. Survival rates, hemoglobin, plasmatic albumin, colonic tissue of interleukin-1ß, interleukin-6, tumor necrosis factor alpha, prostaglandin E2, catalase, superoxide dismutase, thiobarbituric acid-reactive substances, chemiluminescence induced by tert-butil hydroperoxides, and tissue and plasmatic leukotriene B4 were determined. Results The groups treated with diclofenac or indometacin presented lower survival rates, hemoglobin and albumin, higher tissue and plasmatic leukotriene B4 and tissue superoxide dismutase than the group treated with celecoxib. Ketoprofen presented an intermediary behavior between diclofenac/indometacin and celecoxib, concerning to survival rate and albumin. The groups without colitis, with colitis and with colitis treated with celecoxib showed leukotriene B4 and superoxide dismutase lower levels than the groups treated with nonselective cyclo-oxygenase 2 inhibitors. Conclusions Diclofenac and indometacin presented the highest degree of induced colitis exacerbation with nonsteroidal anti-inflammatory drugs, celecoxib did not show colitis exacerbation, and ketoprofen presented an intermediary behavior between diclofenac/indometacin and celecoxib. These results suggest that leukotriene B4 and superoxide dismutase can be

  18. URETERAL ACCESS SHEATH INFLUENCE ON THE URETERAL WALL EVALUATED BY CYCLOOXYGENASE-2 AND TUMOUR NECROSIS FACTOR- α IN A PORCINE MODEL

    DEFF Research Database (Denmark)

    Lildal, Søren Kissow; Nørregaard, Rikke; Andreassen, Kim Hovgaard;

    2017-01-01

    OBJECTIVE: To examine the effect of ureteral access sheaths (UAS) on the expression of the proinflammatory mediators cyclooxygenase-2 (COX-2) and tumour necrosis factor-α (TNF-α) in the ureteral wall. MATERIAL AND METHODS: In 22 pigs a ureteral access sheath was inserted and removed after 2 minutes......, respectively. CONCLUSION: The pro-inflammatory mediators COX-2 and TNF-α were significantly up-regulated in the ureteral wall by the influence of ureteral access sheaths. These findings may have implications for postoperative pain, drainage and complications....

  19. Single-dose safety and pharmacokinetic evaluation of fluorocoxib A: pilot study of novel cyclooxygenase-2-targeted optical imaging agent in a canine model

    OpenAIRE

    Cekanova, Maria; Uddin, Md. Jashim; Legendre, Alfred M.; Galyon, Gina; Bartges, Joseph W.; Callens, Amanda; Martin-Jimenez, Tomas; Marnett, Lawrence J.

    2012-01-01

    We evaluated preclinical single-dose safety, pharmacokinetic properties, and specific uptake of the new optical imaging agent fluorocoxib A in dogs. Fluorocoxib A, N-[(5-carboxy-X-rhodaminyl)but-4-yl]-2-[1-(4-chlorobenzoyl)-5-methoxy-2-methyl-1H-indol-3-yl]acetamide, selectively binds and inhibits the cyclooxygenase-2 (COX-2) enzyme, which is overexpressed in many cancers. Safety pilot studies were performed in research dogs following intravenous (i.v.) administration of 0.1 and 1  mg/kg fluo...

  20. Skeletal muscle blood flow and oxygen uptake at rest and during exercise in humans: a PET study with nitric oxide and cyclooxygenase inhibition

    DEFF Research Database (Denmark)

    Heinonen, Ilkka; Saltin, Bengt; Kemppainen, Jukka

    2011-01-01

    The aim of the present study was to determine the effect of nitric oxide and prostanoids on microcirculation and oxygen uptake specifically in the active skeletal muscle by use of positron emission tomography (PET). Healthy males performed 3 five min bouts of light knee-extensor exercise. Skeletal...... muscle blood flow and oxygen uptake were measured at rest and during the exercise using PET with H(2)O(15) and (15)O(2) during: 1) control conditions; 2) nitric oxide synthase (NOS) inhibition by arterial infusion of L-NMMA and 3) combined NOS and cyclooxygenase (COX) inhibition by arterial infusion of L...

  1. Dipyrone elicits substantial inhibition of peripheral cyclooxygenases in humans: new insights into the pharmacology of an old analgesic.

    Science.gov (United States)

    Hinz, Burkhard; Cheremina, Olga; Bachmakov, Jouri; Renner, Bertold; Zolk, Oliver; Fromm, Martin F; Brune, Kay

    2007-08-01

    Dipyrone (INN, metamizol) is a common analgesic used worldwide. Its widespread prescription or over-the-counter use in many countries (e.g., Brazil, Israel, Mexico, Russia, Spain) requires insight into its mode of action. This study therefore addressed the impact of its metabolites 4-methyl-amino-antipyrine (MAA) and 4-amino-antipyrine (AA) on peripheral cyclooxygenases (COX). Pharmacokinetics of metabolites and ex vivo COX inhibition were assessed in five volunteers receiving dipyrone at single oral doses of 500 or 1000 mg. Coagulation-induced thromboxane B2 formation and lipopolysaccharide-induced prostaglandin E2 synthesis were measured in vitro and ex vivo in human whole blood as indices of COX-1 and COX-2 activity. In vitro, metabolites elicited no substantial COX-1/COX-2 selectivity with MAA (IC50=2.55 micromol/L for COX-1; IC50=4.65 micromol/L for COX-2), being approximately 8.2- or 9-fold more potent than AA. After administration of dipyrone, MAA plasma concentrations remained above the IC50 values for each isoform for at least 8 h (500 mg) and 12 h (1000 mg) postdose. COX inhibition correlated with MAA plasma levels (ex vivo IC50 values of 1.03 micromol/L [COX-1] and 0.87 micromol/L [COX-2]). By contrast, plasma peak concentrations of AA after the 1000 mg dose were 2.8- and 6.5-fold below its IC50 values for COX-1 and COX-2, respectively. Maximal inhibitions of COX-1 and COX-2 were 94% and 87% (500 mg), 97% and 94% (1000 mg). Taken together, dipyrone elicits a substantial and virtually equipotent inhibition of COX isoforms via MAA. Given the profound COX-2 suppression by dipyrone, which was considerably above COX-2 inhibition by single analgesic doses of celecoxib and rofecoxib, a significant portion of its analgesic action may be ascribed to peripheral mechanisms. In view of the observed COX-1 suppression, physicochemical factors (lack of acidity) rather than differential COX-1 inhibition may be responsible for dipyrone's favorable gastrointestinal

  2. Curcumin improves prostanoid ratio in diabetic mesenteric arteries associated with cyclooxygenase-2 and NF-κB suppression

    Directory of Open Access Journals (Sweden)

    Sirada Rungseesantivanon

    2010-12-01

    Full Text Available Sirada Rungseesantivanon1, Naris Thengchaisri4, Preecha Ruangvejvorachai2, Suthiluk Patumraj31Interdepartment of Physiology, Graduate School, 2Department of Pathology, 3Department of Physiology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand; 4Department of Companion Animal Clinical Sciences, Faculty of Veterinary Medicine, Kasetsart University, Bangkok, ThailandBackground: Curcumin, the active ingredient from turmeric rhizomes, has been shown to have a wide range of pharmacological properties including antioxidant and anti-inflammatory effects. Curcumin has been reviewed for its multiple molecular action on inhibiting tumor angiogenesis via its mechanisms of cyclooxygenase (COX-2, and vascular endothelial growth factor (VEGF inhibition. In this present study, we aimed to assess the effects of curcumin on preventing diabetes-induced vascular dysfunction in association with COX-2, nuclear factor-κB (NF-κB expression, and prostanoid production.Methods: Twelve-week-old male Wistar rats were separated into five groups: 1 diabetes with 0.9% normal saline (DM-NSS; n = 10, 2 diabetes treated with curcumin 30 mg/kg (n = 10, 3 diabetes treated with curcumin 300 mg/kg (n = 10, 4 the control with 0.9% normal saline (n = 10, and 5 the control treated with 300 mg/kg (n = 10. Daily oral feeding of curcumin was started at 6 weeks after the streptozotocin injection. Levels of 6-keto prostaglandin (PG F1α and thromboxane (TX B2 were determined from mesenteric perfusates using enzyme immunoassay kits. Protein kinase C (PKC-ßII and COX-2 with NF-κB levels were analyzed in the mesenteric arteries by immunofluorescent staining and immunohistochemistry, respectively.Results: The ratio of 6-keto-PGF1α and TXB2 was significantly decreased in DM-NSS compared with the control (P < 0.05. Double-immunofluorescent staining with specific antibodies for PKC-βII and a-smooth muscle actins showed that the diabetic mesenteric arteries contained increased

  3. Cyclooxygenase 2,pS2,inducible nitric oxide synthase and transforming growth factor alpha in gastric adaptation to stress

    Institute of Scientific and Technical Information of China (English)

    Shi-Nan Nie; Hai-Chen Sun; Xue-Hao Wu; Xiao-Ming Qian

    2004-01-01

    AIM: To determine the role of mucosal gene expression of cyclooxygenase 2 (COX-2), pS2 (belongs to trefoil peptides),inducible nitric oxide synthase (iNOS) and transforming growth factor alpha (TGFα) in gastric adaptation to water immersion and restraint stress (WRS) in rats.METHODS: Wistar rats were exposed to single or repeated WRS for 4 h every other day for up to 6 d. Gastric mucosal blood flow (GMBF) was measured by laser Doppler fiowmeter3. The extent of gastric mucosal lesions were evaluated grossly and histologically and expressions of COX-2, pS2,iNOS and TGFα were determined by reverse transcriptase polymerase chain reaction (RT-PCR) and Western blot.RESULTS: The damage to the surface of gastric epithelium with focal areas of deep haemorrhagic necrosis was induced by repeated WRS.The adaptative cytoprotection against stress was developed with activation of cell proliferation in the neck regions of gastric glands. The ulcer index (UI) in groups Ⅱ, Ⅲ and Ⅳ was markedly reduced as compared with group Ⅰ (Ⅰ: 47.23±1.20; Ⅳ: 10.39±1.18,P<0.01). GMBF significantly decreased after first exposure to WRS with an adaptive increasement of GMBF in experimental groups after repetitive challenges with WRS. After the 4th WRS,the value of GMBF almost restored to normal level (Ⅰ:321.87±8.85; Ⅳ: 455.95±11.81,P<0.01). First WRS significantly decreased the expression of pS2 and significantly increased the expressions of COX-2, iNOS and TGFα. After repeated WRS, pS2 and TGFα expressions gradually increased (pS2: Ⅰ: 0.37±0.02; Ⅳ: 0.77±0.01; TGFα: Ⅰ:0.86±0.01; Ⅳ: 0.93±0.03, P<0.05) with a decrease in the expressions of COX-2 and iNOS (COX-2: Ⅰ: 0.45±0.02; Ⅳ:0.22±0.01; iNOS: Ⅰ: 0.93±0.01; Ⅳ: 0.56±0.01, P<0.01).Expressions of pS2, COX-2, iNOS and TGFα showed regular changes with a good relationship among them.CONCLUSION: Gastric adaptation to WRS injury involves enhanced cell proliferation, increased expression of pS2 and

  4. The effect of body weight on altered expression of nuclear receptors and cyclooxygenase-2 in human colorectal cancers

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    Rullier Eric

    2007-09-01

    Full Text Available Abstract Background Epidemiological studies on risk factors for colorectal cancer (CRC have mainly focused on diet, and being overweight is now recognized to contribute significantly to CRC risk. Overweight and obesity are defined as an excess of adipose tissue mass and are associated with disorders in lipid metabolism. Peroxisome proliferator-activated receptors (PPARs and retinoid-activated receptors (RARs and RXRs are important modulators of lipid metabolism and cellular homeostasis. Alterations in expression and activity of these ligand-activated transcription factors might be involved in obesity-associated diseases, which include CRC. Cyclooxygenase-2 (COX-2 also plays a critical role in lipid metabolism and alterations in COX-2 expression have already been associated with unfavourable clinical outcomes in epithelial tumors. The objective of this study is to examine the hypothesis questioning the relationship between alterations in the expression of nuclear receptors and COX-2 and the weight status among male subjects with CRC. Method The mRNA expression of the different nuclear receptor subtypes and of COX-2 was measured in 20 resected samples of CRC and paired non-tumor tissues. The association between expression patterns and weight status defined as a body mass index (BMI was statistically analyzed. Results No changes were observed in PPARγ mRNA expression while the expression of PPARδ, retinoid-activated receptors and COX-2 were significantly increased in cancer tissues compared to normal colon mucosa (P ≤ 0.001. The weight status appeared to be an independent factor, although we detected an increased level of COX-2 expression in the normal mucosa from overweight patients (BMI ≥ 25 compared to subjects with healthy BMI (P = 0.002. Conclusion Our findings show that alterations in the pattern of nuclear receptor expression observed in CRC do not appear to be correlated with patient weight status. However, the analysis of COX-2

  5. The cyclooxygenase-2 inhibitor celecoxib induces apoptosis by blocking Akt activation in human prostate cancer cells independently of Bcl-2.

    Science.gov (United States)

    Hsu, A L; Ching, T T; Wang, D S; Song, X; Rangnekar, V M; Chen, C S

    2000-04-14

    This study investigates the apoptotic activity of the cyclooxygenase-2 (COX-2) inhibitor celecoxib in prostate carcinoma cells. COX-2 is constitutively expressed in androgen-responsive LNCaP and androgen-nonresponsive PC-3 cells. Exposure of these cells to celecoxib induces characteristic features of apoptosis, including morphological changes, DNA laddering, and caspase-3 activation, whereas piroxicam, a COX-1-specific inhibitor, displays no appreciable effect on either cancer cell line even after prolonged exposure. Moreover, the potency of celecoxib in apoptosis induction is significantly higher than that of other COX-2 inhibitors examined despite the observation that these inhibitors exhibit similar IC(50) in COX-2 inhibition. It is noteworthy that normal human prostate epithelial cells, expressing a marginally detectable level of COX-2, are insensitive to the induction of apoptosis by celecoxib. These data suggest a correlation between COX-2 expression and sensitivity to the apoptotic effect of the COX-2 inhibitor. In an effort to delineate the underlying mechanism, we examined the effect of celecoxib on the expression of Bcl-2 as well as the activation of the key anti-apoptotic kinase Akt. In contrast to an earlier report that attributed the apoptotic activity of NS398 in LNCaP cells to Bcl-2 down-regulation, we provide evidence that the induction of apoptosis by celecoxib in LNCaP and PC-3 cells is independent of Bcl-2. First, treatment with celecoxib does not alter the cellular Bcl-2 level in both cell lines. Second, enforced Bcl-2 expression in PC-3 cells does not confer protection against the induction of apoptosis by celecoxib. Our data show that celecoxib treatment blocks the phosphorylation of Akt. This correlation is supported by studies showing that overexpression of constitutively active Akt protects PC-3 cells from celecoxib-induced apoptosis. Nevertheless, how celecoxib down-regulates Akt is not clear because the drug does not adversely affect

  6. Altered mRNA editing and expression of ionotropic glutamate receptors after kainic acid exposure in cyclooxygenase-2 deficient mice.

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    Luca Caracciolo

    Full Text Available Kainic acid (KA binds to the AMPA/KA receptors and induces seizures that result in inflammation, oxidative damage and neuronal death. We previously showed that cyclooxygenase-2 deficient (COX-2(-/- mice are more vulnerable to KA-induced excitotoxicity. Here, we investigated whether the increased susceptibility of COX-2(-/- mice to KA is associated with altered mRNA expression and editing of glutamate receptors. The expression of AMPA GluR2, GluR3 and KA GluR6 was increased in vehicle-injected COX-2(-/- mice compared to wild type (WT mice in hippocampus and cortex, whereas gene expression of NMDA receptors was decreased. KA treatment decreased the expression of AMPA, KA and NMDA receptors in the hippocampus, with a significant effect in COX-2(-/- mice. Furthermore, we analyzed RNA editing levels and found that the level of GluR3 R/G editing site was selectively increased in the hippocampus and decreased in the cortex in COX-2(-/- compared with WT mice. After KA, GluR4 R/G editing site, flip form, was increased in the hippocampus of COX-2(-/- mice. Treatment of WT mice with the COX-2 inhibitor celecoxib for two weeks decreased the expression of AMPA/KA and NMDAR subunits after KA, as observed in COX-2(-/- mice. After KA exposure, COX-2(-/- mice showed increased mRNA expression of markers of inflammation and oxidative stress, such as cytokines (TNF-α, IL-1β and IL-6, inducible nitric oxide synthase (iNOS, microglia (CD11b and astrocyte (GFAP. Thus, COX-2 gene deletion can exacerbate the inflammatory response to KA. We suggest that COX-2 plays a role in attenuating glutamate excitotoxicity by modulating RNA editing of AMPA/KA and mRNA expression of all ionotropic glutamate receptor subunits and, in turn, neuronal excitability. These changes may contribute to the increased vulnerability of COX-2(-/- mice to KA. The overstimulation of glutamate receptors as a consequence of COX-2 gene deletion suggests a functional coupling between COX-2 and the

  7. Cyclo-oxygenase-2 selective inhibitors and nonsteroidal anti-inflammatory drugs: balancing gastrointestinal and cardiovascular risk

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    McQuay Henry J

    2007-08-01

    Full Text Available Abstract Background Differences between gastrointestinal and cardiovascular effects of traditional NSAID or cyclooxygenase-2 selective inhibitor (coxib are affected by drug, dose, duration, outcome definition, and patient gastrointestinal and cardiovascular risk factors. We calculated the absolute risk for each effect. Methods We sought studies with large amounts of information to calculate annualised rates for clearly defined gastrointestinal (complicated upper gastrointestinal perforations, ulcers, or bleeds, but not symptomatic or endoscopic ulcers and serious cardiovascular outcomes (antiplatelet trial collaborators – APTC – outcome of fatal or nonfatal myocardial infarction or stroke, or vascular death. Results Meta-analyses and large randomised trials specifically analysing serious gastrointestinal bleeding or cardiovascular events occurring with five different coxibs had appropriate data. In total there were 439 complicated upper gastrointestinal events in 49,006 patient years of exposure and 948 serious cardiovascular events in 99,400 patient years of exposure. Complicated gastrointestinal events occurred less frequently with coxibs than NSAIDs; serious cardiovascular events occurred at approximately equal rates. For each coxib, the reduction in complicated upper gastrointestinal events was numerically greater than any increase in APTC events. In the overall comparison, for every 1000 patients treated for a year with coxib rather than NSAID, there would be eight fewer complicated upper gastrointestinal events, but one more fatal or nonfatal heart attack or stroke. Three coxib-NSAID comparisons had sufficient numbers of events for individual comparisons. For every 1000 patients treated for a year with celecoxib rather than an NSAID there would be 12 fewer upper gastrointestinal complications, and two fewer fatal or nonfatal heart attacks or strokes. For rofecoxib there would be six fewer upper gastrointestinal complications, but three

  8. Arterial stiffness induces remodeling phenotypes in pulmonary artery smooth muscle cells via YAP/TAZ-mediated repression of cyclooxygenase-2.

    Science.gov (United States)

    Dieffenbach, Paul B; Haeger, Christina Mallarino; Coronata, Anna Maria F; Choi, Kyoung Moo; Varelas, Xaralabos; Tschumperlin, Daniel J; Fredenburgh, Laura E

    2017-09-01

    Pulmonary arterial stiffness is an independent risk factor for mortality in pulmonary hypertension (PH) and plays a critical role in PH pathophysiology. Our laboratory has recently demonstrated arterial stiffening early in experimental PH, along with evidence for a mechanobiological feedback loop by which arterial stiffening promotes further cellular remodeling behaviors (Liu F, Haeger CM, Dieffenbach PB, Sicard D, Chrobak I, Coronata AM, Suárez Velandia MM, Vitali S, Colas RA, Norris PC, Marinković A, Liu X, Ma J, Rose CD, Lee SJ, Comhair SA, Erzurum SC, McDonald JD, Serhan CN, Walsh SR, Tschumperlin DJ, Fredenburgh LE. JCI Insight 1: e86987, 2016). Cyclooxygenase-2 (COX-2) and prostaglandin signaling have been implicated in stiffness-mediated regulation, with prostaglandin activity inversely correlated to matrix stiffness and remodeling behaviors in vitro, as well as to disease progression in rodent PH models. The mechanism by which mechanical signaling translates to reduced COX-2 activity in pulmonary vascular cells is unknown. The present work investigated the transcriptional regulators Yes-associated protein (YAP) and WW domain-containing transcription regulator 1 (WWTR1, a.k.a., TAZ), which are known drivers of downstream mechanical signaling, in mediating stiffness-induced changes in COX-2 and prostaglandin activity in pulmonary artery smooth muscle cells (PASMCs). We found that YAP/TAZ activity is increased in PAH PASMCs and experimental PH and is necessary for the development of stiffness-dependent remodeling phenotypes. Knockdown of YAP and TAZ markedly induces COX-2 expression and downstream prostaglandin production by approximately threefold, whe